Circuit board and electronic device

Abstract

The present disclosure relates to a circuit board and an electronic device, the circuit board comprising a substrate and a shield cover fixed to the substrate by a plurality of pads, wherein the plurality of pads are arranged along an edge of the shield cover, and there is a gap between the shield cover and the substrate at least at a bending position of the edge of the shield cover. Through the above technical solution, the circuit board in the present disclosure forms a gap between the shield cover and the substrate, avoiding stress concentration on the substrate at this position, leading to excessive deformation of the substrate, and causing damage to the conductive circuit in the substrate.

Description

Technical Field

[0001] This disclosure relates to the field of circuit boards, and more particularly to a circuit board and an electronic device. Background Technology

[0002] Circuit boards are core components of electronic devices, used to carry and connect electronic components. A circuit board typically includes a substrate, a shielding cover, and conductive lines embedded in the substrate. In related technologies, when an electronic device is subjected to impact, the circuit board inside the device is also subjected to the impact force. Significant stress is generated at the points on the substrate where it connects to the shielding cover, causing considerable deformation at these points and potentially leading to the breakage of the conductive lines within the substrate. Utility Model Content

[0003] To overcome the problems existing in the related technologies, this disclosure provides a circuit board and an electronic device.

[0004] According to a first aspect of the present disclosure, a circuit board is provided, including a substrate and a shield fixed to the substrate by a plurality of pads, wherein the plurality of pads are arranged along the edge of the shield and a gap is formed between the shield and the substrate at least at the bending position of the edge of the shield.

[0005] In some possible implementations, the circuit board includes copper foil strips disposed on the substrate, and multiple segments of a first solder resist coating spaced apart on the copper foil strips, with the copper foil strips between adjacent segments of the first solder resist coating forming the pads. In this way, the first solder resist coating prevents the shield from soldering to the substrate, allowing a gap to be formed between the substrate and the shield. Simultaneously, the copper foil strips between adjacent segments of the first solder resist coating, unaffected by the first solder resist coating, can be exposed on the substrate surface, forming pads.

[0006] In some possible implementations, the dimension L1 of the first solder resist coating in the thickness direction of the circuit board satisfies: 10um ≤ L1 ≤ 25um. If the dimension L1 is too small, it will affect the solder resist effect of the first solder resist coating, which may easily lead to the shielding cover being soldered to the copper foil strip with the first solder resist coating. If the dimension L1 is too large, it will increase the thickness of the circuit board and reduce the size of the gap, thus reducing the gap and avoiding stress concentration on the substrate.

[0007] In some possible implementations, the circuit board includes a plurality of spaced copper foil plates disposed on the substrate, the copper foil plates forming the pads. In this way, the copper foil plates can be directly exposed on the surface of the substrate to form pads, and no pads are formed in the gaps between two copper foil plates. Thus, the shield and the substrate cannot be soldered together via pads, and a gap can be formed between the shield and the substrate.

[0008] In some possible implementations, two adjacent copper foils and the substrate located between the two adjacent copper foils define a break groove, and the circuit board further includes a second solder resist coating applied to the inner wall of the break groove. Thus, by providing the break groove, multiple copper foils can be spaced apart through the break groove, allowing the copper foils to form solder pads. The second solder resist coating also prevents solder paste from flowing into the break groove during the soldering process.

[0009] In some possible implementations, in the arrangement direction of the plurality of pads, the distance L2 between the ends of two adjacent pads satisfies: 0.1mm ≤ L2 ≤ 2mm. If the distance L2 is too small, the gap size will be too small, reducing the effectiveness of the gap in preventing stress concentration on the substrate. If the distance L2 is too large, the gap size will be too large, reducing the electromagnetic shielding effect of the shielding cover.

[0010] In some possible implementations, in the arrangement direction of the plurality of pads, the distance L3 between the two ends of the pads satisfies: L3 > 2 * L2. If the distance L3 is too small, it indicates that the extension length of the pad is too short, which may result in too many gaps on the circuit board, and the distance between two adjacent gaps is too close, which will reduce the electromagnetic shielding effect of the shielding cover.

