Electronic module
Through the coordination structure of cantilever beams and bumps and grooves, the problems of insufficient electromagnetic shielding capacity and high cost of electronic modules are solved, and the stability and anti-static capacity are improved, reducing production costs.
Patent Information
- Application Number
- CN202510315698.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-17
- Publication Date
- 2025-07-08
AI Technical Summary
The existing electronic modules have insufficient electromagnetic shielding capabilities and high costs. Traditional methods such as unstable tin dot connections and expensive GASKETs, resulting in weaker electromagnetic shielding capabilities or increased costs.
The cantilever beam is adapted to the coordinating point and groove. The cantilever beam is assembled by the fastening screws of the metal shell, PCBA plate and the mating shell. The cantilever beam is deformed and falls into the groove, forming elastic contact, replacing the function of GASKET, ensuring the stability of electromagnetic shielding capacity and reducing costs.
It realizes the stability of the electromagnetic shielding capability and the anti-static ability of the electronic module, while reducing the production cost, reducing the use of GASKET, and improving the competitiveness and detachability of the product.
Smart Images
Figure CN120282398A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of vehicle electronic control technology, and in particular to an electronic module. Background Art
[0002] Generally speaking, the devices that drive electronic modules need to be installed on a printed circuit board (PCB) to form a PCBA (Printed Circuit Board Assembly) board. These devices are composed of components and circuits that are potential interference sources and sensitive to electromagnetic energy. Therefore, PCB EMC design is one of the most important issues in EMC design. The location of active components, the routing of printed lines, impedance matching, grounding design, and circuit filtering should all be considered in EMC design. Due to various reasons, it is difficult for high-frequency circuits to solve EMI problems in the PCB design stage. Most of them need to further shield the casing to achieve electromagnetic shielding effects.
[0003] In the existing designs, most of them connect the upper and lower shells through the tin points on the copper leakage of the PCBA board, and apply a certain pressure to the shell to crush the tip of the tin point to maintain the connection. However, this has two obvious disadvantages. First, the flatness accuracy of the shell mounting surface of the mold part is not high, and it is difficult to ensure that each tin point is crushed or even pressed. Second, once the tin point is crushed, the tin point will not rebound after the shell is disassembled. It is difficult to ensure that the shell and the tin point are in contact again during re-installation, resulting in a significant weakening of the electromagnetic shielding capability, making it difficult to shield high-frequency signals.
[0004] Another existing method is to add conductive foam (SMT GASKET) to the tin point based on SMT technology. GASKET has good conductivity, resilience, compression rate from 10% to 50%, high temperature resistance, can meet the design verification requirements, and can greatly improve the electromagnetic shielding ability. However, GASKET is expensive, costing about 0.3 yuan per piece, and an ECU requires about 20 pieces, which increases the total cost by 5 to 6 yuan per month, which does not meet the current requirements of cost reduction and efficiency improvement.
[0005] In addition, there are solutions that use conductive glue, beryllium copper sheets, conductive foam and other fillers on the upper and lower covers, and there are also solutions that directly add a shielding cover to the high-frequency source, but these solutions have the disadvantages of increased materials, more processes and increased costs. Summary of the invention
[0006] The purpose of the present application is to provide an electronic module to improve the electromagnetic shielding capability of the electronic module and reduce the manufacturing cost of the electronic module.
[0007] To achieve the above object, an embodiment of the present application provides an electronic module, which includes a metal housing, a PCBA board, and a mating housing connected by a plurality of connectors. The PCBA board is located between the metal housing and the mating housing;
[0008] At least one cantilever beam is provided on the PCBA board. A copper leakage area is formed on one side surface of the PCBA board area where the at least one cantilever beam is located facing the metal housing. A solder point is provided at the end of each cantilever beam, and the solder point is located in the copper leakage area;
[0009] At least one bump corresponding to the solder points of the at least one cantilever beam is provided on the metal housing;
[0010] At least one groove corresponding to the solder points of the at least one cantilever beam is provided on the mating housing;
[0011] Wherein, the bump contacts and presses down the cantilever beam where the solder point is located, so that the end of the cantilever beam where the solder point is located deforms, and the deformed part of the cantilever beam sinks into the groove corresponding to the solder point.
[0012] The electronic module provided by the embodiment of the present application has the following beneficial effects:
[0013] Through the cooperation of the cantilever beam with the bump and the groove, the function of the GASKET is replaced. The metal housing, the mating housing, and the PCBA are assembled by fastening screws. After assembly, good contact between the solder points of the PCBA cantilever beam and the metal housing can be ensured. Moreover, the deformation of the cantilever beam is elastic deformation, and it has good resilience performance, so that the electronic module can be disassembled and assembled repeatedly without affecting the electromagnetic shielding ability, greatly improving the stability and competitiveness of the electronic module; compared with the scheme using GASKET, the above two electronic modules reduce the use of GASKET, thereby reducing costs; at the same time, since the contact between the metal housing and the cantilever beam provides a path for electrostatic discharge, the internal electronic components are protected, and the anti-static ability of the product is improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required in the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings.
