In the SMT placement production process, it is often necessary to use SMD adhesive, solder paste, stencil and other auxiliary materials, these auxiliary materials in the SMT whole assembly production process, the product quality, production efficiency plays a vital role.
1. Storage period (Shelf Life)
Under the specified conditions, the material or product can still meet the technical requirements and maintain the appropriate performance of the storage time.
2. Placement time (Working Time)
Chip adhesive, solder paste in use before exposure to the specified environment can still maintain the specified chemical and physical properties of the longest time.
3. Viscosity (Viscosity)
Chip adhesive, solder paste in the natural drip of the adhesive properties of the drop delay.
4. Thixotropy (Thixotropy Ratio)
Chip adhesive and solder paste has the characteristics of fluid when extruded under pressure, and quickly become solid plastic after extrusion or stop applying pressure. This characteristic is called thixotropy.
5. Slumping (Slump)
After the printing of the stencil printer due to gravity and surface tension and temperature rise or parking time is too long and other reasons caused by the height reduction, the bottom area beyond the specified boundary of the slump phenomenon.
6. Spreading
The distance that the adhesive spreads at room temperature after dispensing.
7. Adhesion (Tack)
The size of the adhesion of the solder paste to the components and the change of its adhesion with the change of storage time after the printing of the solder paste.
8. Wetting (Wetting)
The molten solder in the copper surface to form a uniform, smooth and unbroken state of the solder thin layer.
9. No-clean Solder Paste (No-clean Solder Paste)
Solder paste that contains only a trace of harmless solder residue after soldering without cleaning the PCB.
10. Low Temperature Solder Paste (Low Temperature Paste)
Solder paste with melting temperature lower than 163℃.
Post time: Mar-16-2022