Do you know these parameters about lead-free solder paste for SMT?

UseSMTLead-free solder pasteThere will be many parameters. There are several types of lead-free solder paste, with different components and parameters. With these parameters, we can reduce misunderstandings about the use of solder paste. JJY solder Paste Manufacturer will share the following parameters with you:

First, the speed of the scraper: generally, it is10-150mm/sIf the speed is too fast, the scraper will slide, resulting in missed printing;The scraper is too slow, causing the edge of the solder paste mark to be uneven, thereby contaminating the substrate surface;A moderate printing speed can ensure the amount of solder paste printed for fine printing.

Secondly, the Angle of the scraper: The Angle of the scraper is60-90When the degree is between, the best printing efficiency and transferability can be achieved through appropriate printing force.

The third is the printing pressure: Generally, the printing pressure is set at0.1-0.3Kg/cm2. If the pressure is too low, the amount of solder paste transferred will be insufficient; if it is too high, the printed solder paste will be too thin, increasing the possibility of solder paste contaminating the reverse side of the steel mesh and the substrate. Usually, it should be adjusted gradually from small to large until the solder paste is just scraped off the surface of the steel mesh.

The fourth factor is the hardness and material of the scraper: The hardness of the scraper should be at80-90HRCBetween them, the material is either stainless steel or plastic.

The fifth is the reflux curve: The maximum heating rate of the preheating zone is2.5℃/sExcessive temperature rise will produce tin balls;The temperature in the insulation area should be at150℃-210℃Between them, the heating time is60s-90sThe maximum heating rate is2.5℃/s;The maximum temperature in the reflux zone is225℃-255℃Between217℃The above-mentioned time should be at40s-70sBetween;The fastest cooling rate in the cooling zone is40℃/s. The optimal reflow temperature curve varies depending on the performance of the substrate and reflow soldering equipment. Please confirm the actual temperature curve based on the substrate and reflow soldering equipment used. The recommended working environment temperature is25±2℃The humidity is45%-65%.

Finally, regarding the storage of solder paste: It is recommended to store it in0-10℃Between, from the production date6Use within one month.0℃The following storage will affect the rheological properties of solder paste.

15For many years, JJY has been dedicated to the research and development, production and sales of solder paste, providing customers with a complete set of electronic soldering solutions. If you want to learn more about solder paste, please keep following JJY Solder Paste Manufacturer and leave a message online to interact with us.