# US 2019/0174624 A1 · PCB Optical Isolation By Nonuniform Catch Pad Stack > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0174624 A1 - Document ID: US20190174624A1 - Status: Published application - Kind: A1 - Application number: 16/204,882 - Filed: 2018-11-29 - Published: 2019-06-06 - Earliest claimed: 2017-06-05 - Assignees: Waymo LLC - Applicants: Waymo LLC - Inventors: Augusto Tazzoli; Blaise Gassend - Web page: https://patentgrep.com/patent/US20190174624A1 ## CPC - H05K 1/0274: {Optical details, e.g. printed circuits comprising integral optical means (H05K1/0269 takes precedence; coupling light guides with opto-electronic components G02B6/42)} - G01S 7/4813: {Housing arrangements} - G01S 17/42: Simultaneous measurement of distance and other co-ordinates (indirect measurement G01S17/46) - G01S 17/931: of land vehicles - H05K 1/113: {Via provided in pad; Pad over filled via} - H05K 1/115: {Via connections; Lands around holes or via connections (H05K1/112 takes precedence)} - H05K 1/116: {Lands, clearance holes or other lay-out details concerning the surrounding of a via} - H05K 2201/0108: Transparent - H05K 2201/094: Array of pads or lands differing from one another, e.g. in size, pitch or thickness; Using different connections on the pads - H05K 2201/09454: Inner lands, i.e. lands around via or plated through-hole in internal layer of multilayer PCB - H05K 2201/09481: Via in pad; Pad over filled via - H05K 2201/10121: Optical component, e.g. opto-electronic component - H05K 2201/10151: Sensor - H05K 2203/107: Using laser light - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract A Printed Circuit Board (PCB) includes a via extending through at least one layer of the PCB. The PCB may also include a first catch pad connected to the via and located within a first metal layer of the PCB. The first catch pad may have a first size. The PCB may further include a second catch pad connected to the via and located within a second metal layer of the PCB. The second catch pad may have a second size greater than the first size. The second catch pad may overlap horizontally with a portion of a metallic feature in the first metal layer to obstruct light incident on a first side of the PCB from transmission to a second side of the PCB through a region of dielectric material near the via. ## Claims ### Claim 1 An apparatus comprising: a single-photon light sensor disposed on a printed circuit board (PCB); and a light-obstructing structure surrounding the single-photon light sensor and formed by the PCB interfacing with an enclosure configured to direct light from a portion of an environment onto the single-photon light sensor through an aperture, wherein the PCB is structured to block photons from reaching the single-photon light sensor such that the single-photon light sensor senses photons substantially only through the aperture. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the PCB comprises a plurality of metal layers, and wherein, at all points along a horizontal expanse of the PCB, at least one of the plurality of metal layers contain a metallic feature that blocks photons from reaching the single-photon light sensor. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the PCB comprises: a via extending through at least one layer of the PCB; a first catch pad connected to the via and located within a first metal layer of the PCB, wherein the first catch pad has a first size; and a second catch pad connected to the via and located within a second metal layer of the PCB, wherein the second catch pad has a second size greater than the first size, and wherein the second catch pad overlaps horizontally with a portion of a metallic feature in the first metal layer. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the metallic feature in the first metal layer is different from the first catch pad and is located in a different position than the first catch pad. ### Claim 5 (depends on 3) The apparatus of claim 3, wherein the PCB further comprises a third metal layer, and wherein a plurality of metallic features in the first metal layer and the third metal layer are routed to create continuous horizontal overlap with an outer boundary of the second catch pad. ### Claim 6 (depends on 3) The apparatus of claim 3, wherein the PCB further comprises a third catch pad connected to the via and located within a third metal layer of the PCB, wherein the third catch pad has a third size smaller than the second size, wherein the second metal layer is positioned between the first metal layer and the third metal layer, wherein the second catch pad interposes horizontally between the portion of the metallic feature in the first metal layer and a portion of another metallic feature in the third metal layer. ### Claim 7 (depends on 3) The apparatus of claim 3, wherein a volume of the via is filled by a metal to obstruct light transmission through the via. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the PCB forms part of a Light Detection and Ranging (LIDAR) system. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the light-obstructing structure is disposed within a housing of the LIDAR system. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the PCB interfaces with the enclosure by way of a gasket disposed therebetween and configured to block light from reaching the single-photon light sensor. ### Claim 11 An apparatus comprising: a printed circuit board (PCB) including a first side and a second side; a light sensor connected to the second side of the PCB and configured to sense light incident on the light sensor from the second side of the PCB; a via extending through at least one layer of the PCB; a first catch pad connected to the via and located within a first metal layer of the PCB, wherein the first catch pad has a first size; and a second catch pad connected to the via and located within a second metal layer of the PCB, wherein the second catch pad has a second size greater than the first size, and wherein the second catch pad overlaps horizontally with a portion of a metallic feature in the first metal layer; and an enclosure disposed about the light sensor and configured to direct light from a portion of an environment onto the light sensor through an aperture. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the metallic feature in the first metal layer is different from the first catch pad and is located in a different position than the first catch pad. ### Claim 13 (depends on 11) The apparatus of claim 11, wherein the PCB comprises a third metal layer, wherein a plurality of metallic features in the first metal layer and the third metal layer are routed to create continuous horizontal overlap with an outer boundary of the second catch pad. ### Claim 14 (depends on 11) The apparatus of claim 11, wherein the PCB further comprises a third catch pad connected to the via and located within a third metal layer of the PCB, wherein the third catch pad has a third size smaller than the second size, wherein the second metal layer is positioned between the first metal layer and the third metal layer, wherein the second catch pad interposes horizontally between the portion of the metallic feature in the first metal layer and a portion of another metallic feature in the third metal layer. ### Claim 15 An apparatus comprising: an integrated circuit (IC) device having a first side and a second side; a light sensor disposed on the second side of the IC device and configured to sense light incident on the light sensor from the second side of the IC device; a via extending through at least one layer of the IC device; a first catch pad connected to the via and located within a first metal layer of the IC device, wherein the first catch pad has a first size; and a second catch pad connected to the via and located within a second metal layer of the IC device, wherein the second catch pad has a second size greater than the first size, and wherein the second catch pad overlaps horizontally with a portion of a metallic feature in the first metal layer; and an enclosure disposed about the light sensor and configured to direct light from a portion of an environment onto the light sensor through an aperture. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the metallic feature in the first metal layer is different from the first catch pad and is located in a different position than the first catch pad. ### Claim 17 (depends on 15) The apparatus of claim 15, wherein the IC comprises a third metal layer, and wherein a plurality of metallic features in the first metal layer and the third metal layer are routed to create continuous horizontal overlap with an outer boundary of the second catch pad. ### Claim 18 (depends on 15) The apparatus of claim 15, wherein the IC forms part of a Light Detection and Ranging (LIDAR) system. ### Claim 19 (depends on 15) The apparatus of claim 15, wherein the enclosure is disposed within a housing of the LIDAR system. ### Claim 20 (depends on 15) The apparatus of claim 15, further comprising: a third catch pad connected to the via and located within a third metal layer of the IC, wherein the third catch pad has a third size smaller than the second size, wherein the second metal layer is positioned between the first metal layer and the third metal layer, wherein the second catch pad interposes horizontally between the portion of the metallic feature in the first metal layer and a portion of another metallic feature in the third metal layer.