Recommendation for de-soldering station for through-hole repair

[timg11]

I have a number of almost 40 year old double-sided boards with unsocketed DIP ICs I'm working on restoring and repairing.


I'm looking for a good quality desoldering station that will allow the DIP ICs to be removed without damaging the board or traces.

I've looked at the Chinese "Proskit" type, but they seem to be too low of quality, and are not available from reputable sources.
I was able to borrow a Hakko FR-301 for a day, and it kind of worked, but didn't seem to extract enough solder to allow the DIP removal, and left so much residue in the hole that a socket could not be inserted.

Can anyone recommend other options for desoldering stations? There don't seem to be that many around these days....

[kripton2035]

it helps often to extract, then put fresh soldier on the pins, and extract again.
the fresh flux inside the soldier makes the removing easier.

[bdunham7]

It can be tricky, especially if the boards are dirty.  I'd start by cleaning the area with IPA.  PDIP removal can be tricky, here's what works for me.

First, the FR-301 is excellent.  I haven't used the Pro'skit one, but Pro'skit stuff is generally of acceptable quality.  The key points with desoldering are making sure the equipment is working perfectly and having the right nozzle. I use an extended snout 1.0mm with the FR-301, I'm not sure what is available with the Pro'skit model.

Some items you need or may want, depending on what procedure you want to use and whether you want to save the chips themselves:

PDIP puller: https://www.ebay.com/itm/124627920061?hash=item1d046724bd:g:PhcAAOSwjGVgSrnb

1.0mm extended nozzle: https://gokimco.com/collections/hakko/products/hakko-n61-12-high-power-desoldering-nozzle

Low-temp solder and flux: https://www.amazon.com/ChipQuik-SMD1-Leaded-Temperature-Removal/dp/B0019UZP7I

Hot air station with small nozzle: https://www.amazon.com/Rework-Solder-Station-Soldering-Welding/dp/B07Y7ZCVT2

or, possibly, a PDIP soldering iron tip (not the way I do it) : https://www.digikey.com/en/products/detail/stan-rubinstein-assoc.,-inc-dba-sra-soldering-products/AOLF-1403/10709949

So there are two ways I might remove the PDIP.  If the board is very high value and the chip is toast, I may nip all of the leads off the body of the IC, then grab each one with a locking hemostat and put some tension on it while I desolder it with the desoldering gun.  The other way is to remove as much of the solder as I can with the gun, then put some tension on the whole IC with the PDIP puller while I heat the area with the hot air gun, carefully working it out.  This is usually successful, but if I'm very concerned about damage or if I want to save the chips, after the initial desoldering I will add flux then then resolder with the ChipQuik solder.  Then desolder again, and carefully work the chip out with the PDIP puller while heating with the gun--the advantage is that you can use a lower temperature during this last part which will reduce damage to the chip, board and surrounding solder joints.

After you are done, clean up the pads carefully with the desoldering gun.  You want to clear the holes with vacuum if you possibly can, because poking or drilling can damage the traces or through-hole plating.

[timg11]

@bdunham7 thanks for the helpful post.

Good to know the FR-301 is a good choice and thanks for the tip on the extended 1mm nozzle.
Some of the PDIPs are rare and I try to preserve them. Others are still available, so I've used the "cut off the leads and remove one by one" process. Sometimes depending on clearances, I've tried cutting the DIP down the middle so the package can be split into two SIPs, which can be gripped with hemostats and sometimes are faster to remove that way.

The low-temp solder is an intriguing idea - I have some 63/37 eutectic solder, but this stuff must be an alloy that contains lots of silver and platinum, given the price.

I've got the DIP puller and hot air station. I even have a solder pot for the situation where the component is wanted but the board is expendable.

That DIP-shaped soldering tip is an interesting idea - I remember seeing those years ago.  I searched recently, but but didn't find it anywhere, let alone Digikey.  I can't tell what type of soldering iron it goes into -  probably not my Weller WES51 or my Metcal.

