JP4729336B2 - Power module substrate - Google Patents

Description

The present invention relates to a substrate for power module.

  Patent Document 1 discloses a conventional insulated circuit board. This insulating circuit board includes an aluminum wiring layer on which a power device such as a semiconductor chip is mounted on one side, an insulating ceramic insulating board bonded to the other side of the wiring layer, and the other side of the insulating board. And a heat dissipation layer made of aluminum joined to the surface. The insulated circuit board includes a plurality of fins on the other surface side of the insulated substrate. Specifically, a metal plate having a plurality of pores formed on the other surface of the heat dissipation layer is joined with solder or the like, and a fin having a tongue shape or a thin plate is inserted into each pore. Bonded with solder or the like.

  In the insulated circuit board of Patent Document 1 having such a configuration, a power device is mounted on one surface of a wiring layer. And this insulating circuit board is mounted in the heat sink which forms a refrigerant | coolant chamber and distribute | circulates a cooling medium in a refrigerant | coolant chamber, for example, and becomes a power module. The power module is applied to an inverter circuit of a moving body such as a hybrid car having an electric motor as a drive source, for example, so that the power supplied to the electric motor or the like according to the operating state of the moving body To control. In this power module, high heat generated by the power device is transmitted to the fins via the wiring layer, the insulating substrate, the heat dissipation layer, and the metal plate, and further transmitted from the fins to the cooling medium of the heat sink to dissipate the heat.

  Patent Document 2 discloses another conventional insulated circuit board. This insulated circuit board includes a wiring layer, an insulated substrate, and a heat dissipation layer that have substantially the same configuration as the insulated circuit board disclosed in Patent Document 1. The insulated circuit board includes a heat sink on the other surface side of the insulated substrate. The heat radiating plate includes a flat plate portion and a plurality of fins integrally formed on the other surface of the flat plate portion. In this heat radiating plate, one surface of the flat plate portion is joined to the other surface of the heat radiating layer with solder or the like.

  The insulated circuit board of Patent Document 2 having such a configuration is also mounted on a heat sink to form a power module, similar to that of Patent Document 1, and generates high heat generated by the power device as a wiring layer, an insulating substrate, a heat dissipation layer, and a heat dissipation. The heat is transferred to the fin through the flat plate portion of the plate, and further transferred from the fin to the cooling medium of the heat sink to release the heat.

JP-A-8-107166 JP 2004-247684 A

  However, the insulated circuit boards of Patent Documents 1 and 2 have the following problems with respect to manufacturing cost and durability.

  That is, regarding the manufacturing cost, in the insulated circuit board of Patent Document 1, in order to improve the heat dissipation performance, a large number of pores must be formed in the metal plate, and a large number of heat dissipation fins must be individually manufactured. It is difficult to shorten the part processing process. In this insulated circuit board, a large number of fins must be inserted into each of a large number of pores of the metal plate one by one, and it is difficult to shorten the assembly process. For this reason, with this insulated circuit board, it has been difficult to reduce the manufacturing cost.

  Further, even in the insulated circuit board of Patent Document 2, if a large number of thin fins are formed on the heat dissipation plate in order to improve the heat dissipation performance, the processing cost such as cutting and extrusion increases, and the manufacturing cost is reduced. It was difficult.

Further, regarding durability, in the insulated circuit boards of Patent Documents 1 and 2, since the flat part of the metal plate or the heat sink is joined to the other surface side of the insulating board, the insulating board and the metal plate or the heat sink Due to the difference in thermal expansion due to the difference in linear expansion coefficient with the flat plate portion, there has been a concern of problems such as cracking or cracking of the insulating substrate. Specifically, since the insulating substrate is made of ceramic or the like, the linear expansion coefficient is small (the linear expansion coefficient of aluminum nitride (AlN) is about 3.2 × 10 ⁻⁶ / ° C.), a metal plate or a heat radiating plate. Since the flat plate portion is made of a metal such as aluminum, the linear expansion coefficient is larger than that of the insulating substrate (the linear expansion coefficient of the aluminum alloy is about 23 × 10 ⁻⁶ / ° C.). For this reason, as the temperature of both bonded members rises, a difference in thermal expansion occurs between them, a shearing force acts on the bonding surface, a force that warps the whole acts, and the insulating substrate breaks, It may cause problems such as cracks.

The present invention was made in view of the above conventional circumstances, while improving the heat radiation performance, providing a substrate for power module capable of implementing the improvement of the cost reduction and durability of the manufacturing cost This is a problem to be solved.

The power module substrate of the present invention includes a wiring layer on which a power device is mounted on one surface, an insulating substrate bonded to the other surface of the wiring layer, and a plurality of fins formed in a wave shape. An insulated circuit board comprising a corrugated fin with the top of each fin joined to the other surface side of
A refrigerant chamber, an inflow path and an outflow path are formed, the inflow path has a cooling medium flowing into the refrigerant chamber, and the outflow path has a heat sink that allows the cooling medium to flow out of the refrigerant chamber;
In a state where the corrugated fin is housed in the refrigerant chamber and the insulating substrate seals the refrigerant chamber, the periphery of the insulating substrate is fixed to the heat sink ,
The corrugated fin is characterized in that a portion excluding the top of each fin is divided by a cut extending in the wavelength direction .

Such a power module substrate of the present invention have a configuration, in the power device is mounted on one surface of the wiring layer, the power module.

The power module is applied to an inverter circuit of a moving body such as a hybrid car having an electric motor as a drive source, for example, so that the power supplied to the electric motor or the like according to the operating state of the moving body To control. And, in this power module, the high heat of the power device emits through the wiring layer and the insulating substrate, Den example each fin of the corrugated fin, the heat conveyed to the coolant flowing through the coolant chamber of the heat sink from the fins radiator To do.
Here, in the power module substrate of the present invention, the peripheral edge of the insulating substrate is fixed to the heat sink in a state where the corrugated fins are housed in the refrigerant chamber and the insulating substrate seals the refrigerant chamber. Heat from the power device can be transferred from each fin of the corrugated fin to the cooling medium without going through the heat sink itself. For this reason, this power module substrate can significantly shorten the heat transfer path from the power device to each fin, and can improve the heat dissipation performance.

