Patent ID: 6221693
Filing Date: 2001-04-24
Classification: H01L,H05K

Abstract:
A method of forming a package for mounting of at least one row of Ball Grid Array chips by forming an interconnect substrate on a metal panel, comprising the steps of:providing a metal substrate having a Coefficient of Thermal Expansion, said metal substrate further having a first surface and a second surface;cleaning the first surface of said metal substrate;depositing a first layer of dielectric having a Coefficient of Thermal Expansion over said first surface of said metal substrate;depositing a thin film interconnect layer having a surface over said first layer of dielectric, forming the first layer of an interconnect substrate, said first layer of interconnect substrate having a surface comprising a partially exposed second layer of dielectric, further comprising copper contact pads;creating a first Build Up Multilayer (BUM) layer over said thin film interconnect layer, forming a second layer of said interconnect substrate, said second layer of interconnect substrate having a surface comprising a partially exposed third layer of dielectric, further comprising copper contact pads;creating a second Build Up Multilayer (BUM) layer over said first Build Up Multilayer layer, forming a third layer of an interconnect substrate, said third layer of interconnect substrate having a surface comprising a partially exposed fourth layer of dielectric, further comprising copper contact pads;coating said second BUM layer with a solder mask;exposing metal pads within said second BUM layer thereby creating openings for BGA solder connections;masking and etching said second surface of said metal substrate, creating at least one opening for the insertion of at least one BGA chip, furthermore exposing portions of said first layer of dielectric within said openings;creating openings in said exposed first layer of dielectric, providing electrical access to said interconnect substrate for said at least one BGA chip; andsubdividing said metal substrate into individual BGA substrates.