JP4620617B2 - Directly cooled power semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power semiconductor device by which crevice corrosion in a seal part can be efficiently prevented. <P>SOLUTION: The direct-cooling power semiconductor device is provided with a metal base plate which has first and second major surfaces opposed to each other, and which has a power semiconductor element on the first major surface through a resin layer or directly; and a cooling structure having a concave part to which a cooling liquid for cooling the power semiconductor element is flowed back. The concave part of the cooling structure is arranged oppositely to the second major surface, and the cooling structure is mounted on the metal base plate in such a manner that it presses an O-ring consisting of an elastic body which is arranged around the concave part. In this case, a metal base coating film for preventing corrosion is formed in a part of the second major surface of the metal base plate which is exposed to the cooling liquid remaining in a crevice formed near the contact end between the O-ring and the metal base plate. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a semiconductor device including a power module on which a power semiconductor element such as an IGBT is mounted and a liquid cooling structure 201.

  In recent semiconductor devices for electric power, the direct liquid cooling method having high cooling performance is often used instead of the indirect liquid cooling method in order to meet the demand for improvement in power density. As a typical structure of this direct liquid cooling method, the cooling surface of the power module and the opening provided in the liquid cooling structure through which the cooling liquid flows are sealed to prevent leakage of the cooling liquid and complete the flow path. Structure. In general, O-rings, gaskets, and packings (hereinafter referred to as O-rings) are used as sealing materials at this time (Patent Documents 1 and 2).

On the other hand, in the direct liquid cooling type power semiconductor device, in order to improve the cooling performance of the power semiconductor module, the cooling surface contacting the cooling liquid on the back surface of the metal base plate is made as large as possible, and the cooling liquid Need to flow. Furthermore, in order to achieve miniaturization of the module or the semiconductor device, it is necessary to make the shape of the seal portion as small as possible.
JP-A-9-246443 JP 2005-136278 A

  However, when sealing with an O-ring, a minute gap is formed at the contact portion with the seal surface, and the coolant enters the minute gap, and the coolant may stay because the gap is small. As described above, when the cooling liquid stays, the oxygen concentration in the liquid becomes non-uniform, and local corrosion of metal (called crevice corrosion) occurs. This phenomenon is particularly remarkable in aluminum and copper used for the cooling base of the module and the liquid cooling structure 201. If the crevice corrosion progresses, it may cause liquid leakage from the seal portion.

  Therefore, the present invention has been made to solve the above-described conventional problems, and an object thereof is to provide a power semiconductor device that can effectively prevent crevice corrosion of a seal portion. And

In order to achieve the above object, a direct cooling power semiconductor device according to the present invention has a first main surface and a second main surface facing each other, and the power semiconductor element is a resin on the first main surface. A metal base plate provided directly or via a layer, and a cooling structure having a recess through which a cooling liquid for cooling the power semiconductor element is circulated, the cooling structure being provided on the second main surface In the direct cooling type power semiconductor device that is disposed so that the recesses face each other and is attached to the metal base plate so as to press an O-ring made of an elastic body provided around the recesses,
Corrosion occurs in a part of the second main surface of the metal base plate that is exposed to a coolant that is retained in a gap formed in the vicinity of a contact end between the O-ring and the metal base plate. The cooling structure has an O-ring storage groove around the recess, the O-ring is disposed in the O-ring storage groove, and the cooling structure includes: On the recess side of the partition wall that separates the O-ring housing groove and the recess, an interval is provided such that the distance from the second main surface increases continuously or stepwise as the recess approaches. The metal base coating film is provided to extend to a portion facing the inclined portion .

  In the direct cooling power semiconductor device according to the present invention configured as described above, a gap formed in the vicinity of a contact end between the O-ring on the second main surface of the metal base plate and the metal base plate. Since the metal base coating film for preventing corrosion is formed on the portion exposed to the coolant that stays in the gap, crevice corrosion at the seal portion can be effectively prevented.