[RayRay]

You don't really need a desoldering station, just to use proper technique and tools!
Before I'd get to the technique part, I'll point out what you need to have:

1. A proper PCB holder, so you could work more easily on circuit boards:
https://www.aliexpress.com/item/4000083032653.html

2. A set of solder assist tools:
https://www.aliexpress.com/item/32824103889.html

3. A set of tweezers:
https://www.aliexpress.com/item/32945877194.html

4. A set of chip removal tools:
https://www.aliexpress.com/item/1005002612794435.html

Of course you could also get these locally from places like Amazon (but they'd prob cost you double!)
Now, to the technique part, bridging is your friend! Use leaded 63/37 solder, bridge all pins of each chip (from the rear end of course), do it one set of pins at a time, then heat up the pins, while pulling the chip from the other end at the same time (with one of the above tools), get one half ot it out, then repeat with the other til it's all out. When done, use solder wick (or a combination of solder pump+wick) to clean up the solder. Bridging is an excellent technique for removing multi-pin components and connectors, and I've used it dozens of times myself. Good luck!

[bdunham7]

Some of the PDIPs are rare and I try to preserve them.

Then the ChipQuik + double desoldering is the way to go.  I recently removed some 20-pin PDIPs that I wanted intact and they had been originally installed by bending all the pins over before soldering.  I was able to mostly straighten them on the first desolder fairly quickly, and then a bit more on the second round, then pulling them through the holes straightened them out the rest of the way.  Board and IC survived.  You definitely don't want to linger with the heat and you should allow cooling between rounds.

[coppercone2]

pace works fine for this, get the tip that is a good size for the hole, the problem you have sounds like wrong tip size more then anything else, it has to make good thermal contact but also have the correct suction clearance, and if you are using a use tool the tip might be worn (the bore size increases as its used more, eventually leaving to bad thermal contact and too large suction area (the pump has optimal channel dimensions for removal)

[wasyoungonce]

I do have a vacc de-solder station.....mostly I wouldn't bother using it to remove thru hole I'd cut the legs de-solder the pin with an iron and tweezers as suggested. 

But if the ICs are valuable and unknown if faulty.......yes a de-solder iron is very helpful.  You can save ICs (I prefer not to).   Hold the PCB vertically...put on flux (both side), reflow the pin with a touch new solder.   Let it cool, now hit the desired pin from top side with std iron and base side (same pin) with de-solder tool. This ensures all the solder is at melt point.

Ensure at melt point....Vacc it out.   Let it all cool, repeat for all pins.  This is the best way to removal "all" solder.   Or you can use the vacc tool in circular motions on the pin....which helps but tends to tear at pads.   I ensure I only have the irons on for seconds as rework like this easily kills pads.

Which brings us back to "cut the leg" method......its quick saves pads.

FWIW

[tooki]

I have a number of almost 40 year old double-sided boards with unsocketed DIP ICs I'm working on restoring and repairing.


I'm looking for a good quality desoldering station that will allow the DIP ICs to be removed without damaging the board or traces.

I've looked at the Chinese "Proskit" type, but they seem to be too low of quality, and are not available from reputable sources.
I was able to borrow a Hakko FR-301 for a day, and it kind of worked, but didn't seem to extract enough solder to allow the DIP removal, and left so much residue in the hole that a socket could not be inserted.

Can anyone recommend other options for desoldering stations? There don't seem to be that many around these days....

That is almost 100% certainly due to improper technique. I work with apprentices all day long, and desoldering is a constant problem, as most have never been trained in proper desoldering technique. The biggest mistakes they make are not properly tinning the desoldering tip, not waiting for full solder melt, not moving the pin during suction, and not applying suction long enough (resulting in clogging).

Watch this video from PACE. It’s part of a video manual for an old model of theirs, so you can ignore the product-specific bits, but the technique shown is applicable to any continuous-vacuum desoldering device. The actual THT desoldering process is at 17:55–22:25, but I recommend at least skimming through the whole video.

https://youtu.be/IqE1KA0OAnM

[tooki]

Ensure at melt point....Vacc it out.   Let it all cool, repeat for all pins.  This is the best way to removal "all" solder.   Or you can use the vacc tool in circular motions on the pin....which helps but tends to tear at pads.   I ensure I only have the irons on for seconds as rework like this easily kills pads.

