Applied with double sided material to make pattern on both side then add on cover layer on each side , that's the double sided flexible boards.
Double-Layer Process
Double-Layer Process
1.Film Cutting
2.NC Drilling
3.Black Hole
4.Plating Thought Hole
5.Dry Film Lamination
6.Exposure
7.Development
8.Pattern Etch
9.Film Stripping
10.Pre-Lamination
11.Hot Press Lamination
12.PSR Screen
13.PSR Exposure
14.PSR Development
15.PSR Roast
16.Surface Treatment
17.1st Piercing Punch
18.O/S Testing
19.2nd Piercing Punch
20.FPCA middle QC
21.SMT
22.F/T
23.Final Testing