Authored By:
Jesse Greenwood
Hazardous Print Consulting Inc.
Summary
Six decades of legacy experience makes the specification and production of screens and masks to produce repeatable precision results mostly an exercise in matching engineering needs with known ink and substrate performance to specify screen and stencil characteristics. New types of functional and electronic devices, flex circuits and medical sensors, industrial printing, ever finer circuit pitch, downstream additive manufacturing processes coupled with new substrates and inks that are not optimized for the rheological, mechanical and chemical characteristics for the screen printing process are becoming a customer driven norm. Many of these materials do not work within legacy screen making, curing or press set-up parameters. Many new materials and end uses require new screen specifications.
This case study presents a DOE based method to pre-test new materials to categorize ink and substrate rheology, compatibility and printed feature requirement to allow more accurate screen recipes and on-press setting expectations before the project enters the production environment where time and materials are most costly and on-press adjustment methods may be constrained by locked, documented or regulatory processes, equipment limitations and employee experience.
Conclusions
Raw material pre-testing for new screen specifications will require creating processes for how the testing is conducted in order to mirror actual production floor print capability. The basic metrology tools for screen and ink measurement must be acquired. This method is best served with in-house screen making ability. In facilities where screen making is outsourced, this pre-testing/recipe specification process is even more critical to insure that the outgoing screen recipe specification is correct and that incoming screens actually meet that specification.
Initially Published in the IPC Proceedings
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