# US 2012/0074597 A1 · Flexible underfill compositions for enhanced reliability > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2012/0074597 A1 - Document ID: US20120074597A1 - Status: Published application - Kind: A1 - Application number: 12/890,545 - Filed: 2010-09-24 - Published: 2012-03-29 - Earliest claimed: 2010-09-24 - Assignees: Intel Corporation - Inventors: Dingying Xu; Nisha Ananthakrishnan; Hong Dong; Rahul N. Manepalli; Nachiket Raravikar; Gregory S. Constable - Web page: https://patentgrep.com/patent/US20120074597A1 ## CPC - C08G 59/02: Polycondensates containing more than one epoxy group per molecule - C07F 7/0838: {Compounds with one or more Si-O-Si sequences (compounds with a ring containing only alternating Si and O atoms, i.e. cyclosilanes C07F7/21)} - C08G 59/3254: {containing atoms other than carbon, hydrogen, oxygen or nitrogen} - C08G 59/38: together with di-epoxy compounds - C08L 23/0884: Epoxide-containing esters - H10W 74/012: {of encapsulations on active surfaces of flip-chip devices, e.g. forming underfills} - H10W 74/15: on active surfaces of flip-chip devices, e.g. underfills - H10W 74/47: comprising organic materials, e.g. plastics or resins - H10W 72/072: {of bump connectors} - H10W 72/073: {of die-attach connectors} - H10W 72/90: Bond pads, in general - H10W 72/9415: {relative to the surface, e.g. recessed, protruding} - H10W 90/724: {between a chip and a stacked insulating package substrate, interposer or RDL} - Y10T 428/31515: As intermediate layer - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract Underfill materials for fabricating electronic devices are described. One embodiment includes an underfill composition including an epoxy mixture, an amine hardener component, and a filler. The epoxy mixture may include a first epoxy comprising a bisphenol epoxy, a second epoxy comprising a multifunctional epoxy, and a third epoxy comprising an aliphatic epoxy, the aliphatic epoxy comprising a silicone epoxy. The first, second, and third epoxies each have a different chemical structure. Other embodiments are described and claimed. ## Claims ### Claim 1 An underfill composition comprising: an epoxy mixture comprising a first epoxy comprising a bisphenol epoxy, a second epoxy comprising a multifunctional epoxy, and a third epoxy comprising an aliphatic epoxy, the aliphatic epoxy comprising a silicone epoxy; the first, second, and third epoxies each having a different chemical structure; an amine hardener component; and a filler. ### Claim 2 (depends on 1) The underfill composition of claim 1, wherein the silicone epoxy has the chemical formula C16H34O5Si2. ### Claim 3 (depends on 1) The underfill composition of claim 1, wherein the silicone epoxy has the following structure: where R is a group selected from the group consisting of methyl and ethyl groups. ### Claim 4 (depends on 1) The underfill composition of claim 1, wherein the silicone epoxy comprises a linear epoxy containing a flexible substituted silicone structure. ### Claim 5 (depends on 1) The underfill composition of claim 1, wherein the bisphenol epoxy comprises a bisphenol F epoxy. ### Claim 6 (depends on 1) The underfill composition of claim 1, wherein the silicone epoxy has the following structure: where R is a group selected from the group consisting of methyl groups and ethyl groups. ### Claim 7 (depends on 6) The underfill composition of claim 6, wherein the silicone epoxy has the chemical formula C23H43O6Si3. ### Claim 8 An underfill composition comprising: an epoxy mixture comprising a first epoxy comprising a bisphenol epoxy, a second epoxy comprising a multifunctional epoxy, and a third epoxy comprising an aliphatic epoxy, the aliphatic epoxy comprising a glycol epoxy; the first, second, and third epoxies each having a different chemical structure; an amine hardener component; and a filler. ### Claim 9 (depends on 8) The underfill composition of claim 8, wherein the glycol epoxy comprises a polypropylene glycol epoxy. ### Claim 10 (depends on 9) The underfill composition of claim 9, wherein the polypropylene glycol epoxy has the following structure: where n equals 3 to 9. ### Claim 11 (depends on 10) The underfill composition of claim 10, where n equals 9. ### Claim 12 (depends on 8) The underfill composition of claim 8, wherein the glycol epoxy comprises a polyethylene glycol epoxy. ### Claim 13 (depends on 11) The underfill composition of claim 11, wherein the polyethylene glycol epoxy has the following structure: where n equals 6 to 12. ### Claim 14 (depends on 8) The underfill composition of claim 8, wherein the bisphenol epoxy comprises a bisphenol F epoxy. ### Claim 15 An assembly comprising: a die; a substrate; the die electrically coupled to the substrate; a gap between the die and the substrate; an underfill material in the gap, the underfill material comprising first, second, and third epoxies, each having a different chemical structure, the first epoxy comprising a bisphenol epoxy, the second epoxy comprising a multifunctional epoxy, and the third epoxy comprising an aliphatic epoxy selected from the group consisting of silicone epoxies and glycol epoxies. ### Claim 16 (depends on 15) The assembly of claim 15, wherein the underfill material further comprises an amine hardener and a filler. ### Claim 17 (depends on 15) The assembly of claim 15, wherein the third epoxy comprises a linear silicone epoxy. ### Claim 18 (depends on 15) The assembly of claim 15, wherein the third epoxy comprises a glycol epoxy selected from the group consisting of polypropylene glycol epoxy and polyethylene glycol epoxy. ### Claim 19 (depends on 14) The underfill composition of claim 14, wherein the bisphenol epoxy comprises a bisphenol F epoxy.