PCBA OEM processing skills are disclosed

1. When the solder paste is opened and used, it must be warmed and mixed through two important processes.；

2. The common manufacturing methods of steel plates are: etching, laser, electroforming；

3. The full name of SMT patch processing is Surface mount technology, which means surface adhesion (or mounting) technology in Chinese.；

4. There are four types of flux based on rosin: R, RA, RSA, and RMA.；

5. Whether the SMT segment exclusion is directional or not;

6. The solder paste currently sold on the market has a viscosity time of only 4 hours in practice.；

7. SMT PCB positioning methods are: vacuum positioning, mechanical hole positioning, clamp positioning on both sides and board edge positioning.；

8. The screen printing (symbol) is a resistor of 272 with a resistance value of 2700Ω, and the symbol (screen printing) of a resistor with a resistance value of 4 or 8MW is 485.；

9. The screen printing on the BGA body includes information such as manufacturer, manufacturer part number, standard and Datecode/(LotNo).；

10. The volume ratio of tin powder particles to Flux (flux) in solder paste is about 1:1, and the component ratio is about 9:1.；

11. The principle of access to solder paste is first in, first out；

12. The quality policy of all staff is: all quality control, follow the guidelines, and supply the quality required by customers; the policy of full participation and timely handling to achieve zero defects；

13. The three principles of quality are: do not accept defective products, do not manufacture defective products, and do not flow out defective products.；

14. In the seven methods of QC, 4M1H refers to (Chinese): people, machines, materials, methods, and environment.；

15、208pinQFP‘s pitch is 0、5mm；

16. The correct component ratio and volume ratio of tin powder to flux in the composition of solder paste are 90%: 10%, 50%: 50%；

17. Commonly used passive components are: resistors, capacitors, inductors (or diodes), etc.; Active components are: triodes, ICS, etc.；

18. The raw material of the commonly used SMT steel plate is stainless steel；

19. The full Chinese name of ECN is: Engineering change notice; the full Chinese name of SWR is: Special work order, it is necessary to be signed by the relevant parts, and the documents are distributed in the middle to be useful.；

20. The specific content of 5S is sorting, sorting, cleaning, cleaning, and quality.；

21. The intention of PCB vacuum packaging is to be dust-proof and moisture-proof；

22. The opening type of steel plate is square, triangular, round, star-shaped, and Ben Lei-shaped.；

23. The raw material of the computer-side PCB currently used is: glass fiber board FR4；

24. What kind of substrate ceramic plate should the solder paste of Sn62Pb36Ag2 be used for?

25. The thickness of the commonly used SMT steel plate is 0.15mm；

26. The types of electrostatic charges that occur are conflict, separation, induction, electrostatic conduction, etc.; The effects of electrostatic charges on the electronics industry are: ESD failure, electrostatic pollution; the three principles of electrostatic elimination are electrostatic neutralization, grounding, and shielding.

27. Imperial scale length x width 0603=0.06inch*0.03inch, metric scale length x width 3216=3.2mm*1.6mm；

28. The 8th code “4” of the exclusion ERB-05604-J81 indicates that it is 4 loops with a resistance value of 56 ohms.Capacitor ECA-0105Y-M31 capacitance value is C=106PF=1NF=1X10-6F；

29. Generally speaking, the regular temperature of the SMT patch processing workshop is 25±3℃.；

30. When printing solder paste, the information and things that need to be prepared are solder paste, steel plate, scraper, wiping paper, dust-free paper, detergent, and mixing knife.；

31. The composition of the commonly used solder paste alloy is Sn/Pb alloy, and the alloy share is 63/37；

32. The full name of ESD is Electro-staTIcdischarge, which means electrostatic discharge in Chinese.；

33、制版过程中，制版过程中包括部分数据；Markdata；Feederdata；Nozzledata；Partdata；

34. The melting point of lead-free solder Sn/Ag/Cu96, 5/3, 0/0, and 5 is 217C；

35. The relative temperature and humidity of the parts drying oven is "10%；

36. The composition of solder paste includes: metal powder, sol, flux, anti-sagging agent, and active agent; according to the component, metal powder accounts for 85-92%, and metal powder accounts for 50% by volume; in the meantime, the primary components of metal powder are tin and lead, with a share of 63/37 and a melting point of 183℃.；

37. When the solder paste is used, it is necessary to remove it from the refrigerator and warm it back. The intention is to return the temperature of the refrigerated solder paste to room temperature to facilitate printing. If the temperature is not warmed back, the defects that are prone to occur after the PCBA enters the reflow are tin beads.；

38. The document supply forms of the machine are: preparatory form, priority communication form, communication form and quick connection form；

39. The primary ingredients in solder paste are divided into two major groups: tin powder and flux.

40. The primary role of flux in welding is to remove oxides, damage the outer tension of molten tin, and avoid re-oxidation.