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WO-2026095043-A1 - COPPER MATERIAL AND INSULATING SUBSTRATE

WO2026095043A1WO 2026095043 A1WO2026095043 A1WO 2026095043A1WO-2026095043-A1

Abstract

A copper material, wherein: the Cu content is in the range of 99.9-99.999 mass%; one or more group A elements selected from Al, Be, Cd, Mg, Pb, Ni, P, Sn, Cr, Si, Ti, Zr, Hf, Mn, Fe, Ag, Zn, In, Ga, Ge, and Sb are contained in a total amount of 2-20 mass ppm; the electrical conductivity is 95% IACS or more; and area ratios S(110), S(311), S(331), S(210), S(321), and S(211) of respective crystal orientations in a plane orthogonal to the plate thickness direction satisfy S(110) + S(311) + S(331) + S(210) + S(211) > S(321).

Inventors

  • NISHIMURA, TORU
  • MAKI, KAZUNARI
  • ITO, YUKI

Assignees

  • 三菱マテリアル株式会社

Dates

Publication Date
20260507
Application Date
20251031
Priority Date
20241101

Claims (7)

  1. The Cu content is within the range of 99.9 mass% to 99.999 mass%, and it contains one or more Group A elements selected from Al, Be, Cd, Mg, Pb, Ni, P, Sn, Cr, Si, Ti, Zr, Hf, Mn, Fe, Ag, Zn, In, Ga, Ge, Sb in a total amount of 2 mass ppm to 20 mass ppm. The conductivity is 95% IACS or higher. A copper material characterized in that, in a plane perpendicular to the thickness direction, the area ratios of crystal orientations <110>, <311>, <331>, <210>, <321>, and <211> are S(110), S(311), S(331), S(210), S(321), and S(211), respectively, and the material satisfies the following equation (1). (1) Formula: S(110)+S(311)+S(331)+S(210)+S(211)>S(321)
  2. The copper material according to claim 1, characterized in that, in a plane perpendicular to the thickness direction, the area ratios of crystal orientations <110>, <311>, <331>, <210>, <321>, and <211> are S(110), S(311), S(331), S(210), S(321), and S(211), respectively, satisfy the following relationship. S(110)<0.2 S(311)<0.3 S(331)<0.2 S(210)<0.3 S(321)>0.1 S(211)<0.3
  3. The copper material according to claim 1, characterized in that, in a plane perpendicular to the thickness direction, the area ratio of crystal grains with an average crystal grain size D ave of 2 × D ave or more is 10% or less.
  4. The copper material according to claim 1, characterized by containing one or more B group elements selected from Ca, Sr, and Ba in a total amount of 10 mass ppm or more and 200 mass ppm or less.
  5. An insulating substrate comprising a ceramic substrate and a copper plate bonded to at least one surface of the ceramic substrate, The insulating substrate is characterized in that the copper plate is made of the copper material described in any one of claims 1 to 4.
  6. The insulating substrate according to claim 5, characterized in that the ceramic substrate is silicon nitride, alumina, or aluminum nitride.
  7. The insulating substrate according to claim 5, characterized in that a plating layer is formed on the side of the copper plate opposite to the ceramic substrate.

Description

Copper material and insulating substrate The present invention relates to a copper material suitable for electrical and electronic components such as heat sinks and thick copper circuits, and more particularly to a copper material used in insulating substrates for power semiconductors, and to an insulating substrate using this copper material. This application claims priority based on Japanese Patent Application No. 2024-192645, filed in Japan on November 1, 2024, and the contents of that application are incorporated herein by reference. Traditionally, highly conductive copper materials have been used in electrical and electronic components such as heat sinks and thick copper circuits. Recently, with the increasing amount of current used in electrical and electronic equipment components, resistive heating has become a problem. In electronic devices such as semiconductor devices, for example, insulating substrates are used that consist of a ceramic substrate to which copper material is bonded, forming the aforementioned heat sink or thick copper circuit. When bonding ceramic substrates and copper materials, a high-temperature atmosphere and pressurized treatment are performed. This can lead to coarsening or uneven growth of the copper material's crystal grain, resulting in poor bonding, appearance defects, and problems during the inspection process. To solve this problem, copper materials are required to have minimal change in grain size and uniform grain size even after heat treatment. Therefore, for example, Patent Documents 1 and 2 propose techniques for suppressing crystal growth in copper materials. Patent Document 1 states that by including 0.0006 to 0.0015 wt% of S, it is possible to adjust the crystal grains to a certain size even when heat-treated at a temperature above the recrystallization temperature. Furthermore, Patent Document 2 states that by including Ca and specifying the ratio of Ca content to the total content of O, S, Se, and Te, it is possible to suppress grain coarsening even when heat-treated at 800°C. This is a schematic diagram illustrating an electronic device using an insulating substrate according to this embodiment.This is a flowchart of the method for manufacturing copper material according to this embodiment. Below, a copper material and an insulating substrate, which are embodiments of one invention, will be described with reference to the attached drawings. The copper material in this embodiment is used as a material for electrical and electronic components such as heat sinks and thick copper circuits, and is bonded to a ceramic substrate, for example, when forming the aforementioned electrical and electronic components, to form an insulating substrate. Figure 1 shows an insulating substrate 10, which is an embodiment of the present invention, and an electronic device 1 using this insulating substrate 10. The electronic device 1 shown in Figure 1 comprises an insulating substrate 10 according to this embodiment, an electronic component 3 bonded to one side of the insulating substrate 10 (upper side in Figure 1) via a first solder layer 2, and a heat sink 51 bonded to the other side of the insulating substrate 10 (lower side in Figure 1) via a second solder layer 8. In this embodiment, the electronic component 3 is a power semiconductor element, and the electronic device 1 is a power module. The insulating substrate 10 comprises a ceramic substrate 11, a circuit layer 12 disposed on one side of the ceramic substrate 11 (the upper surface in Figure 1), and a metal layer 13 disposed on the other side of the ceramic substrate 11 (the lower surface in Figure 1). The ceramic substrate 11 prevents electrical connection between the circuit layer 12 and the metal layer 13. The ceramic substrate 11 is made of ceramics such as silicon nitride ( Si₃N₄ ), aluminum nitride (AlN), or alumina ( Al₂O₃ ), which have excellent insulating and heat dissipation properties. In this embodiment, the ceramic substrate 11 is made of silicon nitride ( Si₃N₄ ), which has particularly excellent heat dissipation properties. Furthermore, the thickness of the ceramic substrate 11 is set to a range of, for example, 0.2 mm or more and 1.5 mm or less, and in this embodiment, it is set to 0.32 mm. The circuit layer 12 is formed by bonding a copper plate to one side of the ceramic substrate 11. A circuit pattern is formed on this circuit layer 12, and one side of it (the top surface in Figure 1) is the mounting surface on which the electronic component 3 is mounted. Furthermore, it is preferable that a plating layer, such as Ni or Ag, is formed on the side of the circuit layer 12 opposite to the ceramic substrate 11. The metal layer 13 is formed by bonding a copper plate to the other surface of the ceramic substrate 11. This metal layer 13 has the effect of efficiently transferring heat from the electronic component 3 to the heat sink 51. Furthermore, it is preferable that a plating layer, such as Ni or Ag, is f