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wave solder process

Tony

#10994

wave solder process | 17 June, 1999

Does anyone know where I can find a list of things to do to when troubleshooting issues during the wave solder process?

for example:

Solder Bridge 1.verify amount of flux been aplied. 2.verify turbulance on your solder wave. 3.etc. etc. etc..

will appriciate any feed back.

Thanks

Tony A

reply »

Vic Lau

#10995

Re: wave solder process | 17 June, 1999

| Does anyone know where I can find a list of things to do to when troubleshooting issues during the wave solder process? | | for example: | | Solder Bridge | 1.verify amount of flux been aplied. | 2.verify turbulance on your solder wave. | 3.etc. etc. etc.. | | will appriciate any feed back. | | Thanks | | Tony A | | Dear Tony,

You can gather such information from the Howard Manko books (classic, for example Solder and Soldering. Herein you can find all the things that about wave soldering.

Vic

reply »


K

#10996

Re: wave solder process | 17 June, 1999

| Does anyone know where I can find a list of things to do to when troubleshooting issues during the wave solder process? | | for example: | | Solder Bridge | 1.verify amount of flux been aplied. | 2.verify turbulance on your solder wave. | 3.etc. etc. etc.. | Try this web page: http://www.enthone-omi.com/waves.html

| will appriciate any feed back. | | Thanks | | Tony A | |

reply »

Earl Moon

#10997

Re: wave solder process | 17 June, 1999

| Does anyone know where I can find a list of things to do to when troubleshooting issues during the wave solder process? | | for example: | | Solder Bridge | 1.verify amount of flux been aplied. | 2.verify turbulance on your solder wave. | 3.etc. etc. etc.. | | will appriciate any feed back. | | Thanks | | Tony A | | Manko, many years ago, defined soldering as the joining of two metal surfaces (emphasis on surfaces), using a solder medium (a tin/lead alloy, as an example), without requiring diffusion or intermetallic formation. I still adhere to this definition based upon the understanding of surface.

To surface scientists (I'm not one but do work with them often), surface is defined as an object's area having no depth. They define depth in terms of a finite number of angstroms, though we all know angstroms are not a unit of measure. Once this number is reached, depth begins and is measurable.

Manko, and many othes, subscribed that solder wetting, or surface joining using a solder medium, was effected at the atomic level. This tracks with surface science needs, and does not violate the depth consideration, nor does is violate the definition of difusion or intermetallic formation.

Having said all this, wave soldering is another form of metal surface joining at a temperature below 800 degrees F. Beyond this, I define wave soldering as a process made up of several sub processes, and many individual activities. It's at the activity level, most defects are effected provided all else is acceptable.

All else is defined as everything entering, or used in, the process is as specified. Everything includes solder, PCB solder termination area, component lead (why wave solder if no through hole components are used), and machine capability quality is as specified.

Now, the wave soldering process is foremost. It is made up of sub processes, and systems, as the fluxer, conveyor, preheater, and wave. Each sub process must be setup, as required for a particular board type (based mostly on thermal mass).

Flux must be as specified (specific gravity determined using a hygrometer and/or using titration methods to verify composition and quality) and must be applied to ensure wetting on the board's bottom side and through all holes to the top side. Conveyor speed must be calibrated (I use a yard stick and stop watch) and set (usually between 3-6 feet per minute) to ensure proper topside board preheat temperature (to ensure flux penetration and activation), and to ensure proper contact time/area over the wave.

Wave temperature must be as specified. The old DOD-STD-2000 medled in our affairs by specifying a temperature of 500 + or - 5 degrees F. In our times, we often tweak temperatures to suit our needs as minimizing chip component cracking, as an example. Currently, on one of our wave solder machines, the solder pot is maintained at 470 degrees and few components fail.

Solder purity must be as specified in accordance with ANSI-J-STD 001, table 5, as I recall. If not in conformance, the solder pot must be dealt with appropriately.

Solder wave contact time and area must be assured as specified for a particular board type. Usually, using a Lev-Check glass plate, I set the contact area between 1.5 and 2.5 inches assuring paralellism across the plate. The contact time should be between 2-3 seconds and the board should be immersed in the wave not more than 50% of its thickness. Don't forget board angle over the wave at about 7-10 degrees depending on requirements. This may vary for selective wave pallets.

