JP4946488B2 - Circuit module - Google Patents

Description

The present invention relates to a circuit module excellent in heat dissipation.

Conventionally, as an example of a circuit module in consideration of heat dissipation, a first substrate having a bottom surface made of a heat dissipation member having excellent thermal conductivity and an electronic component mounted on the surface side, a second substrate, and a second substrate A case provided so as to cover the substrate, a terminal guide provided at a position facing the terminal of the case so that the terminal protrudes from the case when the case is mounted on the first substrate, and the case 2 having a high thermal diffusibility filling resin filled in a space formed when mounted on the substrate of 2 and silicon, epoxy, and a gap between the case and the first substrate having adhesiveness, The case is attached to the second board by filling it with any acrylic case mounting sealant and filling the gap between the terminal guide, the second board and the terminal with a resin leakage prevention sealant. By sealing the space that can be formed, it is possible to fill the module parts without leaking the filling resin, and the temperature of the electronic parts is averaged with the filling resin to keep the temperature rise of the electronic parts low. (For example, refer to Patent Document 1).
JP 20042544397 A

  However, in the above-mentioned conventional configuration, a sealed structure is formed in the case, all the circuits have substantially the same temperature, and a filling resin having further excellent thermal conductivity is indispensable in order to be able to cope with a larger current, as well as in production. There are restrictions on the shape of the module from the standpoint of performance and expansion coefficient.

The present invention solves the above-described conventional problems, and an object thereof is to provide a circuit module excellent in heat dissipation.

In order to solve the conventional problem, the present invention includes a first metal plate, a heat conductive resin provided on an upper surface of the first metal plate, and the first metal plate on the upper surface side of the heat conductive resin. A first heat radiating substrate which is provided with a plurality of bent portions which are provided with electrical insulation from one metal plate and whose end portions are bent by approximately 90 ° on the upper surface side; A power semiconductor element mounted on a substrate; a second metal plate; a circuit board resin provided on an upper surface of the second metal plate; and the second metal plate on an upper surface side of the circuit board resin. A second heat dissipation board comprising a circuit pattern provided in an electrically insulated manner, and a control IC mounted on the second heat dissipation board and generating a smaller amount of heat than the power semiconductor, The lower surface of the second metal plate is brought into surface contact with the top surface side of the power semiconductor. The first heat radiating board and the second heat radiating board are laminated and arranged by electrically connecting the lead frame and the circuit pattern via the bent portion, and the heat conductive resin. Is made of a composite material containing an inorganic filler, and the thermal conductivity of the thermal conductive resin is higher than the thermal conductivity of the circuit board resin.

The present invention makes it possible to improve the heat dissipation of the heat generating component in the circuit module and to suppress the influence of heat on the control component.

(Embodiment 1)
Hereinafter, a circuit module and a manufacturing method thereof according to Embodiment 1 of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a circuit module according to Embodiment 1 of the present invention, and FIG. 2 is an exploded perspective view thereof.

  1 and 2, reference numeral 1 denotes a first metal substrate excellent in thermal conductivity. For example, an aluminum plate, a copper plate, or an iron plate is preferable from the viewpoints of availability and thermal conductivity characteristics.

  The aluminum plate and the copper plate are preferable from the viewpoint of thermal conductivity, and the iron plate is particularly inferior in thermal conductivity, but can be a heat dissipation substrate having an electromagnetic shielding effect.

  Reference numeral 2 denotes a lead frame having excellent thermal conductivity such as copper. The lead frame 2 has a predetermined thickness and can handle a large current, and has a characteristic excellent in thermal conductivity. It can easily cope with processing into a shape.

  Reference numeral 3 denotes a heat conductive resin made of a composite material such as an epoxy resin and an inorganic filler having excellent heat conductivity, and the heat conductive resin 3 is selected from an epoxy resin, a phenol resin, or a silicon resin. Heat conduction by comprising at least one kind of resin and at least one kind of inorganic filler selected from the group consisting of alumina, magnesium oxide, boron nitride, silicon oxide, silicon carbide, silicon nitride and aluminum nitride. It can be set as the heat conductive resin 3 which has the characteristic excellent in the property and insulation. In addition, the first metal substrate 1 and the lead frame 2 are joined together through the heat conductive resin 3 and the lead frame 2 is embedded in the heat conductive resin 3 so as to be more thermally conductive. It is possible to exert the effect of increasing

  Furthermore, by making the exposed surface of the lead frame 2 and the surface of the heat conductive resin 3 flush with each other, it is possible to realize a heat dissipating board excellent in mountability such as surface mount components.

