Underfill composition and packaged solid state device
View Patent ↗An underfill composition with enhanced adhesion and improved resistance to cracking comprising an epoxy resin in combination with a difunctional siloxane anhydride epoxy hardener and optional reagents. In some embodiments, the epoxy resin includes a functionalized colloidal silica filler having a particle size ranging from about 1 nm to about 500 nm. The difunctional siloxane anhydride epoxy hardener can optionally be combined with liquid anhydride epoxy hardeners. Cure catalysts, hydroxyl-containing monomers, adhesion promoters, flame retardants and defoaming agents may also be added to the composition. Further embodiments of the present disclosure include packaged solid state devices comprising the underfill compositions.
1. An underfil composition comprising;
at least one epoxy resin in combination with at least one epoxy hardener, the at least one epoxy hardener comprising at least one difunctional siloxane anhydride, and
further comprising a colloidal silica filler functionalized with an organoalkoxysilane and having a particle size in a range of from about 1 nanometer to about 500 nanometers, and wherein the colloidal silica is endcapped by a silylating agent.
2. The underfill composition in accordance with claim 1 , wherein the at least one difunctional siloxane anhydride has the formula:
where X is from 0 to 50 inclusive, each R′ and R″ are independently selected from the group consisting of C 1-22 alkyl, C 1-22 alkoxy, C 2-22 alkenyl, C 6-14 aryl, C 6-22 alkyl-substituted aryl, and C 6-22 arylalkyl, and where Y is represented by the following formula:
where R 9 -R 15 are each independently selected from the group consisting of hydrogen, halogen, C (1-13) monovalent hydrocarbon radicals and substituted C (1-13) monovalent hydrocarbon radicals, and W is selected from the group consisting of —O— and —CR 2 —, wherein R is selected from the group consisting of hydrogen, halogen, C (1-13) monovalent hydrocarbon radicals and substituted C (1-13) monovalent hydrocarbon radicals.
3. The underfill composition of claim 2 , wherein X in formula (1) is from 0 to 10 inclusive.
4. The underfill composition of claim 2 , wherein X in formula (1) is from 1 to 6 inclusive.
5. The underfill composition of claim 2 , wherein R′ and R″ in formula (1) are selected from the group consisting of C 1-22 fluoroalkyl, methyl, ethyl, and phenyl.
6. The underfill composition of claim 2 , wherein the at least one difunctional siloxane anhydride comprises a mixture of oligomers of formula (1), and wherein X in formula (1) is from 0 to 10 inclusive.
7. The underfill composition in accordance with claim 1 , wherein the at least one difunctional siloxane anhydride has the formula:
where X is from 0 to 50 inclusive, and each R′ and R″ are independently selected from the group consisting of C 1-22 alkyl, C 1-22 alkoxy, C 2-22 alkenyl, C 6-14 aryl, C 6-22 alkyl-substituted aryl, and C 6-22 arylalkyl.
8. The underfill composition of claim 7 , wherein X in formula (3) is from 0 to 10 inclusive.
9. The underfill composition of claim 7 , wherein X in formula (3) is from 1 to 6 inclusive.
10. The underfill composition of claim 7 , wherein R′ and R″ in formula (3) are selected from the group consisting of C 1-22 fluoroalkyl, methyl, ethyl, and phenyl.
11. The underfill composition of claim 7 , wherein the at least one difunctional siloxane anhydride comprises a mixture of oligomers of formula (3) and wherein X in formula (3) is from 0 to 10 inclusive.
12. The underfill composition of claim 1 , further comprising at least one anhydride epoxy hardener selected from the group consisting of methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 1,2-cyclohexartedicarboxylic arthydride, bicyclo(2.2.1)hept-5-ene-2,3-dicarboxylic anhydride, methylbicyclo(2.2.1)hept-5-ene-2,3-dicarboxylic arthydride, phthalic anhydride, pyromellitic dianhydride, hexahydrophthalic anhydride, dodecenylsuccinic anhydride, dichioromaleic anhydride, chlorendic anhydride, tetrachlorophthalic anhydride, and mixtures thereof.
13. The underfill composition of claim 1 , further comprising a liquid epoxy hardener selected from the group consisting of methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, and tetrahydrophthalic anhydride.
14. The underfill composition of claim 1 , wherein the colloidal silica filler is functionalized with phenyltrimethoxysilane.
