Method for detecting resistance welding alignment of circuit board
The test module is designed on the edge of the circuit board process, and the tested pads are used to detect the bias bias of the seamless detection window to solve the problem of damaging damage in the existing technology, and the detection accuracy and production efficiency are improved.
Patent Information
- Application Number
- CN202411254930.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2025-01-24
AI Technical Summary
When the prior art detects the solder resist alignment of the pads in the circuit board, it is easy to damage the board surface or the board needs to be damaged to determine the deviation, resulting in damage to the circuit board quality and increased production costs.
Design a detection module, set at least one detection module on the side of the circuit board process, and use multiple detection windows to be enlarged by multiple detection pads and step by step to simulate the welding windows of the pads. Disk bias.
It significantly improves the detection accuracy of solder mask alignment, reduces the process scrap rate, improves production efficiency and quality yield, and avoids circuit board damage.
Smart Images
Figure CN119353998A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of circuit board detection, and in particular to a method for detecting solder mask alignment of a circuit board. Background Art
[0002] With the increasing development of the communications industry, 5G communications have higher and higher functional requirements for circuit boards, especially for the dimensional accuracy and welding area of the pads on the surface of the circuit boards. Among them, when designing the normal solder mask opening for the pads in the circuit board, it is necessary to detect whether the solder mask alignment of the pads in the board is offset to ensure the pass rate of the circuit board. However, to confirm the offset of the solder mask, it is necessary to measure the pads in the board, but this measurement method can easily damage the board surface, causing scratches on the board surface. Or it is necessary to destroy the board by slicing to determine whether the pad is offset. Both of the above detection methods are likely to damage the circuit board and affect the quality of the circuit board, while increasing production costs. Summary of the invention
[0003] In view of this, the present invention provides a method for detecting the solder mask alignment of a circuit board, which can effectively detect whether the solder mask of a pad is offset without damaging the structure inside the board.
[0004] The purpose of the present invention is achieved through the following technical solutions: A method for detecting solder mask alignment of a circuit board, the method is to design at least one detection module on the process edge of the circuit board, and use the detection module to assist in determining whether there is solder mask deviation in the pad of the circuit board; the design method of the detection module includes the following steps: S1, determining the setting position of the detection module on the process edge of the circuit board; S2, designing two pad groups on the circuit layer in the detection module, each of the pad groups including a plurality of detection pads having the same shape and size; S3, a detection window is designed for each detection pad with a solder resist, wherein the shape of the detection window is the same as the shape of the detection pad, and the multiple detection windows in each pad group are enlarged step by step in equal proportion, and the window design of the smallest detection window in each pad group is the same as the smallest window design of the pad in the circuit board.
[0005] In the above technical scheme, by ensuring that the detection window in each pad group is enlarged proportionally step by step when designing the detection module, and the minimum detection window is consistent with the minimum window design of the pad in the circuit board, it can accurately simulate the solder mask window situation of the pad in the board in actual production, and the multi-stage amplification design in the detection module makes the solder mask deviation problem clear at a glance. When the circuit board is subjected to the power test process, if the detection pad is offset, the deviation distance can be judged according to the detection pad that issues an alarm, thereby significantly improving the detection accuracy of the solder mask alignment, facilitating timely adjustment of the production process of the circuit board, effectively reducing the process scrap rate of the circuit board, and improving the production efficiency and quality yield of the circuit board.
[0006] Optionally, in a possible implementation, the multiple detection windows in one of the pad groups are larger than the detection pad corresponding to the detection window, and the multiple detection windows in another pad group are smaller than the detection pad corresponding to the detection window.
[0007] In the above technical solution, the design of the two pad groups and the detection window corresponds to the design of the pads in the circuit board, that is, NSMD and SMD pads, wherein the NSMD pad is a design in which the solder resist window is larger than the pad, and the SMD pad is a design in which the solder resist window is smaller than the pad. That is to say, the design of the above pad group enables the detection module to detect circuit boards with different pad forms, and its application range is wider and has better universality.
