PCB News - There are some things I have to say about PCB circuit boards

There are some things I have to say about PCB circuit boards

PCB circuit board plates, also called copper clad laminates, are the key basic materials for the production of printed circuit boards; only based on good plates can high-quality PCB circuit board products be produced. Regarding PCB board, some things have to be said...

1. The manufacturing process of the plate:

1. Solvents, hardeners, accelerators, resins, etc. are adjusted and blended and mixed with reinforcing materials such as glass fiber cloth to form a film;

2. After the film inspection procedure, cut and stack the pieces, and then add copper foil, after hot pressing, cutting, inspection and cutting, the copper foil substrate is finally made.

Second, the classification of plates

1. According to the different reinforcing materials of the board, it can be divided into five categories: paper base, glass fiber cloth base, composite base, multi-layer laminate base and special material base (ceramic, metal core base, etc.).

2. According to the different resin adhesives used in the board, it can be classified as follows:

(1) Common paper-based CCI: phenolic resin (XPc, XxxPC, FR-1, FR-2, etc.), epoxy resin (FE-3), polyester resin, etc.;

(2) Common glass fiber cloth base CCL: epoxy resin (FR-4, FR-5).

(3) Other special resins (with glass fiber cloth, polyamide fiber, non-woven fabric, etc. as additional materials): bismaleimide modified triazine resin (BT), polyimide resin (PI), Diphenylene ether resin (PPO), maleic anhydride imine-styrene resin (MS), polycyanate resin, polyolefin resin, etc.

3. According to the classification of CCL's flame-retardant performance, it can be divided into two types: flame-retardant (UL94-VO, UL94-V1) and non-flame-retardant (UL94-HB).

In recent years, as more attention is paid to environmental protection issues, a new type of non-bromine-free CCL has been divided into flame-retardant CCL, which can be called "green flame-retardant CCL".

4. According to 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 degree Celsius), low thermal expansion coefficient CCL (usually used on package substrates) ) And other types.

Three, the main standard of the board

1. National standard: GB/T4721-47221992 and GB4723-4725-1992, China Taiwan standard: CNS.

2. International standards: JIS (Japanese Standard), ASTM, NEMA, MIL, IPc, ANSI, UL (American Standard), Bs (British Standard), DIN, VDE (German Standard), NFC, UTE (French Standard), CSA (Canadian Standard), AS (Australian Standard), IEC (International Standard), etc.

Four, detailed explanation of the parameters of the plate

1. PCB board suppliers, common and commonly used ones are: Shengyi \ Kingboard \ International, etc.

2. PCB board introduction: According to the brand quality level from low to high, it is divided as follows: 94HB-94VO-CEM-1-CEM-3-FR-4.

3. The detailed parameters and uses are as follows:

(1) 94HB: ordinary cardboard, not fireproof (the lowest grade material, die punching, can not be used as a power supply board);

(2) 94V0: flame-retardant cardboard (punched by die);

(3) 22F: Single-sided half glass fiber board(die punching);

(4) CEM-1: Single-sided fiberglass board (computer drilling is necessary, not die punching)

(5) CEM-3: Double-sided half glass fiber board(simple double-sided board can use this material)

(6) FR-4: Double-sided glass fiber board.

a. The classification of flame retardant properties can be divided into four types: 94VO-V-1 -V-2 -94HB;

b. Semi-cured film: 1080=0.0712mm, 2116=0.1143mm, 7628=0.1778mm;

c. FR4 and CEM-3 all mean sheet material, FR4 is glass fiber board, and cem3 is composite substrate;

d. Halogen-free refers to the base material that does not contain halogen (fluorine, bromine, iodine and other elements), because bromine will produce toxic gas when burned, environmental protection requirements;

e. Tg is the glass transition temperature, that is, the melting point; this value is related to the dimensional durability of the PCB board.

The above are some things that have to be said about PCB boards. With the development and continuous progress of electronic technology, new requirements are continuously put forward for PCB boards, thereby promoting the continuous development of PCB board-copper clad laminate standards. In order to ensure the stability, durability, and safety of PCB circuit board production, please be sure to choose a board that meets national (international) standards.