JP2022075284A - Semiconductor device - Google Patents

Abstract

To provide a semiconductor device capable of suppressing rotation of a substrate for a heat sink.SOLUTION: A semiconductor device 10 comprises a substrate 20 mounted with a semiconductor element 24, and a heat sink 40. The heat sink 40 comprises an end wall 41 for mounting a first surface 21 in a thickness direction of the substrate 20, and a peripheral wall 42 provided integrally with the end wall 41 and provided along a side surface 23 of the substrate 20. The end wall 41 and the peripheral wall 42 form a housing part 43 for housing the substrate 20. A first adhesion layer 61 and a second adhesion layer 62 are provided which are composed of an adhesive Ad for bonding between the end wall 41 and the first surface 21 of the substrate 20 and between the peripheral wall 42 and the side surface 23 of the substrate 20.SELECTED DRAWING: Figure 5

Description

The present invention relates to a semiconductor device.

Conventionally, the semiconductor device described in Patent Document 1 is known.
The above-mentioned semiconductor device includes a substrate on which a semiconductor element such as a switching element is mounted, and a heat sink for cooling the substrate. The substrate is provided with terminal electrodes extending upward from the upper surface of the substrate. The substrate is mounted on the upper surface of the heat sink. The board and the heat sink are fixed to each other by screws.

Japanese Unexamined Patent Publication No. 2018-38145

However, for example, when the substrate is fixed to the heat sink with screws, or when an external device is electrically connected to the terminal electrodes, the substrate may rotate with respect to the heat sink.

A semiconductor device for solving the above problems includes a substrate on which a semiconductor element is mounted and a heat sink, and the heat sink has an end wall for mounting a first surface in the thickness direction of the substrate and the end. It has a peripheral wall provided integrally with the wall and provided along a side surface intersecting the first surface of the substrate, and the end wall and the peripheral wall form an accommodating portion for accommodating the substrate. An adhesive layer composed of an adhesive for adhering between the end wall and the first surface and between the peripheral wall and the side surface is provided.

According to this, an adhesive layer is provided between the end wall of the heat sink and the first surface of the substrate, and between the peripheral wall of the heat sink and the side surface of the substrate. Therefore, the strength of the bond between the substrate and the heat sink is improved. Further, since the adhesive layer fills the space between the peripheral wall and the side surface of the substrate, it becomes difficult for the substrate to rotate with respect to the peripheral wall. Therefore, the rotation of the substrate with respect to the heat sink can be suppressed.

In the above semiconductor device, the end wall has a mounting surface facing the first surface, and the height from the previously described mounting surface to the second surface located on the side opposite to the first surface of the substrate. It is preferable that the height is lower than the height from the above-mentioned mounting surface to the open end of the peripheral wall.

According to this, when the substrate is accommodated in the accommodating portion of the heat sink, the adhesive is easily transferred from the side surface of the substrate to the second surface of the substrate, and is difficult to be transferred to the open end of the peripheral wall. Therefore, it is possible to suppress the leakage of the adhesive to the outside of the semiconductor device.

In the above semiconductor device, the end wall has a mounting surface facing the first surface, and the height from the previously described mounting surface to the second surface located on the side opposite to the first surface of the substrate. It is preferable that the height is higher than the height from the above-mentioned mounting surface to the open end of the peripheral wall.

According to this, when the substrate is accommodated in the accommodating portion, a part of the substrate including the second surface is located outside the heat sink. That is, when the operator accommodates the substrate in the accommodating portion, it becomes easy to hold the substrate in the accommodating portion until the accommodation of the substrate is completed. Therefore, the quality at the time of manufacturing the semiconductor device can be maintained.

In the above semiconductor device, the adhesive layer may extend from between the peripheral wall and the side surface to a second surface located on the opposite side of the first surface of the substrate.
According to this, the portion of the adhesive layer extending to the second surface of the substrate makes it difficult for the substrate to peel off from the end wall when the substrate vibrates in the thickness direction. Therefore, the strength of joining the substrate to the end wall is improved.

In the above semiconductor device, it is preferable to further include a cover that closes the opening of the peripheral wall by being placed on the opening end of the peripheral wall.
According to this, by covering the opening of the peripheral wall with a cover, it is possible to prevent foreign matter from adhering to the substrate from the outside of the semiconductor device.

In the above semiconductor device, the substrate may have a rectangular shape when viewed from the thickness direction, and the peripheral wall may have a rectangular ring shape when viewed from the thickness direction.
According to this, even if the substrate tries to rotate with respect to the heat sink, the peripheral wall restricts the rotation of the substrate via the adhesive layer. Even if the peripheral wall receives the rotating force of the substrate, since the peripheral wall is provided integrally with the end wall, the rotating force of the substrate can be distributed not only to the peripheral wall but also to the end wall. Therefore, the rotation of the substrate with respect to the heat sink can be further suppressed.

