Patent ID: 6892781
Filing Date: 2005-05-17
Classification: B30B,B32B,H01L,Y10T

Abstract:
1. A fixture for applying heat and pressure to a workpiece comprising: a bottom plate forming the base of the fixture; an expansion block opposed to the bottom plate and comprising a first material having a first coefficient of thermal expansion, CTE a top plate opposed to the expansion block and forming the top of the fixture; an alignment means aligning the bottom plate and second plate and comprising a second material having a second coefficient of thermal expansion, CTE a pressure means spacing the expansion block and top plate a fixed distance apart at room temperature, the pressure means comprising a third material having a third coefficient of thermal expansion, CTE wherein, in operation, a workpiece is placed between the bottom plate and expansion block and pressure is applied to the workpiece by the pressure means on the expansion block to keep the workpiece from moving wherein the bottom plate is separated from the expansion block by a gap, the workpiece and fixture are then placed in an oven heated to a predetermined temperature, the heat causing the expansion block, alignment means and pressure means to expand with a net displacement so as to change the gap to thereby cause pressure to be applied to the workpiece while being heated.