another smd removal method
Psyko, Thu Jun 22 2006, 09:59AMtake an horizontal toaster, your board, and voila, almost nothing remains on.
It works wonderfully with modern pcbs, you can remove smds as well as through hole components.
Re: another smd removal method
Marko, Thu Jun 22 2006, 10:34AM
I used common high-temperature fan for unsoldering almost anything (not just smd).
It can easily heat lots of pins together without overheating conponents for much.
Maybe a hair-dryer would also work, possibly motor would need to be slowed down, and plastic parts removed from the cavity.
There is also a termal sensor that would need to be disabled.
I didn't try this as I'm happy with my current fan.
Marko, Thu Jun 22 2006, 10:34AM
I used common high-temperature fan for unsoldering almost anything (not just smd).
It can easily heat lots of pins together without overheating conponents for much.
Maybe a hair-dryer would also work, possibly motor would need to be slowed down, and plastic parts removed from the cavity.
There is also a termal sensor that would need to be disabled.
I didn't try this as I'm happy with my current fan.
Re: another smd removal method
ragnar, Thu Jun 22 2006, 11:11AM
Lovely, psyko!
But why not a normal toaster? Just drop the board in, set it it to "nuke", and retrieve your components from the crumb tray! ^^ ROFL
Completely automatic!
Well, might need occasional agitation/jiggling to get the more resistant (pun not intended) components to drop off.
ragnar, Thu Jun 22 2006, 11:11AM
Lovely, psyko!
But why not a normal toaster? Just drop the board in, set it it to "nuke", and retrieve your components from the crumb tray! ^^ ROFL
Completely automatic!
Well, might need occasional agitation/jiggling to get the more resistant (pun not intended) components to drop off.
Re: another smd removal method
HV Enthusiast, Thu Jun 22 2006, 12:39PM
i'd be real careful about how much heat a toaster gives off. you could very well be damaging the pads on your board causing them to delaminate from the FR-4.
HV Enthusiast, Thu Jun 22 2006, 12:39PM
i'd be real careful about how much heat a toaster gives off. you could very well be damaging the pads on your board causing them to delaminate from the FR-4.
Re: another smd removal method
Michael W., Thu Jun 22 2006, 02:19PM
Unless a component falls off and bridges a heating filiment...~SHORT!~...
Michael W., Thu Jun 22 2006, 02:19PM
Unless a component falls off and bridges a heating filiment...~SHORT!~...
Re: another smd removal method
GimpyJoe, Thu Jun 22 2006, 05:05PM
Do you put it on component side up and then whack the board on a table to make the components fall off?
GimpyJoe, Thu Jun 22 2006, 05:05PM
Do you put it on component side up and then whack the board on a table to make the components fall off?
Re: another smd removal method
Psyko, Thu Jun 22 2006, 07:36PM
Board facing up on the toaster, I just remove the components one by one. This method was inspired by
It is kinda magic, it is as if components were never soldered.
I was able to remove a whole pentium socket very easily with this method
Psyko, Thu Jun 22 2006, 07:36PM
Board facing up on the toaster, I just remove the components one by one. This method was inspired by
It is kinda magic, it is as if components were never soldered.
I was able to remove a whole pentium socket very easily with this method
Re: another smd removal method
HV Enthusiast, Thu Jun 22 2006, 09:26PM
Just curious - why would you want to remove all the components from a board anyways? I personally can't think of any reasons why one would do this.
HV Enthusiast, Thu Jun 22 2006, 09:26PM
Just curious - why would you want to remove all the components from a board anyways? I personally can't think of any reasons why one would do this.
Re: another smd removal method
Marko, Thu Jun 22 2006, 09:41PM
So you can trash thm and save big amounts of space.
Tiny unneded conponents can also be removed easily and trashed saving even more space.
(Rich people who buy just everything usually don't understand us Scavengers)
Fan worked excellently for me, it can heat precisely as much as needed and conponents can be removed far before they reach temperature of the solder.
Toaster is fine as long as you can save the board and conponents before burning out, that seems a bit trickier with toaster.
Marko, Thu Jun 22 2006, 09:41PM
So you can trash thm and save big amounts of space.
Tiny unneded conponents can also be removed easily and trashed saving even more space.
(Rich people who buy just everything usually don't understand us Scavengers)
Fan worked excellently for me, it can heat precisely as much as needed and conponents can be removed far before they reach temperature of the solder.
