At UltraSource, Inc., customer supplied computer-aided-design (CAD) files play a critical role in supporting the manufacture of every thin film component we build. Customer furnished CAD files are used to fabricate the photomasks that are used in manufacturing to pattern the circuit images via photolithography and etching on to the ceramic substrate. And although our customers typically know that the preparation of the photomasks are a critical part of the thin film manufacturing processes, we find that CAD files will often contain layout and/or data errors.
Today’s complex thin film components increasingly require more physical layers and features. A few years ago the typical thin film component may only have required two or three layers. Now, common designs require up to six layers and sophisticated designs need up to ten layers. A modern thin film component or circuit design may include many elements such as tuning pads, RF or microwave features, optical features, resistors, capacitors, vias, selective solder pads, solder stops, polyimide dielectrics, vision recognition alignment targets, and custom labeling. If the CAD design contains data or layout errors such as gaps and misalignments in between the polygons that make up the design, detecting and repairing the errors may cause a significant delay in the fabrication of the photomask(s) and the end products. In a worst case scenario, data or layout errors in the CAD can cause an erroneous design to be fabricated.
The key to reducing the time to market and avoiding errors is for customers designing thin film components and circuits to be diligent in generating CAD designs that follow industry standards and generally accepted good practices. This application note was written in order to help our customers understand how they can help ensure their products rapidly turn into the exact manufactured component they have designed. By keeping some simple design rules in mind, you can avoid having us contact you to resolve your design issues after you have placed your order and need your parts urgently. We derived these 10 rules from the most common issues we encounter in our daily design and CAD review processes.