SEMICONDUCTOR DEVICE

Abstract

Semiconductor device comprising: a base plate (1, 1A); a heat dissipation component (13, 13A) arranged on a lower surface of the base plate (1, 1A); and a rectangular resin housing (2, 2A, 2B, 2C) in plan view, which is arranged on an upper surface of the base plate (1, 1A) and houses a semiconductor element, wherein in a state in which the resin housing (2, 2A, 2B, 2C) is arranged on the heat dissipation component (13) via the base plate (1, 1A), the resin housing (2, 2A, 2B, 2C) is attached to the heat dissipation component (13) with a screw (10), the resin housing (2, 2A, 2B, 2C) has a recessed part area (3) formed at its corner, in which a head of the screw (10) is placed, a fastening hole (4) formed below the recessed part area (3), into which a shaft part area of ​​the screw (10) is inserted, and at least one groove (6, 6a, 6b) formed between a wall part area (5) on an inner circumferential side, which forms the recessed part area (3), and the fastening hole (4), wherein which at least one groove (6, 6a, 6b) is arc-shaped in plan view, an end of at least one groove (6, 6a, 6b) reaches an outer circumferential end of the resin housing (2, 2A, 2B, 2C), and The contours of the base plate (1), the resin housing (2, 2A, 2B, 2C) and the heat dissipation component (13) are the same in top view. the semiconductor device further features: a hole (12) which is formed in the base plate (1) and is connected to the mounting hole (4).

Description

BACKGROUND OF THE INVENTION Area of ​​the invention

[0001] The present disclosure relates to a semiconductor device comprising a resin housing containing a semiconductor element and a heat dissipation component to which the resin housing is fixed. Description of the background technology

[0002] The resin housing containing the semiconductor element is fixed to the heat dissipation component, such as a heat sink, with the rear surface of the base plate being in contact with the heat dissipation component, thereby efficiently dissipating the heat generated in the semiconductor element to the outside through the base plate and the heat dissipation component.

[0003] There was a problem that if excessive stress was applied to the resin housing during the tightening of the screws to fix the resin housing to the heat dissipation component, cracks would form around the mounting holes of the resin housing.

[0004] To solve such a problem, JP 2019-161129A, for example, discloses a configuration in which a protrusion is provided around a through-hole (corresponding to a mounting hole) of a screw base in a resin housing. When the resin housing is screwed onto the heat dissipation component, an excessive increase in bending stress is suppressed by the screwing of the component into the heat dissipation component while the protrusion is compressed. As a result, cracks are prevented from forming around the mounting holes of the resin housing.

[0005] JP H09-139 463 A discloses a main housing and annular metal fitting of an IGBT module, which are formed in one piece by insert molding. The upper end of a lower annular part of the annular metal fitting protrudes from the rear of a screw hole so that it can be in contact with a radiation plate.

[0006] JP H09-45 852 A discloses a resin-sealed semiconductor device having a structure in which power semiconductor elements and an integrated control circuit element, mounted on a metal substrate and interconnected by fine metal wires, are surrounded by a resin. Notched sections are formed as deformable areas in each mounting part of a housing.

[0007] US 4 887 149 A discloses a housing for semiconductor devices that is provided with an encapsulated metallic heat sink, wherein an encapsulating resin body extends beyond the circumference of the heat sink to form two lateral extensions that are diametrically opposed with respect to a central section of the body and are elastically decoupled from such a central section of the resin body by means of at least one thinned zone of the resin body. SUMMARY

[0008] However, in the technique described in JP 2019-161129A, stress relief is insufficient because the resin housing is only deformed by the height of the protrusion. Therefore, stress can concentrate around the mounting hole of the resin housing and may cause it to break.

[0009] One objective of the present disclosure is to provide a technique capable of relieving the stress that is exerted during the fixing of the resin housing containing the semiconductor element to the heat dissipation component with a screw around the mounting hole of the resin housing.

[0010] This problem is solved by the features of the independent claim. The dependent claim describes an advantageous embodiment of the invention.

