This is quite common. Even though we are a "pattern" plate shop, every board we build has some panel plate on it.
We process through electroless copper then add what we call a strike plate, essentially a few 100 microinches of electrolytic copper. Then we follow with pattern plate.
What's critical here is that the pattern plate copper height cannot exceed the thickness of the photoresist used to make the pattern. Depending on the requirements of the board, the amount of strike (panel) is varied to avoid this issue. Boards with high minimum PTH copper, higher aspect ratio, and/or areas of higher current density will get more panel with a corresponding decrease in etch capability.
This is why it's a bad idea to put fine lines on thick boards with small holes.
Mike McMaster
RF Product Engineer
Merix Corporation
503-992-4263
----------
From: Ian Shute[SMTP:[log in to unmask]]
Reply To: TechNet E-Mail Forum.;Ian Shute
Sent: Wednesday, November 05, 2003 7:21 AM
To: [log in to unmask]
Subject: [TN] Pattern & panel plating why both ?
All,
Any insight as to why a PCB house would panel then pattern plate a board?
My mis-guided time in the industry has lead me to believe it's one or the other?
Thanks
Ian
---------------------------------------------------
Technet Mail List provided as a free 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 847-509-9700 ext.5315
-----------------------------------------------------