Abstract: The present invention comprises an improvement in the surface treatment of copper surfaces. It produces a strong and stable bond, resistant to chemical attack and to thermal and mechanical stresses between said copper foil surfaces and adjacent surfaces of resinous layers. It is especially useful in multilayer printed circuit fabrication and in the treatment of copper circuit lines and areas which are disconnected from each other, that is, which do not have electrically conductive continuity. In a method according to the invention, an oxidized cooper surface is reduced in the presence of a polymer addition agent, and the partially reduced surface is then exposed to a nonoxidizing reagent. The result is a reticulated metallic copper microstructure capable of forming a strong adhesive bond with a resinous substrate, and having a high resistance to thermal, mechanical, and chemical (e.g. acid) stress.

Abstract: The present invention comprises an improvement in the surface treatment of copper surfaces. It produces a strong and stable bond, resistant to chemical attack and to thermal and mechanical stresses between said copper foil surfaces and adjacent surfaces of resinous layers. It is especially useful in multilayer printed circuit fabrication and in the treatment of copper circuit lines and areas which are disconnected from each other, that is, which do not have electrically conductive continuity. In a method according to the invention, an oxidized copper surface is reduced in the presence of a polymer addition agent, and the partially reduced surface is then exposed to a nonoxidizing reagent. The result is a reticulated metallic copper microstructure capable of forming a strong adhesive bond with a resinous substrate, and having a high resistance to thermal, mechanical, and chemical (e.g. acid) stress.

Abstract: A resinous product is disclosed which possesses a resinous surface coatable with a layer of metal which can be bonded through an array of microdendrites extending below the resinous surface. The resinous products are prepared by coating the surface of a metal plate with microdendrites, pressing the microdendrite covered metal surface into the resinous surface, curing the resin and stripping away the plate to leave the microdendrites embedded in the cured resinous surface. The embedded microdendrites are dissolved away to produce a micro-rough resinous surface having an array of microdendrite-shaped cavities. The resinous product can be used for printed circuits and the like.

Abstract: The apparatus for electrodeposition of a metal includes a cylindrical cathode which is rotated about a horizontal axis and is partly submerged in an electrolyte, the cylindrical cathode having a surface layer thereon upon which metal from the electrolyte may be deposited and from which a deposited layer of the metal may be stripped, comprising a plurality of strips of dimensionally stable anode, means for supporting each of the plurality of strips parallel to the horizontal axis and spaced a predetermined distance from the surface layer to form a generally annular space between the surface and the plurality of strips extending about substantially the entire portion of the surface layer which is submerged in the electrolyte.

Abstract: A drum for copper foil production by an electrodeposition method is composed of an inner support cylinder formed of a copper alloy material having both high electrical conductivity and good elastic properties, and an outer cylinder formed of titanium, zirconium or tantalum having good stripping characteristics which has been shrunk fit to the support cylinder. The support cylinder is provided with spaced raised portions. The alloy used to form the support cylinder is also chosen to have a substantially higher coefficient of expansion than titanium, zirconium, or tantalum.As a result of this shrink fitting process, the cylinder of titanium, zirconium or tantalum is biased into intimate contact with the raised portions only of the inner support cylinder. This effectively increases the pressure as, by reducing the interface area, the force per unit area increases.

Abstract: At least one conductive metal foil is preliminarily bonded to an electrically insulating resinous substrate by squeezing the layers together under heat and pressure in a continuous mode, as by passing the layers through a nip roll to produce a partially cured resinous layer subjacent to the metal foil. The thus preliminarily bonded laminate is further processed in an autoclave, under heat and pressure, whereby the bonding layer between the metal and the substrate is cured. The laminate formed by this process is useful for metal-clad boards, particularly printed circuit boards. These boards may be either flexible or rigid.