Mine was an evolution. It started out when i wanted to solve library sharing between people. then it seemed an obvious addition to start tracking the stock items. The wrirting modules to do things like creating PNP files directly for loading..
Rather that corrupt another thread, what vapour phase oven are you using? I'm looking at oven options at the moment, somewhat keen changing to VP. A largish batch machine would be fine, but I see they do inline machines too...very spendy.
Rather that corrupt another thread, what vapour phase oven are you using? I'm looking at oven options at the moment, somewhat keen changing to VP. A largish batch machine would be fine, but I see they do inline machines too...very spendy.
I'm now using somethign i built myself, after getting one from germany. ( IEDMS ) . The IEDMS machines are conceptually clever, but absolutely terribly made. Avoid them like the plauge. The controller is just crazy, and mine was electriclaly unsafe. It also started falling apart. AVOID one of these like the plauge.
i'll take some pics. But basically its much much simpler than you think,,, Baiscally just need to heat up some galden.
I have been dreaming of a batch sized vapor phase machine.....like a while before I can afford it though.
It seems like a great option for modern power electronics that mix big and small devices. It seems to be much less stress on the components by bringing them all to the same temperature at the same rate.
I have been dreaming of a batch sized vapor phase machine.....like a while before I can afford it though.
Time i publish my plans perhaps. I think for about $300 and some time you'll be able to do it. IT just dpends how much you want to optimize it.
[/quote]
It seems like a great option for modern power electronics that mix big and small devices. It seems to be much less stress on the components by bringing them all to the same temperature at the same rate.
[/quote]
Absolutely, i have a board that has a big Inductor on it, and 0402 and .4mm QFP.
Time i publish my plans perhaps. I think for about $300 and some time you'll be able to do it. IT just dpends how much you want to optimize it.
In general - I was hoping to avoid DIY but the price of professional solutions is very high. Maybe it is a good idea to try.
The best guess is that a modest performing vapor phase system is likely to be better than my convection batch oven.
Have you done any experiments?
I still shopping for a new oven too, considering moving from a fairly large batch oven to a conveyor one. VP seems so awesome but the quotes I have for commercial quality batch machines are eye watering...making me really rethink the shift to VP.
I have not yet figured out what drives the cost on the commercial vapor phase systems. Perhaps I am missing a lot of the details, but they seem remarkably expensive relative to the task.
Short and misplld from my mobile......
By trading off speed and efficiency the complexity comes down a lot and it can be much much simpler.
The commerical systems are keeping the vapour cloud going all the time, and have a carrier system that takes the board into the vapour and then pulls it back out. They have preheat and they have to build the system in such a way that you dont' loose the 'soft vapour' ( the 'thin' cloud above the main cloud ) as you put the board in/out.. So you need complex vapor proof locks etc. etc.
With the 'heater in a bucket' its super cheap, but you essentially are putting your boards on a static carrier in a cold tank. You then heat the entire thing up.. which takes quite a bit of time and energy. Wiht some smarts you can heat it up on a sensible 'preheat', ( following a curve ).. When it hits 230C, you then let it cool down, back to room temp, and take the boards out. A cycle typically takes me about 20 minutes. A commercail system will be more like 6.
I've found that i can stack boards up, several high. ( i've done as many as four panels deep ).. Runn several tanks side by side, and i shoudl be able to get to 50-60 panels per hour, ( panel is typically A4 Size )..
It just saves so much drama with profiling and overheating.. its worth the effort.
I have not yet figured out what drives the cost on the commercial vapor phase systems. Perhaps I am missing a lot of the details, but they seem remarkably expensive relative to the task.
Aren't most current commercial offerings of the continuous operation type? Those are quite complex. When I see the occasional ad for a small batch type VP machine it seems like the crude, made in someone's back yard shed, kind of thing that mrpackethead bought and regretted. The more professional makers seem to have given up on small VP machines for prototypers, which is ironic as VP is where the big growth seems to be in overall board production.
IIRC the commercial VP machines have at least two chambers.
One is where the Galden is heated and stored (lower part) and the other is where the boards are placed and removed.
So you place the boards, the top lid of the top chamber is locked, the under lid is retracted and the boards lowered to the height where the damp is.
Then they higher the boards , close off the hot Galden reservoir and then actively cool the upper chamber walls with an AC unit and small fan forcing the low amount of escaped Galden damp back in liquid state.