Further , in the insulated circuit board in the power module substrate of the present invention, the top of each fin of the corrugated fin is joined to the other surface side of the insulated substrate, and the metal plate or the like in the insulated circuit board of Patent Documents 1 and 2 is used. There is no intervention. For this reason, this insulated circuit board can greatly shorten the heat transfer path from the power device to each fin, and can improve the heat dissipation performance.

  In addition, this insulated circuit board uses corrugated fins in which a plurality of fins are formed in a wave shape. For this reason, in this insulated circuit board, even when a large number of fins are formed in order to improve the heat dissipation performance, the processing steps of the corrugated fins are not so long, and the processing costs are not so high. Further, in this insulated circuit board, the top of each fin can be bonded to the other surface side of the insulating substrate at a time or a small number of times, so a large number of fins can be relatively easily attached to the other surface side of the insulating substrate. Can be assembled. For this reason, it is not necessary to form a large number of pores in the metal plate as in the insulated circuit board of Patent Document 1 and to manufacture a large number of heat dissipating fins individually, and the part processing step can be greatly shortened. Further, it is not necessary to insert a large number of fins one by one in each of a large number of pores of a metal plate as in the insulated circuit board of Patent Document 1, and the assembly process can be greatly shortened. Further, since it is not necessary to form a large number of thin fins by cutting or extrusion molding as in the insulated circuit board of Patent Document 2, the processing cost can be suppressed. For this reason, this insulated circuit board can realize a reduction in manufacturing cost while improving heat dissipation performance.

  In addition, this insulating circuit board is merely formed by bonding the tops of the corrugated fins made of thin plates on the other surface side of the insulating substrate in a band shape with a gap therebetween. For this reason, in this insulated circuit board, when the corrugated fin thermally expands due to heat from the power device, the force acting to warp the insulated board is not so great. For this reason, in this insulated circuit board, problems such as cracking of the insulated substrate and generation of cracks due to a difference in thermal expansion between the insulated substrate and the corrugated fins are suppressed, and improvement in durability can be realized.

Therefore, the power module substrate of the present invention can realize a reduction in manufacturing cost and an improvement in durability while improving the heat dissipation performance.
Further, in the power module substrate of the present invention, the corrugated fin is divided by a cut extending in the wavelength direction except for the top of each fin. For this reason, since the anisotropy that the rigidity differs between the wavelength direction of the corrugated fin and the direction perpendicular to the wavelength direction is greatly eliminated, the occurrence of problems such as cracking or cracking of the insulating substrate is caused. Further suppression can be achieved. Moreover, since the corrugated fin has a part which is not divided at the top and can be handled as an integral part, the workability in the assembly process is not lowered.
In the power module substrate of the present invention, as a specific example in which the periphery of the insulating substrate is fixed to the heat sink, the area of the wiring layer and the heat dissipation layer is made slightly smaller than the insulating substrate to expose the vicinity of the periphery of the insulating substrate. In addition, the vicinity of the periphery of the insulating substrate can be fixed to the heat sink. In this case, the member for fixing the insulating circuit board and the wiring layer can be prevented from contacting each other. Here, since the member for fixing the insulating circuit board is highly likely to be made of metal, it is not necessary to insulate the two, which contributes to a reduction in manufacturing cost.

  The wiring layer can be constituted by a thin layer made of aluminum, copper or the like having a thickness of about 0.4 mm.

The insulating substrate can be constituted by a thin plate made of an insulating ceramic such as aluminum nitride (AlN), alumina (Al ₂ O ₃ ), silicon nitride (Si ₃ N ₄ ) having a thickness of about 0.5 to 3 mm. From the viewpoint of suitable thermal conductivity, it is preferably made of aluminum nitride.

  The corrugated fin can be constituted by a thin plate made of thin aluminum or aluminum alloy having a thickness of about 0.1 to 1 mm, copper or copper alloy, stainless steel, or the like.

In the power module substrate of the present invention, it is preferable that a heat dissipation layer is provided between the insulating substrate and the corrugated fin.

  In this case, when joining each top part of a corrugated fin to the other surface side of an insulated circuit board, it can carry out easily by simple methods, such as brazing. Further, if the heat dissipation layer has a higher thermal conductivity than the insulating substrate, the heat transmitted from the power device is diffused in the surface direction in the heat dissipation layer, so that the heat dissipation performance can be further improved.

  The heat dissipation layer can be formed of a thin layer made of aluminum, copper or the like having a thickness of about 0.1 to 0.6 mm. Basically, the heat dissipation layer is made of the same material as that of the wiring layer described above, and the thickness thereof is about the same as that of the wiring layer. It is possible to suppress warping caused by a difference in thermal expansion between the one surface side and the other surface side of the circuit board to some extent.

  Moreover, as this insulated circuit board, the conventionally well-known insulated circuit board which consists of a wiring layer, an insulated substrate, and a thermal radiation layer, and a corrugated fin, for example, and the top part of each fin may be joined to the thermal radiation layer may be sufficient. As a conventionally known insulating circuit board, a DBA (Direct Brazed Aluminum (registered trademark)) substrate, a DBC (Direct Bonded Cupper (registered trademark)) substrate, or the like can be adopted.

In the power module substrate of the present invention, the heat dissipation layer may be thinner than the wiring layer.

  This is because the top of each fin joined to the heat dissipation layer has a slight reinforcing effect on the heat dissipation layer, so even if the heat dissipation layer is made thinner than the wiring layer, one side of the insulated circuit board This is because warpage caused by a difference in thermal expansion between the side and the other surface side can be suppressed.

In the power module substrate of the present invention, a reinforcing plate may be bonded to the bottom of each fin that is the other side of each top of the corrugated fin.

  In this case, the rigidity of the entire insulating circuit board is improved by the reinforcing plate joined to the bottom of each of the fins, and the occurrence of problems such as cracking or cracking of the insulating board can be suppressed. Further, the corrugated fin itself has anisotropy having different stiffnesses in the wavelength direction and the direction orthogonal to the wavelength direction, but if this reinforcing plate is joined, the anisotropy of the corrugated fin can be relaxed.

