JP4396366B2 - Semiconductor device - Google Patents

Description

  The present invention relates to a semiconductor device, and more particularly to a semiconductor device having a semiconductor chip as a heating element and a heat sink on which the semiconductor chip is mounted.

2. Description of the Related Art Conventionally, there is known a semiconductor device in which a semiconductor chip on which a semiconductor element is formed is disposed on a heat sink, and the heat generated by the semiconductor chip is cooled by the heat sink (for example, see Patent Document 1). The heat sink (heating element cooling device) disclosed in Patent Document 1 is provided with a partition plate having an opening therein. When the coolant flowing through the heat sink passes through the opening, the jet of coolant directly collides with the back surface of the heat sink corresponding to the position where the semiconductor chip is disposed. Thereby, highly efficient cooling of the semiconductor chip which is a heat generating body is attained.
JP 2002-237691

  However, when the semiconductor chip is actually mounted on the heat sink, it is difficult to mount the semiconductor chip directly on the main surface of the heat sink by soldering or the like as shown in FIG. As an example of a general mounting method, a semiconductor chip is mechanically fixed to a flat plate such as a ceramic substrate by soldering or the like, and electrical connection with an electrode pad on the surface of the semiconductor chip is performed in advance using a bonding wire or a bump. After that, there is a method of mounting this ceramic substrate on the heat sink main surface through silicon grease or the like. That is, in reality, it is common to have a laminated structure in which a ceramic substrate is mounted on the main surface of the heat sink via silicon grease, etc., and a semiconductor element is mounted on the ceramic substrate via solder. Therefore, the thermal resistance between the heat sink and the semiconductor chip is large, and efficient cooling is difficult.

  In addition, since the internal structure of the heat sink having an opening through which the coolant passes is complicated, it is difficult to mold it as an integral structure. It is practical to divide the heat sink into several components and join them to form the entire heat sink. That is, the entire heat sink is formed by joining the bottom plate of the heat sink, the partition plate having the apertures, and the top plate using methods such as soldering, brazing, welding, and bonding using the side plates. The upper surface plate and the side surface plate, or the lower surface plate and the side surface plate can be respectively molded as an integral structure.

  Therefore, the following problems occur due to the above-described realistic structure. That is, in order to cool the semiconductor chip more efficiently, it is effective to cause the jet of the coolant to directly collide with the back surface of the ceramic substrate on which the semiconductor chip is mounted without using silicon grease having a relatively large thermal resistance. It is believed that there is. However, when directly bonding the ceramic substrate to the upper surface of the heat sink using a low thermal resistance bonding material such as soldering, the temperature rise condition required in the soldering process is not possible because the inside of the heat sink is hollow or the back side of the upper surface of the heat sink is not necessarily flat. It is difficult to obtain and difficult to realize. Usually, when a semiconductor chip is mounted by soldering, it is heated from the back side of the base plate. If the back surface of the base plate is not flat, it is difficult to perform this heating uniformly, which hinders the soldering process. In addition, when wire bonding connection is made to the electrode pads arranged on the surface of the semiconductor chip, it is difficult to reliably hold the ceramic substrate unless the back surface of the base plate is flat, which hinders the same process.

The present invention is characterized in that a base plate having a first main surface and a second main surface opposite to the first main surface, a semiconductor chip bonded to the first main surface, and a second main surface A semiconductor device having a heat sink including a main body portion having a bonded bonding surface, and an annular or frame-shaped convex portion disposed in the vicinity of a position corresponding to an end portion of the semiconductor chip on the second main surface. The first opening is formed on the joint surface of the main body corresponding to the position where the semiconductor chip is disposed, and the refrigerant chamber through which the refrigerant flows is formed from the inside of the main body and the first opening. Defined in the region surrounded by the exposed second main surface and the convex portion, the refrigerant flowing through the refrigerant chamber is in direct contact with the second main surface and the convex portion through the first opening, The gist is that the side surface of the convex portion is in contact with the side surface of the first aperture.

  ADVANTAGE OF THE INVENTION According to this invention, the semiconductor device which prevents the leakage of a refrigerant | coolant can be provided simultaneously with cooling the semiconductor chip which is a heat generating body with low thermal resistance.

