 
| Subject: | |
| From: | |
| Reply To: | DesignerCouncil E-Mail Forum. |
| Date: | Fri, 16 Apr 1999 10:00:26 -0400 |
| Content-Type: | text/plain |
| Parts/Attachments: |
|
|
Bob,
You might also want to look into NiAu and NiPd plating among others.
They should both be much flatter than standard HASL and some of the
drawbacks of OSP might not be there. It's best to contact your bare
board vendor directly, each of them seems to have a somewhat unique
solution to this problem.
- Jon DeGenova
-----Original Message-----
From: Bob Walker [mailto:[log in to unmask]]
Sent: Friday, April 16, 1999 9:32 AM
To: [log in to unmask]
Subject: [DC] OSP vs HASL
I've designed a board that has four BGA's on it, the smallest has 272
balls while the largest has 600. The initial prototypes were made using
the HASL process, but after talking to a contract manufacturer about
assembling the production boards, he is recommending that I use an OSP
process to keep the BGA pads flat. I'm told that because of using the
OSP process, there will be some exposed copper after the boards have
been completely assembled, but that there aren't any negative effects of
the exposed areas based on some studies that he has read about. My
questions are as follows:
1. Are there potential reliability problems with the exposed copper?
2. Is OSP a better way to go when dealing with BGA packages?
3. Since I've never dealt with the OSP process before are there any
other design considerations that I need to be aware of?
I'd appreciate any comments or recommendations concerning this
situation.
Regards,
Bob Walker
Sandgate Technologies
[log in to unmask]
################################################################
DesignerCouncil 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 DesignerCouncil <your full name>
To unsubscribe: SIGNOFF DesignerCouncil
################################################################
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
################################################################
|
|
|
