Laminate, heat dissipation substrate, and method for manufacturing laminate

Abstract

To provide a laminate with excellent insulation properties, a heat dissipation substrate, and a method for manufacturing the laminate.SOLUTION: The laminate 1 has a metal substrate 2 and an amorphous inorganic insulating layer 3 in order in the direction of thickness.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a laminate, a heat dissipation substrate, and a method for manufacturing the laminate. [Background technology]

[0002] A laminate including a metal substrate and an insulating layer is known (see, for example, Patent Document 1 below). In the laminate described in Patent Document 1, the insulating layer is crystalline. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 58-103156 Summary of the Invention [Problem to be solved by the invention]

[0004] A laminate is required to have excellent insulating properties. However, the laminate described in Patent Document 1 has limitations in terms of improving the insulating properties.

[0005] The present invention provides a laminate having excellent insulating properties, a heat dissipation substrate, and a method for manufacturing the laminate. [Means for solving the problem]

[0006] The present invention (1) includes a laminate comprising a metal substrate and an amorphous inorganic insulating layer in that order in the thickness direction.

[0007] In this laminate, the inorganic insulating layer is amorphous and therefore has high insulating properties, so that the laminate has excellent insulating properties.

[0008] The present invention (2) includes the laminate according to (1), in which the material of the metal substrate is copper or a copper alloy.

[0009] The present invention (3) includes the laminate according to (1) or (2), in which the material of the inorganic insulating layer is at least one selected from the group consisting of oxides, nitrides, and oxynitrides.

[0010] The present invention (4) includes the laminate according to any one of (1) to (3), in which the material of the inorganic insulating layer includes at least one selected from the group consisting of silicon, aluminum, and titanium.

[0011] The present invention (5) includes the laminate according to any one of (1) to (4), in which the inorganic insulating layer has a thickness of 10 μm or less.

[0012] The present invention (6) includes the laminate according to any one of (1) to (5), wherein the metal substrate includes one surface and the other surface in the thickness direction and a side surface connecting a peripheral edge of the one surface and a peripheral edge of the other surface, and the inorganic insulating layer is disposed on the one surface and the side surface of the metal substrate.

[0013] The present invention (7) includes a heat dissipation substrate comprising the laminate according to any one of (1) to (6).

[0014] The present invention (8) is a method for producing the laminate according to any one of (1) to (6), and includes a method for producing a laminate, in which an amorphous inorganic insulating layer is formed on one surface of a metal substrate in a thickness direction by using a vacuum film formation method. Effect of the Invention

[0015] The laminate and the heat dissipating substrate obtained by the laminate producing method of the present invention have excellent insulating properties. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a cross-sectional view of one embodiment of a laminate of the present invention. [Diagram 2] FIG. 2 is a plan view of the laminate shown in FIG. [Diagram 3] FIG. 11 is a cross-sectional view of a laminate of a modified example. [Figure 4] 1 is a GIXD chart of Example 3 and Comparative Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] 1. One embodiment of the laminate An embodiment of the laminate of the present invention will be described with reference to Fig. 1 and Fig. 2. The laminate 1 has a thickness. The laminate 1 has a plate shape. In this embodiment, the laminate 1 has a rectangular plate shape. The laminate 1 extends in a planar direction. The planar direction is perpendicular to the thickness direction. The laminate 1 includes a metal substrate 2 and an inorganic insulating layer 3.

[0018] 1.1 Metal substrate 2 The metal substrate 2 has a plate shape. In this embodiment, the metal substrate 2 has a rectangular plate shape. The metal substrate 2 includes one surface 21 and another surface 22 in the thickness direction, and a side surface 23 connecting the peripheral edge of the one surface 21 and the peripheral edge of the other surface 22.

[0019] Each of the first surface 21 and the second surface 22 has a flat shape. The first surface 21 and the second surface 22 are parallel to each other. The first surface 21 and the second surface 22 are perpendicular to the thickness direction.

