Dynamic compensation method for impedance lines

Abstract

The invention relates to the field of printed circuit boards, and particularly relates to a dynamic compensation method for impedance lines. When the minimum line or the minimum pad position on the whole board is at the etching and cutting compensation place, the compensation value of an impedance line in a unit and on an impedance bar is changed to the compensation value consistent with the minimum line or the minimum pad position, and the problem that the minimum line width is close to a lower limit or the minimum pad position size width is close to the lower limit and the impedance line iswide to enable the impedance value to be low caused by dynamic compensation is solved. The qualified rate of impedance after etching is improved, the production efficiency is greatly improved, and thequality scrapping cost is reduced.

Description

technical field [0001] The invention relates to the field of printed circuit boards, in particular to a dynamic compensation method for impedance lines. Background technique [0002] At present, when designing circuit boards, the dynamic compensation method of impedance lines is generally supplemented by the same dynamic compensation method as that of ordinary lines. Large, then fine-tune some parts where the gap is insufficient, and then properly reduce the compensation there to meet the minimum gap requirement. The biggest advantage of dynamic compensation is that it can find and solve the lack of clearance in some positions and ensure the clearance corresponding to the thickness of copper to be etched. [0003] Generally, places where gaps are insufficient are between lines and lines, between lines and pads, and between pads and pads. The place where the gap is insufficient is often the line width of the minimum line (or the minimum PAD width). After the circuit board i...

AI Technical Summary

Problems solved by technology

The place where the gap is insufficient is often the line width of the minimum line (or the minimum PAD width). After the circuit board is designed and manufactured for dynamic compensation, the gap can meet the requirements, but the minimum line width (or PAD width) compensation The value is smaller than the compensation value of other lines, so the following situation will occur: when the whole board is etched, the etching amount of copper to be etched on the board surface is basically uniform. After etching, when the minimum line width (or PAD width) When the minimum limit is reached, the impedance line on the impedance strip in the unit is compensated in advance, so the line width of the minimum line is likely to be centered, the upper limit or even exceed the upper limit; correspondingly, during the impedance test, the impedance line in the unit and on the impedance bar The impedance value is easy to be low or exceed the lower limit, which cannot meet the customer's requirements for impedance value

Therefore, the disadvantage of using dynamic compensation is: it will cause the minimum line (or PAD) compensation to be out of sync with the line width compensation of the impedance line in the unit and on the impedance bar, making it difficult to control the impedance value of the impedance line during production

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