PCB Tech - Classification of PCB materials

what is the material PCB? The usual answer is FR4. Well, when I don't ask, I still don't know what the material is. Therefore, it is necessary to popularize the relevant classification of PCB materials, which is only based on some common applications.

The PCB material we mentioned usually refers to the base material. It is actually composed of copper foil and adhesive sheet (for convenience of introduction, we temporarily use p sheet and prepreg), and copper foil and P sheet have many classifications according to different applications. Today, we only introduce some resin systems related to FR4, and then introduce other resin systems according to the situation.

FR4 is a kind of epoxy or modified epoxy resin as adhesive and glass fiber cloth as reinforcing material, that is, as long as the material of this system can be called FR4, so FR4 is the general name of this resin system. At present, the printed boards using FR4 material are the largest and most used printed boards in the world. Now I know why someone answered that using FR4 actually doesn't know which PCB material to use!

PCB material

Generally, FR4 is classified according to the following types.

1. Name and classification according to glass fiber cloth weaving

106, 1067, 1080, 1078, 2116, 2113, 3313, 7628, etc

These are the types of commonly used glass cloth. Of course, there are others. Each kind of glass cloth is defined in the IPC specification. Therefore, the same type of glass cloth used by different manufacturers basically has little difference, because there are many glass cloth manufacturers, but the same type of glass cloth provided by different manufacturers must meet the requirements of the IPC specification.

2. Classification by glass type

E-glass: e stands for electrical, which means electrically insulating glass. It is a kind of calcium aluminosilicate glass with little alkali metal oxide (generally less than 1%), so it is also called alkali free glass with high resistivity. E-glass has become the most commonly used component of glass fiber. If there is no special designation, E-glass is generally used for many materials.

NE glass: also known as low DK glass, it is a low dielectric fiber glass developed by Japan's Nitto Textile Co., Ltd. with its dielectric constant ε( 1MHz) is 4.6 (E glass is 6.6), loss factor Tan δ( 1MHz) is 0.0007 (E glass is 0.0012), and common ne glass materials such as m7ne, it968se and it988gse.

3. Classification according to the resin system used by the supplier and its properties

Lianmao iteq: it180a / it170gra1 / it958g / it968 / it968se / it988gse

Taiyao TUC: Tu 862hf / tu872lk / tu872slk / tu872slk-sp / tu883 / tu933+

Panasonic Panasonic: megtron4 / M4S / megtron6 / M6G / m7e / m7ne

Park meteorwave series: mw1000 / 2000 / 3000 / 4000 / 8000

Shengyi: s1000-2 (m) / s7439 / S6 / sh260, etc

Rogers: ro4003 / ro3003 / ro4350b / rt5880 / rt5870/ ro6006 / ro3010 (radio frequency material), etc;

isola: isola 370hr / isola fr408

4. Classification by loss level

It can be divided into ordinary loss materials (DF ≥ 0.02), medium loss materials (0.01 < DF < 0.02), low loss materials (0.005 < DF < 0.01), ultra-low loss materials (DF < 0.005), etc. These are classified according to the DF value of materials. The classification here is extensive and only a general classification. Different people may have different classification ranges.

5. Classification according to flame retardancy

Flame retardant (ul94-vo, ul94-v1) and non flame retardant (ul94-hb)

Of course, there are other classifications. Back to our previous question, what PCB materials do you usually use? I would like to hear the material name corresponding to the resin system and performance used by a supplier, such as it180a / s1000-2 / it968 / M4S, etc. According to different losses and material names of different manufacturers, we have made the following material pyramid, which is mainly based on the common medium and high-speed materials with less loss than ordinary FR4, while ordinary FR4, such as it180a, s1000-2 / m, tu752 / 768, basically have little difference in these DF, which are also the most used hi TG PCBmaterial.