Thermally conductive plastic heat dissipation units, lighting equipment, electronic devices

Abstract

To provide a thermally conductive plastic heat dissipation unit that prevents the thermal resistance of a thermally conductive adhesive or a thermally conductive gasket layer from affecting heat transfer between a heat sink and a PCB (printed circuit board), and that improves manufacturing efficiency by eliminating the need to attach a thermally conductive adhesive or a thermally conductive gasket, thereby reducing overall costs. [Solution] A thermally conductive plastic heat dissipation unit including a heat sink (1) and a PCB (2), wherein the heat sink (1) has a heat dissipation area, the PCB (2) has a heat transfer area on its rear surface, the heat transfer area covers part or all of the rear surface of the PCB (2), and the circuits and / or electronic components on the PCB (2) are arranged to avoid the heat transfer area, the heat sink (1) is made of a thermally conductive plastic with a thermal conductivity of 3 to 50 W / (m·K), and the heat sink (1) and PCB (2) are integrally molded using an insert molding process, bringing the heat dissipation area and the heat transfer area into close contact.

Description

[Technical Field]

[0001] The present invention relates to the field of heat dissipation technology, specifically to thermally conductive plastic heat dissipation units, lighting devices, and electronic devices. [Background technology]

[0002] With the rapid development of electronic technology, PCBs (Printed Circuit Boards), also known as circuit boards, integrated circuit boards, control boards, etc., as supports for electronic components, are becoming increasingly integrated and miniaturized. To extend the service life of PCBs, it is necessary to quickly dissipate the heat generated by heat sources such as CPUs, GPUs, and LED units on the PCB.

[0003] For heat sources with high heat dissipation needs, additional heat sink structures are generally used to achieve heat dissipation. There are solutions using metal materials for the heat sink, solutions using thermally conductive plastic materials, and even solutions using thermally conductive plastic to increase the contact between the metal piece and the heat source, thereby improving the heat dissipation effect of the thermally conductive plastic heat sink. However, due to the shrinkage of the heat sink during the injection molding and cooling process, the heat dissipation area is microscopically uneven and not flat (this may also appear macroscopically). The microscopic flatness is insufficient, and when it is directly attached to the heat source of the PCB, gaps remain between the uneven areas, and the gaps are often filled with a medium such as air, which greatly reduces the heat conduction effect of the area. Therefore, in the prior art, a thermally conductive adhesive or a thermally conductive gasket is placed between the heat source and the heat sink to fill in the uneven microscopic structure in the heat dissipation area as much as possible, thereby realizing a heat dissipation path between the PCB and the heat sink. However, the thermally conductive adhesive or the thermally conductive gasket has the following technical problems: 1. Low cost, but poor thermal conductivity, which limits the heat dissipation effect between the heat source and the heat sink; 2. Even if the thermal conductivity performance is good, the cost is too high, and the cost of the heat dissipation solution is too high, making it difficult to be widely used; 3. After that, the installation step of thermal conductive adhesive or thermal conductive gasket needs to be added, and it is generally performed manually, resulting in low manufacturing efficiency and high overall costs; 4. The PCB cannot be fixed simply by thermally conductive adhesive or a thermally conductive gasket, but needs to be drilled with screw holes and then locked to the heatsink with screws. This solution requires manual operations to drill holes in the PCB and fix the PCB and the heatsink together, resulting in low manufacturing efficiency. Summary of the Invention [Problem to be solved by the invention]

[0004] In order to overcome the above-mentioned technical problems in the prior art, the present invention aims to provide a thermally conductive plastic heat dissipation unit, lighting device, and electronic device with good heat dissipation effect, low overall cost, and high manufacturing efficiency, which is specifically achieved by the following technical solutions: [Means for solving the problem]

[0005] A thermally conductive plastic heat dissipation unit includes a heat sink and a PCB, the heat sink has a heat dissipation area, the PCB has a heat transfer area on its rear surface, the area of ​​the heat transfer area covers part or all of the rear surface of the PCB, circuits and / or electronic components on the PCB are arranged to avoid the heat transfer area, the heat sink uses a thermally conductive plastic with a thermal conductivity of 3 to 50 W / (m·K), and the heat sink and PCB are integrally molded using an insert molding process, so that the heat dissipation area and the heat transfer area are in close contact with each other.

