JP2012079741A - Electronic control unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic control unit which effectively radiates heat of a semiconductor module mounted thereon with a simple structure.SOLUTION: A resin body 62 of a semiconductor module 6 is formed in a plate like shape so as to cover a semiconductor chip 61. In a metal plate 64, a surface 641 is exposed from a surface 621 of a resin body 62, and a surface 642 electrically connects with the semiconductor chip 61. The semiconductor module 6 is surface-mounted on a substrate 3 so that the surface 621 of the resin body 62 faces the substrate 3. A cover member 7 is provided so as to cover the semiconductor module 6 side of the substrate 3. The metal plate 64 has an extension part 66 which extends from the resin body 62 in a plate surface direction and is soldered to a second wiring pattern 5 on the substrate 3. The cover member 7 has a first protruding part 71 formed so as to protrude toward the extension part 66. A first heat conduction member 81 is provided to fill gaps among the extension part 66, the resin body 62, and the first protruding part 71.

Description

  The present invention relates to an electronic control unit, and more particularly to an electronic control unit applicable to an electric power steering system.

  In recent years, motor control of vehicles has progressed, and the number of motors and electronic control units that control them has been increasing. On the other hand, in order to provide a comfortable space for the user, attempts have been made to expand the vehicle interior space. Therefore, securing a space for arranging the motor and the electronic control unit is an issue, and miniaturization of the motor and the electronic control unit is important.

  For example, an electronic control unit used in an electric power steering system is disposed on the back side of an engine room or an instrument panel. However, since the electronic control unit used in the electric power steering system drives the motor with a large current (about 100 A), heat generation of the semiconductor module having a switching function increases. Therefore, in order to reduce the size of such an electronic control unit, a high heat dissipation structure is required.

  Patent Documents 1 and 2 disclose techniques for improving the heat dissipation of a semiconductor module by devising the structure of the semiconductor module or the electronic control unit. For example, in the semiconductor modules disclosed in Patent Documents 1 and 2, a heat sink (metal or insulating material) having a larger area than one surface of the resin body covering the semiconductor chip is attached to the resin body, and the semiconductor chip is formed by the heat sink. The heat dissipation is aimed at.

Japanese Utility Model Publication No. 58-187153 JP 2002-83912 A JP 2009-54701 A

  Patent Document 2 discloses a configuration in which a semiconductor module is disposed inside a box-shaped case, and the heat of the semiconductor module is radiated to the case side by filling grease around the semiconductor module. However, in this configuration, it is necessary to prepare a case and grease separately for each semiconductor module, and there is a concern that the member cost may increase especially when heat radiation of a plurality of semiconductor modules is intended.

  Further, Patent Documents 1 and 2 do not describe anything about the details of the relative size of the heat sink with respect to the resin body. Therefore, for example, when the extent of extension in the surface direction of the heat radiating plate with respect to the resin body (area ratio between the surface of the resin body and the surface of the heat radiating plate) is extremely small, the heat radiation effect is considered to be small. On the other hand, if the extent to which the heat sink extends in the surface direction with respect to the resin body is extremely large, the weight of the heat sink and the member cost increase, and the installation space for the semiconductor module and other electronic components on the board can be secured. May be difficult.

  In Patent Document 3, a cover member covering the semiconductor module side of the substrate is formed with a recess that is recessed so as to surround the semiconductor module corresponding to the shape of the outer edge of the semiconductor module, and a heat conductive material is provided between the recess and the semiconductor module. A configuration is disclosed in which the heat radiation of the semiconductor module to the cover member side is improved. However, in this electronic control unit, it is necessary to form a recess so as to surround the semiconductor module corresponding to the shape of the outer edge of the semiconductor module, which may increase the processing cost. Moreover, since the semiconductor module of patent document 3 does not have a heat sink like the semiconductor modules of patent documents 1 and 2, it is considered that the effect of heat radiation to the cover member side is low.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an electronic control unit that can effectively dissipate heat of a semiconductor module to be mounted with a simple configuration.

  The invention described in claim 1 includes a plate member, a substrate, a first wiring pattern, a second wiring pattern, a semiconductor module, a cover member, and a first heat conducting member. The resin substrate is installed on a metal plate member. The first wiring pattern and the second wiring pattern are provided on the surface of the substrate opposite to the plate member. The semiconductor module has a semiconductor chip, a resin body, a plurality of terminals, and a metal plate. The plate-like resin body is formed so as to cover the semiconductor chip having a switching function. The plurality of terminals are electrically connected to the semiconductor chip, protrude from the resin body, and are soldered to the first wiring pattern on the substrate. One surface of the metal plate is exposed from one surface of the resin body, and the other surface is electrically connected to the semiconductor chip. The semiconductor module is surface-mounted on the surface of the substrate opposite to the plate member so that one surface of the resin body faces the substrate. The cover member is provided so as to protect the semiconductor module by covering the semiconductor module side of the substrate.

  In the present invention, the metal plate has an extending portion that extends from the resin body in the plate surface direction and is soldered to the second wiring pattern on the substrate. Moreover, the cover member has the 1st convex part formed so that it may protrude toward the extension part of a metal plate. And the 1st heat conductive member is provided so that the clearance gap between the extending part of a metal plate and a resin body and the 1st convex part of a cover member may be filled. Thereby, the heat of the semiconductor chip that generates heat by the switching operation can be transmitted and radiated to the cover member side via the metal plate, the resin body, and the first heat conducting member. The heat of the semiconductor chip is also transmitted to the substrate side through the extended portion of the metal plate and the second wiring pattern, and is radiated.