In the power module substrate of the present invention, each of the corrugated fins may be rectangular.

In this case, in this power module substrate, the bonding surface at the top of each fin bonded to the other surface side of the insulating circuit substrate or the bonding surface at the bottom of each fin bonded to the reinforcing plate is set to a predetermined area. It becomes easy. For this reason, the power module substrate can further easily adjust the reinforcing effect of the corrugated fin on the one surface side of the insulating circuit substrate, and can further improve the durability.

In the power module substrate of the present invention, the peripheral edge of the absolute Enmoto plate and the heat sink is preferably the insulating substrate is fixed by a spring member for pressing to said heat sink by an elastic force.

In this case, the heat sink and the insulated circuit board can be fixed to each other with acceptable dimensional changes . This allows a difference in thermal expansion between a heat sink made of a material such as aluminum having a relatively large linear thermal expansion coefficient and an insulating substrate made of a material such as aluminum nitride having a relatively small linear thermal expansion coefficient. It is possible to suppress problems such as cracking of the insulating substrate and cracking.
In this case , the insulating circuit board can be more easily fixed to or removed from the heat sink than other methods such as screwing. For this reason, this insulated circuit board can be easily assembled and maintained. In this case, if such an intervening sealing means such as an O-ring between the periphery of the heat sink and absolute Enmoto plate, while permitting the dimensional change of the two, it is possible to seal more preferred.

  Examples 1 to 9 embodying the present invention will be described below with reference to the drawings. In each drawing, the upper side is the front surface and the lower side is the back surface.

(Example 1)
As shown in FIGS. 1 to 4, the insulated circuit board 11 according to the first embodiment includes a wiring layer 21 on which a power device 91 is mounted on the front surface, an insulating substrate 31 bonded to the back surface of the wiring layer 21, and a plurality of substrates. The fin 41a is formed in a wave shape, and the corrugated fin 41 is provided on the back side of the insulating substrate 31 and the top 41b of each fin 41a is joined. A heat radiation layer 51 is provided between the back surface of the insulating substrate 31 and the corrugated fins 41.

  The wiring layer 21 is composed of a thin aluminum layer having a thickness of about 0.4 mm. When the insulated circuit board 11 is used, a power device 91 such as a semiconductor chip is mounted on the wiring layer 21 by means such as wire bonding.

Since the insulating substrate 31 is required to have insulating properties and suitable thermal conductivity, the insulating substrate 31 is made of an insulating ceramic and is made of a thin aluminum nitride plate having a thickness of 0.635 mm. Since the linear expansion coefficient of aluminum nitride is 3.2 × 10 ⁻⁶ / ° C., the insulating substrate 31 has a characteristic that is difficult to thermally expand.

  The heat dissipating layer 51 is composed of a layer made of aluminum having a thickness of about 0.3 mm that is slightly thinner than the wiring layer 21.

  Regarding the vertical and horizontal dimensions of the wiring layer 21, the insulating substrate 31, and the heat dissipation layer 51, the insulating substrate 31 has a rectangular shape with a length of about 40 mm and a width of about 40 mm. In addition, the wiring layer 21 and the heat dissipation layer 51 are rectangular with a length of about 30 mm and a width of about 30 mm, which is slightly smaller than the insulating substrate 31. For this reason, the front surface and the back surface near the periphery of the insulating substrate 31 are exposed.

  The corrugated fin 41 is formed by undulating a plurality of fins 41a by repeatedly bending an aluminum thin plate having a thickness of about 0.2 mm. The top part 41b and the bottom part 41c of each fin 41a connect each adjacent fin 41a while curving round. The corrugated fin 41 has a height of 5 mm, and the interval between the fins 41a is about 2 mm.

  The insulated circuit board 11 of Example 1 configured as described above is manufactured as follows, for example.

  First, a thin plate made of an aluminum clad material to be the wiring layer 21, an insulating substrate 31, and a thin plate made of an aluminum clad material to be the heat dissipation layer 51 are laminated in this order from above. And it heats to such a high temperature that the surface layer of the thin plate of aluminum clad material is melted, and then cools to obtain a laminated body in which these are joined.

  Next, the top portion 41b of the corrugated fin 41 is brought into contact with the back surface of the heat dissipation layer 51 below the laminated body via an aluminum brazing material, and is sandwiched by a jig or the like. Then, the aluminum brazing material is heated to such a high temperature that it melts, and then cooled. Thereby, the insulated circuit board 11 in which the top 41b of the corrugated fin 41 is joined to the back surface of the heat dissipation layer 51 is completed. In the insulated circuit board 11 obtained in this way, as shown in an enlarged view in FIGS. 3 and 4, a row of joint portions 41 d in which the top portions 41 b of the corrugated fins 41 are aluminum brazed to the back surface of the heat radiation layer 51 is formed. .

  The insulated circuit board 11 of Example 1 is manufactured by methods other than the above manufacturing method. For example, a thin plate made of an aluminum clad material to be the wiring layer 21, an insulating substrate 31, a thin plate made of an aluminum clad material to be the heat dissipation layer 51, and a corrugated fin 41 made of a thin plate made of an aluminum clad material are arranged in this order from above. Are stacked with a jig or the like. And it is also possible to obtain the insulated circuit board 11 to which these were joined by heating at high temperature and cooling after that.

  In the insulated circuit board 11 of Example 1 having such a configuration, the power device 91 is mounted on the surface of the wiring layer 21 as shown in FIG. The insulated circuit board 11 is mounted on the heat sink 61.

The heat sink 61 is made of an aluminum alloy. The linear expansion coefficient of the aluminum alloy is about 23 × 10 ⁻⁶ / ° C., which is larger than the linear expansion coefficient (about 3.2 × 10 ⁻⁶ / ° C.) of aluminum nitride constituting the insulating substrate 31. For this reason, when both the heat sink 61 and the insulating circuit board 11 are heated by the heat generated by the power device 91, the heat sink 61 tends to thermally expand more than the insulating substrate 31.

  The surface of the heat sink 61 is provided with a recess 61b that constitutes a part of the refrigerant chamber 61a, and an O-ring groove 61c is formed around the recess 61b. An O-ring 61d is mounted in the O-ring groove 61c.

