Substrate selection: High purity PS, PC, PET roll sheets are commonly used, and the selection is based on the product's suitability for the scene. PS material is suitable for conventional small and medium-sized surface mount components, PC material is suitable for deep cavity, high-strength, and bending resistant scenarios, and PET material is suitable for high transparency and high toughness precision packaging scenarios. All substrates must be scratch free, bubble free, impurity free, uniform in thickness, and meet batch performance consistency standards.