Method for improving resistance value precision of printed circuit board of buried resistor

Abstract

The invention discloses a method for improving the resistance value precision of a printed circuit board of a buried resistor. The method comprises the following steps of designing a buried resistor pattern on a film according to a target resistance value set by a buried resistor layer in the printed circuit board and reserving alignment allowance on the edge of the film; covering a dry film of a substrate with a film designed with the buried resistor pattern and aligning the film and the dry film of the substrate; carrying out automatic compensation alignment exposure treatment on the dry film according to an LDI machine and exposing the buried resistor pattern on the dry film according to the calibration size; and carrying out developing, etching and demolding treatment on the dry film subjected to exposure treatment to obtain the buried resistor with the improved resistance value precision of the printed circuit board. According to the method disclosed by the invention, the resistance precision of the printed circuit board of the buried resistor can be improved and the performance of a printed circuit board product can be improved.

Description

technical field [0001] The invention relates to a printed circuit board for embedding passive components, in particular to a method for improving the resistance value precision of the printed circuit board for embedded resistors. Background technique [0002] At present, the circuit pattern and embedded resistance pattern of the traditional core board are produced separately, and the specific scheme is as follows: [0003] 1) When making a buried resist pattern, firstly perform exposure, and then develop, etch, remove the film and other processes. During the exposure to etching process, due to the influence of factors such as temperature and humidity changes, handling, and dust stickiness, it is difficult to accurately estimate the expansion and contraction of the embedded resistance core board in advance, which brings certain difficulties to the exposure process; [0004] 2) Before making the embedded resistor pattern, the circuit pattern must be completed first. When maki...

AI Technical Summary

Problems solved by technology

During the exposure to etching process, due to the influence of factors such as temperature and humidity changes, handling, and dust stickiness, it is difficult to accurately estimate the expansion and contraction of the embedded resistance core board in advance, which brings certain difficulties to the exposure process;

[0004] 2) Before making the embedded resistor pattern, the circuit pattern must be completed first. When making the circuit pattern, the embedded resistor core board will expand and shrink to different degrees due to factors such as etching. bring certain difficulties;

[0006] Therefore, it is difficult to accurately control the resistance value of the above-mentioned buried resistance layer, and at least the following three factors need to be considered: the temperature change during the etching process causes the resistance chip to be subject to different degrees of expansion and contraction, and the resistance chip may be subject to different degrees of resistance when making circuit patterns. Expansion and contraction, and the products are subject to different degrees of expansion and contraction during the pressing process. According to the current production process, it is difficult to accurately control the resistance value of the embedded resistance layer in the printed circuit board, which affects the performance of the printed circuit board product

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