  Embodiments of the present invention will be described below with reference to the drawings. In the description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

(First embodiment)
In the first to sixth embodiments of the present invention, as an example of a device having a heat generating element and a heat sink that cools the heat generated from the heat generating element, a semiconductor chip on which a semiconductor element is formed and heat generated from the semiconductor chip are used. A semiconductor device including a heat sink for cooling will be described.

  As shown in FIG. 1, the semiconductor device according to the first embodiment of the present invention includes a base plate 1 having a first main surface 15a and a second main surface 15b opposite to the first main surface 15a. The semiconductor chip 2 joined to the first main surface 15a by soldering or the like, the heat sink 8 including the main body 3 having the joint surface 16 joined to the second main surface 15b, and the second main surface 15b. At least, a rubber member 31 disposed along the side surface of the first opening 9, and a ceramic substrate 33 disposed between the semiconductor chip 2 and the base plate 1.

  A first opening 9 is formed on the bonding surface 16 of the main body 3 corresponding to the position where the semiconductor chip 2 is disposed. The convex portion 19 is inserted into the first opening 9. The refrigerant chamber 11 in which the refrigerant that cools the heat from the semiconductor chip 2 circulates is surrounded by the inside of the main body 3 and the second main surface 15 b and the protrusion 19 exposed from the first opening 9. Defined in the region. The refrigerant flowing through the refrigerant chamber 11 directly contacts the second main surface 15 b and the convex portion 19 through the first opening 9. The side surface of the convex portion 19 is in contact with the side surface of the first opening portion 9 through the rubber member 31.

  The heat sink 8 further includes a partition plate 5 disposed in parallel to the base plate 1 inside the main body 3 and a pressing portion 4 disposed on the outer peripheral portion of the first main surface 15a. Further, the semiconductor device further includes a fixing component (for example, a screw 27) that press-joins the pressing portion 4 and the main body portion 3 with each other. The main body 3 and the pressing portion 4 sandwich the base plate 1 and the adhesive layer 32 with screws 27. The partition plate 5 has a second opening 10 corresponding to the position where the semiconductor chip 2 is disposed. The refrigerant chamber 11 is divided into a first refrigerant chamber 12 and a second refrigerant chamber 13 located on the base plate 1 side with the partition plate 5 as a boundary. Although illustration is omitted, a refrigerant inflow hole for allowing the refrigerant to flow into the refrigerant chamber 11 is arranged in a part of the second refrigerant chamber 13, and the refrigerant for the refrigerant to flow out of the refrigerant chamber 11. An outflow hole is disposed in a part of the first refrigerant chamber 12.

  As shown in FIG. 2, when the base plate 1 side is viewed from the first refrigerant chamber 12, the convex portion 19 is a radiating fin having an annular or frame shape, and the radiating fin 19 has a first radiating fin on the inner side. 2 main surface 15b is exposed. The rubber member 31 is disposed in contact with the entire outer periphery of the heat dissipating fin 19, and the main body 3 of the heat sink 8 is disposed in contact with the entire outer periphery of the rubber member 31. That is, the rubber member 31 is fitted into the entire first opening 9, and the heat radiating fins 19 provided on the second main surface 15 b of the base plate 1 are fitted inside the rubber member 31. The heat radiating fins 19 are arranged in the vicinity of the position corresponding to the outer peripheral end of the semiconductor chip 2. The radiating fins 19 are bonded to the second main surface 15b of the base plate 1 by bonding. The second main surface 15b of the base plate 1 is also bonded to the bonding surface 16 of the heat sink 3 by adhesion.

  The refrigerant (for example, water) flows into the second refrigerant chamber 13 from the refrigerant inflow hole, flows through the second opening portion 10 from the second refrigerant chamber 13 to the first refrigerant chamber 12, and then flows out of the refrigerant outflow hole. Spill from. When passing through the second opening 10 and flowing from the second refrigerant chamber 13 to the first refrigerant chamber 12, the jet of the refrigerant passes through the first opening 9 and the second main surface of the base plate 1. Collide directly with 15b.