After a time period the fan stops, the top lid opens so the boards can be removed.
The (escaped) liquid Galden remains on the lid where it can be left without evaporating, next cycle it is drained back into the hot Galden reservoir when the cover re-opens. Something like that, was shown to me somewhere in 2004 I believe, and indeed without the AC unit it could be build for a couple of hundred $, which would be the price you could buy them for if two million people in the world wanted one.
The rest of the price at this moment is that they are is not mass produced machines and you need a ROI.
I always compare it to the sous vide machines, those can heat a waterbasin to 0,1oC from 30-100oC and those were ten years ago all over $2000. I build one myself. Today you can buy them everywhere for $300 and even the small standalone heaters you can put in any pan costs <$90.
IIRC the commercial VP machines have at least two chambers.
One is where the Galden is heated and stored (lower part) and the other is where the boards are placed and removed.
So you place the boards, the top lid of the top chamber is locked, the under lid is retracted and the boards lowered to the height where the damp is.
Then they higher the boards , close off the hot Galden reservoir and then actively cool the upper chamber walls with an AC unit and small fan forcing the low amount of escaped Galden damp back in liquid state.
After a time period the fan stops, the top lid opens so the boards can be removed.
The (escaped) liquid Galden remains on the lid where it can be left without evaporating, next cycle it is drained back into the hot Galden reservoir when the cover re-opens. Something like that, was shown to me somewhere in 2004 I believe, and indeed without the AC unit it could be build for a couple of hundred $, which would be the price you could buy them for if two million people in the world wanted one.
The rest of the price at this moment is that they are is not mass produced machines and you need a ROI.
That sounds like the machines which were common for small scale production in the 80s. These things have a long history, so whatever price they go for now isn't likely to change very much.
That sounds like the machines which were common for small scale production in the 80s. These things have a long history, so whatever price they go for now isn't likely to change very much.
How do modern VP machines preserve the Galden ?
Vapor phase is great on paper and seemingly addresses many issues (as does Vacuum) however it does have a weakness, very few electrolytics can handle the process with most specifically excluding it as a suitable process in the datasheet. In the UK there are two visible VP phase brands ASSCON and IBL and while they are continuous operation machines the ranges are weighted to batch processing not in one end out the other. In fact my LinkedIn feed would suggest there is only one UK installation of a fully inline VP reflow process and it is new
http://www.geminitec.co.uk/en/news-events-press-articles-a-more.The other major reflow vendors either don't or barely offer VP, it has been the next big thing for years, hasn't happened yet. (IR by contrast is so dead it is barely worth mentioning).
There is something eerily similar about a number of the smaller lift in | out style machines like the Exmore and Roland Hecht which cost ~£20k which is very competitive with a convection reflow oven of potentially similar throughput (you can fill the 500x500 area up for each cycle).
The Roland Hecht IIRC quotes aloss of 1g/cycle of Galden
I hadn't even considered if data sheets mentioned the process. If it's so safe why would device manufacturers specifically exclude it?
Does Galden ever get trapped (condense) in things like those shielded/covered modules or under parts? If so, does that cause problems for RF? Is there any residue on boards, if so how is that removed?
The machines don't seem to have vents for fumes, so presumably does that tend to coat the insides of the machine or cause contamination of the galden over time?
I hadn't even considered if data sheets mentioned the process. If it's so safe why would device manufacturers specifically exclude it?
I think its all about the time/temperature profiles. With vapour phase the vapour can be just 10C above the melting point of the solder, rather than the 30C or more you see in convection/IR systems. However, the peak temperature is sustained for longer. Many electrolytics react badly to the soldering temperature being sustained for too long.
I think the problem is that VP work by getting every part of the assembly up to reflow temperature, electrolytics rely to some extent on the aluminum can protecting the inner. In VP the can cannot do this so the electrolyte gets a little toasty (boils). Electrolytics are one of those things that can throw up issues in reflow although I have never managed to destroy any myself..
Worth checking datasheet for any reflow advice, it can include other things like reflow once only or atypical reflow temps which might in turn affect which side of the board you could put it on for a double sided assembly.
The other major reflow vendors either don't or barely offer VP, it has been the next big thing for years, hasn't happened yet. (IR by contrast is so dead it is barely worth mentioning).
