# US 2016/0354864 A1 · Method of manufacturing a holding plate, in particular for a clamp for holding wafers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0354864 A1 - Document ID: US20160354864A1 - Status: Published application - Kind: A1 - Application number: 15/164,435 - Filed: 2016-05-25 - Published: 2016-12-08 - Earliest claimed: 2015-06-03 - Assignees: Berliner Glas KGaA Herbert Kubatz GmbH & Co. - Applicants: Berliner Glas KGaA Herbert Kubatz GmbH & Co. - Inventors: Ralf HAMMER; Stefan HOESCHELER; Mike FISCHER; Gregor HASPER - Web page: https://patentgrep.com/patent/US20160354864A1 ## CPC - B23K 26/355: {Texturing} - B23K 26/0006: {taking account of the properties of the material involved (B23K26/32, B23K26/40 take precedence)} - B23K 26/0622: by shaping pulses - B23K 26/0884: {in at least three axial directions, e.g. manipulators, robots} - B23K 26/352: for surface treatment - B23K 26/361: for deburring or mechanical trimming (B23K26/351 takes precedence) - B23K 26/402: involving non-metallic material, e.g. isolators - B23K 37/0235: {the guide member forming part of a portal} - H10P 72/722: {Details of electrostatic chucks} - H10P 72/78: using vacuum or suction, e.g. Bernoulli chucks - B23K 2103/52: {Ceramics} - 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 - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 ## Abstract Method of manufacturing holding plate (11) including ceramic material of several chemical elements and configured for holding apparatus (10) for holding a component by electrostatic forces or vacuum, includes the steps of material removal from holding plate (11) by laser ablation, wherein by laser irradiation (1) protrusions (13) are formed on holding plate (11), end faces (13.1) of which span a carrier surface for the component, and surface modification of holding plate (11) by laser irradiation (1), wherein irradiation parameters of laser irradiation (1) are set such that at least one of the chemical elements of the ceramic material is enriched on the surface of holding plate (11). A method is also described of manufacturing holding apparatus (10) for holding a component by electrostatic forces or vacuum, holding plate (11) which is produced with the inventive method, and holding apparatus (10) with at least one holding plate (11). ## Claims ### Claim 1 A method of manufacturing of a holding plate, which comprises a ceramic material of several chemical elements and is configured for a holding apparatus for holding a component by electrostatic forces or vacuum, with the steps of material removal from the holding plate by laser ablation, wherein by a laser irradiation a plurality of protrusions is formed on the holding plate, the end faces of which span a carrier surface for the component, and surface modification of the holding plate by the laser irradiation, wherein irradiation parameters of the laser irradiation are set such that at least one of the chemical elements of the ceramic material is enriched on the surface of the holding plate. ### Claim 2 (depends on 1) The method according to claim 1, wherein a gloss is formed on the surface of the holding plate by the at least one enriched chemical element. ### Claim 3 (depends on 1) The method according to claim 1, wherein the at least one enriched chemical element is enriched exclusively on the surface of the protrusions. ### Claim 4 (depends on 3) The method according to claim 3, wherein the at least one enriched chemical element is enriched exclusively on sidewise lateral surfaces of the protrusions. ### Claim 5 (depends on 1) The method according to claim 1, wherein the material removal takes place in layers in several irradiation steps, wherein in each irradiation step, a layer of the ceramic material is removed corresponding to a predefined irradiation pattern of the laser irradiation. ### Claim 6 (depends on 5) The method according to claim 5, wherein in each irradiation step, the irradiation pattern of the laser irradiation is changed and the protrusions are formed with a predefined lateral contour. ### Claim 7 (depends on 6) The method according to claim 6, wherein in each irradiation step, the irradiation pattern of the laser irradiation is changed and the protrusions are formed with at least one of rounded edge portions and rounded base portions. ### Claim 8 (depends on 1) The method according to claim 1, wherein the material removal takes place across the surface with the exception of the protrusions with an aspect ratio such that the end faces comprise less than 10% of a total surface area exposed to the laser irradiation. ### Claim 9 (depends on 8) The method according to claim 8, wherein the material removal takes place across the surface with the exception of the protrusions with an aspect ratio such that the end faces comprise less than 5% of the total surface area exposed to the laser irradiation. ### Claim 10 (depends on 1) The method according to claim 1, wherein: the laser irradiation is generated with a laser source which is moved relative to the holding plate with a carrier head which can be moved along at least three axes, the laser irradiation takes place successively in several surface regions of the holding plate, an extension of each of which is less than a maximum working area of the carrier head, and the carrier head and the holding plate are moved relative to each other between the irradiations of the surface regions such that the surface regions overlap. ### Claim 11 (depends on 1) The method according to claim 1, wherein the ceramic material comprises SiC, SiSiC, Si3N4, CrN, WC, B4C, AlN or Al2O3. ### Claim 12 (depends on 11) The method according to claim 11, wherein the ceramic material comprises Si3N4, SiC or SiSiC, and the irradiation parameters of the laser irradiation are set such that the surfaces of the holding plate have a higher Si proportion than a volume material. ### Claim 13 (depends on 1) The method according to claim 1, wherein the protrusions have at least one of the features the protrusions comprise burls having a cylindrical, truncated pyramid or frustoconical form, the protrusions comprise burls with an end face with a diameter of less than 300 μm, the protrusions comprise burls with a height of more than 25 μm, the protrusions comprise burls which are connected to the holding plate via a base portion which has a rounded casing contour, and the protrusions comprise at least one of webs and ribs. ### Claim 14 (depends on 1) The method according to claim 1, wherein the laser irradiation has at least one of the features the laser irradiation comprises laser pulses with a pulse duration in a range of 2 ns to 300 ns, the laser irradiation comprises laser pulses with a repetition rate in a range of 30 kHz to 200 kHz, and the laser irradiation has a wavelength at which absorptions of phases of the ceramic material overlap to a maximum. ### Claim 15 (depends on 1) The method according to claim 1, wherein the material removal after laser ablation additionally comprises a removal of volume material between the protrusions by at least one of a mechanically acting tool and sink erosion. ### Claim 16 (depends on 1) A method of manufacturing a holding apparatus for holding a component by electrostatic forces or vacuum, wherein at least one holding plate of the holding apparatus is produced with the method according to claim 1. ### Claim 17 A holding plate which comprises a ceramic material of several chemical elements and is configured for a holding apparatus for holding a component by electrostatic forces or vacuum, said holding plate comprising a plurality of protrusions, wherein on a surface of the holding plate, at least one of the chemical elements of the ceramic material is enriched in comparison with a distribution of other elements in a volume of the ceramic material. ### Claim 18 (depends on 17) The holding plate according to claim 17, wherein a gloss is formed on the surface of the holding plate by the at least one enriched chemical element. ### Claim 19 (depends on 17) The holding plate according to claim 17, wherein the at least one enriched chemical element is enriched on the surface of the protrusions. ### Claim 20 (depends on 17) The holding plate according to claim 17, wherein the at least one enriched chemical element is enriched on sidewise lateral surfaces of the protrusions. ### Claim 21 (depends on 17) The holding plate according to claim 17, wherein the protrusions are connected to the holding plate via base portions which have a rounded lateral contour. ### Claim 22 (depends on 17) The holding plate according to claim 17, wherein the ceramic material comprises Si3N4, SiC or SiSiC, and the surface of the holding plate has a higher Si proportion than the volume material. ### Claim 23 (depends on 17) A holding apparatus for holding a component by electrostatic forces or vacuum, comprising at least one holding plate according to claim 17.