Mounting substrate and method for manufacturing same

Abstract

A mounting substrate (1) is provided with a metal substrate (2) and an insulating layer (3). The insulating layer (3) is disposed on one surface (21) of the metal substrate (2) in the thickness direction. The insulating layer (3) has a plurality of inorganic insulating portions (31) and elastic insulating portions (32). The inorganic insulating portion (31) is disposed on a first portion (211) of one surface (21) of the metal substrate (2). The plurality of inorganic insulating portions (31) are spaced apart from each other in the plane direction. The elastic insulating portion (32) is disposed on a second portion (212) of the one surface (21) of the metal substrate (2). The elastic insulating portion (32) is disposed between the inorganic insulating portions (31) adjacent to each other.

Description

Technical Field

[0001] This invention relates to a mounting substrate and a method for manufacturing the same. Background Technology

[0002] Mounting substrates containing metallic materials are known (see, for example, Patent Document 1 below). The mounting substrate described in Patent Document 1 includes a base substrate and a thermally conductive layer disposed on its surface. The base substrate contains aluminum. Fine holes are formed on the surface of the base substrate. The thermally conductive layer fills the fine holes. The base substrate is continuous in the lower surface direction.

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2014-127633 Summary of the Invention

[0004] The problem that the invention aims to solve Depending on the application and purpose, stress may sometimes be applied to the mounting substrate. In the mounting substrate of Patent Document 1, there is a defect that the base substrate cannot adequately relax the aforementioned stress, and cracks are easily generated in the base substrate.

[0005] This disclosure provides a mounting substrate capable of adequately relaxing stress and suppressing crack formation, and a method for manufacturing the same.

[0006] Methods for solving problems This disclosure [1] includes a mounting substrate comprising: a metal substrate; and an insulating layer disposed on one side of the metal substrate in the thickness direction, the insulating layer having: a plurality of inorganic insulating portions disposed on a portion of the aforementioned one side of the metal substrate and spaced apart from each other in a plane direction orthogonal to the aforementioned thickness direction; and elastic insulating portions disposed on the remaining portion of the aforementioned one side of the metal substrate and disposed between adjacent inorganic insulating portions.

[0007] In this mounting substrate, multiple inorganic insulating portions in the insulating layer are spaced apart from each other in the planar direction. Therefore, even if stress is applied to one inorganic insulating portion, it is not easy to apply stress to the inorganic insulating portions adjacent to it. In addition, the inorganic insulating portions can be made smaller, thus reducing the likelihood of cracks forming in the insulating layer.

[0008] Furthermore, the insulating layer has elastic insulating portions disposed between adjacent inorganic insulating portions. Therefore, the elastic insulating portions can relax the aforementioned stress. As a result, crack formation in the insulating layer can be suppressed.

[0009] This disclosure [2] includes a mounting substrate as described in [1], the mounting substrate further comprising a wiring layer disposed on one side of the aforementioned insulating layer in the aforementioned thickness direction.

[0010] This disclosure [3] includes a mounting substrate as described in [1], the mounting substrate further comprising a wiring layer disposed on the other side of the aforementioned metal substrate in the aforementioned thickness direction.

[0011] This disclosure [4] includes a method for manufacturing a mounting substrate, which is the method for manufacturing a mounting substrate described in [1], the method comprising: step (1), preparing a metal substrate; and step (2), forming an insulating layer on one side of the metal substrate in the thickness direction, the step (2) comprising: step (3), forming a photoresist on a portion of the aforementioned side of the metal substrate in the aforementioned thickness direction; step (4), forming an inorganic insulating portion on the remaining portion of the aforementioned side of the metal substrate exposed from the photoresist by anodizing, spaced apart from each other in a plane direction orthogonal to the aforementioned thickness direction; and step (5), removing the photoresist.

[0012] This disclosure [5] includes a method for manufacturing a mounting substrate as described in [4], wherein the aforementioned step (2) has a step (6): after the aforementioned step (5), a photosensitive resin composition is disposed on one side of the aforementioned inorganic insulating portion and the aforementioned portion to form a photosensitive layer, and an elastic insulating portion is formed from the aforementioned photosensitive layer by photolithography.

