Tube Furnace is the Real Hotness
We aren’t sure what [theglassman] is working on, but based on his recent projects, we think it is probably something interesting. He’s been decapping ICs, growing oxide on silicon substrates, and has built a tube furnace capable of reaching 1200 °C.
What would you do with something that can melt cast iron? We aren’t sure, but maybe you’ll tell us in the comments. We do have a fair idea of what [theglassman] is doing, though.
The core of the oven is a quartz tube. Insulation is via refractory cement and alumina ceramic wool. The heating itself is classic Nichrome wire and a tiny thermocouple. The real key, though, is to the proper controller. [theglassman] suggests a ramp/soak controller. These allow you to program sequences that heat up and then stop, which, if done properly, can prevent your fragile quartz tube from cracking.
Naturally, you need the tube furnace to grow oxides on silicon. It is less clear why he’s decapping ICs. We were nervous about his process of boiling down sulfuric acid (fuming nitrate works better, anyway, if you just want to remove the epoxy). If you want to remove everything like he does, sodium hydroxide will also work well.
Obviously, we need to keep an eye on [theglassman]. We are curious what he’s working towards. Maybe making a custom transistor? Or, dare we hope, a homemade IC?