Difficult soldering problem

You did not make it clear, but have you actually tried wave soldering?

A solder wave can usually thoroughly and quickly heat up even a big, solid ground plane.

I've just done a board with groundplanes both sides and a dense forest of thermal vias. They all filled up with solder nicely.

If the back side is bare, you could use a hotplate to heat the PCB itself up to just under the solder's melting temp, then an iron could solder those joints without letting anything else move. Otherwise, a preheat in an oven might help.

Perhaps a hot air gun on the back side of the pcb might work also.

Are those connectors hand-soldered? If yes: I normally use the big iron for that, a 150W standard soldering iron (Ersa brand) with a tip of huge thermal mass. At a client I ran into a similar issue so we bought one of those 100/140W Weller soldering guns. The ones that sell for $39 and sometimes are on sale for $29 at hardware stores. Home Depot and Lowes usually carry them.

Chances are the layouter may have forgotten to put thermal reliefs in. I'd check the Gerbers.

You either need a massive thermal mass in the iron or it has to keep pumping large amounts of energy into the tip like the Weller gun does. A normal small Weller station pencil doesn't have enough mass and not enough power to feed the tip for such jobs.

That won't work. I always use a heat gun (aka paint stripper, BBQ lighter) for these kind of jobs.

Joerg wrote in news:yDtIj.23180$ snipped-for-privacy@newssvr13.news.prodigy.net:

I used to be able to solder almost anything with a 60w unregulated Hexacon iron with a 1/4" solid copper chisel tip.

Any power rating can be sufficient if the tip has enough mass. But you can't solder one after the other with that, got to let it heat back up. I found that 100W is pretty much the lower limit for heavy connectors so I bought a 150W iron for those jobs.

Maybe look for something installed as press-fit, not relying on solder for a gas-tight connection. Not so common in SMA.

Amp does rf and fibre-optic housings.

The square pin in the round hole technique can work for ground if the signal pin is suitably dressed.If the board and housing are noble metals, you don't want solder in there anyways.

This can be just as labour-intensive as manual soldering, however.

RL

There are a few things that one can do to insure a heavy duty solder joint gets formed correctly.

For this, I would make sure to have some liquid flux of the type you use in your process. This is key, and is beyond what is supplied inside the solder being used.

Then, I would add a bit of flux to the four ground lug/legs of the connector (if I got your description right). Set it aside... the flux will de-oxidize the pins and make them easier to wet with the solder.

While that marinades you should add a tiny amount of flux to the PCB. I do this by adding a tiny drop onto the end of my solder, then I apply the solder to the PCB. The drop transfers. Then, take a heat gun, and pre-heat the PCB a couple hundred degrees. Be sure to localize it if there are parts in proximity (or put the connector on first), snap in the connector and keep heating. Add a drop of flux to your solder, and grab your high wattage iron and turn off the heat gun, and make the solder joint. The flux drop hits the hot parts at the moment your touch, and the iron makes the joint better because of the pre-heat.

Pre-heating the entire assembly is also acceptable, if that is your preference.

The key is flux and pre-heat, and a good hot iron.

Sweet. My Dad has a 300W iron with a bare copper tip that was used for explosive rivets back in the day. It also makes quick work of RF enclosures and pesky connectors. But I have to constantly file down the tip as the copper dissolves. One day, the tip'll be gone.

Sometimes when you have multilayer boards, you have more than one ground plane. If the properties are not properly set up, the CAD package will tie the ground pins of the connector on each plane... This makes a "thermal relief" into a full contact.

Use Ersin sav-a-bit solder. it already has about 2% copper in the alloy to stop the erosion.

I've used HOT AIR irons to push solder into the holes. it seems to work for me.. It takes a little practice how ever to get it right.

I have the similar experience. The solder does not flow into the hole, not because the heat is not enough. it might be the pin is dirty or rusty, you may clean it first, and treat it with some solder oil if possible.

Hope this would help.

Use Ersin Multicore Savbit and the problem with the bare copper tip will "magically" dissappear. The trick is that Savbit has 2-3% copper in a eutectic alloy with tin and lead.

...

I have a big mongo iron (> 100W) that I "liberated" from the USAF. I've used it for car radiator repair. ;-)

Cheers! Rich

...

Just for the sake of pedantry, the item you're marinating marinates in the marinade. ;-)

(or maybe that's "gets marinated"...) ;-)

Cheers! Rich

"mongo"? I always thought the word was "mondo" (probably due to the release of the movie "Mondo Cane" in my student years and the subsequent studentese word "mondo" referring to anything large or numerous.

You're never seen "Blazing Saddles"?!

Rich Webb wrote in news: snipped-for-privacy@4ax.com:

the guy who punches out the horse! (played by Alex Karras)

The right word IS mondo, and it has been for decades. Surely long before the movie came out.

In other words, saying:

"You are a mondo idiot."

is correct, whereas saying:

"You are a mongo idiot."

sounds more like you are the butt buddy of a big oaf.