Electronic device and heat dissipation grounding structure thereof

Abstract

The present disclosure relates to an electronic device and a heat dissipation grounding structure thereof, the heat dissipation grounding structure comprising: a printed circuit board comprising a heating element; a heat sink arranged on a side of the printed circuit board where the heating element is arranged, for heat dissipation of the heating element; an elastic support arranged on a side of the printed circuit board away from the heat sink; and a conductive elastic member and a conductive fastener, the conductive fastener being used to connect the elastic support, the printed circuit board and the heat sink, the conductive elastic member being sleeved around the conductive fastener, one end of the conductive elastic member being connected with the conductive fastener, and the other end being connected with a pad on the printed circuit board. The present disclosure directly grounds the heat sink to the printed circuit board by means of the conductive fastener and the conductive elastic member sleeved around the conductive fastener, which can reduce the area of the pad on the printed circuit board, reduce the manufacturing cost, and also save the occupied area of the printed circuit board.

Description

Technical Field

[0001] This disclosure relates to the field of electronic and electrical design technology, and more specifically, to an electronic device and its heat dissipation and grounding structure. Background Technology

[0002] Components on printed circuit boards (PCBs) of electronic devices generate heat during operation, such as graphics cards. To ensure their proper functioning, heatsinks are typically installed for cooling. However, the PCIe protocol (Peripheral Component Interconnect Express, a high-speed serial computer expansion bus standard) imposes height restrictions on the back of graphics cards. Specifically, the maximum height of any mechanism or component mounted on the back of the graphics card cannot exceed 2.67mm from the back of the PCB. As power consumption continues to increase, heatsinks are becoming increasingly heavy. Therefore, traditional spring screw designs alone cannot provide sufficient spring force to secure the heatsink within this height limit.

[0003] Most current mid-to-high-end graphics card designs have abandoned the previous method of fixing the heatsink with four spring screws, and instead use leaf springs to fix the heatsink. The leaf springs can provide sufficient elasticity, and the torque generated after locking is very small, resulting in less PCB board deformation. This reduces the risk of solder joint cracking, improves the reliability of the main chip, and the back-mounted design ensures the integrity of the heatsink fins on the front, thus improving the product's heat dissipation capacity.

[0004] In related technologies, in order to solve the grounding problem of the heat sink in the flexible support structure, additional costs are required to connect multiple grounding springs between the front of the printed circuit board and the metal heat sink. This setup requires reserving multiple pad positions on the printed circuit board, which occupies a lot of valuable space on the printed circuit board. Summary of the Invention

[0005] The purpose of this disclosure is to provide an electronic device and its heat dissipation grounding structure. This heat dissipation grounding structure uses conductive fasteners and conductive elastic elements sleeved on the conductive fasteners to directly ground the heat sink to the printed circuit board, which can reduce the area of ​​the solder pads on the printed circuit board, reduce manufacturing costs, and also save the area occupied by the printed circuit board.

[0006] To achieve the above objectives, in a first aspect, this disclosure provides a heat dissipation grounding structure for an electronic device, the heat dissipation grounding structure comprising:

[0007] Printed circuit boards, including heat-generating elements;

[0008] A heat sink is provided on the side of the printed circuit board where the heat-generating element is located, for dissipating heat from the heat-generating element;

[0009] A flexible support is provided on the side of the printed circuit board away from the heat sink; and

[0010] A conductive elastic element and a conductive fastener are provided. The conductive fastener is used to connect the elastic bracket, the printed circuit board and the heat sink. The conductive elastic element is sleeved around the conductive fastener, and one end of the conductive elastic element is connected to the conductive fastener, and the other end is connected to the pad on the printed circuit board.

[0011] Optionally, the heat dissipation grounding structure includes a back plate, which is disposed on the side of the printed circuit board away from the heat sink, and the elastic bracket is disposed between the printed circuit board and the back plate.

[0012] Optionally, the conductive elastic element is configured as a spring, and the conductive fastener is configured as a screw;

[0013] The elastic bracket is provided with a first mounting hole for the screw to pass through; the printed circuit board is provided with a second mounting hole for the screw to pass through and corresponding to the first mounting hole;

[0014] The screw passes through the first mounting hole and the second mounting hole and is connected to the heat sink. The spring is sleeved on the screw and is located in the first mounting hole. One end of the spring abuts against the solder pad and the other end is connected to the screw.

[0015] Optionally, the spring is a tower-shaped spring.

[0016] Optionally, the pad is arranged around the circumference of the second mounting hole, and the inner diameter of the pad coincides with the outer diameter of the second mounting hole, and the outer diameter of the pad is larger than the large end diameter of the tower spring.

