JP6459843B2 - Semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device.

  Conventionally, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-110969, a semiconductor device including a guide mechanism for a disc spring is known. In FIG. 7 and paragraph 0045 of this publication, it is described that a recess is provided in a region where the disc spring is placed in the heat receiving block.

JP 2001-110969 A

  In the case where a positioning portion is provided around the disc spring mounting region in order to position the disc spring, there is no problem as long as the disc spring is correctly placed inside the positioning portion. However, if an error occurs in the mounting position, the edge of the disc spring may ride on the positioning portion. As a result, there is a problem that a disc spring is not correctly sandwiched.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an improved semiconductor device so as to suppress poor positioning.

A semiconductor device according to a first invention is
A heat dissipating member;
A surface provided on the heat radiating member, facing the opposite side of the heat radiating member, and a side surface provided along a peripheral edge of the surface, and surrounding the disc spring mounting region and the disc spring mounting region on the surface A positioning module provided with a positioning projection, and a semiconductor module provided with a terminal on the side surface ,
A disc spring mounted on the disc spring mounting area;
A holding plate overlaid on the disc spring;
A coupling member that couples the pressing plate and the heat dissipation member so as to sandwich the disc spring and the semiconductor module between the pressing plate and the heat dissipation member;
With
At least an upper end portion of the positioning protrusion is provided with a slope inclined with respect to the surface so as to descend toward the center side of the disc spring mounting region ,
The positioning protrusion includes an annular protrusion formed of an insulating material and surrounding the disc spring mounting region .

A semiconductor device according to a second invention is
A heat dissipating member;
Wherein provided on the heat radiating member, and a side surface which is provided along the periphery of the opposite side faces a surface wherein the surface of the heat radiating member includes a positioning recess formed in the insulating material to the surface, the A semiconductor module provided with terminals on the side surfaces ;
A disc spring placed inside the positioning recess;
A holding plate overlaid on the disc spring;
A coupling member that couples the pressing plate and the heat dissipation member so as to sandwich the disc spring and the semiconductor module between the pressing plate and the heat dissipation member;
With
The positioning recess includes a bottom surface on which the disc spring rides and a side surface surrounding the bottom surface,
At least an upper end portion of the side surface is provided with a slope inclined with respect to the bottom surface so as to descend toward the center side of the bottom surface.

  According to the first aspect, since the disc spring is guided inside the positioning projection by the inclined surface of the positioning projection, it is possible to prevent the disc spring from riding on the positioning projection.

  According to the second aspect, since the edge of the disc spring is guided by the inclined surface provided on the side surface of the positioning recess, it is possible to prevent the disc spring from climbing on the edge of the positioning recess.

1 is a plan view showing a semiconductor device according to a first embodiment of the present invention. It is sectional drawing which shows the semiconductor device concerning Embodiment 1 of this invention. It is sectional drawing which shows the semiconductor device concerning Embodiment 1 of this invention. It is sectional drawing which shows the semiconductor device concerning Embodiment 1 of this invention. 1 is an exploded view showing a semiconductor device according to a first embodiment of the present invention. 1 is a diagram illustrating a semiconductor device according to a first embodiment of the present invention. 1 is an enlarged side view showing a semiconductor device according to a first embodiment of the present invention. It is a top view which shows the semiconductor module applied to the semiconductor device concerning the modification of Embodiment 1 of this invention. It is a top view which shows the semiconductor module applied to the semiconductor device concerning the modification of Embodiment 1 of this invention. It is a top view which shows the semiconductor module applied to the semiconductor device concerning the modification of Embodiment 1 of this invention. It is a top view which shows the semiconductor module applied to the semiconductor device concerning the modification of Embodiment 1 of this invention. It is a side view which shows the semiconductor device concerning the modification of Embodiment 1 of this invention. It is an enlarged side view which shows the semiconductor device concerning the modification of Embodiment 1 of this invention. It is a side view which shows the semiconductor module applied to the semiconductor device concerning the modification of Embodiment 1 of this invention. It is a top view which shows the semiconductor module applied to the semiconductor device concerning Embodiment 2 of this invention. It is sectional drawing which shows the semiconductor device concerning Embodiment 2 of this invention. It is an expanded sectional view which shows the semiconductor device concerning Embodiment 2 of this invention. It is an expanded sectional view which shows the semiconductor device concerning the modification of Embodiment 2 of this invention. It is an enlarged side view which shows the semiconductor device concerning the comparative example with respect to embodiment. It is an expanded sectional view which shows the semiconductor device concerning the comparative example with respect to embodiment. It is a top view of the semiconductor module applied to the semiconductor device concerning the modification of Embodiment 2 of this invention. It is a top view of the semiconductor module applied to the semiconductor device concerning the modification of Embodiment 2 of this invention.