  As described above, according to the first embodiment of the present invention, the second main surface 15b of the base plate 1 exposed from the inside of the main body 3 and the first aperture 9 and the convex portion (heat dissipation). The region surrounded by the fins 19 is defined as the refrigerant chamber 11, and the refrigerant flowing through the refrigerant chamber 11 passes through the first opening 9 to the second main surface 15 b of the base plate 1 and the radiation fins 19. You will be in direct contact. Therefore, the semiconductor chip 2 that is a heating element can be cooled with low thermal resistance. That is, the heat generated in the semiconductor chip 2 can be transferred to the refrigerant without passing through a portion having a relatively large thermal resistance, such as conventional silicon grease. Furthermore, since the heat radiating fins 19 that are in direct contact with the refrigerant increase the heat exchange area, a further reduction in thermal resistance is realized. Furthermore, since the convex portion is the annular or frame-shaped heat radiation fin 19, the semiconductor chip 2 can be further cooled with a low thermal resistance.

  Further, since the radiating fin 19 and the side surface of the first opening 9 are brought into contact with each other through the rubber member 31, even when the heat sink 8 is thick, the radiating fin 19 itself has a function as a stopper. Thus, it is possible to reliably prevent the refrigerant contacting the second main surface 15b of the base plate 1 from leaking outside the refrigerant chamber 11.

  Further, the refrigerant flows from the second refrigerant chamber 13 through the second opening 10 to the first refrigerant chamber 12, whereby the refrigerant jet flows through the first opening 9 and the second plate of the base plate 1. It directly collides with the main surface 15b. Therefore, the semiconductor chip 2 on the base plate 1 can be further efficiently cooled.

  Furthermore, since the heat radiation fins 19 are provided at positions corresponding to the end portions of the semiconductor chip 2 and the jet of the refrigerant directly collides with the second main surface 15b of the base plate 1, the semiconductor chip on which the jet actually collides In the position corresponding to the center part of 2, heat exchange is performed by the turbulent flow by a collision jet. At the same time, the radiating fins 19 arranged at positions corresponding to the end portions of the semiconductor chip 2 exhibit high heat exchange capability. Thereby, the semiconductor chip 2 can be cooled with much lower thermal resistance. Also in this case, the leakage of the refrigerant can be reliably prevented by the contact between the radiating fin 19 and the first opening 9.

  Further, since the radiating fin 19 has an annular or frame-like shape, the radiating fin 19 is not mechanically deformed by a force generated when the radiating fin 19 is inserted while being in contact with the first opening 9. It is possible to easily provide strength.

  Further, the rubber member 31 is fitted into the first opening 9 and the rubber member 31 is interposed at the contact portion between the side surface of the radiating fin 19 and the side surface of the first opening 9, thereby sealing the rubber member 31. The role as a stopper is exhibited, and it is possible to more reliably prevent refrigerant leakage from the contact surface between the radiating fin 19 and the first opening 9. Even if a fine variation in processing accuracy occurs between the heat dissipating fins 19 and the first opening 9, the rubber member 31 can be deformed and sealed to prevent refrigerant leakage. For this reason, it becomes possible to prevent an increase in the processing cost due to increasing the processing accuracy of the radiating fins 19 and the first opening 9.

  Here, the reason why the low thermal resistance is realized by the first embodiment will be described with reference to FIGS. FIG. 3A shows an outline of a cross-sectional structure in the vicinity of the semiconductor chip 2 when the heat dissipating fins 19 are provided, and FIG. 3B shows a cooling capacity per unit area. The horizontal axis in FIG. 3B simulates the distance from the center of the semiconductor chip 2, and the vertical axis simulates the cooling capacity per unit area by the refrigerant. The central portion of the chip 2 exhibits a high cooling capacity when the refrigerant jet collides with it. Further, since the heat radiating fins 19 are also arranged at the end portion of the semiconductor chip 2 so that the refrigerant collides when the refrigerant flows laterally after the collision, a relatively high cooling capacity can be exhibited. On the other hand, FIG. 4A shows an outline of a cross-sectional structure in the vicinity of the semiconductor chip 2 in the absence of the heat radiating fins 19, and FIG. 4B shows cooling capacity per unit area. The heat exchange capability other than the portion where the jets directly collide is relatively low compared to the case where the heat dissipating fins 19 are present. Therefore, according to the first embodiment, a high cooling capacity is exhibited over the entire mounting portion of the semiconductor chip 2, and as a result, cooling with low thermal resistance is possible.