[0017] Optionally, the tower spring is configured to compress along its height direction to a wire diameter height.

[0018] Optionally, the screw includes a screw head and a threaded rod for connection with the heat sink;

[0019] The diameter of the screw head is larger than the diameter of the first mounting hole.

[0020] Optionally, a countersunk hole is provided on the side of the first mounting hole away from the printed circuit board, which is coaxially arranged with the first mounting hole, and the diameter of the countersunk hole is larger than the diameter of the screw head.

[0021] Optionally, the screw includes an intermediate section and a lower section. One end of the intermediate section is connected to the screw head, and the other end is connected to the lower section. The lower section has an external thread, and the diameter of the lower section is smaller than the diameter of the intermediate section.

[0022] Optionally, the difference between the diameter of the intermediate rod segment and the diameter of the lower rod segment is greater than or equal to 0.9 mm.

[0023] Optionally, the screw further includes an upper rod section, the diameter of which is smaller than the diameter of the intermediate rod section and larger than the diameter of the lower rod section.

[0024] Optionally, the spring is a tower spring, wherein the diameter of the small end of the tower spring is greater than or equal to the diameter of the upper rod segment and less than the diameter of the middle rod segment; and the diameter of the large end of the tower spring is less than the diameter of the first mounting hole and greater than the diameter of the second mounting hole.

[0025] Optionally, the back plate has a receiving portion for mounting the elastic bracket on the side facing the printed circuit board.

[0026] Optionally, the minimum gap between the elastic support and the bottom wall of the receiving part is 0.1 mm;

[0027] The gap between the elastic support and the printed circuit board is 0.1-0.9 mm.

[0028] In a second aspect, this disclosure also provides an electronic device, which includes the above-described heat dissipation grounding structure.

[0029] The above-described technical solution, namely the heat dissipation grounding structure disclosed herein, involves placing an elastic bracket on the side of the printed circuit board away from the heat sink to support the printed circuit board and the heat sink thereon. Conductive fasteners connect the elastic bracket, the printed circuit board, and the heat sink, and conductive elastic elements are fitted onto the conductive fasteners. This allows the elastic bracket to provide sufficient elasticity to lock the heat sink in place, preventing deformation of the printed circuit board. Simultaneously, the conductive elastic elements and conductive fasteners connect the pads on the side of the printed circuit board away from the heat sink to the heat sink, thus grounding the heat sink. This structural arrangement, using conductive fasteners and conductive elastic elements fitted onto the conductive fasteners to directly ground the heat sink to the printed circuit board, reduces the area of ​​the pads on the printed circuit board, lowers manufacturing costs, and saves the footprint of the printed circuit board.

[0030] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0031] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0032] Figure 1This is a disassembled diagram of the heat dissipation grounding structure of an electronic device provided in some embodiments of this disclosure;

[0033] Figure 2 This is a diagram showing the connection structure of the elastic bracket, screws, and springs of the heat dissipation grounding structure of an electronic device provided in some embodiments of this disclosure;

[0034] Figure 3 This is an anatomical diagram of the printed circuit board, elastic bracket, screws, and springs of the heat dissipation grounding structure of an electronic device provided in some embodiments of this disclosure;

[0035] Figure 4 This is a diagram showing the connection structure of screws and springs in the heat dissipation grounding structure of an electronic device provided in some embodiments of this disclosure;

[0036] Figure 5 This is a structural diagram of the screws of the heat dissipation grounding structure of the electronic device provided in some embodiments of this disclosure;

[0037] Figure 6 This is a structural diagram of the tower-shaped spring in the heat dissipation grounding structure of an electronic device provided in some embodiments of this disclosure;

[0038] Figure 7 This is a side sectional view of a first form of the heat dissipation grounding structure of an electronic device provided in some embodiments of this disclosure;

[0039] Figure 8 Based on Figure 7 A magnified view of a portion of the image;

[0040] Figure 9 This is a side sectional view of a second form of the heat dissipation grounding structure of an electronic device provided in some embodiments of this disclosure;

[0041] Figure 10 Based on Figure 9 A magnified view of a portion of the image.

