Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


VOC Free Flux

WDR

#11495

VOC Free Flux | 12 May, 1999

I am looking for anyone who has converted over to VOC Free flux. I need some info on any problems, etc. that you might have had.

Please E-mail me at wes.ruggles@vickers-systems.com or call at (513) 494-5229

Thanks Wes Ruggles

reply »

#11496

Re: VOC Free Flux | 12 May, 1999

| I am looking for anyone who has converted over to VOC Free flux. I need some info on any problems, etc. that you might have had. | | Please E-mail me at wes.ruggles@vickers-systems.com or call at (513) 494-5229 | | Thanks | Wes Ruggles | Hi Wes,

As a manufacturer of the VOC fluxes, I can give you a broad description of some of the problems faced by customers attempting to implement VOC Free. The primary problem is that VOC Free fluxes replace alchohol solvents with water, as water doesn't evaporate as quickly/easily as alch, solderballs result from the h20 hitting the molten solder. Typically IR preheat is insufficient to drive all the water off, but your board style will determine if cranking them up will suffice. If not, you may have to investigate convection pre-heaters if you don't already have them. So, solderballs due to moisture remaining on the board is the first hurdle. The other issues you may encounter are typical to VOC Free and VOC bearing fluxes. Gotta go - to watch Pedro mow down the Mariners! Tim o'Neill AIM

reply »

#11497

Re: VOC Free Flux | 13 May, 1999

| I am looking for anyone who has converted over to VOC Free flux. I need some info on any problems, etc. that you might have had. | | Please E-mail me at wes.ruggles@vickers-systems.com or call at (513) 494-5229 | | Thanks | Wes Ruggles | Wes,

There's a couple of postings in the SMTNet Library on VOC-Free flux evaluations and on spray fluxer evaluations, as well.

Chrys

reply »

C.K.

#11498

Re: VOC Free Flux | 13 May, 1999

| | I am looking for anyone who has converted over to VOC Free flux. I need some info on any problems, etc. that you might have had. | | | | Please E-mail me at wes.ruggles@vickers-systems.com or call at (513) 494-5229 | | | | Thanks | | Wes Ruggles | | | Wes, | | There's a couple of postings in the SMTNet Library on VOC-Free flux evaluations and on spray fluxer evaluations, as well. | | Chrys |

My own evaluations on VOC-Frees have begun!! Here were my initial observations:

I "dropped in" the Alpha (nr310b) last Wednesday (May 5), and guess what - it dramatically reduced our solder skips on 0603's! We had a run of roughly 400 boards and got only 3 or 4 skips (probably glue related).

A few things that HAVE changed, however include:

1.) Our flux spray station daily maintenance requirements�.there's lots of "dried up" residue all over the spray station, and more liquid deposit inside the spray tank�.and I'll bet a million bucks it's because the new flux is water-based, and of course, water just don't evaporate as fast as alcohol

Did the same thing happen with anyones else's spray station also??

2.) Our top-side PCB temps. are in the 220 - 230 ballpark. Bottom-side is about the same. The board literally SIZZLES upon exit - and yes, I did here some snackling, crackling, and popping upon contact with the wave. One of our operators complained of fumes upon exit also.

Should I reprofile to get higher top-side temps. to avoid sizzling? my original intention was NOT to have to reprofile anything.

Anyone else experience anything similar??? Chrys....help me please!!

Other than that, the "good" things that've changed were better solderability on hard-to-solder stuff like 0603's.

reply »