[0015] Figure 1 It is the overall assembly schematic diagram of the electronic module in the embodiment of the present application.
[0016] Figure 2 It is the schematic diagram of the cantilever beam in the embodiment of the present application.
[0017] Figure 3 Schematic diagram of the metal housing and its bumps in the embodiment of the present application.
[0018] Figure 4 Schematic diagram of the mating housing and its grooves in the embodiment of the present application.
[0019] Figure 5 Partial sectional view after the overall assembly of the electronic module in the embodiment of the present application.
[0020] Figure 6a Stress nephogram after the deformation of the cantilever beam during the simulation process in the embodiment of the present application.
[0021] Figure 6b Schematic diagram of the reaction force of the support corresponding to the deformation of the cantilever beam during the simulation process in the embodiment of the present application.
[0022] Figure 6c Schematic diagram of the reaction force of the deformation of the cantilever beam during the simulation process in the embodiment of the present application.
[0023] Figure 7 Schematic diagram of the formation of copper leakage areas and solder joints on both the upper and lower surfaces of the area where the cantilever beam of the PCBA board is located in the embodiment of the present application.
[0024] Markings in the figure:
[0025] 1 - Metal housing; 11 - Bump; 2 - PCBA board; 21 - Cantilever beam; 22 - Solder joint; 3 - Mating housing; 31 - Groove; 4 - Connector. Detailed description of the specific implementation
[0026] The detailed description of the drawings is intended to be an illustration of the current embodiment of the present application, rather than representing the only form in which the present application can be implemented. It should be understood that the same or equivalent functions can be achieved by different embodiments intended to be included within the spirit and scope of the present application.
[0027] An embodiment of the present application provides an electronic module, as Figure 1 shown, including a metal housing 1, a PCBA (Printed Circuit Board Assembly) board, and a mating housing 3 connected by a plurality of connectors 4. The PCBA board 2 is located between the metal housing 1 and the mating housing 3; in Figure 1In the example, several fastening screws are selected as the connecting member 4. There are positioning posts on the metal housing 1. The PCBA board 2 is placed on the metal housing 1 through the positioning posts. The positioning posts are used to ensure the accurate position of the PCBA board 2 inside the metal housing 1, prevent the PCBA from moving inside the housing, and thus avoid connection problems caused by vibration or impact. There are several screw holes on the metal housing 1, the PCBA board 2 and the mating housing 3 for installing and fixing the fastening screws. The metal housing 1 serves as an upper cover, which can provide strong protection against damage to the PCBA board 2 caused by external physical impacts and dust, etc. The mating housing 3 serves as a lower cover, which forms a closed space together with the upper cover to further protect the internal electronic components from environmental influences. At the same time, the metal housing 1 has a good electromagnetic shielding effect, which can effectively block external electromagnetic interference (EMI) from entering the module and prevent internal electromagnetic radiation from leaking to the outside.
[0028] Refer to Figure 2 , there is at least one cantilever beam 21 on the PCBA board 2. The surface of the area of the PCBA board 2 where the at least one cantilever beam 21 is located facing the metal housing 1 forms a copper leakage area. There is a solder joint 22 at the end of each cantilever beam 21, and the solder joint 22 is located in the copper leakage area. Specifically, the solder joint 22 refers to a metal solder joint welded on the circuit board. The solder joint 22 is usually composed of solder made of tin (Sn) or tin-lead (SnPb) alloy.
[0029] Refer to Figure 3 , there are at least one bump 11 on the metal housing 1 that corresponds one-to-one with at least one solder joint 22. Specifically, the one-to-one correspondence between the at least one solder joint 22 and the at least one bump 11 means precise alignment in position.
[0030] Refer to Figure 4 , there are at least one groove 31 on the mating housing 3 that corresponds one-to-one with at least one solder joint 22. Specifically, the one-to-one correspondence between the at least one solder joint 22 and the at least one groove 31 means precise alignment in position.
