Semiconductor device and method of manufacturing semiconductor device

Abstract

A semiconductor device and a method for manufacturing the semiconductor device are provided. The device enables high-precision alignment of the positions of holes formed in the housing and the metal substrate, respectively. The housing (30) of the semiconductor device (10) includes sidewall portions (32a-32d) that surround the side of the metal substrate (20) along its side surface; and a cover portion (33) that covers the front surface of the metal substrate (20) surrounded by the sidewall portions (32a-32d) and has through-holes (35c, 35d) corresponding to the mounting holes (21a-21d). When viewed from above, protrusions (36a, 36b) are formed on the inner sides of the sidewall portions (32a-32d) facing each other across the annular holes (35c, 35d). Thus, the metal substrate is inserted into the area surrounded by the sidewall portions (32a-32d) of the housing (30) and reliably fixed. Furthermore, the mounting holes of the inserted metal substrate and the annular holes of the housing are aligned with high precision.

Description

Technical Field

[0001] This invention relates to a semiconductor device and a method for manufacturing a semiconductor device. Background Technology

[0002] Semiconductor devices include, for example, semiconductor elements such as IGBTs (Insulated Gate Bipolar Transistors), power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), FWDs (Free Wheeling Diodes), and SBDs (Schottky Barrier Diodes). In this semiconductor device, a substrate on which the IGBT and FWD are bonded is disposed on a metal substrate, and a housing covering the IGBT, etc., is provided on the metal substrate (see, for example, Patent Document 1).

[0003] Furthermore, through holes are formed in both the housing and the metal substrate of the semiconductor device. These holes align and function as fastening holes when the semiconductor device is mounted to external devices, etc. For such fastening holes, misalignment occurs as the metal substrate is mounted to the housing, requiring an effective hole diameter even with slight misalignment between the holes in the housing and the holes in the metal substrate. Therefore, to accommodate misalignment, the diameter of the holes formed in the metal substrate is made relatively large.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-195717 Summary of the Invention

[0007] Technical issues

[0008] However, due to limitations in the external dimensions of the metal substrate and the location of the holes formed on it, the diameter of the holes cannot be made large. Therefore, if such a metal substrate is placed in a housing, the effective diameter of the fastening holes during installation may not be adequately guaranteed.

[0009] The present invention was made in view of this situation, and its object is to provide a semiconductor device and a method for manufacturing the semiconductor device capable of precisely aligning holes formed on a housing and a metal substrate respectively.

[0010] Technical solution

[0011] According to one aspect of the present invention, a semiconductor device is provided, comprising: a flat metal substrate, which is rectangular in shape when viewed from above, and having through mounting holes formed around its periphery; a housing having sidewall portions and a cover portion, wherein the sidewall portions surround the side surfaces of the metal substrate along the side surfaces, the cover portion covers the front surface of the metal substrate surrounded by the sidewall portions, and has through annular holes corresponding to the mounting holes, and protrusions are formed on the inner sides of the sidewall portions opposite to the annular holes when viewed from above.

[0012] In addition, according to one aspect of the present invention, a method for manufacturing the above-described semiconductor device is provided.

[0013] Invention Effects

[0014] According to the disclosed technology, holes formed on the housing and metal substrate respectively can be aligned with high precision, ensuring the effective diameter of the fastening holes during installation. Attached Figure Description

[0015] Figure 1 This is a diagram illustrating a semiconductor device used to explain an implementation method.

[0016] Figure 2 This is a diagram illustrating the metal substrate included in the semiconductor device used to explain the implementation method.

[0017] Figure 3 This is one of the diagrams illustrating the housing included in a semiconductor device for illustrating an embodiment.

[0018] Figure 4 This is Figure (2) illustrating the housing included in the semiconductor device for explaining the implementation method.

[0019] Figure 5 This is a diagram illustrating the semiconductor units included in a semiconductor device for explaining an embodiment.

[0020] Figure 6 This is a diagram illustrating a method for manufacturing a semiconductor device according to an embodiment.

[0021] Figure 7 is a diagram illustrating the insertion of a metal substrate into the housing of a semiconductor device according to an embodiment.

[0022] Figure 8 This is a cross-sectional view of the housing into which the metal substrate is inserted in the embodiment of the semiconductor device.

[0023] Figure 9 This is one of the diagrams illustrating another manufacturing method of a semiconductor device for demonstrating an embodiment.

[0024] Figure 10 This is a diagram (second of two) illustrating another manufacturing method of a semiconductor device for demonstrating an implementation method.

[0025] Figure 11 This is a diagram of the housing included in the semiconductor device of the first modified example.

[0026] Figure 12 This is a diagram of the housing and metal substrate included in the semiconductor device of the second modification.

