JP5452345B2 - Insulated circuit board and manufacturing method thereof, power module base and manufacturing method thereof - Google Patents

Description

  The present invention relates to an insulating circuit board and a manufacturing method thereof, a power module base and a manufacturing method thereof, and more specifically, an insulating circuit board on which an electronic element such as a power device is mounted, a manufacturing method thereof, and an insulating circuit board. The present invention relates to a power module base used for cooling an electronic element such as a mounted power device, and a method for manufacturing the same.

  In this specification, the term “aluminum” includes aluminum alloys in addition to pure aluminum, except when expressed as “pure aluminum”.

  For example, in a power module equipped with a power device composed of a semiconductor element (electronic element) such as an IGBT (Insulated Gate Bipolar Transistor), the heat generated from the semiconductor element is efficiently dissipated to keep the temperature of the semiconductor element below a predetermined temperature. Need to keep. Therefore, conventionally, a power module base for mounting a power device includes an aluminum heat sink and an insulating circuit board brazed to the heat sink. The insulating circuit board is a ceramic insulating board brazed to the heat sink, and an insulating board. The circuit board made of aluminum brazed to the surface opposite to the surface brazed to the heat sink in the circuit board, the surface of the circuit board opposite to the surface brazed to the insulating plate is the electronic element mounting portion What is made into the wiring surface which has is known (refer patent document 1).

  The power module base described in Patent Document 1 is used as a power module in which a power device is mounted on an electronic element mounting portion on a wiring surface of a circuit board of an insulated circuit board. The heat generated from the power device is transmitted to the heat sink through the circuit board and the insulating plate, and is radiated.

  By the way, the power module base described in Patent Document 1 is formed by laminating a heat sink, an insulating plate, and a circuit board in a state where a brazing material is disposed between adjacent ones, and pressurizing the heat sink, the insulating plate, and the circuit board. It is manufactured by brazing the heat sink and the insulating plate and the insulating plate and the circuit board by heating while heating.

  However, in the power module base manufacturing method described in Patent Document 1, when the heat sink, the insulating plate, and the circuit board are heated in a laminated state, the brazing material first starts to melt from the outer peripheral edge, and then gradually toward the center. Since the heat is conducted and the melting proceeds, when trying to heat until the central part of the brazing material is melted, before that, the brazing material existing on the outer peripheral edge of the brazing material and already melted is There is a possibility that the liquid oozes out between the plate and the insulating plate and further aggregates due to the surface tension to flow to the electronic element mounting portion on the wiring surface through the side surface (the brazing material flow portion) of the circuit board.

  For example, when brazing a circuit board made of pure aluminum to an insulating board made of ceramics using an Al-Si alloy-based brazing material containing Si, the brazing material hardened after melting becomes harder than the circuit board. Therefore, if the electronic element is soldered to a portion where the brazing material that has flowed and solidified on the wiring surface of the circuit board is present, the thermal cycle life of the electronic element may be reduced.

  Therefore, as a method of manufacturing a power module base that solves these problems, one side of the ceramic insulating plate and the aluminum circuit board are brazed, and at the same time, the other side of the insulating plate and the aluminum heat transfer plate are brazed. A method of brazing or soldering a heat transfer plate of an insulated circuit board to a heat sink after manufacturing the insulated circuit board is proposed (see Patent Document 2). In the method described in Patent Document 2, the brazing of the insulating plate, the circuit board, and the heat transfer plate is performed by arranging a brazing material layer between the insulating plate, the circuit board, and the heat transfer plate. The layer includes an outer peripheral portion where the outer peripheral edge portion of the circuit board is disposed on the surface, and an inner portion surrounded by the outer peripheral portion, and the inner portion is made of ultrafine powder having a diameter of 0.1 μm or less. The outer peripheral portion is formed of a brazing material having a particle diameter larger than that of the inner portion.

  However, in the method for manufacturing the power module base described in Patent Document 2, the cost of the brazing material layer used for brazing the insulating plate, the circuit board, and the heat transfer plate is increased, and the insulating circuit board and the power module base are not manufactured. There is a problem that the manufacturing cost becomes high.

No. 8-10202 JP 2008-181939 A

  An object of the present invention is to solve the above problems and provide an insulated circuit board and a manufacturing method thereof, a power module base and a manufacturing method thereof that are low in manufacturing cost.

  In order to achieve the above object, the present invention comprises the following aspects.

1) A metal circuit board is brazed to one surface of the insulating plate, and the surface of the circuit board opposite to the surface brazed to the insulating plate is a wiring surface having an electronic element mounting portion. The brazing material flow portion where the molten brazing material flows from the space between the insulating plate and the circuit board to the wiring surface side when the insulating plate and the circuit board are brazed,
A brazing material reservoir recess for storing the brazing material is formed between the electronic element mounting portion and the brazing material flow portion on the wiring surface of the circuit board, and the molten brazing material is transferred to the circuit board from the brazing material flow portion. An insulated circuit board on which a brazing material guiding groove is formed to guide the wire.

  2) The insulated circuit board according to 1) above, wherein a plurality of brazing material reservoir recesses are formed on the wiring surface of the circuit board, and an interval between two adjacent brazing material reservoir recesses is 15 mm or less.

3) The above 1) or 2) , wherein the brazing material guiding groove is formed by a concave groove formed on each side surface of the circuit board and extending in the length direction of each side surface, and a communication groove through which the concave groove and the brazing material reservoir concave portion pass. The insulated circuit board as described.

4) For the power module in which the surface opposite to the surface where the circuit board is brazed in the insulating plate of the insulated circuit board described in any one of 1) to 3) above is brazed to the heat sink. base.

5) A power module in which a power device is soldered to an electronic element mounting portion of a circuit board in the insulated circuit board of the power module base described in 4) above .

6) A metal circuit board is brazed to one surface of the insulating plate, and the surface of the circuit board opposite to the surface brazed to the insulating plate is a wiring surface having an electronic element mounting portion. A method of manufacturing an insulated circuit board in which a brazing material flow portion flows from the gap between the insulating plate and the circuit board to the wiring surface side during brazing between the insulating board and the circuit board,
A brazing material reservoir recess for storing brazing material is formed between the electronic element mounting portion and the brazing material flow portion on the wiring surface of the circuit board, and the molten brazing material is brazed from the brazing material flow portion to the circuit board. A brazing material guiding groove is formed in the material reservoir recess, and the insulating plate and the circuit board are laminated so that the wiring surface of the circuit board faces outside with the brazing material placed between them. A method of manufacturing an insulated circuit board, comprising heating a plate and a circuit board while applying pressure to braze the two.