#11499

Re: VOC Free Flux | 14 May, 1999

| | | I am looking for anyone who has converted over to VOC Free flux. I need some info on any problems, etc. that you might have had. | | | | | | Please E-mail me at wes.ruggles@vickers-systems.com or call at (513) 494-5229 | | | | | | Thanks | | | Wes Ruggles | | | | | Wes, | | | | There's a couple of postings in the SMTNet Library on VOC-Free flux evaluations and on spray fluxer evaluations, as well. | | | | Chrys | | | | My own evaluations on VOC-Frees have begun!! Here were my initial observations: | | I "dropped in" the Alpha (nr310b) last Wednesday (May 5), and guess what - it dramatically reduced our solder skips on 0603's! We had a run of roughly 400 boards and got only 3 or 4 skips (probably glue related). | | A few things that HAVE changed, however include: | | 1.) Our flux spray station daily maintenance requirements�.there's lots of "dried up" residue all over the spray station, and more liquid deposit inside the spray tank�.and I'll bet a million bucks it's because the new flux is water-based, and of course, water just don't evaporate as fast as alcohol | | Did the same thing happen with anyones else's spray station also?? | | 2.) Our top-side PCB temps. are in the 220 - 230 ballpark. Bottom-side is about the same. The board literally SIZZLES upon exit - and yes, I did here some snackling, crackling, and popping upon contact with the wave. One of our operators complained of fumes upon exit also. | | Should I reprofile to get higher top-side temps. to avoid sizzling? my original intention was NOT to have to reprofile anything. | | | Anyone else experience anything similar??? Chrys....help me please!! | | Other than that, the "good" things that've changed were better solderability on hard-to-solder stuff like 0603's. | | | Here in the environmentally-conscious state of New Jersey, we've been VOC-free since the early nineties. So there's always been water in the drip pan of the fluxer, for pretty much as far back as anyone can remember.

When we put the top two VOC-frees (Heraeus SURF11 and Alpha NR 310B) head to head, the operators made a list of important criteria. Ease of cleanup was one of them; smell of boards at the exit was another. It seems that the Alpha cleaned up relatively easily and had the least obnoxious smell, especailly when compared to the Kester 970 that we had been using. I think these issues are all part of the game with the VOC-frees, you just gotta find the lesser of the evils, ya know?

The crust (or fluxcicles, as we call them) really do wipe off esily with the Alpha. Other products required hot water or alcohol, and even scotch-brite to break the crust. Weekly ceanup of the fluxer chassis went from about an hour down to five or ten minutes. We were psyched. If you're going from 2 minutes up to 10 minutes, I can see where that would be a bummer.

Snap, crackle, pop at the wave definitely means the board is hitting it wet. One option is to deposit less flux from the sprayer. The range for the 310 is to deposit 500 to 1500 ug/in^2. We're running right about 550. This stuff is nicely active, so you don't really need a whole lot. The other option (if you're looking for solderability and not VOC-free) is to try the Alpha Lonco 65. It's pretty close to the 310 in terms of thermal stability and performance, but it's alcohol based.

Sizzling upon exit sounds like there's moisture in the boards themselves. Any leftover water from the flux gets evaporated at the wave.

Reprofiling everything would not be fun. Unless you have a co-op , summer intern, technician, or good operator to delegate it to! You would have to lower preheat temps and slow the conveyor to get more time in the preheat zones. Then you'd have to modify your wave height to get the right contact at the lower conveyor speed. Yuck. Sounds like a can o'worms. I'd really work to try for less flux deposition with good solderability. Then I'd see if all my assemblies were crackling at wave contact or just a few. And the ones that are crackling, I'd look for solderballing and determine if it's really a big, bad issue worth reprofiling over. Unless of course, I had that summer intern coming in June... ;-)

reply »

Steve Skinner

#11500

Re: VOC Free Flux | 14 May, 1999

| I am looking for anyone who has converted over to VOC Free flux. I need some info on any problems, etc. that you might have had. | | Please E-mail me at wes.ruggles@vickers-systems.com or call at (513) 494-5229 | | Thanks | Wes Ruggles

| Dear Wes Switching to a voc free does require changes in your process. There is usually no way around it. Water does not evaporate as quickly as alcohol.

I am not certain the combination of LOWER preheat and slower conveyor speed is the right way to go. The ideal way to profile and fine tune the process is by using a M.O.L.E. so you can see exactly what is occurring to your board while in the wave.

The board should be at at least 100 C when it hits the solder wave. This will minimize, and probably eliminate, the sizzle heard when the board hits the wave. This is water degassing at the wave.

My experience has shown that the preheat needs to be increased and the conveyor needs to be slowed down to achieve the proper time and temp relationship that the water needs to evaporate.

Convection preheat surely enhances the performance, but unless you have this on your wave it can be quite costly to add it to the wave. You can get by without convection.

This of course leaves the performance of the spray fluxer. Control of the flux deposition becomes crucial to the proper application and the overall process. You have to spray as little flux as possible.