[0042] Explanation of reference numerals in the attached figures

[0043] 100 - Heat sink; 200 - Printed circuit board; 200a - Solder pad; 200b - Second mounting hole; 300 - Flexible bracket; 300a - First mounting hole; 305 - Screw; 305a - Screw head; 305b - Upper rod section; 305c - Middle rod section; 305d - Lower rod section; 310 - Tower spring; 310a - Small end; 310b - Large end; 400 - Back plate; 405 - Receiving part. Detailed Implementation

[0044] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0045] In this disclosure, unless otherwise stated, directional terms such as "upper," "lower," "left," and "right" generally refer to the upper, lower, left, and right of the corresponding figures; "inner" and "outer" refer to the inner and outer contours of the corresponding components; and "far" and "near" refer to the corresponding structure or component being away from or near another structure or component. Furthermore, the terms "first," "second," etc., used in this disclosure are for distinguishing one element from another and do not have sequential or importance implications. In addition, in the following description, when referring to the figures, unless otherwise explained, the same reference numerals in different figures denote the same or similar elements. The above definitions are for explanation and illustration only and should not be construed as limiting this disclosure.

[0046] like Figures 1 to 10 As shown, to achieve the above objectives, the first aspect of this disclosure provides a heat dissipation grounding structure for an electronic device. This heat dissipation grounding structure includes: a printed circuit board 200, including a heat-generating element; wherein the heat-generating element includes, but is not limited to, a graphics card, and is disposed on the upper side of the printed circuit board 200. A heat sink 100 is disposed on the side of the printed circuit board 200 where the heat-generating element is located, for heat dissipation of the heat-generating element; the heat sink 100 can be made of metal and can have any suitable structure, which is not specifically limited in this disclosure. An elastic bracket 300 is disposed on the side of the printed circuit board 200 away from the heat sink 100, for providing an elastic force towards the lower surface of the printed circuit board 200, supporting the printed circuit board 200 and the heat sink 100, reducing deformation of the printed circuit board 200, thereby reducing the risk of solder joint cracking, improving the reliability of the main chip, and being locked from the back, ensuring the integrity of the heat sink 100 fins on the front, improving the product's heat dissipation capacity. The conductive elastic element and conductive fastener are used to connect the elastic bracket 300, the printed circuit board 200 and the heat sink 100. The conductive elastic element is sleeved around the conductive fastener, and one end of the conductive elastic element is connected to the conductive fastener, for example, it can be a fixed connection or an abutment, which is not specifically limited here. The other end is connected to the pad 200a on the printed circuit board 200.

[0047] Through the above-described technical solution, namely the heat dissipation grounding structure disclosed herein, the side of the printed circuit board 200 away from the heat sink 100 of the elastic bracket 300 is used to support the printed circuit board 200 and the heat sink 100 thereon. Conductive fasteners connect the elastic bracket 300, the printed circuit board 200, and the heat sink 100, and conductive elastic elements are fitted onto the conductive fasteners, enabling the elastic bracket 300 to provide sufficient elasticity to lock the heat sink 100 and prevent deformation of the printed circuit board 200. Simultaneously, the conductive elastic elements and conductive fasteners electrically connect the pads 200a on the side of the printed circuit board 200 away from the heat sink 100 to the heat sink 100, thereby achieving grounding of the heat sink 100. This structural arrangement, using conductive fasteners and conductive elastic elements fitted onto the conductive fasteners to directly ground the heat sink 100 to the printed circuit board 200, reduces the area of ​​the pads 200a on the printed circuit board 200, lowers manufacturing costs, and also saves the area occupied by the printed circuit board 200.

[0048] In some embodiments, the heat dissipation grounding structure further includes a back plate 400, which is disposed on the side of the printed circuit board 200 away from the heat sink 100, and an elastic bracket 300 is disposed between the printed circuit board 200 and the back plate 400. The back plate 400 may also be fixedly connected to the side of the printed circuit board 200 facing away from the heat sink 100. The upper side of the elastic bracket 300 may abut against the printed circuit board 200, and the lower side may abut against the back plate 400. The elasticity of the elastic bracket 300 provides support for the printed circuit board 200, which facilitates the fastening of the printed circuit board 200 and the heat sink 100 disposed on the printed circuit board 200.

[0049] In some embodiments, the conductive elastic element can be constructed as a spring, and the conductive fastener can be constructed as a screw 305; the elastic bracket 300 is provided with a first mounting hole 300a for the screw 305 to pass through; the printed circuit board 200 is provided with a second mounting hole 200b for the screw 305 to pass through and corresponding to the first mounting hole 300a; after the screw 305 passes through the first mounting hole 300a and the second mounting hole 200b, it is connected to the heat sink 100, the spring is sleeved on the screw 305 and is located in the first mounting hole 300a, one end of the spring abuts against the pad 200a, and the other end is connected to the screw 305.

[0050] It is understandable that there are multiple first mounting holes 300a on the elastic bracket 300 and multiple second mounting holes 200b on the printed circuit board 200, which are one-to-one correspondences, and can be used to securely connect the elastic bracket 300, the printed circuit board 200 and the heat sink 100.