7) Insulation according to 6) above, wherein the brazing material guiding groove is formed of a concave groove formed on each side surface of the circuit board and extending in the length direction of each side surface, and a communication groove passing through the concave groove and the brazing material reservoir concave portion. A method of manufacturing a circuit board .

8) A metal circuit board is brazed to one surface of the insulating plate, and the surface of the circuit board opposite to the surface brazed to the insulating plate is a wiring surface having an electronic element mounting portion. A method of manufacturing an insulated circuit board in which a brazing material flow portion flows from the gap between the insulating plate and the circuit board to the wiring surface side during brazing between the insulating board and the circuit board,
A brazing material reservoir recess was formed between the electronic element mounting part and the brazing material flow part on the circuit board wiring surface, and the brazing material was placed between the insulating plate and the circuit board. In this state, the circuit board is laminated so that the wiring surface faces outward, and the insulating board and the circuit board are heated while being pressurized and brazed together, and the insulating board and the circuit board are pressed. It is performed by pressing the circuit board to the insulating plate side using a jig, and a release agent is applied to at least a portion corresponding to the brazing material reservoir recess in the surface of the jig that contacts the circuit board. A method for manufacturing an insulated circuit board .

9) on the wiring surface of the circuit board previously formed a plurality of braze reservoir recess, of the above 6) to 8) to the spacing between two Tsunorou material reservoir recess adjacent to 15mm below according to any A method for manufacturing an insulated circuit board.

10) Any of the above 6) to 9) satisfying the relationship of 0.1 ≦ X / Y, where X is the total internal volume of all brazing material reservoir recesses on the circuit board and Y is the volume of the brazing material used. A method for producing an insulated circuit board according to claim 1.

11) Consists of a heat sink and an insulated circuit board brazed to the heat sink, and the insulated circuit board is brazed to the insulating plate brazed to the heat sink and to the surface of the insulating plate opposite to the surface brazed to the heat sink. The surface of the circuit board opposite to the surface brazed to the insulating board is a wiring surface having an electronic element mounting portion. The circuit board includes the insulating board and the circuit board. A method of manufacturing a power module base in which a brazing material flow portion is present in which a molten brazing material flows from a space between an insulating plate and a circuit board to a wiring surface side during brazing,
A plurality of brazing material reservoir recesses for storing brazing material are formed between the electronic element mounting portion and the brazing material flow portion on the wiring surface of the circuit board, and the molten brazing material is placed on the circuit board. In the state where the brazing material guiding groove for guiding to the brazing material reservoir recess is formed and the brazing material is disposed between the heat sink, the insulating plate and the circuit board, the wiring surface of the circuit board faces the outside. A method for manufacturing a base for a power module, wherein the heat sink, the insulating plate, and the circuit board are laminated while facing each other and heated while applying pressure to braze the heat sink, the insulating plate, and the insulating plate to the circuit board.

12) The power according to the above 11), wherein the brazing material guiding groove is formed of a concave groove formed on each side surface of the circuit board and extending in the length direction of each side surface, and a communication groove passing through the concave groove and the brazing material reservoir concave portion. Manufacturing method of module base .

13) Consists of a heat sink and an insulated circuit board brazed to the heat sink. The surface of the circuit board opposite to the surface brazed to the insulating board is a wiring surface having an electronic element mounting portion. The circuit board includes the insulating board and the circuit board. A method of manufacturing a power module base in which a brazing material flow portion is present in which a molten brazing material flows from a space between an insulating plate and a circuit board to a wiring surface side during brazing,
A plurality of brazing material reservoir recesses for accumulating brazing material are formed between the electronic element mounting portion and the brazing material flow portion on the wiring surface of the circuit board, and the heat sink, insulating plate, and circuit board are connected to each other. With the brazing material placed in between, the circuit board is laminated so that the wiring surface faces outward, and the heat sink, insulating plate, and circuit board are heated while being pressurized to heat sink, insulating plate, insulating plate, and circuit board. And pressurizing the heat sink, the insulating plate, and the circuit board by pressing the circuit board against the insulating plate and the heat sink side using a jig, and on the surface of the jig contacting the circuit board A power module base manufacturing method, wherein a release agent is applied to at least a portion corresponding to a brazing material reservoir recess .

14) The method for producing a base for a power module as described in 13) above, wherein a protrusion that fits into the brazing material reservoir recess is provided in a portion corresponding to the brazing material reservoir recess on the surface that contacts the circuit board of the jig .

15) The volume of the protrusion of the jig is made smaller than the internal volume of the brazing material reservoir recess into which the protrusion fits, and the total difference between the volume of the protrusion and the internal volume of the brazing material reservoir recess into which the protrusion fits is Z The method for producing a base for a power module as described in 14) above, wherein, when the volume of the brazing material to be used is Y, the relationship 0.1 ≦ Z / Y is satisfied .

16) The method for producing a power module base according to any one of the above 11) to 15), wherein an interval between two adjacent brazing material reservoir recesses formed on the wiring surface of the circuit board is 15 mm or less.

17) Any of the above 11) to 16) satisfying the relationship of 0.1 ≦ X / Y, where X is the total internal volume of all brazing material reservoir recesses on the circuit board and Y is the volume of the brazing material used. A method for manufacturing a base for a power module according to claim 1.

According to the insulated circuit boards of 1) to 3) above, since the brazing material reservoir recess for storing the brazing material is formed between the electronic element mounting portion and the brazing material flow portion on the wiring surface of the circuit board, When brazing the insulation board to the circuit board at the time of manufacturing the insulated circuit board, the brazing material disposed between the insulation board and the circuit board melts, and the molten brazing material flows into the brazing material flow portion of the circuit board. Even if it flows to the wiring surface side of the circuit board, the molten brazing material enters into the brazing material reservoir recess and is stored there. Therefore, the brazing material cured after melting is suppressed from being present in the electronic element mounting portion on the wiring surface of the circuit board, and even when the electronic element is soldered to the electronic element mounting portion, the thermal cycle life of the electronic element is reduced. Reduction is suppressed. In addition, an ordinary brazing material can be used for brazing the insulating plate and the circuit board, and the manufacturing cost is lower than that of the insulating circuit board manufactured by the method described in Patent Document 2.

According to the insulated circuit boards of 1) and 3) above, the molten brazing material can be effectively put into the brazing material reservoir recess by the function of the brazing material guiding groove when the insulated circuit board is manufactured .

