JP2009224445A - Circuit module and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that since a force by a screw stop does not directly contribute to make a heat dissipation substrate very strong with a conventional heat dissipation substrate, when a very strong tensility, a very strong vibration or the like are added, the conventional heat dissipation substrate may be partially peeled or disconnected. <P>SOLUTION: A circuit module 116 includes: a metal plate 101 and a heat transmission layer 102; a heat dissipation substrate 120 having lead frames 103 and connecting terminals 104; a resin structure 113 provided on this heat dissipation substrate 120; and fixing clamps such as screws 114 or the like for fixing this resin structure 113. The heat dissipation substrate 120 and the circuit module 116 can be made very strong, since it is so constituted that binding forces by the screws 114 or the like may negate external forces given from exteriors to the lead frames 103 and the connecting terminals 104. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a circuit module used in a hybrid car including a mild hybrid car and an industrial device, and a manufacturing method thereof.

  In recent years, hybrid cars and various industrial devices that achieve low power consumption by accumulating regenerative power during braking in an electric double layer capacitor or the like have attracted attention.

  Such a device requires a circuit module that handles a large current, such as a DCDC converter that controls a large current exceeding 100 A with high accuracy (herein, DCDC means a converter that converts a DC input into a DC output). The power semiconductor and the like used for these are mounted on a heat dissipation board corresponding to heat dissipation and a large current to constitute a circuit module. Here, the circuit module is a voltage converter with a large current of 50 A or more, including a power supply module, a DCDC converter, and the like.

  Then, it is necessary to install a circuit board on which various electronic components such as a semiconductor chip for controlling the power semiconductor and the odd-shaped parts are mounted at high density as close as possible to the circuit module on which the power semiconductor is mounted. This is to reduce the size of the circuit module and to prevent circuit noise.

  Further, in order to reduce the size and weight of a circuit module, it is required to mount a semiconductor chip body (for example, a bare chip) using a mounting method such as a bonding wire instead of a resin-molded semiconductor.

  In order to deal with such a problem, Patent Document 1 proposes mounting a semiconductor in a bare chip.

  9A and 9B are cross-sectional views of a semiconductor module which is an example of a conventional heat dissipation board. 9A corresponds to a cross-sectional view of the semiconductor module 15 before being attached to the housing 16, and FIG. 9B corresponds to a cross-sectional view of the semiconductor module 15 after being attached to the housing 16 with screws or the like.

  9A and 9B, a metal foil 3 is formed in a predetermined pattern on an aluminum base plate 1 with an insulating layer 2 interposed therebetween. On the metal foil 3, a power semiconductor element 5 is fixed via a solder 4 or the like and wired by a bonding wire 6.

  The aluminum base plate 1 is fixed to the frame body 14 in which the terminals 10 are embedded with an adhesive 7 or the like by the opening 12 or the like, and the aluminum base plate 1 protrudes by a certain amount as indicated by an arrow 18c. . This is to ensure contact between the housing 16 and the aluminum base plate 1.

  Further, the protruding portion 13 provided on the frame body 14 is for securing the protruding amount of the aluminum base plate 1. An electronic component 9 or the like is mounted on the control circuit board 8, and the whole is protected with a sealing resin 11 to constitute a semiconductor module 15.

  When the semiconductor module 15 is attached to the housing 16 with screws 17 or the like and further subjected to a vibration test or the like as indicated by arrows 18a or 18b, the portions indicated by dotted lines 19 are indicated by arrows 18e and 18d. Such a problem such as peeling may occur.

  Such a problem is because the aluminum base plate 1 protrudes by a certain amount as indicated by an arrow 18c, and is due to attachment by the screw 17. When only one of the frame 14 and the aluminum base plate 1 is used as the screw 17, stress due to mounting with the screw 17 hardly occurs, but a vibration test (for example, XYZ) required for an in-vehicle product. When the direction is 5 to 30 G. G is a unit of vibration), a problem as shown in FIG. 9B may occur.

  On the other hand, Patent Document 2 proposes another structure in which a control circuit board is installed substantially in parallel on a power semiconductor mounted on a bare chip.

