Might be an age old question here,
Im starting to think my soldering skills are not quite as good as I thought.
I have this cute little station
X-TRONIC 3000 SERIES - MODEL #3010-XTS VARIABLE POWER 70 WATT SOLDERING STATION WITH EXTRA HEATING ELEMENT AND SPONGE, BRASS SOLDERING TIP CLEANER INCLUDED WITH A SUPPLY OF FLUX IN THE BOTTOM OF THE CAN - - Amazon.com
And what I thought was a bad transistor shipped to me, but im starting to think I am burning things up with the iron. My boards are loosing their glue also. But the solder is not melting "as seen on tv", unless the iron is turned up.
How hot is too hot?
And any suggestions how to repair a burned/broken connection on a board?
The metal round tabs on the board have literally come off (from heat i believe)
Im starting to think my soldering skills are not quite as good as I thought.
I have this cute little station
X-TRONIC 3000 SERIES - MODEL #3010-XTS VARIABLE POWER 70 WATT SOLDERING STATION WITH EXTRA HEATING ELEMENT AND SPONGE, BRASS SOLDERING TIP CLEANER INCLUDED WITH A SUPPLY OF FLUX IN THE BOTTOM OF THE CAN - - Amazon.com
And what I thought was a bad transistor shipped to me, but im starting to think I am burning things up with the iron. My boards are loosing their glue also. But the solder is not melting "as seen on tv", unless the iron is turned up.
How hot is too hot?
And any suggestions how to repair a burned/broken connection on a board?
The metal round tabs on the board have literally come off (from heat i believe)
Probably you need more experience, so practice on some scrap pcbs, and use only eutectic solder (63/37 type).
The solder should melt within a second or two, but only run the iron just hot enough to do this.
Wipe on a wet sponge just before soldering each joint.
That's problem with them Higher power/Hot as hell Irons dude....especially anything PCB/Silicon related...too easy to overheat/burn/melt stuff.....get you lower power/colder iron.
I do all of this. And tin the iron all the time. Is it the iron or the tip? I have read preferences between fat tips an the thin "pencil" tip.
To get the solder to melt within a few seconds, the iron seems to have to be turned up. But then Im risking the board.
Should I go with a fatter tip?
I do confess that I turn the iron on about half way, let it warm up.. touch the solder... doesnt melt... turn it higher...doesnt melt.. turn it higher... poof,,there goes another burn spot on the board.
Thats when I started thinking, why does the tip not melt the solder?, but when I tilt the iron slightly to catch the fatter part of the tip, it seems to work ok. Unfortunattly, some of the components are hard to get to when tilting the iron
Very frustrating
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Yes, the shape of the tip is very important, a small chisel tip is the most useful type in typical work.
Don't use a long narrow tip of any type, too much temperature drop along the tip.
And thats what I have, the long narrow tip. Was extremely hot, but not melting anything, just over heating. And I think I burned some of my MOSFETs in the process. The heat was to the point where I couldnt touch the Mosfets, yet was not melting the solder.
Time to change
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It sounds like the iron has poor temperature regulation, nothing you can do about that.
A long heat up time, patience required.
Low thermal conductivity between the element and the tip, try a bit with a fatter tip.
Also possibly poor tip plating so that the tinning hasn't worked.
If the FETS are dying it might be leakage current. Is there a connection between the tip and mains earth? It should read some resistance between the tip and earth.
A long heat up time, patience required.
Low thermal conductivity between the element and the tip, try a bit with a fatter tip.
Also possibly poor tip plating so that the tinning hasn't worked.
If the FETS are dying it might be leakage current. Is there a connection between the tip and mains earth? It should read some resistance between the tip and earth.
Not much warm up time, and I can hear it cycle on and off to keep constant temp. I will try a fatter tip.
Thanks,
It is leakage current.
With FET (supposibly) off, im still getting 239mV, with on I get the normal 498mV. Between Source and Drain (with diode mode)
Unless you ment leaking voltage between solder tip and FET, then excuse the post
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Is the tip bright shiny and clean? If it is adjustable, set it for something average like 700 degrees and leave it. Once it has warmed up, does touching solder to the tip melt right onto the tip? Or do you have to hold solder to the tip for a few seconds and then the solder melts into a little glob, but doesn't "wet" the tip?
