Batch Cleaners

All Y'All: A recent (10/98) article in "Circuits Assembly" magazine touted the use batch cleaners using a aqueous alcohol solvent. Reported benefits of this approach were:

1 Better use of floor space 2 Ability to develop custom recipes 3 Ability to meet through-put demands 4 Lower capital and operating costs 5 Lower water use

Questions on this approach are:

1 What is your experience with batch cleaners? (Mine is limited to using Sears washers to bridge until the in-line cleaner is delivered.) 2 Are batch cleaners primarily aimed at single product process lines or are they effective in high product mix flex lines? 3 If used in high mix environments, how do you control the recipe? Do you clean boards according to batch cleaned by recipe? 4 Who makes the better batch washers?

Thanks

Dave F

reply »

Hey there Dave!

We used to use a batch cleaner when we used water-clean paste. It was similar to a dishwasher, except that it had a digital menu for entering the number of wash cycles, water temp., amount of saponifier (we just used DI water), and number of dry cycles. The dry cycle blew hot air over the PCBs and gradually cooled the air. I gues the advantage over a simple dishwasher was the exact control over water temp, the number of cycles, and the amount of saponifier. We were making double sided, mixed tech, medium density (3-4, 20-25 mil parts, plus others)boards in 100-300 board runs. They were cleaned spotless, as long as we kept the DI filter system clean. The water was recycled by a DI fileter system. It would exit, run through a series of filters, and sit in a holding tank until it was needed again. Boom, no discharge. We could customize the menu for each board type. Larger, more complex boards usually required more wash cycles to get the flux from between all the parts, pads; as well as a longer dry cycle. Conversely, smaller boards could be washed faster and dryed faster. It worked like a charm until we moved to no-clean. It was also becoming a bottle-neck with larger runs, we could build faster than we could clean. Although, I guess we could have purchased an additional machine. Hope this helps!

Ryan Jennens Phoenix Engineering Design, Inc.

| All Y'All: A recent (10/98) article in "Circuits Assembly" magazine touted the use batch cleaners using a aqueous alcohol solvent. Reported benefits of this approach were: | | 1 Better use of floor space | 2 Ability to develop custom recipes | 3 Ability to meet through-put demands | 4 Lower capital and operating costs | 5 Lower water use | | Questions on this approach are: | | 1 What is your experience with batch cleaners? (Mine is limited to using Sears washers to bridge until the in-line cleaner is delivered.) | 2 Are batch cleaners primarily aimed at single product process lines or are they effective in high product mix flex lines? | 3 If used in high mix environments, how do you control the recipe? Do you clean boards according to batch cleaned by recipe? | 4 Who makes the better batch washers? | | Thanks | | Dave F |

reply »

Hi all,

Only observation I would make is that it depends upon what you term as clean?

Now isn't that an old thorny question. Care to comment?

Regards Graham

| Hey there Dave! | | We used to use a batch cleaner when we used water-clean paste. It was similar to a dishwasher, except that it had a digital menu for entering the number of wash cycles, water temp., amount of saponifier (we just used DI water), and number of dry cycles. The dry cycle blew hot air over the PCBs and gradually cooled the air. I gues the advantage over a simple dishwasher was the exact control over water temp, the number of cycles, and the amount of saponifier. We were making double sided, mixed tech, medium density (3-4, 20-25 mil parts, plus others)boards in 100-300 board runs. They were cleaned spotless, as long as we kept the DI filter system clean. The water was recycled by a DI fileter system. It would exit, run through a series of filters, and sit in a holding tank until it was needed again. Boom, no discharge. We could customize the menu for each board type. Larger, more complex boards usually required more wash cycles to get the flux from between all the parts, pads; as well as a longer dry cycle. Conversely, smaller boards could be washed faster and dryed faster. It worked like a charm until we moved to no-clean. It was also becoming a bottle-neck with larger runs, we could build faster than we could clean. Although, I guess we could have purchased an additional machine. Hope this helps! | | Ryan Jennens | Phoenix Engineering Design, Inc. | | | | All Y'All: A recent (10/98) article in "Circuits Assembly" magazine touted the use batch cleaners using a aqueous alcohol solvent. Reported benefits of this approach were: | | | | 1 Better use of floor space | | 2 Ability to develop custom recipes | | 3 Ability to meet through-put demands | | 4 Lower capital and operating costs | | 5 Lower water use | | | | Questions on this approach are: | | | | 1 What is your experience with batch cleaners? (Mine is limited to using Sears washers to bridge until the in-line cleaner is delivered.) | | 2 Are batch cleaners primarily aimed at single product process lines or are they effective in high product mix flex lines? | | 3 If used in high mix environments, how do you control the recipe? Do you clean boards according to batch cleaned by recipe? | | 4 Who makes the better batch washers? | | | | Thanks | | | | Dave F | | | |

