JP5114323B2 - Semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device in which a stress relaxation member is provided between an insulating substrate and a heat sink, and the insulating substrate and the heat sink are coupled so as to conduct heat.

  As a semiconductor device, a metal plate such as pure aluminum is bonded to both front and back surfaces of an insulating substrate made of aluminum nitride, etc., and a semiconductor element is bonded to a front surface metal plate by soldering, and a back surface metal plate and a heat sink (heat dissipation device) Are combined in a state where they can conduct heat with each other. In this semiconductor device, the heat generated by the semiconductor element is radiated from the heat sink joined to the back metal plate. By the way, in the semiconductor device, it is required that the heat dissipation performance of the heat sink is maintained over a long period of time. However, according to the conventional configuration, the linear expansion coefficient of the insulating substrate, the metal plate, and the heat sink depends on the use conditions. There is a risk that the thermal stress generated due to the difference will cause cracks and warpage in the joint, resulting in a reduction in heat dissipation performance.

  Therefore, conventionally, in order to solve such a problem, there has been proposed a semiconductor module provided with a thermal stress relaxation portion including a step, a groove, and a recessed portion having a predetermined depth with respect to the metal plate on the back surface side (for example, , See Patent Document 1). And in the semiconductor module of patent document 1, the number and magnitude | size of a thermal-stress relaxation part are set so that the volume ratio of the metal plate of the back surface side with respect to the metal plate of the surface side may be 0.6 or less. .

In addition, a non-joint region composed of holes or grooves and a joint region where no holes or grooves are formed are formed on the joint surface with the heat dissipation device with respect to the back metal plate. A semiconductor module having a range of 65% to 85% with respect to the entire area has been proposed (see, for example, Patent Document 2).
JP 2003-17627 A JP 2007-173405 A

  By the way, the semiconductor module described in Patent Document 1 relaxes the thermal stress generated in the semiconductor module when the temperature changes due to the steps, grooves, and recesses as thermal stress relaxation portions formed on the metal plate on the back surface side. ing. For this reason, in the semiconductor module, it is preferable that the step, the groove, and the recessed portion are made as large as possible and provided as the thermal stress relaxation portion. However, when the thermal stress relaxation portion is enlarged, the portion of the metal plate on the back side is increased accordingly. Since the thermal conductivity is lowered, it is necessary to consider the balance between the thermal conductivity and the stress relaxation function. However, in this semiconductor module, the thermal conductivity of the metal plate on the back surface side is reduced in proportion to the increase in the thermal stress relaxation part, and thus there is a limit to the improvement of the stress relaxation function.

  Similarly, in the semiconductor module described in Patent Document 2, since the thermal conductivity of the back metal plate decreases in proportion to the increase in the non-bonded region, there is a limit to the improvement of the stress relaxation function. It was.

  The present invention has been made in view of the above problems, and an object thereof is to provide a semiconductor device capable of improving the stress relaxation function of the stress relaxation member while suppressing a decrease in the thermal conductivity of the stress relaxation member. There is to do.

  In order to achieve the above object, according to the first aspect of the present invention, a metal wiring layer is bonded to one surface of an insulating substrate and a semiconductor element is bonded to the metal wiring layer. In the semiconductor device in which a stress relaxation member made of a high thermal conductivity material is provided between the heat sink disposed on the other surface side and the insulating substrate and the heat sink are coupled to each other so as to conduct heat, the heat sink A stress absorbing portion having a plurality of partition walls which are long in one direction and spaced apart from each other, and the stress relaxation member includes a through-hole penetrating in the thickness direction or a bottomed hole opening in the thickness direction. The length along the longitudinal direction of the partition wall in the through hole is longer than the length along the parallel direction of the plurality of partition walls in the through hole, and the length of the partition wall in the bottomed hole is longer The length along the is summarized in that longer than the length along the arrangement direction of the plurality of partition walls in the closed bottom hole.

