SMD Pin Cutters

[dknguyen]

Is anyone able to confirm if the expensive tip cutters such as the Erem 670EP or 670EPF are small enough to cut individual 0.5mm pitch SMD pins on an IC?

I mean...the catalog has a picture of them doing it. I have a pair of Plato 170SMD which are no longer made and as small as they are, they still aren't able to do that so I find it a bit difficult to believe without a real human being confirming it. They are too expensive at $200 a pair for me to gamble on without knowing that.

 

[Pommie]

I've not had any success with cutters on SMD pins. Last time I had to remove one I used a dremel with a cutting wheel. There is also the technique where you use a fine wire threaded behind the pins and use a combination of tugging the wire and hot air to lift each side.

Mike.

 

[dknguyen]

I've not had any success with cutters on SMD pins. Last time I had to remove one I used a dremel with a cutting wheel. There is also the technique where you use a fine wire threaded behind the pins and use a combination of tugging the wire and hot air to lift each side.

Mike.

Okay. Maybe I'll search for alternative methods.

 

[Ylli]

It's been 4 years now since I retired, but I seem to remember being able to do it with a 622NB. Looks to be the same as the 670 except it is not ESD-safe and half the price.
https://www.qsource.com/m-81-erem.a...tyIDs=@(15197)@(15200)@(20822)@*Sort=5*ava=0]

 

[dknguyen]

It's been 4 years now since I retired, but I seem to remember being able to do it with a 622NB. Looks to be the same as the 670 except it is not ESD-safe and half the price.
https://www.qsource.com/m-81-erem.a...tyIDs=@(15197)@(15200)@(20822)@*Sort=5*ava=0]

The jaws between the 670 and 622 look different. The 622 looks more like the traditional angled-tapered jaws. with a cutting edge the entire length of the jaw. The 670 has relief only at the tip and the cutting jaws are only at the tip. Do you remember if it was QFPs 64+ pins you were working on?

 

[Ylli]

Yes, the 622 has a cutting edge the entire length of the jaw. Yes to the QFPs. I do remember it was tough getting the first pin cut. After that there was a bit more room to get the cutter in.

 

[tomizett]

I've come across the method of using Stanley knife to slice off the leads - if all you want to do is remove the IC. Having tried it myself a couple of times, I've found the theory is ok, but you have to be very careful to avoid cutting into the board below, and the "wedging" action of the blade forcing the lead away from the IC body can lift the pads off the board. The jury is still out on that technique as far as I am concerned... A Dremmel sounds like a good idea though, I'd definitely give that a go.

Are you just looking for ways to remove an entire IC, or do you need to be able to isolate individual pins?

 

[dknguyen]

I've come across the method of using Stanley knife to slice off the leads - if all you want to do is remove the IC. Having tried it myself a couple of times, I've found the theory is ok, but you have to be very careful to avoid cutting into the board below, and the "wedging" action of the blade forcing the lead away from the IC body can lift the pads off the board. The jury is still out on that technique as far as I am concerned... A Dremmel sounds like a good idea though, I'd definitely give that a go.

Are you just looking for ways to remove an entire IC, or do you need to be able to isolate individual pins?

Removal. Currently I am using a 0.3mm conical tip that was dropped on a linoleum floor and therefore has a 1mm bend at the very tip. I wedge it behind the pin at the end of the row and out some slight pressure on it and twist back and forth and the bent lifts the pin when it's hot enough. It's worked so far but relies on damaged tip and at times is a bit more forceful than I would like. It's lifted traces before but so far only ever isolated pads that go nowhere.

I do recall having a square chisel exacto blade somewhere. I should try that. I tend not to do so well with slicing motions in such a small space. Pushing straight down might work though.

 

[large_ghostman]

if its whole chip removal and you dont care about the chip, then a Stanly knife works well. Like mike if its handy on the bench then dremel is used, dont slip with it as i can confirm a dremel goes through copper tracks like hot knife in butter!! Thats alot of cash for cutters!! I would want them to pick up the soldering iron and desolder it for me at that price!!

 

[dknguyen]

if its whole chip removal and you dont care about the chip, then a Stanly knife works well. Like mike if its handy on the bench then dremel is used, dont slip with it as i can confirm a dremel goes through copper tracks like hot knife in butter!! Thats alot of cash for cutters!! I would want them to pick up the soldering iron and desolder it for me at that price!!

That's exactly the reason I'm uncomfortable with taking a power tool to the PCB. It cuts too much like hot butter.