Yes.
My guess is around the 700 mark. (alittle past 3/4 full level on the station)
The solder has trouble at the point of the tip. But tinning works well.
The glob stops at a certain temp, but that same temp is tending to damage the component and board.
I will try a fatter tip.
The problem, is that the point wont melt, the solder right away. I have to bring the solder up alittle on the fatter part and let it leak down on to the board, but by then the board is bubbleing...lol
the Tip of the point might not be tinned.
Don't scrape it. You could remove the iron coating.
Try using a more aggressive flux to ensure the tinning extends right down to the tip.
Once you have the tip tinned properly and the temperature set high enough the "tip" should melt your 22g cored solder.
Is your solder flux cored?
Is your solder lead based?
Is your solder electrical grade? 60/40 will do at a push, but 63/37 is eutectic and is what you should buy.
40/60 is no good for electrical work.
Don't scrape it. You could remove the iron coating.
Try using a more aggressive flux to ensure the tinning extends right down to the tip.
Once you have the tip tinned properly and the temperature set high enough the "tip" should melt your 22g cored solder.
Is your solder flux cored?
Is your solder lead based?
Is your solder electrical grade? 60/40 will do at a push, but 63/37 is eutectic and is what you should buy.
40/60 is no good for electrical work.
I did mean leakage current from the soldering iron, though I didn't make it clear. As the FET gates are high impedance the soldering iron may be applying enough current hence voltage to blow the FETs which could be causing the FET leakage current that you describe.
Thanks. I figure its either the heat or leaking voltage from the iron, hence "irion killed my FETs"...lol
But I think by changing the iron's tip for alittle fatter, the iron wont have to sit on the board as long to damage anything.
I presume this is a small-signal FET (like a small, 2N2222 size transistor) and a "regular" size trace on the PCB. These should be easily solderable with a thin "small" tip. First rule is keep the tip clean and tinned. If the tip doesn't melt a thin wire of solder when touched to it almost instantly, then the tip is either dirty or not hot enough.
If the connection is to a large area of copper on the board, then putting the tip on the board may suck up a lot of heat, possibly lowering the temperature below the solder melting point, or causing a 'cold' (bad) solder joint. For this, a larger chisel-style tip is needed.
For static-sensitive stuff (which a FET clearly is), connect a jumper between the iron and a "ground" trace on the PCB before soldering. This will prevent a voltage difference between the iron and any component on the board.
This is another thing - with the tip barely hot enough to melt solder, it may take several seconds for the solder to melt and make the connection. This gives time for the heat to go up the lead into the component and overheat it. The tip should be hot enough that the solder melts on the board and "wets" the component wire within about a half second to one second, and then once you notice it has melted and connected everything you should immediately pull away the solder and tip, and let it cool. Be sure component leads and the PCB are clean to get good heat transfer from the tip to them.
Also, did anyone say something about keeping the tip clean? Wipe all sides of it on a damp paper towel, then immediately touch a bit of the solder wire to it. Then you're ready to solder a connection.
Also, you can use a "heat sink" for the leads of heat-sensitive components. Heathit transisorized kits used to include these, with instructions for use. But you can use needle-nose pliers with a rubber band around the handle to keep them closed, and clamp each lead between the board and the component as you solder it on the other side.
Modern semiconductors can tolerate higher temperatures than they could back then (when I was a 10 year old building Heathkits), but if you're worried and/or it takes you several seconds to solder a connection, you can still do it.
Wrap all 3 legs of the MOSFET with a thin metal wire so that they are all shorted before inserting the component into the PCB, then solder and unwrap the wire. You will not kill a MOSFET again with your iron.
Make sure the board and components are prepped for soldering. By this I mean that very often there is oxidation on the copper traces and donuts, and on the leads of components. This can reduce flux effectiveness and heat transfer, preventing the solder from wetting. The oxidation can be removed with emory cloth, an ink eraser, a small file, etc.
And don't overheat the board or parts. If soldering isn't successful the first try, remove the iron and let things cool. Then try again.
And don't overheat the board or parts. If soldering isn't successful the first try, remove the iron and let things cool. Then try again.
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