Lifted pads

[spleenharvester]

Hi all,

Very frequently (at least 1/2 the time) when I do motherboard SMD soldering (eg ceramic caps, SOP-8 packages) I seem to pull the pads off when I lift the part, even though the solder appears to be nice and fluid.

I use a cheapo 20W soldering iron, flux paste, leaded solder, desolder braid. When I try and desolder a SOP-8 for example, I usually lift the legs on one side by running a cocktail stick into the 'groove' behind them, but there always seems to be a pad come off with them.

Does anyone have any idea what I'm doing wrong? Is my soldering iron temp too low? Should I buy a temp-controlled iron, or maybe some sort of hot air gun?

Thanks

[vinceroger69]

Re: Lifted pads

I only do electronics as a hobby but have one of these hot air stations and use it a lot on smd parts/mobile phone/tablet screens and recently changing tv leds it works fine for what i want it for i offered them £25.00 and they accepted ive had mine about two years now and no issues so far with it.
https://www.ebay.co.uk/itm/2-in-1-So...EAAOSw43haHCvX

[diif]

Re: Lifted pads

Hot air every time, unless it's a tiny thing I can remove with a blob of solder on my iron.

[vinceroger69]

Re: Lifted pads

Hot air every time, unless it's a tiny thing I can remove with a blob of solder on my iron.

Diif any idea how you check the calibration on these cheap units? the temperature is easy but air flow do you calibrate it on max or what my usually working air speed would be.

[diif]

Re: Lifted pads

It depends on the job as to the temperature and speed. I work by feel so I don't need to calibrate it. I have it so SMD stuff is not blown around and rarely change it. It's usually the temperature I play around with a little.

[eccerr0r]

Re: Lifted pads

My cheapo hot air unit came with this weird two prong wire thing. It actually is a "pusher" that you use to gently push things off their pads when using hot air. The prongs are made of spring steel and are thin so you can only give so much force to push it off the pads. Of course don't spring it up, lest the component goes flying when the solder melts - it is a spring after all!

I don't know what you can do with a solder iron, sounds like a recipe for destruction if you're using it for surface mount.

[vinceroger69]

Re: Lifted pads

It depends on the job as to the temperature and speed. I work by feel so I don't need to calibrate it. I have it so SMD stuff is not blown around and rarely change it. It's usually the temperature I play around with a little.

This is what ive been doing too be honest, i just heard calibration mentioned in youtube video regarding these stations but i think this was regarding hacked firmware and mines just standard.

[spleenharvester]

Re: Lifted pads

Thanks very much all, I didn't realise hot air was the go-to tool - I thought soldering was first line for basic SMD stuff. I'll buy one of those hot air stations now.

[stj]

Re: Lifted pads

yep, search 858d on ebay.

dont go over 360' and dont leave it on it's side - it can melt it's own case if you abuse it.

[vinceroger69]

Re: Lifted pads

I only do electronics as a hobby but have one of these hot air stations and use it a lot on smd parts/mobile phone/tablet screens and recently changing tv leds it works fine for what i want it for i offered them £25.00 and they accepted ive had mine about two years now and no issues so far with it.
https://www.ebay.co.uk/itm/2-in-1-So...EAAOSw43haHCvX

i forgot too add the link for the extra nozzles i brought
https://www.ebay.co.uk/itm/10pcs-Hea...4383.l4275.c10

[llonen]

Re: Lifted pads

I would not recommend for professional rework purposes and have not used it in a long long time, but Quick Chip might get you out trouble with some SMD rework its a low melting solder alloy which allows the joints to remain fluid for longer. I would say though as above invest in a decent hot air station.

[petehall347]

Re: Lifted pads

quick chip can be bought from elsewhere for lower cost . it is also use for pipe bending in working steam engine models . cant remember its proper name right now .

[llonen]

Re: Lifted pads

Yeah I certainly would not pay what they are asking for quick chip, which is only a Tin Bismuth Sn42Bi58 alloy with a melting point of around 138° C, there are a number of companies that supply the stuff on rolls.