At work I use a tube of sticky flux applied with a pin to keep the components in place. It helps most with the hot air tool but is generally good stuff, acts a little like honey. I wouldn't even try this at home but maybe I'm spoiled. For all the passive components having two irons is the only way to go, then you can pick them up and move them around without worrying about solder wick. Some ICs will have a center pad soldered to the ground plane. This acts as a heat sink. Don't know how you're going to get that off without air but you can flip the board over and see if they might have put a via through to it, then you can stick an iron in there until it falls off the other side.
Something which is of course essential but needs mentioning is a good light over the work place.
It also helps to have a variety of methods of olding the board at various angles and positions - large magnets, velcro, vice, "helping hands" etc. (Wife and children can also be used but seem to have a short attention span and don't respond well to hot solder)
Andy
It also helps to have a variety of methods of olding the board at various angles and positions - large magnets, velcro, vice, "helping hands" etc. (Wife and children can also be used but seem to have a short attention span and don't respond well to hot solder)
Andy
nice directions. thanks mooly.
i don't know what the more experienced of ya'll would say to the below method...
i watched my friend remove soic8's by applying excess solder to one side of the ic (hitting all the feet) while prying (delicately) up that side of the ic with a jewelers screwdriver. then the same on the other side. it's a bit messy, but very fast - just have more solder to clean up later and the legs of the ic may be a bit bent.
seems this would only work for 2 sided ic's and not so well for 4 sided... (and if the ic your working on is going the way of the dodo of course).
as well, of course the caveat that prying up as opposed to sideways motion is much riskier for the pcb contacts. but hey, we're all diy'ers here right?
AT
i don't know what the more experienced of ya'll would say to the below method...
i watched my friend remove soic8's by applying excess solder to one side of the ic (hitting all the feet) while prying (delicately) up that side of the ic with a jewelers screwdriver. then the same on the other side. it's a bit messy, but very fast - just have more solder to clean up later and the legs of the ic may be a bit bent.
seems this would only work for 2 sided ic's and not so well for 4 sided... (and if the ic your working on is going the way of the dodo of course).
as well, of course the caveat that prying up as opposed to sideways motion is much riskier for the pcb contacts. but hey, we're all diy'ers here right?
AT
Hi Karl,
I've worked with smt's for many years with a normal (good) iron. The major difference is that I use solder probes to pop the leads up. I have had to move 132 pin chips from one board to another. Not recommended, and it was a warranty job. The distributor told me to do that (Korg)! Worked fine and looked factory.
I use a bit off a "gluestick" to fix IC's in place. Add a little under the chip, warm the part and leave it. Now it's stuck fast! I always use liquid flux as well. It causes the solder to move to the pads and helps avoid solder bridges. A nice, wide screwdriver tip seems to work the best here. Tried the small ones, hate 'em!
I recently bought a Kada 850D. It works well and I like it, but poor quality control (rear PCB broken free, broken nylon stand offs). After the board was properly mounted, it's been working great. One thing I have noticed though. I am pretty sure the part gets more heat with a hot air station over an iron. I've seen those butane irons with the hot air attachment work also. Sharp service was doing it that way 10 years ago.
-Chris
I've worked with smt's for many years with a normal (good) iron. The major difference is that I use solder probes to pop the leads up. I have had to move 132 pin chips from one board to another. Not recommended, and it was a warranty job. The distributor told me to do that (Korg)! Worked fine and looked factory.
I use a bit off a "gluestick" to fix IC's in place. Add a little under the chip, warm the part and leave it. Now it's stuck fast! I always use liquid flux as well. It causes the solder to move to the pads and helps avoid solder bridges. A nice, wide screwdriver tip seems to work the best here. Tried the small ones, hate 'em!
I recently bought a Kada 850D. It works well and I like it, but poor quality control (rear PCB broken free, broken nylon stand offs). After the board was properly mounted, it's been working great. One thing I have noticed though. I am pretty sure the part gets more heat with a hot air station over an iron. I've seen those butane irons with the hot air attachment work also. Sharp service was doing it that way 10 years ago.
-Chris
Hi Chris,
Well I have to confess I have been out of the "sharp end" of the repair trade for a few years now, but I suspect it's as you mentioned in another thread
, when you are working daily trying to find solutions etc engineers often come up with their own methods that probably seem a bit, well bizare sometime I guess. My treasured jewellers screwdriver -- complete with chip out of the blade, fit's SMD IC legs to perfection. No good on the packages where the pins are underneath though.