  In the first embodiment, the base plate 1 and the main body 3 of the heat sink 8 are joined by pressing the pressing portion 4 and the main body 3 with a pressure contact member such as a screw 27. Thereby, since the holding | suppressing part 4 and the main-body part 3 can be couple | bonded firmly, the coupling force of the base plate 1 and the main-body part 3 of the heat sink 8 also increases. Therefore, even if pressure due to refrigerant collision or the like is applied to the second main surface 15b of the base plate 1 by weight, it is possible to more reliably prevent refrigerant leakage.

  Moreover, you may join the press part 4 and the main-body part 3 by adhesion | attachment instead of using a press-contact member. In this case, refrigerant leakage can be prevented easily and without providing a space for screwing. Further, the heat sink 8 can be easily configured with a small amount of constituent materials, and the cost of the heat sink 8 can be further reduced.

  Further, even when the pressure member is used and when adhesion is used, even when the base plate 1 and the heat sink 8 are made of different materials and have different thermal expansion coefficients, it is possible to avoid reliability concerns due to thermal stress. . In this case, by forming the pressing portion 4 and the main body portion 3 with the same kind of material, there is no concern about reliability due to thermal stress at these joint portions.

  Although the case where the semiconductor chip 2 is mounted on the first main surface 15a of the base plate 1 via the ceramic substrate 33 has been described, the present invention is not limited to this. For example, the base plate 1 may be a ceramic substrate or a laminated substrate made of a ceramic substrate and a metal member. In this case, since there is no thermal resistance of the base plate 1 portion, the semiconductor chip 2 can be further cooled with low thermal resistance. Further, even if the thermal expansion coefficient differs between the ceramic substrate and the heat sink 8, there is no concern about reliability due to thermal stress. Alternatively, the base plate 1 may be made of a metal plate, and the semiconductor chip 2 may be mounted on the surface (first main surface 15a) of the metal plate, and an insulating layer may be provided on the back surface of the metal plate. In this case, the base plate 1 has a function as a wiring layer of the semiconductor chip 2 and can be electrically insulated by the insulating layer. Furthermore, since there is no thermal resistance of the ceramic substrate portion, the semiconductor chip 2 can be further cooled with a low thermal resistance, and it is possible to reduce the cost by not using a generally expensive ceramic substrate.

  Further, in the heating element cooling device disclosed in Patent Document 1 shown in the background art section, the semiconductor chip is mounted on the ceramic substrate, the upper surface of the heat sink is opened, and the back surface of the ceramic substrate is in direct contact with the refrigerant. When configured, it is difficult to take a structural measure for preventing refrigerant leakage at the bonding interface between the heat sink opening and the ceramic substrate. When bonded by bonding, soldering or welding, the ceramic substrate and the metal material constituting the heat sink generally have different thermal expansion coefficients, and there is a concern about reliability due to thermal stress. Furthermore, since the pressure of the refrigerant acts in the direction to peel off the joint, the possibility of refrigerant leakage cannot be denied, coupled with the above-described reliability concerns. In addition, there is a problem that the semiconductor chip is damaged by a high temperature process when soldering or welding the ceramic substrate on which the semiconductor chip is mounted, or that it is difficult to raise the temperature to a necessary temperature. On the other hand, according to the semiconductor device according to the first embodiment of the present invention, as described above, the bonding reliability between the base plate 1 and the heat sink 8 is high, and it is possible to more reliably prevent refrigerant leakage. I can do it.