If all else comes together, as operator activity performance and acceptable boards, components, and solder purity, perfect solder joints will be effected. Of course, if I haven't already discussed, designs, solder mask, and other factors must be as specified.

There's much more. It depends on application and process management requirements, but it's a start.

Earl Moon

reply »

#10998

Re: wave solder process | 17 June, 1999

| Does anyone know where I can find a list of things to do to when troubleshooting issues during the wave solder process? | | for example: | | Solder Bridge | 1.verify amount of flux been aplied. | 2.verify turbulance on your solder wave. | 3.etc. etc. etc.. | | will appriciate any feed back. | | Thanks | | Tony A | | I'll post a paper on controlling the wave solder process to the library tomoorrow. It covers defects, causes, and prevention through proper control. I'd post it now, but it's on a Zip disk in a giant box of office crap out in my garage, so I have to go dig it up.

Chrys

reply »

Tony

#10999

Re: wave solder process | 17 June, 1999

| | Does anyone know where I can find a list of things to do to when troubleshooting issues during the wave solder process? | | | | for example: | | | | Solder Bridge | | 1.verify amount of flux been aplied. | | 2.verify turbulance on your solder wave. | | 3.etc. etc. etc.. | | | | will appriciate any feed back. | | | | Thanks | | | | Tony A | | | | | Manko, many years ago, defined soldering as the joining of two metal surfaces (emphasis on surfaces), using a solder medium (a tin/lead alloy, as an example), without requiring diffusion or intermetallic formation. I still adhere to this definition based upon the understanding of surface. | | To surface scientists (I'm not one but do work with them often), surface is defined as an object's area having no depth. They define depth in terms of a finite number of angstroms, though we all know angstroms are not a unit of measure. Once this number is reached, depth begins and is measurable. | | Manko, and many othes, subscribed that solder wetting, or surface joining using a solder medium, was effected at the atomic level. This tracks with surface science needs, and does not violate the depth consideration, nor does is violate the definition of difusion or intermetallic formation. | | Having said all this, wave soldering is another form of metal surface joining at a temperature below 800 degrees F. Beyond this, I define wave soldering as a process made up of several sub processes, and many individual activities. It's at the activity level, most defects are effected provided all else is acceptable. | | All else is defined as everything entering, or used in, the process is as specified. Everything includes solder, PCB solder termination area, component lead (why wave solder if no through hole components are used), and machine capability quality is as specified. | | Now, the wave soldering process is foremost. It is made up of sub processes, and systems, as the fluxer, conveyor, preheater, and wave. Each sub process must be setup, as required for a particular board type (based mostly on thermal mass). | | Flux must be as specified (specific gravity determined using a hygrometer and/or using titration methods to verify composition and quality) and must be applied to ensure wetting on the board's bottom side and through all holes to the top side. Conveyor speed must be calibrated (I use a yard stick and stop watch) and set (usually between 3-6 feet per minute) to ensure proper topside board preheat temperature (to ensure flux penetration and activation), and to ensure proper contact time/area over the wave. | | Wave temperature must be as specified. The old DOD-STD-2000 medled in our affairs by specifying a temperature of 500 + or - 5 degrees F. In our times, we often tweak temperatures to suit our needs as minimizing chip component cracking, as an example. Currently, on one of our wave solder machines, the solder pot is maintained at 470 degrees and few components fail. | | Solder purity must be as specified in accordance with ANSI-J-STD 001, table 5, as I recall. If not in conformance, the solder pot must be dealt with appropriately. | | Solder wave contact time and area must be assured as specified for a particular board type. Usually, using a Lev-Check glass plate, I set the contact area between 1.5 and 2.5 inches assuring paralellism across the plate. The contact time should be between 2-3 seconds and the board should be immersed in the wave not more than 50% of its thickness. Don't forget board angle over the wave at about 7-10 degrees depending on requirements. This may vary for selective wave pallets. | | If all else comes together, as operator activity performance and acceptable boards, components, and solder purity, perfect solder joints will be effected. Of course, if I haven't already discussed, designs, solder mask, and other factors must be as specified. | | There's much more. It depends on application and process management requirements, but it's a start. | | Earl Moon | This is GREAT.. I can't believe the great feed back that I am getting. I know this is helping me alot and I know that there is alot of smtnet viewers are taking advantage of these type of info.

Thank you all..