  Thus, in this invention, the 1st convex part formed in a cover member is a comparatively simple shape, and it provides a metal plate by providing a 1st heat conductive member between a 1st convex part and an extension part. This heat can be effectively transferred to the cover member. Therefore, the heat of the semiconductor module can be effectively radiated with a simple configuration.

  Further, in the present invention, the heat of the semiconductor module can be effectively radiated from the cover member side, so that the specifications of the substrate can be reduced (such as making the wiring pattern thinner, reducing the substrate size). Therefore, it is possible to reduce the cost and size and weight of the electronic control unit.

  In the invention according to claim 2, the cover member has a first recess formed so as to be recessed corresponding to the shape of the first protrusion at a position corresponding to the first protrusion on the surface opposite to the substrate. Have. Thereby, even when providing a 1st convex part in a cover member, the increase in the volume of a cover member, a weight, and member cost can be suppressed. Further, in the case of the cover member having this configuration, it can be formed by a relatively simple method such as press working.

  According to a third aspect of the present invention, the second wiring pattern on the substrate is formed to extend so as to spread outward more than the outer edge of the extending portion of the metal plate. And the 1st heat conductive member is extended and formed so that the clearance gap between a 2nd wiring pattern and a 1st convex part may be filled up. Thereby, the heat transmitted from the extending part of the metal plate to the second wiring pattern on the substrate can be transmitted and radiated to the cover member side via the first heat conducting member. Therefore, the effect of radiating the heat of the semiconductor module can be further enhanced.

  In the invention according to claim 4, the cover member has the 2nd convex part formed so that it may protrude toward a plurality of terminals of a semiconductor module. And the 2nd heat conductive member provided so that the clearance gap between a some terminal and a resin body and a 2nd convex part may be further provided. Thereby, the heat of the semiconductor chip that generates heat by the switching operation can be transmitted and radiated to the cover member side via the plurality of terminals, the resin body, and the second heat conducting member. Therefore, the effect of radiating the heat of the semiconductor module can be further enhanced.

  In the invention according to claim 5, the cover member has a second recess formed to be recessed corresponding to the shape of the second protrusion at a position corresponding to the second protrusion on the surface opposite to the substrate. Have. Thereby, even when providing a 2nd convex part in a cover member, the increase in the volume of a cover member, weight, and member cost can be suppressed. Further, in the case of the cover member having this configuration, it can be formed by a relatively simple method such as press working.

  The invention according to claim 6 further includes a third heat conducting member provided so as to fill a gap between the other surface of the resin body and the cover member. Thereby, the heat of the semiconductor chip that generates heat by the switching operation can be transmitted and radiated to the cover member side via the resin body and the third heat conducting member. Therefore, the effect of radiating the heat of the semiconductor module can be further enhanced.

  Here, the area of the extended portion of one surface of the metal plate is Sm, the area of one surface of the resin body is Sr, and the metal plate and the resin body satisfy the relationship of Sm / Sr <0.5. In such a case, there is a concern that the effect of heat dissipation by the metal plate is reduced. On the other hand, when the metal plate and the resin body are formed so as to satisfy the relationship of 1.0 <Sm / Sr, there is a concern about an increase in the weight of the metal plate and the member cost, and installation of other electronic components on the substrate. There arises a problem that it is difficult to secure a space.

  Therefore, in the invention according to claim 7, when the area of the extending portion of one surface of the metal plate is Sm and the area of one surface of the resin body is Sr, the metal plate and the resin body are 0.5 It is formed so as to satisfy the relationship of ≦ Sm / Sr ≦ 1.0. By forming the metal plate and the resin body so as to satisfy the relationship of 0.5 ≦ Sm / Sr, the surface area and the volume (heat mass) of the metal plate (extension part) can be secured at a predetermined value or more. Thereby, the semiconductor module can effectively radiate the heat generated from the semiconductor chip via the metal plate. Further, by forming the metal plate and the resin body so as to satisfy the relationship of Sm / Sr ≦ 1.0, an increase in the weight of the metal plate and the member cost is suppressed, and an installation space for other electronic components on the substrate Can be easily secured.

  In the invention according to claim 8, the metal plate and the resin body are formed so as to satisfy the relationship of Sm / Sr = 0.75. As a result, it is possible to achieve both the effect of heat dissipation via the metal plate and the effect of suppressing an increase in weight and member cost, and to maximize each effect.

  In the invention according to claim 9, at least one of an insulating heat radiation sheet and heat radiation grease is provided between the plate member and the substrate. Thereby, the heat | fever of a semiconductor module can be effectively transmitted to the board member side via a board | substrate and an insulation thermal radiation sheet or thermal radiation grease. Therefore, the heat of the semiconductor module can be effectively radiated not only from the cover member but also from the plate member.

  In a tenth aspect of the present invention, the plate member has a protruding portion formed so as to protrude toward the portion of the substrate on which the semiconductor module is mounted. Thereby, a board member (projection part) can be made to adjoin to or contact easily a part in which a semiconductor module was mounted among substrates. Therefore, the heat of the semiconductor module can be effectively transmitted to the plate member side via the substrate. Therefore, the heat of the semiconductor module can be effectively radiated not only from the cover member but also from the plate member. Furthermore, since the heat mass of the plate member can be increased by the thickness of the protruding portion, the effect of radiating the heat of the semiconductor module can be further enhanced.