15. The underfill composition of claim 1 , wherein the silylating agent is hexamethyldisilazane.
16. The underfill composition in accordance with claim 1 , wherein the epoxy resin comprises a cycloaliphatic epoxy monomer, an aliphatic epoxy monomer, an aromatic epoxy monomer, a silicone epoxy monomer, or combinations thereof.
17. The underfill composition in accordance with claim 1 , further comprising a cure catalyst selected from the group consisting of amines, phosphines, metal salts, salts of nitrogen-containing compounds, and combinations thereof.
18. The underfill composition in accordance with claim 1 , further comprising a hydroxyl-containing monomer selected from the group consisting of alcohols, alkane diols, glycerol, and phenols.
19. An underfill composition comprising at least one epoxy resin in combination with a colloidal silica filler functionalized with an organoalkoxysilane and having a particle size ranging from about 1 nanometer to about 500 nanometer, and at least one epoxy hardener, wherein the at least one epoxy hardener comprises a difunctional siloxane anhydride of the formula:
where X is from 0 to 50 inclusive, and each R′ and R″ are independently selected from the group consisting of C 1-22 alkyl, C 1-22 alkoxy, C 2-22 alkenyl, C 6-14 aryl, C 6-22 alkyl-substituted aryl, and C 6-22 arylalkyl, and wherein the colloidal silica filler is functionalized with phenyltrimethoxysilane and wherein the colloidal silica is endcapped by a silylating agent.
20. The underfill composition of claim 19 , wherein the silylating agent is hexamethyldisilazane.
21. A packaged solid state device comprising:
a package;
a chip; and
an encapsulant comprising at least one epoxy resin in combination with a colloidal silica filler functionalized with an organoalkoxysilane and having a particle size ranging from about 1 nanometer to about 500 nanometer, and at least one epoxy hardener, wherein the at least one epoxy hardener comprises a difunctional siloxane anhydride of the formula:
where X is from 0 to 50 inclusive, and each R′ and R″ are independently selected from the group consisting of C 1-22 alkyl, C 1-22 alkoxy, C 2-22 alkenyl, C 6-14 aryl, C 6-22 alkyl-substituted aryl, and C 6-22 arylalkyl, and
wherein the colloidal silica is endcapped by a silylating agent.
22. The packaged solid state device of claim 21 , wherein X in formula (3) is from 0 to 10 inclusive.
23. The packaged solid state device of claim 21 , wherein X in formula (3) is from 1 to 6 inclusive.
24. The packaged solid state device of claim 21 , wherein R′ and R″ in formula (3) are independently selected from the group consisting of C 1-22 fluoroalkyl, methyl, ethyl, and phenyl.
25. The packaged solid state device of claim 21 , wherein the at least one difunctional siloxane anhydride in the encapsulant comprises a mixture of oligomers of formula (3) and wherein X in formula (3) is from 0 to 10 inclusive.
26. The packaged solid state device of claim 21 , wherein the encapsulant further comprises at least one anhydride epoxy hardener selected from the group consisting of methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 1,2-cyclohexanedicarboxylic anhydride, bicyclo(2.2.1)hept-5-ene-2,3-dicarboxylic anhydride, methylbicyclo(2.2.1)hept-5-ene-2,3-dicarboxylic anhydride, phthalic anhydride, pyromellitic diarthydride, hexahydrophthalic anhydride, dodecenylsuccinic anhydride, dichioromaleic anhydride, chiorendic anhydride, tetrachlorophthalic anhydride, and mixtures thereof.
27. The packaged solid state device of claim 21 , wherein the encapsulant further comprises a liquid epoxy hardener selected from the group consisting of methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, and tetrahydrophthalic anhydride.
28. The packaged solid state device of claim 21 , wherein the colloidal silica filler in the encapsulant is functionalized with phenyltrimethoxysilane.
29. The packaged solid state device of claim 21 , wherein the silylating agent is hexamethyldisilazane.
30. The packaged solid state device of claim 21 , wherein the epoxy resin in the encapsulant comprises a cycloaliphatic epoxy monomer, an aliphatic epoxy monomer, an aromatic epoxy monomer, a silicone epoxy monomer, or combinations thereof.
31. The packaged solid state device of claim 21 , wherein the encapsulant further comprises a cure catalyst selected from the group consisting of amines, phosphines, metal salts, salts of nitrogen-containing compounds, and combinations thereof.