[0051] like Figure 1As shown, in some embodiments, the number of first mounting holes 300a and second mounting holes 200b can both be four, and they are arranged in a rectangular shape. It should be noted that the elastic bracket 300 can be constructed using any suitable structure. The elastic bracket 300 can be constructed as an elastic part and a plurality of connecting parts connected to the circumference of the elastic part. The first mounting hole 300a can be provided on the connecting parts. The upper side of the elastic part at least partially abuts against the lower side of the printed circuit board 200, and the lower side of the connecting parts at least partially abuts against the back plate 400, so as to form a support between the back plate 400 and the printed circuit board 200.

[0052] The spring can be made of any conductive spring structure. In some embodiments, the spring can be a tower spring 310. Compared to other types of springs, the tower spring 310 can be further compressed in the height direction to reduce its height dimension, which facilitates meeting the height limit requirements of the PCIe protocol, that is, the maximum height of any mechanism or component mounted on the back of the graphics card cannot exceed 2.67mm from the back of the printed circuit board 200.

[0053] It should be noted that the aforementioned heat-generating component, which is a graphics card, is exemplary. The heat-generating component can also be other components in electronic devices that require heat dissipation, such as CPU (Central Processing Unit) and camera module. Therefore, the elastic bracket 300 and backplate 400 located on the back of the printed circuit board 200 are no longer limited by the height limit of the PCIe protocol, and can be any suitable height for the corresponding arrangement position. Therefore, this disclosure is not only a design limited by the height limit of the PCIe protocol, but can also be a design of other similar or analogous structures that are not limited by the height of the back.

[0054] like Figure 3 As shown, in some embodiments, the pad 200a surrounds the circumference of the second mounting hole 200b, and the inner diameter of the pad 200a coincides with the outer diameter of the second mounting hole 200b. The outer diameter of the pad 200a is larger than the diameter of the large end 310b of the tower spring 310. The pad 200a can be disposed on an annular structure on the lower side of the printed circuit board 200, and the inner diameter of this annular structure corresponds to the outer diameter of the second mounting hole 200b. Its outer diameter is larger than the diameter of the large end 310b of the tower spring 310, and the diameter of the large end 310b of the tower spring 310 needs to be larger than the diameter of the second mounting hole 200b so that the large end 310b of the tower spring 310 can also abut against the pad 200a during compression, ensuring grounding requirements and grounding quality.

[0055] It should be noted that, in some embodiments, in order to ensure the reliability of grounding, the diameter of the large end 310b of the tower spring 310 needs to be at least 1 mm larger than the diameter of the second mounting hole 200b on the printed circuit board 200, and the outer diameter of the pad 200a needs to be at least 2 mm larger than the diameter of the large end 310b of the tower spring 310.

[0056] To further reduce the overall height of the backplate 400 and the flexible bracket 300 on the back side (lower side) of the printed circuit board 200, such as Figure 9 and Figure 10 As shown, in some embodiments, the tower spring 310 is configured to compress along its height direction to a wire diameter height.

[0057] The number of coils and wire diameter of the tower spring 310 can be designed according to actual conditions. The selection should be such that when it is compressed to the maximum compression, all coils are pressed onto a plane, that is, the tower spring 310 can be compressed to the height of a wire diameter, so that the height value at that point can reach a limit value to meet the height limit requirements of the PCIE protocol.

[0058] In some embodiments, the screw 305 includes a screw head 305a and a threaded rod for connecting to the heat sink 100; the diameter of the screw head 305a is larger than the diameter of the first mounting hole 300a. The lower surface of the heat sink 100 is provided with screw holes or stud structures corresponding to the first mounting hole 300a and the second mounting hole 200b, so that the threaded rod of the screw 305 can pass through the first mounting hole 300a and the second mounting hole 200b in sequence and connect to the heat sink 100, thereby connecting the elastic bracket 300, the printed circuit board 200, and the heat sink together.

[0059] In some embodiments, a countersunk hole is provided on the side of the first mounting hole 300a away from the printed circuit board 200, coaxially arranged with the first mounting hole 300a. The diameter of the countersunk hole is larger than the diameter of the screw head 305a. The screw head 305a of the screw 305 can be disposed in the countersunk hole, which can also save space in the thickness direction to a certain extent. It is understood that the depth of the countersunk hole can be greater than or equal to the length of the screw head 305a, so that the entire screw head 305a can be completely placed inside the countersunk hole without being exposed, so that the elastic bracket 300 can directly abut against the back plate 400.

