Method for manufacturing laminate

Abstract

To provide a method of manufacturing a laminate having excellent film quality while controlling the damage of an inorganic insulation layer.SOLUTION: A method for manufacturing a laminate 1 comprises steps of: preparing a metal base 2 and forming an inorganic insulation layer 3 on one surface 21 of the metal base 2 in the thickness direction using sputtering. A film deposition temperature in the sputtering is 400°C or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing a laminate. [Background technology]

[0002] 2. Description of the Related Art A method for producing a laminate is known in which an inorganic insulating layer is formed on the surface of a metal substrate by using plasma CVD and ion plating, respectively (see, for example, Patent Document 1 below).

[0003] In the plasma CVD described in Patent Document 1, SiH 4 and C.H. 4 A metal substrate is heated to 500°C using a mixed gas (source gas) containing the organic components (CH 4 ) is thermally decomposed, SiO 2 An inorganic insulating layer made of the above is formed.

[0004] In addition, in the ion plating described in Patent Document 1, SiO 2 The deposition material consisting of SiO is sublimated and positively charged, while the metal substrate is negatively charged. 2 The gas is attracted to the metal substrate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Unexamined Patent Publication No. 58-103156 Summary of the Invention [Problem to be solved by the invention]

[0006] In the plasma CVD described in Patent Document 1, a metal substrate is heated at a high temperature (high-temperature CVD). Generally, the thermal expansion coefficient of a metal substrate is higher than that of an inorganic insulating layer. Then, when the metal substrate and the inorganic insulating layer are cooled, the metal substrate contracts significantly relative to the inorganic insulating layer. This causes a problem of deformation of the laminate.

[0007] The deformation includes warping of the laminate. When the laminate warps as described above, stress is applied to the inorganic insulating layer, in other words, the inorganic insulating layer includes a large internal stress, and the inorganic insulating layer is damaged. The damage includes cracks in the inorganic insulating layer.

[0008] On the other hand, in order to suppress the above-mentioned damage, CVD (low-temperature CVD) in which the heating temperature of the metal substrate is lowered has been proposed. However, in this case, the organic components are not sufficiently pyrolyzed and remain in large amounts in the inorganic insulating layer, making it impossible to achieve high-quality film formation.

[0009] In addition, ion plating is also a deposition method, and the internal stress of the inorganic insulating layer formed increases depending on the deposition material, so there is a limit to how much damage can be prevented from the inorganic insulating layer.

[0010] The present invention provides a method for producing a laminate having good film quality while suppressing damage to an inorganic insulating layer. [Means for solving the problem]

[0011] The present invention (1) includes a method for producing a laminate, comprising the steps of preparing a metal substrate and forming an inorganic insulating layer on one surface of the metal substrate in a thickness direction by sputtering, wherein the film formation temperature in the sputtering is 400°C or less.

[0012] The present invention (2) includes the method for producing a laminate according to (1), in which the film formation temperature is 350° C. or lower.

[0013] The present invention (3) includes the method for producing a laminate according to (1) or (2), wherein the inorganic insulating layer has a thickness of 10 μm or less.

[0014] The present invention (4) includes the method for producing a laminate according to any one of (1) to (3), wherein the material of the metal substrate includes copper or a copper alloy.

[0015] The present invention (5) includes the method for producing a laminate according to (4), wherein the metal substrate has a first layer and a second layer in that order toward one side in a thickness direction, the material of the first layer is copper or a copper alloy, and the material of the second layer is at least one metal selected from the group consisting of chromium, nickel, iron, tungsten, molybdenum, zinc, tantalum, titanium, platinum, gold, and silver.

[0016] The present invention (6) includes the method for producing a laminate according to any one of (1) to (5), wherein the material of the inorganic insulating layer is at least one selected from the group consisting of oxides, nitrides, and oxynitrides.

[0017] The present invention (7) includes the method for producing the laminate according to any one of (1) to (6), wherein the material of the inorganic insulating layer contains at least one selected from the group consisting of aluminum, magnesium, zinc, silicon, yttrium, and titanium.

[0018] The present invention (8) includes the method for manufacturing a laminate described in any one of (1) to (7), wherein the metal substrate includes one surface and the other 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, and in the step of forming the inorganic insulating layer, the inorganic insulating layer is formed on the side surface of the metal substrate. Effect of the Invention

[0019] The method for producing a laminate of the present invention can produce a laminate with good film quality while suppressing damage to the inorganic insulating layer. [Brief description of the drawings]

[0020] [Figure 1]1A and 1B are process diagrams of a method for producing a laminate of the present invention. Fig. 1A shows a process for preparing a metal substrate. Fig. 1B shows a process for forming an inorganic insulating layer. [Diagram 2] 4 is a laminate obtained by a modified manufacturing method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] 1. One embodiment of the manufacturing method 1A and 1B, one embodiment of a method for producing a laminate of the present invention will be described. The method for producing a laminate 1 includes a step of preparing a metal substrate 2 and a step of forming an inorganic insulating layer 3. The step of preparing the metal substrate 2 and the step of forming the inorganic insulating layer 3 are carried out in this order.