[0006] Preferably, the substrate of the PCB includes an aluminum plate or a ceramic plate.

[0007] Preferably, the PCB is further provided with an insert fixing hole that can fix the position of the PCB during the insert molding process.

[0008] Preferably, the positioning mechanism includes a position limiting post provided on the heat sink and a position limiting hole provided on the PCB to engage with the position limiting post.

[0009] Preferably, the heat sink is further provided with a fixing mechanism for assembling the heat sink.

[0010] Preferably, the heat sink is provided with several fins.

[0011] Preferably, the area of ​​the heat transfer region covers part or all of the back surface of the PCB.

[0012] Preferably, when the area of ​​said heat transfer area covers a part of the back surface of the PCB, the area of ​​the heat dissipation area on the heat sink is correspondingly equal to or greater than the area of ​​the heat transfer area.

[0013] The present application further provides a lighting device, comprising a thermally conductive plastic heat dissipation unit according to any one of the solutions above, wherein an LED module is provided on the PCB, and the heat transfer area comprises the heat dissipation portion of the LED module.

[0014] The present application further provides an electronic device, which includes the thermally conductive plastic heat dissipation unit according to any one of the above solutions. [Effects of the Invention]

[0015] Compared to the prior art, the present invention has the following beneficial advantages: The thermally conductive plastic heat sink and PCB are integrally molded using an insert molding process, allowing the heat transfer area and heat dissipation area to be directly in contact with each other. This avoids the thermal resistance of the thermally conductive adhesive or gasket layer that affects heat transfer between the heat sink and PCB, unlike prior art solutions that use thermally conductive adhesive or gaskets. It also eliminates the need for the installation step of the thermally conductive adhesive or gasket, improving manufacturing efficiency, reducing overall costs, and contributing to widespread adoption. In this application, there is no need to drill fixing holes in the PCB to secure the heat sink to the PCB with screws, increasing the PCB's integration density and further reducing the overall volume, saving space in the entire module and better meeting the trend toward miniaturization. Furthermore, there is no need to screw the PCB and heat sink together, eliminating the manual assembly step, further improving manufacturing efficiency. In the solution of the present application, for thermally conductive plastics with a thermal conductivity in the range of 3 to 50 W / (m·K), the circuits and / or electronic components on the PCB are restricted to be placed away from the heat dissipation area, thereby avoiding problems such as creeping discharge, short circuits, and circuit failure due to conduction that may be adversely affected by filling thermally conductive plastics with conductive materials such as graphene. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a three-dimensional view of the thermally conductive plastic heat dissipation unit described in Example 1. FIG. [Figure 2] FIG. 2 is an exploded view of the thermally conductive plastic heat dissipation unit described in Example 1. [Figure 3] 1 is a three-dimensional view of the rear surface of the PCB of the thermally conductive plastic heat dissipation unit described in Example 1. FIG. [Figure 4] FIG. 10 is a three-dimensional view of the thermally conductive plastic heat dissipation unit described in Example 2. [Figure 5] FIG. 10 is an exploded view of the thermally conductive plastic heat dissipation unit described in Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, specific embodiments of the present application will be described in detail through examples. However, the specific embodiments of the present application do not limit the technical solutions of the present application, and any non-substantial changes, such as replacing conventional technical solutions in the art with the technical solutions described in the examples of the present application, fall within the scope of protection of the present application.

[0018] In the present application, the thermally conductive plastic having a thermal conductivity of 3 to 50 W / (m·K) may be a conventional material or may be directly purchased from a commercially available source. In the examples of the present application, the thermal conductivity is measured according to the ASTM E1641 standard.

[0019] Here, the electronic components in the "circuits and / or electronic components on the PCB are arranged to avoid the heat dissipation area" described in this application are heat sources that require heat dissipation and do not include electronic components that do not require insulation performance. For example, CPUs, GPUs, processors, LED modules, etc. require heat dissipation and are directly attached to the heat transfer surface, so they are not affected by the weak electrical conductivity of thermally conductive plastics.

