Semiconductor equipment

Abstract

To provide a semiconductor device with improved adhesion between the case and the base plate. [Solution] The device comprises a circuit board, a base plate, a case, and a recess. The circuit board has semiconductor elements mounted on it. The base plate supports the circuit board with a support surface. The case is bonded to the base plate in an adhesive area in the direction normal to the support surface. The case encloses the circuit board. The base plate has a first bevel. The first bevel is inclined with respect to the support surface. The case has a second bevel. The second bevel is parallel to the first bevel and faces the first bevel in the direction normal to it. Adhesive areas are provided on both the first and second bevels. The recess opens outward between the base plate and the case. At least one of the first and second bevels is exposed in the recess.

Description

Technical Field

[0001] Embodiments of the present invention relate to semiconductor devices.

Background Art

[0002] In a semiconductor device such as a power module, a semiconductor is connected on a base plate having internal wiring, and is composed of a resin case having signal terminals and a main circuit, and a filler such as resin for protecting the semiconductor.

[0003] In the above semiconductor device, when attaching the case on the base plate, since the sealing performance and adhesive strength of the case are required, there is a process of applying an adhesive called a joining agent on the base plate and bonding the base plate and the case. When there is variation in the application position of the adhesive, there is a risk that the adhesive will protrude outside the base plate and the side surface of the case when the case is bonded. In order to suppress the risk of protrusion, it is common to provide a skirt structure that extends from the side surface of the case toward the base plate and covers the side surface of the base plate from the outside. However, in a semiconductor device with determined external dimensions, a structure that protrudes from the side surface cannot be provided.

[0004] Therefore, a chamfered notch is provided inside the lower end of the side wall of the case to accommodate the protrusion of the adhesive. However, when the application position of the adhesive is shifted inward from the lower end of the case, a gap is generated between the adhesive and the case, and air enters through this gap. When the semiconductor device is repeatedly heated during operation, the air expands and contracts. Therefore, when the air spreads to the filler inside the case, there is a concern that the filler may peel off, leading to a decrease in reliability. On the other hand, when the application position of the adhesive is shifted outward from the lower end of the case, as described above, there is a concern that the adhesive may protrude outside.

[0005] Furthermore, since the base plate warps due to heating during reflow soldering, the base plate is pre-curved in the opposite direction to compensate for this warping. However, when joining a case to a warped base plate, the gap between the case and the base plate becomes excessive, creating a gap at the bonding site and increasing the risk of the filler material leaking out. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2023-48526 [Overview of the project] [Problems that the invention aims to solve]

[0007] The problem that this invention aims to solve is to provide a semiconductor device in which the adhesion between the case and the base plate is improved. [Means for solving the problem]

[0008] The semiconductor device of the embodiment includes a circuit board, a base plate, a case, and a recess. Semiconductor elements are mounted on the circuit board. The base plate supports the circuit board with a support surface. The case is bonded to the base plate in an adhesive area in the direction normal to the support surface. The case surrounds the circuit board. The base plate has a first bevel. The first bevel is inclined with respect to the support surface. The case has a second bevel. The second bevel is parallel to the first bevel and faces the first bevel in the direction normal to it. The adhesive areas are provided on the first bevel and the second bevel, respectively. The recess opens outward between the base plate and the case. At least one of the first bevel and the second bevel is exposed in the recess. [Brief explanation of the drawing]

[0009] [Figure 1] A plan view of the semiconductor device of the embodiment. [Figure 2] Cross-sectional view AA in Figure 1. [Figure 3] Cross-sectional view of the semiconductor device of the embodiment. [Figure 4] Cross-sectional view of BB in Figure 1. [Figure 5] Cross-sectional view of BB in Figure 1. [Figure 6] Cross-sectional view of BB in Figure 1. [Figure 7] A partial cross-sectional view of the semiconductor device of the second embodiment. [Figure 8] A partial cross-sectional view of the semiconductor device of the third embodiment. [Figure 9] A partial cross-sectional view of the semiconductor device of the fourth embodiment. [Figure 10] A partial cross-sectional view of the semiconductor device of the fifth embodiment. [Modes for carrying out the invention]

[0010] The semiconductor device of the embodiment will be described below with reference to the drawings. In the following description, components having the same or similar functions will be denoted by the same reference numerals. Duplication of these components may be omitted.

