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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Dave Celestian

#14325

Wave Solder Fixtures: Biting the dust FAST! | 11 September, 1998

I am running composite fixtures on my wave solder machine and after about 500 passes each (1 month)they are showing serious signs of wear in that the composite surface is bubbling up and glass fibers are also starting to show. The problem here is that the fixtures are starting to smell really bad when they exit the machine since they are holding more flux due to their now more porous surface. Handling the fixtures is also an issue since they feel more like R-10 home insulation to the bare hands than composite. Does anyone else have this problem? WHat is causing it? Fixtures are too expensive to constantly relace. (We use a no-clean Kester 958 flux and run at 4 ft/min with (3) zones at ~300C preheat (4 feet of preheat). Solder temp is 500F.) Spray fluxer. THanks, Dave

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Upinder Singh

#14334

Re: Wave Solder Fixtures: Biting the dust FAST! | 11 September, 1998

Dave, What exactly is the material used for making the fixtures? Upinder ====================== | I am running composite fixtures on my wave solder machine and after about 500 passes each (1 month)they are showing serious signs of wear in that the composite surface is bubbling up and glass fibers are also starting to show. | The problem here is that the fixtures are starting to smell really bad when they exit the machine since they are holding more flux due to their now more porous surface. Handling the fixtures is also an issue since they feel more like R-10 home insulation to the bare hands than composite. Does anyone else have this problem? WHat is causing it? Fixtures are too expensive to constantly relace. | (We use a no-clean Kester 958 flux and run at 4 ft/min with (3) zones at ~300C preheat (4 feet of preheat). Solder temp is 500F.) Spray fluxer. | THanks, Dave

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Eric Miller

#14335

Re: Wave Solder Fixtures: Biting the dust FAST! | 11 September, 1998

Hey Dave, sounds like your material is delaminating at a rapid rate, I would not recommend using them through your process, delaminating material has to go some where! When composite material is made, layers of fibre glass and epoxy resin are placed in a " mold ". This is then pressed together for a length of time. In some cases, the material simply falls apart! Your pallet manufacturer should be made aware of the problem. If the material is at fault and not the workmanship, the pallets should be replaced at no cost to you. We have an aggreement with all of our suppliers of composite material that if there material fails during the wave solder or reflow process, they will replace the material at no cost and cover the machine and labor of the replacement parts. | Dave, What exactly is the material used for making the fixtures? | Upinder | ====================== | | I am running composite fixtures on my wave solder machine and after about 500 passes each (1 month)they are showing serious signs of wear in that the composite surface is bubbling up and glass fibers are also starting to show. | | The problem here is that the fixtures are starting to smell really bad when they exit the machine since they are holding more flux due to their now more porous surface. Handling the fixtures is also an issue since they feel more like R-10 home insulation to the bare hands than composite. Does anyone else have this problem? WHat is causing it? Fixtures are too expensive to constantly relace. | | (We use a no-clean Kester 958 flux and run at 4 ft/min with (3) zones at ~300C preheat (4 feet of preheat). Solder temp is 500F.) Spray fluxer. | | THanks, Dave

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Earl Moon

#14333

Re: Wave Solder Fixtures: Biting the dust FAST! | 14 September, 1998

| I am running composite fixtures on my wave solder machine and after about 500 passes each (1 month)they are showing serious signs of wear in that the composite surface is bubbling up and glass fibers are also starting to show. | The problem here is that the fixtures are starting to smell really bad when they exit the machine since they are holding more flux due to their now more porous surface. Handling the fixtures is also an issue since they feel more like R-10 home insulation to the bare hands than composite. Does anyone else have this problem? WHat is causing it? Fixtures are too expensive to constantly relace. | (We use a no-clean Kester 958 flux and run at 4 ft/min with (3) zones at ~300C preheat (4 feet of preheat). Solder temp is 500F.) Spray fluxer. | THanks, Dave

