• Metrigraphics

Micro Induction Coils

The coils are made using electroformed Nickel Cobalt over-plated with pure or hard gold, depending on the application. Coils can also be produced using copper. The process starts with a photolithographic image of the desired shape in photo resist, and then either electroplated for a thicker coil material, or sputtered for extremely fine coils. Individual traces can be fabricated as small as 3 microns, but more typically in the 5-10 micron range, with metal thickness equal to the trace width. Aspect ratios of 2.5 to 1 are also being fabricated and higher ratios are possible. Current samples have been fabricated on glass for ease of handling, but other substrates are possible and include silicon, alumina, cast polyamides and other sheet materials.There are two types of coils being produced:

• Single layer multiple turn electroformed coils in a variety of sizes, both in round configurations and square configurations for ease of fit into specific applications
• Multi-layer coils with greater field density for more high-end applications