Method of clamping a circuit package to enhance heat transfer

Claim 1

A method to form a compact circuit package with improved construction for clamping to enhance heat transfer, comprising the steps of forming an insulating housing with a circuit retaining cavity substantially surrounded by a peripheral side wall including a wall portion terminating at a rim located substantially within a first plane, providing said housing with means to limit the depth of entry into said cavity, placing a heat conducting electrically insulating substrate into engagement with said depth limiting means to substantially enclose said cavity with a first side of said substrate facing said cavity and containing a heat generating electrical component and a second oppositely disposed side located substantially within a second plane spaced from said first plane so that said rim extends outward from said substrate second side, and removing an outer portion of said rim substantially along said second plane to provide a reduced rim located substantially within said second plane so that said reduced rim and said second substrate side form a clamping surface to be clamped to an external heat dissipating object to permit increased substantial clamping pressure without damaging said substrate and said side wall.

Claim 2

A method to form a compact circuit package with improved construction for clamping to enhance heat transfer, comprising the steps of forming an insulating housing with a circuit retaining cavity substantially surrounded by a peripheral side wall including a wall portion terminating at a rim located substantially within a first plane, providing said housing with means to limit the depth of entry into said cavity, placing a heat conducting electrically insulating substrate into engagement with said depth limiting means to substantially enclose said cavity with a first side of said substrate facing said cavity and containing a heat generating electrical component and a second oppositely disposed side located substantially within a second plane spaced from said first plane so that said rim extends outward from said substrate second side, and removing an outer portion of said rim substantially along said second plane to provide a reduced rim located substantially within said second plane so that said reduced rim and said second substrate side form a clamping surface to be clamped to an external heat dissipating object to permit increased substantial clamping pressure without damaging said substrate and said side wall.

Claim 6

A method to form a compact circuit package with improved construction for clamping to enhance heat transfer, comprising the steps of forming an insulating housing with a circuit retaining cavity having a base surface surrounded by a peripheral side wall including a first pair of spaced side walls each terminating at a first rim located substantially within a first plane and a second pair of spaced side walls each terminating at a second rim located substantially within a third plane spaced from said first plane with said first and second rims surrounding an opening into said cavity, providing an abutment on each of said first and second side walls to limit the depth of entry into said cavity, placing a heat conducting electrically insulating substrate into said opening to engage said abutments and substantially enclose said cavity with a first side of said substrate facing said cavity and containing a heat generating electrical component and a second oppositely disposed side located substantially within a second plane located adjacent said first plane and spaced from said third plane so that only said second rims extend outwardly from said second plane, and removing an outer portion of said second rims by applying a belt sander until substantially at said second plane to render said second and third planes substantially co-extensive to form a clamping surface including said second rims and said substrate second side to be clamped to a substantially planar external heat dissipating object to permit increased substantial clamping pressures without damaging said substrate and said side walls.

Claim 7

A method to form a compact circuit package with improved construction for clamping to enhance heat transfer, comprising the steps of forming an insulating housing with a circuit retaining cavity having a base surface surrounded by a peripheral side wall including a first pair of spaced side walls each terminating at a first rim located substantially within a first plane and a second pair of spaced side walls each terminating at a second rim located substantially within a third plane spaced from said first plane with said first and second rims surrounding an opening into said cavity, providing an abutment on each of said first and second side walls to limit the depth of entry into said cavity, placing a heat conducting electrically insulating substrate into said opening to engage said abutments and substantially enclose said cavity with a first side of said substrate facing said cavity and containing a heat generating electrical component and a second oppositely disposed side located substantially within a second plane located adjacent said first plane and spaced from said third plane so that only said second rims extend outwardly from said second plane, and removing an outer portion of said second rims by applying a belt sander until substantially at said second plane to render said second and third planes substantially co-extensive to form a clamping surface including said second rims and said substrate second side to be clamped to a substantially planar external heat dissipating object to permit increased substantial clamping pressures without damaging said substrate and said side walls.