# US 10,319,705 B2 · Elastomeric layer fabrication for light emitting diodes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,319,705 B2 - Document ID: US10319705B2 - Status: Granted - Kind: B2 - Application number: 15/789,275 - Filed: 2017-10-20 - Published: 2019-04-25 - Granted: 2019-06-11 - Earliest claimed: 2017-10-20 - Assignees: Facebook Technologies, LLC - Applicants: Facebook Technologies, LLC - Inventors: Daniel Brodoceanu; Oscar Torrents Abad - Web page: https://patentgrep.com/patent/US10319705B2 ## CPC - H10W 90/00: Package configurations - G03F 7/038: Macromolecular compounds which are rendered insoluble or differentially wettable (G03F7/075 takes precedence; macromolecular azides G03F7/012; macromolecular diazonium compounds G03F7/021) - G03F 7/039: Macromolecular compounds which are photodegradable, e.g. positive electron resists (G03F7/075 takes precedence; macromolecular quinonediazides G03F7/023) - G03F 7/162: {Coating on a rotating support, e.g. using a whirler or a spinner} - G03F 7/168: {Finishing the coated layer, e.g. drying, baking, soaking} - G03F 7/2004: {characterised by the use of a particular light source, e.g. fluorescent lamps or deep UV light} - G03F 7/32: Liquid compositions therefor, e.g. developers - H01S 5/0201: {Separation of the wafer into individual elements, e.g. by dicing, cleaving, etching or directly during growth} - H01S 5/02325: Mechanically integrated components on mount members or optical micro-benches - H01S 5/423: {having a vertical cavity} - H10H 20/01: Manufacture or treatment - H10H 20/018: {Bonding of wafers} - H10H 29/14: comprising multiple light-emitting semiconductor components - H10P 72/0446: {Apparatus for mounting on conductive members, e.g. leadframes or conductors on insulating substrates} - H10P 72/74: {using temporarily an auxiliary support} - H01S 5/22: having a ridge or stripe structure - H01S 5/343: in AIIIBV compounds, e.g. AlGaAs-laser {, InP-based laser} - H10H 20/812: within the light-emitting regions, e.g. having quantum confinement structures - H10H 20/819: characterised by their shape, e.g. curved or truncated substrates - H10H 20/824: comprising only Group III-V materials, e.g. GaP - H10P 72/7434: {used in a transfer process involving at least two transfer steps, i.e. including an intermediate handle substrate} - H10W 72/0198: {batch processes} - H10W 72/0711: {Apparatus therefor} - H10W 72/07173: {Means for moving chips, wafers or other parts, e.g. conveyor belts} - H10W 72/07204: {using temporary auxiliary members, e.g. sacrificial coatings} - H10W 72/07232: {Compression bonding, e.g. thermocompression bonding} - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract An elastomeric interface layer (elayer) is formed over multiple light emitting diode (LED) dies by depositing photoresist materials across multiple LED dies, and using the LED dies as a photolithography mask to facilitate formation of the elayer on each LED die. The elayer facilitates adhesive attachment of each LED die with a pick and place head (PPH), allowing the LED dies to be picked up and placed onto a display substrate including control circuits for sub-pixels of an electronic display. In some embodiments, the LED dies are micro-LED (μLED) dies. ## Claims ### Claim 1 A method, comprising: depositing a photoresist material on and between light emitting diode (LED) dies on a carrier substrate; applying light through the carrier substrate towards the LED dies and the deposited photoresist material, responsive to depositing the photoresist material; absorbing a portion of the light incident on the LED dies to retain soluble first portions of the photoresist material on the LED dies; exposing portions of photoresist material between the LED dies to another portion of the light to render second portions of the photoresist material between the LED insoluble; removing the first portions of photoresist material, responsive to applying the light; depositing an elastomeric material on each LED die and between the second portions of photoresist, responsive to removing the first portions; and removing the second portions of the photoresist material responsive to depositing the elastomeric material, the elastomeric material forming elastomeric interface layers on the LED dies. ### Claim 2 (depends on 1) The method of claim 1, further comprising: picking up at least a portion of the LED dies on the carrier substrate by attaching a non-conformable pick-up head to the elastomeric interface layers over the LED dies; and placing the at least a portion of the LED dies attached to the non-conformable pick-up head on a display substrate defining pixel control circuits of an electronic display. ### Claim 3 (depends on 1) The method of claim 1, further comprising: fabricating the LED dies on a native substrate; attaching a carrier film capable of expanding to a first side of the LED dies on the native substrate; detaching the native substrate from the LED dies; singulating the LED dies attached to the carrier film; separating the LED dies by expanding the carrier film to define the open regions between the LED dies; bringing the carrier substrate to a second side of the LED dies, the carrier substrate including a substrate layer and an adhesive layer, the LED dies being attached to the adhesive layer of the carrier substrate with the open regions being defined between the LED dies; and separating the carrier film from the first side of the LED dies to expose the first side of the LED dies to the depositing of the elastomeric material. ### Claim 4 (depends on 1) The method of claim 1, wherein the carrier substrate includes an adhesive layer and a glass substrate layer, the LED dies attached to the carrier substrate by the adhesive layer. ### Claim 5 (depends on 1) The method of claim 1, wherein: removing the first portions of photoresist material includes dissolving the first portions with a first