Embodiments according to the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a sectional view showing a direct liquid-cooled power semiconductor device according to the first embodiment of the present invention.
In the first embodiment, the power module 100 includes a power device 101 such as an insulated gate bipolar transistor (IGBT), a copper wiring pattern 102, a metal base plate 105 made of copper, aluminum, or the like, which is a good thermal conductor. And a case 106. In this power module 100, the copper wiring pattern 102 is bonded to the metal base plate 105 by the adhesive resin layer 104, and for example, a plurality of power devices 101 are fixed on the copper wiring pattern 102 by solder (not shown) or the like. An electrode (not shown) provided on the surface of the power device 101 is electrically joined to a part of the copper wiring pattern by a thin metal wire such as an aluminum wire 103.

  In this state, in order to protect the power device 101, the copper wiring pattern 102, the aluminum wire 103, and the like from the external environment, a case 106 is fixed to the periphery of the metal base plate 105. Although not shown, the electrode of the power device 101 is electrically connected to the external electrode provided outside the case 106 through the copper wiring pattern 102, and the external electrode is connected to an external circuit. An electrical signal is extracted from the power module 100.

  In the power module 100, heat generated in the power device 101 is transmitted to the back surface of the metal base plate 105 through the copper wiring pattern 102, the adhesive resin layer 104 and the metal base plate 105, and is released from the back surface of the metal base plate 105. .

In the direct liquid-cooled power semiconductor device of the first embodiment, in order to cool the metal base plate 105 with respect to the power module 100 configured as described above, the liquid cooling structure 201 includes a metal base plate. It is attached to the back surface of 105. The liquid cooling structure 201 includes a recess through which the coolant 205 is circulated, an O-ring storage groove 203 provided so as to surround the opening 202 of the recess, and a supply / discharge port (not shown). Become. The liquid cooling structure 201 configured as described above is arranged so that the opening 202 faces the back surface of the metal base plate 105, and the O-ring 204 provided in the O-ring storage groove 203 allows the cooling liquid 205 to be externally provided. The metal base plate 105 is sealed so as not to leak out and attached to the back surface of the metal base plate 105.
The liquid cooling structure 201 can be made of a metal such as aluminum or copper, or a resin such as PPS (poly-phenylene-sulfide).

  With such a configuration, in the power semiconductor device of the first embodiment, the refluxed coolant 205 is in direct contact with the back surface of the metal base plate 105 to cool the metal base plate 105, so that the power module 100 can be efficiently used. Can be cooled.

Here, in particular, in the first embodiment, the coating film 108 is provided on the contact portion of the metal base plate 105 with the O-ring to effectively prevent crevice corrosion of the seal portion, and for highly reliable power use. It is possible to provide a semiconductor device.
Hereinafter, the configuration of the seal portion will be described in detail.

FIG. 2 is an enlarged cross-sectional view of a part of FIG. 1 for easy understanding of the structure of the seal portion in the first embodiment.
As shown in FIG. 2, the coating film 108 is formed wider than the maximum width of the contact surface of the O-ring 204 that is tightened by the metal base plate 105 and the liquid cooling structure 201 and expands in the lateral direction. Corrosion of the metal base plate 105 due to the retention of the liquid 205 is prevented.

  That is, since the O-ring 204 is an elastic body, the O-ring 204 is distorted in the lateral direction by being tightened by the metal base plate 105 and the liquid cooling structure 201, and as a result, a minute amount is formed at the boundary between the contact portion of the O-ring 204 and the metal base plate 105 A gap 107 is formed. When the cooling liquid 205 is flowed in this state, the cooling liquid 205 that has flowed into the gap portion stays in the gap and hardly flows because the gap is small. However, in the first embodiment, since the coating film 108 is formed on the surface of the metal base plate 105 located in the portion where the cooling liquid 205 stays, the crevice corrosion that has been a problem in the past is prevented. be able to.

