Re: soft and hard board
Hello nafah,
The name Soft & Hard board is used based on the substrate material type...
Soft Boards or Duroid Boards
Details:
Etch back process
Nominal conductor thickness 18 µm (½ oz rolled Cu)
Drilled before etching for PTH and plate up
Drilled after etching and plate up for NPTH
Cutting tool to mill
Hard Boards or Alumina Boards
Details:
Plate Up process
Nominal conductor thickness 3-5 µm
Au Laser Drilled/routed
Thin film technology
Resistors TaN or NiCr
---manju---