Vitronics Soltec Wave Problems

Turbulant wave will get into the close quarter areas of your SMDs.

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80-90% of an average SM component is non wetable (pushing away solder). So if you would use a single smooth lambda wave (massive amount of molten metal) the negative force of the non-wetable part of the component would be so high that the solder would not reach the solderable part on the side of the component.

That�s why you need certain turbulence in the first wave or additional wave pressure in a single wave to overcome these negative forces.

This can be done with turbulent 1st wave almost splashing solder on the solderable side of the components and pads. Or can be done with a jet wave (thin solder fountain) so the component body sits in air instead of massive metal. Or with a single omega wave (back and forward moving plate in front of the wave) creating enough force and vibration to reach the component solderable sides. Or with a rotating octangle (smart wave) in the front of the main wave creating turbulence and vibrating pressure in the front of the wave.

Double waves have a tendency to create a higher defect rate because:

A)Part of the flux activity is used in the first wave

B)Shorts created in the first (turbulent) chip wave can not always be eliminated by the main wave.

Hope this helps, Patrick

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