According to the present invention, the rotation of the substrate with respect to the heat sink can be suppressed.

A split perspective view of a semiconductor device. FIG. 2 is a cross-sectional view taken along the line 2-2 of FIG. FIG. 3 is a cross-sectional view taken along the line 3-3 of FIG. Schematic view of the opening of the peripheral wall of the heat sink as seen from the front. Sectional drawing of the semiconductor device of 2nd Embodiment. Sectional drawing of the semiconductor device of 2nd Embodiment. Schematic view of the modified example board from the front.

Hereinafter, an embodiment embodying a semiconductor device will be described with reference to FIGS. 1 to 3. The semiconductor device of the present embodiment is an inverter for driving a three-phase AC motor for traveling an industrial vehicle such as a forklift.

As shown in FIG. 1, the semiconductor device 10 includes a substrate 20, a plurality of terminals 30, a heat sink 40, and a cover 50. The semiconductor device 10 includes a control board (not shown).

The substrate 20 has a rectangular shape in a plan view in the thickness direction. The substrate 20 intersects a rectangular first surface 21 located in the thickness direction, a rectangular second surface 22 located on the opposite side of the first surface 21, and the first surface 21 and the second surface 22. It has a side surface 23. The first surface 21 and the second surface 22 have a rectangular shape having a short side and a long side. The side surface 23 is continuous with the first surface 21 and the second surface 22. The substrate 20 is a resin substrate in which a conductive metal member is incorporated in the resin. The second surface 22 of the substrate 20 is provided with a pattern formed by exposing the metal member. The direction in which the short side of the first surface 21 and the second surface 22 extends is the short side direction, and the direction in which the long side extends is the long side direction.

A plurality of semiconductor elements 24 are mounted on the second surface 22 of the substrate 20. All semiconductor elements 24 are electrically connected to a pattern provided on the second surface 22 of the substrate 20. The semiconductor element 24 is, for example, a MOSFET. The plurality of semiconductor elements 24 are divided into six semiconductor element groups G1, G2, G3, G4, G5, and G6. In each semiconductor element group G1, G2, G3, G4, G5, G6, each semiconductor element 24 is arranged in a row in the short side direction of the substrate 20. The semiconductor element groups G1, G2, G3, G4, G5, and G6 are arranged at intervals in the longitudinal direction of the substrate 20. Each semiconductor element group G1, G2, G3, G4, G5, G6 constitutes a three-phase upper and lower arm in the inverter. In addition, all the semiconductor elements 24 of this embodiment may be switching elements such as isolated gate bipolar transistors. The semiconductor elements 24 may be arranged in a row in the long side direction of the substrate 20, or may be arranged in any manner as long as they are arranged on the second surface 22 of the substrate 20.

A plurality of terminals 30 are mounted on the second surface 22 of the substrate 20. All terminals 30 are electrically connected to a pattern provided on the second surface 22 of the substrate 20. All terminals 30 project from the second surface 22. Each of all the terminals 30 has a columnar shape. The base ends of all the terminals 30 are electrically connected to the second surface 22 of the substrate 20. At the tips of all the terminals 30, screw holes 30a recessed in the axial direction of the terminals 30 are provided. A female screw groove is formed on the inner peripheral surface of the screw hole 30a.

As shown in FIG. 2, the terminal 30 is fixed to the substrate 20 by a bolt B inserted from the first surface 21 to the second surface 22 of the substrate 20. The bolt B penetrates the base end of the terminal 30 in the axial direction and is screwed to the terminal 30.

As shown in FIG. 1, in this embodiment, five terminals 30 are adopted. The five terminals 30 are a positive electrode input terminal 31, a negative electrode input terminal 32, and three output terminals 33. The positive electrode input terminal 31, the negative electrode input terminal 32, and the output terminal 33 are made of a metal such as aluminum-based metal or copper.

The positive electrode input terminal 31, the negative electrode input terminal 32, and the three output terminals 33 are arranged at intervals in the longitudinal direction of the substrate 20. The positive electrode input terminal 31, the negative electrode input terminal 32, and the three output terminals 33 are arranged so as to form a line in the longitudinal direction of the substrate 20. In a plan view from the thickness direction of the substrate 20, the positive electrode input terminal 31, the negative electrode input terminal 32, and the three output terminals 33 have a pair of short edges of the substrate 20 from the center of one of the pair of short edges of the substrate 20. They are arranged in a row along a virtual straight line extending toward the center of the other side of the. The positive electrode input terminal 31 and the negative electrode input terminal 32 are arranged so as to sandwich the semiconductor element groups G1, G2, G3, G4, G5, G6 in the longitudinal direction of the substrate 20. The positive electrode input terminal 31 and the negative electrode input terminal 32 are arranged near a pair of short edges of the substrate 20. The positive electrode input terminal 31, the negative electrode input terminal 32, and the three output terminals 33 were arranged so as to form an example in the longitudinal direction of the substrate 20, but since they are arranged on the second surface 22 of the substrate 20. If there is, it may be arranged in any way.