[0027] Figure 13 This is a diagram used to illustrate the protrusions included in the semiconductor device of the third modified example.

[0028] Symbol Explanation

[0029] 10: Semiconductor devices

[0030] 20, 20a: Metal substrate

[0031] 21a~21f: Mounting holes

[0032] 22a~22d: Side view

[0033] 23a: Front

[0034] 23b: Back

[0035] 24: Collapsed corner face

[0036] 30, 30a: Shell

[0037] 31: Storage Area

[0038] 32a~32d: Side wall portion

[0039] 32a1~32d1: External connection terminals

[0040] 33: Covered part

[0041] 34a~34d: Annular region

[0042] 35a~35f: Annular holes

[0043] 36a~36d: Protrusions

[0044] 36b1: Conical part

[0045] 36b2: Flat part

[0046] 37: Opening

[0047] 38: Housing cover

[0048] 39: Ring

[0049] 40: Semiconductor unit

[0050] 41: Ceramic circuit board

[0051] 42: Insulation board

[0052] 43a~43c: Circuit patterns

[0053] 44: Metal plate

[0054] 45, 46: Semiconductor chips Detailed Implementation

[0055] The following uses, with reference to the attached diagram. Figure 1 The semiconductor device of the embodiment will be described. Figure 1 This is a diagram illustrating a semiconductor device used to explain an embodiment. It should be noted that, in the embodiment, the front side refers to... Figure 1 The semiconductor device 10 faces upwards, while the back side refers to the side facing upwards. Figure 1 The downward-facing surface of the semiconductor device 10. Besides Figure 1 In addition, front and back refer to the same directionality.

[0056] The semiconductor device 10 includes a metal substrate 20, a housing 30 surrounding a semiconductor unit (not shown) disposed on the metal substrate 20, and a housing cover 38 that closes the opening of the housing 30 (not shown). Additionally, the semiconductor device 10 has annular holes 35a and 35d formed at its four corners. It should be noted that... Figure 1 Only annular holes 35a and 35d out of the four annular holes are shown. Screws for fastening cooling fins or external devices are screwed into annular holes 35a and 35d.

[0057] Next, use Figures 2-5 The details of each component of the semiconductor device 10 will be explained. Figure 2 This is a diagram illustrating the metal substrate included in the semiconductor device according to the embodiment. It should be noted that... Figure 2 (A) represents a top view of the front side 23a of the metal substrate 20. Figure 2 (B) indicates Figure 2 The cross-sectional view at the single-dotted line XX in (A). Figure 3 and Figure 4 This is a diagram illustrating the housing included in the semiconductor device according to the embodiment. It should be noted that... Figure 3 (A) indicates the front of the housing 30. Figure 3 (B) indicates the back side of housing 30. Figure 4 (A) Figure 4 (B) respectively represent Figure 3 (A) Figure 3 The cross-sectional view at the dashed lines X1-X1 and X2-X2 in (B). Additionally, Figure 5 This is a diagram illustrating the semiconductor units included in the semiconductor device used to explain the implementation method. It should be noted that... Figure 5(A) represents a top view of semiconductor cell 40. Figure 5 (B) indicates Figure 5 The cross-sectional view at the single-dotted line XX in (A).

[0058] First, such as Figure 2 As shown, the metal substrate 20 is rectangular and flat when viewed from above, and has sides 22a to 22d. Through-holes 21a to 21d are formed around the periphery of the metal substrate 20. It should be noted that the thickness of the sides 22a to 22d of the metal substrate 20 is preferably 1 mm or more and 5 mm or less, for example, 2.8 mm or more and 3.2 mm or less. The diameter of the mounting holes 21a to 21d is 5.2 mm or more and 5.8 mm or less. Furthermore, such a metal substrate 20 is made of a metal with excellent thermal conductivity, such as aluminum, iron, silver, copper, or an alloy containing at least one of these. In addition, to improve the corrosion resistance of the metal substrate 20, metals such as nickel and / or gold can be formed on the surface of the metal substrate 20, for example, through electroplating. Specifically, in addition to nickel and gold, nickel-phosphorus alloys, nickel-boron alloys, etc., are also used. Furthermore, gold can be laminated onto a nickel-phosphorus alloy. Furthermore, such a metal substrate 20 can be obtained by stamping from a metal plate, and mounting holes 21a to 21d are formed at each corner. In addition, the metal substrate 20 can be pre-curved in such a way that the back surface 23b is convex (downward convex).

