JP2020155502A - Substrate module - Google Patents

Abstract

To provide a substrate module with improved heat dissipation effect.SOLUTION: A substrate module 1 includes: a substrate on one surface side of which a component is mounted; and a heat radiating member 3. The heat radiating member 3 includes: a rectangular body 31 having a flat connection portion that is thermally connected corresponding to the component on one surface side of the substrate; a first fixed portion 33 provided on both end sides in a longitudinal direction of the rectangular body 31 and fastened to the substrate; and a to-be-connected portion 34, provided on an end side of the rectangular body 31 in a lateral direction and mounted on the substrate, electrically connected to a conductive member 23 conducting with a grounding electric circuit.SELECTED DRAWING: Figure 3

Description

The present invention relates to a substrate module.

Conventionally, a method of cooling by a heat sink has been proposed as a method of cooling a heat source such as a semiconductor component mounted on a substrate. For example, Patent Document 1 discloses a power module including a heat sink in contact with a non-electrode surface of a horizontal semiconductor chip. The heat sink is made of copper and is formed in a rectangular shape larger than a horizontal semiconductor chip. Further, the heat sink is bonded to the non-electrode surface of the horizontal semiconductor chip via a heat conductive bonding member, and is thermally connected.

JP-A-2018-125460

However, when the heat sink is enlarged, it is assumed that noise is received from mounting components, external radio waves, etc., and the noise is propagated to the electric circuit on the circuit. On the other hand, if the heat sink is made smaller, the heat source may not be sufficiently cooled.

In view of the above points, it is an object of the present invention to provide a substrate module having an improved heat dissipation effect.

The substrate module of the present invention has a rectangular shape in which a substrate on which a component is mounted on one surface side and a connection flat portion corresponding to the component and thermally connected are formed on the one surface side of the substrate. The main body, the first fixed portion provided on both ends in the longitudinal direction of the rectangular main body and fastened to the substrate, and the end side of the rectangular main body in the lateral direction are provided. It is characterized by including a heat-dissipating member including a connected portion mounted on the substrate and electrically connected to a conductive member that conducts with the grounding electric circuit.

According to the present invention, it is possible to provide a substrate module having an improved heat dissipation effect.

It is a perspective view seen from the front side of the substrate module which concerns on embodiment of this invention. It is a perspective view seen from the back side of the substrate module which concerns on embodiment of this invention. It is a III-III sectional view of the substrate module of FIG. 1 which concerns on embodiment of this invention. It is an IV-IV sectional view of the substrate module of FIG. 1 which concerns on embodiment of this invention. It is an enlarged view around the conduction member corresponding to the cross-sectional position of III-III which showed the modification of the conduction member which concerns on embodiment of this invention, (a) shows modification 1 and (b) shows modification 2. Shown.

Hereinafter, modes for carrying out the present invention will be described. 1 and 2 are a perspective view seen from the front side and a perspective view seen from the back side of the substrate module 1 of the present embodiment, respectively. The board module 1 includes a circuit board 2 and a heat radiating member 3 fixed on the circuit board 2.

The circuit board 2 is formed in the shape of a rectangular plate as a whole. The circuit board 2 is formed as, for example, a double-sided mounting board, and electronic components of various sizes depending on the purpose of the circuit are placed on the first surface 2a side on which the heat radiation member 3 is arranged and on the second surface 2b side opposite to the first surface 2a. Is implemented. The circuit board 2 may be formed as a multilayer board.

An electronic component 21 which is a main heat source component is mounted on the first surface 2a side of the circuit board 2 of the present embodiment (see also the cross-sectional views of FIGS. 3 and 4). The electronic component 21 can be, for example, a processing unit such as a CPU or DSP, and is formed as a substantially rectangular flat plate as a whole. The electronic component 21 is electrically connected to the electric circuit board 2 by, for example, a plurality of wire terminals extending laterally from the outer peripheral side of the electronic component 21. Further, on the first surface 2a side of the circuit board 2, a substantially rectangular parallelepiped electronic component 22 formed higher than the electronic component 21 and a conductive member 23 are mounted.

