A printed circuit board and a printed circuit board assembly
By setting a groove structure in the stress-sensitive area of the circuit board, the problem of damage to stress-sensitive components when removing the transition edge is solved, thus improving the yield of the circuit board.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN CITY SIGLENT TECH
- Filing Date
- 2025-05-07
- Publication Date
- 2026-06-09
AI Technical Summary
When removing the transition edge of the circuit board, stress-sensitive components are easily damaged, affecting the yield rate.
In stress-sensitive areas of the circuit board, groove structures are set to limit the transmission of stress to the soldering position. These include hollow grooves or thinning grooves, which weaken the stress transmission path.
This reduces the risk of damage to stress-sensitive components and improves the yield rate of circuit boards.
Smart Images
Figure CN224343434U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of printed circuit board design and processing technology, specifically to a printed circuit board and a printed circuit board assembly. Background Technology
[0002] Currently, electronic products are becoming increasingly integrated, leading to a greater demand for miniaturized circuit boards. This results in smaller circuit board sizes and higher component density. In particular, components and traces are getting closer to the board edges. To meet production requirements, transition edges need to be pre-installed on the board edges for clamping and positioning. These transition edges are then removed during the assembly process after the components are mounted.
[0003] Removing the transition edge generates stress transfer, which is transmitted through the board to the components on it. This can easily damage some stress-sensitive components (such as surface mount thin film resistors, relays, and crystal oscillators), affecting the yield rate. Utility Model Content
[0004] This application provides a printed circuit board and a printed circuit board assembly to address the problem that stress-sensitive components are easily damaged when removing transition edges.
[0005] According to a first aspect, one embodiment provides a printed circuit board, comprising:
[0006] substrate;
[0007] and a transition edge, the transition edge being located at at least one edge of the substrate;
[0008] The substrate has a stress-sensitive region adjacent to the transition edge. At least one welding position for welding stress-sensitive components is provided in the stress-sensitive region. A groove structure is provided on the transition edge. The groove structure is located on the side of the welding position in a direction perpendicular to the extension direction of the transition edge and is adjacent to the substrate. It is used to limit the transmission of stress generated when the transition edge is removed to the sensitive component placement position.
[0009] In one embodiment, the groove structure is a hollow groove, which is disposed through the thickness direction of the transition edge.
[0010] In one embodiment, the dimensions of the hollow groove along the length direction of the transition edge are configured such that, based on the corresponding welding position, it extends to both sides along the length direction of the transition edge to exceed the edge of the welding position by at least 15 mm.
[0011] In one embodiment, the stress-sensitive area is a continuous strip-shaped region no more than 20 mm from the interface between the transition edge and the substrate.
[0012] In one embodiment, the distance between the welding position and the interface between the transition edge and the substrate is not less than 1 mm.
[0013] In one embodiment, one of the groove structures corresponds to at least two welding positions.
[0014] In one embodiment, the welding position corresponding to one of the slot structures includes at least two relay welding positions and one surface mount resistance welding position. Each welding position is arranged sequentially in a direction parallel to the extension direction of the transition edge, and the distance between the surface mount resistance welding position and the transition edge is greater than the distance between the relay welding position and the transition edge.
[0015] According to a second aspect, one embodiment provides a printed circuit board assembly, comprising:
[0016] The printed circuit board described in any of the above embodiments;
[0017] And a stress-sensitive component, at least one of the stress-sensitive components being disposed at the soldering position on the printed circuit board.
[0018] In one embodiment, the stress-sensitive component includes at least one of a surface-mount thin-film resistor, a relay, and a crystal oscillator; the package size of the surface-mount thin-film resistor is not less than 2.0 mm × 1.0 mm.
[0019] In one embodiment, at least two stress-sensitive components are disposed within the stress-sensitive region, and each stress-sensitive component is arranged at intervals in a planar array.
[0020] In the printed circuit board according to the above embodiment, the circuit board bends under force and accumulates stress when the transition edge is removed. When the transition edge is broken, the circuit board rebounds rapidly due to inertia and elasticity, releasing the stress and generating vibration. Stress-sensitive components located at soldering positions in the stress-sensitive area adjacent to the transition edge are easily affected by vibration and suffer mechanical damage. By pre-setting a groove structure at the position corresponding to the soldering position on the transition edge, the local structure of the transition edge is actively weakened to limit stress transmission. This helps to reduce the impact of stress release during transition edge removal on stress-sensitive components at adjacent soldering positions, reducing their damage risk and improving yield. Attached Figure Description
[0021] Figure 1 This is a partial structural diagram of a printed circuit board without a slot structure according to one embodiment;
[0022] Figure 2 This is a schematic diagram of the structure of a printed circuit board according to one embodiment;
[0023] Figure 3This is a partial structural schematic diagram of a printed circuit board according to another embodiment;
[0024] Figure 4 This is a schematic diagram of the structure of a printed circuit board assembly according to one embodiment.