  In order to achieve the above object, according to a fourth aspect of the present invention, a metal wiring layer is bonded to one surface of an insulating substrate, a semiconductor element is bonded to the metal wiring layer, and the insulating substrate and the insulating substrate In the semiconductor device in which a stress relaxation member made of a high thermal conductivity material is provided between the heat sink disposed on the other surface side and the insulating substrate and the heat sink are coupled to each other so as to conduct heat, the heat sink A plurality of partition walls that are long in one direction and spaced apart from each other, and the stress relaxation member includes a plurality of partition walls that penetrate in the thickness direction and are arranged along the longitudinal direction of the partition walls. A stress absorbing part composed of a group of holes formed by through holes is provided, and all the through holes have an opening width along the parallel arrangement direction of the partition walls larger than an opening width along the longitudinal direction of the partition walls. Formed in Kunar so, the sum of the longitudinal direction along the opening width of the partition wall in the hole group is summarized in that longer than the maximum width along the arrangement direction of the plurality of partition walls in the stress absorbing portion.

  In the first and fourth aspects of the invention, the stress relaxation member is easily deformed in the longitudinal direction of the partition wall. And when thermal stress occurs due to the difference in linear expansion coefficient between the insulating substrate and the heat sink, there is a partition wall extending in one direction, so that the thermal stress in the longitudinal direction of the partition wall is the direction in which the partition walls are arranged side by side However, the stress relaxation member can further relax the thermal stress along the longitudinal direction of the partition wall. Therefore, the stress relaxation function of the stress relaxation member is improved.

  Moreover, even if a stress absorbing part is formed in the stress relaxation member, it is possible to suppress an increase in the length along the juxtaposed direction of the plurality of partition walls in the stress absorbing part. Therefore, for example, as compared with the case where the stress relaxation function of the stress relaxation member is improved by enlarging the perfect circular hole or hole, the amount of reduction in the portion made of the high thermal conductivity material in the stress relaxation member can be suppressed. The heat generated from the semiconductor element is smoothly transmitted to the heat sink through the first metal plate, the insulating substrate, and the stress relaxation member, and the heat transmitted to the heat sink is released to the outside from the heat sink. Therefore, it is possible to suppress a decrease in the thermal conductivity of the stress relaxation member due to the enlargement of the stress absorbing portion provided in the stress relaxation member.

  According to a second aspect of the present invention, in the first aspect of the present invention, a metal plate is bonded to the other surface of the insulating substrate, and the stress relaxation member is provided separately from the metal plate. Is the gist.

  In this invention, since the stress relaxation member can be processed in a state separate from the semiconductor element or the substrate, it is necessary to consider the influence on the semiconductor element or the substrate when forming the hole or hole in the stress relaxation member. There is no. Therefore, the stress absorbing portion of the stress relaxation member can be formed by performing mechanical processing such as press processing on the high thermal conductivity material.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the stress absorbing portion is not formed in a portion corresponding to the semiconductor element in the stress relaxation member, and the semiconductor The gist is that it is configured as a heat conducting portion capable of conducting heat generated from the element.

  The part corresponding to the semiconductor element in the stress relaxation member is a part where heat generated from the semiconductor element reaches early. Therefore, according to the present invention, the portion corresponding to the semiconductor element is a heat conducting portion having no stress relaxation portion so that the heat generated from the semiconductor element can quickly pass through the stress relaxation member and reach the heat sink. Can be configured.

  ADVANTAGE OF THE INVENTION According to this invention, the stress relaxation function by a stress relaxation member can be improved, suppressing the heat conductive fall of a stress relaxation member.

  Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS. 1 and 2. 1 and 2 schematically show the structure of the semiconductor device. For convenience of illustration, in order to exaggerate some of the dimensions, the width and length of each part are easy to understand. The ratio of dimensions such as thickness is different from the actual ratio.

  As shown in FIG. 1, the semiconductor device 10 includes an insulating circuit substrate 11, and a semiconductor element (semiconductor chip) 12 is mounted on the insulating circuit substrate 11. The insulated circuit board 11 has a first metal plate (metal circuit board) 14 joined to a surface 13a of a ceramic substrate 13 as an insulated substrate, and a second metal plate 15 joined to a back surface 13b of the ceramic substrate 13. It is configured. The first metal plate 14 and the second metal plate 15 are made of aluminum or copper.

  The upper side in FIG. 1 is the surface 13a side on which the semiconductor element 12 is mounted, and the ceramic substrate 13 is joined to the first metal plate 14 that functions as a metal wiring layer on the mounting surface of the semiconductor element 12 in the surface 13a. Has been. The semiconductor element 12 is joined to the first metal plate 14 via solder (not shown). As the semiconductor element 12, for example, an IGBT (Insulated Gate Bipolar Transistor), a MOSFET, or a diode is used.

