Jet Soldering Preheating Coils for Through-Hole Wetting

The patent applies electromagnetic induction heating coils specifically positioned around the jet nozzle to create localized heating zones at the soldering position and through hole areas. This allows different regions of the PCB to receive different heating intensities - the soldering position receives focused heating while peripheral areas receive less heating, resolving the contradiction between achieving high temperature at the soldering position and maintaining uniform temperature distribution.

The patent replaces conventional hot air or radiation heating methods with electromagnetic induction heating. The induction heating system uses electromagnetic fields to directly heat conductive materials (electrodes, patterns, and solder) at the soldering position, eliminating the need for thermal conduction through the substrate. This substitution resolves the issue of excessive peripheral substrate heating while maintaining effective heating at the soldering position.

The patent divides the heating system into multiple independent electromagnetic induction heating coils that can be positioned around different soldering positions. Each coil can be independently controlled to heat specific through holes or soldering positions. This segmentation allows the system to handle complex configurations such as multi-row connector terminals by activating only the necessary heating zones, resolving the limitation of conventional single-zone induction heating.

The patent applies electromagnetic induction heating to preheat the through hole, electrodes, and patterns before solder application. This preliminary heating action ensures that the soldering position and through hole are already at the required temperature when the molten solder is applied, preventing solder solidification and ensuring proper wetting and spreading. The heating occurs in advance of the solder application, resolving the timing issue between heating and soldering.