[0011] In some possible implementations, the shielding cover has multiple spaced weld seams between it and each of the pads. The shielding cover and pads are connected by segmented welding. This allows for gaps between the pads and shielding cover even where there are no weld seams, thus dispersing and absorbing stress.

[0012] In some possible implementations, the weld size L4 in the thickness direction of the circuit board satisfies: 40µm ≤ L4 ≤ 50µm. If size L4 is too large, it indicates that the weld is too thick, which will affect the installation position of the shield and further affect the thickness of the circuit board. If size L4 is too small, it will affect the welding strength between the edge of the shield and the pad.

[0013] According to a second aspect of the present disclosure, an electronic device is provided, the electronic device including the circuit board described in any one of the foregoing embodiments.

[0014] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects: Through the above technical solution, the circuit board in this embodiment of the disclosure, by forming a gap between the shielding cover and the substrate, avoids the placement of solder pads at specific locations between the shielding cover and the substrate, thus preventing stress concentration at those locations. Considering that stress concentration is more likely to occur at the bending points of the shielding cover's edges, a gap is formed between the shielding cover and the substrate at least at the bending points of the shielding cover's edges. In this way, when the substrate is subjected to impact, the shielding cover will not hinder the deformation of the substrate, and the substrate corresponding to the bending points of the shielding cover's edges can deform appropriately. Appropriate deformation of the substrate not only does not affect the conductive lines within the substrate but also effectively absorbs and disperses the impact force, preventing stress concentration on the substrate and avoiding excessive deformation that could damage the conductive lines within the substrate. Simultaneously, setting the solder pads to be multiple and spaced apart can prevent stress concentration on the substrate without affecting the electromagnetic shielding effect of the shielding cover. Furthermore, this spaced-out arrangement of solder pads also reduces the amount of solder paste used when soldering the shielding cover and the substrate, lowering the cost of connecting the shielding cover and the substrate.

[0015] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0017] Figure 1 This is a schematic diagram of the structure of the substrate in the related technology; Figure 2 This is a schematic diagram of the stress at the bending position of the substrate at the edge of the shield in related technologies; Figure 3 This is a schematic diagram of the structure of a circuit board according to an exemplary embodiment; Figure 4 This is a schematic diagram of the stress at the bending position of the substrate at the edge of the shield in this disclosure; Figure 5 This is a cross-sectional view of a circuit board according to an exemplary embodiment in a first embodiment; Figure 6 This is a top view of the substrate according to an exemplary embodiment in a first embodiment; Figure 7 This is a cross-sectional view of a circuit board according to an exemplary embodiment, in a second embodiment. Figure 8 This is a top view of the substrate according to an exemplary embodiment, in a second embodiment; Figure 9This is a schematic diagram of the weld seam structure of a circuit board according to an exemplary embodiment; Figure 10 This is a top view of the solder joint of a circuit board according to an exemplary embodiment.

[0018] Explanation of reference numerals in the attached figures 1-Substrate, 11-Gap, 12-Conductive line, 2-Pad, 2'-Solder strip, 3-Shielding cover, 4-Copper foil strip, 41-Copper foil plate, 5-First solder resist coating, 51-Second solder resist coating, 6-Cut groove, 7-Weld. Detailed Implementation

[0019] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0020] Circuit boards are core components of electronic devices, used to carry and connect electronic components. A circuit board typically includes a substrate 1, a shielding cover 3, and conductive lines 12 disposed within the substrate 1. When an electronic device is subjected to impact, the circuit board inside the device is also subjected to impact force, resulting in significant stress at the location on the substrate 1 where it connects to the shielding cover 3. In related technologies, the shielding cover 3 is generally constructed as a hollow shell structure with an opening that fits onto the substrate 1. The edge of the opening, i.e., the edge of the shielding cover 3, is used for connection to the substrate 1. In this disclosure, unless otherwise specified, the edge of the shielding cover 3 refers to the edge of the opening on the shielding cover 3 that is used to fit onto the substrate 1.

