Electronics > Mechanical & Automation Engineering

fixture for opening RF solder can?

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So I got a little used to resistance soldering and brazing and using a big resistance transformer to heat things. I want to open a soldered together RF amplifier, but the problem is the geometry of the part. I thought to glue a pull handle to the top of the module and then to make some kind of aparatus that injects current into the lid and sides to heat it up with high current power.

I thought maybe to wrap RF-braid around the part to act as one of the electrodes, tensioning it some how, but I am at a loss how to get the current into the lid, do i need multiple contact points to inject current around the perimeter ?

The other idea I have is to glue a handle to the top like the previous case, smear around it with antiseize then drop a block I heated on a hot plate on top of it (the block would have a hole in the middle around where the pull handle is), then immediately start pulling on it so it melts the solder.

It is like a thick aluminum gold plated can that they some how soldered a lid to, diameter 1.5x1.5 inches, similar to what is in the 8447 amplifiers from hP.

I am curious what a good high temperature thermal transfer compound is, the best that comes to mind is antiseize, which may function at solder melting temperatures.

Or perhaps instead of heating it on a hot plate, to wire a the resistance transformer to the block to make a hot block that sits on top and is heated by the transformer (voltage is ~1V), but I am almost thinking externally heating it is better since its more similar to natural soldering?

The idea is not to damage the parts or damage the coaxial SMA connectors. I think it 50 ohm so they are delerin, if it was 75 ohm I would be much more confident with heat.. usually when I have a thermal problem I switch to 75 ohm teflon connectors, which fare far better.

Or I thought to put a bunch of heat block on the connectors (I have a heat block 'putty' thing for welding) and just blast the top with a torch.

Or try to preheat the whole thing to a safe temperature on a hot plate then use a pace electric solder pump to try to get it off?

Or to heat the block up first but leave an electrical connection and then heat the block more right after putting it down to try to maintain temperature better.

Sounds like you are way overcomplicating this, or I am missing something...  Just use a hot plate?

A Metcal or JBC iron with a big fat tip, combined with desolder braid will open most RF cans IME

I am worried a hot plate will give too much heat into the thing. I suppose I can put a hot plate on it upside down. I don’t want to risk desoldering an 4 pin tiny rf package by heating it upside down and as for heating it right side up I am worried the 50 ohm coaxial connector dielectric will get damaged since the can has high thermal mass and it will take a long time to cool. Maybe a upside down plate would work.. maybe solder braid would weaken it enough to pry open. Maybe that’s ok since this one is 3ghz only... I never had solder wick work good enough for a part to fall off, usually it just gets weakened. I don’t want to damage the housing

This one looks like a thick can, like the ones that are normally screwed on tight. Not a wimpy sheet metal one over a pcb


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