[0059] like Figure 3 and Figure 4 As shown, the housing 30 includes sidewall portions 32a to 32d and a covering portion 33. As described later, the sidewall portions 32a to 32d are integrally formed with curved surfaces at their corners, corresponding to the side surfaces 22a to 22d of the metal substrate 20. That is, the sidewall portions 32a and 32b correspond to the side surfaces 22a and 22b of the metal substrate 20 along its long side. The sidewall portions 32c and 32d correspond to the side surfaces 22c and 22d of the metal substrate 20 along its short side. The covering portion 33 is formed along the sidewall portions 32a to 32d and is frame-shaped with an opening 37. It should be noted that, as described above, Figure 3 The sidewall portions 32a to 32d of the housing 30 shown are examples of cases where the corners of the sidewall portions 22a to 22d of the metal substrate 20 are curved. However, this is not a limitation; if the corners of the metal substrate 20 are approximately right angles, then the corners of the sidewall portions 32a to 32d of the housing 30 are also approximately right angles. Furthermore, external connection terminals 32a1 to 32d1 extending vertically upwards from the front surface of the semiconductor device 10 can be provided on these sidewall portions 32a to 32d.

[0060] Furthermore, the covered portion 33 has annular hole regions 34a-34d with through-holes 35a-35d. As described later, when the metal substrate 20 is mounted to the housing 30, these annular hole regions 34a-34d support the metal substrate 20 in a way that prevents excessive penetration of the metal substrate 20 into the housing 30. Additionally, at this time, the annular holes 35a-35d formed in the annular hole regions 34a-34d are close to and opposite the mounting holes 21a-21d of the metal substrate 20. Furthermore, the covered portion 33 is integrally formed with external connection terminals electrically connected to the semiconductor chip, as described later, as needed. Additionally, when screws are screwed into the annular holes 35a-35d, metal rings (not shown) can be inserted into these annular holes 35a-35d using screws with a diameter compatible with the inserted ring. Alternatively, screws with a diameter compatible with the annular holes 35a-35d can be used without using rings.

[0061] Furthermore, in the housing 30, protrusions 36a and 36b are formed on the inner sides of the opposing sidewall portions 32a to 32d, which are separated by annular holes 35a to 35d when viewed from above. The sidewall portions 32a to 32d and the protrusions 36a and 36b can be integrally constructed from the same material. For example, protrusions 36a are formed on the sidewall portions 32a and 32b separated by annular holes 35b, and protrusions 36b are formed on the sidewall portions 32c and 32d separated by annular holes 35b. Thus, when viewed from above, the protrusions 36a and 36b separated by annular holes 35a to 35d are formed in parallel regions of the opposing sidewall portions 32a to 32d. Furthermore, when the distance L1 between the opposing sidewall portions 32c and 32d and the distance L2 between the opposing protrusions 36b are, (L1-L2) / 2 is preferably in the range of 0.05 mm or more and 0.5 mm or less. More preferably, it is in the range of 0.15 mm or more and 0.3 mm or less. Additionally, (L1-L2) / 2 can be more than 1 / 20 and less than 1 / 10 of the thickness of the sides 22a to 22d of the metal substrate 20. This also applies to the opposing sidewall portions 32a and 32b and the opposing protrusions 36a.

[0062] Such a shell 30 is made of, for example, a thermoplastic resin, with the sidewalls 32a to 32d and the covering portion 33 integrally formed. Examples of such resins include polyphenylene sulfide (PPS), polybutylene terephthalate (PBT) resin, polybutylene succinate (PBS) resin, polyamide (PA) resin, or acrylonitrile butadiene styrene (ABS) resin.

[0063] Next, as Figure 5As shown, the semiconductor unit 40 includes a ceramic circuit board 41 and semiconductor chips 45 and 46 disposed on the ceramic circuit board 41. The ceramic circuit board 41 has an insulating plate 42, a metal plate 44 formed on the back side of the insulating plate 42, and circuit patterns 43a to 43c formed on the front side of the insulating plate 42. It should be noted that the shape and number of circuit patterns 43a to 43c are just examples. The insulating plate 42 is made of a ceramic with high thermal conductivity, such as alumina, aluminum nitride, or silicon nitride. The metal plate 44 is made of a metal with high thermal conductivity, such as aluminum, iron, silver, copper, or an alloy containing at least one of these. The circuit patterns 43a to 43c are made of a metal with high electrical conductivity, such as copper or copper alloy. As a ceramic circuit board 41 having such a configuration, for example, a DCB (Direct Copper Bonding) substrate or an AMB (Active Metal Brazed) substrate can be used. The ceramic circuit board 41 can conduct the heat generated by the semiconductor chips 45 and 46 through the circuit patterns 43a and 43b, the insulating plate 42, and the metal plate 44 to the circuit substrate. Figure 5 Heat dissipation is carried out on the lower middle side. It should be noted that the thickness of the circuit patterns 43a to 43c is preferably 0.1 mm or more and 1 mm or less, more preferably 0.2 mm or more and 0.5 mm or less.

