A type of PCB board

Abstract

This utility model discloses a PCB board for injection molding onto a circuit board, comprising a substrate, a center of which is provided with an assembly area for assembling PCS (Precast Composition Components). The assembly area includes a cutout area extending along the length / width direction of the substrate and a connection area connected to the cutout area. PCS are respectively connected to the cutout area and the connection area, and in the vertical direction perpendicular to the PCB board, the upper surface of the PCS is higher than the upper surface of the connection area. Compared with the prior art, this utility model can ensure uniform flow of the adhesive during injection molding, thus guaranteeing the quality of the finished product.

Description

Technical Field

[0001] This utility model relates to a PCB board and belongs to the field of circuit board technology. Background Technology

[0002] In the field of electronics manufacturing, PCBs (printed circuit boards) serve as the carriers of electronic components and the hubs of electrical connections. Their design and manufacturing have a crucial impact on the performance, reliability, and production efficiency of electronic products. As electronic devices continue to evolve towards miniaturization, thinner profiles, and higher performance, higher demands are being placed on the processing and manufacturing processes of PCBs.

[0003] Traditional PCB designs have limitations in the injection molding process. During injection molding, the adhesive needs to be evenly filled into all areas between the PCB and the PCS (Printed Circuit Board Assembly) to ensure a good bond and overall structural stability. However, existing PCB and PCS assembly designs often lack effective guiding structures, making it prone to problems such as insufficient or uneven filling of the adhesive during flow, and even the formation of air bubbles. This not only affects the connection strength between the PCB and PCS but may also lead to unstable product performance and reduced reliability.

[0004] Furthermore, in some complex-shaped or high-density assembled electronic devices, the assembly space between the PCB board and PCS is limited, and traditional assembly methods are insufficient to meet the requirements of efficient injection molding and high-quality molding. For example, when the assembly area of ​​the PCS and the PCB board is on the same plane, the adhesive may not be able to completely fill the cavity during the injection molding process due to excessive flow resistance, or eddies may form during the filling process, leading to internal defects. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides a PCB board that can ensure that the adhesive is uniformly filled between the PCB board and the PCS during injection molding, thereby ensuring the stability between the two.

[0006] The technical solution of this utility model is:

[0007] A PCB board for injection molding into a circuit board includes a substrate. The center of the substrate has an assembly area for assembling PCS. The assembly area includes a cutout area extending along the length / width direction of the substrate and a connection area connected to the cutout area. The PCS is connected to the cutout area and the connection area respectively. In the vertical direction perpendicular to the PCB board, the upper surface of the PCS is higher than the upper surface of the connection area.

[0008] As a further improvement of this utility model, multiple PCS are provided and arranged at intervals in the assembly area. The connection area includes a transition area and a waste area connected to the transition area. In the vertical direction perpendicular to the PCB board, the upper surface of the PCS is at the same height as the upper surface of the transition area, and the upper surface of the PCS is higher than the upper surface of the waste area.

[0009] As a further improvement of this utility model, the transition region is approximately U-shaped and includes two first transition regions connected to the hollowed-out region and a second transition region connecting the two first transition regions. The first transition regions are located between two adjacent PCS.

[0010] As a further improvement of this utility model, the ratio of the width of the first transition region to the width of the second transition region is between 8:1 and 12:1.

[0011] As a further improvement of this utility model, a grid of copper is provided on the waste area to form a plurality of recessed adhesive tanks on the waste area.

[0012] As a further improvement of this utility model, in the vertical direction perpendicular to the PCB board, the height difference between the upper surface of the PCS and the adhesive tank is 0-20um.

[0013] As a further improvement of this utility model, at least two of the hollowed-out areas and the connecting areas are provided and arranged at intervals within the assembly area.

[0014] As a further improvement of this utility model, the side of the substrate connected to the assembly area is a liquid-passing side lower than the assembly area, and a waste flow channel is formed between the connection area and the liquid-passing side.

[0015] As a further improvement of this utility model, a copper grid is provided on the liquid-passing side to form a plurality of recessed adhesive grooves on the liquid-passing side.

[0016] As a further improvement of this utility model, the liquid-passing side is provided with a plurality of positioning holes and a monitoring hole for monitoring the positioning holes, the monitoring hole being configured to monitor the deviation of the positioning holes.