It is a figure which shows the electronic control unit by 1st Embodiment of this invention, Comprising: (A) is a figure which shows the state which removed the cover member and the 1st heat conductive member, (B) is the BB line of (A). Sectional drawing. Schematic which shows the state which applied the electronic control unit by 1st Embodiment of this invention to the electric power steering system. It is a figure which shows the principal part of the electronic control unit by 2nd Embodiment of this invention, Comprising: (A) is sectional drawing which shows a semiconductor module and its vicinity, (B) is a top view which shows a semiconductor module and its periphery. Sectional drawing which shows the semiconductor module of the electronic control unit by 3rd Embodiment of this invention, and its vicinity. Sectional drawing which shows the semiconductor module of the electronic control unit by 4th Embodiment of this invention, and its vicinity. Sectional drawing which shows the semiconductor module of the electronic control unit by 5th Embodiment of this invention, and its vicinity. Sectional drawing which shows the semiconductor module of the electronic control unit by 6th Embodiment of this invention, and its vicinity. It is a figure which shows the principal part of the electronic control unit by 7th Embodiment of this invention, Comprising: (A) is sectional drawing which shows a semiconductor module and its vicinity, (B) is a top view which shows a semiconductor module and its periphery. Sectional drawing which shows the semiconductor module of the electronic control unit by 8th Embodiment of this invention, and its vicinity. The top view which shows the semiconductor module of the electronic control unit by 9th Embodiment of this invention, and its periphery.

Hereinafter, an electronic control unit according to a plurality of embodiments of the present invention will be described with reference to the drawings. Note that, in a plurality of embodiments, substantially the same components are denoted by the same reference numerals, and description thereof is omitted.
(First embodiment)
An electronic control unit according to a first embodiment of the present invention is shown in FIG. As shown in FIG. 2, the electronic control unit 1 is used in an electric power steering system 100 for a vehicle, and drives and controls a motor 101 that generates steering assist force based on a steering torque signal and a vehicle speed signal. is there.

As shown in FIGS. 1A and 1B, the electronic control unit 1 includes a plate member 2, a substrate 3, a first wiring pattern 4, a second wiring pattern 5, a semiconductor module 6, a cover member 7, and a first heat. A conductive member 81 and the like are provided.
The plate member 2 is formed in a substantially rectangular plate shape using a metal such as aluminum (see FIG. 1A).
The substrate 3 is a printed wiring board such as FR-4 made of glass fiber and epoxy resin, for example. The substrate 3 is formed in a substantially rectangular shape like the plate member 2, and the outer shape is smaller than the plate member 2. The substrate 3 is fixed to the plate member 2 with screws 25 so that the plate surface thereof is substantially parallel to the plate surface of the plate member 2.

In the present embodiment, the first wiring pattern 4 includes first wiring patterns 41 and 42. The first wiring patterns 41 and 42 are formed of a metal thin film such as copper, for example, and are provided on the surface of the substrate 3 opposite to the plate member 2.
Similar to the first wiring patterns 41 and 42, the second wiring pattern 5 is formed of a metal thin film such as copper, and is provided on the surface of the substrate 3 opposite to the plate member 2.

The first wiring patterns 41 and 42 and the second wiring pattern 5 are formed on the surface of the substrate 3 by a method such as a subtractive method or an additive method.
A plurality of wiring patterns 11 as intermediate layers are provided inside the substrate 3. A wiring pattern 12 is provided on the surface of the substrate 3 on the plate member 2 side (see FIG. 1B).

As shown in FIG. 1B, the semiconductor module 6 includes a semiconductor chip 61, a resin body 62, a terminal 63, a metal plate 64, and the like.
The semiconductor chip 61 is a field effect transistor such as a MOSFET, for example. The semiconductor chip 61 allows or blocks the flow of current between the source and the drain by inputting a control signal to the gate. Thus, the semiconductor chip 61 has a switching function.

  The resin body 62 is formed in a plate shape with resin and covers the semiconductor chip 61. Thereby, the semiconductor chip 61 is protected from external impact, moisture, and the like. In the present embodiment, the resin body 62 is formed in a rectangular plate shape. Therefore, the resin body 62 has one surface 621, the other surface 622, and side surfaces (four) between the surface 621 and the surface 622.

The terminal 63 is made of metal. In the present embodiment, three terminals 63 (631 to 633) are provided (see FIG. 1A).
The terminal 631 is provided so that one end is electrically connected to the source of the semiconductor chip 61 and the other end protrudes from the side surface of the resin body 62. The terminal 631 is formed so that it protrudes from the side surface of the resin body 62 and then bends to the surface 621 side, and further, the distal end portion (the other end portion) is bent to the side opposite to the resin body 62.

One end of the terminal 632 is electrically connected to the drain of the semiconductor chip 61 via a metal plate 64 described later. The terminal 632 is provided so that the other end protrudes from the side surface of the resin body 62.
The terminal 633 is provided so that one end is electrically connected to the gate of the semiconductor chip 61 and the other end protrudes from the side surface of the resin body 62. Similarly to the terminal 631, the terminal 633 is formed such that it protrudes from the side surface of the resin body 62 and then bends to the surface 621 side, and further, the distal end portion (the other end portion) is bent to the opposite side to the resin body 62. ing.

  The metal plate 64 is formed in a plate shape with a metal such as aluminum. The metal plate 64 includes a main body portion 65 and an extension portion 66. The main body portion 65 and the extending portion 66 are connected to each other in the plate surface direction and are integrally formed (see FIG. 1B).

  The metal plate 64 is provided on the surface 621 side of the resin body 62 so that one surface 641 is positioned on the same plane as the surface 621 of the resin body 62. Here, the main body portion 65 of the metal plate 64 is covered with the resin body 62 except for the surface 641. That is, the main body 65 has a surface 641 exposed from the surface 621 of the resin body 62.

