Disclosed herein relates to a copper foil having a low roughness property by roughening a matte side, wherein a thickness of the copper foil is from 5 μm to 70 μm, and profilometer-measured mean roughness of the roughened surface of the copper foil is from 0.5 μm to 2.0 μm, and wherein profilometer-measured mean roughness Rz JIS of the roughened matte side of the copper foil is lower than that of a shiny side of the copper foil. The copper foil provided in the present invention has excellent adhesion with a resin and an electrical property while having low roughness through surface roughening.

Phenolic-terminated and phenolic pendent curable polyimides with very good dielectric properties have been prepared. These materials in combination with epoxy resins and other co-curable resins are ideal for being transformed into flexible films that are ready to be laminated for example between copper foils for applications such as copper-clad laminates for a variety of electronics applications.

A copper clad laminate and a printed-circuit board. The copper clad laminate comprises a dielectric substrate layer and a copper foil layer. The copper foil layer is located on at least one surface of the dielectric substrate layer, wherein the copper foil layer comprises an iron element in a weight content of less than 10 ppm, a nickel element in a weight content of less than 10 ppm, a cobalt element in a weight content of less than 10 ppm, and a molybdenum element in a weight content of 10 ppm. The copper clad laminate has a passive intermodulation PIM of less than −158 dBc (700 MHz/2600 MHz).

A substrate for a printed circuit board according to an embodiment of the present invention includes a base film and a metal layer disposed on at least one of surfaces of the base film. In the substrate for a printed circuit board, an amount of nitrogen present per unit area, the amount being determined on the basis of a peak area of a N1s spectrum in XPS analysis of a surface of the base film exposed after removal of the metal layer by etching with an acidic solution, is 1 atomic % or more and 10 atomic % or less.

A stretchable laminate to be fixed to a fabric includes a stretchable circuit board including a stretchable insulating layer having an elongation rate of 10% or more, a fabric base material, and an adhesive layer that bonds the stretchable circuit board and the fabric base material together.

Provided is a resin composition that has a low melt viscosity, and is capable of being turned into a cured product having a high heat resistance, a high adhesion and a high glass-transition temperature, though having a low permittivity and a low dielectric tangent. The resin composition is a cyclic imide resin composition containing: (a) a cyclic imide compound represented by the following formula (1),

##STR00001## (b) a cyclic imide compound represented by the following formula (2),

##STR00002##

and (c) a curing catalyst.

A black liquid-crystal polymer film that contains a black pigment and a liquid crystal polymer and the black liquid-crystal polymer film has a lightness of 45 or less, a dielectric loss tangent of 0.0035 or less, a minimum dielectric breakdown strength of 60 kV/mm or more, and a maximum-to-minimum ratio of in-plane thermal linear expansion coefficient in the range of 1.0 to 2.5.

Provided are an electrodeposited copper foil, an electrode comprising the same, and a lithium-ion secondary battery comprising the same. The electrodeposited copper foil has a drum side and a deposited side opposing the drum side, wherein at least one of the drum side and the deposited side exhibits a void volume value (Vv) in the range of 0.17 μm.sup.3/μm.sup.2 to 1.17 μm.sup.3/μm.sup.2; and an absolute value of a difference between a maximum height (Sz) of the drum side and a Sz of the deposited side is in the range of less than 0.60 μm.

Disclosed is a copper foil including a copper layer and an anticorrosive layer disposed on the copper layer, wherein the copper foil has a peak to arithmetic mean roughness (PAR) of 0.8 to 12.5, a tensile strength of 29 to 58 kgf/mm.sup.2, and a weight deviation of 3% or less, wherein the PAR is calculated in accordance with the following Equation 1:
PAR=Rp/Ra  [Equation 1] wherein Rp is a maximum profile peak height and Ra is an arithmetic mean roughness.

The present invention relates to a method of producing a ceramic substrate, the method including: joining a metal layer to each of opposite surfaces of a ceramic base material; forming, on the metal layers, a first electrode layer and a second electrode layer having a larger volume than the first electrode layer; calculating the volumes of the first and second electrode layers; and controlling a thickness of the second electrode layer, thereby controlling warpage which may occur due to a difference between the volumes of the first and second electrode layers. The present invention can reduce the defect rate of a ceramic substrate by controlling warpage that may occur due to the difference in volume taken up by the metal layers on the opposite surfaces of the base material.