Editing Flexible electronics (section)

===Polymer thick film flex circuits===
Polymer thick film (PTF) flex circuits print circuit elements onto a polymer film. They are typically single conductor layer structures, however two or more metal layers can be printed sequentially separated by printed insulating layers. While lower in conductivity and thus limited to certain applications, PTF circuits have found a home in low-power applications at slightly higher voltages. Keyboards are a common application.