[0011] In this specification, the upward direction in Figure 2 may be described as "up" and the downward direction in the drawing as "down" to indicate the positional relationship of parts, etc. In this specification, the concepts of "up" and "down" do not necessarily indicate a relationship to the direction of gravity.

[0012] [Class 1 Embodiment of a Semiconductor Device] The configuration of the first embodiment of the semiconductor device will be described below. Figure 1 is a plan view of the semiconductor device of the embodiment. Figure 2 is a cross-sectional view of AA in Figure 1.

[0013] One example of the semiconductor device 100 in this embodiment is a power semiconductor module. As shown in FIGS. 1 and 2, the semiconductor device 100 includes a first semiconductor element (semiconductor element) 10, a second semiconductor element (semiconductor element) 12, a base plate 14, a circuit board 16, a case 18, an adhesive region 20, a first power terminal 22, a second power terminal 23, bonding wires 26, and a sealing material 28.

[0014] The first semiconductor element 10 and the second semiconductor element 12 are, for example, an IGBT (Insulated Gate Bipolar Transistor), a MOSFET (Metal Oxide Field Effect Transistor), or a diode.

[0015] The first semiconductor element 10 and the second semiconductor element 12 are mounted on the circuit board 16. The circuit board 16 is provided on the base plate 14. The circuit board 16 is provided between the base plate 14 and the first semiconductor element 10, and between the base plate 14 and the second semiconductor element 12. The circuit board 16 has a function of electrically separating (insulating) the base plate 14 from the first semiconductor element 10 and the second semiconductor element 12.

[0016] The base plate 14 supports the circuit board 16 on a support surface 14a. The support surface 14a is the upper plane of the circuit board 16. As shown in FIG. 1, the base plate 14 is rectangular in plan view when viewed in the normal direction of the support surface 14a (hereinafter simply referred to as the normal direction). The base plate 14 is formed of metal as an example. The base plate 14 is formed of copper, for example. For example, when the semiconductor device 100 is mounted on a product, a heat sink (not shown) is connected to the back surface of the base plate 14. The base plate 14 and the heat sink are fastened and fixed by fastening members inserted into holes 14c formed at the four corners of the base plate 14.

[0017] The base plate 14 is deformed by warping due to heat shrinkage or the like during the assembly of the semiconductor device 100. As shown in FIG. 3, before the case 18 is adhered to the base plate 14, for example, the back surface 14b of the base plate 14, which will be described later, has a shape that is convex upward. In other words, the base plate 14 is curved downward at the ends with respect to the central portion. The above-described shape is corrected in consideration of deformation due to heat shrinkage or the like in order to enhance the adhesion between the back surface 14b of the base plate 14 and the heat sink when assembled as a final product.

[0018] In addition, the back surface 14b of the base plate 14, which will be described later, may have a shape that is convex downward in addition to the shape that is convex upward. The semiconductor device 100 of the embodiment is applicable to both the shape in which the back surface 14b is convex upward and the shape in which the back surface 14b is convex downward.

[0019] FIG. 4 is a cross-sectional view taken along the line B-B in FIG. 1. As shown in FIG. 2, among the short sides of the rectangular base plate 14 in plan view, the upper side edge on the short side is flush with the support surface 14a. On the other hand, as shown in FIG. 4, a first inclined surface 24 is formed on the upper edge that is the long side of the rectangular base plate 14 in plan view. The first inclined surface 24 is inclined at an angle θ with respect to the support surface 14a. The angle θ is preferably, for example, 10° or more and 80° or less. The first inclined surface 24 is inclined in the normal direction with respect to the support surface 14a and toward the back surface 14b on the side opposite to the support surface 14a of the base plate 14 as it faces outward. The first inclined surface 24 is connected to the first side surface 25 facing the outside of the base plate 14.

