Analysis of SMT plug-in processing when what are the problems
In the mass consumer products and automotive products, cost is the key factor.
In PCB SMT plug-in processing on a pile of capacitance may not need, is certainly not acceptable.
In order to obtain the success, will shorten the design cycle to week to month, without thinking.
Now, can't just for the sake of repair and optimize power supply layer and formation take the time to redo the PCB again.
SMT plug-in processing for the modern electronic products design power system is a daunting challenge.
DDR memory work at 1600 MBPS, and will soon run into four patterns of 2200 MBPS.
To make matters worse, it is a kind of single-ended output, means that your power supply system must deal with power supply current sudden challenge.
Door may switch at the same time, the number in the device power integrity engineer described the features as synchronous switching noise.
Serial communication with difficult power demand.
3 ba Ethernet standard required data rate for 40 GBPS and 100 GBPS.
Metallographic happens because the old circuit board surface treatment, the possible soldering problem, while the moisture intrusion can lead to and/or in actual use in the assembly process layer, the inner layer and separation of hole wall,
Wait for a problem.
Copper clad tolerance can meet the demands of IPC4101ClassB/L, and benefits: strictly control the dielectric layer thickness can reduce the electrical performance expected value deviation.
Inferior ink can cause adhesion, solvent resistance and hardness of the problem.
All of these problems can result in resistance welding layer away from the circuit board, and eventually lead to corrosion of copper circuit.
Poor insulation properties can be caused by accidental electrical connectivity/arc short circuit.
In principle to do PCB components library, and then do the SCH component library.
PCB components library demand is higher, it directly affect the installation of the board;
SCH component library requirements is relatively loose, as long as attention to define good pin attributes and corresponding relationship with the PCB components.
Including preparation component library and schematic diagram.
'To do a good job, must first sharpen his', to make a good board, in addition to good design principle, also.
Should be prepared before the PCB design, the first principle diagram element library of SCH and PCB components library (
This is a step -
Is very important)
Component library can use Protel's own library, but usually it is hard to find a suitable, good is according to the standard size of the selected device data themselves do component library.