Substrate having insulating layers to prevent it from warping and the method of making the same

Abstract

A substrate has a substrate member, which is made of a polar material, such as Polymethyl methacrylate (PMMA), Methyl methacrylate/Styrene copolymer (MS) or Polycarbonate (PC), having a first side and a second side. On the fist side and the second side of the substrate member provided with an insulating layers respectively, wherein the insulating layers are made of a non-polar material with a low water absorption, such as Cyclic Olefin Polymer (COP) or Cyclic Olefin Copolymer (COC). The water absorption of COP or COC is less than the water absorption of PMMA, MS or PC to prevent the substrate member from warping while the substrate is heated at a single side. Two adhesive layers, which is made of a material with a chemical structure with a non-polar segment and a polar segment, such as olefin/acrylate copolymer, to bond the insulating layers on the substrate member.

Dependencies are inferred from the claim text.