[0021] When the circuit board is subjected to impact, the substrate 1 will deform due to the impact. The location on the substrate 1 that connects to the edge of the shielding cover 3 is difficult to deform due to the connection structure between them. However, this connection point generates significant stress, potentially causing greater deformation. Consequently, the conductive lines 12 within the substrate 1 corresponding to this connection point are easily damaged due to the significant deformation of the substrate 1. At the bend in the substrate 1 where it connects to the edge of the shielding cover 3, the substrate 1 in this area is typically subjected to stress in multiple directions, resulting in more pronounced deformation. The conductive lines 12 within this area are more prone to damage.

[0022] In related technologies, the shielding cover 3 and the substrate 1 are soldered together via solder pads. As described below, this disclosure mainly improves upon the solder pad 2. To easily distinguish the solder pad 2 in this disclosure from the solder pads in related technologies, please refer to... Figure 1 and Figure 3 The solder strip 2' represents the area that can be soldered after multiple solder pads 2 are arranged according to a predetermined path. That is, the solder strip 2' here can be understood as the strip structure formed by the solder pads 2 arranged along the edge of the shield 3.

[0023] For details, please refer to Figure 1 ,exist Figure 1 As can be seen, the trajectory of the solder strip 2' extends along the bend of the edge of the shield 3. (Refer to...) Figure 2 , Figure 2 This is a graph showing the results of simulating the substrate 1 in the relevant technology using stress simulation software. The simulated location is the point on the substrate 1 where it connects to the edge of the shielding cover 3 at a bend. Figure 2 The horizontal axis represents time, and "1E-3" next to the X-axis represents 10 to the power of negative 3. The vertical axis represents the maximum principal strain of substrate 1. Strain is a physical quantity that describes the degree of deformation of an object under stress. Substrate 1 may produce strain in multiple directions when subjected to stress, and the maximum principal strain represents the maximum value of the strain in the possible directions. Figure 2 In the curve, the maximum value of the principal strain exceeds 15000ue, and is approximately 18000ue.

[0024] To address the problems existing in the relevant technologies, the following will be combined with the appendix. Figure 3 To be continued Figure 10 A detailed description of the scheme disclosed herein.

[0025] like Figures 3 to 10 As shown, this disclosure provides a circuit board including a substrate 1 and a shield 3 fixed to the substrate 1 by a plurality of pads 2, wherein the plurality of pads 2 are arranged along the edge of the shield 3, and at least at the bending position of the edge of the shield 3, there is a gap 11 between the shield 3 and the substrate 1.

[0026] The function of the shielding cover 3 is to block electromagnetic waves from the outside of the shielding cover 3 from interfering with the components inside the shielding cover 3, and at the same time suppress electromagnetic waves generated by the components inside the shielding cover 3 from interfering with other devices outside the shielding cover 3. These electromagnetic waves can be radio frequency signals. In related technologies, the shielding cover 3 cannot be directly connected to the substrate 1. Generally, the shielding cover 3 needs to be connected to the substrate 1 through solder pads 2. Solder pads 2 generally refer to the exposed metal contacts on the surface of the circuit board. Solder pads 2 can serve as connection points between components and the circuit board. When components need to be mounted on the circuit board, they can be soldered onto the solder pads 2, thus mounting the components on the circuit board.

[0027] In this disclosure, since the shield 3 needs to be connected to the substrate 1 through the pads 2, when there is a gap 11 between the shield 3 and the substrate 1 at least at the bend position of the edge of the shield 3, it means that at this time, the area on the substrate 1 corresponding to the bend position of the edge of the shield 3 is not provided with pads 2, indicating that the gap area between the ends of two adjacent pads 2 is formed on the substrate 1 in the area corresponding to the bend position of the edge of the shield 3.