  On the other hand, the lower side of the ceramic substrate 13 in FIG. 1 is a back surface 13b as an opposite surface of the front surface 13a, and a second metal plate 15 that functions as a bonding layer for bonding the ceramic substrate 13 and the heat sink 16 is joined to the back surface 13b. Has been.

  The heat sink 16 to which the ceramic substrate 13 is coupled is made of metal and functions as a forced cooling type cooler that forcibly removes the heat generated in the semiconductor element 12. The cooling capacity of the heat sink 16 is such that when the semiconductor element 12 is in a steady heat generation state (normal state), the heat generated in the semiconductor element 12 is conducted to the heat sink 16 through the insulating circuit board 11 and smoothly removed. Is set. The heat sink 16 is formed in a substantially rectangular shape in a plan view in which the longitudinal direction is the left-right direction in FIG. 2 and the short side direction is the up-down direction in FIG. Yes.

  The case portion 17 is provided with a plurality of partition walls 18 extending linearly therein. As shown in FIGS. 1 and 2, the plurality of partition walls 18 are arranged at equal intervals and are configured to be parallel to each other. The plurality of partition walls 18 define a plurality of refrigerant passages 19 through which fluid (for example, cooling water) flows by the adjacent partition walls 18 and the partition walls 18 and the inner wall portion 17a of the case portion 17. The plurality of partition walls 18 are juxtaposed in the longitudinal direction of the heat sink 16 and extend long along the short direction of the heat sink 16. And between the heat sink 16 and the 2nd metal plate 15 in the insulated circuit board 11, the stress relaxation member 20 which couple | bonds the insulated circuit board 11 and the heat sink 16 is provided.

  The stress relaxation member 20 is made of aluminum as a high thermal conductivity material and is formed in a flat plate shape having a substantially rectangular shape in plan view. The entire surface 20 a of the stress relaxation member 20 is brazed to the second metal plate 15, and the entire other surface 20 b facing away from the one surface 20 a is brazed to the heat sink 16. That is, joints made of a brazing material are formed between the stress relaxation member 20 and the second metal plate 15 and between the stress relaxation member 20 and the heat sink 16. For this reason, the insulating circuit board 11 and the heat sink 16 are coupled to each other through the stress relaxation member 20 so as to be able to conduct heat, and heat generated from the semiconductor element 12 is conducted in the order of the insulating circuit board 11 and the stress relaxation member 20. Then, it is transmitted to the heat sink 16. The stress relaxation member 20 is formed with a plurality of through-holes 21 as ellipsoidal shapes (12 in the present embodiment) in a plan view that penetrate only in the thickness direction of the stress relaxation member 20.

  The through hole 21 is formed by subjecting a flat plate constituting the stress relaxation member 20 to press working (machining). As shown in FIG. 2, each through-hole 21 has a length T1 along the longitudinal direction of the partition wall 18 (the arrow Y direction shown in FIG. 2), and the parallel direction of the partition walls 18 (in FIGS. 1 and 2). It is formed longer than the length T2 along the arrow X direction shown. The through holes 21 are all formed in the same shape, and two or more through holes 21 are arranged along the longitudinal direction of the partition wall 18. Each through-hole 21 is formed such that its major axis is parallel to the longitudinal direction of the partition wall 18 and its minor axis is parallel to the parallel arrangement direction of the partition walls 18. That is, the stress relaxation member 20 is configured to be easily deformed in the longitudinal direction of the partition wall 18 as compared with the direction in which the partition walls 18 are arranged side by side. Each through hole 21 is arranged point-symmetrically with respect to the reference point P of the stress relaxation member 20 corresponding to the center of the semiconductor element 12. Further, the through hole 21 is not formed in the portion immediately below the semiconductor element 12 in the stress relaxation member 20 and is configured not to overlap the semiconductor element 12 in plan view. The part of the stress relaxation member 20 corresponding to the semiconductor element 12 is the part closest to the semiconductor element 12, and is configured as a heat conductive portion 22 having better thermal conductivity than the through hole 21.

