Hand soldering is one of the most time consuming in making electronics. There are alot of possibility of mistakes too.
Looking at the factory manufactured PCB's, they are cleanly, neatly soldered, by flow solder (wave solder?). Hand solder is for repair only.
How to DIY a solder bath?
I think about this. Making the bath from stainless steel, heat it with ironing element (the one your wifes use for ironing your clothes).
But I fear about oxidized tin. The upper tin will be exposed to air, and if not circulated it will form oxidized tin, which is not good, not sticking to the pcb, and produces dull color.
Wave solder has somekind of tin-fountain, so the tin is always circulating, and the new one (not oxidized) is the one sticking to the pads in the pcb.
Naah...maybe it wont work. How can I DIY a solder bath?
Looking at the factory manufactured PCB's, they are cleanly, neatly soldered, by flow solder (wave solder?). Hand solder is for repair only.
How to DIY a solder bath?
I think about this. Making the bath from stainless steel, heat it with ironing element (the one your wifes use for ironing your clothes).
But I fear about oxidized tin. The upper tin will be exposed to air, and if not circulated it will form oxidized tin, which is not good, not sticking to the pcb, and produces dull color.
Wave solder has somekind of tin-fountain, so the tin is always circulating, and the new one (not oxidized) is the one sticking to the pads in the pcb.
Naah...maybe it wont work. How can I DIY a solder bath?
I don't think it is DIYable because the solder wave probably needs to be precision controlled to avoid applying too much solder. DIY reflow would be much easier.
Best bang for buck though would probably be some form of SMT rework kit...it could be used for assembly almost like reflow but is also usable for rework.
Best bang for buck though would probably be some form of SMT rework kit...it could be used for assembly almost like reflow but is also usable for rework.
It costs rather much money to make a good wave soldering equipment. About oxidizing: Our gear at work has oil on top of the floating tin in order to keep the air out. It is also important to have pre heating and cooling under controlled conditions. If you have much to solder. why don't get in contact with somebody who has soldering machines?
I've seen full SMT line with SMT oven and automatic rolling CNC solder machine, with preheating, pre-fluxing etc, after solder treatment, etc. No,no, those cannot be DIYed.
I'm not thinking about such a complicated machine. I think about how to make a simple bath (static, not flowing), can advoid tin oxidizing (peranders gives good idea).
I will be solder pcbs by attaching the pcb to a stick, dip it, and pull it. That simple. Dont need CNC conveyor etc.
What is DIY reflow? Is it a simple static solder bath?
What is a SMT rework kit like?
I'm not thinking about such a complicated machine. I think about how to make a simple bath (static, not flowing), can advoid tin oxidizing (peranders gives good idea).
I will be solder pcbs by attaching the pcb to a stick, dip it, and pull it. That simple. Dont need CNC conveyor etc.
How do factories finish their pcb?
Making DIY electronics starting with inserting components into the places. Then I bend the excess component legs, cut them and hand solder them.
The factory made is so neat and clean. How they do that?
1. Who is inserting components into pcb? Man? Inserting machine?
2. After factory insert componets, what is the next step? Do they bend the excess legs and cut them or they machine-solder first and cut the excess legs after solder? Is there any pictures that I can see?
3. Who/what machine bends the excess legs and cut them?
Making DIY electronics starting with inserting components into the places. Then I bend the excess component legs, cut them and hand solder them.
The factory made is so neat and clean. How they do that?
1. Who is inserting components into pcb? Man? Inserting machine?
2. After factory insert componets, what is the next step? Do they bend the excess legs and cut them or they machine-solder first and cut the excess legs after solder? Is there any pictures that I can see?
3. Who/what machine bends the excess legs and cut them?
Mass soldering parts
The leads are pre trimmed so about 1/2 to 1cm is sticking through the board when inserted.
The parts are inserted by hand or machine depending on how many we're building.
After wave soldering, a horizontal trimming saw cuts all the leads to a uniform length as desired.
Back in the 70's, I tried what this guy is asking about.
If you want to dip solder boards, I tried that once with a soldering pot. I bought a 6" x 12" soldering pot and filled it with solder.
The boards, after stuffing with pre-trimmed parts, I held it up carefully and sprayed the bottom of the board and the leads with liquid flux.
Then, before each dip I had to scrape the dross off the top of the solder and then I dipped the boardfor a certain time I found by experimentation while trying to not breathe to many fumes. The result at first was a disaster. Everything was shorted. I had to buy solder mask and screen that onto the boards as well.
Once, I did it with masked boards, it worked reasonably well but I still had to touch up 20% of the joints by hand. However, it seemrd like we always missed one that needed it, resulting in a horrible reject rate and a horrid warranty claim rate.
Now, we assemble prototypes with hand soldering. Larger quantities, we either wave solder ourselves or we send to an outside contractor.
Dip soldering was fine in theory but it was too hard to get consistent work. For oneboard, forget it.
