Nanoparticle filled underfill

• US 7,482,201 B2
• Filed: 01/11/2008
• Issued: 01/27/2009
• Est. Priority Date: 05/23/2002
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Gross, Kathleen M., Charles, Scott B., Thompson, Wendy L., Schultz, William J., Hackett, Steven C., Kropp, Michael A.
• Primary Examiner(s): Monbleau; Davienne
• Assistant Examiner(s): Nguyen; Dilinh P
• Application Number:
  US11/972,904
• Publication Number:
  US 20080108180A1
• Time in Patent Office: 382 Days
• Field of Search: 438/106, 438/108, 438/112, 438/118, 438/124, 438/126, 438/127, 438/612, 438/613, 438/666
• US Class Current: 438/108
• CPC Class Codes: H01L 21/563 Encapsulation of active face of flip-chip device, e.g. underfilling or underencapsulation of flip-chip, encapsulation preform on chip or mounting substrate
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/2929 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/29386 with a principal constituent of the material being a non metallic, non metalloid inorganic material
• CPC Class Codes: H01L 2224/73203 Bump and layer connectors
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 23/293 Organic, e.g. plastic
• CPC Class Codes: H01L 23/295 containing a filler H01L23/296 takes precedence
• CPC Class Codes: H01L 24/29 of an individual layer connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01012 Magnesium [Mg]
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/0102 Calcium [Ca]
• CPC Class Codes: H01L 2924/01021 Scandium [Sc]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01046 Palladium [Pd]
• CPC Class Codes: H01L 2924/01057 Lanthanum [La]
• CPC Class Codes: H01L 2924/01063 Europium [Eu]
• CPC Class Codes: H01L 2924/01066 Dysprosium [Dy]
• CPC Class Codes: H01L 2924/01067 : Holmium [Ho]
• CPC Class Codes: H01L 2924/01068 : Erbium [Er]
• CPC Class Codes: H01L 2924/01077 : Iridium [Ir]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01087 : Francium [Fr]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/05442 : SiO2
• CPC Class Codes: H01L 2924/0665 : Epoxy resin
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H05K 3/305 : Affixing by adhesive

Abstract

The invention provides electronic articles and methods of making said articles. The electronic articles comprise an electronic component bonded and electrically connected to a substrate using an underfill adhesive comprising the reaction product of a thermosetting resin, curing catalyst, and surface-treated nanoparticles that are substantially spherical, non-agglomerated, amorphous, and solid.

Claims

1. 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; and

surface-treated nanoparticles that are substantially spherical, non-agglomerated, amorphous, and solid, said surface-treated nanoparticles comprising silica, said curable underfill bonding composition having a viscosity of from 1,000 to about 100,000 centipoise at 25°

C.;

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.

2. The method of claim 1 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.

3. The method of claim 1 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.

4. The method of claim 1 wherein the surface treated nanoparticles have a mean particle size of from about 5 to about 600 nanometers.

5. The method 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.

6. The method of claim 1 wherein heat is applied to also reflow the solder.

7. The method of claim 1 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.