[0013] Invention Effects In the mounting substrate of the present invention manufactured by the manufacturing method of the present invention, the generation of cracks in the insulating layer can be suppressed. Attached Figure Description

[0014] [ Figure 1 [This is a top view of one embodiment of the mounting substrate of the present invention.]

[0015] [ Figure 2 ]for Figure 1 The cross-sectional view of the mounting substrate shown is along line AA.

[0016] [ Figure 3 ] Figure 3 A to Figure 3 F is a process diagram of the manufacturing method of the mounting substrate; Figure 3 A represents the process of preparing the metal substrate; Figure 3 B represents the process of forming the oxide layer; Figure 3 C represents the process of forming the resist; Figure 3 D represents the process of forming the inorganic insulating part; Figure 3 E represents the process of removing the resist; Figure 3 F represents the process of forming the elastic insulating part.

[0017] [ Figure 4 This is a cross-sectional view of a mounting substrate with a wiring layer. Detailed Implementation

[0018] 1. One embodiment of the wiring circuit board Reference Figure 1 and Figure 2 The mounting base plate 1 will be described.

[0019] like Figure 1 As shown, the mounting substrate 1 has a rectangular shape, for example, when viewed from above. Viewing from above is synonymous with viewing along the thickness direction. The mounting substrate 1 has a plate shape extending along the surface direction. The surface direction is orthogonal to the thickness direction. For example... Figure 2 As shown, the mounting substrate 1 includes a metal substrate 2 and an insulating layer 3.

[0020] 1.1 Metal substrate 2 The metal substrate 2 is the other side portion of the mounting substrate 1 in the thickness direction. The metal substrate 2 extends in the surface direction. The metal substrate 2 includes one side 21 and another side 22. The other side 22 is the other side of the mounting substrate 1 in the thickness direction. The other side 22 has a flat shape. The one side 21 is spaced apart from the other side 22 in the thickness direction. The one side 21 has an uneven shape. The one side 21 includes a plurality of first portions 211 and second portions 212.

[0021] Multiple first parts 211 are part of a surface 21. The multiple first parts 211 are spaced apart from each other in the surface direction. For example... Figure 1 As shown, each of the plurality of first parts 211 has a rectangular shape, for example, when viewed from above.

[0022] The second part 212 is the remaining portion of one surface 21, excluding the first part 211. The second part 212 is positioned between adjacent first parts 211 in the surface direction. For example, the second part 212 has a lattice shape when viewed from above. Figure 2 As shown, the second part 212 is located on one side of the first part 211 in the thickness direction. The second part 212 and the first part 211 are connected via a connecting surface 213.

[0023] The connecting surface 213 connects the outer peripheral edge of the second part 212 to the inner peripheral edge of the first part 211. The connecting surface 213 extends along the thickness direction.

[0024] like Figure 1 As shown, it should be noted that the second part 212 may also be disposed around the first part 211 disposed at the periphery of one side 21. The second part 212 described above has a frame shape.

[0025] The Young's modulus of the metal substrate 2 at 25°C is, for example, greater than 1 GPa, preferably 10 GPa or more, more preferably 40 GPa or more, even more preferably 50 GPa or more, and also less than 200 GPa. The Young's modulus of the metal substrate 2 can be determined from the material and literature values ​​described later. The Young's modulus of the metal substrate 2 can also be measured.

[0026] Examples of materials that can be used as the metal substrate 2 include aluminum, titanium, tantalum, niobium, hafnium, zirconium, zinc, tungsten, bismuth, antimony, and their oxides. From the viewpoint of ensuring high insulation, aluminum and aluminum oxide are preferred materials for the metal substrate 2.

[0027] It should be noted that, as Figure 2 As shown, the metal substrate 2 may have an oxide layer 23 and a monomer layer 24. The oxide layer 23 includes a second portion 212 on one side 21 and another side 22. The oxide layer 23 extends along the surface direction. The material of the oxide layer 23 is, for example, the oxide described above, preferably aluminum oxide.

[0028] The thickness of the oxide layer 23 is, for example, 100 nm or less, preferably 20 nm or less, more preferably 15 nm or less, and, for example, 1 nm or more.

