Composite substrate and manufacturing method thereof

A method for manufacturing a composite substrate, comprising:

• stacking a first fluoropolymer layer, a liquid crystal polymer layer, and a second fluoropolymer layer in a bottom-to-top sequence, wherein the first fluoropolymer layer and the second fluoropolymer layer independently comprise:
• 30 parts by weight to 50 parts by weight of a fluoropolymer;
• 1 part by weight to 5 parts by weight of a dispersant;
• 1 part by weight to 10 parts by weight of a plurality of inorganic particles;
• and
• 1 part by weight to 5 parts by weight of a macromolecule resin, wherein the macromolecule resin is different from the fluoropolymer;
• and
• performing a heating process to bond the first fluoropolymer layer, the liquid crystal polymer layer, and the second fluoropolymer layer, wherein a temperature of the heating process is 200° C. to 400° C. or a glass transition temperature of the fluoropolymer to a melting point of the fluoropolymer +40° C.