Embodiment 1 FIG.
FIG. 1 is a plan view showing a semiconductor device 10 according to the first embodiment of the present invention. 2 to 4 are cross-sectional views showing the semiconductor device 10. 2 is a cross section taken along the line AA ′ of FIG. 1, FIG. 3 is a cross section taken along the line CC ′ of FIG. 1, and FIG. 4 is a cross section taken along the line BB ′ of FIG. FIG. 5 is an exploded view showing the semiconductor device 10.

  The semiconductor device 10 includes a cooling fin 2, a semiconductor module 20, a disc spring 6, a pressing plate 8, and screws 9. On the cooling fin 2, the semiconductor module 20 on which the heat radiation grease 4 is printed is mounted. In order to spread the printed heat-dissipating grease 4 uniformly on the back surface of the semiconductor module 20, the semiconductor module 20 is pressed against the cooling fin 2 using the disc spring 6 and the holding plate 8.

  The semiconductor module 20 is provided on the cooling fin 2 and has a surface 22 a facing the opposite side of the cooling fin 2. The semiconductor module 20 covers a power semiconductor element (not shown), a lead terminal 24 electrically connected to the power semiconductor element by a wire (not shown), a part of the lead terminal 24 and the semiconductor element. And a sealing resin body 22 that exposes another part of the lead terminal 24. The sealing resin body 22 has a flat outer shape having a constant thickness as a whole, and has a front surface and a back surface opposite to each other. The surface 22a of the sealing resin body 22 is provided with a plurality of positioning protrusions 26 as will be described later. The power semiconductor element is a switching element such as an IGBT (insulated gate bipolar transistor) or a MOSFET (MOS field effect transistor) made of silicon or a wide band gap semiconductor, or a diode. Specifically, the wide band gap semiconductor is SiC, a GaN-based material, or diamond.

  The disc spring 6 is placed on the surface of the semiconductor module 20, in other words, the surface of the sealing resin body 22. Of the surface of the sealing resin body 22, the region on which the disc spring 6 is placed is particularly referred to as a “disc spring mounting region”. According to the plan view of FIG. 1, a region inside the circle illustrated by a broken line is a disc spring mounting region. The same applies to the modified examples described later. Four positioning protrusions 26 are provided on the surface 22a of the sealing resin body 22 so as to surround the disc spring mounting region.

  The disc spring 6 is a spring in which a well-known disc spring can be applied, and a disc-like plate having a hole in the center is formed into a conical shape and is shaped like a plate without a bottom. The disc spring 6 has a hollow disc shape as a whole (a donut shape in plan view) because the hole is opened at the center of the bottom, and the central side of the disc spring 6 is convex. The convex side of the disc spring 6 faces the holding plate 8. By doing in this way, when the edge on the inner peripheral side of the disc spring 6 is pressed by the holding plate 8, the semiconductor module 20 can be pressed against the cooling fin 2 by the edge on the outer peripheral side of the disc spring 6. As the shape of the disc spring 6 itself, a well-known disc spring may be applied as appropriate, so that further explanation is omitted.

  It is overlaid on the presser plate 8 and the disc spring 6. FIG. 5 shows a fixing method using screws 9 as an example. The screw 9 is a coupling member that couples the pressing plate 8 and the cooling fin 2. The cooling fin 2 has a screw boss 3. A screw boss 3 is provided on the cooling fin 2. By inserting the screw 9 into the screw boss 3, the holding plate 8 is fixed with the screw. Accordingly, the disc spring 6 and the semiconductor module 20 can be sandwiched between the presser plate 8 and the cooling fin 2, and the disc spring 6 can be pressed against the surface 22 a of the semiconductor module 20.

