Mark point structure

Abstract

The utility model discloses a Mark point structure, which adopts at least two rectangular parts which are arranged in a crossed manner to form a bonding pad area, and compared with a traditional circular structure, the composite geometric shape of the bonding pad area can provide higher feature vector dimension in a machine vision system, the HOG feature value is improved by at least 30%, the algorithm identification accuracy is greatly improved, and the reliability of the structure is improved. Especially in a high-density BGA packaging area, the positioning precision of the center coordinates of the cross points can reach + / -0.01 mm, the identification degree of the Mark points on the PCB is greatly improved, and the problem that the Mark points are difficult to distinguish due to the low identification degree is effectively solved.

Description

Technical Field

[0001] This utility model relates to the field of circuit board technology, and more specifically, to a Mark point structure. Background Technology

[0002] In PCB design, Mark points are important reference points for optical positioning, mainly used by automatic placement machines to identify and position components, thereby improving placement accuracy and efficiency.

[0003] Mark points are key points on a PCB board used for optical recognition, and their main functions include:

[0004] (1) Positioning reference: Provides a precise positioning reference for the automatic placement machine to ensure that the components can be correctly placed in the designated position.

[0005] (2) Improve placement accuracy: By using optical recognition Mark points, the pick-and-place machine can accurately identify the position of components on the PCB board and reduce placement errors.

[0006] (3) Preventing misjudgment: By designing a reasonable distribution of Mark points, machine misjudgment caused by symmetry or positional errors can be avoided.

[0007] Many Mark points exist in the form of pads, typically consisting of a 1mm diameter circular pad, along with a release liner and an outer protective line. However, this circular pad is easily the same size or similar to other circular pads on the PCB. Furthermore, the outer protective line lacks solder mask and bright copper, failing to create a clear visual contrast, further reducing the Mark point's recognizability and making it difficult for PCB manufacturers to accurately distinguish it from numerous circular pads. Utility Model Content

[0008] To overcome the shortcomings of the existing technology, this utility model provides a Mark point structure to solve the problem that the low recognizability of Mark points on PCB boards makes it difficult for board manufacturers to accurately distinguish Mark points from numerous circular pads when searching.

[0009] The technical solution of this utility model is as follows: A Mark point structure includes a substrate and a pad area disposed on the surface of the substrate. The pad area includes at least two rectangular portions arranged in an intersecting manner. A solder mask opening area and a no-wiring area are arranged sequentially around the periphery of the pad area.

[0010] Furthermore, there are two rectangular portions, which are arranged in a cross shape to form a cross-shaped structure.

[0011] Furthermore, four rectangular portions are provided, and the four rectangular portions are arranged in an intersecting manner to form a star-shaped structure, with the included angle between two adjacent rectangular portions being 45°.

[0012] Furthermore, the prohibited wiring area is located outside the solder mask opening area, and both the solder mask opening area and the prohibited wiring area are rectangular.

[0013] Furthermore, the solder mask opening area is square, and the length of the solder mask opening area is 80 mil, and the width of the solder mask opening area is 80 mil.

[0014] Furthermore, the prohibited wiring area is square, and the length of the prohibited wiring area is 90 mil, and the width of the solder mask opening area is 90 mil.

[0015] Furthermore, the length of the rectangular portion is 60 mil, and the width of the rectangular portion is 12 mil.

[0016] Furthermore, the area 'a' formed by the solder pad region and the area 'b' formed by the solder resist window region satisfy the following relationship: 65% ≤ a / b ≤ 70%.

[0017] Furthermore, the area a formed by the pad area and the area c formed by the prohibited wiring area satisfy the following relationship: 50%≤a / b≤55%.

[0018] The advantages of this utility model based on the above solution are as follows:

[0019] This invention provides a Mark point structure that uses at least two intersecting rectangular portions to form a pad area. Compared to the traditional circular structure, the composite geometry of the pad area can provide a higher feature vector dimension in machine vision systems, increasing HOG feature values ​​by at least 30% and significantly improving algorithm recognition accuracy. Particularly in high-density BGA package areas, the positioning accuracy of the intersection point center coordinates can reach ±0.01mm, meeting component placement requirements.

[0020] This invention provides a Mark point structure in which the solder pad area of ​​the Mark point is surrounded by a solder mask window area and a no-route area. The solder mask window area prevents solder from spreading around the Mark point, ensuring its cleanliness and clarity, and making its boundary well-defined. The no-route area prevents other lines or components from approaching the Mark point, reducing interference and confusion, further highlighting the Mark point, and improving its recognizability both visually and functionally. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is one of the schematic diagrams of the Mark point structure in this utility model;

[0023] Figure 2 This is the second schematic diagram of the Mark point structure in this utility model.

[0024] In the diagram, 1 is the substrate; 2 is the pad area; 21 is the rectangular section; 3 is the solder mask opening area; and 4 is the no-wiring area. Detailed Implementation

[0025] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments.

