Four layers of fpc soft and hard bonding plate: 4L
Structure: 1R 2F 1R
Plate thickness: 1.6
Outer copper thickness: 1 OZ
Inner copper thickness: 1 OZ
Minimum hole diameter: 0.25mm
Minimum line width/line spacing: 4mil
Surface treatment: gold deposit
Product application: electron microscope
Process difficulties: high requirements for expansion and contraction control