Printed Circuit Imaging

Overview

As treated in this manual, any method that can be used to deposit a protective (etchant resistant) pattern onto copperclad prior to final circuit formation, is considered to be an "imaging technique". Although historically reserved for image formation using photosensitive polymers, the list has grown to include:

photoresist imaging:
exposing circuit patterns into photoresist using an ultra-violet source and photographic artwork

soldermask imaging:
exposing pad masters into soldermask using an ultra-violet source and photographic artwork

liquid-ink direct imaging using an X-Y plotter:
creating a resist pattern directly onto copperclad using special plotter pens filled with a low-viscosity, chemically resistant ink

UV light direct imaging of photoresist using an X-Y plotter:
creating an exposure pattern in photoresist using a fiber optic "light pen" and a high-intensity UV spot source.

ink-jet direct imaging:
creating a resist pattern directly onto copperclad using a scanning ink-jet head filled with a low-viscosity, chemically resistant ink

thermal toner transfer imaging:
creating a chemically resistant "decal" using a common laser printer and thermally transferring it onto copperclad

mechanical etching:
although it does not involve the deposition of any kind of protective layer, mechanical etching "images" a circuit pattern by cutting away unwanted copper to isolate each circuit element