PCB Fabrication Materials
Although there is a wide variety available, all PCB fabrication materials are supposed to meet some standard criteria. The properties needed include high dielectric properties, low flammability in laminated plates, high conductivity for materials used on connecting components together etc. We will describe the most used PCB fabrication materials individually in the paragraphs below.
Copper-- is the metal used for conducting lines serving power and signal connections. Copper has a very high electrical conductivity and is relatively cheap.
Fiberglass-- is a fiber reinforced plastic used as an insulating material. It also had rigid property and is quite resistant to mechanical forces. There are standard thickness of fiberglass boards and standard types. Most types used are FR-2 and FR-4 which have better performance, but FR-2 is more expensive than FR-4.
Gold-- is sometimes used to connect chip pins because of its good corrosion resistance performance.
Lacquer-like polymer-- is a polymer type used for soldering masks. The solder mask is a layer stretched across the entire PCB to prevent corrosion, external electric charge and dust. Different materials are added to the solder mask to get different colors, but mostly they are green.
Polyester-- is a naturally existed polymer in some plants. It is biodegradable and therefore eco-friendly. Polyester is used for printing silkscreen on the PCB board surface.
Polyimide-- is a polymer type used in flexible PCB boards. Polyimide is characterized with highly flexible, high dielectric properties, thermo-resistance, and is well-known for its unique orange color.
Solder alloy-- is a metal mixture of copper, tin, cadmium, silver, and other materials used to solder components on the board. It has a lower melting temperature than other materials it has contact with during soldering process. It has good electrical conductivity properties, close to those of copper and silver.
Except those materials mentioned above, there are dozens of other PCB manufacturing materials. The type of materials used depends on the quality you require, total product fabrication budget, and the environment in which the PCB will operate.