  The insulated circuit board 11 is placed from above the recessed part 61b and fixed by the spring material 61e so that the corrugated fins 41 on the back surface side of the insulated circuit board 11 are accommodated in the recessed part 61b of the heat sink 61. Thus, the insulating circuit board 11 and the recess 61b form the refrigerant chamber 61a, and the cooling medium can flow along the corrugated fins 41 in the refrigerant chamber 61a.

The spring member 61e is elastic deformability is high Iba I steel plate. One of the spring members 61 e is bent in a crank shape so as to press the peripheral edge of the insulating circuit board 11 from above toward the surface of the heat sink 61, and the other is brazed to the surface of the heat sink 61. Even if a dimensional change due to a difference in thermal expansion between the heat sink 61 and the insulating circuit board 11 occurs, the spring material 61e having such a shape can follow the dimensional change.

  At this time, the surface of the heat sink 61 and the vicinity of the peripheral edge of the back surface of the insulating substrate 31 constituting the insulating circuit substrate 11 fixed by the spring material 61e are in contact with each other via the O-ring 61d. Thus, the heat sink 61 and the insulating circuit board 11 are sealed so that the cooling medium does not leak.

Thus, the insulating circuit board 11 of the first embodiment is mounted on a heat sink 61, enters the power module, for example, it is applied to the electric motor to the inverter circuit in a mobile body such as a hybrid car that is part of a drive source Thereby, the electric power supplied to an electric motor etc. is controlled according to the driving | running | working condition of a moving body. Then, the power modules are high fever wiring layer 21 power device 91 emits, via the insulating substrate 31 and the heat dissipation layer 51, transmitted to the fins 41a of the corrugated fin 41, the refrigerant chamber 61a of the heat sink 61 from the fins 41a The heat is transferred to the cooling medium that circulates inside and dissipated.

  Here, in the insulated circuit board 11 of Example 1, the top portions 41b of the fins 41a of the corrugated fins 41 are joined to the back side of the insulated substrate 31, and the metal plates and the like in the insulated circuit boards of Patent Documents 1 and 2 are used. There is no intervention. For this reason, this insulated circuit board 11 can greatly shorten the heat transfer path from the power device 91 to each fin 41a, and can improve the heat dissipation performance.

  In addition, the insulated circuit board 11 uses corrugated fins 41 in which a plurality of fins 41a are formed in a wave shape. For this reason, in this insulated circuit board 11, even when a large number of fins 41a are formed in order to improve the heat dissipation performance, the processing steps of the corrugated fins 41 are not so long, and the processing cost does not increase so much. Moreover, in this insulated circuit board 11, since the top part 41b of each fin 41a can be joined to the back surface side of the insulating substrate 31 at once or with a small number of times, a large number of fins 41a are relatively arranged on the back surface side of the insulating substrate 31. It can be assembled easily. For this reason, it is no longer necessary to form a large number of pores in a metal plate as in the insulated circuit board of Patent Document 1 and to manufacture a large number of heat dissipating fins individually, which can greatly shorten the component processing process. is made of. Further, it is not necessary to insert a large number of fins one by one in each of a large number of pores of a metal plate as in the insulated circuit board of Patent Document 1, and the assembly process can be greatly shortened. ing. Moreover, since it is no longer necessary to form a large number of thin fins by cutting or extrusion molding as in the insulated circuit board of Patent Document 2, the processing cost can be reduced. For this reason, the insulated circuit board 11 can realize a reduction in manufacturing cost while improving the heat dissipation performance.

  In addition, the insulating circuit board 11 is simply formed by bonding the top portions 41b of the fins 41a of the corrugated fins 41 made of a thin plate to the back side of the insulating substrate 31 with a gap therebetween. For this reason, in this insulated circuit board 11, when the corrugated fin 41 is thermally expanded by the heat from the power device 91, the force acting to warp the insulated substrate 31 is not so great. For this reason, in this insulated circuit board 11, defects such as cracks and cracks in the insulated substrate 31 due to a difference in thermal expansion between the insulated substrate 31 and the corrugated fins 41 are suppressed, and an improvement in durability can be realized. ing.

  Therefore, the insulated circuit board 11 of Example 1 can realize a reduction in manufacturing cost and an improvement in durability while improving the heat dissipation performance.

  Further, in this insulated circuit board 11, a heat radiation layer 51 having a higher thermal conductivity than that of the insulated substrate 31 is provided between the insulated substrate 31 and the corrugated fins 41. When joining each top 41b of 41, it can carry out easily by simple methods, such as brazing. Moreover, the heat transmitted from the power device 91 is diffused in the surface direction in the heat dissipation layer 51, and the heat dissipation performance can be further improved.

  Further, in the insulated circuit board 11, the heat dissipation layer 51 is thinner than the wiring layer 21 (the wiring layer 21 has a thickness of about 0.4 mm, whereas the heat dissipation layer 51 has a thickness of about 0.3 mm). The reason is that the top portion 41b of each fin 41a joined to the heat dissipation layer 51 has a slight reinforcing effect on the heat dissipation layer 51. Therefore, even if the heat dissipation layer 51 is made thinner than the wiring layer 21 by that amount, This is because the warpage caused by the difference in thermal expansion between the front surface side and the back surface side of the insulated circuit board 11 can be suppressed.

  Further, in the power module substrate 1 to which the insulating circuit board 11 is applied, the insulating circuit board 11 is fixed to the heat sink 61 in a state in which the refrigerant chamber 61a is sealed while the corrugated fins 41 are housed in the refrigerant chamber 61a. Has been. For this reason, in the power module substrate 1, the heat from the power device 91 can be transmitted from the fins 41 a of the corrugated fins 41 to the cooling medium without passing through the heat sink 61 itself. For this reason, this power module substrate 1 can significantly shorten the heat transfer path from the power device 91 to each fin 41a, and can improve the heat dissipation performance.

  Further, in the power module substrate 1, the exposed periphery of the insulating substrate 31 constituting the insulating circuit substrate 11 is fixed to the heat sink 61 by a metal spring material 61 e. For this reason, since the spring material 61e for fixing the insulating circuit board 11 and the wiring layer 21 do not come into contact with each other, it is not necessary to insulate them, which contributes to a reduction in manufacturing cost.

