TECHNET Archives

January 1998

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Ted Stern <[log in to unmask]>
Reply To:
Date:
Mon, 12 Jan 1998 16:32:25 -0800
Content-Type:
text/plain
Parts/Attachments:
text/plain (38 lines)
Hello All:

I need help trying to minimize "organic" contamination occuring in a
cupric chloride final etch.  The contamination is a "black", gummy
material which floats on the surface of the bath in clumps.  If the line
is not cleaned periodically, black spots on the surface of copper
(typically not the laminate), can be seen in inspection.

The DES line processes only innerlayers utilizing CibaGiegy (0.9 mil
nominal thickness) and Dyanchem FL 1.3 mil photopolymers as etch
resists. An FTIR scan has been performed on the residue, both
photopolymers, and the "rollers". While not entirely conclusive, the
scans more closely resembled the photopolymers and not the rollers.
Visually, the rollers do not seem to be swelling or deteriorating.

The etching bath is operated at 1.3 N HCl, regenerated via chlorine gas
(ORP control), and sees both 1 oz and 2 oz copper.  I am unsure of the
laminate being employed.  Continuous carbon filtration has been employed
with some degree of success.  The carbon filters are changed weekly:
one 30" filter per 450 gallons of bath.

Can anyone offer suggestions to better control or eliminate this
residue?!  Thanks in advance

Ted Stern

##############################################################
TechNet Mail List 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://www.ipc.org/html/forum.htm) for additional information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
##############################################################


ATOM RSS1 RSS2