  FIGS. 10A and 10B are cross-sectional views of a semiconductor module in which a control circuit board is installed substantially in parallel on a power semiconductor mounted on a bare chip. 10A and 10B, the power semiconductor 20 is mounted on a lead frame 21 fixed on an aluminum base plate 1 with an insulating adhesive sheet 23. A part of the lead frame 21 serves as a main terminal 22 and is connected to the wiring board 24.

  A control circuit component 25 is mounted on the wiring board 24, and controls the power semiconductor 20 through the main terminal 22 and the bonding wire 6. Further, the circuit board 24 is held by the exterior resin mold 26 and the sealing resin 11 is injected into the circuit board 24 while being fixed by the exterior resin mold 26, thereby configuring the power conversion device 27.

  Thereafter, as shown in FIG. 10B, the power converter 27 is fixed to the housing 14 with screws 17 or the like.

FIG. 10B is a cross-sectional view for explaining the problem of the power converter 27. Even when the power converter 27 is fixed with screws 17 or the like, each part is peeled off (or detached) by a vibration test or the like as indicated by an arrow 18. ) There is a possibility.
Japanese Patent No. 3898158 Japanese Patent No. 3547333

  However, in the case of the conventional heat dissipation substrate shown in FIGS. 9A and 9B and FIGS. 10A and 10B, the fixing force with the screws 17 or the like is applied to the frame body 14 or the exterior resin mold 26 and the aluminum base. Since the plate 1 and the plate 1 were added separately, there was a possibility that these members were peeled off at these interfaces (or connection surfaces, bonding surfaces, etc.).

  In order to solve the above problems, the present invention provides a metal plate, a heat transfer layer including a sheet-like thermosetting resin and an inorganic filler provided thereon, and a lead frame embedded in the heat transfer layer. A heat dissipating substrate having a terminal formed by peeling a part of the lead frame from the heat transfer layer and bending it substantially vertically; a resin structure provided on the heat dissipating substrate; and fixing the resin structure A circuit module comprising: a fixing module that includes a structure that reinforces a part of the lead frame or the terminal by fixing the resin structure to the heat dissipation board by the fixing tool. Circuit module.

  As described above, according to the present invention, the resin structure is fixed to the heat radiating board with a fixing tool such as a screw, thereby further multiplexing the lead frame constituting the heat radiating board and the terminals composed of a part of the lead frame. (Or double).

  As a result, the resin structure firmly fixes a part or more of the base portion of the terminal in the circuit module (that is, the portion bent from the lead frame or the portion peeled off from the heat transfer layer) by the resin structure. As a result, the adhesive force between the heat transfer layer and the lead frame (physical, chemical, etc.) is between the base part of the heat dissipation board (especially the lead frame that becomes the base part of the terminal) and the heat transfer layer that fixes it. ) And the physical fixing force by the resin structure, the mechanical strength is increased by a double effect (or synergistic effect).

  Note that some of the manufacturing steps shown in the embodiment of the present invention are performed using a molding die or the like. However, the molding die is not shown unless it is necessary for explanation. Further, the drawings are schematic views and do not show the positional relations in terms of dimensions.

(Embodiment 1)
Hereinafter, as a first embodiment of the present invention, the structure of a resin structure used for increasing the strength of a heat dissipation substrate will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a circuit module reinforced with a resin structure. In FIG. 1, 101 is a metal plate, 102 is a heat transfer layer, 103 is a lead frame, 104 is a connection terminal, 105 is a fixing part, 106 is a bare chip, 107 is a bonding wire, 108 is a sealing material, 109 is a heat generating component, 110 is a circuit board, 111 is an electronic component, 112 is a hole, 113 is a resin structure, 114 is a screw, 115 is an arrow, 116 is a circuit module, 117 is a dotted line, and 118 is a housing. Here, the housing 118 includes a chassis and the like.

