JP6401945B2 - heatsink - Google Patents

Description

  The present invention relates to a heat sink for dissipating heat generated from an electronic component.

  Conventionally, for the purpose of radiating heat generated from electronic components such as a thermistor and a switching element, a radiator called a heat sink is used in contact with the electronic components. Since the heat sink dissipates heat from the electronic component, the electronic component can be prevented from being damaged or damaged by the heat. For example, Patent Document 1 and Patent Document 2 disclose a thermistor with a heat sink.

International Publication No. 2009/054061 International Publication No. 2008/120421

  However, in the above prior art, since the heat sink is provided in contact with only the main part of the electronic component, the heat of the main part can be dissipated by the heat sink, but the heat conducted to the terminal part including the lead wire is The heat sink cannot radiate heat. In addition, since the terminal part has a small heat radiation area, heat from the electronic component is not sufficiently dissipated but is conducted from the terminal part to the wiring board. there's a possibility that.

  Then, an object of this invention is to provide the heat sink which can suppress that the heat | fever from an electronic component is conducted to a wiring board.

  As a result of various studies, the present inventor has found that the above object is achieved by the present invention described below.

  That is, the heat sink according to the present invention is a heat sink connected to an electronic component arranged with a gap between the wiring substrate and one end of the heat sink is connected to the wiring substrate for energizing the electronic component. A terminal is joined to the other end.

  According to this configuration, since the heat sink is connected between the wiring board and the electronic component, and the electronic component is disposed with a gap between the wiring board and the electronic component, it is conducted from the terminal of the electronic component to the wiring substrate. The heat to be generated is radiated by the heat sink with a heat dissipation area secured by the heat sink. Therefore, the heat sink can effectively suppress the heat from the electronic components including the terminals from being conducted to the wiring board.

  The heat sink is preferably a metal or a conductive heat conductive resin plate. According to this configuration, the heat sink for heat conduction can be used also as the wiring for energizing the electronic component.

  In the heat sink, the electronic component is preferably a power thermistor. As a result, the power thermistor can be used at high power.

  Preferably, the heat sink is composed of a pair of heat sink pieces, and the terminals of the electronic component are a pair, and each of the pair of terminals is joined to the other end of each of the heat sink pieces. . According to this configuration, when the pair of heat sink pieces have conductivity, the heat sink can be energized respectively to the anode terminal and the cathode terminal of the electronic component by connecting each heat sink to the positive electrode and the negative electrode of the power source, for example. .

  The pair of heat sink pieces constituting the heat sink are erected on the wiring board opposite to each other, and each has a pedestal at the bent end of the other end portion serving as an upper end, excluding the terminals. In a state where the main body of the electronic component is interposed between the pair of heat sink pieces, the corresponding terminal of the electronic component is joined to each of the pedestals. According to this configuration, the heat sink has a form in which the main part of the electronic component is suspended from, for example, the other end (pedestal) of the heat sink between the pair of heat sink pieces. The dimension in the height direction can be suppressed.

  In the heat sink, it is preferable that a through hole is provided between the one end and the other end. According to this configuration, since the cross-sectional area with respect to the heat conduction direction of the heat sink is reduced by the through-hole, the heat sink conducts heat from the wiring board to the electronic component when soldering the one end to the wiring board, for example. , And heat conduction to the wiring board generated in the electronic component can be suppressed. Furthermore, the amount of heat conduction can be adjusted by adjusting the position, size, shape, and the like of the through hole.

  In the heat sink, it is preferable that the other end portion has a restricting portion that engages with the terminal of the electronic component and restricts a joining position of the terminal. According to this configuration, the heat sink can further ensure the positional relationship between the heat sink and the electronic component. In addition, according to this configuration, the heat sink and the electronic component can be stably integrated by joining the heat sink and the terminal of the electronic component at the regulating portion by using a jig or the like outside the wiring board. And workability is good.

  The heat sink according to the present invention can suppress conduction of heat from the electronic component to the wiring board.

It is a figure which shows the heat sink with which the electronic component which concerns on this embodiment was attached, a figure (a) shows a front view, and a figure (b) shows a side view. It is a figure which shows the heat sink piece which concerns on this embodiment, A figure (a) is a top view, A figure (b) is a front view, A figure (c) shows a side view.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted suitably unless there is description of special change etc.

  FIG. 1 shows a state in which an electronic component is supported on a heat sink according to an embodiment. FIG. 1 shows a heat sink 200 in which an electronic component 10 is attached to a pair of heat sink pieces 100 having the same shape. The heat sink 200 may be composed of one or three or more heat sink pieces 100. In the present embodiment, the heat sink 200, that is, the pair of heat sink pieces 100 are erected substantially vertically on the wiring board 20 so as to face each other so as to be plane-symmetric. A pair of current-carrying terminals 12 and 13 including lead wires of the electronic component 10 are joined to the top of each heat sink piece 100. At this time, the main body 11 of the electronic component 10 is supported between the pair of heat sink pieces 100 in a suspended state with a gap S between the electronic component 10 and the wiring board 20.

