Subject: | |
From: | |
Reply To: | TechNet E-Mail Forum. |
Date: | Tue, 5 May 1998 15:37:17 +0200 |
Content-Type: | multipart/mixed |
Parts/Attachments: |
|
|
Hello Edward,
From time to time we also see the same type of defects. It tends to be batch related.
The defects has a resistance from 10 kW to 10 MW.
In microsectioning of the boards I have seen, what looks like a mist of copper around the drilled holes.
I think the mechanism is called "vicking" and is related to drill-parameters.
In the next period of time I will try to registrate the defect and compare it to the drilling-parametre.
I will also check if we have problems with residues in the black oxide.
With best regards
CHEMITALIC A/S
Jan Thuesen
-----Oprindelig meddelelse-----
Fra: Eltek Ltd. - Process Engineering [SMTP:[log in to unmask]]
Sendt: 5. maj 1998 09.04
Til: [log in to unmask]
Emne: [TN] High resistance internal shorts
Hi Technetters !
During the past period we made a lot of improvements in our production to
reduce the scrap due to internal shorts . At this moment 90% of internal
shorts are " isolation shorts " , it mean high resisitivity .
Some of this shorts were located and we found unidentificed spots in the
laminates. The spots are located under the conductors ( laminate side ) ,
they have irregular shapes and are very thin . Such spots are bridging two
adjacent conductors . Such spots are not result of unetched copper since
they are running deep into the laminate ( more than 25 microns ) .
I will appreciate comments on this problem via technet or to my private e-mail .
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
################################################################
|
|
|