  In FIG. 1, a bare chip 106 is a semiconductor that generates heat, such as a transistor, FET, LED (light emitting diode), or semiconductor laser. These semiconductor components that generate heat are fixed as bare chips 106 on the lead frame 103 with solder or a heat transfer adhesive for die bonding. The heat generating component 109 is an electronic component that generates heat, such as a resin-molded transistor, FET, LED (light emitting diode), or semiconductor laser. In addition to the power semiconductor, the heat generating component 109 may be a large-sized transformer (such as a transformer or choke coil) (or a complicated shape or an irregular shape).

  As the sealing material 108, a commercially available product such as silicon, epoxy, or polyurethane can be used. After mounting a power semiconductor or the like on the lead frame 103 in the state of the bare chip 106 or the like, the reliability is improved by covering the lead frame 103 with a sealing material 108.

  The circuit board 110 is a glass epoxy board formed by impregnating glass fibers with an epoxy resin, for example, and a surface layer or an inner layer of which a copper foil pattern is formed is used (a copper foil pattern and an interlayer connection portion are illustrated). Absent). The electronic component 111 mounted on the circuit board 110 is, for example, a chip component or a control semiconductor element (for example, for signal processing or logic) and the like, and is a component that hardly generates heat or is easily affected by heat. It is. This is because the electronic component 111 can be separated from the bare chip 106 and the heat generating component 109 by a fixed distance by mounting the electronic component 111 on the circuit board 110 side instead of the heat dissipation board 120 side, thereby preventing the influence of heat.

  The bare chip 106 is fixed on the lead frame 103 by using solder or die bond adhesive as the fixing portion 105.

  As shown in FIG. 1, the resin structure 113 is fixed to the metal plate 101 with screws 114. Note that the lead frame 103 and the connection terminal 104 are reinforced by fixing the resin structure 113 to the housing 118 with screws 114.

  The lead frame 103 is fixed on the metal plate 101 by a sheet-like heat transfer layer 102. Further, a part of the lead frame 103 fixed to the sheet-like heat transfer layer 102 is peeled off from the heat transfer layer 102 and bent substantially vertically to form the connection terminal 104.

  The screw 114 includes fixing means (or a fixture) such as a bolt, a nut, a pin, and a metal fitting, and the screw 114 is a general term for these fixtures.

  A portion indicated by a dotted line 117 in FIG. 1 is a structure that reinforces a part of the lead frame 103 or (or more) the connection terminal 104 by fixing the resin structure 113 to the heat dissipation board with a fixing tool such as a screw 114. This structure portion will be described in more detail with reference to FIGS.

  2A and 2B are cross-sectional views showing an example of a structure part in which the resin structure 113 reinforces a part of the lead frame 103 and the connection terminal 104 or more.

  FIG. 2A is a cross-sectional view for explaining how the resin structure 113 reinforces the lead frame 103 and the base of the connection terminal 104 formed by bending a part of the lead frame 103.

  As shown in FIG. 2A, the resin structure 113 is fixed to the metal plate 101 and further to the housing 118 with screws 114 or the like, so that a fixing force as shown by an arrow 115a is generated in the lead frame 103. To do. As a result, even when a tensile force (arrow 115b) is generated, the fixing force indicated by arrow 115a cancels this tensile force (arrow 115b).

  FIG. 2B is a cross-sectional view of the screw 114 portion. As shown in FIG. 2B, the screw 114 and the lead frame 103 are insulated to prevent the influence of noise and the like due to the screw 114. A dotted line 117 in FIG. 2B indicates the position of the lead frame 103 hidden behind the heat transfer layer 102.

  As shown in FIG. 2 (B), the resin structure 113 is fixed to the metal plate 101 and further to the housing 118 with screws 114 or the like, so that a fixing force as shown by an arrow 115a is generated in the lead frame 103. To do. As a result, even when a tensile force (arrow 115b) is generated, the fixing force indicated by arrow 115a cancels this tensile force (arrow 115b).

