94HB/94VO/22F/CEM-1/CEM-3/FR-4：
Details are as follows:
94HB: ordinary paperboard, not fireproof (lowest grade material, die punch, can't make power board);
94V0: flame retardant board (die punch);
22F: single-sided semi-fiberglass plate (die punch);
Cem-1: single-sided fiberglass board (computer drilling is required, no die punching is allowed);
Cem-3: double-sided semi-fiberglass board (except double-sided paperboard, it is the lowest material of double-panel, which can be used for simple double-panel, and it will be 5~10 yuan/square meter cheaper than fr-4);
Fr-4: double sided fiberglass board.
PCB main classification:
I. grade classification of c flame retardant properties can be divided into four types: 94V -- 0 / v-1 / v-2 and 94-hb;
Ii. Semi-cured tablets: 1080=0.0712mm, 2116=0.1143mm, 7628=0.1778mm;
3.FR4 cem-3 is for sheet, FR4 is for glass fiber board, and cem3 is for composite substrate:
Four. Halogen free refers to does not contain halogen (fluorine bromine iodine and other elements) of the substrate, because bromine in combustion will produce toxic gas, environmental protection requirements.
Tg is the glass conversion temperature, the melting point.
Circuit board must be resistant to fire, in a certain temperature can not burn, can only be softened. At this time, the temperature point is called the glass transition temperature (Tg point), which is related to the size stability of the PCB board.
What are the advantages of using high Tg PCB:
When the temperature of high Tg PCB reaches a certain area, the substrate will change from "glass state" to "rubber state", and the temperature at this time is called the glass transition temperature (Tg) of the plate. In other words, Tg is the highest temperature (℃) at which the substrate remains rigid. That is to say, common PCB substrate materials under high temperature, not only produce softening, deformation, melting and other phenomena, but also show in the mechanical, electrical characteristics of the sharp decline (I think we do not want to see the classification of PCB board to see their own products appear in this case). Please do not copy the contents of this site:
Generally, Tg plates are above 130 degrees, high Tg is generally greater than 170 degrees, and medium Tg is about greater than 150 degrees.
PCB printed boards with Tg≥170℃ are usually referred to as high Tg printed boards.
With the improvement of Tg of substrate, the heat resistance, moisture resistance, chemical resistance and stability of PCB will be improved. The higher the TG value, the better the temperature resistance of the plate, especially in lead-free process, the higher the TG application is.
High Tg refers to high heat resistance. With the rapid development of the electronic industry, especially the electronic products represented by the computer, towards the development of high function and high multi-layer, the higher heat resistance of PCB substrate material is needed as an important guarantee. With the emergence and development of high density installation technology represented by SMT and CMT, PCB is more and more inseparable from the support of high heat resistance of substrate in the aspects of small aperture, fine wiring and thin type.
Therefore, the difference between general fr-4 and high Tg fr-4 is that under the hot state, especially under the heat after hygroscopicity, the mechanical strength, dimensional stability, adhesion, water absorption, thermal decomposition, thermal expansion and other conditions of the material are different, and high Tg products are obviously better than ordinary PCB substrate materials.
In recent years, the demand for the production of high Tg PCB customers increased year by year.
PCB knowledge and standards
At present, there are several types of copper-coated plate widely used in China, and their characteristics are shown in the following table: copper-coated plate type, copper-coated plate knowledge.
There are a variety of classification methods of copper-clad sheet. Generally, according to the different reinforcing materials of the board, it can be divided into: paper base, glass fiber PCB board classification cloth base,
There are five types of composite substrates (CEM series), multilayer substrates and special material substrates (ceramic, metal core substrates, etc.). If press board used)
Different resin adhesives are classified as common paper based CCI. Have: phenolic resin (XPc, XxxPC, FR-1,2,etc.), epoxy resin (FE 1,3), polyester resin and other types. The most common type of fiberglass cloth CCL is epoxy resin (FR 1,4, fr-5), which is the most widely used type of fiberglass cloth. In addition, there are other special resins (glass fiber cloth, polyamide fiber, non-woven cloth, etc.) : bismaleimide modified triazine resin (BT), polyimide resin (PI), diphenyl ether resin (PPO), maleic anhydride imide - styrene resin (MS), polycyanate resin, polyolefin resin, etc. According to the classification of CCL flame retardant properties, it can be divided into two types of flame retardant (UL94 - VO, UL94 - V1 class) and non-flame retardant (UL94 - HB class). In the past one or two years, with more attention to environmental protection, a new type of CCL without bromine has been introduced into the flame retardant CCL, which can be called "green flame retardant CCL". With the rapid development of electronic products technology, cCL has higher performance requirements. Therefore, according to the performance classification of CCL, it can be divided into general performance CCL, low dielectric constant CCL, high heat resistance CCL(general plate L above 150℃), low thermal expansion coefficient CCL(generally used in packaging substrate) and other types. With the development and continuous progress of electronic technology, new requirements for PCB substrate materials have been put forward, so as to promote the continuous development of copper-clad plate standards. At present, the main standards of substrate materials are as follows.
At present, China's national standards on the classification of substrate materials PCB board GB/t4721-47221992 and gb4723-4725-1992, the Taiwan area of China's copper foil plate standard for CNS standard, based on the Japanese JIs standard developed in 1983.
Other national standards mainly include: Japanese JIS standard, American ASTM, NEMA, MIL, IPc, ANSI, UL standard, British Bs standard, German DIN, VDE standard, French NFC, UTE standard, Canadian CSA standard, Australian AS standard, former Soviet union FOCT standard, international IEC standard and so on Original PCB design material suppliers, common and commonly used are: shengyi jiantao international and so on Accept document: protel autocad powerpcb orcad gerber or solid board copy board
● plate type: cem-1, cem-3 FR4, high TG material
Maximum panel size: 600mm*700mm(24000mil*27500mil)
Thickness: 0.4mm-4.0mm(15.75mil-157.5mil)
● highest number of layers: 16Layers
Thickness of copper foil: 0.5-4.0(oz)
Thickness tolerance of finished plate: +/-0.1mm(4mil)
Forming dimension tolerance: computer milling: 0.15mm(6mil) die punching plate: 0.10mm(4mil)
Minimum line width/spacing: 0.1mm(4mil) line width control capability: < + -20%
● finished product minimum hole aperture: 0.25mm(10mil)
Finished product minimum punching aperture: 0.9mm(35mil)
Finished product aperture tolerance: PTH: +-0.075mm(3mil)
NPTH: + 0.05 mm (2 mil)
● copper thickness of finished hole wall: 18-25um (0.71-0.99mil)
Minimum SMT patch spacing: 0.15mm(6mil)
● surface coating: chemical precipitation, tin spraying, whole plate nickel plating (water/soft gold), silk screen blue glue
Thickness of resistance welding film on plate: 10-30 mm (0.4-1.2mil)
● stripping strength: 1.5n /mm (59N/mil)
● resistance welding film hardness: BBB 0 5H
Resistance welding plug hole capacity: 0.3-0.8mm(12mil-30mil)
● dielectric constant: = 2.1-10.0
Low insulation resistance: 10 k Ω Ω - 20 m
● characteristic impedance: 60 ohm± 10%
● thermal shock: 288℃, 10 SEC
● finished sheet warping: < 0.7%
Product application: communication equipment, automotive electronics, instrumentation, global positioning system, computer, MP4, power supply, home appliances, etc.