Common sense in SMT process

In PCBA SMT processing, there are some small knowledge that cannot be ignored. This is also common sense in SMT processing and is easily ignored by people. Below, the technicians of China SMT factory have sorted out some common sense in SMT processing for everyone.

1. Commonly used Fiducial Mark shapes are: square, circle, cross, swastika, diamond, triangle;

2. In the preheating area and cooling area of the SMT process, due to the wrong Reflow Profile setting, the parts will be micro-cracked;

3. When SMT is mounted, uneven heating on both ends of the parts is easy to cause: offset, missing solder, tombstoning;

4. Tools for repairing SMT components: electric soldering iron, hot air gun, suction gun, tweezers;

5. QC testing is divided into: IQC, IPQC, FQC and OQC;

6. The high-speed placement machine can mount resistors, capacitors, ICs and transistors;

7. The characteristics of static electricity: all are small current and are greatly affected by humidity;

8. Cycle time of high-speed placement machine and ordinary placement machine should be balanced as much as possible;

9. The definition of quality is "to do well the first time";

10. The placement machine should first place small components, and then place large components;

11. BIOS is a basic input and output system, the full English name is: Base Input/Output System;

12. SMT components can be divided into LEAD and LEADLESS according to the presence or absence of pins;

13. There are two basic types of common placement machines: continuous placement and multiple handover placement machines;

14. In SMT processing, it can be proceed without LOADER;

15. The SMT process is a board feeding system: solder paste printer-high speed machine-general purpose machine-reflow soldering-board receiving machine;

16. When the temperature and humidity sensitive parts are opened, only the color in the circle of the humidity card is blue, and the parts can be used.