Patent ID: 6119920
Filing Date: 2000-09-19
Classification: B23K,H01L

Abstract:
A method of simultaneously attaching a plurality of solderable lids to a like plurality of surface acoustic wave circuits on a common substrate to form a plurality of SAW circuit packages that can be separated into individual packages, the method comprising the steps of:forming a plurality of SAW circuits on a substrate in a predetermined pattern array, each of said SAW circuits having a solderable seal ring surrounding said circuit;arranging a like plurality of said solderable lids in a lid fixture in a corresponding predetermined pattern array, each of said solderable lids having at least a solderable peripheral flange;providing a like plurality of solder preforms each having an undesired oxide layer thereon and that has a shape for mating with corresponding ones of said solderable seal rings and said solderable peripheral lid flange;placing said substrate in superimposed relationship with said lid fixture so as to arrange each of said fluxless solder preforms in superimposed abutting relationship with a corresponding one of said solderable seal rings and solderable peripheral lid flanges; andheating said superimposed substrate and lid fixture in a furnace having a reducing atmosphere until any undesired oxide layer in said preform, seal ring, or solderable lid flange combines with said reducing atmosphere to create substantially oxide-free bonding surfaces and said solder melts and bonds to said solderable seal ring and solderable lid to sealingly attach said solderable lids over and around corresponding ones of said SAW circuits on said substrate.