The extending portion 66 of the metal plate 64 is not covered with the resin body 62 and is formed to extend from the side surface of the resin body 62 in the plate surface direction. That is, the extending part 66 is a part of the metal plate 64 that is exposed and extended from the resin body 62.
The metal plate 64 (main body portion 65) has the other surface 642 electrically connected to the drain of the semiconductor chip 61.

  The tip end portion (the other end portion) of the terminal 631 of the semiconductor module 6 is soldered to the first wiring pattern 41 on the substrate 3. Further, the tip end portion (the other end portion) of the terminal 633 of the semiconductor module 6 is soldered to the first wiring pattern 42 on the substrate 3. Further, the extending portion 66 of the metal plate 64 of the semiconductor module 6 is soldered to the second wiring pattern 5 on the substrate 3. In this manner, the position of the semiconductor module 6 on the substrate 3 is stabilized by soldering a plurality of locations.

  As described above, in the present embodiment, the semiconductor module 6 is surface-mounted on the surface of the substrate 3 opposite to the plate member 2. That is, the semiconductor module 6 is an SMD type electronic component. Four semiconductor modules 6 are mounted on the electronic control unit 1.

  The cover member 7 is made of a metal such as aluminum or zinc. In the present embodiment, the cover member 7 is formed in a rectangular box shape with a bottom. The cover member 7 is attached to the plate member 2 such that the opening is in contact with the outer edge portion of the plate member 2. In this state, the substrate 3 is located inside the cover member 7. Therefore, the semiconductor module 6 mounted on the substrate 3 and an electronic component to be described later are protected from an external impact or the like by the cover member 7. That is, the cover member 7 is provided so as to protect the semiconductor module 6 by covering the semiconductor module 6 side of the substrate 3.

As shown in FIG. 1B, the cover member 7 has a first convex portion 71 formed so as to protrude toward the extending portion 66 of the metal plate 64 of the semiconductor module 6. Here, the first convex portion 71 is not in contact with the extending portion 66, and forms a predetermined gap with the extending portion 66.
In the present embodiment, the cover member 7 is formed so as to be recessed corresponding to the shape of the first protrusion 71 at a position corresponding to the first protrusion 71 on the surface opposite to the substrate 3. A recess 72 is provided.
In this embodiment, the 1st convex part 71 and the 1st recessed part 72 can be formed by press work, for example. Or after forming the 1st convex part 71 by die-casting, the method of forming the 1st recessed part 72 by cutting etc. is also considered.

  In the present embodiment, the first heat conducting member 81 is made of, for example, insulating heat dissipation grease. The heat dissipating grease is, for example, a gel-like grease having a small thermal resistance and using silicon as a base material. As shown in FIG. 1B, the first heat conducting member 81 has a gap between the extending portion 66 of the metal plate 64 and the resin body 62 of the semiconductor module 6 and the first convex portion 71 of the cover member 7. It is provided to fill.

Next, the electronic control unit 1 on which the semiconductor module 6 is mounted will be described.
As shown in FIG. 1A, on the substrate 3 of the electronic control unit 1, in addition to the semiconductor module 6, a microcomputer 13, a custom IC 14, three capacitors 15, a coil 16, relays 17 and 18, a shunt resistor 19, etc. The electronic parts are mounted.

  A connector 9 is provided on one of the four sides of the substrate 3. The connector 9 includes a PIG (power supply voltage) terminal 91, a GND (ground) terminal 92, a motor terminal 93, and the like (see FIG. 1A). A harness 102 is connected to the connector 9 (see FIG. 2). Conductive wire 103 of harness 102 electrically connects the positive side of battery 105 and PIG terminal 91. The conductive wire 104 of the harness 102 electrically connects the winding terminal of the motor 101 and the motor terminal 93.

  The PIG terminal 91, the GND terminal 92, and the motor terminal 93 of the connector 9, the semiconductor module 6, the microcomputer 13, the custom IC 14, the capacitor 15, the coil 16, the relays 17 and 18, and the shunt resistor 19 are the first wiring patterns 41 and 42. The second wiring pattern 5, the wiring pattern 11, and the wiring pattern 12 are electrically connected via the wiring pattern.

  Here, the first wiring pattern 41 is connected to the PIG terminal 91. That is, the terminal 631 (source) of the semiconductor module 6 is connected to the PIG terminal 91 via the first wiring pattern 41. The first wiring pattern 42 is connected to the custom IC 14. That is, the terminal 633 (gate) of the semiconductor module 6 is connected to the custom IC 14 via the first wiring pattern 42. Further, the second wiring pattern 5 is connected to the GND terminal 92 or the plate member 2. That is, the metal plate 64 (drain) is connected to the GND terminal 92 or the plate member 2 via the second wiring pattern 5.

  The microcomputer 13 controls the switching operation by the semiconductor chip 61 by transmitting a control signal to the terminals 633 (gates) of the plurality of semiconductor modules 6 via the custom IC 14. As a result, the current flowing through the motor terminal 93, that is, the winding of the motor 101 is controlled. As a result, the motor 101 rotates. Thus, the microcomputer 13 and the custom IC 14 control the rotational drive of the motor 101 by controlling the switching operation of the plurality of semiconductor modules 6.

  The capacitor 15 suppresses a surge voltage generated by the switching (on / off) operation of the semiconductor module 6. The coil 16 is a so-called choke coil and removes noise from the battery 105. The relay 17 allows or blocks current flow between the PIG terminal 91 and the coil 16, the capacitor 15, and the semiconductor module 6. The relay 18 allows or blocks the flow of current between the semiconductor module 6 and the motor terminal 93. The shunt resistor 19 detects the magnitude of the current flowing through the semiconductor module 6. Thereby, the microcomputer 13 and the custom IC 14 can control the rotational drive of the motor 101 with high accuracy based on the current value detected by the shunt resistor 19.