The conduction member 23 of the present embodiment is an on-board clip for EMI (ElectroMagnetic Interference) countermeasures short-circuited with a grounding electric circuit formed in the circuit board 2, that is, a grounding point (GND point). Is. As shown in FIG. 3 and the like, the conductive member 23 can be formed by bending a conductive flat plate member such as metal. The conductive member 23 is formed into a plate-shaped fixing portion 231 fixed to the circuit board 2 so as to substantially abut with the first surface 2a of the circuit board 2, and bifurcated so as to be elastic from both end sides of the fixing portion 231. It has a plate-shaped connecting portion 232. On the tip end side of both elastic connecting portions 232, a contact portion 232a that is bent inward from each other and extends toward the circuit board 2 side is formed. The tip end side of the contact portion 232a is slightly separated from the base end portion side of the connection portion 232. The abutting portion 232a is bent so that the facing surfaces protrude from each other so that a part thereof is narrow. A plurality of conductive members 23 of the present embodiment are arranged on both side ends of the circuit board 2 sandwiching the electronic component 21 in a plan view of the circuit board 2 (see FIGS. 1 and 2). Although not shown, various electronic components, terminals, fastening members, and the like can be mounted and arranged on the circuit board 2.

The heat radiating member 3 is formed of a metal having thermal conductivity and conductivity. The heat radiating member 3 includes a main body 31 formed in an elongated rectangular flat plate shape, a recess 32 which is a flat connection portion thermally connected to the electronic component 21, and a first fixed portion 33 fixed to the circuit board 2. And a connected portion 34 which is sandwiched between the conductive members 23 and electrically connected. The main body 31 is arranged so as to be substantially parallel to the circuit board 2.

The recess 32 is formed so as to be recessed from the main body 31 in a substantially long rectangular shape by drawing or the like. The bottom plate portion 321 of the recess 32 is formed in a rectangular flat plate shape (see also FIG. 4). The bottom plate portion 321 and the main body portion 31 are formed to have substantially the same thickness. Further, the elongated direction of the recess 32 is formed so as to substantially coincide with the elongated direction of the main body 31. As shown in FIGS. 3 and 4, the heat conductive member 4 is arranged between the electronic component 21 and the lower surface of the recess 32. As the heat conductive member 4, for example, a rectangular flat plate-shaped sheet member having flexibility and heat conductivity such as putty-shaped sircon (registered trademark) formed of a silicone rubber product can be used. The heat conductive member 4 is closely pressed between the recess 32 and the electronic component 21 by, for example, about 20%. Therefore, the recess 32 is thermally connected to the electronic component 21 via the heat conductive member 4. The heat generated in the electronic component 21 is conducted to the main body 31 via the heat conductive member 4 and the recess 32. The heat transferred to the main body 31 is dissipated through the air in contact with the main body 31.

The recess 32 is formed wider than the electronic component 21 and the heat conductive member 4 in the longitudinal direction of FIG. 3 and the lateral direction of FIG. Further, the heat conductive member 4 is formed wider than the electronic component 21 in the longitudinal direction of FIG. 3 and the lateral direction of FIG.

The first fixed portion 33 is provided at two locations on both side ends in the longitudinal direction of the main body portion 31 sandwiching the recess 32 in a plan view of the heat radiating member 3. Therefore, the first fixed portion 33 can stably fix the heat radiating member 3 to the circuit board 2. The first fixed portion 33 is substantially parallel to the hanging portion 331 extending from the main body portion 31 at a substantially right angle to the circuit board 2 side and from the hanging portion 331 to the first surface 2a of the circuit board 2. It has a contact portion 332 further extended to the surface. The contact portion 332 extends far away from the recess 32. A fixing hole 332a (first hole) penetrating in the plate thickness direction is formed in the contact portion 332 (see FIG. 3). The fixing holes 332a are arranged so as to correspond to the fixing holes 2c (second hole portion, second fixed portion) formed on the circuit board 2 side so as to penetrate in the plate thickness direction. Therefore, the screw 5 is inserted into the fixing holes 332a and 2c provided in the heat radiating member 3 and the circuit board 2, and the heat radiating member 3 is used together with the circuit board 2 in the housing of the device (not shown) by the first fixed portion 33. Can be tightened and fixed. By providing the first fixed portion 33 in the longitudinal direction of the main body portion 31, the heat radiating member 3 can prevent the circuit board 2 from swinging and can be stably fixed together with the circuit board 2.

As shown in FIG. 1, substantially rectangular notches 311 (311a, 311b) are formed at both side ends of the main body 31 in the lateral direction. From the inner edge of the notch 311, a long rectangular flat plate-shaped connected portion 34 extends so as to bend downward. The connected portions 34 are arranged at two locations on both side ends of the main body 31 in the lateral direction so as to sandwich the recess 32 in a plan view. In the heat radiating member 3 shown in FIG. 1, the two cutout portions 311a and 311b are formed so as to have different cutout depths. The notch depth of the notch 311 can be appropriately set according to the mounting position of the conductive member 23 connected to the connected portion 34.

