PDF Solutions, Inc. Form S-8
Table of Contents

As filed with the Securities and Exchange Commission on January 14, 2003
Registration No. 333-

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM S-8
REGISTRATION STATEMENT

Under The Securities Act of 1933

PDF SOLUTIONS, INC.

(Exact Name of Registrant as Specified in Its Charter)
     
Delaware
(State or Other Jurisdiction of
Incorporation or Organization)
  25-1701361
(I.R.S. Employer
Identification Number)

333 West San Carlos Street, Suite 700
San Jose, California 95110
(Address of Principal Executive Offices) (Zip Code)

2001 STOCK PLAN
2001 EMPLOYEE STOCK PURCHASE PLAN

(Full Title of the Plans)

JOHN K. KIBARIAN
President and Chief Executive Officer
PDF Solutions, Inc.
333 West San Carlos Street, Suite 700
San Jose, California 95110

(Name and Address of Agent for Service)

(408) 280-7900
(Telephone Number, Including Area Code, of Agent for Service)

Copy to:

Peter Cohn, Esq.
Orrick, Herrington & Sutcliffe LLP
1020 Marsh Road
Menlo Park, California 94025
(650) 614-7400

CALCULATION OF REGISTRATION FEE

                                 

            Proposed Maximum   Proposed Maximum        
Title of Securities to be   Amount To Be   Offering   Aggregate Offering   Amount of
Registered   Registered (1)   Price Per Share (2)   Price   Registration Fee

Common Stock, $0.00015 par value (2001 Stock Plan)
    2,301,159     $ 6.86     $ 15,785,950     $ 1,452.31  

Common Stock, $0.00015 par value (2001 Employee Stock Purchase Plan)
    920,463     $ 6.86       6,314,376       580.93  

Total
    3,221,622                     $ 2,033.24  

(1)   This Registration Statement shall also cover any additional shares of Common Stock which become issuable under any of the Plans by reason of any stock dividend, stock split, recapitalization or other similar transaction effected without the Registrant’s receipt of consideration which results in an increase in the number of the Registrant’s outstanding shares of Common Stock.
 
(2)   The Proposed Maximum Offering Price Per Share represents a weighted average of the following estimates calculated in accordance with Rule 457(h) under the Securities Act of 1933, as amended (the “Securities Act”). With respect to 3,221,622 shares of Common Stock available for future grant under the 2001 Stock Plan and the 2001 Employee Stock Purchase Plan, the estimated Proposed Maximum Offering Price Per Share was calculated pursuant to Rules 457(c) and 457(h) under the Securities Act on the basis of $6.86 per share, the average of the high and low price of the Common Stock on the Nasdaq National Market on January 7, 2003.

 


TABLE OF CONTENTS

PART II
Item 3. Incorporation of Documents by Reference
Item 4. Description of Securities
Item 5. Interests of Named Experts and Counsel
Item 6. Indemnification of Directors and Officers
Item 7. Exemption From Registration Claimed
Item 8. Exhibits
Item 9. Undertakings
SIGNATURES
EXHIBIT INDEX
EXHIBIT 4.1
EXHIBIT 4.2
EXHIBIT 5.1
EXHIBIT 23.1
EXHIBIT 99.1


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PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference

PDF Solutions, Inc. (the “Registrant”) hereby incorporates by reference into this Registration Statement the following documents previously filed with the Securities and Exchange Commission (the “Commission”):

       (a) The Registrant’s Annual Report on Form 10-K for the fiscal year ended December 31, 2001, filed with the SEC on April 1, 2002 (File No. 000-31311);
 
       (b) All other reports filed pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934 (the “Exchange Act”) since the end of the fiscal year covered by the Registrant document referred to in (b) above; and
 
       (c) The Registrant’s Registration Statement on Form 8-A12G, as amended, filed with the SEC on August 10, 2000 (File No. 000-31311), in which are described the terms, rights and provisions applicable to the Registrant’s Common Stock.

All documents subsequently filed by the Registrant pursuant to Sections 13(a), 13(c), 14, and 15(d) of the Exchange Act, prior to the filing of a post-effective amendment which indicates that all securities offered have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference in this Registration Statement and to be a part hereof from the date of filing of such documents.

Item 4. Description of Securities

Not applicable.

Item 5. Interests of Named Experts and Counsel

The validity of the common stock being registered hereby will be passed upon for the Registrant by Orrick, Herrington & Sutcliffe LLP, Menlo Park, California. As of the date of this Registration Statement, Peter Cohn, a partner of Orrick, Herrington & Sutcliffe LLP, is the Secretary of PDF Solutions, Inc.

Item 6. Indemnification of Directors and Officers

Section 145 of the Delaware General Corporation Law provides that a corporation may indemnify directors and officers, as well as other employees and individuals, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by any such person in connection with any threatened, pending or completed actions, suits or proceedings in which such person is made a party by reason of such person being or having been a director, officer, employee or agent of the Registrant. The Delaware General Corporation Law provides that Section 145 is not exclusive of other rights to which those seeking indemnification may be entitled under any bylaw, agreement, vote of stockholders or disinterested directors or otherwise. Article XII of the Registrant’s Amended and Restated Certificate of Incorporation and Article VI of the Registrant’s Bylaws provide for indemnification by the Registrant of its directors and officers to the fullest extent permitted by the Delaware General Corporation Law.

Section 102(b)(7) of the Delaware General Corporation Law permits a corporation to provide in its certificate of incorporation that a director of the corporation shall not be personally liable to the corporation or its stockholders for monetary damages for breach of fiduciary duty as a director, except for liability (i) for any breach of the director’s duty of loyalty to the corporation or its stockholders, (ii) for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, (iii) for unlawful payments of dividends or unlawful stock repurchases, redemptions or other distributions, or (iv) for any transaction from which the director derived an improper personal benefit. The Registrant’s Amended and Restated Certificate of Incorporation provides for such limitation of liability.

The Registrant has obtained directors’ and officers’ insurance providing indemnification for certain of the Registrant’s directors, officers and employees for certain liabilities.

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The Registrant has entered into indemnification agreements with each director and executive officer which provide indemnification under certain circumstances for acts and omissions which may not be covered by any directors’ and officers’ liability insurance.

Item 7. Exemption From Registration Claimed

Not applicable.

Item 8. Exhibits

     
Exhibit    
Number   Name

 
     
4.1     2001 Stock Plan.
     
4.2     2001 Employee Stock Purchase Plan.
     
5.1     Opinion of Orrick, Herrington & Sutcliffe LLP.
     
23.1   Independent Auditors’ Consent.
     
23.2   Consent of Orrick, Herrington & Sutcliffe LLP is included in Exhibit 5.1 to this Registration Statement.
     
24      Power of Attorney. (See page 5)
     
99.1   Selected Financial Data Additional Disclosure for FASB No. 142

Item 9. Undertakings

     (a)  The undersigned Registrant hereby undertakes:

       (1) To file, during any period in which offers or sales are being made, a post-effective amendment to this Registration Statement:
 
            (i) To include any prospectus required by Section 10(a)(3) of the Securities Act;
 
            (ii) To reflect in the prospectus any facts or events arising after the effective date of the Registration Statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the Registration Statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective Registration Statement;
 
            (iii) To include any material information with respect to the plan of distribution not previously disclosed in the Registration Statement or any material change to such information in the Registration Statement;
 
       (2) That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.
 
       (3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

     (b)  The undersigned Registrant hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of the Registrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section

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15(d) of the Exchange Act) that is incorporated by reference in the Registration Statement shall be deemed to be a new Registration Statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

     (c)  Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the Commission such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of San Jose, State of California, on the 14th day of January, 2003.

         
    PDF SOLUTIONS, INC.
(Registrant)
         
    By:   /s/ John K. Kibarian
John K. Kibarian
President and Chief Executive Officer

POWER OF ATTORNEY

Each of the undersigned directors of PDF Solutions, Inc., a Delaware corporation (the “Company”), hereby constitutes and appoints John K. Kibarian and P. Steven Melman, and each of them, his true and lawful attorneys-in-fact, with full power of substitution, for him or her and in his or her name, place and stead, in his or her capacity as a director, to execute a Registration Statement or Registration Statements on Form S-8 under the Securities Act of 1933, as amended, relating to 3,221,622 shares of Common Stock that are issuable under the PDF Solutions, Inc. 2001 Stock Plan and the 2001 Employee Stock Purchase Plan (the “Plans”) and any and all amendments (including post-effective amendments) to such Registration Statements, and to file such Registration Statements and any and all amendments thereto, with exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto such attorneys-in-fact full power and authority to do and perform each and every act and thing necessary or desirable to be done in and about the premises, as fully to all intents and purposes, as he or she might or could do in person, and ratify and confirm all that such attorneys-in-fact or their substitutes may lawfully do or cause to be done by virtue hereof, and hereby consents to such registration of the Shares and the issuance thereof pursuant to the terms of the Plan. Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.