[0026] To better understand this utility model, the following description, in conjunction with the accompanying drawings and embodiments, will further illustrate the present utility model:

[0027] See Figure 1 As shown, the present invention provides a Mark point structure including a substrate 1 and a pad area 2 disposed on the surface of the substrate 1. The pad area 2 includes at least two rectangular portions 21 arranged in an intersecting manner. The pad area 2 is surrounded by a solder mask opening area 3 and a no-wiring area 4 in sequence.

[0028] Specifically, the pad area 2 is formed by at least two intersecting rectangular portions 21. Compared with the traditional circular structure, the composite geometry of the pad area 2 can provide a higher feature vector dimension in the machine vision system, increasing the HOG feature value by at least 30%, thus significantly improving the algorithm's recognition accuracy. Especially in the high-density BGA package area, the positioning accuracy of the center coordinates of the intersection point can reach ±0.01mm, meeting the component placement requirements.

[0029] In this embodiment, the solder pad area 2 of the Mark point is surrounded by a solder mask window area 3 and a no-route area 4. The solder mask window area 3 prevents solder from spreading around the Mark point, ensuring the Mark point is clean and clear, and making the boundary of the Mark point well-defined. The no-route area 4 prevents other lines or components from approaching the Mark point, reducing interference and confusion, further highlighting the Mark point, and improving its recognizability both visually and functionally.

[0030] See Figure 1 As shown, in one embodiment, two rectangular portions 21 are provided, and the two rectangular portions 21 are arranged in a cross shape to form a cross-shaped structure.

[0031] Specifically, on complex PCB boards, numerous ordinary pads are often uniform in shape and densely distributed, which can easily make it difficult for board manufacturers to find Mark points. However, the cross-shaped Mark point, with its intersecting rectangular portion 21, can improve the recognizability and make the identification process easier. This greatly improves the recognizability of Mark points on PCB boards and effectively solves the problem of difficulty in distinguishing them due to low recognizability.

[0032] It's worth noting that precise positioning and calibration are essential in all stages of PCB manufacturing, including cutting, drilling, component placement, and soldering. Taking component placement as an example, the placement machine determines the PCB's coordinates by identifying the positions of Mark points. These cross-shaped Mark points provide precise positioning references, enabling the placement machine to accurately place components in their designated locations. This reduces placement errors caused by positioning deviations and improves product quality and yield.

[0033] See Figure 2 As shown, in another embodiment, four rectangular portions 21 are provided, and the four rectangular portions 21 are arranged in an intersecting manner to form a star-shaped structure, with the included angle between two adjacent rectangular portions 21 being 45°.

[0034] Specifically, in the SMT (Surface Mount Technology) production process, precise circuit board positioning is crucial for ensuring accurate placement of electronic components. Conventional Mark points are often simple circles or squares. In this application, four rectangular portions 21 are arranged in an intersecting pattern to form a star-shaped structure, with adjacent rectangular portions 21 forming a 45° angle. This Mark point design significantly improves positioning accuracy. The star-shaped structure formed by the four intersecting rectangular portions 21 provides feature edges and vertices in multiple directions. These feature points can constitute rich geometric information in a machine vision recognition system. Using a common Cartesian coordinate system, ordinary circular Mark points only provide simple positioning information such as the center coordinates. However, the star-shaped Mark points, based on their unique intersecting shape and angular relationships, can determine multiple key coordinate points in the coordinate system. By calculating the distances, angles, and other geometric relationships between these points, precise position and angle deviation data can be provided to the equipment, thereby guiding the placement machine to accurately place components on the circuit board. This effectively reduces component placement offset and skewing problems caused by inaccurate positioning, improving the electrical performance and stability of the product.

[0035] It is worth mentioning that when light shines on the star-shaped Mark point, due to the intersecting layout of multiple rectangular parts 21, the surface at different angles will produce reflected light of different intensities and directions. Even under uneven lighting conditions, some of the reflected light can be captured by the machine vision system, thus providing a stable recognition signal. In contrast, conventionally designed Mark points may have their reflected light weakened or blocked if the lighting angle is poor, leading to recognition difficulties. At the same time, even with slight dust or stains, the multiple feature areas of the star-shaped structure can complement each other. As long as some areas can be recognized, the machine vision system can still determine the position and orientation of the entire Mark point through algorithmic analysis. In contrast, conventionally designed Mark points may fail to be accurately recognized due to partial occlusion. This reduces the number of downtimes and scrap rates caused by recognition problems during production, ensuring the continuity and efficiency of production.

[0036] Traditional Mark point designs often require a large area to ensure positioning accuracy and recognition performance. However, the star-shaped structure enhances positioning functionality without significantly increasing the area. The four rectangular sections 21 intersect and combine to create a complex yet efficient positioning feature within a limited pad area 2, occupying a smaller area compared to other complex Mark point structures with the same positioning accuracy requirements. This allows for more space for other electronic components and circuit layouts during circuit board design, especially in high-density circuit board designs, facilitating miniaturization and integration to meet the evolving design needs of electronic products.

