Method of making integrated circuit die package

Claim 1

A method of forming a package for an integrated circuit die comprising: a) providing a planar ceramic base having a first surface thereon and capable of functioning as a heat sink to dissipate heat generated by an integrated circuit die subsequently thermally coupled thereto; b) bonding to the periphery of said first surface of said ceramic base a lead frame with a central opening; c) bonding to both said lead frame and the peripheral potions of the same surface of said ceramic base exposed between leads on said lead frame a raised frame member having a thickness greater than the thickness of the integrated circuit die to be bonded to said planar ceramic base, and having a central opening therein to thereby form a recessed opening bounded by said planar ceramic base, said lead frame, and said raised frame member; d) bonding an integrated circuit die to an exposed central portion of said first surface of said ceramic base in said recessed opening surrounded by said lead frame and said raised frame member using a high purity thermally conductive adhesive: i) containing no more than 10 ppm of any halogen, alkali metal. Or alkaline earth metal impurity; ii) capable of withstanding a temperature of at least 300° C; and iii) containing a thermally conductive filler capable of enhancing thermal coupling of said die to said ceramic base; to thereby thermally couple said die to said ceramic base; e) electrically connecting said die to leads on said lead frame; and f) placing a curable high purity plastic potting material, containing no more than 10 ppm of any halogen, alkali metal, or alkaline earth metal impurity, in said recessed opening over and around the edges of said integrated circuit die, and in the space between said die and said lead frame and said frame member, and in contact with the exposed portion of said first surface of said ceramic base adjacent said die, whereby said ceramic base and said plastic potting material completely surround said integrated circuit die, said walls of said recessed opening, comprising said lead frame and said raised frame member, acting to form a dam to retain said potting material around and over said die prior to curing of said potting material; and g) heating said structure to a temperature sufficient to cure said potting material to thereby encapsulate said die without deforming said ceramic base.

Claim 2

A method of forming a package for an integrated circuit die comprising: a) providing a planar ceramic base having a first surface thereon and capable of functioning as a heat sink to dissipate heat generated by an integrated circuit die subsequently thermally coupled thereto; b) bonding to the periphery of said first surface of said ceramic base a lead frame with a central opening; c) bonding to both said lead frame and the peripheral potions of the same surface of said ceramic base exposed between leads on said lead frame a raised frame member having a thickness greater than the thickness of the integrated circuit die to be bonded to said planar ceramic base, and having a central opening therein to thereby form a recessed opening bounded by said planar ceramic base, said lead frame, and said raised frame member; d) bonding an integrated circuit die to an exposed central portion of said first surface of said ceramic base in said recessed opening surrounded by said lead frame and said raised frame member using a high purity thermally conductive adhesive: i) containing no more than 10 ppm of any halogen, alkali metal. Or alkaline earth metal impurity; ii) capable of withstanding a temperature of at least 300° C; and iii) containing a thermally conductive filler capable of enhancing thermal coupling of said die to said ceramic base; to thereby thermally couple said die to said ceramic base; e) electrically connecting said die to leads on said lead frame; and f) placing a curable high purity plastic potting material, containing no more than 10 ppm of any halogen, alkali metal, or alkaline earth metal impurity, in said recessed opening over and around the edges of said integrated circuit die, and in the space between said die and said lead frame and said frame member, and in contact with the exposed portion of said first surface of said ceramic base adjacent said die, whereby said ceramic base and said plastic potting material completely surround said integrated circuit die, said walls of said recessed opening, comprising said lead frame and said raised frame member, acting to form a dam to retain said potting material around and over said die prior to curing of said potting material; and g) heating said structure to a temperature sufficient to cure said potting material to thereby encapsulate said die without deforming said ceramic base.

Claim 19

A method of forming a package for an integrated circuit die comprising: a) providing a planar ceramic base having a first surface thereon and formed from a material capable Of dissipating heat from an integrated circuit die to be bonded thereto; b) securing a lead frame with a central opening to the periphery of said first surface of said ceramic base with a first epoxy adhesive capable of withstanding a temperature of 300° C.; c) securing a ceramic raised frame member, having a thickness greater than the thickness of said integrated circuit die and having a central opening therein, to both said lead frame and the peripheral portions of the same surface of said ceramic base exposed between leads on said lead frame with a second epoxy adhesive capable of withstanding a temperature of 300° C. to thereby form a central recessed region on said planar ceramic base; d) mounting an integrated circuit die to an exposed central portion of said first surface of said ceramic base in said recessed region formed by said lead frame and said raised frame member with a high purity silver-filled epoxy adhesive capable of withstanding a temperature of 300° C. and containing no more than 10 ppm of any halogen, alkali metal, or alkaline earth metal impurity to thermally couple said die to said ceramic base; e) electrically connecting said integrated circuit die to leads on said lead frame; and f) placing a curable epoxy potting material over and around the edges of said integrated circuit die, and in the space between said die and said lead frame and said frame member in said recessed region, and in contact with the exposed portion of said first surface of said ceramic base adjacent said die, said recessed region formed by said lead frame and said frame member acting as a dam to retain said curable epoxy potting material around and over said die until mid curable epoxy potting material is cured, said epoxy potting material being capable of withstanding a temperature of 300° C. and containing no more than 10 ppm of any halogen, alkali metal, or alkaline earth metal impurity, whereby said ceramic base and said epoxy potting resin completely surround said integrated circuit die; and g) then heating said structure to a temperature not exceeding 300° C., but sufficient to cure said epoxy potting material to thereby encapsulate said die in said package.

Claim 20

A method of forming a package for an integrated circuit die comprising: a) providing a planar ceramic base having a first surface thereon and formed from a material capable Of dissipating heat from an integrated circuit die to be bonded thereto; b) securing a lead frame with a central opening to the periphery of said first surface of said ceramic base with a first epoxy adhesive capable of withstanding a temperature of 300° C.; c) securing a ceramic raised frame member, having a thickness greater than the thickness of said integrated circuit die and having a central opening therein, to both said lead frame and the peripheral portions of the same surface of said ceramic base exposed between leads on said lead frame with a second epoxy adhesive capable of withstanding a temperature of 300° C. to thereby form a central recessed region on said planar ceramic base; d) mounting an integrated circuit die to an exposed central portion of said first surface of said ceramic base in said recessed region formed by said lead frame and said raised frame member with a high purity silver-filled epoxy adhesive capable of withstanding a temperature of 300° C. and containing no more than 10 ppm of any halogen, alkali metal, or alkaline earth metal impurity to thermally couple said die to said ceramic base; e) electrically connecting said integrated circuit die to leads on said lead frame; and f) placing a curable epoxy potting material over and around the edges of said integrated circuit die, and in the space between said die and said lead frame and said frame member in said recessed region, and in contact with the exposed portion of said first surface of said ceramic base adjacent said die, said recessed region formed by said lead frame and said frame member acting as a dam to retain said curable epoxy potting material around and over said die until mid curable epoxy potting material is cured, said epoxy potting material being capable of withstanding a temperature of 300° C. and containing no more than 10 ppm of any halogen, alkali metal, or alkaline earth metal impurity, whereby said ceramic base and said epoxy potting resin completely surround said integrated circuit die; and g) then heating said structure to a temperature not exceeding 300° C., but sufficient to cure said epoxy potting material to thereby encapsulate said die in said package.