     
Signature   Title

 
     
/s/ John K. Kibarian
John K. Kibarian
  Chief Executive Officer,
President and Director
     
/s/ P. Steven Melman
P. Steven Melman
  Chief Financial Officer and Vice
President, Finance and Administration
     
/s/ Kimon Michaels

Kimon Michaels
  Vice President, Integration Practice
and Director
     
/s/ B.J. Cassin
B. J. Cassin
  Director
     
/s/ Donald L. Lucas
Donald L. Lucas
  Director
     
/s/ Lucio L. Lanza
Lucio L. Lanza
  Director

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EXHIBIT INDEX

     
Exhibit    
Number   Name

 
     
4.1     2001 Stock Plan.
     
4.2     2001 Employee Stock Purchase Plan.
     
5.1     Opinion of Orrick, Herrington & Sutcliffe LLP.
     
23.1   Independent Auditors’ Consent.
     
23.2   Consent of Orrick, Herrington & Sutcliffe LLP is included in Exhibit 5.1 to this Registration Statement.
     
24      Power of Attorney. (See page 5)
     
99.1   Selected Financial Data Additional Disclosure for FASB No. 142.

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EXHIBIT 4.1 PDF SOLUTIONS, INC. 2001 STOCK PLAN EFFECTIVE AS OF JULY 26, 2001

SECTION 1. INTRODUCTION.................................................... 1 SECTION 2. DEFINITIONS..................................................... 1 (a) "Affiliate"............................................... 1 (b) "Award"................................................... 1 (c) "Board"................................................... 1 (d) "Change In Control"....................................... 1 (e) "Code".................................................... 2 (f) "Committee"............................................... 2 (g) "Common Stock"............................................ 2 (h) "Company"................................................. 2 (i) "Consultant".............................................. 3 (j) "Director"................................................ 3 (k) "Disability".............................................. 3 (l) "Employee"................................................ 3 (m) "Exchange Act"............................................ 3 (n) "Exercise Price".......................................... 3 (o) "Fair Market Value"....................................... 3 (p) "Grant"................................................... 3 (q) "Incentive Stock Option" or "ISO"......................... 3 (r) "Key Employee"............................................ 4 (s) "Non-Employee Director"................................... 4 (t) "Nonstatutory Stock Option" or "NSO"...................... 4 (u) "Option".................................................. 4 (v) "Optionee"................................................ 4 (w) "Parent".................................................. 4 (x) "Participant"............................................. 4 (y) "Plan".................................................... 4 (z) "Restricted Stock"........................................ 4 (aa) "Restricted Stock Agreement".............................. 4 (bb) "Securities Act".......................................... 4 (cc) "Service"................................................. 4 (dd) "Share"................................................... 4 (ee) "Stock Option Agreement".................................. 4

(ff) "Stock Purchase Right".................................... 4 (gg) "Subsidiary".............................................. 4 (hh) "10-Percent Shareholder".................................. 5 SECTION 3. ADMINISTRATION.................................................. 5 (a) Committee Composition..................................... 5 (b) Authority of the Committee................................ 5 (c) Indemnification........................................... 6 SECTION 4. ELIGIBILITY..................................................... 6 (a) General Rules............................................. 6 (b) Incentive Stock Options................................... 6 (c) Non-Employee Director Options............................. 6 SECTION 5. SHARES SUBJECT TO PLAN.......................................... 7 (a) Basic Limitation.......................................... 7 (b) Annual Addition........................................... 7 (c) Additional Shares......................................... 7 (d) Limits on Options......................................... 7 (e) Limits on Stock Purchase Rights........................... 7 SECTION 6. TERMS AND CONDITIONS OF OPTIONS................................. 8 (a) Stock Option Agreement.................................... 8 (b) Number of Shares.......................................... 8 (c) Exercise Price............................................ 8 (d) Exercisability and Term................................... 8 (e) Modifications or Assumption of Options.................... 8 (f) Transferability of Options................................ 9 (g) No Rights as Stockholder.................................. 9 (h) Restrictions on Transfer.................................. 9 SECTION 7. PAYMENT FOR OPTION SHARES....................................... 9 (a) General Rule.............................................. 9 (b) Surrender of Stock........................................ 9 (c) Promissory Note........................................... 9 (d) Other Forms of Payment.................................... 10 SECTION 8. TERMS AND CONDITIONS FOR AWARDS OF STOCK PURCHASE RIGHTS........ 10

(a) Time, Amount and Form of Awards........................... 10 (b) Agreements................................................ 10 (c) Payment for Restricted Stock.............................. 10 (d) Vesting Conditions........................................ 10 (e) Assignment or Transfer of Restricted Stock................ 10 (f) Trusts.................................................... 10 (g) Voting and Dividend Rights................................ 11 SECTION 9. PROTECTION AGAINST DILUTION..................................... 11 (a) Adjustments............................................... 11 (b) Participant Rights........................................ 11 SECTION 10. EFFECT OF A CHANGE IN CONTROL................................... 11 (a) Merger or Reorganization.................................. 11 (b) Acceleration.............................................. 12 SECTION 11. LIMITATIONS ON RIGHTS........................................... 12 (a) Retention Rights.......................................... 12 (b) Stockholders' Rights...................................... 12 (c) Regulatory Requirements................................... 12 SECTION 12. WITHHOLDING TAXES............................................... 12 (a) General................................................... 12 (b) Share Withholding......................................... 12 SECTION 13. DURATION AND AMENDMENTS......................................... 13 (a) Term of the Plan.......................................... 13 (b) Right to Amend or Terminate the Plan...................... 13 SECTION 14. EXECUTION....................................................... 13

PDF SOLUTIONS, INC. 2001 STOCK PLAN EFFECTIVE AS OF JULY 26, 2001 SECTION 1. INTRODUCTION. The Company's Board of Directors adopted the PDF Solutions, Inc. 2001 Stock Plan on June 12, 2001 (the "Adoption Date"), and the Company's stockholders approved the Plan on July 6, 2001. The Plan is effective on the date of our initial public offering. The purpose of the Plan is to promote the long-term success of the Company and the creation of shareholder value by offering Key Employees an opportunity to acquire a proprietary interest in the success of the Company, or to increase such interest, and to encourage such selected persons to continue to provide services to the Company and to attract new individuals with outstanding qualifications. The Plan seeks to achieve this purpose by providing for Awards in the form of Stock Purchase Rights granting Restricted Stock and Options which may be Incentive Stock Options or Nonstatutory Stock Options. The Plan shall be governed by, and construed in accordance with, the laws of the State of Delaware (except its choice-of-law provisions). Capitalized terms shall have the meaning provided in Section 2 unless otherwise provided in this Plan or the applicable Stock Option Agreement or Restricted Stock Agreement. SECTION 2. DEFINITIONS. (a) "AFFILIATE" means any entity other than a Subsidiary, if the Company and/or one or more Subsidiaries own not less than 50% of such entity. For purposes of determining an individual's "Service," this definition shall include any entity other than a Subsidiary, if the Company, a Parent and/or one or more Subsidiaries own not less than 50% of such entity. (b) "AWARD" means any award of an Option or Stock Purchase Right under the Plan. (c) "BOARD" means the Board of Directors of the Company, as constituted from time to time. (d) "CHANGE IN CONTROL" except as may otherwise be provided in a Stock Option Agreement or Restricted Stock Agreement, means the occurrence of any of the following: (i) The consummation of a merger or consolidation of the Company with or into another entity or any other corporate reorganization, if more than

