Circuit board through hole and back hole concentricity detection method

Abstract

The invention relates to the technical field of circuit board processing, in particular to a circuit board through hole and back hole concentricity detection method, which comprises the following steps: capturing an image of the surface of a circuit board to obtain a first image; identifying the first image to obtain a first coordinate value of a first center C1 of an opening of the through hole H1 on the upper surface; capturing an image of the surface of the circuit board to obtain a second image and identifying the second image to obtain a first coordinate value of a second center C2 of the opening of the back hole H4 on the upper surface; the offset of the center position of the through hole H1 and the offset of the center position of the back hole H4 can be obtained by calculating the first offset between the first coordinate value and the second coordinate value, so that offset detection of the center position of the through hole and the center position of the back hole can be carried out, and compensation can be conveniently carried out on subsequent circuit board processing. And the technical problem of follow-up poor batch is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of circuit board processing, and in particular to a method for detecting the concentricity of a through hole and a back hole of a circuit board. Background Art

[0002] Circuit boards are used to electrically connect electronic components or devices, and to transmit electronic signals between electronic components. Existing circuit boards include a multilayer board structure formed by overlapping multiple circuit layers. In addition to forming circuits on the surface, each circuit layer also forms a circuit. Therefore, the circuit board will be provided with multiple through holes to connect the circuit layers, and the hole walls of the through holes have a metal coating, which enables electrical connections to be formed between the circuit layers. For some circuit layers that do not form an electrical connection structure in the circuit design, a back hole is usually drilled on one side of the through hole to form a back hole, so as to remove the metal coating on the hole wall of the through hole.

[0003] Due to errors during machine operation, the center position of the through hole and the center position of the back hole are usually offset, resulting in the inability to completely remove the metal plating on the inner wall of the through hole, making the circuit board a defective product. The existing technology is unable to detect the offset between the center position of the through hole and the center position of the back hole and compensate for the subsequent circuit board processing, resulting in subsequent batch defects. Summary of the invention

[0004] The purpose of the present invention is to provide a method for detecting the concentricity of a through hole and a back hole of a circuit board, aiming to solve the problem in the prior art that due to errors in machine operation, the center position of the through hole and the center position of the back hole are usually offset, resulting in the inability to completely remove the metal plating on the inner wall of the through hole, making the circuit board a defective product. The prior art is unable to detect the offset between the center position of the through hole and the center position of the back hole and then compensate for the subsequent circuit board processing, resulting in subsequent batch defects.

[0005] To achieve the above-mentioned purpose, the present invention adopts a method for detecting the concentricity of a through hole and a back hole of a circuit board. The detected circuit board has two surfaces arranged opposite to each other and a through hole H1 penetrating the circuit board, a through hole H2 and at least one back hole H4 drilled on any one surface and connected to the through hole H1 or the through hole H2;

[0006] The steps include:

[0007] Step 1, capturing an image of the surface of the circuit board to obtain a first image;

[0008] Step 2, identifying the first image to obtain a first coordinate value (x1, y1) of a first center C1 of the opening of the through hole H1 on the upper surface;

[0009] Step 3, capturing an image of the circuit board surface to obtain a second image;

[0010] Step 4, identifying the second image to obtain a first coordinate value (x2, y2) of a second center C2 of the opening of the back hole H4 on the upper surface;

[0011] Step 5: Calculate the first offset Ca between the first coordinate value (x1, y1) and the second coordinate value (x2, y2) to obtain the offset between the center position of the through hole H1 and the center position of the back hole H4, where:

[0012] Before capturing the image of the circuit board surface to obtain the first image, it is necessary to determine, based on the design of the circuit board, that the surface of the circuit board where the back hole is to be drilled faces upward.

[0013] Before capturing the image of the circuit board surface to obtain the second image, a back hole H4 needs to be drilled on the upper surface of the circuit board P.

[0014] In step 4, the diameter of the drilled back hole H4 is larger than that of the back hole H1.

[0015] The first coordinate value (x1, y1) and the second coordinate value (x2, y2) are coordinate values ​​based on the origin of the captured surface.

[0016] The inner wall of the through hole H1 has a metal coating.

