Plastic pin grid array package

Claim 1

A method of producing a plastic pin grid array package comprising a planar main body member having a top and a bottom surface and a centrally disposed recessed cavity formed in the top surface, an electronic device enclosed in the recessed cavity, a metal heat sink for removal of heat from the device, and a plurality of terminal pins arranged around the recessed cavity, at least some of these pins being electrically connected to pads on said device, which comprises: a) assembling into a laminate preassembly a plurality of coextensive sheets to be laminated into a planar main body, said preassembly including a top and a bottom sheet of C-stage synthetic organic polymer, a sheet of metal placed between the top and bottom sheets and having a higher index of thermal conductivity than the top and bottom sheets, and B-stage synthetic organic polymer sheets individually placed intermediate the metal sheet and the top and bottom sheets, said metal sheet having clearance holes at positions where it is desirable to pass certain of the terminal pins through the metal sheet without making an electrical contact with the metal sheet, b) subjecting the laminate preassembly to heat and pressure so as to form a laminated main body, the pressure forcing B-stage synthetic organic polymer into the clearance holes in the metal sheet in the form of plugs of said polymer, c) forming in the laminated main body a plurality of plated-through holes extending between the top and bottom surfaces of the main body, some of the plated-through holes being electrical contact with the metal sheet and some other of the plated-through holes passing through the plugs in the metal sheet out of contact with the metal sheet, d) forming conductors in the top and bottom surfaces of the main body, e) forming a recessed cavity in the top surface of the main body so as to expose in the cavity the surface of the metal sheet, the exposed surface of the metal sheet acting as the base of the recessed cavity, f) electroplating through a mask the exposed metal base of the cavity and portions of conductors adjacent the cavity in succession with Ni and Au, g) inserting terminal pins into the plated-through-holes and securing them by means of solder, h) adhesively securing the bottom surface of the device to the exposed metal surface in said recessed cavity, i) electrically connecting pads on the top surface of the device to the conductors on the top surface of the main body, these conductors extending between selected ones of the plated-through holes and edges of the recess cavity, and j) encapsulating the device and portions of electrical conductors connected to the pads on the device with a synthetic organic polymer.

Claim 2

A method of producing a plastic pin grid array package comprising a planar main body member having a top and a bottom surface and a centrally disposed recessed cavity formed in the top surface, an electronic device enclosed in the recessed cavity, a metal heat sink for removal of heat from the device, and a plurality of terminal pins arranged around the recessed cavity, at least some of these pins being electrically connected to pads on said device, which comprises: a) assembling into a laminate preassembly a plurality of coextensive sheets to be laminated into a planar main body, said preassembly including a top and a bottom sheet of C-stage synthetic organic polymer, a sheet of metal placed between the top and bottom sheets and having a higher index of thermal conductivity than the top and bottom sheets, and B-stage synthetic organic polymer sheets individually placed intermediate the metal sheet and the top and bottom sheets, said metal sheet having clearance holes at positions where it is desirable to pass certain of the terminal pins through the metal sheet without making an electrical contact with the metal sheet, b) subjecting the laminate preassembly to heat and pressure so as to form a laminated main body, the pressure forcing B-stage synthetic organic polymer into the clearance holes in the metal sheet in the form of plugs of said polymer, c) forming in the laminated main body a plurality of plated-through holes extending between the top and bottom surfaces of the main body, some of the plated-through holes being electrical contact with the metal sheet and some other of the plated-through holes passing through the plugs in the metal sheet out of contact with the metal sheet, d) forming conductors in the top and bottom surfaces of the main body, e) forming a recessed cavity in the top surface of the main body so as to expose in the cavity the surface of the metal sheet, the exposed surface of the metal sheet acting as the base of the recessed cavity, f) electroplating through a mask the exposed metal base of the cavity and portions of conductors adjacent the cavity in succession with Ni and Au, g) inserting terminal pins into the plated-through-holes and securing them by means of solder, h) adhesively securing the bottom surface of the device to the exposed metal surface in said recessed cavity, i) electrically connecting pads on the top surface of the device to the conductors on the top surface of the main body, these conductors extending between selected ones of the plated-through holes and edges of the recess cavity, and j) encapsulating the device and portions of electrical conductors connected to the pads on the device with a synthetic organic polymer.