[0064] Semiconductor chip 45 includes switching elements such as IGBTs and power MOSFETs. Such a semiconductor chip 45 has, for example, an input electrode (drain or collector electrode) serving as the main electrode on its back side, and a control electrode (gate electrode) and an output electrode (source or emitter electrode) serving as the main electrode on its front side. The back side of the semiconductor chip 45 is bonded to circuit patterns 43a and 43b by solder (not shown). Semiconductor chip 46 includes diodes such as SBDs and FWDs. Such a semiconductor chip 46 has an output electrode (cathode electrode) serving as the main electrode on its back side, and an input electrode (anode electrode) serving as the main electrode on its front side. The back side of the semiconductor chip 46 is bonded to circuit patterns 43a and 43b by solder (not shown).

[0065] Next, use Figures 6-8 The manufacturing method of such a semiconductor device 10 will be described. Figure 6 Figure 7 is a diagram illustrating the manufacturing method of the semiconductor device according to the embodiment. Figure 7 is a diagram illustrating the insertion of a metal substrate into the housing of the semiconductor device according to the embodiment. It should be noted that Figure 7(A) is a cross-sectional view at the dashed line XX in Figure 7(B), and Figure 7(B) is a top view of the back side of the semiconductor device 10. Figure 8 This is a cross-sectional view of the housing into which the metal substrate is inserted in the semiconductor device of the embodiment. It should be noted that... Figure 8This is an enlarged view of the area enclosed by the dashed line in Figure 7(A).

[0066] First, components of the semiconductor device 10, such as the metal substrate 20, housing 30, and semiconductor units 40, are prepared (step S1). Next, the semiconductor units 40 are bonded to a predetermined area on the front side 23a of the metal substrate 20 using solder (not shown) (step S2). At this time, a required number of semiconductor units 40 are bonded. Next, an adhesive is applied to at least one of the back side of the sidewall portions 32a to 32d of the housing 30 and the outer periphery of the metal substrate 20 to which the semiconductor units 40 are bonded (step S3).

[0067] Next, as shown in FIG. 7, the metal substrate 20 is inserted into the receiving area 31 covered by the sidewall portions 32a to 32d of the housing 30 (step S4). In FIG. 7 at this time, the semiconductor unit 40 bonded to the metal substrate 20 is omitted. It should be noted that the metal substrate 20 can be pressed into the receiving area 31 of the housing 30. For example, as... Figure 3 As shown, in the housing 30, the distance L1 between the sidewall portions 32c and 32d is longer than the distance L2 between the protrusions 36b. At this time, the length L3 of the metal substrate 20 in the long side direction before pressing is set to be shorter than distance L1 and longer than distance L2 (distance L1 > length L3 > distance L2). The distance L1 - distance L2 is preferably greater than 0 mm and less than 0.6 mm, more preferably greater than 0 mm and less than 0.3 mm. Furthermore, the distance L1 - length L3 is preferably greater than 0 mm and less than 0.6 mm, more preferably greater than 0 mm and less than 0.3 mm. Additionally, the length L3 - distance L2 is preferably greater than 0 mm and less than 0.6 mm, more preferably greater than 0 mm and less than 0.3 mm. It should be noted that although the figures are omitted, the length of the metal substrate 20 in the short side direction is also the same as the length of the metal substrate 20 relative to the housing 30. The sides 22a-22d of the metal substrate 20, which are pressed into the housing 30, are held reliably and with high positional accuracy by protrusions 36a and 36b formed on the sidewall portions 32a-32d of the housing 30. That is, a gap is provided between the sides 22a-22d of the metal substrate 20 and the sidewall portions 32a-32d of the housing 30. By allowing an adhesive (not shown) to enter this gap, sufficient adhesive thickness for reliably bonding the metal substrate 20 to the housing 30 can be ensured.

