Abstract: A resin sheet that contains one or more kinds of resin materials and a liquid crystal polymer, wherein a weight of the liquid crystal polymer is less than a total weight of the one or more kinds of resin materials. The resin sheet has a thermal expansion coefficient in a plane direction smaller than a thermal expansion coefficient in the plane direction of a comparative resin sheet containing the one or more kinds of resin materials and not containing the liquid crystal polymer.

Abstract: A resin multilayer substrate that includes a substrate having a plurality of laminated resin layers containing a norbornene-based polymer. A resin layer has an altered portion altered by a surface treatment and formed at an interface with a resin layer adjacent thereto in a lamination direction. An adhesion at an interface having the altered portion is greater than an adhesion at an interface with a non-altered portion.