Shielding cover, combination circuit board, and electronic device

Abstract

The utility model discloses a shielding case, combined circuit board and electronic equipment relates to electronic equipment technical field. Shielding case is installed in circuit board, and the surface of circuit board is provided with electrical element, and the shielding case includes outer frame and top cap, and the outer frame is connected with circuit board, and the outer frame is surrounded in the outside of electrical element, top cap is arranged on the side of outer frame away from circuit board, and the top cap is surrounded with the outer frame and forms shielding cavity, top cap is provided with glue injection hole and the inspection hole of interval arrangement with glue injection hole, and glue injection hole and inspection hole all communicate with shielding cavity, and definition: the projection of glue injection hole and electrical element is projected on circuit board respectively first projection and second projection, then, the center of first projection coincides with the center of second projection.

Description

Technical Field

[0001] This utility model relates to the field of electronic equipment technology, and in particular to a shielding cover, a combined circuit board, and an electronic device. Background Technology

[0002] For circuit boards (PCBAs) in electronic devices, shielding covers are typically used to cover the electrical components on the circuit board to achieve electromagnetic shielding. A shielding cover generally consists of a bracket and a cover. During assembly, the bracket is first installed on the circuit board, then thermal pads or thermally conductive adhesive are applied to the surface of the electrical components facing away from the circuit board, and finally the cover is placed on the bracket to complete the assembly.

[0003] However, this shielding structure makes it difficult to reduce the production cost of the combined circuit board. Furthermore, during assembly, using a thermal pad as the heat-conducting medium reduces the thermal conductivity between the electrical components and the shielding cover; using thermal adhesive as the heat-conducting medium makes it difficult to control the coating area and amount of the adhesive, making it impossible to guarantee that the adhesive will fill the space between the electrical components and the shielding cover as designed, which also reduces the thermal conductivity between the electrical components and the shielding cover. Utility Model Content

[0004] The main purpose of this invention is to provide a shielding cover, a combined circuit board, and an electronic device, which aims to reduce the production cost of the combined circuit board while ensuring the thermal conductivity between the electrical components and the shielding cover.

[0005] To achieve the above objectives, this utility model proposes a shielding cover, which is mounted on a circuit board, and electrical components are mounted on the surface of the circuit board. The shielding cover includes: An outer frame, which is connected to the circuit board and surrounds the outside of the electrical component; A top cover is disposed on the side of the outer frame away from the circuit board, and the top cover and the outer frame enclose a shielding cavity; The top cover has an injection hole and an inspection hole spaced apart from the injection hole. Both the injection hole and the inspection hole are connected to the shielding cavity. Defined as: the injection hole and the projection of the electrical component onto the circuit board are the first projection and the second projection, respectively. The center of the first projection coincides with the center of the second projection. Attached Figure Description

[0006] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0007] Figure 1 This is a schematic diagram of the structure of an embodiment of the combined circuit board provided by this utility model; Figure 2 for Figure 1 A top-view structural diagram; Figure 3 for Figure 1 A schematic diagram of the decomposed structure; Figure 4 A schematic diagram of the structure of an embodiment of the shielding cover provided by this utility model; Figure 5 for Figure 4 A structural diagram from another perspective; Figure 6 for Figure 2 A schematic diagram of the cross-sectional structure of section AA.

[0008] Explanation of icon numbers: 10. Shielding cover; 1. Outer frame; 2. Top cover; 21. Injection hole; 22. Inspection hole; 23. Support protrusion; 3. Injection space; 20. Circuit board; 30. Electrical components; 40. Thermal conductive adhesive.