  Thus, since the coating film 108 prevents corrosion of the metal base plate 105 due to the retention of the cooling liquid 205, the coating film is exposed to the cooling water that stays at least from the contact portion with the O-ring 204. What is necessary is just to be formed in the part. Specifically, the coating film 108 is formed so that the perpendicular line extending from the maximum diameter portion 204b of the central portion of the O-ring 204 that spreads laterally to the metal base plate 105 reaches a position 105b where the back surface of the metal base plate 105 intersects. It only has to be done.

  Further, in the present invention, the cross-sectional shape of the O-ring is not a circle, and it is conceivable that the gap portion becomes shallow if it is a rectangle or other irregular shape. Similar to the case of the O-ring, the coating film 108 may be formed.

The coating film 108 has high adhesion to the metal base plate 105, and is not deformed or deteriorated when the O-ring 204 is tightened. Also, the coating film 108 does not deteriorate or deteriorate even when exposed to the cooling liquid 205 for a long time. There is no limitation as long as it is made of a material, but for example, a material that is difficult to get wet with water, which is the main component of the cooling liquid 205, such as a silicone resin, is preferable.
Further, the coating film 108 can be made smooth by covering the unevenness of the surface of the metal base plate 105, has no defects such as pinholes, and the cooling liquid 205 does not reach the metal surface through the coating film. As long as the above conditions are satisfied, it is preferable that the thickness is as thin as possible. Specifically, the thickness is preferably set in the range of 0.002 mm to 0.050 mm.

The coating film 108 can be formed by, for example, a method in which a resin is sprayed on a surface that is covered with a mask but not covered with a mask, except for a portion to be formed, and uniformly applied.
Also, a method of applying a resin to the surface of the metal base plate 105 by pressing the jig soaked with a soft tip on the surface of the metal base plate 105, or transferring the resin by a stamp-like jig molded into the applied shape It can also be formed by a method, and the formation method is not particularly limited.

As described above, according to the direct liquid-cooled power semiconductor device of the first embodiment, crevice corrosion is achieved with a simple configuration in which the coating film 108 is formed on the back surface of the metal base plate 105 in contact with the O-ring. Can be prevented. In other words, in the configuration of the first embodiment, crevice corrosion can be prevented only by forming the coating film to a width slightly larger than the contact width of the O-ring. There is no need to increase the size of the opposing portion of the cold structure 201.
Therefore, in the first embodiment, since a special design near the O-ring is not made, downsizing of the semiconductor device is not hindered.

  In the configuration of the first embodiment, since the coating film 108 can be formed on the back surface of the metal base plate 105 before the cooling structure is attached to the power module 100, the formation state of the coating film 108 before the attachment. And the film quality can be inspected, and the occurrence of defects can be prevented. Furthermore, the assembly process can be shortened without the complexity of the assembly.

  Further, in the first embodiment, since the coating film is formed on the metal base plate 105, the liquid cooling structure is made of a resin having poor adhesiveness such as PPS (polyphenylene sulfide) resin. Even if it is, it is applicable.

  Therefore, according to the first embodiment, a direct liquid-cooling type that solves the conventional problems and can prevent crevice corrosion easily and at low cost without impairing the cooling performance and downsizing. A power semiconductor device can be provided.

Embodiment 2. FIG.
In the configuration of the first embodiment, it has been shown that crevice corrosion due to retention of the coolant 205 in the gap formed by the O-ring and the metal base plate 105 can be prevented.
However, in the sealed portion by the ring 204, the gap between the metal base plate 105 and the liquid cooling structure 201 is also small, and the retention of the cooling liquid 205 in this gap may be a problem.

  The direct liquid-cooled power semiconductor device according to the second embodiment has a seal portion that can prevent crevice corrosion due to the coolant 205 staying in the gap between the metal base plate 105 and the liquid-cooled structure 201. FIG. 3A shows an enlarged cross section of the seal portion.