I worked closely with Delco Electronics on development of and implementation of their move to VOC free fluxes. There are some secrets which I would be willing to share with you, simply give me a call at 847/740-2728.

One thing that helps is to preheat the board prior to going into the wave. This can be difficult to do but the results are well worth the hassle.

On my spray fluxers I offer an optional flux control valve specifically for VOC free applications. This gives even more control to the flux deposition. I have a customer in New Jersey using my sprayer with the additional control valve and they have been very successful. I do not know what type of sprayer you are using but perhaps the valve could be added to your machine. The valve sell for about $425.

I also recommend you take a look at HyGrade's VOC free flux. It is in my opinion one of, if not the best, VOC frees out there.

I can also offer that if you want expert advice from the gentleman from Delco who implemented the program there, he is now retired and consulting on just such matters.

His name is Gene Hanaway, and his number is 219/223-5209. I consider him to be the foremost expert and premier wave soldering guru in the U.S.

I hope I have helped.

Regards,

Steve Skinner

reply »

Ryan

#11501

Re: VOC Free Flux | 14 May, 1999

| | | | I am looking for anyone who has converted over to VOC Free flux. I need some info on any problems, etc. that you might have had. | | | | | | | | Please E-mail me at wes.ruggles@vickers-systems.com or call at (513) 494-5229 | | | | | | | | Thanks | | | | Wes Ruggles | | | | | | | Wes, | | | | | | There's a couple of postings in the SMTNet Library on VOC-Free flux evaluations and on spray fluxer evaluations, as well. | | | | | | Chrys | | | | | | | My own evaluations on VOC-Frees have begun!! Here were my initial observations: | | | | I "dropped in" the Alpha (nr310b) last Wednesday (May 5), and guess what - it dramatically reduced our solder skips on 0603's! We had a run of roughly 400 boards and got only 3 or 4 skips (probably glue related). | | | | A few things that HAVE changed, however include: | | | | 1.) Our flux spray station daily maintenance requirements�.there's lots of "dried up" residue all over the spray station, and more liquid deposit inside the spray tank�.and I'll bet a million bucks it's because the new flux is water-based, and of course, water just don't evaporate as fast as alcohol | | | | Did the same thing happen with anyones else's spray station also?? | | | | 2.) Our top-side PCB temps. are in the 220 - 230 ballpark. Bottom-side is about the same. The board literally SIZZLES upon exit - and yes, I did here some snackling, crackling, and popping upon contact with the wave. One of our operators complained of fumes upon exit also. | | | | Should I reprofile to get higher top-side temps. to avoid sizzling? my original intention was NOT to have to reprofile anything. | | | | | | Anyone else experience anything similar??? Chrys....help me please!! | | | | Other than that, the "good" things that've changed were better solderability on hard-to-solder stuff like 0603's. | | | | | | | Here in the environmentally-conscious state of New Jersey, we've been VOC-free since the early nineties. So there's always been water in the drip pan of the fluxer, for pretty much as far back as anyone can remember. | | When we put the top two VOC-frees (Heraeus SURF11 and Alpha NR 310B) head to head, the operators made a list of important criteria. Ease of cleanup was one of them; smell of boards at the exit was another. It seems that the Alpha cleaned up relatively easily and had the least obnoxious smell, especailly when compared to the Kester 970 that we had been using. I think these issues are all part of the game with the VOC-frees, you just gotta find the lesser of the evils, ya know? | | The crust (or fluxcicles, as we call them) really do wipe off esily with the Alpha. Other products required hot water or alcohol, and even scotch-brite to break the crust. Weekly ceanup of the fluxer chassis went from about an hour down to five or ten minutes. We were psyched. If you're going from 2 minutes up to 10 minutes, I can see where that would be a bummer. | | Snap, crackle, pop at the wave definitely means the board is hitting it wet. One option is to deposit less flux from the sprayer. The range for the 310 is to deposit 500 to 1500 ug/in^2. We're running right about 550. This stuff is nicely active, so you don't really need a whole lot. The other option (if you're looking for solderability and not VOC-free) is to try the Alpha Lonco 65. It's pretty close to the 310 in terms of thermal stability and performance, but it's alcohol based. | | Sizzling upon exit sounds like there's moisture in the boards themselves. Any leftover water from the flux gets evaporated at the wave. | | Reprofiling everything would not be fun. Unless you have a co-op , summer intern, technician, or good operator to delegate it to! You would have to lower preheat temps and slow the conveyor to get more time in the preheat zones. Then you'd have to modify your wave height to get the right contact at the lower conveyor speed. Yuck. Sounds like a can o'worms. I'd really work to try for less flux deposition with good solderability. Then I'd see if all my assemblies were crackling at wave contact or just a few. And the ones that are crackling, I'd look for solderballing and determine if it's really a big, bad issue worth reprofiling over. Unless of course, I had that summer intern coming in June... ;-) | If the board is 220-230 F when it enters the wave, how is it possible that the flux carrier (water) is still on the board when water turns to steam at 212 F? I have always wondered how, if your board follows the correct pre-heat recommendations, it would be possible for any water to be present at the wave. Unless, of course, the board was absolutely saturated and the water was boiling when it hit the wave. What gives?

