A composite metal foil and a preparation method thereof are provided. The composite metal foil includes a carrier layer, a barrier layer, a striping layer, and a metal foil layer. The carrier layer, the barrier layer, the striping layer, and the metal foil layer are sequentially stacked, the barrier layer includes a metal bonding layer and a high-temperature resistant layer stacked, and the metal bonding layer is disposed between the carrier layer and the high-temperature resistant layer. The striping layer is disposed between the carrier layer and the metal foil layer so as to facilitate peeling of the carrier layer, and the barrier layer is disposed between the carrier layer and the metal foil layer so as to prevent the carrier layer and the metal foil layer from diffusing mutually to cause bonding at a high temperature, so that the carrier layer and the metal foil layer are easy to peel off. In addition, the metal bonding layer is disposed between the carrier layer and the high-temperature resistant layer, so that the barrier layer is not easy to separate from the carrier layer, and peeling between the barrier layer and the carrier layer is prevented.

A substrate for a printed circuit board according to an embodiment of the present invention includes a base film having insulating properties and a sintered layer formed of a plurality of metal particles, the sintered layer being stacked on at least one surface of the base film, in which a region of the sintered layer extending from an interface between the sintered layer and the base film to a position 500 nm or less from the interface has a porosity of 1% or more and 50% or less.

The present invention relates to a carrier foil-attached metal foil including a release layer having a specific composition and structure, a method of manufacturing the carrier foil-attached metal foil, and a laminate for forming a printed circuit board including the carrier foil-attached metal foil. The laminate for forming a printed circuit board according to the present invention comprises the carrier foil-attached metal foil, so that a defect rate can be minimized.

A supported copper foil is disclosed, comprising: a poly-based film that contains polyimide and polytetrafluoroethylene; a thin copper foil; and an adhesive provided between the poly-based film and the thin copper foil, the adhesive removably coupling the poly-based film to the copper foil.

An extremely thin copper foil is provided that enables formation of highly fine different wiring patterns with a line/space (L/S) of 10 μm or less/10 μm or less on two sides of the copper foil and is thus usable as an inexpensive and readily processable substitution for silicon and glass interposers. The extremely thin copper foil includes, in sequence, a first extremely thin copper layer, an etching stopper layer, and the second extremely thin copper layer. Two sides of the extremely thin copper foil each have an arithmetic average roughness Ra of 20 nm or less.

Provide are a method for manufacturing a wiring board or a wiring board material, and the wiring board obtained by the method, which allows columnar metal members to be inserted into the wiring board at once using a simple operation, enables alignment without requiring strict accuracy, can handle columnar metal members having different shapes, and imparts sufficiently high adhesive strength to the columnar metal members. The method includes the steps of: laminating a laminate material LM including the support sheet 10 having the columnar metal members 14 formed thereon, a wiring board WB or a wiring board material WB′ having a plurality of openings in portions corresponding to the columnar metal members 14, and a prepreg 16′ having a plurality of openings in portions corresponding to the columnar metal members 14 and containing a thermosetting resin such that the columnar metal members 14 are positioned in the respective openings; integrating the laminate material LM by heating and pressing to obtain a laminate LB including a thermosetting resin filled between an inner surface of each of the openings of the wiring board WB or the wiring board material WB′ and each of the columnar metal members 14; and peeling at least the support sheet 14 from the laminate LB.

A reel-to-reel method to laser-ablate a circuitry pattern on the fly in a reel-to-reel machine as part of a process to fabricate a printed flexible circuit. The laser ablation method includes using an appropriate laser to irradiate a metal sheet thus ablating the edges of an intended circuitry pattern. Slugs can be removed by using an optional sacrificial liner, and the slugs can be optionally ablated into smaller parts first. The laser ablation can also include an optional method of creating tie bars to provide structural support to the web of circuitry patterns.

Provided is a carrier-attached metal foil which has excellent carrier-releasability and excellent selective metal layer-etchability, and can achieve a reduction in transmission loss and resistance in a semiconductor package (for example, a millimeter-wave antenna substrate) manufactured using the same. The carrier-attached metal foil includes: (a) a carrier; (b) a release functional layer on the carrier and including (b1) an adhesion layer disposed closer to the carrier and having a thickness of more than 10 nm and less than 200 nm and (b2) a release assistance layer disposed farther from the carrier and having a thickness of 50 nm or more and 500 nm or less; and (c) a composite metal layer on the release functional layer and including (c1) a carbon layer disposed closer to the release assistance layer, and (c2) a first metal layer disposed farther from the release assistance layer and mainly composed of Au or Pt.

Disclosed is a method for manufacturing an FCCL capable of controlling flexibility and stiffness of a conductive pattern. The method for manufacturing an FCCL (Flexible Copper Clad Laminate) includes: an electroforming step of forming a conductive pattern on a mold for electroforming through electroforming; and a transfer step of transferring the conductive pattern from the mold for electroforming to the bottom of a polymer plastic film, wherein the electroforming process is performed in a plating bath equipped with a first metal, a second metal and a third metal, wherein the first metal is copper (Cu), the second metal serves to add flexibility and is one of tin (Sn), gold (Au), silver (Ag) and aluminum (Al), and the third metal serves to add stiffness and is one of nickel (Ni), cobalt (Co), chrome (Cr), iron (Fe), tungsten (W) and titanium (Ti).

A manufacturing method of copper foil and circuit board assembly for high frequency transmission are provided. Firstly, a raw copper foil having a predetermined surface is produced by an electrolyzing process. Subsequently, a roughened layer including a plurality of copper particles is formed on the predetermined surface by an arsenic-free electrolytic roughening treatment and an arsenic-free electrolytic surface protection treatment. Thereafter, a surface treatment layer is formed on the roughened layer, and the roughened layer is made of a material which includes at least one kind of non-copper metal elements and the concentration of the non-copper metal elements is smaller than 400 ppm. By controlling the concentration of the non-copper elements, the resistance of the copper foil can be reduced.