As shown in FIGS. 1, 2, and 3, the heat sink 40 is made of a metal such as an aluminum-based metal or copper. The heat sink 40 has an end wall 41 and a peripheral wall 42. The end wall 41 has a plate shape. The end wall 41 has a rectangular shape in a plan view in the thickness direction. The end wall 41 has a rectangular mounting surface 41a facing the first surface 21 of the substrate 20 in the thickness direction. The mounting surface 41a is slightly larger than the first surface 21 of the substrate 20.

The peripheral wall 42 projects from the end wall 41 so as to be separated from the mounting surface 41a in the thickness direction of the end wall 41. The peripheral wall 42 is provided integrally with the end wall 41. In a plan view of the end wall 41 in the thickness direction, the peripheral wall 42 has a rectangular annular shape. The heat sink 40 is formed with an accommodating portion 43 surrounded by an end wall 41 and a peripheral wall 42.

The open end of the peripheral wall 42 forms an annular surface 421a forming a rectangular annular shape. The peripheral wall 42 has a rectangular shape having an outer edge and an inner edge having a short side and a long side. The direction in which the short side of the outer edge and the inner edge of the peripheral wall 42 extends is the same as the direction of the short side of the substrate 20. The direction in which the long side of the outer edge and the inner edge of the peripheral wall 42 extends is the same as the long side direction of the substrate 20. The peripheral wall 42 has a pair of long wall portions 42a and 42a extending in the long side direction and a pair of short wall portions 42b and 42b extending in the short side direction. The height from the mounting surface 41a of the end wall 41 to the annular surface 421a of the peripheral wall 42 is larger than the thickness of the substrate 20.

The end wall 41 is provided with a long groove 44 recessed from the mounting surface 41a in the thickness direction of the end wall 41. In a plan view of the end wall 41 in the thickness direction, the long groove 44 is a virtual straight line extending from the center of one of the pair of short wall portions 42b, 42b toward the center of the other of the pair of short wall portions 42b, 42b. It extends linearly along it.

By providing the long groove 44 in the end wall 41, the mounting surface 41a is divided into two in the short side direction of the peripheral wall 42 in a plan view of the end wall 41 in the thickness direction. Each of the two divided surfaces on the mounting surface 41a is referred to as a first mounting surface 411a and a second mounting surface 412a. The first mounting surface 411a and the second mounting surface 412a have a pair of short sides in the short side direction in which the pair of short wall portions 42b and 42b extend in a plan view of the end wall 41 in the thickness direction. It is a rectangular plane having a long side in the long side direction in which the long wall portions 42a and 42a extend.

Before the substrate 20, the heat sink 40, and the cover 50 are assembled, the adhesive Ad is applied to the first mounting surface 411a and the second mounting surface 412a. For example, the adhesive Ad is applied to the first mounting surface 411a and the second mounting surface 412a by a dispenser nozzle so as to form a ridge portion extending between the pair of short wall portions 42b and 42b. The adhesive Ad may be applied in a plane shape in the long side direction along the first mounting surface 411a and the second mounting surface 412a, for example.

The cover 50 has a first wall 51 and a second wall 52. The first wall 51 has a plate shape. The first wall 51 has a rectangular shape in a plan view in the thickness direction. The first wall 51 has a rectangular shape having a short side and a long side in a plan view in the thickness direction. The direction in which the long side of the first wall 51 extends is the same as the direction in which the long side of the substrate 20 extends. The direction in which the short side of the first wall 51 extends is the same as the direction in which the short side of the substrate 20 extends.

The first wall 51 is provided with five through holes 51a. The five through holes 51a penetrate the first wall 51 in the thickness direction. The five through holes 51a are arranged so as to form a line at intervals in the long side direction of the first wall 51. In a plan view of the first wall 51 in the thickness direction, the five through holes 51a are located from the center of one of the pair of short sides of the first wall 51 to the center of the other of the pair of short sides of the first wall 51. It is provided so as to form a line along a virtual straight line extending toward it. The second wall 52 projects from the first wall 51 in the thickness direction of the first wall 51. The second wall 52 is provided integrally with the first wall 51. The second wall 52 has a rectangular annular shape in a plan view of the first wall 51 in the thickness direction. The open end of the second wall 52 forms an annular surface 521a forming a rectangular annular shape. The second wall 52 has a rectangular shape having an outer edge and an inner edge having a short side and a long side. The direction in which the short side of the outer edge and the inner edge of the second wall 52 extends is the same as the direction of the short side of the substrate 20. The direction in which the long side of the outer edge and the inner edge of the second wall 52 extends is the same as the long side direction of the substrate 20. The cover 50 is formed with a storage space S surrounded by the first wall 51 and the second wall 52.

