Copper is the most commonly used material for circuit traces and offers the most cost effective solution. Thickness typically ranges from .0007" to .0028". Tech-Etch works with both adhesive based and adhesiveless substrate materials.
Our Flex Circuit Construction
page explains these processes in more detail. Tech-Etch also has the capability to manufacture circuits from specialty metals to support specific applications. Some examples are stainless steel for corrosion resistance, BeCu for spring properties, Cupronickel for high resistance applications, and selective tungsten segments when radiopacity is desired.
Polyimide film is the most common insulator material used for flex circuits. Tech-Etch uses this film as the base layer on single metal layer flex circuits and for inner layers of multilayer circuits.
FR-4 and prepreg combine to make up the insulating layers in the rigid portion of a rigid-flex circuit. Tech-Etch has the ability to work with most commercially available laminates and prepregs including high speed and high Tg / Td materials.
Plated Through Vias
Tech-Etch can provide circuits with plated through, buried, or blind vias. A through via is a metalized hole through all layers that connects two or more of the conductive layers of a flexible circuit.
Blind vias where the via connects an outer layer with the adjacent inner layer, but does not go all the way through the circuit. Buried vias connect internal layers, but also do not connect to the outer layers. These advanced via types can help increase space within the circuit for other features such as component pads or additional trace routing.
In some applications, rigid-flex products can benefit from the via fill process. This process involves filling the via with either conductive or non-conductive epoxy, planarizing, and plating over the epoxy resulting in a smooth / flat via capture pad that is also suitable as a component attachment pad.
Tech-Etch has the ability to drill vias as small as .001" diameter using laser drill technology. Visit the flex circuit Tolerance page
for via size Guidelines.