Generally speaking, the specified temperature in SMT workshop is 253℃;
2.
Materials and tools needed for solder paste printing: solder paste and steel plate? Scraper? Wipe paper, dust-free paper? Cleaning agent? Stirring knife;
3.
The commonly used solder paste alloy composition is Sn/Pb alloy, and the alloy ratio is 63/37.
4.
The main components in solder paste are divided into two parts: tin powder and flux.
5.
The main function of flux in welding is to remove oxides? Destroy the surface tension of molten tin? Prevent reoxidation.
6.
The volume ratio of tin powder particles to rising tide (flux) in solder paste is about 1: 1.
The weight ratio is about 9:1;
7.
The use principle of solder paste is first in first out;
8.
When solder paste is used in Kaifeng, it must be preheated through two important processes. Stir;
9.
What are the common manufacturing methods of steel plates? Etching? Laser? Electroforming;
10.
The full name of SMT is surface riding (or equipment)
Technology, which means surface adhesion (or mounting) technology in Chinese;
1 1.
The full name of ESD is electroplating supplies-electrostatic unloading.
Chinese means electrostatic discharge;
12.
When making SMT equipment programs,
The plan includes five parts,
These five parts are PCB data;
Tag data; Breeder data;
Nozzle data;
Partial data;
13.
Tin/silver/copper lead-free solder
The melting point of 96.5/3.0/0.5 is
2 17C；
14.
The relative temperature and humidity of the parts drying box are controlled as follows
& lt
10%;
15.
Commonly used passive components (passive devices) are: resistance, capacitance, point inductance (or diode) and so on. Active components (movable devices) include transistors, integrated circuits, etc.
16.
The commonly used SMT steel plate is stainless steel;
17.
The thickness of commonly used SMT steel plate is 0. 15mm (or 0.12 mm);
18.
What kind of electrostatic charge is friction? Separation? Induction? Electrostatic conduction and so on? What is the effect of electrostatic charge on electronic industry? а n electrostatic pollution? The three principles of electrostatic elimination are electrostatic neutralization? Grounding? Shielding.
19.
English dimension length x width 0603=
0.06 inch * 0.03 inch? Metric dimension length x width 3216 = 3.2mm *1.6mm;
20.
Exclude ERB-05604-J8 1 The eighth code "4" is indicated as 4.
A circuit with a resistance of 56 ohms. electric capacity
2 1.
What is the full Chinese name of ECN? Engineering change notice? What is the Chinese full name of SWR? Special demand work order?
Must be countersigned by all relevant departments,
Document center distribution,
To be effective;
22.
What is the specific content of 5S? Rectify? Cleaning? Clean? Literacy;
23.
The purpose of vacuum packaging of PCB is to prevent dust and moisture.
24.
What is the quality policy? Total quality control? Implementation system? Provide the quality required by customers? Full participation? in time
Deal with it? In order to achieve the goal of zero defects;
25.
What is the quality three noes policy? Do not accept defective products? No defective products? No defective products flow out;
26.
Among the seven methods of QC, 4M 1E means (in Chinese):
mankind