Cooling fin and printed circuit board device with same

Abstract

The utility model discloses a radiating fin, which comprises a first heat conduction part and a second heat conduction part, the first heat conduction part and the second heat conduction part are arranged in a spaced mode in the first direction; the flexible heat conduction structure is connected with the second heat conduction part and the first heat conduction part in the first direction, and the flexible heat conduction structure is configured to be supported between the first heat conduction part and the second heat conduction part and transmit heat between the second heat conduction part and the first heat conduction part; the flexible heat conduction structure can deform under the action of external force, so that the second heat conduction part moves relative to the first heat conduction part. The radiating fin provided by the utility model can reduce thermal resistance, improve thermal conductivity, and improve the heat conduction effect between the printed circuit board and the metal shell. The utility model also discloses a printed circuit board device comprising the radiating fin.

Description

Technical Field

[0001] The utility model relates to the technical field of printed circuit boards, in particular to a heat sink and a printed circuit board device with the heat sink. Background Art

[0002] At present, the heat dissipation solution adopted by high-heat-generating power devices on printed circuit boards (PCBs) is that the high-heat-generating power devices are in contact with a metal shell through a thermal pad, so that the heat is transferred to the metal shell through the thermal pad to achieve the purpose of heat dissipation.

[0003] However, the thermal conductivity of the thermal pad is low, resulting in high thermal resistance of the thermal pad and unsatisfactory heat dissipation effect. In addition, in actual application, a thicker thermal pad is often required to buffer and compensate for the tolerance between the printed circuit board and the metal shell, which results in worse heat dissipation effect. Summary of the invention

[0004] The utility model aims to solve the problem of poor heat dissipation effect of the existing printed circuit board. The utility model provides a heat sink that can reduce thermal resistance, increase thermal conductivity, and improve the heat conduction effect between the printed circuit board and the metal shell.

[0005] To solve the above technical problems, an embodiment of the utility model discloses a heat sink, comprising: a first heat-conducting portion; a second heat-conducting portion, wherein the first heat-conducting portion and the second heat-conducting portion are arranged at intervals along a first direction; a flexible heat-conducting structure, wherein the flexible heat-conducting structure connects the second heat-conducting portion and the first heat-conducting portion along the first direction, and the flexible heat-conducting structure is configured to be supported between the first heat-conducting portion and the second heat-conducting portion, and to transfer heat between the second heat-conducting portion and the first heat-conducting portion; wherein the flexible heat-conducting structure can be deformed under the action of an external force so that the second heat-conducting portion moves relative to the first heat-conducting portion.

[0006] By adopting the above technical solution, the flexible heat-conducting structure of the embodiment of the present application is supported between the first heat-conducting part and the second heat-conducting part to transfer heat between the first heat-conducting part and the second heat-conducting part. Compared with the thermal pad in the prior art, on the one hand, the heat sink of the embodiment of the present application has low thermal conductivity and good heat dissipation effect. On the other hand, under the action of external force, the flexible heat-conducting structure of the embodiment of the present application can be deformed so that the distance between the first heat-conducting part and the second heat-conducting part of the heat sink changes with the deformation of the flexible heat-conducting structure, thereby compensating for the tolerance between the printed circuit board and the metal shell.

[0007] According to another specific embodiment of the utility model, the embodiment of the utility model discloses a heat sink, the flexible heat-conducting structure includes a plurality of heat-conducting fins extending along a second direction, the plurality of heat-conducting fins are arranged at intervals along a third direction, along the first direction, one end of each of the heat-conducting fins is connected to a side of the first heat-conducting part close to the second heat-conducting part, and the other end is connected to a side of the second heat-conducting part close to the first heat-conducting part, the second direction intersects with the first direction, and the third direction is perpendicular to the first direction; wherein the heat-conducting fins can be deformed under the action of external force.

[0008] According to another specific embodiment of the present utility model, the embodiment of the present utility model discloses a heat sink, wherein the angle between the second direction and the first direction is α, and 0 degrees <α < 90 degrees.

