Abstract: A thin-film multilayer wiring board with first and second metallic wiring layers formed on a substrate and an organic insulating layer interposed between the metallic wiring layers. The insulating layer has the first metallic wiring layer and via holes in a thickness of the insulating layer. The lands of the first and second metallic wiring layers are electrically connected by via studs which are made of a conductive metal filled in the via holes.

Abstract: A thin-film multilayer wiring board comprising a first and a second metallic wiring layers formed on a substrate with an organic insulating layer interposed between the metallic wiring layers, wherein the lands of the first and second metallic wiring layers are electrically connected by via studs made of a conductive metal filler formed by electroless plating, and the difference between the top end diameter and the base diameter of each via stud is 10% or less, or the angle made by the taper of the interface between the insulating layer and each via stud against the axis thereof is 5° or less, can provide a high wiring density and signal transmission performance.

Abstract: A multi-layer wiring assembly including a stack of insulating layers, e.g. of polyimide, alternating with wiring patterns, typically of copper. To establish the circuit pattern, successive wiring patterns are connected to one another through the intervening insulating layers at predetermined locations, by metal stud connections. The studs are formed during assembly of the stack by wire-bonding a stud onto an underlying wiring pattern through a through-hole of the insulating layer above, and then stamping the exposed end of the wire-bonded stud to spread it into contact with the uppermost wiring pattern. The wire-bonded studs e.g. of Au, form strong bonds with the underlying conductor and are quick to apply in an automated process using a wire-bonding machine.

Abstract: A composite of metal and an organic film having a high adhesiveness without deterioration of film quality is provided by exposing the surface of organic film to at least one of chemically reactive gas phase molecules and gas phase ions thereby forming functional groups on the surface of organic film, and forming a metallic film thereon through the functional groups.

Abstract: The present invention provides a process for producing a metal/polyimide composite article such as high-density wiring boards. This metal/polyimide composite article is produced by a method which comprises coating a polyamic acid alkyl ester represented by the following formula on a metallic film and curing it: ##STR1## wherein R.sub.1 and R.sub.2 which may be identical or different each represents an organic group of 1 or more carbon atoms.