  The four positioning projections 26 are provided in a square shape in plan view so as to surround the disc spring mounting region. As can be seen from the enlarged sectional view of FIG. 7 described later, the positioning protrusion 26 includes a slope 27 inclined with respect to the surface 22a. The inclined surface 27 is inclined so as to go down to the center side of the disc spring mounting region. The inclined surface 27 and the surface 22a intersect on the disc spring mounting region side, and as shown in FIG. 7, the angle θ formed by the inclined surface 27 and the surface 22a is an acute angle (that is, less than 90 degrees). The angle θ can be variously modified, and may be, for example, 60 degrees, 45 degrees, 30 degrees, or larger or smaller. The slope 27 is provided from the upper end of the positioning projection 26 to the base, and the lower end of the slope 27 is connected to the surface 22 a of the sealing resin body 22. However, only the upper end portion may be a slope as in a modified example of FIG. 14 described later.

  FIG. 6 is a diagram illustrating the semiconductor device 10 according to the first embodiment of the present invention. When the screw 9 is tightened, the disc spring 6 is compressed. The semiconductor module 20 is firmly pressed and fixed to the cooling fin 2 side by the elastic force of the disc spring 6.

  FIG. 7 is an enlarged side view showing the semiconductor device 10 according to the first embodiment of the present invention. When the disc spring 6 is moved by a transfer device such as an arm (not shown), the disc spring 6 is brought close to the surface 22a after the edge of the disc spring 6 is placed on the inclined surface 27 of the positioning projection 26 as shown in FIG. Is moved along the X1 direction. Here, for convenience, the surface 22a is a horizontal plane, and the X1 direction is a vertical direction. Alternatively, it is assumed that the disc spring 6 is moved in the X1 direction by its own weight. At this time, the disc spring 6 is guided to the inside of the positioning projection 26 by the inclined surface 27, the disc spring 6 moves in the direction of the arrow X2, and enters the area surrounded by the positioning projection 26 on the surface 22a (that is, the disc spring mounting area). The disc spring 6 is stored.

  FIG. 19 is an enlarged side view showing a semiconductor device according to a comparative example (comparative example 1) with respect to the embodiment. In the structure of the comparative example, the positioning protrusion 426 is a cylindrical or prismatic protrusion and does not have the inclined surface 27. Therefore, when the mounting position of the disc spring 6 is shifted even a little, the disc spring 6 is stationary with the edge of the disc spring 6 riding on the positioning projection 426, and the disc spring 6 is likely to be misaligned. After the disc spring 6 is mounted, the disc spring 6 is tightened with the screw 9 as it is, so that the disc spring 6 is not properly sandwiched and an assembly failure occurs. Further, when an impact is applied during conveyance after the disc spring 6 is mounted, the disc spring 6 that should be accurately arranged may ride on the positioning protrusion 426 as shown in FIG.

  In this regard, according to the semiconductor device 10 according to the first embodiment, the positioning protrusion 26 has the inclined surface 27 as the invitation structure, so that the disc spring 6 can be prevented from being displaced. That is, the problem that the disc spring 6 rides on the positioning protrusion 26 as shown in FIG. 19 can be prevented. Furthermore, it is possible to suppress the positional shift due to the impact of conveyance after mounting. Furthermore, there is an advantage that the assembling property of the semiconductor device 10 is easy as well as reducing the mounting failure of the disc spring. In other words, since mounting accuracy is not required, there is an advantage that it is not necessary to add a high function such as an image recognition function to the mounting machine.

  In the first embodiment described above, the semiconductor module 20 is a module having a resin mold structure, and the positioning protrusions 26 are also formed of resin. However, the positioning protrusion 26 may not be molded integrally with the sealing resin body 22. For example, the positioning protrusion 26 may be formed as a separate part and fixed to the surface of the sealing resin body 22. In the case of such a separate part, the material of the positioning protrusion 26 is not limited, and a material other than resin, such as metal or ceramics, may be used.

