JP2012119633A - Heat sink and method for fitting heat sink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat sink which is stably and easily attached to a substrate.SOLUTION: The heat sink for radiating heat to a space by contacting with a heating component mounted on a front surface of a substrate, comprises: a hook passing through from the front surface of the substrate to its rear surface and being latched on the rear side of the substrate; a turn-around part for turning around the rear surface side from the front surface side on a peripheral part of the substrate; and a press part for pressing the substrate on the rear surface of the substrate. More preferably, the heat sink comprises a first press part and a second press part, and the heat sink is latched to the substrate such that the hook, the first press part and the second press part define an isosceles triangle having the hook as a vertex in plan view.

Description

  The present invention relates to a heat sink that can be easily attached and a method of attaching the heat sink.

  2. Description of the Related Art Conventionally, various heat sinks are known that are used to dissipate a semiconductor element in contact with a semiconductor element such as an IC. For example, Patent Document 1 below discloses a semiconductor element fixing clip having a clip-type structure.

  According to this document, it is intended to improve the stability of an electronic device as a semiconductor element fixing clip having a structure in which no gap is generated between the semiconductor element fixing clip and the edge of the chassis. It is described that the posture of the clip is stabilized by forming a semiconductor element fixing clip having a step formed so as to bend the base portion of the leg member and contact the edge portion of the heat dissipation plate.

  In addition, a heat sink that is fixed to the circuit board with screws or screwed to an electronic component so that the mounting to the circuit board can be simplified, and an electronic component mounting structure using such a heat sink, It is disclosed in Patent Document 2 below.

  According to this document, the lead plate is screwed to the electronic component soldered to the circuit board, the first plate body side, and the inverted T-shaped locking portion at the lower end is inserted into the insertion hole of the circuit board. In addition, it is described that a heat radiating plate including a second plate body side locked and fixed on the opposite surface by twisting the lateral member of the locking portion on the opposite surface of the circuit board is described. .

  Further, in this document, heat generated by the electronic component is absorbed by the heat radiating plate through the first plate body, and the absorbed heat is absorbed by the first plate body, the second plate body, and the third plate body. It is disclosed that it is dissipated in the air via

  On the other hand, since various electronic components are mounted on the circuit board, there may be a case where screwing work on the circuit board is not easy.

JP 2007-273860 A Japanese Patent Laid-Open No. 8-306834

  While the conventional screw-type heat sink can be expected to have a strong fixing action, it requires screwing work on the circuit board during installation, so when mounting components are mounted on the circuit board at high density May occur when the screwing operation becomes difficult.

  Further, in the clip-type semiconductor element fixing method, the mounting operation is easy, but there is a concern that the clip may be pulled out unexpectedly due to vibration or the like.

  The present invention has been made in view of the above-described problems, and an object thereof is to realize a heat sink that can be stably and easily attached to a substrate.

  The heat sink of the present invention is a heat sink that contacts a heat-generating component mounted on the surface of the substrate and dissipates the heat to the space. The hook is inserted from the surface of the substrate to the back surface and locked on the back surface side of the substrate. A wraparound portion that wraps around from the front surface side to the back surface side at the edge portion of the substrate and a pressing portion that presses the substrate at the back surface of the substrate are provided.

  The heat sink of the present invention preferably includes a first pressing portion and a second pressing portion, and is an isosceles triangle having the hook as a vertex in plan view by three points of the hook, the first pressing portion, and the second pressing portion. It is characterized by being locked to the substrate.

  More preferably, the heat sink of the present invention is integrally formed of a single metal plate.

  The heat sink of the present invention is more preferably characterized in that the hook, the first pressing portion, and the second pressing portion are each fixed in a corresponding through hole of the substrate.

  The heat sink of the present invention is more preferably characterized in that the through hole is a non-through hole.

  The heat sink of the present invention is more preferably characterized in that the through hole is a plated through hole, and the hook, the first pressing portion, and the second pressing portion are each fixed to the corresponding plated through hole by soldering. To do.

  The heat sink of the present invention is further characterized in that it includes a heat radiating portion extending parallel to the substrate from the lower end of the wraparound portion on the back surface side of the substrate.

  The heat sink of the present invention is more preferably made of phosphor bronze.

