# US 5,706,178 A · Ball grid array integrated circuit package that has vias located within the solder pads of a package > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,706,178 A - Document ID: US5706178A - Status: Granted - Kind: A - Application number: 08/603,444 - Filed: 1996-02-20 - Granted: 1998-01-06 - Earliest claimed: 1995-12-20 - Assignees: Intel Corporation - Inventors: Michael Barrow - Web page: https://patentgrep.com/patent/US5706178A ## CPC - H05K 3/0094: {Filling or covering plated through-holes or blind plated vias, e.g. for masking or for mechanical reinforcement} - B23K 1/0016: {Soldering of electronic components} - B23K 11/11: Spot welding - H05K 3/3436: {having an array of bottom contacts, e.g. pad grid array or ball grid array components} - H10W 70/635: {Through-vias} - H10W 74/117: {the substrate having spherical bumps for external connection} - H10W 90/701: {characterised by the relative positions of pads or connectors relative to package parts} - B23K 2101/40: Semiconductor devices - H05K 1/113: {Via provided in pad; Pad over filled via} - H05K 1/114: {Pad being close to via, but not surrounding the via} - H05K 3/3452: Solder masks - H05K 3/3465: Application of solder - H05K 3/3478: Application of solder preforms; Transferring prefabricated solder patterns - H05K 2201/0959: Plated through-holes or plated blind vias filled with insulating material - H05K 2201/10666: Plated through-hole for surface mounting on PCB - H05K 2201/10734: Ball grid array [BGA]; Bump grid array - H05K 2203/041: Solder preforms in the shape of solder balls - H05K 2203/1178: Means for venting or for letting gases escape - H05K 2203/1394: Covering open PTHs, e.g. by dry film resist or by metal disc - H10W 74/00: Encapsulations, e.g. protective coatings - H10W 90/754: {between a chip and a stacked insulating package substrate, interposer or RDL} - 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 - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract A ball grid array (BGA) integrated circuit package which has a plurality of elliptically shaped solder pads located on a bottom surface of a package substrate. The bottom surface also has a solder mask which contains a number of holes that expose the solder pads. The holes allow solder balls to be attached to the solder pads. The solder balls can be reflowed to attach the package to a printed circuit board. The elliptical shaped solder pads have a width that is smaller than the length of the pads. The narrow pad portions provide additional routing space for the bottom surface of the package. The solder mask hole diameters are less than the lengths of the solder pads so that portions of the pads are anchored by the maskant material. The anchored portions increase the peel strength of the pads. ## Claims ### Claim 1 A ball grid array package, comprising: a substrate that has a first surface; an elliptical solder pad located on said first surface of said substrate, said elliptical solder pad having a major diameter and a minor diameter; a solder mask located on said first surface, said solder mask having an opening that exposes said elliptical solder pad and which has a diameter equal to said minor diameter of said elliptical solder pad so that a portion of said elliptical solder pad is covered by said solder mask; and, a solder ball that is attached to said elliptical solder pad. ### Claim 2 (depends on 1) The package as recited in claim 1, further comprising a via that terminates within said elliptical solder pad. ### Claim 3 (depends on 2) The package as recited in claim 2, wherein said via is off-set from a center of said elliptical solder pad. ### Claim 4 (depends on 2) The package as recited in claim 2, wherein said via is located at a center of said elliptical solder pad. ### Claim 5 (depends on 1) The package as recited in claim 1, further comprising a routing trace that is located between two elliptical solder pads. ### Claim 6 An integrated circuit ball grid array package, comprising: a substrate that has a first surface and a second opposite surface; an elliptical solder pad located on said first surface of said substrate, said elliptical solder pad having a major diameter and a minor diameter; a solder mask located on said first surface, said solder mask having an opening that exposes said elliptical solder pad and which has a diameter equal to said minor diameter of said elliptical solder pad so that a portion of said elliptical solder pad is covered by said solder mask; a solder ball that is attached to said elliptical solder pad; and, an integrated circuit that is mounted to said second surface of said substrate and coupled to said elliptical solder pad. ### Claim 7 (depends on 6) The package as recited in claim 6, further comprising a via that terminates within said elliptical solder pad. ### Claim 8 (depends on 7) The package as recited in claim 7, wherein said via is off-set from a center of said elliptical solder pad. ### Claim 9 (depends on 7) The package as recited in claim 7, wherein said via is located at a center of said elliptical solder pad. ### Claim 10 (depends on 6) The package as recited in claim 6, further comprising a routing trace that is located between two elliptical solder pads. ### Claim 11 A method for constructing an electronic package, comprising the steps of: a) forming an elliptical solder pad on a first surface of a substrate, wherein said elliptical solder pad has a minor diameter and a major diameter; b) forming a solder mask on said first surface of said substrate so that said solder mask has an opening that exposes said elliptical solder pad, said opening having a diameter equal to said minor diameter of said elliptical solder pad so that a portion of said elliptical solder pad is covered by solder mask; and, c) attaching a solder ball to said elliptical solder pad. ### Claim 12 (depends on 11) The method as recited in claim 11, further comprising the step of forming a via in said substrate. ### Claim 13 (depends on 12) The method as recited in claim 12, further comprising the steps of mounting an integrated circuit to a second surface of said substrate and coupling said integrated circuit to said solder pad.