During the switching operation of the semiconductor module 6, a relatively large current flows through the semiconductor module 6 and the shunt resistor 19. Therefore, the semiconductor module 6 and the shunt resistor 19 generate heat and reach a relatively high temperature.
As shown in FIGS. 1 (A) and 1 (B), the plate member 2 has a protruding portion formed to protrude toward the substrate 3 in a portion corresponding to a region where the semiconductor module 6 and the shunt resistor 19 are arranged. 21. The protrusion 21 is formed in a substantially rectangular column shape in accordance with the shape (rectangle) of the region where the semiconductor module 6 and the shunt resistor 19 are disposed.

As shown in FIG. 1B, the metal plate 64 of the semiconductor module 6 is in contact with and soldered to the second wiring pattern 5 on the substrate 3. Thereby, the heat generated from the semiconductor chip 61 is effectively transmitted to the substrate 3 via the metal plate 64 and the second wiring pattern 5. An insulating heat radiation sheet 26 and heat radiation grease 27 are provided between the protruding portion 21 of the plate member 2 and the substrate 3. The insulating heat dissipation sheet 26 is an insulating sheet having a small thermal resistance including, for example, silicon. Similarly to the first heat conducting member 81, the heat dissipating grease 27 is a gel-like grease having, for example, silicon as a base material and a small thermal resistance. By filling the gap between the protrusion 21 and the substrate 3 with the insulating heat dissipation sheet 26 and the heat dissipation grease 27, the heat of the substrate 3 (semiconductor module 6) is effectively transmitted to the protrusion 21, and the heat is dissipated from the protrusion 21. can do.
Thus, the protrusion 21 serves as a heat sink. In the present embodiment, since the wiring patterns 11 and 12 are provided on the substrate 3, the heat of the semiconductor module 6 can be effectively transferred to the protruding portion 21.

  In the present embodiment, the first heat conducting member 81 (heat dissipating grease) is provided between the extending portion 66 and the resin body 62 of the metal plate 64 of the semiconductor module 6 and the first convex portion 71 of the cover member 7. Is provided. Thereby, the heat generated by the semiconductor chip 61 is effectively transmitted to the cover member 7 side via the metal plate 64 (extending portion 66), the resin body 62, and the first heat conducting member 81. As a result, the cover member 7 can be used as a heat radiating member, and the heat of the semiconductor module 6 can be effectively radiated.

  Since the terminals 631 and 633 of the semiconductor module 6 are soldered to the first wiring patterns 41 and 42 on the substrate 3, respectively, the heat generated by the semiconductor chip 61 is the terminals 631 and 633 and the first wiring pattern 41. , 42, and transmitted through the substrate 3 to the protruding portion 21 of the plate member 2.

  As described above, in the present embodiment, the metal plate 64 has the extending portion 66 that extends from the resin body 62 in the plate surface direction and is soldered to the second wiring pattern 5 on the substrate 3. The cover member 7 has a first convex portion 71 formed so as to protrude toward the extending portion 66 of the metal plate 64. And the 1st heat conductive member 81 is provided so that the clearance gap between the extending part 66 of the metal plate 64 and the resin body 62, and the 1st convex part 71 of the cover member 7 may be filled up. Thereby, the heat of the semiconductor chip 61 that generates heat by the switching operation can be transmitted and radiated to the cover member 7 side via the metal plate 64, the resin body 62, and the first heat conducting member 81. Further, the heat of the semiconductor chip 61 is also transmitted to the substrate 3 side through the extended portion 66 of the metal plate 64 and the second wiring pattern 5 to be radiated.

  Thus, in this embodiment, the 1st convex part 71 formed in the cover member 7 is a comparatively simple shape, and the 1st heat conductive member 81 is provided between the 1st convex part 71 and the extension part 66. FIG. By providing the heat, the heat of the metal plate 64 can be effectively transmitted to the cover member 7. Therefore, the heat of the semiconductor module 6 can be effectively radiated with a simple configuration.

  Further, in the present embodiment, since the heat of the semiconductor module 6 can be effectively radiated from the cover member 7 side, it is possible to reduce the specifications of the substrate 3 (thinning of the wiring pattern, reduction of the substrate size, etc.). it can. Accordingly, the electronic control unit 1 can be reduced in cost and size and weight.

  In the present embodiment, the cover member 7 is formed so as to be recessed corresponding to the shape of the first protrusion 71 at a position corresponding to the first protrusion 71 on the surface opposite to the substrate 3. A recess 72 is provided. Thereby, even when providing the 1st convex part 71 in the cover member 7, the increase in the volume of the cover member 7, a weight, and member cost can be suppressed. In the case of the cover member 7 having this configuration, it can be formed by a relatively simple method such as press working.

  Moreover, in this embodiment, the plate member 2 has the protrusion part 21 formed so that it may protrude toward the part in which the semiconductor module 6 of the board | substrate 3 was mounted. Thereby, the board member 2 (projection part 21) can be made to adjoin easily to the part in which the semiconductor module 6 was mounted among the board | substrates 3. FIG. Further, an insulating heat radiating sheet 26 and a heat radiating grease 27 are provided between the plate member 2 (projecting portion 21) and the substrate 3. With this configuration, the heat of the semiconductor module 6 can be effectively transferred to the plate member 2 side via the substrate 3. Therefore, the heat of the semiconductor module 6 can be effectively radiated not only from the cover member 7 but also from the plate member 2. Furthermore, since the heat mass of the plate member 2 can be increased by the thickness of the protruding portion 21, the effect of radiating the heat of the semiconductor module 6 can be further enhanced.

