# US 10,121,043 B2 · Printed circuit board assembly with image sensor mounted thereon > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,121,043 B2 - Document ID: US10121043B2 - Status: Granted - Kind: B2 - Application number: 14/543,936 - Filed: 2014-11-18 - Published: 2016-05-19 - Granted: 2018-11-06 - Earliest claimed: 2014-11-18 - Assignees: SunASIC Technologies, Inc. - Applicants: SunASIC Technologies, Inc. - Inventors: Chi-Chou Lin; Zheng-Ping He - Web page: https://patentgrep.com/patent/US10121043B2 ## CPC - G06V 40/1306: {non-optical, e.g. ultrasonic or capacitive sensing} - H05K 1/184: associated with components inserted in holes through the PCBs and wherein terminals of the components are connected to printed contacts on the walls of the holes or at the edges thereof or protruding over or into the holes - H05K 3/4644: {by building the multilayer layer by layer, i.e. build-up multilayer circuits (making via holes in the insulating layers H05K3/0011; special circuit boards as base or core whereon the multilayer is built H05K3/4602)} - H10W 70/68: Shapes or dispositions thereof - H10W 70/6875: {being on a metallic substrate, e.g. insulated metal substrates [IMS]} - H05K 3/321: by conductive adhesives - H05K 2201/10151: Sensor - H10W 70/685: comprising multiple insulating layers - H10W 72/5522: {comprising gold [Au]} - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING - 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 ## Abstract A printed circuit board assembly (PCBA) and a method to assemble the PCBA are disclosed. The PCBA includes a printed circuit board (PCB), an image sensing chip and a protection layer. The PCB includes a first insulation layer, a second insulation layer, a first electrically conductive layer, a second electrically conductive layer, and a third electrically conductive layer. The image sensing chip has a number of bonding pads with a sensor portion facing down through the second opening. The PCBA can function as an image sensing module and make the module have the thinnest thickness. ## Claims ### Claim 1 A printed circuit board assembly (PCBA), comprising: a printed circuit board (PCB), comprising: a first insulation layer, having a first opening formed therein; a second insulation layer, having a second opening formed therein; a first electrically conductive layer, forming a first specific circuit on a partial top surface of the first insulation layer; a second electrically conductive layer, forming a second specific circuit and a plurality of connectors between the first insulation layer and the second insulation layer; and a third electrically conductive layer, forming a third specific circuit on a partial bottom surface of the second insulation layer, wherein the second opening is smaller than the first opening and formed beneath the first opening; a platform is formed on a top surface of the second insulation layer enclosed by peripherals of the first opening; the plurality of connectors are formed on the platform; an image sensing chip, having a plurality of bonding pads with a sensor portion facing down through the second opening, and fixed on the platform with each bonding pad connected to one corresponding connector; and a protection layer formed over some portions of the top surface of the first insulation layer, the first electrically conductive layer and a whole bottom surface of the image sensing chip opposite to the sensor portion for providing resistance when a force is exerted on the sensor portion, wherein the first insulation layer and the whole bottom surface of the image sensing chip together form a flat surface for the protection layer to be formed thereon; and wherein a non-conductive adhesive is applied in gaps between the sensor portion and the second opening while the sensor portion has a size smaller than the second opening or applied along peripheral of the sensor portion while the sensor portion has a size the same as the second opening to form a fixture to provide tension when a finger exerts force on the sensor portion of the image sensing chip. ### Claim 2 (depends on 1) The PCBA according to claim 1, wherein the bonding pad and the corresponding connector are connected by a conductive adhesive. ### Claim 3 (depends on 2) The PCBA according to claim 2, wherein the conductive adhesive is silver paste. ### Claim 4 (depends on 1) The PCBA according to claim 1, wherein the non-conductive adhesive is further included in gaps between sidewalls of the first insulation layer and peripherals of the image sensing chip. ### Claim 5 (depends on 4) The PCBA according to claim 4, wherein the non-conductive adhesive is epoxy resin. ### Claim 6 (depends on 1) The PCBA according to claim 1, wherein the protection layer is formed by the non-conductive adhesive. ### Claim 7 (depends on 6) The PCBA according to claim 6, the non-conductive adhesive is further applied along peripherals of the sensor portion and adjacent portions of the second electrically conductive layer and/or the second insulation layer. ### Claim 8 (depends on 1) The PCBA according to claim 1, wherein the protection layer is made of organic coating material. ### Claim 9 (depends on 2) The PCBA according to claim 2, wherein the conductive adhesive is printed on the top of each bonding pad, respectively, before connecting to the corresponding connector. ### Claim 10 (depends on 1) The PCBA according to claim 1, wherein the image sensing chip is a fingerprint reader sensor chip. ### Claim 11 (depends on 1) The PCBA according to claim 1, wherein the size of the sensor portion is substantially the same as or slightly smaller than that of the second opening, and the shape of the first opening is the similar to that of the image sensing chip but large enough in size so that the image sensing chip can be allocated in the first opening. ### Claim 12 (depends on 1) The PCBA according to claim 1, wherein a step gap between a level of a surface opposite to the sensor portion and the first insulation layer and/or the first electrically conductive layer after the image sensing chip is fixed on the platform is less than 0.1 mm.