As shown in FIG. 3, the connected portion 34 is sandwiched by the connecting portion 232 from both sides. Therefore, the heat radiating member 3 is supported so as not to swing in the lateral direction, which is the holding direction, with respect to the circuit board 2. Further, the connected portion 34 is electrically connected to the conductive member 23 connected to the grounding electric circuit of the circuit board 2. Therefore, it is possible to prevent the connected portion 34 from escaping the noise received from the electronic components on the circuit board 2 and the outside to the grounding electric circuit and propagating the noise into the circuit.

When the board module 1 is configured as described above, the internal space S1 on which electronic components and the like are mounted between the circuit board 2 and the heat radiating member 3 is formed along the outer peripheral side edge of the circuit board 2 and the heat radiating member 3. It will be connected to the external space through the opening S2 with the first fixed portion 33 and the connected portion 34. Therefore, by increasing the size and number of the first fixed portion 33 and the connected portion 34 to reduce the opening area of the opening S2, the electronic components and circuits mounted on the first surface 2a side in the internal space S1. However, it becomes easier to shield external noise, and the function as a shield can be improved. Further, by increasing the number of connection points between the connected portion 34 and the conductive member 23, the number of paths between the heat radiating member 3 and the grounding electric circuit in the circuit is increased, and the influence of noise can be reduced.

For example, a plurality of first fixed portions 33 and a plurality of connected portions 34 may be provided at three or more locations, respectively. As a result, the connection between the heat radiating member 3 and the circuit board 2 can be further stabilized, and the influence of noise on the electronic components and circuits arranged in the internal space S1 can be reduced. At this time, the connected portion and the conductive member 23 may be arranged at the side end portion in the longitudinal direction of the heat radiating member 3.

Further, since the heat radiating member 3 is provided with the recess 32, the thickness of the heat conductive member 4 can be reduced when the heat is connected to the electronic component 21, and the heat conduction in the heat conductive member 4 can be efficiently performed. By forming the heat conductive member 4 thinly, the cost of the heat conductive member 4 can also be reduced.

Further, in the outer peripheral portion of the electronic component 21 which is a heat source component, the internal space S1 between the circuit board 2 and the heat radiating member 3 can be widened, so that the electronic component having a height (for example, the electron shown in FIG. 4 or the like) can be widened. Even when the component 22) is arranged, it is possible to prevent the heat radiating member 3 from interfering with the component 2. Further, as an EMI countermeasure, since the heat radiating member 3 is electrically connected to the conductive member 23, the circuit formed on the circuit board 2 can be protected from noise. Therefore, it is easy to widen the plate surface of the heat radiating member 3, and the heat radiating effect of the heat source component can be improved.

Next, a modification 1 and a modification 2 of the conductive member 23 will be described with reference to FIG. 5 (a) according to the modified example 1 and FIG. 5 (b) according to the modified example 2 show the conduction corresponding to the cross-sectional position III-III of FIG. 3 when the conductive member 23A and the conductive member 23B are applied, respectively. It is an enlarged view around the members 23A and 23B.

The conductive member 23A shown in FIG. 5A has a fixing portion 231 fixed so as to substantially abut with the first surface 2a of the circuit board 2, and a fixed portion 231 extending upward from one end side of the fixing portion 231, and then the first It has a plate-shaped connecting portion 232A formed by bending substantially parallel to one surface 2a. The connecting portion 232A is formed in a cantilevered leaf spring shape. The tip of the connected portion 34 can come into contact with the upper surface of the connecting portion 232A while receiving an elastic force, and can be electrically connected to the conductive member 23A.

In the first modification, the configuration of the conductive member 23A can be simplified. Further, since the connecting portion 232A can be repelled toward the heat radiating member 3, the connecting portion 232A and the connected portion 34 can be easily connected.

The conductive member 23B shown in FIG. 5B has a fixing portion 231 fixed so as to substantially abut with the first surface 2a of the circuit board 2, and heat is dissipated after being extended upward from one end side of the fixing portion 231. It has a connecting portion 232B that is bent and formed so as to project toward the member 3. The connecting portion 232B is formed high so that the bent portion at the upper end of the connecting portion 232B can come into contact with the heat radiating member 3. Further, the connecting portion 232B can also be formed in the shape of a cantilever leaf spring.