[0022] 1.1 Step of preparing metal substrate 2 1A, the metal substrate 2 has a thickness. The metal substrate 2 has a plate shape. In this embodiment, the metal substrate 2 has a rectangular plate shape. The metal substrate 2 extends in a planar direction. The planar direction is perpendicular to the thickness direction.

[0023] The metal substrate 2 includes one surface 21 and the other 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.

[0024] 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.

[0025] 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.

[0026] The metal substrate 2 is a single layer or multiple layers. In this embodiment, the metal substrate 2 is preferably a multiple layer, specifically including a first layer 2A and a second layer 2B in that order toward one side in the thickness direction.

[0027] The first layer 2A is the other side portion of the metal substrate 2 in the thickness direction. The first layer 2A forms the other surface 22 of the metal substrate 2 in the thickness direction. The thickness of the first layer 2A is, for example, 30 μm or more, preferably 50 μm or more, and for example, 1000 μm or less, preferably 500 μm or less. The ratio of the thickness of the first layer 2A to the thickness of the metal substrate 2 is, for example, 0.95 or more, preferably 0.97 or more, and for example, less than 1.

[0028] The second layer 2B is one side portion (one end portion) of the metal substrate 2 in the thickness direction. The second layer 2B forms one surface 21 of the metal substrate 2 in the thickness direction. The second layer 2B is disposed on one surface of the first layer 2A in the thickness direction. The second layer 2B contacts the entire one surface of the first layer 2A. In this embodiment, the second layer 2B is thinner than the first layer 2A. The thickness of the second layer 2B is, for example, 3 nm or more, preferably 10 nm or more, and, for example, 1000 nm or less, preferably 500 nm or less. The ratio of the thickness of the second layer 2B to the thickness of the metal substrate 2 is, for example, 0.000003 or more, preferably 0.00001 or more, and, for example, 0.035 or less, preferably 0.02 or less. The ratio of the thickness of the second layer 2B to the thickness of the first layer 2A is, for example, 0.000003 or more, preferably 0.00001 or more, and for example, 0.035 or less, preferably 0.02 or less.

[0029] The material of the metal substrate 2 is not limited. The material of the metal substrate 2 is preferably copper, copper alloy, chromium, nickel, iron, tungsten, molybdenum, zinc, tantalum, titanium, platinum, gold, and silver. When the metal substrate 2 has the first layer 2A and the second layer 2B, the first layer 2A is made of copper or a copper alloy, and the second layer 2B is made of at least one metal selected from the group consisting of chromium, nickel, iron, tungsten, molybdenum, zinc, tantalum, titanium, platinum, gold, and silver. If the first layer 2A is made of copper or a copper alloy, and the second layer 2B is made of at least one metal selected from the group consisting of chromium, nickel, iron, tungsten, molybdenum, zinc, tantalum, titanium, platinum, gold, and silver, the metal substrate 2 can obtain excellent heat dissipation due to the copper or copper alloy, while ensuring adhesion to the inorganic insulating layer 3 due to the above-mentioned metal.

[0030] 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.

[0031] An example of a method for forming the second layer 2B is a method for forming the inorganic insulating layer 3 (sputtering) described later. However, in this embodiment, in the method for forming the second layer 2B, the target is the material of the second layer 2B described above (at least one metal selected from the group consisting of chromium, nickel, iron, tungsten, molybdenum, zinc, tantalum, titanium, platinum, gold, and silver). The sputtering gas (described later) is a rare gas, and the film formation temperature (heating temperature of the first layer 2A) is not limited.

[0032] The second layer 2B can also be formed by a wet process, including plating.

[0033] 1.2 Step of forming inorganic insulating layer 3 As shown in FIG. 1B, in the step of forming the inorganic insulating layer 3, the inorganic insulating layer 3 is formed on one surface 21 of the metal substrate 2 in the thickness direction by sputtering.

[0034] The film formation temperature in sputtering is 400° C. or less.

[0035] On the other hand, if the film formation temperature exceeds 400° C., when the metal substrate 2 and the inorganic insulating layer 3 are cooled, the metal substrate 2 will shrink significantly relative to the inorganic insulating layer 3, causing the laminate 1 to warp. This will cause stress to be applied to the inorganic insulating layer 3, in other words, the inorganic insulating layer 3 will contain a large internal stress, causing cracks to occur in the inorganic insulating layer 3.