  In the direct liquid-cooled power semiconductor device of the second embodiment, as shown in FIG. 3A, the partition wall upper surface 206 that separates the O-ring housing groove 203 and the recess through which the coolant 205 is circulated, and the metal base plate 105 There is a possibility that the cooling liquid 205 may stay in the gap. Therefore, in the direct liquid-cooled power semiconductor device according to the second embodiment, the coating film 108 is formed so as to extend to the portion of the metal base plate 105 facing the partition upper surface 206, and An inclined portion 206b is formed on the inner side so as to widen the distance from the metal base plate 105.

  In the second embodiment, by forming the inclined portion 206b, the range in which the cooling liquid 205 stays in the gap between the partition upper surface 206 and the metal base plate 105 is narrowed and further extended. The coating film 108 prevents crevice corrosion due to the stagnation of the coolant 205.

Here, the coating film 108 on the back surface of the metal base plate 105 is formed at least halfway through the inclined portion 206b exposed to the cooling liquid 205 staying on the back surface of the metal base plate 105.
3A, the same members as those in FIGS. 1 and 2 are denoted by the same reference numerals.

  As described above, in the second embodiment, the minute gap 107 near the contact portion boundary between the O-ring 204 and the metal base plate 105, the gap between the partition upper surface 206 and the metal base plate 105, and the inclined portion 206b and the metal base. Since the back surface of the metal base plate 105 facing the part of the gap between the plates 105 where the cooling liquid 205 may stay is completely covered with the coating film 108, the crevice corrosion due to the staying of the cooling liquid 205 is prevented. can do.

In Embodiment 2 described above, the inclined surface 206b is formed inside the partition upper surface 206. However, in the present invention, a curved surface 206c may be formed as shown in FIG. As shown in FIG. 3, it may be a stepped surface 206d, or may be an inclined surface 206e with protrusions as shown in FIG. 3D.
That is, in the present invention, if the distance from the metal base plate 105 toward the inside is a surface that expands continuously or stepwise, it can be formed instead of the inclined surface 206b.
In other words, the inclined surface 206b or a surface replacing it may be a surface where the region where the coolant 205 does not stay can be clearly identified and the end of the coating film can be determined.

  Furthermore, the end of the coating film 108 only needs to reach the region where the coolant 205 does not stay in the inclined inner portion of the O-ring housing groove 203, but the end of the coating film affects the cooling performance. As long as it does not affect the surface, there is no problem even if it extends slightly further inward.

Embodiment 3 FIG.
As shown in FIG. 4, the direct liquid-cooled power semiconductor device according to the third embodiment of the present invention is the same as the direct liquid-cooled power semiconductor device according to the first embodiment, except that the coating film 208 is formed on the bottom surface of the O-ring housing groove 203. The bottom surface of the O-ring housing groove 203 and the O-ring 204 are in contact with each other through the coating film 208.

In this way, when the liquid cooling structure 201 is made of metal, crevice corrosion due to retention of the cooling liquid 205 in the gap between the liquid cooling structure 201 and the O-ring 204 can be prevented.
Therefore, according to the structure of the third embodiment shown in FIG. 4, the liquid cooling structure 201 can be formed of a metal such as copper or aluminum.

  In the end portion of the coating film 208 in the third embodiment, as shown in the first embodiment, the coating portion has a perpendicular line dropped from the maximum portion 204b at the central portion of the O-ring 204 to the liquid cooling structure 201. Of course, it is sufficient that the O-ring housing groove 203 is formed so as to cover the outer side from the position where it intersects the bottom surface of the O-ring housing groove 203.

As described above, in Embodiment 3, it is possible to prevent crevice corrosion not only on the metal base plate 105 side but also on the liquid cooling structure 201 side, and the material of the metal base plate 105 and the liquid cooling structure 201 are made of the same material. Can be configured.
In the third embodiment, the coating film can be composed of the same as in the first embodiment.

Embodiment 4 FIG.
As shown in FIG. 5, the direct liquid-cooled power semiconductor device according to the fourth embodiment of the present invention is the same as that of the direct liquid-cooled power semiconductor device according to the second embodiment. The bottom surface of the O-ring housing groove 203 and the O-ring 204 are in contact with each other through the coating film 208, and the coating film 208 is extended to the middle of the inclined surface 206b through the partition wall upper surface 206. Forming.

