Considerations for Printing Lead free Solder Pastes Abstract SMT printing will require reexamination and process adjustment when lead free soldering is implemented. If a high quality solder paste is used and standard rules for SMT printing are followed, consistent stencil life, aperture release, print definition, high speed print capabilities
NXG1 Solder Paste Kester NXG1 is a lead free, no clean solder paste designed to be used in air and nitrogen atmospheres and handle the thermal requirements of lead free alloys. The paste flux system allows joint appearances that closely resemble that achieved with SnPb alloys.
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This is important to ensure there is good release of solder paste from the apertures and to obtain the correct volume of solder paste to achieve the desired solder joint. Typically the stencil thickness would be between 4 thou and 8 thou thick. If the stencil is too thick for the size of apertures then it can lead to the paste being held by ...
The stencil printing process is the most critical process in surface mount electronics assembly. It tremendously influences the quality of the final PCB assembly. This course will provide a thorough understanding of the print process for lead based and lead free solder paste print applications.
When printing low temperature lead free solder paste it is important to use the correct machine settings to achieve a consistent high quality print. As detailed above the print speed is typically set to 25mm per second and the squeegee pressure set to 500 grams of pressure per 25mm of squeegee blade.
Kester NP545 is a zero halogen, lead free, no clean solder paste formula designed for consistency and repeatability. NP545 is extremely stable and has an unrefrigerated shelf life of 12 months with no print or solderability degradation. NP545 consistently delivers paste transfer efficiencies of 0.55 to 0.5AR.
However, care should be taken not to over mix the solder paste by stirring too vigorously or for too long. This can result in shear thinning the solder paste, which can result in slumping and/or bridging. Though not a recommended practice, used solder paste from the stencil may be stored in a separate container, then re used.
These solder paste stencils are designed for high volume screen printing on printed circuit boards. Foils are permanently mounted into aluminum frames Provide optimum solder paste volume control Large variety of standard frames for every printer
High quality Oubel 500g No Clean Lead Free Solder Paste For Screen Stencil Printing from China, China39;s leading silver solder paste product, with strict quality control no clean solder paste factories, producing high quality no clean solder paste products.