[0009] According to another specific embodiment of the utility model, the embodiment of the utility model discloses a heat sink, wherein the thickness of the first heat conducting part includes 0.3mm to 0.6mm, the thickness of the second heat conducting part includes 0.3mm to 0.6mm, the thickness of the heat conducting fin includes 0.05 to 0.07mm, and the length of the heat conducting fin includes 3.1mm to 3.4mm.

[0010] According to another specific embodiment of the present invention, the embodiment of the present invention discloses a heat sink, wherein the first heat conducting portion includes a copper plate, the second heat conducting portion includes a copper plate, and the heat conducting fin includes a copper sheet.

[0011] By adopting the above technical solution, the embodiment of the present application uses a heat sink made of copper, and the high thermal conductivity of copper can be used to significantly reduce the thermal resistance of the heat sink.

[0012] An embodiment of the utility model further discloses a printed circuit board device, comprising: a metal shell; a printed circuit board, configured to be installed on the metal shell; a thermal pad, disposed on a side of the printed circuit board close to the metal shell; the heat sink described in any of the above embodiments, wherein the heat sink is disposed between the metal shell and the printed circuit board along the first direction, the first thermal conductive portion is configured to abut against the thermal conductive pad, and the second thermal conductive portion is configured to be welded to the metal shell.

[0013] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a printed circuit board device, wherein the thickness of the thermal pad is 0.1 mm to 0.3 mm.

[0014] By adopting the above technical solution, the heat sink in the embodiment of the present application has both high thermal conductivity and the function of providing flexibility to compensate for the tolerance between the printed circuit board and the metal shell. Compared with the thicker thermal pad used in the prior art, the thickness of the thermal pad in the embodiment of the present application is small, which can not only avoid collision between the printed circuit board and the metal shell, but also make the overall thermal conductivity efficiency between the printed circuit board and the metal shell higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram showing the structure of a printed circuit board in some embodiments;

[0016] Figure 2 A schematic diagram showing the structure of a printed circuit board provided by an embodiment of the utility model is shown;

[0017] Figure 3 A schematic diagram showing the structure of a heat sink provided by an embodiment of the utility model is shown;

[0018] Figure 4 Show Figure 3 A partial enlarged schematic diagram of area A in the middle. DETAILED DESCRIPTION

[0019] The following specific embodiments illustrate the implementation of the present invention, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this implementation. On the contrary, the purpose of introducing the invention in conjunction with the implementation is to cover other options or modifications that may extend based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will include many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that, in the absence of conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0020] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0021] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model.

[0022] The terms “first”, “second”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0023] In the description of this embodiment, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this embodiment can be understood according to specific circumstances.

[0024] In order to make the purpose, technical solution and advantages of the present invention more clear, the implementation mode of the present invention will be further described in detail below with reference to the accompanying drawings.

[0025] refer to Figure 1 , Figure 1 FIG. 1 shows a schematic structural diagram of a printed circuit board device 1. Figure 1 As shown, the printed circuit board 101 (ie, PCB board) is connected to the metal housing 103 via a thermal pad 102 .

[0026] Specifically, continue to refer to Figure 1 , along the first direction (such as Figure 1 A high-power transistor 104 is arranged on one side of the printed circuit board 101 (shown in the Z direction), and the other side is connected to a thermal pad 102, and the thermal pad 102 is arranged between the printed circuit board 101 and the metal housing 103. Therefore, the heat generated by the transistor 104 on the printed circuit board 101 can be transferred to the metal housing 103 through the thermal pad 102, and then the metal housing 103 transfers the heat away, thereby achieving the purpose of heat dissipation.

[0027] The thermal pad 102 has two functions, including: 1. reducing the thermal resistance between the printed circuit board 101 and the metal housing 103; 2. the thermal pad 102 can be compressed under the action of external force to compensate for the tolerance between the printed circuit board 101 and the metal housing 103. Exemplarily, the thickness h0 of the thermal pad 102 includes 0.08 mm to 0.10 mm.