  As described above, the metal plate 101, the heat transfer layer 102 including the sheet-like thermosetting resin and the inorganic filler provided thereon, the lead frame 103 embedded in the heat transfer layer 102, and the lead frame 103, a heat dissipation substrate having a connection terminal 104 formed by peeling a part of the heat transfer layer 102 from the heat transfer layer 102, and a resin structure 113 provided on the heat dissipation substrate, and the resin structure 113. A circuit module 116 comprising a fixing tool such as a screw 114 for fixing the lead frame 103 or the connection by fixing the resin structure 113 to the heat radiating substrate with the fixing tool such as the screw 114. By using the circuit module 116 having a structure that reinforces a part or more of the terminal 104, the strength of the circuit module 116 is increased. .

(Embodiment 2)
In the circuit module 116 described in the second embodiment, the circuit board 110 is fixed on the heat dissipation board via the resin structure 113. The heat dissipation board itself is a kind of circuit module 116. This is because the bare chip 106 and the heat generating component 109 are mounted to function as a circuit module.

  Next, an example of a method for manufacturing the circuit module 116 will be described with reference to FIGS.

  FIGS. 3A and 3B are cross-sectional views showing an example of a method for manufacturing a heat sink composed of the lead frame 103, the heat transfer layer 102, and the metal plate 101.

  In FIG. 3A, 119 is a heat transfer material, and the heat transfer material 119 is made of a thermosetting resin and an inorganic filler. Reference numeral 120 denotes a heat dissipation substrate. The heat dissipation substrate 120 includes at least a metal plate 101, a heat transfer layer 102 including a sheet-like thermoplastic resin and an inorganic filler provided thereon, and leads embedded in the heat transfer layer 102. The frame 103 and a connection terminal 104 formed by peeling a part of the lead frame 103 from the heat transfer layer 102 and bending it substantially vertically.

  First, as shown in FIG. 3A, a lead frame 103 processed into a predetermined shape is set on a metal plate 101 via a heat transfer material 119. Thereafter, as indicated by an arrow 115, the heat transfer material 119 is formed into a sheet shape by a press or a mold (both not shown), and at least a part of the lead frame 103 is embedded. Thereafter, the heat transfer material 119 is cured as shown in FIG.

  Next, as indicated by an arrow 115 in FIG. 3B, a part of the lead frame 103 is bent. At this time, a part of the lead frame 103 is peeled off from the heat transfer layer 102 to secure a creepage distance between the metal plate 101 and the heat dissipation substrate 120.

  FIG. 4 is a cross-sectional view for explaining how the resin structure 113 is attached to the heat dissipation substrate 120. In FIG. 4, a part of the lead frame 103 constituting the heat dissipation substrate 120 is peeled off from the heat transfer layer 102 to provide an opening 121. The opening 121 provides an effect of ensuring a creepage distance between the metal plate 101 and the lead frame 103 (or the connection terminal 104 which is a part of the lead frame 103).

  In FIG. 4, the resin structure 113 is provided with a hole 112 a for inserting the connection terminal 104 and a hole 112 b for inserting the screw 114. Note that the holes 112a and 112b are not necessarily provided adjacent to each other, and may be provided at optimal positions. Further, the holes 112a and 112b are not necessarily inserted with the screw 114 or the connection terminal 104. In this way, the number of holes 112a and 112b and the positions thereof are designed to have a margin. Thus, the cost of the resin structure 113 can be reduced by making one resin structure 113 correspond to a plurality of types of circuit modules 116.

  Note that an arrow 115 a in FIG. 4 shows a state in which a part of the lead frame 103 is bent substantially vertically to form the connection terminal 104. An arrow 115 b indicates the insertion direction of the screw 114 and the insertion direction of the connection terminal 104 into the resin structure 113.

  An arrow 115c in FIG. 4 indicates a step provided positively in part of the resin structure 113. By locally providing a step as indicated by an arrow 115 c in FIG. 4, the tightening force of the screw 114 is evenly applied to the resin structure 113. In order to make effective use of the tightening force, the position and shape of a step or the like (note that the step may be thin / thick on the walls of the holes 112a, 112b, etc. This is a similar effect on stress design. Is obtained). In designing such a step, etc. (the step includes the thickness of the resin structure 113 and the structure of the beam. This is because the same effect can be obtained in the stress design). Design optimization using simulation.