Ryan Jennens TelGen Corporation

reply »

#11502

Re: VOC Free Flux | 14 May, 1999

| | | | | I am looking for anyone who has converted over to VOC Free flux. I need some info on any problems, etc. that you might have had. | | | | | | | | | | Please E-mail me at wes.ruggles@vickers-systems.com or call at (513) 494-5229 | | | | | | | | | | Thanks | | | | | Wes Ruggles | | | | | | | | | Wes, | | | | | | | | There's a couple of postings in the SMTNet Library on VOC-Free flux evaluations and on spray fluxer evaluations, as well. | | | | | | | | Chrys | | | | | | | | | | My own evaluations on VOC-Frees have begun!! Here were my initial observations: | | | | | | I "dropped in" the Alpha (nr310b) last Wednesday (May 5), and guess what - it dramatically reduced our solder skips on 0603's! We had a run of roughly 400 boards and got only 3 or 4 skips (probably glue related). | | | | | | A few things that HAVE changed, however include: | | | | | | 1.) Our flux spray station daily maintenance requirements�.there's lots of "dried up" residue all over the spray station, and more liquid deposit inside the spray tank�.and I'll bet a million bucks it's because the new flux is water-based, and of course, water just don't evaporate as fast as alcohol | | | | | | Did the same thing happen with anyones else's spray station also?? | | | | | | 2.) Our top-side PCB temps. are in the 220 - 230 ballpark. Bottom-side is about the same. The board literally SIZZLES upon exit - and yes, I did here some snackling, crackling, and popping upon contact with the wave. One of our operators complained of fumes upon exit also. | | | | | | Should I reprofile to get higher top-side temps. to avoid sizzling? my original intention was NOT to have to reprofile anything. | | | | | | | | | Anyone else experience anything similar??? Chrys....help me please!! | | | | | | Other than that, the "good" things that've changed were better solderability on hard-to-solder stuff like 0603's. | | | | | | | | | | | Here in the environmentally-conscious state of New Jersey, we've been VOC-free since the early nineties. So there's always been water in the drip pan of the fluxer, for pretty much as far back as anyone can remember. | | | | When we put the top two VOC-frees (Heraeus SURF11 and Alpha NR 310B) head to head, the operators made a list of important criteria. Ease of cleanup was one of them; smell of boards at the exit was another. It seems that the Alpha cleaned up relatively easily and had the least obnoxious smell, especailly when compared to the Kester 970 that we had been using. I think these issues are all part of the game with the VOC-frees, you just gotta find the lesser of the evils, ya know? | | | | The crust (or fluxcicles, as we call them) really do wipe off esily with the Alpha. Other products required hot water or alcohol, and even scotch-brite to break the crust. Weekly ceanup of the fluxer chassis went from about an hour down to five or ten minutes. We were psyched. If you're going from 2 minutes up to 10 minutes, I can see where that would be a bummer. | | | | Snap, crackle, pop at the wave definitely means the board is hitting it wet. One option is to deposit less flux from the sprayer. The range for the 310 is to deposit 500 to 1500 ug/in^2. We're running right about 550. This stuff is nicely active, so you don't really need a whole lot. The other option (if you're looking for solderability and not VOC-free) is to try the Alpha Lonco 65. It's pretty close to the 310 in terms of thermal stability and performance, but it's alcohol based. | | | | Sizzling upon exit sounds like there's moisture in the boards themselves. Any leftover water from the flux gets evaporated at the wave. | | | | Reprofiling everything would not be fun. Unless you have a co-op , summer intern, technician, or good operator to delegate it to! You would have to lower preheat temps and slow the conveyor to get more time in the preheat zones. Then you'd have to modify your wave height to get the right contact at the lower conveyor speed. Yuck. Sounds like a can o'worms. I'd really work to try for less flux deposition with good solderability. Then I'd see if all my assemblies were crackling at wave contact or just a few. And the ones that are crackling, I'd look for solderballing and determine if it's really a big, bad issue worth reprofiling over. Unless of course, I had that summer intern coming in June... ;-) | | | If the board is 220-230 F when it enters the wave, how is it possible that the flux carrier (water) is still on the board when water turns to steam at 212 F? I have always wondered how, if your board follows the correct pre-heat recommendations, it would be possible for any water to be present at the wave. Unless, of course, the board was absolutely saturated and the water was boiling when it hit the wave. What gives? | | Ryan Jennens | TelGen Corporation | Hey Ryan,