  In the circuit module according to the first embodiment, the lead frame 2 peeled off from the heat conductive resin 3 is bent from the heat conductive resin 3 by approximately 90 degrees, and a plurality of lead frames 2 are arranged substantially in parallel, and the lead frame 2 is bent by approximately 90 degrees. The first heat dissipation board and the second heat dissipation board are integrated via the lead frame 2. As a result, it is possible to realize a circuit module that can be easily integrated and has improved thermal conductivity. The lead frame 2 electrically connects the electric circuit configured on the first heat dissipation board and the electric circuit configured on the second heat dissipation board, and at least a part of the lead frame 2 is connected to the second heat dissipation board. By joining to the metal substrate 5, it is possible to efficiently dissipate heat.

  Further, a part of the lead frame 2 embedded in the thermal conductive resin 3 of the first heat dissipation substrate is used as a terminal electrode, and a heat generation which is a semiconductor element corresponding to a large current such as a power transistor or a power FET is provided on the terminal electrode. The component 4 is mounted. Then, a part of the end portion of the lead frame 2 is peeled off from the embedded heat conductive resin 3 and folded at about 90 degrees.

  Further, by using the lead frame 2 as a lead frame containing copper as a main component, the lead frame 2 excellent in solderability, thermal conductivity and workability can be realized.

  The lead frame 2 can be made of aluminum. In this case, the same effect as described above can be obtained by providing solderability by surface treatment such as plating. An integrated circuit module can be realized.

  Next, the configuration of the second heat dissipation board will be described. The second heat radiating substrate is obtained by bonding a second metal substrate 5 and a circuit pattern 6 formed by patterning a copper foil or the like by etching through a resin 7. The resin 7 is preferably an insulating resin containing at least one resin selected from an epoxy resin, a phenol resin, or a silicon resin.

  The circuit pattern 6 can be formed by bonding the copper foil and the second metal substrate 5 with the resin 7 and then performing etching, and further using a thin film process or a printing process. 6 can also be formed.

  And when this resin 7 wants to suppress the influence of the heat to the control circuit 8, it is preferable to use resin with low heat conductivity. On the other hand, when it is necessary to mount the heat generating component 4 also on the control circuit 8, the resin 7 can be used as a composite resin containing an inorganic filler having excellent thermal conductivity.

  On the second heat dissipation board, a control circuit 8 for controlling a semiconductor element corresponding to a large current such as a power transistor or a power FET which is the heat generating component 4 is mounted. The control circuit 8 includes a control IC 9 and a passive component 10 such as a resistor and a capacitor. The control circuit 8 has a circuit configuration with relatively little heat generation. An opening 11 for penetrating the lead frame 2 is formed at a predetermined position in the second heat dissipation board. Then, the bent lead frame 2 is inserted into the opening 11, and the lead frame 2 and the second heat dissipation board are bonded to each other to be firmly bonded.

  Then, by making at least one lead frame 2 serving as a ground terminal conductive to the second metal substrate 5 as a ground, the same potential can be obtained, and the other lead frame 2 is provided on the second heat dissipation substrate. By connecting to the respective connection terminals of the circuit pattern 6, a circuit module can be obtained by connecting the first heat dissipation board and the surface mount component mounted on the second heat dissipation board.

  Here, what is important is to join the lead frame 2 and the second heat radiating substrate while adjusting so that one surface of the heat generating component 4 and the surface of the second metal substrate 5 are in surface contact. As a result, the heat generated from the heat generating component 4 is diffused through the lead frame 2 and then into the heat conductive resin 3, and then radiated to the first metal substrate 1. Furthermore, heat dissipation of the heat generating component 4 can be enhanced by conducting heat to the second metal substrate 5 that is in surface contact with the heat generating component 4.

  In addition, as a method of making the surface contact, it is preferable to directly contact one surface of the heat generating component 4 and one surface of the second metal substrate 5 using a spring property. If the surface contact is insufficient, the heat conductive resin 3 may be used for bonding.

  However, if the heat generating components 4 have the same height, all the heat generating components 4 can be brought into surface contact with one surface of the second metal substrate 5, but when the heat generating components 4 having different heights must be mounted. By inserting a spacer made of the same material as that of the second metal substrate 5 into the gap, it is possible to conduct heat to the second metal substrate 5.