(Second Embodiment)
A part of the electronic control unit according to the second embodiment of the present invention is shown in FIG. The second embodiment differs from the first embodiment in the size of the extending portion of the metal plate and the first convex portion of the cover member.

  As shown in FIGS. 3A and 3B, in the second embodiment, the amount of extension of the metal plate 64 from the resin body 62, that is, the size of the extension portion 66 is different from that of the first embodiment. In comparison, it is formed larger. Of the one surface 641 of the metal plate 64, the area of the extending portion 66 is Sm (the area of the region indicated by the hatched grid in FIG. 3B), and the area of the one surface 621 of the resin body 62 is Sr (FIG. 3 (B), the metal plate 64 and the resin body 62 are formed so as to satisfy the relationship of 0.5 ≦ Sm / Sr ≦ 1.0. Here, it is preferable that the metal plate 64 and the resin body 62 are formed so as to satisfy the relationship of Sm / Sr = 0.75.

In the present embodiment, the first convex portion 71 of the cover member 7 is formed larger than the first embodiment so as to correspond to the shape and size of the extending portion 66. And the 1st heat conductive member 81 is provided so that the clearance gap between the extension part 66 of the metal plate 64 and the resin body 62, and the 1st convex part 71 of the cover member 7 may be filled similarly to 1st Embodiment. It has been.
The second embodiment is the same as the first embodiment except for the points (configurations) described above.

  As described above, in the present embodiment, the metal plate 64 and the resin body 62 are formed so as to satisfy the relationship of 0.5 ≦ Sm / Sr ≦ 1.0. By forming the metal plate 64 and the resin body 62 so as to satisfy the relationship of 0.5 ≦ Sm / Sr, it is possible to secure the surface area and volume (heat mass) of the metal plate 64 (extension part 66) at a predetermined value or more. it can. Thereby, the semiconductor module 6 can effectively radiate the heat generated by the semiconductor chip 61 via the metal plate 64. Further, by forming the metal plate 64 and the resin body 62 so as to satisfy the relationship of Sm / Sr ≦ 1.0, an increase in the weight and member cost of the metal plate 64 can be suppressed, and other electronic components on the substrate 3 can be suppressed. Etc. can be easily secured. Here, when the metal plate 64 and the resin body 62 are formed so as to satisfy the relationship of Sm / Sr = 0.75, the effect of heat dissipation via the metal plate 64 and the effect of suppressing the increase in weight and member cost are obtained. In addition to being able to achieve both, each effect can be maximized.

(Third embodiment)
A part of the electronic control unit according to the third embodiment of the present invention is shown in FIG. The third embodiment differs from the second embodiment in the shape of the cover member near the first convex portion.

In the third embodiment, the cover member 7 does not have a configuration corresponding to the first recess 72 shown in the second embodiment. That is, the surface of the cover member 7 opposite to the first convex portion 71 is formed in a flat shape. The cover member 7 of the third embodiment can be formed by die casting, for example.
The third embodiment is the same as the second embodiment except for the points (configurations) described above.

  As described above, in the present embodiment, the cover member 7 does not have a configuration corresponding to the first recess 72 shown in the second embodiment. Therefore, compared with the second embodiment, although the weight and member cost of the cover member 7 are increased, the volume (heat mass) of the cover member 7 (first convex portion 71) is increased, and therefore the first convex portion 71 is routed. The effect of heat radiation from the cover member 7 can be further enhanced.

(Fourth embodiment)
A part of the electronic control unit according to the fourth embodiment of the present invention is shown in FIG. The fourth embodiment differs from the second embodiment in the shape of the cover member.

In the fourth embodiment, the cover member 7 has a second convex portion 73 formed so as to protrude toward the terminals 631 and 633 of the semiconductor module 6. Here, the second convex portion 73 is not in contact with the terminals 631 and 633, and a predetermined gap is formed between the second convex portion 73 and the terminals 631 and 633.
In the present embodiment, the cover member 7 is formed so as to be recessed corresponding to the shape of the second protrusion 73 at a position corresponding to the second protrusion 73 on the surface opposite to the substrate 3. A recess 74 is provided.

  In this embodiment, the 2nd convex part 73 and the 2nd recessed part 74 can be formed by press work, for example. Or after forming the 2nd convex part 73 by die-casting, the method of forming the 2nd recessed part 74 by cutting etc. is also considered.

The present embodiment further includes terminals 631, 632, 633 and a second heat conducting member 82 provided so as to fill the gaps between the resin body 62 and the second convex portion 73. Similar to the first heat conducting member 81, the second heat conducting member 82 is a gel-like insulating grease having a low thermal resistance, for example, using silicon as a base material.
The fourth embodiment is the same as the second embodiment except for the points (configurations) described above.

  As described above, in the present embodiment, the cover member 7 has the second convex portion 73, and the second heat conducting member 82 is provided between the second convex portion 73 and the terminals 631, 632, and 633. ing. Thereby, the heat of the semiconductor chip 61 that generates heat by the switching operation can be transmitted and radiated to the cover member 7 side via the terminals 631, 632, 633, the resin body 62, and the second heat conducting member 82. Therefore, compared with the second embodiment, the effect of radiating the heat of the semiconductor module 6 can be further enhanced.

(Fifth embodiment)
A part of the electronic control unit according to the fifth embodiment of the present invention is shown in FIG. The fifth embodiment differs from the fourth embodiment in that there is one more component.