For a dozen, do them by hand.
For more, contract them out to professional assemblers.
The leads are pre trimmed so about 1/2 to 1cm is sticking through the board when inserted.
The parts are inserted by hand or machine depending on how many we're building.
After wave soldering, a horizontal trimming saw cuts all the leads to a uniform length as desired.
Back in the 70's, I tried what this guy is asking about.
If you want to dip solder boards, I tried that once with a soldering pot. I bought a 6" x 12" soldering pot and filled it with solder.
The boards, after stuffing with pre-trimmed parts, I held it up carefully and sprayed the bottom of the board and the leads with liquid flux.
Then, before each dip I had to scrape the dross off the top of the solder and then I dipped the boardfor a certain time I found by experimentation while trying to not breathe to many fumes. The result at first was a disaster. Everything was shorted. I had to buy solder mask and screen that onto the boards as well.
Once, I did it with masked boards, it worked reasonably well but I still had to touch up 20% of the joints by hand. However, it seemrd like we always missed one that needed it, resulting in a horrible reject rate and a horrid warranty claim rate.
Now, we assemble prototypes with hand soldering. Larger quantities, we either wave solder ourselves or we send to an outside contractor.
Dip soldering was fine in theory but it was too hard to get consistent work. For oneboard, forget it.
For a dozen, do them by hand.
For more, contract them out to professional assemblers.
Most leaded components are machine inserted . Some parts are hand inserted if they are not easily handled by insertion machines.The leads are bent by the same machine immediately after insertion. In the machines I saw , the leads were cut off before soldering by passing over high speed rotating blades. The boards passed over a foaming flux bath and then over the solder wave . There was also a hot air blast immediately after soldering to break solder bridges. You can't have a DIY version because you need lots of flux, solder , large air compressor and heaters etc.
From cold state to functioning state the machine consumes lots of power and takes time. This is strictly pro . If you have enough boards to do , you can use the servces of companies who do just that. For 10 , 20 board it is a waste .
Cheers.
From cold state to functioning state the machine consumes lots of power and takes time. This is strictly pro . If you have enough boards to do , you can use the servces of companies who do just that. For 10 , 20 board it is a waste .
Cheers.
Hijack your design
Assembly companies do just that. They don't get a schematic form you. All they want is the boards, the parts, a layout saying where the parts go and a sample board to compare. Unless you pay a lot extra, they don't test the boards and generally they have no one on staff who even knows much about electronics. They merely do the physical grunt work of putting it together.
That is assuming you use a local company and don't send it to Asia. Asian companies will rip off anything you give them without mercy.
But forget the dip soldering. You might want to know, I just sold our old wave soldering machine on Ebay. The buyer just picked it up. We got all of $50.00 for it. That's what happens when you insist that you won't ship it and your buyer pool is limited to greater Los Angeles.
Assembly companies do just that. They don't get a schematic form you. All they want is the boards, the parts, a layout saying where the parts go and a sample board to compare. Unless you pay a lot extra, they don't test the boards and generally they have no one on staff who even knows much about electronics. They merely do the physical grunt work of putting it together.
That is assuming you use a local company and don't send it to Asia. Asian companies will rip off anything you give them without mercy.
But forget the dip soldering. You might want to know, I just sold our old wave soldering machine on Ebay. The buyer just picked it up. We got all of $50.00 for it. That's what happens when you insist that you won't ship it and your buyer pool is limited to greater Los Angeles.
When eventually lead-free solder is all you can buy, it will get just that much harder again. To get really professional results you gotta be running jillions of boards through the machine so you can fiddle just about every parameter to get it right. Like trying to run an oil refinery - not the sort of thing that is easy to start and stop any convenient time. 
Used equipment
We got $50.00 for ours but this is unusually low as we were selling it as-is and were not able to ship it. Our market was restricted to as far as someone was willing to pick it up. However, we were glad to just have someone take it because otherwise, because of the lead content in it, we would have had to dispose of it as hazardous waste. As for the rest of the gear, we priced the lowest cost mass soldering, trimming, etc., setup at maybe $15,000. This sort of equipment is only available in small factory size because that is what is meant for. You either build prototypes by hand or you do mass production. In between, you use assembly contractors.
Actually, if I was starting out now, I never would have started assembling boards here. There are so many contractors around who have spent the money to do it right, that I would have just gone to them. However, the company started doing their own many years ago and it is hard to change overnight. However, we do contract out 100% of our boards that use surface mount parts. This volume will grow too as many parts are not available in anything but surface mount.
I find that about 20% of assembly contractors are a bit iffy. Mostly, the poorer ones seem to lose parts. Even with the best ones, you have to give them 10% extra parts for everything. However, track the number of printed circuit boards. Insist that all boards be returned to you, even the rejects. By making sure you get 100 boards back for every 100 boards you give them, you can be assured that none are being diverted, even if yu hive them 110 or each part. The contactors will give back the unused parts.
