 
| Subject: | |
| From: | |
| Reply To: | TechNet E-Mail Forum. |
| Date: | Mon, 24 May 1999 16:34:04 EDT |
| Content-Type: | text/plain |
| Parts/Attachments: |
|
|
In a message dated 5/24/99 10:12:01, [log in to unmask] writes:
>Hello Engelmaier!
>How does it change does it increase or decrease? Do you know
>any information about etchants to decorate grain boundaries.
>Thanks,
>Yasmeen
Hi Yasmeen,
The grains generally increase in size during annealing, but more importantly
they change shape. Most commercial electrodeposited copper foil has a
columnar grain structure where the grains are packed columns running through
the thickness of the foil; there also is a difference in the machine and
cross-machine directions. Rolled copper foil has a needle-like structure with
the needles running in the rolling direction of the foil; this produces large
(much larger than E-foil) differences in foil properties in the machine and
cross-machine directions. Annealing will produce more uniform grain
structures.
For the appropriate etchants (they depend on what in the grain structure you
want to emphasize) I need to send you to experts in this area. Since your
internal lab does not seem to be experienced in this area, I would suggest to
have the cross-sectioning, polishing and etching done by a commercial
laboratory. Any of the labs that are IPC members can be recommended (I have
seen some rather bad results from some other labs); so pick one conveniently
located to you out of the IPC membership directory.
Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL 32174 USA
Phone: 904-437-8747, Fax: 904-437-8737
E-mail: [log in to unmask], Website: www.engelmaier.com
################################################################
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's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################
|
|
|