  In the power module substrate 1, the heat sink 61 and the insulating circuit substrate 11 are fixed to each other by a spring material 61e and an O-ring 61d so that the dimensional change can be allowed. For this reason, the thermal expansion difference between the heat sink 61 made of an aluminum alloy having a relatively large linear thermal expansion coefficient and the insulating substrate 31 made of aluminum nitride having a relatively small linear thermal expansion coefficient is allowed. For this reason, this power module substrate 1 can suppress problems such as the insulating substrate 31 being cracked or cracked.

(Example 2)
As shown in FIGS. 6 to 9, the insulated circuit board 12 of the second embodiment is divided by the cuts 42 e extending in the wavelength direction with respect to the corrugated fins 41 of the insulated circuit board 11 of the first embodiment. The difference is that the fins 42f are composed of a plurality of fin members 42f and the pitch of the fins 42a adjacent to each other across the cut 42e is shifted. Other configurations are the same as those of the insulated circuit board 11 of the first embodiment, and thus description thereof is omitted.

  The corrugated fin 42 includes a plurality of fin members 42f. Each fin member 42f is formed by repeatedly bending an aluminum thin plate having a thickness of about 0.2 mm to form a plurality of fins 42a in a wavy shape and extending with a narrow width in the wavelength direction. Each top part 42b and each bottom part 42c of each fin 42a connect each adjacent fin 42a, curving roundly. Each fin member 42f has a height of 5 mm and an interval between the fins 42a of about 2 mm.

  In the insulated circuit board 12 according to the second embodiment, the plurality of fin members 42f having such a shape are arranged in parallel on the back surface of the heat dissipation layer 51 of the insulated circuit board 12 with a predetermined gap, and then each fin. The top part 42b of the member 42f is joined to the back surface of the heat dissipation layer 51 by brazing or the like. Thus, the gap between the fin members 42f is a cut 42e that divides the adjacent fin members 42f.

  At this time, the plurality of fin members 42 f arranged in parallel are arranged so as to be shifted from each other in the wavelength direction. For this reason, in the insulated circuit board 12 obtained in this manner, the pitches of the adjacent corrugated fins 42 across the cuts 42e are shifted as shown in FIG. In the insulated circuit board 12, a row of joint portions 42 d in which the top portions 42 b of the corrugated fins 42 are brazed with aluminum on the back surface of the heat dissipation layer 51 is formed.

  Also in the insulated circuit board 12 of the second embodiment having such a configuration, the power device 91 is mounted on the surface of the wiring layer 21 as shown in FIG. And this insulated circuit board 12 is mounted in the heat sink 61 in the state by which the corrugated fin 42 was accommodated in the refrigerant | coolant chamber 61a.

  Here, the insulated circuit board 12 of the second embodiment is fixed to the heat sink 61 by the spring material 62e. Since the other configurations related to the heat sink 61 are all as described in the first embodiment, description thereof will be omitted.

  The spring material 62e is bent in an “N” shape in the middle of the spring material 61e of the first embodiment. For this reason, the spring material 62e further improves the followability to the dimensional change between the heat sink 61 and the insulating circuit board 12 as compared with the spring material 61e of the first embodiment.

Thus, the insulating circuit board 12 of the embodiment 2 also, are mounted to the heat sink 61 becomes a power module, for example, it is mounted on a mobile body such as a hybrid car, the same effect as an insulating circuit substrate 11 of Example 1 There is an effect.

  In addition, in the insulated circuit board 12 according to the second embodiment, the corrugated fin 42 includes a plurality of fin members 42f divided by cuts 42e extending in the wavelength direction. For this reason, the anisotropy that the rigidity differs between the wavelength direction of the corrugated fin 42 and the direction orthogonal to the wavelength direction is largely eliminated, and the occurrence of defects such as cracking or cracking of the insulating substrate 31 occurs. Can be further suppressed.

  In the insulated circuit board 12 of the second embodiment, the pitch of the adjacent fins 42a is shifted between the corrugated fins 42 with the cuts 42e interposed therebetween. While flowing from the upstream to the downstream along the fin 42a, it is divided by the next fin 42a whose pitch is shifted. For this reason, a cooling medium distribute | circulates, stirring moderately. As a result, in this insulated circuit board 12, it is possible to suppress the problem that the boundary layer of the circulating cooling medium is prominently generated near the fins 42a and the heat dissipation performance is deteriorated. For this reason, this insulated circuit board 12 can further improve the heat dissipation performance.

(Example 3)
As shown in FIGS. 11 and 12, the insulated circuit board 13 according to the third embodiment is different from the corrugated fins 41 according to the first embodiment and the corrugated fins 42 according to the second embodiment with the top portions 43b of the fins 43a of the corrugated fins 43. The difference is that the part to be removed is divided by a cut 43e extending in the wavelength direction and each fin 43a is rectangular. Other configurations are the same as those of the insulated circuit board 11 of the first embodiment, and thus description thereof is omitted.

  The top portion 43b and the bottom portion 43c of each fin 43a connect adjacent fins 43a while being bent at a right angle. As a result, as shown in FIG. 11, the bending cross section of each fin 43a is rectangular. .

  In the insulated circuit board 13 of Example 3 having such a configuration, the power device 91 is mounted on the surface of the wiring layer 21. Then, similarly to the insulating circuit board 12 of the second embodiment shown in FIG. 10, the insulating circuit board 13 is also mounted on the heat sink 61 in a state where the corrugated fins 43 are accommodated in the refrigerant chamber 61a. Since the structure of the heat sink 61 is as described in the second embodiment, the description thereof is omitted.

  Thus, the insulated circuit board 13 of the third embodiment is also mounted on the heat sink 61 and becomes a power module, similarly to the insulated circuit board 11 of the first embodiment. For example, the insulated circuit board 13 is mounted on a moving body such as a hybrid car. The same effects as those of the first insulating circuit board 11 and the insulating circuit board 12 of the second embodiment can be obtained.

