Induction Soldering Glass Feedthroughs

Objective Heat a kovar fiber optic housing with glass feed-throughs to 400°F (204.4°C) within 20 seconds for a soldering application, to form a hermetic seal Material Kovar housing with 18 glass feed-throughs, solder preforms
and flux
Temperature 400 ºF(204.4°C)
Frequency 300 kHz
Equipment • Power of 6 kW RF induction heating system equipped with a remote workhead
• An induction heating coil designed and developed specifically for this application
Process A specially designed single-turn, pancake coil is used to provide uniform heating to the kovar housing. The coil position is adjusted to heat only the front portion of the assembly. The feedthroughs and solder preforms are assembled with flux. Power is applied for 20 seconds, causing the solder to flow cleanly around the feed-throughs.
Results/Benefits Induction heating provides:
• All 18 feedthroughs can be soldered at the same time
• Faster production time & more economical
• Controllable, repeatable results

Soldering Glass Feedthroughs