Abstract: An inspection mark structure has an inspection via hole, which is provided in substrate sheets to be heat-pressed constituting at least two layers of laminates; a round pattern electrode, which is formed on one main face side of the substrate sheet provided with the inspection via hole, and provided around the end face of the inspection via hole at such a predetermined distance as not to come into contact with the end face; and a conduction electrode, which is formed on the other main face side of the substrate sheet provided with the inspection via hole, and provided so as to be electrically connected with the end face of the inspection via hole.

Abstract: The present invention provides a method of manufacturing a printed circuit board, which includes preparing a dielectric substrate, coating surfaces of the dielectric substrate, filling a via hole with a conductor, peeling mold-releasing films, compressing the dielectric substrate and forming metal foils. The dielectric substrate has patterned wiring layers on both surfaces, and the wiring layers are connected electrically with each other by the conductor. The dielectric substrate is made of a glass cloth or a glass nonwoven fabric impregnated with a thermosetting epoxy resin mixed with fine particles, and the conductive filler in the conductor has an average particle diameter larger than that of the fine particles. Accordingly, the printed circuit board has an improved moisture resistance as a whole and also excellent connection reliability and repair resistance. In addition, the dielectric substrate of the printed circuit board has an improved mechanical strength such as flexural rigidity.

Abstract: A multilayer circuit board includes: two or more layers of electrical insulative base members; and two or more layers of conductive patterned layers. At least two of the conductive patterned layers include coil patterns that will be a part of a coil, through holes are provided at predetermined positions of the electrical insulative base members, the positions being sandwiched between the coil patterns, so as to enable communication between respective end portions of the coil patterns, and conductive paste charged in the through holes allows electrical connection to be established between the respective end portions. The coil is formed so as to be wound in a direction perpendicular to a thickness direction of the multilayer circuit board. With this configuration, a multilayer circuit board can be provided, which facilitates increasing the winding number of a coil and has excellent flexibility of circuit design.

Abstract: A circuit board of the present invention, includes: an electrical insulating layer including at least one layer of electrical insulating base; and a conductive portion formed in a via hole provided in the electrical insulating base. A land for mounting only is disposed on at least one surface of the electrical insulating base that is arranged at an outermost layer. According to a method for manufacturing a circuit board of the present invention, includes the steps of: forming a via hole in an electrical insulating base; filling the via hole with a conductive paste; laminating a metal foil or a releasing sheet on the electrical insulating base, and placing a jig for pressing above and below the lamination, followed by hot-pressing so as to apply heat and pressure thereto, so as to form a conductive portion made of the conductive paste in the via hole; and forming a land for mounting only on at least one surface of the electrical insulating base that is arranged at an outermost layer.

Abstract: There is provided a wiring substrate for intermediate connection comprising: (1) a wiring board having a plurality of wiring layers which are connected through a via hole conductor(s) with each other; and (2) a prepreg sheet having a via hole conductor(s) at a predetermined position(s) which sheet is disposed on at least one side of the wiring board.

Abstract: A member for a circuit board according to the present invention includes a prepreg and a mold release film that is provided on at lease one side of the prepreg. The mold release film contains or is coated with a heat absorbing substance having a heat absorbing property. A method of manufacturing a member for a circuit board according to the present invention includes allowing a mold release film to adhere to at least one side of a prepreg by heating and pressing. The mold release film contains or is coated with a heat absorbing substance having a heat absorbing property. In the method, the heating is performed at a temperature not lower than a softening point of the prepreg and not higher than an endothermic temperature of the heat absorbing substance.

Abstract: A printed circuit board of the present invention is formed of an electrical insulating base material with through holes that are formed in a thickness direction of the electrical insulating base material and are filled with an electrical conductor; the electrical insulating base material including a core layer formed by impregnating a holder with a resin and resin layers formed on both sides of the core layer; and wiring layers that are formed on both surfaces of the electrical insulating base material into a predetermined pattern and are electrically connected to each other by the electrical conductor. The wiring layer is embedded in at least one of the resin layers. The resin layers on the both sides have different thicknesses from each other, and a thinner layer out of the resin layers has a thickness equal to or smaller than a mean particle diameter of an electrically conductive filler contained in the electrical conductor.

