At present, a small and small-sized PCBA board integrates countless components of various types, which is currently the most commonly used and easy to distinguish method.
1: The method of color ring resistance to identify the resistance parameter, the first green is 5 and the second brown is 1, these two have calibration values, the third yellow is 4, and the fourth gold is the identification difference, such as Graph calculation
Resistance value 510000Ω=510KΩ, the error is ±5%
2: The five color ring resistors are precision resistors, and the five color rings represent its resistance. The first, second, and third color rings represent valid values; the fourth color ring represents the number of zeros; the fifth color ring represents the error range of the resistance value, that is, the error value
Resistance value: 4750Ω=4.75KΩ, the error is ±1%
3: There are several ways to indicate the direction of the chip:
This chip is a QFN package. When identifying the direction of the chip, it is the first pin of the chip at the gap of the inner pad. It will be marked as a dot in the PCB silk screen picture, and it is only here when mounting The point corresponds to the chip's notch, it is correct, and the pin will not be misplaced or pasted upside down.
This chip is marked with a cross symbol on the front of the IC, and the corresponding pin of the symbol is the first pin.
When the PCB is used as a pad, it is necessary to increase the pad by about 10%, so that it is easy to solder when making a patch, and it is not easy to fake solder, etc.;
4: Identification of the direction and parameters of the tantalum capacitor on the PCBA board
In this white box, the triangle point is to mark the positive electrode of the capacitor, which corresponds to a thick line of the capacitor
Represents 47×106PF=47UF
C means: C type
Means: positive
Means: negative electrode
5: The direction and parameter identification of the patch electrolytic capacitor on the PCBA board
CS means capacitor brand
220 means the capacitance value of the capacitor is 220UF
35V means capacitor withstand voltage 35V
The gap indicates the positive electrode of the capacitor
This ribbon represents the negative pole of the capacitor