[0029] A monomer layer 24 is disposed between the oxide layer 23 of the second portion 212 and the oxide layer 23 of the other side 22. The monomer layer 24 extends along the surface direction. The monomer layer 24 at the first portion 211 on one side 21 is separated (independent) from the oxide layer 23. The monomer layer 24 located near the other side of the oxide layer 23 containing the second portion 212 is positioned on one side in the thickness direction compared to the first portion 211. The monomer layer 24 located at the above position is a protrusion. The protrusion protrudes from the first portion 211 in the monomer layer 24 in the thickness direction.

[0030] The ratio of the thickness of the oxide layer 23 to the thickness of the monomer layer 24 is, for example, 0.1 or less, preferably 0.01 or less, and more preferably 10. -6 The thickness of the monomer layer 24 is the length between the oxide layer 23 of the second part 212 and the oxide layer 23 of the other side 22. Specifically, the thickness of the monomer layer 24 is, for example, 30 to 300 μm.

[0031] The length of the connecting surface 213 is, for example, 0.1 μm to 10 μm, preferably 0.3 μm to 2 μm.

[0032] The thickness T0 of the metal substrate 2 is, for example, 50 μm to 500 μm, preferably 100 μm to 300 μm. The thickness T0 of the metal substrate 2 is the thickness direction length between the second portion 212 on one side 21 and the other side 22.

[0033] 1.2 Insulation layer 3 An insulating layer 3 is disposed on one side 21 of the metal substrate 2 in the thickness direction. The insulating layer 3 is a portion of one side of the mounting substrate 1 in the thickness direction. The insulating layer 3 extends in the surface direction. The insulating layer 3 has a plurality of inorganic insulating portions 31 and elastic insulating portions 32.

[0034] 1.2.1 Inorganic Insulation Part 31 Multiple inorganic insulating portions 31 are disposed on a first portion 211, which is part of one side 21 of the metal substrate 2. The inorganic insulating portions 31 are also disposed on a connecting surface 213. The inorganic insulating portions 31 extend along the surface direction. The multiple inorganic insulating portions 31 are spaced apart from each other in the surface direction. Figure 1 As shown, each of the plurality of inorganic insulating portions 31 has, for example, a rectangular shape when viewed from above. Figure 2 As shown, each of the plurality of inorganic insulating portions 31 has a rectangular shape when viewed in cross-section. Each inorganic insulating portion 31 has a front surface 311, a back surface 312, and a side surface 313.

[0035] One side 311 has a flat shape. One side 311 is located on one side in the thickness direction compared to the second part 212.

[0036] The other side 312 is spaced apart from the first side 311 in the thickness direction. The other side 312 is in contact with the first portion 211 in the metal substrate 2. The other side 312 has a flat shape.

[0037] Side surface 313 connects the outer peripheral edge of one side 311 to the outer peripheral edge of another side 312. A portion of the other side of side surface 313 in the thickness direction contacts the connecting surface 213 in the metal substrate 2. Another portion of side surface 313 contacts the side surface of the oxide layer 23 and the side surface of the protrusion in the monomer layer 24.

[0038] It should be noted that the inorganic insulating part 31 is anodized through process (4) (described later, see below). Figure 2 It is formed by (D), and is therefore called an anodic oxide film.

[0039] The Young's modulus of the inorganic insulating portion 31 at 25°C is, for example, greater than 10 GPa, preferably 50 GPa or more, more preferably 100 GPa or more, even more preferably 300 GPa or more, and also less than 1000 GPa. The Young's modulus of the inorganic insulating portion 31 can be determined from the material and literature values ​​described later. The Young's modulus of the inorganic insulating portion 31 can also be measured experimentally.

[0040] Examples of materials for the inorganic insulating portion 31 include at least one anodic oxide selected from the group consisting of aluminum, titanium, tantalum, niobium, hafnium, zirconium, zinc, tungsten, bismuth, and antimony. Alumina is a preferred material for the inorganic insulating portion 31, and γ-alumina crystals are more preferred.

[0041] The thickness T1 of the inorganic insulating portion 31 is, for example, 0.1 μm to 10 μm, preferably 0.3 μm to 2 μm. The ratio (T1 / T0) of the thickness T1 of the inorganic insulating portion 31 to the thickness T0 of the metal substrate 2 is, for example, 0.001 to 0.1, preferably 0.003 to 0.01.