  As shown in FIG. 2, the heat sink piece 100 is made of a single metal plate, and is bent at a right angle, for example, at two points in the longitudinal direction to form a crank shape. The heat sink piece 100 may be, for example, a conductive heat conductive resin plate. The heat sink piece 100 is divided by the two bent portions 102 b and 102 c that are bent, and includes a main body portion 101, a pedestal 102, and a restricting portion 103. In the present embodiment, in the side views of FIG. 1B and FIG. 2C, the main body portion 101 has a substantially rectangular shape with a length × width of about 25 mm × 7 mm, and the regulating portion 103 has a length × width of about 3 mm × It is a shape that fits within a 7 mm approximately rectangular shape. The pedestal 102 has a substantially rectangular shape with a length × width of about 7 mm × 6 mm in a plan view of FIG.

  The main body portion 101 has, for example, a flat plate shape, and a mounting leg 101a is continuously provided on the same plane at a lower end portion which is one end portion in the longitudinal direction of the main body portion 101. The heat sink piece 100 is erected on the wiring board 20 as described above by joining the mounting legs 101a to the wiring board 20 of FIG. The wiring board 20 and the mounting leg 101a are joined by, for example, soldering or bonding with a conductive resin, but in this embodiment, they are soldered. On the other hand, the pedestal 102 and the restricting portion 103 are arranged at the upper end portion which is the other end portion of the heat sink piece 100.

  The pedestal 102 shown in FIG. 2 is a portion that is continuous with the main body portion 101 at the other end of the heat sink piece 100, for example, at the tip of the first bent portion 102b that is bent substantially at right angles, that is, at the other end. As shown in FIG. 1A, the pedestal 102 is joined to a terminal (hereinafter also referred to as a lead wire) 12 or a terminal 13 for energizing the electronic component 10. Here, the electronic component 10 is, for example, a power thermistor, and includes lead wires 12 and 13 and a main body 11. In addition, although the said joining is made by soldering or adhesion | attachment by a conductive resin, for example, it joins by the soldering 30 in this embodiment.

  The restricting portion 103 shown in FIG. 2 is a portion that is continuous with the pedestal 102 via the second bent portion 102c on the pedestal 102 opposite to the first bent portion 102b. The second bent portion 102c is bent at a substantially right angle, whereby the main body portion 101 and the restricting portion 103 are substantially parallel. The restricting portion 103 is composed of restricting portion pieces 103a and 103a that are arranged with a gap 103b formed as a gap formed by cutting away a portion. The length A in the front-rear direction of the restriction piece 103a is about 3 mm, and the length B in the front-rear direction of the gap 103b is about 1 mm. The restricting portion 103 is not limited to this form. For example, the restricting portion 103 may be formed of a plate having a concave portion corresponding to the gap 103b, or two protrusions protruding substantially perpendicularly from the pedestal 102. A groove formed on the upper surface of 102 may be used. A portion of the pedestal 102 adjacent to the gap 103b has, for example, a semicircular cutout 102a.

  The lead wires 12 and 13 shown in FIG. 1 (a) are bent substantially at right angles in opposite directions so as to face the left and right outer sides from the main body 11 of the electronic component 10, and are each cut out 102a (see FIG. 1). 2 (a)) and the gap 103b (FIG. 2C), it is placed on the upper surface of the pedestal 102 and joined to the pedestal 102 as described above. The portions of the lead wires 12 and 13 that are bent at a substantially right angle are accommodated in the notches 102a. Alternatively, the portions of the lead wires 12 and 13 that are bent at a substantially right angle are each close to the notch 102a and the position in the left-right direction X is restricted. At this time, the main body 11 of the power thermistor 10 exists between the pair of heat sink pieces 100 as described above.

  On the other hand, the restricting portion 103 joins the lead wires 12 and 13 between the restricting portion pieces 103a and 103a shown in FIG. Regulate the position. Therefore, the positional relationship between the heat sink piece 100 and the electronic component 10 becomes more reliable, and the lead wires 12 and 13 of the electronic component 10 can be soldered to the base 102 in this stable state. In the side view, the size of the main body 11 of the electronic component 10 is smaller than the size of the main body portion 101, and the main body 11 can be accommodated in the main body portion 101, so that the whole is not visible.