The opening 52a formed by the opening end of the second wall 52 has a rectangular shape in a plan view of the first wall 51 in the thickness direction. The opening 52a is slightly larger than the second surface 22 of the substrate 20. The opening 52a is larger than the outer peripheral edge of the substrate 20. The opening 52a has the same size as the opening formed by the opening end of the peripheral wall 42 of the heat sink 40.

When assembling the substrate 20, the heat sink 40, and the cover 50, the first surface 21 of the substrate 20 and the mounting surface 41a of the end wall 41 face each other. At this time, in the thickness direction of the substrate 20 and the end wall 41, the direction in which the five terminals 30 mounted on the substrate 20 are lined up coincides with the extending direction of the long groove 44 of the end wall 41. The substrate 20 is brought close to the mounting surface 41a, and the substrate 20 is accommodated in the accommodating portion 43 of the heat sink 40. When the substrate 20 is accommodated in the accommodating portion 43, the side surface 23 of the substrate 20 faces the entire circumference of the inner surface of the peripheral wall 42. That is, the peripheral wall 42 is provided along the entire circumference of the side surface 23 of the substrate 20. When the substrate 20 is accommodated in the accommodating portion 43, the bolts B for fixing each of all the terminals 30 to the substrate 20 are accommodated in the long groove 44. When the substrate 20 is accommodated in the accommodating portion 43, the first surface 21 of the substrate 20 spreads the adhesive Ad onto the first mounting surface 411a and the second mounting surface 412a. Then, the first surface 21 of the substrate 20 is placed on the mounting surface 41a via the adhesive Ad. That is, the end wall 41 is provided for mounting the first surface 21 of the substrate 20.

In a state where the substrate 20 is accommodated in the accommodating portion 43, the substrate 20 is fixed to the mounting surface 41a of the heat sink 40 by fastening members such as bolts and screws (not shown). The control board described above is arranged at a distance from the second surface 22 of the board 20 and is fixed to the heat sink 40 by a fixing member (not shown).

Next, the cover 50 is arranged so that the open end of the second wall 52 of the cover 50 abuts against the open end of the peripheral wall 42. At this time, the tips of the five terminals 30 are arranged at positions corresponding to the five through holes 51a provided in the first wall 51. The open end of the second wall 52 of the cover 50 is placed on the open end of the peripheral wall 42 of the heat sink 40. The annular surface 521a of the second wall 52 and the annular surface 421a of the peripheral wall 42 come into surface contact with each other. That is, the annular surfaces 421a and 521a form a sealing surface between the heat sink 40 and the cover 50.

When the second wall 52 is brought into contact with the peripheral wall 42, the cover 50 closes the opening of the peripheral wall 42. When the second wall 52 is brought into contact with the peripheral wall 42, a plurality of terminals 30 mounted on the second surface 22 of the substrate 20 and the above-mentioned control board are accommodated inside the accommodation space S of the cover 50. Further, the tips of each of the five terminals 30 are fitted into each of the five through holes 51a. That is, the screw holes 30a of each of the five terminals 30 are exposed to the outside of the semiconductor device 10 from the first wall 51. The heat sink 40 and the cover 50 are fastened to each other by, for example, bolts.

The semiconductor device 10 is completed when the substrate 20, the heat sink 40, and the cover 50 are assembled and the adhesive Ad has been dried.
In the semiconductor device 10 configured in this way, the positive electrode of the battery is electrically connected to the tip of the positive electrode input terminal 31 via an external cable. The negative electrode of the battery is electrically connected to the tip of the negative electrode input terminal 32 via an external cable. A three-phase AC motor is electrically connected to the tips of the three output terminals 33 via an external cable. In the present embodiment, a male screw groove is formed in a terminal provided on an external cable electrically connected to the positive electrode and the negative electrode of the battery, and the terminal is a screw hole of the positive electrode input terminal 31 and the negative electrode input terminal 32, respectively. It is screwed to 30a. Further, in the present embodiment, a male screw groove is formed in a terminal provided on an external cable electrically connected to each phase of the three-phase AC motor, and the terminal is a screw hole of each of the three output terminals 33. It is screwed to 30a. As a result, the external cable and each of all the terminals 30 are firmly coupled.

The control board described above has a control circuit for controlling each semiconductor element group G1, G2, G3, G4, G5, G6. By controlling each semiconductor element group G1, G2, G3, G4, G5, G6 by the control circuit, the DC power supplied from the battery to the substrate 20 via the positive electrode input terminal 31 and the negative electrode input terminal 32 is AC power. Is converted to and supplied to the three-phase AC motor from the three output terminals 33.

When the above-mentioned semiconductor device 10 is used, the amount of heat generated by the plurality of semiconductor elements 24 mounted on the substrate 20 increases, and the substrate 20 is heated. However, the substrate 20 is thermally heated to the heat sink 40 via the adhesive Ad. It is connected. Therefore, the heat generated in the substrate 20 is dissipated to the outside of the semiconductor device 10 via the heat sink 40. That is, the heat sink 40 has a function of cooling the substrate 20.