[0042] The minimum length L1 in the surface direction of the inorganic insulating portion 31 is, for example, 1000 μm or less, preferably 500 μm or less, more preferably 200 μm or less, and also 10 μm or more. If the inorganic insulating portion 31 has a rectangular shape when viewed from above, the aforementioned minimum length L1 corresponds to the short side. If the minimum length L1 in the surface direction of the inorganic insulating portion 31 is less than or equal to the aforementioned upper limit, the inorganic insulating portion 31 can be reduced in size, and cracks in the insulating layer 3 can be effectively suppressed.

[0043] 1.2.2 Elastic Insulation Part 32 The elastic insulating portion 32 is disposed in the second portion 212, which is the remaining portion of one side 21 of the metal substrate 2. Additionally, a portion of the elastic insulating portion 32 is disposed between adjacent inorganic insulating portions 31. The elastic insulating portion 32 has a filling portion 321.

[0044] A filling portion 321 is disposed between one side portions of the side surfaces 313 of adjacent inorganic insulating portions 31. The filling portion 321 fills the recess 30. The recess 30 is divided by the second portion 212 and the two side surfaces 313. The filling portion 321 contacts the second portion 212 and the two side surfaces 313. The filling portion 321 and the recess 30 have the same shape.

[0045] The thickness T21 of the filling portion 321 is, for example, 0.1 μm to 10 μm, preferably 0.3 μm to 2 μm. The thickness T21 of the filling portion 321 is the length in the thickness direction of the second part 212 of the metal substrate 2 and one side 311 of the inorganic insulating portion 31.

[0046] The width W21 of the filling portion 321 is, for example, 1 μm to 100 μm, preferably 5 μm to 50 μm. The width W21 of the filling portion 321 is the length between the side surfaces 313 of adjacent inorganic insulating portions 31.

[0047] In addition to the filling portion 321, the elastic insulating portion 32 also includes a bulge 322. The bulge 322 bulges outward from one end edge of the filling portion 321 in the thickness direction towards one side in the thickness direction and outward in the surface direction. The peripheral end of the bulge 322 contacts the peripheral end of one side surface 311 of the inorganic insulating portion 31. The bulge 322 spans across the adjacent inorganic insulating portion 31. The elastic insulating portion 32 has a T-shape when viewed in cross-section. One side of the elastic insulating portion 32 in the thickness direction is located to one side compared to the second portion 212 of the metal substrate 2 in the thickness direction.

[0048] The thickness T22 of the bulge 322 is, for example, greater than 0 μm and less than 10 μm, preferably 0.1 μm to 5 μm. The thickness T22 of the bulge 322 is the length in the thickness direction between one side of the bulge 322 and one side 311 of the inorganic insulating portion 31.

[0049] The width W22 of the bulge 322 is, for example, 1 μm to 120 μm, preferably 5 μm to 60 μm.

[0050] The thickness T2 of the elastic insulating portion 32 is 0.1 μm to 10 μm, preferably 0.4 μm to 5 μm. The thickness T2 of the elastic insulating portion 32 is the sum of the thickness T21 of the filling portion 321 and the thickness T22 of the bulge portion 322. The width W2 of the elastic insulating portion 32 is the same as the width W22 of the bulge portion 322. The ratio (T1 / T2) of the thickness T1 of the inorganic insulating portion 31 to the thickness T2 of the elastic insulating portion 32 is, for example, 0.05 to 2, preferably 0.1 to 1.

[0051] The Young's modulus of the elastic insulating portion 32 at 25°C is, for example, 7 GPa or less, preferably 5 GPa or less, and also, for example, 0.1 GPa or more. Since the Young's modulus of the elastic insulating portion 32 is below the aforementioned upper limit, the elastic insulating portion 32 can efficiently relax the stress applied to the insulating layer 3. The Young's modulus of the elastic insulating portion 32 can be determined based on the materials and literature values ​​described later. The Young's modulus of the elastic insulating portion 32 can also be measured experimentally.

[0052] Materials used as the elastic insulating part 32 include, for example, resins. Examples of resins include polyimide resins, epoxy resins, phenolic resins, and poly(p-phenylenebenzodioxazole) resin (PBO).