  8 to 10 are plan views respectively showing semiconductor modules 120 to 128 applied to the semiconductor device according to the modification of the first embodiment of the present invention. The semiconductor module 20 in the semiconductor device 10 may be replaced with the semiconductor modules 120 to 128 according to the modification.

  As in the semiconductor module 120 shown in FIG. 8, an annular positioning protrusion 261 surrounding the disc spring mounting area may be provided instead of the positioning protrusion 26. As shown in FIG. 8, the positioning protrusion 261 may have an annular shape in a plan view of the surface 22 a, but is not limited thereto, and may have an annular shape such as a square shape in a plan view of the surface 22 a. Even in such a plan view shape, the inclined surface 27 may be provided at least at the upper end portion of the positioning projection 261. In other words, according to this modification, it is possible to provide the positioning protrusion having an inclined surface that is inclined from the outside of the ring toward the center.

  Like the semiconductor module 122 shown in FIG. 9, the number of the positioning protrusions 26 may be three, and may be arranged in an equilateral triangle shape so as to surround the disc spring 6. Further, as another modification (not shown), the number of positioning protrusions 26 may be five or more.

  As shown in FIGS. 10A to 10C, the shape of the positioning projection 26 in plan view can be changed into various shapes. For example, it may be L-shaped in a plan view like a positioning protrusion 263 shown in the modification of FIG. Like the positioning protrusion 264 shown in the modified example of FIG. 10B, two U-shaped positioning protrusions are arranged so as to sandwich the disc spring mounting region and the U-shaped openings face each other. Also good. Alternatively, as shown in the modification of FIG. 10 (c), it may be a C-shaped positioning protrusion 265 in plan view, and two C-shaped positioning protrusions face each other as shown in FIG. 10 (c). May be provided. Alternatively, the configuration of FIG. 10C may be further modified to provide three or more C-shaped positioning protrusions so as to surround the disc spring mounting region. Each of these positioning protrusions 263 to 265 has a recess that opens toward the center of the disc spring mounting region when the surface 22a of the semiconductor module 20 is viewed in plan. Even in these various plan-view shapes, the slope 27 may be provided at least at the upper end of the positioning protrusions 263 to 265.

  FIG. 11 is a plan view showing a semiconductor module 130 applied to the semiconductor device 210 according to the modification of the first embodiment of the present invention, and FIG. 12 is a side view of the semiconductor device 210. Although not shown in FIG. 12 for the sake of convenience, also in the semiconductor device 210, the cooling fin 2 has the screw boss 3 similarly to the semiconductor device 10, and the screw 9 connects the holding plate 8 and the cooling fin 2. FIG. 13 is an enlarged side view showing the semiconductor device 210 in which the vicinity of the disc spring 6 is enlarged. The modification of FIG. 11 has a positioning protrusion 266 in which the size of the positioning protrusion 26 is increased. The slope 271 as an invitation structure is enlarged. Increasing the slope 271 can increase the effect of suppressing misalignment. Further, when the disc spring 6 is put on the surface 22 a of the sealing resin body 22, for example, even when the disc spring 6 is put on the end portion of the sealing resin body 22 to some extent, the disc spring 6 is moved by the inclined surface 271. Can work guide function. For this reason, since the positional accuracy at the time of arrange | positioning the disc spring 6 may be low, there also exists an advantage that assembly property can be made easy.

  FIG. 14 is a side view showing a semiconductor module 132 applied to the semiconductor device according to the modification of the first embodiment of the present invention. The semiconductor module 20 in the semiconductor device 10 may be replaced with the semiconductor module 132 according to the modification. As in the modification of FIG. 14, only the upper end portion of the positioning projection 267 may be the inclined surface 27, and the root side surface 28 of the positioning projection 267 may be vertical. In this case, even if the disc spring 6 moves in parallel with the surface 22a of the sealing resin body 22 from the state of FIG. 14, the edge of the disc spring 6 does not run on the slope 27, and the base side surface 28 reliably The movement of the spring 6 can be stopped.