  In addition, in the insulated circuit board 13 of the third embodiment, the corrugated fins 43 are divided by cuts 43e extending in the wavelength direction except for the tops 43b of the fins 43a. For this reason, since the corrugated fin 43 has a part which is not divided by the top part 43b and can be handled as an integral part, compared with the corrugated fin 41 of the first embodiment, in the assembling process. Workability has not deteriorated.

  Moreover, in the insulated circuit board 13 of Example 3, since each fin 43a of the corrugated fin 43 is a rectangle, the junction area of the top part 43b of each fin 43a joined to the back surface of the thermal radiation layer 51 is set to a predetermined area. It is easy to do. For this reason, it is easier to adjust the reinforcing effect of the corrugated fins 43 on the back surface side of the insulating circuit board 13, and the durability can be further improved.

Example 4
As shown in FIGS. 13 to 16, the insulating circuit board 14 of the fourth embodiment is reinforced on the bottom 42 c of each fin 42 a that is the other side of each top 42 b of the corrugated fin 42 of the insulating circuit board 12 of the second embodiment, as shown in FIGS. 13 to 16. The plate 49 is joined. Other configurations are the same as those of the insulated circuit board 12 of the second embodiment, and thus description thereof is omitted.

  The reinforcing plate 49 is an aluminum alloy plate having a thickness of 2 mm, and the vertical and horizontal dimensions are the same as those of the wiring layer 21 and the heat dissipation layer 51.

  The reinforcing plate 49 is joined to the corrugated fin 42 at the same time when the corrugated fin 42 is joined to the back surface of the heat dissipation layer 51. Specifically, the surface of the reinforcing plate 49 is brought into contact with the bottom 43c of each fin 42a and joined by brazing. In the insulating circuit board 14 thus obtained, as shown in enlarged views in FIGS. 15 and 16, a row of joint portions 49 a in which the bottom portions 42 c of the corrugated fins 42 are brazed with aluminum on the surface of the reinforcing plate 49 is formed. .

  In the insulated circuit board 14 of the fourth embodiment having such a configuration, the power device 91 is mounted on the surface of the wiring layer 21 as shown in FIG. And this insulated circuit board 14 is mounted in the heat sink 61 in the state by which the corrugated fin 42 and the reinforcement board 49 were accommodated in the refrigerant | coolant chamber 61a. Since the configuration of the heat sink 61 is as described above, a description thereof will be omitted, except that the spring material 64e is fixed to the surface of the heat sink 61 with bolts 64f instead of brazing. Thereby, the spring material 64e can be attached and detached, and the insulated circuit board 14 can be removed.

Thus, the insulating circuit board 14 of the fourth embodiment is also mounted on the heat sink 61 becomes a power module, for example, is mounted on a mobile body such as a hybrid car, in the first embodiment insulating circuit board 11 and Example 2 The same effect as that of the insulated circuit board 12 can be obtained.

  In addition, in the insulated circuit board 14 of the fourth embodiment, a reinforcing plate 49 is joined to the bottom 42c of each fin 42a that is the other side of each top 42b of the corrugated fin 42. For this reason, the rigidity of the whole insulated circuit board 14 is improved, and it is possible to suppress the occurrence of problems such as the insulating board 31 being cracked or cracked. Further, the corrugated fin 42 itself has anisotropy having different stiffnesses in the wavelength direction and the direction orthogonal to the wavelength direction, but the anisotropy of the corrugated fin 42 is relaxed by joining the reinforcing plate 49. Is able to. According to the results calculated by the inventors, if the height of the corrugated fin 42 is sufficiently secured to be about 5 mm, the warp of the insulating substrate 31 to which the reinforcing plate 49 is bonded can be extremely reduced. (Warp is 2 μm or less). However, it is understood that the warp of the insulating substrate 31 tends to increase as the height of the corrugated fins 42 decreases.

(Example 5)
The power module substrate 5 of the fifth embodiment is obtained by improving the power module substrates 1 to 4 described in the first to fourth embodiments and mounting a plurality of insulating circuit substrates by a simple method. As the power module substrate 5 of the fifth embodiment, any one of the insulated circuit boards 11 to 14 of the first to fourth embodiments can be adopted, but here, for convenience, the insulated circuit board 11 of the first embodiment is adopted. To explain.

  As shown in FIGS. 18 and 19, the power module substrate 5 of the fifth embodiment includes six insulating circuit substrates 11 (arranged in 2 × 3 rows) and a heat sink 65.

  In the heat sink 65, six sets (arranged in 2 × 3 rows) of refrigerant chambers 65a, an inflow path 65g, and an outflow path 65h are formed on one base plate 65z. The inflow path 65g allows the cooling medium to flow into the refrigerant chamber 65a, and the outflow path 65h allows the cooling medium to flow out of the refrigerant chamber 65a.

  Each insulated circuit board 11 is fixed to the heat sink 65 in a sealed state by a spring material 65e and an O-ring 61d. At this time, the corrugated fins 41 of the respective insulating circuit boards 11 are stored in the refrigerant chamber 65a.

The spring material 65e is made of a spring steel plate having a high elastic deformability. As shown in FIGS. 20 and 21, when viewed from above, the spring material 65e has a rectangular shape with a large opening 651e at the center, and each of the four sides is bent downward. Thus, a locking projection 652e is formed on the lower end side. As shown in FIGS. 18 and 19, the spring material 65 e is applied from above the insulating circuit board 11 placed on the heat sink 65, and a locking projection 652 e is formed on the heat sink 65. by the Ruco fitted in the recess 653E, the insulating circuit board 11 adapted to secure the heat sink 65. At this time, since the O-ring 61d is interposed between the heat sink 65 and the insulating circuit board 11, the heat sink 65 and the insulating circuit board 11 are sealed, and the heat sink 65 and the insulating circuit board 11 However, the mutual dimensional change is acceptable.

Power module substrate 5 of Example 5 such a configuration, a plurality of insulated circuit board 11 that the power device 91 is mounted is mounted, enters the power module, for example, in a mobile object such as a hybrid car It is mounted and the above-mentioned operational effects can be achieved. In addition, the power module substrate 5 can be mounted with a plurality of insulating circuit substrates 11 by a simple method. In particular, the insulating circuit board 11 can be easily attached and detached by the spring material 65e, and the maintainability is greatly improved.