Tony

reply »

Earl Moon

#11000

Re: wave solder process | 17 June, 1999

| | | Does anyone know where I can find a list of things to do to when troubleshooting issues during the wave solder process? | | | | | | for example: | | | | | | Solder Bridge | | | 1.verify amount of flux been aplied. | | | 2.verify turbulance on your solder wave. | | | 3.etc. etc. etc.. | | | | | | will appriciate any feed back. | | | | | | Thanks | | | | | | Tony A | | | | | | | | Manko, many years ago, defined soldering as the joining of two metal surfaces (emphasis on surfaces), using a solder medium (a tin/lead alloy, as an example), without requiring diffusion or intermetallic formation. I still adhere to this definition based upon the understanding of surface. | | | | To surface scientists (I'm not one but do work with them often), surface is defined as an object's area having no depth. They define depth in terms of a finite number of angstroms, though we all know angstroms are not a unit of measure. Once this number is reached, depth begins and is measurable. | | | | Manko, and many othes, subscribed that solder wetting, or surface joining using a solder medium, was effected at the atomic level. This tracks with surface science needs, and does not violate the depth consideration, nor does is violate the definition of difusion or intermetallic formation. | | | | Having said all this, wave soldering is another form of metal surface joining at a temperature below 800 degrees F. Beyond this, I define wave soldering as a process made up of several sub processes, and many individual activities. It's at the activity level, most defects are effected provided all else is acceptable. | | | | All else is defined as everything entering, or used in, the process is as specified. Everything includes solder, PCB solder termination area, component lead (why wave solder if no through hole components are used), and machine capability quality is as specified. | | | | Now, the wave soldering process is foremost. It is made up of sub processes, and systems, as the fluxer, conveyor, preheater, and wave. Each sub process must be setup, as required for a particular board type (based mostly on thermal mass). | | | | Flux must be as specified (specific gravity determined using a hygrometer and/or using titration methods to verify composition and quality) and must be applied to ensure wetting on the board's bottom side and through all holes to the top side. Conveyor speed must be calibrated (I use a yard stick and stop watch) and set (usually between 3-6 feet per minute) to ensure proper topside board preheat temperature (to ensure flux penetration and activation), and to ensure proper contact time/area over the wave. | | | | Wave temperature must be as specified. The old DOD-STD-2000 medled in our affairs by specifying a temperature of 500 + or - 5 degrees F. In our times, we often tweak temperatures to suit our needs as minimizing chip component cracking, as an example. Currently, on one of our wave solder machines, the solder pot is maintained at 470 degrees and few components fail. | | | | Solder purity must be as specified in accordance with ANSI-J-STD 001, table 5, as I recall. If not in conformance, the solder pot must be dealt with appropriately. | | | | Solder wave contact time and area must be assured as specified for a particular board type. Usually, using a Lev-Check glass plate, I set the contact area between 1.5 and 2.5 inches assuring paralellism across the plate. The contact time should be between 2-3 seconds and the board should be immersed in the wave not more than 50% of its thickness. Don't forget board angle over the wave at about 7-10 degrees depending on requirements. This may vary for selective wave pallets. | | | | If all else comes together, as operator activity performance and acceptable boards, components, and solder purity, perfect solder joints will be effected. Of course, if I haven't already discussed, designs, solder mask, and other factors must be as specified. | | | | There's much more. It depends on application and process management requirements, but it's a start. | | | | Earl Moon | | | This is GREAT.. | I can't believe the great feed back that I am getting. | I know this is helping me alot and I know that there is alot of smtnet viewers are taking advantage of these type of info. | | Thank you all.. | | Tony | Damn Tony,

It's a pleasure helping - even if I left out one small detail. Seems there's a preheater sub process/system in there somewhere. How thoughtless.

Anyway, the preaheater must be set and verified at a specified temperature. This must be done to effect specified top side board temperature to activate flux, precondition boards, precondition components - all to avoid thermal shock over the wave.

I told you there's more. I ought to edit what I right more often. Besides, Chrys will set it all straight with his paper.

