Murata Manufacturing Co., Ltd.

Ryo Asai

Hayato Katsu

Keisuke Nishida

Shinsuke Tani

Takayuki Okada

A flexible wiring board that includes a flexible substrate; a flexible wiring over the flexible substrate; and a protective layer over the flexible substrate, where the protective layer includes: a first region that overlaps with the flexible wiring and a second region that does not overlap with the flexible wiring as viewed from a thickness direction of the flexible substrate, and a low flexibility part that is higher in flexibility ratio than the first region and is disposed along an extending direction of the flexible wiring in the second region.

Flexible wiring board

A stretchable mounting board that includes a stretchable substrate having a main surface, a stretchable wiring disposed on the main surface of the stretchable substrate, a mounting electrode section electrically connected to the stretchable wiring, solder electrically connected to the mounting electrode section and including bismuth and tin, and an electronic component electrically connected to the mounting electrode section with the solder interposed therebetween. The mounting electrode section has a first electrode layer on a side thereof facing the stretchable wiring and which includes bismuth and tin, and a second electrode layer on a side thereof facing the solder and which includes bismuth and tin. A concentration of the bismuth in the first electrode layer is lower than a concentration of the bismuth in the second electrode layer.

Stretchable mounting board

A stretchable mounting board that includes a mounting electrode section electrically connected to stretchable wiring, and solder electrically connected to the mounting electrode section. The mounting electrode section has a first electrode layer on a side thereof facing the stretchable wiring and which includes bismuth and tin, and a second electrode layer on a side thereof facing the solder and which includes bismuth and tin. A concentration of the bismuth in the first electrode layer is lower than a concentration of the bismuth in the second electrode layer, and the concentration of the bismuth in the second electrode layer is constant along a thickness direction thereof.

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Nagaokakyo, Japan

Ryo Asai