Setting up a PCB washing "system" and the facilities required for a cost effective and repeatable cleaning process depend heavily on the application (water soluble versus chemistry cleaning), (batch cleaner versus ln-line) and local factors (quality of incoming water, discharge regulations, and overall company philosophy on environmental considerations.
Major facilities considerations for the DI water system would be as follows. 1. Incoming water quality 2. Flow rate and pressure requirements 3. Hours of operation 4. Open loop (effluent to drain) or Closed Loop Recycling 5. Location of the cleaning equipment versus DI plant 6. Water quality specification
Process questions: 1. Water soluble or chemistry cleaning 2. Batch or in-line 3. Use of water soluble mask / tape
Once these items are established it is a matter of matching the most appropriate water purification techniques with the application.
Classic approaches to water purification: 1. Reverse osmosis tap water purification 2. Carbon / Ion exchange tap water purification 3. Carbon / Ion exchange effluent recycling
An often overlooked component of a DI water system is the heating capacity. particularly for in-line machines, a heated final rinse is required. While the in-line cleaning systems have integrated heaters, they exist to maintain temperature not heat incoming final rinse water. Point-of-use heaters are typically the best choice, especially when considering they need to be DI water compatible.
I would recommend contacting a reputable DI water equipment manufacturer that has experience with PCB cleaning. Flow diagrams, equipment profiles, and cost models are available to assist in setting up the appropriate system for your specific application.
www.resysinc.com
Brian
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