Wiring board and method for manufacturing wiring board

A wiring board comprising:

• a stretchable portion having stretchability and having a first surface and a second surface opposite to the first surface, the stretchable portion including
• a plurality of first regions lined up in each of a first direction and a second direction that intersects the first direction and each including a first member,
• a plurality of second regions including first portions and second portions and including a second member having a lower modulus of elasticity than the first member, the first portion extending from one of two first regions neighboring each other in the first direction to the other of the two first regions among the plurality of first regions, the second portion extending from one of two first regions neighboring each other in the second direction to the other of the two first regions among the plurality of first regions, and
• a third region surrounded by the second regions;
• an interconnection wire located adjacent to the first surface of the stretchable portion, the interconnection wire overlapping at least the second region when viewed in a direction normal to the first surface of the stretchable portion;
• a support portion located between the interconnection wire and the first surface of the stretchable portion, wherein the support portion has a crest portion and a valley portion respectively corresponding to a crest portion and a valley portion of an undulating portion of the interconnection wire, and the support portion supports the interconnection wire;
• and
• an adhesive layer that joins the stretchable portion to the support portion.

A wiring board on which electronic components are mountable, the wiring board comprising:

• a stretchable portion having stretchability and having a first surface and a second surface opposite to the first surface, the stretchable portion including
• a plurality of first regions lined up in each of a first direction and a second direction that intersects the first direction,
• a plurality of second regions including first portions and second portions, the first portion extending from one of two first regions neighboring each other in the first direction to the other of the two first regions among the plurality of first regions, the second portion extending from one of two first regions neighboring each other in the second direction to the other of the two first regions among the plurality of first regions, and
• a third region surrounded by the second regions,
• the first regions overlapping the electronic components mounted on the wiring board when viewed in a direction normal to the first surface of the stretchable portion,
• the second regions having a lower modulus of elasticity than the first region;
• and
• an interconnection wire located adjacent to the first surface of the stretchable portion, the interconnection wire being electrically connected to the electronic components mounted on the wiring board, the interconnection wire overlapping the second region when viewed in the direction normal to the first surface of the stretchable portion, wherein
• the stretchable portion includes a first member located in the first region and a second member that overlaps the first member in the first region and extends over the first regions and the second regions,
• the second member has a lower modulus of elasticity than the first member,
• the stretchable portion further includes an adhesive layer located between the interconnection wire and the second member, and
• the first member of the stretchable portion is located closer to the interconnection wire than a surface of the second member adjacent to the interconnection wire and is in contact with the adhesive layer in an in-plane direction of the wiring board.

A method for manufacturing a wiring board on which electronic components are mountable, the method comprising:

• a step of preparing a stretchable portion having stretchability and having a first surface and a second surface opposite to the first surface, the stretchable portion including a plurality of first regions lined up in each of a first direction and a second direction that intersects the first direction, a plurality of second regions including first portions and second portions, and a third region surrounded by the second region, the first regions overlapping the electronic components mounted on the wiring board when viewed in a direction normal to the first surface of the stretchable portion, the second region having a lower modulus of elasticity than the first region, the first portion extending from one of two first regions neighboring each other in the first direction to the other of the two first regions among the plurality of first regions, the second portion extending from one of two first regions neighboring each other in the second direction to the other of the two first regions among the plurality of first regions;
• a stretch step of stretching the stretchable portion by applying tensile stress to the stretchable portion in at least two of in-plane directions of the first surface of the stretchable portion;
• a wiring step of disposing, on the first surface of the stretchable portion that is stretched, an interconnection wire to be electrically connected to the electronic components mounted on the wiring board such that the interconnection wire overlaps the second region when viewed in the direction normal to the first surface of the stretchable portion, wherein the wiring step includes joining a support portion, on which the interconnection wire is disposed, to the first surface of the stretchable portion that is stretched;
• and
• a contraction step of removing the tensile stress from the stretchable portion.