[0053] 1.2 Manufacturing method of mounting substrate Next, refer to Figure 3 A to Figure 3 F will be used to describe the manufacturing method of the mounting substrate 1. The manufacturing method includes process (1) and process (2). Process (1) and process (2) are performed sequentially.

[0054] 1.2.1 Process (1) like Figure 3 A and Figure 3 As shown in B, in process (1), the metal substrate 2 is prepared. Specifically, firstly, as shown in Figure B... Figure 3 As shown in Figure A, a metal substrate 2 containing a monomer layer 24 is prepared.

[0055] Next, as Figure 3 As shown in Figure B, an oxide layer 23 is formed on one and the other sides of the monomer layer 24 in the thickness direction. Specifically, the monomer layer 24 is heated in an atmospheric atmosphere. The heating temperature is, for example, 400°C to 800°C. The heating time is, for example, 10 minutes to 5 hours.

[0056] Thus, a metal substrate 2 having a monomer layer 24 and two oxide layers 23 is prepared.

[0057] 1.2.2 Process (2) like Figure 3 As shown in F, in process (2), an insulating layer 3 is formed on one side 21 of the metal substrate 2 in the thickness direction.

[0058] Process (2) has processes (3), (4), (5), and (6). Processes (3), (4), (5), and (6) are performed sequentially.

[0059] like Figure 3 As shown in C, in process (3), a resist 5 is formed on the second portion 212 (remaining portion) of one side 21 of the metal substrate 2 in the thickness direction. Specifically, as shown in Figure C... Figure 3 As shown by the imaginary line C, firstly, a photosensitive dry film resist 50 is disposed on the entire surface 21 of one side of the metal substrate 2. Then, as shown by the solid line, a resist 5 with the same pattern as the second portion 212 is formed from the dry film resist 50 by photolithography. It should be noted that the dry film resist 50 can be either positive or negative.

[0060] like Figure 3 As shown in D, in process (4), inorganic insulating portions 31 are formed at intervals in the planar direction on the first portion 211 (remaining portion) of one side 21 of the metal substrate 2 exposed from the resist 5 by anodizing. Specifically, the metal substrate 2 on which the resist 5 is provided is used as the anode, and a carbon electrode is used as the cathode, and they are immersed in an electrolytic bath. Examples of electrolytic baths include ammonium borate aqueous solution and sodium borate aqueous solution. The voltage in the anodizing process is, for example, 100V to 2,000V, and the current density in the anodizing process is 1mA / cm. 2 ~100mA / cm 2 The temperature of the electrolytic bath is, for example, 25°C to 95°C. The processing time is, for example, 5 minutes to 60 minutes.

[0061] During anodizing, the first portion 211 of one side 21 moves (recedes) to the opposite side in the thickness direction relative to the second portion 212. This is caused by the material in the first portion 211 exposed from the resist 5 dissolving into the electrolyte. At this time, the oxide layer 23 corresponding to the first portion 211 is removed, and further, one end edge of the monomer layer 24 corresponding to the first portion 211 is removed.

[0062] In conjunction with this, the inorganic insulating portion 31 is deposited on the first portion 211.

[0063] In particular, when the metal substrate 2 contains aluminum, the anodizing process is called Alumite treatment (aluminum anodizing treatment).

[0064] like Figure 3 As shown in E, in step (5), the resist 5 is removed. For example, a stripping solution is used to remove the resist 5. The stripping solution, for example, contains N-methyl-2-pyrrolidone (NMP).

[0065] Subsequently, the inorganic insulating portion 31 is heated as needed. By heating the inorganic insulating portion 31, stress relaxation of the inorganic insulating layer 3 can be achieved beforehand, and crack resistance after installation can be further improved. The heating temperature is, for example, 150°C to 350°C. The heating time is, for example, 1 minute to 30 minutes.

[0066] like Figure 3 As shown in F, in step (6), the elastic insulating portion 32 is formed after step (5). In step (6), firstly, as shown by the imaginary lines, the photosensitive layer 320 is formed on all one side of the inorganic insulating portion 31 and the second portion 212. Specifically, a photosensitive resin composition is disposed on one side of the inorganic insulating portion 31 and the second portion 212. The resin composition contains a photosensitive component and the aforementioned resin and / or precursor.