  FIG. 5 is a cross-sectional view for explaining how the strength of the lead frame 103, the connection terminal 104, and the like is increased by combining the resin structure 113 with the heat dissipation substrate 120 to form the circuit module 116. As shown in FIG. 5, by tightening a fixing tool such as a screw 114, a force indicated by an arrow 115a is generated in the resin structure 113, and a pulling force or the like of the connection terminal 104 indicated by an arrow 115b is canceled.

  In the first embodiment and the second embodiment, the lead frame 103 is mounted with the bare chip 106, and the bare chip 106 is surrounded by the heat dissipation substrate 120 and the resin structure 113 provided on the heat dissipation substrate 120. Among them, the reliability of the circuit module 116 that is resin-sealed by the sealing material 108 is increased.

  Note that the circuit module 116 has a structure portion for fixing the circuit module 116 to the housing 118 (note that the housing 118 includes a chassis or the like) by a fixing tool such as a screw 114 for fixing the resin structure 113. The strength of the circuit module 116 itself is increased.

  As described above, the step of fixing the lead frame 103 on the metal plate 101 with the heat transfer layer 102 containing the sheet-like thermosetting resin and the inorganic filler so as to expose a part of the lead frame 103, and the lead frame 103 Part of the connection terminal 104 is peeled off from the heat transfer layer 102 and bent substantially vertically to form the connection terminal 104, and a part of the connection terminal 104 (especially the vicinity of the root is protected. Note that the vicinity of the root is bent substantially vertically. The circuit module 116 having excellent durability and strength can be stably manufactured by the method of manufacturing the circuit module 116 having the step of attaching the resin structure 113 so as to protect the radius of the portion from the portion to be 10 mm or less.

(Embodiment 3)
In the third embodiment, a circuit module 116 combined with the circuit board 110 will be described with reference to FIGS.

  In the third embodiment, a metal plate 101, a heat transfer layer 102 including a sheet-like thermosetting resin and an inorganic filler provided on the metal plate 101, and a lead frame 103 embedded in the heat transfer layer 102 are provided. A heat dissipation board having a connection terminal 104 formed by peeling a part of the lead frame 103 from the heat transfer layer 102 and bending it substantially vertically, and a resin structure 113 provided on the heat dissipation board, A circuit module 116 including a fixing tool such as a screw 114 for fixing the resin structure 113 and a circuit board 110 installed substantially parallel to the heat dissipation board, wherein the resin structure is fixed by the fixing tool such as the screw 114. By fixing 113 to the heat radiating substrate, a structure part that reinforces a part or more of the lead frame 103 or (or more) the connection terminal 104 is provided. The circuit module 116 is described that.

  FIG. 6 is a cross-sectional view illustrating a state in which the heat dissipation board 120, the resin structure 113, and the circuit board 110 are integrated by a fixing tool such as a screw 114 to form a circuit module 116.

  In FIG. 6, a bare chip 106 and a heat generating component 109 are mounted on the heat dissipation substrate 120. The bare chip 106 is connected to each other by a bonding wire 107 or the like and covered with a sealing material 108. The bare chip 106 and the heat generating component 109 are mounted on the heat dissipation board 120 in FIG. 6 after mounting the circuit board 110 on the heat dissipation board 120 via the resin structure 113. This is because it cannot be done.

  An arrow 115 in FIG. 6 indicates that the screw 114 and the connection terminal 104 are inserted into the hole 112 formed in the resin structure 113. The screw 114 may be attached to the housing 118 via the heat dissipation substrate 120. By so doing, not only the heat dissipation substrate 120, the resin structure 113, and the circuit board 110 can be fixed, but also the entire circuit module 116 and the housing 118 can be fixed, thereby reducing costs and increasing strength. .