[0020] Example 1 The thermally conductive plastic heat dissipation unit of Figures 1, 2, and 3 includes a heat sink 1 and a PCB 2, wherein the heat sink 1 has a heat dissipation area 11, the rear surface of the PCB 2 has a heat transfer area 21, the area of ​​the heat transfer area 21 covers part or all of the rear surface of the PCB 2, the circuits and / or electronic components on the PCB 2 are arranged to avoid the heat transfer area 21, the heat sink 1 is made of a thermally conductive plastic with a thermal conductivity of 3 to 50 W / (m·K), and the heat sink 1 and PCB 2 are integrally molded using an insert molding process, so that the heat dissipation area 11 and the heat transfer area 21 are in close contact with each other.

[0021] In this embodiment, the substrate 23 of the PCB 2 is an aluminum plate. In this embodiment, the PCB 2 is basically composed of the substrate 23, an insulating layer, a circuit printed on the insulating layer, and electronic components fixed to the insulating layer. The aluminum plate has a higher thermal conductivity and a better heat transfer effect, quickly dissipating the temperature of the heat source and then transferring it to the heat sink for heat dissipation. In other embodiments, the substrate 23 may be a ceramic plate or a circuit board made of a general plastic material, and may be positioned away from the heat transfer area 21 and closely contact the heat dissipation area 11. Filling a thermally conductive plastic with a conductive material such as graphene with high thermal conductivity avoids adverse effects on the circuit or electronic components, such as creepage discharge, short circuits, and circuit failure due to conduction.

[0022] Here, it will be understood by those skilled in the art that the shape of the PCB 2 in FIG. 1 is merely an example and is not limiting.

[0023] In this embodiment, the heat dissipation area 11 and the heat transfer area 21 are closely attached by fitting the substrate 23 of the PCB 2 into the recess of the heat sink 1, thereby reducing the overall volume of the thermally conductive plastic heat dissipation unit, saving space and contributing to the miniaturization of electronic devices. In other embodiments, the need for a fitted arrangement is not necessary, as long as the need for a close attachment between the heat dissipation area 11 and the heat transfer area 21 is met through the insert molding process.

[0024] In this embodiment, the positioning mechanism includes a position limiting post 12 on the heatsink 1 and a position limiting hole 25 on the PCB 2 that engages with the position limiting post 12. This prevents the heatsink 1 and PCB 2 from shifting relative to each other along their mating surfaces. At the same time, friction between the side of the position limiting post 12 and the thickness direction of the PCB 2 prevents the PCB 2 from slipping out of the heatsink 1 in a direction perpendicular to the mating surfaces, thereby improving the connection strength of the insert. The position limiting posts 12 and the position limiting holes 25 may be one or more, and may be configured by those skilled in the art according to their needs. See FIG. 2. Other positioning mechanisms may be used in other embodiments, as long as they prevent the heatsink 1 and PCB 2 from shifting relative to each other.

[0025] In this embodiment, the PCB 2 is further provided with insert fixing holes 24 that can fix the position of the PCB 2 during the insert molding process.

[0026] In this embodiment, the heat sink 1 is further provided with a fixing mechanism 14 for assembling the heat sink 1, and the fixing mechanism 14 has a hollow hole structure and is used to engage with a bolt or a screw for fixing. In other embodiments, those skilled in the art may select and combine solutions such as a post, a screw hole, a buckle, etc. according to needs, and all of them fall within the scope of the solution of this application.

[0027] In this embodiment, the heat sink 1 is provided with several fins 13, which are arranged side by side on the other side of the heat sink area 11.

[0028] In this embodiment, the area of ​​the heat transfer region 21 covers the entire rear surface of the PCB 2, i.e., it completely encloses the rear surface of the PCB 2.

[0029] In another embodiment, the area of ​​the heat transfer area 21 covers a part of the rear surface of the PCB 2, and the area of ​​the heat dissipation area 11 on the heat sink 1 is correspondingly equal to or greater than the area of ​​the heat transfer area 21. This solution can be adopted when there are other electronic components on the rear surface of the PCB 2 in addition to the heat transfer area 21, making it difficult to fit them all to the heat sink 1. Other situations are also possible, for example, if there are no other electronic components on the rear surface of the PCB 2 that need to be avoided from the heat transfer area, the heat transfer area 21 and the heat dissipation area 11 can be fitted together.