[0020] In the embodiment, when centered on the centers of the short side and the long side of the rectangular base plate 14 in plan view, the side that faces the center in the direction along the support surface 14a is referred to as the inner side. Also, the side that moves away from the center in the direction along the support surface 14a is referred to as the outer side.

[0021] The case 18 is provided around the base plate 14 and the circuit board 16. The case 18 encloses the base plate 14 and the circuit board 16. The case 18 is an example of a frame. The case 18 has the function of protecting the first semiconductor element 10, the second semiconductor element 12, and the circuit board 16.

[0022] Case 18 has a rectangular outer contour when viewed in the normal direction. Case 18 is a rectangular tube shape with a rectangular through hole 19 that penetrates in the normal direction when viewed in the normal direction. Case 18, with its rectangular outer contour, has a first side wall 18A which is the short side and a second side wall 18B which is the long side. As shown in Figure 2, the lower end of the first side wall 18A is bonded to the support surface 14a of the base plate 14 in the normal direction by an adhesive area 20.

[0023] As shown in Figure 4, the lower end of the second side wall 18B has a second inclined surface 32 and a third inclined surface 33. The second inclined surface 32 is parallel to the first inclined surface 24 and faces the first inclined surface 24 in the normal direction. That is, the second inclined surface 32 is inclined at an angle θ with respect to the support surface 14a. The third inclined surface 33 is connected to the second inclined surface 32 and extends away from the first inclined surface 24. The third inclined surface 33 extends upward as it moves outward from the lower end of the second inclined surface 32. The third inclined surface 33 is connected to the second side surface 36 facing the outside of the second side wall 18B. In a cross section perpendicular to the support surface 14a, the second inclined surface 32 is longer than the third inclined surface 33. Because the second inclined surface 32 is longer than the third inclined surface 33, the bonding length with the first inclined surface 24 is increased, allowing the base plate 14 and the case 18 to be stably bonded and fixed.

[0024] When the first inclined surface 24 and the second inclined surface 32 are joined in the normal direction, a recess 35 is formed between the base plate 14 and the case 18. In the recess 35, a space with a V-shaped cross-section is formed, surrounded by the first inclined surface 24 and the third inclined surface 33 and opening outwards. The first inclined surface 24 and the third inclined surface 33 are exposed in the recess 35.

[0025] The adhesive region 20 is the area on the base plate 14 and the case 18 to which adhesive is applied. The adhesive region 20 is located at the position where the case 18 is bonded to the base plate 14 by adhesive in the normal direction. That is, as shown by the dashed line in Figure 1, the adhesive region 20 has a first adhesive region 20A and a second adhesive region 20B.

[0026] Of the adhesive regions 20, the first adhesive region 20A is provided on the short edge of the rectangular base plate 14 and case 18. Specifically, as shown in Figure 2, the first adhesive region 20A is provided on the lower end of the first side wall 18A and on the support surface 14a facing the lower end of the first side wall 18A in the direction normal to it.

[0027] Of the adhesive areas 20, the second adhesive area 20B is provided on the long edge of the rectangular base plate 14 and case 18. Specifically, as shown in Figure 4, the second adhesive area 20B is provided on the first slope 24 and the second slope 32, respectively.

[0028] The adhesive applied to the bonding area 20 may include, for example, a resin. The adhesive may include, for example, silicone. The adhesive may be, for example, a silicone resin. Other resins, such as epoxy resin, may also be used as the adhesive.

[0029] The adhesive is, for example, a thermosetting resin. The viscosity of the adhesive before curing is, for example, 30 Pa·s or more and 1000 Pa·s or less.