[0017] The present invention provides a method for detecting the concentricity of a through hole and a back hole of a circuit board. When used, first, according to the design of the circuit board, the surface of the circuit board where the back hole is to be drilled is facing upward, and then an image of the surface of the circuit board is captured to obtain a first image, and the first image is identified to obtain a first coordinate value (x1, y1) of a first center C1 of the opening of the through hole H1 on the upper surface. Then, a back hole H4 is drilled on the upper surface of the circuit board P and an image of the surface of the circuit board is captured to obtain a second image, and the second image is identified to obtain a first coordinate value (x2, y2) of a second center C2 of the opening of the back hole H4 on the upper surface. Finally, the first coordinate value (x1, y1) and the second coordinate value (x2, y2) are calculated. The first offset Ca between the coordinate values ​​(x2, y2) can be used to obtain the offset between the center position of the through hole H1 and the center position of the back hole H4, which can be used as reference data for compensation during subsequent processing, thereby improving processing accuracy and thereby improving product yield. In this way, the problem in the prior art that due to errors in machine operation, the center position of the through hole and the center position of the back hole are usually offset, resulting in the inability to completely remove the metal plating on the inner wall of the through hole, making the circuit board a defective product, and the prior art is unable to detect the offset between the center position of the through hole and the center position of the back hole and then compensate for the subsequent circuit board processing, resulting in subsequent batch defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a structural schematic diagram of a circuit board through-hole and back-hole concentricity detection device of the present invention.

[0020] Figure 2 It is a flow chart of the steps of the circuit board through hole and back hole concentricity detection method of the present invention.

[0021] Figure 3 It is a cross-sectional view of the circuit board after a through hole is drilled in the present invention.

[0022] Figure 4 It is a schematic diagram of the first image capturing step of the present invention.

[0023] Figure 5 It is a cross-sectional view of the circuit board after the back hole is drilled.

[0024] Figure 6 It is a schematic diagram of the second image capturing step of the present invention.

[0025] Figure 7 It is a top view of the upper surface of the circuit board after the through holes are drilled according to the present invention.

[0026] Figure 8 It is a top view of the upper surface of the circuit board after the back hole is drilled according to the present invention.

[0027] Fig. 9 It is a schematic diagram of calculating the first offset of the through hole and the back hole of the present invention.

[0028] 1-drilling tool module, 2-image capture module, 3-image recognition module, 4-computer control module, 11-drilling tool body, 12-movable platform, C1-first center, C2-second center, H1-through hole, H2-through hole, H3-blind hole, H4-back hole, P-circuit board, P1-core board, P2-insulating layer, P3-insulating layer, R1-circuit layer, R2-circuit layer, R3-circuit layer, R4-circuit layer. DETAILED DESCRIPTION

[0029] Embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0030] See also Figure 1-Figure 9 , Figure 1 It is a schematic diagram of the structure of the circuit board through hole and back hole concentricity detection device of the present invention, Figure 2 It is a flow chart of the steps of the method for detecting the concentricity of the through hole and the back hole of the circuit board of the present invention. Figure 3 is a cross-sectional view of the circuit board after the through hole is drilled in the present invention, Figure 4 is a schematic diagram of the first image capturing step of the present invention, Figure 5 This is a cross-sectional view of the circuit board after the back hole is drilled. Figure 6 is a schematic diagram of the second image capturing step of the present invention, Figure 7 is a top view of the upper surface of the circuit board after the through holes are drilled in the present invention, Figure 8 is a top view of the upper surface of the circuit board after back holes are drilled in the present invention, Fig. 9 It is a schematic diagram of calculating the first offset of the through hole and the back hole of the present invention.

[0031] The present invention provides a method for detecting the concentricity of a through hole and a back hole of a circuit board.

[0032] The steps include:

[0033] S101, capturing an image of the surface of the circuit board by an image capture module 2 in a circuit board through-hole and back-hole concentricity detection device to obtain a first image;

[0034] According to the present embodiment, before capturing the image of the circuit board surface to obtain the first image, the computer control module 4 in the circuit board through hole and back hole concentricity detection device first controls the drill tool body 11 and the moving platform 12 in the drill tool module 1 according to the set coordinate values ​​to drill through holes H1 and H2 penetrating the circuit board P and blind holes H3 opening on the corresponding surface on the surface of the circuit board P; Figure 7 As shown, it shows the state after drilling through holes H1 and H2. The present invention is explained by taking a circuit board with four circuit layers as an example. The circuit board P used in the present invention includes a core board P1, circuit layers R1 and R2 arranged on opposite sides of the core board P1, insulating layers P2 and P3 arranged on the circuit layers R1 and R2, and circuit layers R3 and R4 arranged on the insulating layers P2 and P3. After drilling through holes and blind holes, the surface of the circuit board where the back hole needs to be drilled is facing upward according to the design of the circuit.

[0035] Step 2, identifying the first image to obtain a first coordinate value (x1, y1) of a first center C1 of the opening of the through hole H1 on the upper surface;

[0036] According to this specific embodiment, the first image is transmitted to the image recognition module 3 via the computer control module 4 . The image recognition module 3 recognizes the first image to obtain a first coordinate value (x1, y1) of a first center C1 of the opening of the through hole H1 on the upper surface.