[0028] When there is a gap 11 between the shielding cover 3 and the area on the substrate 1 corresponding to the bending position of the edge of the shielding cover 3, the bending position of the edge of the shielding cover 3 cannot be connected to the substrate 1 because there is no corresponding pad 2. When the other edges of the shielding cover 3 are welded to their corresponding pads 2, a weld 7 will be formed between the shielding cover 3 and the substrate 1. At this time, the area of ​​the shielding cover 3 that is not connected to the pad 2 will form a gap between it and the substrate 1, which is the gap 11. The part with the gap 11 between the shielding cover 3 and the substrate 1 indicates that the shielding cover 3 and the substrate 1 are disconnected at this time. With the gap 11 set, when the substrate 1 is subjected to an impact force, the shielding cover 3 will not hinder the deformation of the substrate 1. The substrate 1 corresponding to the bending position of the edge of the shielding cover 3 can be appropriately deformed. The appropriate deformation of the substrate 1 will not only not affect the conductive lines 12 in the substrate 1, but also fully absorb and disperse the impact force, avoiding stress concentration on the substrate 1, which would lead to excessive deformation of the substrate 1 and damage to the conductive lines 12 in the substrate 1. The substrate 1 corresponding to the gap 11 position will no longer be unable to deform due to the influence of the shield 3, further avoiding the phenomenon of stress concentration at the connection between the substrate 1 and the shield 3.

[0029] Through the above technical solution, the circuit board of this disclosure, by forming a gap 11 between the shielding cover 3 and the substrate 1, avoids the placement of solder pads 2 at specific positions between the shielding cover 3 and the substrate 1, thus preventing the edge of the shielding cover 3 from being soldered to the substrate 1 at these positions and avoiding stress concentration at these positions. Considering that stress concentration is more likely to occur at the bending positions of the edge of the shielding cover 3, a gap 11 is formed between the shielding cover 3 and the substrate 1 at least at the bending positions of the edge of the shielding cover 3. In this way, when the substrate 1 is subjected to impact force, the shielding cover 3 will not hinder the deformation of the substrate 1, and the substrate 1 corresponding to the bending position of the edge of the shielding cover 3 can deform appropriately. Appropriate deformation of the substrate 1 will not only not affect the conductive lines 12 inside the substrate 1, but also fully absorb and disperse the impact force, avoiding stress concentration on the substrate 1, which could lead to excessive deformation of the substrate 1 and damage to the conductive lines 12 inside the substrate 1. Meanwhile, by setting the solder pads 2 to be multiple and spaced apart, stress concentration on the substrate 1 can be avoided without affecting the electromagnetic shielding effect of the shielding cover 3. Furthermore, the spaced solder pads 2 also reduce the amount of solder paste used when soldering the shielding cover 3 and the substrate 1, thereby reducing the cost of connecting the shielding cover 3 and the substrate 1.

[0030] For details, please refer to Figure 3 and Figure 4 ,exist Figure 3 In the design, at the bend of the edge of the shielding cover 3, no solder pads 2 are provided between the shielding cover 3 and the substrate 1, so that there is a gap 11 between the shielding cover 3 and the substrate 1. (Refer to...) Figure 4 , Figure 4 The graph is a simulation result of the substrate 1 in this disclosure using stress simulation software. The simulation location is the position within the substrate 1 where it connects to the edge of the shielding cover 3. Figure 4 The horizontal axis represents time, and "1E-3" next to the X-axis represents 10 to the power of negative 3. The vertical axis represents the maximum principal strain of substrate 1. Strain is a physical quantity that describes the degree of deformation of an object under stress. Substrate 1 may produce strain in multiple directions when subjected to stress, and the maximum principal strain represents the maximum value of the strain in the possible directions. Figure 4 In the curve, the maximum value of the principal strain exceeds 10000 uE, and is approximately 11000 uE. (Through...) Figure 4 and Figure 2 As can be seen, after adopting the gap 11 design in this disclosure, the maximum principal strain of the substrate 1 in the region where the shield 3 bends is reduced from approximately 18000µe to approximately 11000µe, and the strain of the substrate 1 can be significantly reduced. It is understood that... Figure 2 and Figure 4 The circuit boards in the images are all the same type of circuit board. Figure 4 The circuit board in the middle adopts a gap of 11. Figure 2 and Figure 4The conditions for medium stress simulation are all the same as Figure 2 The same.

