# US 10,373,995 B2 · Image sensor bending using tension > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,373,995 B2 - Document ID: US10373995B2 - Status: Granted - Kind: B2 - Application number: 14/491,928 - Filed: 2014-09-19 - Published: 2016-03-24 - Granted: 2019-08-06 - Earliest claimed: 2014-09-19 - Assignees: Microsoft Technology Licensing, LLC - Applicants: Microsoft Technology Licensing, LLC - Inventors: Brian K. Guenter - Web page: https://patentgrep.com/patent/US10373995B2 ## CPC - H10F 39/806: {Optical elements or arrangements associated with the image sensors} - H10F 39/011: {Manufacture or treatment of image sensors covered by group H10F39/12} - H10F 39/8027: {Geometry of the photosensitive area} - H10F 39/804: {Containers or encapsulations} - H10F 39/18: Complementary metal-oxide-semiconductor [CMOS] image sensors; Photodiode array image sensors - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION ## Abstract Techniques for fabricating an image sensor chip having a curved surface include placing a bending substrate on a first surface of an imaging sensor chip. The first surface of the imaging sensor chip includes light sensors to generate electrical signals in response to receiving light. Fabricating also includes bending the bending substrate so as to impart forces on the image sensor chip to produce a curved imaging sensor chip. A second surface of the curved imaging sensor chip may be adhered to a backside substrate. The second surface is opposite the first surface. The bending substrate may be removed from the first surface of the imaging sensor chip. ## Claims ### Claim 1 A method comprising: adhering or depositing a bending substrate on a first surface of an imaging sensor chip, wherein the first surface of the imaging sensor chip includes one or more light sensors to generate electrical signals in response to receiving light onto the first surface, wherein a stiffness of the bending substrate varies over different portions of the imaging sensor chip due to one or both of notches or grooves in the bending substrate, wherein the stiffness of the bending substrate is based on a thickness of the bending substrate, wherein the thickness of the bending substrate are different at different portions of bending substrate, and wherein the one or both of the notches or the grooves are distributed concentrically about a center region of the bending substrate; and applying forces to the bending substrate so as to bend the bending substrate and to resultantly impart bending forces, which are based at least in part on the stiffness of the bending substrate, on the image sensor chip to produce a curved imaging sensor chip. ### Claim 2 (depends on 1) The method of claim 1, further comprising: adhering a second surface of the curved imaging sensor chip to a backside substrate, wherein the second surface is opposite the first surface; and subsequent to adhering the second surface, removing the bending substrate from the first surface of the curved imaging sensor chip. ### Claim 3 (depends on 2) The method of claim 2, wherein removing the bending substrate from the first surface of the curved imaging sensor chip comprises thermally de-bonding the bending substrate from the first surface of the curved imaging sensor chip. ### Claim 4 (depends on 2) The method of claim 2, wherein the backside substrate includes at least one curved surface having a radius of curvature at least approximately equal to an inverse focal length of the first surface of the curved imaging sensor chip. ### Claim 5 (depends on 1) The method of claim 1, wherein adhering or depositing the bending substrate on the first surface of the imaging sensor chip comprises adhering the bending substrate to the first surface of the imaging sensor chip using an adhesive. ### Claim 6 (depends on 1) The method of claim 1, wherein adhering or depositing the bending substrate on the first surface of the imaging sensor chip comprises forming the bending substrate on the first surface of the imaging sensor chip using a deposition process. ### Claim 7 (depends on 1) The method of claim 1, further comprising: before adhering or depositing the bending substrate on the first surface of the imaging sensor chip, forming the one or both of the notches or the grooves in the bending substrate, wherein the stiffness of the bending substrate is further based on the notches or the grooves in the bending substrate. ### Claim 8 (depends on 1) The method of claim 1, wherein bending the bending substrate comprises applying a pressurized gas or liquid onto the bending substrate. ### Claim 9 (depends on 1) The method of claim 1, wherein the first surface of the curved imaging sensor chip is concave. ### Claim 10 An apparatus comprising: a curved imaging sensor chip having a first side and an opposite second side, wherein the first side includes one or more light sensors to generate electrical signals in response to receiving light onto the first side; a bending substrate covering the first side of the curved imaging sensor chip, wherein a stiffness of the bending substrate varies over different portions of the curved imaging sensor chip, wherein the stiffness of the bending substrate is based on a thickness of the bending substrate due to one or both of notches or grooves located on both a first surface of bending substrate that is the same side of the curved imaging sensor chip and a second surface of bending substrate that an opposite side of the curved imaging sensor chip, and wherein the thickness of the bending substrate are different at different portions of bending substrate, and wherein forces are applied to the bending substrate so as to bend the bending substrate and to resultantly impart bending forces, which are based at least in part on the stiffness of the bending substrate, on an image sensor chip to produce the curved imaging sensor chip; a backside substrate covering the second side of the curved imaging sensor chip; and an adhesive between the backside substrate and the curved imaging sensor chip. ### Claim 11 (depends on 10) The apparatus of claim 10, wherein the bending substrate comprises a deposited material that is bonded to the first side of the curved imaging sensor chip by deposition. ### Claim 12 (depends on 10) The apparatus of claim 10, wherein the bending substrate is bonded to the first side of the curved imaging sensor chip by an adhesive. ### Claim 13 (depends on 10) The apparatus of claim 10, wherein the curved imaging sensor chip includes corners that are rounded. ### Claim 14 (depends on 10) The apparatus of claim 10, wherein the curved imaging sensor chip has a radius of curvature that is at least approximately equal to an inverse focal length of the first side of the curved imaging sensor chip. ### Claim 15 A system comprising: a curved imaging sensor chip having a first side and an opposite second side, wherein the first side includes one or more light sensors to generate electrical signals in response to receiving light onto the first side; a substrate covering the first side of the curved imaging sensor chip, wherein a stiffness of the substrate varies over different portions of the curved imaging sensor chip, wherein the stiffness of the substrate is based on a thickness of the substrate, wherein the thickness of the substrate are different at different portions of substrate due to one or both of notches or grooves in the bending substrate, and wherein the one or both of the notches or the grooves are distributed concentrically about a center region of the bending substrate; a backside substrate covering the second side of the curved imaging sensor chip; a gap between the backside substrate and the curved imaging sensor chip; an adhesive at least partially filling the gap; and a pressurized gas applying a force onto the substrate such that the force, which is based at least in part on the stiffness of the substrate, bends the substrate and the curved image sensor chip toward the backside substrate so that a size of the gap decreases. ### Claim 16 (depends on 15) The system of claim 15, further comprising one or more lenses to direct electromagnetic energy to the first side of the curved imaging sensor chip. ### Claim 17 (depends on 15) The system of claim 15, wherein the curved imaging sensor chip comprises germanium and the directed electromagnetic energy comprises infrared energy. ### Claim 18 (depends on 15) The system of claim 15, wherein a stiffness of the curved imaging sensor chip is greater than the stiffness of the bending substrate. ### Claim 19 (depends on 7) The method of claim 7, wherein a plurality of the notches or the grooves in the bending substrate vary in depth. ### Claim 20 (depends on 1) The method of claim 1, wherein the one or both of the notches or the grooves are located on both a first surface of bending substrate that is the same side of the imaging sensor chip and a second surface of bending substrate that an opposite side of the imaging sensor chip.