Claims
- 1. An electronic assembly comprising:
an electronic component electrically bonded to a substrate with an underfill adhesive between the electronic component and substrate, wherein the underfill adhesive comprises the reaction product of a curable underfill bonding composition comprising a mixture of polyepoxide resin; curing catalyst; and surface-treated nanoparticles that are substantially spherical, non-agglomerated, amorphous, and solid.
- 2. The electronic assembly of claim 1 wherein the curable underfill bonding composition further comprises a fluxing agent.
- 3. The electronic assembly of claim 1 wherein the surface treated nanoparticles have a mean particle size of from about 5 to about 600 nanometers.
- 4. The electronic assembly of claim 1 wherein the surface treated nanoparticles are present in the underfill adhesive in an amount of from about 30 to about 70 weight percent.
- 5. The electronic assembly of claim 1 wherein the surface treated nanoparticles are surface treated with an organosilane.
- 6. The electronic assembly of claim 1 wherein the CTE of the underfill adhesive ranges from about 20 to about 50 ppm/° C.
- 7. The electronic assembly of claim 1 wherein the surface-treated nanoparticles comprise silica.
- 8. The electronic assembly of claim 1 wherein the polyepoxide is present in the underfill adhesive in an amount of from 10 to 70 parts per 100 parts of the total composition.
- 9. The electronic assembly of claim 1 wherein the surface treated nanoparticles are present in the underfill adhesive in an amount of from about 35 to about 65 weight percent.
- 10. The electronic assembly of claim 1 wherein the polyepoxide is substantially free of hydroxyl functionality.
- 11. The electronic assembly of claim 1 wherein the surface treated nanoparticles have a mean particle size of from about 10 to about 300 nanometers.
- 12. The electronic assembly of claim 1 wherein the surface treated nanoparticles have a mean particle size of from about 20 to about 150 nanometers.
- 13. The electronic assembly of claim 1 wherein the surface treated nanoparticles have a mean particle size of from about 20 to about 125 nanometers.
- 14. The electronic assembly of claim 1 wherein the surface treated nanoparticles have a mean particle size of from about 100 to about 500 nanometers.
- 15. The electronic assembly of claim 2 wherein the fluxing agent is selected from the group consisting of carboxylic acids, acid anhydrides, chelating agents, and combinations thereof.
- 16. The electronic assembly of claim 1 wherein the polyepoxide is a mixture of diglycidyl ether of Bisphenol F and triglycidyl ether of para-aminophenol.
- 17. The electronic assembly of claim 1 wherein the surface treated nanoparticles comprises a blend of two or more surface treated nanoparticles, each having a mean particle size of from about 10 to about 150 nanometers.
- 18. The electronic assembly of claim 1 further comprising filler particles having an average particle diameter of greater than 1 micrometer.
- 19. The electronic assembly of claim 1 wherein the electronic component is selected from the group consisting of integrated circuit chips, resistors, capacitors, packages, and combinations thereof.
- 20. The electronic assembly of claim 1 wherein the substrate is a printed circuit board or a flexible circuit.
- 21. A method of making an electrical assembly comprising the steps of:
providing an electronic component; providing a substrate, either the electronic component or the substrate having solder bumps and the other having electrical bonding pads; providing a curable underfill bonding composition comprising:
polyepoxide resin; curing catalyst; fluxing agent; surface-treated nanoparticles that are substantially spherical, non-agglomerated, amorphous, and solid; positioning the curable composition between the electronic component and the substrate such that the solder bumps align with the electrical bonding pads to form a curable assembly; and applying heat to the curable assembly to cure the bonding composition.
- 22. The method of claim 21 wherein the curable underfill bonding composition is positioned between the electronic component and the substrate prior to aligning the solder bumps with the electrical bonding pads.
- 23. The method of claim 21 wherein the curable underfill bonding composition is positioned between the electronic component and the substrate after aligning the solder bumps with the electrical bonding pads and reflowing the solder.
- 24. The method of claim 21 wherein the viscosity of the curable underfill adhesive composition ranges from about 1,000 to about 100,000 centipoise at 25° C.
- 25. The method of claim 21 wherein the surface treated nanoparticles have a mean particle size of from about 5 to about 600 nanometers.
- 26. The method of claim 21 wherein the surface treated nanoparticles are present in the underfill adhesive in an amount of from about 30 to about 70 weight percent.
- 27. The method of claim 21 wherein the surface-treated nanoparticles comprise silica.
- 28. The method of claim 21 wherein heat is applied to also reflow the solder.
- 29. The method of claim 21 wherein the surface treated nanoparticles are present in the curable underfill bonding composition in an amount of from about 35 to about 65 weight percent.
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent Application No. 60/383,379, filed on May 23, 2002.
Provisional Applications (1)
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Number |
Date |
Country |
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60383379 |
May 2002 |
US |