Next, the operation of the semiconductor device 10 configured as described above will be described.
The semiconductor device 10 is mounted on a hybrid vehicle, and is used in a state where the heat sink 16 communicates with a cooling medium circulation path (not shown) via a pipe. The cooling medium circulation path is provided with a pump and a radiator, and the radiator includes a fan that is rotated by a motor so that heat is efficiently radiated from the radiator. For example, water is used as the refrigerant.

  When the semiconductor element 12 mounted on the semiconductor device 10 is driven, heat is generated from the semiconductor element 12. Heat generated from the semiconductor element 12 is conducted directly below the semiconductor element 12, and is conducted in the order of the first metal plate 14, the ceramic substrate 13, the second metal plate 15, the stress relaxation member 20, and the heat sink 16. In the stress relaxation member 20, the through hole 21 is not formed immediately below the semiconductor element 12, and the heat conduction portion 22 is formed. Therefore, the heat transmitted to the stress relaxation member 20 is smoothly absorbed by the heat sink. It can conduct up to 16.

  When heat conduction is performed in this manner, the insulating circuit board 11 and the heat sink 16 become high temperature and thermally expand. At this time, for example, when a hole having a shape like the perfect circular virtual hole R1 indicated by a two-dot chain line in FIG. 2 is formed without considering the longitudinal direction of the partition wall 18, the partition wall is long in one direction. 18 is present, the stress due to thermal expansion generated between the heat sink 16 and the ceramic substrate 13 in the longitudinal direction of the partition wall 18 is generated between the heat sink 16 and the ceramic substrate 13 in the parallel direction of the partition wall 18. It becomes larger than the stress due to thermal expansion. That is, the thermal expansion is generated in the semiconductor device 10 due to the difference in the linear expansion coefficient between the ceramic substrate 13 and the heat sink 16 and the first and second metal plates 14 and 15, and in particular, the heat sink 16 and the ceramic substrate 13 In between, a large thermal stress tends to be generated in the longitudinal direction of the partition wall 18. Here, in order to relieve the thermal stress in the longitudinal direction, the hole may be enlarged like the virtual hole R2, but the portion made of the high thermal conductivity material is reduced and the thermal conductivity is lowered. In the present embodiment, considering the direction of the partition wall 18 of the heat sink 16, the stress relaxation member 20 is configured to be easily deformed in the longitudinal direction of the partition wall 18, so that the thermal stress in the longitudinal direction of the partition wall 18 is parallelized. It relaxes more than the thermal stress in the installation direction. As a result, the thermal stress in the longitudinal direction and the juxtaposed direction are brought closer to each other. Therefore, since the through hole is not enlarged more than necessary, it is possible to suppress a decrease in thermal conductivity. Furthermore, when the temperature of the semiconductor device 10 rises, cracks occur in the joint between the ceramic substrate 13 and the second metal plate 15, and warpage occurs in the joint surface of the heat sink 16 to the insulating circuit substrate 11. It can be suppressed more.

  On the other hand, when the heat generation from the semiconductor element 12 is stopped, the temperature of the ceramic substrate 13 and the heat sink 16 is lowered and the heat shrinks. In the present embodiment, the partition wall and the stress relaxation member 20 are deformed in the longitudinal direction of the partition wall 18 with respect to the thermal stress between the heat sink 16 and the second metal plate 15 at this time as well. Relieve thermal stress in the direction more. Therefore, when the temperature of the semiconductor device 10 is lowered, cracks occur in the joint between the ceramic substrate 13 and the second metal plate 15, and warpage occurs in the joint surface of the heat sink 16 to the insulating circuit substrate 11. It can be suppressed more.

  Further, when heat is conducted to the heat sink 16, heat exchange is performed between the case portion 17, the partition wall 18, and the refrigerant flowing through the refrigerant passage 19, and the heat generated from the semiconductor element 12 is carried away by the refrigerant. . That is, since the heat sink 16 is forcibly cooled by the cooling medium flowing through the refrigerant passage 19, the temperature gradient in the heat conduction path from the semiconductor element 12 or the like to the heat sink 16 increases, and the heat generated in the semiconductor element 12 is insulated from the insulation circuit. It is efficiently removed through the substrate 11.

According to this embodiment, the following effects can be obtained.
(1) A plurality of through holes 21 are formed in the stress relaxation member 20. And each through-hole 21 is formed so that length T1 along the longitudinal direction of the partition wall 18 may become long compared with length T2 along the parallel arrangement direction of the some partition wall 18. As shown in FIG. Therefore, the stress relaxation member 20 can be easily deformed in the longitudinal direction of the partition wall 18 and the stress relaxation function can be improved.

