How can I desolder a DIP28 package?

desolder dip chip

Hello,

I've been trying to find a suitable desoldering solution to repair my boards with faulty 28-pin DIP multiplexers on them.

I've searched quite a bit and only found Leister's contactless desoldering stations which are extremely expensive.

I've been told that Weller and Ersa have products that have interchangeable tips for DIP sockets. They are high power soldering stations presumably, and when you change the standard soldering tip with a 28 piece one, the increased power enables you to heat all the pins of the IC at once and take it away with a tweezer.

I have found neither of the brands' products that match this description. Not only there is almost no reference to available tips, most of their soldering stations are 60W.

If anyone has any experience or know of a way to desolder a 28-pin DIP package, please let me know. If I can choose, I would prefer Ersa tips because I have Xytronic soldering station and Ersa tips might be compatible with it.

thanks
norm

desolder multiple pins

If I have access to, I'm using a good vacuum desolder tool, e. g. Weller. I sometimes replaced Z80 processors this way. If the component has very tight drill diameter at it's pads, it may be easier to cut the pins and desolder them individually with tweezers.

The said Ersa desolder tips are still available up to DIL16, I'm not sure if larger variants have been manufactured previously. By the way, a toolmaker should be able to make a custom desolder tip, brass would be a compromise that gives some (limited) lifetime without a galvanized steel surface.

16 pin ic desoldering tip

There are high power soldering irons with bits that will cover allpins, but they are rubbish.
If the device is faulty then you are better doing as FvM sugests & cutting pins & desoldering individually.

how do i desolder

Thanks for the replies

If you have any part numbers you can point me to, it would greatly aid in my research. We will try to build a custom soldering tip for the DIP28 package, but I'm not sure if the poewr output of our soldering station would support it.

We would buy a new soldering station if need be, but we have no product numbers to go by, so we are lost in the redundant universe of brand catalogs.

tssop desolder

I have removed lots of similar chips using just solder wick. This has always worked. Perhaps you might have difficulty if the drill is too small or there are multiple internal PCB layers.
If solder wick does not work, I would suggest getting a hot air rework station. You can use the pencil tip nozzle to wave across the pins and heat them all.
If you have lots of boards to do, another solution is to get a solder pot. These have a little pool of melted solder. You have to make a mask to shield the area that you don't want unsoldered. The you dip the bottom of the board at the DIP28 chip in the melted solder pool and pull the chip from the top.

The good thing about either hot air or the solder pot is that you are not limited to only one size component.

Regardless of the removal method used, you will still need either solder wick or a vacuum desoldering tool to remove the solder from the holes before installing the new chip.

heat tool to desolder chips

Pins attached to power planes can be stubborn to unsolder. I prefer to cut all the pins, remove the body, and desolder the pins individually. The technique also works for smaller parts such as TSSOP ICs. My favorite cutters are the Lindstrom Rx series, such as the Rx8147. They are expensive (about $60 US) but worth it. Don't drop them or cut heavy stuff.
**broken link removed**

tool to desolder ics

For cutting DIP pins on crowded boards, I often use an X-Acto knife with a very pointy triangular blade. Stick the point of the knife between pins 1 and 2 with the sharp edge on pin 1. Then using pin 2 as a fulcrum point lever the knife to slice through pin 1 at the point where it enters the body. Repeat the process of all other pins on that side. The final pin on each side you have to cut with snips as no fulcrum is available.
This method will chew up your X-Acto blade after a couple of ICs, but these are very cheap.

desolder dip tweezer

Use a desoldering tool to remove solder in every pin hole until you can see through to the other side.

In this state use a flat blade screwdriver to alternately prise each end of the IC off the board. The force applied is enough to shear off the small amounts of solder still sticking any pin to the PCB.

If cutting of pins is needed use a mini cutter plier with jaws slim and pointed enough to cut each pin easily.

dip desolder

check http://www.renex.info/pokaz_kategorie.php?cid=75

desolder multiple pin ic

If you do not have the correct tool for the job -----

If you are going to remove the chip, one assumes it is because it is faulty, and needs replacing. ?
CUT the LEGS, and remove each soldered leg individually -- The BOARD is far more important than a $1-$5 chip !!

pace desoldering tips chip

Well, all those are TIPS wonderful, and if you can afford a Pace Desoldering station,
they work wonderful.....but, here is Cheap Charlie's way...

Radio Shack has a Cheap desoldering bulb attached to an iron. I have one,
along with several new tips, because the tips seem to go fast.

You will also need a good 25 Watt (I prefer Weller) Iron with a pencil tip, that
is well tinned, and clean. I have worn out one weller and I am on my second.
They last for years and heat up fast.

Get some .063 Solder (I prefer 63/37) and solder every pin of the IC you are going
to be removing. This will flux the joint and make removing the old solder easier.
Now, heat up the desoldering iron, and remove as much of the solder as possible,
trying to get a free pin. When done take the Weller and flick each pin trying to make
sure it is free and will move. If it is stuck tight, solder it again, and then remove the
solder with the Bulb Iron. Keep repeating these steps until all pins are free and easy
to remove. Then easily use a chip remover to grab the IC and wiggle it free from
the circuit board very easily, because you can very easily lift a pad or rip a trace
right off the circuit board if there is too much solder remaining. I know for sure.
DO NOT PRY UNDER THE IC WITH A POCKET SCREWDRIVER, as you will cut a
trace and won't know it.

I have used this method to repair countless Commodore C-64 back in their day.
The method works good if you aren't in a BIG HURRY. You can also take a small
pocket screwdriver and flick each IC pin to test if it is indeed free of the circuit board.
One that feels tight needs to be reworked.

lkraemer