According to the insulated circuit board of 2), even when the molten brazing material flows to the wiring surface side of the circuit board through the brazing material flow part of the circuit board during the production of the insulated circuit board, the molten brazing material is effective. Thus, it can be placed in the brazing material reservoir recess.

According to the power module base of 4) above, the brazing material disposed between the insulating plate and the circuit board melts when the insulating plate and the circuit board are brazed at the time of manufacturing the power module base. At the same time, even if the molten brazing material flows to the wiring surface side of the circuit board through the brazing material flow portion of the circuit board, the molten brazing material enters the brazing material reservoir recess and is stored therein. Therefore, the brazing material cured after melting is suppressed from being present in the electronic element mounting portion on the wiring surface of the circuit board, and even when the electronic element is soldered to the electronic element mounting portion, the thermal cycle life of the electronic element is reduced. Reduction is suppressed. In addition, an ordinary brazing material can be used for brazing the insulating plate to the circuit board, and the manufacturing cost is lower than that of the power module base manufactured by the method described in Patent Document 2.

According to the method for producing an insulated circuit board of the above 6) to 10) , the brazing material disposed between the insulating board and the circuit board is melted and brazed when the insulating board and the circuit board are brazed. Even if the material flows to the wiring surface side of the circuit board through the brazing material flow portion of the circuit board, the molten brazing material enters the brazing material reservoir recess and is stored here. Therefore, the brazing material cured after melting is suppressed from being present in the electronic element mounting portion on the wiring surface of the circuit board, and even when the electronic element is soldered to the electronic element mounting portion, the thermal cycle life of the electronic element is reduced. Reduction is suppressed. In addition, an ordinary brazing material can be used for brazing the insulating plate to the circuit board, and the manufacturing cost is lower than that of the method described in Patent Document 2.

According to the method for manufacturing an insulated circuit board of the above 6) and 7), the molten brazing material can be effectively put into the brazing material reservoir recess by the function of the brazing material guiding groove .

According to the method for manufacturing an insulated circuit board of 8), the jig can be peeled off from the circuit board relatively easily even after the brazing material is solidified .

According to the method for producing an insulated circuit board of 9) above, even if the molten brazing material flows to the wiring surface side of the circuit board through the brazing material flow portion of the circuit board, the molten brazing material is effectively used as the brazing material. It can be placed in the reservoir recess.

According to the method for producing an insulated circuit board of 10) , the brazing filler metal can be effectively stored in the brazing material reservoir recess when the insulating board and the circuit board are brazed at the time of production of the insulated circuit board. In addition, the insulating plate and the circuit board can be brazed well.

According to the power module base manufacturing method of the above 11) to 16) , when brazing the insulating plate and the circuit board, the brazing material disposed between the insulating plate and the circuit board is melted and melted. Even if the brazing material flows to the wiring surface side of the circuit board through the brazing material flow portion of the circuit board, the molten brazing material enters the brazing material reservoir recess and is stored here. Therefore, the brazing material hardened after melting is suppressed from being present in the electronic element mounting portion on the wiring surface of the circuit board, and even if soldered to the electronic element mounting portion, a decrease in the thermal cycle life of the electronic element is suppressed. The In addition, an ordinary brazing material can be used for brazing the insulating plate to the circuit board, and the manufacturing cost is lower than that of the method described in Patent Document 2.

According to the power module base manufacturing method of the above 11) and 12), the molten brazing material can be effectively put into the brazing material reservoir recess by the function of the brazing material guiding groove .

According to the power module base manufacturing method of 13) above, the jig can be peeled off the circuit board relatively easily even after the brazing material has solidified .

According to the power module base manufacturing method of the above 14), since the projection of the jig fits in the brazing material reservoir recess, positioning with respect to the heat sink of the circuit board can be performed, so that productivity is improved, The positional accuracy with respect to the heat sink of the circuit board which has the electronic element mounting part which should mount an electronic element can be improved .

According to the method for producing a power module base of 15) above, when the insulating plate and the circuit board are brazed, the molten brazing material can be effectively stored in the brazing material reservoir recess, and the insulating plate and The circuit board can be brazed well .

According to the power module base manufacturing method of 16) above, even if the molten brazing material flows to the wiring surface side of the circuit board through the brazing material flow portion of the circuit board, the molten brazing material is effectively brazed. It can be placed in the material reservoir recess.

According to the power module base manufacturing method of the above 17) , when brazing the insulating plate and the circuit board, the molten brazing material can be effectively stored in the brazing material reservoir recess, and the insulating plate and The circuit board can be brazed well.

It is a vertical sectional view showing a power module configured by mounting a power device on a power module base having an insulated circuit board manufactured by the method of the present invention. It is a perspective view which shows the insulated circuit board used for the base for power modules of FIG. FIG. 2 is a vertical sectional view showing a method for manufacturing the power module base of FIG. 1. 4A shows a state before the projection of the jig in the method for manufacturing the power module base of FIG. 1 is fitted into the brazing material reservoir recess, and FIG. 4B shows the projection of the jig in the brazing material reservoir recess. It is a figure corresponded in the elements on larger scale of FIG. 3 which shows the state fitted to. It is a perspective view which shows the 1st modification of an insulated circuit board. It is a perspective view which shows the 2nd modification of an insulated circuit board. It is a perspective view which shows the 3rd modification of an insulated circuit board. It is a perspective view which shows the 4th modification of an insulated circuit board. It is a perspective view which shows the 5th modification of an insulated circuit board.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the upper and lower sides and the left and right sides in FIG.

  FIG. 1 shows a power module in which a power device is mounted on an electronic element mounting portion of a circuit board in a power module base having an insulated circuit board according to the present invention, and FIG. 2 shows an insulated circuit board. 3 and 4 show a method for manufacturing a power module base.

  In FIG. 1, the power module (1) includes a power module base (2) and a power device (3) (electronic element) mounted on the power module base (2).

  The power module base (2) is made of a square ceramic insulating plate (5) and a square aluminum circuit board (6) (metal circuit board) brazed to the upper surface of the insulating plate (5). The circuit board (4) includes an aluminum heat sink (7) to which the insulating plate (5) of the insulating circuit board (4) is brazed. In FIG. 1, only one insulated circuit board (4) is shown, but a plurality of insulated circuit boards (4) are generally brazed to the heat sink (7). In FIG. 1, the brazing material brazing the insulating plate (5) and the circuit board (6) and the brazing material brazing the insulating plate (5) and the heat sink (7) are shown. Omitted.