[0031] Among them, the at least one bump 11 contacts the at least one solder joint 22 and presses down the at least one cantilever beam 21, so that the end of the at least one cantilever beam 21 deforms, and the deformed part of the at least one cantilever beam 21 sinks into the at least one groove 31;
[0032] Specifically, as Figure 5As shown in the figure, when the metal housing 1, the PCBA board 2, and the mating housing 3 are assembled through the connecting member 4, at least one bump 11 on the metal housing 1 will come into contact with at least one solder pad 22 on the PCBA board 2 in a one-to-one correspondence. As the metal housing 1 is further pressed down, each bump 11 will apply pressure to the corresponding cantilever beam 21. The cantilever beam 21 is an elastic structure designed on the PCBA board 2. When the bump 11 presses down the cantilever beam 21, the end of the cantilever beam 21 will undergo elastic deformation. This deformation is a key step in the design because it ensures that the cantilever beam 21 can form a reliable contact with the metal housing 1. A groove 31 corresponding to the deformed part of the cantilever beam 21 is provided on the mating housing 3. When the end of the cantilever beam 21 deforms due to the pressure of the bump 11, the deformed part will sink into the groove 31, thereby forming a tight fit between the cantilever beam 21 and the groove 31.
[0033] Based on the above description, it can be seen that the electronic module of the embodiment replaces the function of the GASKET through the cooperation of the cantilever beam 21 with the bump 11 and the groove 31. The metal housing 1, the mating housing 3, and the PCBA are assembled through fastening screws. After assembly, it can ensure good contact between the solder pad 22 of the PCBA cantilever beam 21 and the metal housing 1, and the deformation of the cantilever beam 21 is elastic deformation with good resilience performance, enabling the electronic module to be disassembled and assembled repeatedly without affecting the electromagnetic shielding ability, greatly improving the stability and competitiveness of the electronic module. Compared with the GASKET solution, the above two electronic modules reduce the use of the GASKET, thereby reducing costs and the technological process. An ECU can save more than 5 yuan to 6 yuan. At the same time, since the contact between the metal housing 1 and the cantilever beam 21 provides a path for electrostatic discharge, it protects the internal electronic components and improves the anti-static ability of the product.
[0034] Specifically, the width and length of the cantilever beam 21 are based on simulation calculations to ensure that the cantilever beam 21 does not exceed the yield strength after deformation. In the embodiment, the metal housing 1 contacts the solder pad 22 through the bump 11 and presses down the cantilever beam 21 to cause its deformation. According to the simulation of a deformation of 0.15 mm, the maximum stress received by the cantilever beam 21 is 50 Mpa, which does not reach the yield strength of 100 Mpa and is within the elastic range. Therefore, it can meet the requirement of repeated disassembly and assembly without permanent deformation, and the grounding reliability is guaranteed. Secondly, through simulation, its deformation reaction force is 8.82 N. The radial force generated after tightening 5 screws is sufficient to cause 20 cantilever beams 21 to deform, indicating that this method is feasible. The simulation data is as Figures 6a - 6c shown. Figure 6a is the stress nephogram after the deformation of the cantilever beam 21. Figure 6b is the schematic diagram of the reaction force corresponding to the deformation of the cantilever beam 21. Figure 6c is the schematic diagram of the deformation reaction force, and the maximum value of the deformation reaction force is 8.8201 N.
[0035] In some embodiments, the height of the bumps 11 of the electronic module, the deformation amount of the cantilever beams 21, and the depth of the grooves 31 are the same.
[0036] Specifically, the height of the bumps 11 determines the magnitude of the pressure applied to the cantilever beams 21. Since the heights of all the bumps 11 are the same, they provide uniform pressure when pressing into the cantilever beams 21. The deformation amount of the cantilever beams 21 refers to the distance that the end of the cantilever beam 21 can bend under the action of an external force. In this embodiment, it specifically refers to the deformation amount of the cantilever beam 21 in the vertical direction, and the deformation amount of the cantilever beam 21 depends on the material of the cantilever beam 21. The depth of the grooves 31 matches the deformation amount of the cantilever beams 21 to ensure that the cantilever beams 21 can completely sink into the grooves 31 after deformation, which helps to achieve a uniform contact and fixing effect, helps to eliminate gaps, and improves the electromagnetic shielding effect.
[0037] In some embodiments, at least one notch is provided on at least two sides of the PCBA board 2 of the electronic module to form at least one cantilever beam 21 on each side. Figure 2 In an example, at least one notch is provided on each of the three sides of the PCBA board 2 to form at least one cantilever beam 21. One notch forms one cantilever beam 21. By providing notches, the cantilever beam 21 has a certain elastic deformation ability.
[0038] In some embodiments, the shapes of the multiple notches on the same side of the PCBA board 2 of the electronic module are the same, and the multiple cantilever beams 21 on the same side are arranged at equal intervals. Figure 2 In an example, the shape of the notch on each side is L-shaped, forming a right-angled turning structure. The cantilever beams 21 are arranged at equal intervals on the same side, ensuring that the contact points between the PCBA board 2 and the metal housing 1 are evenly distributed. The equal-interval arrangement helps to evenly disperse the pressure of the housing on the PCBA board 2 and reduce local stress concentration.
