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Topic: Soldering Hell (Read 4026 times) previous topic - next topic

codlink


Do your boards have soldermask?


Yea

I tried tinning the wick and it works.  But I still want to get the solder to flow correctly without having to "clean up."  I have few ideas that I am going to try, one of them is to tin the pads before placing the IC.
//LiNK

oric_dan

Good point, which should have been mentioned previously. I always dab a bit of solder
on the chip pins before placing on the board, and I also usually take the exacto knife
and scrape the oxidation off the pins before that. I'll bet if you try this last bit it will
make a big difference. The solder will flow right to where it belongs without blobbing
up. Flip the chip over, and pre-tin the legs after scraping.

I'm sure the "official" smt fab schemes are designed to get around these silly extra
steps, but I don't do much smt fab.

bosleymusic

If you're using paste, you should try using a stencil instead of a syringe. You can also get cheap boards with solder mask in low runs from a company called OSH Park. Solder mask can make a world of difference in how the solder flows and lays out.

Boardburner2

#33
Feb 12, 2015, 01:14 am Last Edit: Feb 13, 2015, 03:15 pm by Boardburner2
This is an old thread.

I have had similar threads pop up recently for no apparent reason



raschemmel

#34
Feb 12, 2015, 02:49 am Last Edit: Feb 12, 2015, 02:51 am by raschemmel
I agree that flux is a great thing to have, but I solder all the time and don't usually need it. I know I need it if the solder doesn't flow onto the part and then I go hunt some down .  I think the problem is none of the above but the OP's technique.

@OP,
Are you  aware that the iron tip needs to "tinned" before you can start ?
Do you know what that means ?
Do you know that if the solder doesn't melt when you touch it to the iron tip at the point of contact, 2 to 3 seconds after touching the iron to the part that something is wrong ?
STEP-1: Warm up iron
        2: Tin iron tip
        3: pick up solder with left hand
        4: pick up iron with right hand
        5: touch tip to part, wait about 1 to 2 seconds
        6:  touch solder to part at point of contact closest to the iron tip
         7: wait a second or two for the solder to flow
         8: when the solder flows, remove tip. (tip should not be in contact with part > 5 seconds

If the solder isn't flowing either the part is contaminated (and needs cleaning with Muriatic acid (10%)
or you need flux to get it to flow. Flux is essential for surface mount work and soldering heavy guage
wire but isn't 100% necessary all the time. As I said, I know right away if I need it and that's when
I get it. If I'm working on surface mount I won't start without it.


Quote
This is an old thread. 
Oh damn ! I didn't catch that . oh well...
Arduino UNOs, Pro-Minis, ATMega328, ATtiny85, LCDs, MCP4162, keypads,<br />DS18B20s,74c922,nRF24L01, RS232, SD card, RC fixed wing, quadcopter

Marmotjr

Necro'ing an old thread such as this one is not bad, as there seemed to be lots of good info in it.  It's when somebody answers an old thread as if it's an actual response and doesn't add anything pertinent, that's a problem. 

Boardburner2

Thanks all for the quick replies.

I have a temperature controlled iron from Maplin (which I run at 350c, it'll go to 450c though) and I broke out some new tips this evening just for the sensor, I've got 1.2mm lead free solder.

This is the iron I use: http://www.maplin.co.uk/48w-lcd-display-solder-station-98133

I have a flux pen but if I'm honest I don't know how and when it should be used.

My solder station came with a sponge which I use all the time to keep things clean.

I'll get some leaded solder and see how that goes as a starting point.

Dave
Sorry I cant follow that link.

I had one from maplin where the tips were very difficult to wet for some reason

Boardburner2

Oh damn ! I didn't catch that . oh well...
ARRGH
Done it again

Marmotjr

ARRGH
Done it again
Seriously?  LOL.

You necro'd your own necro.... that's a new one.... I'll have to add that to my scoring system...

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