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 |
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