[0036] The film formation temperature is preferably 350° C. or less, more preferably 300° C. or less, even more preferably 250° C. or less, and particularly preferably 50° C. or less. When the film formation temperature is equal to or less than the above-mentioned upper limit, damage including cracks in the inorganic insulating layer 3 can be further suppressed.

[0037] The lower limit of the film formation temperature is 10° C. or higher, preferably 20° C. or higher.

[0038] In sputtering, a sputtering device (not shown) equipped with a film-forming member (not shown) is used, and the temperature of the film-forming member corresponds to the film-forming temperature. Examples of the film-forming member include a film-forming plate or a film-forming roll. The film-forming member is temperature-adjustable. The film-forming member is capable of contacting the other surface 22 of the metal substrate 2. The film-forming substrate can also function as an anode.

[0039] In this embodiment, the sputtering apparatus includes a target (not shown), a pressure reducing section (not shown), a gas supply section (not shown), and a magnet section (not shown) in addition to the above-mentioned film forming members.

[0040] The target is disposed opposite the film-forming member with a gap therebetween. The target is made of the material (described later) of the inorganic insulating layer 3. The target can also function as a cathode.

[0041] The pressure reducing section is capable of reducing the pressure inside the sputtering device.

[0042] The gas supply unit can supply a sputtering gas into the sputtering device. Examples of the sputtering gas include a rare gas, nitrogen, a first mixed gas containing a rare gas and oxygen, a second mixed gas containing a rare gas and nitrogen, and a third mixed gas containing a rare gas, oxygen, and nitrogen. A mixed gas is preferable. Examples of the rare gas include argon, helium, neon, krypton, and xenon. The respective ratios of the gases in the first mixed gas to the third mixed gas are not limited.

[0043] The magnet section is disposed on the opposite side of the film forming member with respect to the target. When the sputtering apparatus includes the magnet section, it is capable of performing magnetron sputtering.

[0044] In this embodiment, to form the inorganic insulating layer 3 using a sputtering device, the above-mentioned metal substrate 2 is brought into contact with a film forming member adjusted to a predetermined temperature (400° C. or less). Then, the pressure inside the sputtering device is reduced by the pressure reducing unit. The reduced pressure inside the sputtering device is not limited.

[0045] Thereafter, the sputtering gas is supplied into the sputtering device by the gas supply unit. The pressure of the sputtering gas in the sputtering device is, for example, 0.01 Pa or more, preferably 0.1 Pa or more, and, for example, 10 Pa or less, preferably 1 Pa or less, more preferably 0.5 Pa or less.

[0046] In this sputtering device, power is applied to each of the deposition substrate and the target to generate plasma. Examples of the power include direct current (DC), alternating current (RF), unipolar pulse, and bipolar pulse, and RF is preferred. The power output is, for example, 5 mW / mm 2 More than 15mW / mm 2 or more, for example, 300 mW / mm 2 Less than 120mW / mm 2 Less than or equal to 80 mW / mm2 As a result, cations of the rare gas contained in the sputtering gas collide with the target. Then, molecules of the target material are ejected from the target and adhere to one surface 21 of the metal substrate 2. As a result, the inorganic insulating layer 3 is formed on one surface 21.

[0047] 1.3 Inorganic insulating layer 3 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. The inorganic insulating layer 3 is crystalline or amorphous.

[0048] Examples of the material of the inorganic insulating layer 3 include inorganic substances. Examples of the inorganic substances include oxides, nitrides, and oxynitrides. Examples of the material of the inorganic insulating layer 3 include at least one selected from the group consisting of aluminum, magnesium, zinc, silicon, yttrium, and titanium. A preferable example of the material of the inorganic insulating layer 3 is silicon.

[0049] Examples of oxides include aluminum oxide, magnesium oxide, zinc oxide, and silicon oxide (SiO 2 , silica), yttrium oxide, and titanium oxide.

[0050] Nitrides include, for example, aluminum nitride and silicon nitride.

[0051] Examples of oxynitrides include aluminum oxynitride and silicon oxynitride.

[0052] The inorganic insulating layer 3 is a single layer or multiple layers.

[0053] As the inorganic substance, preferably, an oxide is used from the viewpoint of improving insulating properties, and more preferably, silicon oxide is used.

[0054] The inorganic insulating layer 3 has a thickness of, for example, 10 nm or more, or 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.

[0055] The inorganic insulating layer 3 has a thickness of, for example, 10 μm or less, preferably 1 μm or less, and more preferably 200 nm 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 a heat dissipation substrate 10 because the heat dissipation substrate 10 has excellent heat dissipation properties.

[0056] 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.

[0057] 1.4 Uses of Laminate 1 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 (not shown) disposed on one surface of the laminate 1 in the thickness direction. The electrode has a pattern. The electrode is disposed on a part of one surface of the inorganic insulating layer 3 in the thickness direction. The electrode is made of a conductor. Examples of the conductor include copper and titanium. The electrode is a single layer or multiple layers.