[0030] In the embodiment, the semiconductor device 100 is fixed between the base plate 14 and the case 18 by an adhesive area 20. In addition to fixing with adhesive in the adhesive area 20, the semiconductor device 100 may also be fastened and fixed to the base plate 14 and the case 18 by a fastening member 17, for example, as shown in Figure 1. By fastening and fixing the base plate 14 and the case 18 with the fastening member 17, the joints between the first inclined surface 24 and the second inclined surface 32 are arranged apart in the short-side direction, which can suppress problems such as the second inclined surface 32 shifting along the first inclined surface 24 and the case 18 tilting relative to the base plate 14.

[0031] Case 18 has a fitting projection 51B at the lower end of the right-side first side wall 18A where the second power terminal 23 is located. As shown in Figure 2, the fitting projection 51B protrudes downward from the first side wall 18A. The protruding length of the fitting projection 51B is shorter than the thickness of the base plate 14. As shown in Figure 1, the fitting projection 51B is provided on the outer edge of the first side wall 18A. The fitting projections 51B are located on both sides of the roughly rectangular case 18 in the short-side direction. Each fitting projection 51B is located between the hole 14c and the fastening member 17 in the short-side direction. When viewed from above, each fitting projection 51B has an elongated semicircular shape, where the elongated shape with the short-side direction as the major axis is halved in the short-side direction.

[0032] Furthermore, the case 18 is provided with a fitting projection 52B at the lower end of the left side of the first side wall 18A where the first power terminal 22 is located. As shown in Figure 2, the fitting projection 52B protrudes downward from the first side wall 18A. The protruding length of the fitting projection 52B is shorter than the thickness of the base plate 14. As shown in Figure 1, the fitting projection 52B is provided on the outer edge of the first side wall 18A. The fitting projections 52B are located on both sides of the case 18 in the short direction. Each fitting projection 52B is located between the hole 14c and the fastening member 17 in the short direction. When viewed from above, each fitting projection 52B is semicircular in shape.

[0033] The base plate 14 has two fitting protrusions 51B and fitting recesses 51A at positions opposite each other in the vertical direction. The fitting recesses 51A penetrate the base plate 14 in the vertical direction. Each fitting recess 51A is semicircular in shape when viewed from above. The fitting protrusions 51B are fitted into each fitting recess 51A from above.

[0034] Furthermore, the base plate 14 is provided with fitting recesses 52A at positions opposite each other in the vertical direction to the two fitting protrusions 52B. The fitting recesses 52A penetrate the base plate 14 in the vertical direction. Each fitting recess 52A is semicircular in shape when viewed from above. The fitting protrusions 52B are fitted into each fitting recess 52A from above.

[0035] The case 18 and base plate 14 are positioned in a direction perpendicular to the vertical direction by fitting the mating projection 51B of the case 18 and the mating recess 51A of the base plate 14 into two positions on the right side, and fitting the mating projection 52B of the case 18 and the mating recess 52A of the base plate 14 into two positions on the left side. Furthermore, because the mating projection 51B and mating recess 51A are semicircular in shape, and the mating projection 52B and recess 52A are semicircular in shape, the mating of the recess and projection becomes impossible when either the case 18 or the base plate 14 is rotated 180°, thus preventing incorrect assembly of the case 18 and base plate 14.

[0036] The first power terminal 22 and the second power terminal 23 are provided on the upper part of the first side wall 18A of the case 18. A negative voltage is applied to the first power terminal 22, for example. A positive voltage is applied to the second power terminal 23, for example.

[0037] The bonding wire 26 electrically connects, for example, the first power terminal 22 to the first semiconductor element 10, the metal layer of the circuit board 16 to the second semiconductor element 12, the metal layer of the circuit board 16 to the second power terminal 23. The bonding wire 26 is, for example, an aluminum wire.

[0038] The sealing resin 28 is filled into the case 18. The sealing resin 28 is surrounded by the case 18. The sealing resin 28 covers the first semiconductor element 10, the second semiconductor element 12, and the circuit board 16. The sealing resin 28 is an example of a sealing material. The sealing resin 28 has the function of protecting the first semiconductor element 10, the second semiconductor element 12, and the circuit board 16. It also has the function of insulating the first semiconductor element 10, the second semiconductor element 12, and the circuit board 16.