The insulating plate (5) of the insulating circuit board (4) may be formed of any ceramic as long as it satisfies the required insulating properties, thermal conductivity and mechanical strength. For example, AlN, It is formed of Al ₂ O ₃ , Si ₃ N ₄ or the like. The circuit board (6) is made of a metal such as aluminum or copper having excellent conductivity, but it has high electrical conductivity, high deformability, and excellent solderability with semiconductor elements. It is preferable that it is formed of aluminum.

  As shown in FIG. 2, the upper surface of the circuit board (6) of the insulating circuit board (4), that is, the surface opposite to the surface brazed to the insulating plate (5) has a plurality of, here two electronic elements. The wiring surface (9) has a mounting portion (8). When the insulating plate (5) and the circuit board (6) are brazed, the peripheral surface of the circuit board (6) is connected to the wiring surface (9) between the insulating plate (5) and the circuit board (6). ) Side is the brazing material flow part (11). And between the electronic element mounting part (8) and the brazing material flow part (11) on the wiring surface (9) of the circuit board (6), a plurality of brazing members that are circular when viewed from above and accumulate brazing material The material reservoir recesses (12) are formed at intervals so as to be scattered. The brazing material reservoir recess (12) is formed at the four corners of the circuit board (6) and the middle part in the length direction of each side part, and in the middle of the length direction of each side part of the circuit board (6). The brazing material reservoir recess (12) formed in the part is located between the two electronic element mounting parts (8). The distance (P) between two adjacent brazing material reservoir recesses (12) is preferably 15 mm or less, and more preferably 0.5 to 10 mm. Here, in all pairs of two adjacent brazing material reservoir recesses (12), the spacing (P) between two adjacent brazing material reservoir recesses (12) is equal, but in at least one pair The spacing may be different from the spacing in other pairs. Even when the distances in at least one pair are different from the distances in the other pairs, all the distances are preferably 15 mm or less, and preferably 0.5 to 10 mm. Although illustration is omitted, in the brazing material reservoir recess (12), the molten brazing material that flows when the insulating plate (5) and the circuit board (6) are brazed is solidified and collected.

  The heat sink (7) is preferably a flat hollow shape in which a plurality of cooling fluid passages (13) are provided in parallel, is excellent in thermal conductivity, and is preferably formed of lightweight aluminum. Either a liquid or a gas may be used as the cooling fluid.

  The power device (3) is soldered onto the electronic element mounting portion (8) on the wiring surface (9) of the circuit board (6) of the insulated circuit board (4), thereby the power module base (2). Has been implemented. Heat generated from the power device (3) is transferred to the heat sink (7) through the circuit board (6) and the insulating plate (5), and is dissipated to the cooling fluid flowing in the cooling fluid passage (13). ing.

  Hereinafter, a method for manufacturing the power module base (2) will be described with reference to FIGS.

  First, the insulating plate (5) is disposed on the heat sink (7), and the circuit board (6) having a plurality of brazing material reservoir recesses (12) is disposed on the insulating plate (5). Although illustration is omitted, an aluminum brazing material layer is provided between the heat sink (7) and the insulating plate (5) and between the insulating plate (5) and the circuit board (6). The brazing material layer is made of an aluminum brazing material containing, for example, Si 10% by mass and Mg 1% by mass, and the balance Al and inevitable impurities. The brazing material layer disposed between the heat sink (7) and the insulating plate (5) is made of a foil made of an aluminum brazing material, an aluminum brazing sheet in which a brazing material layer is formed on both sides of the core material, or the like. The brazing material layer disposed between the insulating plate (5) and the circuit board (6) is made of a foil made of aluminum brazing material or an aluminum brazing sheet in which a brazing material layer is formed on both sides of the core material. The brazing material layer disposed between the insulating plate (5) and the circuit board (6) may be clad in advance on the lower surface of the circuit board (6).

  Next, a jig (15) for pressurizing the circuit board (6), the insulating board (5) and the heat sink (7) from above is arranged above the circuit board (6) (see FIG. 4 (a)). A protrusion (16) that fits in the brazing material reservoir recess (12) is formed on the lower surface of the jig (15), that is, on the surface that contacts the circuit board (6), corresponding to the brazing material reservoir recess (12). deep. The volume of the protrusion (16) of the jig (15) is smaller than the internal volume of the brazing material reservoir recess (12) in which the protrusion (16) fits. Also, it corresponds to the vicinity of the protrusion (16) on the peripheral surface of the protrusion (16) of the jig (15) and the lower surface of the jig (15), that is, at least the brazing material reservoir recess (12) on the lower surface of the jig (15). A release agent (17) made of carbon, boron nitride or the like is applied to the portion to be applied.

  Next, the protrusion (16) is fitted into the brazing material reservoir recess (12), and the lower surface of the jig (15) is brought into contact with the upper surface of the circuit board (6) (see FIG. 3 and FIG. 4 (b)). Here, the sum of the difference between the volume of the protrusion (16) of the jig (15) and the inner volume of the brazing material reservoir recess (12) to which the protrusion (16) fits, that is, the protrusion in each brazing material reservoir recess (12). When the total internal volume of the space (12a) not filled with (16) is Z and the volume of the brazing material used is Y, it is preferable that the relationship 0.1 ≦ Z / Y is satisfied. It is desirable to satisfy the relationship 3 ≦ Z / X ≦ 5. When the relationship is satisfied, the molten brazing material can be effectively stored in the brazing material reservoir recess (12) when the insulating plate (5) and the circuit board (6) are brazed. A large amount of brazing material can be used for brazing the insulating plate (5) and the circuit board (6), and both can be brazed well.

  After that, the circuit board (6), the insulating board (5) and the heat sink (7) are pressed with a jig (15) and temporarily fixed in a vacuum furnace and put into an appropriate temperature. The insulating circuit board (4) is manufactured by brazing the circuit board (6) and the insulating board (5) at the same time, and at the same time, the insulating board (5) and the heat sink of the insulating circuit board (4). The power module base (2) is manufactured by brazing (7).

