Research on dimensional change characteristics of silver halide films for multi-layer PCBs
The layer numbers and the density of circuit wiring increase day by day to meet the demand of the multifunction and miniaturization of electronic products during the manufacturing of printed circuit boards (PCBs). The dimensional stability of films determines the size and the alignment accuracy of images in each layer. This paper mainly discusses two aspects of silver halide films, the changing regularity of the film size after plotting and the influence of the exposure times on the film dimensional stability. It is indicated that silver halide films turn to be lengthening significantly in the first 9 hours after being plotted, and then trend to be stable. Film size contacts with the increase of exposure times during the exposure process.