Method and apparatus for measuring thermal warpage
Patent 5601364 Issued on February 11, 1997. Estimated Expiration Date: 
June 14, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
June 14, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 1346793 3292418 3566078 3614237 3762818 Multizone electrical furnace methods and apparatus General purpose rocket furnace Environmental hood for testing printed circuit cards Dual heater stabilization apparatus and method for a crystal oven Apparatus and method for indicating stress in an object InventorAssigneeApplicationNo. 259434 filed on 06/14/1994US Classes:374/57, Of susceptibility to thermally induced deteriouration, flaw, or failure250/237G, Gratings (moire fringes)356/605MoireExaminersPrimary: Gutierrez, DiegoAttorney, Agent or FirmInternational ClassesG01N 017/00G01N 003/60 G01B 011/24 G01B 011/30 AbstractA method and apparatus for measuring thermally induced warpage in test elements such as printed wiring boards and printed wiring assemblies, including a heating chamber having a transparent window and support structure for supporting a printing wiring board in an observation orientation and position parallel to the transparent window. A glass grating placed adjacent the window and a light source shines through the window onto the printed wiring board under test. A camera is positioned for capturing images of shadow moire fringes formed over time as the oven heats up the printed wiring board or printed wiring assembly to simulate actual process conditions. A computer is used for controlling operation of the apparatus and for evaluating the captured images of the moire fringes in relation to the temperature as a function of time. | |