The semiconductor device 10 adopts a configuration that suppresses the rotation of the substrate 20 with respect to the heat sink 40. Hereinafter, a description will be given according to FIGS. 2 and 3.
As shown in FIGS. 2 and 3, the side surface 23 located on the first mounting surface 411a of the substrate 20 is referred to as the first side surface 231 and the side surface 23 located on the second mounting surface 412a of the substrate 20 is the second side surface. The side surface is 232.

As shown in FIG. 4, in the plan view of the open end of the peripheral wall 42 of the heat sink 40, each of the first side surface 231 and the second side surface 232 has a mirror-symmetrical U-shape. The plan view of the open end of the peripheral wall 42 of the heat sink 40 is synonymous with the plan view of the end wall 41 and the substrate 20 in the thickness direction.

As shown in FIGS. 2 and 3, the semiconductor device 10 includes a first adhesive layer 61. The first adhesive layer 61 is composed of the adhesive Ad. The first adhesive layer 61 is formed by drying and solidifying the adhesive Ad. The first adhesive layer 61 has a first layer 611, a second layer 612, and a third layer 613. The first layer 611 is provided over the entire area between the first mounting surface 411a and the first surface 21. The first layer 611 adheres between the first mounting surface 411a and the first surface 21. A part of the first layer 611 projects over a part of the inner surface of the long groove 44. The second layer 612 is provided integrally with the first layer 611. The second layer 612 is provided between the inner side surface of the peripheral wall 42 facing the first side surface 231 and the first side surface 231 of the substrate 20. The second layer 612 adheres between the peripheral wall 42 and the first side surface 231. The third layer 613 is provided integrally with the second layer 612. The third layer 613 is provided on the outer peripheral edge portion continuous with the first side surface 231 on the second surface 22 of the substrate 20. That is, the first adhesive layer 61 is an adhesive layer composed of an adhesive Ad that adheres between the end wall 41 and the first surface 21 of the substrate 20 and between the peripheral wall 42 and the side surface 23 of the substrate 20. .. Further, the first adhesive layer 61 extends from between the peripheral wall 42 and the side surface 23 to the second surface 22 of the substrate 20.

As shown in FIG. 4, the third layer 613 has a U-shape when the open end of the peripheral wall 42 of the heat sink 40 is viewed in a plan view. That is, the second layer 612 also has a U-shape along the first side surface 231 when the open end of the peripheral wall 42 of the heat sink 40 is viewed in a plan view.

As shown in FIG. 2, the semiconductor device 10 includes a second adhesive layer 62. The second adhesive layer 62 is composed of the adhesive Ad. The second adhesive layer 62 is formed by drying and solidifying the adhesive Ad. The second adhesive layer 62 has a first layer 621, a second layer 622, and a third layer 623. The first layer 621 is provided in the entire area between the second mounting surface 412a and the first surface 21. The first layer 621 adheres between the second mounting surface 412a and the first surface 21. A part of the first layer 621 projects over a part of the inner surface of the long groove 44. The second layer 622 is provided integrally with the first layer 621. The second layer 622 has the same shape as the second layer 612 of the first adhesive layer 61. Although only a part of the second layer 622 is shown in FIG. 2, the second layer 622 is formed between the inner surface of the peripheral wall 42 facing the second side surface 232 and the second side surface 232 of the substrate 20. It is provided. That is, the second layer 622 adheres between the peripheral wall 42 and the second side surface 232.

The third layer 623 is provided integrally with the second layer 622. The third layer 623 is provided on the outer peripheral edge portion continuous with the second side surface 232 on the second surface 22 of the substrate 20. That is, the second adhesive layer 62 is an adhesive layer composed of an adhesive Ad that adheres between the end wall 41 and the first surface 21 of the substrate 20 and between the peripheral wall 42 and the side surface 23 of the substrate 20. .. Further, the second adhesive layer 62 extends from between the peripheral wall 42 and the side surface 23 to the second surface 22 of the substrate 20.

As shown in FIG. 4, the third layer 623 has a U-shape when the open end of the peripheral wall 42 of the heat sink 40 is viewed in a plan view. That is, the second layer 622 also has a U-shape along the second side surface 232 when the open end of the peripheral wall 42 of the heat sink 40 is viewed in a plan view.