[0011] A semiconductor device according to one aspect of the present disclosure comprises a base plate, a heat dissipation component, and a resin housing, all rectangular in plan view. The heat dissipation component is arranged on the lower surface of the base plate. The resin housing is arranged on the upper surface of the base plate and contains a semiconductor element. In a state where the resin housing is positioned over the base plate on top of the heat dissipation component, the resin housing is attached to the heat dissipation component by a screw. The resin housing has a recessed portion, a mounting hole, and at least one groove. The recessed portion is formed at one corner, and the screw head is placed therein. Below the recessed portion is the mounting hole, into which the shank portion of the screw is inserted.At least one groove is formed between a section of the wall on the inner circumferential side, which forms the recess, and the mounting hole. One end of the at least one groove reaches an outer circumferential end of the resin housing.

[0012] The configuration allows the corners of the resin housing containing the semiconductor element to bend downwards from at least one groove of the resin housing as a starting point when the resin housing is fixed to the heat dissipation component with the screws, thus ensuring the relief of the stress acting around the mounting holes of the resin housing.

[0013] These and other tasks, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when it is carried out in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a top view illustrating a state before a resin housing and a base plate contained in a semiconductor device according to embodiment 1 are attached to a heat dissipation component; Fig. 2 is a cross-sectional view taken along a line AA from Fig. 1; Fig. Figure 3 is a cross-sectional view illustrating the semiconductor device according to embodiment 1; Fig. Figure 4 is a top view illustrating a state before a resin housing and base plate contained in a semiconductor device according to a modification of embodiment 1 are attached to a heat dissipation component; Fig. Figure 5 is a cross-sectional view taken along a line BB from Fig. 4; Fig. Figure 6 is a top view illustrating a state before a resin housing and base plate contained in a semiconductor device according to Comparative Example 1 are attached to a heat dissipation component; Fig. 7 is a cross-sectional view taken along a line CC on Fig. 6; Fig. Figure 8 is a cross-sectional view illustrating the semiconductor device according to comparative example 1; Fig. 9A and Fig. 9B are enlarged cross-sectional views around a groove before and after a screw fastening; Fig. Figure 10 is a top view illustrating a state before a resin housing and base plate contained in a semiconductor device according to Comparative Example 2 are attached to a heat dissipation component; Fig. Figure 11 is a cross-sectional view taken along a line DD from Fig. 10; Fig. Figure 12 is a cross-sectional view illustrating the semiconductor device according to comparative example 2; Fig. 13A and Fig. 13B are enlarged cross-sectional views around a groove before and after a screw fastening; Fig. Figure 14 is a top view illustrating a state before a resin housing and base plate, contained in a semiconductor device according to Comparative Example 3, are attached to a heat dissipation component; and Fig. Figure 15 is a cross-sectional view taken along a line EE from Fig. 14. DESCRIPTION OF PREFERRED EXECUTION FORMS AND COMPARISON EXAMPLES<Ausführungsform 1>

[0014] With reference to the drawings, embodiment 1 is described. Fig. Figure 1 is a top view illustrating a state before a resin housing 2 and a base plate 1, which are contained in a semiconductor device 100 according to embodiment 1, are attached to a heat dissipation component 13. Fig. 2 is a cross-sectional view taken along a line AA from Fig. 1. Fig. Figure 3 is a cross-sectional view illustrating the semiconductor device 100.

[0015] As in Fig. 1, Fig. 2 to Fig. As illustrated in Figure 3, the semiconductor device 100 comprises the base plate 1, the resin housing 2 and the heat dissipation component 13.

[0016] The base plate 1 is a rectangular metal plate in plan view. The heat dissipation component 13 is a metal heat sink arranged on the lower surface of the base plate 1. The heat dissipation component 13 has a rectangular shape in plan view and is designed as a thick plate.

[0017] The resin housing 2 is arranged on the upper surface of the base plate 1 and contains a semiconductor element. Specifically, an insulating substrate with a circuit structure is arranged on the upper surface of the base plate 1, the semiconductor element is mounted on the upper surface of the circuit structure, and these mounted components are sealed with a sealing material such as epoxy resin to form the resin housing 2, which has a rectangular shape in plan view. Conductor traces or wire connections are formed between the semiconductor element and the circuit structure, and between the circuit structure and terminal electrodes 11, which are provided on the upper surface of the resin housing 2.

[0018] In a state in which the resin housing 2 is arranged on the heat dissipation component 13 via the base plate 1, the resin housing 2 is attached to the heat dissipation component 13 with screws 10.

