{"id":2202,"date":"2025-04-18T05:55:04","date_gmt":"2025-04-18T05:55:04","guid":{"rendered":"https:\/\/blogs.lcsc.com\/blog\/?p=2202"},"modified":"2025-08-05T07:49:36","modified_gmt":"2025-08-05T07:49:36","slug":"solder-ball-formation-in-smt-the-hidden-risks-how-to-fix-them","status":"publish","type":"post","link":"https:\/\/blogs.lcsc.com\/blog\/solder-ball-formation-in-smt-the-hidden-risks-how-to-fix-them\/","title":{"rendered":"Solder Ball Formation in SMT: The Hidden Risks & How to Fix Them"},"content":{"rendered":"

Optimization for Solder Paste Printing Process to Reduce Solder Ball Formation<\/span><\/b><\/h2>\n

During the solder paste printing<\/a> process, a series of advanced techniques ensures quality and reduces solder ball formation when employed. The implementation of precise control over the solder paste viscosity, printing speed, and squeegee pressure is to ensure the paste is evenly and accurately on the pads when applied.<\/span><\/p>\n

In the stencil aperture design, laser cutting technology is for the purpose of creating the aperture, which results in fewer burrs and greater precision. Afterward, the stencil surface is typically polished or etched, and some may undergo a nano-treatment process after polishing. These treatments help achieve a smoother surface, reducing printing resistance. For the aperture design, the apertures are usually the size of the PCB pads, but for special components, they need targeted optimizations. For example, for SMD<\/a> (0805 and above packages), to prevent solder paste dispersion during the pick-and-place process, which can lead to solder balls after reflow, the stencil apertures are reduced by approximately 1\/3 in length and width, forming a semi-circular groove. This particularly serves as a preventive measure against solder ball formation.<\/span><\/p>\n

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Surface Mount Device (SMD) (Image source: online)<\/figcaption><\/figure>\n<\/div>\n<\/div>\n

Proper Setting of Reflow Soldering Temperature Profiles\u00a0<\/span><\/b><\/h2>\n

Adjust the reflow soldering temperature profile based on the solder’s melting point and the properties of the PCB material. Use appropriate cooling and heating rates to avoid temperature fluctuations that are too fast or too slow.<\/span><\/p>\n

Improvement of PCB Layout Design to Avoid <\/span><\/b>Solder Ball Formation<\/span><\/b><\/h2>\n

Increase the pad size properly and optimize the pad layout in order to avoid excessively tight spacing, thereby reducing the risk of solder ball formation.<\/span><\/p>\n

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The spacing between Surface Mount Devices (Image source: online)<\/figcaption><\/figure>\n<\/div>\n<\/div>\n