As shown in FIGS. 2 and 3, the entire substrate 20 is accommodated in the accommodating portion 43. The height from the mounting surface 41a to the second surface 22 of the substrate 20 is lower than the height from the mounting surface 41a to the annular surface 421a of the peripheral wall 42. In a state where the substrate 20 is housed in the housing portion 43, the height of the third layer 613 of the first adhesive layer 61 and the third layer 623 of the second adhesive layer 62 from the mounting surface 41a is the mounting surface 41a. It is lower than the height from the peripheral wall 42 to the annular surface 421a. That is, the third layer 613,623 does not reach the annular surface 421a of the peripheral wall 42. The height of the third layer 613,623 from the mounting surface 41a is determined by the amount of the adhesive Ad applied to the mounting surface 41a and the pressurizing conditions on the mounting surface 41a of the substrate 20. The height of the peripheral wall 42 from the mounting surface 41a is set so that at least the adhesive Ad does not reach the annular surface 421a, and the physique of the semiconductor device 10 is set not to be unnecessarily large.

The operation of this embodiment will be described.
In the semiconductor device 10, for example, when the substrate 20 is fixed to the mounting surface 41a of the heat sink 40 by a fastening member, or to electrically connect an external device such as a battery or a three-phase AC motor to a plurality of terminals 30. When the terminal of the external cable is screwed into the screw hole 30a, the substrate 20 may rotate with respect to the heat sink 40.

In the present embodiment, the first adhesive layer 61 and the second adhesive layer 62 are between the end wall 41 of the heat sink 40 and the first surface 21 of the substrate 20 and between the peripheral wall 42 of the heat sink 40 and the side surface 23 of the substrate 20. Is provided. Therefore, the strength of the bond between the substrate 20 and the heat sink 40 is improved. Further, since the first adhesive layer 61 and the second adhesive layer 62 fill the space between the peripheral wall 42 and the side surface 23 of the substrate 20, the substrate 20 is less likely to rotate with respect to the peripheral wall 42.

The effect of this embodiment will be described.
(1) A first adhesive layer 61 and a second adhesive layer 62 are provided between the end wall 41 of the heat sink 40 and the first surface 21 of the substrate 20, and between the peripheral wall 42 of the heat sink 40 and the side surface 23 of the substrate 20. Therefore, the rotation of the substrate 20 with respect to the heat sink 40 can be suppressed.

(2) The second surface 22 of the substrate 20 is located closer to the end wall 41 than the annular surface 421a of the peripheral wall 42. Therefore, when the substrate 20 is accommodated in the accommodating portion 43 of the heat sink 40, the adhesive Ad easily moves from the side surface 23 of the substrate 20 to the second surface 22 of the substrate 20, and is difficult to move to the annular surface 421a of the peripheral wall 42. .. Therefore, it is possible to suppress the leakage of the adhesive Ad to the outside of the semiconductor device 10.

(3) The first adhesive layer 61 and the second adhesive layer 62 extend to the second surface 22 of the substrate 20. Therefore, the third layer 613,623 makes it difficult for the substrate 20 to peel off from the end wall 41 when the substrate 20 vibrates in the thickness direction. Therefore, the strength of joining the substrate 20 to the end wall 41 is improved.

(4) By covering the opening of the peripheral wall 42 with the cover 50, it is possible to prevent foreign matter from adhering to the substrate 20 from the outside of the semiconductor device 10.
(5) When the substrate 20 and the end wall 41 are viewed in a plan view from the thickness direction, the substrate 20 has a rectangular shape, and the peripheral wall 42 also has a rectangular shape. Therefore, even if the substrate 20 tries to rotate with respect to the heat sink 40, the peripheral wall 42 restricts the rotation of the substrate 20 via the first adhesive layer 61 and the second adhesive layer 62. Even if the peripheral wall 42 receives the rotating force of the substrate 20, since the peripheral wall 42 is provided integrally with the end wall 41, the rotating force of the substrate 20 is distributed not only to the peripheral wall 42 but also to the end wall 41. Can be done. Therefore, the rotation of the substrate 20 with respect to the heat sink can be further suppressed.

(6) When the terminals of the external cable are screwed into the screw holes 30a of all the terminals 30, a fastening torque acts on the substrate 20 via each of the plurality of terminals 30. The fastening torque acting on the substrate 20 can be dispersed in the first adhesive layer 61 and the second adhesive layer 62. Therefore, in the present embodiment, the strength of joining the substrate 20 to the heat sink 40 is improved with respect to the fastening torque acting on the substrate 20.

(7) Since the second surface 22 of the substrate 20 is located closer to the end wall 41 than the annular surface 421a of the peripheral wall 42, it is possible to prevent the adhesive Ad from adhering to the sealing surface between the heat sink 40 and the cover 50. can.

(8) If the adhesive Ad is applied in a planar shape in the direction in which the first mounting surface 411a and the second mounting surface 412a extend, the substrate is spread when the adhesive Ad is spread by the first surface 21 of the substrate 20. The amount of deformation of 20 can be suppressed. As a result, the load on the components such as the semiconductor element 24 and the terminal 30 mounted on the substrate 20 can be reduced.

