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# Marking of SMD resistance and function of SMD adhesive

MARKing of SMD resistance and function of SMD adhesive
Marking method on SMT chip resistor
As an important part of SMT chip processing, chip resistors are usually SMAll in size, so they are usually printed with numbers and letters instead of words. What do these characters mean? Next, let me show you how to quICkly identify these resistors.
1. Nominal method of digital cable location
J-means the accuracy is 5%, F-means the accuracy is 1%.
(1) The 5% precision resistance value indicates: the first two digits indicate the effective real number, the third digit indicates the number of zeros, and the basic organization is Î), for example: 302=3000=3K Î), and the third digit "2" indicates two zeros. Mainly used for E24 series.
(2) The 1% precision resistance value indicates that the first three bits are effective real numbers, the fourth bit indicates how many zeros there are, and the basic organization is Î, for example: 3002=30000 Î), and the fourth bit "2" indicates two zeros. Mainly used for E24 and E29 series.
(3) If it is a decimal point, use R to represent the decimal point, for example: 3R5 represents 3.5 Î ©， R35 represents 0.35 Î ©
2. Color circle naming method
SMD resistors are the same as ordinary resistors. Most of them use four rings (sometimes three) to express their resistance. The first ring and the second ring are significant figures, and the third ring is the magnification. For example, "brown green black" means 15 ° C); "Blue Grey Liuding Silver" means "68k Î ©” The error is ± 10%.

3. E96 mixed digit and letter nomenclature
You need to look up the code table for the E96 series. There is a special table, such as 39X, where 39 represents 249, and X represents a power from 10 to - 1, i.e. 24.9 Î).
Different SMT manufacturers have different printing rules for chip resistors, but in general, most of the rules follow sub rules
SMT adhesive or SMT patch adhesive plays a special role in SMT patch processing. The heat hardening process of SMT patch adhesive is irreversible. Glue has this feature, and it is usually produced together with parts to complete the processing of circuit boards.