In the second modification, since the circuit board 2 to the upper end of the connecting portion 232B are formed high, it is not necessary to provide the heat radiating member 3 with a connected portion extending so as to hang down from the main body portion 31. That is, the heat radiating member 3 can form the connected portion 34B with the conductive member 23B as a part of the main body portion 31. By using the conductive member 23B, the configuration of the heat radiating member 3 can be simplified.

The heat radiating member 3 shown above may be arranged on both sides of the first surface 2a side and the second surface 2b side with respect to the circuit board 2. The heat radiating member 3 arranged on the second surface 2b side can also radiate heat such as an electronic component which is a heat source component on the second surface 2b side via the heat conductive member 4. In this way, the heat source components formed on both sides can be cooled respectively.

In the heat radiating member 3 and the substrate module 1 described above in each embodiment, the main body 31 formed in a rectangular shape and the heat source component recessed with respect to the main body 31 and mounted on the circuit board 2 are thermally connected. A circuit is provided on the recess 32, the first fixed portion 33 provided on both side ends in the longitudinal direction of the main body and fixed to the circuit board 2, and the side end side in the lateral direction of the main body 31. The configuration includes a connected portion 34 mounted on the substrate 2 and electrically connected to the conductive member 23 connected to the grounding electric circuit. As a result, heat dissipation measures can be taken in the necessary area on the circuit board 2, and a wide space can be secured in the area where the heat dissipation measures are not necessary, and various components can be mounted without interfering with each other. That is, a plurality of various electronic components having different heights may be mounted on the mounting surface of the substrate. However, since the recess 32 is formed in the main body 31, it is possible to prevent the main body 31 from interfering with various electronic components. Further, since the connected portion 34 and the conductive member 23 are electrically connected, the influence of noise on the circuit board 2 can be reduced. In this way, the heat radiating member 3 can be formed large and the internal space S1 can be widened to effectively dissipate heat from the heat source component.

It is assumed that a rectangular main body 31 having a recess 32 (flat connection portion) thermally connected to the electronic component 21 is formed on one surface side of the circuit board 2, but the configuration is limited to this. Absent. For example, a convex portion may be formed at a position corresponding to the electronic component 21 of the rectangular main body portion 31. Alternatively, another plate-shaped member may be attached at a position corresponding to the electronic component 21 of the rectangular main body 31. As described above, if the connection flat portion increases the rigidity of the main body portion 31 which is a flat surface portion, the main body portion 31 can surely come into contact with the heat conductive member 4, and thus is not limited to the recess 32.

Further, the circuit board 2 has a second fixed portion at a position corresponding to the first fixed portion 33, and the heat radiating member 3 is attached to the housing together with the circuit board 2 by the first fixed portion 33 and the second fixed portion. On the other hand, it is configured to be tightened together. As a result, the heat radiating member 3 can be fixed together with the circuit board 2 in a simple configuration. The heat radiating member 3 and the housing of the device can be electrically connected to each other via appropriate screws 5 or the like at the time of joint tightening, and the noise received by the heat radiating member 3 is grounded. be able to. Since the screw 5 is electrically connected to the grounding electric circuit of the circuit board 2 via the heat radiating member 3, the grounding electric circuit and the housing of the device can have a common potential.

The position where the connected portion 34 is formed is preferably a position corresponding to the electronic component 21. With such a configuration, the electronic component 21 can be easily shielded and the function as a shield can be improved.

Further, the conductive member 23 has a bifurcated elastic connecting portion 232, the connected portion 34 is formed in a flat plate shape, and the heat radiating member 3 sandwiched by the connecting portion 232 is attached to the circuit board 2. It can be easily attached and detached, and can be stably fixed in the lateral direction of the circuit board 2.

Further, the main body portion 31 is formed in a flat plate shape, and the first fixed portion 33 is a contact portion 332 having a hanging portion 331 extending from the main body portion 31 and a contact portion 332 extending further from the hanging portion 331 to form a fastening hole. The heat radiating member 3 having the above can be fixed by stably contacting the first fixed portion 33 with the circuit board 2.

Further, a plurality of first fixed portions 33 are arranged on both side end portions side sandwiching the recess 32 in a plan view, and a plurality of connected portions 34 are arranged on both end sides sandwiching the recess 32 in a plan view. Therefore, the heat radiating member 3 can be connected to the conductive member 23 at both ends on one end side and the other end side in the lateral direction, and the heat radiating member 3 can be stably supported by the circuit board 2.