[0039] The sealing resin 28 contains a resin. The sealing resin 28 is, for example, a silicone gel. Other resins, such as epoxy resin or polyimide resin, can also be used for the sealing resin 28.

[0040] In the semiconductor device 100 with the above configuration, if the second bonding region 20B is offset inward (to the right in Figure 4), the bonding length between the first slope 24 and the second slope 32 in a cross section perpendicular to the support surface becomes longer compared to when the lower end is flush with the support surface 14a, as in the case of the first side wall 18A. As a result, it becomes more difficult for air to reach the sealing material 28.

[0041] Furthermore, as shown in Figure 5, if the second bonding area 20B is shifted outward (to the left in Figure 5), the adhesive may overflow from the intersection of the second inclined surface 32 and the third inclined surface 33. In this case, since a recess 35 surrounded by the first inclined surface 24 and the third inclined surface 33 is formed between the base plate 14 and the case 18, the overflowing adhesive is contained in the recess 35, preventing it from overflowing beyond the first side surface 25 and the second side surface 36.

[0042] Here, since the third inclined surface 33 extends upward as it moves outward from the lower end of the second inclined surface 32, the area of ​​the cross-section of the recess 35 becomes larger compared to the case where the third inclined surface 33 extends outward parallel to the support surface 14a from the lower end of the second inclined surface 32. As a result, the amount of excess adhesive that can be contained is increased, and the excess adhesive is further suppressed from spilling out beyond the first side surface 25 and the second side surface 36.

[0043] Furthermore, because the adhesive that has spilled into the recess 35 comes into contact with both the first inclined surface 24 and the third inclined surface 33 due to surface tension, the position of the outer tip of the adhesive is inward compared to the case where the adhesive comes into contact only with the first inclined surface 24, and the spillage of the adhesive beyond the first side surface 25 and the second side surface 36 is further suppressed.

[0044] Furthermore, as mentioned above, the base plate 14 is curved downwards at its edges relative to its center. As a result, as shown in Figure 6, the gap in the normal direction between the base plate 14 and the case 18 becomes larger during bonding, and there is a possibility that the adhesive applied to the second bonding area 20B may not be able to fill the gap between the base plate 14 and the case 18. In this case, air may enter through the unfilled gap, potentially causing the problems described above. There is also a risk that the sealing material 28 may leak through the gap.

[0045] In this embodiment, to join the first inclined surface 24 and the second inclined surface 32, the gap dimension b between the first inclined surface 24 and the second inclined surface 32 is a × cosθ, which is smaller than the gap dimension a between the base plate 14 and the case 18 in the normal direction. For example, when the angle θ is 45°, the gap dimension b can be reduced to approximately 70% of the gap dimension a.

[0046] Therefore, in this embodiment, by joining the first slope 24 and the second slope 32, the gap dimension b between the first slope 24 and the second slope 32 is reduced compared to the case where the lower end is flush with the support surface 14a, as in the first side wall 18A. This suppresses problems caused by air entering through the unfilled gap. Furthermore, by reducing the gap dimension b, the risk of the filler 28 leaking from the gap between the first slope 24 and the second slope 32 is also reduced.

[0047] Furthermore, considering the size of the gap dimension a, a high-viscosity adhesive is often used to ensure sufficient thickness to fill the gap. While a high-viscosity adhesive can ensure sufficient thickness, its adhesive strength is relatively weaker compared to a low-viscosity adhesive. Therefore, in the semiconductor device 100, a material that exhibits minimal warping due to heating is often selected for the base plate 14. In this embodiment, since the gap dimension b is small, it becomes possible to use an adhesive with low viscosity and high adhesive strength, thereby suppressing the peeling of the adhesive due to thermal expansion and contraction after bonding the base plate 14 and the case 18. In addition, it becomes possible to use materials such as copper, which exhibit relatively large warping but have high thermal conductivity and excellent cooling efficiency.

