Solder resist printing screen modification system

Abstract

A solder resist printing stencil modification system is disclosed to solve the problem of conventional solder resist printing overflow. The system includes: a database for storing several wiring configurations, several specification conditions, and reference values ​​for a printed circuit board. The specification conditions include an arm length (the protruding length of a alignment mark extending horizontally or vertically), a first spacing (the shortest distance between the alignment mark and a stencil pattern), and a second spacing (the shortest distance between the alignment mark and a trace plus the arm length); and a processing module for analyzing the wiring configurations and specification conditions of a printed circuit board, and adjusting the stencil pattern according to a comparison of each specification condition with its reference value using several modification conditions. This can prevent alignment marks from being covered and improve package alignment accuracy.

Claims

1. A solder resist printing stencil modification system, comprising: a database for storing several wiring patterns of a printed circuit board, several specifications for each wiring pattern, and reference values ​​for each specification, wherein the several specifications include an arm length, a first spacing, and a second spacing, the arm length being the length of a pair of alignment marks extending horizontally or vertically, the first spacing being the shortest distance between the alignment mark and a stencil pattern, and the second spacing being the shortest distance between the alignment mark and a line plus the arm length; and a processing module coupled to the database for analyzing the wiring patterns and specifications of a printed circuit board, and adjusting the stencil pattern with several modification conditions based on the comparison results of each specification and its reference value.

2. As in request item 1, the solder resist printing screen modification system, wherein, If the first spacing is less than a first reference value but greater than zero, the screen pattern is adjusted with an inward shrinkage width as the change condition. The first reference value is 150 micrometers, and the inward shrinkage width is 25 micrometers to 50 micrometers.

3. As in request item 2, the solder resist printing screen modification system, wherein, Adjust the side of the screen pattern closest to the alignment mark to form an outwardly convex arc with both ends tapering inward by the width of the inward tapering.

4. As in request item 2, the solder resist printing screen modification system, wherein, Adjust the side of the screen pattern closest to the alignment mark to form a concave arc with the central narrowing width.

5. As in request item 1, the solder resist printing screen modification system, wherein, If the alignment mark is aligned with the edge of the screen pattern, and the second spacing is greater than or equal to a second reference value, the screen pattern is adjusted with an inward width and a tapered length as the change conditions, so that the screen pattern is close to the side of the alignment mark. Starting at a distance of one interval from the line, the pattern gradually shrinks inward with the tapered length to reach the inward width. The second reference value is 250 micrometers, and the maximum value of the tapered length is 100 micrometers.

6. As in request item 5, the solder resist printing screen modification system, wherein, The end position of the tapered pattern is aligned with the arm length of the alignment mark. The interval plus the tapered length and the arm length equal the second spacing. The maximum value of the arm length is 100 micrometers.

7. As in request item 1, the solder resist printing screen modification system, wherein, If the alignment mark is aligned with the edge of the screen pattern, and the second spacing is less than a second reference value and greater than or equal to the arm length plus a third reference value, the screen pattern is adjusted with an inward width and a tapered length as the change conditions, so that the screen pattern is close to the side of the alignment mark, and begins to tapered at the boundary position of the line to reach the inward width, and the third reference value is 50 micrometers.

8. As in request item 7, the solder resist printing screen modification system, wherein, The tapered length plus the arm length equals the second spacing, and the minimum value of the tapered length is the third reference value.

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