Go get 'em Chrys,

Moonman

reply »

#11001

Brush-Up Your Intermetalics!!! | 17 June, 1999

| | Does anyone know where I can find a list of things to do to when troubleshooting issues during the wave solder process? | | | | for example: | | | | Solder Bridge | | 1.verify amount of flux been aplied. | | 2.verify turbulance on your solder wave. | | 3.etc. etc. etc.. | | | | will appriciate any feed back. | | | | Thanks | | | | Tony A | | | | | Manko, many years ago, defined soldering as the joining of two metal surfaces (emphasis on surfaces), using a solder medium (a tin/lead alloy, as an example), without requiring diffusion or intermetallic formation. I still adhere to this definition based upon the understanding of surface. | | To surface scientists (I'm not one but do work with them often), surface is defined as an object's area having no depth. They define depth in terms of a finite number of angstroms, though we all know angstroms are not a unit of measure. Once this number is reached, depth begins and is measurable. | | Manko, and many othes, subscribed that solder wetting, or surface joining using a solder medium, was effected at the atomic level. This tracks with surface science needs, and does not violate the depth consideration, nor does is violate the definition of difusion or intermetallic formation. | | Having said all this, wave soldering is another form of metal surface joining at a temperature below 800 degrees F. Beyond this, I define wave soldering as a process made up of several sub processes, and many individual activities. It's at the activity level, most defects are effected provided all else is acceptable. | | All else is defined as everything entering, or used in, the process is as specified. Everything includes solder, PCB solder termination area, component lead (why wave solder if no through hole components are used), and machine capability quality is as specified. | | Now, the wave soldering process is foremost. It is made up of sub processes, and systems, as the fluxer, conveyor, preheater, and wave. Each sub process must be setup, as required for a particular board type (based mostly on thermal mass). | | Flux must be as specified (specific gravity determined using a hygrometer and/or using titration methods to verify composition and quality) and must be applied to ensure wetting on the board's bottom side and through all holes to the top side. Conveyor speed must be calibrated (I use a yard stick and stop watch) and set (usually between 3-6 feet per minute) to ensure proper topside board preheat temperature (to ensure flux penetration and activation), and to ensure proper contact time/area over the wave. | | Wave temperature must be as specified. The old DOD-STD-2000 medled in our affairs by specifying a temperature of 500 + or - 5 degrees F. In our times, we often tweak temperatures to suit our needs as minimizing chip component cracking, as an example. Currently, on one of our wave solder machines, the solder pot is maintained at 470 degrees and few components fail. | | Solder purity must be as specified in accordance with ANSI-J-STD 001, table 5, as I recall. If not in conformance, the solder pot must be dealt with appropriately. | | Solder wave contact time and area must be assured as specified for a particular board type. Usually, using a Lev-Check glass plate, I set the contact area between 1.5 and 2.5 inches assuring paralellism across the plate. The contact time should be between 2-3 seconds and the board should be immersed in the wave not more than 50% of its thickness. Don't forget board angle over the wave at about 7-10 degrees depending on requirements. This may vary for selective wave pallets. | | If all else comes together, as operator activity performance and acceptable boards, components, and solder purity, perfect solder joints will be effected. Of course, if I haven't already discussed, designs, solder mask, and other factors must be as specified. | | There's much more. It depends on application and process management requirements, but it's a start. | | Earl Moon | Gesh Earl: I know you�re just trying to cause trouble. That being said, as you know and choose not to accept change in mid-1980s soldering dogma, you are swimming against the tide of fact and science in your failure to accept that intermetallic compounds are necessary to form a solder connection. Intermetallics can be seen using an optical microscope and have been documented in numerous books on soldering. For example:

Coombs, CF, "Printed Circuits Handbook," ISBN 0-07-012754-9, p 28.7 Frear, et al, "Solder Mechanics: A State of the Art Assessment," ISBN 0-87339-166-7, various in Ch 2 Lau, JH, "Solder Joint Reliability," ISBN 0-0442-00260-2, p 176, 236-243 Lea, C, "A Scientific Guide To Surface Mount Technology," ASIN: 0-90115-022-3, someone has my book so I can�t quote chapter and verse, but it�s in there. Hwang, JS, "Ball Grid Array & Fine Pitch Peripheral Interconnections," ISBN 0-901150-29-0, p 156 Klein Wassink, RJ, "Soldering In Electronics," ISBN 0-901150-24-X, p 150 Rahn, A, "The Basics Of Soldering," ISBN 0-471-58471-1, p 26 Woodgate, RW, "The Handbook Of Machine Soldering," ISBN 0-471-13904-1, p 8 Yost, et al, "The Mechanics Of Solder Alloy Wetting And Spreading," ISBN 0-442-01752-9, p 178

Further, in a 1988 vintage book "Solders And Soldering," ISBN 0-07-039970-0, p 99, Manko says "Intermetallic crystals of copper and tin are formed in the molten solder."

