PDF SOLUTIONS INC — Director's Dealing 2009

May 20, 2009

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: PDF SOLUTIONS INC (PDFS)
CIK: 0001120914
Period of Report: 2009-05-15

Reporting Person: Caulfield Thomas (Director)

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	10715	Direct

Footnotes

F1: This amount includes 10,715 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. 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. This Form 4 is being filed in connection with the partial vesting of the RSRs on May 15, 2009 and to move the RSRs from Table II to Table I.