50% of the combined voting power of the continuing or surviving entity's securities outstanding immediately after such merger, consolidation or other reorganization is owned by persons who were not stockholders of the Company immediately prior to such merger, consolidation or other reorganization; (ii) The sale, transfer or other disposition of all or substantially all of the Company's assets; (iii) A change in the composition of the Board, as a result of which fewer that one-half of the incumbent directors are directors who either (i) had been directors of the Company on the date 24 months prior to the date of the event that may constitute a Change in Control (the "original directors") or (ii) were elected, or nominated for election, to the Board with the affirmative votes of at least a majority of the aggregate of the original directors who were still in office at the time of the election or nomination and the directors whose election or nomination was previously so approved; (iv) Any transaction as a result of which any person becomes the "beneficial owner" (as defined in Rule 13d-3 under the Exchange Act), directly or indirectly, of securities of the Company representing at least 20% of the total voting power represented by the Company's then outstanding voting securities. For purposes of this Paragraph (iii), the term "person" shall have the same meaning as when used in sections 13(d) and 14(d) of the Exchange Act but shall exclude: (A) A trustee or other fiduciary holding securities under an employee benefit plan of the Company or a subsidiary of the Company; (B) A corporation owned directly or indirectly by the stockholders of the Company in substantially the same proportions as their ownership of the common stock of the Company; and (C) The Company; or (v) A complete liquidation or dissolution of the Company. (e) "CODE" means the Internal Revenue Code of 1986, as amended. (f) "COMMITTEE" means a committee consisting of one or more members of the Board that is appointed by the Board (as described in Section 3) to administer the Plan. (g) "COMMON STOCK" means the Company's common stock. (h) "COMPANY" means PDF Solutions, Inc. (i) "CONSULTANT" means an individual who performs bona fide services to the Company, a Parent, a Subsidiary or an Affiliate other than as an Employee or Director or Non-Employee Director. 2

(j) "DIRECTOR" means a member of the Board who is also an Employee. (k) "DISABILITY" means that the Key Employee is unable to engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment which can be expected to result in death or which has lasted or can be expected to last for a continuous period of not less than 12 months. (l) "EMPLOYEE" means any individual who is a common-law employee of the Company, a Parent, a Subsidiary or an Affiliate. (m) "EXCHANGE ACT" means the Securities Exchange Act of 1934, as amended. (n) "EXERCISE PRICE" means, in the case of an Option, the amount for which a Share may be purchased upon exercise of such Option, as specified in the applicable Stock Option Agreement. (o) "FAIR MARKET VALUE" means the market price of Shares, determined by the Committee as follows: (i) If the Shares were traded on a stock exchange on the date in question, then the Fair Market Value shall be equal to the last trading price reported by the applicable composite transactions report for such date; (ii) If the Shares were traded over-the-counter on the date in question and were classified as a national market issue, then the Fair Market Value shall be equal to the last trading price quoted by the NASDAQ system for such date; (iii) If the Shares were traded over-the-counter on the date in question but were not classified as a national market issue, then the Fair Market Value shall be equal to the mean between the last reported representative bid and asked prices quoted by the NASDAQ system for such date; and (iv) If none of the foregoing provisions is applicable, then the Fair Market Value shall be determined by the Committee in good faith on such basis as it deems appropriate. Whenever possible, the determination of Fair Market Value by the Committee shall be based on the prices reported in the Wall Street Journal. Such determination shall be conclusive and binding on all persons. (p) "GRANT" means any grant of an Award under the Plan. (q) "INCENTIVE STOCK OPTION" or "ISO" means an incentive stock option described in Code section 422(b). (r) "KEY EMPLOYEE" means an Employee, Director, Non-Employee Director or Consultant who has been selected by the Committee to receive an Award under the Plan. 3

(s) "NON-EMPLOYEE DIRECTOR" means a member of the Board who is not an Employee. (t) "NONSTATUTORY STOCK OPTION" or "NSO" means a stock option that is not an ISO. (u) "OPTION" means an ISO or NSO granted under the Plan entitling the Optionee to purchase Shares. (v) "OPTIONEE" means an individual, estate or other entity that holds an Option. (w) "PARENT" means any corporation (other than the Company) in an unbroken chain of corporations ending with the Company, if each of the corporations other than the Company owns stock possessing fifty percent (50%) or more of the total combined voting power of all classes of stock in one of the other corporations in such chain. A corporation that attains the status of a Parent on a date after the adoption of the Plan shall be considered a Parent commencing as of such date. (x) "PARTICIPANT" means an individual or estate or other entity that holds an Award. (y) "PLAN" means this PDF Solutions, Inc. 2001 Stock Plan as it may be amended from time to time. (z) "RESTRICTED STOCK" means a Share awarded under the Plan pursuant to a Stock Purchase Right. (aa) "RESTRICTED STOCK AGREEMENT" means the agreement described in Section 8 evidencing Restricted Stock that may be purchased following the Award of a Stock Purchase Right. (bb) "SECURITIES ACT" means the Securities Act of 1933, as amended. (cc) "SERVICE" means service as an Employee, Director, Non-Employee Director or Consultant. (dd) "SHARE" means one share of Common Stock. (ee) "STOCK OPTION AGREEMENT" means the agreement described in Section 6 evidencing each Grant of an Option. (ff) "STOCK PURCHASE RIGHT" means the right to acquire Restricted Stock pursuant to Section 8. (gg) "SUBSIDIARY" means any corporation (other than the Company) in an unbroken chain of corporations beginning with the Company, if each of the corporations other than the last corporation in the unbroken chain owns stock possessing fifty percent (50%) or more of the total combined voting power of all classes of stock in one of the other corporations in such chain. A corporation that attains the status of a Subsidiary on a date after the adoption of the Plan shall be considered a Subsidiary commencing as of such date. 4

(hh) "10-PERCENT SHAREHOLDER" means an individual who owns more than ten percent (10%) of the total combined voting power of all classes of outstanding stock of the Company, its Parent or any of its subsidiaries. In determining stock ownership, the attribution rules of section 424(d) of the Code shall be applied. SECTION 3. ADMINISTRATION. (a) COMMITTEE COMPOSITION. A Committee appointed by the Board shall administer the Plan. The Board shall designate one of the members of the Committee as chairperson. If no Committee has been approved, the entire Board shall constitute the Committee. Members of the Committee shall serve for such period of time as the Board may determine and shall be subject to removal by the Board at any time. The Board may also at any time terminate the functions of the Committee and reassume all powers and authority previously delegated to the Committee. With respect to officers or directors subject to Section 16 of the Exchange Act, the Committee shall consist of those individuals who shall satisfy the requirements of Rule 16b-3 (or its successor) under the Exchange Act with respect to Awards granted to persons who are officers or directors of the Company under Section 16 of the Exchange Act. Notwithstanding the previous sentence, failure of the Committee to satisfy the requirements of Rule 16b-3 shall not invalidate any Awards granted by such Committee. The Board may also appoint one or more separate committees of the Board, each composed of one or more directors of the Company who need not qualify under Rule 16b-3, who may administer the Plan with respect to Key Employees who are not considered officers or directors of the Company under Section 16 of the Exchange Act, may grant Awards under the Plan to such Key Employees and may determine all terms of such Awards. Notwithstanding the foregoing, the Board shall constitute the Committee and shall administer the Plan with respect to all Awards granted to Non-Employee Directors. (b) AUTHORITY OF THE COMMITTEE. Subject to the provisions of the Plan, the Committee shall have full authority and discretion to take any actions it deems necessary or advisable for the administration of the Plan. Such actions shall include: (i) selecting Key Employees who are to receive Awards under the Plan; (ii) determining the type, number, vesting requirements and other features and conditions of such Awards; (iii) interpreting the Plan; and (iv) making all other decisions relating to the operation of the Plan. The Committee may adopt such rules or guidelines, as it deems appropriate to implement the Plan. The Committee's determinations under the Plan shall be final and binding on all persons. 5