  In addition, as shown in FIG. 6, after mounting the bare chip 106 and the circuit module 116, it is desirable to protect them with a sealing material 108. As shown in FIG. 6, since the resin structure 113 is firmly fixed to the heat dissipation substrate 120 using screws 114 or the like, the resin structure 113 is formed into a frame shape, for example. Even if the sealing material 108 is injected into the portion surrounded by 113, the sealing material 108 does not flow out of the gap. As a result, the sealing material 108 having low viscosity and high fluidity can be selected, and bubbles (for example, air bubbles) hardly remain in the sealing material 108 even when the bare chip 106 or the like is sealed. , Increase its sealing performance.

  FIG. 7 is a cross-sectional view illustrating a state in which the heat dissipation substrate 120, the resin structure 113, and the circuit substrate 110 are integrated by a fixing tool such as a screw 114 to form a circuit module 116. The difference from FIG. 6 is that the sealing resin 108 is partially formed. By using the sealing resin 108 having a relatively high viscosity in this way, the vicinity of the bare chip 106 (including the bonding wire 107) is protected by the sealing resin 108.

  Thereafter, as shown by arrows 115a and 115b in FIG. 7, screws 114 and connection terminals 104 are inserted into the resin structure 113 and fixed. As a result, a circuit module 116 as shown in FIG. 1 is obtained.

  FIG. 8 is a cross-sectional view for explaining how the heat dissipation board 120, the resin structure 113, and the circuit board 110 are integrated with a fixing tool such as a screw 114 to form a circuit module 116 and then attached to the housing 118. It is.

  As shown in FIG. 8, the heat radiation board 120, the resin structure 113, and the circuit board 110 are integrated by using a screw 114, an adhesive or the like (not shown) in advance to create a circuit module 116. deep. Thereafter, the circuit module 116 is changed to a circuit module 116 as shown in FIG.

  Further, by inserting the connection terminal 104 into the hole 112 provided in the resin structure 113, even if the connection terminal 104 remains bent or distorted, the bending or distortion of the connection terminal 104 is corrected (or Effect). As a result, the insertability into the hole 112 formed in the circuit board 110 is improved.

  Furthermore, the metal plate 101 can be made thinner and lighter because the resin module 113 can be used to increase the strength of the circuit module 116 main body. Note that the resin structure 113 is made of a resin having high heat resistance, thereby increasing the reliability of the heat. The resin is used for moldability into a predetermined shape (including injection molding) and weight reduction, and the resin is cheaper in terms of workability and material cost than ceramics. .

  The resin structure 113 does not need to be made of a single resin, but can be increased in strength by combining it with a metal part or the like. Further, the resin structure 113 may be divided into a plurality of parts. Thus, a resin structure 113 composed of a plurality of parts is prepared, and these may be combined to form one resin structure 113. In this way, the resin structure 113 can be generalized.

  Furthermore, by devising how to attach the resin structure 113, in addition to the tensile strength of the lead frame 103 in the heat dissipation substrate 120, it is possible to increase the strength (or reinforcement) in terms of pressing strength, torsional strength, vibration resistance, and the like. . In addition, the filling rate of the inorganic filler and the like in the heat transfer layer 102 is increased by the amount of this reinforcing effect, and the heat dissipation performance of the heat dissipation substrate 16 is improved.

  In addition, the structure of the pressing part by the resin structure 113, how to attach it, etc. are designed in the optimal shape according to the use.

  The circuit board 110 may be a multilayer circuit board, and the hole 112 formed in the circuit board 110 may be a through hole (including through hole plating).

  A slight gap between the hole 112 provided in the circuit board 110 and the resin structure 113 inserted therebelow (desirably 0.3 mm or more. If it is less than 0.3 mm, the dimensional variation of the resin structure 113, It is desirable to provide a circuit board 110 that may be affected by distortion of the circuit board 110.

  This is because when the circuit board 110 and the connection terminal 104 are connected by solder (not shown), excess solder may sag or flow downward, and even in such a case, By forming a gap between the circuit board 110 and the resin structure 113, the flow of solder can be controlled and visual inspection can be performed.

(Embodiment 4)
Next, as Embodiment 4, members used for the heat dissipation substrate 120 and the like will be described.

