Ultrathin copper foil with carrier and printed circuit board using same
An ultrathin copper foil with a carrier not causing blistering at a release layer interface, having a low carrier peeling force, friendly to the environment, and enabling easy peeling of a carrier foil and an ultrathin copper foil even under a high temperature environment and a printed circuit board enabling a stable production quality of a base of a printed circuit board for fine pattern applications using the ultrathin copper foil with the carrier, that is, an ultrathin copper foil with a carrier comprising a carrier foil, a release layer, and an ultrathin copper foil, wherein the release layer is formed by a metal A for retaining a release property and a metal B for facilitating plating of the ultrathin copper foil, a content a of the metal A and a content b of the metal B forming the release layer satisfying an equation: 10≦ a /( a+b )*100≦70 and a printed circuit board prepared by using such an ultrathin copper foil with a carrier.
1. An ultrathin copper foil with a carrier comprising a carrier foil, a first release layer and a second release layer, and an ultrathin copper foil,
said first release layer consisting of a metal A for retaining a release property and a metal B which is a different metal from said metal A for facilitating plating of the ultrathin copper foil,
said second release layer consisting of the metal A and the metal B, and
said first release layer and second release layer are both chromium-free.
2. The ultrathin copper foil with a carrier of claim 1 , wherein
said first release and second release layer have composition ratios of the metal A and the metal B respectively,
said composition ratios are defined by the following equation:
| c /( c+d )− e /( e+f )|*100≧3
where, c is the content in weight of the metal A in said first release layer,
d is the content in weight of the metal B in said first release layer,
e is the content in weight of the metal A in said second release layer, and
f is the content in weight of the metal B in said second release layer.
3. An ultrathin copper foil with the carrier of claim 2 , wherein the metal A is Mo, Ta, V, Mn, or W, and the metal B is Fe, Co, or Ni.
4. An ultrathin copper foil with the carrier of claim 3 , wherein a total of the amount of deposition of said first release layer and said second release layer is 0.05 mg/dm 2 to 50 mg/dm 2 .
5. A printed circuit board for high density ultrafine interconnect application comprising an ultrathin copper foil having the carrier of claim 4 which is laminated on a resin substrate.
6. A printed circuit board for a high density ultrafine interconnect application comprising an ultrathin copper foil having the carrier of claim 3 with the ultrathin copper foil is laminated on a resin substrate.