PCB Technical - PCB board specific those types?

PCB board specific those types?

From bottom to top, the grade is divided as follows:

94HB, 94vo circuit board, 22F, CEM-1, CEM-3, FR-4

Detailed introduction is as follows:

94HB: Plain cardboard, not fireproof (lowest grade material, die punching, no power board)

94V0: Flame retardant cardboard (die punching)

22F: Single-sided semi-fiberglass board (die punching)

CEM-1: Single-sided fiberglass board (must be computer drilling, not die punching)

CEM-3: double-sided half fiberglass board (in addition to double-sided cardboard belongs to the lowest end of the double panel material, simple double panel can use this material, than FR-4 will be cheaper 5~10 yuan/square meter)

Fr-4: Double-sided fiberglass board

A. C flame retardant properties can be divided into 94vo circuit board /V-1 /V-2, 94-HB four

Two. Semi-cured tablets: 1080=0.0712mm, 2116=0.1143mm, 7628=0.1778mm

Three.FR4 CEM-3 is the board, FR4 is a fiberglass board, CEM3 is a composite substrate

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

6.Tg is the glass conversion temperature, or melting point.

The circuit board must be flame resistant, not burn at a certain temperature, only soften. At this time the temperature point is called the glass state conversion temperature (Tg point), this value is related to the size stability of PCB board.

94HB board is what board?

Ordinary cardboard, not fireproof (the lowest grade material, die punching, can not be used as power board)

What standard is 94V0?

94V0 refers to the combustion of materials, also known as flame retardant, self-extinguishing fire resistance, flame retardant, fire resistance, flammability and other combustibility is to assess the ability of materials to resist combustion.

The combustible material sample is ignited with a flame conforming to the requirements, and the flame is removed within a specified time. The combustibility grade is graded according to the degree of combustion of the sample, which is divided into three levels.

Horizontal placement of samples is the horizontal test method, which is divided into FH1,FH2 and FH3 levels. Vertical placement of samples is the vertical test method, which is divided into FV0,FV1 and VF2 levels.

Solid PCB board has HB board and V0 board.

HB plate has low flame retardancy and is mostly used for single panel.

VO plate high flame retardant, mostly used for double panel and multi - layer board

94V0 is only a flame retardant standard for UL

This type of PCB that meets the requirements of THE V-1 fire rating becomes FR-4.

V-0,V-1, and V-2 are rated for fire protection.

What is a high Tg PCB circuit board? What are the advantages of using a high Tg PCB?

High Tg printed board When the temperature rises to a certain area, the substrate will change from "glass state" to "rubber state", this temperature is called the glass transition temperature (Tg) of the board. That is, Tg is the maximum temperature (° C) at which the substrate remains rigid. That is to say, ordinary PCB substrate material at high temperature, not only softening, deformation, melting and other phenomena, but also in the mechanical and electrical characteristics of the sharp decline (I think we do not want to see the classification of PCB board to see their own products this situation).

General Tg plate is more than 130 degrees, high Tg is generally more than 170 degrees, medium Tg is about more than 150 degrees.

Usually Tg≥170 degree Celsius PCB printed board, called high Tg printed board.

The Tg of the substrate is increased, and the heat resistance, moisture resistance, chemical resistance, stability and other characteristics of the printed board will be improved and improved. The higher the TG value, the better the temperature resistance of the plate, especially in the lead-free process, high TG is used more.

High Tg refers to high heat resistance. With the rapid development of the electronic industry, especially the electronic products represented by computers, towards the development of high function, high multilayer, need PCB substrate material's higher heat resistance as an important guarantee. The emergence and development of high density installation technology represented by SMT and CMT make PCB more and more inseparable from the support of high heat resistance of substrate in terms of small aperture, fine line and thin type.

Therefore, the difference between general FR-4 and high Tg FR-4 is that the mechanical strength, dimensional stability, bonding, water absorption, thermal decomposition, thermal expansion and other conditions of the material are different under the thermal state, especially under the heat after hygroscopic, and high Tg products are significantly better than ordinary PCB substrate materials.

In recent years, the demand of high Tg PCB production customers increased year by year.