Embodiment 2. FIG.
The semiconductor device 310 according to the second embodiment has the same configuration as the semiconductor device 10 according to the first embodiment except that the semiconductor module 20 is replaced with the semiconductor module 320. Therefore, in the following description, the same or corresponding components as those in the first embodiment will be described with the same reference numerals, and differences from the first embodiment will be mainly described, and common items will be briefly described. Or omitted.

  FIG. 15 is a plan view showing a semiconductor module 320 applied to the semiconductor device 310 according to the second embodiment of the present invention, and FIG. 16 is a cross-sectional view showing the semiconductor device 310 (cross-section EE ′ in FIG. 15). It is. FIG. 17 is an enlarged cross-sectional view showing the semiconductor device 310, and is an enlarged view of the vicinity of the disc spring 6.

  The semiconductor device 310 is provided on the cooling fin 2 and includes a semiconductor module 20 having a sealing resin body 322 having a surface 322 a facing the opposite side of the cooling fin 2, and a disc spring placed inside the positioning recess 326. 6, a pressing plate 8 stacked on the disc spring 6, and a screw 9 that couples the pressing plate 8 and the cooling fin. This is the same as the semiconductor device 10 according to the first embodiment. The semiconductor module 320 does not have the positioning protrusion 26, and instead includes a positioning recess 326 on the surface 322 a of the sealing resin body 322. Other configurations are the same as those of the semiconductor module 20 in the first embodiment.

  The positioning recess 326 includes a bottom surface 326b and a side surface 326a. The disc spring 6 is placed on the bottom surface 326b, and the side surface 326a surrounds the bottom surface 326. Since the bottom surface of the positioning recess 326 is larger than the diameter of the disc spring 6, and the disc spring 6 is entirely contained in the positioning recess 326, it does not run on the side surface 326a unless misalignment occurs. . For this reason, when the disc spring 6 is pressed by the holding plate 8, the pressing force by the restoring force of the disc spring 6 can be exerted over the entire outer peripheral side of the bottom surface 326, and the semiconductor module 322 is pressed and fixed with sufficient force. be able to.

  The entire side surface 326a is inclined at an angle θ with respect to the bottom surface 326b so as to be lowered toward the center of the bottom surface 326b. Since the edge of the disc spring 6 is guided by the side surface 326 a of the positioning recess 326, it is possible to prevent the disc spring 6 from riding on the outside of the positioning recess 326. The disc spring 6 can be prevented from climbing on the edge of the positioning recess 326, and the resin surface can be reliably pushed across the disc spring 6.

  The displacement can be suppressed, and by providing the positioning recess 326, the creeping distance (arrow F1 in FIG. 17) between the disc spring 6 and the lead terminal 24 can be increased, and the insulation can be improved. . FIG. 20 is an enlarged cross-sectional view illustrating a semiconductor device according to a comparative example (Comparative Example 2) with respect to the embodiment. Compared to the arrow F2 in FIG. 20, the semiconductor module 320 according to the second embodiment has the positioning recess 326, and thus the creepage distance F1 is longer.

  FIG. 18 is an enlarged cross-sectional view showing a semiconductor device 330 according to a modification of the second embodiment of the present invention. Of the side surfaces of the positioning recess 336, a connection portion connected to the bottom surface 336b is a vertical surface 336a perpendicular to the bottom surface 336b. A slope 336c is provided on the side surface of the positioning recess 336 above the connection portion. In this way, it is only necessary that the slope 336c be provided at least at the upper end of the side surface of the positioning recess 336. According to this modification, it is possible to reliably stop the disc spring 6 from moving in the lateral direction, similarly to the configuration of FIG. Further, in the positioning recess 336 according to this modification, compared to the case where the entire side surface 326a is inclined like the positioning recess 326, the vertical surface 336a is present at the corner of the bottom surface 336b from the lead terminal 24 to the disc spring 6. There is also an advantage that the creepage distance increases.