[0048] According to at least one embodiment described above, the base plate 14 has a first inclined surface 24, the case 18 has a second inclined surface 32 facing the first inclined surface 24, adhesive areas 20 are provided on each of the first inclined surface 24 and the second inclined surface 32, and a recess 35 is formed between the base plate 14 and the case 18 in which at least one of the first inclined surface 24 and the second inclined surface 32 is exposed. Therefore, even if the adhesive areas 20 are misaligned, the outward leakage of adhesive and the reach of air that enters through the gap to the sealant 28 can be suppressed, thereby improving the adhesion between the case 18 and the base plate 14.

[0049] Furthermore, according to at least one embodiment, the gap dimension b between the first inclined surface 24 and the second inclined surface 32 can be made smaller than the gap dimension a in the normal direction, thereby suppressing problems caused by air entering through the gap, and enabling the use of an adhesive with low viscosity and high adhesive strength, as well as the use of materials such as copper with high thermal conductivity and excellent cooling efficiency, thereby improving versatility.

[0050] [Second Embodiment of Semiconductor Device] Next, a second embodiment of the semiconductor device 100 will be described with reference to Figure 7. In this figure, elements identical to those in the first embodiment shown in Figures 1 to 6 are denoted by the same reference numerals, and their descriptions are omitted.

[0051] Figure 7 is a partial cross-sectional view showing the semiconductor device 100 of the second embodiment. As shown in Figure 7, the base plate 14 has a first roughened portion 24A on the surface of the first bevel 24, which has been roughened. The case 18 has a second roughened portion 32A on the second bevel 32 and the third bevel 33, which have been roughened. The surface roughness of the first roughened portion 24A and the second roughened portion 32A is greater than that of the support surface 14a. The surface roughness of the first roughened portion 24A and the second roughened portion 32A is preferably Ra 10 or higher. Examples of roughening treatments include chemical treatments such as etching and physical treatments such as sandblasting. The other configurations are the same as those of the first embodiment described above.

[0052] In the semiconductor device 100 with the above configuration, the surface area of ​​the first bevel 24 and the second bevel 32 is increased because it has a first roughened portion 24A and a second roughened portion 32A. As a result, the adhesion strength of the adhesive on the first bevel 24 and the second bevel 32 is increased. Consequently, the peeling of the adhesive due to thermal expansion and contraction after bonding can be further suppressed.

[0053] Furthermore, in the semiconductor device 100 with the above configuration, the adhesive that protrudes into the recess 35 from the intersection of the first inclined surface 24 and the third inclined surface 33 extends along the first inclined surface 24 and the third inclined surface 33 in the first roughened portion 24A and the second roughened portion 32A due to capillary action, so that the surface exposed to the outside becomes concave. Therefore, the outward protrusion of the adhesive that has protruded into the recess 35 is further suppressed.

[0054] According to at least one embodiment, in addition to obtaining the same effects and benefits as in the first embodiment, the adhesion strength of the adhesive on the first slope 24 and the second slope 32 can be increased, thereby further suppressing the peeling of the adhesive, and further suppressing the adhesive that has squeezed out into the recess 35 from spreading to the outside.

[0055] [Third Embodiment of a Semiconductor Device] Next, a third embodiment of the semiconductor device 100 will be described with reference to Figure 8. In this figure, elements identical to those in the first embodiment shown in Figures 1 to 6 are denoted by the same reference numerals, and their descriptions are omitted.

[0056] Figure 8 is a partial cross-sectional view showing the semiconductor device 100 of the third embodiment. As shown in Figure 8, the first inclined surface 24 connects to the first side surface 25 facing the outside of the base plate 14. The second inclined surface 32 connects to the second side surface 36 facing the outside of the case 18. The case 18 does not have a third inclined surface 33. Therefore, the semiconductor device 100 does not have a recess 35. The other configurations are the same as those of the first embodiment described above.