[0009] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0010] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0011] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0012] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0013] In the field of electronic equipment manufacturing, printed circuit boards (PCBAs), as core components, are typically designed to resist electromagnetic interference (EMI). To suppress EMI, the industry commonly uses shielding structures to protect the electrical components on the circuit board. This structure consists of two parts: a support frame and a shielding cover. Assembly requires following a specific process: first, the support frame is fixed to the circuit board surface using reflow soldering to form a stable support frame; then, thermal pads or thermally conductive adhesives are applied to the exposed surfaces of the electrical components away from the circuit board, depending on design requirements, as a heat transfer medium; finally, the shielding cover is precisely snapped onto the support frame, and the entire package is completed by mechanical pressing. This layered assembly method achieves both electromagnetic shielding and heat dissipation through the thermally conductive medium, transferring the heat generated by the components to the shielding cover for cooling.

[0014] However, the applicant's research revealed that current shielding design solutions suffer from both cost and performance optimization issues. From a manufacturing cost perspective, shielding components require separate molds for the bracket and cover, and the assembly process is complex, leading to high material and labor costs. Regarding thermal management, if pre-formed thermal pads are used, their fixed shape cannot perfectly conform to the minute undulations on the surface of electrical components, resulting in air gaps at the contact surface and significantly reducing heat transfer efficiency. While liquid thermal adhesive can better fill the contact surface, the lack of precise control during the coating process makes it prone to insufficient coating area leading to localized overheating, or excessive overflow contaminating the circuit board, similarly affecting the heat dissipation efficiency of electrical components.

[0015] In view of this, the present invention proposes a shielding cover to solve or at least alleviate the above-mentioned problems.

[0016] Please see Figures 1 to 3In one embodiment of this utility model, the shielding cover 10 is mounted on a circuit board 20, and an electrical component 30 is mounted on the surface of the circuit board 20. The shielding cover 10 includes an outer frame 1 and a top cover 2. The outer frame 1 is connected to the circuit board 20 and surrounds the outside of the electrical component 30. The top cover 2 covers the side of the outer frame 1 away from the circuit board 20, and the top cover 2 and the outer frame 1 together form a shielding cavity, in which the electrical component 30 is located. Please refer to the following: Figure 4 and Figure 5 The top cover 2 has an injection hole 21 and an inspection hole 22 spaced apart from the injection hole 21. Both the injection hole 21 and the inspection hole 22 are connected to the shielding cavity. Let the projections of the injection hole 21 and the electrical component 30 onto the circuit board 20 be the first projection and the second projection, respectively. Then the center of the first projection coincides with the center of the second projection.

[0017] Specifically, the shielding cover 10 provided in this embodiment only includes an interconnected outer frame 1 and a top cover 2, eliminating the need for a separate bracket for mounting the shielding cover 10, thus saving material and design costs. During assembly, the shielding cover 10 is first mounted entirely on the circuit board 20, with the electrical components 30 housed inside the shielding cover 10. Then, thermally conductive adhesive 40 is injected between the electrical components 30 and the top cover 2 through the injection hole 21. This requires only two assembly steps, thereby reducing labor costs. Thus, the shielding cover 10 provided in this embodiment can reduce the production cost of the combined circuit board.

[0018] On the other hand, by providing the injection hole 21, the thermally conductive adhesive 40 can be squeezed in after the shielding cover 10 is installed on the circuit board 20. Compared to the method of first applying the thermally conductive adhesive 40 and then covering the shielding cover 10, the technical solution of this embodiment allows the thermally conductive adhesive 40 to flow along the gap between the top cover 2 and the electrical component 30. During the flow process, the thermally conductive adhesive 40 will also form a uniform and dense thermally conductive layer on the contact surface between the top cover 2 and the electrical component 30 due to its own viscosity and surface tension. This thermally conductive layer not only improves the heat conduction efficiency between the top cover 2 and the electrical component 30, but also plays a certain role in buffering and shock absorption. Furthermore, by setting the center of the injection hole 21 to correspond to the center of the electrical component 30, the thermally conductive adhesive 40 can diffuse outward along the center of the electrical component 30, which helps to improve the uniformity of the distribution of the thermally conductive adhesive 40 on the surface of the electrical component 30. While ensuring the heat transfer efficiency between the electrical component 30 and the top cover 2, it can reduce the rework rate caused by uneven injection, which is beneficial to production efficiency and product quality stability.

