# US 2010/0164362 A1 · Metal base circuit board > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0164362 A1 - Document ID: US20100164362A1 - Status: Published application - Kind: A1 - Application number: 12/600,377 - Filed: 2008-05-14 - Published: 2010-07-01 - Earliest claimed: 2007-05-18 - Assignees: Denki Kagaku Kogyo Kabushiki Kaisha - Inventors: Takeshi Miyakawa; Kenji Miyata; Taiki Nishi; Yoshihiko Okajima - Web page: https://patentgrep.com/patent/US20100164362A1 ## 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)} - H05K 1/056: {the metal substrate being covered by an organic insulating layer} - H05K 3/28: Applying non-metallic protective coatings {(H05K3/0091 takes precedence; methods for intermediate insulating layers for build-up multilayer circuits H05K3/4673)} - H05K 2201/0209: Inorganic, non-metallic particles - H05K 2201/0227: Insulating particles having an insulating coating - H05K 2201/0266: Size distribution - H05K 2201/0338: Layered conductor, e.g. layered metal substrate, layered finish layer or layered thin film adhesion layer - H05K 2201/09909: Special local insulating pattern, e.g. as dam around component - H05K 2201/10106: Light emitting diode [LED] - H05K 2201/2054: Light-reflecting surface, e.g. conductors, substrates, coatings, dielectrics - H10H 20/856: Reflecting means - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS ## Abstract Provided is a metal base circuit board having a new function of a light reflection in addition to the conventional printed circuit board function for mounting electronic parts. The metal base circuit board has a circuit arranged on a metal plate via an insulation layer. A white film is arranged at least one the insulation layer. ## Claims ### Claim 1 A metal base circuit board, characterized in being a metal base circuit board wherein a circuit is provided on top of a metal plate through an insulating layer, and a white film is provided at least on top of the insulating layer. ### Claim 2 (depends on 1) A metal base circuit board according to claim 1, characterized in that the reflectivity of said white film for light having wavelengths of 460 nm, 525 nm, and 620 nm is 80% or greater for each. ### Claim 3 (depends on 1) A metal base circuit board according to claim 1, characterized in that the minimum value of the reflectivity of said white film for light having a wavelength of 420 to 800 nm is 70% or greater. ### Claim 4 (depends on 1) A metal base circuit board according to claim 1, characterized in that the thermal conductivity of said insulating layer is 1 W/mK. ### Claim 5 (depends on 1) A metal base circuit board according to claim 1, characterized in that said insulating layer contains an inorganic filler, an epoxy resin, and a curing agent for said epoxy resin. ### Claim 6 (depends on 5) A metal base circuit board according to claim 5, characterized in that 70 to 95 mass portions of said inorganic filler is blended in relative to a total amount of 100 mass portions for the inorganic filler, epoxy resin, and the curing agent for said epoxy resin. ### Claim 7 (depends on 1) A metal base circuit board according to claim 1, characterized in that said insulating layer contains a bifunctional epoxy resin. ### Claim 8 (depends on 7) A metal base circuit board according to claim 7, characterized in that said insulating layer contains anhydrides or phenols. ### Claim 9 (depends on 8) A metal base circuit board according to claim 8, characterized by containing anhydrides or phenols so as to make the activated hydrogen equivalent weight be 0.8 to 1 times the epoxy equivalent weight of said bifunctional epoxy resin. ### Claim 10 (depends on 1) A metal base circuit board according to claim 1, characterized in that said insulating layer contains 25 to 50% by volume of a thermosetting resin, the remainder being an inorganic filler having two types of average grain sizes, of 0.6 to 2.4 μm, and of 5 to 20 μm, and the shapes thereof being spherical, crushed, or scale-like. ### Claim 11 (depends on 1) A metal base circuit board according to claim 1, characterized in that said white film contains titanium dioxide as a white pigment, and said titanium dioxide is rutile type, the surface thereof being coated with aluminum hydroxide or silicon dioxide. ### Claim 12 A metal base circuit board characterized by being a metal base circuit board wherein a plurality of insulating layers and circuits are alternately provided on top of a metal plate, and a white film is provided at least on top of the insulating layer that is furthest from the metal plate. ### Claim 13 (depends on 12) A metal base circuit board according to claim 12, characterized in that said insulating layer that is furthest from the metal plate contains at least one white pigment selected from among zinc oxide, calcium carbonate, titanium dioxide, alumina, and smectite. ### Claim 14 (depends on 12) A metal base circuit board according to claim 12, wherein said insulating layer that is furthest from the metal plate contains titanium dioxide, and said titanium dioxide is rutile type, the surface thereof being coated with aluminum hydroxide or silicon dioxide. ### Claim 15 (depends on 12) A metal base circuit board according to claim 12, wherein said white film contains titanium dioxide, and said titanium dioxide is rutile type, the surface thereof being coated with aluminum hydroxide or silicon dioxide. ### Claim 16 A metal base circuit board, characterized by being a metal base circuit board wherein are layered a metal plate, an insulating layer formed on one or both sides of said metal plate, a circuit formed with a metal foil, and on top of said circuit, a metal of a different type from that forming said circuit, said circuit being formed from copper foil, and a nickel layer or an aluminum layer being layered on top of one portion or the entirety of said copper foil. ### Claim 17 (depends on 16) A metal base circuit board according to claim 16, characterized in that said circuit is formed from aluminum foil, and a nickel layer or a copper layer is layered on top of one portion or the entirety of said aluminum foil. ### Claim 18 (depends on 16) A metal base circuit board according to claim 16, characterized in that said insulating layer is white. ### Claim 19 (depends on 16) A metal base circuit board according to claim 16, characterized in that the reflectivity of the circuit portion for visible light having a wavelength of 460 nm, 525 nm, and 620 nm is 80% or greater for each. ### Claim 20 (depends on 18) A metal base circuit board according to claim 18, characterized in that said insulating layer contains a white pigment, and said white pigment is either one or both of zinc oxide and a rutile type titanium dioxide. ### Claim 21 (depends on 20) A metal base circuit board according to claim 20, characterized in that the surface of said white pigment is coated by either “aluminum hydroxide” or “aluminum hydroxide and silicon dioxide”. ### Claim 22 (depends on 16) A metal base circuit board according to claim 16, characterized in that the thermal conductivity of said insulating layer is 0.5 W/mK or greater and 4.0 W/mK or less. ### Claim 23 (depends on 16) A metal base circuit board according to claim 16, characterized in that a white film is on top of said insulating layer and said circuit. ### Claim 24 (depends on 23) A metal base circuit board according to claim 23, characterized in that said white film contains a rutile type titanium dioxide, or zinc oxide, as a white pigment. ### Claim 25 (depends on 24) A metal base circuit board according to claim 24, characterized in that said white pigment is coated by either “aluminum hydroxide” or “aluminum hydroxide and silicon dioxide”. ### Claim 26 (depends on 16) ED module having a metal base circuit according to claim 16.