[0017] The beneficial technical effects of this utility model are as follows: A PCB board of this utility model has an assembly area for assembling PCS in the center of the substrate. The assembly area includes a hollow area extending along the length / width direction of the substrate and a connection area connected to the hollow area. The PCS is connected to the hollow area and the connection area respectively. In the vertical direction perpendicular to the PCB board, the upper surface of the PCS is higher than the upper surface of the connection area. This creates a reasonable height difference structure on the PCB board to better guide the flow of adhesive and ensure that the adhesive can be fully and evenly filled into the required area during injection molding, thereby improving the overall quality of the product and production efficiency. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a PCB board conforming to a preferred embodiment of the present utility model.

[0019] Figure 2 yes Figure 1 A magnified view of a portion of the image.

[0020] Figure 3 yes Figure 1 A magnified view of a portion of the image, b. Detailed Implementation

[0021] In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit the scope of this utility model.

[0022] Please see Figures 1 to 3 As shown, this utility model discloses a PCB board 100, including a substrate 1. The substrate 1 has a central assembly area 2 for assembling PCS 200. The assembly area 2 includes a cutout area 21 extending along the length / width direction of the substrate 1 and a connection area 22 connected to the cutout area 21. The PCS 200 is connected to both the cutout area 21 and the connection area 22. In the vertical direction perpendicular to the PCB board 100, the upper surface of the PCS 200 is higher than the upper surface of the connection area 22. Thus, by setting a reasonable height difference structure on the PCB board 100, the flow of the adhesive can be better guided, ensuring that the adhesive can fully and evenly fill the required area during injection molding, thereby improving the overall product quality and production efficiency.

[0023] Specifically, multiple PCS200s are provided and arranged at intervals within the assembly area 2. The connection area 22 includes a transition area (not shown) and a waste area 221 connected to the transition area. In the vertical direction perpendicular to the PCB board 100, the upper surface of the PCS200 is at the same height as the upper surface of the transition area, and the upper surface of the PCS200 is higher than the upper surface of the waste area 221. This arrangement ensures that the adhesive will not contaminate the PCS200 during the flow process, thereby affecting the quality of the finished product.

[0024] Preferably, the transition region is approximately U-shaped and includes two first transition regions connected opposite to each other in the hollowed-out region 21 and a second transition region connecting the two first transition regions. The first transition regions are located between two adjacent PCS200s. That is, the transition region has a structure that surrounds the PCS200 on three sides.

[0025] Preferably, the ratio of the width of the first transition region to the width of the second transition region is between 8:1 and 12:1. In this embodiment, the width of the first transition region can be 0.8mm, 1mm, 1.2mm, etc., and the width of the second transition region can be 0.08mm, 0.1mm, 0.12mm, etc. This achieves the effect of blocking adhesive without affecting space utilization, while remaining imperceptible to the naked eye.

[0026] In this embodiment, a grid of copper 3 is arranged on the waste area 22 to form several recessed adhesive grooves 222 on the waste area 22. During the molding process, comparative experiments showed that after glue injection, the height difference between the waste edge and the finished board thickness of the PCB board 100 with the grid copper design was significantly reduced, stabilizing within the range of 0-20µm. Further observation of the adhesive flow revealed that the grid copper 3 played a good guiding role in the flow of the adhesive, and the adhesive flowed orderly along the adhesive grooves 222, avoiding poor flow or eddy currents caused by excessive height differences, thus improving the integrity and uniformity of the encapsulation and meeting the process requirements. Preferably, in the vertical direction perpendicular to the PCB board 100, the height difference between the upper surface of the PCS200 and the adhesive grooves 222 is 0-20µm.

[0027] Preferably, at least two of the cutout areas 21 and the connecting areas 22 are provided and arranged at intervals within the assembly area 2. In this embodiment, there are two assembly areas 2, which are located on both sides of the PCB board 100 to ensure maximum space utilization of the PCB board 100.

[0028] The side of the substrate 1 connected to the assembly area 2 is a liquid-passing side 4 lower than the assembly area 2, and a waste flow channel is formed between the connecting area 22 and the liquid-passing side 4. In this embodiment, the liquid-passing side 4 is only provided on one side, which is the side away from the glue inlet in the injection molding process, so as to drain excess glue.

[0029] A grid of copper 3 is provided on the liquid-passing side 4 to form several recessed adhesive grooves 222 on the liquid-passing side 4. That is, both the liquid-passing side 4 and the waste area 221 are provided with grid of copper 3. Preferably, the PCB board 100 is provided with grid of copper 3 on the outer periphery relative to the assembly area 2, because these areas are all waste board materials in the later stage. Therefore, the design of the grid of copper 3 guides the flow of adhesive without affecting the quality of the finished product.