[0060] It should be noted that when the screw 305 is fastened to the elastic bracket 300, the strength and assembly requirements are ensured by the sufficiently large support contact surface and thickness of the screw head 305a. The screw head 305a can be a flat head screw 305 or a beveled head screw 305. The contact surface with the elastic bracket 300 can be either beveled or flat. The beveled contact has a self-positioning function and can provide strong support strength, while the flat contact can absorb more installation tolerances.

[0061] In some embodiments, the screw may include an intermediate section 305c and a lower section 305d. One end of the intermediate section 305c is connected to the screw head 305a, and the other end is connected to the lower section 305d. The lower section 305d has an external thread, and its diameter is smaller than that of the intermediate section 305c. The external thread is used to connect with a screw hole or threaded hole on the radiator 100. The smaller diameter of the lower section 305d with the external thread compared to the intermediate section 305c provides a locking and positioning function, ensuring positioning accuracy. Furthermore, it provides a support platform when the lower section 305d reaches its locked position, supporting the radiator 100.

[0062] To ensure connection with the radiator 100 and to form a sufficiently large support platform, in some embodiments, the diameter difference between the intermediate rod segment 305c and the lower rod segment 305d is greater than or equal to 0.9mm, which is used to form a sufficiently large support platform at the junction of the intermediate rod segment 305c and the lower rod segment 305d to ensure positioning accuracy.

[0063] like Figure 5 As shown, in some embodiments, the screw further includes an upper rod section 305b, the diameter of which is smaller than the diameter of the middle rod section 305c and larger than the diameter of the lower rod section 305d. A concave surface is formed at the upper rod section 305b relative to the screw head 305a and the middle rod section 305c, facilitating the connection of the small end 310a of the tower spring 310 into the concave surface, thus facilitating the positioning of the tower spring 310.

[0064] like Figure 6 As shown, in some embodiments, the spring is a tower-shaped spring 310. The diameter of the small end 310a of the tower-shaped spring 310 is greater than or equal to the diameter of the upper rod segment 305b and less than the diameter of the middle rod segment 305c; the diameter of the large end 310b of the tower-shaped spring 310 is less than the diameter of the first mounting hole 300a and greater than the diameter of the second mounting hole 200b. The diameters of the small end 310a and the large end 310b of the tower-shaped spring 310 are further defined so that the small end 310a can be hooked into the concave surface of the upper rod segment 305b, facilitating the assembly of the screw 305 and the tower-shaped spring 310 into a single unit, thus facilitating transportation and production line assembly. Simultaneously, the diameter of the upper rod segment 305b must be less than the diameter of the middle rod segment 305c, and the minimum diameter of the upper rod segment 305b must not be less than the diameter of the lower rod segment 305d of the screw, to avoid increasing the offset of the tower-shaped spring 310 after installation, which could easily lead to structural interference.

[0065] It is understood that this disclosure does not limit the type of screw 305. Different sizes of heat sinks 100 can be secured with different types of screw 305, as long as the above-mentioned size relationship is met and they are manufacturable.

[0066] To further reduce the height of the components on the back of the printed circuit board 200, such as Figure 1 As shown, in some embodiments, the back plate 400 has a receiving portion 405 for mounting the elastic bracket 300 on the side facing the printed circuit board 200. The receiving portion 405 corresponds in shape to the elastic bracket 300, such that at least a portion of the elastic bracket 300 can be positioned within the receiving portion 405 and contact the bottom of the receiving portion 405. Simultaneously, under the action of the conductive fastener formed by the screw 305, at least a portion of the upper side of the elastic bracket 300 abuts against the lower side of the printed circuit board 200. Furthermore, this configuration of the back plate 400 eliminates the need for cutouts at the corresponding elastic bracket 300 to meet height requirements, thus improving the aesthetic design of the product.

[0067] It should be noted that in some embodiments, the depth of the receiving portion 405 can be less than the thickness of the back plate 400 and less than the thickness of the elastic bracket 300. That is, it can ensure that part of the elastic bracket 300 is located in the receiving portion 405, and at the same time, the back plate 400 can be used without drilling holes in the direction towards the heat sink 100, thereby improving the overall aesthetics.

[0068] The backplate 400 can be connected to the lower side of the printed circuit board 200 using any suitable structure. For example, it can also be fixedly connected to the printed circuit board 200 by multiple screws.

[0069] In some embodiments, the minimum gap between the elastic bracket 300 and the bottom wall of the receiving portion 405 is 0.1mm; the gap between the elastic bracket 300 and the printed circuit board 200 is 0.1-0.9mm. While satisfying the elastic support, it can also meet the requirement of the PCIE protocol that the gap on the back of the graphics card cannot exceed 2.67mm.

