JP2021048185A - Semiconductor device - Google Patents

Abstract

To provide a semiconductor device capable of maintaining fastening by a fastening part.SOLUTION: A semiconductor device 10 comprises: a metal radiator plate 20; a semiconductor module 31 provided onto the radiator plate 20; a resin case 60 being provided to the radiator plate 20 and fixed to the semiconductor module 31; and a plate spring 40 provided onto the semiconductor module 31. Also, the semiconductor device 10 comprises a pressing member 50. The pressing member 50 includes a fastening part 52 for being fastened with the radiator plate 20, and presses the plate spring 40 to the semiconductor module 31 by fastening the fastening part 52 and the radiator plate 20. The pressing member 50 positions a resin case 60 to the radiator plate 20, and the fastening part 52 and the radiator plate 20 are fastened without passing through the resin case 60.SELECTED DRAWING: Figure 6

Description

The present invention relates to a semiconductor device including a pressing member that presses an elastic member toward a semiconductor module.

As a semiconductor device, a structure is known in which a semiconductor module is pressed against a heat radiating plate by a leaf spring, which is an example of an elastic member (for example, Patent Document 1). The semiconductor device disclosed in Patent Document 1 includes a heat radiating plate, a semiconductor module provided on the heat radiating plate, a leaf spring provided on the semiconductor module, a reinforcing beam provided on the leaf spring, and a heat radiating plate. A frame portion provided on the top and covering the outer periphery of the semiconductor module is provided.

The leaf spring presses the semiconductor module against the heat dissipation plate. The frame portion reinforces the heat radiating plate. Reinforcing beams reinforce leaf springs. The leaf spring is fastened to the heat radiating plate by screwing a screw, which is an example of a fastening member penetrating the leaf spring, into the heat radiating plate via a frame portion with an axial force larger than the reaction force of the leaf spring.

Japanese Unexamined Patent Publication No. 2008-258241

However, in the semiconductor device of Patent Document 1, there is a risk that the screws may loosen and the fastening cannot be maintained due to the vibration of the frame portion or the expansion of the frame portion due to the heat generated from the semiconductor module.

An object of the present invention is to provide a semiconductor device capable of maintaining fastening by a fastening portion.

Semiconductor devices for solving the above problems include a metal heat radiating plate, a semiconductor module provided on the heat radiating plate, and a resin frame provided on the heat radiating plate and fixed to the semiconductor module. It has an elastic member provided on the semiconductor module and a fastening portion for fastening to the heat radiating plate, and by fastening the fastening portion and the heat radiating plate, the elastic member is directed toward the semiconductor module. A pressing member for pressing is provided, and the pressing member positions the resin frame with respect to the heat radiating plate, and the fastening portion and the heat radiating plate are fastened without the resin frame. Is the gist.

According to this, in the structure in which the fastening portion of the pressing member and the heat radiating plate are fastened, even if the resin frame expands due to the heat generated from the semiconductor module or the resin frame rattles due to the vibration of the semiconductor device, the fastening is performed. The portion is not affected by the expansion or vibration of the resin frame, and the fastening by the fastening portion can be maintained.

Further, with respect to the semiconductor device, the fastening portion may be located outside the outer circumference of the resin frame.
According to this, for example, a projecting piece is provided along the inner peripheral surface of the resin frame, and the projecting piece is sandwiched between the fastening portion of the pressing member and the heat radiating plate, and the fastening portion and the heat radiating plate are fastened to fasten the resin frame. As a comparative example, the case where is fastened together with the fastening portion and the heat radiating plate. Compared with this comparative example, the fastening portion can be separated from the outer circumference of the resin frame, and the pressing force acting on the resin frame at the time of fastening can be reduced.

According to the present invention, the fastening by the fastening portion can be maintained.

The perspective view which shows the semiconductor device of an embodiment. The plan view which shows the semiconductor device of an embodiment. An exploded perspective view showing the semiconductor device of the embodiment. The side view which shows the semiconductor device of embodiment. (A) is a partial cross-sectional view showing the semiconductor device of the embodiment, and (b) is an enlarged view showing the vicinity of the bonding frame. FIG. 5 is a cross-sectional view showing the semiconductor device of the embodiment.

Hereinafter, an embodiment embodying the semiconductor device description will be described with reference to FIGS. 1 to 6.
As shown in FIGS. 1, 2 or 3, the semiconductor device 10 is provided on a heat radiating plate 20, a plurality of semiconductor modules 30 and 31 provided on the heat radiating plate 20, and a semiconductor on the heat radiating plate 20. A resin case 60 as a resin frame fixed to the modules 30 and 31 is provided. Further, the semiconductor device 10 includes a leaf spring 40 which is an example of an elastic member provided on the semiconductor modules 30 and 31, and a pressing member 50 which presses the leaf spring 40 toward the semiconductor modules 30 and 31.