[0019] Meanwhile, by opening an inspection hole 22 and connecting it to the shielding cavity, the operator can observe the application of the thermally conductive adhesive 40 in a timely manner. When the thermally conductive adhesive 40 flows to the bottom of the inspection hole 22, the operator can stop the application process. This ensures that the coverage area of ​​the thermally conductive adhesive 40 meets design requirements, avoiding poor heat dissipation of the electrical component 30 due to insufficient application area. It also avoids waste caused by excessive application of thermally conductive adhesive 40, reducing production costs and improving production efficiency. Moreover, this method of judging the application of thermally conductive adhesive 40 through the inspection hole 22 is simple and convenient to operate, requiring no complex testing equipment or cumbersome testing procedures. Operators can master it after simple training, which helps improve operational efficiency.

[0020] Regarding the setting of the inspection hole 22, it should be noted that a preset distance is set between the inspection hole 22 and the injection hole 21. This preset distance needs to be determined according to the size of the electrical component 30. This preset distance should ensure that the thermally conductive adhesive 40 can cover the surface of the electrical component 30 as much as possible, but without excessive overflow of the thermally conductive adhesive 40. In this embodiment, the thermally conductive adhesive 40 includes one of thermally conductive silicone grease and thermally conductive gel.

[0021] According to the technical solution of this embodiment, the structure and assembly process of the shielding cover 10 are simplified, which helps to reduce the production cost of the combined circuit board. Furthermore, by opening the inspection hole 22 and the injection hole 21, the process of injecting thermally conductive adhesive 40 between the electrical component 30 and the top cover 2 is achieved, ensuring that the coverage area of ​​the thermally conductive adhesive 40 meets the design requirements and that the distribution of the thermally conductive adhesive 40 is more uniform, thereby guaranteeing the thermal conductivity between the electrical component 30 and the shielding cover 10.

[0022] It should also be noted that commonly used shielding covers include a bracket and a cover. The bracket and cover are pressed together. Specifically, the bracket has multiple grooves on its side, and the cover has protrusions at corresponding positions. By pressing the cover towards the circuit board, the protrusions engage with the grooves, thus completing the connection between the cover and the bracket. However, with this shielding cover structure, in audio products, the sound emitted by the speaker causes relative displacement between the cover and the bracket, resulting in friction and noise. This phenomenon is called vibration.

[0023] With the technical solution of this embodiment, the shield 10 will not rub or collide with other structures, thus eliminating the risk of vibration.

[0024] In another embodiment of this utility model, please refer to Figure 4 and Figure 5The number of inspection holes 22 is multiple, and the multiple inspection holes 22 are arranged in an array with the injection hole 21 as the center. "Multiple" refers to two or more. In this embodiment, there are four inspection holes 22, which are arranged in a circumferential array, with the injection hole 21 located at the geometric center of this circumferential array. The projection of the inspection holes 22 onto the circuit board 20 coincides with the second projection portion, that is, the inspection holes 22 are correspondingly located at the edge of the electrical component 30, so that the thermally conductive adhesive 40 covers the surface of the electrical component 30 as much as possible, further improving the thermal conductivity between the electrical component 30 and the top cover 2.

[0025] For further information, please refer to [link / reference]. Figure 4 and Figure 5 In one embodiment of this utility model, the top cover 2 is recessed towards the electrical component 30 to form a support protrusion 23. The support protrusion 23 abuts against the side of the electrical component 30 away from the circuit board 20. The distance between the support protrusion 23 and the injection hole 21 is defined as the first gap, and the distance between the inspection hole 22 and the injection hole 21 is defined as the second gap. Therefore, along the extending direction of the top cover 2 away from the electrical component 30, the first gap is greater than or equal to the second gap. The support protrusion 23 supports the top cover 2, enabling a stable injection gap to be formed between the top cover 2 and the electrical component 30. By making the first gap greater than the second gap, the support protrusion 23 can be prevented from obstructing the flow of the thermally conductive adhesive 40, thus avoiding air bubbles or voids in the thermally conductive adhesive 40 around the support protrusion 23, which would affect the thermal conductivity.

