# US 11,079,683 B2 · Aperture system for preceramic polymer stereolithography > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,079,683 B2 - Document ID: US11079683B2 - Status: Granted - Kind: B2 - Application number: 15/606,861 - Filed: 2017-05-26 - Published: 2018-11-29 - Granted: 2021-08-03 - Earliest claimed: 2017-05-26 - Assignees: HRL Laboratories, LLC - Applicants: Hrl Laboratories, LLC - Inventors: Jacob M. Hundley; Zak C. Eckel; Emily C. Schueller; Scott M. Biesboer - Web page: https://patentgrep.com/patent/US11079683B2 ## CPC - G03F 7/70416: {2.5D lithography} - B29C 35/0888: {using transparant moulds} - B29C 37/0075: {using release sheets} - B29C 64/124: using layers of liquid which are selectively solidified - B29C 64/135: the energy source being concentrated, e.g. scanning lasers or focused light sources - B29C 64/255: Enclosures for the building material, e.g. powder containers - B33Y 30/00: Apparatus for additive manufacturing; Details thereof or accessories therefor - B33Y 40/00: Auxiliary operations or equipment, e.g. for material handling - G03F 7/0037: {Production of three-dimensional images} - B29C 2035/0827: {using UV radiation} - 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) - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING ## Abstract An aperture system for a bottom-up stereolithography device including a reservoir having a lower opening, an aperture including a flexible membrane positioned within the reservoir and covering the lower opening, and a boundary seal positioned around a periphery of the flexible membrane, the boundary seal including one or more boundary seal components and immobilizing the periphery of the flexible membrane against the reservoir. The flexible membrane is formed of a material having a low affinity for a liquid resin used in the stereolithography device as well as cured photopolymer resin parts produced by the device. In addition, the flexible membrane is able to deform as the cured resin part is pulled away from the aperture, thus enabling lower energy mixed mode adhesive failure to occur at the interface between the cured resin and the aperture and reducing the chance of cohesive damage to the cured photopolymer part. ## Claims ### Claim 1 A reservoir structure for a bottom-up stereolithography device, the reservoir structure comprising: a reservoir having a lower opening; an aperture system comprising: a flexible membrane positioned within the reservoir and covering the lower opening; a boundary seal positioned around a periphery of the flexible membrane, the boundary seal comprising one or more boundary seal components and immobilizing the periphery of the flexible membrane against the reservoir; and a compliant release layer below the flexible membrane and spanning the lower opening, the compliant release layer being attached to edges of the reservoir structure defining the lower opening or to the boundary seal, and being separable from the flexible membrane, wherein the compliant release layer has a durometer of about 30 Shore OO to about 65 Shore A. ### Claim 2 (depends on 1) The reservoir structure of claim 1, the aperture system further comprising: a transparent window under the flexible membrane and in the lower opening of the reservoir, the transparent window covering the lower opening. ### Claim 3 (depends on 1) The reservoir structure of claim 1, wherein the flexible membrane is configured to have a contact angle greater than about 40° with a resin used for stereolithography. ### Claim 4 (depends on 1) The reservoir structure of claim 1, wherein the flexible membrane is configured to have an interlayer peel strength of less than about 200 N/m with a cured photopolymer resin part. ### Claim 5 (depends on 1) The reservoir structure of claim 1, wherein the flexible membrane is formed of a material selected from the group consisting of polystyrene (PS), polymethylpentene (PMP), cyclic olefin copolymers (COC), fluorinated ethylene propylene (FEP), perfluoroalkoxyalkane (PFA), polytetrafluoroethylene (PTFE), and mixtures thereof. ### Claim 6 (depends on 1) The reservoir structure of claim 1, wherein the flexible membrane has a thickness of about 10 μm to about 750 μm. ### Claim 7 (depends on 1) The reservoir structure of claim 1, wherein the boundary seal components comprise a reversible mechanical attachment. ### Claim 8 (depends on 7) The reservoir structure of claim 7, wherein the reversible mechanical attachment comprises a magnet having a magnetic force of about 5 lbs. to about 60 lbs. ### Claim 9 (depends on 1) The reservoir structure of claim 1, wherein the boundary seal components are formed of a material selected from the group consisting of an epoxy adhesive, an acrylate adhesive, a silicone sealant, a urethane sealant, and mixtures thereof. ### Claim 10 (depends on 1) The reservoir structure of claim 1, wherein the boundary seal components comprise a vacuum chuck to maintain contact between the flexible membrane and the reservoir. ### Claim 11 (depends on 2) The reservoir structure of claim 2, wherein the transparent window is formed of a material selected from the group consisting of glass, polyethylene terephthalate (PET), biaxially-oriented polyethylene terephthalate (BOPET), polymethylpentene (PMP), cyclic olefin copolymers (COC), polycarbonate, polymethylmethacrylate (PMMA), and mixtures thereof. ### Claim 12 (depends on 2) The reservoir structure of claim 2, wherein the transparent window has a thickness of about 0.1 mm to about 16 mm. ### Claim 13 (depends on 1) The reservoir structure of claim 1, wherein the compliant release layer is formed of a material selected from the group consisting of silicone, urethane, fluorinated polymers, and mixtures thereof. ### Claim 14 (depends on 1) The reservoir structure of claim 1, wherein the compliant release layer has a thickness of about 0.1 mm to about 13 mm. ### Claim 15 (depends on 1) The reservoir structure of claim 1, the aperture system further comprising a volume of gas or liquid between the flexible membrane and the compliant release layer. ### Claim 16 (depends on 2) The reservoir structure of claim 2, wherein the compliant release layer and transparent window are integrated and included in the lower opening as a single body. ### Claim 17 (depends on 1) A stereolithography device comprising: a build platform; the reservoir structure of claim 1 positioned below the build platform so that the build platform can be lowered into or raised out of the reservoir structure; and an exposure source positioned below the reservoir structure and configured to emit a light that passes through the aperture system. ### Claim 18 A reservoir structure for a bottom-up stereolithography device, the reservoir structure comprising: a reservoir having a lower opening; an aperture system comprising: a flexible membrane positioned within the reservoir and covering the lower opening; and a boundary seal positioned around a periphery of the flexible membrane, the boundary seal comprising one or more boundary seal components and immobilizing the periphery of the flexible membrane against the reservoir, wherein the boundary seal comprises a resin exchange feature.