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 * HARTGRING CORNELIS   2. Issuer Name and Ticker or Trading Symbol PDF SOLUTIONS INC [PDFS] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) VP&GM Manu.Process Solutions (Last) (First) (Middle) 333 WEST SAN CARLOS STREET, SUITE 700 3. Date of Earliest Transaction (Month/Day/Year) 01/04/2007 (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 01/04/2007   M(1)   61 A $ 5.4 3,643 (2) D   Common Stock 01/04/2007   S   61 D $ 14.95 3,582 D

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

2001 Stock Plan Option (Right to Buy)

$ 5.4

01/04/2007

M

61

(3)

09/02/2012

Common Stock

61

$ 0

134,939

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
HARTGRING CORNELIS 333 WEST SAN CARLOS STREET SUITE 700 SAN JOSE, CA 95110			VP&GM Manu.Process Solutions

Signatures

/s/ P. Steven Melman, Attorney for Cornelis Hartgring		01/08/2007
**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)	All transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 Sales Plan.
(2)	Includes 60 shares that were purchased on December 29, 2006 under the PDFS Employee Stock Purchase Plan.
(3)	The original stock option grant awarded in September 2002 granted the Reporting Person the right to buy 200,000 shares of common stock of PDFS (the "Total Shares") Twenty-five percent (25%) of the Total Shares vested on September 3, 2003 and 1/48th of the Total Shares continued to vest on the 3rd day of each month thereafter.

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