solvent; and removing the second portions of the photoresist material responsive to depositing the elastomeric material includes dissolving the second portions of the photoresist material with a second solvent different from the first solvent. ### Claim 6 (depends on 5) The method of claim 5, wherein: the first solvent is benign to the insoluble second portions of the photoresist material; and the second solvent is benign to the elastomeric material forming the elastomeric interface layers on the LED dies. ### Claim 7 (depends on 1) The method of claim 1, wherein the LED dies are micro-LEDs and include Gallium nitride (GaN), gallium arsenide (GaAs), or gallium phosphide (GaP). ### Claim 8 A method, comprising: depositing a photoresist material on and at side surfaces of a light emitting diode (LED) die on a carrier substrate; applying light through the carrier substrate towards the LED die and the deposited photoresist material, responsive to depositing the photoresist material; absorbing a portion of the light incident on the LED die to retain a soluble first portion of the photoresist material on the LED die; exposing portions of photoresist material at the side surfaces of the LED die to another portion of the light to render second portions of the photoresist material at the side surfaces of the LED insoluble; removing the first portion of photoresist material, responsive to applying the light; depositing an elastomeric material on the LED die and between the second portions of photoresist, responsive to removing the first portion; and removing the second portions of the photoresist material responsive to depositing the elastomeric material, the elastomeric material forming elastomeric interface layer on the LED die. ### Claim 9 (depends on 8) The method of claim 8, wherein the LED dies absorbs Ultraviolet (UV) light incident on the LED dies through the carrier substrate. ### Claim 10 (depends on 8) The method of claim 8, further comprising: picking up the LED die on the carrier substrate by attaching a non-conformable pick-up head to the elastomeric interface layer over the LED die; and placing the LED die attached to the non-conformable pick-up head on a display substrate defining pixel control circuits of an electronic display. ### Claim 11 (depends on 8) The method of claim 8, wherein the carrier substrate includes an adhesive layer and a glass substrate layer, the LED die is attached to the carrier substrate by the adhesive layer. ### Claim 12 (depends on 8) The method of claim 8, wherein: removing the first portion of photoresist material includes dissolving the first portion with a first solvent; and removing the second portions of the photoresist material responsive to depositing the elastomeric material includes dissolving the second portions of the photoresist material with a second solvent different from the first solvent. ### Claim 13 (depends on 12) The method of claim 12, wherein: the first solvent is benign to the insoluble second portions of the photoresist material; and the second solvent is benign to the elastomeric material forming the elastomeric interface layer on the LED die. ### Claim 14 (depends on 8) The method of claim 8, wherein the LED die includes Gallium nitride (GaN), gallium arsenide (GaAs), or gallium phosphide (GaP). ### Claim 15 (depends on 8) The method of claim 8, wherein the LED die is a micro-LED or vertical-cavity surface-emitting laser (VCSEL). ### Claim 16 (depends on 8) The method of claim 8, wherein the LED die absorbs Ultraviolet (UV) light incident on the LED die through the carrier substrate. ### Claim 17 An electronic display panel fabricated by a method, comprising: depositing a photoresist material on and between light emitting diode (LED) dies on a carrier substrate; applying light through the carrier substrate towards the LED dies and the deposited photoresist material, responsive to depositing the photoresist material; absorbing a portion of the light incident on the LED dies to retain soluble first portions of the photoresist material on the LED dies; exposing portions of photoresist material between the LED dies to another portion of the light to render second portions of the photoresist material between the LED insoluble; removing the first portions of photoresist material, responsive to applying the light; depositing an elastomeric material on each LED die and between the second portions of photoresist, responsive to removing the first portions; removing the second portions of the photoresist material responsive to depositing the elastomeric material, the elastomeric material forming elastomeric interface layers on the LED dies picking up at least a portion of the LED dies on the carrier substrate by attaching a non-conformable pick-up head to the elastomeric interface layers over the LED dies; and placing the at least a portion of the LED dies attached to the non-conformable pick-up head on a display substrate defining pixel control circuits of an electronic display. ### Claim 18 (depends on 17) The electronic display panel of claim 17, wherein: removing the first portions of photoresist material includes dissolving the first portions with a first solvent; and removing the second portions of the photoresist material responsive to depositing the elastomeric material includes dissolving the second portions of the photoresist material with a second solvent different from the first solvent. ### Claim 19 (depends on 18) The electronic display panel of claim 18, wherein: the first solvent is benign to the insoluble second portions of the photoresist material; and the second solvent is benign to the elastomeric material forming the elastomeric interface layers on the LED dies. ### Claim 20 (depends on 17) The electronic display panel of claim 17, wherein the LED dies are micro-LEDs and include Gallium nitride (GaN), gallium arsenide (GaAs), or gallium phosphide (GaP).