A multilayer board includes thermoplastic resin layers laminated together, a first-class conductor pattern including a conductor foil on a first surface of one of the thermoplastic resin layers, a second-class conductor pattern in contact with a second surface of the one of the thermoplastic resin layers, and an interlayer connection conductor in the one of the thermoplastic resin layers and including a first end surface connected to the first-class conductor pattern and a second end surface connected to a second-class conductor pattern. The second-class conductor pattern and the first interlayer connection conductor include a conductor of a single material including a resin, or a conductor of a single material including a metal with a melting point lower than that of the conductor foil.

The present invention relates to a resin composition containing a compound having a maleimido group, a divalent group having at least two imido bonds and a saturated or unsaturated divalent hydrocarbon group.

This publication discloses an electronic module, comprising a first conductive pattern layer and a first insulating-material layer on at least one surface of the first conductive pattern layer, at least one opening in the first insulating-material layer that extends through the first insulating-material layer, a component having a contact surface with contact terminals, the component being arranged at least partially within the opening with its contact terminals electrically coupled to the first conductive pattern layer, a second insulating-material layer provided on the first insulating-material layer, and a conductive pattern embedded between the first and second insulating material layers. This publication additionally discloses a method for manufacturing an electronic module.

An electromagnetic wave transmission board proofed against internal signal leakage includes an inner plate, a first outer plate, a second outer plate, a first plate bump, a first conductive bump, a second plate bump, and a second conductive bump. The inner plate defines a first through hole with a plated metal layer on the hole wall. The first and second plated bumps are disposed between the first outer and inner plates. The second plate bump and the second conductive bump are disposed between the second outer plate and the inner plate. The plate metal layer, the first plate bump, the first conductive bump, the first outer plate, the second outer plate, the second conductive bump, and the second plated bump jointly form an air-filled chamber. A method for manufacturing the electromagnetic wave transmission board is also provided.

A packaging process for embedded chips includes: (1) mounting at least one IC chip on a circuit substrate, the IC chip having at least one exposed pin; (2) attaching a self-adhesive copper foil film to the surface of the circuit substrate, wherein the self-adhesive copper foil film has a copper foil layer and a B-stage insulating adhesive layer, the copper foil layer has at least one to-be-opened copper foil area corresponding to the pin, the insulating adhesive layer is applied on the copper foil layer, has no glass fiber, covers the IC chip, and has at least one to-be-opened insulating adhesive area corresponding to the pin, and the pin is in contact with the insulating adhesive layer but not with the copper foil layer; (3) removing the to-be-opened copper foil area; (4) removing the to-be-opened insulating adhesive area with an etching solution; and (5) curing the insulating adhesive layer completely.

A rigid-flex board is manufactured by attaching multiple self-adhesive copper foil films to a flexible circuit board through multiple build-up processes, thereby eliminating the need to pre-fabricate a rigid board and slot the rigid board. The build-up processes of the self-adhesive copper foil films allow the resulting rigid boards to be highly uniform in thickness so that thickness deviation of the rigid-flex board can be reduced.

A high-frequency electronic component includes a ceramic multilayer substrate, ground electrodes provided at different layers of the ceramic multilayer substrate, and a shielding film covering at least a side surface among surfaces of the ceramic multilayer substrate. Two or more of the ground electrodes are exposed to the side surface of the ceramic multilayer substrate but do not protrude from this side surface, and are electrically connected to the shielding film. On the side surface of the ceramic multilayer substrate, the two or more of the ground electrodes at least partially overlap each other in a thickness direction of the ceramic multilayer substrate, with a distance in the thickness direction between the overlapping ground electrodes being 5 μm or greater.

A flexible circuit board includes liquid crystal polymer (LCP) layers and metal layers including circuit routes. Each of the LCP layers includes via structures. The metal layers and the LCP layers are alternatively stacked to form a multi-layer structure. Adjacent metal layers are electrically connected through the via structures. Some via structures of different LCP layers are substantially aligned with one another to form a stack of via structures. Each of the via structures includes openings filled with conductive material. The size of the opening fulfils the following equation: Vb≥cos(Bh/Vh)*Vt/k*2, where Vb is a diameter of a smaller aperture, Vt is a diameter of a bigger aperture, Vh is a combined thickness of a LCP layer and a metal layer, Bh is a thickness of a LCP layer and k is a tensile modulus.

A wiring board, comprising: wiring patterns that are buried in the wiring board, in which a region positioned between wiring patterns disposed in an in-plane direction of the same plane has an elastic modulus at 140° C. equal to or less than 0.1 MPa, and a dielectric loss tangent is equal to or less than 0.006.

A method of manufacturing a multilayer board includes forming conductor patterns on four or more insulating base material layers, forming a multilayer body by stacking the insulating base material layers in a state in which the conductor patterns face each other with prepreg layers therebetween, and heat-pressing the multilayer body. In a state before the step of heat-pressing, among the prepreg layers, a thickness of an outermost prepreg layer is larger than a thickness of a prepreg layer other than the outermost prepreg layer.