solder recommendations / opinions?

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maxtim
 
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Post by maxtim »

kokoon wrote:hello i have another question :)
i just bought solder that reads Sn60 Pb38 Cu2.

hmm i wonder if it's got any flux hidden in it... cause if it hasn't i don't like it.

it also says Fg.2,5%
what do you think about this one?
63/37 tin lead would be easier to work with, but the solder quoted will be OK. It does have a 2.5% flux content.
You can test it by just melting it on a safe surface. If it balls up it has flux. if it does not form itself into a ball it is dry.
Make it easier on yourself and get some ROSIN FLUX.

I wouldn't worry too much about tin wiskers. Not that I deny that they are a true phenominon, but the industries general concern is not in assemblies of this scale (the x0xb0x), the concern is in micro circuits using chip-scale packages (way smaller and tighter than that 1 SMT USB microchip on the x0xb0x) with extreemly tight tolerences (space between solder connections). Tin wiskers have not been known to grow long enough to effect the spacing apparent in the x0xb0x's circuit board. Even if it did happen in a circuit of this nature (relatively high-power analog circuitry), it would probabblu just be voporized by the amout of current and voltage present.

:idea: Speaking of the smallest chip on this board. The surface-mount microprossesor. To solder this part is pretty easy if you have good eysight( or a visual aid of some sort ) and most importantly a steady hand (don't injest caffeen and get sleep befor attemping). Also, decent, clean, fully functional equipment is key. Test the tip of your iron. When you melt solder on it, does the solder spead over the entire tip or does it ball up and fall away. If it balls up and is repelled fron the tip, the iron tip is corroded and will not work. You can try to revive it by scraping the layer of corrosion off gently (the plating is delicate) while adding solder at the same time till the molten solder spreads cleaned surface of the tip.
To solder this component:
1) Put a fine layer of flux on all the pads on the PC board.
2) Add small amount of solder to the bottom right pad (assuming right handedness on this and all other steps)
3) With your left hand with a pair of tweezers, grip the compenet by the body and correctly orientate and position it on top of and in the middle of all the pads
4) Maintain position and with your right hand use the soldering iron and tap the 1 pre-tinned pad (the one with solder on it). It should melt and attach.
5) solder 1 pin on the opposit side of the component (or 2, no worries if it bridges at this point)
6) Check alignment of all leads (component legs).This is key. The better the alignment, the easier the soldering will be. A little drift is OK, but if the leads are more than 20% off the pads you will have to do a little adjusting by heating one of the 2 solder connections and re adjusting the component.
7) Now add flux agin to the part of the component leads that are on top of the pads.
8} Find a way (angle) in which your iron tip will touch 2 leads at the same time.
9) Very gently place (not push) your soldering iron on tips 2 leads, slowly add solder and at the same time start to drag your iron down accross (left to right) the row of leads. Look sharp and you will see the solder will follow the heat source (the iron tip) and if you dont add more solder than what will bridge only between 2 leads, the perfect amount of solder will be left behind on each lead as you drag past it with the little ball of molten solder on the tip of you iron.
10) if done correctly you will have only the last 2 leads end up bridged. Add a little flux to the bridge (this will work for any solder bridge you may come accross) clean all solder from the tip of your iron. Put the iron tip in the middle of the bridge and pull straigt away once the solder melts. It will always migrat to the heat source, so now the excess solder is now on your iron tip and no more bridge.
11) repeat for remaining 3 sides of the component.
12) Inspect your work and touch up any problems (opens and/or bridges). Use solder wick if more than 2 leads in a row are bridged. Add flux to your wick to make it work really well.
This method (drag soldering) will work on any multi-leaded component, even the Through-hole IC's and such.

Hope that made sense. I used to train personnell in this method. If this is your first try soldering, get the chip pre-installed, unless you can find something else to practice on at least a couple of times.

Cheers :)

cheesy
 
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Post by cheesy »

What are the risks involved with and precautions that should be taken when using lead solder?

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maxtim
 
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Post by maxtim »

Danger of lead solder :shock: :
Keep it away from children. It causes growth problems.
Cumulative toxin that your body cannot rid itself of.
Just don't put it into your mouth. Wash your hands after use. Don't eat while soldering. Don't handle it if you have open wounds on your hands.
The smoke that is produced while soldering does not contain lead, it is just the flux burning. Lead is a heavy element.