[0037] Step 3, using the image capture module 2 in the circuit board through-hole and back-hole concentricity detection device to capture an image of the circuit board surface to obtain a second image;

[0038] According to the present specific embodiment, the computer control module 4 controls the drilling tool body 11 and the movable platform 12 to drill the back hole H4 on the upper surface of the circuit board P according to the set coordinate values.

[0039] Step 4, identifying the second image to obtain a first coordinate value (x2, y2) of a second center C2 of the opening of the back hole H4 on the upper surface;

[0040] According to this specific embodiment, the first image is transmitted to the image recognition module 3 via the computer control module 4 , and the image recognition module 3 recognizes the first image to obtain the first coordinate value (x2, y2) of the second center C2 of the opening of the back hole H4 on the upper surface.

[0041] Step 5: Calculate the first offset Ca between the first coordinate value (x1, y1) and the second coordinate value (x2, y2) to obtain the offset between the center position of the through hole H1 and the center position of the back hole H4, where:

[0042] In step 4, the back hole H4 is drilled with a diameter larger than that of the back hole H1.

[0043] The first coordinate value (x1, y1) and the second coordinate value (x2, y2) are coordinate values ​​based on the origin of the captured surface.

[0044] A method for detecting the concentricity of a through hole and a back hole of a circuit board according to the present invention is used. First, according to the design of the circuit board, the surface of the circuit board where the back hole is to be drilled is facing upward. Then, an image of the surface of the circuit board is captured to obtain a first image, and the first image is identified to obtain a first coordinate value (x1, y1) of a first center C1 of the opening of the through hole H1 on the upper surface. Then, a back hole H4 is drilled on the upper surface of the circuit board P and an image of the surface of the circuit board is captured to obtain a second image. The second image is identified to obtain a first coordinate value (x2, y2) of a second center C2 of the opening of the back hole H4 on the upper surface. Finally, the first coordinate value (x1, y1) and the second coordinate value (x2, y2) are calculated. The first offset Ca between the two coordinate values ​​(x2, y2) can be used to obtain the offset between the center position of the through hole H1 and the center position of the back hole H4, which can be used as reference data for compensation during subsequent processing, thereby improving the processing accuracy and thereby improving the product yield. In this way, the problem in the prior art that due to errors during machine operation, the center position of the through hole and the center position of the back hole are usually offset, resulting in the inability to completely remove the metal plating on the inner wall of the through hole, making the circuit board a defective product, and the prior art is unable to detect the offset between the center position of the through hole and the center position of the back hole and then compensate for the subsequent circuit board processing, resulting in subsequent batch defects.

[0045] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A method for detecting the concentricity of a through hole and a back hole of a circuit board, characterized in that: The circuit board to be inspected has two surfaces arranged opposite to each other, and a through hole H1 and a through hole H2 penetrating the circuit board, and at least one back hole H4 drilled on any one surface and connected to the through hole H1 or the through hole H2; The steps include: Step 1, capturing an image of the surface of the circuit board to obtain a first image; Step 2, identifying the first image to obtain a first coordinate value (x1, y1) of a first center C1 of the opening of the through hole H1 on the upper surface; Step 3, capturing an image of the circuit board surface to obtain a second image; Step 4, identifying the second image to obtain a first coordinate value (x2, y2) of a second center C2 of the opening of the back hole H4 on the upper surface; Step 5: Calculate the first offset Ca between the first coordinate value (x1, y1) and the second coordinate value (x2, y2) to obtain the offset between the center position of the through hole H1 and the center position of the back hole H4, where:

2. The method for detecting concentricity of through holes and back holes of a circuit board according to claim 1, characterized in that: Before capturing an image of the circuit board surface to obtain a first image, it is necessary to determine, based on the design of the circuit board, that the surface of the circuit board where the back hole is to be drilled faces upward.

3. The method for detecting concentricity of through holes and back holes of a circuit board as claimed in claim 2, characterized in that: Before capturing the image of the circuit board surface to obtain the second image, a back hole H4 needs to be drilled on the upper surface of the circuit board P.

4. The method for detecting concentricity of through holes and back holes of a circuit board as claimed in claim 3, characterized in that: In step 4, the back hole H4 is drilled with a diameter larger than that of the back hole H1.

5. The method for detecting concentricity of through holes and back holes of a circuit board as claimed in claim 4, characterized in that: The first coordinate value (x1, y1) and the second coordinate value (x2, y2) are coordinate values ​​based on the origin of the captured surface.

6. The method for detecting concentricity of through holes and back holes of a circuit board as claimed in claim 5, characterized in that: The inner wall of the through hole H1 has a metal plating layer.

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