[0008] Optionally, in a possible implementation manner, the multiple detection windows in each group of the pad groups are enlarged one by one with a single-side spacing of 0.5 mil-1 mil.
[0009] In the above technical solution, multiple detection windows in the same group are enlarged one by one with a single-side spacing of 0.5mil-1mil. This fine spacing control enables the detection module to accurately detect the offset range of the pads in the board, that is, the offset distance of the solder pads in the board is accurate to 0.5mil or 1mil, so that the staff can better specify correction measures according to the offset and improve the accuracy of the correction.
[0010] Optionally, in a possible implementation, a first isolation zone is provided on the periphery of each detection pad, a second isolation zone is provided on the periphery of the detection module, and both the first isolation zone and the second isolation zone are formed of a substrate of a circuit board.
[0011] In the above technical solution, the setting of the first isolation zone and the second isolation zone, especially that they are composed of the substrate of the circuit board, effectively establishes a physical barrier between the detection pad and the surrounding circuit, and between the detection module and the external environment, so that the multiple detection pads are independent of each other, and the substrate itself has good insulation properties, which further enhances the electrical isolation between the detection pad and the surrounding circuit, and reduces the risk of failure caused by short circuit or leakage.
[0012] Optionally, in a possible implementation manner, the structure of the detection pad is any one of a circular shape, a square shape, an elliptical shape, an island shape or a polygonal shape.
[0013] In the above technical solution, the design of multiple shapes greatly enhances flexibility and adaptability. The diverse shape selection enables the detection pad to be customized according to the layout of different circuit boards, the arrangement of components and the requirements of detection accuracy to meet diverse design requirements. It can also be optimally laid out according to the available space on the circuit board, thereby maximizing the use of limited circuit board area.
[0014] Optionally, in a possible implementation manner, when the detection pad is circular, the diameter of the detection pad is 1-2 mm; when the detection pad is square, the diameter of the detection pad is (1-1.5 mm)*(1-1.5 mm).
[0015] In the above technical solution, a specific size range is set for the inspection pad, such as the diameter of a circular pad is 1-2mm, and the side length of a square pad is 1-1.5mm. Such precise control ensures the consistency and repeatability of the pad. In the manufacturing process, this clear size standard helps reduce errors and improve production efficiency and product quality.
[0016] Optionally, in a possible implementation manner, the number of detection pads in each pad group is 2-5.
[0017] In the above technical solution, the number of detection pads in the pad group is reasonably set within the limited circuit board space, which can optimize the layout and space utilization of the pads. While ensuring the detection effect, it can reduce the interference and occupied space between the pads, and improve the overall performance and aesthetics of the circuit board.
[0018] Optionally, in a possible implementation manner, the plurality of detection pads in the pad group are arranged in a linear array, a rectangular array, or a circular array.
[0019] In the above technical solution, the arrangement of multiple detection pads in the pad group can be flexibly designed according to the shape and size of the circuit board. For example, when the process edge of the circuit board is wider, a rectangular array or a circular array arrangement can be adopted. When the process edge of the circuit board is longer, a linear arrangement can be adopted. This can effectively improve the flexibility and applicability of the detection module setting.
[0020] Optionally, in a possible implementation, there are multiple detection modules, and the multiple detection modules are distributed at intervals on the process edge of the circuit board.
[0021] In the above technical solution, the setting of multiple detection modules can improve the comprehensiveness and accuracy of detection. When a module has a problem, other modules can still work normally to ensure the continuity and stability of detection. This redundant design enhances the fault tolerance and reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0023] Figure 1 It is a schematic diagram of the overall structure of an embodiment.
[0024] Figure 2 Schematic diagram of the structure of a detection module according to an embodiment.
[0025] Figure numerals: 1-circuit board; 11-process edge; 2-detection module; 20-pad group; 21-detection pad; 22-detection window; 23-first isolation zone; 24-second isolation zone. DETAILED DESCRIPTION
[0026] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.