[0026] During the injection of thermally conductive adhesive 40, the supporting protrusion 23 stably supports the top cover 2, ensuring a uniform and constant injection gap. This allows the thermally conductive adhesive 40 to fill the gap evenly, preventing uneven injection caused by the top cover 2 being recessed. The operator can observe the filling status of the thermally conductive adhesive 40 within the injection gap through the inspection hole 22, including whether the thermally conductive adhesive 40 covers the surface of the electrical component 30 as designed, and whether there are defects such as air bubbles or voids. Once the thermally conductive adhesive 40 is observed to be well-filled and meets the predetermined design requirements, the injection operation can be stopped. This structural design ensures the quality and stability of the thermally conductive adhesive 40 injection process.

[0027] Further, please refer to Figures 4 to 6In one embodiment of this utility model, there are multiple supporting protrusions 23, which are arranged in an array around the injection hole 21. The multiple supporting protrusions 23 enclose an injection space 3, which is connected to the injection hole 21 and used to allow the thermally conductive adhesive 40 to enter. Specifically, this embodiment provides four supporting protrusions 23. In this embodiment, the side of the electrical component 30 away from the circuit board 20 is a rectangular surface. The four supporting protrusions 23 are respectively positioned at the four corners of this rectangular surface and arranged in a rectangular array to avoid affecting the flow of the thermally conductive adhesive 40. Furthermore, an injection hole 21 is provided at the geometric center of the rectangular array formed by the four supporting protrusions 23, so that the thermally conductive adhesive 40 flows along the injection hole 21 towards the supporting protrusion 23 when injected. This arrangement allows the multiple supporting protrusions 23 to provide a stable support structure between the top cover 2 and the electrical component 30, which helps improve the uniformity of the thermally conductive adhesive 40 injection.

[0028] In one embodiment of this utility model, the projection of the adhesive injection space 3 onto the circuit board 20 is called the third projection, and the area ratio between the third projection and the second projection is r; then, r satisfies: 0.8 ≤ r < 1. This is beneficial to increasing the coverage area of ​​the thermally conductive adhesive 40 on the surface of the electrical component 30, so as to ensure the thermal conductivity between the electrical component 30 and the top cover 2.

[0029] In one embodiment of this utility model, the outer frame 1 and the top cover 2 are integrally formed parts. That is, the shielding cover 10 is an integrally formed part. Specifically, the shielding cover 10 is integrally stamped. Integral stamping eliminates the connection gaps between the various parts of the shielding cover 10, making the overall structure more stable. Moreover, the integral stamping production method can also improve production efficiency. Compared with the traditional step-by-step assembly process, integral molding reduces the processing and assembly of multiple parts, reduces the complexity and error rate in the production process, and can complete the production of a large number of shielding covers 10 in a shorter time to meet the large-scale market demand for the product.

[0030] In one embodiment of this utility model, an adhesive layer or a soldering layer is provided between the outer frame 1 and the circuit board 20. That is, the connection between the outer frame 1 and the circuit board 20 includes soldering and bonding. Specifically, reflow soldering can be used to solder the outer frame 1 and the circuit board 20. Reflow soldering, as a mature and efficient soldering process, has many outstanding advantages. During the soldering process, reflow soldering can precisely control the temperature profile, allowing the solder paste to undergo preheating, reflow, and cooling processes sequentially at specific temperature stages, thereby achieving a reliable and uniform connection between the outer frame 1 and the circuit board 20. This precise temperature control can effectively avoid soldering defects caused by excessively high or low temperatures, such as cold solder joints, poor solder joints, or component damage, which is beneficial to improving soldering quality.

