Vacum pomp for desoldering but i need info!! - Electronic Circuits Projects Diagrams Free

vedo35 · 26th February 2007, 03:07 PM

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

j.p.bill · 26th February 2007, 06:15 PM

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).

Russlk · 27th February 2007, 01:41 AM

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.

stevez · 27th February 2007, 09:58 AM

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.

SYE · 27th February 2007, 10:01 AM

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.

**Nigel Goodwin** · 27th February 2007, 10:19 AM

How do you overcome the glue under the SM chip?.

mvs sarma · 27th February 2007, 10:38 AM

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.

**Nigel Goodwin** · 27th February 2007, 11:45 AM

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.

mvs sarma · 27th February 2007, 11:51 AM

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.

**Nigel Goodwin** · 27th February 2007, 12:17 PM

Quote:

Originally Posted by mvs sarma

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?.

SYE · 27th February 2007, 01:10 PM

Quote:

Originally Posted by Nigel Goodwin

How do you overcome the glue under the SM chip?.

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

justDIY · 27th February 2007, 01:52 PM

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.

mvs sarma · 27th February 2007, 02:33 PM

Quote:

Originally Posted by Nigel Goodwin

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?.

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.

**Nigel Goodwin** · 27th February 2007, 03:01 PM

Quote:

Originally Posted by mvs sarma

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

Sceadwian · 27th February 2007, 03:58 PM

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.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Latest
missing info for robo dog	The Electricuted	Datasheet/Parts Requests	1	9th March 2006 05:05 AM
Books and general info	Timmymna	General Electronics Chat	8	4th October 2004 10:29 PM
Black Star 2308 Datalogger info wanted	mechie	Datasheet/Parts Requests	0	22nd September 2004 12:43 PM
data to serial port and musicmatch program info	leprien	Electronic Projects Design/Ideas/Reviews	3	28th September 2003 01:02 AM
Info on cold cathode lights and inverters	ChemMan	General Electronics Chat	1	23rd August 2003 09:20 PM

26th February 2007, 03:07 PM	(permalink)
vedo35	Vacum pomp for desoldering but i need info!! 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

26th February 2007, 06:15 PM	(permalink)
j.p.bill	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).

27th February 2007, 01:41 AM	(permalink)
Russlk	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. __________________ see my website: www.geocities.com/russlk

27th February 2007, 09:58 AM	(permalink)
stevez	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. __________________ stevez

27th February 2007, 10:01 AM	(permalink)
SYE	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.

27th February 2007, 10:19 AM	(permalink)
Nigel Goodwin	How do you overcome the glue under the SM chip?. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

27th February 2007, 10:38 AM	(permalink)
mvs sarma	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. __________________ Regards, Sarma.

27th February 2007, 11:45 AM	(permalink)
Nigel Goodwin	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. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

27th February 2007, 11:51 AM	(permalink)
mvs sarma	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. __________________ Regards, Sarma.

27th February 2007, 01:52 PM	(permalink)
justDIY	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. __________________ If you don't have a planet, what good are gold bars? want to contact me directly? gmail gordonthree check out my project website: http://projects.dimension-x.net Favorite numbers: 09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0

27th February 2007, 03:58 PM	(permalink)
Sceadwian	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. __________________ "Because I be what I be. I would tell you what you want to know if I could, mum, but I be a cat, and no cat anywhere ever gave anyone a straight answer, har har."