(Example 6)
The power module substrate 6 of Example 6 differs from the spring material 65e of the power module substrate 5 of Example 5 in the shape of the spring material 66e as shown in FIGS. Since other configurations are the same as those of the power module substrate 5 of the fifth embodiment, description thereof is omitted.

  Similarly to the spring material 65e, the spring material 66e is made of a spring steel plate having a high elastic deformability, and as shown in FIGS. 23 and 24, the spring material 66e has a rectangular shape with a large opening 661e at the center as seen from above, and has four sides. Each of them is bent upward at one end and then bent downward to form a locking hole 662e on the lower end side. As shown in FIG. 22, the spring material 66 e is covered from above the insulating circuit board 11 placed on the heat sink 65, and a locking projection 663 e formed on the heat sink 65 with a locking hole 662 e. The insulated circuit board 11 is fixed to the heat sink 65 by being fitted to the heat sink 65. At this time, since the O-ring 61d is interposed between the heat sink 65 and the insulating circuit board 11, the heat sink 65 and the insulating circuit board 11 are sealed, and the heat sink 65 and the insulating circuit board 11 However, the mutual dimensional change is acceptable.

Power module substrate 6 of Example 6 is such a structure, like the power module substrate 5 of Example 5, an insulating circuit board 11 that the power device 91 is mounted is mounted, and the power module Thus, similar operational effects can be achieved.

(Example 7)
As shown in FIG. 25, the power module substrate 7 of Example 7 includes a heat sink 65 and an insulating circuit substrate 11 instead of the spring members 65e and 66e of the power module substrates 5 and 6 of Examples 5 and 6. It is different in that it is fixed by an adhesive 67e capable of allowing dimensional changes. Since other configurations are the same as those of the power module substrate 5 of the fifth embodiment, description thereof is omitted.

  The adhesive 67e is a silicon-based elastic adhesive having high heat resistance, water resistance, and elastic deformability. As shown in FIG. 25, the adhesive 67e is interposed between the two when the insulating circuit board 11 is placed on the heat sink 65, and the peripheral edge on the back surface side of the insulating circuit board 11 is bonded and fixed to the heat sink 65. It is like that. The adhesive 67e seals the heat sink 65 and the insulating circuit board 11, and allows the heat sink 65 and the insulating circuit board 11 to allow dimensional changes.

Similarly to the power module substrates 5 and 6 of the fifth and sixth embodiments, the power module substrate 7 of the seventh embodiment having such a configuration is mounted with the insulating circuit substrate 11 on which the power device 91 is mounted. It becomes a power module, which can provide a similar effect. In addition, since the number of parts can be reduced, the manufacturing cost can be reduced.

(Example 8)
In the power module substrates 1 to 7 of the first to seventh embodiments, the insulating circuit substrates 11 to 14 and the heat sinks 61 and 65 are separate from each other, whereas the power module substrate 8 of the eighth embodiment is used. However, as shown in FIGS. 26 to 28, the insulating circuit board 11 and the heat sink 68 are integrated. The power module substrate 8 of Example 8, it is possible to adopt any of the insulating circuit board 11 to 14 of Examples 1 to 4, wherein for convenience, the insulating circuit board 11 of Example 1 Adopt and explain.

  In the power module substrate 8 of Example 8, the insulating circuit substrate 11 is integrally bonded and fixed to the surface of the base plate 68z of the heat sink 68 in advance through the peripheral wall member 68j in the manufacturing process before the power device 91 is mounted. Is done.

  The peripheral wall member 68j is made of iron or copper whose surface is galvanized or nickel-plated. As shown in FIG. 28, the peripheral wall member 68j has a rectangular side wall 681j and a side wall 681j. The upper surface portion 682j extends horizontally outward from the upper end and the lower surface portion 683j extends horizontally outward from the lower end of the side wall portion 681j.

  The insulating circuit board 11, the peripheral wall member 68j, and the base plate 68z are integrated as follows.

  First, the peripheral wall member 68j is placed on the surface of the base plate 68z in which the inflow path 68g and the outflow path 68h are processed. At this time, an aluminum brazing material is interposed between the surface of the base plate 68z and the lower surface portion 683j. Next, the insulated circuit board 11 is placed above the peripheral wall member 68j. At this time, an aluminum brazing material is interposed between the back surface of the heat dissipation layer 51 of the insulating circuit board 11 and the upper surface portion 682j of the peripheral wall member 68j. Then, by heating and cooling these, the insulating circuit board 11, the peripheral wall member 68j, and the base plate 68z are integrated by aluminum brazing. At this time, the corrugated fins 41 of the insulating circuit board 11 are accommodated in a refrigerant chamber 65a surrounded by the insulating circuit board 11, the side wall portion 681j of the peripheral wall member 68j, and the base plate 68z.

  In this way, as shown in FIG. 26, the power device 91 is mounted on the insulating circuit board 11 previously integrated with the peripheral wall member 68j and the base plate 68z, and the flow path member 68y having a recessed flow path is formed on the back surface of the base plate 68z. After the lid member 68x that is assembled and protects the insulating circuit board 11 is assembled to the surface of the base plate 68z, these are fixed by the bolts 68w to complete the power module substrate 8 of the eighth embodiment. Thus, the completed power module substrate 8 of the eighth embodiment is also completed as a power module since the power device 91 is already mounted. For example, the power module substrate 8 is mounted on a moving body such as a hybrid car and the above-mentioned. The effect of this can be achieved.

  In addition, in the power module substrate 8 of the eighth embodiment, in the manufacturing process before the power device 91 is mounted on the insulating circuit substrate 11, the insulating circuit substrate 11 is provided on the surface of the base plate 68 z of the heat sink 68 in advance on the peripheral wall member. 68j is joined and fixed integrally. For this reason, in the power module substrate 8, the work process from the mounting of the power device 91 to the completion of the power module is greatly reduced, which contributes to the improvement of the work efficiency of the assembly work.

Example 9
The power module substrate 9 of Example 9 differs from the peripheral wall member 68j of the power module substrate 8 of Example 8 in the shape of the peripheral wall member 69j, as shown in FIGS. Since other configurations are the same as those of the power module substrate 8 of the eighth embodiment, description thereof is omitted.

