The circuit board is found in almost every kind of electronic equipment, it is the carrier of all electronic equipment, computer everywhere the figure of PCB, small household appliances in daily life, to the vehicle electronic equipment, but the manufacturing process of the circuit board to which materials under?
The original material of the circuit board is covered with copper substrate, which is referred to as the substrate. The substrate is a resin plate with two sides of copper. Now the most commonly used sheet code name is FR-4. FR-4 is mainly used in computers, communication equipment and other grades of electronic products. Requirements for plates: one is flammability, two is Tg, and three is dielectric constant. The circuit board must be flammable and not burn at a certain temperature and can only be softened.
2, copper foil
Copper foil is the conductor on which the conductor is formed on the substrate. There are two ways to make the copper foil: calendering and electrolysis.
PP is an indispensable raw material for circuit board manufacture, and its function is adhesive between layers. Simply put, the substrate sheet in B-stage is called PP. The specifications for PP are the thickness and the amount of gum (resin).
4, Dry film
The photosensitive film is referred to as the dry film, the main ingredient is a resin material sensitive to specific spectral and photochemical reaction. The utility model has three layers of dry film, and the photosensitive layer is sandwiched between the upper and the lower two layers to protect the plastic film. According to the chemical characteristics of photosensitive substances, there are two kinds of dry film, photopolymerization and photolysis. The photopolymer type dry film hardens under the irradiation of a particular spectrum and becomes insoluble from water soluble substances, whereas photolysis is just the opposite.
5, anti welding paint
Solder resist paint is actually a solder resist, a liquid photosensitive material that has no affinity for liquid solder. It, like a photosensitive dry film, changes and hardens under the light of a particular spectrum. When in use, the solder paint must be mixed with the hardener. Anti - Welding paint, also known as ink. The color of the boards we usually see is actually the color of the solder paint.
Our negatives are similar to photographic negatives, all of which use light-sensitive material to record images. The customer will route the designed circuit to the circuit board factory, which will output the wiring diagram from the workstation at the center of the CAM, but not through a common printer, but a light plotter. The role of the negative plate in the circuit board factory is very important. All the objects on the substrate should be changed into negatives by using the principle of image transfer.