  When the circuit board (6), the insulating board (5) and the heat sink (7) are pressed and temporarily fixed, they are placed in a heating furnace in a vacuum atmosphere and heated to an appropriate temperature for an appropriate time. The brazing material forming the brazing material layer between the circuit board (6) and the insulating board (5) is melted, and the molten brazing material is moved from between the circuit board (6) and the insulating board (5) to the outside. By flowing out and further aggregating with the surface tension, it flows upward through the brazing material flow part (11) of the circuit board (6) and reaches the wiring surface (9). The molten brazing material reaching the wiring surface (9) of the circuit board (6) has a gap between the peripheral surface of the protrusion (16) of the jig (15) and the opening edge of the brazing material reservoir recess (12). It passes through and enters the brazing material reservoir recess (12) and is stored in the brazing material reservoir recess (12). Therefore, the brazing material cured after melting is suppressed from being present in the electronic element mounting portion (8) on the wiring surface (9) of the circuit board (6).

  In the above embodiment, a plurality of brazing material reservoir recesses (12) are formed in the circuit board (6), and brazing material reservoirs are formed in portions corresponding to the respective brazing material reservoir recesses (12) on the lower surface of the jig (15). Since the projection (16) that fits into the recess (12) is formed, the circuit board (6) can be positioned with respect to the heat sink (7), resulting in improved productivity and circuit board (6). The positional accuracy with respect to the heat sink (7) can be improved. However, the protrusion (16) of the jig (15) is not necessarily required. In this case, if the total internal volume of all the brazing material reservoir recesses (12) of the circuit board (6) is X and the volume of the brazing material to be used is Y, the relationship of 0.1 ≦ X / Y is satisfied. It is preferable that the relationship of 0.3 ≦ X / Y ≦ 5 is satisfied. Also in this case, it is preferable to apply a release agent (17) made of carbon, boron nitride or the like to at least a portion corresponding to the brazing material reservoir recess (12) on the lower surface of the jig (15). .

  In the power module shown in FIG. 1, a plate-like aluminum stress relaxation member having a plurality of through holes is disposed between the insulating plate (5) of the insulating circuit board (4) and the heat sink (7). The insulating plate (5) and the heat sink (7) may be brazed. In this case, it is preferable to use a stress relaxation member made of an aluminum brazing sheet comprising a core material and a brazing material skin material covering both surfaces of the core material.

  5 to 9 show modified examples of the insulated circuit board.

  The circuit board (21) of the insulated circuit board (20) shown in FIG. 5 has a brazing material guiding groove (22) for guiding the molten brazing material from the brazing material flow portion (11) to the brazing material reservoir recess (12). Is formed. The brazing material guiding groove (22) is formed on each side surface (21a) of the circuit board (21) and extends in the length direction of each side surface (21a), and the concave groove (23) and the brazing material. It consists of a communication groove (24) that passes through the reservoir recess (12). The recessed grooves (23) on the adjacent side surfaces (21a) are connected. The communication grooves (24) are formed in the same number as the brazing material reservoir recesses (12).

  The other configuration is the same as that of the insulated circuit board (4) shown in FIG. 2, and the base for the power module including the insulated circuit board (20) and the insulated circuit board (20) is the insulated circuit board (shown in FIG. 1). Manufactured in the same manner as 4) and power module base (2).

  Between the electronic element mounting part (8) and the brazing material flow part (11) on the wiring surface (9) of the circuit board (26) of the insulated circuit board (25) shown in FIG. 27) are formed at intervals. The brazing material reservoir recess (27) is formed in a portion of the rectangular circuit board (26) near each side so as to extend in the length direction of each side. The interval (P) between two adjacent brazing material reservoir recesses (27) is preferably 15 mm or less, and more preferably 0.5 to 10 mm. Here, in all pairs of two adjacent brazing material reservoir recesses (27), the spacing (P) between two adjacent brazing material reservoir recesses (27) is equal, but in at least one pair The spacing may be different from the spacing in other pairs. Even when the distances in at least one pair are different from the distances in the other pairs, all the distances are preferably 15 mm or less, and preferably 0.5 to 10 mm.

  The other configuration is the same as that of the insulated circuit board (4) shown in FIG. 2, and the base for the power module including the insulated circuit board (25) and the insulated circuit board (25) is the insulated circuit board (shown in FIG. 1). Manufactured in the same manner as 4) and power module base (2). In addition, a protrusion that fits in each brazing material reservoir recess (27) is provided on the lower surface of the jig that pressurizes the circuit board (26), the insulating board (5), and the heat sink (7) from above during manufacture. There are cases where it is not provided.

  The circuit board (31) of the insulated circuit board (30) shown in FIG. 7 has a brazing material guiding groove (32) for guiding the molten brazing material from the brazing material flow portion (11) to the brazing material reservoir recess (27). Is formed. The brazing material guiding groove (32) includes a concave groove (33) formed on each side surface (31a) of the circuit board (31) and extending in the length direction of each side surface (31a), and the concave groove (33) and the brazing material. A communication groove (34) is formed through the reservoir recess (27). The concave grooves (33) on the adjacent side surfaces (31a) are connected. A plurality of communication grooves (34) are formed at intervals in the length direction of each concave groove (33).

  The other configuration is the same as that of the insulated circuit board (25) shown in FIG. 6, and the base for the power module including the insulated circuit board (30) and the insulated circuit board (30) is the insulated circuit board (shown in FIG. 6). 25) and a base for a power module provided with an insulating circuit board (25).

  Between the electronic element mounting portion (8) and the brazing material flow portion (11) on the wiring surface (9) of the circuit board (36) of the insulated circuit board (35) shown in FIG. A plurality of brazing material reservoir recesses (37) for accumulating brazing material are formed at intervals so as to be scattered. The brazing material reservoir recesses (37) are formed in portions of the rectangular circuit board (36) close to the respective sides, with an interval in the length direction of each side. The distance (P) between two adjacent brazing material reservoir recesses (37) is preferably 15 mm or less, and more preferably 0.5 to 10 mm. Here, in all pairs of two adjacent brazing material reservoir recesses (37), the spacing (P) between the two adjacent brazing material reservoir recesses (37) is equal, but in at least one pair The spacing may be different from the spacing in other pairs. Even when the distances in at least one pair are different from the distances in the other pairs, all the distances are preferably 15 mm or less, and preferably 0.5 to 10 mm.

  Also, there is a recess extending in the length direction of the electronic element mounting portions (8) on both sides between the adjacent electronic element mounting portions (8) on the wiring surface (9) of the circuit board (36) of the insulating circuit board (35). A groove (38) is formed. The concave groove (38) also has a function of collecting the brazing material that has flowed through the brazing material flow portion (11) and reached the wiring surface (9).