That is, in the fourth embodiment, it is assumed that the liquid cooling structure 201 is made of a metal such as copper or aluminum, and the gap between the metal base plate 105 and the middle of the partition upper surface 206 and the inclined surface 206b. The coating film 208 prevents the portion of the liquid cooling structure 201 from being corroded by the retention of the cooling liquid 205.
In the fourth embodiment, the reason why the coating film 208 is extended to the middle of the inclined surface 206b is that the entire portion of the inclined surface 206b stays because the coating film 208 is exposed to the liquid cooling body that stays there. If there is a risk of exposure to the liquid cooling body, the coating film 208 may be extended to the lower end of the inclined surface 206b.

Further, as in the second embodiment, the back surface of the metal base plate 105 can be prevented from being corroded by the coating film 108 due to the retention of the coolant 205.
Needless to say, the formation of the inclined portion 206b can narrow the region in which the coolant 205 stays in the vicinity of the groove 204.

Further, instead of the inclined portion, a curved surface 206c may be formed as shown in FIG. 3B, a stepped surface 206d may be used as shown in FIG. 3C, or as shown in FIG. 3D. Alternatively, the inclined surface 206e having a protrusion may be used.
In addition, the material of the metal base plate 105 and the liquid cooling structure 201 may be the same material. In that case, the coating agent can be configured using the material exemplified in the first embodiment.
In addition, the liquid cooling structure 201 can be configured using a metal different from the metal base plate 105, and the material of the coating film in that case can be the material exemplified in the first embodiment. A more suitable material can be selected according to the material of the structure 201.

Embodiment 5.
The direct liquid-cooled power semiconductor device according to the fifth embodiment of the present invention is configured in the same manner as in the first embodiment except that the structure of the seal portion by the O-ring 204 is different from that in the first embodiment.
FIG. 6 is a cross-sectional view showing the structure of the O-ring seal portion of the direct liquid-cooled power semiconductor device according to the fifth embodiment.
In the direct liquid-cooled power semiconductor device of the fifth embodiment, the surface of the O-ring 204 sandwiched between the metal base plate 105 and the liquid-cooled structure 201, a part of the back surface of the metal base plate 105, and the O-ring housing groove 203 are used. It is characterized in that a continuous coating film is formed over the inner surface.

  In FIG. 6, a coating film covering the surface of the O-ring 204 is denoted by reference numeral 207 a, a coating film covering a part of the back surface of the metal base plate 105 is denoted by reference numeral 207 b, and a coating film covering the inner surface of the O-ring housing groove 203. In the following description, the coating film 207a, the coating film 207b, and the coating film 207c are formed by continuous coating. It is a membrane.

  That is, in the direct liquid-cooled power semiconductor device of the fifth embodiment, the metal base is formed in the vicinity of the contact end between the O-ring 204 and the metal base plate 105 and the minute O-ring gap 107 in which the coolant 205 will stay. A coating film 207 b continuous from the coating film 207 a is formed on the surface of the plate 105, thereby preventing the metal base plate 105 from being corroded by the cooling liquid 205 staying in the O-ring gap 107.

  Further, in the direct liquid-cooled power semiconductor device of the fifth embodiment, it is formed in the vicinity of the contact end between the bottom surfaces of the O-ring 204 and the O-ring housing groove 203, and in a minute O-ring gap where the coolant 205 will stay. A coating film 207c continuous from the coating film 207a is formed on the bottom surface of the groove, thereby preventing crevice corrosion on the inner surface of the O-ring housing groove 203 due to the coolant 205 staying in the O-ring gap.

