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Earl Moon

#12860

Fountain Wave Soldering and Repair/Rework Equipment | 21 January, 1999

Hello,

I will be evaluating and qualifying two equipment types. The first is a fountain soldering device. I need practical advice on all the stuff you guys and gals know about as good, bad, ugly, best applications, setup, limitations, and all the rest. I've never used one of these things and would appreciate any experienced input.

I am inheriting an SRT 1000 BGA/Fine pitch rework/repair station. So far it looks straight forward and easy to program and operate. I do question having to edit INI files to set some parameters for board and component types, and sequences, etc. Additionally, the very long removal and replacement arm/rod/tube seems very vulnerable and I can't help wondering about repeatabillity let alone initial accuracy though, from what I've seen so far, no worries? Any experienced input concerning operations, do's, dont's, capabilities, limitations, etc. also would be appreciated.

Thanks everyone,

Earl Moon

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dean

#12861

Re: Fountain Wave Soldering and Repair/Rework Equipment | 21 January, 1999

| Hello, | | I will be evaluating and qualifying two equipment types. The first is a fountain soldering device. I need practical advice on all the stuff you guys and gals know about as good, bad, ugly, best applications, setup, limitations, and all the rest. I've never used one of these things and would appreciate any experienced input. | | I am inheriting an SRT 1000 BGA/Fine pitch rework/repair station. So far it looks straight forward and easy to program and operate. I do question having to edit INI files to set some parameters for board and component types, and sequences, etc. Additionally, the very long removal and replacement arm/rod/tube seems very vulnerable and I can't help wondering about repeatabillity let alone initial accuracy though, from what I've seen so far, no worries? Any experienced input concerning operations, do's, dont's, capabilities, limitations, etc. also would be appreciated. | | Thanks everyone, | | Earl Moon | Hi Earl.I have an SRT Summit 2000. I don't know how much of the two machines crosses-over, but I bet their very similar. True, the pickup tube is very long. But as long as you describe your device thickness accurately, it will be fine ( I have driven it into a PCB at full throttle and it didn't bend at all)! Accuracy. I run a glass reticle placement accuracy verification test once every 4 weeks. The placement accuracy specified for our machine is +/- 0.002 inch @ 3 Sigma. I have my machine calibrated to 0.001 inch @ 3 Sigma. The glass reticle I use has 0.001 inch artwork with a 0.010 inch ball pattern (flip chip footprint). Placement reliability over the 7 months I have had this machine has been excellent. Initially I had a 0.005 inch drift in the optics. I believe this was due to thermal expansion mismatch between the optics and allumnium housing) and overall "settleing in" (the optics sit over the heaters). To counter this I keep the supplied heater shield in place at all times. Since that resolution, my machine has needed no further :"tuning" (not bad for 6 months and over 1000 device remove-replaces). Editing the .ini files is a breeze. Ernie or Rey LaFleur at SRT can help if needed. They generally supply a healthy library with the machine but its good they allow for those ever pesky "specials" which rear their ugly heads now and then. I am most impressed with the sequence editing and controll available with the software. It allows for virtually limitless program process generation. Good reworking to you... Dean

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Earl Moon

#12862

Re: Fountain Wave Soldering and Repair/Rework Equipment | 21 January, 1999

| | Hello, | | | | I will be evaluating and qualifying two equipment types. The first is a fountain soldering device. I need practical advice on all the stuff you guys and gals know about as good, bad, ugly, best applications, setup, limitations, and all the rest. I've never used one of these things and would appreciate any experienced input. | | | | I am inheriting an SRT 1000 BGA/Fine pitch rework/repair station. So far it looks straight forward and easy to program and operate. I do question having to edit INI files to set some parameters for board and component types, and sequences, etc. Additionally, the very long removal and replacement arm/rod/tube seems very vulnerable and I can't help wondering about repeatabillity let alone initial accuracy though, from what I've seen so far, no worries? Any experienced input concerning operations, do's, dont's, capabilities, limitations, etc. also would be appreciated. | | | | Thanks everyone, | | | | Earl Moon | | | Hi Earl.I have an SRT Summit 2000. I don't know how much of the two machines crosses-over, but I bet their very similar. | True, the pickup tube is very long. But as long as you describe your device thickness accurately, it will be fine ( I have driven it into a PCB at full throttle and it didn't bend at all)! | Accuracy. I run a glass reticle placement accuracy verification test once every 4 weeks. The placement accuracy specified for our machine is +/- 0.002 inch @ 3 Sigma. I have my machine calibrated to 0.001 inch @ 3 Sigma. The glass reticle I use has 0.001 inch artwork with a 0.010 inch ball pattern (flip chip footprint). | Placement reliability over the 7 months I have had this machine has been excellent. Initially I had a 0.005 inch drift in the optics. I believe this was due to thermal expansion mismatch between the optics and allumnium housing) and overall "settleing in" (the optics sit over the heaters). To counter this I keep the supplied heater shield in place at all times. Since that resolution, my machine has needed no further :"tuning" (not bad for 6 months and over 1000 device remove-replaces). | Editing the .ini files is a breeze. Ernie or Rey LaFleur at SRT can help if needed. They generally supply a healthy library with the machine but its good they allow for those ever pesky "specials" which rear their ugly heads now and then. | I am most impressed with the sequence editing and controll available with the software. It allows for virtually limitless program process generation. | Good reworking to you... | Dean | | Dean,

That was an excellent reply and very helpful. It totally tracks with the half dozen responses I received today from IPC TechNetters.

