JP-7855992-B2 - Manufacturing method for insulating circuit boards
Inventors
- 櫻井 晶
- 寺▲崎▼ 伸幸
- 五明 美佳
Assignees
- 三菱マテリアル株式会社
Dates
- Publication Date
- 20260511
- Application Date
- 20221129
- Priority Date
- 20211130
Claims (4)
- A method for manufacturing an insulating circuit board comprising a ceramic substrate and a circuit layer and a metal layer formed by joining metal pieces to a first surface and a second surface of the ceramic substrate, respectively, A bonding paste printing step in which bonding paste is printed on the first surface and the second surface of the ceramic substrate, respectively, A lamination step of laminating the ceramic substrate and the metal piece that will become the circuit layer via the bonding paste, and laminating the ceramic substrate and the metal piece that will become the metal layer via the bonding paste, A bonding step in which the stacked metal pieces and the ceramic substrate are heat-treated to bond the metal pieces and the ceramic substrate, It has, In the bonding paste printing process, the bonding paste is printed on the first surface of the ceramic substrate, then the ceramic substrate is inverted and placed on a printing stage having a recess on its mounting surface, and the bonding paste is printed on the second surface of the ceramic substrate. In the printing stage, a support portion is formed on the periphery of the recess to support the end of the ceramic substrate, and a suction portion is formed on the bottom side of the recess. A method for manufacturing an insulating circuit board, characterized in that when the inverted ceramic substrate is placed on the circuit board, the bonding paste printed on the first surface is contained within the recess, and the bonding paste is printed on the second surface of the ceramic substrate while the ceramic substrate is fixed in place by the suction part.
- The method for manufacturing an insulating circuit board according to claim 1, characterized in that the bonding paste is printed on the first surface of the ceramic substrate, the printed bonding paste is dried, and then the bonding paste is printed on the second surface of the ceramic substrate.
- A method for manufacturing an insulating circuit board according to claim 1 or 2, characterized in that the ceramic substrate has scribe lines formed on it, and the recesses are provided with ribs at positions corresponding to the scribe lines on the placed ceramic substrate.
- The bonding paste contains metal powder, acrylic resin, a plasticizer consisting of an adipic acid ester, and a solvent, wherein the content of the plasticizer is within the range of 3.2 mass% to 10.4 mass%, and the ratio A/B of the weight A of the plasticizer to the weight B of the acrylic resin is within the range of 0.2 ≤ A/B ≤ 1.3, characterized in that this is the method for manufacturing an insulating circuit board according to claim 1 or 2.
Description
This invention relates to a method for manufacturing an insulating circuit board comprising a ceramic substrate, a circuit layer formed on one side of the ceramic substrate, and a metal layer formed on the other side of the ceramic substrate. In power modules, LED modules, and thermoelectric modules, the structure is such that power semiconductor elements, LED elements, and thermoelectric elements are bonded to an insulating circuit board, which has a circuit layer made of a conductive material formed on one side of a ceramic substrate. Furthermore, the aforementioned insulating circuit board has a structure in which a highly conductive metal piece is bonded to one side of a ceramic substrate to form a circuit layer, and a metal piece with excellent heat dissipation properties is bonded to the other side of the ceramic substrate to form a metal layer. Furthermore, in order to efficiently dissipate the heat generated by the elements mounted on the circuit layer, an insulated circuit board with a heat sink is also provided, in which a heat sink is bonded to the other side of the ceramic substrate. For example, Patent Document 1 proposes an insulating circuit board in which a circuit layer and a metal layer are formed by bonding copper plates to one and the other surface of a ceramic substrate. In this Patent Document 1, copper plates are placed on one and the other surface of the ceramic substrate with an Ag-Cu-Ti brazing material interposed, and the copper plates are bonded by heat treatment (so-called activated metal brazing method). Furthermore, Patent Document 2 proposes a power module substrate in which a copper plate made of copper or a copper alloy and a ceramic substrate made of AlN or Al₂O₃ are joined using a bonding material containing Ag and Ti. Furthermore, Patent Document 3 proposes a power module substrate in which a copper plate made of copper or a copper alloy and a ceramic substrate made of silicon nitride are joined using a bonding material containing Ag and Ti. Furthermore, Patent Document 4 discloses an insulating circuit board in which a circuit layer made of an aluminum plate is formed on one side of a ceramic substrate, and a metal layer made of an aluminum plate is formed on the other side. In this case, an Al-Si-based brazing material is used to join the ceramic substrate to the circuit layer and the aluminum plate forming the metal layer. Patent No. 3211856Patent No. 5757359Japanese Patent Publication No. 2018-008869Patent No. 3171234 This is a cross-sectional diagram illustrating a power module using an insulating circuit board manufactured by an insulating circuit board manufacturing method according to an embodiment of the present invention.This is a flowchart showing a method for manufacturing an insulating circuit board, which is an embodiment of the present invention.This is an explanatory diagram showing a method for manufacturing an insulating circuit board, which is an embodiment of the present invention.This is an explanatory diagram showing the bonding paste printing process in a method for manufacturing an insulating circuit board, which is an embodiment of the present invention.This is a schematic diagram illustrating the printing stage used in the bonding paste printing process. Embodiments of the present invention will be described below with reference to the attached drawings. Figure 1 shows an insulating circuit board 10 manufactured by an insulating circuit board manufacturing method according to an embodiment of the present invention, and a power module 1 using this insulating circuit board 10. This power module 1 comprises an insulating circuit board 10, a semiconductor element 3 bonded to one side of the insulating circuit board 10 (the upper side in Figure 1) via a solder layer 2, and a heat sink 31 disposed on the other side of the insulating circuit board 10 (the lower side in Figure 1). The solder layer 2 is, for example, made of Sn-Ag, Sn-Cu, Sn-In, or Sn-Ag-Cu solder material (so-called lead-free solder material). The semiconductor element 3 is an electronic component equipped with a semiconductor, and various semiconductor elements are selected according to the required function. As shown in Figure 1, the insulating circuit board 10 comprises a ceramic substrate 11 that serves as an insulating layer, a circuit layer 12 disposed on the first surface (upper surface in Figure 1) of the ceramic substrate 11, and a metal layer 13 formed on the second surface (lower surface in Figure 1) of the ceramic substrate 11. The ceramic substrate 11 (insulating layer) prevents electrical connection between the circuit layer 12 and the metal layer 13, and is made of a highly insulating material such as AlN (aluminum nitride) or Si3N4 (silicon nitride ). The thickness of the ceramic substrate 11 is set within the range of 0.2 mm to 1.5 mm. In this embodiment, AlN (aluminum nitride) is used as the ceramic substrate, and its thickness is set to 0.635 mm. Furthermore, when usi