Resin multilayer substrate and method for manufacturing resin multilayer substrate

A resin multilayer substrate comprising:

• a substrate having a plurality of laminated resin layers,
• wherein the plurality of laminated resin layers include a plurality of first resin layers and a second resin layer, where at least one first resin layer of the plurality of first resin layers is bonded to the second resin layer, and the plurality of first resin layers comprise a norbornene-based polymer having at least one repeating unit represented by the following formula (1):
• where
• X represents O, —CH2—, or —CH2—CH2—,
• each of substituents R1, R2, R3, and R4 represents (1) hydrogen, (2) a linear or branched organic group, or (3) a group containing a group selected from derivatives in which a part of the linear or branched organic group is substituted with a halogen or nitrile group,
• wherein the linear or branched organic group is:
• an organic group containing an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, an alkoxysilyl group, or an epoxy group, an organic group containing an ether group, an organic group containing a (meth)acrylic group, an organic group containing an ester group, or an organic group containing a ketone group, and these groups may be bonded through an alkyl group, an ether group, or an ester group and may be the same as or different from each other,
• m is an integer of 10 to 10,000, and
• n1 is an integer of 0 to 5, and
• an adhesion of the second resin layer to the at least one first resin layer is higher than an adhesion between the plurality of first resin layers.

A method for manufacturing a resin multilayer substrate, the method comprising:

• forming a substrate by laminating a plurality of resin layers together,
• wherein the plurality of resin layers include two first resin layers adjacent to each other in a lamination direction among the plurality of laminated resin layers, the two first resin layers each comprising a norbornene-based polymer having at least one repeating unit represented by the following formula (1):
• where
• X represents O, —CH2—, or —CH2—CH2—,
• each of substituents R1, R2, R3, and R4 represents (1) hydrogen, (2) a linear or branched organic group, or (3) a group containing a group selected from derivatives in which a part of the linear or branched organic group is substituted with a halogen or nitrile group,
• wherein the linear or branched organic group is:
• an organic group containing an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, an alkoxysilyl group, or an epoxy group, an organic group containing an ether group, an organic group containing a (meth)acrylic group, an organic group containing an ester group, or an organic group containing a ketone group, and these groups may be bonded through an alkyl group, an ether group, or an ester group and may be the same as or different from each other,
• m is an integer of 10 to 10,000, and
• n1 is an integer of 0 to 5, and
• reacting the norbornene-based polymer of at least one of the two first resin layers with an additive by a surface treatment to generate a gradient in a composition of the at least one of the two first resin layers between a material before the reaction and the material after the reaction in a thickness direction according to attenuation of an effect of the surface treatment.