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dnny
Joined: Mar 12, 2005 Posts: 519 Location: Helsinki, Finland
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Posted: Tue Jun 28, 2005 2:27 pm Post subject:
soldering temperatures ? |
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hi
i was just thinking that i have been soldering for a while now but i don´t know how my iron should be set?
i know that IC´s are pretty sensitive but how about other components?
what is the save temperature for IC´s and there must be some time limits also - is there any general guidelines to this or is it different on every IC?
i just keep it hot - but some times i am afraid that i damage the components.
thanks
daniel |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
Audio files: 278
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Posted: Tue Jun 28, 2005 2:50 pm Post subject:
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Hot is not a bad idea as you can work faster that way, too cold is a disaster and doing much more damage to both components and PCB. I think the girls at my workplace use about 240/250 deg Celecius normally, hotter for components with a lot of heat capacity (like when the heatsink of a component has to be soldered onto the PCB).
But don't worry too much, reflow soldering imposes more heat stress onto components than hand soldering does (assuming some experience of course), and most components nowadays are rated for reflow soldering. Reflow soldering has to be tuned carefully, especialy when mixing large and small components.
In the days of germanium transisors we were tought to use tweezers on the leads to keep the heat out of the transistors. Those days are over luckily but still take care a bit with opto isolators - when they get too hot the isolating transparent window can get opaque.
Jan. |
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3phase
Joined: Jul 27, 2004 Posts: 1183 Location: Berlin
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Posted: Sun Jul 31, 2005 4:55 am Post subject:
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Blue Hell wrote: | Hot is not a bad idea as you can work faster that way, too cold is a disaster and doing much more damage to both components and PCB. I think the girls at my workplace use about 240/250 deg Celecius normally, hotter for components with a lot of heat capacity (like when the heatsink of a component has to be soldered onto the PCB).
But don't worry too much, reflow soldering imposes more heat stress onto components than hand soldering does (assuming some experience of course), and most components nowadays are rated for reflow soldering. Reflow soldering has to be tuned carefully, especialy when mixing large and small components.
In the days of germanium transisors we were tought to use tweezers on the leads to keep the heat out of the transistors. Those days are over luckily but still take care a bit with opto isolators - when they get too hot the isolating transparent window can get opaque.
Jan. |
I wanted to mess around with germanium transistors a bit ...and came across your germanium quote...
Are there special reqirements in handling them? Are they more sensetiv to heat than silicium transistors?....
On my soldering station I usually are around 310 deg... But its more used for kabeling... But found it convienient for electromics aswell...At least these kind of electronics where you still use normal szise components.
As Jan said this way its quick, and cold soldering points can´t happen when you do it too fast for the solder to really swim in place.
A thing that easy happens when you lots of points next to each other.
So beeing too carefull with the components can lead into more trouble than heating it up in an quick ,precise and thoroughly way.
Its really about giving the heat no time to travel up in the component...
There fore really forcing it at the beginning can help.
You also have to understand that the solder is actually like a liquid that just looks solid because it moves too slow.
When you want it to go to a specific place you have to warm it up in the same time you applying heat to the new housing for the solder.
Giving it a warm place where it can sneak in when its liquid enough.
Lots of soldering beginners apply heat only to the parts to be soldered ..and that heats the components up to a degree where they can be destroyed. The solder is transporting the heat much better once in its thin state as the tip of your soldering icon can do.. The solder slips in the smallest holes bringing the heat there. Its really like a liqued..once the soldering point is flushed you see when it comes to a rest and the little soldering lake is shiny... So you also know when having applyd to much solder. When it looks rather like a ball than a lake its too much
I just got an idea why in the old valve equipment every part is wrapped arround 3 times or more around the soldering pins..
They was more aware about the liquid nature of solder and havent trusted the connections so much |
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jksuperstar
Joined: Aug 20, 2004 Posts: 2503 Location: Denver
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Posted: Sun Jul 31, 2005 8:41 pm Post subject:
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700 deg F is what I use. Although 600-800 is used in general. It heavily depends on
1.) how much mass your soldering iron has compared to what you are soldering
2.) What temp your solder will flow at
3.) how sensitive your electronics are.
Like Jan said, today's electronics are "wonderful" to work with, though we may rethink this once lead-free is ubiqutous You have to crank up your iron to solder something very large -- ie-something too large for your iron:)
But, practice with your soldering gun and the solder you use...I try to have the solder melt within 2 seconds (or so), and completely flow under surface pins or into vias with 3-4 seconds. Once you get everything "right", it should take about 2 seconds *total* time for smaller pins & surface mount, and maybe 3 seconds for a through-hole part. My technique is to touch the "dry" pin/pad for a second or so, then apply solder. This preheats the metals to be soldered, and allows the solder to attach to them easily. This is important, as a cold solder joint (something that looks soldered but isn't) often takes several seconds to reheat/flow, causing much heat to be absorbed by the part your soldering. That's when I pull out my pair of tweezers or hemostats (the kind that default to closed when you let them go, and you have to force them open).
But, I often need to desolder a component, by using solder braid, which takes even longer than reflowing a cold joint. And things haven't failed (much). That should make you feel comfortable about it.
Last, for packages like DIP or SOIC (etc), you can solder every other pin, or zig-zag from side to side, to distribute the heat, instead of concentrating on each pin consecutively. |
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