  (2) The through hole 21 has a length T2 along the juxtaposed direction of the plurality of partition walls 18 shorter than a length T1 along the longitudinal direction of the partition walls 18, and the stress relaxation function of the stress relaxation member 20. Compared with the case where the virtual hole R <b> 1 itself is enlarged in order to improve it, it is possible to suppress the decrease amount of the joint portion of the stress relaxation member 20. Therefore, the heat generated from the semiconductor element 12 can smoothly conduct through the stress relaxation member 20 and reach the heat sink 16. Therefore, a decrease in thermal conductivity in the stress relaxation member 20 can be suppressed.

  (3) The second metal plate 15 is bonded to the back surface 13 b of the ceramic substrate 13. In addition, a stress relaxation member 20 is provided between the heat sink 16 and the second metal plate 15 in the insulated circuit board 11 separately from the insulated circuit board 11. Therefore, since the through hole 21 can be formed by processing the flat plate constituting the stress relaxation member 20 in a state different from the semiconductor element 12 and the ceramic substrate 13, the influence on the semiconductor element 12 and the ceramic substrate 13 is considered. There is no need to do. Therefore, the through-hole 21 of the stress relaxation member 20 can be easily formed by, for example, machining such as press working.

  (4) In the stress relaxation member 20, a portion immediately below the semiconductor element 12 and corresponding to the semiconductor element 12 is formed as a heat conducting portion 22 through which heat generated from the semiconductor element 12 passes. Therefore, by configuring the portion immediately below the semiconductor element 12 where the heat generated from the semiconductor element 12 of the stress relaxation member 20 reaches the earliest as the heat conducting portion 22, the heat generated from the semiconductor element 12 is smooth. The stress relaxation member 20 can be conducted to reach the heat sink 16.

  (5) The plurality of through holes 21 penetrates in the thickness direction of the stress relaxation member 20. Therefore, the stress relaxation member 20 can be configured to be more easily deformed than a case where a plurality of bottomed holes are formed in a plate made of a high thermal conductivity material to form a stress relaxation member.

The embodiment is not limited to the above, and may be configured as follows, for example.
The through hole 21 may not be formed so that its long axis is parallel to the longitudinal direction of the partition wall 18. For example, if the length T1 along the longitudinal direction of the partition wall 18 is longer than the length T2 along the parallel direction of the partition walls 18, the long axis intersects the longitudinal direction of the partition wall 18. An elliptical through hole 21 may be formed.

○ The number of through holes 21 is not particularly limited. When using the stress relaxation member 20 with a large dimension, you may increase the number of the through-holes 21 provided.
○ The size of the through hole 21 may be changed. If the length T1 along the longitudinal direction of the partition wall 18 is longer than the length T2 along the parallel direction of the partition wall 18, the through hole 21 may be made smaller or larger. May be. Therefore, for example, a through hole 21 having a length T2 along the direction in which the partition walls 18 are juxtaposed may be longer than the diameter of the virtual hole R1.

  ○ The shape of the through hole 21 may be changed. For example, as shown in FIG. 3A, the through-hole 30 is formed in a rectangular shape in plan view, and the length T3 along the longitudinal direction of the partition wall 18 in the through-hole 30 is the parallel arrangement direction of the partition walls 18. You may form so that it may become long compared with length T4 along. Moreover, you may change so that each through-hole 30 arranged along the longitudinal direction of the partition wall 18 may continue. For example, as shown in FIG. 3B, a through hole 31 formed so as to extend continuously along the longitudinal direction of the partition wall 18 may be provided. However, in this case, the portion of the stress relaxation member 20 located immediately below the semiconductor element 12 needs to be configured as the heat conducting portion 22 so that the through hole 31 does not exist.