reply »

First, let me say that I am a manufacturer of batch cleaning systems. The following information is not intended to be a commercial for our cleaners, but rather a commentary about batch cleaners in general.

Batch cleaners come in all sizes and configurations. Sears, Maytag and other residential dishwashers are not terribly uncommon. Their practical use, however, is limited to OA flux on through-hole technology on boards not destined for ionic contamination testing.

As far as batch cleaners actually designed for post solder flux / paste removal, the most common are high-power, spray-in-air (dishwasher-like) cleaners.

The typical batch cleaner is capable of cleaning both through-hole and surface mount assemblies. Although their speed is not as fast as in-line cleaners, their cleanliness abilities are, in most cases, superior.

Batch cleaners are normally used in high-mix, medium volume applications. Unlike dedicated in-line cleaning applications, batch cleaners easily adapt to various cleaning applications. Many batch cleaners are equipped with multiple program memories. Memory # 1, for example, may be programmed for RMA paste removal using Armakleen saponifier @ 10% concentration. Memory #2 may be programmed to use only 6% chemical injection on reworked boards. Memory #3 may be programmed to run with no chemistry for OA paste removal applications.

Most batch cleaners are equipped with a built-in resistivity controller that allows the operator to preset a desired level of product cleanliness. With this "cleanliness control", large boards with more flux / paste will take longer to clean than smaller boards. Additionally, boards with higher solids content fluxes will take longer to clean than lower solids fluxes. This would be an automatic function of the machine's controller rather than a change in "recipes".

As for your question #4 (who make the better batch washers), that answer would best come from other readers of this forum.

You may want to refer to EP&P's October issue. They published an article about cleaning circuit assemblies where they discuss both batch and in-line technologies.

I hope this helps.

Mike Konrad

| All Y'All: A recent (10/98) article in "Circuits Assembly" magazine touted the use batch cleaners using a aqueous alcohol solvent. Reported benefits of this approach were: | | 1 Better use of floor space | 2 Ability to develop custom recipes | 3 Ability to meet through-put demands | 4 Lower capital and operating costs | 5 Lower water use | | Questions on this approach are: | | 1 What is your experience with batch cleaners? (Mine is limited to using Sears washers to bridge until the in-line cleaner is delivered.) | 2 Are batch cleaners primarily aimed at single product process lines or are they effective in high product mix flex lines? | 3 If used in high mix environments, how do you control the recipe? Do you clean boards according to batch cleaned by recipe? | 4 Who makes the better batch washers? | | Thanks | | Dave F |

reply »

Dave, Be careful if you plan to clean misprinted PCBs in a spray type batch cleaner. There is an article written by Dick Clouthier of AMTX Stencils regarding batch cleaners and their use for cleaning misprints. He describes it as a "solder ball nightmare." The article can be found at: www.smartsonic.com click on the "Recommended Reading" button. Good luck.

| All Y'All: A recent (10/98) article in "Circuits Assembly" magazine touted the use batch cleaners using a aqueous alcohol solvent. Reported benefits of this approach were: | | 1 Better use of floor space | 2 Ability to develop custom recipes | 3 Ability to meet through-put demands | 4 Lower capital and operating costs | 5 Lower water use | | Questions on this approach are: | | 1 What is your experience with batch cleaners? (Mine is limited to using Sears washers to bridge until the in-line cleaner is delivered.) | 2 Are batch cleaners primarily aimed at single product process lines or are they effective in high product mix flex lines? | 3 If used in high mix environments, how do you control the recipe? Do you clean boards according to batch cleaned by recipe? | 4 Who makes the better batch washers? | | Thanks | | Dave F |

reply »

Graham: I agree. Very thorny. What is clean?? And how is that controlled??