The gluesticks a great idea !! We had one rep trying to sell us some special stuff once, cost a fortune I remember. Or someone trys super-glue, then no one can see for a month afterwards.
Just going from SMD for moment. In the days of line output transformers ( those were the days ) you know how in later years the better manufacturers put rivets in the PCB holes the legs soldered into. Nightmare to unsolder -- you needed half a mile of braid and you could never get the pin free anyway. Well a colleague gave me this wonderful gadget, a double ended "hollow tube" made of stainless. Large hole at one end, small at the other together with a fluted middle section to get hold of it. Now solder as we know doesn't take to stainless. You could fly round the joints on a LOPTX in seconds. Just melt the solder and shove this over the leg pushing hard. Remove the iron and the pin was totally free.
Well I have to confess I have been out of the "sharp end" of the repair trade for a few years now, but I suspect it's as you mentioned in another thread
, when you are working daily trying to find solutions etc engineers often come up with their own methods that probably seem a bit, well bizare sometime I guess. My treasured jewellers screwdriver -- complete with chip out of the blade, fit's SMD IC legs to perfection. No good on the packages where the pins are underneath though. The gluesticks a great idea !! We had one rep trying to sell us some special stuff once, cost a fortune I remember. Or someone trys super-glue, then no one can see for a month afterwards.
Just going from SMD for moment. In the days of line output transformers ( those were the days ) you know how in later years the better manufacturers put rivets in the PCB holes the legs soldered into. Nightmare to unsolder -- you needed half a mile of braid and you could never get the pin free anyway. Well a colleague gave me this wonderful gadget, a double ended "hollow tube" made of stainless. Large hole at one end, small at the other together with a fluted middle section to get hold of it. Now solder as we know doesn't take to stainless. You could fly round the joints on a LOPTX in seconds. Just melt the solder and shove this over the leg pushing hard. Remove the iron and the pin was totally free.
Hi Mooly,
For those wonderful large components, there are a couple things you could try. My favorite is a solder sucker. Those larger blue ones with recoil, the small ones are completely worthless. Then follow with solder wick to clean up after. Saves a ton of wick! The other really important thing is to use a thick tip on your iron. One that allows the heat energy to flow into the joint. Again, I use a 2mm screwdriver tip at 300 °C. That tip does everything really well, coupled with an adjustable temperature station and you're all set for anything. I don't use the other tips any more.
For chassis connections, a heavy iron or soldering gun on the outside with your iron on the joint will usually do the trick.
Hi albin,
I use my glasses and a magnifying glass. I used to be able to see everything fine, even the markings on smt stuff. Approaching 50 now and my eyes really don't wok that well any more, not for close up stuff anyway.
-Chris
For those wonderful large components, there are a couple things you could try. My favorite is a solder sucker. Those larger blue ones with recoil, the small ones are completely worthless. Then follow with solder wick to clean up after. Saves a ton of wick! The other really important thing is to use a thick tip on your iron. One that allows the heat energy to flow into the joint. Again, I use a 2mm screwdriver tip at 300 °C. That tip does everything really well, coupled with an adjustable temperature station and you're all set for anything. I don't use the other tips any more.
For chassis connections, a heavy iron or soldering gun on the outside with your iron on the joint will usually do the trick.
Hi albin,
I use my glasses and a magnifying glass. I used to be able to see everything fine, even the markings on smt stuff. Approaching 50 now and my eyes really don't wok that well any more, not for close up stuff anyway.
-Chris
Hi Chris,
You know, I think if we worked together we would get on just fine
Not used a sucker for years, we had one tech, there's always one isn't there, nice chap extremely knowledgeable, but a bit temperamental. The end flew off and hit him in the face. The sucker flew through the air and embedded itself in the wall. He was always getting shocks off mains plugs, you know the 0.1 across L & N. Would get hold of the mains lead and stand there smashing the plug to bits on the end of the bench. The tales I could tell, could write a book on it
Back to irons, yes bigger the better most times. I was very protective of my soldering station at work and I used to have " holiday bits " to put in. You know what it's like, two weeks off and the tips like a bent poker when you come back. Same with scope leads, well that's my cover blown if anyone I know is reading this.
My eyes work the other way. Take the glasses off to see the finest detail perfectly, but can't tell whats 6 foot away.
