4L rigid-flex board

Structure:1R+2F+1R
Layers    4L
Thickness   0.55mm
Out Layer Copper Thickness:  1 OZ
Inner Layer Copper Thickness:H OZ
Min hole size:0.2mm
Min Line Width/Space:  3mil
Surface finish:ENIG
Product use:Leica camera
Difficulties:High quality of impedance matching