In the semiconductor device 10, the semiconductor modules 30 and 31 are provided on the heat radiating plate 20 in a state of being housed in the resin case 60. The pressing member 50 is provided on the leaf spring 40. The pressing member 50 has a fastening portion 52, and the fastening portion 52 and the heat radiating plate 20 are fastened by a screw 70 as a fastening member. The pressing member 50 presses the leaf spring 40 toward the semiconductor modules 30 and 31 by fastening the fastening portion 52 and the heat radiating plate 20.

The heat radiating plate 20 has a rectangular shape in a plan view. The heat radiating plate 20 is made of, for example, copper or aluminum. In a plan view of the heat radiating plate 20, the longitudinal direction of the heat radiating plate 20 is defined as the first direction X of the semiconductor device 10, and the lateral direction of the heat radiating plate 20 is defined as the second direction Y of the semiconductor device 10. The heat radiating plate 20 includes an adhesive groove 21 recessed from the upper surface 20a facing the resin case 60 and the semiconductor modules 30 and 31. The adhesive groove 21 has a square frame shape in a plan view.

The heat radiating plate 20 includes six pressing member fastening portions 22. Three fastening portions 22 for pressing members are provided on each of the pair of longitudinal portions of the heat radiating plate 20 at intervals in the first direction X. Further, the six pressing member fastening portions 22 are arranged so that the two pressing member fastening portions 22 face each other in the second direction Y. The pressing member fastening portion 22 projects cylindrically from the upper surface 20a of the heat radiating plate 20. Each pressing member fastening portion 22 is provided with a female screw 23 on the inner peripheral surface.

The resin case 60 has a rectangular bottom wall 61 in a plan view, a square frame-shaped peripheral wall 62 protruding in one direction from the peripheral edge of the bottom wall 61, and a direction opposite to one direction from the peripheral edge of the bottom wall 61. It has a protruding square frame-shaped adhesive frame 63. The resin case 60 is placed on the heat radiating plate 20 so that the longitudinal direction of the bottom wall 61 coincides with the first direction X of the semiconductor device 10 and the lateral direction of the bottom wall 61 coincides with the second direction Y of the semiconductor device 10. It is provided in. The resin case 60 is provided with positioning protrusions 65 on both ends in the longitudinal direction of the bottom wall 61. The two positioning protrusions 65 project in a columnar shape from the upper surface 61b of the bottom wall 61.

The peripheral wall 62 has a pair of long side walls 62a protruding in one direction from each of the pair of long side portions of the bottom wall 61, and a pair of short side walls 62b protruding in one direction from each of the pair of short side portions of the bottom wall 61. Be prepared. One positioning protrusion 65 is located between one short side wall 62b and the semiconductor module 30, and the other positioning protrusion 65 is located between the other short side wall 62b and the semiconductor module 31.

As shown in FIG. 5A or FIG. 6, the resin case 60 is provided on the heat radiating plate 20 so as to be sandwiched between the pressing member fastening portions 22 of the heat radiating plate 20 in the second direction Y, and the adhesive frame. 63 is inserted into the adhesive groove 21 of the heat radiating plate 20. Then, the adhesive frame 63 and the heat radiating plate 20 are adhered to each other by the adhesive 24 filled in the adhesive groove 21.

As shown in FIG. 5B, the semiconductor device 10 includes a resin layer 25 provided along the inner peripheral surface of the adhesive frame 63. The resin layer 25 is formed by thermosetting a thermosetting resin. The semiconductor device 10 includes a cooling grease 27 applied to a portion of the upper surface 20a of the heat radiating plate 20 surrounded by the resin layer 25. The wet spread of the cooling grease 27 is regulated by the resin layer 25.

Cooling grease 27 is interposed between the lower surface 61a of the bottom wall 61 of the resin case 60 (the surface facing the upper surface 20a of the heat radiating plate 20) and the upper surface 20a of the heat radiating plate 20. As shown in FIG. 5A, the semiconductor modules 30 and 31 are mounted on the upper surface 61b of the bottom wall 61 (the surface of the bottom wall 61 opposite to the lower surface 61a). The heat generated in the semiconductor modules 30 and 31 is transferred to the heat radiating plate 20 via the bottom wall 61 of the resin case 60 and the cooling grease 27, and the semiconductor modules 30 and 31 are dissipated. Further, the resin case 60 insulates the semiconductor modules 30 and 31 from the heat radiating plate 20.