[0067] Next, the elastic insulating portion 32 is formed from the photosensitive layer 320 by photolithography.

[0068] Thus, a mounting substrate 1 having a metal substrate 2 and an insulating layer 3 is manufactured.

[0069] like Figure 4As shown, the mounting substrate 1 may include a wiring layer 4 in addition to the metal substrate 2 and the insulating layer 3. In this variation, the wiring layer 4 is disposed on one side of the insulating layer 3 in the thickness direction. The wiring layer 4 has a patterned shape. The wiring layer 4 can be formed solidly. For example, the wiring layer 4 is disposed on the surface (thickness direction side and peripheral side) of one side 311 of two adjacent inorganic insulating portions 31 (31A, 31B) and the filling portion 321 between them. The wiring layer 4 extends in the surface direction. A plurality of wiring layers 4 are disposed at intervals from each other in a direction intersecting the extension direction. The wiring layer 4 is formed by a wiring forming method.

[0070] Or, such as Figure 4 As shown by the imaginary lines, the wiring layer 4 can also be disposed on the other side 22 of the metal substrate 2 in the thickness direction. The mounting substrate 1 may have both the wiring layer 4 shown by the imaginary lines and the solid lines, or it may only have the wiring layer 4 shown by the imaginary lines.

[0071] A semiconductor element is mounted on one side of the mounting substrate 1 in the thickness direction. The electrodes (not shown) of the semiconductor element are electrically connected to the wiring layer 4.

[0072] 2. Effects of one implementation method In the mounting base plate 1, such as Figure 2 As shown, the plurality of inorganic insulating portions 31 in the insulating layer 3 are spaced apart from each other in the planar direction. Therefore, even if stress is applied to one inorganic insulating portion 31A, it is not easy to apply stress to the inorganic insulating portion 31B adjacent to it. In addition, the inorganic insulating portions 31 can be reduced, thus making it less likely for cracks to form in the insulating layer 3.

[0073] Furthermore, the insulating layer 3 has elastic insulating portions 32 disposed between adjacent inorganic insulating portions 31. Therefore, the elastic insulating portions 32 can relax the aforementioned stress. As a result, cracking in the insulating layer 3 can be suppressed.

[0074] 3. Variations In the variations, the same reference numerals are used for the same components and processes as in the first embodiment, and detailed descriptions are omitted. Furthermore, the variations, unless otherwise specified, can achieve the same effects as the first embodiment. Moreover, the first embodiment and its variations can be appropriately combined.

[0075] Although not shown in the figure, the metal substrate 2 may also have only a monomer layer 24 instead of an oxide layer 23.

[0076] Preferred options Figure 2As shown in one embodiment, the metal substrate 2 has an oxide layer 23. In one embodiment, the metal substrate 2 has an oxide layer 23, so that an inorganic insulating portion 31 with excellent insulating properties can be formed in the anodizing process (4).

[0077] Although not shown in the figure, the elastic insulating portion 32 may not include the bulge 322.

[0078] Example The specific values ​​of proportions (including proportions), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values ​​(values ​​defined in the form of "less than" or "less than") or lower limit values ​​(values ​​defined in the form of "above" or "more than") of the proportions (including proportions), physical property values, parameters, etc., recorded in the "Specific Embodiments" above.

[0079] Example 1 Process (1): like Figure 3 As shown in Figure A, an aluminum plate is prepared as the metal substrate 2, which is used as the single layer 24. The thickness of the metal substrate 2 is 150 μm.

[0080] like Figure 3 As shown in Figure B, the metal substrate 2 is heated at 550°C for 3 hours in an atmospheric atmosphere, forming oxide layers 23 on one side and the other side of the monomer layer 24 in the thickness direction. The thickness of each of the two oxide layers 23 is less than 100 nm. The Young's modulus of the metal substrate 2 at 25°C is 69 GPa. The thickness T0 of the heated metal substrate 2 is 150 μm.

[0081] Process (2) (Processes (3) to (6)): like Figure 3 As shown in C, a negative dry film resist (manufactured by Asahi Kasei Corporation, "Sunfort AQ") 50 is bonded to one side 21 of the metal substrate 2 by vacuum lamination (110°C, 0.4 MPa). By photolithography, a resist 5 with the same pattern as the second part 212 is formed from the dry film resist 50 (step (3)).