  ○ Instead of the stress absorbing portion consisting of the through hole 21, a hole group consisting of a plurality of holes penetrating in the thickness direction of the stress relaxation member 20 and arranged along the longitudinal direction of the partition wall 18 is provided as the stress absorbing portion. Also good. For example, as shown in FIG. 3 (c), a hole group 40 is provided at a portion where the through hole 21 has been formed, and all the hole groups 40 have a plurality of opening widths t 1 along the longitudinal direction of the partition wall 18. It is formed by a plurality of rectangular through holes 41 shorter than the opening width t2 along the direction in which the partition walls 18 are arranged side by side. The through holes 41 constituting the hole group 40 are arranged along the longitudinal direction of the partition wall 18, and only the through holes 41 are formed in the stress relaxation member 20. In the hole group 40 constituting the stress absorbing portion, the sum of the opening width t1 along the longitudinal direction of the partition wall 18 is equal to the opening width t2 of the through hole 41 along the parallel direction of the partition wall 18 (width of the stress absorbing portion). ) To be longer than The interval H1 between the hole groups 40 adjacent in the longitudinal direction of the partition wall 18 is the interval H2 between the through holes 41 adjacent in the longitudinal direction of the partition wall 18 among the plurality of through holes 41 constituting the hole group 40. It is formed to be longer. If such a hole group 40 is provided, the stress relaxation member 20 can be easily deformed in the longitudinal direction of the partition wall 18, so that the thermal stress in the longitudinal direction of the partition wall 18 can be further relaxed. Mitigation function is improved. In addition, since the stress absorbing portion is constituted by the hole group 40 including the plurality of through holes 41 penetrating in the thickness direction of the stress relaxing member 20, the stress absorbing member 20 is more formed than the stress absorbing portion including the bottomed hole. It can be configured to be easily deformed. Moreover, if the maximum width of the hole group 40 along the direction in which the partition walls 18 are juxtaposed does not exceed the total sum of the opening widths t1 along the longitudinal direction of the partition wall 18 in the hole group 40, You may comprise the hole group 40 from the several through-hole 41 arranged along the longitudinal direction of the partition wall 18 in the state shifted | deviated slightly in the installation direction.

  The arrangement of the through holes 21 formed in the stress relaxation member 20 may be changed. For example, the plurality of through holes 21 may be formed in the stress relaxation member 20 so that the plurality of through holes 21 are arranged in a staggered manner.

  A bottomed hole that opens only in the thickness direction may be formed in the stress relaxation member 20 instead of the through hole 21 as a stress absorbing portion. In this case, for example, a bottomed hole whose opening width along the longitudinal direction of the partition wall 18 is longer than the opening width along the parallel direction of the partition wall 18 may be formed on the other surface 20b of the stress relaxation member 20. In this case, the opening of the bottomed hole faces the heat sink 16 side. Further, in the case where a bottomed hole is formed in the stress relaxation member 20 instead of the through hole 21, the bottomed hole can be used if the stress relaxation member 20 can obtain a function capable of sufficiently relaxing the thermal stress generated in the semiconductor device 10. There is no particular limitation on the depth.

  (Circle) you may comprise so that the 2nd metal plate 15 may serve as the stress relaxation member 20 together. For example, the stress relaxation member 20 is omitted, and the length along the longitudinal direction of the partition wall 18 on the surface of the second metal plate 15 on the heat sink 16 side is longer than the length along the parallel direction of the partition walls 18. A plurality of long holes may be formed, and the second metal plate 15 may be used as a stress relaxation member. With this configuration, the second metal plate 15 functions as a stress relaxation member that relaxes the thermal stress generated in the semiconductor device 10 when the temperature of the semiconductor device 10 changes. In addition, since the second metal plate 15 can be greatly deformed in the longitudinal direction of the partition wall 18 as compared with a conventional stress relaxation member made of a hole having a circular shape in plan view as a stress absorbing portion, the second metal plate 15 has a higher stress than the conventional one. Mitigation function is improved.

  O The direction in which each partition wall 18 extends may be changed. If each partition wall 18 is a partition wall that is long in one direction, the extending direction is not particularly limited. For example, even if a partition wall 18 that extends in a direction intersecting the short direction of the heat sink 16 is provided. Good.

  O Each partition wall 18 may be configured to extend continuously in the juxtaposed direction. Therefore, for example, each partition wall 18 may be configured by using continuous corrugated fins. In this case, the upper end of the partition wall 18 and the upper end of another partition wall 18 are continuous, and the lower end of the partition wall 18 and the lower end of another partition wall 18 are configured to be continuous.