[0028] It is understood by those skilled in the art that in order to compensate for the tolerance between the printed circuit board 101 and the metal housing 103, it is necessary to select a thermal pad 102 with a large thickness. However, when the size of the thermal pad 102 is constant, the thermal resistance of the thermal pad 102 is proportional to the thickness of the thermal pad. That is, the greater the thickness of the thermal pad 102, the greater the thermal resistance of the thermal pad 102. Therefore, in the above-mentioned embodiment of the prior art, the heat dissipation effect between the printed circuit board 101 and the metal housing 103 is not good.

[0029] Based on the above problems, reference Figure 2 Combined with Figure 3 , an embodiment of the present application provides a printed circuit board device 2. Figure 2 shows a schematic structural diagram of a printed circuit board device 2, Figure 3 FIG. 2 shows a schematic diagram of the structure of the heat sink 203. Figure 2 As shown, the printed circuit board device 2 includes: a printed circuit board 201, a thermal pad 202, a heat sink 203 and a metal shell 204. The printed circuit board 201 is configured to be installed on the metal shell 204, and the thermal pad 202 is arranged on a side of the printed circuit board 201 close to the metal shell 204, along a first direction (such as Figure 2 The heat sink 203 is disposed between the metal housing 204 and the thermal pad 202. For example, the thickness h1 of the thermal pad 202 in the embodiment of the present application is comprised between 0.1 mm and 0.3 mm.

[0030] Specifically, the first heat conducting portion 2031 (described later) of the heat sink 203 is configured to abut against the thermal pad 202, and the second heat conducting portion 2032 (described later) of the heat sink 203 is configured to be welded to the metal housing 204. However, the present invention is not limited to this, and the embodiment of the present application does not limit the connection method between the heat sink 203 and the printed circuit board 201 and the metal housing 204, as long as the heat sink 203 can conduct heat between the printed circuit board 201 and the metal housing 204.

[0031] The heat sink 203 of the embodiment of the present application is described in detail below with reference to the accompanying drawings.

[0032] like Figure 3 As shown, the heat sink 203 provided in the embodiment of the present application includes: a first heat conducting portion 2031, a second heat conducting portion 2032 and a flexible heat conducting structure 2033. The first heat conducting portion 2031 and the second heat conducting portion 2032 are arranged along a first direction (eg Figure 3 (shown in the Z direction) interval setting.

[0033] Specifically, along the first direction Z, the flexible heat-conducting structure 2033 connects the second heat-conducting part 2032 and the first heat-conducting part 2031 , and is configured to be supported between the first heat-conducting part 2031 and the second heat-conducting part 2032 and transfer heat between the second heat-conducting part 2032 and the first heat-conducting part 2031 .

[0034] In some possible implementations, reference Figure 3 Combined with Figure 4 The flexible heat-conducting structure 2033 includes a plurality of Figure 3 The thermal conductive fin 20331 extends in the Y direction.

[0035] Specifically, the plurality of heat conducting fins 20331 are arranged along a third direction (eg Figure 3 X direction) are arranged at intervals, along the first direction (as shown in Figure 3 One end 20332 of each heat-conducting fin is connected to a side of the first heat-conducting portion 2031 close to the second heat-conducting portion 2032 , and the other end 20333 is connected to a side of the second heat-conducting portion 2032 close to the first heat-conducting portion 2031 .

[0036] Exemplarily, the first heat conducting part 2031 includes a copper plate, the second heat conducting part 2032 includes a copper plate, and the heat conducting fins 2033 include a copper sheet, thereby utilizing the high thermal conductivity of copper to significantly reduce the thermal resistance of the heat sink. However, this is not limited to this, and the embodiment of the present application does not limit the material of the heat sink 203.

[0037] Exemplarily, the second direction Y (i.e., the extension direction of the heat conducting fin 20331) intersects with the first direction Z, and the third direction X is perpendicular to the first direction Z. The angle between the second direction Y and the first direction Z is α, 0 degrees <α < 90 degrees; but not limited to this, the embodiment of the present application does not specifically limit the angle α, for example, it can be 15 degrees, 30 degrees, 45 degrees, 55 degrees, 80 degrees, etc.

