Patent ID: 6140144
Filing Date: 2000-10-31
Classification: B81B,B81C,G01L,H01L

Abstract:
A method of packaging a sensor unit having an active face which includes a sensor element on the active face of said sensor unit, said method comprising the steps of:providing a substrate having a rear surface, a front surface, and electrical connection means on said rear surface;forming a cavity in said substrate;locating said sensor unit over said substrate, with said active face facing in the direction of said rear surface of said substrate, and said sensor element over said cavity;electrically connecting said sensor unit to said electrical connection means;securing said sensor unit to said substrate;dispensing an underfill material at an interface between said sensor unit and said substrate;due to capillary force on said underfill material, drawing said underfill material between said interface such that said underfill material fills at least a portion of said interface between said sensor unit and said substrate without covering said sensor element; andforming a seal at said interface between said sensor unit and said substrate, said seal completely circumscribing said sensor element and isolating said sensor element and said cavity from said rear surface of said substrate.