PCB from single to plural, and remained their development trend. Due to constantly to develop in the direction of high precision, high density and high reliability, shrinking volume, reduce costs, improve performance, makes the PCB in the future development of the electronic equipment engineering, still maintained a strong vitality. Electronic equipment adopts the PCB, due to the consistency of the same kind of PCB, so as to avoid the artificial connection error, and can realize automatic instrumentation or SMT electronic components, automatic soldering, automatic detection, ensure the quality of the electronic equipment, improve the labor productivity, reduces the cost, and easy maintenance.
The material of PCB:
22 f single composite substrate: single half a glass fiber sheet. (die can generally requires high computer drill)
CEM - 1 single composite substrate: this material need to adopt CNC drilling. (die can generally requires high computer drill)
CEM - 3 double composite substrate: minimum low-end double panel material, belongs to a half glass fiber materials. (except double-sided board belongs to the bottom double panel material, simple double panel can use this material, cheaper than FR - 4 5-10 yuan / ㎡).
FR - 4 epoxy glass fiber board: the most commonly used PCB material.
PCB fire hierarchies: according to the base board of UL standard combustion characteristic from high to low is divided into the following four categories: UL - 94 where v0, UL - 94 v1 v2, UL, UL - 94-94 - hb.
Half cure piece: used to produce multilayer PCB, commonly used models such as 1080, 2116, 7628 specifications.
94 hb board: the most common cardboard material, basic single panel are used to make low grade, the price is cheap. Because it has no flame retardant effect, there is a requirement for fire prevention for the power supply and a series of products can't be used.
94 where v0 board: board material, with flame retardant effect is compared with the 94 hb cardboard material add have flame retardant benefit its composition. (die punching)
Were reviewed at home and abroad in the future technology development trend of PCB manufacturing is basically consistent, namely to high density, high precision, small aperture, thin wire, small spacing, high reliability, multiple stratification, high-speed transmission, light weight, thin, on the production at the same time to improve productivity, reduce costs, reduce pollution, to adapt to many varieties, small batch production. Printed circuit technology development level, general with the line width on the PCB, aperture, thickness/diameter ratio.
Keywords：