  The peripheral wall member 69j is obtained by cutting an aluminum extruded hollow square material having a low material cost into a predetermined length.

  By adopting such a peripheral wall member 91, the power module substrate 9 of the ninth embodiment can achieve the same operational effects as the power module substrate 8 of the eighth embodiment, and the manufacturing cost can be reduced. It is possible.

  In the above, the present invention has been described with reference to the first to ninth embodiments. However, the present invention is not limited to the first to ninth embodiments, and can be appropriately modified and applied without departing from the spirit of the present invention. Needless to say.

  For example, the spring members 61e, 62e, and 64e are used in Examples 1, 2, and 4, respectively, but are not limited to this combination. Moreover, in Examples 2-4, although the corrugated fin was arrange | positioned so that the pitch of the adjacent fin may shift | deviate on both sides of a cut | interruption, you may arrange | position a corrugated fin so that a pitch may not shift | deviate.

The present invention is applicable to power module substrate.

1 is a schematic front view of an insulated circuit board of Example 1. FIG. 1 is a schematic side view of an insulated circuit board of Example 1. FIG. FIG. 2 is a partial enlarged view of a Z portion in FIG. 1 according to the insulated circuit board of Example 1. FIG. 4 is a partial enlarged cross-sectional view showing an AA cross section of FIG. 3 according to the insulated circuit board of Example 1. It is a schematic sectional drawing of the power module to which the insulated circuit board of Example 1 was applied. 6 is a schematic front view of an insulated circuit board of Example 2. FIG. 6 is a schematic side view of an insulated circuit board of Example 2. FIG. FIG. 7 is a partial enlarged view of a Y portion in FIG. 6 according to the insulated circuit board of Example 2. FIG. 9 is a partial enlarged cross-sectional view showing the BB cross section of FIG. 8 according to the insulated circuit board of Example 2. It is a schematic sectional drawing of the power module to which the insulated circuit board of Example 2 was applied. FIG. 7 is a partial enlarged view of FIG. 6 relating to an insulated circuit board of Example 3. FIG. 12 is a partial enlarged cross-sectional view illustrating a cross section taken along the line CC in FIG. 11 according to the insulated circuit board of Example 3. 6 is a schematic front view of an insulated circuit board of Example 4. FIG. 7 is a schematic side view of an insulated circuit board according to Example 4. FIG. FIG. 14 is an enlarged view of a portion X in FIG. 13 according to the insulated circuit board of Example 4. FIG. 16 is a partial enlarged cross-sectional view showing a DD cross section of FIG. 15 according to the insulated circuit board of Example 4. It is a schematic sectional drawing of the power module to which the insulated circuit board of Example 4 was applied. 6 is a schematic cross-sectional view of a power module substrate of Example 5. FIG. FIG. 19 is a schematic cross-sectional view showing a cross section taken along line EE of FIG. 18 in connection with the power module substrate of Example 5. FIG. 10 is a schematic top view of a spring material for fixing an insulating circuit board according to the power module substrate of Example 5. FIG. 10 is a schematic front view of a spring material for fixing an insulating circuit board according to the power module substrate of Example 5. It is a fragmentary sectional view of the board | substrate for power modules of Example 6. FIG. It is a schematic top view of the spring material which fixes the insulated circuit board concerning the board | substrate for power modules of Example 6. FIG. It is a schematic front view of the spring material which fixes the insulated circuit board concerning the board | substrate for power modules of Example 6. FIG. It is a fragmentary sectional view of the board for power modules of Example 7. It is a schematic sectional drawing which concerns on the board | substrate for power modules of Example 8, and shows the state assembled | attached with the flow-path member and the cover member. It is a schematic sectional drawing of the board | substrate for power modules of Example 8. FIG. FIG. 10 is a schematic perspective view of a peripheral wall member according to a power module substrate of Example 8. It is a schematic sectional drawing of the board | substrate for power modules of Example 9. FIG. FIG. 10 is a schematic perspective view of a peripheral wall member according to a power module substrate of Example 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 12, 13, 14 ... Insulation circuit board 21 ... Wiring layer 31 ... Insulation board 41, 42, 43 ... Corrugated fin 41a, 42a, 43a ... Fin 41b, 42b, 43b ... Top part 41c, 42c, 43c ... Bottom part 42e, 43e ... cut 42f ... fin member 49 ... reinforcing plate 51 ... heat radiation layer 61a, 65a ... refrigerant chamber 65g, 68g ... inflow path 65h, 68h ... outflow path 61, 65, 68 ... heat sink 61e, 62e, 64e, 65e, 66e ... Spring material 67e… Adhesive 91… Power device

Claims (6)

A wiring layer on which a power device is mounted on one surface, an insulating substrate bonded to the other surface of the wiring layer, and a plurality of fins are formed in a wave shape, and each fin is formed on the other surface side of the insulating substrate. An insulated circuit board comprising a corrugated fin joined to the top of
A refrigerant chamber, an inflow path and an outflow path are formed, the inflow path has a cooling medium flowing into the refrigerant chamber, and the outflow path has a heat sink that allows the cooling medium to flow out of the refrigerant chamber;
In a state where the corrugated fin is housed in the refrigerant chamber and the insulating substrate seals the refrigerant chamber, the periphery of the insulating substrate is fixed to the heat sink ,
The corrugated fin is a substrate for a power module , wherein a portion of each fin excluding the top is divided by a cut extending in the wavelength direction .   The power module substrate according to claim 1, wherein a heat dissipation layer is provided between the insulating substrate and the corrugated fin.   The power module substrate according to claim 2, wherein the heat dissipation layer is thinner than the wiring layer.   4. The power module substrate according to claim 1, wherein a reinforcing plate is joined to a bottom portion of each fin that is the other side of each top portion of the corrugated fin. 5. The corrugated fins, any one power module substrate according to claim 1 to 4, characterized in that each said fin is rectangular. The power according to any one of claims 1 to 5 , wherein the heat sink and the peripheral edge of the insulating substrate are fixed by a spring material that presses the insulating substrate toward the heat sink by an elastic force. Module board.

Images