[0037] Preferably, the prohibited wiring area 4 is located outside the solder mask opening area 3, and both the solder mask opening area 3 and the prohibited wiring area 4 are rectangular.

[0038] Specifically, the solder mask opening area 3 is square, with a length of 80 mil and a width of 80 mil; the no-route area 4 is square, with a length of 90 mil and a width of 90 mil.

[0039] In this embodiment, the length of the rectangular portion 21 is 60 mil and the width of the rectangular portion 21 is 12 mil.

[0040] In one embodiment, the area a enclosed by the pad region 2 and the area b enclosed by the solder mask opening region 3 satisfy the following relationship: 65% ≤ a / b ≤ 70%.

[0041] In one embodiment, the area a enclosed by the pad region 2 and the area c enclosed by the no-route region 4 satisfy the following relationship: 50% ≤ a / b ≤ 55%.

[0042] Specifically, the area 'a' enclosed by the solder pad area 2 and the area 'b' enclosed by the solder mask window area 3 satisfy 65% ​​≤ a / b ≤ 70%. This design ensures that the area of ​​the solder mask window area 3 is neither too large nor too small relative to the solder pad area 2. If the area of ​​the solder mask window area 3 is too large, the surrounding area will be too spacious, which is not conducive to the overall layout compactness; if the area of ​​the solder mask window area 3 is too small, it will not be able to fully perform its function of preventing solder diffusion, and the solder will easily spread to the Mark point, resulting in blurred boundaries, dirt, and affecting visual recognition and reducing recognizability.

[0043] The above design effectively prevents solder from spreading around the Mark point, ensuring the cleanliness and clarity of the Mark point and maintaining its clear boundary.

[0044] In addition, the area 'a' enclosed by pad region 2 and the area 'c' enclosed by no-route region 4 satisfy 50% ≤ a / b ≤ 55%. This design ensures that, on the one hand, if the area of ​​no-route region 4 is much larger than that of pad region 2, it will occupy too much space on substrate 1, restricting the reasonable layout of other components and affecting the flexibility of the overall circuit design; on the other hand, if the area of ​​no-route region 4 is too small, it will be difficult to prevent other lines or components from approaching the Mark point, and interference and confusion cannot be effectively reduced.

[0045] Within this ratio range, the visual independence of the Mark point can be highlighted, while potential interference from circuits and components can be prevented, thereby improving the recognizability of the Mark point and ensuring the smooth and high-precision placement of components in the electronic assembly process.

[0046] It should be noted that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product is usually placed in during use, or the orientation or positional relationship that is commonly understood by those skilled in the art, or the orientation or positional relationship that the product is usually placed in during use. It is only for the purpose of facilitating the description of this application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application.

[0047] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

[0048] The present utility model patent has been described above with reference to the accompanying drawings. Obviously, the implementation of the present utility model patent is not limited to the above-described manner. Any improvements made by adopting the inventive concept and technical solution of the present utility model patent, or the direct application of the inventive concept and technical solution of the present utility model patent to other occasions without modification, are all within the protection scope of the present utility model.

Claims

1. A Mark point structure, characterized in that, The invention includes a substrate and a pad area disposed on the surface of the substrate. The pad area includes at least two rectangular portions arranged in an intersecting manner. A solder mask opening area and a no-wiring area are sequentially disposed around the periphery of the pad area.

2. The Mark point structure as described in claim 1, characterized in that: The rectangular portion is provided in two parts, and the two rectangular portions are arranged in a cross shape to form a cross-shaped structure.

3. A Mark point structure as described in claim 1, characterized in that: The rectangular portion is provided in four ways, and the four rectangular portions are arranged in an intersecting manner to form a star-shaped structure, with the included angle between two adjacent rectangular portions being 45°.

4. A Mark point structure as described in claim 1, characterized in that: The prohibited wiring area is located outside the solder mask window area, and both the solder mask window area and the prohibited wiring area are rectangular.

5. A Mark point structure as described in claim 4, characterized in that: The solder mask opening area is square, and the length of the solder mask opening area is 80 mil, and the width of the solder mask opening area is 80 mil.

6. A Mark point structure as described in claim 4, characterized in that: The prohibited wiring area is square, and the length of the prohibited wiring area is 90 mil, and the width of the solder mask opening area is 90 mil.

7. A Mark point structure as described in claim 4, characterized in that: The rectangular portion has a length of 60 mil and a width of 12 mil.

8. A Mark point structure as described in claim 4, characterized in that: The area 'a' enclosed by the solder pad region and the area 'b' enclosed by the solder resist window region satisfy the following relationship: 65% ≤ a / b ≤ 70%.

9. A Mark point structure as described in claim 4, characterized in that: The area 'a' enclosed by the pad area and the area 'c' enclosed by the prohibited wiring area satisfy the following relationship: 50% ≤ a / b ≤ 55%.

Images