As shown in FIG. 2 or 3, the leaf spring 40 is made of a spring steel plate, and has a shape in which the length extends in the first direction X in a plan view as a whole. The leaf spring 40 presses the semiconductor modules 30 and 31 against the bottom wall 61 while pressing the bottom wall 61 against the cooling grease 27. The leaf spring 40 has a pair of main body portions 41 provided at intervals in the longitudinal direction, a connecting portion 42 extending in the first direction X and connecting the pair of main body portions 41, and connecting portions 42 from each main body portion 41. It has a pair of projecting portions 43 projecting in a direction opposite to the projecting direction of the above. Each main body 41 includes a rectangular pressed portion 41a and two pressing portions 41b extending obliquely from each of the pair of long side portions of the pressed portion 41a. A mounting groove hole 43a is formed at the end of each protruding portion 43 on the opposite side to the pressed portion 41a. A positioning protrusion 65 is inserted into each mounting groove hole 43a.

The pressing member 50 is made of a metal plate material such as aluminum. The pressing member 50 has a main body 51 having a rectangular shape in a plan view, and a fastening portion 52 protruding from both longitudinal portions of the main body 51 by three. The length L1 in the longitudinal direction of the main body 51 is longer than the length M1 in the longitudinal direction of the bottom wall 61 in the resin case 60. Further, the length L2 of the main body 51 in the lateral direction is shorter than the length M2 of the bottom wall 61 in the resin case 60 in the lateral direction.

More specifically, three fastening portions 52 are provided on each of the pair of longitudinal portions of the main body 51 at intervals in the first direction X. Further, the six fastening portions 52 are arranged so that the two fastening portions 52 face each other in the second direction Y. A through hole 52a is formed in the fastening portion 52. The length of the straight line N connecting the center points of the pair of through holes 52a facing the main body 51 in the lateral direction is longer than the length M2 of the bottom wall 61 in the resin case 60 in the lateral direction. The pressing member 50 is provided with through holes 51a on both ends in the longitudinal direction of the main body 51. A positioning protrusion 65 that penetrates the mounting groove hole 43a of the leaf spring 40 is inserted into each through hole 51a.

In the semiconductor device 10, the pressing member 50 is fastened to the heat radiating plate 20 by screwing a screw 70 as a fastening member penetrating the through hole 52a into the female screw 23 of the pressing member fastening portion 22 of the heat radiating plate 20. ing. The screw 70 fastens the pressing member 50 to the heat radiating plate 20 against the reaction force of the leaf spring 40. In the semiconductor device 10, the fastening portion 52 of the pressing member 50 and the pressing member fastening portion 22 of the heat radiating plate 20 are fastened without a resin case 60 in between, and the fastening portion 52 and the pressing member fastening portion are fastened to each other. 22 is in contact.

As shown in FIG. 5A or FIG. 6, the resin case 60 is sandwiched between the pressing member 50 and the heat radiating plate 20, and is positioned with respect to the heat radiating plate 20 by the pressing member 50. Specifically, as shown in FIG. 2 or 4, the lower surface of the main body 51 on one end side in the longitudinal direction (the surface facing the resin case 60 on one end side in the longitudinal direction of the main body 51) is one short of the resin case 60. It is in contact with the upper surface of the side wall 62b (the surface extending in the direction intersecting the protruding direction of the short side wall 62b). The lower surface of the main body 51 on the other end side in the longitudinal direction (the surface of the main body 51 facing the resin case 60 on the other end side in the longitudinal direction) intersects the upper surface of the other short side wall 62b of the resin case 60 (the protruding direction of the short side wall 62b). It is in contact with the surface extending in the direction).

Further, the lower surface of the three fastening portions 52 (the surface of the fastening portion 52 facing the long side wall 62a) protruding outward from one longitudinal portion of the main body 51 is the upper surface (long side wall) of one long side wall 62a of the peripheral wall 62. It is in contact with a surface extending in a direction intersecting the projecting direction of 62a). The lower surface of the three fastening portions 52 (the surface of the fastening portion 52 facing the long side wall 62a) protruding outward from the other longitudinal portion of the main body 51 is the upper surface of the other long side wall 62a of the peripheral wall 62 (the long side wall 62a). It is in contact with the surface extending in the direction intersecting the projecting direction). As a result, the pressing member 50 positions the resin case 60 with respect to the heat radiating plate 20.

