Circuit structure of printed circuit board

Abstract

The invention discloses a circuit structure of a printed circuit board. The width of the upper surface of a circuit is defined as an upper circuit width, the width of the lower surface of the circuit is defined as a lower circuit width, the difference of the lower circuit width and the upper circuit width is defined as a difference value, the difference value is less than or equal to 0.5mil; and during the design, the difference value is set to be 0.5mil, the circuit size structure ensures that the resistance of the circuit is easier to control, is beneficial to reduction of abnormal resistance and accords with the actual process capability.

Description

technical field [0001] The invention relates to an improved circuit structure of a printed circuit board, in particular to a circuit structure design capable of reducing abnormal impedance. Background technique [0002] Due to the different contact amount and contact time of the printed circuit board with the etching solution during etching, the cross section of the etched circuit is not a square, but a trapezoid, that is, the width of the upper surface of the circuit - the width of the upper line is smaller than the width of the lower surface of the circuit One by one, the difference between the lower line width and the upper line width is called the difference value (R value) in the printed circuit board industry. In a circuit with resistance, inductance and capacitance, the resistance to alternating current is called impedance. The difference between the upper and lower line widths will have a certain impact on the impedance of the line. When designing, the difference b...

AI Technical Summary

Problems solved by technology

When designing, the difference between the upper and lower line widths of the line is generally designed to be about 1mi1 (0.0254mm), which will make the impedance difficult to control

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