[0058] 2. Effects of one embodiment In the manufacturing method of this embodiment, the inorganic insulating layer 3 is formed on one side 21 of the metal substrate 2 using sputtering at a film formation temperature of 400° C. or less, so that a laminate 1 with good film quality can be manufactured while suppressing damage to the inorganic insulating layer 3.

[0059] In more detail, sputtering does not use a source gas containing organic components as in CVD, but uses a sputtering gas containing a rare gas, so that mixing of organic components into the inorganic insulating layer 3 can be suppressed, and a laminate 1 with good film quality can be produced.

[0060] Furthermore, unlike ion plating, sputtering makes it possible to produce a laminate 1 with better film quality by appropriately adjusting the sputtering gas pressure (and, if necessary, the power output).

[0061] Also, unlike high-temperature CVD exceeding 400° C. and sputtering exceeding 400° C., in this embodiment, the film formation temperature is 400° C. or lower. Therefore, damage (cracks) to the inorganic insulating layer 3 caused by deformation (warping) of the laminate 1 can be suppressed.

[0062] 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.

[0063] 2, in the laminate 1 of the modified example, the inorganic insulating layer 3 is disposed on one surface 21 and a side surface 23 of the metal substrate 2. The inorganic insulating layer 3 continuously covers the one surface 21 and the side surface 23. The inorganic insulating layer 3 follows the shapes of the one surface 21 and the side surface 23. The inorganic insulating layer 3 disposed on the side surface 23 has a shape extending in the thickness direction.

[0064] 3.1 Effects of modified versions In the laminate 1 of the 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. EXAMPLES

[0065] 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".

[0066] <Example 1> <Step of Preparing Metal Substrate 2> First, a first layer 2A having a thickness of 150 μm and made of copper was prepared.

[0067] Next, a second layer 2B made of chromium and having a thickness of 20 nm was formed by DC magnetron sputtering under the following sputtering conditions.

[0068] Target: Chrom Sputtering gas: Ar Sputtering gas pressure: 0.2 Pa Output: 80mW / mm 2 Sputtering temperature: 25℃

[0069] In this way, a metal substrate 2 having a first layer 2A and a second layer 2B was prepared, as shown in FIG. 1A.

[0070] <Step of forming inorganic insulating layer 3> Then, as shown in FIG. 1B, silicon oxide (SiO 2 ) and an inorganic insulating layer 3 having a thickness of 100 nm was formed. The sputtering conditions were as follows:

[0071] Target: Silicon oxide (SiO 2 ) Sputtering gas: Ar / O 2 Gas mixtures Sputtering gas pressure: 0.2 Pa Output: 100mW / mm 2 Sputtering temperature: 25℃ (room temperature)

[0072] <Example 2, Example 3, Comparative Example 1> A laminate 1 was produced in the same manner as in Example 1. However, the deposition temperature in sputtering of the inorganic insulating layer 3 (the temperature of the metal substrate 2) was changed as shown in Table 1.

[0073] <Evaluation> <Inorganic insulating layer 3> The inorganic insulating layer 3 was observed with an optical microscope to see if it had any cracks (damage). The results are shown in Table 1.

[0074] [Table 1] [Explanation of symbols]

[0075] 1. Laminate 2 Metal Substrate 3. Inorganic insulating layer 10 Heat dissipation board 21 One side 22 Other side 23 Side

Claims

1. Providing a metal substrate; forming an inorganic insulating layer on one surface of the metal substrate in a thickness direction by sputtering; The method for producing a laminate, wherein the film formation temperature in the sputtering is 400° C. or less.

2. The method for producing a laminate according to claim 1 , wherein the film formation temperature is 350° C. or less.

3. The method for producing a laminate according to claim 1 or 2, wherein the inorganic insulating layer has a thickness of 10 μm or less.

4. The method for producing a laminate according to claim 1 , wherein the material of the metal substrate includes copper or a copper alloy.

5. The metal substrate includes a first layer and a second layer in this order toward one side in a thickness direction, the material of the first layer is copper or a copper alloy; 5. The method for manufacturing a laminate according to claim 4, wherein the material of the second layer is at least one metal selected from the group consisting of chromium, nickel, iron, tungsten, molybdenum, zinc, tantalum, titanium, platinum, gold, and silver.

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

7. 7. The method for producing a laminate according to claim 1, wherein a material of the inorganic insulating layer contains at least one selected from the group consisting of aluminum, magnesium, zinc, silicon, yttrium, and titanium.

8. the metal substrate includes the one surface and the other 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 method for producing a laminate according to claim 1 , wherein in the step of forming the inorganic insulating layer, the inorganic insulating layer is formed on the side surface of the metal substrate.

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