  Further, in the heating element cooling device disclosed in Patent Document 1 shown in the background art section, when the ceramic substrate on which the semiconductor chip is mounted and the upper surface of the heat sink are joined via an O-ring, the width of the O-ring itself In addition, in order to uniformly apply a large load to the O-ring, an area for press contact with a screw or the like is also required. For this reason, it causes a big hindrance to the miniaturization of the device. On the other hand, according to the semiconductor device according to the first embodiment of the present invention, it is not necessary to use an O-ring, so that the entire device can be reduced in size.

(Second Embodiment)
As shown in FIG. 5, in the semiconductor device according to the second embodiment of the present invention, the radiating fins 19 and the base plate 1 are joined by an adhesive 34. Other components are the same as those of the semiconductor device shown in FIGS.

  As described above, according to the second embodiment of the present invention, since the back surface (second main surface 15b) side of the base plate 1 can be flattened in the manufacturing process, before the radiation fins 19 are mounted. First, when the semiconductor chip 2 is mounted on the first main surface 15a of the base plate 1 and bonding pad electrodes and the like are connected, problems in the manufacturing process caused by the back surface of the base plate 1 being not flat are eliminated. Therefore, the manufacturing cost can be reduced.

  Further, since the radiating fin 19 has an annular or frame shape, the mechanical strength against the force generated when the radiating fin 19 is inserted into the first opening 9 while being in contact with the first opening 9 via the rubber member 31 is radiated. 19 itself has. For this reason, it is possible to prevent the radiating fins 19 from being peeled off from the base plate 1.

  Furthermore, the semiconductor chip 2 is cooled by a coolant that collides with a position with respect to the central portion of the semiconductor chip 2, and the heat radiation fins 19 positioned at the end of the semiconductor chip 2 are bonded to each other so High cooling capacity can be obtained over the entire area.

(Third embodiment)
As shown in FIG. 6, in the semiconductor device according to the third embodiment of the present invention, the base plate 1 is made of a ceramic substrate 33. Other components are the same as those of the semiconductor device shown in FIG.

  As described above, according to the third embodiment of the present invention, since the thermal resistance of the metal plate portion is eliminated in the base plate portion, the semiconductor chip 2 can be further cooled with a lower thermal resistance.

  Further, by adhering a small-area radiating fin 19 to the back surface (second main surface 15b) of the ceramic substrate 33, the stress generated at the bonding interface by the adhesive 34 is suppressed to a small level, and the adhesive 34 generally has a stress relaxation function. May cause a reliability concern. As in the first embodiment, even if the thermal expansion coefficient differs between the constituent materials of the ceramic substrate 33 and the heat sink 8, there is no concern about reliability due to thermal stress.

  Furthermore, since the semiconductor chip 2 can be mounted on the ceramic substrate 33 by a conventional mounting process, the manufacturing cost of the device can also be reduced.

(Modification of the third embodiment)
As shown in FIG. 7, in the semiconductor device according to the modification of the third embodiment of the present invention, the base plate 1 includes a heat spreader composed of a metal plate 35 to which a semiconductor chip 2 is bonded, and a second of the metal plate 35. And an insulating layer 36 disposed on the main surface 15b side. That is, the base plate 1 is a metal plate 35, the semiconductor chip 2 is mounted on the surface (first main surface 15 a) of the metal plate 35, and an insulator region is provided on the back surface of the metal plate 35. Other components are the same as those of the semiconductor device shown in FIG.

  As described above, according to the modification of the third embodiment of the present invention, the base plate (metal plate 35) has a function as the wiring of the semiconductor chip 2 and the insulating layer 36 is used to Insulation can be achieved.

  Further, since the thermal resistance of the ceramic substrate 33 portion of FIG. 1 is eliminated, the semiconductor chip 2 can be further cooled with a lower thermal resistance than the semiconductor device of FIG. 1, and generally the high-cost ceramic substrate 33 is not used. Cost reduction can be achieved.

  Further, the adhesive 34 having a small area is bonded to the insulating layer 36 on the back surface of the metal plate 35 to suppress the stress generated at the bonding interface, and the adhesive 34 generally has a stress relaxation function. Does not occur. As in the first embodiment, there is no concern about reliability due to thermal stress even if the thermal expansion coefficient differs between the material of the base plate (metal plate 35) and the heat sink 8.

