SMTShort-circuit defects in surface mount technology (SMT) processing are more common in fine-pitch applicationsICBetween the pins, there are dense pinsICUsually, the pointer pins are relatively denseICComponents, and the spacing between the pins is small, with dense pinsICSome conditions are required to weld well. Below is Shenzhen JJYSolder paste manufacturerLet me briefly introduce to you the common ways to avoid thick feetICThe method of short circuit:

1. Steel mesh

For0.5Millimeters and belowICThe opening method of the steel mesh remains unchanged in the length direction, but the width is usually0.5to0.75The width of the pad and the thickness are generally0.12to0.15For millimeters, the steel mesh must be made by laser cutting technology and polished to ensure that the opening shape is an inverted trapezoid and the inner surface is smooth, so as to achieve a good tinning and forming printing effect.

Ii. Solder paste

inSMTFor the dense pins in the patchICThe granularity needs to be selected20~38um(PITCH≤0.4mm)The viscosity is160~220pa.sThe solder paste, the activity of the solder paste is usually adoptedRMAGrade.

Iii. Printing

Solder paste printing forSMTThe soldering effect of surface mount technology (SMT) processing also has a direct impact. Solder paste printing usually needs to pay attention to the following aspects:

The types of scrapers mainly include plastic and steel materials. For fine-pin chips, steel scrapers should be selected to facilitate the formation of solder paste.

2The Angle of the scraper: The scraper should45°The operation Angle of solder paste printing can improve the imbalance phenomenon of different steel mesh openings facing upwards.

3Printing speed: AtSMTThe speed of the squeegee is also a key parameter in the solder paste printing of surface mount technology. If the speed is too fast, it may cause the solder paste to be missed. If the speed is too slow, the solder paste may stop rolling, resulting in poor resolution of the solder paste on the pad, usually for those with dense pinsIC PCBPrinting speed10mm/s~20mm/s.

4Printing methods: In actual production and processing, the common printing methods mainly include contact printing and non-contact printing. Contact printing has higher precision and is more suitable for fine-pitch solder paste printing.

Iv. Mounting Height

SMTFor processing plantsPITCH≤0.5mmtheICIt should be adopted during mounting0Distance or0-0.1~-0.1mmThe mounting height should be adjusted to prevent the solder paste from forming and collapsing due to an excessively low mounting height, which could cause a short circuit during backflow.

Shenzhen JJY Industrial Technology Co., Ltd. is mainly engaged inLEDManufacturers of solder paste, lead-containing solder paste, lead-containing silver-containing solder paste, wave soldering strips, automatic soldering wires, etc.