Great question. If the top of the board is 220F, how can there still be water on the bottom if it boils at 212F? Great answer - if the water was still boiling when it hits the wave. Remember back to thermodynamics class (anurism time!) At std pressures, water never gets hotter than 212. It just keeps boiling at 212, no matter how hot your heat source is. The excess energy is given off as steam, but it doesn't all go to steam right away. The more energy you put into it, the faster the water will be converted to steam.

If you don't believe me, put a pot of water on the stove. Get it boiling, and take the temp. 212. Turn the flame all the way up so its rapidly boiling. Still 212. Turn the flame low enough to just maintain the boil. Still 212. The only difference between the high and low flame is that the high flame makes steam faster - the higher input of energy causes a faster evaporation rate. So the high flame will boil the pot dry faster than the low flame, but the liquid in the pot will always be 212 at sea level.

Which brings me to a tangential rambling on the most important thing I learned in six years of engineering school. Ice water chills beer faster than ice alone in the cooler. If there's ice in water, even if the ice is 10 degrees, the water never gets colder than 32F. And the ice cube will never get warmer than 32F. They'll reach equilibrium at the phase change and stay there, with the warmer water (and beer) giving up energy to melt the ice. Couple that with the thin film heat transfer coeficient of water (as compared to air), and your beer goes from 80F to 32F in ten minutes flat. The single most important thing I learned. And by far the most highly utilized, to date. Almost made suffering through thermo and heat worth the effort.

Okay, no more Friday afternoon ramblings. The water is still boiling when it hits the wave. It is also trapped in the pores of the solder mask, under components, and in holes. And the snap, crackle, pop, is the rapid vaporization from the sudden surge of energy that the hot solder puts into it.

Sorry for the ramblings,

Chrys

reply »