[0030] The liquid-passing side 4 is provided with a plurality of positioning holes 41 and monitoring holes 42 for monitoring the positioning holes 41. The monitoring holes 42 are configured to monitor the misalignment of the positioning holes 41. In this way, the overall misalignment of the PCB board 100 during the process can be avoided.

[0031] Before injection molding, it is necessary to ensure that there are no height differences on the surface of PCS200 on PCB board 100. Therefore, the top layer of PCB board 100 is printed twice, using 72T and 140T screen printing plates respectively, with ink printed twice in the order of first between circuit lines and then on the top layer lines. Experiments show that the ink height difference between the top layer lines and between lines can be less than 8um, further avoiding height differences between PCS200.

[0032] Preferably, after solder resist treatment, the PCB board 100 is subjected to nickel-palladium-gold electroplating. For example, a 3µm thick nickel layer is first plated, followed by a 0.1µm thick palladium layer, and finally a 0.1µm thick gold layer. In the molding process, actual injection tests showed that the adhesive flowed smoothly along the path formed by the waste channel, and excess adhesive was effectively guided to the liquid-passing side 4, avoiding accumulation inside the encapsulation section and ensuring the flatness of the encapsulation surface. Testing revealed that the treated waste channel surface was flat, free of residual solder resist ink, and its adhesion, oxidation resistance, and solderability all met process requirements. Furthermore, the encapsulated PCB board 100 showed no adhesive residue or contamination in the waste channel, and exhibited good electrical connection performance.

[0033] In this embodiment, the PCS200 includes a folded portion 201 located in the hollowed-out area 21 and a functional portion 202 located in the connecting area 22. The transition area surrounds the outer periphery of the functional portion 202, and the upper surface of the functional portion 202 is higher than the upper surface of the waste area 221.

[0034] In summary, the PCB board 100 of this utility model provides an assembly area 2 for assembling PCS 200 at the center of the substrate 1. The assembly area 2 includes a hollow area 21 extending along the length / width direction of the substrate 1 and a connection area 22 connected to the hollow area 21. The PCS 200 is connected to the hollow area 21 and the connection area 22 respectively. In the vertical direction perpendicular to the PCB board 100, the upper surface of the PCS 200 is higher than the upper surface of the connection area 22. This provides a reasonable height difference structure on the PCB board 100 to better guide the flow of adhesive and ensure that the adhesive can be fully and evenly filled into the required area during injection molding, thereby improving the overall quality of the product and production efficiency.

[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A PCB board for injection molding into a circuit board, characterized in that, The PCB includes a substrate, the center of which is provided with an assembly area for assembling PCS. The assembly area includes a cutout area extending along the length / width direction of the substrate and a connection area connected to the cutout area. The PCS is connected to the cutout area and the connection area respectively, and in the vertical direction perpendicular to the PCB, the upper surface of the PCS is higher than the upper surface of the connection area.

2. The PCB board according to claim 1, characterized in that, Multiple PCS are provided and arranged at intervals in the assembly area. The connection area includes a transition area and a waste area connected to the transition area. In the vertical direction perpendicular to the PCB board, the upper surface of the PCS is at the same height as the upper surface of the transition area, and the upper surface of the PCS is higher than the upper surface of the waste area.

3. The PCB board according to claim 2, characterized in that, The transition region is roughly U-shaped and includes two first transition regions connected to the hollowed-out region and a second transition region connecting the two first transition regions. The first transition regions are located between two adjacent PCS.

4. The PCB board according to claim 3, characterized in that, The ratio of the width of the first transition region to the width of the second transition region is between 8:1 and 12:

1.

5. The PCB board according to claim 2, characterized in that, A copper grid is provided on the waste area to form several recessed adhesive tanks on the waste area.

6. The PCB board according to claim 5, characterized in that, In the vertical direction perpendicular to the PCB board, the height difference between the upper surface of the PCS and the adhesive tank is 0-20µm.

7. The PCB board according to claim 1, characterized in that, Both the hollowed-out area and the connecting area are provided in at least two places and are arranged at intervals within the assembly area.

8. The PCB board according to claim 1, characterized in that, The side of the substrate connected to the assembly area is a liquid-passing side lower than the assembly area, and a waste flow channel is formed between the connection area and the liquid-passing side.

9. The PCB board according to claim 8, characterized in that, A copper grid is provided on the liquid-passing side to form several recessed adhesive grooves on the liquid-passing side.

10. The PCB board according to claim 9, characterized in that, The liquid-passing side is provided with a plurality of positioning holes and a monitoring hole for monitoring the positioning holes. The monitoring hole is configured to monitor the deviation of the positioning holes.

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