  Furthermore, although the thermal conductivity is slightly reduced, the gap between the heat generating component 4 and the second metal substrate 5 is filled with the thermal conductive resin 3, and heat is applied to the second metal substrate 5 through the thermal conductive resin 3. It is also possible to conduct.

  In addition, by making the first metal substrate 1 a copper or aluminum circuit module and the second metal substrate 5 an iron circuit module, a circuit module that exerts an effect on heat dissipation and electromagnetic shielding is obtained. Can be realized.

  And you may attach the heat sink for improving heat dissipation to the 1st metal substrate 1 or the 2nd metal substrate 5. FIG.

  The lead frame 2 not connected to the circuit is formed on the first heat dissipating board, and the lead frame 2 not connected to the circuit is directly joined to the second metal board 5 to thereby remove the heat generating component 4. The radiated heat can be efficiently radiated to the second metal substrate 5. The lead frame 2 and the second metal substrate 5 can be joined by soldering, brazing, or a conductive adhesive.

  In addition, the lead frame 2 a can be used as an independent electrode by being electrically insulated from the second metal substrate 5 and joining the resin 7 and the adhesive 13. At this time, the opening 11 is opened in a shape larger than the outer shape of the lead frame 2a, and the lead frame 2a is inserted into the opening 11 and then bonded by applying and bonding an insulating bonding agent in the gap. can do. This is effective in increasing the strength and heat dissipation of the circuit module.

  Further, the circuit pattern 6 formed on the resin 7 and the lead frame 2a are joined with the solder 12 or the conductive adhesive 13, so that the first heat radiating board and the second heat radiating board are formed. It is also possible to connect each formed circuit pattern.

  With the configuration of the circuit module as described above, the control circuit 8 and the heat generating component 4 can be connected in the shortest time, and a circuit module excellent in heat dissipation can be realized.

  Next, a method for manufacturing the circuit module according to the first embodiment will be described. First, an example of the manufacturing method of the 1st thermal radiation board | substrate used for the circuit module which is a 1st process is demonstrated. The lead frame 2 is obtained by processing a copper plate or the like into a wiring shape by pressing or the like.

  Then, a sheet-like uncured heat conductive resin 3 is disposed on the first metal substrate 1, and the lead frame 2 is set on the heat conductive resin 3. Thereafter, the laminate is molded in a predetermined mold so that it can be embedded in the heat conductive resin 3 so that one surface of the lead frame 2 is exposed and integrally molded.

  Then, the 1st heat dissipation board | substrate can be produced by putting in a heating furnace in this state, and thermally curing the heat conductive resin 3. FIG.

  Next, as a second step, the heat-generating component 4 that is a power semiconductor device or an FET device is surface-mounted on the first heat dissipation substrate using solder or the like (terminal electrodes and soldered portions of the heat-generating component 4 are illustrated in FIG. Then, the lead frame 2 is bent at a substantially right angle.

  Here, the heat conductive resin 3 is obtained by preliminarily forming a heat conductive material, which will be described later, into a sheet shape, and is formed by using a film having releasability when producing the first heat dissipation substrate. It is possible to prevent the heat conductive resin 3 from adhering to the surface of a machine or a mold as dirt.

  In addition, by using a film as a cushioning material (or packing or sealing material) between the press or mold and the lead frame 2, the heat conductive resin 3 is prevented from wrapping around the surface of the lead frame 2. Or press pressure can be increased. As a result, the heat conductive resin 3 can be surely wound around every corner of the lead frame 2 composed of a plurality of leads.

  Here, as the sheet-like heat conductive resin 3, a heat conductive composite material composed of a thermosetting resin and a filler can be used. For example, the member is desirable from 70% to 95% by weight of the inorganic filler and 5% to 30% by weight of the thermosetting resin. Here, the inorganic filler has a substantially spherical shape, and its diameter is suitably from 0.1 to 100 μm (if it is less than 0.1 μm, it becomes difficult to disperse in the resin, and if it exceeds 100 μm, the heat conductive resin 3 Thickness increases and affects thermal diffusivity). Therefore, the filling amount of the inorganic filler in the heat conductive resin 3 is filled at a high concentration of 70 to 95% by weight in order to increase the heat conductivity. In particular, in the first embodiment, the inorganic filler is a mixture of two types of alumina having an average particle size of 3 μm and an average particle size of 12 μm. By using alumina having two kinds of large and small particle diameters, it is possible to fill the gaps between the large particle diameters of alumina with small particle diameters, so that alumina can be filled at a high concentration to nearly 90% by weight. As a result, the heat conductivity of the heat conductive resin 3 is about 5 W / (m · K). The inorganic filler may include at least one selected from the group consisting of alumina, magnesium oxide, boron nitride, silicon oxide, silicon carbide, silicon nitride, and aluminum nitride.