[0068] Furthermore, the metal substrate 20 may not need to be pressed into the storage area 31 of the housing 30; it can simply be fitted into the storage area 31 via protrusions 36a and 36b. For example... Figure 3As explained, the distance L1 between the sidewall portions 32c and 32d in the housing 30 is longer than the distance L2 between the protrusions 36b. In this case, without pressing in, the length L3 of the metal substrate 20 in the long side direction is naturally shorter than the distance L1, and is also set to be the same as or shorter than the distance L2 (distance L1 > distance L2 ≥ length L3). The distance L1 - distance L2 is preferably greater than 0 mm and less than 0.6 mm, more preferably greater than 0 mm and less than 0.3 mm. Furthermore, the distance L2 - length L3 is preferably more than 0 mm and less than 0.6 mm, more preferably more than 0 mm and less than 0.3 mm. It should be noted that although the figures are omitted, the length of the metal substrate 20 in the short side direction is also the same as the length of the metal substrate 20 relative to the housing 30. The sides 22a-22d of the metal substrate 20, which are thus inserted into the housing 30, are supported at points with good positional accuracy by protrusions 36a and 36b formed on the sidewall portions 32a-32d of the housing 30. That is, a gap is provided between the sides 22a-22d of the metal substrate 20 and the sidewall portions 32a-32d of the housing 30. By allowing an adhesive (not shown) to enter this gap, sufficient adhesive thickness for reliably bonding the metal substrate 20 to the housing 30 can be ensured.

[0069] Furthermore, the annular hole regions 34a to 34d (shown as annular hole regions 34c and 34d in FIG. 7) of the covering portion 33 of the housing 30 maintain the position of the inserted metal substrate 20 relative to the depth direction of the receiving region 31 of the housing 30. Also, the annular holes 35a to 35d formed in the annular hole regions 34a to 34d (shown as annular holes 35c and 35d in FIG. 7) are brought close to the mounting holes 21a to 21d (shown as mounting holes 21c and 21d in FIG. 7) of the metal substrate 20.

[0070] Example of mounting hole 21d and annular hole 35d and its use Figure 8 The mounting holes 21a-21d of the metal substrate 20 and the annular holes 35a-35d of the housing 30 will be described in detail below. The same applies to the other mounting holes 21a-21c and annular holes 35a-35c. It should be noted that the holes formed on the metal substrate 20 are shown in detail below. Figure 8The case shown is where a metal ring 39 with a diameter W2 (< diameter W1) is inserted into the annular hole 35d of the housing 30 with a diameter W1. As described above, the metal substrate 20 is inserted into the receiving region 31 of the housing 30. At this time, the protrusion 36b forms a tapered portion 36b1 on the back side of the semiconductor device 10, and a flat portion 36b2 that continues to be flat from the tapered portion 36b1 is formed on the receiving region 31 side. Therefore, the metal substrate 20 is easily inserted into the receiving region 31 through the tapered portion 36b1 of the protrusion 36b, and is pressed parallel to the main surface direction of the metal substrate 20 by the flat portion 36b2. At this time, the gap G between the side surface 22c of the metal substrate 20 and the side wall portion 32c of the housing 30 can be in the range of 0.05 mm or more and 0.9 mm or less. Preferably, it is in the range of 0.05 mm or more and 0.5 mm or less. More preferably, it is in the range of 0.15 mm or more and 0.3 mm or less. It should be noted that the longitudinal height H1 of the protrusion 36b is preferably 0.8 mm or more and 4.5 mm or less, for example, 1.8 mm or more and 2 mm or less, and the longitudinal height H2 of the flat portion 36b2 of the protrusion 36b is preferably 0.5 mm or more and 2.5 mm or less, for example, 0.9 mm or more and 1.1 mm or less. Furthermore, the thickness T of the metal substrate 20, as described above, is preferably 1 mm or more and 5 mm or less, for example, 2.8 mm or more and 3.2 mm or less. Thus, the metal substrate 20 is inserted into the receiving area 31 of the housing 30 and reliably fixed. It should be noted that at this time, the metal substrate 20 is inserted with the collapsed corner surface 24 becoming the back side 23b. By making the opposite side of the collapsed corner surface 24 of the metal substrate 20 the front side 23a, the side surface 22c of the metal substrate 20 is reliably fixed to the protrusion 36b, and its front side 23a reliably abuts against the annular hole area 34d. Furthermore, the mounting hole 21d of the metal substrate 20 with a diameter W3 is aligned with the annular hole 35d of the housing 30. Therefore, even when the diameter W3 of the mounting hole 21d on the metal substrate 20 cannot be made large due to constraints on the external dimensions of the metal substrate 20 and the formation position of the mounting hole 21d, the mounting hole 21d can still be appropriately aligned with the annular hole 35d of the housing 30. This ensures the effective aperture as a target. It should be noted that the effective aperture at this time refers to diameters W2 and W3. It should be noted that misalignment between the mounting hole 21d and the annular hole 35d is permissible as long as the range of the target effective aperture is obtained. For example, in... Figure 8 When the diameters W2 and W3 are 5.5mm, the effective aperture is obtained if the diameters W2 and W3 are within the range of 5.5mm ± 0.3mm.