  The heat sink of the present invention is more preferably characterized in that the pressing portion is formed by being bent from the wraparound portion on the back side of the substrate.

  The heat sink of the present invention is more preferably characterized in that the bent portion is a thin portion having a relatively thin plate thickness.

  A heat sink mounting method of the present invention is a method of mounting any of the above heat sinks on a substrate, a step of inserting a hook into the substrate, a heat generating component mounted on the surface of the substrate, and an inner surface of the heat sink. And a step of wrapping the wraparound portion from the front surface side to the back surface side at the edge of the substrate and a step of bending the pressing portion from the wraparound portion to press the back surface of the substrate. To do.

  The heat sink mounting method of the present invention includes a step of soldering and fixing the pressing portions and the hooks to the corresponding through holes of the substrate, respectively.

  According to the present invention, it is possible to provide a heat sink that can be stably and easily attached to a substrate and a method for attaching the heat sink.

It is a figure explaining the state which is going to attach the heat sink of embodiment to the board | substrate with which the heat-emitting component was mounted, Comprising: (a) is a top view of a heat sink, (b) is a front view of a heat sink, (c) is a heat sink. It is a figure explaining a bottom view, respectively. (A) is a right view explaining the state which observed the heat sink from the right side, (b) is a figure explaining the state which cuts and forms a heat sink integrally from a metal plate. It is a figure explaining the state which attached the heat sink to the board | substrate with which the heat-emitting component was mounted. It is a figure explaining a heat sink alone, Comprising: (a) is a top view of a heat sink, (b) is a front view of a heat sink, (c) is a bottom view of a heat sink, (d) is a heat sink It is a right view. It is sectional drawing explaining the plate | board thickness of the heat sink in a bending part. It is a figure explaining the heat sink which is not provided with a thermal radiation part. It is a flowchart explaining the process of attaching a heat sink to a board | substrate sequentially.

  Heat generation components such as semiconductors require heat dissipation, and usually a heat sink such as a heat sink is attached to the heat generation components in order to dissipate heat quickly. The heat sink described in the embodiment can improve the degree of freedom of attachment in the manufacturing and assembly stages by devising the shape and its attachment structure / attachment method.

  Further, the heat sink of the embodiment can be brought into contact with a heat-generating component such as a semiconductor without screwing or soldering. Furthermore, by using a heat sink that is fixed to the substrate with three-point support, it is possible to stably mount the substrate on the substrate and maintain a good contact surface with the heat-generating component.

  In addition, this heat sink has a structure that wraps around from the front side to the back side of the board on which the heat-generating components to be radiated are mounted, so that the area of the metal plate that contributes to heat dissipation on the back side can be increased or decreased as appropriate. Can be adjusted. In addition, by providing through holes in the board at positions corresponding to the three points where the heat sink is supported by the board, the support location becomes a heat sink locked to the through hole, enabling stable fixed support. It becomes. Further, by performing plating through-hole processing on the through-hole, it is possible to fix the soldering heat later at each of the three points to be supported, and to further firmly fix the heat sink.

(First embodiment)
FIG. 1 is a diagram illustrating a state in which the heat sink 100 according to the embodiment is to be attached to a substrate 300 on which a heat generating component 200 is mounted. FIG. 1A is a plan view of the heat sink 100, FIG. 1B is a front view of the heat sink 100, and FIG. 1C is a bottom view of the heat sink 100.

  As shown in FIG. 1, the heat sink 100 is in contact with the heat generating component 200 such as a semiconductor mounted on the surface side of the substrate 300 on the surface side, and heat conduction is performed from the contact surface portion. The heat sink 100 includes a hook 110 that is inserted into the through hole 310 from the front surface side of the substrate 300 and is locked on the back surface side of the substrate 300.

  Further, the heat sink 100 includes a wraparound portion 140 located at a position facing the hook 110 with respect to the heat generating component 200 in a plan view shown in FIG. The wraparound portion 140 has a structure that wraps around the edge of the substrate 300 from the front surface side to the back surface side of the substrate 300.

  In addition, the heat sink 100 includes a heat dissipating part 120 that extends in parallel to the substrate 300 from the wraparound part 140 on the back surface side of the substrate 300. The heat dissipating part 120 may be formed by arbitrarily adjusting its shape and size as appropriate. For example, when the heat generation amount of the heat generating component 200 is large, the area of the heat radiating part 120 may be formed large in order to achieve higher heat radiating capability. In addition, when a higher mounting density is required to reduce the size and weight of an electronic device or the like that accommodates the substrate 300, the size of the heat dissipating part 120 is made small and compact, and the occupied space is reduced. May be.