Toaster is fine as long as you can save the board and conponents before burning out, that seems a bit trickier with toaster.
Re: another smd removal method
Psyko, Thu Jun 22 2006, 09:42PM
It's my pleasure
Just kidding. When you have found something powerfull, you try it with everything you can to improve the process. Actually, all the boards I build today are nearly full cms. With my brand new toaster, I have all components I need.
Psyko, Thu Jun 22 2006, 09:42PM
It's my pleasure
Just kidding. When you have found something powerfull, you try it with everything you can to improve the process. Actually, all the boards I build today are nearly full cms. With my brand new toaster, I have all components I need.Re: another smd removal method
ragnar, Thu Jun 22 2006, 10:28PM
EVR, I can understand where they're coming from. Since any surface-mount components I need aren't worth buying (i.e. I don't need quantities, and only order from digikey every few months, when I'm desperate), this is a good way to always have a floating stock of a few SMDs.
It's sortof like acrylic/plastic sheet offcuts - they're perfect for jigs, fixtures and lasercutter work, so I never throw them out =)
ragnar, Thu Jun 22 2006, 10:28PM
EVR, I can understand where they're coming from. Since any surface-mount components I need aren't worth buying (i.e. I don't need quantities, and only order from digikey every few months, when I'm desperate), this is a good way to always have a floating stock of a few SMDs.
It's sortof like acrylic/plastic sheet offcuts - they're perfect for jigs, fixtures and lasercutter work, so I never throw them out =)
Re: another smd removal method
rev, Fri Jun 23 2006, 12:55AM
hmm. i have a full box of goodies for model r/c plane building that involve heat. i'm gona need to check temps.
maybe that and some solder paste and i can finaly work with smd
rev, Fri Jun 23 2006, 12:55AM
hmm. i have a full box of goodies for model r/c plane building that involve heat. i'm gona need to check temps.
maybe that and some solder paste and i can finaly work with smd
Re: another smd removal method
HV Enthusiast, Fri Jun 23 2006, 02:15AM
i never trust SMD components after they are removed.
HV Enthusiast, Fri Jun 23 2006, 02:15AM
i never trust SMD components after they are removed.
Re: another smd removal method
ragnar, Fri Jun 23 2006, 02:46AM
I never trust SMD components.
:P
ragnar, Fri Jun 23 2006, 02:46AM
I never trust SMD components.
:P
Re: another smd removal method
WaveRider, Fri Jun 23 2006, 10:45AM
SMD components are great if you build circuits for frequencies >100MHz...no lead parasitics to worry about. Just need a steady hand, pair of pointy tweezers, fine-tipped soldering iron...
WaveRider, Fri Jun 23 2006, 10:45AM
SMD components are great if you build circuits for frequencies >100MHz...no lead parasitics to worry about. Just need a steady hand, pair of pointy tweezers, fine-tipped soldering iron...
Re: another smd removal method
Simon, Fri Jun 23 2006, 10:47PM
Which is a point I was going to raise.
How reliable are second hand SMDs removed this way? It looks brutish for such wee, sensitive beings.
Simon, Fri Jun 23 2006, 10:47PM
EastVoltResearch wrote ...
i never trust SMD components after they are removed.
i never trust SMD components after they are removed.
Which is a point I was going to raise.
How reliable are second hand SMDs removed this way? It looks brutish for such wee, sensitive beings.
Re: another smd removal method
Avalanche, Sat Jun 24 2006, 09:24AM
You can heat whole SMD components to the melting point of solder, without harming them. When the board is assembled it is heated slowly in an oven, so the removing them like this is no more destructive than when the thing was made. The only time you can damage them is heating them unevenly, or too quickly - same goes for when they cool down. The ovens on a work placement I did once had a conveyor belt running through them, and the temperature decreased towards the end to cool them slowly. SMD components are almost indestructible!
Avalanche, Sat Jun 24 2006, 09:24AM
You can heat whole SMD components to the melting point of solder, without harming them. When the board is assembled it is heated slowly in an oven, so the removing them like this is no more destructive than when the thing was made. The only time you can damage them is heating them unevenly, or too quickly - same goes for when they cool down. The ovens on a work placement I did once had a conveyor belt running through them, and the temperature decreased towards the end to cool them slowly. SMD components are almost indestructible!