As shown in FIG. 5A or FIG. 6, the leaf spring 40 is pressed toward the semiconductor modules 30 and 31 by the pressing member 50. The pressed portion 41a of each main body 41 is pressed toward the semiconductor modules 30 and 31 by the main body 51. When the pressed portion 41a is pressed toward the semiconductor modules 30 and 31 by the pressing member 50, the pressing portion 41b extending from the main body portion 41 toward the semiconductor modules 30 and 31 is pressed against the semiconductor modules 30 and 31. Elastically deforms. The semiconductor modules 30 and 31 are urged toward the bottom wall 61 by the reaction force that tries to return to the original shape of the elastically deformed pressing portion 41b. By this urging force, the semiconductor modules 30 and 31 are pressed toward the bottom wall 61, and the bottom wall 61 is pressed against the cooling grease 27.

Next, the operation of the semiconductor device 10 will be described.
The heat generated from the semiconductor modules 30 and 31 is transferred to the bottom wall 61 and the peripheral wall 62, and the peripheral wall 62 of the resin case 60 may expand. Further, the resin case 60 may rattle due to the vibration of the semiconductor device 10. The expansion and rattling of the peripheral wall 62 are received by the main body 51.

Next, a method of manufacturing the semiconductor device 10 will be described.
The adhesive 24 is injected into the adhesive groove 21 of the heat radiating plate 20, and the adhesive frame 63 of the resin case 60 is inserted into the adhesive groove 21. The semiconductor modules 30 and 31 are already mounted on the upper surface 61b of the bottom wall 61 of the resin case 60. Further, the thermosetting resin is applied along the inner peripheral surface of the adhesive frame 63, and the cooling grease 27 is applied to the inside of the thermosetting resin on the upper surface 20a of the heat radiating plate 20. The leaf spring 40 is placed on the semiconductor modules 30 and 31 housed in the resin case 60, and the pressing member 50 is placed on the leaf spring 40.

At this time, each positioning protrusion 65 of the resin case 60 is inserted into each through hole 51a of the pressing member 50, and the pressing member 50 is positioned with respect to the resin case 60. Then, the through hole 52a of each fastening portion 52 of the pressing member 50 matches the female screw 23 of the fastening portion 22 for the pressing member. Then, the pressing member 50 is fastened to the heat radiating plate 20 by screwing the screw 70 penetrating each through hole 52a into the female screw 23. Then, the lower surface of the pressing member 50 comes into contact with the upper surface of the peripheral wall 62 of the resin case 60, the resin case 60 is restricted from moving in the direction away from the heat radiating plate 20, and the resin case 60 is fixed to the heat radiating plate 20. To. Further, the leaf spring 40 presses the semiconductor modules 30 and 31 toward the bottom wall 61, and the bottom wall 61 is pressed against the cooling grease 27.

Then, the thermosetting resin is heat-cured to form the resin layer 25. Further, when the adhesive 24 is cured and the resin case 60 is adhered to the heat radiating plate 20, the semiconductor device 10 is manufactured.
According to the above embodiment, the following effects can be obtained.

(1) Since the resin case 60 does not expand or vibrate on the fastening portion 52 of the pressing member 50 in the semiconductor device 10, the screw 70 is suppressed from loosening and the pressing member 50 is fastened by the fastening portion 52. Can be maintained. As a result, the heat generated in the semiconductor modules 30 and 31 can be efficiently transferred to the heat radiating plate 20 via the bottom wall 61 of the resin case 60 and the cooling grease 27.

(2) Since the fastening portion 52 of the pressing member 50 is fastened to the heat radiating plate 20 against the reaction force of the leaf spring 40, the screw 70 requires a required axial force, but the screw 70 has a required axial force. Since the resin case 60 does not intervene between the pressing member fastening portion 22 and the fastening portion 52, the resin case 60 is not damaged or deformed.

(3) Using the pressing member 50 for pressing the leaf spring 40 against the semiconductor modules 30 and 31, positioning when the resin case 60 is adhered to the heat radiating plate 20 can be performed. Therefore, the component for positioning the resin case 60 on the heat radiating plate 20 can also be used as a screw 70 for fastening the fastening portion 52 of the pressing member 50 to the heat radiating plate 20. Therefore, the step of positioning the resin case 60 on the heat radiating plate 20 with a part different from the screw 70 can be deleted, and the part for positioning different from the screw 70 can be deleted, so that the manufacturing cost of the semiconductor device 10 can be reduced. Can be planned.

