[maxyeah]

i've tried many times but all failed.i've seen tangent's vedio about desolding ic ,but i think that will be to harmful to the original ic....i also tried a solder wick with rosin but it didn't work(the wick is not normal cheap one which cost me a lot)........i totally feel very helpless......please tell me some tips about soldering and desoldering soic ics.....

thanks a lot!

 

[Jambo]

The way I like to do it is using low melting point solder and lots of flux. The low melting point solder is called "chip quik", but it is pretty expensive.

Either way, I generally find to remove components the best way is to ADD solder. This gives you a bigger reservoir of heat so you can get around all of the pins. Also add flux, this helps the solder flow around under the pins.

Using normal solder, try heating one side of the IC (lay your iron along all of the pins) and then the other, then back to the first one and lift it off with tweezers. Be really careful not to lift pads tho, if it is ready to come off it won't need any force.

Another wee tip, use leaded solder if you can get it - lead free is higher melting point so makes this job harder.

Edit: Just to clarify - I was on about desoldering throughout that post...

 

[tangent]

Quote:

Originally Posted by maxyeah /img/forum/go_quote.gif i've seen tangent's vedio about desolding ic ,but i think that will be to harmful to the original ic

I used to sell AD8610s and 20s mounted on Brown Dog adapters. I probably did a few hundred of them. I don't recall a single one being returned because it was electronically DOA. (A few were smashed by USPS, but...) I used the very same technique as shown in the videos.

No doubt the experience of soldering all those chips improved my technique, but the purpose of the video is to let you look over the shoulder of the master

so that you may emulate him.

Keep trying. Practice makes perfect.

 

[DaKi][er]

Using lots of flux, stick the length of the iron's tip to heat along all the pins on one side and use a thin blade to leaver it up, not using too much pressure as it is easy to lift tracks. The other side is done the same but you can use tweezer instead to lift the part off. If the pins are getting hard to heat up, add more solder and don't be afraid to pile it on there as it is easily cleaned up with solder braid afterwards

I wouldn't be worrying too much about damaging the parts by heating them too much, they'll take a lot more than you think.

 

[holland]

What kind of IC in what package form? It would be very difficult for most DIY people to de-solder some packages and maintain utility afterwards. A package like QFP is very daunting.

For opamps, there are a number of options, the chip quick mentioned. You can get hot tweezers for some soldering irons. You can use some fat chisel tips on some irons (I use this method now) and just lay it across the opamp legs and lift off each side as the chisel tip is big enough to cover one side of the opamp. You can flood and lift. You can suck up all the solder, put a wire underneath, heat up the pad and pull the wire out, lifting up the pins in the process. A heat gun is another, but I've only heard about this and never used it.

Those are all the methods I know and the easiest is to cut the legs and de-solder each individually, which works for everything.

 

[maxyeah]

i have success in 1.27mm (soic ,sop package)sorldering and desoldering with a lot of flux that i bought this morning... but got stuck in 0.65mm(tssop,plcc)....anyway,thanks you all...!!!!

o(∩_∩)o...

 

[Sarchi]

Tangentsoft has a bunch of great online tutorials on this stuff.
Tangent Tutorials

 

[UserNotFound]

Quote:

Originally Posted by holland /img/forum/go_quote.gif A heat gun is another, but I've only heard about this and never used it.

This is by far the easiest way to remove parts from a board. Sometimes you may need a board heater if it has a large groundplane connected to the part, though. And with solder paste, the same method can be used to replace the parts, but I generally just use an extremely fine tip on my Weller.