  The main body 101 has a through hole 101b between the one end and the other end. In the present embodiment, the through hole 101b penetrates the main surface of the main body portion 101 in a direction orthogonal to the main surface. By the through hole 101b, the cross-sectional area perpendicular to the direction of heat conduction of the heat sink piece 100, that is, the longitudinal direction of the main body part 101 is reduced in the region of the main body part 101 where the through hole 101b exists. Therefore, through the through hole 101b, the heat sink piece 100, for example, heat conduction from the wiring board 20 to the electronic component 10 when the heat sink piece 100 is soldered to the wiring board 20, and heat sink pieces of heat generated in the electronic component 10 are used. Thermal conduction to the wiring board 20 via 100 can be suppressed. The amount of heat conduction can be adjusted by adjusting the position, size, shape, and the like of the through hole 101b. In the present embodiment, the through hole 101b has a substantially circular shape with a diameter of about 3 mm when viewed from the front, and the distance C from the tip of the mounting leg 101a near the center in the short side direction (width direction) of the main body 101 (see FIG. c)) is about 8 mm in center.

  Next, a procedure for attaching the heat sink 200 to which the power thermistor 10 shown in FIG. 1A is attached to the wiring board 20 will be described. First, by using a jig (not shown), a pair of heat sink pieces 100 are erected so as to face each other, and each of the bent lead wires 12 and 13 is placed on the upper surface of the pedestal 102 so that the power After the main body 11 of the thermistor 10 is suspended between the pair of heat sink pieces 100, the lead wires 12 and 13 are joined to the two bases 102 by soldering 30. The heat sink 200 completed with the power thermistor 10 is attached to the wiring board 20 in an integrated state. A flow soldering method is generally known as soldering of electronic components such as ICs, resistors, capacitors, etc. to a wiring board. The mounting legs 101a of the heat sink 200 integrated by the above procedure are connected from the surface of the wiring board 20. The heat sink 200 can be soldered to the wiring board 20 by being inserted into the mounting hole 20 a and flow soldering from the back surface of the wiring board 20. This makes it possible to maintain the efficiency of component mounting on the wiring board.

  Each heat sink piece 100 of the heat sink 200 is made of metal, the mounting legs 101a of the wiring board 20 and the pair of heat sink pieces 100 are soldered, and the lead wires 12 and 13 of the power thermistor 10 are the base 102 or the base. 102 and the restricting portion 103 are soldered, so that the pair of heat sink pieces 100 are also used as current-carrying metal wiring, and the power thermistor 10 is connected to the power thermistor 10 from the power supply wiring on the wiring board 20 or the power supply inner layer. Power can be supplied. Further, in the heat sink 200, the longitudinal direction of the heat sink piece 100 is the height direction with respect to the wiring board 20, so that the mounting area of the heat sink 200 is the distance between the pair of heat sink pieces 100 in the left-right direction X and the front and rear shown in FIG. Since it is almost determined by the product of the width of the heat sink piece 100 in the direction Y, the mounting area can be reduced.

  According to the present embodiment, since the heat sink 200 is connected between the wiring board 20 and the electronic component 10 and the electronic component 10 is disposed with the gap S between the wiring board 20 and the electronic component 10. The heat conducted from the terminals 12 and 13 to the wiring board 20 is effectively radiated by the heat sink 200 having a large heat radiation area. Therefore, the heat sink 200 can suppress conduction of heat from the electronic component 10 to the wiring board 20.

  The present invention is not limited to the above-described embodiments, and various additions, modifications, or deletions are possible within the scope not departing from the gist of the present invention. Therefore, such a thing is also included in the scope of the present invention. For example, when one lead wire 12 of the electronic component 10 is joined to the heat sink piece 100 and the other lead wire 13 is connected to another electronic circuit component without passing through the heat sink piece 100, the heat sink 200 is a single piece. The heat sink piece 100 may be used.

10 Power thermistor (electronic parts)
12, 13 Lead wire (terminal)
20 Wiring board 100 Heat sink piece 101a Mounting leg 101b Through hole 102 Base 103 Restriction part 200 Heat sink

Claims (5)

A heat sink connected to an electronic component disposed with a gap between the wiring board,
One end is joined to the wiring board, a terminal for energization of the electronic component is joined to the other end ,
It consists of a pair of heat sink pieces,
And the terminals of the electronic component are a pair, and each of the pair of terminals is joined to the other end of each of the heat sink pieces,
The pair of heat sink pieces are erected on the wiring board opposite to each other, and each has a pedestal at the bent end of the other end portion serving as an upper end,
A heat sink in which the corresponding terminal of the electronic component is joined to each of the pedestals in a state where the main body of the electronic component excluding the terminal is interposed between the pair of heat sink pieces .   2. The heat sink according to claim 1, wherein the heat sink is a metal or a conductive heat conductive resin plate.   3. The heat sink according to claim 1, wherein the electronic component is a power thermistor. The heat sink according to any one of claims 1 to 3 , wherein a through hole is provided between the one end and the other end. In any one of claims 1 4, wherein at the other end, engaged with the terminal of the electronic component, the heat sink having a regulating portion for regulating the bonding position of the terminal.

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