[0070] In a second aspect, this disclosure also provides an electronic device that includes the aforementioned heat dissipation grounding structure. Therefore, the electronic device also possesses all the advantages of the aforementioned heat dissipation grounding structure, which will not be elaborated here.

[0071] In one specific embodiment of this disclosure, the dimensional relationship between various structures or components is described using an M2.5 screw 305 as an example. Of course, in actual use, the specific dimensions can be adjusted according to different screw 305 models, as long as the following size relationship is met and it can be manufactured.

[0072] The screw head 305a of screw 305 has a thickness range of 0.5-0.6mm (±0.1mm) and a diameter range of 6.6-7.2mm. The diameter of the first mounting hole 300a on the elastic bracket 300 ranges from 5.6-6.2mm. The diameter of the selected screw head 305a must be at least 1mm larger than the diameter of the selected first mounting hole 300a.

[0073] The male thread diameter of the lower section 305d of screw 305 is 2.5mm, and the length of the lower section 305d should be greater than 5 thread pitches. It needs to be compatible with the female thread size on the heat sink 100. For example, a relatively large heat sink 100 may use an M3.0 screw 305 to be compatible, that is, the diameter of the lower section 305d is 3.0mm.

[0074] The intermediate shank 305c of screw 305 has a diameter of 3.4mm. The diameter of the intermediate shank 305c must be at least 0.9mm larger than the diameter of the lower shank 305d to ensure the positioning accuracy of screw 305 during assembly.

[0075] The diameter of the upper rod section 305b on screw 305 is 2.8mm. The diameter of the upper rod section 305b must be 0.5mm smaller than the diameter of the middle rod section 305c. The minimum diameter of the upper rod section 305b must not be less than the nominal diameter of screw 305 (i.e., the male thread diameter of the lower rod section 305d) to avoid increasing the offset of the tower spring 310 after installation, which could easily lead to structural interference.

[0076] The diameter of the second mounting hole 200b on the printed circuit board 200 is 3.8mm. The diameter of the central screw must be at least 0.3mm smaller than the diameter of the second mounting hole 200b, or the tolerance calculation can be performed without affecting the assembly.

[0077] The initial height of the tower spring 310 is 3mm, the total number of coils is 2.5, and the wire diameter is 0.3mm (±0.03mm). The design selection of the number of coils and wire diameter of the tower spring 310 should ensure that when compressed to the maximum amount, all coils can be pressed onto a single plane, that is, compressed to the height of one wire diameter.

[0078] The diameter of the small end 310a of the tower spring 310 is 3.2-3.3 mm. The diameter of the small end 310a is 0.1-0.3 mm smaller than the diameter of the middle section of the screw 305.

[0079] The diameter of the large end 310b of the tower spring 310 ranges from 5.3 to 5.8 mm. The selection of the large end 310b diameter must be at least 0.4 mm smaller than the diameter of the first mounting hole 300a on the elastic bracket 300. Adaptation is also required; if interference occurs, the diameter range of the large end 310b of the tower spring 310 can be appropriately reduced, or the diameter of the first mounting hole 300a can be increased. The diameter of the large end 310b must be at least 1 mm larger than the diameter of the second mounting hole 200b on the printed circuit board 200.

[0080] The outer diameter of pad 200a on printed circuit board 200 is 7.6mm. The outer diameter of pad 200a must be at least 2mm larger than the diameter of the large end 310b of tower spring 310.

[0081] The wall thickness of the back plate 400 can be 1 mm, and the thickness of the receiving portion 405 of the back plate 400 at the position corresponding to the elastic bracket 300 is 0.5 mm (+0.1 mm).

[0082] The thickness of the elastic bracket 300 can be 1mm. After installation, the gap between the elastic bracket 300 and the receiving part 405 of the back plate 400 is 0.1mm. After installation, the distance between the elastic bracket 300 and the printed circuit board 200 fluctuates between 0.1mm and 0.9mm.