(c) INDEMNIFICATION. Each member of the Committee, or of the Board, shall be indemnified and held harmless by the Company against and from (i) any loss, cost, liability, or expense that may be imposed upon or reasonably incurred by him or her in connection with or resulting from any claim, action, suit, or proceeding to which he or she may be a party or in which he or she may be involved by reason of any action taken or failure to act under the Plan or any Stock Option Agreement or Restricted Stock Agreement, and (ii) from any and all amounts paid by him or her in settlement thereof, with the Company's approval, or paid by him or her in satisfaction of any judgment in any such claim, action, suit, or proceeding against him or her, provided he or she shall give the Company an opportunity, at its own expense, to handle and defend the same before he or she undertakes to handle and defend it on his or her own behalf. The foregoing right of indemnification shall not be exclusive of any other rights of indemnification to which such persons may be entitled under the Company's Certificate of Incorporation or Bylaws, by contract, as a matter of law, or otherwise, or under any power that the Company may have to indemnify them or hold them harmless. SECTION 4. ELIGIBILITY. (a) GENERAL RULES. Only Employees, Directors, Non-Employee Directors and Consultants shall be eligible for designation as Key Employees by the Committee. (b) INCENTIVE STOCK OPTIONS. Only Key Employees who are common-law employees of the Company, a Parent or a Subsidiary shall be eligible for the grant of ISOs. In addition, a Key Employee who is a 10-Percent Shareholder shall not be eligible for the grant of an ISO unless the requirements set forth in section 422(c)(5) of the Code are satisfied. (c) NON-EMPLOYEE DIRECTOR OPTIONS. Non-Employee Directors shall also be eligible to receive Options as described in this Section 4(c) from and after the date the Board has determined to implement this provision. (i) Each eligible Non-Employee Director elected or appointed after the effective date of the Company's initial public offering shall automatically be granted an NSO to purchase 30,000 Shares (after giving effect to the June 2001 stock split) (subject to adjustment under Section 9) as a result of his or her initial election or appointment as a Non-Employee Director. Upon the conclusion of each regular annual meeting of the Company's stockholders following his or her initial appointment, each eligible Non-Employee Director who will continue serving as a member of the Board and who received an initial grant thereafter shall receive an NSO to purchase 7,500 Shares (after giving effect to the June 2001 stock split) (subject to adjustment under Section 9). All NSOs granted pursuant to this Section 4 shall vest and become exercisable provided the individual is serving as a director of the Company as of the vesting date as follows: 25% one year from the date of grant, then in 36 equal monthly installments commencing on the date one month and one year after the date of grant. 6

(ii) All NSOs granted to Non-Employee Directors under this Section 4(c) shall become exercisable in full in the event of Change in Control with respect to the Company. (iii) The Exercise Price under all NSOs granted to a Non-Employee Director under this Section 4(c) shall be equal to one hundred percent (100%) of the Fair Market Value of a Share of Common Stock on the date of grant, payable in one of the forms described in Section 7. (iv) All NSOs granted to a Non-Employee Director under this Section 4(c) shall terminate on the earlier of: (1) The 10th anniversary of the date of grant; or (2) The date ninety (90) days after the termination of such Non-Employee Director's Service for any reason. SECTION 5. SHARES SUBJECT TO PLAN. (a) BASIC LIMITATION. The stock issuable under the Plan shall be authorized but unissued Shares or treasury Shares. The aggregate number of Shares reserved for Awards under the Plan shall not exceed 3,000,000 Shares (after giving effect to the June 2001 stock split). (b) ANNUAL ADDITION. Beginning with the first fiscal year of the Company beginning after the Effective Date, on the first day of each fiscal year, Shares will be added to the Plan equal to the lesser of (i) 3,000,000 Shares (after giving effect to the June 2001 stock split), (ii) five percent (5%) of the outstanding shares on the last day of the prior fiscal year, or (iii) such lesser number of Shares as may be determined by the Board in its sole discretion. (c) ADDITIONAL SHARES. If Awards are forfeited or terminate for any other reason before being exercised, then the Shares underlying such Awards shall again become available for Awards under the Plan. (d) LIMITS ON OPTIONS. No Key Employee shall receive Options to purchase Shares during any fiscal year covering in excess of 1,000,000 Shares(after giving effect to the June 2001 stock split), or 2,000,000 Shares (after giving effect to the June 2001 stock split)in the first fiscal year of a Key Employee's employment with Company. (e) LIMITS ON STOCK PURCHASE RIGHTS. No Key Employee shall receive an Award of Stock Purchase Rights during any fiscal year covering in excess of 500,000 Shares (after giving effect to the June 2001 stock split), or 1,000,000 Shares (after giving effect to the June 2001 stock split) in the first fiscal year of a Key Employee's employment with Company. 7

SECTION 6. TERMS AND CONDITIONS OF OPTIONS. (a) STOCK OPTION AGREEMENT. Each Grant under the Plan shall be evidenced by a Stock Option Agreement between the Optionee and the Company. Such Option shall be subject to all applicable terms and conditions of the Plan and may be subject to any other terms and conditions that are not inconsistent with the Plan and that the Committee deems appropriate for inclusion in a Stock Option Agreement. The provisions of the various Stock Option Agreements entered into under the Plan need not be identical. A Stock Option Agreement may provide that new Options will be granted automatically to the Optionee when he or she exercises the prior Options. The Stock Option Agreement shall also specify whether the Option is an ISO or an NSO. (b) NUMBER OF SHARES. Each Stock Option Agreement shall specify the number of Shares that are subject to the Option and shall provide for the adjustment of such number in accordance with Section 9. (c) EXERCISE PRICE. An Option's Exercise Price shall be established by the Committee and set forth in a Stock Option Agreement. The Exercise Price of an ISO shall not be less than 100% of the Fair Market Value (110% for 10-Percent Shareholders) of a Share on the date of Grant. In the case of an NSO, a Stock Option Agreement may specify an Exercise Price that varies in accordance with a predetermined formula while the NSO is outstanding. (d) EXERCISABILITY AND TERM. Each Stock Option Agreement shall specify the date when all or any installment of the Option is to become exercisable. The Stock Option Agreement shall also specify the term of the Option; provided that the term of an ISO shall in no event exceed ten (10) years from the date of Grant. An ISO that is granted to a 10-Percent Shareholder shall have a maximum term of five (5) years. No Option can be exercised after the expiration date provided in the applicable Stock Option Agreement. A Stock Option Agreement may provide for accelerated exercisability in the event of the Optionee's death, disability or retirement or other events and may provide for expiration prior to the end of its term in the event of the termination of the Optionee's service. A Stock Option Agreement may permit an Optionee to exercise an Option before it is vested, subject to the Company's right of repurchase over any Shares acquired under the unvested portion of the Option (an "early exercise"), which right of repurchase shall lapse at the same rate the Option would have vested had there been no early exercise. In no event shall the Company be required to issue fractional Shares upon the exercise of an Option. (e) MODIFICATIONS OR ASSUMPTION OF OPTIONS. Within the limitations of the Plan, the Committee may modify, extend or assume outstanding options or may accept the cancellation of outstanding options (whether granted by the Company or by another issuer) in return for the grant of new Options for the same or a different number of Shares and at the same or a different Exercise Price. The foregoing notwithstanding, no modification of an Option shall, without the consent of the Optionee, alter or impair his or her rights or obligations under such Option. 8

(f) TRANSFERABILITY OF OPTIONS. Except as otherwise provided in the applicable Stock Option Agreement and then only to the extent permitted by applicable law, no Option shall be transferable by the Optionee other than by will or by the laws of descent and distribution. Except as otherwise provided in the applicable Stock Option Agreement, an Option may be exercised during the lifetime of the Optionee only or by the guardian or legal representative of the Optionee. No Option or interest therein may be assigned, pledged or hypothecated by the Optionee during his lifetime, whether by operation of law or otherwise, or be made subject to execution, attachment or similar process. (g) NO RIGHTS AS STOCKHOLDER. An Optionee, or a transferee of an Optionee, shall have no rights as a stockholder with respect to any Common Stock covered by an Option until such person becomes entitled to receive such Common Stock by filing a notice of exercise and paying the Exercise Price pursuant to the terms of such Option. (h) RESTRICTIONS ON TRANSFER. Any Shares issued upon exercise of an Option shall be subject to such rights of repurchase, rights of first refusal and other transfer restrictions as the Committee may determine. Such restrictions shall apply in addition to any restrictions that may apply to holders of Shares generally and shall also comply to the extent necessary with applicable law. SECTION 7. PAYMENT FOR OPTION SHARES. (a) GENERAL RULE. The entire Exercise Price of Shares issued upon exercise of Options shall be payable in cash at the time when such Shares are purchased, except as follows: (i) In the case of an ISO granted under the Plan, payment shall be made only pursuant to the express provisions of the applicable Stock Option Agreement. The Stock Option Agreement may specify that payment may be made in any form(s) described in this Section 7. (ii) In the case of an NSO granted under the Plan, the Committee may in its discretion, at any time accept payment in any form(s) described in this Section 7. (b) SURRENDER OF STOCK. To the extent that this Section 7(b) is applicable, payment for all or any part of the Exercise Price may be made with Shares which have already been owned by the Optionee for such duration as shall be specified by the Committee. Such Shares shall be valued at their Fair Market Value on the date when the new Shares are purchased under the Plan. (c) PROMISSORY NOTE. To the extent that this Section 7(c) is applicable, payment for all or any part of the Exercise Price may be made with a full-recourse promissory note. (d) OTHER FORMS OF PAYMENT. To the extent that this Section 7(d) is applicable, payment may be made in any other form that is consistent with applicable laws, regulations and rules. 9