  In addition, when an inorganic filler is used, heat dissipation can be improved. However, when magnesium oxide is used in particular, the linear thermal expansion coefficient can be increased. Further, when silicon oxide is used, the dielectric constant can be reduced, and when boron nitride is used, the linear thermal expansion coefficient can be reduced. In this way, the thermal conductive resin 3 having a thermal conductivity of 1 to 20 W / (m · K) can be formed. In addition, when heat conductivity is less than 1 W / (m * K), it influences the heat dissipation of a heat conductive board | substrate. Moreover, when it is going to make thermal conductivity higher than 20 W / (m * K), it is necessary to increase the amount of fillers and may affect the workability at the time of a press.

  Further, if the thickness of the heat conductive resin 3 is designed to be thin, the heat of the lead frame 2 can be easily transferred to the first metal substrate 1, but conversely, the withstand voltage becomes a problem. Moreover, since thermal resistance will become large when the thickness of the heat conductive resin 3 is too thick, 50-1000 micrometers which is the optimal thickness in view of a withstand voltage and a thermal resistance is preferable.

  Next, the manufacturing method of the 2nd heat sink which is a 3rd process is demonstrated. The manufacturing method of the second heat dissipation substrate can be manufactured in substantially the same manner as the manufacturing method of the first heat dissipation substrate. That is, a second metal substrate 5 such as a copper plate is prepared, an uncured epoxy resin or the like processed into a sheet is laminated and laminated, and a circuit pattern 6 produced by etching a copper foil or the like is laminated thereon. Heat cure while molding using a mold. Thereafter, the second IC substrate having the control circuit 8 formed thereon can be manufactured by surface-mounting the control IC 9 and the passive component 10 constituting the control circuit 8 on the electrode terminal portion formed in the circuit pattern 6.

  Next, the fourth step will be described. An opening 11 for penetrating the lead frame 2 is formed at a predetermined position of the second heat dissipation board by a drilling machine. Thereafter, the second heat radiating board is arranged so that one surface of the heat generating component 4 mounted on the first heat radiating board and the one surface of the second metal substrate 5 are in surface contact while the lead frame 2 corresponding to the opening 11 is inserted. A circuit module can be manufactured by bonding the lead frame 2 to each other. By providing the opening 11, the lead frame 2 can be fixed to an arbitrary position of the second heat dissipation board.

  In addition, this opening part 11 can be arrange | positioned in the arbitrary positions of a 2nd thermal radiation board | substrate, and can be arrange | positioned and joined in the optimal position from a viewpoint of mechanical strength, a circuit connection, or a heat conductive characteristic.

  Moreover, the same effect can be exhibited by forming a recess in the peripheral edge of the second heat dissipation substrate and fixing the lead frame 2 to the recess.

  By setting it as such a circuit module, the small circuit module excellent in heat dissipation can be produced easily. Furthermore, since the heat generating component 4 mounted on the first heat dissipation board and the control circuit 8 mounted on the second heat dissipation board can be electrically connected in the shortest time, the noise resistance characteristics of the circuit module can be improved. This can reduce power consumption.

  Moreover, it is preferable that the first metal substrate 1 is made of aluminum, copper, or an alloy mainly composed of aluminum, which has good thermal conductivity. In the first embodiment, the thickness of the first metal substrate 1 is 1 mm. Although the thickness is preferably 0.1 to 50 mm, the thickness can be designed according to the product specifications. (If the thickness of the first metal substrate 1 is 0.1 mm or less, the heat dissipation and the strength are insufficient. Also, if the thickness of the first metal substrate 1 exceeds 50 mm, it is disadvantageous in terms of weight).

  Note that a part of the lead frame 2 is peeled off from the heat conductive resin 3 and bent (or bent) by approximately 90 degrees as necessary, whereby the wiring on the first heat dissipation board and the heat generating component 4 are formed. The heat generated can be directly radiated from the lead frame 2 into the air, and the heat radiation effect can be further enhanced by forming the lead frame 2 in the central portion (particularly in the vicinity of the heat generating component 4).