[0031] It should be noted that, as described above, the edge of the shield 3 is used to connect with the substrate 1. That is, in this disclosure, the extension trajectory of the pads 2 should correspond to the extension direction of the edge of the shield 3, and the arrangement direction of the multiple pads 2 can also correspond to the extension direction of the edge of the shield 3. The bending position of the edge of the shield 3 can refer to the rounded corner of the edge of the shield 3. The rounded corner refers to an arc. Replacing the intersection of two edges with an arc can make the transition of the edge of the shield 3 smoother.

[0032] In some embodiments, in the arrangement direction of the plurality of pads 2, the distance L2 between the ends of two adjacent pads 2 can satisfy: 0.1mm ≤ L2 ≤ 2mm, for example, L2 can be 0.1mm, 0.5mm, 0.8mm, 1mm, 1.5mm and 2mm. Preferably, the size of the distance L2 can also satisfy: 0.8mm ≤ L2 ≤ 1mm, for example, L2 can be 0.9mm, which makes the circuit board with the gap 11 designed in this disclosure more suitable for use in portable electronic devices such as mobile phones. If the distance L2 is too small, the size of the gap 11 will be too small, which will reduce the effect of the gap 11 in avoiding stress concentration on the substrate 1. If the distance L2 is too large, the size of the gap 11 will be too large, which will reduce the electromagnetic shielding effect of the shielding cover 3.

[0033] In this embodiment, distance L2 represents the distance between the ends of two adjacent pads 2 along the path formed by the arrangement direction of the pads 2. When this part of the path is a straight line, that is, when the gap 11 is set at a straight position on the edge of the shield 3, distance L2 represents the length of the straight line. When the gap 11 is set at a bend in the edge of the shield 3, distance L2 represents the length of the bend or arc. Taking the gap 11 being set at a bend in the edge of the shield 3 as an example, please refer to [reference needed]. Figures 5 to 8 , Figure 5 and Figure 7 The distances L2 and L2 are shown in the figures. Figure 6 and Figure 8 The distance L2 is represented by a dashed line. Figure 5 and Figure 7 This is a cross-sectional view of the circuit board disclosed herein under two embodiments mentioned below. It is understood that... Figure 5 and Figure 7 The corresponding cut surface should extend along the bend at the edge of the shield 3. That is, in Figure 6 In the middle, by making a cross-section along the bend of the edge of the shield 3, we can obtain Figure 5 Cross-sectional view in; Figure 8In the middle, by making a cross-section along the bend of the edge of the shield 3, we can obtain Figure 7 Cross-sectional view.

[0034] In some embodiments, in the arrangement direction of the plurality of pads 2, the distance L3 between the two ends of the pad 2 can be greater than twice the distance L2. If the distance L3 is too small, it means that the extension length of the pad 2 is too short, which may result in too many gaps 11 on the circuit board, and the distance between two adjacent gaps 11 is too close, which will reduce the electromagnetic shielding effect of the shielding cover 3.

[0035] In this disclosure, the formation of multiple pads 2 can be implemented in various ways. In a first embodiment, please refer to [specific details]. Figure 5 and Figure 6 The circuit board may include copper foil strips 4 disposed on a substrate 1, and multiple segments of first solder resist coating 5 disposed at intervals on the copper foil strips 4, with the copper foil strips 4 between two adjacent segments of the first solder resist coating 5 forming solder pads 2. In this way, the first solder resist coating 5 can prevent the shield 3 from being soldered to the substrate 1, so that a gap 11 can be formed between the substrate 1 and the shield 3. At the same time, the copper foil strips 4 between two adjacent segments of the first solder resist coating 5 can be exposed on the surface of the substrate 1 and form solder pads 2 due to the absence of the influence of the first solder resist coating 5.