For parts like basic resistors and capacitors you can often buy these through the contractor and take advantage of their much higher volume purchasing costs.
Otherwise, where do you find stuff? Get on the net and look. Use Google.
We got $50.00 for ours but this is unusually low as we were selling it as-is and were not able to ship it. Our market was restricted to as far as someone was willing to pick it up. However, we were glad to just have someone take it because otherwise, because of the lead content in it, we would have had to dispose of it as hazardous waste. As for the rest of the gear, we priced the lowest cost mass soldering, trimming, etc., setup at maybe $15,000. This sort of equipment is only available in small factory size because that is what is meant for. You either build prototypes by hand or you do mass production. In between, you use assembly contractors.
Actually, if I was starting out now, I never would have started assembling boards here. There are so many contractors around who have spent the money to do it right, that I would have just gone to them. However, the company started doing their own many years ago and it is hard to change overnight. However, we do contract out 100% of our boards that use surface mount parts. This volume will grow too as many parts are not available in anything but surface mount.
I find that about 20% of assembly contractors are a bit iffy. Mostly, the poorer ones seem to lose parts. Even with the best ones, you have to give them 10% extra parts for everything. However, track the number of printed circuit boards. Insist that all boards be returned to you, even the rejects. By making sure you get 100 boards back for every 100 boards you give them, you can be assured that none are being diverted, even if yu hive them 110 or each part. The contactors will give back the unused parts.
For parts like basic resistors and capacitors you can often buy these through the contractor and take advantage of their much higher volume purchasing costs.
Otherwise, where do you find stuff? Get on the net and look. Use Google.
Reflow soldering can be done with water based solder paste.
The solder is suspended in a paste that forms a fluidic carrier for it. It's particularly useful for SMT work.
The paste gets squirted onto the pads where the components will sit while it is cold. The components are then positioned on the boards and their pads sit in the paste.
The boards then go through a reflow oven. The oven heats the boards up for a predetermined time using a predetermined pattern. The heat causes the fluidic part of the paste to evaporate. As the temperature rises, the solder, that was once contained in the paste, melts and flows into the join.
Then the oven cools the boards back down and they leave it with the components, theoretically, all soldered in place and ready to go.
You can buy the paste from electronics suppliers in syringes.
There is a web site on google all about this idea and how to DIYerise it. Search for 'DIY reflow soldering' and then looking for a page called 'Have you seen my new soldering iron'.
That particularly page will give you a good example of how to perform high tech advanced SMT rewflow soldering in a toasty oven at home.
My soldering leaves pretty much everything to be desired, it's a technique that I have never been able to master.
Can anyone offer particular advice - such as: is a thermostatically controlled soldering station really necessary and are there any recommendable on-line guides one could be directed to ?
Of interest, a solder bath project was published recently in 'Instructibles' website.
Can anyone offer particular advice - such as: is a thermostatically controlled soldering station really necessary and are there any recommendable on-line guides one could be directed to ?
Of interest, a solder bath project was published recently in 'Instructibles' website.
It doesn't matter how much you read up on the subject, you need practice. A temperature controlled iron is very desirable but not essential to begin with. For small components you need at least a 25 watt iron, and a 40 watt for larger stuff such as solder tags and anything that will soak the heat up.
Make sure you use a large enough bit. Small pencil types hold no heat and you will end up with crusty dry looking joints.
Also be sure to use the correct solder. Don't use lead free, its not as easy to work with as more conventional 60/40 types. Make sure it is a type for electronic work and that it has a rosin type flux core and not acid (such as plumbers solder).
Practice soldering resistors and wires to a scrap board or perf board. You will soon get the hang of it.
Make sure you use a large enough bit. Small pencil types hold no heat and you will end up with crusty dry looking joints.
Also be sure to use the correct solder. Don't use lead free, its not as easy to work with as more conventional 60/40 types. Make sure it is a type for electronic work and that it has a rosin type flux core and not acid (such as plumbers solder).
Practice soldering resistors and wires to a scrap board or perf board. You will soon get the hang of it.
My soldering leaves pretty much everything to be desired, it's a technique that I have never been able to master.
Can anyone offer particular advice - such as: is a thermostatically controlled soldering station really necessary and are there any recommendable on-line guides one could be directed to ?
Of interest, a solder bath project was published recently in 'Instructibles' website.
Can anyone offer particular advice - such as: is a thermostatically controlled soldering station really necessary and are there any recommendable on-line guides one could be directed to ?
Of interest, a solder bath project was published recently in 'Instructibles' website.
No you don't need an expensive soldering station. I do 80% of my soldering with a £15 25w Antex, i've had it for over 10 years and it's still going strong. There are quite a few YouTube vids showing how to solder, so I'd hit Ebay/AliExpress for half a dozen cheap $1 electronics kits from China, (led flashers, noise generators etc.) then just watch the vids and practice. It really isn't that difficult.
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