(Fourth embodiment)
As shown in FIG. 8, in the semiconductor device according to the fourth embodiment of the present invention, the rubber member 37 extends on the bonding surface 16 of the main body 3. Specifically, the inner periphery of the rubber member 37 is fitted along the side surface of the first opening 9 and is stretched as it is on the joining surface 16, and the outer peripheral end of the rubber member 37 is the side surface of the main body 3. Has reached to. Therefore, the base plate 1 is disposed on the bonding surface 16 of the main body portion 3 via the rubber member 37, and the pressing portion 4 and the main body portion 3 sandwich the rubber member 37 and the base plate 1. Other components are the same as those of the semiconductor device shown in FIG.

  As described above, according to the fourth embodiment of the present invention, the contact area between the rubber member 37, the base plate 1 and the main body 3 is increased, so that it is possible to more reliably prevent refrigerant leakage. . In addition, since the rubber member 37 is not disposed at a position corresponding to the semiconductor chip 2 that is a heating element, the thermal resistance of the semiconductor chip 2 is not affected at all.

(Fifth embodiment)
As shown in FIG. 9, in the semiconductor device according to the fifth embodiment of the present invention, the semiconductor chip is sealed with a mold resin 38, and the semiconductor chip sealed with the mold resin 38 is bonded to the base plate 1. The heat spreader made of the metal plate 35 and the insulating layer 36 disposed on the second main surface 15b side of the metal plate 35 are provided. Other components are the same as those of the semiconductor device shown in FIG.

  As described above, according to the fifth embodiment of the present invention, the semiconductor chip packaged with the mold resin 38 is mounted on the base plate 1, and the first to fourth embodiments described above are mounted. The same operation effect as the semiconductor device concerning can be produced. In general, a semiconductor chip package-sealed with a mold resin 38 has the semiconductor chip 2 mounted on the first main surface 15a of a heat spreader made of a metal plate 35, and the vicinity of the semiconductor chip 2 is molded with a mold resin 38 or the like. Manufactured by sealing. For this reason, the back surface of the insulating layer 36 and the joint surface 16 of the main body 3 can be easily joined by soldering or the like.

  In addition, by joining the radiating fins 19 to the second main surface 15b of the insulating layer 36 with the adhesive 34, the soldered joining portion between the heat spreader and the base plate is not affected.

 Furthermore, it is possible to cool a semiconductor chip encapsulated in a mold resin package which is generally produced industrially and is easy to reduce costs with low thermal resistance.

(Sixth embodiment)
As shown in FIG. 10, in the semiconductor device according to the sixth embodiment of the present invention, as a sealed body in which a plurality of semiconductor chips are sealed with a mold resin on the first main surface 15a side of the base plate 1. The module 39 is disposed, and the main body 3 and the pressing unit 4 sandwich the base plate 1 and the module 39. The base plate 1 is a support substrate for a sealed body 39 in which a plurality of semiconductor chips 2 are mounted on the first main surface 15a and sealed with a mold resin.

  Moreover, the edge part of the holding | suppressing part 4 has U-shape, and the side surface of the main-body part 3 and the baseplate 1 is inserted in the inside of U-shape. That is, the bonding surface 16 of the heat sink 8 has holes corresponding to the positions of the plurality of semiconductor chips. On the second main surface 15b of the base plate 1, the above-described convex portions (radiating fins) 19 are arranged at portions corresponding to the positions of the plurality of semiconductor chips. The sealed module body 39 and the heat sink 8 are bonded together by bonding or a pressure contact member such as a screw 27. The first opening 9 is formed corresponding to the position where the plurality of semiconductor chips 2 are arranged. The convex portions (radiating fins) 19 and the rubber member 31 are also arranged corresponding to the positions where the plurality of semiconductor chips 2 are arranged. Further, the partition plate 5 is formed with second opening portions 10 corresponding to the positions where the plurality of semiconductor chips 2 are arranged.

  Other components are the same as those of the semiconductor device shown in FIG.