[0025] In the diagram, 100 is the printed circuit board; 110 is the substrate; 111 is the stress-sensitive area; 112 is the soldering position; 1121 is the relay soldering position; 1122 is the surface mount thin-film resistor soldering position; 120 is the transition edge; and 121 is the cutout groove.
[0026] 200. Stress-sensitive components. Detailed Implementation
[0027] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. Similar elements in different embodiments are referred to by related similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the present application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to the present application are not shown or described in the specification. This is to avoid obscuring the core parts of the present application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.
[0028] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.
[0029] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).
[0030] To facilitate the clamping and positioning of the printed circuit board 100 during the processing equipment transfer process, please refer to... Figure 1A transition edge 120 needs to be reserved at the edge of the printed circuit board 100. The transition edge 120 is usually removed after the components are mounted. When removing the transition edge 120 (especially by hand), the printed circuit board 100 will bend under force and accumulate stress. When the transition edge 120 is broken, the printed circuit board 100 will quickly rebound due to inertia and elasticity, release the stress, and generate vibration. Components placed near the transition edge 120 will also be driven to vibrate. Among them, components that are sensitive to stress are easily affected by vibration and suffer mechanical damage (for example, causing misalignment of internal contacts of relays, crystal oscillators and other high-precision components, causing them to fail; or causing the surface-mount thin film resistor to break, etc.).
[0031] In this embodiment, by defining a stress-sensitive region 111 adjacent to the transition edge 120 and dividing the stress-sensitive region 111 into welding positions 112 for welding stress-sensitive components 200, a groove structure can be pre-set on the transition edge 120 at a position opposite to the welding positions 112. When the transition edge 120 is removed, the groove structure can limit the transmission of stress to the stress-sensitive components 200 at the welding positions 112. By actively weakening the local structure of the transition edge 120 to limit stress transmission, the risk of damage to the stress-sensitive components 200 during the removal of the transition edge 120 is reduced, thus improving the yield rate.
[0032] Examples of printed circuit boards in this application:
[0033] In one embodiment, please refer to Figure 1 A printed circuit board is provided, including a substrate 110 and a transition edge 120 located at at least one edge of the substrate 110.
[0034] When the transition edge 120 is removed, stress is transmitted to the substrate 110. Since stress-induced vibrations gradually decrease with transmission, the area adjacent to the transition edge 120 on the substrate 110 is most affected by stress, and components located in this area are prone to mechanical damage. Therefore, the area on the substrate 110 adjacent to the transition edge 120 is designated as a stress-sensitive region 111. It is understood that the width of the stress-sensitive region 111 is limited. In one embodiment, a continuous strip-shaped area no more than 20 mm from the interface between the transition edge 120 and the substrate 110 can be used as the stress-sensitive region 111. In other embodiments, regions of other widths or shapes can be used as the stress-sensitive region 111 according to actual needs.
[0035] Due to the functional requirements of the printed circuit board 100, please refer to the following embodiments. Figure 1 and Figure 2At least one soldering position 112 is also provided in the stress-sensitive region 111, and solder joints are provided on the soldering position 112 for soldering stress-sensitive components 200. In different embodiments, the soldering position 112 being provided in the stress-sensitive region 111 can be understood as the soldering position 112 being entirely located therein, or it can be understood as at least a portion of the soldering position 112 being located therein, for example, at least 50% of the soldering positions being located in the stress-sensitive region 111.
[0036] In one embodiment, the distance between the soldering position 112 and the interface between the transition edge 120 and the substrate 110 can be set to not less than 1 mm; such as 1 mm, 3 mm, 5 mm, 10 mm, etc. This is to prevent the stress-sensitive component 200 and the transition edge 120 from being too close, which helps to reduce the risk of damage to the stress-sensitive component 200 and surrounding circuitry during the board separation process.
[0037] To limit the transmission of stress generated during the removal of transition edge 120 to weld position 112, in one embodiment, please refer to... Figure 2 A groove structure is provided on the transition edge 120. The groove structure is located on the side of the welding position 112 in a direction perpendicular to the extension direction of the transition edge 120 and adjacent to the substrate 110. It is used to limit the stress generated when the transition edge 120 is removed from the sensitive component placement position.