[0020] The side surface 23 is aligned along the thickness direction. In this embodiment, the side surface 23 is perpendicular to the one surface 21 and the other surface 22.

[0021] There is no limitation on the material of the metal substrate 2. The material of the metal substrate 2 is preferably copper or a copper alloy.

[0022] The metal substrate 2 has a thickness of, for example, 30 μm or more, preferably 50 μm or more, and for example, 1000 μm or less, preferably 500 μm or less.

[0023] 1.2 Inorganic insulating layer 3 The inorganic insulating layer 3 is disposed on one surface 21 of the metal substrate 2. The inorganic insulating layer 3 contacts the entire one surface 21 of the metal substrate 2. The inorganic insulating layer 3 follows the shape of the one surface 21. In this embodiment, the inorganic insulating layer 3 has a shape extending in the planar direction.

[0024] The inorganic insulating layer 3 is amorphous. On the other hand, if the inorganic insulating layer 3 is crystalline, the insulating properties of the laminate 1 cannot be improved.

[0025] The inorganic insulating layer 3 being amorphous is <1> Grazing incidence X-ray diffraction (GIXD), <2> Out-of-plane crystal analysis by X-ray diffraction (XRD), or <3> This can be confirmed by observing the crystal grains using a transmission electron microscope (TEM). <1> The details of the conditions will be described in the Examples below.

[0026] Examples of materials for the inorganic insulating layer 3 include inorganic substances. Examples of inorganic substances include oxides, nitrides, and oxynitrides. Examples of materials for the inorganic insulating layer 3 include silicon, aluminum, titanium, niobium, and tantalum, and preferably silicon, aluminum, and titanium. The above-mentioned materials can be used alone or in combination.

[0027] Examples of oxides include silicon oxide (SiO 2 ), aluminum oxide (Al 2 O 3 ), titanium dioxide (TiO 2 ), niobium oxide (NbO 2 ), and tantalum oxide (Ta 2 O 5 ) As the oxide, preferably, silicon oxide, aluminum oxide, and titanium oxide are included.

[0028] Nitrides include, for example, aluminum nitride and silicon nitride.

[0029] Examples of oxynitrides include aluminum oxynitride and silicon oxynitride.

[0030] The inorganic insulating layer 3 is a single layer or multiple layers.

[0031] As the inorganic substance, preferably, an oxide is used from the viewpoint of improving insulating properties.

[0032] The inorganic insulating layer 3 has a thickness of, for example, 10 nm or more, preferably 25 nm or more, and more preferably 50 nm or more. When the inorganic insulating layer 3 has a thickness equal to or more than the above-mentioned lower limit, the laminate 1 has excellent insulating properties.

[0033] The thickness of the inorganic insulating layer 3 is, for example, 10 μm or less, preferably 5 μm or less, more preferably 2 μm or less, more preferably 1 μm or less, and even more preferably 0.5 μm or less. If the thickness of the inorganic insulating layer 3 is equal to or less than the above-mentioned upper limit, the laminate 1 has excellent heat dissipation properties. If the laminate 1 has excellent heat dissipation properties, it is preferable that the laminate 1 is provided on the heat dissipation substrate 10 because the heat dissipation substrate 10 has excellent heat dissipation properties.

[0034] The ratio of the thickness of the inorganic insulating layer 3 to the thickness of the metal substrate 2 is, for example, 0.00001 or more, preferably 0.0001 or more, and for example, 0.35 or less, preferably 0.1 or less.

[0035] 1.3 Manufacturing method of the laminate 1 A method for producing the laminate 1 will be described. To produce the laminate 1, first, a metal substrate 2 is prepared, and then an inorganic insulating layer 3 is formed on one surface 21 of the metal substrate 2 by a vacuum film-forming method. Examples of the vacuum film-forming method include a vapor deposition method, a sputtering method, and an ion plating method. A preferred example of the vacuum film-forming method is a sputtering method.

