RTF Copper Foil
RTF, or reverse-treated electrolytic copper foil, undergoes roughening on both sides to different extents. This enhances the peel strength of the copper foil on both sides, simplifying its application as an intermediate layer for bonding with other materials. Additionally, the varying degree of treatments on both sides facilitates the etching of the thinner side of the roughened layer. In the construction of a printed circuit board (PCB) panel, the roughened side of the copper foil is positioned on the dielectric material. The roughened drum side is treated to be considerably rougher than the other side, resulting in superior adhesion to the dielectric material. This is a major advantage in comparison to standard electrolytic copper. The matte side is free from any mechanical or chemical treatments before applying photoresist, as it is sufficiently rough to ensure strong laminating adhesion.
Properties of RTF Copper Foil
Classification | Unit | 1/3OZ (12μm) | 1/2OZ (18μm) | 1OZ (35μm) | |
Cu Content | % | min. 99.8 | |||
Area Weight | g/m2 | 107±3 | 153±5 | 283±5 | |
Tensile Strength | R.T.(25℃) | Kg/mm2 | min. 28.0 | ||
H.T.(180℃) | min. 15.0 | min. 15.0 | min. 18.0 | ||
Elongation | R.T.(25℃) | % | min. 5.0 | min. 6.0 | min. 8.0 |
H.T.(180℃) | min. 6.0 | ||||
Roughness | Shiny(Ra) | μm | max. 0.6/4.0 | max. 0.7/5.0 | max. 0.8/6.0 |
Matte(Rz) | max. 0.6/4.0 | max. 0.7/5.0 | max. 0.8/6.0 | ||
Peel Strength | R.T.(23℃) | Kg/cm | min. 1.1 | min. 1.2 | min. 1.5 |
Degraded rate of HCΦ(18%-1hr/25℃) | % | max. 5.0 | |||
Change of color(E-1.0hr/190℃) | % | None | |||
Solder Floating 290℃ | Sec. | max. 20 | |||
Pinhole | EA | Zero | |||
Preperg | ---- | FR-4 | |||