(4) A projecting piece is provided along the inner peripheral surface of the peripheral wall 62, and the projecting piece is fastened while being sandwiched between the fastening portion 52 of the pressing member 50 and the pressing member fastening portion 22 of the heat radiating plate 20, and the resin case. A case where 60 is fastened together with the pressing member 50 and the heat radiating plate 20 is taken as a comparative example. In the present embodiment, the fastening portion 52 projects outward from the outer periphery of the peripheral wall 62 of the resin case 60 and is fastened to the pressing member fastening portion 22 of the heat radiating plate 20. Therefore, as compared with the comparative example, the fastening portion 52 can be separated from the outer periphery of the peripheral wall 62 to the outside, the pressing force acting on the peripheral wall 62 at the time of fastening can be reduced, and damage or deformation of the peripheral wall 62 can be suppressed. ..

Further, since the fastening portion 52 is outside the peripheral wall 62 of the resin case 60 that covers the outer peripheral side of the semiconductor modules 30 and 31, it is easy to secure the insulation between the fastening portion 52 and the semiconductor modules 30 and 31.

This embodiment can be modified and implemented as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
○ In the embodiment, two semiconductor modules are used, but the number thereof is not limited and may be appropriately changed according to the specifications of the semiconductor device 10. The same applies to the leaf spring 40, and it is sufficient that the number of main body portions 41 corresponding to the number of semiconductor modules is formed.

○ In the embodiment, the cooling grease 27 is used between the semiconductor modules 30 and 31 and the heat radiating plate 20, but other heat conductive members such as a heat radiating sheet may be used.
○ The cooling grease 27 and the resin layer 25 may be omitted.

○ The adhesive frame 63 of the resin case 60 may be omitted, and in this case, the adhesive groove 21 and the adhesive 24 of the heat radiating plate 20 are also eliminated.
○ The fastening portion 52 of the pressing member 50 is located inside the long side wall 62a of the resin case 60, and the fastening portion 22 for the pressing member of the heat radiating plate 20 is located inside the long side wall 62a. It may be provided through the above. In this case, the fastening portion 52 is located inside the inner circumference of the resin case 60. The lower surfaces of both ends of the main body 51 in the longitudinal direction come into contact with the upper surfaces of both short side walls 62b of the peripheral wall 62, and the resin case 60 is sandwiched between the pressing member 50 and the heat radiating plate 20.

○ The fastening portion 52 of the pressing member 50 may be provided so as to protrude from the pair of short portions of the main body 51. In short, the fastening portion 52 may protrude from any position of the main body 51.

○ The method of fastening the pressing member 50 to the heat radiating plate 20 is screwed, but caulking may also be used.
A washer may be interposed between the pressing member fastening portion 22 of the heat radiating plate 20 and the pressing member fastening portion 52 of the pressing member 50.

○ In the above embodiment, the resin case 60 is used as the resin frame, but the resin frame is not limited to the case shape, and may be at least a frame shape surrounding the semiconductor module and fixed to the semiconductor module. When the resin frame has a frame shape, for example, the resin frame functions as a shield to prevent the resin from flowing out of the resin frame when the periphery of the semiconductor module is hardened with the resin. Further, in this case, the semiconductor modules 30 and 31 are directly pressed against the cooling grease 27 by the pressing of the leaf spring 40 by the pressing member 50.

○ The elastic member may be other than the leaf spring 40, and may be a coil spring, a leaf rubber, or the like.
Next, the technical idea that can be grasped from the above embodiment and another example will be added below.
(1) The elastic member is a leaf spring.

(2) The resin frame is adhered to the heat radiating plate, and the pressing member positions the resin frame on the heat radiating plate when the resin frame is adhered to the heat radiating plate with an adhesive.
(3) The heat radiating plate and the fastening portion of the pressing member are fastened with screws.

10 ... Semiconductor device, 20 ... Heat dissipation plate, 30, 31 ... Semiconductor module, 40 ... Leaf spring as an elastic member, 50 ... Pressing member, 52 ... Fastening part, 60 ... Resin case as a resin frame.

Claims (2)

With a metal heat dissipation plate
A semiconductor module provided on the heat radiating plate and
A resin frame provided on the heat radiating plate and fixed to the semiconductor module,
An elastic member provided on the semiconductor module and
It has a fastening portion for fastening to the heat radiating plate, and includes a pressing member that presses the elastic member toward the semiconductor module by fastening the fastening portion and the heat radiating plate.
The pressing member is a semiconductor device characterized in that the resin frame is positioned with respect to the heat radiating plate, and the fastening portion and the heat radiating plate are fastened without the resin frame. The semiconductor device according to claim 1, wherein the fastening portion is located outside the outer circumference of the resin frame.

Images