[0019] Next, details of resin housing 2 will be described. As in Fig. 1, Fig. 2 to Fig. As illustrated in Figure 3, the resin housing 2 has recessed sections 3, mounting holes 4, and grooves 6. The recessed sections 3 are formed at four corners of the resin housing 2, and the heads of the screws 10 are placed in the recessed sections 3. Specifically, the recessed sections 3 are formed by recessing the four corners of the resin housing 2, and each section has a shape defined by a wall section 5 on the inner perimeter and a bottom section 5a adjoining the lower end of the wall section 5. In plan view, the wall section 5 has an arc shape.

[0020] The mounting hole 4 is formed below the central portion of the recess portion 3 such that it communicates with the recess portion 3, and the shank portion of the screw 10 is inserted therein. In embodiment 1, the contours of the base plate 1, the resin housing 2, and the heat dissipation component 13 are identical in plan view; therefore, holes 12 communicating with the mounting holes 4 are formed at the four corners of the base plate 1; and (not illustrated) holes communicating with the holes 12 are formed at the four corners of the heat dissipation component 13. Accordingly, the resin housing 2 is attached to the heat dissipation component 13 via the base plate 1 by the screws 10.

[0021] The groove 6 is formed on the upper surface side of the resin housing 2, specifically in the area between the wall section 5 and the mounting hole 4. In plan view, the groove 6 runs along the wall section 5 on the bottom section 5a in an arc shape, with both ends of the groove 6 reaching the outer circumferential end of the resin housing 2. The groove 6 is either circular or square, extending from the upper surface to the lower surface of the resin housing 2. The widening of the groove 6 allows the corners of the resin housing 2 to bend downwards from the groove 6 when the resin housing 2 is fastened to the heat dissipation component 13 with the screws 10, thus relieving the stress around the mounting holes 4.In accordance with the effect of the bending moment, the stress is further reduced by shortening the distance between the fixing point of the screw 10, which is the force point, and the groove 6, which is the pivot point.

[0022] Although it has been described that both ends of the groove 6 reach the outer circumferential part of the resin housing 2, the groove 6 is also widened when the resin housing 2 is fixed to the heat dissipation component 13 with the screws 10, if at least the end of the groove 6 reaches the outer peripheral part of the resin housing 2, and this allows the corner of the resin housing 2 to bend downwards from the groove 6 as the starting point.

[0023] Furthermore, the groove 6 can be formed on the side of the lower surface of the resin housing 2, that is, in the area between the wall section 5 and the mounting hole 4 on the lower surface of the resin housing 2, extending from the lower surface of the resin housing 2 towards the upper surface. Accordingly, a narrowing of the grooves 6 allows the corners of the resin housing 2 to bend downwards from the grooves 6 as a starting point when the resin housing 2 is fixed to the heat dissipation component 13 with the screws 10, thus relieving the stress around the mounting holes 4. The groove 6 can also be formed on both the upper and lower surfaces of the resin housing 2.

[0024] As in Fig. 4 and Fig. As illustrated in Figure 5, two grooves 6 can also be formed on the upper surface side of each of the four corners of the resin housing 2. Two grooves 6 can also be formed on the lower surface side of each of the four corners of the resin housing 2, or they can be formed on both the upper and lower surface sides of each of the four corners of the resin housing 2. Compared to a case where one groove 6 is formed in each corner of the resin housing 2, the corners of the resin housing 2 consequently bend much more easily. Fig. Figure 4 is a top view illustrating a state before the resin housing 2 and the base plate 1, which are contained in a semiconductor device according to a modification of embodiment 1, are attached to a heat dissipation component 13. Fig. Figure 5 is a cross-sectional view taken along a line BB from Fig. 4.

[0025] As described above, the semiconductor device 100 according to embodiment 1 comprises the base plate 1, the heat dissipation component 13 arranged on the lower surface of the base plate 1, and the resin housing 2, having a rectangular shape in plan view, arranged on the upper surface of the base plate 1 and housing the semiconductor element, wherein, in a state in which the resin housing 2 is arranged over the base plate 1 on the heat dissipation component 13, the resin housing 2 is attached to the heat dissipation component 13 by the screws 10, the resin housing 2 includes the recess part region 3 in which the head of the screw 10 is placed, the mounting hole 4 formed below the recess part region 3 into which the shank part region of the screw 10 is inserted, and at least one groove 6 between the wall part region on the inner circumferential side forming the recess part region 3,and is formed by the mounting hole 4, and one end of the groove 6 reaches the outer circumferential end of the resin housing 2.