But yeah, I understand what you mean about the price. I was sitting here trying to decide whether two $80 soldering catridges designed to heat up two different sizes of QFPs would be better. It certainly would be faster but it sort of locks in the size of QFPs you can work with. I've never needed to isolate an individual pin yet where I couldn't just cut the trace with a drill bit.

I'll try the knife method though. I personally have always found it took more force than I wanted it too and produced less accuracy than I would like using an exacto to cut traces (I use a hand hand held twist drill or engraving bit to cut traces now) so it never occurred to me to press straight down with a chisel exacto blade on the pin.

 

[JimB]

Have you ever considered a hot air tool?

JimB

 

[dknguyen]

Have you ever considered a hot air tool?

JimB

I didn't really like the times I used one and don't think I can justify the cost for one (at least the kind I would like to have if I did have one).

 

[Nigel Goodwin]

I didn't really like the times I used one and don't think I can justify the cost for one (at least the kind I would like to have if I did have one).

It's a LOT cheaper than the cutters you're considering

 

[jbeng]

I've removed all kinds of SMDs with no problems at all using a Weller 6966C heat gun with a 6958 reducing baffle.


.
I've also used the cutters to clip the chip leads for removal and damaged the PCB in the process.

 

[Pommie]

I tried to find a video of the wire method but couldn't. To use this method you thread a fine wire under one full side of pins. You then tack one end of the wire to a nearby component. You can then lift the loose end and unsolder the pins one at a time whilst lifting them with the wire. The unsoldering starts at the end away from the tacked end of the wire.

Hope that makes sense to others. It makes sense to me but it's very difficult to describe something like this without pictures.

Mike.

 

[dknguyen]

I tried to find a video of the wire method but couldn't. To use this method you thread a fine wire under one full side of pins. You then tack one end of the wire to a nearby component. You can then lift the loose end and unsolder the pins one at a time whilst lifting them with the wire. The unsoldering starts at the end away from the tacked end of the wire.

Hope that makes sense to others. It makes sense to me but it's very difficult to describe something like this without pictures.

Mike.

No, yeah I understood. It was self explanatory the instant you mentioned it. Though, what I had in mind was more to loop the wire back up onto itself rather than tack solder one end and then heat up the entire side of the IC with the iron at the same time and lift (but maybe that's just because I have tips that can do that).

 

[Pommie]

You don't heat an entire side, just the end pin and then work along. So, assuming tacked end to right, heat leftmost pin whilst tugging gently on wire, When pin is detached (and bends up slightly) move onto next one.

Mike.

 

[Western]

I regularly use a utility knife (like a small stanley knife) to cut off pins to remove micros and memory chips etc.

I've tried the dremel method ... but that can make a real mess with pads if a pin catches and pulls sideways ... ripping the pad and track etc ... apart from slipping as mentioned above. Ask me how I know.

With the method I settled on ... I place the board on a padded surface and hold the knife with both hands ... then roll my fists forward, pressing down on the furthermost pin first ... blade vertical against chip body ... but angled forward at 45 degrees.

If it's a good clean IC ... a couple pins will cut at once ... then lift hands ... move back a mm or two then repeat.

By rolling your fists, you can control the depth of each sheering movement ... and I cut just one or two pins each movement ... allowing the next pin to stop me rolling too far forward and touching the board.

Very satisfying every little click as a pin lets go.

Definitely NO SLICING.

Most of mine are coated in a thick solid conformal coating ... so that is a lot more painful to cut through ... but I still use the same method ... it's just slower. You don't hear a click ... you have to constantly lift the knife to see the progress.

Some of the larger ones really thickly coated ... I use a v-shaped file first to expose the tops of the pins so I don't have to press so hard.

 

[tomizett]

I use hot air when I can, but I do find that (using the small nozzles I have available) it's difficult to get an even heat all round on bigger ICs (144 pin etc) - it's too easy to leave a few pins cold and pull up the pads. Gripping the IC is also tricky. One of those vacuum pickup tools would probably be best, although I've never used one.
Hot air stations can be had for very little money. Obviously, the cheap ones aren't as good as the expensive ones, but they're a world away from not having one at all - I wouldn't go back to being without one now.

 

[rjenkinsgb]

I use some cheap cutters by Toolcraft [816745] for fine work; they have completely pointed flush-cut jaws and I have used them to remove surface mount devices in the past, starting from the end of the pin row.

They don't last anywhere near as long as Lindstrom etc., but they are a tenth the price and a lot better than a tenth the lifespan.

They are also cheap enough to file up if you need a different tip shape.

Example:
https://www.rapidonline.com/Toolcra...gonal-Cutters-No-Facet-125mm-50-6135?IncVat=1