I'm just finishing the on-line operations procedures while almost enjoying the machine, INI file editing and all, and am finding another true friend in this machine. I'll let you know how it goes.

Keep your top and bottom heaters burning hot,

Earl

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Chrys

#12863

Re: Fountain Wave Soldering and Repair/Rework Equipment | 22 January, 1999

| Hello, | | I will be evaluating and qualifying two equipment types. The first is a fountain soldering device. I need practical advice on all the stuff you guys and gals know about as good, bad, ugly, best applications, setup, limitations, and all the rest. I've never used one of these things and would appreciate any experienced input. | | I am inheriting an SRT 1000 BGA/Fine pitch rework/repair station. So far it looks straight forward and easy to program and operate. I do question having to edit INI files to set some parameters for board and component types, and sequences, etc. Additionally, the very long removal and replacement arm/rod/tube seems very vulnerable and I can't help wondering about repeatabillity let alone initial accuracy though, from what I've seen so far, no worries? Any experienced input concerning operations, do's, dont's, capabilities, limitations, etc. also would be appreciated. | | Thanks everyone, | | Earl Moon | Hi Earl!

Ah, solder fountains - a necessary evil. What do you want first? The good, the bad, or the ugly?

The good: - quick removal of high pin count devices. Ever try solder-sucking a PGA with a bent pin? You're gonna be there for a while. - Increased throughput vs hand soldering connectors and other things that are located contrary to the solder side of the board, or on DSR boards with tall components that cannot fit in selective solder pallets.

The bad: - Unless you're gonna spend big bucks to automate, this is a highly operator dependent process. The lack of motion normally found in wave sodlering doesn't exist, so you don't get a nice "peel-off" to break bridges. When the fountain of solder drops, you get icicle-type bridges. - A good operator can finesse the board out at an angle to mimic a peel-off and reduce the bridging rate. But everyone developes their own technique. I actually saw one operator develop a technique that involved smacking the board against the nozzle while the solder was still hot to aid in the debridging process. (Yikes!!!! Wouldn't buy that card!!!) - Can't handle fine pitch (below 60 mil) connectors or ones with short lead lengths - bridge city.

The ugly: - Manual fluxing - depending on technique, the product will have unprocessed flux on it wherever flux was applied but not contacted by solder. Paste flux helps. Liquid flux - forget it. - Rapid thermal expansion (okay, call it shock). I don't have to tell Earl the implications here, but for any other readers... What I have found is that if the device being solder fonutained is near the edge of the board, there is a path for the X-Y expansion and contraction, and visually the board looks allright. If the device is located in the center of the board, however, the surrounding rigid laminate prevents expansion in X and Y, so the Z-axis takes the brunt of it. Rework a PGA twice on a board, look carefully, and you'll see the delamination and cracking around it. Cross-section if you dare. That being said, many fountain systems now come equipped with board heating devices to prevent the scenario I just described. Some also provide motion to help debrige. Other will add a little atomized fluxer that will spray through an aperture the size of the nozzle to eleiminate the worry of unprocessed flux.

It all depends on how much you're willing to spend. If you are inheriting a system, you probably don't have a lot of choice, but with a little ingenuity, you can pull a Steve Gregory: Grab some duct tape, a book of matches, and a videotaped rerun of MacGyver for inspiration. Then add an old section of conveyor that no one wants, some blocks to elevate one end of it, an old PITA time/pressure dispensing system that you ripped out of your adhesive dispenser in a fit of rage, the hot air blower from the Pace station that's had its optics canibalized, and an updraft duct for ventilation, and, VIOLA! you've made yourself a miniature wave soldering machine in your spare time.

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Steve Gregory

#12864

Re: Fountain Wave Soldering and Repair/Rework Equipment | 22 January, 1999

>> If you are inheriting a system, you probably don't have a lot of choice, >>but with a little ingenuity, you can pull a Steve Gregory: Grab some duct >>tape, a book of matches, and a videotaped rerun of MacGyver for >>inspiration.

HEY! Whaddya mean?

You sayin' that I Rube Goldburg things? Why Thank-you! I've always been the resourceful one!

I will admit that my creativity kinda' got me in trouble when I was a little fart though. My mom and dad didn't like me "fixing" things around the house. Maybe it was because of my invention that allows you to use BOTH sides of toilet paper. Okay...it did have one little flaw, your fingers could get a little poopy sometimes. Ah well...that's in the past. On to bigger and better inventions!

I'm working on one now that allows you to use a flour sifter to put resistors and capacitors on a board with, just need to work out a few bugs...I'll let ya'll know when I've perfected it...(GRIN)

-Steve "balin' wire and bubblegum" Gregory-

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