The fifth embodiment further includes a third heat conducting member 83 provided so as to fill a gap between the other surface 622 of the resin body 62 of the semiconductor module 6 and the cover member 7. The third heat conducting member 83 is a gel-like insulating grease with a low thermal resistance, for example, based on silicon, like the first heat conducting member 81 and the second heat conducting member 82. In the present embodiment, the first heat conducting member 81, the second heat conducting member 82, and the third heat conducting member 83 are provided so as to be integrated. Therefore, the cover member 7 side of the semiconductor module 6 is covered with the first heat conductive member 81, the second heat conductive member 82, and the third heat conductive member 83.
The fifth embodiment is the same as the fourth embodiment except for the points (configurations) described above.

  As described above, in the present embodiment, the third heat conducting member 83 is provided between the other surface 622 of the resin body 62 of the semiconductor module 6 and the cover member 7. Thereby, the heat of the semiconductor chip 61 that generates heat by the switching operation can be transmitted and radiated to the cover member 7 via the resin body 62 and the third heat conducting member 83. Therefore, compared with the fourth embodiment, the effect of radiating the heat of the semiconductor module 6 can be further enhanced.

(Sixth embodiment)
A part of the electronic control unit according to the sixth embodiment of the present invention is shown in FIG. The sixth embodiment is different from the fifth embodiment in the shape in the vicinity of the first convex portion and the shape in the vicinity of the second convex portion of the cover member.

In the sixth embodiment, the cover member 7 does not have a configuration corresponding to the second recess 74 shown in the fifth embodiment. That is, the surface of the cover member 7 opposite to the second convex portion 73 is formed in a flat shape. Further, the cover member 7 does not have a configuration corresponding to the first concave portion 72, and the surface of the cover member 7 opposite to the first convex portion 71 is formed in a flat shape. The cover member 7 of the sixth embodiment can be formed by, for example, die casting.
The sixth embodiment is the same as the fifth embodiment except for the points (configurations) described above.

  As described above, in the present embodiment, the cover member 7 does not have a configuration corresponding to the first recess 72 and the second recess 74 shown in the fifth embodiment. Therefore, compared with the fifth embodiment, although the weight and member cost of the cover member 7 are increased, the volume (heat mass) of the cover member 7 (first convex portion 71, second convex portion 73) is increased. The effect of heat dissipation from the cover member 7 via the convex portion 71 and the second convex portion 73 can be further enhanced.

(Seventh embodiment)
A part of the electronic control unit according to the seventh embodiment of the present invention is shown in FIG. The seventh embodiment differs from the second embodiment in the size of the second wiring pattern on the substrate and the first convex portion of the cover member.

As shown in FIGS. 8A and 8B, in the seventh embodiment, the second wiring pattern 5 on the substrate 3 extends so as to expand outward more than the outer edge of the extending portion 66 of the metal plate 64. Is formed.
In the present embodiment, the first convex portion 71 of the cover member 7 is formed larger than the second embodiment so as to correspond to the shape and size of the second wiring pattern 5.
Further, the first heat conducting member 81 is formed to extend so as to fill the gap between the second wiring pattern 5 and the first convex portion 71 (see FIGS. 8A and 8B).
The seventh embodiment is the same as the second embodiment except for the points (configurations) described above.

  As described above, in the present embodiment, the second wiring pattern 5 on the substrate 3 is formed to extend so as to expand outward more than the outer edge of the extending portion 66 of the metal plate 64. The first heat conducting member 81 is formed so as to fill the gap between the second wiring pattern 5 and the first convex portion 71. Thereby, the heat transmitted from the extending portion 66 of the metal plate 64 to the second wiring pattern 5 on the substrate 3 can be transmitted and radiated to the cover member 7 side via the first heat conducting member 81. Therefore, the effect of radiating the heat of the semiconductor module 6 can be further enhanced.

(Eighth embodiment)
FIG. 9 shows a part of an electronic control unit according to the eighth embodiment of the present invention. The eighth embodiment differs from the seventh embodiment in the shape of the cover member near the first convex portion.

In the eighth embodiment, the cover member 7 does not have a configuration corresponding to the first recess 72 shown in the seventh embodiment. That is, the surface of the cover member 7 opposite to the first convex portion 71 is formed in a flat shape.
The eighth embodiment is the same as the seventh embodiment except for the points (configurations) described above.

  As described above, in this embodiment, the cover member 7 does not have a configuration corresponding to the first recess 72 shown in the seventh embodiment. Therefore, although the weight and member cost of the cover member 7 are increased as compared with the seventh embodiment, the volume (heat mass) of the cover member 7 (first convex portion 71) is increased, so that the first convex portion 71 is routed. The effect of heat radiation from the cover member 7 can be further enhanced.

(Ninth embodiment)
A part of the electronic control unit according to the ninth embodiment of the present invention is shown in FIG. The ninth embodiment differs from the seventh embodiment in the shape of the second wiring pattern on the substrate.

As shown in FIG. 10, in the ninth embodiment, the second wiring pattern 5 on the substrate 3 includes a pattern 51 and a pattern 52. The pattern 51 is formed in the same size and shape (rectangular shape) as the second wiring pattern 5 shown in the second embodiment, and is in contact with the metal plate 64 of the semiconductor module 6. The pattern 52 is formed in a U shape so as to surround the three sides of the pattern 51. Thereby, a U-shaped gap C is formed between the pattern 51 and the pattern 52. The gap C can be formed, for example, by forming the second wiring pattern 5 after providing a U-shaped resist on the substrate 3. The shape of the outer edge of the pattern 52 substantially matches the outer edge of the second wiring pattern 5 shown in the seventh embodiment. The first heat conducting member 81 is formed to extend so as to fill the gap between the second wiring pattern 5 (pattern 51 and pattern 52) and the first convex portion 71. The ninth embodiment is the point described above ( The configuration is the same as in the seventh embodiment except for the configuration.

