A calibration method for high-precision alignment of white oil blocks in a screen printing process

Abstract

The application discloses a calibration method for high-precision alignment of white oil blocks in a silk-screen printing process, relates to a PCB manufacturing process, and aims at the problem of white oil block silk-screen printing misalignment in the prior art. A positioning mark is pre-printed on the upper surface of a resist layer at a preset white oil block position; the positioning mark is used as a reference for silk-screen printing operation before silk-screen printing of the white oil block; and the white oil block completely covers the positioning mark after silk-screen printing. The method has the advantages that the alignment mode based on a plate edge hole in the prior art is completely abandoned, and the positioning mark for silk-screen printing is directly preset inside the ideal position of the white oil block. Therefore, the problem of white oil block silk-screen printing deviation caused by problems such as shrinkage or expansion of inner layers of the plate, expansion or shrinkage of PNL and a screen plate, and the like can be completely avoided. Moreover, because the positioning mark is preset inside the white oil block, the positioning mark can be completely shielded by the white oil block after subsequent silk-screen printing, and thus the appearance requirement of a customer is not affected.

Description

Technical Field

[0001] This invention relates to PCB manufacturing processes, and more particularly to a calibration method for high-precision alignment of white ink blocks in screen printing processes. Background Technology

[0002] PCS is a single product unit. Multi-layered PNL working blocks are fabricated on PCS, and the surface of the PNL working blocks is a solder resist layer.

[0003] When producing products online, some clients design only a single white ink block for the characters (for client-side coding), and do not accept design changes or the addition of other external positioning methods (such as white ink ring positioning along the process edge, white ink block positioning corner lines, etc.). However, during the multi-layer lamination process, actual deviations such as inter-layer expansion and contraction and screen expansion and contraction will inevitably occur, leading to deviations in the position of the screen-printed white ink block. Ultimately, this results in misaligned QR codes when used by the client for coding, posing a quality risk.

[0004] The main issue is that when screen printing white ink, only the edge holes of the PNL workpiece board can be used as a reference for aligning the screen. However, screen printing cannot account for interlayer expansion and contraction errors. Due to board expansion and contraction and screen stretching errors, the position of the white ink blocks within the PCS deviates during screen printing. Figures 1 to 4 As shown.

[0005] in Figure 3 The white ink block shifted upwards and deviated during screen printing on the PCS, while the client maintained the original design position for printing. As a result, the QR code was located on the bottom of the PCS after printing, showing obvious misalignment. Figure 4 The white ink block shifted to the right during screen printing on the PCS, while the client maintained the original design position for printing. As a result, the QR code was located on the left side of the PCS after printing, showing a clear misalignment. Summary of the Invention

[0006] The purpose of this invention is to provide a calibration method for high-precision alignment of white ink blocks in screen printing processes, so as to solve the problems existing in the prior art.

[0007] The present invention describes a calibration method for high-precision alignment of white ink blocks in screen printing process, wherein positioning marks are pre-printed on the upper surface of the solder resist layer within a preset position of the white ink block; the positioning marks are used as the reference for screen printing operation before screen printing the white ink block; and the white ink block is made to completely cover the positioning marks after screen printing.

[0008] The calibration method for high-precision alignment of white ink blocks in screen printing, as described in this invention, has the advantage of completely abandoning the alignment method based on board edge holes in existing technologies. Instead, it directly presets the positioning marks for screen printing positioning inside the ideal position of the white ink block. Therefore, it can completely avoid screen printing deviations caused by interlayer shrinkage or the expansion and contraction of PNL and the screen. Furthermore, because the positioning marks are preset inside the white ink block, they can be completely covered by the white ink block after subsequent screen printing, without affecting the customer's appearance requirements. Attached Figure Description

[0009] Figure 1 This is a schematic diagram illustrating the principle behind the misalignment of white ink blocks in existing screen printing technology.

[0010] Figure 2 It is a computer-generated design rendering of PCS in the existing technology.

[0011] Figure 3 This is a photograph of an actual case where misalignment of the white ink block during screen printing caused misalignment of the subsequent pattern printing.

[0012] Figure 4 This is a photograph of an actual object where misalignment of the subsequent pattern printing is caused by misalignment of the white ink block screen printing in the existing technology.

[0013] Figure 5 This is a schematic diagram illustrating the principle of the calibration method described in this invention.

[0014] Figure 6 This is a schematic diagram of a PCS computer design based on the calibration method described in this invention.

[0015] Figure 7 The image shows a photograph of a positioning marker based on the calibration method described in this invention.

[0016] Figure 8 The image shows a photograph of a white oil block prepared based on the calibration method described in this invention.

[0017] Figure label:

[0018] 10-PNL working block, 11-solder mask layer, 12-ideal board edge hole, 13-actual board edge hole, 14-white oil block in ideal position, 15-actual white oil block, 16-positioning mark; 20-Web version. Detailed Implementation

[0019] like Figures 1 to 5As shown, PCS is a single product unit. Multi-layered PNL working blocks are fabricated on the PCS, and the surface of the PNL working blocks is a solder resist layer. The calibration method for high-precision alignment of white ink blocks in screen printing, as described in this invention, involves pre-printing positioning marks on the upper surface of the solder resist layer within a preset white ink block position; using these positioning marks as the reference for screen printing operations before screen printing the white ink block; and ensuring the white ink block completely covers the positioning marks after screen printing. The positioning marks are line segment marks, located on the inner sides of the four sides of the preset white ink block position. The width of each positioning mark is 4 mil, and the distance from the nearest edge of the white ink block is 4 mil. Figure 5 and Figure 6 As shown.

[0020] After the characters are silkscreened with white ink blocks, they can cover the positioning marks, and the positioning deviation of each white ink block is controlled within ±0.1mm. This ensures that when the client uses the coding tool, there will be no quality abnormalities such as the white ink block being misaligned and the coding failing to be recognized. Figure 7 and Figure 8 As shown.

[0021] The calibration method for high-precision alignment of white ink blocks in screen printing, as described in this invention, completely abandons the alignment method based on board edge holes in existing technologies. Instead, it directly presets the positioning marks for screen printing positioning inside the ideal position of the white ink block. Therefore, it can completely avoid screen printing deviations caused by interlayer shrinkage or the expansion and contraction of PNL and the screen. Furthermore, because the positioning marks are preset inside the white ink block, they can be completely covered by the white ink block after subsequent screen printing, without affecting the customer's appearance requirements.

[0022] For those skilled in the art, various other corresponding changes and modifications can be made based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of this invention.

Claims

1. A calibration method for high-precision alignment of white ink blocks in screen printing processes, characterized in that, Pre-print positioning marks on the upper surface of the solder resist layer within the preset position of the white ink block; use the positioning marks as the reference for screen printing operation before screen printing the white ink block; after screen printing, make the white ink block completely cover the positioning marks.

2. The calibration method for high-precision alignment of white ink blocks in screen printing process according to claim 1, characterized in that, The positioning mark is a line segment mark.

3. The calibration method for high-precision alignment of white ink blocks in screen printing process according to claim 2, characterized in that, The positioning marks are located on the inner sides of the four sides of the preset white oil block position.

4. The calibration method for high-precision alignment of white ink blocks in screen printing process according to claim 3, characterized in that, The width of the positioning mark is 4 mil.

5. The calibration method for high-precision alignment of white ink blocks in screen printing process according to claim 4, characterized in that, The positioning mark is 4 mil away from the edge of the nearest white oil block.

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