[0036] The use of this laminate 1 is not limited. Preferably, the laminate 1 is provided in a heat dissipation substrate 10. That is, the heat dissipation substrate 10 includes the laminate 1 described above. The heat dissipation substrate 10 may further include an electrode 4 (virtual line) arranged on one surface of the laminate 1 in the thickness direction. The electrode 4 has a pattern. The electrode 4 is arranged on a part of one surface of the inorganic insulating layer 3 in the thickness direction. The electrode 4 is made of a conductor. Examples of the conductor include copper and titanium. The electrode 4 is a single layer or multiple layers.

[0037] 2. Effects of one embodiment In this laminate 1, the inorganic insulating layer 3 is amorphous, and therefore the inorganic insulating layer 3 has high insulating properties. Therefore, the laminate 1 has excellent insulating properties.

[0038] In the method for producing the laminate 1, the inorganic insulating layer 3 is formed by a vacuum film-forming method, so that the inorganic insulating layer 3 can be formed easily.

[0039] 3. Modifications In the following modifications, the same components and steps as those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. In addition, each modification can achieve the same effects as those in the above-described embodiment, unless otherwise specified. Furthermore, the embodiment and the modifications can be appropriately combined.

[0040] 3.1 First modified example As shown in FIG. 3, in the laminate 1 of the first modified example, the inorganic insulating layer 3 is disposed on one surface 21 and side surface 23 of the metal substrate 2. The inorganic insulating layer 3 continuously covers the one surface 21 and side surface 23. The inorganic insulating layer 3 follows the shapes of the one surface 21 and side surface 23. The inorganic insulating layer 3 disposed on the side surface 23 has a shape extending in the thickness direction. The inorganic insulating layer 3 disposed on the side surface 23 is also amorphous. The inorganic insulating layer 3 disposed on the side surface 23 has the same physical properties as the inorganic insulating layer 3 disposed on the one surface 21.

[0041] 3.1.1 Effects of the First Modification In the laminate 1 of the first modified example, the inorganic insulating layer 3 is also formed on the side surface 23 of the metal substrate 2, so that the insulation properties of the side surface 23 of the laminate 1 are excellent.

[0042] 3.2 Second variant The laminate 1 may further include an adhesion layer 5, as shown by the imaginary line in FIG. 1. The adhesion layer 5 is disposed between one surface 21 of the metal substrate 2 and the inorganic insulating layer 3. An example of the adhesion layer 5 is a chromium layer. The thickness of the adhesion layer 5 is, for example, 10 nm or more and 100 nm or less. The adhesion layer 5 is formed, for example, by a vacuum film formation method. EXAMPLES

[0043] The present invention will be described in more detail below with reference to examples. Note that the present invention is not limited to the examples. In addition, the specific numerical values ​​of the blending ratio (content ratio), physical property values, parameters, etc. used in the following description can be replaced with the upper limit (a numerical value defined as "not more than" or "less than") or lower limit (a numerical value defined as "not less than" or "exceeding") of the corresponding blending ratio (content ratio), physical property values, parameters, etc. described in the above "Form for carrying out the invention".

[0044] <Example 1> A metal substrate 2 was prepared. The metal substrate 2 had a thickness of 150 μm and was made of copper.

[0045] Next, an adhesion layer 5 made of chromium and having a thickness of 20 nm was formed by vacuum film formation under the following film formation conditions.

[0046] Vacuum deposition method: DC magnetron sputtering method Sputtering gas: Ar Sputtering pressure: 0.2Pa Output: 80W Sputtering temperature: 25℃

[0047] Then, silica oxide (SiO 2) and an inorganic insulating layer 3 having a thickness of 50 nm was formed. The film formation conditions were as follows.

[0048] Vacuum deposition method: RF magnetron sputtering method Sputtering gas: Ar / O 2 Gas mixtures Sputtering pressure: 0.2Pa Output: 100W Sputtering temperature: 25℃

[0049] <Example 2 to Example 4> A laminate 1 was produced in the same manner as in Example 1. However, the material and thickness of the inorganic insulating layer 3 were changed as shown in Table 1.