[0030] Example 2 4 and 5, the heat dissipation unit is made of thermally conductive plastic and has the same structure as that of Example 1, except that in this example, the heat dissipation area 11 and the heat transfer area 21 are not fitted in the recess of the heat sink 1 by structural reasons, but are directly in contact with each other. See FIG. 5 for details.

[0031] In this embodiment, there is one position limiting post 12 and one position limiting hole 25 that engages with it, and the position limiting post 12 is oval in shape, which can simultaneously limit the rotational displacement along the position limiting post 12. In other embodiments, multiple position limiting posts may be provided, and they may be used in combination with the cylindrical post of the first embodiment.

[0032] Example 3 A lighting device includes the thermally conductive plastic heat dissipation unit according to Example 1, in which the PCB 2 in this example is provided with an LED module 22, and the heat transfer area 21 includes the heat dissipation portion of the LED module 22. For ease of understanding, this is shown in FIG. 2 of Example 1, and is not separately illustrated in this example.

[0033] In another embodiment, the LED module 22 may further include the heat-conductive plastic heat dissipation unit as described in the second embodiment, and the LED module 22 may be referred to in FIG. 5 and will not be described further here.

[0034] Example 4 An electronic device includes the thermally conductive plastic heat dissipation unit described in Example 1. In this example, the PCB 2 is provided with a heat source that requires heat dissipation, such as a CPU or GPU, and the heat transfer area 21 includes a heat dissipation portion of the heat source that requires heat dissipation, such as the CPU or GPU.

[0035] Here, the above examples are not exhaustive and are merely illustrative. Those skilled in the art may determine the specific position and shape of each component based on the concept of this application and in combination with actual needs, without exceeding the scope of protection of this application. [Explanation of symbols]

[0036] 1...radiator; 11...heat dissipation area; 12 ···Position limiting column; 13 ···Fin; 14...Fixing mechanism; 2 ··· PCB; 21 ···Heat transfer area; 22 ···LED module; 23 ···Substrate; 24 ···insert fixing holes; 25 ···Position limiting hole.

Claims

1. A thermally conductive plastic heat dissipation unit comprising a heat sink and a PCB, wherein the heat sink has a heat dissipation area, the rear surface of the PCB has a heat transfer area, the area of ​​the heat transfer area covers part or all of the rear surface of the PCB, circuits and / or electronic elements on the PCB are arranged to avoid the heat transfer area, the heat sink is made of a thermally conductive plastic having a thermal conductivity of 3 to 50 W / (m·K), the heat sink and the PCB are integrally molded by an insert molding process, and the heat dissipation area and the heat transfer area are closely attached to each other.

2. 2. The heat dissipation unit of claim 1, wherein the PCB substrate comprises an aluminum plate or a ceramic plate.

3. 2. The heat dissipation unit according to claim 1, wherein the positioning mechanism includes a position limiting post provided on the heat sink and a position limiting hole provided on the PCB to engage with the position limiting post.

4. 2. The thermally conductive plastic heat dissipation unit according to claim 1, wherein the PCB further comprises an insert fixing hole for fixing the position of the PCB during an insert molding process.

5. The heat dissipation unit according to claim 1 , wherein the heat dissipation unit further comprises a fixing mechanism for assembling the heat dissipation unit.

6. 2. The heat-dissipating unit of claim 1, wherein the heat sink is provided with several fins.

7. The thermally conductive plastic heat dissipation unit of claim 1 , wherein the area of ​​the heat transfer region covers a part or the whole of the rear surface of the PCB.

8. The thermally conductive plastic heat dissipation unit of claim 7, wherein when the area of ​​the heat transfer area covers a portion of the rear surface of the PCB, the area of ​​the heat dissipation area on the heat sink is correspondingly equal to or greater than the area of ​​the heat transfer area.

9. 10. A lighting device comprising the thermally conductive plastic heat dissipation unit according to claim 1, wherein the PCB is provided with an LED module, and the heat transfer area includes the heat dissipation portion of the LED module.

10. An electronic device comprising the thermally conductive plastic heat dissipation unit according to any one of claims 1 to 8.

Images