  Moreover, as shown in FIG.1 (b), the heat sink 100 is provided with the symmetrical 1st press part 130 (1) and the 2nd press part 130 (2) (henceforth the press part 130 suitably). The first pressing portion 130 (1) and the second pressing portion 130 (2) are bent at bent portions 150 (1) and 150 (2) indicated by broken lines, respectively, and the back surface side of the substrate 300 and the through hole 330. 320, respectively, and the back side of the substrate 300 is pressed. However, FIG. 1B shows a state before the heat sink 100 is bent at the bent portions 150 (1) and 150 (2) for convenience of explanation.

  The through-hole 310 with which the hook 110 engages, the through-hole 330 with which the first pressing portion 130 (1) engages, and the through-hole 320 with which the second pressing portion 130 (2) engages are, in plan view, An isosceles triangle having the through hole 310 as a vertex is formed. As can be understood from FIG. 1, the heat generating component 200 has a perpendicular line extending from the vertex of the isosceles triangle (that is, the through hole 310) to the opposite side (that is, one side formed by the through hole 330 and the through hole 320). It is preferable to arrange symmetrically.

  Positional relationship in which at least a part of the heat generating component 200 is disposed in an isosceles triangle in plan view formed by the hook 110 of the heat sink 100, the first pressing portion 130 (1), and the second pressing portion 130 (2). As a result, the heat sink 100 is stably in contact with the heat generating component 200 and is stably fixed to the substrate 300.

  FIG. 2A is a right side view for explaining a state where the heat sink 100 shown in FIG. 1 is observed from the right side. FIG. 2B is a view for explaining a state in which the heat sink 100 is integrally cut out from a single metal plate.

  FIG. 2A shows a state before the pressing portion 130 is bent by the bending portion 150. In addition, as shown in FIG. 2B, the heat sink 100 can be integrally formed by cutting out a metal plate such as phosphor bronze. In FIG. 2B, a bent portion for making the heat sink 100 into a completed shape from the hollowed metal plate is indicated by a broken line.

  As can be understood from FIG. 2A, the center position of the heat generating component 200 in a side view coincides with the arrangement of the through holes 320 and 330. That is, the center position of the heat generating component 200 in a side view coincides with the back-side pressing portion of the substrate 300 by the first pressing portion 130 (1) and the second pressing portion 130 (2).

  Further, as can be understood from FIG. 2B, the bent portions 150 (1) and 150 (2) are not perpendicular to or parallel to the other bent portions, and are formed obliquely so as to have an angle. Thus, by providing the bent portions 150 (1) and 150 (2) diagonally, the pressing portion 130 heads toward the back surface corresponding to the degree of bending so that the pressing portion 130 presses against the back surface of the substrate 300. .

  FIG. 3 is a diagram illustrating a state in which the heat sink 100 is completely attached to the substrate 300 on which the heat generating component 200 is mounted. 3A is a plan view of the heat sink 100, FIG. 3B is a front view of the heat sink 100, FIG. 3C is a bottom view of the heat sink 100, and FIG. FIG. In FIG. 3, the same portions as those in FIGS. 1 and 2 are denoted by the same reference numerals, and the description thereof is omitted here in order to avoid duplication of description.

  As shown in FIG. 3, the pressing portion 130 bent by the bending portion 150 is shallowly fitted and locked in the through holes 320 and 330 provided in the substrate 300 to press the substrate 300 from the back side. As a reaction, the heat sink 100 receives a force in a direction away from the back surface of the substrate 300, while the hook 110 is locked on the integrally formed surface side, so that the inner surface of the heat sink 100 generates heat. It will be in close contact with the component 200 stably.

  Furthermore, since the hook 110 disposed at a position further away from the edge of the substrate 300 toward the middle locks the heat sink 100 to the substrate 300, the substrate 300 is supported at three points together with the pressing portion 130. The heat sink 100 fixed to is held by high stability.