[0038] In addition, the heat conducting fins 20331 can be deformed under the action of external force, that is, the flexible heat conducting structure 2033 can be deformed under the action of external force, so that the second heat conducting part 2032 moves relative to the first heat conducting part 2031 .

[0039] That is, when the first heat-conducting part 2031 and / or the second heat-conducting part 2032 of the heat sink 203 is subjected to external force, since the two ends of the heat-conducting fin 20331 are respectively connected to the first heat-conducting part 2031 and the second heat-conducting part 2032, the external force exerted on the first heat-conducting part 2031 and / or the second heat-conducting part 2032 will be transmitted to at least part of the multiple heat-conducting fins 20331, so as to drive the heat-conducting fins 20331 to deform.

[0040] Those skilled in the art will appreciate that the flexible heat-conducting structure 2033 is capable of supporting the first heat-conducting part 2031 and the second heat-conducting part 2032 when no external force is applied, and is deformed when an external force is applied, for example, a portion of the heat-conducting fin 20331 is deformed to deviate from the second direction Y (i.e., the extension direction of the heat-conducting fin 20331).

[0041] Thus, the flexible heat-conducting structure 2033 of the embodiment of the present application is supported between the first heat-conducting part 2031 and the second heat-conducting part 2032 to transfer heat between the first heat-conducting part 2031 and the second heat-conducting part 2032. Compared with the thermal pad 102 in the prior art, on the one hand, the heat sink 203 of the embodiment of the present application has a low thermal conductivity and a good heat dissipation effect. On the other hand, under the action of external force, the flexible heat-conducting structure 2033 of the embodiment of the present application can be deformed so that the distance between the first heat-conducting part 2031 and the second heat-conducting part 2032 of the heat sink 203 changes with the deformation of the flexible heat-conducting structure 2033, thereby compensating for the tolerance between the printed circuit board 201 and the metal shell 204.

[0042] For example, Figure 3 and Figure 4 As shown, the thickness h2 of the first heat conducting part 2031 is 0.3 mm to 0.6 mm, the thickness h3 of the second heat conducting part 2032 is 0.3 mm to 0.6 mm, the thickness h4 of the heat conducting fin 20331 is 0.05 mm to 0.07 mm, and the length L1 of the heat conducting fin 20332 is 3.1 mm to 3.4 mm.

[0043] The thermal resistance of the printed circuit board device 2 provided in the embodiment of the present application is compared with that of the printed circuit board device 1 in the prior art by way of example below.

[0044] Assuming that the length×width×thickness of the thermal pad 102 is 20 mm×10 mm×0.08 mm and the thermal conductivity is 5 W, the thermal resistance of the thermal pad 102 is:

[0045] 0.0008m / (5W / m 2 K×0.02m×0.01m)=0.8℃ / W

[0046] Therefore, the thermal resistance of the printed circuit board assembly 1 in the prior art is 0.8° C. / W.

[0047] Assuming that the length×width×thickness of the thermal pad 202 is 20 mm×10 mm×0.02 mm and the thermal conductivity is 5 W, the thermal resistance of the thermal pad 102 is:

[0048] 0.0002m / (5W / m 2 K×0.02m×0.01m)=0.2℃ / W

[0049] The thermal conductivity of the heat sink 203 is 398W, and the length×width×thickness of the first heat conducting part 2031 and the second heat conducting part 2032 is

[0050] =20mm×10mm×0.05mm, the thermal resistance of the first heat conducting part 2031 and the second heat conducting part 2032 is:

[0051] 0.0005m / (398W / m 2 K×0.02m×0.01m)=0.006℃ / W

[0052] The length×width×thickness of the heat conducting fin 20331=0.06mm×10mm×0.3mm, so the thermal resistance of a single heat conducting fin 20331 is:

[0053] 0.003m / (398W / m 2 K×0.0006m×0.01m)=1.3℃ / W

[0054] There are 135 heat conducting fins 20331 in total, so the thermal resistance of the heat conducting fins 20331 connected in parallel is: 1.3 / 135=0.01℃ / W