[0082] Anodizing was performed using a 0.5M sodium borate aqueous solution as the electrolytic bath, with a metal substrate 2 coated with resist 5 as the anode and a carbon electrode as the cathode. The electrolytic bath temperature was set to 20°C, and the electrolytic bath was stirred while maintaining a constant current density (2.5 mA / cm²) until the voltage reached 1000V. 2 Anodizing is then performed. After reaching 1000V, the voltage is switched to maintain a constant 1000V for one minute of anodizing. Thus, as... Figure 3 As shown in D, an inorganic insulating part 31 is formed (step (4)).

[0083] The dimensions and Young's modulus of the inorganic insulating part 31 are as follows.

[0084] Thickness T1: 0.9μm Minimum length L1 in the plane direction: 80 μm Young's modulus at 25℃: 360 GPa After that, as Figure 3 As shown in E, NMP is used to peel off (dissolve and remove) resist 5 (step (5)).

[0085] Then, the inorganic insulating part 31 is heated at 300°C for 30 minutes.

[0086] A photosensitive resin composition (negative type, manufactured by Nippon Kayaku Co., Ltd., permanent resist film SU-8) is spin-coated onto one side of the inorganic insulating portion 31 and the second portion 212 to form a 5 μm photosensitive layer 320. Next, the photosensitive layer 320 is heated at 95°C for 4 minutes using a heating plate. Afterward, the elastic insulating portion 32 is formed from the photosensitive layer 320 by photolithography. (Step (6)).

[0087] The dimensions and Young's modulus of the elastic insulating part 32 are as follows.

[0088] The thickness T2 of the elastic insulating part 32 is 5 μm. Thickness T21 of filler 321: 1 μm Thickness T22 of bulge 322: 4μm Width W2 of elastic insulating portion 32 (= Width W22 of bulge 322): 30μm Width W21 of filling portion 321: 20μm The Young's modulus of the elastic insulating part 32 at 25℃ is 2.7 GPa. Explanation of reference numerals in the attached figures 1. Mounting substrate 2 metal substrate 21 One side 3 Insulation layer 31, 31A, 31B Inorganic insulation parts 32. Elastic insulation portion 320 photosensitive layer 4. Wiring layer 5. Corrosion resist It should be noted that the above-described invention is provided as an illustrative embodiment of the present invention, but this is merely illustrative and should not be interpreted as limiting. Modifications of the present invention that will be apparent to those skilled in the art are included in the above claims.

[0089] Industrial availability The mounting substrate and manufacturing method of the present invention can be suitably used in various industrial fields that use wiring circuit boards.

Claims

1. A mounting substrate, which includes: Metal substrate; and An insulating layer is disposed on one side of the metal substrate in the thickness direction. The insulating layer has: A plurality of inorganic insulating portions are disposed on a portion of one side of the metal substrate and spaced apart from each other in a planar direction orthogonal to the thickness direction; and An elastic insulating portion is disposed on the remaining portion of one side of the metal substrate and between adjacent inorganic insulating portions.

2. The mounting substrate as claimed in claim 1, further comprising a wiring layer disposed on one side of the insulating layer in the thickness direction.

3. The mounting substrate as claimed in claim 1, further comprising a wiring layer disposed on the other side of the metal substrate in the thickness direction.

4. A method for manufacturing a mounting substrate, which is the method for manufacturing a mounting substrate as described in claim 1, the method comprising: Step (1), prepare the metal substrate; and Step (2) involves forming an insulating layer on one side of the metal substrate in the thickness direction. The process (2) has the following characteristics: In step (3), a resist is formed on a portion of one side of the metal substrate in the thickness direction; Step (4) involves forming an inorganic insulating portion, spaced apart from each other in a planar direction orthogonal to the thickness direction, on the remaining portion of the side of the metal substrate exposed from the resist, by anodizing; and Step (5) involves removing the resist.

5. The method for manufacturing a mounting substrate as described in claim 4, wherein, The process (2) has the following characteristics: Step (6): After step (5), a photosensitive resin composition is disposed on one side of the inorganic insulating portion and the portion to form a photosensitive layer, and an elastic insulating portion is formed from the photosensitive layer by photolithography.

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