Epoxy resinous molding compositions having low coefficient of thermal expansion and high thermal conductivity

Claim 2

In an epoxy molding composition capable of conversion to a thermoset condition upon application of heat and pressure and suitable for encapsulating micro electronic devices, said composition comprising epoxy resin, hardener therefor and from about 40% to about 80% by weight based on total composition of filler, the improvement wherein from about 25% to about 100% by weight of the filler is an anisotropic, polycrystalline sintered ceramic product having cordierite as its primary phase and consisting essentially on an analytical oxide basis of 11.5 to 16.5% RO, 33 to 41% Al 2 O 3 and 46.6 to 53% SiO 2 and having a coefficient of thermal expansion in at least one direction of less than 11.0×10 -7 in./in./°C. over the range of 25° to 1000° C., and wherein RO consists essentially of one member selected from the group consisting of NiO, CoO, FeO, MnO and TiO 2 , the NiO when selected being less than 25% by weight of the RO, the CoO when selected being less than 15% by weight of the RO, the FeO when selected being less than 40% by weight of the RO, the MnO when selected being less than 98% by weight of the RO, the TiO 2 when selected being less than 15% by weight of the RO, and the balance of the RO being substantially all MgO, said anisotropic polycrystalline sintered ceramic product being relatively non-abrasive and free of ionic contaminants and imparting to said epoxy molding composition a linear coefficient of thermal expansion below the glass transition temperature of less than 23×10 -6 /°C. and a thermal conductivity greater than 25×10 -4 cal./°C./cm./sec.

Claim 3

The composition of claim 1 wherein RO consists essentially of MgO.

Claim 4

The composition of claim 1 wherein about 100% by weight of the filler is said anisotropic, polycrystalline sintered ceramic product.

Claim 5

In an epoxy molding composition capable of conversion to a thermoset condition upon application of heat and pressure and suitable for encapsulating microelectronic devices, said composition comprising epoxy resin, hardener therefor and from about 40% to 80% by weight based on total composition of filler, the improvement wherein from about 25% to about 100% by weight of the filler is an anisotropic, polycrystalline sintered ceramic product having cordierite as its primary phase and consisting essentially on an analytical oxide basis of 11.5 to 16.5% MgO, 33 to 41% Al 2 O 3 and 46.6 to 53% SiO 2 and having a coefficient of thermal expansion in at least one direction of less than 11.0×10 -7 in./in./°C. over the range of 25° to 1000° C., said anisotropic polycrystalline sintered ceramic product being relatively nonabrasive and free of ionic contaminants and imparting to said epoxy molding composition a linear coefficient of thermal expansion below the glass transition temperature of less than 23×10 -6 /°C. and a thermal conductivity greater than 25×10 -4 cal./°C./cm/sec.

Claim 6

In an epoxy molding composition capable of conversion to a thermoset condition upon application of heat and pressure and suitable for encapsulating microelectronic devices, said composition comprising epoxy resin, hardener therefor and from about 40% to 80% by weight based on total composition of filler, the improvement wherein from about 25% to about 100% by weight of the filler is an anisotropic, polycrystalline sintered ceramic product having cordierite as its primary phase and consisting essentially on an analytical oxide basis of 11.5 to 16.5% MgO, 33 to 41% Al 2 O 3 and 46.6 to 53% SiO 2 and having a coefficient of thermal expansion in at least one direction of less than 11.0×10 -7 in./in./°C. over the range of 25° to 1000° C., said anisotropic polycrystalline sintered ceramic product being relatively nonabrasive and free of ionic contaminants and imparting to said epoxy molding composition a linear coefficient of thermal expansion below the glass transition temperature of less than 23×10 -6 /°C. and a thermal conductivity greater than 25×10 -4 cal./°C./cm/sec.

Claim 7

The composition of claim 4 wherein about 100% by weight of the filler is said anisotropic polycrystalline sintered ceramic product.

Claim 8

A process for preparing an epoxy molding composition capable of conversion to a thermoset condition upon application of heat and pressure and suitable for encapsulating microelectronic devices, said composition having a linear coefficient of thermal expansion below the glass transition temperature of less than 23×10 -6 /°C. and a thermal conductivity which is greater than 25×10 -4 cal./°C./cm/sec., said process comprising admixing an epoxy resin, hardener therefor and from about 40% to about 80% by weight based on total composition of filler, 25% to about 100% by weight of said filler being an anisotropic, polycrystalline sintered ceramic product having cordierite as its primary phase and consisting essentially on an analytical basis of 11.5 to 16.5% RO, 33 to 41% Al 2 O 3 and 46.6 to 53% SiO 2 and having a coefficient of thermal expansion in at least one direction of less than 11.0×10 -7 in./in./°C. over the range of 25° to 1000° C., and wherein RO consists essentially of one member selected from the group consisting of NiO, CoO, FeO, MnO and TiO 2 , and the NiO when selected being less than 25% by weight of the RO, the CoO when selected being less than 15% by weight of the RO, the FeO when selected being less than 40% by weight of the RO, the MnO when selected being less than 98% by weight of the RO, the TiO 2 when selected being less than 15% by weight of the RO, and the balance of the RO being substantially all MgO, said anisotropic polycrystalline sintered ceramic product being relatively non-abrasive and free of ionic contaminants, and subjecting said mixture to momentary heat and pressure to compact and densify same.

Claim 9

A process for preparing an epoxy molding composition capable of conversion to a thermoset condition upon application of heat and pressure and suitable for encapsulating microelectronic devices, said composition having a linear coefficient of thermal expansion below the glass transition temperature of less than 23×10 -6 /°C. and a thermal conductivity which is greater than 25×10 -4 cal./°C./cm/sec., said process comprising admixing an epoxy resin, hardener therefor and from about 40% to about 80% by weight based on total composition of filler, 25% to about 100% by weight of said filler being an anisotropic, polycrystalline sintered ceramic product having cordierite as its primary phase and consisting essentially on an analytical basis of 11.5 to 16.5% RO, 33 to 41% Al 2 O 3 and 46.6 to 53% SiO 2 and having a coefficient of thermal expansion in at least one direction of less than 11.0×10 -7 in./in./°C. over the range of 25° to 1000° C., and wherein RO consists essentially of one member selected from the group consisting of NiO, CoO, FeO, MnO and TiO 2 , and the NiO when selected being less than 25% by weight of the RO, the CoO when selected being less than 15% by weight of the RO, the FeO when selected being less than 40% by weight of the RO, the MnO when selected being less than 98% by weight of the RO, the TiO 2 when selected being less than 15% by weight of the RO, and the balance of the RO being substantially all MgO, said anisotropic polycrystalline sintered ceramic product being relatively non-abrasive and free of ionic contaminants, and subjecting said mixture to momentary heat and pressure to compact and densify same.

Claim 10

The process of claim 6 wherein the RO consists essentially of MgO.

Claim 11

The process of claim 6 wherein about 100% by weight of the filler is said anisotropic polycrystalline sintered ceramic product.

Claim 12

The process of claim 7 wherein about 100% by weight of the filler is said anisotropic polycrystalline sintered ceramic filler.

Claim 13

A semiconductor device encapsulated with the thermoset composition of claim 1.