Manufacturing method of circuit board

Abstract

The invention discloses a manufacturing method of a circuit board. The manufacturing method of the circuit board includes the following steps that a cover plate is provided, through holes are formed corresponding to plated-through holes in the cover plate and the circuit board, the surface of the electroplated circuit board is covered with the cover plate, and the through holes are aligned with the plated-through holes of the circuit board; resin material with good copper surface invasion is provided, and resin is fully stirred under the vacuum condition; the surface of the cover plate is coated with the stirred resin, the through holes of the cover plate are filled with the resin through a single stroke of a scraper of a screen printing machine, the resin is stuffed into the plated-through holes through the through holes, and the resin remaining on the surface of the cover plate is scraped with an oil return knife; an electroplated copper layer needing to be preserved is covered with a corrosion resistant dry film, figures needing to be preserved are protected, copper rings at the position of at least one end hole opening of the plated-through holes are exposed, etch is conducted by the adoption of acid etching liquid, the copper rings without protection of the corrosion resistant dry film are eliminated, and etch for a predetermined depth is conducted. By means of the manufacturing method of the circuit board, hole opening copper rings of the plated-through holes can be eliminated, via-hole insulation of the circuit board can be achieved, and the back drilling technology can be effectively replaced.

Description

technical field [0001] The invention relates to the technical field of circuit board manufacturing, and more particularly relates to a circuit board manufacturing method capable of realizing through-hole insulation. Background technique [0002] A printed circuit board (PCB) is the provider of electrical connections for electronic components. PCB board metallized hole technology is one of the keys to printed circuit board manufacturing technology. Metallized hole refers to plating a thin layer of copper on the inner wall of the hole with a chemical reaction on the hole wall between the top layer and the bottom layer of the PCB board. , so that the top layer and the bottom layer of the PCB board are connected to each other. For some wireless communication products mounted with metallized structural parts, in order to ensure the reliability of product insulation, the earliest method is to slot the metal structural parts to process components. Please refer to figure 1 As sho...

AI Technical Summary

Problems solved by technology

However, this method has quality problems in practical application. For example, ① when filling the metallized hole with anti-corrosion material, it is easy to form a plug hole depression, which may expose part of the hole copper. The pad at the end of the hole will also etch away part of the copper on the hole wall, causing the etching depth to exceed the standard; ②During the process of plugging the hole, air bubbles are likely to remain in the anti-corrosion material, and when the air bubbles at the hole are close to the copper on the hole wall, it is easy to hide the potion , there is a risk of failure due to long-term erosion of the copper on the hole wall; ③ If there is resin residue after the ceramic grinding plate, residual copper in the hole is easy to appear after etching, resulting in failure of the insulation of the printed board via hole. In order to ensure zero defects in the product manufacturing process, After the circuit board etching is completed, AOI detection (that is, the detection of residual copper in the hole) is required. However, since the circuit board is usually placed for a period of time, the copper on the board surface is easy to oxidize and darken, which reduces the contrast between the copper and the substrate surface, resulting in defects. The problem of underreporting, so the AOI workshop is generally equipped with a pickling and deoxidation line to remove the oxide layer on the copper surface to enhance the contrast between the copper and the substrate. However, the circuit board contains CaCO in the plugging resin. 3 Composition, pickling will cause the resin to fall off and expose the copper in the hole, and there will be no color difference with the residual copper in the hole, which will interfere with the detection process, resulting in many false points in the detection process, affecting the detection and repair efficiency

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