SECTION 8. TERMS AND CONDITIONS FOR AWARDS OF STOCK PURCHASE RIGHTS. (a) TIME, AMOUNT AND FORM OF AWARDS. Awards under this Section 8 may be granted in the form of Stock Purchase Rights pursuant to which Restricted Stock will be awarded to a Key Employee. Such Rights may also be awarded in combination with NSOs, and such an Award may provide that the Restricted Stock will be forfeited in the event that the related NSOs is exercised. (b) AGREEMENTS. Each Award of a Stock Purchase Right under the Plan shall be evidenced by a Restricted Stock Agreement between the Participant and the Company. Such Awards shall be subject to all applicable terms and conditions of the Plan and may be subject to any other terms and conditions that are not inconsistent with the Plan and that the Committee deems appropriate for inclusion in the applicable Agreement. The provisions of the various Agreements entered into under the Plan need not be identical. (c) PAYMENT FOR RESTRICTED STOCK. Restricted Stock may be issued pursuant to the Award of a Stock Purchase Right with or without cash consideration under the Plan. (d) VESTING CONDITIONS. Each Award of Restricted Stock shall become vested, in full or in installments, upon satisfaction of the conditions specified in the applicable Agreement. An Agreement may provide for accelerated vesting in the event of the Participant's death, Disability or retirement or other events. (e) ASSIGNMENT OR TRANSFER OF RESTRICTED STOCK. Except as provided in Section 13, or in a Restricted Stock Agreement, or as required by applicable law, an Award granted under this Section 8 shall not be anticipated, assigned, attached, garnished, optioned, transferred or made subject to any creditor's process, whether voluntarily, involuntarily or by operation of law. Any act in violation of this Section 8(e) shall be void. However, this Section 8(e) shall not preclude a Participant from designating a beneficiary who will receive any outstanding Restricted Stock in the event of the Participant's death, nor shall it preclude a transfer of Restricted Stock by will or by the laws of descent and distribution. (f) TRUSTS. Neither this Section 8 nor any other provision of the Plan shall preclude a Participant from transferring or assigning Restricted Stock to (a) the trustee of a trust that is revocable by such Participant alone, both at the time of the transfer or assignment and at all times thereafter prior to such Participant's death, or (b) the trustee of any other trust to the extent approved in advance by the Committee in writing. A transfer or assignment of Restricted Stock from such trustee to any person other than such Participant shall be permitted only to the extent approved in advance by the Committee in writing, and Restricted Stock held by such trustee shall be subject to all of the conditions and restrictions set forth in the Plan and in the applicable Restricted Stock Agreement, as if such trustee were a party to such Agreement. (g) VOTING AND DIVIDEND RIGHTS. The holders of Restricted Stock acquired pursuant to a Stock Purchase Right awarded under the Plan shall have the same voting, dividend and 10

other rights as the Company's other stockholders. A Restricted Stock Agreement, however, may require that the holders of Restricted Stock invest any cash dividends received in additional Restricted Stock. Such additional Restricted Stock shall be subject to the same conditions and restrictions as the Award with respect to which the dividends were paid. Such additional Restricted Stock shall not reduce the number of Shares available under Section 5. SECTION 9. PROTECTION AGAINST DILUTION. (a) ADJUSTMENTS. In the event of a subdivision of the outstanding Shares, a declaration of a dividend payable in Shares, a declaration of a dividend payable in a form other than Shares in an amount that has a material effect on the price of Shares, a combination or consolidation of the outstanding Shares (by reclassification or otherwise) into a lesser number of Shares, a recapitalization, reorganization, merger, liquidation, spin-off or a similar occurrence, the Committee shall make such adjustments as it, in its reasonable discretion, deems appropriate in order to prevent the dilution or enlargement of rights hereunder in one or more of: (i) the number of Shares available for future Awards and the per person Share limits under Section 5; (ii) the number of Shares covered by each outstanding Award; or (iii) the Exercise Price under each outstanding Option. (b) PARTICIPANT RIGHTS. Except as provided in this Section 9, a Participant shall have no rights by reason of any issue by the Company of stock of any class or securities convertible into stock of any class, any subdivision or consolidation of shares of stock of any class, the payment of any stock dividend or any other increase or decrease in the number of shares of stock of any class. SECTION 10. EFFECT OF A CHANGE IN CONTROL. (a) MERGER OR REORGANIZATION. In the event that the Company is a party to a merger or other reorganization, outstanding Awards shall be subject to the agreement of merger or reorganization. Such agreement may provide, without limitation, for the assumption of outstanding Awards by the surviving corporation or its parent, for their continuation by the Company (if the Company is a surviving corporation), for accelerated vesting or for their cancellation with or without consideration. (b) ACCELERATION. Except as otherwise provided in the applicable Stock Option Agreement or Restricted Stock Agreement, in the event that a Change in Control occurs with respect to the Company and the applicable agreement of merger or reorganization provides for assumption or continuation of Awards pursuant to Section 10(a), no acceleration of vesting shall occur. In the event that a Change in Control occurs with 11

respect to the Company and there is no assumption or continuation of Awards pursuant to Section 10(a), all Awards shall vest and become immediately exercisable. SECTION 11. LIMITATIONS ON RIGHTS. (a) RETENTION RIGHTS. Neither the Plan nor any Award granted under the Plan shall be deemed to give any individual a right to remain an employee, consultant or director of the Company, a Parent, a Subsidiary or an Affiliate. The Company and its Parents and Subsidiaries and Affiliates reserve the right to terminate the Service of any person at any time, and for any reason, subject to applicable laws, the Company's Certificate of Incorporation and Bylaws and a written employment agreement (if any). (b) STOCKHOLDERS' RIGHTS. A Participant shall have no dividend rights, voting rights or other rights as a stockholder with respect to any Shares covered by his or her Award prior to the issuance of a stock certificate for such Shares. No adjustment shall be made for cash dividends or other rights for which the record date is prior to the date when such certificate is issued, except as expressly provided in Section 9. (c) REGULATORY REQUIREMENTS. Any other provision of the Plan notwithstanding, the obligation of the Company to issue Shares under the Plan shall be subject to all applicable laws, rules and regulations and such approval by any regulatory body as may be required. The Company reserves the right to restrict, in whole or in part, the delivery of Shares pursuant to any Award prior to the satisfaction of all legal requirements relating to the issuance of such Shares, to their registration, qualification or listing or to an exemption from registration, qualification or listing. SECTION 12. WITHHOLDING TAXES. (a) GENERAL. A Participant shall make arrangements satisfactory to the Company for the satisfaction of any withholding tax obligations that arise in connection with his or her Award. The Company shall not be required to issue any Shares or make any cash payment under the Plan until such obligations are satisfied. (b) SHARE WITHHOLDING. If a public market for the Company's Shares exists, the Committee may permit a Participant to satisfy all or part of his or her withholding or income tax obligations by having the Company withhold all or a portion of any Shares that otherwise would be issued to him or her or by surrendering all or a portion of any Shares that he or she previously acquired. Such Shares shall be valued at their Fair Market Value on the date when taxes otherwise would be withheld in cash. In no event may the Company allow Shares to be withheld in an amount that exceeds the minimum statutory withholding rates for federal and state tax purposes, including payroll taxes. Any payment of taxes by assigning Shares to the Company may be subject to restrictions, including, but not limited to, any restrictions required by rules of the Securities and Exchange Commission. 12

