Ramon:
In the world I inhabit, the work being plated is nominally defined as being the cathode....
At this site, the ions in solution, which are positively charged, are converted to metal by adding electrons...
This may be in violation of other conventions, or not, I am not sure, but in the world of electroplating, the cathode receives electrons pumped from the anode, and feeds them to the positively charged ions, to convert them...
I do not try to understand these things, I just report the news...
Have a good weekend.
Rudy Sedlak
"Dehoyos, Ramon" <[log in to unmask]> wrote:
The electron source is the cathode (negative polarity,
excess electrons) and the receiving end is the anode ( positive
polarity, missing electrons).
Ramon
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of R Sedlak
Sent: Wednesday, May 24, 2006 6:26 PM
To: [log in to unmask]
Subject: Re: [TN] electroless gold thickness'
Cheryl:
Plating from solutions involves transfering electrons to ions floating
in solution, converting them to metals, hopefully on the surface we
want.
There are three kinds of plating from solutions...
immersion plating
electroless plating
electrolytic plating
The three different methods differ in the source of the electrons...
In immersion plating, some of the substrate dissolves, releasing
electrons, which cause the metal in solution to plate out. This kind
of plating is self-limiting, when the substrate material gets covered,
plating stops. This is why you cannot get gold over about 0.25 micron
in IMMERSION gold.
In electroless plating, another chemical in solution donates electrons
to the metal ions in solution, causing them to plate out. There is
theoretically no limit to the thickness you can achieve using
electroless plating... thus achieving 0.5 micron gold can be done with
ELECTROLESS gold.
And for the record, the rectifier, also known as the "electron pump",
pumps electrons from the anode to the cathode in electrolytic plating.
Rudy Sedlak
RD Chemical Company
Cheryl Johnson wrote: I believe I have
seen this somewhere, and have tried searching the archives, but am
having trouble finding it.
Does anyone know of any processes for electroless gold that can obtain >
.5 micron thickness (without needing bus bars?) Or any way to get > .5
micron gold on a flex without bus bars?
Thank you!
Sincerely,
-----------------------------------
Cheryl Johnson, C.I.D.+
Manager
ExcelStor US Office, Engineering Services
Email: [log in to unmask]
Tel: (303) 684-7291
Fax: (303) 684-7268
Mobile: (303) 809-5815
-----------------------------------
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e To
unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or
(re-start) delivery of Technet send e-mail to [log in to unmask]: SET
Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the
posts: send e-mail to [log in to unmask]: SET Technet Digest Search the
archives of previous posts at: http://listserv.ipc.org/archives Please
visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for
additional information, or contact Keach Sasamori at [log in to unmask] or
847-615-7100 ext.2815
-----------------------------------------------------
---------------------------------
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e To
unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or
(re-start) delivery of Technet send e-mail to [log in to unmask]: SET
Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the
posts: send e-mail to [log in to unmask]: SET Technet Digest Search the
archives of previous posts at: http://listserv.ipc.org/archives Please
visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for
additional information, or contact Keach Sasamori at [log in to unmask] or
847-615-7100 ext.2815
-----------------------------------------------------
Be a chatter box. Enjoy free PC-to-PC calls with Yahoo! Messenger with
Voice.
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------
---------------------------------
---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------
Sneak preview the all-new Yahoo.com. It's not radically different. Just radically better.
|
