FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * MICHAELS KIMON   2. Issuer Name and Ticker or Trading Symbol PDF SOLUTIONS INC [PDFS] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Co-VP of Client Services (Last) (First) (Middle) 333 WEST SAN CARLOS STREET, SUITE 700 3. Date of Earliest Transaction (Month/Day/Year) 05/15/2009 (Street) SAN JOSE, CA 95110 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 05/15/2009   F   8,193 D $ 1.84 1,455,038 (1) D   Common Stock 05/15/2009   F   2,165 D $ 1.84 75,195 (2) I By Spouse

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
MICHAELS KIMON 333 WEST SAN CARLOS STREET SUITE 700 SAN JOSE, CA 95110	X		Co-VP of Client Services

Signatures

/s/ Keith A. Jones, Substitute Attorney-in-Fact for Kimon W. Michaels		05/19/2009
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	This amount includes 42,762 shares of restricted stock rights ("RSRs") that were previously reported as derivative securities in Table II on the Form 4/A filed on August 26, 2008 (an additional 8,193 RSRs that were also previously reported in Table II were withheld by PDF Solutions, Inc. on May 15, 2009, to cover taxes.) Each RSR represents a bookkeeping entry equal in value to one (1) share of common stock of PDF Solutions, Inc. that will be automatically settled in shares upon vesting of the RSR.
(2)	This amount includes 11,501 shares of RSRs that were previously reported as derivative securities in Table II on the Form 5 filed on February 17, 2009 (an additional 2,165 RSRs that were also previously reported in Table II were withheld by PDF Solutions, Inc. on May 15, 2009, to cover taxes.) Each RSR represents a bookkeeping entry equal in value to one (1) share of common stock of PDF Solutions, Inc. that will be automatically settled in shares upon vesting of the RSR.
Remarks: Exhibit List: Exhibit 24:  Confirming Statement

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