Abstract: The present invention provides a printed circuit board, which includes a dielectric substrate having via holes formed in the thickness direction, and a conductor including a conductive filler is filled in the via holes. The dielectric substrate has patterned wiring layers on both surfaces, and the wiring layers are connected electrically with each other by the conductor. The dielectric substrate is made of a glass cloth or a glass nonwoven fabric impregnated with a thermosetting epoxy resin mixed with fine particles, and the conductive filler in the conductor has an average particle diameter larger than that of the fine particles. Accordingly, the printed circuit board has an improved moisture resistance as a whole and also excellent connection reliability and repair resistance. In addition, the dielectric substrate of the printed circuit board has an improved mechanical strength such as flexural rigidity. The present invention also provides a method of manufacturing such a printed circuit board.

Abstract: The present invention provides a printed circuit board, which includes a dielectric substrate having via holes formed in the thickness direction, and a conductor including a conductive filler is filled in the via holes. The dielectric substrate has patterned wiring layers on both surfaces, and the wiring layers are connected electrically with each other by the conductor. The dielectric substrate is made of a glass cloth or a glass nonwoven fabric impregnated with a thermosetting epoxy resin mixed with fine particles, and the conductive filler in the conductor has an average particle diameter larger than that of the fine particles. Accordingly, the printed circuit board has an improved moisture resistance as a whole and also excellent connection reliability and repair resistance. In addition, the dielectric substrate of the printed circuit board has an improved mechanical strength such as flexural rigidity. The present invention also provides a method of manufacturing such a printed circuit board.

Abstract: A circuit board is configured so as to include not less than two wiring layers, an insulator layer for electric insulation between the wiring layers, and an inner-via-hole conductive member provided in the insulator layer in a thickness direction of the insulator layer, for electric connection between the wiring layers. The insulator layer is made of a composite material containing an organic resin and a material having a smaller thermal expansion coefficient than that of the organic resin, and includes a surface part, a core part, and a surface part laminated in the stated order, the surface part having a high content of the organic resin, the core part having a low content of the organic resin. The wiring layers have a land portion that is connected with the inner-via-hole conductive member, the land portion being embedded so as to be substantially in contact with the core part, and the inner-via-hole conductive member has a thickness substantially equal to a thickness of the core part.

Abstract: An electrically insulating base material includes a core layer 102, a resin layer 101 on each surface of the core layer 102 and a conductive material 105 filled into through holes 104 formed in a thickness direction. On each surface of the electrically insulating base material, a metal foil 106 is laminated, and a laminate thus obtained is heated and pressed. A conductive filler in the conductive material 105 has a mean particle diameter equal to or larger than a thickness of the resin layer 101, and thus the conductive filler can be prevented from being diffused into the resin layer 101 in a heating and pressing process. As a result, the conductive filler can be densified, thereby allowing a printed wiring board with via hole connection having high connection reliability to be obtained.

Abstract: A circuit board is configured so as to include not less than two wiring layers, an insulator layer for electric insulation between the wiring layers, and an inner-via-hole conductive member provided in the insulator layer in a thickness direction of the insulator layer, for electric connection between the wiring layers. The insulator layer is made of a composite material containing an organic resin and a material having a smaller thermal expansion coefficient than that of the organic resin, and includes a surface part, a core part, and a surface part laminated in the stated order, the surface part having a high content of the organic resin, the core part having a low content of the organic resin. The wiring layers have a land portion that is connected with the inner-via-hole conductive member, the land portion being embedded so as to be substantially in contact with the core part, and the inner-via-hole conductive member has a thickness substantially equal to a thickness of the core part.