  In the second embodiment, the rectangular positioning recess 326 is provided in a plan view of the surface 322a, but a plan view shape other than a square may be used. 21 and 22 are plan views showing semiconductor modules 340 and 360 applied to the semiconductor device according to the modification of the second embodiment of the present invention. For example, like the semiconductor module 340 in FIG. 21, a circular positioning recess 346 may be provided in the plan view of the surface 322a. Alternatively, it may be a triangular, pentagonal, hexagonal or other polygonal positioning recess, and as an example, a regular hexagonal positioning recess 366 may be provided as in the semiconductor module 360 shown in FIG. Each of the positioning recesses 346 and 366 includes a bottom surface 346b and 366b on which the disc spring 6 is placed, and side surfaces 346a and 366a surrounding the bottom surface 346b and 366b. Similar to the side surface 326a or the inclined surface 336c, these side surfaces 346a and 366a may be configured. Specifically, at least the upper end portions of the side surfaces 346a and 366a may be configured to include slopes inclined with respect to the bottom surfaces 346b and 366b so as to descend toward the center of the bottom surfaces 346b and 366b.

10, 310, 330 Semiconductor device, 26, 261 to 267, 426 Positioning protrusion, 2 Cooling fin, 3 Screw boss, 4 Radiation grease, 6 Belleville spring, 8 Holding plate, 9 Screw, 20, 120 to 132, 320 Semiconductor module, 22, 322 Sealing resin body, 22a, 322a surface, 24 lead terminal, 27, 271 slope, 28 base side surface, 326, 336, 346, 366 positioning recess, 326a, 346a, 366a side surface, 326b, 336b, 346b, 366b Bottom surface, 336a Vertical surface, 336c Slope, F1, F2 Creepage distance

Claims (5)

A heat dissipating member;
A surface provided on the heat radiating member, facing the opposite side of the heat radiating member, and a side surface provided along a peripheral edge of the surface, and surrounding the disc spring mounting region and the disc spring mounting region on the surface A positioning module provided with a positioning projection, and a semiconductor module provided with a terminal on the side surface ,
A disc spring mounted on the disc spring mounting area;
A holding plate overlaid on the disc spring;
A coupling member that couples the pressing plate and the heat dissipation member so as to sandwich the disc spring and the semiconductor module between the pressing plate and the heat dissipation member;
With
At least an upper end portion of the positioning protrusion is provided with a slope inclined with respect to the surface so as to descend toward the center side of the disc spring mounting region ,
The positioning protrusion is a semiconductor device including an annular protrusion formed of an insulating material and surrounding the disc spring mounting region . A heat dissipating member;
A semiconductor module provided on the heat dissipating member, having a surface facing the opposite side of the heat dissipating member, and comprising a disc spring mounting region and a positioning protrusion provided on the surface so as to surround the disc spring mounting region; ,
A disc spring mounted on the disc spring mounting area;
A holding plate overlaid on the disc spring;
A coupling member that couples the pressing plate and the heat dissipation member so as to sandwich the disc spring and the semiconductor module between the pressing plate and the heat dissipation member;
With
At least an upper end portion of the positioning protrusion is provided with a slope inclined with respect to the surface so as to descend toward the center side of the disc spring mounting region,
The positioning protrusions, including the semi-conductor device a plurality of projections provided so as to surround the disc spring mounting region. A heat dissipating member;
Wherein provided on the heat radiating member, and a side surface which is provided along the periphery of the opposite side faces a surface wherein the surface of the heat radiating member includes a positioning recess formed in the insulating material to the surface, the A semiconductor module provided with terminals on the side surfaces ;
A disc spring placed inside the positioning recess;
A holding plate overlaid on the disc spring;
A coupling member that couples the pressing plate and the heat dissipation member so as to sandwich the disc spring and the semiconductor module between the pressing plate and the heat dissipation member;
With
The positioning recess includes a bottom surface on which the disc spring rides and a side surface surrounding the bottom surface,
A semiconductor device, wherein at least an upper end portion of the side surface is provided with a slope inclined with respect to the bottom surface so as to descend toward the center side of the bottom surface. The semiconductor device according to claim 3 , wherein the entire side surface is inclined with respect to the bottom surface so as to be lowered toward the center of the bottom surface. The semiconductor device according to claim 3 , wherein a connection portion connected to the bottom surface of the side surface is perpendicular to the bottom surface, and the inclined surface is provided above the connection portion of the side surface.

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