At 17:12 14/02/98 -0500, you wrote:
>Technet,
>
>The recent discussion surrounding tap water versus DI for black oxide
>rinses begs the question
>
>Why use DI anywhere in the PCB shop?

In Israel tap water has high concentration of dissolved salts ( conductivity
more than 1200 microsiemens/cm and hatdness more than 300 ppm as CaCO3 ) .
As general guideline , at least in my plant , DI rinse is considered for the
following reasons:
1 ) last rinse before drying to avoid salts spots on the boards
2 ) last rinse before processing in solution with very low replenishing rate
, to avoid build up of certain ions in such solutions .

>In a past life a shop had a DI system that leached hydrochloric acid
>after regeneration and maybe still does (?).  That was something in its
>own to deal with.
>
>What does one do when the DI unit needs regenerated for water?  Shut
>down operations?

We have two parallel units , one in operation , the second stand-by or
regeneration .

Best regards
Edward Szpruch
Eltek Ltd - Israel
Tel  972 3 9395050
Fax 972 3 9309581
E-mail :  [log in to unmask]

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
################################################################