Re: another smd removal method
HV Enthusiast, Sat Jun 24 2006, 01:13PM
SMD components are not almost indestructible. Any SMD components which are removed should always be suspect of being damaged. Period. I would never use SMD components again if they were already removed, and certaintly would NEVER buy them second hand that way.
HV Enthusiast, Sat Jun 24 2006, 01:13PM
SMD components are not almost indestructible. Any SMD components which are removed should always be suspect of being damaged. Period. I would never use SMD components again if they were already removed, and certaintly would NEVER buy them second hand that way.
Re: another smd removal method
Wolfram, Sat Jun 24 2006, 02:06PM
For the hobby stuff we do, recycled SMD-components most likely won't be a problem, unless it's something demanding very high reliability. Recycling SMD components can save lots of money, and certain SMD chips are very hard to get in single-unit quantities. My favorite method of removing SMDs with leads on two sides (won't work for TQFP and the like) is to put a thin wire under all of the pins on one side, put solder all over those pins, heat up and slowly pull up the wire. All the pins on that side will be lifted up. After that, you can apply solder to all of the pins on the other side, heat them and remove the chip.
Wolfram, Sat Jun 24 2006, 02:06PM
For the hobby stuff we do, recycled SMD-components most likely won't be a problem, unless it's something demanding very high reliability. Recycling SMD components can save lots of money, and certain SMD chips are very hard to get in single-unit quantities. My favorite method of removing SMDs with leads on two sides (won't work for TQFP and the like) is to put a thin wire under all of the pins on one side, put solder all over those pins, heat up and slowly pull up the wire. All the pins on that side will be lifted up. After that, you can apply solder to all of the pins on the other side, heat them and remove the chip.
Re: another smd removal method
Marko, Sat Jun 24 2006, 02:12PM
I was trying such lots-of-solder method but ends up messy as it is hard to heat everything equally with iron.
Also pins are left linked together and it's annoying to remove it later.
Hot air fan proved simple, quick and great for almost any mass-desoldering stuff.
I aslo found a technique to cover copper prefboards with thin layers of solder using fan and steel wool. Board cannot rust anymore and it becomes a real sweet spot for soldering.
Marko, Sat Jun 24 2006, 02:12PM
I was trying such lots-of-solder method but ends up messy as it is hard to heat everything equally with iron.
Also pins are left linked together and it's annoying to remove it later.
Hot air fan proved simple, quick and great for almost any mass-desoldering stuff.
I aslo found a technique to cover copper prefboards with thin layers of solder using fan and steel wool. Board cannot rust anymore and it becomes a real sweet spot for soldering.
Re: another smd removal method
Simon, Sun Jun 25 2006, 12:56AM
Next point: flux fumes. How bad a problem is this? (Not that ventilation couldn't help fix it.)
I remember when I very first used a soldering iron there were fumes (and blobs of solder) everywhere. With practice, or course, you get more sophisticated but popping a board in a toaster, while a neat idea, does not spell sophisticated.
Simon, Sun Jun 25 2006, 12:56AM
Next point: flux fumes. How bad a problem is this? (Not that ventilation couldn't help fix it.)
I remember when I very first used a soldering iron there were fumes (and blobs of solder) everywhere. With practice, or course, you get more sophisticated but popping a board in a toaster, while a neat idea, does not spell sophisticated.
Re: another smd removal method
ragnar, Sun Jun 25 2006, 01:04AM
Flux fumes, resin fumes, or other fumes?
When I put my HCl flux on anything hot, I can see (and taste!!!) the yellow smoke.
The resin is pongy, but seems inert enough, and it makes sense to blow the fumes away from your eyes, face, furniture, etc.
As for lead/tin fumes, it smokes a great deal with fresh solder, yes, but when was the last time you saw a plume of smoke come out of a joint when you tried to desolder it? =D
ragnar, Sun Jun 25 2006, 01:04AM
Flux fumes, resin fumes, or other fumes?
When I put my HCl flux on anything hot, I can see (and taste!!!) the yellow smoke.
The resin is pongy, but seems inert enough, and it makes sense to blow the fumes away from your eyes, face, furniture, etc.
As for lead/tin fumes, it smokes a great deal with fresh solder, yes, but when was the last time you saw a plume of smoke come out of a joint when you tried to desolder it? =D
Print this page