is also called solder paste. For the introduction of solder paste, solder paste is divided into unleaded solder paste and leaded solder paste. The solder paste produced by double Chile solder paste manufacturers is a 500-gram can, and the lead-free environmental protection is a green plastic can. Leaded for white plastic cans
Summary of requirements for solder paste:
1. Excellent rolling characteristics.
2. It has low viscosity during printing and high viscosity after printing.
3. It has a good separation effect with steel mesh and scraper.
4. It is not suitable for drying at indoor temperature, but it is easy to dry at preheating temperature.
5. High metal content, low chemical composition.
6. Low oxidation.
7. There is no separation between chemical composition and metal composition.
Solder paste storage should follow the principle of first-in, first-out. It should be refrigerated in refrigerator. Storage temperature: 2~10℃. When taking out solder paste, the date and time of taking out the refrigerator should be marked on the paste bottle; after taking out, return to room temperature. For 4 hours, it is recommended to stir the solder paste by hand for about 4 minutes after returning to temperature. It can be printed manually or printed by an automatic semi-automatic printing machine. Refrigerated storage for 6 months. After moisture absorption, the solder paste will become thinner and the composition will change, resulting in poor moisture retention and thixotropic properties of the solder paste, and defects such as tinning, collapse, and tipping are more likely to occur during printing.
What are the requirements for the environment where the solder paste is used?
Solder paste is generally stored at 2-10 degrees in the refrigerator, and what are the requirements for the use environment of solder paste?
Greenhouse temperature requirements for solder paste: temperature: 20-26 degrees; humidity: 40%-60%.
The solder paste has strict requirements on the environment. The temperature cannot be too high or too low. If the temperature is too high, the flux in the solder paste will lose its activity prematurely, and the solder paste will easily absorb moisture and cause poor soldering. It is beneficial to printing, and the solvent in the solder paste is volatilized.
Solder paste should also pay attention to:
a. Different types of solder paste cannot be mixed (different solder pastes cannot be used at the same time during solder paste printing)
b. Do not put the old and new solder paste in the same jar (do not put the solder paste remaining on the stencil in the newly opened solder paste jar)
c. The printed PCB board is reflowed within 2 hours.
d. Gloves must be worn during the process of stirring and adding solder paste, and hands should be washed before eating to prevent damage caused by the entrance of the solder paste.
e. When stirring and adding solder paste, use a bakelite spatula instead of a metal spatula.