  Other configurations are the same as those of the insulated circuit board (4) shown in FIG. 2, and the base for the power module including the insulated circuit board (35) and the insulated circuit board (35) is the insulated circuit board (shown in FIG. 1). Manufactured in the same manner as 4) and power module base (2). During manufacture, protrusions that fit in the brazing material reservoir recesses (37) are provided on the lower surface of the jig that pressurizes the circuit board (36), the insulating plate (5), and the heat sink (7) from above. There are cases where it is not provided.

  A plurality of, here two, circuit boards (41) are brazed at intervals to the insulating board (5) of the insulating circuit board (40) shown in FIG. The upper surface of each circuit board (41) is a wiring surface (43) having one electronic element mounting portion (42). Each circuit board (41) and the electronic element mounting portion (42) have irregular shapes and are substantially L-shaped when viewed from above. When the peripheral surface of each circuit board (41) is brazed between the insulating board (5) and the circuit board (41), the molten brazing material is placed between the insulating board (5) and the circuit board (41) from the wiring surface ( 43) It is a brazing material flow part (11) flowing to the side. Then, between the electronic element mounting portion (42) and the brazing material flow portion (11) on the wiring surface (43) of the circuit board (41), a plurality of brazing members that are circular when viewed from above and accumulate brazing material. The material reservoir recesses (44) are formed at intervals so as to be scattered. A plurality of brazing material reservoir recesses (44) are formed at intervals in the circumferential direction at a portion from the periphery of the circuit board (41). The distance (P) between two adjacent brazing material reservoir recesses (44) is preferably 15 mm or less, and more preferably 0.5 to 10 mm. Here, in all pairs of two adjacent brazing material reservoir recesses (44), the spacing (P) between the two adjacent brazing material reservoir recesses (44) is equal, but in at least one pair The spacing may be different from the spacing in other pairs. Even when the distances in at least one pair are different from the distances in the other pairs, all the distances are preferably 15 mm or less, and preferably 0.5 to 10 mm.

  The other configuration is the same as that of the insulated circuit board (4) shown in FIG. 2, and the base for the power module including the insulated circuit board (40) and the insulated circuit board (40) is the insulated circuit board (shown in FIG. 1). Manufactured in the same manner as 4) and power module base (2). In addition, a protrusion that fits into each brazing material reservoir recess (44) is provided on the lower surface of the jig that pressurizes the circuit board (41), the insulating board (5), and the heat sink (7) from above during manufacture. There are cases where it is not provided.

  In the insulated circuit boards (35) and (40) shown in FIGS. 8 and 9, the molten brazing material is transferred from the brazing material flow portion (11) to the brazing material reservoir recess (37) ( A brazing material guiding groove for guiding to 44) may be formed. The brazing material guiding groove is formed through, for example, a concave groove formed on each side surface of the circuit board (36) (41) and extending in the length direction of each side surface, and the concave groove and the brazing material reservoir concave portion (37) (44). It consists of a communication groove.

  The circuit boards (21), (26), (31), (36), and (41) of the insulated circuit boards (20), (25), (30), (35), and (40) shown in FIGS. It is made of the same material as the circuit board (6) of the circuit board (4).

  Also in the case of a power module base including the insulating circuit boards (20) (25) (30) (35) (40) shown in FIGS. 5 to 9, the insulating circuit boards (20) (25) (30 ) (35) (40) between the insulating plate (5) and the heat sink (7), a plate-shaped aluminum stress relief member having a plurality of through holes is disposed, and the insulating plate (5) and the heat sink (7) may be brazed.

  When manufacturing the base for a power module including the insulated circuit boards (25), (30), (35), and (40) and the insulated circuit boards (25), (30), (35), and (40) shown in FIGS. When using a jig having protrusions, it is preferable that the volume of the protrusions of the jig be smaller than the internal volume of the brazing material reservoir recesses (27), (37) and (44) into which the protrusions fit. When the sum of the difference between the volume of the projection and the inner volume of the brazing material reservoir recess (27) (37) (44) into which the projection fits is Z and the volume of the brazing material used is Y, 0.1 ≦ Z It is preferable that the relationship / Y is satisfied, and it is preferable that the relationship 0.3 ≦ Z / Y ≦ 5 is satisfied. When the relationship is satisfied, when brazing the insulating plate (5) and the circuit board (26) (31) (36) (41), the molten brazing material is effectively used as the brazing material reservoir recess (27). (37) (44) can be stored in the tank, and a sufficient amount of brazing material can be used for brazing the insulating plate (5) to the circuit boards (26) (31) (36) (41). Both can be brazed well.

  On the other hand, the power provided with the insulated circuit boards (20) (25) (30) (35) (40) and the insulated circuit boards (20) (25) (30) (35) (40) shown in FIGS. When using a jig that does not have protrusions when manufacturing a module base, the total internal volume of all brazing material reservoir recesses (12) (27) (37) (44) is X, and the volume of brazing material used is In the case of Y, it is preferable that the relationship 0.1 ≦ X / Y is satisfied, and it is preferable that the relationship 0.3 ≦ X / Y ≦ 5 is satisfied. If the relationship is satisfied, the brazing material reservoir concave portion is effectively removed when brazing the insulating plate (5) to the circuit board (21) (26) (31) (36) (41). (12) (27) (37) (44) can be stored in the insulation plate (5) and circuit board (21) (26) (31) (36) (41) It can be used for brazing, and both can be satisfactorily brazed.

  Next, specific examples of the present invention will be described together with comparative examples.

Example 1
In this embodiment, the power module base shown in FIG. 1 is manufactured.

  Thickness: 0.6 mm, length: 20 mm, width: 20 mm AlN insulating board (5) and pure aluminum with a purity of 99.99 wt%, thickness: 0.6 mm, length: 17 mm, width: 17 mm circuit board (6) and a heat sink (7) made of JIS A3003 were prepared. Further, a brazing material foil containing 10% by mass of Si and 1% by mass of Mg, made of an aluminum brazing material composed of the balance Al and inevitable impurities and having a thickness of 50 μm was prepared.

  The distance (P) between the adjacent brazing material reservoir recesses (12) that are closest to each other on the circuit board (6) was set to 5 mm. Further, when the total internal volume of all brazing material reservoir recesses (12) of the circuit board (6) is X and the volume of the brazing material foil to be used is Y, X / Y = 0.5.

  Next, the heat sink (7), the insulating plate (5) and the circuit board (6) are placed between the heat sink (7) and the insulating plate (5) and between the insulating plate (5) and the circuit board (6). Laminate in a state where the material foil is arranged, and press the circuit board (6), the insulating board (5) and the heat sink (7) with a jig whose surface is in contact with the circuit board (6). Temporarily stopped.