  As the lead frame 103, it is desirable to use a member having high thermal conductivity such as copper or aluminum. The thickness of the lead frame 103 is desirably 0.2 mm or more (desirably 0.3 mm or more). When the thickness of the lead frame 103 is less than 0.2 mm, the strength of the connection terminal 104 decreases, and there is a possibility that the lead frame 103 is bent or deformed during the operation.

  The thickness of the lead frame 103 is desirably 10.0 mm or less (preferably 5.0 mm or less). When the thickness of the lead frame 103 exceeds 10.0 mm, there is a possibility of affecting the fine patterning of the connection terminals 104.

  In addition, even if a thick lead frame 103 (for example, 0.2 mm or more, desirably 0.3 mm or more) is used by embedding a part or more of the lead frame 103 in the heat transfer layer 102, the thickness is radiated. Since it does not appear as a step on the surface of the substrate 120, the printability of a solder resist (not shown) on the lead frame 103 is improved.

  Next, the heat transfer layer 102 will be described. The heat transfer layer 102 is made of, for example, a resin and a filler, so that the thermal conductivity can be increased. And the reliability is improved by using a thermosetting resin as resin.

  Here, as the inorganic filler, for example, it has a substantially spherical shape, and its diameter is suitably 0.1 μm or more and 100 μm or less (if it is less than 0.1 μm, it becomes difficult to disperse in the resin. The thickness of 102 increases and affects the thermal diffusivity). In this embodiment, the inorganic filler is a mixture of two types of alumina having an average particle diameter of 3 μm and an average particle diameter 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 thermal conductivity of these heat transfer layers 102 is about 5 W / (m · K).

  The inorganic filler is at least one selected from the group consisting of alumina, magnesium oxide, boron nitride, silicon oxide, silicon carbide, silicon nitride, and aluminum nitride, zinc oxide, silica, titanium oxide, tin oxide, and zircon silicate. It is desirable from the viewpoint of thermal conductivity and cost.

  In addition, when using a thermosetting resin, what contains at least 1 type of thermosetting resin chosen from the group of an epoxy resin, a phenol resin, cyanate resin, a polyimide resin, an aramid resin, and PEEK resin is desirable. This is because these resins are excellent in heat resistance and electrical insulation.

  On the other hand, in order to further improve the heat dissipation of the heat transfer layer 102, it is necessary to increase the content of the inorganic filler. As a result, the content of the thermosetting resin in the heat transfer layer 102 may be reduced. is there. And when the content rate of the thermosetting resin in the heat-transfer layer 102 is reduced, the adhesive force between the heat-transfer layer 102 and the lead frame 103 may fall. As a result, there is a possibility that the interface between the heat transfer layer 102 and the lead frame 103 in the heat dissipation substrate 120 is peeled off.

  In such a case, as shown in FIGS. 1 to 8, the lead frame 103 (particularly, the interface between the lead frame 103 and the heat transfer layer 102 near the base of the connection terminal 104) is firmly fixed with a screw 114 or the like. 113 is physically pressed against the heat transfer layer 102 side to increase the physical strength of the portion, and prevents the heat dissipation substrate 120 from peeling at the interface between the heat transfer layer 102 and the lead frame 103. To do. Alternatively, the thermal conductivity of the heat transfer layer 102 is increased accordingly.

  In addition, by using the resin structure 113 (further fixing the resin structure 113 with a screw 114 or the like), the entire heat dissipation board 120 or the circuit module 116 is structurally a kind of ramen structure (ramen is a frame in German). Meaning higher strength (including improved vibration resistance). Further, since the resin structure 113 can be easily replaced, repayment, maintenance, replacement, and the like are facilitated.

  Note that a part or more of the base of the connection terminal 104 is fixed to the heat transfer layer 102 by the resin structure 113. Here, the base of the connection terminal 104 is within a radius of 10 mm from a portion bent substantially perpendicularly from the lead frame 103. If this exceeds the radius of 10 mm, it is far from the root, and the pressing effect and fixing strength by the connection terminal 104 may be reduced. Further, by sharpening the tip of the connection terminal 104 (or forming a corner or a taper), the insertion property into the hole 112 formed in the resin structure 113 is improved.