If you’re damaging pads, then you’re doing it wrong. Watch the same segment of video I recommend in my previous reply, as it specifically addresses this problem.

[wasyoungonce]

I can guarantee you "circling the vac tip" can put enough pressure on a pad to do this.  Depends upon how well the PCB was made.   Also not all Pads/drill holes/pins are the same.  So use tight drill tolerance some not.   

The Video is simplistic stating the tip never touches the pad.....errr Yes it does in practice.   I understand what they are saying but in practice is a lot different.  They stated you should have a complete vacc clean in 2-5 seconds...I kinda agree...but like to be a bit quicker than 5 seconds.   They also went from pin to pin too fast not allowing cooling.

Military multilayer PCB quality is a better standard than most.   But we found its better to use 2 irons, one top of leg, vac on base.   F18 micromin PCB repair.  Quicker easier, less heat as twin irons makes it quick.   That said sometimes we use 2 persons to do this.

Indeed they do this is the Pace video...this is my (and was for micromin....but may have changed) preferred method.

[PA4TIM]

Pace SX-100. I repair too (as a business) and often a repair of an industrial or maritime board is desoldering all ICs and semiconductors and then test them with my big collection of component testers. The SX-100 is the best I have tried. It gets everything loose, from heatsinks to tiny zeners. I seldom damage a pad. Tips are cheap. I use 8 different sizes and the right size is the key to successful desoldering. My pump/psu unit is over 25 years old and the pump is still like new.
Pace has some videos about how to desolder. I learned a lot from them.

- the right size tip, as stated this is the most important key to succes.
- first "resolder" old "dried/oxidised" solderjoints that will not melt all the way through.
- circle the desoldered pin to prevent rewetting
- if holes are small compared to the pin you always get some rewetting. You can sometimes "break" the rewetted joints with a tweezer. But for severe cases I remover all solder and then use my hot air station. It takes about 10 to 20 seconds to then come loose.
- There are boards with very thin pads. The tip must be as big as the pad. If the nozzle is to big you go not heat the pad and hence, do not touch the solder
- The hardest are double sided boards without vias. They are rare in my type of work but I have seen them in very old (tube area) stuff. Remove the bottom tin. Then melt the top and pull the pin.
- single layer pads without vias like in cheap consumer stuff is hard to desolder. Not to melt the solder but the pads are glued to the board and come loose  just by looking angry at them.
- do not use tips as a crowbar to straighten bend pins if you want them to last long.
- Never press the tip on a pad. The weight of the handpiece must be enough. Pressing harder is the way to remove or damage pads.
- use your ears. You can hear the air sucking through the hole and if you desolder 8 pins they need to sound alike. I one sounds different most times it not desoldered enough
- If the tin on the topside does not melt it is often better to resolder the part before sucking again
- If the first suck is not enough to complete remove the solder then first resolder the pin and try again. You need enough solder to transport the heat effective from tip to solder/pin/pad/via
- conformal coating makesthings a lot harder

My personal experience, I prefer a higher temperature (350-375 degrees C) and for many-multi-layer boards with huge heat absorbing planes I sometimes go up to 425. But keep in mind: high heat AND a shorter time. More heat,  to much pressure and a longer time is the receipt of killing a lot of pads.
But I desoldered a lot components over the years and like soldering, desoldering is an art on its own you need to learn by theory and then a lot of practice. So practice on old boards.


 

[Shock]

I also own a Pace SX100. It's more expensive than the Hakko but it's a station based handpiece rather than a gun so lighter and easier to use both horizontally and vertically. Has a larger range of tips and overall cheaper to run.

One of the problems of vacuum desoldering pumps is clogging, so frequent (and cost effective) filter changes are import. If wear occurs in an integrated part or tip some models get crazy expensive to run. The Pace SX100 negates a lot of this as the breakdown of the entire vacuum path and tips are low cost consumables, I'm not exaggerating this.
 
When soldering/desoldering apply as little pressure to the pad as possible. Often a reason people put pressure on a joint is they were originally wave or lead free soldered. So there is next to no solder on the joint or a oxidized layer acting as a thermal barrier. To solve this add a little solder with your iron beforehand that way it breaks up oxidization and flows the joint and can make desoldering easier. Same goes for a hand vacuum pump.

