Vacum pomp for desoldering but i need info!!

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vedo35

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Dear electro-tech-online forum friends. I want to buy a vacum pomp machine for desoldering. I saw some products from ebay and from web pages products. But i need desoldering of the hard computer mainboards or printer main board pcb`s. You know this pcb`s are very hard and they are using very quality pcb boards and double layers. I have 2 kind desoldering pomps but manual working and not so much strong. Thats why i have alot of trobule for desoldering and after desoldering mostly ic pins are looking terrible or broken.
My question is what is the best vacum power? with bar or mmhg.
Because some products technic info giving of this technic words.
For example i found from conrad electronic and panda electronic from nederland. Conrad products vacum power is 0.35 bar for me cheap but i dont know how is good vacum. Panda electronic has another products vacum power is 680mmHg. Which one is good product?

Pls send me some info about this and best vacum power. i want to buy nederland one but expensive than conrad. What is your advice?

Have a nice days
 
Interesting question. We had a deslodering pump for some time, but gave up on it. The problems with clogged filters and generally poor removal of solder led to the discontinuance. i have no data on the pumps you are asking about.

If you really think it's necessary, see if you can use one before buying to see if it really suits your needs. The old manual solder sucker pulls harder and seems to do better with modern lead-free solder (although cleaning it is also a pain).
 
The vacuum pump works for thru hole parts but for surface mount parts desoldering braid works best. I forget what a perfect vacuum is in mm of Hg but 680mm would seem to be close.

I use desoldering braid exclusively and am able to remove ICs without damaging the PC board or IC.
 
Vacuum pumps are made with many applications in mind. Two important characteristics (among many others) are the level of vacuum and the flow rate. Quite often you will see the level of vacuum at a given flow rate - and often the pump characteristics can be described graphically - a curve, so to speak - where pressure (vacuum) and flow are compared. It would seem that vacuum level without flow - or flow without vacuum is not sufficient to describe a pump. I would expect that the vacuum and flow requirements are governed by the tools, nozzles or fixtures that you are using.

One thing to note - that everything you suck in could make it's way to the pump. Some pumps are quite tolerant - some are quite sensitive. A filter may not remove corrosive gases or condensibles that could harm the pump.
 
Hi,
I usually use a hot air gun (the type normally used for stripping paint) to de-solder large pin count and through hole devices, it takes some practice to avoid damaging the PCB so practice a bit on some old boards, but once you get the hang of it it's possible to de-solder large smd ic's in less than a minute.
If your thinking about trying this buy one with a variable heat setting, mine cost about £12 (UK) and gives excellent results.
 
Hi, Nigel
I saw some of my friends using hotair SMD rework station and the glue did not pose any problem while removing the devices. with all the facilities, skill matters in overall heating and lifting the device from a coner.
 
I regularly have to replace 80 pin uP's in Sony TV's - and they are glued down with NINE spots of glue - our Pace rework station won't shift them.

My (crude!) technique is to cut all the pins off with a sharp knife, then remove the pins with the soldering iron. Next I place a large flat bladed screwdriver on the edge of the chip and hit the handle a few times with a hammer! - this eventually knocks the chip off the board

A little clean up, and the board is perfect to fit the new chip.
 
It is really painful toknow, SONY needs that many replacements of the same chip-- or perhapsyou attend that manymany TVs. however, it is nice that chip comes out without breaking tracks during hammering. If it is frequent replacement-- you need to analyse the reasons and you can save on chips.
 

I already know the reason!.

The LOPTX transformer breaks down inside and arcs over - this kills the LOPT transistor - if you replace just the transistor it fails instantly you switch on again. For some reason this LOPTX arcing over very often kills the main micro, but almost aways ONLY on 4:3 sets, 16:9 sets seem to survive OK.

We do sell a LOT of Sony TV's, we're a top tier Sony dealer, and probably shift more Sony TV's than any corresponding sized company?.
 
Nigel Goodwin said:
How do you overcome the glue under the SM chip?.
Click to expand...

The heat softens the glue and the chip simply lifts of leaving nice clean pads.
I used to work for Sherwood (Hi-Fi Manufacturer) and have replaced in excess of 1000 80 pin tqfp's using this method
 
I don't know much personally about using a vacuum to desolder, but I did hack myself a cheap vacuum pump for another project.

I took one of those $20 tire inflater gizmos, that's powered by 12vdc. it has a tiny little piston driven compressor inside it. once you open it up, you will see how the check valves operate. There are two one-way valves, one to pressurize a tire, the other to releave the vacuum in the piston for the return stroke. I removed the vacuum valve which lived in a hole in the top of the piston cylinder. I then epoxied a small piece of plastic tubing into the hole, and attached an external check valve made for aquarium air systems. from the other side of the check, I attached a longer hose which is now the suction side. It works well for my application except it is very loud. one of these days I'll build a sound reducing box for it to live in.
 

Hi Nigel
It is nice to know that you deal and service SONY as top level dealer. Definitely a lot (batch) of LOPTs supplied by a vender are doubtful and perhaps it can be back traced in the 9001-2000 scenario.

if this is the status of QA for UK supplies, i fear how Indian customers are suffering. these products are now manufactured in India by SONY. 16:9 is at low volumes.

Coming to technology issues, perhaps subsequent supplies would have been improved a lot.
 

The replacement transformers have a different P/N, which is probably a good sign! - the original ones are made in Slovakia, which I suspect is an indication of their quality
 
I'm going to hazard a guess that the glue either breaks down from the heat or melts? Most 'glue' I've seen used on PCB's is nothing more than your typical hot glue which should come right off with heat. I don't know about under IC's though, I've never desoldered anything like that.
 

Considering the glue is there to hold the chip in place (against gravity) while it's flow soldered, it can't be too heat sensitive? - and trying to melt the glue through the chip can't be good?. The main thing is to keep the PCB in good condition, the chip is faulty anyway, cutting the pins off keeps the board safe.
 
wouwww dear my forum friends. I am so happy with your sooo much useful help answers. So Than i want to buy nederlands one. So far that is the best. I have already SMD hot air gun(Aoye mark) i dont have problem desoldering of the smd ics,tr and resistors. Only i had this vacum pomp desoldering. So Thank you so much for your answers. Have a nice days.
 
vedo35 said:
pomp
Click to expand...
Pump.

pcb`s
Click to expand...
PCBs.

There's a desoldering vacuum pump where I work, all it is, is a soldering iron connected to a vacuum pump with a tubular bit but it looks quite expensive.

I suppose you could even make your own using a piece of thin aluminium tube, a vacuum cleaner and some steel wool (as a solder filter) but it won't be as good as a real desoldering machine.
 
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