# US 7,745,912 B2 · Stress absorption layer and cylinder solder joint method and apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,745,912 B2 - Document ID: US7745912B2 - Status: Granted - Kind: B2 - Application number: 11/089,995 - Filed: 2005-03-25 - Published: 2006-09-28 - Granted: 2010-06-29 - Earliest claimed: 2005-03-25 - Assignees: Intel Corporation - Inventors: Jiun Hann Sir - Web page: https://patentgrep.com/patent/US7745912B2 ## CPC - H05K 3/3436: {having an array of bottom contacts, e.g. pad grid array or ball grid array components} - H05K 3/303: with surface mounted components (H05K3/32 takes precedence) - H05K 3/42: Plated through-holes {or plated via connections} - H05K 2201/0133: Elastomeric or compliant polymer - H05K 2201/10378: Interposers - H05K 2203/0191: Using tape or non-metallic foil in a process, e.g. during filling of a hole with conductive paste - Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract An apparatus, method, and system for providing a stress absorption layer for integrated circuits includes a stiffening layer adapted to limit flexing. A compliance layer is physically associated with the stiffening layer, with the compliance layer adapted to absorb stress caused by mismatched thermal properties between two materials. A thru hole passes through both the stiffening layer and the compliance layer, with the thru hole being adapted to receive a solder joint. The stress absorption layer contacts both a semiconductor package and a substrate. The solder joint disposed in the thru hole connects the semiconductor package to the substrate. ## Claims ### Claim 1 An apparatus comprising: a semiconductor package including a die mounted on a package substrate; a printed circuit board; a non-conductive stiffening layer configured to limit flexing, the stiffening layer having a first surface and a second surface; a non-conductive first compliance layer physically associated with the first surface of the stiffening layer and in direct physical contact with a major surface of the package substrate; a non-conductive second compliance layer physically associated with the second surface of the stiffening layer opposite the first surface, and in direct physical contact with a major surface of the printed circuit board, at least one of the first compliance layer and the second compliance layer being configured to absorb stress between the stiffening layer and at least one of the semiconductor package and the printed circuit board; and a thru hole passing through the stiffening layer, the first compliance layer, and the second compliance layer. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the stiffening layer is adapted to limit flexing between a semiconductor package and a printed circuit board. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the stiffening layer is a composite material including a reinforcer and a resin. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the reinforcer is a fiber, woven glass, or expanded PTFE, and wherein the resin is epoxy, a hydrocarbon, ceramic, or thermoset polyester. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein at least one of the first compliance layer and the second compliance layer is adapted to absorb stress caused by mismatched thermal properties between the mechanical insert and a selected one of a semiconductor package and a printed circuit board. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein at least one of the first compliance layer and the second compliance layer includes an elastomer. ### Claim 7 (depends on 1) The apparatus of claim 1, further comprising a plurality of other thru holes forming an array. ### Claim 8 (depends on 1) The apparatus of claim 1, further comprising a solder joint in the thru hole. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the solder joint is cylindrical in shape and entirely within the thru hole. ### Claim 10 (depends on 8) The apparatus of claim 8, wherein the thru hole includes metallic plating. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the metallic plating is adapted to metallurgically bond to the solder joint. ### Claim 12 (depends on 10) The apparatus of claim 10, wherein the metallic plating is copper. ### Claim 13 (depends on 1) The apparatus of claim 1, wherein the die is mounted on a first major surface of a package substrate, and the non-conductive first compliance layer is in direct physical contact with a second major surface of the package substrate, the second major surface of the package substrate being opposite the first major surface of the package substrate. ### Claim 14 A system comprising: a semiconductor package including a die mounted on a package substrate; a printed circuit board; a mechanical insert including: a non-conductive stiffening layer configured to limit flexing; a non-conductive first compliance layer physically associated with a first surface of the stiffening layer and in direct physical contact with a major surface of the package substrate; a non-conductive second compliance layer physically associated with a second surface opposite the first surface of the stiffening layer, and in direct physical contact with a major surface of the printed circuit board, at least one of the first compliance layer and the second compliance layer configured to absorb stress between the mechanical insert and at least one of the semiconductor package and the printed circuit board; and a thru hole passing through the stiffening layer, the first compliance layer, and the second compliance layer; a solder joint disposed in the thru hole and connecting the semiconductor package to the printed circuit board; a bus coupled to the semiconductor package; and a mass storage coupled to the bus. ### Claim 15 (depends on 14) The system of claim 14, wherein the system is selected from the group consisting of a set-top box, a digital camera, a CD player, a DVD player, a wireless mobile phone, a tablet computing device, and a laptop computing device. ### Claim 16 (depends on 14) The system of claim 14, wherein the thru hole includes metallic plating, and the solder joint is metallugically bonded to the metallic plating. ### Claim 17 (depends on 14) The system of claim 14, wherein the stiffening layer is adapted to limit flexing between the semiconductor package and the printed circuit board. ### Claim 18 (depends on 14) The system of claim 14, wherein the die is mounted on a first major surface of a package substrate, and the non-conductive first compliance layer is in direct physical contact with a second major surface of the package substrate, the second major surface of the package substrate being opposite the first major surface of the package substrate.