According to Prismark statistics, mobile terminal PCB demand is mainly HDI and flexible board (HDI board accounts for about 50.68%), and has 26.36% packaging substrate demand.
PCB circuit opening and short circuit are the problems encountered by PCB manufacturers almost every day, which has been troubling the production and quality management personnel.
In a high speed PCB, wiring is more than just connecting two points. As a qualified engineer, wiring is a hybrid knowledge carrier including resistance, capacitance and inductance.
Starting from the most basic PCB board, this paper discusses the function and design skills of PCB stacking in controlling EMI radiation.
All of these problems can cause the solder shield to detach from the circuit board and eventually lead to corrosion of the copper circuit.
In terms of PCB design, 50 ohm is also selected after comprehensive consideration. In terms of PCB wiring performance, generally low impedance is better.
When PCB is used for hot air leveling and component welding, the board is subjected to high temperature (> 200), will also release trace amounts of hydrogen bromide。
With the development of large-scale integrated circuit and super-large scale integrated circuit, the multilayer printed board (PCB) will be used more and more.
The circuit working at high frequency should consider the interference between components. The general circuit should make parallel arrangement of components as far as possible to facilitate wiring;
Too low density of alkaline etching solution will aggravate side erosion, choosing etching solution with high copper concentration is very beneficial to reduce side erosion.
high heat dissipation devices in connection with the substrate should be able to reduce the thermal resistance between them.
To evaluate the heat dissipation capacity of PCB, it is necessary to calculate the equivalent thermal conductivity (9EQ) of the insulating substrate for PCB, which is composed of various materials with different thermal conductivity.
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