  As described above, according to the sixth embodiment of the present invention, the power semiconductor chip in the so-called power module in which the power semiconductor chip is packaged with the resin can be cooled with low thermal resistance. In a power module that is generally produced industrially and easily reduced in cost, it is possible to reduce the thermal resistance in cooling the power semiconductor chip.

  In addition, by adhering the radiating fins 19 to the positions corresponding to the respective semiconductor chips in the module 39, the structure of the power module is not changed, and there is no fear of deterioration of the performance of the semiconductor chip due to the high temperature application process. This configuration can be realized. As a result, the cost can be further reduced.

  Furthermore, if the module 39 and the heat sink 8 are bonded together, these adhesive bondings can be easily performed. Alternatively, when the module 39 and the heat sink 8 are joined by a pressure contact member such as the screw 27, they can be joined more firmly, and refrigerant leakage can be further reliably prevented.

  Furthermore, generally, since the power module has an opening for screwing, there is no cost associated with processing a new power module. Further, the refrigerant leakage prevention mechanism is realized by the contact between the above-described heat radiation fin 19 and the first opening 9. Therefore, it is not necessary to perform many screw fastenings, and it is possible to realize low thermal resistance and low cost while avoiding an increase in the area of the entire device.

  Furthermore, when one large opening is formed at a position corresponding to all the semiconductor chips 2, the area of the opening becomes large. As a result, the refrigerant pressure applied to the back surface of the base plate 1 is large, and it is difficult to prevent refrigerant leakage at the joint surface 16 between the base plate 1 and the heat sink 8. On the other hand, according to the semiconductor device according to the sixth embodiment of the present invention, the refrigerant pressure is applied to the back surface of the base plate 1 by forming the plurality of first apertures 9 having a small area. Thus, refrigerant leakage at the joint between the base plate 1 and the joint surface 16 of the heat sink 8 can be reliably prevented.

(Other embodiments)
As described above, the present invention has been described according to the first to sixth embodiments of the present invention and modifications thereof. However, the description and the drawings that form a part of this disclosure limit the present invention. Should not be understood. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art. That is, it should be understood that the present invention includes various embodiments not described herein. Therefore, the present invention is limited only by the invention specifying matters according to the scope of claims reasonable from this disclosure.

  As described above, according to the first to sixth embodiments of the present invention, a particularly difficult part in the manufacturing process and a process that deteriorates the performance of the semiconductor chip 2 are not used, and silicon grease or the like is used. It is possible to provide a semiconductor device that can cool the semiconductor chip 2 with a low thermal resistance without going through a region having a large thermal resistance.

  Further, with respect to prevention of refrigerant leakage at the joint portion between the base plate 1 and the first opening 9, which has been likely to be a concern for reliability in the past, the prevention of refrigerant leakage is more reliably achieved. Can do.

  Furthermore, since the area where the refrigerant directly contacts the second main surface 15b of the base plate 1 is small, the load due to the refrigerant pressure is small. For this reason, the above-mentioned refrigerant leakage prevention effect is further improved. Also, reliability concerns due to thermal stress due to differences in the thermal expansion coefficients of the constituent materials can be avoided.

  INDUSTRIAL APPLICABILITY The present invention can be used industrially as an inverter device provided for driving an AC motor as a load such as an electric vehicle motor.