[0026] Therefore, it is made possible that, at the time of fixing the resin housing 2 containing the semiconductor element to the heat dissipation component 13 with the screws 10, the corners of the resin housing 2 bend downwards from the grooves 6 of the resin housing 2 as a starting point, so that the relief of the stress acting around the mounting holes of the resin housing 2 is ensured.

[0027] As in Fig. 4 and Fig. As illustrated in Figure 5, the semiconductor device includes two grooves 6 formed on at least one surface of the resin housing 2; therefore, compared to the case where only one groove 6 is formed, the corner of the housing 2 bends even more easily. As a result, the stress applied around the mounting holes 4 of the resin housing 2 is further relieved. <Vergleichsbeispiel 1>

[0028] Next, a semiconductor device 100A will be described according to a comparative example 1. Fig. Figure 6 is a top view illustrating a state before a resin housing 2A and a base plate 1A, contained in the semiconductor device 100A according to Comparative Example 2, are attached to a heat dissipation component 13A. Fig. 7 is a cross-sectional view taken along a line CC from Fig. 6. Fig. Figure 8 is a cross-sectional view illustrating the semiconductor device 100A. Fig. 9A is an enlarged cross-sectional view around a groove 6 before a screw 10 is fastened. Fig. Figure 9B is an enlarged cross-sectional view around the groove 6 after the screw 10 has been tightened. It should be particularly noted that in Comparative Example 1, the same components as those described in Embodiment 1 are designated with the same reference numerals, and their descriptions are omitted.

[0029] As in Fig. 6, Fig. 7 to Fig. As illustrated in Figure 8, in the comparative example 1 the heat dissipation component 13A has a shape in which its upper surface curves in an arc shape, and the resin housing 2A is fixed to the heat dissipation component 13A, whose upper surface is an arc shape.

[0030] The contour of the base plate 1A in plan view is smaller than the contour of the resin housing 2A in plan view, and the corners of the resin housing 2A project beyond the base plate 1A towards the outer circumferential side. Therefore, the corners of the resin housing 2A are fixed directly to the heat dissipation component 13A without the base plate 1A being positioned between them.

[0031] As in Fig. As illustrated in Figure 9A, groove 6 is a circular groove that extends from the upper surface to the lower surface of the resin housing 2A. As shown in Figure 9A, the groove is a circular groove that extends from the upper surface to the lower surface of the resin housing 2A. Fig. 8 and Fig. As illustrated in Figure 9B, the groove 6 widens, and it is permitted that, at the time of fixing the resin housing 2A to the heat dissipation component 13A with the screws 10, the corner of the resin housing 2A bends downwards from the groove 6 as the starting point; this ensures that the resin housing 2A is fixed along the shape of the upper surface of the heat dissipation component 13A.

[0032] As described above, in the semiconductor device 100A according to Comparative Example 1, the heat dissipation component 13A has a shape in which its upper surface is curved in an arc shape, the groove 6 is a round groove that is recessed from the side of the upper surface to the side of the lower surface of the resin housing 2A, the corners of the resin housing 2A project beyond the base plate 1A towards the outer circumferential side, and in a state in which the grooves 6 are widened, the corners of the resin housing 2A are bent downwards.

[0033] Accordingly, the base plate 1A is not positioned on the rear side of the corners of the resin housing 2A; therefore, when the resin housing 2A is fixed to the heat dissipation component 13A with the screws 10, the corners of the resin housing 2A are allowed to bend downwards; thus, the stress exerted around the mounting holes 4 of the resin housing 2A can be further relieved. At this point, the groove 6 widens, allowing the corner of the resin housing 2A to bend downwards and ensuring that the resin housing 2A is fixed along the shape of the upper surface of the heat dissipation component 13A. <Vergleichsbeispiel 2>