Earl brush-up your intermetallics!!!! If for no other reason, do it for the children.

And, you know, it wouldn�t take too much to do it either. The Minerals, Metals, and Materials Society still offers "Solder Mechanics: A State of the Art Assessment." A get this ... It�s currently a $10 sale book. Shipping and handling for this book would be $5.00 in the US, $10 in Canada and Mexico, and $15 in all other countries.

They do require prepayment for all their publications. You can order from Shirley Wilson by fax at 724-776-3770 or phone at 724-776-9000 or E-mail at csc@tms.org using a credit card.

This is an above average book, but a little goofily arranged. So for a case, it could be a step towards rehabing yourself. Maybe then you�d feel like trying Klein Wassink or Yost. Actually, I know you�re for the case, but I�ve done my part.

FWIW

Dave F

reply »

#11002

Re: wave solder process | 17 June, 1999

| Does anyone know where I can find a list of things to do to when troubleshooting issues during the wave solder process? | | for example: | | Solder Bridge | 1.verify amount of flux been aplied. | 2.verify turbulance on your solder wave. | 3.etc. etc. etc.. | | will appriciate any feed back. | | Thanks | | Tony A | | Tony: Try:

Klein Wassink, RJ, "Soldering In Electronics," ISBN 0-901150-24-X, p 661

Ta

Dave F

reply »