It is sectional drawing which shows the semiconductor device concerning the 1st Embodiment of this invention. It is a top view when the baseplate side is seen from the 1st refrigerant | coolant chamber. FIG. 3A is a schematic diagram showing an outline of a cross-sectional structure in the vicinity of the semiconductor chip in the case where there are radiating fins, and FIG. 3B is a graph showing the cooling capacity per unit area in the case where there are radiating fins. . FIG. 4A is a schematic diagram showing an outline of a cross-sectional structure in the vicinity of the semiconductor chip when there is no radiation fin, and FIG. 4B is a graph showing the cooling capacity per unit area when there is no radiation fin. . It is sectional drawing which shows the semiconductor device concerning the 2nd Embodiment of this invention. It is sectional drawing which shows the semiconductor device concerning the 3rd Embodiment of this invention. It is sectional drawing which shows the semiconductor device concerning the modification of the 3rd Embodiment of this invention. It is sectional drawing which shows the semiconductor device concerning the 4th Embodiment of this invention. It is sectional drawing which shows the semiconductor device concerning the 5th Embodiment of this invention. It is sectional drawing which shows the semiconductor device concerning the 6th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base plate 2 ... Semiconductor chip 3 ... Main-body part 4 ... Holding part 5 ... Partition plate 8 ... Heat sink 9 ... 1st opening part 10 ... 2nd opening part 11 ... Refrigerant chamber 12 ... 1st refrigerant | coolant chamber 13 ... 2nd refrigerant | coolant chamber 15a ... 1st main surface 15b ... 2nd main surface 16 ... Joining surface 19 ... Convex part (radiation fin)
27 ... Screw 31 ... Rubber member 32, 37 ... Adhesive layer 33 ... Ceramic substrate 34 ... Adhesive 35 ... Metal plate 36 ... Insulating layer 38 ... Mold resin 39 ... Sealed body (module)

Claims (15)

A base plate having a first main surface and a second main surface opposite to the first main surface;
A semiconductor chip bonded to the first main surface;
A heat sink comprising a main body having a joint surface joined to the second main surface;
An annular or frame-like convex portion arranged in the vicinity of a position corresponding to an end portion of the semiconductor chip in the second main surface;
A first opening is formed in the joint surface corresponding to the position where the semiconductor chip is disposed, and the second main body exposed from the inside of the main body and the first opening. The refrigerant flowing through the refrigerant chamber defined by the area surrounded by the surface and the convex portion is in direct contact with the second main surface and the convex portion via the first aperture, and the convex portion A side surface of the semiconductor device is in contact with the side surface of the first opening.   The heat sink further includes a partition plate disposed in parallel to the base plate in the main body, and the partition plate has a second opening corresponding to a position where the semiconductor chip is disposed. And the refrigerant chamber is divided into a first refrigerant chamber and a second refrigerant chamber located on the base plate side with the partition plate as a boundary, and the refrigerant is separated from the second refrigerant chamber to the second refrigerant chamber. 2. The semiconductor device according to claim 1, wherein the semiconductor device collides with the second main surface through the first opening by flowing into the first refrigerant chamber through the opening. The semiconductor device according to claim 1, wherein said convex portion is heat fin release.   The semiconductor device according to claim 3, wherein the radiating fin is bonded to the base plate by bonding.   It further has a rubber member disposed along the side surface of the first aperture portion, and the side surface of the convex portion is in contact with the side surface of the first aperture portion via the rubber member. The semiconductor device according to any one of claims 1 to 4.   The semiconductor device according to claim 1, wherein the base plate is bonded to the heat sink by bonding.   The heat sink further includes a pressing portion disposed on an outer peripheral portion of the first main surface, and the main body portion and the pressing portion sandwich the base plate. The semiconductor device described.   The semiconductor device according to claim 7, further comprising a fixing component that press-joins the pressing portion and the main body portion.   The semiconductor device according to claim 1, further comprising a ceramic substrate disposed between the semiconductor chip and the base plate.   9. The semiconductor device according to claim 1, wherein the base plate is made of a ceramic substrate or a laminated substrate of a ceramic substrate and a metal member.   The said base plate is equipped with the metal plate to which the said semiconductor chip was joined, and the insulating layer arrange | positioned at the said 2nd main surface side of the said metal plate, The any one of Claim 1 thru | or 8 characterized by the above-mentioned. Semiconductor device.   The semiconductor device according to claim 5, wherein the rubber member is extended on a joint surface of the main body.   The semiconductor device according to claim 1, wherein the semiconductor chip is sealed with a mold resin.   A module as a sealed body in which a plurality of semiconductor chips are sealed with mold resin is disposed on the first main surface of the base plate, and the main body portion and the pressing portion sandwich the base plate and the module. 9. The semiconductor device according to claim 7, wherein the semiconductor device is characterized in that:   15. The semiconductor device according to claim 1, wherein the semiconductor device comprises an inverter device used for driving an AC motor as a load.