3 ms·

If you are already making your own PCBs, making your own kiln with a thermocouple, PID, and heating element ought to be no sweat. Just buy a handful of softbric

by abakker 10y ago

If you are already making your own PCBs, making your own kiln with a thermocouple, PID, and heating element ought to be no sweat. Just buy a handful of softbricks, cut them with a saw, and put them together. I've made kilns like this that go up to 1950F. 300 - 400 should be really easy.

TaylorAlexander 10y ago
It is significantly easier to hit buy it now than it is to construct a functional temperature controlled oven. People who want to DIY often modify toaster ovens, but I haven't heard of anyone construction their own heating chamber as you've described. Note that portability is a concern for me, since I move often.
Animats 10y ago
It's not about getting it hot enough. Surface mount soldering requires a careful temperature profile. You first preheat to about 50C below the melting point of solder for about two minutes. Then, the temperature is raised to above the reflow point and held there for about 20 seconds, which is when the soldering takes place. It's easy to damage the components at this point; many components have a maximum temperature tolerance of only 30 seconds at reflow temperature.[1] Then there's a cool-down period. There are ramp rate limitations - heating up too fast causes solvent "pops" in the flux, and heating up too slowly cooks the components. Cooling too fast causes cracks in the solder; cooling too slowly cooks the components. A brick kiln would have too much thermal mass for all those controlled temperature changes. Once it's all tuned and controlled properly, it works great as a cheap production process. The commercial systems work like a hamburger cooker at Burger King - there's a chain conveyor and several zones of different temperature through which the product passes. Once one of those ovens is warmed up and stabilized, it produces consistent results. It's doing this on one-offs that's hard. Leaded soldering is about 2x more tolerant of temperature variations than lead-free. [1] http://www.latticesemi.com/~/media/LatticeSemi/Documents/ApplicationNotes/PT/SolderReflowGuideforSurfaceMountDevices.pdf?document_id=8902 http://www.latticesemi.com/~/media/LatticeSemi/Documents/App...

by abakker 10y ago

TaylorAlexander 10y ago

It is significantly easier to hit buy it now than it is to construct a functional temperature controlled oven. People who want to DIY often modify toaster ovens, but I haven't heard of anyone construction their own heating chamber as you've described. Note that portability is a concern for me, since I move often.

Animats 10y ago

It's not about getting it hot enough. Surface mount soldering requires a careful temperature profile. You first preheat to about 50C below the melting point of solder for about two minutes. Then, the temperature is raised to above the reflow point and held there for about 20 seconds, which is when the soldering takes place. It's easy to damage the components at this point; many components have a maximum temperature tolerance of only 30 seconds at reflow temperature.[1] Then there's a cool-down period. There are ramp rate limitations - heating up too fast causes solvent "pops" in the flux, and heating up too slowly cooks the components. Cooling too fast causes cracks in the solder; cooling too slowly cooks the components. A brick kiln would have too much thermal mass for all those controlled temperature changes. Once it's all tuned and controlled properly, it works great as a cheap production process. The commercial systems work like a hamburger cooker at Burger King - there's a chain conveyor and several zones of different temperature through which the product passes. Once one of those ovens is warmed up and stabilized, it produces consistent results. It's doing this on one-offs that's hard. Leaded soldering is about 2x more tolerant of temperature variations than lead-free. [1] http://www.latticesemi.com/~/media/LatticeSemi/Documents/ApplicationNotes/PT/SolderReflowGuideforSurfaceMountDevices.pdf?document_id=8902 http://www.latticesemi.com/~/media/LatticeSemi/Documents/App...