Method for improving accuracy of resistance value of buried resistance printed circuit board

Abstract

The invention provides a method for improving the accuracy of a resistance value of a buried resistance printed circuit board. The method comprises the following steps of: 1, providing a board with a buried resistance layer, wherein the board comprises an insulating dielectric layer, the buried resistance layer and a copper foil layer; 2, pasting a first photoresist film, performing primary exposure, printing a line graph of a negative film on the first photoresist film, and performing primary development, wherein the line graph consists of a resistance line and a normal line, each of long sides of a line width of the resistance line is prolonged by 6mil, and each of wide sides of the line width of the resistance line is prolonged by 1.25mil; 3, performing primary etching and secondary etching; 4, pasting a second photoresist film, performing secondary exposure, printing a resistance graph of a positive film on the second photoresist film, and performing secondary development, wherein each of long sides of a line width of the resistance graph is shortened by 0.6mil, and each of wide sides of the line width of the resistance graph is widened by 6mil; 5, performing tertiary etching; and 6, performing blackening treatment on the surface of the board in a way of controlling a microetching amount within 1.1 to 1.5 mu.m, and performing additional compensation of -12 percent on the resistance graph of the positive film.

Description

technical field [0001] The invention relates to a buried element type printed circuit board, in particular to a method for improving the resistance value precision of a buried resistor printed circuit board. Background technique [0002] In order to improve the assembly density and performance of products and reduce the volume and weight of products, it is an effective way to integrate passive components into circuit boards, so printed circuit boards with buried resistors emerge as the times require. Buried resistance printed circuit boards have the following advantages in the design of high-speed transmission circuits: improve the impedance matching of the line, shorten the path of signal transmission, reduce parasitic inductance, eliminate the inductance generated in the surface mount or plug-in process, and reduce signal crosstalk , noise and electromagnetic interference. [0003] Buried resistance printed circuit boards often use buried resistance ink (TU-XX-08 series o...

AI Technical Summary

Problems solved by technology

[0003] Buried resistance printed circuit boards often use buried resistance ink (TU-XX-08 series of Asahi) as buried resistance for processing. Due to the limitation of silk screen printing process and equipment, small-sized resistors cannot be made, and the resistance line width must be greater than 15mil; at the same time Screen printing production is extremely difficult, with poor precision, poor reproducibility, and poor stability. Under the current production conditions, the promotion of this process is slow, and most of them are in the stage of prototype and small batch production.

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