PCB board knowledge and standard

At present, there are several types of copper plate widely used in China, whose characteristics are shown in the following table: copper plate type, copper plate knowledge

There are various classifications of copper clad laminates. Generally, according to the different reinforcement materials of the board, it can be divided into: paper based, glass fiber PCB classification cloth,

Composite substrate (CEM series), laminated laminated plate base and special material base (ceramic, metal core base) five categories. If the board by the use of _)(^%T resin adhesive different classification, 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 CCL epoxy resin (FR 4, FR-5), it is currently the most widely used glass fiber cloth 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), diphenyl ether resin (PPO), maleic anhydride imine - styrene resin (MS), polycyanate resin, polyolefin resin, etc. According to the classification of flame retardant properties of CCL, it can be divided into two types: flame retardant (UL94-VO, UL94-V1) and non-flame retardant (UL94-HB). In recent one or two years, with more attention paid to environmental protection, a new type of non-bromine CCL was identified among the flame retardant CCL, which can be called "green flame retardant CCL". With the rapid development of electronic product technology, cCL has higher performance requirements. Therefore, according to the performance classification of CCL, CCL can be divided into general performance CCL, low dielectric constant CCL, high heat resistance CCL(the L of general plate is above 150 degree Celsius), low thermal expansion coefficient CCL(generally used on the packaging substrate) and other types. With the development and continuous progress of electronic technology, new requirements for PCB substrate materials are put forward constantly, thus promoting the continuous development of copper clad laminate standards. At present, the main standards for substrate materials are as follows.

At present, China's national standards for the classification of PCB substrate materials are GB/T4721-47221992 and GB4723-4725-1992. The Taiwan copper clad laminate standard is CNS standard, which is based on The Japanese JIs standard and was issued in 1983.

2.  Other national standards are mainly: 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, FOCT standard of the former Soviet Union, international IEC standard, etc

The suppliers of original PCB design materials are: Shengyi, Jiantao, International and so on

. Accepted files: Protel autocad powerPCB OrCAD Gerber or solid board copy, etc

. Plate type: CEM-1,CEM-3 FR4, high TG material;

. Maximum panel size: 600mm700mm(24000mil27500mil)

. Processing plate thickness: 0.4mm-4.0mm(15.75mil-157.5mil)

. the highest number of processing layers: 16Layers

Thickness of copper foil layer: 0.5-4.0(oz)

Thickness tolerance of finished plate: +/-0.1mm(4mil)

Molding size tolerance: computer milling: 0.15mm(6mIL) Die punching plate: 0.10mm(4MIL)

. Minimum line width/spacing: 0.1mm(4mil) Line width control ability: < ± 20%

. Minimum drilling aperture of finished product: 0.25mm(10mil)

Minimum punching aperture for finished product: 0.9mm(35mil)

Finished aperture tolerance: PTH: ±0.075mm(3mil)

NPTH: + / - 0.05 mm (2 mil)

. Finished wall copper thickness: 18-25um (0.71-0.99mil)

Minimum SMT pitch: 0.15mm(6mil)

. Surface coating: chemical precipitation gold, tin spray, whole plate nickel plated gold (water/soft gold), silk screen blue glue, etc

Thickness of solder film on the plate: 10-30μm(0.4-1.2mil)

. Stripping strength: 1.5n /mm (59N/mil)

Hardness of solder film: > 5H

Welding resistance plug hole capacity: 0.3-0.8mm(12mil-30mil)

. Medium constant: ε= 2.1-10.0

. Insulation resistance: 10K ω -20m ω

Characteristic impedance: 60 ohm± 10%

. Thermal shock: 288 degree Celsius, 10 SEC

. Finished plate warping: < 0.7%

. Application: communication equipment, automotive electronics, instrumentation, global positioning system, computer, MP4, power supply, home appliances, etc

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 laminated board base and special material base (ceramic, metal core base, etc.).

If the resin adhesive used by the board is different classification, 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 CCL epoxy resin (FR 4, FR-5), it is currently the most widely used glass fiber cloth 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), diphenyl ether resin (PPO), maleic anhydride imine - styrene resin (MS), polycyanate resin, polyolefin resin, etc. According to the classification of flame retardant properties of CCL, it can be divided into two types: flame retardant (UL94-VO, UL94-V1) and non-flame retardant (UL94-HB).

In recent one or two years, with more attention paid to environmental protection, a new type of non-bromine CCL was identified among the flame retardant CCL, which can be called "green flame retardant CCL". With the rapid development of electronic product technology, CCL has higher performance requirements. Therefore, according to the performance classification of CCL, CCL can be divided into general performance CCL, low dielectric constant CCL, high heat resistance CCL(the L of general plate is above 150 degree Celsius), low thermal expansion coefficient CCL(generally used on the packaging substrate) and other types.

The classification of flame retardant properties can be divided into 94V0, V-1, V-2, 94HB four.Semi-cured tablets: 1080=0.0712mm, 2116=0.1143mm, 7628=0.1778mm

FR4 CEM-3 board, FR4 fiberglass board, CEM3 is a composite substrate