  4A and 4B are diagrams for explaining the heat sink 100 alone. FIG. 4A is a plan view of the heat sink 100, FIG. 4B is a front view of the heat sink 100, and FIG. 4 is a bottom view of the heat sink 100, and FIG. 4D is a right side view of the heat sink 100.

FIG. 5 is a cross-sectional view illustrating the thickness of the heat sink 100 at the bent portion 150. As shown in FIG. 5, the heat sink 100 is preferably provided with a so-called crease at a bent portion 150 using a press tool or the like. For example, the pressing portion 130 is bent from the state shown in FIG. 1 to the state shown in FIG. 3 by reducing the thickness of the bent portion 150 relative to the thickness T _{1 of the} heat sink 100 relative to T ₂ . This is preferable because the work in the case becomes easy. In addition, the shape of the heat sink 100 can be formed by forming a crease having a relatively small plate thickness as shown in FIG. This is preferable because it becomes easier.

  FIG. 7 is a flowchart for sequentially explaining the process of attaching the heat sink 100 to the substrate 300.

(Step S710)
The hook 110 is inserted into the through hole 310 of the substrate 300. As a result, the hook 110 is locked on the back surface side of the through hole 310.

(Step S720)
The heat generating component 200 and the inner surface of the heat sink 100 are brought into contact with each other, and the wraparound portion 140 is circulated from the front surface to the back surface of the substrate 300 at the edge portion of the substrate 300.

(Step S730)
The bent portions 150 (1) and 150 (2) are bent to form the first pressing portion 130 (1) and the second pressing portion 130 (2).

(Step S740)
The attachment operator determines whether or not the first pressing portion 130 (1) and the second pressing portion 130 (2) are shallowly fitted into the corresponding through holes 330 and 320, respectively. The first pressing portion 130 (1) and the second pressing portion 130 (1) and the second pressing portion 130 (2) are fitted with the front edges of the first pressing portion 130 (1) and the second pressing portion 130 (2) shallowly in the corresponding through holes 330 and 320, respectively. Movement with 130 (2) is restricted.

  When the installation operator determines that the first pressing portion 130 (1) and the second pressing portion 130 (2) are shallowly fitted in the corresponding through holes 330 and 320, the process proceeds to step S750. . If the mounting operator does not determine that the first pressing portion 130 (1) and the second pressing portion 130 (2) are shallowly fitted into the corresponding through holes 330 and 320, the process proceeds to step S730. Return.

(Step S750)
The substrate 300 and the heat sink 100 are soldered and fixed at three points of the through holes 310, 320, and 330. In this case, the through holes 310, 320, and 330 are preferably formed in advance as plated through holes, respectively. Thereby, the worker can solder and fix the heat sink 100 later using a soldering iron or the like. Furthermore, it is preferable that the through holes 310, 320, and 330 are plated through holes having lands from the viewpoint of performing a reliable soldering and fixing operation more easily.

  Further, the through holes 310, 320, and 330 may be formed as non-through holes (non-conducting holes). In this case, the heat sink 100 is connected to the through holes 310, 320, and 330 without being fixed by soldering. It may be locked.

  The through holes 320 and 330 are not necessarily penetrated from the viewpoint of locking the heat sink 100, and may be, for example, a recess. However, from the viewpoint of matching with the step of forming the substrate 300, it is more preferable to use a through hole such as a plated through hole or a non-through hole. 7 is a typical example, and when the heat sink 100 is attached to the substrate 300, the order is not necessarily limited to the order shown in FIG.

(Second embodiment)
FIG. 6 is a diagram illustrating a heat sink 6100 that does not include the heat radiating unit 120. 6A is a plan view of the heat sink 6100, FIG. 6B is a front view of the heat sink 6100, FIG. 6C is a bottom view of the heat sink 6100, and FIG. FIG.

  As described above, the shape, size, and structure of the heat dissipating part 120 can be appropriately changed according to the required heat dissipating function and the allowable occupied space. In the second embodiment, as a typical example, a heat sink 6100 that does not include the heat dissipation unit 120 will be described.

  In FIG. 6, the heat sink 6100 includes a hook 6110 that is inserted into a through-hole from the front surface side of a substrate (not shown) and locked on the back surface side of the substrate.

  Further, the heat sink 6100 includes a wraparound portion 6140 at a position facing the hook 6110 with respect to a heat generating component (not shown) in a plan view shown in FIG. The wraparound portion 6140 has a structure that wraps around from the front surface side to the back surface side of the substrate at the edge portion of the substrate.