In addition, this embodiment can be implemented by changing as follows. The present embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
○ In a plan view of the substrate 20 and the end wall 41 from the thickness direction, the substrate 20 may have a polygonal shape other than a rectangular shape, and the peripheral wall 42 may have a shape along the side surface 23 of the substrate 20. Even with such a change, the peripheral wall 42 restricts the rotation of the substrate 20 via the first adhesive layer 61 and the second adhesive layer 62. Even if the peripheral wall 42 receives the rotating force of the substrate 20, the peripheral wall 42 is integrally provided with the end wall 41, so that the rotating force of the substrate 20 is distributed not only to the peripheral wall 42 but also to the end wall 41. Can be made to. In a plan view of the substrate 20 and the end wall 41 from the thickness direction, the substrate 20 may have a circular shape and the peripheral wall 42 may have an annular shape.

○ The shape of the substrate 20 may be changed as shown in FIG. FIG. 7 does not show the first adhesive layer 61 and the second adhesive layer 62 for convenience of explanation.
As shown in FIG. 7, in a plan view of the substrate 20 in the thickness direction, the side surface 23 of the substrate 20 has four curved surfaces 23a and four edges 23b extending along the peripheral wall 42. You may. In a plan view of the substrate 20 in the thickness direction, the four curved surfaces 23a connect the adjacent edge portions 23b to each other. The four curved surfaces 23a may be a plane connecting adjacent edge portions 23b to each other. As in this modification, the peripheral wall 42 may be provided along the side surface 23, for example, the peripheral wall 42 is provided not along the four curved surfaces 23a and along at least four edge portions 23b. You just have to. At this time, it is preferable that the second layer 612,622 is provided between the peripheral wall 42 and the four edge portions 23b. Further, a second layer 612,622 may be provided between the peripheral wall 42 and the four curved surfaces 23a. When the substrate 20 described in the present embodiment, the above modification example, and the modification example is used, the peripheral wall 42 is formed along at least two linearly extending edges of the side surface 23 of the substrate 20 in a plan view. It is preferable to be provided. As a result, even if the peripheral wall 42 receives the rotating force of the substrate 20, the peripheral wall 42 is provided integrally with the end wall 41, so that the rotating force of the substrate 20 is applied not only to the peripheral wall 42 but also to the end wall 41. Can be dispersed.

○ The adhesive Ad may reach the annular surface 421a of the peripheral wall 42. In this case, it is preferable to confirm in advance the amount of the adhesive Ad that reaches the annular surface 421a, and to increase the annular surface 421a so that the annular surface 521a of the cover 50 can be placed on the annular surface 421a of the peripheral wall 42.

○ The height of the peripheral wall 42 from the mounting surface 41a may be changed as appropriate. For example, the peripheral wall 42 may be extended to the same position as the tip of each of all the terminals 30. In this case, the cover 50 may be changed to form a plate that closes the opening of the peripheral wall 42.

○ The semiconductor device 10 is composed of a substrate 20, a plurality of terminals 30, and a heat sink 40, and the cover 50 may be omitted.
○ The first adhesive layer 61 is composed of the first layer 611 and the second layer 612, and the third layer 613 may be omitted. The second adhesive layer 62 is composed of the first layer 621 and the second layer 622, and the third layer 623 may be omitted. That is, the first adhesive layer 61 and the second adhesive layer 62 do not have to extend to the second surface 22 of the substrate 20.

○ In the first adhesive layer 61, the first layer 611 of the first adhesive layer 61 is provided in the entire area between the first surface 21 of the substrate 20 and the first mounting surface 411a of the end wall 41. It does not have to be provided in the entire area. Although the first layer 611 and the second layer 612 are integrally provided, the first layer 611 and the second layer 612 may be separately arranged. That is, when the substrate 20 is accommodated in the accommodating portion 43, the adhesive Ad may be applied in advance between the inner side surface of the peripheral wall 42 and the first side surface 231 as well.

○ In the second adhesive layer 62, the first layer 621 of the second adhesive layer 62 is provided in the entire area between the first surface 21 of the substrate 20 and the second mounting surface 412a of the end wall 41. It does not have to be provided in the entire area. Although the first layer 621 and the second layer 622 are integrally provided, the first layer 621 and the second layer 622 may be separately arranged. That is, when the substrate 20 is accommodated in the accommodating portion 43, the adhesive Ad may be applied in advance between the inner side surface of the peripheral wall 42 and the second side surface 232 as well.

○ The first adhesive layer 61 and the second adhesive layer 62 have a mirror-symmetrical U-shape when viewed from the thickness direction of the substrate 20 and the end wall 41. For example, the first adhesive layer 61 has a U-shape. And the second adhesive layer 62 may be made continuous to form an adhesive layer forming a rectangular annular shape. When changing in this way, the first mounting surface 411a and the second mounting surface 412a may be made continuous along the peripheral wall 42. Then, the adhesive Ad when the substrate 20 is accommodated in the accommodating portion 43 may be changed so as to be arranged in the entire area between the side surface 23 of the substrate 20 and the inner side surface of the peripheral wall 42.