[0050] <Comparative Example 1> A laminate 1 was produced in the same manner as in Example 1. However, the material of the inorganic insulating layer 3 was changed as shown in Table 1. The inorganic insulating layer 3 was also made crystalline. To make the inorganic insulating layer 3 crystalline, the inorganic insulating layer 3 after vacuum deposition was annealed in air at 350° C. for 4 hours using a muffle furnace.

[0051] <Evaluation> 1. Amorphous Grazing incidence X-ray diffraction measurements (GIXD) were carried out using an X-ray diffractometer under the following measurement conditions.

[0052] X-ray entrance side: entrance parallel slit, solar slit 5°, vertical limit slit 10 mm, width limit slit 0.1 mm X-ray receiving side: receiving slit 20mm, parallel slit analyzer 0.5° and solar slit 5° X-ray source: Cu Kα radiation (wavelength: 1.5418 Å) with output of 40 kV-50 mA, incidence angle of 0.1°, step width of 0.1°, scan speed of 4° / min

[0053] It was confirmed that in each of Examples 1 to 4, there was no diffraction peak derived from the crystal lattice at an incident angle (2θ) of 20° to 35°, that is, the inorganic insulating layer 3 in each of Examples 1 to 4 was amorphous. On the other hand, in Comparative Example 1, a diffraction peak (101) of an anatase type crystal structure was confirmed at 25.5°. In other words, the inorganic insulating layer 3 of Comparative Example 1 was crystalline.

[0054] The GIXD charts of Example 3 and Comparative Example 1 are shown in FIG.

[0055] 2. Insulation of the laminate 1 An electrode 4 having a length of 2 mm and a width of 2 mm was formed through a metal mask having an opening on one surface of each of the laminates 1 of Examples 1-4 and Comparative Example 1. The electrode 4 includes a titanium layer having a thickness of 50 nm and a copper layer having a thickness of 100 nm, in that order toward one side in the thickness direction.

[0056] The film formation conditions for the electrode 4 are as follows. Vacuum deposition method: DC magnetron sputtering method Sputtering gas: Ar Sputtering pressure: 0.2Pa Output: 80W Sputtering temperature: 25℃

[0057] A digital multimeter 6 (phantom line) was connected to the metal substrate 2 and the electrode 4 via a line 7 (phantom line). The resistance in the thickness direction of the laminate 1 was then measured. The insulation was then evaluated according to the following criteria. The results are shown in Table 1.

[0058] ◯: The resistance was more than 1 MΩ and the insulation was good. ×: The resistance was 1 MΩ or less, and the insulation was poor.

[0059] [Table 1] [Explanation of symbols]

[0060] 1. Laminate 2 Metal Substrate 3. Inorganic insulating layer 10 Heat dissipation substrate 21 On the one hand 22 On the other hand 23 Side surface

Claims

1. A laminate comprising a metal substrate and an amorphous inorganic insulating layer in that order in a thickness direction.

2. The laminate according to claim 1 , wherein the material of the metal substrate is copper or a copper alloy.

3. 3. The laminate according to claim 1, wherein the material of the inorganic insulating layer is at least one selected from the group consisting of oxides, nitrides, and oxynitrides.

4. The laminate according to claim 1 , wherein a material of the inorganic insulating layer includes at least one selected from the group consisting of silicon, aluminum, and titanium.

5. The laminate according to claim 1 , wherein the inorganic insulating layer has a thickness of 10 μm or less.

6. the metal substrate includes one surface and another surface in a thickness direction, and a side surface connecting a peripheral edge of the one surface and a peripheral edge of the other surface; The laminate according to claim 1 , wherein the inorganic insulating layer is disposed on the one surface and the side surface of the metal substrate.

7. A heat dissipation substrate comprising the laminate according to claim 1 .

8. A method for producing the laminate according to any one of claims 1 to 6, A method for manufacturing a laminate, comprising forming an amorphous inorganic insulating layer on one surface of a metal substrate in a thickness direction by using a vacuum film formation method.

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