There seemed to be quite a lot of high vapour phase lines being installed in Chinese a couple of years ago, and the stated reason was generally energy efficiency. I don't know if that trend has continued.
The Vapor Phase fluid is around $260/1kg from what I saw after a brief scan of suppliers.
That kind of shows the benefit of a closed system that recovers as much of the fluid as possible. I guess as @mrpackethead said - if you are not in a big hurry the entire thermal cycle can happen with the chamber closed. That, of course, allows the fluid to condense before the PCB is removed.
A 20min cycle would not be much of a problem with the way I work. Better than spending >$25k++ anyway.
By trading off speed and efficiency the complexity comes down a lot and it can be much much simpler.
The commerical systems are keeping the vapour cloud going all the time, and have a carrier system that takes the board into the vapour and then pulls it back out. They have preheat and they have to build the system in such a way that you dont' loose the 'soft vapour' ( the 'thin' cloud above the main cloud ) as you put the board in/out.. So you need complex vapor proof locks etc. etc.
With the 'heater in a bucket' its super cheap, but you essentially are putting your boards on a static carrier in a cold tank. You then heat the entire thing up.. which takes quite a bit of time and energy. Wiht some smarts you can heat it up on a sensible 'preheat', ( following a curve ).. When it hits 230C, you then let it cool down, back to room temp, and take the boards out. A cycle typically takes me about 20 minutes. A commercail system will be more like 6.
I've found that i can stack boards up, several high. ( i've done as many as four panels deep ).. Runn several tanks side by side, and i shoudl be able to get to 50-60 panels per hour, ( panel is typically A4 Size )..
It just saves so much drama with profiling and overheating.. its worth the effort.
So as the vapor cools it condenses down in the tank. Is there any residue or droplets on the surface of the board when you are ready to remove it?
Aren't most current commercial offerings of the continuous operation type? Those are quite complex. When I see the occasional ad for a small batch type VP machine it seems like the crude, made in someone's back yard shed, kind of thing that mrpackethead bought and regretted. The more professional makers seem to have given up on small VP machines for prototypers, which is ironic as VP is where the big growth seems to be in overall board production.
I bought one of the IEDMS things and yes, it was very much amature hour. Read my other post. I see they are still selling them, i hope they have address much of the electrical safety concerns. The guy did refund my money, and admitted that there were a lot of issues. However while it was potentially lethal, and poorly constructed it did actually work. There was a glimmer of hope for the process.
That sounds like the machines which were common for small scale production in the 80s. These things have a long history, so whatever price they go for now isn't likely to change very much.
How do modern VP machines preserve the Galden ?
My simple 'bucket' machines dont' loose much at all. The main vapour cloud only goes about 50mm above the bottom of the tank, theres a small amount of 'soft' vapour that just condences on the sides of the tank or the lid and falls back into it. A very small amount sometimes is on the boards, but most of it has evaporated off the board, and it realy doesnt become and issue.
Vapor phase is great on paper and seemingly addresses many issues (as does Vacuum) however it does have a weakness, very few electrolytics can handle the process with most specifically excluding it as a suitable process in the datasheet.
Interesting, I've done thousands of 100uF/10V Panasonic Electrolytic, and not had any issues. I must have a deeper look into it. The only thing i've seen a note about was some RF module that claimed it coud'tn use 'Damp Heat' Soldering. ( not sure if that was VP, or not ).
For me, its been a whole lot better than 'great on paper'. Its been great in practice.
I hadn't even considered if data sheets mentioned the process. If it's so safe why would device manufacturers specifically exclude it?
Does Galden ever get trapped (condense) in things like those shielded/covered modules or under parts? If so, does that cause problems for RF? Is there any residue on boards, if so how is that removed?
The machines don't seem to have vents for fumes, so presumably does that tend to coat the insides of the machine or cause contamination of the galden over time?
I dont' use any modules like that, so cna't speak from expereince. However my boards do tend to come out 'dry' as long as you let them cool down far enough ( around to 35C ) before you take them out. At that point all the Galden has evoporated off the boards.. I'm not sure how it woudl work if it was inside a module.
One of the really nice things is how clean the boards come out. The flux ends up in teh bottom of the tank, and after 50 cycles or so, i drain my galden, and filter it through coffee filters, which takes out the vast majority of the crud. Some of it also sticks the sides of the tank. Stainless steel wool and some IPA and a good old scrub is required.