  As shown in FIG. 6B, the heat sink 6100 includes a symmetrical first pressing portion 6130 (1) and a second pressing portion 6130 (2) (hereinafter collectively referred to as a pressing portion 6130 as appropriate). The first pressing portion 6130 (1) and the second pressing portion 6130 (2) are bent at the bent portions 6150 (1) and 6150 (2), respectively, and are respectively engaged with the back surface side of the substrate and the through hole, Press the back side of the substrate. However, FIG. 6B shows a state before the heat sink 6100 is bent at the bent portions 6150 (1) and 6150 (2) for convenience of explanation.

  The through hole with which the hook 110 engages, the through hole with which the first pressing portion 6130 (1) engages, and the through hole with which the second pressing portion 6130 (2) engages form an isosceles triangle in plan view. Form. Moreover, it is preferable that a heat-emitting component (not shown) is positioned symmetrically with respect to a perpendicular line extending from the apex of the isosceles triangle to the opposite side.

  A positional relationship in which at least a part of the heat generating component is disposed in an isosceles triangle in plan view formed by the hook 6110 of the heat sink 6100, the first pressing portion 6130 (1), and the second pressing portion 6130 (2). Therefore, the heat sink 6100 stably contacts the heat generating component and is stably fixed to the substrate. Others are the same as those of the heat sink 100 described in the first embodiment except that the heat radiating unit 120 is not provided, and thus the description thereof is omitted here.

  The above-described heat sinks 100 and 6100 are not limited to the description in each embodiment, and the structure, shape, material, and the like can be changed as appropriate within the obvious range based on the disclosed technical idea. .

  The present invention can be widely applied to electronic devices including a substrate on which various heat generating components are mounted.

  100 ... Heat sink 110 ... Hook 120 ... Heat radiating part 130 ... Pressing part 140 ... Rounding part 150 ... Bent part 200 ... Heating part 300 ... Substrate.

Claims (12)

In the heat sink that contacts the heat-generating component mounted on the surface of the board and dissipates its heat to the space,
A hook that is inserted from the front surface of the substrate to the back surface and locked on the back surface side of the substrate;
A wraparound portion that wraps around from the front side to the back side at the edge of the substrate;
A heat sink, comprising: a pressing portion that presses the substrate on a back surface of the substrate. The heat sink according to claim 1.
A first pressing portion and a second pressing portion;
The three points of the hook, the first pressing portion, and the second pressing portion are locked to the substrate so as to form an isosceles triangle having the hook as a vertex in plan view. heatsink. The heat sink according to claim 1 or 2,
A heat sink characterized by being integrally molded from a single metal plate. The heat sink according to any one of claims 1 to 3,
The hook, the first pressing portion, and the second pressing portion are each fixed in a corresponding through hole of the substrate. The heat sink according to claim 4,
The heat sink, wherein the through hole is a non-through hole. The heat sink according to claim 4,
The through hole is a plated through hole, and the hook, the first pressing portion, and the second pressing portion are each fixed to the corresponding plated through hole by soldering. The heat sink according to any one of claims 1 to 6,
A heat sink, comprising: a heat radiating portion extending in parallel with the substrate from a lower end of the wraparound portion on a back surface side of the substrate. The heat sink according to any one of claims 1 to 7,
A heat sink characterized by being made of phosphor bronze. The heat sink according to any one of claims 1 to 8,
The press part is formed by being bent from the wraparound part on the back side of the substrate. The heat sink according to claim 9,
The heat sink, wherein the bent portion is a thin portion having a relatively thin plate thickness. A method of attaching the heat sink according to any one of claims 1 to 10 to a substrate,
Inserting the hook into the substrate;
A step of bringing the heat-generating component mounted on the surface of the substrate and the inner surface of the heat sink into contact with each other, and wrapping the wraparound portion from the front surface side to the back surface side at the edge portion of the substrate;
A step of bending the pressing portion from the wraparound portion and pressing the back surface of the substrate. A method of attaching a heat sink according to claim 11 to a substrate.
A method of attaching a heat sink, comprising the step of soldering and fixing the pressing portion and the hook to the corresponding through holes of the substrate.

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