SECTION 13. DURATION AND AMENDMENTS. (a) TERM OF THE PLAN. The Plan, as set forth herein, shall become effective on the date of its adoption by the Board, subject to the approval of the Company's stockholders. No Options shall be exercisable until such stockholder approval is obtained. In the event that the stockholders fail to approve the Plan within twelve (12) months after its adoption by the Board, any Awards made shall be null and void and no additional Awards shall be made. The Plan shall terminate on the date that is ten (10) years after its adoption by the Board and may be terminated on any earlier date pursuant to Section 13(b). (b) RIGHT TO AMEND OR TERMINATE THE PLAN. The Board may amend or terminate the Plan at any time and for any reason. The termination of the Plan, or any amendment thereof, shall not affect any Award previously granted under the Plan. No Awards shall be granted under the Plan after the Plan's termination. An amendment of the Plan shall be subject to the approval of the Company's stockholders only to the extent required by applicable laws, regulations or rules. SECTION 14. EXECUTION. To record the adoption of the Plan by the Board, the Company has caused its duly authorized officer to execute this Plan on behalf of the Company. PDF SOLUTIONS, INC. /s/ P. Steven Melman By ______________________________________ Chief Financial Officer Title ___________________________________ 13

EXHIBIT 4.2 PDF SOLUTIONS, INC. 2001 EMPLOYEE STOCK PURCHASE PLAN (AS ADOPTED ON JUNE 12, 2001) SECTION 1 PURPOSE PDF Solutions, Inc. hereby establishes the PDF Solutions, Inc. 2001 Employee Stock Purchase Plan, effective as of the Initial Public Offering Date, in order to provide eligible employees of the Company and its participating Subsidiaries with the opportunity to purchase Common Stock through payroll deductions. The Plan is intended to qualify as an employee stock purchase plan under Section 423(b) of the Code. SECTION 2 DEFINITIONS 2.1 "1934 Act" means the Securities Exchange Act of 1934, as amended. Reference to a specific Section of the 1934 Act or regulation thereunder shall include such Section or regulation, any valid regulation promulgated under such Section, and any comparable provision of any future legislation or regulation amending, supplementing or superseding such Section or regulation. 2.2 "Board" means the Board of Directors of the Company. 2.3 "Code" means the Internal Revenue Code of 1986, as amended. Reference to a specific Section of the Code or regulation thereunder shall include such Section or regulation, any valid regulation promulgated under such Section, and any comparable provision of any future legislation or regulation amending, supplementing or superseding such Section or regulation. 2.4 "Committee" shall mean the committee appointed by the Board to administer the Plan. Any member of the Committee may resign at any time by notice in writing mailed or delivered to the Secretary of the Company. As of the effective date of the Plan, the Plan shall be administered by the Compensation Committee of the Board. 2.5 "Common Stock" means the common stock of the Company. 2.6 "Company" means PDF Solutions, Inc. 2.7 "Compensation" means a Participant's regular wages. The Committee, in its discretion, may (on a uniform and nondiscriminatory basis) establish a different definition of Compensation prior to an Enrollment Date for all options to be granted on such Enrollment Date. 2.8 "Eligible Employee" means every Employee of an Employer, except (a) any Employee who immediately after the grant of an option under the Plan, would own stock

and/or hold outstanding options to purchase stock possessing five percent (5%) or more of the total combined voting power or value of all classes of stock of the Company or of any Subsidiary of the Company (including stock attributed to such Employee pursuant to Section 424(d) of the Code), or (b) as provided in the following sentence. The Committee, in its discretion, from time to time may, prior to an Enrollment Date for all options to be granted on such Enrollment Date, determine (on a uniform and nondiscriminatory basis) that an Employee shall not be an Eligible Employee if he or she: (1) has not completed at least two years of service since his or her last hire date (or such lesser period of time as may be determined by the Committee in its discretion), (2) customarily works not more than 20 hours per week (or such lesser period of time as may be determined by the Committee in its discretion), or (3) customarily works not more than 5 months per calendar year (or such lesser period of time as may be determined by the Committee in its discretion). 2.9 "Employee" means an individual who is a common-law employee of any Employer, whether such employee is so employed at the time the Plan is adopted or becomes so employed subsequent to the adoption of the Plan. 2.10 "Employer" or "Employers" means any one or all of the Company, and those Subsidiaries which, with the consent of the Board, have adopted the Plan. 2.11 "Enrollment Date" means such dates as may be determined by the Committee (in its discretion and on a uniform and nondiscriminatory basis) from time to time. 2.12 "Grant Date" means any date on which a Participant is granted an option under the Plan. 2.13 "Participant" means an Eligible Employee who (a) has become a Participant in the Plan pursuant to Section 4.1 and (b) has not ceased to be a Participant pursuant to Section 8 or Section 9. 2.14 "Plan" means the PDF Solutions, Inc. 2001 Employee Stock Purchase Plan, as set forth in this instrument and as hereafter amended from time to time. 2.15 "Purchase Date" means such dates as may be determined by the Committee (in its discretion and on a uniform and nondiscriminatory basis) from time to time prior to an Enrollment Date for all options to be granted on such Enrollment Date. 2.16 "Subsidiary" means any corporation in an unbroken chain of corporations beginning with the Company if each of the corporations other than the last corporation in the unbroken chain then owns stock possessing fifty percent (50%) or more of the total combined voting power of all classes of stock in one of the other corporations in such chain. SECTION 3 SHARES SUBJECT TO THE PLAN 3.1 Number Available. A maximum of 300,000 shares (after giving effect to the June 2001 stock split) of Common Stock shall be available for issuance pursuant to the Plan. Beginning with the first fiscal year of the Company beginning after the effective date of the Plan, 2

on the first day of each fiscal year of the Company, Shares will be added to the Plan equal to the least of (a) 2% of the outstanding Shares on the last day of the prior fiscal year, (b) 675,000 Shares (after giving effect to the June 2001 stock split), or (c) such lesser amount as determined by the Board. Shares sold under the Plan may be newly issued shares or treasury shares. 3.2 Adjustments. In the event of any reorganization, recapitalization, stock split, reverse stock split, stock dividend, combination of shares, merger, consolidation, offering of rights or other similar change in the capital structure of the Company, the Board may make such adjustment, if any, as it deems appropriate in the number, kind and purchase price of the shares available for purchase under the Plan and in the maximum number of shares subject to any option under the Plan. SECTION 4 ENROLLMENT 4.1 Participation. Each Eligible Employee may elect to become a Participant by enrolling or re-enrolling in the Plan effective as of any Enrollment Date. In order to enroll, an Eligible Employee must complete, sign and submit to the Company an enrollment form in such form, manner and by such deadline as may be specified by the Committee from time to time (in its discretion and on a nondiscriminatory basis). Any Participant whose option expires and who has not withdrawn from the Plan automatically will be re-enrolled in the Plan on the Enrollment Date immediately following the Purchase Date on which his or her option expires. Any Participant whose option has not expired and who has not withdrawn from the Plan automatically will be deemed to be un-enrolled from the Participant's current option and be enrolled as of a subsequent Enrollment Date if the price per Share on such subsequent Enrollment Date is lower than the price per Share on the Enrollment Date relating to the Participant's current option. 4.2 Payroll Withholding. On his or her enrollment form, each Participant must elect to make Plan contributions via payroll withholding from his or her Compensation. Pursuant to such procedures as the Committee may specify from time to time, a Participant may elect to have withholding equal to a whole percentage from 1% to 10% (or such lesser, or greater, percentage that the Committee may establish from time to time for all options to be granted on any Enrollment Date). A Participant may elect to increase or decrease his or her rate of payroll withholding by submitting a new enrollment form in accordance with such procedures as may be established by the Committee from time to time. A Participant may stop his or her payroll withholding by submitting a new enrollment form in accordance with such procedures as may be established by the Committee from time to time. In order to be effective as of a specific date, an enrollment form must be received by the Company no later than the deadline specified by the Committee, in its discretion and on a nondiscriminatory basis, from time to time. Any Participant who is automatically re-enrolled in the Plan will be deemed to have elected to continue his or her contributions at the percentage last elected by the Participant. 3