  Thereafter, the circuit board (6), the insulating board (5) and the heat sink (7) temporarily fixed in a pressurized state are placed in a heating furnace in a vacuum atmosphere, heated at 600 ° C. for 10 minutes, and the circuit board ( 6) and the insulating plate (5) are brazed to produce the insulated circuit board (4), and at the same time, the insulating plate (5) of the insulated circuit board (4) and the heat sink (7) are brazed. A power module base (2) was manufactured.

Example 2
In this embodiment, a base for a power module provided with the insulating circuit board (20) shown in FIG. 5 is manufactured.

  A circuit board (21), an insulating board (5), a heat sink (7) and a brazing material foil similar to the circuit board (6) used in Example 1 except that the brazing material guiding groove (22) is formed. Prepared.

  Then, using the same jig as that used in Example 1, and by brazing the circuit board (21) and the insulating board (5) in the same manner as in Example 1, the insulated circuit board (20) At the same time, the base for a power module was manufactured by brazing the insulating plate (5) of the insulating circuit board (20) and the heat sink (7).

Example 3
In this embodiment, a base for a power module provided with the insulating circuit board (20) shown in FIG. 5 is manufactured.

  A circuit board (21), an insulating board (5), a heat sink (7) and a brazing material foil similar to the circuit board (6) used in Example 1 were prepared.

  The same jig as that used in Example 1 is used, and boron nitride is formed in the portion corresponding to the brazing material reservoir recess (12) on the surface of the jig (15) in contact with the circuit board (21). An insulating circuit board (20) is brazed between the circuit board (21) and the insulating board (5) under the same conditions as in Example 1 except that a release agent comprising a ride is applied. At the same time, a base for a power module was manufactured by brazing the insulating plate (5) of the insulating circuit board (20) and the heat sink (7).

Example 4
In this embodiment, a base for a power module provided with the insulating circuit board (20) shown in FIG. 5 is manufactured.

  A circuit board (21), an insulating board (5), a heat sink (7) and a brazing material foil similar to the circuit board (6) used in Example 1 were prepared.

  As a jig, a projection (16) that fits in the brazing material reservoir recess (12) is formed in a portion corresponding to the brazing material reservoir recess (12) on the surface that contacts the circuit board (21). ) Was used, the volume of which was smaller than the internal volume of the brazing material reservoir recess (12) into which the projection (16) fits. When the total difference between the volume of the protrusion (16) of the jig (15) and the internal volume of the brazing material reservoir recess (12) into which the protrusion (16) fits is Z, and the volume of the brazing material used is Y, Z /Y=0.25. Also, a release agent made of boron nitride is applied to the periphery of the protrusion (16) of the jig (15) and the vicinity of the protrusion (16) on the surface of the jig (15) that contacts the circuit board (21). I kept it.

  The other conditions were the same as in Example 1. The insulating circuit board (20) was manufactured by brazing the circuit board (21) and the insulating board (5), and at the same time, the insulating board of the insulating circuit board (20) was manufactured. A power module base was manufactured by brazing (5) and the heat sink (7).

Example 5
In this embodiment, a base for a power module provided with the insulating circuit board (25) shown in FIG. 6 is manufactured.

  A circuit board (26), an insulating board (5), a heat sink (7), and a brazing material foil having a different shape of the brazing material reservoir recess from the circuit board (6) of Example 1 were prepared.

  The interval (P) between adjacent brazing material reservoir recesses (27) of the circuit board (26) was set to 1 mm. Further, when the total internal volume of all the brazing material reservoir recesses (12) of the circuit board (26) is X and the volume of the brazing material foil to be used is Y, X / Y = 1.1.

  The other conditions were the same as in Example 1. The insulating circuit board (25) was manufactured by brazing the circuit board (26) and the insulating board (5), and at the same time, the insulating board of the insulating circuit board (25) was manufactured. A power module base was manufactured by brazing (5) and the heat sink (7).

Comparative Example A circuit board similar to the circuit board (6) used in Example 1, an insulating board (5), a heat sink (7), and a brazing material foil were prepared except that no brazing material reservoir recess was formed. did.

  Then, using the same jig as that used in Example 1, and by brazing the circuit board (21) and the insulating board (5) in the same manner as in Example 1, the insulated circuit board (20) is mounted. Simultaneously with the manufacturing, the base for the power module was manufactured by brazing the insulating plate (5) of the insulating circuit board) and the heat sink (7).

Evaluation The surface of the circuit board of the power module base manufactured in Examples 1 to 5 and the comparative example was visually observed.

  As a result, in the power module bases manufactured in Examples 1 to 5, the solidified brazing material is accumulated in the brazing material reservoir recess, and the solidified brazing material is present in the electronic element mounting portion of the circuit board. There wasn't. On the other hand, in the power module base manufactured in the comparative example, there was a solidified brazing material on the electronic element mounting portion of the circuit board.

(1): Power module
(2): Base for power module
(3): Power device
(4) (20) (25) (30) (35) (40): Insulated circuit board
(5): Insulating plate
(6) (21) (26) (31) (36) (41): Circuit board
(7): Heat sink
(8) (42): Electronic element mounting part
(9) (43): Wiring surface
(11): Brazing material flow part
(12) (27) (37) (44): Brazing material reservoir recess
(17): Release agent
(22) (32): Brazing material guiding groove
(23) (33): Groove
(24) (34): Communication groove

Claims (17)