[0071] Furthermore, in the semiconductor device 10, protrusions 36a are formed at parallel positions on the sidewall portions 32a and 32b, which are opposite each other across the annular hole 35d when viewed from above. Similarly, protrusions 36b are formed at parallel positions on the sidewall portions 32c and 32d, which are opposite each other across the annular hole 35d. This ensures that even if the metal substrate 20 warps and / or undulates, the mounting hole 21d of the metal substrate 20 can be precisely aligned with the annular hole 35d of the housing 30. However, the annular hole 35d and mounting hole 21d of the semiconductor device 10, with the metal substrate 20 inserted in this way, are screwed into and fixed to an external device, and generate heat as the semiconductor unit 40 is driven. This heat causes warping due to the difference in thermal expansion coefficients between the metal substrate 20 and the semiconductor unit 40. In particular, since the annular hole 35d and mounting hole 21d of the semiconductor device 10 are fixed with screws, stress concentrates around the periphery of the annular hole 35d and mounting hole 21d. Therefore, in the semiconductor device 10, protrusions 36a are formed at parallel positions on the sidewall portions 32a and 32b that are opposite each other and separated by annular holes 35d when viewed from above. Furthermore, protrusions 36b are formed at parallel positions on the sidewall portions 32c and 32d that are opposite each other and separated by annular holes 35d. This allows the metal substrate 20, which is inserted through these protrusions 36a and 36b, to be reliably fixed.

[0072] Next, within one semiconductor unit 40 on the metal substrate 20, multiple semiconductor units 40 are electrically connected together using wires (not shown) (step S5). Such wires are made of metals with excellent conductivity, such as aluminum or copper, or alloys containing at least one of these. Furthermore, their diameter is preferably 100 μm or more and 1 mm or less. Next, a sealing member (not shown) is injected through the opening 37 of the housing 30 to seal the semiconductor units 40, wires, etc., within the housing 30 (step S6). This sealing member is made of silicone, epoxy resin, etc. After such sealing, the opening 37 of the housing 30 is covered with a housing cover 38. Alternatively, the housing cover 38 can be omitted, and the sealing member can be sealed to the opening 37 of the housing 30, allowing the sealing member to be exposed from the opening 37 and cured. A semiconductor device 10 can also be obtained using this method.

[0073] Furthermore, the manufacturing method of the semiconductor device 10 described above is just one example. Using Figure 9 and Figure 10 Another method for manufacturing the semiconductor device 10 other than that described above will be described. Figure 9 and Figure 10 This is a diagram illustrating another manufacturing method of the semiconductor device according to the embodiment. It should be noted that, in Figure 9 and Figure 10 In the middle, to and Figure 6 The same process is labeled with the same step number, and detailed descriptions are omitted. Firstly, as... Figure 9 As shown, steps S3, S4, and S6 can be performed after the wire connection process in step S5, following steps S1 and S2. Alternatively, as... Figure 10 As shown, the wire connection process in step S5 is performed after steps S1 and S2. In step S5, within one semiconductor cell 40 on the metal substrate 20, wire connections are made only between a portion of the multiple semiconductor cells 40. Then, step S5 is performed again after steps S3 and S4. In this step S5, wire connections are made at the remaining locations other than those made in the first step, and finally, step S6 is performed. A semiconductor device 10 can also be obtained using this method. Here, a method of electrical connection using wires (not shown) is shown. Within one semiconductor cell 40 on the metal substrate 20, the electrical connection between multiple semiconductor cells 40 is not limited to wires; conductive wiring components such as strips or lead frames can be used.

[0074] The semiconductor device 10 described above is rectangular in shape when viewed from above, and includes a flat metal substrate 20 with through mounting holes 21a-21d formed around its periphery and a housing 30. The housing 30 includes sidewall portions 32a-32d that surround the side surfaces 22a-22d of the metal substrate 20; and a covering portion 33 that covers the front surface 23a of the metal substrate 20 surrounded by the sidewall portions 32a-32d, and has through annular holes 35a-35d formed corresponding to the mounting holes 21a-21d. In this semiconductor device 10, protrusions 36a and 36b are formed on the inner sides of the sidewall portions 32a-32d that face each other across the annular holes 35a-35d when viewed from above. This allows the metal substrate 20 to be reliably fixed by being inserted into the area surrounded by the sidewall portions 32a-32d of the housing 30. Furthermore, the mounting holes 21a to 21d of the inserted metal substrate 20 are precisely aligned with the annular holes 35a to 35d of the housing 30. It should be noted that the semiconductor device 10 described above will be illustrated by example of bonding the semiconductor unit 40 to the metal substrate 20 using solder. Alternatively, instead of the semiconductor unit 40, an insulating plate and a circuit pattern can be sequentially formed on the metal substrate 20, and a semiconductor chip can be bonded to the circuit pattern.