[0083] Due to tolerances in the chip, printed circuit board 200, and structural components, the gap between the elastic bracket 300 and the printed circuit board 200 will have a certain range of fluctuation after assembly. When this gap is at its maximum, the elastic bracket 300 is furthest from the printed circuit board 200. At this time, the tower spring 310, viewed from the side, is in a state of layered stacking, as... Figure 7 and Figure 8As shown. It is necessary to ensure that this configuration also meets the PCIe protocol requirement that the thickness on the back of the graphics card cannot exceed 2.67mm. According to the design values, the height of the tower spring 310 is 1.2mm, plus the thickness of the screw head 305a (0.7mm), plus the distance between the elastic bracket 300 and the backplate 400 (0.1mm), plus the thickness of the receiving part 405 (0.5mm + 0.1mm), which equals 2.6mm < 2.67mm. Therefore, the 2.67mm requirement can be met. When the gap is at its minimum, the bracket is closest to the printed circuit board 200. At this time, the tower spring 310 is in a near-compressed state, that is, the height of the tower spring 310 is 0.4mm (the height in the compressed state is 0.33mm). Under this condition, the requirement of 2.67mm can be met even better (2.5 layers of tower springs 310 stacked to a height of 0.4mm, plus the thickness of the screw head 305a of 0.7mm, plus the distance between the elastic bracket 300 and the back plate 400 of 0.1mm, plus the thickness of the receiving part 405 of 0.5mm (+0.1mm), equals 1.8mm < 2.67mm).

[0084] To ensure that the tower spring 310 maintains a minimum distance of 0.1mm between the elastic support 300 and the printed circuit board 200 under maximum compression, and to prevent structural interference between the tower spring 310 and the first mounting hole 300a of the elastic support 300 and the pad 200a of the printed circuit board 200 under maximum compression, the design parameters for the number of coils, wire diameter, and diameter of each coil of the tower spring 310 are such that when the tower spring 310 is compressed to its maximum compression, all coils are compressed onto a single plane, i.e., it can be compressed to the height of one wire diameter. Ultimately, as shown... Figure 9 and Figure 10 As shown. Because the height occupied by the tower spring 310 when compressed to one wire diameter is 0.3mm, and the outer diameter of the large end 310b of the tower spring 310 is also smaller than the diameter of the first mounting hole 300a of the elastic bracket 300, its 0.3mm height can be absorbed by the thickness at the first mounting hole 300a of the elastic bracket 300. That is, the compressed tower spring 310 is hidden inside the first mounting hole 300a of the elastic bracket 300, thus meeting the requirement that the distance between the elastic bracket 300 and the printed circuit board 200 after installation is 0.1mm. The tower spring 310 will not cause structural interference with the first mounting hole 300a on the elastic bracket 300 even at maximum compression. The outer diameter of the pad 200a must be at least 2mm larger than the diameter of the large end 310b of the tower spring 310, so it will not exceed the diameter of the pad 200a of the printed circuit board 200.

[0085] Based on the above design parameters, the height of the assembled tower spring 310 fluctuates between 0.4 and 1.2 mm. Depending on the wire diameter, number of turns, material, and compression displacement of the selected tower spring 310 from its original height of 3 mm to 1.2 mm, it can provide a spring force greater than 4 N to ensure the minimum grounding impedance requirement at high frequencies.

[0086] It is worth noting that, in this disclosure, the diameter of each segment of the screw 305 is such that it can pass through the first mounting hole 300a and the second mounting hole 200b, ensuring that it can be matched with different heat sinks 100; at the same time, the specifications and dimensions of the spring are limited to ensure that its design can be integrated with the screw 305, and that the spring can pass smoothly through the first mounting hole 300a of the elastic bracket 300 during installation, and that the spring will not fall into the second mounting hole 200b of the printed circuit board 200 during installation, and fully contact the pads 200a of the printed circuit board 200 to ensure grounding effect.

[0087] In summary, the electronic device and its heat dissipation grounding structure disclosed herein can save the cost of multiple additional grounding springs by directly grounding at the mounting hole position of the screw 305. At the same time, since multiple additional grounding springs are no longer required, valuable space on the printed circuit board 200 can be saved.

[0088] Due to the innovative design of this disclosure, the outer diameter of the pad 200a at the second mounting hole 200b of the printed circuit board 200 can be reduced from 10mm to 7.6mm, further saving the space used by the printed circuit board 200.

[0089] The elastic bracket 300 disclosed herein is connected and fixed using a tower spring 310 and screws 305, which ensures sufficient contact force and can provide lower grounding impedance, thereby providing greater help in reducing electromagnetic radiation than the traditional grounding spring method.

[0090] The tower spring 310 disclosed herein can be mounted on the upper rod section 305b of the screw 305, so that when the integrated tower spring 310 and screw 305 are assembled, the tower spring 310 can smoothly pass through the first mounting hole 300a of the elastic bracket 300 and reliably contact the pad 200a of the printed circuit board 200 without causing any production line assembly reliability problems.

[0091] Despite the height limitations of PCIe, the solution disclosed herein can still use a complete backplate 400 design without needing to cut out the corresponding elastic bracket 300 of the backplate 400, while improving the aesthetic design of the product.