Dave, You are running a pretty interesting experiment. The effects are what would happen to PCB's if you ran them through the wave that many times. They are nothing more than epoxy/glass composites. Earl

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Steve A

#14329

Re: Wave Solder Fixtures: Biting the dust FAST! | 14 September, 1998

| I am running composite fixtures on my wave solder machine and after about 500 passes each (1 month)they are showing serious signs of wear in that the composite surface is bubbling up and glass fibers are also starting to show. | The problem here is that the fixtures are starting to smell really bad when they exit the machine since they are holding more flux due to their now more porous surface. Handling the fixtures is also an issue since they feel more like R-10 home insulation to the bare hands than composite. Does anyone else have this problem? WHat is causing it? Fixtures are too expensive to constantly relace. | (We use a no-clean Kester 958 flux and run at 4 ft/min with (3) zones at ~300C preheat (4 feet of preheat). Solder temp is 500F.) Spray fluxer. | THanks, Dave Dave, Assuming you are running one of the popular engineered composite materials such as CDM 68.650, CDM -ESD 68.610, G10 or ECP Plus, there are a few parameters that would decrease pallet life. Obviously the wavesolder could reduce the pallet life especially if you are using bottom IR heaters that are cranked up high. The length of your preheater (number of zones), would regulate your preheater settings. Another major factor is the thickness of your pallet. This is a tough one. You can increase pallet thickness and gain more life out of the pallets, however you need to make sure that you can achieve proper wave height to sufficiently solder the board. We have pallets that are 8mm and 10mm thick, but then again we have forced convection/IR assist preheaters, and both Lambda and Chip waves with nitrogen blanket to support the thick pallets and increased wave height. (as well as a good tech department to support the additional dross created by the increased solder exposure) Unfortunately we have not found a way to have our cake and eat it too! Good Luck.. Steve A

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Rob Fischer

#14330

Re: Wave Solder Fixtures: Biting the dust FAST! | 15 September, 1998

| | I am running composite fixtures on my wave solder machine and after about 500 passes each (1 month)they are showing serious signs of wear in that the composite surface is bubbling up and glass fibers are also starting to show. | | The problem here is that the fixtures are starting to smell really bad when they exit the machine since they are holding more flux due to their now more porous surface. Handling the fixtures is also an issue since they feel more like R-10 home insulation to the bare hands than composite. Does anyone else have this problem? WHat is causing it? Fixtures are too expensive to constantly relace. | | (We use a no-clean Kester 958 flux and run at 4 ft/min with (3) zones at ~300C preheat (4 feet of preheat). Solder temp is 500F.) Spray fluxer. | | THanks, Dave | Dave, | Assuming you are running one of the popular engineered composite materials such as CDM 68.650, CDM -ESD 68.610, G10 or ECP Plus, there are a few parameters that would decrease pallet life. Obviously the wavesolder could reduce the pallet life especially if you are using bottom IR heaters that are cranked up high. | The length of your preheater (number of zones), would regulate your preheater settings. | Another major factor is the thickness of your pallet. This is a tough one. You can increase pallet thickness and gain more life out of the pallets, however you need to make sure that you can achieve proper wave height to sufficiently solder the board. | We have pallets that are 8mm and 10mm thick, but then again we have forced convection/IR assist preheaters, and both Lambda and Chip waves with nitrogen blanket to support the thick pallets and increased wave height. (as well as a good tech department to support the additional dross created by the increased solder exposure) | Unfortunately we have not found a way to have our cake and eat it too! | Good Luck.. | Steve A Dave, How thick are your PCBs? Do you have adequate topside preheat or are the bottom preheaters turned up to ensure proper filleting on the top side? Rob