Hereinafter, a method for forming a coating film in the sealing structure portion of the fifth embodiment will be described with reference to FIGS. 7A to 7D.
First, as shown in FIG. 7A, before attaching the liquid cooling structure 201 to the power module 100, the O ring 204 is attached to the O ring storage groove 203 of the liquid cooling structure 201, and in this state, A liquid coating resin solution 208a before the reaction curing of the coating resin is dropped.
Here, as the coating resin solution 208a, for example, a silicone resin or the like that has high adhesion to the metal base plate 105, does not cause deterioration due to the O-ring tightening, and is not violated by the coolant 205 is used. Can do. In addition, when the liquid cooling structure 201 is made of resin, it is required that the adhesiveness with the resin is high.

  The amount of dripping is preferably such that when the power module 100 is mounted and tightened, the resin solution fills the O-ring housing groove 203 and does not protrude from the O-ring housing groove 203. However, if the coating film formed after the curing reaction of the resin solution is sufficiently thin, there is no problem even if some solution protrudes from the O-ring housing groove 203. Even when the protruding solution flows and spreads along the inner wall of the opening of the liquid cooling structure 201, the coating film thickness after the curing reaction becomes thin, so the influence on the quality of the product can be ignored.

  FIG. 7B is a cross-sectional view showing a state in which the dropped solution 208b is filled in the O-ring storage groove 203. FIG. Thus, if the resin solution 208b has a low viscosity, the gap between the O-ring housing groove 203 and the O-ring 204 is sufficiently filled, and the O-ring 204 and the bottom surface of the O-ring housing groove 203 of the liquid cooling structure 201 are formed. The gap is also filled.

  FIG. 7C shows a state after the metal base plate 105 of the power module 100 is aligned and mounted on the liquid cooling structure 201. As shown in FIG. 7C, when the O-ring 204 is tightened from above and below, the O-ring 204 is distorted and spreads laterally. As a result, the resin solution 208c filled in the O-ring storage groove 203 is transferred to the back surface of the metal base plate 105 through the O-ring surface. At this time, the resin solution is sufficiently filled in the gap formed by the contact portion between the O-ring 204 and the metal base plate 105 due to the surface tension.

  FIG. 7D shows a state after the resin is cured and reacted in a state (not shown) in which the O-ring 204 is fastened and fixed with a bolt or the like. For the resin curing reaction, after the solvent in the resin solution is removed by drying, for example, in the case of a silicone resin, the reaction proceeds by absorbing the humidity component in the atmosphere and by heating in a high temperature atmosphere. However, there is no problem even if the reaction proceeds in any process. Similarly, the curing of any resin other than silicone is completed by any reaction process.

  Since the solvent in the resin solution is flying when the reaction is completed, a thin coating resin film remains on the wet surface of the resin solution, and a continuous coating film 207a covering the surface of the O-ring 204, and a metal base plate A coating film 207c that covers part of the back surface of 105 and a groove 207c that covers the inside of the groove are formed.

  This method does not require any special equipment or jigs other than using a resin dripping device and a high-temperature bath if necessary, and the process is very simple, with a well-defined shape and high dimensional accuracy. A coating film can be formed.

  As described above, in the fifth embodiment, since the crevice corrosion can be prevented by the coating films 207a, 207b, and 207c formed continuously without a break, the deterioration of the direct liquid-cooled power semiconductor device due to the corrosion can be prevented.

  In the fifth embodiment, in the process of forming the coating film, when the wettability to the resin solution on the surface of the metal base plate 105 is high and there is a possibility that the resin spreads to the opening, the predetermined surface of the metal base plate 105 is predetermined. The spread of the resin can be easily prevented by forming a strip-shaped resin flow stop at the position.

Moreover, when the viscosity of the resin solution for forming the coating film is high, the viscosity may be adjusted so as to obtain appropriate wettability by adding an appropriate solvent.
Further, when the surface of the metal base plate 105 or, in particular, when the liquid cooling structure 201 is made of resin and the adhesiveness of the resin solution for forming the coating film is low, the primer treatment is applied to the surface. Alternatively, surface activation treatment such as UV irradiation or plasma irradiation may be performed.