[0036] In the first embodiment, the dimension L1 of the first solder resist coating 5 in the thickness direction of the circuit board can satisfy: 10µm ≤ L1 ≤ 25µm. (Refer to...) Figure 5 ,exist Figure 5 The distance L1 is shown in the figure. Figure 5 Using the direction of the drawing as a reference, in Figure 5 In the thickness direction of the circuit board, Figure 5 The vertical direction of the drawing. If the size L1 is too small, it will affect the solder resist effect of the first solder resist coating 5, and may easily lead to the shielding cover 3 being soldered to the copper foil strip 4 with the first solder resist coating 5. If the size L1 is too large, it will increase the thickness of the circuit board and reduce the size of the gap 11, thus reducing the effect of stress concentration on the substrate 1.

[0037] In the second implementation method, please refer to the following for details. Figure 7 and Figure 8 The circuit board may include a plurality of spaced copper foil plates 41 disposed on a substrate 1, the copper foil plates 41 forming pads 2. In this way, the copper foil plates 41 can be directly exposed on the surface of the substrate 1 to form pads 2, and the area between two copper foil plates 41 will not form pads 2. Thus, the shield 3 and the substrate 1 cannot be soldered together through the pads 2, and a gap 11 can be formed between the shield 3 and the substrate 1.

[0038] In other words, in the first embodiment, the copper foil strip 4 is complete. By setting the first solder resist coating 5, some of the copper foil strip 4 cannot be exposed on the surface of the substrate 1, and some of the copper foil strip 4 cannot form solder pads 2. A gap 11 can be formed between the shield 3 and the substrate 1. In the second embodiment, multiple copper foil plates 41 are directly and spaced apart on the substrate 1. The copper foil plates 41 directly form solder pads 2, and the area between two copper foil plates 41 will not form solder pads 2.

[0039] In the second embodiment, a groove 6 is defined by two adjacent copper foil plates 41 and the substrate 1 located between the two adjacent copper foil plates 41. The circuit board also includes a second solder resist coating 51 coated on the inner wall of the groove 6. Thus, by providing the groove 6, multiple copper foil plates 41 can be spaced apart through the groove 6, forming solder pads 2. The second solder resist coating 51 also prevents solder paste from flowing into the groove 6 during soldering. For the groove 6, the edges of the copper foil plates 41 form the sidewalls of the groove 6, and the top surface of the substrate 1 forms the bottom of the groove 6. The material of the second solder resist coating 51 can be the same as the material of the first solder resist coating 5. The dimensions of the second solder resist coating 51 in the thickness direction of the circuit board can also be the same as the dimensions of the first solder resist coating 5.

[0040] It is understandable that the formation of the groove 6 can be achieved in any appropriate manner. For example, a complete copper foil plate 41 can be first placed on the substrate 1, and then the copper foil plate 41 can be cut so that the complete copper foil plate 41 is divided into multiple copper foil plates 41. Alternatively, the position of the groove 6 can be marked on the surface of the substrate 1 (e.g., by scribing), and multiple copper foil plates 41 can be placed between two adjacent grooves 6 according to their position and size, thereby breaking the copper foil plate 41 through the groove 6.

[0041] In related technologies, circuit boards can employ multi-layer designs, and some components require a "three-dimensional ground plane" process. Three-dimensional ground plane refers to a process applied to circuit boards where components requiring this process have a conductive material filling the area around their pins and specific regions. In some embodiments, metal foil that can serve as pads 2 in certain areas can also serve as the conductive material in the three-dimensional ground plane process. It is understood that in this disclosure, when copper foil 41 in certain areas of the circuit board needs to serve as the conductive material in the three-dimensional ground plane, the location of the slot 6 can avoid the copper foil 41 in those areas, preventing the slot 6 from affecting the three-dimensional ground plane process on the circuit board.

[0042] In the second embodiment, the depth of the groove 6 can be equal to the thickness of the copper foil 41. This prevents the groove 6 from affecting the thickness of the substrate 1 and the conductive lines 12 inside the substrate 1. At the same time, it also prevents the copper foil 41 from being unable to be disconnected if the groove 6 is too shallow.