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Chrys

#14326

Re: Wave Solder Fixtures: Biting the dust FAST! | 15 September, 1998

| I am running composite fixtures on my wave solder machine and after about 500 passes each (1 month)they are showing serious signs of wear in that the composite surface is bubbling up and glass fibers are also starting to show. | The problem here is that the fixtures are starting to smell really bad when they exit the machine since they are holding more flux due to their now more porous surface. Handling the fixtures is also an issue since they feel more like R-10 home insulation to the bare hands than composite. Does anyone else have this problem? WHat is causing it? Fixtures are too expensive to constantly relace. | (We use a no-clean Kester 958 flux and run at 4 ft/min with (3) zones at ~300C preheat (4 feet of preheat). Solder temp is 500F.) Spray fluxer. | THanks, Dave Dave, Sounds like you have material issues. Been there, done that. Tried 'em all. The best, longest lasting material I've found is called Durostone. It's made by a Roeschling, and most of the big fixture cutting houses now offer it as an option. I've let this stuff sit over a 500 degree wave and 650 degree hot knife for an elapsed time of over 40 hours and it still didn't break down. It's very similar to all the other materials in that it's glass filled epoxy, but the epoxy matrix is much stronger than the competetions'. I explianed the differences in the materials in excruciating detail several months ago. You may want to check the archives for a similar thread in Jan or Feb '98.

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dave c

#14331

Re: Wave Solder Fixtures: Biting the dust FAST! | 15 September, 1998

| Dave, | How thick are your PCBs? Do you have adequate topside preheat or are the bottom preheaters turned up to ensure proper filleting on the top side? | Rob Rob, The average PCB is .062". There is no topside preheaters on our machine so we rely on the bottom preheaters for all heat disipation. About 300C for each preheater (3).

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dave c

#14328

Re: Wave Solder Fixtures: Biting the dust FAST! | 15 September, 1998

| Dave, | Sounds like you have material issues. Been there, done that. Tried 'em all. The best, longest lasting material I've found is called Durostone. It's made by a Roeschling, and most of the big fixture cutting houses now offer it as an option. I've let this stuff sit over a 500 degree wave and 650 degree hot knife for an elapsed time of over 40 hours and it still didn't break down. | It's very similar to all the other materials in that it's glass filled epoxy, but the epoxy matrix is much stronger than the competetions'. I explianed the differences in the materials in excruciating detail several months ago. You may want to check the archives for a similar thread in Jan or Feb '98. Thanks for the info Chief. I think its our flux that may be the culprit. Should we be washing this crap off the boards constantly? We use an acidic (pH = 3.7) no-clean flux and don't wash the fixtures but once every 2 weeks. Regards, Dave Celestian Baxter, Tampa Bay

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Dave Celestian

#14327

Re: Wave Solder Fixtures: Biting the dust FAST! | 15 September, 1998

| Dave, | Sounds like you have material issues. Been there, done that. Tried 'em all. The best, longest lasting material I've found is called Durostone. It's made by a Roeschling, and most of the big fixture cutting houses now offer it as an option. I've let this stuff sit over a 500 degree wave and 650 degree hot knife for an elapsed time of over 40 hours and it still didn't break down. | It's very similar to all the other materials in that it's glass filled epoxy, but the epoxy matrix is much stronger than the competetions'. I explianed the differences in the materials in excruciating detail several months ago. You may want to check the archives for a similar thread in Jan or Feb '98. I can't find that article anywhere in Jan or Feb???

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Rob Fischer

#14332

Re: Wave Solder Fixtures: Biting the dust FAST! | 16 September, 1998

| | Dave, | | How thick are your PCBs? Do you have adequate topside preheat or are the bottom preheaters turned up to ensure proper filleting on the top side? | | Rob | Rob, The average PCB is .062". There is no topside preheaters on our machine so we rely on the bottom preheaters for all heat disipation. About 300C for each preheater (3).

Dave, Try ramping up the preheaters instead of having them all set at 300. This may allow flux to evaporate more than burn into the pallet. Any pallet material would have a hard time with these temperatures. Top side preheats are priced reasonably and may benefit your process in the long term. Cleaning the pallets is also important but be aware that aluminum and DI aren't too compatible. Good luck, Rob

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