System and method of mitigating effects of component deflection in a probe card analyzer
View Patent ↗A system and method of mitigating the effects of component deflections in a probe card analyzer system may implement three-dimensional comparative optical metrology techniques to model deflection characteristics. An exemplary system and method combine non-bussed electrical planarity measurements with fast optical planarity measurements to produce “effectively loaded” planarity measurements.
1. A method of obtaining planarity measurements in a probe card analysis system; said method comprising:
computing planarity effects due to fiducial plate deflection;
combining planarity effects due to probe card deflection and due to probe card fixture deflection; and
responsive to said computing and said combining, calculating a load compensated planarity for said probe card.
2. The method of claim 1 further comprising accounting for planarity effects due to stage deflection and wherein said calculating is further responsive to said accounting.
3. The method of claim 2 , wherein said accounting comprises utilizing a distance sensor proximate to said stage deflection.
4. The method of claim 1 wherein said computing comprises utilizing an optical metrology technique.
5. The method of claim 4 wherein said utilizing an optical metrology technique comprises:
acquiring image data of a fiducial on said fiducial plate;
responsive to said acquiring, identifying deflection data values representative of a
deflection of said fiducial plate; and
responsive to said identifying, providing correction data values enabling a first order correction of said deflection.
6. The method of claim 5 wherein said utilizing an optical metrology technique further comprises:
further identifying rate data values representative of a rate of deflection of said fiducial plate; and
responsive to said further identifying, providing additional correction data values enabling a second order correction of said deflection.
7. The method of claim 1 wherein said combining comprises:
obtaining measurements of optical planarity and electrical planarity for said probe card;
measuring fiducial plate deflection at first electrical contact; and
responsive to said obtaining and said measuring, computing a combined deflection value for said probe card and said probe card fixture.