Cheers

steev
 
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Post by steev »

Ok I've finally found a source for some 63/37, it's available in 0.4mm and 1.2mm..

Will 0.4mm be good for this project?

steev
 
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Post by steev »

steev wrote:Ok I've finally found a source for some 63/37, it's available in 0.4mm and 1.2mm..

Will 0.4mm be good for this project?
I messaged the guy on Ebay and he did have 0.8mm too.

Here you go UK People, 63/37 Rosin cored 0.8mm Solder in 500g (1lb) spools. I just ordered one, the guy was very quick and helpful by email.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 5826292901

steev
 
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Post by steev »

"Thin (Silver) Solder or Solder Paste. For soldering the surface mount component"

Is this just for the USB component? (I had that prefitted).

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subatomic
 
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Post by subatomic »

What temperature iron is everyone using?
Seems this should be on the forum already, but searching I didn't find it...

I've been using 500deg F, any less and it was too hard to melt the stuff.
I keep the iron on less than 3 secs.
I'm using the 63/37 kester, which melts at 361deg.

steev
 
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Post by steev »

Temperature.. Good question which I was about to ask.. I just Picked up a second-hand Weller WS80.. that goes up to about 500 degC I think.

cheesy
 
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Soldering Irons?

Post by cheesy »

How about recommendations for soldering irons? I hear Weller irons are good. Right now I have a crappy Radio Shack iron but would like to invest in a nicer one with adjustable temperature, etc.

Suggestions? Thanks.

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subatomic
 
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Re: Soldering Irons?

Post by subatomic »

cheesy wrote:How about recommendations for soldering irons? I hear Weller irons are good. Right now I have a crappy Radio Shack iron but would like to invest in a nicer one with adjustable temperature, etc.

Suggestions? Thanks.
I bought the $70 Mega RC iron (it is made by Zhongdi).
It has a temperature sensor, and so far has been really nice.
I too had a RadioShack iron, and this is sooooo much better.
Compared to the comparable Weller model, this was very inexpensive.
I'm using the screwdriver tip (you have to buy it separate), which is working well for this project so far.

Image
UPDATE: found this Iron for $40: http://www.mpja.com/
Last edited by subatomic on Sun Nov 20, 2005 9:00 pm, edited 3 times in total.

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subatomic
 
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Post by subatomic »

steev wrote:Temperature.. Good question which I was about to ask.. I just Picked up a second-hand Weller WS80.. that goes up to about 500 degC I think.
Well don't trust me on that number.
I was coming here to ask other people in case I'm burning stuff and not knowing it.

On the other hand, you might like to know I've built both the PSU and the VCO already with no problems (everything tested fine).
So 500deg may be good (i'm sticking with it unless I hear a reason to change).
Last edited by subatomic on Mon Nov 07, 2005 6:29 pm, edited 1 time in total.

steev
 
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Post by steev »

I got a secondhand Weller WS80 on Ebay for £60 including postage ($104US)

They cost about $250 brand new in the UK.. but are probably much cheaper in the US.

It seems to be a pretty similar model to the one suggested in the manual.

Image

bicky
 
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Post by bicky »

there are only three places where salesmen (somehow) make customers feel like dumb noobs :roll:
the record store, the hifi store and... yes, the DIY electronics shop...

but apparently when you start asking for 63/37 solder and the type of flux in it, they look at you like you're coming from Mars... 8)

so to cut things short,
i learnt that
- the 'pro's' from the local electronics shop are noobs like me :)
- the pro's can be found on this forum :)
- and 60/40 solder will have to do :(

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subatomic
 
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Post by subatomic »

bicky wrote: - and 60/40 solder will have to do :(
don't worry too much about it. I also have 60/40 .031" solder and it works almost as well as my 63/37 .020". I only use the thinner 63/37 when I'm really paranoid and want it to melt "instantly".

If I had to guess, the size of the solder wire matters a lot, even more than the melting point, since it would come up to temperature much faster with less mass to heat... I wouldn't want to do this project with a big fat solder wire... :)

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ceedub
 
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Post by ceedub »

I'd like to contribute to the temperature bandwagon. Our Creator informed me that "650-680degF is good". I am using the Weller ES-51, so I took this to mean that the dial should be somewhere between the 60 and 70.

Hope I got that right.

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