How many materials are used for circuit board?
Visit:1570 Date:2020-08-24

Generally, substrate materials for printed boards can be divided into two categories: rigid substrate materials and flexible substrate materials. Generally, an important variety of rigid substrate materials is copper clad laminate. It is made of reinforced material (Reinforeing Material), impregnated with resin adhesive, dried, cut, and laminated into a blank, then covered with copper foil, steel plate is used as a mold, and processed by high temperature and high pressure forming in a hot press Into. The prepregs used for general multilayer boards are semi-finished products in the production process of copper clad laminates (mostly glass cloth is impregnated with resin and processed by drying).
There are many ways to classify copper clad laminates. Generally, according to the different reinforcing materials of the board, it can be divided into five categories: paper base, glass fiber cloth base, composite base (CEM series), multi-layer laminate base and special material base (ceramic, metal core base, etc.). If it is classified according to the different resin adhesives used in the board, the common paper-based CCI. There are: phenolic resin (XPc, XxxPC, FR-1, FR-2, etc.), epoxy resin (FE-3), polyester resin and other types. Common glass fiber cloth base CCL has epoxy resin (FR-4, FR-5), which is currently the most widely used glass fiber cloth base type. In addition, there are other special resins (glass fiber cloth, polyamide fiber, non-woven fabric, etc.): bismaleimide modified triazine resin (BT), polyimide resin (PI) , Diphenylene ether resin (PPO), maleic anhydride imine-styrene resin (MS), polycyanate resin, polyolefin resin, etc.
According to the classification of CCL's flame-retardant performance, it can be divided into two types of flame-retardant (UL94-VO, UL94-V1) and non-flame-retardant (UL94-HB). In the past one or two years, with more attention to environmental issues, a new type of CCL that does not contain bromine has been classified in flame-retardant CCL, which can be called "green flame-retardant cCL". With the rapid development of electronic product technology, there are higher performance requirements for cCL. Therefore, from the performance classification of CCL, it is divided into general performance CCL, low dielectric constant CCL, high heat resistance CCL (normal board L is above 150 ℃), low thermal expansion coefficient CCL (usually used on package substrates) ) And other types.