[0057] According to at least one embodiment, in addition to obtaining the same effects and benefits as in the first embodiment, except for the effects and benefits provided by the third inclined surface 33 and the recess 35, the lengths of the first inclined surface 24 and the second inclined surface 32 can be increased by approximately 1.7 times compared to the case where the lower end is flush with the support surface 14a, such as the first side wall 18A, and even if the position of the adhesive area 20 shifts, the adhesive can be further suppressed from overflowing outwards.

[0058] [Fourth Embodiment of the Semiconductor Device] Next, a fourth embodiment of the semiconductor device 100 will be described with reference to Figure 9. In this figure, elements identical to those in the first embodiment shown in Figures 1 to 6 are denoted by the same reference numerals, and their descriptions are omitted.

[0059] Figure 9 is a partial cross-sectional view showing the semiconductor device 100 of the fourth embodiment. In the above embodiment, the first inclined surface 24 and the second inclined surface 32 are shown as they move outward, tilting toward the back surface 14b (downward side) of the base plate 14 on the opposite side of the support surface 14a relative to the support surface 14a. However, the embodiment is not limited to this configuration. As shown in Figure 9, the first bevel 24 and the second bevel 32 in the semiconductor device 100 of the fourth embodiment are inclined upward at an angle θ as they extend outward. The third bevel 33 is inclined upward at an angle greater than θ as it extends outward from the upper end of the second bevel 32. The internal space of the recess 35 extends in an upward direction as it extends outward. The other configurations are the same as those of the first embodiment described above.

[0060] According to at least one embodiment, in addition to obtaining the same effects and benefits as the first embodiment described above, the opening of the recess 35 is located on the upper side of the internal space, which prevents the adhesive that has entered the recess 35 from overflowing beyond the first side surface 25 and the second side surface 36 due to its own weight.

[0061] [Fifth Embodiment of a Semiconductor Device] Next, a fifth embodiment of the semiconductor device 100 will be described with reference to Figure 10. In this figure, elements identical to those in the first embodiment shown in Figures 1 to 6 are denoted by the same reference numerals, and their descriptions are omitted.

[0062] Figure 10 is a partial cross-sectional view showing a semiconductor device 100 according to the fifth embodiment. As shown in Figure 10, the base plate 14 has an upper surface 14d on the outside of the first inclined surface 24. The upper surface 14d is parallel to the support surface 14a and is located below the support surface 14a. The upper surface 14d is connected to the first side surface 25.

[0063] The first inclined surface 24 connects to the upper surface 14d on the outside. A space is formed in the recess 35 that is surrounded by the first inclined surface 24, the third inclined surface 33, and the upper surface 14d and opens outwards. The first inclined surface 24, the third inclined surface 33, and the upper surface 14d are exposed in the recess 35.

[0064] According to at least one embodiment, in addition to obtaining the same effects and advantages as the first embodiment described above, the upper surface 14d, which is exposed in the internal space of the recess 35 and located on the lower side, is parallel to the support surface 14a and does not extend downward as it goes outward. Therefore, it is possible to suppress the adhesive that has entered the recess 35 from overflowing beyond the first side surface 25 and the second side surface 36 due to its own weight.

[0065] Furthermore, by adopting a configuration in which the upper surface 14d is inclined to extend upward as it moves outward, it is possible to further suppress the adhesive that has entered the recess 35 from overflowing beyond the first side surface 25 and the second side surface 36 due to its own weight.

[0066] In the above embodiment, the first inclined surface 24 and the second inclined surface 32 are provided in the second adhesive region 20B of the long edge of the rectangular base plate 14 and case 18, but they may also be provided in the first adhesive region 20A of the short edge.