[0075] In such a semiconductor device 10, by varying the formation position and shape of the protrusions, the same or better effects as described above can be obtained. Hereinafter, a variation of such a semiconductor device 10 will be described.

[0076] (First variation)

[0077] In the first variation, using Figure 11The case in which protrusions 36c and 36d are also formed between the protrusions 36a and 36b of the side wall portions 32a to 32d of the housing 30 of the semiconductor device 10 will be described. Figure 11 This is a diagram of the housing included in the semiconductor device of the first modification. It should be noted that... Figure 11 The back side of the housing 30 is shown. Protrusions 36c and 36d, formed approximately at the center between protrusions 36a and 36b on the sidewalls 32a-32d of the housing 30, support the central portions of the sides 22a-22d of the inserted metal substrate 20. Therefore, even if the metal substrate 20 warps and / or undulates, the mounting hole 21d of the metal substrate 20 can be precisely aligned with the annular hole 35d of the housing 30. Furthermore, even if the central portions of the front side 23a and back side 23b of the metal substrate 20 warp significantly upwards or downwards due to heat generated by the driving of the semiconductor unit 40, the protrusions 36c and 36d can be used to fix the metal substrate 20.

[0078] (Second variation)

[0079] In the second variation, using Figure 12 The case where mounting holes and annular holes are provided in two locations in the semiconductor device 10 according to specifications, design, etc. will be explained. Figure 12 This is a diagram of the housing and metal substrate included in the semiconductor device of the second modification. It should be noted that... Figure 12 (A) indicates the back side of the casing 30a. Figure 12 (B) indicates the front side 23a of the metal substrate 20a. In the second variation, near the center of the sidewall portions 32c and 32d of the covering portion 33 of the housing 30a, annular holes 35e and 35f are formed opposite each other, separated by an opening 37. On the other hand, mounting holes 21e and 21f are also formed on the metal substrate 20a corresponding to the annular holes 35e and 35f of the housing 30a. At this time, when the housing 30a is viewed from above, protrusions 36a and 36b are formed at parallel positions on the inner sides of the sidewall portions 32a to 32d, which are opposite each other, separated by the annular holes 35e and 35f. For example, protrusions 36a are formed on the sidewall portions 32a and 32b, which are separated by the annular hole 35e. Protrusions 36b are formed opposite each other on the sidewall portions 32c and 32d, which are separated by the annular hole 35e. Thus, the protrusions 36a and 36b are formed in a region parallel to the sidewall portions 32a to 32d, which are opposite each other and separated by annular holes 35e and 35f when viewed from above. Furthermore, in the second modified example, with... Figure 3Similarly, when the distance L1 between the opposing sidewall portions 32c and 32d and the distance L2 between the opposing protrusions 36b are the same, (L1-L2) / 2 is preferably in the range of 0.05 mm or more and 0.5 mm or less. More preferably, it is in the range of 0.15 mm or more and 0.3 mm or less. In addition, (L1-L2) / 2 can be more than 1 / 20 and less than 1 / 10 of the thickness of the sidewalls 22a to 22d of the metal substrate 20. In addition, this also applies to the opposing sidewall portions 32a and 32b and the opposing protrusions 36a. Furthermore, in the second modification, similar to the first modification, protrusions 36c can be formed between the protrusions 36a of the sidewall portions 32a and 32b of the housing 30a. Therefore, even if the metal substrate 20a warps and / or undulates, the mounting holes 21e and 21f of the metal substrate 20a can be precisely aligned with the annular holes 35e and 35f of the housing 30a. Furthermore, even if the metal substrate 20a warps significantly upwards or downwards due to heat generated by the driving of the semiconductor unit 40, the protrusion 36c can be used to fix the metal substrate 20a.

[0080] (3rd variation)

[0081] In the third variation, using Figure 13 Examples of the shapes of protrusions are given. Figure 13 This diagram illustrates the protrusions included in the semiconductor device of the third modification example. It should be noted that... Figure 13 For example, Figure 8 A cross-sectional view at the point indicated by the dashed line XX. Such a... Figure 13 The protrusion 36b shown in (A) is semi-circular in shape, and the side of the metal substrate 20 that abuts is curved. Additionally, Figure 13 The protrusion 36b shown in (B) is pyramidal in shape, and the apex of the side of the metal substrate 20 that abuts is curved. With such a protrusion 36b, the metal substrate 20 can easily enter the receiving area 31, and the curved surface of the protrusion 36b supports the side surface 22c of the metal substrate 20 at a point. Furthermore, the metal substrate 20 is pressed parallel to its main surface direction. In this way, the metal substrate 20 is inserted into the receiving area 31 of the housing 30 and reliably fixed with good positional accuracy. It should be noted that... Figure 13 Regarding the shape of the protrusion 36b shown, the protrusions 36a, 36c, and 36d can also adopt the same shape, and are not limited to the side wall portion 32c of the housing 30. The side wall portions 32a, 32b, and 32d of the housing 30 are also formed in the same way.