[0038] It is understood that the groove structure can be a hollow groove 121, that is, a through groove 120 extending through the thickness direction of the transition edge 120, which helps to cut off stress transmission at the location where the groove structure is set. The groove structure can also be a thinning groove, that is, a region where the thickness of the groove is reduced in the thickness direction of the transition edge 120; for example, the depth of the groove structure can be set to 40% to 60% of the thickness of the transition edge 120, thereby weakening stress transmission. In short, the groove structure can be through or not, as long as it can limit stress transmission to the substrate 110.
[0039] In another embodiment, the groove structure can also be arranged in other directions; for example, multiple groove structures are arranged at intervals along the joint interface between the transition edge 120 and the substrate 110, and each groove structure can be set as a hole type (such as square hole, round hole, waist-shaped hole, etc.) so that a stress weakening structure in the form of a break point can be constructed along the joint interface between the transition edge 120 and the substrate 110 through the cooperation of each groove structure.
[0040] The slot structure can be pre-processed using a high-precision CNC machine tool, which helps reduce the risk of damaging the circuitry in the printed circuit board 100 when setting the slot structure. Furthermore, the slot structure also makes it less likely to damage stress-sensitive components 200 even when the transition edge 120 is removed manually. This allows for the removal of the transition edge 120 to be compatible with both manual removal and mechanical removal (such as using a V-cut depaneling machine or milling machine), thus reducing the requirements for the production environment.
[0041] In one embodiment, please refer to Figure 2 The groove structure is set as the hollow groove 121 described in the above embodiment, and the dimensions of the hollow groove 121 along the length direction of the transition edge 120 are configured as follows: based on the corresponding welding position 112, it extends to both sides along the length direction of the transition edge 120 to exceed the edge of the welding position 112 by at least 15mm.
[0042] Here, "taking the corresponding welding position 112 as a reference" can be understood as the centers of welding position 112 and hollow groove 121 being opposite each other in the length direction of transition edge 120. Since welding position 112 is matched with stress-sensitive component 200, in some embodiments, it can also be understood that the centers of stress-sensitive component 200 and hollow groove 121 of welding position 112 are opposite each other in the length direction of transition edge 120.
[0043] Configuring the slot 121 to extend at least 15 mm beyond the edge of the welding position 112 helps enhance the stress transmission restriction effect of the slot 121, thereby further protecting the stress-sensitive component 200 on the welding position 112. In a further embodiment, the dimension of the slot 121 along the length direction of the transition edge 120 can also be configured such that, based on the corresponding welding position 112, it extends to both sides along the length direction of the transition edge 120 to extend 15 mm-20 mm beyond the edge of the welding position 112; for example, the dimension of the slot 121 extending beyond the edge of the welding position 112 can be 15 mm, 16 mm, 18 mm, 20 mm, etc.
[0044] It is understood that when two adjacent weld positions 112 are provided in the stress-sensitive area 111, and the distance between the two weld positions 112 is less than the sum of the dimensions of their corresponding groove structures extending beyond the edge of the weld position 112, please refer to... Figure 3 The two hollowed-out grooves 121 corresponding to the two welding positions 112 can be connected to form a long hollowed-out groove. For example, when there are two welding positions 112 in the stress-sensitive area 111 with a distance of less than 30mm along the length of the transition edge 120, a hollowed-out groove 121 should be provided for each of the two welding positions 112. However, since both hollowed-out grooves 121 are configured to extend at least 15mm beyond the edge of the corresponding welding position 112, the two hollowed-out grooves 121 will be connected to form a long hollowed-out groove according to the rules.
[0045] In other words, in one embodiment, please refer to Figure 3 A single groove structure can correspond to at least two welding positions 112. This arrangement not only helps to improve the constraint effect on stress transmission, but also helps to reduce processing costs.
[0046] For example, please refer to Figure 3The welding position 112 corresponding to a slot structure includes at least two relay welding positions 1121 and one surface mount thin film resistor welding position 1122. Each welding position 112 is arranged sequentially in a direction parallel to the extension direction of the transition edge 120, and the distance between the surface mount thin film resistor welding position 1122 and the transition edge 120 is greater than the distance between the relay welding position 1121 and the transition edge 120.
[0047] In other embodiments, the welding positions 112 corresponding to the groove structure may also be arranged in other ways, depending on the design and usage requirements of the printed circuit board 100.