[0027] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.
[0028] Please refer to Figure 1 The present embodiment provides a method for detecting the solder mask alignment of a circuit board 1. The method is to design at least one detection module 2 on the process edge 11 of the circuit board 1, and use the detection module 2 to assist in determining whether there is solder mask deviation in the pad of the circuit board 1. The design method of the detection module 2 includes the following steps.
[0029] S1, determine the setting position of the detection module 2 on the process edge 11 of the circuit board 1; set the detection module 2 on the process edge 11, and when performing detection, only the detection module 2 on the process edge 11 needs to be monitored, and there is no need to destroy the main structure of the circuit board 1, which can ensure that the quality of the circuit board 1 is more stable.
[0030] S2, designing two pad groups 20 on the circuit layer in the detection module 2, each pad group 20 includes a plurality of detection pads 21 having the same shape and size; S3, solder resist window design is performed on each detection pad 21 to form a detection window 22, the shape of the detection window 22 is the same as the shape of the detection pad 21, and the multiple detection windows 22 in each pad group 20 are enlarged in proportion step by step, and the window design of the smallest detection window 22 in each pad group 20 is the same as the minimum window design of the pad in the circuit board 1. Specifically, taking the design of one of the pad groups 20 as an example, the detection pad 21 in the pad group 20 has no corresponding relationship with the pad in the circuit board 1, and the two can be designed independently without interfering with each other. However, it should be noted that the design of the minimum detection window 22 in the pad group 20 should be the same as the minimum solder resist window design of the pad in the circuit board 1, that is, when the minimum solder resist window of the pad in the circuit board 1 is 1 mil larger than the pad, then correspondingly, the minimum detection window 22 of one of the detection pads 21 in the pad group 20 should also be 1 mil larger than the detection pad 21, and the remaining detection windows 22 are increased in sequence.
[0031] This embodiment ensures that the detection window 22 in each pad group 20 is enlarged in proportion step by step when designing the detection module 2, and the minimum detection window 22 is consistent with the minimum window design of the pad in the circuit board 1. It can accurately simulate the solder mask window opening of the pad in the board during actual production, and the multi-stage amplification design in the detection module 2 makes the solder mask deviation problem clear at a glance. When the circuit board 1 is subjected to the power test process, if the detection pad 21 is offset, the deviation distance can be judged based on the detection pad 21 that issues an alarm, thereby significantly improving the detection accuracy of the solder mask alignment, facilitating timely adjustment of the production process of the circuit board 1, effectively reducing the process scrap rate of the circuit board 1, and improving the production efficiency and quality yield of the circuit board 1.
[0032] When detecting whether the solder mask of the pad of the circuit board 1 is offset, this embodiment only needs to monitor whether the solder mask of the detection pad 21 in the detection module 2 is offset, and there is no need to break the circuit board 1 itself, which can ensure that the quality of the circuit board 1 is more stable, and the detection method is more convenient and fast, which is suitable for all circuit board 1 designs and has a wide range of applications. At the same time, since the process edge 11 is a structure existing in the circuit board 1 itself, the design of the detection module 2 will not increase the board arrangement space of the circuit board 1, and will not affect the board material utilization rate of the circuit board 1. At the same time, it effectively reduces the process scrap rate of the circuit board 1 and increases product profits.
[0033] In this embodiment, the multiple detection windows 22 in one pad group 20 are larger than the detection pads 21 corresponding to the detection windows 22 , and the multiple detection windows 22 in another pad group 20 are smaller than the detection pads 21 corresponding to the detection windows 22 .
[0034] Specifically, the design of the two pad groups 20 and the detection window 22 corresponds to the design of the pads in the circuit board 1, that is, NSMD and SMD pads, wherein the NSMD pad is a design in which the solder resist window is larger than the pad, and the SMD pad is a design in which the solder resist window is smaller than the pad. In other words, the design of the above-mentioned pad group 20 enables the detection module 2 to detect circuit boards 1 with different pad forms, and its application range is wider and has better universality.