You know, I think if we worked together we would get on just fine
Not used a sucker for years, we had one tech, there's always one isn't there, nice chap extremely knowledgeable, but a bit temperamental. The end flew off and hit him in the face. The sucker flew through the air and embedded itself in the wall. He was always getting shocks off mains plugs, you know the 0.1 across L & N. Would get hold of the mains lead and stand there smashing the plug to bits on the end of the bench. The tales I could tell, could write a book on it
Back to irons, yes bigger the better most times. I was very protective of my soldering station at work and I used to have " holiday bits " to put in. You know what it's like, two weeks off and the tips like a bent poker when you come back. Same with scope leads
, well that's my cover blown if anyone I know is reading this.My eyes work the other way. Take the glasses off to see the finest detail perfectly, but can't tell whats 6 foot away.
Hi Mooly,
My probes, meter, 'scope or whatever are certainly off limits to anyone else. My trigger point too. Not unless I know the person and they know how to behave. I simply remove the soldering iron tip and barrel nut if I'm gone. Why make things any easier?
When I had my own shop, I had my own service room and always locked it tight. There was no other way to keep various adapters and equipment from walking.
-Chris
I have to agree. We respect each others tools and privacy to begin with!
My probes, meter, 'scope or whatever are certainly off limits to anyone else. My trigger point too. Not unless I know the person and they know how to behave. I simply remove the soldering iron tip and barrel nut if I'm gone. Why make things any easier?
When I had my own shop, I had my own service room and always locked it tight. There was no other way to keep various adapters and equipment from walking.
-Chris
As a hobbyist I've had no choice but to use SMD devices otherwise I'd end up making very few things and shooting myself in the foot at the same time.
SMD is actually easier and faster to work with then through hole, that is once you've got the technique down.
It takes me all my time to see and manipulate through hole never mind SMD.
In order to desolder smd ics, pass a thin wire(nonsolderable metal) below a row of pins. Fix one end somewhere. Hold the other end and pull it under the ic pin while heating the pin. The wire should be pulled diagonally. The molten solder under the pin will be broken by the wire. Repeat for other pins.
Gajanan Phadte
Gajanan Phadte
Actually SMD isn't that hard. If you're making your own PCBs, which you are, then SMD makes a lot of sense. As djQUAN mentioned you no longer have to drill millions of holes which in itself is enough reason to give up through hole.
1206 case style parts are readily available for most components and are also pretty convenient shape and size wise. They are large enough that complete resistor values can be printed on them without any kind of stupid colour code being used so it's very easy to do a visual inspection for their value.
The only trouble I have with their orientation is having them the correct way up as they can fall upside down when you release them from the packaging reel.
The way I solder them is quite simple. First of all apply solder to one of the pads where you wish to solder the component in place. Then use a pair of good tweezers to pick up and position the component so that one of its contacts is resting in position over the pre soldered pad. Melt the solder on the pad and the component should fall into place. If need be push down on the contact your trying to solder with the iron tip to push it flush with the board. Remove the iron, let the solder solidify and remove the tweezers, then solder the remaining pad. Shaky hands don't matter too much here as your hand and component is steadied by their contact with the PCB.
It's very easy and very quick, you don't need to push any leads through holes, you don't need to bend any leads into place before they are pushed and you don't have to make sure/worry that the components will stay in place when you flip the board over to solder them in. Oh and you don't have to snip off excess leads either.
The only difficulty you might have is if you're long sighted, but anyone doing DIY, whether through hole or SMD, should have glasses or a visual aid of some sort that will allow them to see small stuff up close without trouble.
yeah i really dont get the dislike for SMD provided you can see ok up close. much easier to make the boards, far easier and quicker to solder if you have the right (not overly specialized) tools and technique. the fear many people show seems unwarranted to me and i can only deduce they havent given it much practice. use a large tip (to overcome ground planes), good tweezers and flux. for multipin connections i often use a variation on the flood and suck method where you flood the whole side of the chip with solder and then remove the excess with some good quality desoldering braid with extra flux on it, then neaten it up with the iron tip.
the secret to me seems to attack it with confidence, plenty of heat and speed; dont be precious about it as the components will handle the heat, they are mostly designed for a much longer heating profile than hand soldering produces.
soon enough, whether we like it or not, everything will be SMD, the days are almost here now if you want to use modern components.
the main negative is some components are very difficult to remove and you cant just pull up a lead for checking failure, so troubleshooting can be difficult
the secret to me seems to attack it with confidence, plenty of heat and speed; dont be precious about it as the components will handle the heat, they are mostly designed for a much longer heating profile than hand soldering produces.
soon enough, whether we like it or not, everything will be SMD, the days are almost here now if you want to use modern components.
the main negative is some components are very difficult to remove and you cant just pull up a lead for checking failure, so troubleshooting can be difficult