[0034] Next, a semiconductor device 100B will be described according to a comparative example 2. Fig. Figure 10 is a top view illustrating a state before a resin housing 2B and a base plate 1A contained in the semiconductor device 100B are attached to a heat dissipation component 13A. Fig. Figure 11 is a cross-sectional view taken along a line DD from Fig. 10. Fig. Figure 12 is a cross-sectional view illustrating the semiconductor device 100B. Fig. 13A is an enlarged cross-sectional view around a groove 6 before a screw 10 is fastened. Fig. Figure 13B is an enlarged cross-sectional view around the groove 6 after the screw 10 has been tightened. It should be particularly noted that in Comparative Example 2, the same components as those described in embodiments 1 and 2 are designated with the same reference numerals, and their descriptions are omitted.

[0035] As in Fig. 10, Fig. 11 to Fig. As illustrated in Figure 12, comparison example 2 differs from comparison example 1 in the position where the groove 6 is formed.

[0036] As in Fig. As illustrated in Figure 13A, groove 6 is a circular groove that extends from the side of the lower surface to the side of the upper surface of the resin housing 2B. As shown in Fig. 12 and Fig. As illustrated in Figure 13B, the groove 6 narrows and allows the corner of the resin housing 2B to bend downwards from the groove 6 as a starting point when the resin housing 2B is fixed to the heat dissipation component 13A with the screws 10; therefore, the resin housing 2B is fixed along the shape of the upper surface of the heat dissipation component 13A.

[0037] As described above, in the semiconductor device 100B according to Comparative Example 2, the heat dissipation component 13A has a shape in which its upper surface is curved in an arc shape, the groove 6 is a round groove that is recessed from the side of the lower surface to the side of the upper surface of the resin housing 2B, the corners of the resin housing 2B project beyond the base plate 1A towards the outer circumferential side, and in a state in which the grooves 6 are narrowed, the corners of the resin housing 2B are bent downwards.

[0038] Accordingly, the base plate 1A is not located on the back side of the corners of the resin housing 2B; therefore, when the resin housing 2B is fixed to the heat dissipation component 13A with the screws 10, the corners of the resin housing 2B are allowed to bend downwards; thus, the stress acting around the mounting holes 4 of the resin housing 2B can be further relieved. At this point, the groove 6 narrows, allowing the corner of the resin housing 2B to bend downwards, and ensuring that the resin housing 2B is fixed along the shape of the upper surface of the heat dissipation component 13A. As further described in Fig. As illustrated in Figure 13B, the groove 6 narrows after the screw 10 is fastened; therefore, it can be prevented that the corner of the resin housing 2B bends further downwards. <Vergleichsbeispiel 3>

[0039] Next, a semiconductor device will be described according to a comparative example 3. Fig. Figure 14 is a top view illustrating a state before a resin housing 2C and a base plate 1A, contained in the semiconductor device according to Comparative Example 3, are attached to a heat dissipation component 13A. Fig. Figure 15 is a cross-sectional view taken along a line EE from Fig. 14. It should be particularly noted that in comparative example 3, the same components as those described in embodiments 1 to 3 are designated with the same reference numerals and their description is omitted.

[0040] As in Fig. 14 and Fig.As illustrated in Figure 15, in Comparative Example 3 the groove 6 is configured with an upper groove 6a and a lower groove 6b, and the upper groove 6a and the lower groove 6b are formed on the side of the upper surface and the side of the lower surface of the resin housing 2C, respectively. Specifically, the upper groove 6a is a circular groove which, as in the case of embodiment 2, is recessed from the side of the upper surface to the side of the lower surface of the resin housing 2C. And the lower groove 6b is a circular groove which, as in Comparative Example 2, is recessed from the side of the lower surface to the side of the upper surface of the resin housing 2C.

[0041] As in the case of comparative examples 1 and 2, consider a case in which the resin housing 2C is fixed to the heat dissipation component 13A by the screws 10. At this point, the upper grooves 6a widen and the lower grooves 6b narrow, allowing the corners of the resin housing 2C to bend downwards from the upper grooves 6a and the lower grooves 6b as a starting point; thus, the resin housing 2C is fixed along the shape of the upper surface of the heat dissipation component 13A.

[0042] The positions of the upper groove 6a and the lower groove 6b in the lateral direction can be aligned or misaligned. If the position of the upper groove 6a is aligned with the position of the lower groove 6b in the lateral direction, the corner of the resin housing 2C bends even more easily.