  ○ The configuration of the heat sink 16 may be changed. For example, instead of the case portion 17, a plate-like heat sink base may be used, and a plurality of partition walls 18 may be provided on one surface of the heat sink base. In this case, the heat sink 16 may be configured as a cooler that removes heat generated in the semiconductor element 12 by joining the stress relaxation member 20 to the other surface of the heat sink base.

  The material constituting the heat sink 16 may be any metal material having a linear expansion coefficient different from that of the ceramic substrate 13. For example, the heat sink 16 may be formed of aluminum, copper, or the like. Aluminum means pure aluminum or an aluminum alloy.

  A specific material constituting the ceramic substrate 13 is not particularly limited. The ceramic substrate 13 may be formed of aluminum nitride, alumina, silicon nitride, or the like.

  The heat sink 16 has a structure in which water flows inside, but may have a structure in which other liquids such as alcohol flow in addition to water. Further, the refrigerant flowing through the heat sink 16 is not limited to a liquid but may be a gas such as air.

  The semiconductor device 10 may be applied not only to in-vehicle use but also to other uses.

1 is a schematic cross-sectional view of a semiconductor device. The partial schematic plan view of the semiconductor device in the state which abbreviate | omitted the insulated circuit board. (A), (b), (c) is the partial schematic plan view of the semiconductor device in the state which abbreviate | omitted the insulated circuit board in another embodiment.

Explanation of symbols

  T1: Length of the through hole along the longitudinal direction of the partition wall, T2: Length of the through hole along the parallel direction of the partition wall, t1: Opening width along the longitudinal direction of the partition wall, t2: Parallel arrangement of the partition walls Opening width along the direction, 10 ... semiconductor device, 12 ... semiconductor element, 13 ... ceramic substrate as an insulating substrate, 13a ... surface as one surface, 13b ... back surface as another surface, 14 ... first metal as a metal wiring layer Plate: 15 ... 2nd metal plate as a metal plate, 16 ... Heat sink, 18 ... Partition wall, 20 ... Stress relaxation member, 21, 30, 31 ... Through hole, 22 ... Heat conduction part, 40 ... Hole group, 41 ... Through hole.

Claims (4)

A metal wiring layer is bonded to one surface of the insulating substrate, and a semiconductor element is bonded to the metal wiring layer, and high thermal conductivity is provided between the insulating substrate and a heat sink disposed on the other surface side of the insulating substrate. In a semiconductor device in which a stress relaxation member made of a material is provided, and the insulating substrate and the heat sink are coupled to each other so as to conduct heat,
The heat sink has a plurality of partition walls that are long in one direction and arranged in parallel at intervals.
The stress relaxation member is provided with a stress absorbing portion consisting of a through hole penetrating in the thickness direction or a bottomed hole opening in the thickness direction,
The length along the longitudinal direction of the partition wall in the through hole is longer than the length along the juxtaposed direction of the plurality of partition walls in the through hole,
The length along the longitudinal direction of the partition wall in the bottomed hole is longer than the length along the juxtaposed direction of the plurality of partition walls in the bottomed hole. A metal plate is bonded to the other surface of the insulating substrate,
The semiconductor device according to claim 1, wherein the stress relaxation member is provided separately from the metal plate.   The portion corresponding to the semiconductor element in the stress relaxation member is configured as a heat conducting part capable of conducting heat generated from the semiconductor element without forming the stress absorbing part. Item 3. The semiconductor device according to Item 2. A metal wiring layer is bonded to one surface of the insulating substrate, and a semiconductor element is bonded to the metal wiring layer, and high thermal conductivity is provided between the insulating substrate and a heat sink disposed on the other surface side of the insulating substrate. In a semiconductor device in which a stress relaxation member made of a material is provided, and the insulating substrate and the heat sink are coupled to each other so as to conduct heat,
The heat sink has a plurality of partition walls that are long in one direction and arranged in parallel at intervals.
The stress relieving member is provided with a stress absorbing portion including a group of holes formed by a plurality of through holes that are arranged so as to penetrate in the thickness direction and along the longitudinal direction of the partition wall.
All the through holes are formed such that the opening width along the parallel direction of the partition walls is longer than the opening width along the longitudinal direction of the partition walls,
The total sum of the opening widths along the longitudinal direction of the partition walls in the hole group is longer than the maximum width along the juxtaposed direction of the plurality of partition walls in the stress absorbing portion.

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