t present, in PCBA processing, the introduction of advanced testing equipment for quality control of the production process. In the process of reflow welding, AOI testing equipment is generally used for quality control.Can provide the smallest package 020
Our conclusion above is that it's better to go through a bigger hole. At this point, we need to introduce you to two formulas. One is the calculation formula of the parasitic capacitance through the hole: C=1.41εTD2/ (D1-D) The other is the calculation fo
Layout engineers think about it! No longer afraid of not painting!Think about purchasing want to cry, more than 10 times more expensive than ordinary through hole plate! Therefore, only products like the iPhone are willing to use. Other phone brands, no o
Electromagnetic shielding: In order to ensure the performance of the circuit, some components in electronic products need to prevent radiation and interference of electromagnetic waves. The aluminum substrate can be used as a shielding plate to shield ele
The classic PCB laminated design is almost all even layers, rather than odd layers. Even layers of printed circuit boards have cost advantages, and even layers can avoid board warping more than odd layers.
Firstly, the overcurrent protection current is preset, and then the voltage value of the regulated power supply is gradually increased, and the input current, input voltage and output voltage are monitored. If there are no problems such as over-current pr
The layout of the components should be convenient for signal flow, so that the signal is as consistent as possible. In most cases, the flow direction of the signal is arranged from left to right or from top to bottom, and the components directly connected
After welding parts to use the soldering iron and tin wire, welding will be maintained at a high temperature of the soldering iron contact the part foot to solder, until the temperature rises enough to melt the tin wire temperature, and then add the tin w
the power plane should be inside the PCB, and the upper and lower layers adjacent to him are 0V planes, and the distance between the two 0V flat faces should be at least 20 times the distance between them and the power plane.
Distinguish screen printing screen plate (negative), working film, positive film and negative film and film surface: screen printing screen has a mother film and working film (subfilm), black and yellow film, positive and negative film;
The solder resistance design between the pad and the pad, and the solder resistance graphic specifications should conform to the design of the welding end distribution of specific components; If the open window block welding between the pad and the pad ca
This line width is generally satisfied for the conventional design, then we can compare the two layers, you will find that the difference between them is that the core is thinner, and then the pp sheet of one or two layers and five or six layers is also t
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