In addition, the lead frame 2 can be obtained by punching a metal plate mainly made of copper or copper alloy into a predetermined shape. This is because copper is excellent in both thermal conductivity and electrical conductivity. As a copper plate used for this, it is desirable to use, for example, tough pitch copper or oxygen-free copper having a thickness of 0.50 to 2.0 mm. As for tough pitch copper, Cu 99.90 wt% or more is desirable, for example, and as for oxygen free copper, Cu 99.96 wt% or more is desirable, for example. When the purity of copper is less than these numbers, it is affected not only by workability but also by thermal conductivity and electrical conductivity due to the influence of impurities (for example, the content of Cu ₂ O due to the influence of oxygen increases) There is. Such a member is inexpensive and excellent in mass productivity.

  As a patterning method for the lead frame 2, etching may be used, but processing by stamping with a press or a die is suitable from the viewpoint of pattern identity and mass productivity.

  Various copper alloys can be selected as the lead frame 2. For example, in order to improve the workability or thermal conductivity of the lead frame 2, at least one kind selected from the group of at least Sn, Zr, Ni, Si, Zn, P, Fe, etc. other than copper is used as the copper material. It is also possible to use an alloy made of the material. For example, a copper alloy material containing Cu as a main component and Sn added thereto can be used. In the case of a copper alloy material, for example, by adding 0.1 to 0.15% by weight of Sn, the softening temperature can be increased to 400 ° C. For comparison, when the lead frame 2 was produced using copper (Cu> 99.96% by weight), the electrical conductivity was low, but distortion may occur in the completed first heat dissipation board. As a result, the softening point of the material was as low as about 200 ° C., and it was expected that the material could be deformed during subsequent component mounting (soldering).

  On the other hand, when a copper alloy material was used, it was not particularly affected by the heat generation of various mounted parts. There was no effect on solderability and die bondability. Therefore, when the softening point of this material was measured, it was found to be 400 ° C. Thus, it is desirable to add some elements mainly composed of copper. In the case of Zr as an element to be added to copper, a range of 0.015 to 0.15% by weight is desirable. When the addition amount is less than 0.015% by weight, the effect of increasing the softening temperature may be small. On the other hand, if the amount added is more than 0.15% by weight, the electrical characteristics may be affected. Also, the softening temperature can be increased by adding Ni, Si, Zn, P or the like. In this case, Ni: 0.1 to 5% by weight, Si: 0.01 to 2% by weight, Zn: 0.1 to 5% by weight, P: 0.005 to 0.1% by weight are desirable. And these elements can make the softening point of a copper raw material high by adding single or multiple in this range. In addition, when there are few addition amounts than the ratio described here, the softening point raise effect may be low. Moreover, when there are more than the ratio described here, there exists a possibility of affecting the electrical conductivity. Similarly, in the case of Fe: 0.1 to 5% by weight, in the case of Cr; 0.05 to 1% by weight is desirable. These elements are the same as those described above.

  The tensile strength of the copper material used for the lead frame 2 is preferably 600 N / square mm or less. In the case of a material having a tensile strength exceeding 600 N / square mm, the workability of these lead frames 2 may be affected. On the other hand, by setting the tensile strength to 600 N / square mm or less (and, if these lead frames 2 require fine and complicated processing, desirably 400 N / square mm or less), the spring back (pressure even if bent to the required angle) The occurrence of rebound by reaction force is suppressed, and the formation accuracy can be improved. As described above, the material of the lead frame 2 is mainly composed of Cu, so that the electrical conductivity can be lowered, and further softening can improve the workability, and further the heat dissipation effect by the lead frame 2 can be enhanced.

  The tensile strength of the copper alloy used for the lead frame 2 is desirably 10 N / square mm or more. This is because the copper alloy used for the lead frame 2 needs to have a strength higher than the tensile strength (about 30 to 70 N / square mm) of general lead-free solder. When the tensile strength of the copper alloy used for these lead frames 2 is less than 10 N / square mm, when the electronic component 22 is mounted by soldering on these lead frames 2, it is not the solder portion but the portion of the lead frame 2. There is a possibility of cohesive failure.

  It is also useful to previously form a solder layer or tin layer on the mounting surface of the lead frame 2 such as the heat generating component 11 so as to improve solderability.

  Further, the first metal substrate 1 and the second metal substrate 5 are made of aluminum, copper, or an alloy containing them as main components, which has good thermal conductivity. In particular, in the first embodiment, the thickness is 1 mm (desirably 0.1 to 5.0 mm), but the thickness can be designed according to product specifications (note that the first metal substrate 1 and the second metal substrate 1). If the thickness of the metal substrate 5 is 0.1 mm or less, heat dissipation and strength may be insufficient, and if it exceeds 5 mm, it is disadvantageous in terms of weight). The first metal substrate 1 is not only a plate-like one but also a fin portion (in order to increase the surface area on the surface opposite to the surface on which the heat conductive resin 3 is laminated in order to further improve heat dissipation. Alternatively, an uneven portion) may be formed.

