# US 5,706,174 A · Compliant microelectrionic mounting device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,706,174 A - Document ID: US5706174A - Status: Granted - Kind: A - Application number: 08/812,202 - Filed: 1997-03-06 - Granted: 1998-01-06 - Earliest claimed: 1994-07-07 - Assignees: Tessera, Inc. - Inventors: Thomas H. Distefano; John W. Smith; Zlata Kovac; Konstantine Karavakis - Web page: https://patentgrep.com/patent/US5706174A ## CPC - H05K 3/4084: {by deforming at least one of the conductive layers} - H10W 44/601: {Capacitive arrangements (H10W44/20 takes precedence)} - H10W 70/047: {Attaching leadframes to insulating supports, e.g. for tape automated bonding [TAB]} - H10W 70/635: {Through-vias} - H10W 70/688: {Flexible insulating substrates} - H10W 72/00: Interconnections or connectors in packages - 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 76/45: Liquid fillings - H10W 90/701: {characterised by the relative positions of pads or connectors relative to package parts} - H05K 1/118: {specially for flexible printed circuits, e.g. using folded portions} - H05K 3/361: {Assembling flexible printed circuits with other printed circuits} - H05K 2201/0133: Elastomeric or compliant polymer - H05K 2201/0394: Conductor crossing over a hole in the substrate or a gap between two separate substrate parts - H05K 2201/0397: Tab - H05K 2201/09081: Tongue or tail integrated in planar structure, e.g. obtained by cutting from the planar structure - H05K 2201/091: Locally and permanently deformed areas including dielectric material - H05K 2203/063: of preperforated insulating layer - H10W 70/655: Fan-out layouts - H10W 72/07236: {Soldering or alloying} - H10W 72/07327: {involving guiding structures, e.g. spacers or supporting members} - H10W 72/856: {Bump connectors and die-attach connectors (bumps embedded in underfills H10W74/15)} - Y10T 29/49124: On flat or curved insulated base, e.g., printed circuit, etc. - Y10T 29/49144: by metal fusion - Y10T 29/49149: by metal fusion bonding - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A compliant microelectronic mounting device. An area array of conductive contact pads are connected into rows by conductive leads on a first side of a flexible substrate. Each of the conductive leads bridges a bonding hole in the substrate which is situated between successive contact pads. Each of the conductive leads further has a frangible portion within or near each bonding hole. A plurality of compliant dielectric buttons, typically composed of an elastomer material, are attached to a second side of the substrate and typically positioned under each contact pad. The component may be attached to a microelectronic device having contacts so that a stand-off is created between the substrate and the device by the compliant dielectric buttons. The frangible portions allow the leads to be cleanly broken, bent and secured into electrical contact with opposed contact pads on the microelectronic device. Each of these connections may be supported by a compliant layer, typically an uncured elastomer which fills the area around the dielectric pads and is then cured. ## Claims ### Claim 1 A microelectronic mounting device, comprising: a flexible substrate having a first side, a second side and a plurality of bonding holes extending through the substrate, a plurality of conductive leads and a plurality of substrate contact pads on said flexible substrate, said substrate contact pads and leads being connected to one another in at least one row, each such row including a plurality of said substrate contact pads and a plurality of said leads arranged in an alternating sequence of substrate contact pads and conductive leads and, the pads and leads of each such row being connected in series with one another, each such conductive lead bridging a bonding hole in the substrate to electrically connect two successive substrate contact pads, each said conductive lead further having a frangible point within or near a perimeter of its respective bonding hole, whereby the pads of each said row may be disconnected from one another and connected to a microelectronic device by breaking each said lead at its frangible point and connecting each said lead to the microelectronic device at its respective bonding hole. ### Claim 2 (depends on 1) A mounting device as claimed in claim 1 wherein said conductive leads are disposed on a first side of said flexible substrate, the device further comprising a compliant layer coupled to the second side of said flexible substrate. ### Claim 3 (depends on 1) A mounting device as claimed in claim 1 wherein said compliant layer includes a plurality of compliant buttons. ### Claim 4 (depends on 1) A mounting device as claimed in claim 1 wherein said at least one row includes a plurality of rows extending alongside one another. ### Claim 5 (depends on 4) A mounting device as claimed in claim 4 wherein said rows of substrate contact pads and said bonding holes are disposed so that said contact pads are disposed in a square array with each square of the array including four contact pads, and so that each bonding hole is disposed in the center of one square of such array. ### Claim 6 A compliant microelectronic mounting device, comprising: a flexible substrate having a first side, a second side and a plurality of bonding holes, the first side of the flexible substrate further having a plurality of conductive leads and a plurality of substrate contact pads, each such lead bridging a bonding hole in the substrate to electrically connect two successive substrate contact pads, each conductive lead further having a frangible point within or near a perimeter of its respective bonding hole; and a plurality of compliant buttons each having a first and second side, the first side of each button being coupled to the second side of the flexible substrate. ### Claim 7 (depends on 5) The device as claimed in claim 5, further comprising: a microelectronic device having at least one device contact pad, each device contact pad being positioned opposite the bonding hole; the second side of each of the compliant buttons being coupled to the microelectronic device; and means for breaking each conductive lead at its frangible point and electrically coupling it to the opposing device contact pad. ### Claim 8 (depends on 7) The device as claimed in claim 7 wherein an open area between the flexible substrate and the microelectronic device is filled with a compliant filler. ### Claim 9 (depends on 8) The device as claimed in claim 8 wherein the compliant filler includes uncured elastomer which is then cured. ### Claim 10 (depends on 7) The device as claimed in claim 7 wherein the at least one bonding hole includes a plurality of bonding holes, the at least one conductive lead includes a plurality of conductive leads, the at least two substrate contact pads includes a plurality of substrate contact pads, the at least one device contact pad includes a plurality of chip contact pads, and the at least two compliant buttons includes a plurality of compliant buttons. ### Claim 11 (depends on 10) The device as claimed in claim 10 wherein each bonding hole is situated between two successive substrate contact pads creating a plurality of rows of substrate contact pads, leads and bonding holes. ### Claim 12 (depends on 10) The device as claimed in claim 10 wherein each bonding hole is situated between four substrate contact pads defining the corners of a square, wherein each conductive lead connects successive, diagonal substrate contact pads across the bonding hole. ### Claim 13 (depends on 7) The device as claimed in claim 7 wherein a highly conductive layer is coupled to the at least one conductive lead within its respective bonding hole and facing opposite its respective device contact pad, whereby the highly conductive layer is placed into electrical contact with the device contact pad when the conductive lead is coupled thereto.