Claims

1. A semiconductor device, characterized in that, have: A flat metal substrate, rectangular in shape when viewed from above, with through mounting holes formed around its perimeter; and The housing includes a sidewall portion and a cover portion. The sidewall portion surrounds the side of the metal substrate, and the cover portion covers the front surface of the metal substrate surrounded by the sidewall portion, and forms a through annular hole corresponding to the mounting hole. When viewed from above, protrusions are formed on the inner sides of the opposing sidewall portions separated by the annular holes. The protrusions abut against the side surfaces of the metal substrate. When viewed from above, the protrusions are formed on the opposing sidewall portions separated by the annular holes and are directly opposite each other.

2. The semiconductor device according to claim 1, characterized in that, The side surface of the metal substrate has a gap between the side surface and the side wall portion.

3. The semiconductor device according to claim 2, characterized in that, The gap between the side surface and the sidewall portion of the metal substrate is 0.05 mm or more and 0.9 mm or less.

4. The semiconductor device according to claim 2, characterized in that, The first distance between the opposing sidewall portions of the housing having opposing protrusions is longer than the second distance between the opposing protrusions of the housing, and the value obtained by subtracting the second distance from the first distance is greater than 0 mm and less than 0.6 mm.

5. The semiconductor device according to claim 4, characterized in that, The second distance between the opposing protrusions of the housing is equal to or longer than the length between the side of the metal substrate supported by the protrusions.

6. The semiconductor device according to claim 5, characterized in that, The value obtained by subtracting the length from the second distance is 0 mm or less, or less than 0.3 mm.

7. The semiconductor device according to any one of claims 1 to 6, characterized in that, The protrusion has a cone-shaped portion formed on the opening side of the sidewall portion.

8. The semiconductor device according to claim 1, characterized in that, A chamfered surface is formed on the periphery of the back side of the metal substrate.

9. The semiconductor device according to claim 1, characterized in that, The mounting holes are respectively formed at the four corners of the metal substrate. The annular hole and the mounting hole are respectively formed on the covered portion.

10. The semiconductor device according to claim 1, characterized in that, The protrusions are also formed in the central portion of the sidewall portion.

11. The semiconductor device according to claim 1, characterized in that, The mounting holes are respectively formed at the center of opposite sides of the metal substrate. The annular hole and the mounting hole are respectively formed on the covered portion.

12. The semiconductor device according to claim 11, characterized in that, The protrusions are also formed on the sidewall portion in a direction perpendicular to the direction in which the annular hole is clamped.

13. The semiconductor device according to claim 1, characterized in that, The protrusion is semi-circular or spire-shaped in a cross-sectional view parallel to the main surface direction of the metal substrate, and the side that abuts against the metal substrate is curved.

14. The semiconductor device according to claim 2 or 3, characterized in that, The side of the metal substrate is tightly attached to the side wall of the housing by an adhesive disposed in the gap.

15. A method for manufacturing a semiconductor device, characterized in that, include: A process for preparing a flat metal substrate and a housing, wherein the flat metal substrate is rectangular in shape when viewed from above and has through mounting holes formed around its perimeter; the housing has sidewalls surrounding a storage area and a cover portion covering the storage area and having through an annular hole formed therein; and protrusions are formed on the inner sides of the sidewalls opposite each other across the annular hole when viewed from above; and In the insertion process, the metal substrate is inserted into the receiving area, and the protrusions support the sides of the metal substrate. After the insertion process, the protrusion abuts against the side of the metal substrate. When viewed from above, the protrusion is formed on the opposite sidewall portion through the annular hole and is directly opposite to each other.

16. The method for manufacturing a semiconductor device according to claim 15, characterized in that, A gap is provided between the side surface and the side wall portion after the insertion process.

17. The method for manufacturing a semiconductor device according to claim 15, characterized in that, During the insertion process, the metal substrate is pressed into the receiving area, and the side of the metal substrate is held by at least a pair of opposing protrusions of the housing.

18. The method for manufacturing a semiconductor device according to claim 17, characterized in that, In the process of preparing the metal substrate and the housing, the length between the side surfaces of the metal substrate supported by the opposing protrusions is shorter than the first distance between the opposing sidewall portions having the opposing protrusions, and longer than the second distance between the opposing protrusions.

19. The method for manufacturing a semiconductor device according to claim 18, characterized in that, The value obtained by subtracting the second distance from the length is greater than 0 mm and less than 0.3 mm.

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