[0043] It should be noted that, in order to maintain the simplicity of the accompanying drawings, Figure 1 and Figure 3 Only the structure of the circuit board portion is shown. Figure 6 and Figure 8 Only the structure of the substrate 1 part is shown. Figures 5 to 10 The substrate 1 shown is for illustrative purposes only and its complete structure is not depicted; for example, the conductive circuitry within the substrate 1 is not shown. Figure 5 and Figure 7 The diagram only shows the weld seam 7, the pad 2, the copper foil strip 4, and the cross-sectional lines on the copper foil plate 41, to facilitate the differentiation between the structures.

[0044] In some embodiments, specific details may be referred to Figure 9 and Figure 10 The shielding cover 3 can have multiple spaced weld seams 7 between it and each pad 2. That is, when the shielding cover 3 is welded to the pad 2, a segmented welding connection is used. This allows gaps to form between the pad 2 and the shielding cover 3 where there are no weld seams 7, achieving stress dispersion and absorption. As mentioned above, the pads 2 are spaced apart at the bends on the edge of the shielding cover 3, and correspondingly, the pads 2 generally extend along the straight line of the edge of the shielding cover 3. When the substrate 1 is subjected to impact, the straight line of the edge of the shielding cover 3 has a relatively small impact on the stress concentration of the substrate 1. In this case, the pads 2 can be connected without interrupting the weld seams; the gaps created by the segmented welding connection can ensure the absorption and dispersion of stress, preventing severe deformation of the substrate 1 under stress.

[0045] In some embodiments, the dimension L4 of the weld seam 7 in the thickness direction of the circuit board can satisfy: 40µm ≤ L4 ≤ 50µm. (Refer to...) Figure 9 ,exist Figure 9 The distance L4 is shown in the figure. Figure 9 The vertical direction in the drawing represents the thickness direction of the circuit board. If dimension L4 is too large, it indicates that the solder joint 7 is too thick, which will affect the installation position of the shielding cover 3 and further affect the thickness of the circuit board. If dimension L4 is too small, it will affect the soldering strength between the edge of the shielding cover 3 and the solder pad 2.

[0046] This disclosure also provides an electronic device that includes a circuit board according to any of the above embodiments and has all of its beneficial effects. The electronic device may be a portable device such as a mobile phone or tablet computer. Taking a mobile phone as an example, in the event of an impact or accidental drop, the design of the embodiments of this disclosure can reduce the risk of damage and improve its durability.

[0047] In the above detailed description, reference has been made to the accompanying drawings, which illustrate specific aspects of this disclosure by way of illustration. In this regard, terms indicating direction or positional relationship, such as “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial,” and “circumferential,” are used with reference to the orientation of the described figures. Since components of the described device can be positioned in multiple different orientations, directional terms are used for illustrative purposes and not for limitation. It should be understood that other aspects can be utilized and structural or logical changes can be made without departing from the concept of this disclosure. Therefore, the following detailed description should not be considered limiting.

[0048] It should be understood that, unless otherwise specifically indicated, features of various embodiments of this disclosure described herein can be combined with each other. As used herein, the term “and / or” includes any one of the relevant listed items and any combination of any two or more; similarly, “at least one of…” includes any one of the relevant listed items and any combination of any two or more.

[0049] It should be understood that, unless otherwise expressly specified and limited, the terms "joining," "attaching," "installing," "connecting," "linking," "fixing," etc., used in the embodiments of this disclosure should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms herein based on the specific circumstances.

[0050] Furthermore, the term "above" as used herein with respect to components, elements, or material layers formed or located "above" a surface may be used to indicate that the component, element, or material layer is "indirectly" positioned (e.g., placed, formed, deposited, etc.) on the surface such that one or more additional components, elements, or layers are arranged between the surface and the component, element, or material layer. However, the term "above" as used with respect to components, elements, or material layers formed or located "above" a surface may also optionally have a specific meaning: that the component, element, or material layer is "directly" positioned (e.g., placed, formed, deposited, etc.) on the surface, for example, in direct contact with the surface.