Abstract: A circuit board is configured so as to include not less than two wiring layers, an insulator layer for electric insulation between the wiring layers, and an inner-via-hole conductive member provided in the insulator layer in a thickness direction of the insulator layer, for electric connection between the wiring layers. The insulator layer is made of a composite material containing an organic resin and a material having a smaller thermal expansion coefficient than that of the organic resin, and includes a surface part, a core part, and a surface part laminated in the stated order, the surface part having a high content of the organic resin, the core part having a low content of the organic resin. The wiring layers have a land portion that is connected with the inner-via-hole conductive member, the land portion being embedded so as to be substantially in contact with the core part, and the inner-via-hole conductive member has a thickness substantially equal to a thickness of the core part.

Abstract: A printed circuit board of the present invention is formed of an electrical insulating base material with through holes that are formed in a thickness direction of the electrical insulating base material and are filled with an electrical conductor; the electrical insulating base material including a core layer formed by impregnating a holder with a resin and resin layers formed on both sides of the core layer; and wiring layers that are formed on both surfaces of the electrical insulating base material into a predetermined pattern and are electrically connected to each other by the electrical conductor. The wiring layer is embedded in at least one of the resin layers. The resin layers on the both sides have different thicknesses from each other, and a thinner layer out of the resin layers has a thickness equal to or smaller than a mean particle diameter of an electrically conductive filler contained in the electrical conductor.

Abstract: A printed circuit board of the present invention is formed of an electrical insulating base material with through holes that are formed in a thickness direction of the electrical insulating base material and are filled with an electrical conductor; the electrical insulating base material including a core layer formed by impregnating a holder with a resin and resin layers formed on both sides of the core layer; and wiring layers that are formed on both surfaces of the electrical insulating base material into a predetermined pattern and are electrically connected to each other by the electrical conductor. The wiring layer is embedded in at least one of the resin layers. The resin layers on the both sides have different thicknesses from each other, and a thinner layer out of the resin layers has a thickness equal to or smaller than a mean particle diameter of an electrically conductive filler contained in the electrical conductor.

Abstract: A circuit board is configured so as to include not less than two wiring layers, an insulator layer for electric insulation between the wiring layers, and an inner-via-hole conductive member provided in the insulator layer in a thickness direction of the insulator layer, for electric connection between the wiring layers. The insulator layer is made of a composite material containing an organic resin and a material having a smaller thermal expansion coefficient than that of the organic resin, and includes a surface part, a core part, and a surface part laminated in the stated order, the surface part having a high content of the organic resin, the core part having a low content of the organic resin. The wiring layers have a land portion that is connected with the inner-via-hole conductive member, the land portion being embedded so as to be substantially in contact with the core part, and the inner-via-hole conductive member has a thickness substantially equal to a thickness of the core part.

Abstract: A printed circuit board of the present invention is formed of an electrical insulating base material with through holes that are formed in a thickness direction of the electrical insulating base material and are filled with an electrical conductor; the electrical insulating base material including a core layer formed by impregnating a holder with a resin and resin layers formed on both sides of the core layer; and wiring layers that are formed on both surfaces of the electrical insulating base material into a predetermined pattern and are electrically connected to each other by the electrical conductor. The wiring layer is embedded in at least one of the resin layers. The resin layers on the both sides have different thicknesses from each other, and a thinner layer out of the resin layers has a thickness equal to or smaller than a mean particle diameter of an electrically conductive filler contained in the electrical conductor.

Abstract: The present invention provides a printed circuit board, which includes a dielectric substrate having via holes formed in the thickness direction, and a conductor including a conductive filler is filled in the via holes. The dielectric substrate has patterned wiring layers on both surfaces, and the wiring layers are connected electrically with each other by the conductor. The dielectric substrate is made of a glass cloth or a glass nonwoven fabric impregnated with a thermosetting epoxy resin mixed with fine particles, and the conductive filler in the conductor has an average particle diameter larger than that of the fine particles. Accordingly, the printed circuit board has an improved moisture resistance as a whole and also excellent connection reliability and repair resistance. In addition, the dielectric substrate of the printed circuit board has an improved mechanical strength such as flexural rigidity. The present invention also provides a method of manufacturing such a printed circuit board.