[0035] It should be noted that SMD and NSMD are two important pad design methods in circuit board design. Among them, SMD, namely Solder Mask Defined, means "solder mask defined pad design". In this design, the size of the pad is defined by the opening of the solder mask layer (usually green paint). Specifically, a layer of solder mask green paint is covered on a larger area of copper foil, and then the copper foil is exposed at the opening of the green paint (that is, the place where the green paint is not covered) to form a pad. NSMD, namely Non-Solder Mask Defined, means "non-solder mask defined pad design", also known as Copper Defined Pad Design (copper foil independent pad design). In this design, the copper foil is designed to be smaller than the opening of the solder mask green paint, and the size of the pad is directly determined by the size of the copper foil.
[0036] In this embodiment, the multiple detection windows 22 in each pad group 20 are enlarged one by one with a single-side spacing of 0.5mil-1mil. Taking the circular detection pad 21 as an example, the detection window 22 is also a circle corresponding to the detection pad 21, and the radius of the multiple detection windows 22 in the same pad group 20 gradually increases with a range of 0.5mil-1mil.
[0037] Multiple detection windows 22 in the same group are enlarged one by one with a spacing of 0.5mil-1mil on one side. This fine spacing control enables the detection module 2 to accurately detect the offset range of the pads in the board, that is, the offset distance of the solder piece in the board is accurate to 0.5mil or 1mil, so that the staff can better specify the correction measures for the offset and improve the accuracy of the correction. More specifically, when the circuit board 1 is subjected to an electrical test, if the solder mask opening of the pad in the circuit board 1 is offset by 0.5mil, then the corresponding detection pad 21 on the detection module 2 will alarm, reminding that the pad on the solder mask offset exceeds 0.5mil. Similarly, if the offset exceeds 1mil, another corresponding detection pad 21 will alarm.
[0038] In this embodiment, a first isolation zone 23 is provided on the periphery of each detection pad 21, and a second isolation zone 24 is provided on the periphery of the detection module 2. The first isolation zone 23 and the second isolation zone 24 are both formed by the substrate of the circuit board 1. Specifically, the circuit board 1 first has a substrate, and then copper foil is coated on the substrate, and then solder mask covers the copper foil and the substrate. The first isolation zone 23 and the second isolation zone 24 are separated from the pad and the surrounding copper foil to avoid being connected together.
[0039] The setting of the first isolation zone 23 and the second isolation zone 24 in this embodiment, especially the fact that they are composed of the substrate of the circuit board 1, effectively establishes a physical barrier between the detection pad 21 and the surrounding circuit, and between the detection module 2 and the external environment, so that the multiple detection pads 21 are independent of each other, and the substrate itself has good insulation properties, which further enhances the electrical isolation between the detection pad 21 and the surrounding circuit, reducing the risk of failure due to short circuit or leakage.
[0040] In the present embodiment, the structure of the detection pad 21 is any one of a circle, a square, an ellipse, an island or a polygon. The design of various shapes greatly enhances flexibility and adaptability, and the diversified shape selection enables the detection pad 21 to be customized according to the layout of different circuit boards, the arrangement of components and the requirements of detection accuracy, meeting the diversified design requirements. It is also possible to carry out the optimal layout according to the available space on the circuit board, thereby maximizing the use of the limited circuit board area.
[0041] It should be noted that when the detection pad 21 is round, the diameter of the detection pad 21 is 1-2 mm, and preferably 1 mm in this embodiment; when the detection pad 21 is square, the diameter of the detection pad 21 is (1-1.5 mm)*(1-1.5 mm), and preferably 1*1 mm in this embodiment.
[0042] This embodiment sets a specific size range for the detection pad 21, such as a diameter of a circular pad of 1-2 mm and a side length of a square pad of 1-1.5 mm. Such precise control ensures the consistency and repeatability of the pad. In the manufacturing process, such a clear size standard helps reduce errors and improve production efficiency and product quality.
