Development of photolithography process for fine pitch application on flexible circuit

Abstract

This paper presents the findings of the development of photolithography process for fine pitch application on flexible circuit. Optimization of dry film lamination in Ni-P surface is the main goal. During lamination, three factors will affect the strength of adhesion which will finally affect the quality of circuit. The three factors are temperature, pressure and speed of lamination roller. In the project, a new hypothesis of plasma pre-treatment which helps to increase the adhesion strength between dry film and Ni-P surface is introduced, follows by manipulating different factors in lamination process with a full factorial experiment. A total number of 193 samples are investigated. The result of the plasma pre-treatment experiment is promising, indicating that 400W of plasma pre-treatment will strengthen the adhesion property. The ranges of temperature, pressure and speed of lamination roller are narrowed down to more precious values that give a highest quality of circuits. The result given in this project provides the higher quality/yield of 16 μm ultra-fine pitch flexible circuits and contributes to the development of applying 16 μm ultra-fine pitch flexible circuit technology in industrial and commercial usage.