  In the present embodiment, when the extending portion 66 of the metal plate 64 is soldered to the second wiring pattern 5, for example, a method of performing soldering by placing the solder and the extending portion 66 on the pattern 51 and melting the solder is adopted. can do. In the present embodiment, since a U-shaped gap is formed between the pattern 51 and the pattern 52, it is suppressed that molten solder flows (moves) from the pattern 51 to the pattern 52 when performing soldering. Is done. For this reason, it is possible to suppress a positional shift when the semiconductor module 6 is mounted on the substrate 3, and it is easy to automate soldering by a robot or an apparatus.

(Other embodiments)
In the above-mentioned embodiment, the example which forms a 1st heat conductive member, a 2nd heat conductive member, and a 3rd heat conductive member with thermal radiation grease was shown. On the other hand, in another embodiment of the present invention, the first heat conducting member, the second heat conducting member, or the third heat conducting member is formed by an insulating sheet (insulating heat radiating sheet) having a low thermal resistance, including, for example, silicon. May be.
In another embodiment of the present invention, if the metal plate of the semiconductor module is used as a ground (drain) terminal, the first convex portion of the cover member and the extending portion of the metal plate are in contact with each other. Also good.

  In the above-mentioned embodiment, the example which provides an insulation heat radiation sheet and heat radiation grease between the protrusion part of the board member and the board | substrate was shown. On the other hand, in other embodiment of this invention, the arrangement | positioning order of the insulation thermal radiation sheet and thermal radiation grease provided between a board member and a board | substrate may be what. Moreover, it is good also as arrange | positioning only any one of an insulation thermal radiation sheet and thermal radiation grease between a board member and a board | substrate. Furthermore, in the case where the plate member and the substrate can be brought into close contact with each other, the insulating heat dissipation sheet or the heat dissipation grease may not be provided between the plate member and the substrate.

  Moreover, in other embodiment of this invention, the board member does not need to have a protrusion part. Further, the plate member and the substrate may be provided in a state in which a predetermined clearance is formed without contact with each other or without an insulating heat radiating sheet or heat radiating grease interposed therebetween.

Moreover, in other embodiment of this invention, as long as there is no obstruction factor, you may implement in any combination of the above-mentioned several embodiment.
The electronic control unit according to the present invention is not limited to an electric power steering system, and may be used to control the rotational drive of a motor of another system.
Thus, the present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist thereof.

DESCRIPTION OF SYMBOLS 1 ... Electronic control unit 2 ... Plate member 3 ... Board | substrate 4, 41, 42 ... 1st wiring pattern 5 ...... 2nd wiring pattern 6 ... Semiconductor module 61 ... Semiconductor chip 62 ... Resin bodies 63, 631, 632, 633 ... Terminal 64 ... Metal plate 66 ... Extension part 7 ... Cover member 71 ... First convex part 81... First heat conducting member

Claims (10)

A metal plate member;
A resin substrate installed on the plate member;
A first wiring pattern and a second wiring pattern provided on a surface of the substrate opposite to the plate member;
A semiconductor chip having a switching function, a plate-shaped resin body formed so as to cover the semiconductor chip, and a plurality of terminals electrically connected to the semiconductor chip and protruding from the resin body and soldered to the first wiring pattern And one surface is exposed from one surface of the resin body, and the other surface has a metal plate electrically connected to the semiconductor chip, and the one surface of the resin body faces the substrate. A semiconductor module that is surface-mounted on the surface of the substrate opposite to the plate member;
A metal cover member provided so as to protect the semiconductor module by covering the semiconductor module side of the substrate;
The metal plate has an extending portion that extends in the plate surface direction from the resin body and is soldered to the second wiring pattern,
The cover member has a first convex portion formed so as to protrude toward the extending portion,
The electronic control unit further comprising a first heat conducting member provided so as to fill a gap between the extending portion and the resin body and the first convex portion.   The cover member has a first recess formed to be recessed corresponding to the shape of the first protrusion at a position corresponding to the first protrusion on the surface opposite to the substrate. The electronic control unit according to claim 1. The second wiring pattern is formed so as to extend to the outside larger than the outer edge of the extension part,
3. The electronic control unit according to claim 1, wherein the first heat conducting member extends to fill a gap between the second wiring pattern and the first convex portion. The cover member has a second protrusion formed to protrude toward the plurality of terminals,
4. The apparatus according to claim 1, further comprising a second heat conducting member provided so as to fill a gap between the plurality of terminals and the resin body and the second convex portion. Electronic control unit as described.   The cover member has a second recess formed to be recessed corresponding to the shape of the second protrusion at a position corresponding to the second protrusion on a surface opposite to the substrate. The electronic control unit according to claim 4.   6. The electron according to claim 1, further comprising a third heat conducting member provided so as to fill a gap between the other surface of the resin body and the cover member. Controller unit. When the area of the extending portion of one surface of the metal plate is Sm and the area of one surface of the resin body is Sr,
The electronic control unit according to claim 1, wherein the metal plate and the resin body are formed so as to satisfy a relationship of 0.5 ≦ Sm / Sr ≦ 1.0. .   The electronic control unit according to claim 7, wherein the metal plate and the resin body are formed so as to satisfy a relationship of Sm / Sr = 0.75.   The electronic control unit according to claim 1, further comprising at least one of an insulating heat radiation sheet and heat radiation grease between the plate member and the substrate.   The electronic control unit according to claim 1, wherein the plate member has a protruding portion formed to protrude toward a portion of the substrate on which the semiconductor module is mounted. .

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