Back 25 or so years ago, soldering was done with high solids rosin fluxes. The issue with cleanliness was ionic contamination. The US military and others set a fairly arbitrary cleanliness limit of less than (up to) 10.07 ugm per square inch NaCl equivalent of ionic contamination. In this ROSE testing, all the ionic contaminates are dissolved in a water/IPA solution, its conductivity measured, and this is compared to the conductivity of salt water.

In the past 5 or so years, soldering has changed. Few people solder with the high solids rosin based fluxes that were the basis of that limit. Setting standards for cleanliness for products manufacture today has gotten ugly, because:

Cleanliness standards that exist are for high solids rosin based fluxes and do not relate to other fluxes. Components have no cleanliness requirements. It's possible that both ionic and non-ionic contaminants require concern when using "modern" fluxes. ROSE testing has doubtful repeatability and accuracy. Surface insulation resistance (SIR) tests do not relate to ROSE test results. Ion chromatography tests do not relate to ROSE test results. Ion chromatography tests do not relate to SIR tests results. Ion chromatography tests are expensive to process. SIR tests require that boards be designed for that test.

Doug Pauls suggests using fabricators supplying to Delco C-7000. Sounds good eh?

TTYL

Dave F

| Hi all, | | Only observation I would make is that it depends upon what you term as clean? | | Now isn't that an old thorny question. Care to comment? | | Regards Graham | | | Hey there Dave! | | | | We used to use a batch cleaner when we used water-clean paste. It was similar to a dishwasher, except that it had a digital menu for entering the number of wash cycles, water temp., amount of saponifier (we just used DI water), and number of dry cycles. The dry cycle blew hot air over the PCBs and gradually cooled the air. I gues the advantage over a simple dishwasher was the exact control over water temp, the number of cycles, and the amount of saponifier. We were making double sided, mixed tech, medium density (3-4, 20-25 mil parts, plus others)boards in 100-300 board runs. They were cleaned spotless, as long as we kept the DI filter system clean. The water was recycled by a DI fileter system. It would exit, run through a series of filters, and sit in a holding tank until it was needed again. Boom, no discharge. We could customize the menu for each board type. Larger, more complex boards usually required more wash cycles to get the flux from between all the parts, pads; as well as a longer dry cycle. Conversely, smaller boards could be washed faster and dryed faster. It worked like a charm until we moved to no-clean. It was also becoming a bottle-neck with larger runs, we could build faster than we could clean. Although, I guess we could have purchased an additional machine. Hope this helps! | | | | Ryan Jennens | | Phoenix Engineering Design, Inc. | | | | | | | All Y'All: A recent (10/98) article in "Circuits Assembly" magazine touted the use batch cleaners using a aqueous alcohol solvent. Reported benefits of this approach were: | | | | | | 1 Better use of floor space | | | 2 Ability to develop custom recipes | | | 3 Ability to meet through-put demands | | | 4 Lower capital and operating costs | | | 5 Lower water use | | | | | | Questions on this approach are: | | | | | | 1 What is your experience with batch cleaners? (Mine is limited to using Sears washers to bridge until the in-line cleaner is delivered.) | | | 2 Are batch cleaners primarily aimed at single product process lines or are they effective in high product mix flex lines? | | | 3 If used in high mix environments, how do you control the recipe? Do you clean boards according to batch cleaned by recipe? | | | 4 Who makes the better batch washers? | | | | | | Thanks | | | | | | Dave F | | | | | | | | |

reply »