Printed wiring board, method for manufacturing printed wiring board, and electric device

A printed wiring board comprising:

• at least three insulation substrates multilayered on one another;
• a first wave-shape wiring provided between the insulation substrates facing each other;
• a second wave-shape wiring provided between the insulation substrates facing each other and three-dimensionally intersecting with the first wave-shape wiring in a plane direction and a thickness direction of the insulation substrates;
• and
• a resist layer provided between the insulation substrates and electrically separating the first wave-shape wiring and the second wave-shape wiring from each other, wherein
• the first wave-shape wiring, the second wave-shape wiring and the resist layer are provided in each of a plurality of interlayer spaces of the insulation substrates, and
• the first wave-shape wirings adjacent to each other and the second wave-shape wirings adjacent to each other in the thickness direction of the insulation substrates are disposed at such positions that the first wave-shape wirings adjacent to each other and the second wave-shape wirings adjacent to each other are plane-symmetrical to each other relative to a bonding surface of the insulation substrates.

A printed wiring board manufacturing method comprising:

• a first step in which at least three insulation substrates multilayered on one another including first and second insulation substrates are prepared,
• one or a plurality of first wiring patterns constituting intermittent portions in part in a first wave-shape wiring and one or a plurality of third wiring patterns constituting of intermittent portions in part in a second wave-shape wiring are formed on the first insulation substrate, and one or a plurality of second wiring patterns constituting the remaining portions other than the portions of the first wiring pattern in the first wave-shape wiring and one or a plurality of fourth wiring patterns constituting the remaining portions other than the portions of the third wiring pattern in the second wave-shape wiring are formed on the second insulation substrate;
• and
• a second step in which the first insulation substrate and the second insulation substrate are stacked on each other with a resist layer interposed therebetween so that surfaces thereof on which the wiring patterns are formed face each other, and the first wiring pattern and the second wiring pattern are connected to each other with a first electrical connection member interposed therebetween so that the first wave-shape wiring is formed, and the third wiring pattern and the fourth wiring pattern are connected to each other with a second electrical connection member interposed therebetween so that the second wave-shape wiring is formed in such a way that the second wave-shape wiring three-dimensionally intersects with the first wave-shape wiring in a plane direction and a thickness direction of the first and second insulation substrates, wherein
• in the first step, the first wave-shape wiring, the second wave-shape wiring and the resist layer are formed in each of a plurality of interlayer spaces of the insulation substrates, and
• the first wave-shape wirings adjacent to each other and the second wave-shape wirings adjacent to each other in the thickness direction of the insulation substrates are formed at such positions that the first wave-shape wirings adjacent to each other and the second wave-shape wirings adjacent to each other are plane-symmetrical to each other relative to a bonding surface of the insulation substrates.

A flexible printed wiring board manufacturing method comprising steps of:

• forming a wiring pattern on a base film having an electrical insulation property and plasticity;
• forming an epoxy-based resin film having photosensitivity and an electrical insulation property on the surface of the base film on which the wiring pattern is formed, and removing the resin film in a section of the wiring pattern and a section of an end surface of the base film;
• providing a conductive material in the section of the wiring pattern from which the resin film is removed;
• and
• bending the base film with the section of the end surface of the base film from which the resin film is removed as a folding base point so that the surface on which the wiring pattern is formed is directed inward, and then electrically connecting the sections of the wiring pattern from which the resin film is removed abutting each other when the base film is bent.