The diversification of PCB in materials, layers, and processes is suitable for different electronic products and their special needs, so its types are relatively diverse. Here are some generic ways to distinguish PCBs, and we can also introduce their classification and manufacturing processes at the same time. Next, let’s analyze it from three aspects.
① Phenolic resin: Phenolic resin, also known as bakelite or bakelite powder. It is originally colorless or yellow brown transparent material, but because of the coloring agents, it is often sold in the market with colors which are red, yellow, black, green, brown, blue, etc., and in the form of granules or powders.
Phenolic resin is resistant to weak acids and bases, decomposes when exposed to strong acids, and corrodes when exposed to strong bases. Insoluble in water, soluble in organic solvents such as acetone and alcohol. It is obtained by condensation of phenolic aldehyde or its derivatives. The picture is as follows.
② Glass Fibre: Glass fiber is an excellent inorganic non-metallic material with a wide variety of properties. Its advantages include good insulation, strong heat resistance, good corrosion resistance, high mechanical strength, but its disadvantages are brittleness and poor wear resistance.
In order to obtain it, we need seven types of ores, including pyrophyllite, quartz sand, limestone, dolomite, boron calcium stone, and boron magnesium stone, then we should go through some processes such as high-temperature melting, drawing, winding, and weaving. The diameter of its single filament ranges from several micrometers to over twenty micrometers, which is equivalent to 1/20-1/5 of a single hair thread. Each bundle of fiber precursor is composed of hundreds or even thousands of single filaments.
Fiberglass is commonly used as a reinforcing material in composite materials, electrical insulation materials, insulation materials, circuit boards, and other fields of the national economy. The picture is as follows.
③ Polyimide: Polyimide resin can be abbreviated as PI, it’s appearance include transparent liquid, yellow powder, brown particles, amber particles, and its types include Polyimide resin liquid, polyimide resin solution, polyimide resin powder, 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.
The forming methods of polyimide include: high temperature curing, compression molding, impregnation, spraying, rolling, injection molding, extrusion, die-casting, coating, casting, lamination, foaming, transfer molding, and compression molding. The picture is as follows.
In addition to the above-mentioned materials, epoxy resin and BT are all organic materials.
① Aluminum PCB: Aluminum PCB is a metal based copper-clad plate with good heat dissipation function, and generally a single panel is composed of a three-layer structure.
These are the circuit layer (copper foil), insulation layer, and metal substrate. It can be typically found in LED lighting products. Aluminum plate has two sides, and the white side is for soldering LED pins, while the other side, exhibiting the natural aluminum color, is typically coated with a thermal paste for direct contact with the heat-conductive components. The picture is as follows.
② Copper PCB: Copper PCB are the most expensive among metal plates, boasting significantly superior thermal conductivity compared to aluminum and iron substrates. They are ideal for high-frequency circuits, areas subject to extreme temperature fluctuations, and the cooling and building decoration industry. The picture is as follows.
Ceramic PCB are also inorganic materials, mainly used for their heat dissipation function.
Rigid PCB a type of board made from PVC which is as the raw material.
PVC hard board is a widely used product in industry, especially in the chemical anti-corrosion industry. PVC is a resin that is resistant to acid, alkali, and salt. Due to its excellent chemical properties and relatively low price, it is widely used in various industries such as chemical, building materials, light industry, and machinery. The picture is as follows.
Flex PCB is made by polyvinyl chloride resin with plasticizers and stabilizers.
It is mainly used as a lining for corrosion-resistant equipment such as acid and alkali, and can also be used as a general electrical insulation and sealing gasket material. The operating temperature is -5℃ to +40℃, and it can be used as a substitute product for rubber sheets. It is a new environmentally-friendly product with a wide range of uses. The picture is as follows.
The birth and development of flex PCB and rigid PCB have given rise to the new product of soft hard bonding boards. Therefore, the Rigid-Flex Printed Board refers to the combination of flexible circuit boards and hard circuit boards, which are pressed together according to relevant process requirements, forming a circuit board with FPC and PCB characteristics. The picture is as follows.
The Single-Sided PCB is on the most basic PCB, with parts concentrated on one side and wires concentrated on the other side. Because the wires only appear on one side, we call this type of PCB Single-Sided PCB.
Because Single-Sided PCB have many strict limitations in designing circuits (as they only have one side, wiring cannot cross and must take separate paths), only early circuits used such boards. The picture is as follows.
Double-Sided PCB is a type of printed circuit board that includes both the top and bottom layers, with copper coated on both sides. Both sides can be wired and soldered, and there is an insulation layer in the middle. It is a commonly used type of printed circuit board.
Because it’s both sides can be wired, which greatly reducing the difficulty of wiring, it is widely adopted. The picture is as follows.
The production method of Multi Layer PCB generally starts with the inner layer graphics, and then uses printing and etching to make a single-sided or double-sided substrate, which is included in the designated interlayer, and then heated, pressurized, and bonded. The subsequent drilling is the same as the plating through hole method of Double-Sided PCB. The picture is as follows.