[0043] In this embodiment, the number of detection pads 21 in each pad group 20 is 2-5. In a limited circuit board space, the number of detection pads 21 in the pad group 20 can be reasonably set to optimize the layout and space utilization of the pads. While ensuring the detection effect, the interference and occupied space between the pads can be reduced, thereby improving the overall performance and aesthetics of the circuit board.
[0044] In this embodiment, the plurality of detection pads 21 in the pad group 20 are arranged in a linear, rectangular array or circular array. The arrangement of the plurality of detection pads 21 in the pad group 20 can be flexibly designed according to the shape and size of the circuit board 1. For example, when the process edge 11 of the circuit board 1 is wider, a rectangular array or a circular array can be used, and when the process edge 11 of the circuit board 1 is longer, a linear arrangement can be used, which can effectively improve the flexibility and applicability of the detection module 2.
[0045] It should be noted that there are multiple detection modules 2, and the multiple detection modules 2 are distributed at intervals on the process edge 11 of the circuit board 1. The setting of multiple detection modules 2 can improve the comprehensiveness and accuracy of detection. When a module has a problem, other modules can still work normally, ensuring the continuity and stability of detection. This redundant design enhances the fault tolerance and reliability of the system.
[0046] In the description of the present invention, it should be understood that terms such as "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.
[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0048] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for detecting solder mask alignment of a circuit board, characterized in that: The method is to design at least one detection module on the process edge of the circuit board, and use the detection module to assist in determining whether there is solder resistance deviation in the pad of the circuit board; the design method of the detection module includes the following steps: S1, determining the setting position of the detection module on the process edge of the circuit board; S2, designing two pad groups on the circuit layer in the detection module, each of the pad groups including a plurality of detection pads having the same shape and size; S3, a detection window is designed for each detection pad with a solder resist, wherein the shape of the detection window is the same as the shape of the detection pad, and the multiple detection windows in each pad group are enlarged step by step in equal proportion, and the window design of the smallest detection window in each pad group is the same as the smallest window design of the pad in the circuit board.
2. The method for detecting the solder mask alignment of a circuit board according to claim 1, characterized in that: The multiple detection windows in one of the pad groups are all larger than the detection pad corresponding to the detection window, and the multiple detection windows in the other pad group are all smaller than the detection pad corresponding to the detection window.
3. The method for detecting the solder mask alignment of a circuit board according to claim 1, characterized in that: The multiple detection windows in each group of pad groups are enlarged one by one with a single-side spacing of 0.5 mil-1 mil.
4. The method for detecting solder mask alignment of a circuit board according to claim 1, characterized in that: A first isolation zone is disposed on the periphery of each detection pad, and a second isolation zone is disposed on the periphery of the detection module. Both the first isolation zone and the second isolation zone are formed by the substrate of the circuit board.
5. The method for detecting solder mask alignment of a circuit board according to claim 1, characterized in that: The structure of the detection pad is any one of a circular shape, a square shape, an elliptical shape, an island shape or a polygonal shape.
6. The method for detecting the solder mask alignment of a circuit board according to claim 5, characterized in that: When the detection pad is circular, the diameter of the detection pad is 1-2 mm; when the detection pad is square, the diameter of the detection pad is (1-1.5 mm)*(1-1.5 mm).
7. The method for detecting the solder mask alignment of a circuit board according to claim 1, characterized in that: The number of detection pads in each pad group is 2-5.
8. The method for detecting solder mask alignment of a circuit board according to claim 1, characterized in that: The plurality of detection pads in the pad group are arranged in a linear array, a rectangular array or a circular array.
9. The method for detecting solder mask alignment of a circuit board according to any one of claims 1 to 8, characterized in that: There are multiple detection modules, and the multiple detection modules are distributed at intervals on the process edge of the circuit board.