SECTION 5 OPTIONS TO PURCHASE COMMON STOCK 5.1 Grant of Option. On each Enrollment Date on which the Participant enrolls or re-enrolls in the Plan, he or she shall be granted an option to purchase shares of Common Stock. 5.2 Duration of Option. Each option granted under the Plan shall expire upon the conclusion of the option's offering period which will end on the earliest to occur of (a) the completion of the purchase of shares on the last Purchase Date occurring within 27 months of the Grant Date of such option, (b) such shorter option period as may be established by the Committee from time to time prior to an Enrollment Date for all options to be granted on such Enrollment Date, or (c) the date on which the Participant ceases to be such for any reason. Until otherwise determined by the Committee for all options to be granted on an Enrollment Date, the period referred to in clause (b) in the preceding sentence shall mean the period from the applicable Enrollment Date through the last business day prior to the immediately following Enrollment Date. 5.3 Number of Shares Subject to Option. The number of shares available for purchase by each Participant under the option will be established by the Committee from time to time prior to an Enrollment Date for all options to be granted on such Enrollment Date. 5.4 Other Terms and Conditions. Each option shall be subject to the following additional terms and conditions: (a) payment for shares purchased under the option shall be made only through payroll withholding under Section 4.2; (b) purchase of shares upon exercise of the option will be accomplished only in accordance with Section 6.1; (c) the price per share under the option will be determined as provided in Section 6.1; and (d) the option in all respects shall be subject to such other terms and conditions (applied on a uniform and nondiscriminatory basis), as the Committee shall determine from time to time in its discretion. SECTION 6 PURCHASE OF SHARES 6.1 Exercise of Option. Subject to Section 6.2, on each Purchase Date, the funds then credited to each Participant's account shall be used to purchase whole shares of Common Stock. Any cash remaining after whole shares of Common Stock have been purchased shall be carried forward in the Participant's account for the purchase of shares on the next Purchase Date. The price per Share of the Shares purchased under any option granted under the Plan shall be eighty-five percent (85%) of the lower of: 4

(a) the closing price per Share on the NASDAQ National Market System on the business day preceding the Grant Date for such option; or (b) the closing price per Share on the NASDAQ National Market System on the Purchase Date; provided, however, that with respect to any Grant Date under the Plan that coincides with the date of the final prospectus for the initial public offering of the Common Stock, the price in clause (a) above shall be the price per Share at which shares of Common Stock are initially offered for sale to the public by the Company's underwriters in such offering. 6.2 Delivery of Shares. As directed by the Committee in its sole discretion, shares purchased on any Purchase Date shall be delivered directly to the Participant or to a custodian or broker (if any) designated by the Committee to hold shares for the benefit of the Participants. As determined by the Committee from time to time, such shares shall be delivered as physical certificates or by means of a book entry system. 6.3 Exhaustion of Shares. If at any time the shares available under the Plan are over-enrolled, enrollments shall be reduced proportionately to eliminate the over-enrollment. Such reduction method shall be "bottom up," with the result that all option exercises for one share shall be satisfied first, followed by all exercises for two shares, and so on, until all available shares have been exhausted. Any funds that, due to over-enrollment, cannot be applied to the purchase of whole shares shall be refunded to the Participants (without interest thereon). SECTION 7 WITHDRAWAL 7.1 Withdrawal. A Participant may withdraw from the Plan by submitting a completed enrollment form to the Company. A withdrawal will be effective only if it is received by the Company by the deadline specified by the Committee (in its discretion and on a uniform and nondiscriminatory basis) from time to time. When a withdrawal becomes effective, the Participant's payroll contributions shall cease and all amounts then credited to the Participant's account shall be distributed to him or her (without interest thereon). SECTION 8 CESSATION OF PARTICIPATION 8.1 Termination of Status as Eligible Employee. A Participant shall cease to be a Participant immediately upon the cessation of his or her status as an Eligible Employee (for example, because of his or her termination of employment from all Employers for any reason). As soon as practicable after such cessation, the Participant's payroll contributions shall cease and all amounts then credited to the Participant's account shall be distributed to him or her (without interest thereon). If a Participant is on a Company-approved leave of absence, his or her participation in the Plan shall continue for so long as he or she remains an Eligible Employee and has not withdrawn from the Plan pursuant to Section 7.1. 5

SECTION 9 DESIGNATION OF BENEFICIARY 9.1 Designation. Each Participant may, pursuant to such uniform and nondiscriminatory procedures as the Committee may specify from time to time, designate one or more Beneficiaries to receive any amounts credited to the Participant's account at the time of his or her death. Notwithstanding any contrary provision of this Section 9, Sections 9.1 and 9.2 shall be operative only after (and for so long as) the Committee determines (on a uniform and nondiscriminatory basis) to permit the designation of Beneficiaries. 9.2 Changes. A Participant may designate different Beneficiaries (or may revoke a prior Beneficiary designation) at any time by delivering a new designation (or revocation of a prior designation) in like manner. Any designation or revocation shall be effective only if it is received by the Committee. However, when so received, the designation or revocation shall be effective as of the date the designation or revocation is executed (whether or not the Participant still is living), but without prejudice to the Committee on account of any payment made before the change is recorded. The last effective designation received by the Committee shall supersede all prior designations. 9.3 Failed Designations. If a Participant dies without having effectively designated a Beneficiary, or if no Beneficiary survives the Participant, the Participant's Account shall be payable to his or her estate. SECTION 10 ADMINISTRATION 10.1 Plan Administrator. The Plan shall be administered by the Committee. The Committee shall have the authority to control and manage the operation and administration of the Plan. 10.2 Actions by Committee. Each decision of a majority of the members of the Committee then in office shall constitute the final and binding act of the Committee. The Committee may act with or without a meeting being called or held and shall keep minutes of all meetings held and a record of all actions taken by written consent. 10.3 Powers of Committee. The Committee shall have all powers and discretion necessary or appropriate to supervise the administration of the Plan and to control its operation in accordance with its terms, including, but not by way of limitation, the following discretionary powers: (a) To interpret and determine the meaning and validity of the provisions of the Plan and the options and to determine any question arising under, or in connection with, the administration, operation or validity of the Plan or the options; (b) To determine any and all considerations affecting the eligibility of any employee to become a Participant or to remain a Participant in the Plan; (c) To cause an account or accounts to be maintained for each Participant; 6

(d) To determine the time or times when, and the number of shares for which, options shall be granted; (e) To establish and revise an accounting method or formula for the Plan; (f) To designate a custodian or broker to receive shares purchased under the Plan and to determine the manner and form in which shares are to be delivered to the designated custodian or broker; (g) To determine the status and rights of Participants and their Beneficiaries or estates; (h) To employ such brokers, counsel, agents and advisers, and to obtain such broker, legal, clerical and other services, as it may deem necessary or appropriate in carrying out the provisions of the Plan; (i) To establish, from time to time, rules for the performance of its powers and duties and for the administration of the Plan; (j) To adopt such procedures and subplans as are necessary or appropriate to permit participation in the Plan by employees who are foreign nationals or employed outside of the United States; (k) To delegate to any one or more of its members or to any other person, severally or jointly, the authority to perform for and on behalf of the Committee one or more of the functions of the Committee under the Plan. 10.4 Decisions of Committee. All actions, interpretations, and decisions of the Committee shall be conclusive and binding on all persons, and shall be given the maximum possible deference allowed by law. 10.5 Administrative Expenses. All expenses incurred in the administration of the Plan by the Committee, or otherwise, including legal fees and expenses, shall be paid and borne by the Employers, except any stamp duties or transfer taxes applicable to the purchase of shares may be charged to the account of each Participant. Any brokerage fees for the purchase of shares by a Participant shall be paid by the Company, but fees and taxes (including brokerage fees) for the transfer, sale or resale of shares by a Participant, or the issuance of physical share certificates, shall be borne solely by the Participant. 10.6 Eligibility to Participate. No member of the Committee who is also an employee of an Employer shall be excluded from participating in the Plan if otherwise eligible, but he or she shall not be entitled, as a member of the Committee, to act or pass upon any matters pertaining specifically to his or her own account under the Plan. 10.7 Indemnification. Each of the Employers shall, and hereby does, indemnify and hold harmless the members of the Committee and the Board, from and against any and all losses, claims, damages or liabilities (including attorneys' fees and amounts paid, with the approval of the Board, in settlement of any claim) arising out of or resulting from the 7

