Cold Heat Soldering

[Witling]

"Cold heat" soldering devices are currently commercially available. How do they work?

Is this a proprietary process?

How does a vacum bottle (usually referred to as a "thermos" bottlle) know whether to keep something cold or to keep something hot?

 

[Torched]

Originally posted by: Witling
"Cold heat" soldering devices are currently commercially available. How do they work?

Probably with a laser. I've heard they don't work too good. I use a soldering iron every day of my life. Prefer to stick with old reliable hakko Mach I 80W iron.

 

[CycloWizard]

Not sure about the cold soldering, but the thermos question is pretty straightforward. There is a parameter that dictates how rapidly energy can be transferred through a barrier: the thermal diffusivity. This is equal to the thermal conductivity divided by the product of density and heat capacity (k/rho*Cp). The process for energy transfer is the same, regardless of whether the thermos contents are hot or cold - only the direction of energy transfer is changed. So, by minimizing the thermal diffusivity, one can create the best-insulated thermos.

On a more complex level, the thermal diffusivity is a proportionality constant in the diffusion equation, the partial differential equation that describes the transient temperature profile: dT/dt=alpha*d^2T/dx^2. T = temperature, t = time, alpha = thermal diffusivity, and x = position within the wall of the thermos. Entire books have been written on the solution of this equation for all types of boundary conditions.

 

[f95toli]

Originally posted by: Torched

Originally posted by: Witling
"Cold heat" soldering devices are currently commercially available. How do they work?

Probably with a laser. I've heard they don't work too good. I use a soldering iron every day of my life. Prefer to stick with old reliable hakko Mach I 80W iron.

There is also ultrasonic "soldering" which generates very little heat, the problem is that you need to use e.g. ITO or someting similar instead or ordinary 60/40.
It is still usefull for soldering things that are sensitve to heat.

 

[dullard]

Cold heat soldering works by forcing current through the solder. Solder has a low enough resistance that high amps can flow through it, but a high enough resistance that the current creates a lot of heat. So the cold heat soldering irons melt the solder with current. The soldering iron itself never gets very hot since its electrical resistance is so low that the heat generated is negligible.

Those soldering irons work the opposite way that you typically solder. Typically you get the iron hot, heat the part you want to solder, and then use the hot part's heat to melt the solder (guaranteeing the solder completely coats the part you want soldered.

With cold heat soldering, you touch the iron to the solder, melt the solder with the iron, and hope the solder coats the cold part that you want soldered. The problem is that the solder freezes up on the cold part and doesn't coat it very well. It only works if the parts you are soldering are quite tiny (so that their thermal mass is too small to freeze the solder).

 

[Mday]

here is how the tip is designed:

d|b

where b and d are 2 pieces of the ceramic used to do the heating, and the | is a plastic insulator. the b and d are connected to the + and - of the power source. at the extreme tip, there is just a gap of space where there is no plastic. when you touch the tip to the solder, the solder closes the circuit, and a current starts to flow between the pieces of ceramic through the solder.

then it's what dullard says exactly.

 

[imported_Kensai]

ColdHeat = Quite ineffective...

I went back to my normal soldering iron.

 

[IamElectro]

Normally i would not answer a question in such a manner but it is 6 am

http://home.howstuffworks.com/thermos.htm

 

[rivan]

Originally posted by: Kensai
ColdHeat = Quite ineffective...

I went back to my normal soldering iron.

Same here. $14 down the drain.

 

[imported_Tick]

AND, if you use it for to long a continuous time, the elements heat up, and shatter.

 

[EbonyDragon]

I have had good luck with mine. I dont try to touch the solder and wire at the same time, but rather use it like a normal soldering iron. The wire must fit between the grove. If it doesnt it will not complete the circuit (which I believe is a basic dead short.) and wont heat the wire enough to melt the solder. They do make different size tips. There is a limit to it though. It doesnt handle large areas well, such as soldering a wire on to a switch terminal. Just cant heat it all up fast enough. Ive used it to do a bunch of wire to wire connections and work on stero plugs. It's a tool and has a place, it just wont replace an all around soldering iron or gun.

 

[0roo0roo]

http://www.dansdata.com/danletters140.htm