Abstract:
The invention is a process for building-up printed wiring boards using metal foil coated with toughened benzocyclobutene-based dielectric polymers. The invention is also a toughened dielectric polymer comprising benzocyclobutene-based monomers or oligomers, ethylenically unsaturated polymer additive, and, optionally, a photoactive compound.
Abstract:
A multi-layer circuit comprises a circuit and a resin covered conductive layer disposed on the circuit, wherein the resin covered conductive layer comprises a liquid crystalline polymer resin laminated to a conductive layer. Such multi-layer circuits are particularly useful for high density circuit applications.
Abstract:
A method for manufacturing a build-up multi-layer printed circuit board is disclosed in which a YAG laser is used upon the formation of a via hole in the multi-layer printed circuit board, such that it can have the following advantages: the manufacturing process would become simple; the component packaging density and freedom for the design of the board would be improved; and a high speed of signal process would be ensured. The method for manufacturing a build-up multi-layer printed circuit board includes the steps of: forming a first printed circuit pattern on a copper clad laminate (CCL) by applying a general photo-etching process, the CCL having a copper foil on the one face thereof; stacking a resin-coated (on one face) copper foil (RCC) on the CCL with the first printed circuit pattern formed thereon, and heating and pressing this structure; irradiating a YAG laser to the board with said RCC stacked so as to form a via hole at a predetermined position by removing said RCC; carrying out an electroless and electro copper plating on the board with the via hole formed therein to form a plated layer; and forming a second printed circuit pattern on said plated layer to electrically connect the layers on which the first and second printed circuit patterns are formed.
Abstract:
An opening is formed in resin 20 by a laser beam so that a via hole is formed. At this time, copper foil 22, the thickness of which is reduced (to 3 nullm) by performing etching to lower the thermal conductivity is used as a conformal mask. Therefore, an opening 20a can be formed in the resin 20 if the number of irradiation of pulse-shape laser beam is reduced. Therefore, occurrence of undercut of the resin 20 which forms an interlayer insulating resin layer can be prevented. Thus, the reliability of the connection of the via holes can be improved.
Abstract:
A method of constructing an electric apparatus, comprising the following steps. First, a set of dielectric layers is provided. Next, a set of conductive features and at least one fiducial marking are formed on a first one of the dielectric layers, in mutual reference to each other so that their relative positions are known to a first tolerance. Then, a set of pin holes is formed in each dielectric layer, each pin hole formed in relation to the fiducial marking for its dielectric layer and all of the sets of pin holes having a mutually identical placement. Finally the dielectric layers are arranged onto a pin fixture having a set of pins that match the mutually identical placement of the pin holes.
Abstract:
The present invention provides a resin compound, which causes very little thermal stress even when a flip chip is mounted, is of low elastic modulus, and has high heat resistance enough for solder floating at 300null C., and also an adhesive film, metal-clad adhesive film, circuit board, and assembly structure using the resin compound. The present invention is a resin compound containing (A) polyamide imide with siloxane bond, (B) acrylic polymer with weight-average molecular weight of 500,000 or more, (C) thermoset resin, and (D) solvent; an adhesive film and a metal-clad adhesive film using the resin compound; and also a circuit board and an assembly structure made with these films.
Abstract:
An etching solution comprising (A) an amine as a solvent, (B) an alkali metal compound, and (C) an alcohol as a solvent, this etching solution being a non-aqueous solution. This etching solution is-effective for etching a cured epoxy resin layer for forming holes for interstitial via holes having a small diameter, in the production of a multilayer printed circuit board. This etching solution is particularly effective for etching a cured epoxy resin layer formed from a thermosetting epoxy resin composition including (a) an epoxy resin, (b) a crosslinking agent, and (c) a polyfunctional epoxy resin, which forms a thermosetting copper-clad adhesive resin sheet which covers an interlayer circuit plate of a multilayer printed circuit board.
Abstract:
A method for manufacturing a build-up multi-layer printed circuit board for use in computers, VTR, or portable telephones is disclosed, in which the method of forming a hole in a circuit layer and the method of forming a hole in an insulating layer are made different from each other by applying a combined formation method, thereby improving the formation precision and efficiency in forming the holes. Specifically, a resin-clad copper foil (RCC) is stacked on a CCL (copper-clad laminate) after forming a printed circuit layer, and this structure is heated and pressed. Then, beams of an Nd-YAG laser are irradiated to remove the copper-clad layer, and then beams of CO.sub.2 laser are irradiated to remove the residual resin insulator, thereby forming a via hole. Then, circuit patterns are formed on the board on which the via hole has been formed.
Abstract:
A multilayer printed wiring board wherein an inner-layer copper circuit is provided on one or both of the surfaces of an inner-layer substrate, and subsequent copper circuit is cumulatively provided through an insulating layer on the outside of the inner-layer copper circuit, characterized in that the inner-layer copper circuit has a cuprous oxide film formed on the surface thereof the insulating layer which remarkably facilitate the interlayer adhesion between the inner-layer copper circuit. This multilayer printed wiring board has high interlayer adhesiveness and moistureproofness without causing any haloing phenomena when soaked with an acidic solution.
Abstract:
A process for preparing said multilayer printed wiring board comprising the steps of (1) adhering copper foils respectively to both the faces of a substrate, masking and etching said foils in a usual way to form circuits, (2) applying copper foils having a semi-cured insulating layer formed on one face thereof respectively to said circuits with the insulating layer facing to said circuit, the insulating layers being as defined above, and then pressing the whole together under heat and (3) masking and etching the copper foils with the insulating layer thereon in a usual way to form circuits, the steps (2) and (3) being repeated as many times as desired.