[0048] Embodiments of the printed circuit board assembly in this application:
[0049] In one embodiment, please refer to Figure 2 and Figure 4 The printed circuit board assembly includes the printed circuit board 100 in any of the above embodiments and stress-sensitive components 200, with at least one stress-sensitive component 200 disposed on a soldering position 112 on the printed circuit board 100.
[0050] The stress-sensitive component 200 can be understood as a component that is sensitive to mechanical stress and easily damaged by vibration, such as a surface-mount thin-film resistor, a relay, and a crystal oscillator. In one embodiment, the stress-sensitive component 200 may include at least one of a surface-mount thin-film resistor, a relay, and a crystal oscillator.
[0051] Those skilled in the art will understand that the larger the package size of a surface-mount thin-film resistor, the more susceptible it is to mechanical vibration, i.e., the more sensitive it is to stress. Conversely, some surface-mount thin-film resistors with smaller package sizes have stronger resistance to vibration and are less prone to mechanical damage from stress. Therefore, in some embodiments, the stress-sensitive device 200 includes a surface-mount thin-film resistor with a package size of not less than 2.0 mm × 1.0 mm. In other embodiments, the stress-sensitive device 200 may also include a surface-mount thin-film resistor with a package size of not less than 1.2 mm × 0.6 mm.
[0052] In some embodiments, the stress-sensitive component 200 includes a relay whose vibration resistance can be at least: able to withstand vibrations of up to 3.3 mm double amplitude (peak-to-peak) in a frequency range of 10 Hz to 55 Hz.
[0053] In one embodiment, at least two stress-sensitive components 200 may be provided in the stress-sensitive area 111, and each stress-sensitive component 200 is arranged at intervals in a planar array, which helps to reduce stress transmission and influence between stress-sensitive components 200 and further reduce the risk of mechanical damage to stress-sensitive components 200.
[0054] The above examples illustrate this application only to aid understanding and are not intended to limit its scope. Those skilled in the art to which this application pertains can make various simple deductions, modifications, or substitutions based on the ideas presented.
Claims
1. A printed circuit board, characterized in that, include: substrate; and a transition edge, the transition edge being located at at least one edge of the substrate; The substrate has a stress-sensitive region adjacent to the transition edge. At least one welding position for welding stress-sensitive components is provided in the stress-sensitive region. A groove structure is provided on the transition edge. The groove structure is located on the side of the welding position in a direction perpendicular to the extension direction of the transition edge and is adjacent to the substrate. It is used to limit the transmission of stress generated when the transition edge is removed to the sensitive component placement position.
2. The printed circuit board as described in claim 1, characterized in that, The groove structure is a hollow groove, which is provided through the thickness direction of the transition edge.
3. The printed circuit board as described in claim 2, characterized in that, The dimensions of the hollow groove along the length direction of the transition edge are configured such that, based on the corresponding welding position, it extends to both sides along the length direction of the transition edge to exceed the edge of the welding position by at least 15 mm.
4. The printed circuit board as described in any one of claims 1 to 3, characterized in that, The stress-sensitive area is a continuous strip-shaped region no more than 20 mm away from the interface between the transition edge and the substrate.
5. The printed circuit board as described in claim 4, characterized in that, The distance between the welding position and the interface between the transition edge and the substrate is not less than 1 mm.
6. The printed circuit board as described in any one of claims 1 to 3, characterized in that, One of the groove structures corresponds to at least two welding positions.
7. The printed circuit board as described in claim 6, characterized in that, Each of the slot structures corresponds to at least two relay welding positions and one surface mount thin-film resistor welding position. The welding positions are arranged sequentially in a direction parallel to the extension direction of the transition edge, and the distance between the surface mount thin-film resistor welding position and the transition edge is greater than the distance between the relay welding position and the transition edge.
8. A printed circuit board assembly, characterized in that, include: Printed circuit board according to any one of claims 1 to 7; And a stress-sensitive component, at least one of the stress-sensitive components being disposed at the soldering position on the printed circuit board.
9. The printed circuit board assembly as claimed in claim 8, characterized in that, The stress-sensitive components include at least one of surface mount thin-film resistors, relays, and crystal oscillators; the package size of the surface mount thin-film resistor is not less than 2.0mm × 1.0mm.
10. The printed circuit board assembly as claimed in claim 8, characterized in that, At least two stress-sensitive components are provided in the stress-sensitive area, and each stress-sensitive component is arranged at intervals in a planar array.