  The bending angle of the lead frame 2 is preferably substantially vertical (preferably vertical ± 20 degrees or less, desirably ± 10 degrees or less, and more preferably ± 5% or less). If the vertical angle exceeds ± 20 degrees, the insertability is adversely affected.

(Embodiment 2)
Hereinafter, a circuit module according to Embodiment 2 of the present invention will be described with reference to the drawings.

  FIG. 3 is a cross-sectional view of the circuit module according to Embodiment 2 of the present invention, and FIG. 4 is a cross-sectional view for explaining a state in which the tip of the lead frame 2 from the circuit module is mounted on the circuit board.

  In FIG. 3, the basic configuration of the circuit module according to the second embodiment is substantially the same as that of the circuit module according to the first embodiment, and the same reference numerals are given and description thereof is omitted. The circuit module in the second embodiment is greatly different from the first embodiment in that a filling resin 15 having thermal conductivity is filled between the first heat dissipation board and the second heat dissipation board. is there.

  Accordingly, it is possible to realize a circuit module in which hot spots due to heat generation of the heat generating component 4 are reduced and the thermal conductivity is further increased by the filling resin 15.

  By adopting such a configuration, even when it is necessary to mount the heat generating components 4 having different heights, it is possible to realize a circuit module with improved thermal conductivity and improved thermal uniformity.

  Further, as shown in FIG. 4, a notch 20 is provided at the leading end portion of the lead frame 2, and a parallel portion 21 is provided by the notch 20.

  Thus, by providing the notch 20 at the tip of the lead frame 2, for example, the through hole 23 provided in the circuit board 22 so as to correspond to the lead frame 2 is smaller than the size of the root portion of the lead frame 2. The diameter is designed.

  Thereby, when the lead frame 2 is inserted into the circuit board 22, the parallel portion 21 of the lead frame 2 is in a state of supporting the circuit board 22.

  With this configuration, the circuit module can be mounted on the circuit board 22 while maintaining high dimensional accuracy efficiently.

  Since the distance between the circuit board 22 and the circuit module can be determined from the viewpoint of thermal design and the length of the lead frame 2 can be processed to a predetermined length, a circuit module with a high degree of freedom in thermal design is realized. can do.

  As described above, the circuit module and the manufacturing method thereof according to the present invention can realize a small circuit module excellent in heat dissipation and a manufacturing method thereof, and are useful for electronic circuit module applications that generate heat such as power supply modules. it can.

Sectional drawing of the circuit module in Embodiment 1 of this invention Exploded perspective view Sectional drawing of the circuit module in Embodiment 2 of this invention Sectional view of the lead frame connection

Explanation of symbols

1 First metal substrate 2, 2a Lead frame 3 Thermally conductive resin 4 Heating component (power component)
5 Second metal substrate 6 Circuit pattern 7 Resin 8 Control circuit 9 Control IC
DESCRIPTION OF SYMBOLS 10 Passive component 11 Opening part 12 Solder 13 Adhesive material 15 Filling resin 20 Notch 21 Parallel part 22 Circuit board 23 Through-hole

Claims (1)

A first metal plate and a thermally conductive resin provided on the upper surface of the first metal plate;
A lead frame having a plurality of bent portions which are provided on the upper surface side of the heat conductive resin so as to be electrically insulated from the first metal plate and whose end portions are bent approximately 90 ° toward the upper surface side. 1 heat dissipation substrate;
A power semiconductor element mounted on the first heat dissipation substrate;
A second metal plate, and a circuit board resin provided on the upper surface of the second metal plate;
A second heat dissipating board comprising a circuit pattern provided on the upper surface side of the circuit board resin so as to be electrically insulated from the second metal plate;
A control IC mounted on the second heat dissipation board and generating a smaller amount of heat than the power semiconductor;
The lower surface of the second metal plate is brought into surface contact with the top surface side of the power semiconductor, and the lead frame and the second heat dissipation substrate are connected to the lead frame via the bent portion. Laminate and arrange the circuit pattern after electrically connecting it,
The circuit module in which the thermal conductive resin is made of a composite material containing an inorganic filler, and the thermal conductivity of the thermal conductive resin is higher than the thermal conductivity of the circuit board resin.

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