implementation of a duty, act or decision with respect to the Plan, so long as such duty, act or decision does not involve gross negligence or willful misconduct on the part of any such individual. SECTION 11 AMENDMENT, TERMINATION, AND DURATION 11.1 Amendment, Suspension, or Termination. The Board, in its sole discretion, may amend or terminate the Plan, or any part thereof, at any time and for any reason. If the Plan is terminated, the Board, in its discretion, may elect to terminate all outstanding options either immediately or upon completion of the purchase of shares on the next Purchase Date, or may elect to permit options to expire in accordance with their terms (and participation to continue through such expiration dates). If the options are terminated prior to expiration, all amounts then credited to Participants' accounts which have not been used to purchase shares shall be returned to the Participants (without interest thereon) as soon as administratively practicable. 11.2 Duration of the Plan. The Plan shall commence on the date specified herein, and subject to Section 11.1 (regarding the Board's right to amend or terminate the Plan), shall remain until June 30, 2011. SECTION 12 GENERAL PROVISIONS 12.1 Participation by Subsidiaries. One or more Subsidiaries of the Company may become participating Employers by adopting the Plan and obtaining approval for such adoption from the Board. By adopting the Plan, a Subsidiary shall be deemed to agree to all of its terms, including (but not limited to) the provisions granting exclusive authority (a) to the Board to amend the Plan, and (b) to the Committee to administer and interpret the Plan. An Employer may terminate its participation in the Plan at any time. The liabilities incurred under the Plan to the Participants employed by each Employer shall be solely the liabilities of that Employer, and no other Employer shall be liable for benefits accrued by a Participant during any period when he or she was not employed by such Employer. 12.2 Inalienability. In no event may either a Participant, a former Participant or his or her Beneficiary, spouse or estate sell, transfer, anticipate, assign, hypothecate, or otherwise dispose of any right or interest under the Plan; and such rights and interests shall not at any time be subject to the claims of creditors nor be liable to attachment, execution or other legal process. Accordingly, for example, a Participant's interest in the Plan is not transferable pursuant to a domestic relations order. 12.3 Severability. In the event any provision of the Plan shall be held illegal or invalid for any reason, the illegality or invalidity shall not affect the remaining parts of the Plan, and the Plan shall be construed and enforced as if the illegal or invalid provision had not been included. 12.4 Requirements of Law. The granting of options and the issuance of shares shall be subject to all applicable laws, rules, and regulations, and to such approvals by any 8

governmental agencies or securities exchanges as the Committee may determine are necessary or appropriate. 12.5 Compliance with Rule 16b-3. Any transactions under this Plan with respect to officers (as defined in Rule 16a-1 promulgated under the 1934 Act) are intended to comply with all applicable conditions of Rule 16b-3. To the extent any provision of the Plan or action by the Committee fails to so comply, it shall be deemed null and void, to the extent permitted by law and deemed advisable by the Committee. Notwithstanding any contrary provision of the Plan, if the Committee specifically determines that compliance with Rule 16b-3 no longer is required, all references in the Plan to Rule 16b-3 shall be null and void. 12.6 No Enlargement of Employment Rights. Neither the establishment or maintenance of the Plan, the granting of options, the purchase of shares, nor any action of any Employer or the Committee, shall be held or construed to confer upon any individual any right to be continued as an employee of the Employer nor, upon dismissal, any right or interest in any specific assets of the Employers other than as provided in the Plan. Each Employer expressly reserves the right to discharge any employee at any time, with or without cause. 12.7 Apportionment of Costs and Duties. All acts required of the Employers under the Plan may be performed by the Company for itself and its Subsidiaries, and the costs of the Plan may be equitably apportioned by the Committee among the Company and the other Employers. Whenever an Employer is permitted or required under the terms of the Plan to do or perform any act, matter or thing, it shall be done and performed by any officer or employee of the Employers who is thereunto duly authorized by the Employers. 12.8 Construction and Applicable Law. The Plan is intended to qualify as an "employee stock purchase plan" within the meaning of Section 423(b) of the Code. Any provision of the Plan which is inconsistent with Section 423(b) of the Code shall, without further act or amendment by the Company or the Committee, be reformed to comply with the requirements of Section 423(b). The provisions of the Plan shall be construed, administered and enforced in accordance with such Section and with the laws of the State of California (excluding California's conflict of laws provisions). 12.9 Captions. The captions contained in and the table of contents prefixed to the Plan are inserted only as a matter of convenience, and in no way define, limit, enlarge or describe the scope or intent of the Plan nor in any way shall affect the construction of any provision of the Plan. EXECUTION 9

IN WITNESS WHEREOF, PDF Solutions, Inc., by its duly authorized officer, has executed this Plan. PDF SOLUTIONS, INC. Dated: June 12, 2001 By: /s/ P. Steven Melman ------------------------ Title: Chief Financial Officer 10

EXHIBIT 5.1 OPINION AND CONSENT OF ORRICK, HERRINGTON & SUTCLIFFE LLP January 10, 2003 PDF Solutions, Inc. 333 West San Carlos Street, Suite 700 San Jose, California 95110 Re: PDF Solutions, Inc. Registration Statement on Form S-8 Ladies and Gentlemen: At your request, we are rendering this opinion in connection with the Registration Statement on Form S-8 (the "Registration Statement") filed by you with the Securities and Exchange Commission (the "Commission") on or about January 10, 2003 in connection with the registration under the Securities Act of 1933, as amended, of a total of 3,221,622 shares of your Common Stock (the "Common Shares") reserved for issuance under the PDF Solutions, Inc. 2001 Stock Plan and the PDF Solutions, Inc. 2001 Employee Stock Purchase Plan. We have examined instruments, documents, and records which we deemed relevant and necessary for the basis of our opinion hereinafter expressed. In such examination, we have assumed the following: (a) the authenticity of original documents and the genuineness of all signatures; (b) the conformity to the originals of all documents submitted to us as copies; and (c) the truth, accuracy, and completeness of the information, representations, and warranties contained in the records, documents, instruments, and certificates we have reviewed. Based on such examination, we are of the opinion that the Common Shares, when issued and sold as described in the Registration Statement, will be legally issued, fully paid and nonassessable. We hereby consent to the filing of this opinion as an exhibit to the above-referenced Registration Statement and to the use of our name wherever it appears in said Registration Statement, including the Prospectus constituting a part thereof, as originally filed or as subsequently amended or supplemented. In giving such consent, we do not consider that we are "experts" within the meaning of such term as used in the Securities Act of 1933, as amended, or the rules and regulations of the Securities and Exchange Commission issued thereunder, with respect to any part of the Registration Statement, including this opinion as an exhibit or otherwise. Very truly yours, /s/ ORRICK, HERRINGTON & SUTCLIFFE LLP

EXHIBIT 23.1 INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in this Registration Statement of PDF Solutions, Inc. on Form S-8, of our reports dated January 18, 2002, appearing in the Annual Report on Form 10-K of PDF Solutions, Inc. filed with the Securities and Exchange Commission on April 1, 2002 (File No. 000-31311). /s/ DELOITTE & TOUCHE LLP San Jose, California January 9, 2003

Exhibit 99.1 SELECTED FINANCIAL DATA (UNAUDITED) ADDITIONAL DISCLOSURE REFLECTING THE PRO FORMA RETROACTIVE APPLICATION OF FASB NO. 142, "GOODWILL AND OTHER INTANGIBLE ASSETS" ("SFAS NO. 142") TO THE FINANCIAL STATEMENTS FOR EACH OF THE THREE YEARS IN THE PERIOD ENDED DECEMBER 31, 2001. The following selected financial data should be read in conjunction with our consolidated financial statements and the notes thereto included in our Annual Report (Form 10-K) for the year ended December 31, 2001, which is incorporated by reference in this Registration Statement on Form S-8. With the adoption of SFAS No. 142, we ceased the amortization of goodwill and intangible assets deemed to have indefinite lives and recharacterized acquired workforce (and the related deferred tax liability) as goodwill on January 1, 2002. We completed our transitional goodwill impairment tests as of January 1, 2002 and found no impairment. The following table presents the pro forma impact of SFAS No. 142 on net loss and net loss per share as if the standard had been in effect for the three years ended December 31, 2001:

December 31, ---------------------------- 2001 2000 1999 ---------------------------- (In thousands, except per share amounts) Reported net loss $(5,491) $(9,097) $ (145) Add back goodwill amortization, net of taxes 88 44 -- Add back workforce amortization, net of taxes 131 65 -- ---------------------------- Adjusted net loss $(5,272) $(8,988) $ (145) ============================ Basic and diluted net loss per share: Reported basic net income (loss) $ (0.38) $ (1.24) $(0.02) per share Add back goodwill amortization per share 0.01 0.01 Add back workforce amortization per share 0.01 0.01 ---------------------------- Adjusted basic net income (loss) per share $ (0.36) $ (1.22) $(0.02) ============================