A process for fabricating high current circuits with high interconnect density

Currently there is no cost-effective technology available for fabricating copper interconnect with thickness greater than 4 mils and large cross-sectional area. In opposition to the photoresist laminate manufacturer´s recommended procedure, a thick photoresist layer was achieved by laminating two layers sequentially on a substrate. Procedures for patterning, developing, and stripping die thick photoresist layer were developed. A process for making greater than 4 mil thick copper conductors with an aspect ratio of 1:1 in a 10 mil pitch has been ascertained and its feasibility demonstrated. The new process will give us a significant advantage in designing and producing high current circuits with high interconnect density requiring low conductor resistance for avoiding signal degradation and minimizing power dissipation