PCB classification

1. Organic materials:

① Phenolic resin: Phenolic resin is also called bakelite, also known as bakelite powder. Originally colorless or yellowish-brown transparent, the market often adds colorants and is red, yellow, black, green, brown, blue and other colors, with particles and powder.

phenolic resin is resistant to weak acid and weak alkali, decomposes in case of strong acid and corrodes in case of strong alkali. Insoluble in water, soluble in organic solvents such as acetone and alcohol. Phenylphenolic aldehyde or its derivatives are obtained by polycondensation. The picture is as follows:

② Glass fiber: Glass fiber (formerly known as: glass fiber in English) is an inorganic non-metallic material with excellent performance. There are many types. The advantages are good insulation, strong heat resistance, good corrosion resistance, and high mechanical strength, but The disadvantage is brittle and poor wear resistance.

, it is made of pyrophyllite, quartz sand, limestone, dolomite, borobalite, and boromite as raw materials through high-temperature melting, wire drawing, winding, weaving and other processes. The diameter of the monofilament is Several microns to more than 20 microns, equivalent to 1/20-1/5 of a hair filament, each bundle of fiber filaments is composed of hundreds or even thousands of monofilaments.

glass fibers are usually used as reinforcing materials in composite materials, electrical insulation materials and thermal insulation materials, circuit substrates and other fields of the national economy. The picture is as follows:

③ Polyimide: polyimide resin is abbreviated as PI, appearance: transparent liquid, yellow powder, brown particles, amber particles, polyimide resin liquid, polyimide resin solution, polyimide resin powder, polyimide resin particles, polyimide resin particles, polyimide resin particles, polyimide resin particles, thermoplastic polyimide resin solution, thermoplastic polyimide resin powder, thermosetting polyimide resin solution, thermosetting polyimide resin powder, thermoplastic polyimide pure resin, thermosetting polyimide pure resin 2. polyimide PI molding method includes: high temperature curing, compression molding, dipping, spraying, calendering, injection molding, extrusion, die casting, coating, casting, lamination, foaming, transfer molding, and compression molding. The picture is as follows:

and our epoxy resin and BT are all organic materials.

2. Inorganic materials:

① Aluminum substrate: Aluminum substrate is a metal-based copper clad laminate with good heat dissipation function. Generally, a single panel is composed of three layers.

are circuit layer (copper foil), insulating layer and metal base layer respectively. Commonly found in LED lighting products. There are positive and negative sides. The white side is welded with LED pins, and the other side is aluminum. Generally, it will contact the heat conductive part after applying heat conductive paste. There are also ceramic substrates and so on. As shown in the figure:

② Copper substrate: Copper substrate is the most expensive metal substrate. Its thermal conductivity is many times better than that of aluminum substrate and iron substrate. It is suitable for heat dissipation and architectural decoration industries of high-frequency circuits, high and low temperature regions and precision communication equipment. As shown in the figure:

and ceramic substrates are all inorganic materials, as long as they take their heat dissipation function.

1. Hard board:

hard board is a kind of board made of PVC. PVC hard board is a widely used product in industry, especially in chemical anti-corrosion industry.

PVC is a kind of resin resistant to acid, alkali and salt. Because of its good chemical properties and relatively low price, it is widely used in chemical industry, building materials, light industry, machinery and other industries. As shown in the figure:

2. Soft board:

soft PVC extrusion board is made by extrusion molding with PVC resin added with plasticizer, stabilizer, etc.

is mainly used for the lining of anti-corrosion equipment such as acid and alkali resistance. It can also be used as a general electrical insulation and sealing gasket material. The operating temperature is -5 to 40 ℃. It can be used as an alternative to rubber sheets and is widely used as a new environmental protection product. As shown in the figure:

3. Soft-hard board:

FPC and PCB gave birth to a new product of hard and soft board. Therefore, the soft and hard bonding board is a flexible circuit board and a hard circuit board, which are combined according to relevant process requirements through pressing and other processes to form a circuit board with FPC characteristics and PCB characteristics. As shown in the figure:

1. Single panel:

single panel is on the most basic PCB, the parts are concentrated on one side and the wires are concentrated on the other side. Because the wires only appear on one side, we call this PCB single-sided.

Because the single panel has many strict restrictions on the design circuit (because there is only one side, the wiring cannot cross and must go around a separate path), only early circuits use this type of board. As shown in the figure:

2. Double-sided panels:

double-sided board is a printed circuit board with copper on both sides, including Top (top layer) and Bottom (bottom layer). Both sides can be wired and welded, with a layer of insulating layer in the middle. It is a commonly used printed circuit board.

can be routed, greatly reducing the difficulty of wiring, so it is widely used. As shown in the figure:

3. Multilayer board:

multi-layer board is generally made by the inner layer pattern first, and then the single-sided or double-sided substrate is made by printing and etching method, which is incorporated into the designated interlayer, and then heated, pressurized and bonded. As for the subsequent drilling It is the same as the plating through-hole method of double-sided board. As shown in the figure:

above is the classification of PCB from three aspects.