 
| Subject: | |
| From: | |
| Reply To: | |
| Date: | Tue, 21 Dec 2004 10:38:33 -0800 |
| Content-Type: | text/plain |
| Parts/Attachments: |
|
|
Tammy,
First you must decide why you would allow LPI to be present anywhere except per the artwork.
If you are going to solder then you must reject all occurrences of mask in solderable holes/areas.
If you are not soldering then it becomes a process indicator that you will want to discuss with you PCB Fabricator.
Mask in vias is not a bad thing as vias are not considered solderable holes, also many designs today prefer mask filled or covered vias.
Slight occurrences of mask in mounting holes are not necessarily rejectable, but they can be an indicator that mask is being partially imaged and/or not being completely washed away and there fore may be also in the solderable holes.
Most important here is communication with your suppliers and customers to assure the end product meets all requirements outlined. If you do not care whether mask is in some holes but not others, then you can communicate this to your supplier to ease some of the restrictions we as designers and IPC place upon them.
Remember that communication solves most issues.
Hope it helps,
FNK
Frank N Kimmey CID+
Principal PCB Designer
Powerwave Technologies Inc
Office 916-941-3159
Fax 916-941-3195
Cellular 916-804-2491
-----Original Message-----
From: Chellis, Tammy [mailto:[log in to unmask]]
Sent: Tuesday, December 21, 2004 10:19 AM
To: [log in to unmask]
Subject: [TN] FW: [TN] Plated through holes
Why is it acceptable in Vias?
-----Original Message-----
From: Jeffrey Bush [mailto:[log in to unmask]]
Sent: Monday, December 20, 2004 7:29 PM
To: TechNet E-Mail Forum; Chellis, Tammy
Subject: RE: [TN] Plated through holes
Vias yes - leaded holes no.
-----Original Message-----
From: Chellis, Tammy [mailto:[log in to unmask]]
Sent: Mon 12/20/2004 5:39 PM
To: [log in to unmask]
Cc:
Subject: [TN] Plated through holes
Is it acceptable for the LPI masking to be left in a plated through hole
preventing proper solder wetting?
---------------------------------------------------
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
<http://listserv.ipc.org/archives>
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
<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
-----------------------------------------------------
|
|
|