[0031] In other embodiments of this utility model, the outer frame 1 and the top cover 2 are connected by welding, thus avoiding the stamping process. The shielding cover 10 can be processed without the use of stamping equipment, which helps to reduce equipment costs.

[0032] In one embodiment of this utility model, the outer frame 1 and the top cover 2 are made of soft metal, that is, the outer frame 1 and the top cover 2 are made of soft metal. Specifically, the shielding cover 10 is made of soft metal by stamping, wherein the soft metal includes one of nickel silver, aluminum alloy, stainless steel and tin-plated tinplate.

[0033] This utility model also proposes a combined circuit board, which includes a shielding cover 10. The specific structure of the shielding cover 10 is as described in the above embodiments. Since this combined circuit board adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here. The combined circuit board also includes a circuit board 20, an electrical component 30, and thermally conductive adhesive 40. The electrical component 30 is mounted on one side of the circuit board 20, and the thermally conductive adhesive 40 is filled between the electrical component 30 and the top cover 2 through the injection hole 21.

[0034] This utility model also proposes an electronic device, including the above-described combined circuit board. Since this electronic device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0035] The above description is merely an exemplary embodiment of the present utility model and does not limit the scope of protection of the present utility model. Any equivalent structural transformations made based on the technical concept of the present utility model and the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present utility model.

Claims

1. A shielding cover, mounted on a circuit board, wherein electrical components are mounted on the surface of the circuit board, characterized in that, include: An outer frame, which is connected to the circuit board and surrounds the outside of the electrical component; A top cover is disposed on the side of the outer frame away from the circuit board, and the top cover and the outer frame enclose a shielding cavity; The top cover has an injection hole and an inspection hole spaced apart from the injection hole. Both the injection hole and the inspection hole are connected to the shielding cavity. Defined as: the injection hole and the projection of the electrical component onto the circuit board are the first projection and the second projection, respectively. The center of the first projection coincides with the center of the second projection.

2. The shielding cover as described in claim 1, characterized in that, The number of inspection holes is multiple, and the multiple inspection holes are arranged in an array with the glue injection hole as the center.

3. The shielding cover as described in claim 2, characterized in that, The top cover is recessed towards the electrical component to form a support protrusion. The support protrusion abuts against the side of the electrical component away from the circuit board. Along the extending direction of the top cover away from the electrical component, the distance between the support protrusion and the glue injection hole is greater than or equal to the distance between the inspection hole and the glue injection hole.

4. The shielding cover as described in claim 3, characterized in that, The number of support protrusions is multiple, and the multiple support protrusions are arranged in an array around the glue injection hole as the center. The multiple support protrusions enclose the glue injection space, and the glue injection hole is connected to the glue injection space.

5. The shielding cover as described in claim 4, characterized in that: the projection of the glue injection space onto the circuit board is defined as a third projection, and the area ratio between the third projection and the second projection is r; The condition r satisfies: 0.8 ≤ r < 1.

6. The shielding cover as described in any one of claims 1 to 5, characterized in that, The outer frame and the top cover are integrally molded parts.

7. The shielding cover as described in any one of claims 1 to 5, characterized in that, An adhesive layer or a soldering layer is provided between the outer frame and the circuit board.

8. The shielding cover as described in any one of claims 1 to 5, characterized in that, The outer frame and the top cover are made of soft metal.

9. A composite circuit board, characterized in that, The combined circuit board, including the shielding cover as described in any one of claims 1 to 8, further includes the circuit board, the electrical component, and thermally conductive adhesive, wherein the electrical component is mounted on one side of the circuit board, and the thermally conductive adhesive is filled between the electrical component and the top cover through the injection hole.

10. An electronic device, characterized in that, Includes the combined circuit board as described in claim 9.

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