SMT chip processing has an important supporting auxiliary materials, is the solder paste.
Solder paste composition mainly contains tin powder alloy particles and flux (flux contains rosin, active agent, solvent, thickener, etc.), solder paste is similar to toothpaste, used for solder paste printing machine solder paste in pcb pad location, so that the placement machine mount sticky electronic components, and then to reflow soldering high temperature hot melt solder paste and then fixed the electronic components to the pad.
Solder paste why to return to temperature stirring?
1. Why does the solder paste need to be warmed up?
Solder paste is generally stored in the refrigerator (5-10 degrees Celsius) environment, from the refrigerator will be taken out of the SMT workshop environment temperature inconsistency, if directly open to use, by the contact temperature inconsistency, the surface of the solder paste will adhere to water vapor, if to reflow soldering high temperature, may appear burst tin, resulting in bad quality of tin beads. Therefore, the solder paste taken out of the refrigerator is generally better to return to temperature 2-4H.
2. Why should the solder paste be stirred?
Solder paste placed in the refrigerator, because of the different components of the solder paste, placed for a long time, the various components of the solder paste will appear layered phenomenon, so you need to stir (stirring in the same direction 20-30 turns can be), if not stirred directly with, then the various components of the solder paste is not mixed, can not play the use of the solder paste itself.
The reason why the solder paste should be kept in the refrigerator instead of directly on the site is that the solder paste contains solvents and rosin, which will evaporate if placed directly in the normal environment, thus causing the air to dry out.
There are automatic solder paste management cabinets on the market, including storage, tempering and automatic stirring, etc. If the company is large and uses a lot of solder paste, you can purchase such equipment to manage and use the solder paste.
Features of NeoDen ND2 automatic stencil printer
1. Accurate Optical Positioning System
Four way light source is adjustable, light intensity is adjustable, light is uniform, and image acquisition is more perfect.
2. High efficiency and high adaptability stencil cleaning system
Soft wear-resistant rubber wiping plate, cleaning methods of dry, wet and vacuum
thorough cleaning, convenient disassembly.
3. Intelligent squeegee system
Intelligent programmable setting, two independent direct motors driven squeegee, built- in precise pressure control system.
4. Special PCB thickness adaptive system
The platform height is automatically calibrated according to PCB thickness setting, which is intelligent, fast, simple and reliable in structure.
5. Solder Paste Printing Quality Inspection
2D function can quickly detect the printing defects, the detection points can be increased arbitrarily.
6. Printing Axis Servo Drive
Improve accuracy grade, provide good printing control platform, operational stability, extend the service life.
Post time: Mar-10-2023