Ngk Spark Plug Company, Limited

Tomoe Suzuki

Kozo Yamasaki

Shinji Yuri

Kazuhisa Sato

The invention provides a method for manufacturing printed wiring substrates which can manufacture printed wiring substrates each having resin dielectric layers of uniform thickness and excellent surface flatness while maintaining favorable cutting performance in a dicing step. A multi-printed wiring-substrate panel is manufactured which includes a metal plate having a first main surface and a second main surface, and resin dielectric layers disposed on the first and second main surfaces. The metal plate has first depression portions and second depression portions. The first depression portions are opened at the first main surface and arranged discontinuously along predetermined cutting lines. The second depression portions are opened at the second main surface and arranged discontinuously along the predetermined cutting lines. The multi-printed wiring-substrate panel is cut along the predetermined cutting lines into a plurality of printed wiring substrates.

Method for manufacturing printed wiring substrates, metal plate for use in manufacturing printed wiring substrates, and multi-printed wiring-substrate panel

A wiring substrate includes a solid layer formed on the core substrate to partially cover the same. At least one resin dielectric layer is formed on the solid layer and the core substrate while a plurality of pads are formed on the resin dielectric layer and are exposed at the main surface of the wiring substrate. First pads are located within a region above the solid layer and second pads located outside of that region. First top-flattened solder bumps are formed on the first pads and second top-flattened solder bumps are formed on the second pads. The bumps all include a top face of the same diameter.

Substrate with top-flattened solder bumps and method for manufacturing the same

A method for manufacturing a wiring substrate includes the steps of applying, through printing, solder paste onto a plurality of pads exposed from the main surface of the substrate; melting the applied solder paste through reflowing, so as to form substantially hemispherical solder bumps; and flattening top portions of the substantially hemispherical solder bumps through the pressing of a flat pressing surface against the top portions, thereby forming top-flattened solder bumps. A pad is classified as a first pad when the pad is located within a region above a solid layer, and as a second pad when the pad is located outside of this region. In the solder paste application step, the amount of solder paste applied onto each first pad is smaller than that of solder paste applied onto each second pad.

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Aichi, Japan

Tomoe Suzuki