Don't be concerned about time so much, 5 seconds is quite reasonable to ensure a proper desolder. It's far better to have a success at a conservative temp than several goes at a high temp due to rushing. Like with soldering you alternate pins to ensure your aren't baking the component in the process.

[wasyoungonce]

Look I agree with the principles involved in thru hole de-soldering by the users above ...but it never works in practice as perfect as that.   I do follow, in general, the above practices but my station tip replacement (old royel ex military de-solder handset and controller) ..ex military micromin PCB repair for fighter acft...it's a bit more difficult to replace tips than the Pace.....yet I have plenty of tips and hand-sets.

The Vac pump capacity is more than enough (I have 2 main de-solder main units) .. Funny enough it  crapped out the other day (it produces Vacc and +ve pressure) ...the vacc pressure was low...I fed thru cleaning solution (as advised by other EEVblog users)...fixed it.....these are 3 A Gast pumps...way over specc'd

cheers

Bren

[coppercone2]

compared to the hand held desoldering tool its amazing, I used it for years and this is basically perfection in comparison.

The other good tool is to get the needle hot air blower, which I bought by accident, because you can blow out holes that for whatever reason have non removable solder in them.. I notice this on old PCB sometimes. I tried to refill and suck with pace and blah blah you can try to put wires in there and then suck around them and fool around or blow it out like a pro, the anteater stuff gets frustrating

I have not had to go into one but a high end high thermal mass switching mode power supply board or high end power RF section is the perfect candidate for the blower tool because i find they have the most difficult extraction jobs in them. Its still a hassle to clean off the solder afterwards but at least its a real solution without fooling around (needs a very professional inspection afterwards to look for errant solder bits).. multilayer high power sections have stuff that just goes wrong with the extraction sometimes

[PA4TIM]

What is a needle hot air blower ? I have a normal hot air station but I do not think it has enough power to blow out the solder from a hole that even my SX100 can not get out (What never happend, but who knows, up to now the heaviest switching PSU I had on the bench was only 6kW    )

[coppercone2]

their irons that plug into the old pace pump stations that have a soldering iron that passes air through the tip the size of a sports ball inflation nozzle
https://www.edsyn.com/product/1036.html

[PA4TIM]

OK, I know them from pictures but I wonder what they are made for. They are still for sale and I wanted to buy one because I often have to fire up my hot air station just to remove one resistor or shrink some tube but it needs time to warm up and only shuts down if it is cooled (all the time making noise)
I have not yet bought one because I think it is not able to (de)solder due to the size and the pump has not a huge amount off air capacity.
But if yours can blow the solder out of a hole I could be wrong and it could be useable. I use it for my work every day.

I have the tweezers but I almost never use them for SMD because it is rather big (I do not have the special pretty expensive IC tips because hot-air works well enough)

[coppercone2]

I only used it to blow out holes that have light coming through them but have dimensional issues where a part lead wont fit because of some amount of solder

and sometimes it wont blow it clean, but instead blow the solder out and have it get stuck on the outside of the PCB like a mound, but then you can use solder wick to get it out since its clear of the plated hole

trying to wick it out on a bus wire is sometimes better though, because this method is pretty messy, it leaves solder splatter. careful around high pin density, maybe its a sign i use too high air pressure. i use the old pace graphite pump boxes that accept 3 prong soldering irons and raise the heat fairly high. careful not to get solder in the heated part because its possible to get it glowing red hot and spit out fireballs (always when you heat it up aim it into a safe area first to make sure nothing got into the tip)

did not use it too much but when I have a job where I know I need to desolder alot of different crap (dip + transistor + capacitor) I turn it on because its highly likely I will be left with some difficulty somewhere

[coppercone2]

also for SMD did you consider pulse heat from pace? I got the resisttweeze (dual resistance heating elements in tweezer configuration) and they are pretty good for taking off 2 component SMD. The big soldering iron chop sticks are no doubt more precise but I think its a good tool even if the thermal control is a little simple in comparison. Looking to try the conductweeze (the direct resistance soldering) on some 4 pin solder cup power connectors for my nanovoltmeter soon... nice benefit for that tool if you also use the thermal wire stripper, its fast to heat up with the foot pedal.

