Topic: Darwin Award for me

[Maumelle Weather]

Hi folks,

Somehow I've managed to solder the SMD that is supposed to go in IC7 to the IC8 spot on the E field amp board. I'm blaming my wife for this one, as she interrupted me in the middle of that. How does one go about removing this, as I have not done that before?

John

[JonathanW]

Hi folks,

Somehow I've managed to solder the SMD that is supposed to go in IC7 to the IC8 spot on the E field amp board. I'm blaming my wife for this one, as she interrupted me in the middle of that. How does one go about removing this, as I have not done that before?

John

Do you have desoldering wick, or a solder sucker (Radio Shack sells both)?

On the other hand, if you move quickly, on a small part like that you might be able to melt the solder quickly enough that constant lifting pressure (e.g. light prying with tweezers) might remove it.

Radio Shack might also sell an attachment for soldering irons designed to heat all pins simultaneously.  At least, they used to.

[W3DRM]

John - solder wick or sucker should do the job nicely. However, whatever you do, do it very carefully and do not overheat the pads or they may come loose.

[Jumpin Joe]

John,

Both methods work well.... I know, I had to remove and re-solder one. I found using the tweezers with a constant upward lifting motion while heatig the feet worked best. Once off, I used a wick to get the pads clean.

I won't tell you know who, that you blamed her..... you'd be staying in the pool house instead of the house. 

I sent you an email.....

Joe

[Einar]

or a solder sucker (Radio Shack sells both)?

If it is the one where you cock a spring and release to suck, please dispose of it where it belongs: In the trash. When it is released it will kick the PCB hard! This can lead to component and/or PCB failure.

If it is the type with a vacuum pump connected to a hollow soldering bit through a hose, it works without any problems. Other than it's elevated price tag.

The bulb type is also OK, although not as effective.

[JonathanW]

or a solder sucker (Radio Shack sells both)?

If it is the one where you cock a spring and release to suck, please dispose of it where it belongs: In the trash. When it is released it will kick the PCB hard! This can lead to component and/or PCB failure.

If it is the type with a vacuum pump connected to a hollow soldering bit through a hose, it works without any problems. Other than it's elevated price tag.

The bulb type is also OK, although not as effective.

Lol - I have the spring type, but just assumed my inability to use it without knocking the board around was due to inexperience   Glad to know it's not just operator error.  I'm much better with the wick.

[Einar]

The wick is fine. Just be aware it should have a "use before date". If it seems it does not work like it used to, that's probably true. Buy a new one. And keep it in a ziplock bag when storing it for some time.

When I did not follow my own advice, I use the liquid flux together with it to save myself from embarrasment.

[Cutty Sark Sailor]

Man, I've been using "solder suckers' since 1968... it's about the specific type, SS Tip, Solder amount and type... experience! and familiarity with the type of SS you're using .... but then wick is great, also, and for many situations wick is the best choice.... both have their applications, and knowing when to use what is also experience. SMD removal can still be a pain, with typical equipment,  and a lot depends on the type solder used and your other tools...  Sometimes ya just have to load the device with gobs of solder, use wick, and pray to whatever Higher Power is nearby... then Joe's method of "gentle upward pressure on each pin" with a tiny fine point 'scribe'... but, if there's an abundance of solder, even that doesn't work well...

Cross your fingers and do your best...

[n2qew]

A technique I've use for surface mount - especially very fine pitch devices much smaller than the soics involved here - is literally lots of solder and resin based flux. Also, a temperature controlled iron.

Basically, to remove that SOIC, I'd basically make a ball of solder around all the pins on both sides, and lift the chip with needlenose pliers. Then clean up the board with solder wick. The key here is work fast, make sure that lots of flux is present, and most of all, make sure that the solder is molten before lifting the chip. Drop chip on damp paper towel or sponge. Then clean pins with solder wick. Ideally, the solder is at less than 500 degrees, and you work fast enough that the chip (and board!) is nowhere near being damaged from heat. Trying to desolder surface mount pins to remove parts is just asking to destroy the board. 

Here's a youtube video. The guy that did it was maybe a little too generous with the solder, and almost had to do other clean up work, but it shows the concept I'm trying to get across. . http://www.youtube.com/watch?v=V0BHk0Js1t4

Before trying it here, play on some junk equipment first, and remove components there.

[Cutty Sark Sailor]

Sometimes ya just have to load the device with gobs of solder, use wick, and pray to whatever Higher Power is nearby... Cross your fingers and do your best...

Basically, to remove that SOIC, I'd basically make a ball of solder around all the pins on both sides, and lift the chip with needlenose pliers. Then clean up the board with solder wick. The key here is work fast, make sure that lots of flux is present, and most of all, make sure that the solder is molten before lifting the chip.

Yeah, somebody always explains it better.. good job n2qew