[0067] This embodiment includes the following appended aspects. (Note 1) A circuit board on which semiconductor elements are mounted, A base plate that supports the circuit board on a support surface, A case is bonded to the base plate in the direction normal to the support surface, and surrounds the circuit board. Equipped with, The base plate has a first inclined surface that is inclined with respect to the support surface, The case has a second slope parallel to the first slope and facing the first slope in the normal direction, The adhesive regions are provided on the first slope and the second slope, A semiconductor device having a recess that opens outward between the base plate and the case, and in which at least one of the first and second inclined surfaces is exposed. (Note 2) The first and second inclined surfaces are inclined toward the back surface of the base plate opposite to the support surface in the direction normal to the support surface as they extend outward. The semiconductor device described in Appendix 1. (Note 3) The first and second slopes have a surface roughness greater than that of the support surface. A semiconductor device as described in Appendix 1 or Appendix 2. (Note 4) The aforementioned case has a third slope that is connected to the second slope and extends away from the first slope. A semiconductor device described in any one of the appendices 1 through 3. (Note 5) In a cross-section perpendicular to the support surface, the second slope is longer than the third slope. Semiconductor device as described in Appendix 4. (Note 6) The third slope has a surface roughness greater than that of the support surface. The semiconductor device described in Appendix 4 or Appendix 5. (Note 7) Viewed in the direction of the normal, the base plate and the case are rectangular. The first and second inclined surfaces are provided on the long edges of the base plate and the case, respectively. A semiconductor device as described in any one of the appendices 1 through 6. (Note 8) A circuit board on which semiconductor elements are mounted, A base plate that supports the circuit board on a support surface, A case is bonded to the base plate in the direction normal to the support surface, and surrounds the circuit board. Equipped with, The base plate has a first inclined surface that is inclined with respect to the support surface, The case has a second slope parallel to the first slope and facing the normal direction, The adhesive regions are provided on the first slope and the second slope, The first slope is connected to the first side surface facing the outside of the base plate, The second slope connects to the second side surface facing the outside of the case, and is a semiconductor device.

[0068] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of Symbols]

[0069] 10...First semiconductor element (semiconductor element), 12...Second semiconductor element (semiconductor element), 14...Base plate, 14a...Support surface, 14b...Back surface, 16...Circuit board, 18...Case, 20...Adhesive area, 24...First bevel, 25...First side surface, 32...Second bevel, 33...Third bevel, 35...Recess, 36...Second side surface, 100...Semiconductor device

Claims

1. A circuit board on which semiconductor elements are mounted, A base plate that supports the circuit board on a support surface, A case is bonded to the base plate in the direction normal to the support surface, and surrounds the circuit board. Equipped with, The base plate has a first inclined surface that is inclined with respect to the support surface, The case has a second slope parallel to the first slope and facing the first slope in the normal direction, The aforementioned bonding regions are provided on the first slope and the second slope, A semiconductor device having a recess that opens outward between the base plate and the case, and in which at least one of the first inclined surface and the second inclined surface is exposed.

2. The first and second inclined surfaces are inclined toward the back surface of the base plate opposite to the support surface in the direction normal to the support surface as they extend outward. The semiconductor device according to claim 1.

3. The first and second slopes have a surface roughness greater than that of the support surface. The semiconductor device according to claim 1 or 2.

4. The aforementioned case has a third slope that is connected to the second slope and extends away from the first slope. The semiconductor device according to claim 1 or 2.

5. In a cross-section perpendicular to the support surface, the second slope is longer than the third slope. The semiconductor device according to claim 4.

6. The third slope has a surface roughness greater than that of the support surface. The semiconductor device according to claim 4.

7. Viewed in the direction of the normal, the base plate and the case are rectangular. The first and second inclined surfaces are provided on the long edges of the base plate and the case, respectively. The semiconductor device according to claim 1 or 2.

8. A circuit board on which semiconductor elements are mounted, A base plate that supports the circuit board on a support surface, A case is bonded to the base plate in the direction normal to the support surface, and surrounds the circuit board. Equipped with, The base plate has a first inclined surface that is inclined with respect to the support surface, The case has a second slope parallel to the first slope and facing the normal direction, The aforementioned bonding regions are provided on the first slope and the second slope, The first slope is connected to the first side surface facing the outside of the base plate, The second slope is connected to the second side surface facing the outside of the case, and is a semiconductor device.

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