[0092] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0093] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0094] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A heat dissipation grounding structure for an electronic device, characterized in that, The heat dissipation grounding structure includes: Printed circuit board (200), including heat-generating elements; A heat sink (100) is disposed on the side of the printed circuit board (200) where the heating element is located, for heat dissipation of the heating element, and the heat sink (100) is made of metal. A flexible support (300) is disposed on the side of the printed circuit board (200) away from the heat sink (100); and Conductive elastic element and conductive fastener, wherein the conductive fastener is used to connect the elastic bracket (300), the printed circuit board (200) and the heat sink (100), the conductive elastic element is sleeved around the conductive fastener, and one end of the conductive elastic element is connected to the conductive fastener, and the other end is connected to the pad (200a) on the printed circuit board (200) to achieve grounding of the heat sink (100); The conductive elastic element is constructed as a spring, and the spring is a tower-shaped spring (310); the large end of the tower-shaped spring (310) abuts against the pad (200a); the outer diameter of the pad (200a) is larger than the diameter of the large end (310b) of the tower-shaped spring (310). The tower spring (310) is configured to be compressible to a wire diameter height along its height direction; and the opposite sides of the tower spring (310) compressed to a wire diameter height abut against the pad (200a) and the nut portion of the conductive fastener, respectively. The heat dissipation grounding structure includes a back plate (400), which is located on the side of the printed circuit board (200) away from the heat sink (100), and the elastic bracket (300) is located between the printed circuit board (200) and the back plate (400). The back plate (400) has a receiving portion (405) for mounting the elastic bracket (300) on the side facing the printed circuit board (200).

2. The heat dissipation grounding structure according to claim 1, characterized in that, The conductive fastener is constructed as a screw (305). The elastic bracket (300) is provided with a first mounting hole (300a) for the screw (305) to pass through; the printed circuit board (200) is provided with a second mounting hole (200b) for the screw (305) to pass through and corresponding to the first mounting hole (300a). The screw (305) passes through the first mounting hole (300a) and the second mounting hole (200b) and is connected to the heat sink (100). The spring is sleeved on the screw (305) and is located in the first mounting hole (300a). One end of the spring abuts against the pad (200a) and the other end is connected to the screw (305).

3. The heat dissipation grounding structure according to claim 2, characterized in that, The pad (200a) is arranged around the second mounting hole (200b) in the circumference, and the inner diameter of the pad (200a) coincides with the outer diameter of the second mounting hole (200b).

4. The heat dissipation grounding structure according to any one of claims 2 or 3, characterized in that, The screw (305) includes a screw head (305a) and a threaded rod for connection with the heat sink (100); The diameter of the screw head (305a) is larger than the diameter of the first mounting hole (300a).

5. The heat dissipation grounding structure according to claim 4, characterized in that, The first mounting hole (300a) has a countersunk hole arranged coaxially with the first mounting hole (300a) on the side away from the printed circuit board (200), and the diameter of the countersunk hole is larger than the diameter of the screw head (305a).

6. The heat dissipation grounding structure according to claim 4, characterized in that, The screw includes an intermediate rod section (305c) and a lower rod section (305d). One end of the intermediate rod section (305c) is connected to the screw head (305a), and the other end is connected to the lower rod section (305d). The lower rod section (305d) has an external thread, and the diameter of the lower rod section (305d) is smaller than the diameter of the intermediate rod section (305c).

7. The heat dissipation grounding structure according to claim 6, characterized in that, The difference between the diameter of the intermediate rod segment (305c) and the diameter of the lower rod segment (305d) is greater than or equal to 0.9 mm.

8. The heat dissipation grounding structure according to claim 6, characterized in that, The screw also includes an upper rod section (305b), the diameter of which is smaller than the diameter of the middle rod section (305c) and larger than the diameter of the lower rod section (305d).

9. The heat dissipation grounding structure according to claim 8, characterized in that, The diameter of the small end (310a) of the tower spring (310) is greater than or equal to the diameter of the upper rod segment (305b) and less than the diameter of the middle rod segment (305c); the diameter of the large end (310b) of the tower spring (310) is less than the diameter of the first mounting hole (300a) and greater than the diameter of the second mounting hole (200b).

10. The heat dissipation grounding structure according to claim 1, characterized in that, The minimum gap between the elastic support (300) and the bottom wall of the receiving part (405) is 0.1 mm; The gap between the elastic support (300) and the printed circuit board (200) is 0.1-0.9 mm.

11. An electronic device, characterized in that, The electronic device includes a heat dissipation grounding structure as described in any one of claims 1-10.

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