○ Either one of the first adhesive layer 61 and the second adhesive layer 62 may be omitted.
The second surface 22 of the substrate 20 was located closer to the end wall 41 than the annular surface 421a of the peripheral wall 42, but the present invention is not limited to this. For example, it may be changed as follows.

As shown in FIGS. 5 and 6, the height from the mounting surface 41a to the second surface 22 of the substrate 20 may be higher than the height from the mounting surface 41a to the annular surface 421a of the peripheral wall 42.
By making such a change, when the substrate 20 is accommodated in the accommodating portion 43, a part of the substrate 20 including the second surface 22 is located outside the heat sink 40. That is, when the operator accommodates the substrate 20 in the accommodating portion 43, it becomes easy to hold the substrate 20 in the accommodating portion 43 until the accommodation of the substrate 20 is completed. Therefore, the quality of the semiconductor device 10 at the time of manufacture can be maintained.

O The number of terminals 30 mounted on the second surface 22 of the board 20 has been five, but the number of terminals 30 may be changed as appropriate.
The opening end of the peripheral wall 42 of the heat sink 40 was an annular surface 421a, but the shape may be appropriately changed as long as the cover 50 can be placed.

○ Each of all the terminals 30 was fixed to the board 20 by bolts B, but for example, the base ends of all the terminals 30 may be soldered to the second surface 22 of the board 20. Of all the terminals 30, a plurality of terminals 30 may be fixed to the substrate 20 with bolts B, and the remaining terminals 30 may be soldered to the second surface 22 of the substrate 20.

○ All semiconductor elements 24 are switching elements such as insulated gate bipolar transistors, but the present invention is not limited to this. Of all the semiconductor elements 24, a plurality of semiconductor elements 24 may be used as switching elements, and the remaining semiconductor elements 24 may be used as components other than switching elements such as diodes.

○ The substrate 20 is not limited to the resin substrate, but may be a printed circuit board or a metal substrate.
○ The end wall 41 is provided with a long groove 44 in which a bolt B for fixing each of all the terminals 30 to the substrate 20 is accommodated, but the present invention is not limited to this. For example, the end wall 41 may be provided with a plurality of round grooves for accommodating each of the bolts B for fixing each of all the terminals 30 to the substrate 20. The round groove may be provided so as to be recessed from the mounting surface 41a in the thickness direction of the end wall 41.

○ A plurality of fins may be provided on the end wall 41 of the heat sink 40. By providing the plurality of fins, the surface area of the heat sink 40 in contact with the outside air is increased, so that the cooling function of the heat sink 40 is improved.

○ The semiconductor device 10 may be other than an inverter. For example, the semiconductor device 10 may be a power conversion device other than an inverter, such as a converter.
○ The semiconductor device 10 does not have to be mounted on an industrial vehicle.

10 ... semiconductor device, 20 ... substrate, 21 ... first surface, 22 ... second surface, 23 ... side surface, 24 ... semiconductor element, 30 ... terminal, 30a ... screw hole, 40 ... heat sink, 41 ... end wall, 41a ... Mounting surface 411a ... 1st mounting surface 412a ... 2nd mounting surface, 42 ... peripheral wall, 43 ... accommodating portion, 50 ... cover, 61 ... first adhesive layer, 62 ... second adhesive layer, Ad ... adhesive Agent.

Claims (6)

The board on which the semiconductor element is mounted and
With a heat sink,
The heat sink is
An end wall for mounting the first surface in the thickness direction of the substrate, and
It has a peripheral wall that is provided integrally with the end wall and is provided along a side surface that intersects with the first surface of the substrate.
The end wall and the peripheral wall form an accommodating portion for accommodating the substrate.
A semiconductor device characterized in that an adhesive layer composed of an adhesive for adhering between the end wall and the first surface and between the peripheral wall and the side surface is provided. The end wall has a mounting surface facing the first surface.
A claim characterized in that the height from the previously described mounting surface to the second surface of the substrate opposite to the first surface is lower than the height from the previously described mounting surface to the open end of the peripheral wall. Item 1. The semiconductor device according to Item 1. The end wall has a mounting surface facing the first surface.
A claim characterized in that the height from the previously described mounting surface to the second surface of the substrate opposite to the first surface is higher than the height from the previously described mounting surface to the open end of the peripheral wall. Item 1. The semiconductor device according to Item 1. One of claims 1 to 3, wherein the adhesive layer extends from between the peripheral wall and the side surface to a second surface of the substrate opposite to the first surface. The semiconductor device according to claim 1. The semiconductor device according to any one of claims 1 to 4, further comprising a cover that closes the opening of the peripheral wall by being placed on the opening end of the peripheral wall. The substrate has a rectangular shape when viewed from the thickness direction,
The semiconductor device according to any one of claims 1 to 5, wherein the peripheral wall has a rectangular annular shape when viewed from the thickness direction.

Images