A metal circuit board is brazed to one surface of the insulating plate, and the surface of the circuit board opposite to the surface brazed to the insulating plate is a wiring surface having an electronic element mounting portion. An insulating circuit board having a brazing material flow portion in which a molten brazing material flows from the space between the insulating plate and the circuit board to the wiring surface side when the board and the circuit board are brazed,
A brazing material reservoir recess for storing the brazing material is formed between the electronic element mounting portion and the brazing material flow portion on the wiring surface of the circuit board, and the molten brazing material is transferred to the circuit board from the brazing material flow portion. An insulated circuit board on which a brazing material guiding groove is formed to guide the wire. 2. The insulated circuit board according to claim 1, wherein a plurality of brazing material reservoir recesses are formed on the wiring surface of the circuit board, and a distance between two adjacent brazing material reservoir recesses is 15 mm or less. The insulation according to claim 1 or 2 , wherein the brazing material guiding groove comprises a concave groove formed on each side surface of the circuit board and extending in the length direction of each side surface, and a communication groove passing through the concave groove and the brazing material reservoir concave portion. Circuit board. The base for power modules in which the surface on the opposite side to the surface where the circuit board was brazed in the insulating plate of the insulated circuit board described in any one of Claims 1-3 is brazed to the heat sink . 5. A power module in which a power device is soldered to an electronic element mounting portion of a circuit board in the insulated circuit board of the power module base according to claim 4 . A metal circuit board is brazed to one surface of the insulating plate, and the surface of the circuit board opposite to the surface brazed to the insulating plate is a wiring surface having an electronic element mounting portion. A method of manufacturing an insulated circuit board in which a brazing material flow portion is present where the molten brazing material flows from the space between the insulating plate and the circuit board to the wiring surface side when the board and the circuit board are brazed,
A brazing material reservoir recess for storing brazing material is formed between the electronic element mounting portion and the brazing material flow portion on the wiring surface of the circuit board, and the molten brazing material is brazed from the brazing material flow portion to the circuit board. A brazing material guiding groove is formed in the material reservoir recess, and the insulating plate and the circuit board are laminated so that the wiring surface of the circuit board faces outside with the brazing material placed between them. A method of manufacturing an insulated circuit board, comprising heating a plate and a circuit board while applying pressure to braze the two . 7. The insulated circuit board according to claim 6, wherein the brazing material guiding groove comprises a concave groove formed on each side surface of the circuit board and extending in the length direction of each side surface, and a communication groove passing through the concave groove and the brazing material reservoir concave portion. Manufacturing method. A metal circuit board is brazed to one surface of the insulating plate, and the surface of the circuit board opposite to the surface brazed to the insulating plate is a wiring surface having an electronic element mounting portion. A method of manufacturing an insulated circuit board in which a brazing material flow portion is present where the molten brazing material flows from the space between the insulating plate and the circuit board to the wiring surface side when the board and the circuit board are brazed,
A brazing material reservoir recess was formed between the electronic element mounting part and the brazing material flow part on the circuit board wiring surface, and the brazing material was placed between the insulating plate and the circuit board. In this state, the circuit board is laminated so that the wiring surface faces outward, and the insulating board and the circuit board are heated while being pressurized and brazed together, and the insulating board and the circuit board are pressed. It is performed by pressing the circuit board to the insulating plate side using a jig, and a release agent is applied to at least a portion corresponding to the brazing material reservoir recess in the surface of the jig that contacts the circuit board. A method for manufacturing an insulated circuit board. The insulated circuit board according to any one of claims 6 to 8, wherein a plurality of brazing material reservoir recesses are formed on the wiring surface of the circuit board, and an interval between two adjacent brazing material reservoir recesses is 15 mm or less. Manufacturing method. 10. The structure according to claim 6, wherein X is a total inner volume of all brazing material reservoir recesses of the circuit board, and Y is a volume of the brazing material to be used, and satisfies a relationship of 0.1 ≦ X / Y. Method for manufacturing an insulated circuit board. The insulating circuit board is brazed to the heat sink, and the insulating circuit board is brazed to the insulating plate brazed to the heat sink and the surface of the insulating plate opposite to the surface brazed to the heat sink. It consists of a metal circuit board, and the surface of the circuit board opposite to the surface brazed to the insulating board is a wiring surface having an electronic element mounting portion, and the circuit board is connected to the insulating board and the circuit board. A method for producing a base for a power module in which a brazing material flow portion flows between the insulating plate and the circuit board to the wiring surface side during brazing,
A plurality of brazing material reservoir recesses for storing brazing material are formed between the electronic element mounting portion and the brazing material flow portion on the wiring surface of the circuit board, and the molten brazing material is placed on the circuit board. In the state where the brazing material guiding groove for guiding to the brazing material reservoir recess is formed and the brazing material is disposed between the heat sink, the insulating plate and the circuit board, the wiring surface of the circuit board faces the outside. A method for manufacturing a base for a power module, wherein the heat sink, the insulating plate, and the circuit board are laminated while facing each other and heated while applying pressure to braze the heat sink, the insulating plate, and the insulating plate to the circuit board . The power module according to claim 11, wherein the brazing material guiding groove includes a concave groove formed on each side surface of the circuit board and extending in a length direction of each side surface, and a communication groove that allows the concave groove and the brazing material reservoir concave portion to pass therethrough. Base manufacturing method . The insulating circuit board is brazed to the heat sink, and the insulating circuit board is brazed to the insulating plate brazed to the heat sink and the surface of the insulating plate opposite to the surface brazed to the heat sink. It consists of a metal circuit board, and the surface of the circuit board opposite to the surface brazed to the insulating board is a wiring surface having an electronic element mounting portion, and the circuit board is connected to the insulating board and the circuit board. A method for producing a base for a power module in which a brazing material flow portion flows between the insulating plate and the circuit board to the wiring surface side during brazing,
A plurality of brazing material reservoir recesses for accumulating brazing material are formed between the electronic element mounting portion and the brazing material flow portion on the wiring surface of the circuit board, and the heat sink, insulating plate, and circuit board are connected to each other. With the brazing material placed in between, the circuit board is laminated so that the wiring surface faces outward, and the heat sink, insulating plate, and circuit board are heated while being pressurized to heat sink, insulating plate, insulating plate, and circuit board. And pressurizing the heat sink, the insulating plate, and the circuit board by pressing the circuit board against the insulating plate and the heat sink side using a jig, and on the surface of the jig contacting the circuit board A power module base manufacturing method, wherein a release agent is applied to at least a portion corresponding to a brazing material reservoir recess . 14. The method of manufacturing a power module base according to claim 13, wherein a protrusion that fits into the brazing material reservoir recess is provided in a portion corresponding to the brazing material reservoir recess on the surface of the jig that contacts the circuit board . The volume of the projection of the jig is made smaller than the inner volume of the brazing material reservoir recess into which the projection fits, and the total difference between the volume of the projection and the inner volume of the brazing material reservoir recess into which the projection fits is Z. The method for manufacturing a base for a power module according to claim 14, wherein when the volume of the brazing material is Y, a relationship of 0.1 ≦ Z / Y is satisfied . The method for manufacturing a power module base according to any one of claims 11 to 15, wherein an interval between two adjacent brazing material reservoir recesses formed on the wiring surface of the circuit board is 15 mm or less . The total internal volume of all brazing material reservoir recesses of the circuit board is X, and when the volume of the brazing material used is Y, the relationship of 0.1 ≦ X / Y is satisfied. Manufacturing method for power module base.

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