[0039] In some embodiments, the interval between any two adjacent cantilever beams 21 on the same side of the PCBA board 2 of the electronic module is less than 1 / 10 of the wavelength at the electromagnetic wave frequency to be shielded.
[0040] Specifically, assume that the electromagnetic wave frequency to be shielded is 2.4 GHz, which is a common frequency in wireless communication, such as Wi-Fi and Bluetooth devices. First, it is necessary to calculate the wavelength at this frequency. The formula for calculating the wavelength is: wavelength = speed of light ÷ frequency. For a frequency of 2.4 GHz, the corresponding wavelength can be calculated to be approximately 0.125 meters. According to the design requirements, the interval between two adjacent cantilever beams 21 should be less than 1 / 10 of the wavelength, that is, the interval should be less than 12.5 mm. Therefore, when designing the PCBA board 2, the interval between each cantilever beam 21 can be selected to be 10 mm, which can effectively block the propagation path of high-frequency electromagnetic waves and reduce electromagnetic leakage.
[0041] In some embodiments, at least one notch is provided in the middle region of the PCBA board 2 of the electronic module to form at least one cantilever beam 21. Refer to Figure 2 For example, since other components need to be assembled in a side region of the PCBA board 2, at least one notch can be selected to be provided in the middle region of the PCBA board 2 to form at least one cantilever beam 21.
[0042] In some embodiments, at least two notches in the middle region of the electronic module include at least two different-shaped notches. Refer to Figure 2 For example, including a U-shaped notch and an irregular-shaped notch.
[0043] In some embodiments, the mating housing 3 of the electronic module is made of plastic material.
[0044] In some embodiments, refer to Figure 7 , on one side surface of the region of the PCBA board 2 where the at least one cantilever beam 21 is located, a copper leakage region is formed facing the mating housing 3, and at least one solder point 22 corresponding to the at least one cantilever beam 21 is provided on the copper leakage region. As Figure 7 shown, the thickness of the solder point 22 in the copper leakage region on the upper surface of the PCBA board 2 should be greater than that of the solder point 22 in the copper leakage region on the lower surface of the PCBA board 2. Further, in this embodiment, the mating housing 3 is made of metal material to ensure good contact on both the front and back sides of the PCBA board 2 to achieve the shielding effect.
[0045] The above has described the embodiments of the present application. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary technical personnel in the technical field to understand the disclosed embodiments.
Claims
1. An electronic module, characterized in that, Comprising a metal housing, a PCBA board, and a mating housing connected by a plurality of connectors, with the PCBA board located between the metal housing and the mating housing; At least one cantilever beam is provided on the PCBA board. On the side surface of the PCBA board area where the at least one cantilever beam is located and facing the metal housing, a copper leakage area is formed. A solder point is provided at the end of each cantilever beam, and this solder point is located in this copper leakage area; At least one bump corresponding to the solder points of the at least one cantilever beam is provided on the metal housing; At least one groove corresponding to the solder points of the at least one cantilever beam is provided on the mating housing; Wherein, the bump contacts and presses down the cantilever beam where the solder point is located, so that the end of the cantilever beam where the solder point is located deforms, and the deformed part of the cantilever beam sinks into the groove corresponding to the solder point.
2. The electronic module according to claim 1, characterized in that The height of the bump, the deformation amount of the cantilever beam, and the depth of the groove are all the same.
3. The electronic module according to claim 1, characterized in that, At least one notch is provided on at least two sides of the PCBA board respectively to form at least one cantilever beam on each side.
4. The electronic module according to claim 3, characterized in that, The shapes of the multiple notches on the same side of the PCBA board are the same, and the multiple cantilever beams on the same side are arranged at equal intervals.
5. The electronic module according to claim 3, characterized in that, The interval between any two adjacent cantilever beams on the same side of the PCBA board is less than 1 / 10 of the wavelength at the electromagnetic wave frequency to be shielded.
6. The electronic module according to claim 3, characterized in that, At least one notch is provided in the middle area of the PCBA board to form at least one cantilever beam.
7. The electronic module according to claim 6, characterized in that, At least two notches in the middle area include at least two different-shaped notches.
8. The electronic module according to any one of claims 1 to 7, characterized in that, The mating housing is made of plastic material.
9. The electronic module according to any one of claims 1 to 7, characterized in that On the side surface of the PCBA board area where the at least one cantilever beam is located and facing the mating housing, a copper leakage area is formed, and at least one solder point corresponding to the at least one cantilever beam is provided in this copper leakage area.
10. The electronic module according to claim 9, characterized in that, The mating housing is made of metal material.