Embodiment 6 FIG.
As shown in FIGS. 8 and 9, the direct liquid-cooled power semiconductor device according to the sixth embodiment of the present invention is formed by forming an inclined portion 209 on the inner side of the partition wall located inside the O-ring housing groove 203. The coating film 207c formed in the groove is further extended to the inclined portion 209 so as to widen the gap with the base plate 105.
Note that a portion extending to the inclined portion 209 is shown as a coating film 207d.

  In the direct liquid-cooled power semiconductor device of the sixth embodiment configured as described above, the metal base plate 105 and / or the coolant 205 staying in the gap between the metal base plate 105 and the inner wall of the liquid-cooling structure 201. Alternatively, corrosion of the liquid cooling structure 201 can be prevented.

  In the sixth embodiment, for example, as shown in FIG. 8, when the metal base plate 105 is mounted so as to face the liquid cooling structure 201 and the O-ring 204 is tightened from above and below, the O-ring 204 is distorted. Spread sideways. As a result, the resin solution 208 c filled in the O-ring storage groove 203 travels along the surface of the O-ring 204 and spreads on the back surface of the metal base plate 105. At this time, if the dripping amount of the resin solution is set to be slightly larger, the resin solution fills the O-ring housing groove 203 and overflows, and the liquid cooling structure 201 between the O-ring housing groove 203 and the opening Overhanging the gap with the metal base plate 105 to the slope 209 on the opening side, a protruding portion 208d of the coating liquid is formed.

  In this state, the solvent is dried to cure the resin. As a result, as shown in FIG. 9, a thin coating resin film remains on the surface wetted with the resin solution, the coating film 207a covering the surface of the O-ring 204, the coating film 207b covering the surface of the metal base plate 105, and the O-ring. A coating film 207 c that covers the inner wall of the storage groove 203 and a coating film 208 d that covers the inclined surface portion 209 are continuously formed.

  The direct liquid-cooled power semiconductor device according to the sixth embodiment configured as described above has the same function and effect as the direct liquid-cooled power semiconductor device according to the fifth embodiment. Even when the coolant 205 stays in the gap between the inner wall of the O-ring storage groove 203 and the back surface of the metal base plate 105 when filling from the O-ring storage groove 203 to the O-ring storage groove 203, the surface of the metal base plate 105 in this region also The surface of the liquid cooling member is also covered with a coating film, and crevice corrosion can be prevented.

  In the sixth embodiment, the inclined surface portion 209 may be a flat surface, a curved surface, or a stepped surface.

Embodiment 7 FIG.
As shown in FIG. 10, the direct liquid-cooled power semiconductor device according to the seventh embodiment of the present invention is characterized in that a liquid reservoir 210 that prevents the resin solution from flowing into the inside is formed. The portion is configured similarly to the direct liquid-cooled power semiconductor device of the sixth embodiment.

  The direct liquid-cooled power semiconductor device according to the seventh embodiment configured as described above can prevent the resin solution that has flowed from collecting in the liquid pool 210 of the inclined portion and flowing to the opening. As a result, even if trouble occurs due to the resin solution flowing into the opening, it can be manufactured without strictly controlling the amount of the resin solution, and the manufacturing process can be simplified.