#11503

Re: VOC Free Flux | 14 May, 1999

| | I am looking for anyone who has converted over to VOC Free flux. I need some info on any problems, etc. that you might have had. | | | | Please E-mail me at wes.ruggles@vickers-systems.com or call at (513) 494-5229 | | | | Thanks | | Wes Ruggles | | | Dear Wes | Switching to a voc free does require changes in your process. There is usually no way around it. Water does not evaporate as quickly as alcohol. | | I am not certain the combination of LOWER preheat and slower conveyor speed is the right way to go. The ideal way to profile and fine tune the process is by using a M.O.L.E. so you can see exactly what is occurring to your board while in the wave. | | The board should be at at least 100 C when it hits the solder wave. This will minimize, and probably eliminate, the sizzle heard when the board hits the wave. This is water degassing at the wave. | | My experience has shown that the preheat needs to be increased and the conveyor needs to be slowed down to achieve the proper time and temp relationship that the water needs to evaporate. | | Convection preheat surely enhances the performance, but unless you have this on your wave it can be quite costly to add it to the wave. You can get by without convection. | | This of course leaves the performance of the spray fluxer. Control of the flux deposition becomes crucial to the proper application and the overall process. You have to spray as little flux as possible. | | I worked closely with Delco Electronics on development of and implementation of their move to VOC free fluxes. There are some secrets which I would be willing to share with you, simply give me a call at 847/740-2728. | | One thing that helps is to preheat the board prior to going into the wave. This can be difficult to do but the results are well worth the hassle. | | On my spray fluxers I offer an optional flux control valve specifically for VOC free applications. This gives even more control to the flux deposition. I have a customer in New Jersey using my sprayer with the additional control valve and they have been very successful. I do not know what type of sprayer you are using but perhaps the valve could be added to your machine. The valve sell for about $425. | | I also recommend you take a look at HyGrade's VOC free flux. It is in my opinion one of, if not the best, VOC frees out there. | | I can also offer that if you want expert advice from the gentleman from Delco who implemented the program there, he is now retired and consulting on just such matters. | | His name is Gene Hanaway, and his number is 219/223-5209. I consider him to be the foremost expert and premier wave soldering guru in the U.S. | | I hope I have helped. | | Regards, | | Steve Skinner | | Question:

If they are Delco's SECRETS, wouldn't sharing them with other people be unethical? Or at least get the folks at Delco a little ticked off? If they are not secrets, can't you share them with the rest of us? We're all here to learn.

Comment:

If you are reaching 230 - 230 F topside and your water has not had time to fully evaporate, you need to slow the conveyor to give it time. If you were to RAISE the temperatures in combination with the slower conveyor, you'd definitely roast your assemblies. If you are spending more time in the preheat zone, you need to LOWER the temps to maintain 220 - 230 at the exit.

reply »

Herb Pabes

#11504

Re: VOC Free Flux | 14 May, 1999

Hi Chrys!

I've also heard stories of the water-based material "attacking" the inner workings of their spray nozzles - probably due to the water hanging around parts and corroding them.

Did you have any such problems with the USI ultrasonic sprayer? We have a couple of old AT&T spray fluxers hanging around here for awhile and i'm pretty nervous about dropping in a Water-based Flux.

reply »

#11505

Re: VOC Free Flux | 17 May, 1999

| Hi Chrys! | | I've also heard stories of the water-based material "attacking" the inner workings of their spray nozzles - probably due to the water hanging around parts and corroding them. | | Did you have any such problems with the USI ultrasonic sprayer? We have a couple of old AT&T spray fluxers hanging around here for awhile and i'm pretty nervous about dropping in a Water-based Flux. | Herb,

I've had my USI's running for two years with water-based flux and had no problems with them. (All my machines should have the USI's uptime record!) So if the corrosion becomes a problem, it takes more than two years at 10 shifts/week to manifest itself.

The USI's have polymer tubing and stainless steel orifices & spray heads. I've witnessed no corrosion anywhere in the system.

Chrys

reply »

Vince Whipple

#11506

Re: VOC Free Flux | 19 May, 1999

Wes, I have been involved with many customers changing over from an alcohol based no-clean to a VOC-free process. The change-over can be made easier by such things as air movement, convection preheat, "drains" or reliefs in pallets (if used), controlled deposition of flux, and temp profiling as described by Chrys Shea (you GO Chrys!). I have also seen a benefit in hitting the first preheat a little hotter, this drives off the vehicle (water) faster and leaves the solids in the preheatlonger in their active temp region. This is of course is a balancing act since you must watch your delta T especially if SMT components are on your ssemblies...USE YOUR MOLE/datapak! Some additional info would be helpful, what type of preheat do you have? how many zones? what type of w.s. machine do you have? what's the board material (paper, fr4)? Do you use pallets? What type? what fluxes are you trying? Feel free to contact me at 914-795-2020 or at vwhipple@sono-tek.com. Good Luck; Vince Whipple ps. I have spoken w/Chrys recently, she's a very good resource on these matters!

| I am looking for anyone who has converted over to VOC Free flux. I need some info on any problems, etc. that you might have had. | | Please E-mail me at wes.ruggles@vickers-systems.com or call at (513) 494-5229 | | Thanks | Wes Ruggles |

reply »

PCB, BGA Rework Services

ii-feed SMT Intelligent Feeder