Earl Moon

#11003

Re: Brush-Up Your Intermetalics!!! | 17 June, 1999

| | | Does anyone know where I can find a list of things to do to when troubleshooting issues during the wave solder process? | | | | | | for example: | | | | | | Solder Bridge | | | 1.verify amount of flux been aplied. | | | 2.verify turbulance on your solder wave. | | | 3.etc. etc. etc.. | | | | | | will appriciate any feed back. | | | | | | Thanks | | | | | | Tony A | | | | | | | | Manko, many years ago, defined soldering as the joining of two metal surfaces (emphasis on surfaces), using a solder medium (a tin/lead alloy, as an example), without requiring diffusion or intermetallic formation. I still adhere to this definition based upon the understanding of surface. | | | | To surface scientists (I'm not one but do work with them often), surface is defined as an object's area having no depth. They define depth in terms of a finite number of angstroms, though we all know angstroms are not a unit of measure. Once this number is reached, depth begins and is measurable. | | | | Manko, and many othes, subscribed that solder wetting, or surface joining using a solder medium, was effected at the atomic level. This tracks with surface science needs, and does not violate the depth consideration, nor does is violate the definition of difusion or intermetallic formation. | | | | Having said all this, wave soldering is another form of metal surface joining at a temperature below 800 degrees F. Beyond this, I define wave soldering as a process made up of several sub processes, and many individual activities. It's at the activity level, most defects are effected provided all else is acceptable. | | | | All else is defined as everything entering, or used in, the process is as specified. Everything includes solder, PCB solder termination area, component lead (why wave solder if no through hole components are used), and machine capability quality is as specified. | | | | Now, the wave soldering process is foremost. It is made up of sub processes, and systems, as the fluxer, conveyor, preheater, and wave. Each sub process must be setup, as required for a particular board type (based mostly on thermal mass). | | | | Flux must be as specified (specific gravity determined using a hygrometer and/or using titration methods to verify composition and quality) and must be applied to ensure wetting on the board's bottom side and through all holes to the top side. Conveyor speed must be calibrated (I use a yard stick and stop watch) and set (usually between 3-6 feet per minute) to ensure proper topside board preheat temperature (to ensure flux penetration and activation), and to ensure proper contact time/area over the wave. | | | | Wave temperature must be as specified. The old DOD-STD-2000 medled in our affairs by specifying a temperature of 500 + or - 5 degrees F. In our times, we often tweak temperatures to suit our needs as minimizing chip component cracking, as an example. Currently, on one of our wave solder machines, the solder pot is maintained at 470 degrees and few components fail. | | | | Solder purity must be as specified in accordance with ANSI-J-STD 001, table 5, as I recall. If not in conformance, the solder pot must be dealt with appropriately. | | | | Solder wave contact time and area must be assured as specified for a particular board type. Usually, using a Lev-Check glass plate, I set the contact area between 1.5 and 2.5 inches assuring paralellism across the plate. The contact time should be between 2-3 seconds and the board should be immersed in the wave not more than 50% of its thickness. Don't forget board angle over the wave at about 7-10 degrees depending on requirements. This may vary for selective wave pallets. | | | | If all else comes together, as operator activity performance and acceptable boards, components, and solder purity, perfect solder joints will be effected. Of course, if I haven't already discussed, designs, solder mask, and other factors must be as specified. | | | | There's much more. It depends on application and process management requirements, but it's a start. | | | | Earl Moon | | | Gesh Earl: I know you�re just trying to cause trouble. That being said, as you know and choose not to accept change in mid-1980s soldering dogma, you are swimming against the tide of fact and science in your failure to accept that intermetallic compounds are necessary to form a solder connection. Intermetallics can be seen using an optical microscope and have been documented in numerous books on soldering. For example: | | Coombs, CF, "Printed Circuits Handbook," ISBN 0-07-012754-9, p 28.7 | Frear, et al, "Solder Mechanics: A State of the Art Assessment," ISBN 0-87339-166-7, various in Ch 2 | Lau, JH, "Solder Joint Reliability," ISBN 0-0442-00260-2, p 176, 236-243 | Lea, C, "A Scientific Guide To Surface Mount Technology," ASIN: 0-90115-022-3, someone has my book so I can�t quote chapter and verse, but it�s in there. | Hwang, JS, "Ball Grid Array & Fine Pitch Peripheral Interconnections," ISBN 0-901150-29-0, p 156 | Klein Wassink, RJ, "Soldering In Electronics," ISBN 0-901150-24-X, p 150 | Rahn, A, "The Basics Of Soldering," ISBN 0-471-58471-1, p 26 | Woodgate, RW, "The Handbook Of Machine Soldering," ISBN 0-471-13904-1, p 8 | Yost, et al, "The Mechanics Of Solder Alloy Wetting And Spreading," ISBN 0-442-01752-9, p 178 | | Further, in a 1988 vintage book "Solders And Soldering," ISBN 0-07-039970-0, p 99, Manko says "Intermetallic crystals of copper and tin are formed in the molten solder." | | Earl brush-up your intermetallics!!!! If for no other reason, do it for the children. | | And, you know, it wouldn�t take too much to do it either. The Minerals, Metals, and Materials Society still offers "Solder Mechanics: A State of the Art Assessment." A get this ... It�s currently a $10 sale book. Shipping and handling for this book would be $5.00 in the US, $10 in Canada and Mexico, and $15 in all other countries. | | They do require prepayment for all their publications. You can order from Shirley Wilson by fax at 724-776-3770 or phone at 724-776-9000 or E-mail at csc@tms.org using a credit card. | | This is an above average book, but a little goofily arranged. So for a case, it could be a step towards rehabing yourself. Maybe then you�d feel like trying Klein Wassink or Yost. Actually, I know you�re for the case, but I�ve done my part. | | FWIW | | Dave F | Damn Dave,

You are the best. Where do you get and store all this stuff? Never mind, I couldn't handle it.

I'm too frail to swim against the tide. However, I'm not so to stir the pot as you indicated.

I do appreciate your interjection and agree both difussion and IMC formations are effected during soldering operations. Further, I agree they continue growth at different rates under different conditions as heat/time relationships. I, as you, have many visuals and x-sections showing this.

My argument centers around, if you did not observe, surface and what constitutes it at what time in the process. I have asked this question many times and have received little assistance but from those dedicating their humble lives to such a small part of the universe. Most surface engineering types concur. Therefore, it's not my invention, but continuing question.

Even though one can see intermetallic growth, my concern is where did it start. Was it at the atomic level then exploding into our visual world - over what period?

Though I've not read all the publications you indicate and no doubt have, I have done some research to ensure "the children" are not rendered helpless/hapless/hopless as I. Simply, I question IMC propogation from surface to whatever level and its deleterious effects on quality over what period as long term reliability with smaller devices and solder joint formations.

I hope you agree the debate will go on for some time. Look how it's evolved from the sixties to eighties (don't we now live in a near new era?) Currently, my main concern is during rework, as in BGA, what effects are realized by overheating surrounding solder joints with hot air generated by the rework process. Is it better to completely reflow all joints, or heat but a few - again, as an example.