[0051] Although terms such as “first,” “second,” and “third” may be used herein to describe various components, parts, regions, layers, or sections, these components, parts, regions, layers, or sections are not limited to these terms. Rather, these terms are used only to distinguish one component, part, region, layer, or section from another. Therefore, without departing from the teachings of the examples described herein, the first component, part, region, layer, or section mentioned in the examples may also be referred to as the second component, part, region, layer, or section. Furthermore, the terms “first” and “second” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as “first” or “second” may explicitly or implicitly include at least one of that feature. In the description herein, “a plurality” means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0052] It should be understood that spatial relative terms, such as “above,” “upper,” “below,” and “lower,” are used herein to describe the relationship between one element and another shown in the figures. In addition to the orientation depicted in the figures, these spatial relative terms are also intended to encompass different orientations of the device in use or operation. For example, if the device in the figures is flipped, an element described as “above” or “upper” relative to another element would be “below” or “lower” relative to that other element. Thus, depending on the spatial orientation of the device, the term “above” encompasses both above and below orientations. Devices may have other orientations (e.g., rotated 90 degrees or in other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0053] Furthermore, the term “exemplary” is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” is not necessarily to be construed as advantageous compared to other aspects or designs. Rather, the use of the term “exemplary” is intended to present the concept in a concrete manner. As used herein, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless otherwise specified or clear from the context, “X applies A or B” is intended to mean any of the natural inclusive arrangements. That is, “X applies A or B” satisfies any of the foregoing instances if X applies A; X applies B; or both X applies A and B. Additionally, unless otherwise specified or clear from the context to refer to the singular form, the articles “a” and “an” as used in this application and the appended claims are generally understood to mean “one or more.”

[0054] Similarly, although this disclosure has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art upon reading and understanding this specification and the accompanying drawings. This disclosure includes all such modifications and variations and is limited only by the scope of the claims. In particular, with respect to the various functions performed by the components described above (e.g., elements, resources, etc.), unless otherwise indicated, the terminology used to describe such components is intended to correspond to any component (functionally equivalent) that performs the specific function of the described component, even if structurally not equivalent to the disclosed structure. Furthermore, although specific features of this disclosure may have been disclosed with respect to only one of several implementations, such features may be combined with one or more other features of other implementations, as may be desired and advantageous to any given or particular application. Moreover, with regard to the terms “comprising,” “owning,” “having,” “having,” or variations thereof as used in the detailed description or claims, such terms are intended to be inclusive in a manner similar to the term “including.”

[0055] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

[0056] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A circuit board, characterized in that, The device includes a substrate and a shielding cover fixed to the substrate by a plurality of pads, wherein the plurality of pads are arranged along the edge of the shielding cover, and at least at the bending position of the edge of the shielding cover, a gap is formed between the shielding cover and the substrate.

2. The circuit board according to claim 1, characterized in that, The circuit board includes a copper foil strip disposed on the substrate, and multiple segments of first solder resist coating disposed at intervals on the copper foil strip, wherein the copper foil strip between two adjacent segments of the first solder resist coating forms the solder pad.

3. The circuit board according to claim 2, characterized in that, In the thickness direction of the circuit board, the dimension L1 of the first solder resist coating satisfies: 10um≤L1≤25um.

4. The circuit board according to claim 1, characterized in that, The circuit board includes a plurality of spaced copper foil plates disposed on the substrate, the copper foil plates forming the pads.

5. The circuit board according to claim 4, characterized in that, The two adjacent copper foil plates and the substrate located between the two adjacent copper foil plates define a groove, and the circuit board further includes a second solder resist coating applied to the inner wall of the groove.

6. The circuit board according to claim 4, characterized in that, In the arrangement direction of the plurality of pads, the distance L2 between the ends of two adjacent pads satisfies: 0.1mm≤L2≤2mm.

7. The circuit board according to claim 6, characterized in that, In the arrangement direction of the plurality of pads, the distance L3 between the two ends of the pads satisfies: L3>2*L2.

8. The circuit board according to claim 1, characterized in that, The shielding cover has multiple spaced weld seams between it and each of the solder pads.

9. The circuit board according to claim 8, characterized in that, In the thickness direction of the circuit board, the weld size L4 satisfies: 40um≤L4≤50um.

10. An electronic device, characterized in that, The electronic device includes the circuit board according to any one of claims 1-9.

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