Soldering Trouble.

[VintageTech]

Hello,

Recently I was trying to salvage some components from a vintage PCB.  Everything was great until i tried to heat up a joint to remove some solder.  The solder melted and I was able to remove most of it, but the component, a DIP package, wouldn't go anywhere.  How should I go about getting these components?  Should I cut and file the PCB?  Should I be tackling this another way?

Thank you,

VintageTech

[rob77]

to remove a DIP package you need to heat all pins at once. when the solder on all pins is melted , then just pick the DIP component.
hot air is the best for the job, but there are various other techniques to heat all pins - search on youtube , you'll find some related videos for sure.

[tautech]

IC's can be hard to remove successfully.
For repair/replacement one would cut the pins and remove them later.

You haven't said what your de-soldering method is.
I just use a sucker.

But when you have as much solder removed as possible, wiggle each pin in the hope that the remaining can be broken and free each pin in turn.
I keep a few different heat solders for component removal.
Often one will need to resolder with low temp solder, then re-suck.
Persistence should pay off.

[ju1ce]

Without the it's major pain as very little residual solder is enough to make the pin stick to the pad (especially with plated holes).

[mariush]

You can also see how Ian desolders this chip , he also gives some tips that may help you:

[wagon]

Another trick that you can try, use a very hot iron & lots of solder.  Use the solder to keep heat and melted solder on all pins at once.  Then pop device out of the board.  Then clean out the holes with wick or a sucker. 

[rob77]

Another trick that you can try, use a very hot iron & lots of solder.  Use the solder to keep heat and melted solder on all pins at once.  Then pop device out of the board.  Then clean out the holes with wick or a sucker.

a solder blob to de-solder a DIP 40 would be extreme and solder is expensive !

a cheap hot-air station (or even a paint stripper on lower temp settings) will do the job of heating all pins at once.
 

[SeanB]

Used the paint stripper today. The old Slot 1 Pentium chip did not survive......... The chip did come off, and so did the lid.

[wagon]

Another trick that you can try, use a very hot iron & lots of solder.  Use the solder to keep heat and melted solder on all pins at once.  Then pop device out of the board.  Then clean out the holes with wick or a sucker.

a solder blob to de-solder a DIP 40 would be extreme and solder is expensive !

a cheap hot-air station (or even a paint stripper on lower temp settings) will do the job of heating all pins at once.

I don't do it with devices with more than about 20pins (DIL).  I don't always have all of my toys at easy access, so you have to make do with what you have at hand.

[Richard Head]

a solder blob to de-solder a DIP 40 would be extreme and solder is expensive !

I think Wagon meant heating ONE row of pins at a time.
I sometimes use two soldering irons simultaneously for some stubborn heavy duty parts. It's a bit like using chop stick!

[Rasz]

Used the paint stripper today. The old Slot 1 Pentium chip did not survive......... The chip did come off, and so did the lid.

slot1 ?? were you trying to desolder cpu from slot1 holder pcb? This is very difficult, 240 pins!


find more victims and practice, start with smaller pin count and learn to heat evenly, start with preheating pcb, control temberature
do not use force

[geek]

I know only 2 options: heat all pins at once or use solder sucker

[Rasz]

I know only 2 options: heat all pins at once or use solder sucker

you can also use big stainless needle to get individual pins

[SeanB]

slot1 ?? were you trying to desolder cpu from slot1 holder pcb? This is very difficult, 240 pins!

I found it lying around, and decided to see if I could get the die out. Sadly Intel with this one mounted the die to the heat spreader then did the wire bonding then filled the cavity with epoxy. So not easy to get the die off the epoxy. Did find another Pentium 100 though in a ceramic package that I had delidded years ago, and the solder under the die had corroded finally so the die popped off.

[jancumps]

In some cases, you can forge a soldering device by folding a copper wire in a rectangle/square form that it can touch all pins of the ic, and wrap the end of the wire around your solder iron's tip.

[REHAN JOIYA]

There are many ways to pull out components from PCBs. 1. In simple form you can use simple soldering iron(small tip up to 60 W)  and manual sucker. 2. Some times you need HOT GUN  with specific air pressure & temperature, But in this case you should take more cautious from rubber(melting) components e.g. harness,connectors  and tiny components e.g. capacitor, resistors and so on.
3.you can use mercury because mercury has greater melting point than solder so you can easily
pullout tiny legs of components from PCB. In all cases try lot of  soldering paste.
4. If you have a special electronic lab: then you have already a soldering plant for pulling and soldering components.                         

[rob77]

There are many ways to pull out components from PCBs. 1. In simple form you can use simple soldering iron(small tip up to 60 W)  and manual sucker. 2. Some times you need HOT GUN  with specific air pressure & temperature, But in this case you should take more cautious from rubber(melting) components e.g. harness,connectors  and tiny components e.g. capacitor, resistors and so on.
3.you can use mercury because mercury has greater melting point than solder so you can easily
pullout tiny legs of components from PCB. In all cases try lot of  soldering paste.
4. If you have a special electronic lab: then you have already a soldering plant for pulling and soldering components.                         

mercury ? seriously ?  where the fuck you've seen using mercury to desolder parts ? mercury is freaking dangerous and it makes amalgams with most of the metals.
please stop spreading bullshit on this forum.

[wagon]

mercury ? seriously ?  where the fuck you've seen using mercury to desolder parts ? mercury is freaking dangerous and it makes amalgams with most of the metals.
please stop spreading bullshit on this forum.

Hasn't done me any harm.

*twitch*

[SeanB]

Seems to not be a worry for the illegal gold smelters here, though they often only live until they are 40 or so in most cases. Not a safe as using another low melting point metal or chipquick to make the original solder either brittle or a very low melting point alloy.

[wagon]

What's in that 'chipquik' stuff?

[SeanB]

Bismuth IIRC. It alloys with the tin or lead and makes an alloy that is brittle with low yield strength and which also has a large plastic range. Thus you can easily pop a SMD part off, or break a pin free from a through plated hole.

[ablacon64]

Without special equipment, I use low melt solder to help removing big ICs.

[SeanB]

Oops wrong about Bismuth, there it is Indium, though you probably could use a mix of alloys of Bismuth, Indium, Gallium and NOT Thallium ( toxic stuff) to make a low melting point alloy with tin solders.

http://en.wikipedia.org/wiki/Galinstan is an alloy ( or if you use enough chipquik) that will melt at room temperature. Common use is in thermometers to replace mercury, though it solidifies at -19C.

[kjn4685]

I use a tweezers iron that works for me.

[mazurov]

If you're salvaging the IC in [CER]DIP package cut the pins close to the PCB and later solder to the "stumps" left on the package. If you're fixing a board cut the IC pins close to the package and then heat them up and pull from PCB one by one.

For salvaging parts a heat gun works well also. For best results, practice on PC power supplies before pulling parts from multi-layer PCBs and do it outside.