TECHNET Archives

April 2007

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:
David Greig <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, David Greig <[log in to unmask]>
Date:
Thu, 26 Apr 2007 18:33:17 +0100
Content-Type:
text/plain
Parts/Attachments:
text/plain (96 lines)
Hi John,

What concerns me is the prospect of:

1. Plated over, but with pinholes
2. Plated over on one side only, with trapped chemistry that will never wash out fully
3. Plated over, but extremely thinly

The problems that may occur are venting during assembly (under BGA's etc) and subsequent leaching out afterwards (even if not
corrosive, surface resistivity and CTI will reduce over time).

I would be happier to specify "plated over, both sides, with a minimum thickness copper each side of xxx".

So far have not run into the prospect of plating over occurring naturally because I go directly to microvia for anything
requiring less than 0.25mm/10mill drills @ 1:6 aspect.


Best Regards
 
David Greig


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of John Foster
Sent: 26 April 2007 16:37
To: [log in to unmask]
Subject: Re: [TN] "plated shut vias"

I am a printed circuit board designer and I will tell you that quite often when I am speaking to a fabricator and I need to take
the vias way down say 8 mils or below the first thing I hear from the fabricator is "Is it okay if the vias are plated shut" 


-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of David Greig
Sent: Thursday, April 26, 2007 8:39 AM
To: [log in to unmask]
Subject: [TN] "plated shut vias"


Hi List,
 
Yet again I've come across fabrication notes on other pcb designers notes that specify that thru board via's may be plated shut.
 
Is there any historical reason for this, or is it just hysterical?
 
I would be rather concerned to see a closed via that is neither blind or filled, mental images of trapped process chemistry etc.
 
Best Regards
 
David Greig
______________________________
 
GigaDyne Ltd
5 Albany Business Centre
Gardeners Street
Dunfermline KY12 0RN
United Kingdom
t: +44 (0)1383 624 975
www.gigadyne.co.uk
______________________________
 

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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 15.0
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
-----------------------------------------------------
-- 
Virus scanned by Lumison.

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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
-----------------------------------------------------

ATOM RSS1 RSS2