[0043] As described above, in the semiconductor device according to Comparative Example 3, the heat dissipation component 13A has a shape in which the upper surface is curved in an arc shape, the upper groove 6a is a round groove that extends from the side of the upper surface to the side of the lower surface of the resin housing 2C, the lower groove 6b is a round groove that extends from the side of the lower surface to the side of the upper surface of the resin housing 2C, and the corners of the resin housing 2C project beyond the base plate towards the outer circumferential side and are bent downwards in a state where the upper groove 6a, which extends from the side of the upper surface to the side of the lower surface of the resin housing 2C, widens and the lower groove 6b, which extends from the side of the lower surface to the side of the upper surface, narrows.

[0044] Accordingly, the base plate 1A is not located on the back side of the corners of the resin housing 2C; therefore, when the resin housing 2C is fixed to the heat dissipation component 13A with the screws 10, the corners of the resin housing 2C are allowed to bend downwards; thus, the stress exerted around the mounting holes 4 of the resin housing 2C can be further relieved. At this point, the upper grooves 6a widen and the lower grooves 6b narrow, allowing the corners of the resin housing 2C to bend downwards; therefore, the extent of bending of the corners of the resin housing 2C can be adjusted. As a result, regardless of the shape of the heat dissipation component, the resin housing 2C is secured along the shape of the upper surface of the heat dissipation component. <Andere Modifikation>

[0045] Although the grooves 6 are preferably formed around the mounting holes 4 formed at the four corners of the resin housing, the grooves 6 can be formed around some of the mounting holes 4. For example, in a condition where the heat dissipation component is fitted with a shape in which the upper surface curves in an arc shape, such as a heat dissipation component 13A, even if the grooves 6 are provided around the mounting hole 4 on one side of the resin housing in plan view and no groove 6 is provided around the mounting holes 4 on the opposite side, the same effect as in any embodiment or comparative example can be obtained.

[0046] If the resin housing does not need to be bent too much, for example if the heat dissipation component 13A has a relatively low degree of curvature, the same effect as in any embodiment or comparative example can be obtained by providing the groove 6 only around the at least one mounting hole 4.

[0047] Furthermore, in comparative examples 1 to 3, two grooves 6 can also be formed for each mounting hole. Compared to the case where one groove is formed for each mounting hole, this makes it even easier to bend the corners of the resin housing. As a result, the stress acting around the mounting holes 4 of the resin housing is further relieved.

[0048] It should be particularly mentioned that embodiments of the present invention and comparative examples can be combined.

Claims

[1] Semiconductor device comprising: a base plate (1, 1A); a heat dissipation component (13, 13A) arranged on a lower surface of the base plate (1, 1A); and a rectangular resin housing (2, 2A, 2B, 2C) in plan view, which is arranged on an upper surface of the base plate (1, 1A) and houses a semiconductor element, wherein in a state in which the resin housing (2, 2A, 2B, 2C) is arranged on the heat dissipation component (13) via the base plate (1, 1A), the resin housing (2, 2A, 2B, 2C) is attached to the heat dissipation component (13) with a screw (10), the resin housing (2, 2A, 2B, 2C) has a recessed part area (3) formed at its corner, in which a head of the screw (10) is placed, a fastening hole (4) formed below the recessed part area (3), into which a shaft part area of ​​the screw (10) is inserted, and at least one groove (6, 6a, 6b) formed between a wall part area (5) on an inner circumferential side, which forms the recessed part area (3), and the fastening hole (4), wherein which at least one groove (6, 6a, 6b) is arc-shaped in plan view, an end of at least one groove (6, 6a, 6b) reaches an outer circumferential end of the resin housing (2, 2A, 2B, 2C), and The contours of the base plate (1), the resin housing (2, 2A, 2B, 2C) and the heat dissipation component (13) are the same in top view. the semiconductor device further features: a hole (12) which is formed in the base plate (1) and is connected to the mounting hole (4). [2] Semiconductor device according to claim 1, wherein the at least one groove (6, 6a, 6b) comprises two grooves (6, 6a, 6b) formed on at least one surface side of the resin housing (2, 2A, 2B, 2C).

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