It should be noted that the embodiments described above are presented as examples, and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

The inventions described in the first claims of the present application are described below.
[1] A board on which components are mounted on one side,
A rectangular main body portion in which a connection flat portion corresponding to the component and to be thermally connected is formed on the one surface side of the substrate, and both ends of the rectangular main body portion in the longitudinal direction are provided. A connected portion that is electrically connected to a first fixed portion that is fastened to the substrate and a conductive member that is provided on the end side of the rectangular main body portion in the lateral direction and is mounted on the substrate and conducts with a grounding electric circuit. The heat dissipation member including the part,
A board module characterized by being provided with.
[2] A hole is formed in the first fixed portion of the heat radiating member.
In the substrate, a hole is formed at a position corresponding to the hole of the first fixed portion.
A screw is inserted into the hole of the first fixed portion and the hole of the substrate so that the heat radiating member is fastened and fixed to the housing together with the substrate by the first fixed portion. The substrate module according to the above [1].
[3] The conductive member includes a bifurcated elastic connecting portion.
The connected portion is formed in a flat plate shape and is sandwiched by the connecting portion.
The substrate module according to the above [1] or the above [2].
[4] The main body is formed in a flat plate shape.
The first fixed portion has a hanging portion extending from the main body portion and a contact portion extending further from the hanging portion to form a fastening hole.
The substrate module according to any one of the above [1] to the above [3].
[5] A heat conductive member is provided between the connecting flat portion formed on the main body of the heat radiating member and the component.
The substrate module according to any one of the above [1] to [4], wherein the heat conductive member is pressed tightly and is in close contact with each other.
[6] The substrate module according to any one of the above [1] to [5], wherein the connection flat portion is a concave portion or a convex portion.
[7] A plurality of the first fixed portions are arranged on both side end sides of the connecting flat portion in a plan view.
A plurality of the connected portions are arranged on both side end portions side of the connected flat portion in a plan view.
The substrate module according to any one of the above [1] to the above [6].

1 Board module 2 Circuit board 2a 1st surface 2b 2nd surface 2c Fixing hole 3 Heat dissipation member 4 Heat conductive member 5 Screw 21 Electronic component 22 Electronic component 23 Conductive member 23A Conductive member 23B Conductive member 31 Main body 32 Recess (flat connection part) ) 33 First fixed part 34 Connected part 34B Connected part 231 Fixed part 232 Connection part 232A Connection part 232B Connection part 232a Contact part 311 Notch part 311a Notch part 311b Notch part 321 Bottom plate part 331 Hanging part 332 Contact part 332a Fixing hole S1 Internal space S2 Gap

Claims (7)

A board with components mounted on one side,
A rectangular main body portion in which a connection flat portion corresponding to the component and to be thermally connected is formed on the one surface side of the substrate, and both ends of the rectangular main body portion in the longitudinal direction are provided. A connected portion that is electrically connected to a first fixed portion that is fastened to the substrate and a conductive member that is provided on the end side of the rectangular main body portion in the lateral direction and is mounted on the substrate and conducts with a grounding electric circuit. The heat dissipation member including the part,
A board module characterized by being provided with. A hole is formed in the first fixed portion of the heat radiating member.
In the substrate, a hole is formed at a position corresponding to the hole of the first fixed portion.
A screw is inserted into the hole of the first fixed portion and the hole of the substrate so that the heat radiating member is fastened and fixed to the housing together with the substrate by the first fixed portion. The substrate module according to claim 1. The conductive member includes a bifurcated elastic connection.
The connected portion is formed in a flat plate shape and is sandwiched by the connecting portion.
The board module according to claim 1 or 2. The main body is formed in a flat plate shape.
The first fixed portion has a hanging portion extending from the main body portion and a contact portion extending further from the hanging portion to form a fastening hole.
The substrate module according to any one of claims 1 to 3, wherein the substrate module is characterized in that. A heat conductive member is provided between the connecting flat portion formed on the main body portion of the heat radiating member and the component.
The substrate module according to any one of claims 1 to 4, wherein the heat conductive member is compressed and brought into close contact with each other. The substrate module according to any one of claims 1 to 5, wherein the connecting flat portion is a concave portion or a convex portion. A plurality of the first fixed portions are arranged on both side end portions sides of the connecting flat portion in a plan view.
A plurality of the connected portions are arranged on both side end portions sides of the connected flat portion in a plan view.
The substrate module according to any one of claims 1 to 6, wherein the substrate module is characterized in that.

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