But what I did is I setup a special repair bench with the pace extractor, pace pulse heat, a hakko fx888 and a old weller station + fluxes, solvents, deoxits, solders, etc.. I work down there now on any repair or assembly job, and its next to my tool boxes which have all the stuff for doing cables, glue, etc. and all the dust cleaning stuff (3 different kind of wipes, etc), and trays for screws..

I find it nice not to have the equipment or assembly jobs on my test bench anymore. I found that combining the two had little practical benefit for me. Since I setup the technician area I was able to service a ridiculous amount of equipment in the last season. I also did a generally better job like cleaner PCBs, nicer fixes, etc since the split. At least for simple devices that generally you know need alot of work, if its repairing intermittent issues in an oscilloscope you have something else completely.. the bench I have in mind is a little 'dull' intellectually but you get everything polished tightened cleaned reliable and so forth, even if the most complex problems are not solved, but that still gets you somewhere. Only things that missing is a sink with ultrasonic nearby (i still do this in the kitchen).. but once its setup well I can take panels out and take em to the garage for buffing or whatever I feel like doing to make it look great, without feeling too overwhelmed.. maybe you can call it a commercial restoration setup or something

but things like taking apart ganged switches on your main work bench? screw that!

Maybe call it a precision small scale electromechanical work area

[aqibi2000]

Desoldering hollow needles are your friend, since you can heat the pin long enough to ensure both layers are fully molten and then push it in.

This is especially useful if you don’t have through hole plated holes.

[PA4TIM]

I have seen those in a video, I would like to have a set for repairs that have damaged vias because the owner first tried it himself.

I am now looking for a second reworkstation but that became more difficult as I thought. The only Pace dealer over here seems to be Farnell but they almost have no stock. There was a Pace department in England and at that time Farnell had a good stock. But the same goes for JBC, there is one Dutch dealer (but it is a very good one) The only brand that seem to have a solid dealerbase is Weller but I have no confidence in the weird looking desolder piece Weller makes. My number one still is Pace (MBT350, SX-100, PS-90 and a thermojet TJ70 or 85) But that is intellyheat and I do not know yet if the tips are interchangable with my sensatemp MBT250.

If not, I think I will also look at JBC (Although I do not like cartridge systems, but on the other hand, I just repaired an industral PCB that costed me 2 desolder tips thanks to the insane hard conformal coating, I can add those to the bill and then 20 euro for a JBC tip is reasonable. (pace tips cost half of that but only sell per 5 and that sucks because there are special sizes I want but almost never need so five is a bit overkill, they last forever) For 200 euros I have the 8 different size JBC tips i want, for Pace that would be almost twice or triple the price (But gives me 40 tips, nice but most of them I would probably never use. There are 2 sizes I use 90% of the time, I need the other sizes but they last for ever) ). I know some people who have very good experience with the JBC solderstations and they have almost everything I like/want. 

But for me the performance of desolder handpiece and availability of tips is the most important. For incidental use even crappy Chinese are usable. But for my kind of work I need the best, and upto now, for me that is the SX100, it does everything I want. But if I have to wait for weeks in the future everytime I need a sparepart or tip, that becomes frustrating (if you are going to spend over 3000 euros for soldering stuff you do not want that) But this is not my topic so I will start a new one if needed.

[aqibi2000]

I’ve used many Metcal desoldeing stations and have had excellent experience with them.


They may be old but work great, many were running almost 2-3 hours a day 5 days a week.

However even after using these so frequently I still opt for my desoldering needles with some leaded solder and high wattage soldering iron

[coppercone2]

i do not like those needles from the videos



looks kinda janky

[SpecialK]

I have a PACE MBT250 at work and a Proskit SS-331H at home.  They both work pretty nuch the same.  Yeah you should probably clean them every time you use them.  I do every other time, but if I was working on larger projects I would do it every use. 

The Proskit seems to have pretty good availability of spare parts on eBay, AliExpress, and Amazon.  The PACE I think I needed to order from Farnell.