And on it goes - plus any direct help you may provide (beyond literary references) would be most appreciated - for my sake as well as the "children's."

Moonman

reply »

Vince Whipple

#11004

Re: wave solder process | 18 June, 1999

Tony, I have a great one page solder defect chart I can fax you, send me an email with your fax # and I'll shoot it over to you. vwhipple@sono-tek.com

Vince ---------------------------------

| Does anyone know where I can find a list of things to do to when troubleshooting issues during the wave solder process? | | for example: | | Solder Bridge | 1.verify amount of flux been aplied. | 2.verify turbulance on your solder wave. | 3.etc. etc. etc.. | | will appriciate any feed back. | | Thanks | | Tony A | |

reply »

JohnW

#11005

Re: wave solder process | 21 June, 1999

| | Does anyone know where I can find a list of things to do to when troubleshooting issues during the wave solder process? | | | | for example: | | | | Solder Bridge | | 1.verify amount of flux been aplied. | | 2.verify turbulance on your solder wave. | | 3.etc. etc. etc.. | | | | will appriciate any feed back. | | | | Thanks | | | | Tony A | | | | | Manko, many years ago, defined soldering as the joining of two metal surfaces (emphasis on surfaces), using a solder medium (a tin/lead alloy, as an example), without requiring diffusion or intermetallic formation. I still adhere to this definition based upon the understanding of surface. | | To surface scientists (I'm not one but do work with them often), surface is defined as an object's area having no depth. They define depth in terms of a finite number of angstroms, though we all know angstroms are not a unit of measure. Once this number is reached, depth begins and is measurable. | | Manko, and many othes, subscribed that solder wetting, or surface joining using a solder medium, was effected at the atomic level. This tracks with surface science needs, and does not violate the depth consideration, nor does is violate the definition of difusion or intermetallic formation. | | Having said all this, wave soldering is another form of metal surface joining at a temperature below 800 degrees F. Beyond this, I define wave soldering as a process made up of several sub processes, and many individual activities. It's at the activity level, most defects are effected provided all else is acceptable. | | All else is defined as everything entering, or used in, the process is as specified. Everything includes solder, PCB solder termination area, component lead (why wave solder if no through hole components are used), and machine capability quality is as specified. | | Now, the wave soldering process is foremost. It is made up of sub processes, and systems, as the fluxer, conveyor, preheater, and wave. Each sub process must be setup, as required for a particular board type (based mostly on thermal mass). | | Flux must be as specified (specific gravity determined using a hygrometer and/or using titration methods to verify composition and quality) and must be applied to ensure wetting on the board's bottom side and through all holes to the top side. Conveyor speed must be calibrated (I use a yard stick and stop watch) and set (usually between 3-6 feet per minute) to ensure proper topside board preheat temperature (to ensure flux penetration and activation), and to ensure proper contact time/area over the wave. | | Wave temperature must be as specified. The old DOD-STD-2000 medled in our affairs by specifying a temperature of 500 + or - 5 degrees F. In our times, we often tweak temperatures to suit our needs as minimizing chip component cracking, as an example. Currently, on one of our wave solder machines, the solder pot is maintained at 470 degrees and few components fail. | | Solder purity must be as specified in accordance with ANSI-J-STD 001, table 5, as I recall. If not in conformance, the solder pot must be dealt with appropriately. | | Solder wave contact time and area must be assured as specified for a particular board type. Usually, using a Lev-Check glass plate, I set the contact area between 1.5 and 2.5 inches assuring paralellism across the plate. The contact time should be between 2-3 seconds and the board should be immersed in the wave not more than 50% of its thickness. Don't forget board angle over the wave at about 7-10 degrees depending on requirements. This may vary for selective wave pallets. | | If all else comes together, as operator activity performance and acceptable boards, components, and solder purity, perfect solder joints will be effected. Of course, if I haven't already discussed, designs, solder mask, and other factors must be as specified. | | There's much more. It depends on application and process management requirements, but it's a start. | | Earl Moon | Tony,

There's this article I read a while back showing fishbones and all that type of stuff on waves, but one of the best thing's it had was a matrix of fault's vs solutions for wave soldering by a group called FRYS..I use it when I'm training folk's on wave and it's a good first hit for thing's, if you want a copy let me know and I'll fax / mail it to you.

JohnW

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