  Further, by separating the bare chip 106 and the heat generating component 109 from the electronic component 111 and the circuit board 110 that control them by a certain distance, the thermal or electromagnetic influence (for example, noise) can be suppressed, and the degree of freedom in design can be reduced. Increase.

  As described above, the heat dissipation substrate according to the present invention, the vertical multiple substrate using the same, and the manufacturing method thereof can increase the strength of the heat dissipation substrate. Can be realized.

Sectional view of a circuit module reinforced with a resin structure (A) (B) is sectional drawing which shows an example of the structure part which a resin structure reinforces a part or more of a lead frame or a connection terminal (A) (B) is sectional drawing which shows an example of the manufacturing method of the heat sink which consists of a lead frame, a heat-transfer layer, and a metal plate together. Sectional drawing explaining how to attach the resin structure to the heat dissipation board Sectional drawing explaining how to increase the strength of lead frames, connection terminals, etc. by combining a resin structure with a heat dissipation board to make a circuit module Sectional drawing explaining a mode that a heat dissipation board, a resin structure, and a circuit board are integrated with fixing tools, such as a screw, to make a circuit module Sectional drawing explaining a mode that a heat dissipation board, a resin structure, and a circuit board are integrated by fixing tools, such as a screw, and a circuit module is carried out Sectional drawing explaining how a heat dissipation board, a resin structure, and a circuit board are integrated with a fixture such as a screw to form a circuit module and then attached to the housing (A) (B) is sectional drawing of the semiconductor module which is an example of the conventional heat sink. (A) and (B) are cross-sectional views of a semiconductor module in which a control circuit board is installed substantially in parallel on a power semiconductor mounted on a bare chip.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Metal plate 102 Heat transfer layer 103 Lead frame 104 Connection terminal 105 Fixing part 106 Bare chip 107 Bonding wire 108 Sealing material 109 Heating component 110 Circuit board 111 Electronic component 112 Hole 113 Resin structure 114 Screw 115 Arrow 116 Circuit module 117 Dotted line 118 Enclosure

Claims (5)

A metal plate, a heat transfer layer including a sheet-like thermosetting resin and an inorganic filler provided thereon, a lead frame embedded in the heat transfer layer, and a part of the lead frame from the heat transfer layer A heat dissipation board having a connection terminal that is peeled off and bent substantially vertically;
A resin structure provided on the heat dissipation substrate;
A fixture for fixing the resin structure;
A circuit module comprising:
A circuit module having a structure part that reinforces a part of the lead frame or the connection terminal by fixing the resin structure to the heat dissipation board by the fixing tool. A metal plate, a heat transfer layer including a sheet-like thermosetting resin and an inorganic filler provided thereon, a lead frame embedded in the heat transfer layer, and a part of the lead frame from the heat transfer layer A heat dissipation board having a connection terminal that is peeled off and bent substantially vertically;
A resin structure provided on the heat dissipation substrate;
A fixture for fixing the resin structure;
A circuit board installed substantially parallel to the heat dissipation board;
A circuit module comprising:
A circuit module having a structure part that reinforces a part of the lead frame or the connection terminal by fixing the resin structure to the heat dissipation board by the fixing tool. The lead frame is mounted with a bare chip,
The circuit module according to claim 1, wherein the bare chip is resin-sealed while surrounded by a heat dissipation substrate and a resin structure provided on the heat dissipation substrate. 3. The circuit module according to claim 1, further comprising: a structure unit that fixes the circuit module to the housing or the chassis by a fixing tool that fixes the resin structure. 4. Fixing on a metal plate with a heat transfer layer containing a sheet-like thermosetting resin and an inorganic filler so as to expose a part of the lead frame;
A step of peeling a part of the lead frame from the heat transfer layer and bending it substantially vertically to form a connection terminal;
Attaching a resin structure so as to protect a part of the connection terminal;
A method for manufacturing a circuit module.

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