Abstract:
A metal layer 18 is sandwiched between insulating layers 14 and 20 so that required strength is maintained. Hence it follows that the thickness of a core substrate 30 can be reduced and, therefore, the thickness of a multi-layer printed circuit board can be reduced. Formation of non-penetrating openings 22 which reach the metal layer 18 in the insulating layers 14 and 20 is simply required. Therefore, small non-penetrating openings 22 can easily be formed by applying laser beams. Thus, through holes 36 each having a small diameter can be formed.
Abstract:
A multiplayer printed wiring board (100) consisting of one-sided circuit boards (A, B) to house an IC chip (70), and being capable of connecting an IC module (120) to a printed wiring board via a BGA (56) on the rear surface, with the BGAs (56) disposed on the front and rear surfaces and the IC module (120) mounted via a BGA (56) on the front surface. Accordingly, a freedom of configuring an IC module to be mounted is enhanced to allow mounting of various IC modules.
Abstract:
A multi-layer flexible wiring board wherein interlayer connections can be accomplished without fail, a high reliability can be ensured, and wherein an external layer wiring board can be stacked. The present invention realizes such a multi-layer flexible wiring board and a method for making the same. Such a multi-layer flexible wiring board comprises (1) a plurality of one-sided wiring boards having, on one side of a support substrate, a wiring pattern and conductive two-layer posts extending from the wiring pattern and protruding from the opposite side of the support substrate, wherein the support substrate other than the most external layer has, on its opposite side to the conductive two-layer posts, pads for connection to the conductive posts and wherein no surface coating is provided to the wiring pattern, (2) a flexible wiring board having, on at least one side thereof, pads for connection to the conductive two-layer posts, and having such a wiring pattern that a surface coating is provided on a flexible part and that no surface coating is provided on a multi-layer part, and (3) an adhesive layer with a flux function, wherein the conductive posts are connected to the pads via the adhesive layer by use of a metal or alloy and wherein the wiring patterns are electrically connected.
Abstract:
Disclosed is a conductive paste which is obtained by kneading conductive particles into an epoxy resin and can be easily filled into a via hole. Such a conductive paste enables to form a connected portion wherein the connection resistance does not change over time even under high temperature, high humidity conditions. Also disclosed is a method for manufacturing a multilayer printed wiring board wherein such a conductive paste is used. Specifically disclosed is a conductive paste which is characterized by containing conductive particles and a resin mixture wherein the epoxy resin content with a molecular weight of not less than 10,000 is 30-90% by weight in the total resin component and the elastic modulus at 85˚C after curing is not more than 2 GPa. This conductive paste is also characterized in that the conductive particle content is 30-75% by volume. Also disclosed is a method for manufacturing a multilayer printed wiring board by using such a conductive paste.
Abstract:
According to the present invention, there is provided a process for manufacturing a circuit board wherein a first substrate having a conductor post and a second substrate having a conductor pad for receiving the conductor post are laminated through an interlayer adhesive, and the conductor post and the conductor pad are electrically connected, comprising, as a first step, bonding the conductor pad with the conductor post by thermocompression under predetermined first conditions while the first and the second substrates are arranged such that the conductor pad faces the conductor post through the interlayer adhesive; thermocompressing the first substrate and the second substrate under predetermined second conditions while the conductor pad is bonded with the conductor post; and thermocompressing the first substrate and the second substrate under predetermined third conditions while the conductor pad is bonded with the conductor post, wherein the first, the second and the third conditions are different from each other.
Abstract:
A wired circuit board includes: a first insulating layer; a conductive pattern formed on the first insulating layer and having a terminal portion; and a second insulating layer formed on the first insulating layer to cover the conductive pattern. A surface of the terminal portion is formed to be exposed from the first insulating layer and the second insulating layer. A tin alloy layer is formed at least on a top surface and both side surfaces of the terminal portion.
Abstract:
A base for multilayer wiring boards in which a conductive layer (112) forming a wiring pattern is provided on one side of an insulating base (insulating resin layer (111)), and an adhesive layer (113) for interlayer adhesion is provided on the other side, and a through hole (114) extending through the conductive layer, the insulating base, and the adhesive layer is filled with a conductive resin composition (115) for interlayer electrical connection. The diameter of the conductive layer portion (114b) of the through hole is smaller than those of the insulating base portion and the adhesive layer portion (114a). The electrical connection between the conductive resin composition and the conductive layer is ensured through the back (112a) of the conductive layer.
Abstract:
A sheet-form connector capable of forming an electrode structure having a small-diameter surface electrode unit, positively attaining a stable electric connection condition for a circuit device having electrodes formed at a small pitch, and providing a high durability without the electrode structure coming off an insulating sheet; and a production method and an application therefore. The sheet-form connector comprises an insulating sheet and a plurality of electrode structures provided to the insulating sheet to extend through the sheet in its thickness direction, wherein each of the electrode structures comprises a surface electrode part exposed to and protruding from the surface of the insulating sheet, a rear electrode part exposed to the rear surface of the insulating sheet, a shorting part extending continuously from the base end of the surface electrode part through the insulating sheet in its thickness direction until connected to the rear electrode part, and a holding part extending continuously from the base end of the surface electrode part along the surface of the insulating sheet toward the outer side.