Dry film photo resists and polymers - the low cost option for standard and 3-D wafer level packaging

Driving packaging cost down is essential to make products cheaper. There are several options to reduce costs: One is to switch from one packaging technology to another (cheaper) one. The other is to cut costs for an existing process step by using cheaper material and/or a more cost effective process flow. For 3-D-packages dry films can be used as a photo mask for Si dry etching. They do have the capability to bridge over etched cavities or to create 3-D structure. Opportunities provided by the use of dry films will be discussed in the paper.