Introduction to PCB substrate

Classification of substrates

General printed board substrate materials can be divided into two categories: rigid substrate materials and flexible substrate materials. An important type of general rigid substrate material is copper clad laminate. It is made of Reinforeing Material, impregnated with resin binder, dried, cut and laminated into blank, then covered with copper foil, using steel sheet as a mold, and processed by high temperature and high pressure in a hot press. General multilayer semi-cured sheet, is copper clad in the production process of semi-finished products (mostly glass cloth soaked in resin, through drying processing).

There are various classification methods for copper clad laminate. Generally, according to the different reinforcement materials of the board, it can be divided into five categories: paper base, glass fiber cloth base, composite base (CEM series), laminated multilayer board base and special material base (ceramics, metal core base, etc.). If the board used by different resin adhesives for classification, 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. The common CCL is epoxy resin (FR-4, FR-5), which is the most widely used type of glass fiber cloth. In addition, there are other special resins (glass fiber cloth, polyamide fiber, non-woven cloth, etc., as added materials) : bismaleimide modified trizine resin (BT), polyimide resin (PI), diphenyl ether resin (PPO), maleic anhydride imide — styrene resin (MS), polycyanate ester resin, polyolefin resin, etc.

According to the flame retardant performance of CCL, it can be divided into flame retardant type (UL94-VO, UL94-V1) and non-flame retardant type (Ul94-HB). In the past 12 years, as more attention has been paid to environmental protection, a new type of flame-retardant CCL without bromine has been separated, which can be called “green flame-retardant CCL”. With the rapid development of electronic product technology, cCL has higher performance requirements. Therefore, from the CCL performance classification, and divided into general performance CCL, low dielectric constant CCL, high heat resistance CCL(general plate L in 150℃ above), low thermal expansion coefficient CCL(generally used on the packaging substrate) and other types.

 

Standard of substrate implementation

With the development and continuous progress of electronic technology, new requirements are constantly put forward for printed board substrate materials, so as to promote the continuous development of copper clad plate standards. At present, the main standards for substrate materials are as follows.
1) National Standards for Substrates At present, The national standards for substrates in China include GB/T4721 — 4722 1992 and GB 4723 — 4725 — 1992. The standard for copper clad laminates in Taiwan region of China is the CNS standard, which is based on the Japanese JIs standard and was issued in 1983.

With the development and continuous progress of electronic technology, new requirements are constantly put forward for printed board substrate materials, so as to promote the continuous development of copper clad plate standards. At present, the main standards for substrate materials are as follows.
1) National Standards for Substrates At present, China’s national standards for substrates include GB/T4721 — 4722 1992 and GB 4723 — 4725 — 1992. The standard for copper clad laminates in Taiwan region of China is the CNS standard, which is based on the Japanese JIs standard and was issued in 1983.
2) Other national standards include Japanese JIS standard, American ASTM, NEMA, MIL, IPc, ANSI and UL standard, British Bs standard, German DIN and VDE standard, French NFC and UTE standard, Canadian CSA standard, Australian AS standard, FOCT standard of the former Soviet Union, and international IEC standard

The national standard name summary standard is referred to as the department of standard name formulation
JIS- Japan Industrial Standard – Japan Specification Association
ASTM- American Society for Laboratory Materials Standards -American Society fof Testi ‘ng and Materials
NEMA- National Association of Electrical Manufactures Standard -Nafiomll Electrical Manufactures
MH- United States Military Standards -Department of Defense Military Specific Tions and Standards
IPC- American Circuit Interconnection and Packaging Association Standard -The week true for Interoonnecting and Packing EIectronics Circuits
ANSl- American National Standard Institute


Post time: Dec-04-2020

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