[0055] The thermal conductivity of solder 205 = 66.8W, the length × width × thickness of solder 205 = 20mm × 10mm × 0.02mm, then the thermal resistance of solder 205 is:

[0056] 0.0002m / (66.8W / m 2 K×0.02m×0.01m)=0.015℃ / W

[0057] Total thermal resistance = 0.2 + 0.006 × 2 + 0.01 + 0.015 = 0.237 ° C / W

[0058] Therefore, the thermal resistance of the printed circuit board device 2 provided in the embodiment of the present application is 0.237° C. / W, which is 70% lower than the thermal resistance of the printed circuit board device 2 in the prior art.

[0059] In summary, the heat sink 203 in the embodiment of the present application has both high thermal conductivity and the function of providing flexibility to compensate for the tolerance between the printed circuit board 201 and the metal shell 204. Compared with the thermal pad 102 with a larger thickness (for example, 0.8 mm) used in the prior art, the thermal pad 202 in the embodiment of the present application has a smaller thickness (for example, 0.2 mm), which can avoid collision between the printed circuit board 201 and the metal shell 204 and also make the overall thermal conductivity efficiency between the printed circuit board 201 and the metal shell 204 higher.

[0060] Although the present invention has been illustrated and described with reference to certain preferred embodiments of the present invention, it should be understood by those skilled in the art that the above contents are further detailed descriptions of the present invention in combination with specific embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. Those skilled in the art may make various changes in form and details, including making several simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A heat sink, characterized in that: include: a first heat conducting portion; A second heat conducting portion, wherein the first heat conducting portion and the second heat conducting portion are spaced apart along a first direction; A flexible heat-conducting structure, along the first direction, the flexible heat-conducting structure connects the second heat-conducting part and the first heat-conducting part, the flexible heat-conducting structure is configured to be supported between the first heat-conducting part and the second heat-conducting part, and transfer heat between the second heat-conducting part and the first heat-conducting part; wherein, The flexible heat-conducting structure can be deformed under the action of an external force, so that the second heat-conducting part moves relative to the first heat-conducting part.

2. The heat sink according to claim 1, characterized in that: The flexible heat-conducting structure includes a plurality of heat-conducting fins extending along a second direction, wherein the plurality of heat-conducting fins are arranged at intervals along a third direction, and along the first direction, one end of each of the heat-conducting fins is connected to a side of the first heat-conducting portion close to the second heat-conducting portion, and the other end is connected to a side of the second heat-conducting portion close to the first heat-conducting portion, the second direction intersects the first direction, and the third direction is perpendicular to the first direction; wherein the heat-conducting fins can be deformed under the action of an external force.

3. The heat sink according to claim 2, characterized in that: The included angle between the second direction and the first direction is α, 0 degrees < α < 90 degrees.

4. The heat sink according to claim 2, characterized in that: The thickness of the first heat conducting portion is 0.3 mm to 0.6 mm, the thickness of the second heat conducting portion is 0.3 mm to 0.6 mm, the thickness of the heat conducting fin is 0.05 mm to 0.07 mm, and the length of the heat conducting fin is 3.1 mm to 3.4 mm.

5. The heat sink according to any one of claims 2 to 4, characterized in that: The first heat conducting part includes a copper plate, the second heat conducting part includes a copper plate, and the heat conducting fin includes a copper sheet.

6. A printed circuit board device with a heat sink, characterized in that: include: Metal housing; a printed circuit board configured to be mounted on the metal housing; A thermal pad is provided on a side of the printed circuit board close to the metal shell; The heat sink according to any one of claims 1 to 5, along the first direction, the heat sink is arranged between the metal shell and the thermal pad, the first thermal conductive portion is configured to abut against the thermal conductive pad, and the second thermal conductive portion is configured to be welded to the metal shell.

7. The printed circuit board device with heat sink according to claim 6, characterized in that: The thickness of the thermal pad is in a range of 0.1 mm to 0.3 mm.

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