1 is a cross-sectional view showing a direct liquid-cooled power semiconductor device according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view showing a part of FIG. 1 in order to show the structure of a seal portion in the first embodiment. It is sectional drawing which shows the structure of the seal | sticker part in the direct liquid cooling type power semiconductor device of Embodiment 2 which concerns on this invention. It is sectional drawing which shows the curved surface 206c in the direct liquid-cooling type | mold power semiconductor device of the modification concerning Embodiment 2. FIG. It is sectional drawing which shows the step-shaped surface 206d in the direct liquid-cooling type | mold power semiconductor device of the modification concerning Embodiment 2. FIG. It is sectional drawing which shows the inclined surface 206e with a protrusion in the direct liquid cooling type power semiconductor device of the modification concerning Embodiment 2. FIG. It is sectional drawing which shows the structure of the seal | sticker part in the direct liquid cooling type power semiconductor device of Embodiment 3 which concerns on this invention. It is sectional drawing of the sealing part in the direct liquid cooling type power semiconductor device of Embodiment 4 which concerns on this invention. It is sectional drawing which shows the structure of the O-ring seal part of the direct liquid cooling type power semiconductor device in this Embodiment 5. In Embodiment 5, it is sectional drawing which shows a mode when a resin solution is dripped. In Embodiment 5, it is sectional drawing which shows the state with which the dripped solution 208b was filled in the O-ring accommodation groove | channel 203. FIG. In Embodiment 5, it is sectional drawing which shows the state after aligning and mounting the metal base board 105 of the power module 100 in the liquid cooling structure 201. FIG. In Embodiment 5, it is sectional drawing which shows the state after carrying out hardening reaction of the resin in the state which fastened and fixed O-ring 204 with the volt | bolt etc. FIG. In the manufacturing process of the direct liquid-cooled power semiconductor device of Embodiment 6 which concerns on this invention, it fills with the resin solution in the O-ring accommodation groove | channel 203, and is sectional drawing which shows the state clamped from the upper and lower sides. It is sectional drawing which shows the structure of the sealing part in the direct liquid cooling type power semiconductor device of Embodiment 6 which concerns on this invention. It is sectional drawing which shows the structure of the sealing part in the direct liquid cooling type power semiconductor device of Embodiment 7 which concerns on this invention.

Explanation of symbols

  100 power module, 101 power device, 102 copper wiring pattern, 103 aluminum wire, 104 adhesive resin layer, 105 metal base plate, 106 case, 107 minute gap, 108, 207a, 207b, 207c, 207d, 208 coating film, 201 Liquid cooling structure, 203 O-ring storage groove, 204 o ring, 205 cooling liquid, 206 partition wall upper surface, 206b inclined surface, 206c curved surface, 206e inclined surface with protrusion, 208c resin solution, 209 inclined portion, 210 liquid reservoir.

Claims (6)

A metal base plate having a first main surface and a second main surface facing each other, and a power semiconductor element provided on the first main surface via a resin layer or directly, and cooling the power semiconductor element And a cooling structure having a recess through which the coolant is circulated, and the cooling structure is disposed so that the recess faces the second main surface, and is provided around the recess. In the direct cooling type power semiconductor device attached to the metal base plate so as to press the O-ring composed of
Corrosion occurs in a part of the second main surface of the metal base plate that is exposed to a coolant that is retained in a gap formed in the vicinity of a contact end between the O-ring and the metal base plate. forming a metal-based coating film for preventing,
The cooling structure has an O-ring storage groove around the recess, and the O-ring is disposed in the O-ring storage groove; and
In the cooling structure, the distance from the second main surface toward the concave portion of the partition wall that separates the O-ring storage groove from the concave portion increases continuously or stepwise as it approaches the concave portion. A direct-cooling type power semiconductor device having an inclined portion, wherein the metal base coating film extends to a portion facing the inclined portion . In the O-ring storage groove, at least a part of the bottom surface of the O-ring storage groove, which is exposed to a coolant staying in a gap formed in the vicinity of a contact end between the bottom surface and the O-ring. , the direct cooling type power semiconductor device according to claim 1, wherein the forming the cooling structure coating to prevent corrosion of the bottom surface. The direct cooling type power semiconductor device according to claim 2, wherein the cooling structure coating film is provided so as to extend to the inclined portion. 4. The direct cooling type power semiconductor device according to claim 2 , wherein a part of the cooling structure coating film is sandwiched between bottom surfaces of the O-ring and the O-ring housing groove.   The O-ring coating film provided on the surface of the O-ring is further formed as a continuous film in which the metal base coating film, the O-ring coating film, and the cooling structure coating film are continuous. 3. The direct cooling type power semiconductor device according to 3. The direct-cooling type power semiconductor according to any one of claims 1 to 4 , wherein a part of the metal base coating film is sandwiched between the O-ring and the second main surface of the metal base plate. apparatus.

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