Hi Steve,
Sorry if I didn't present the question clearly. The question I am asking is refer to the
spacing (gap) between two solder joints not the pitch of a BGA component. For example, in a
1.27mm (50 mil) pitch BGA, a solder joint is roughly 35 mil after reflow, that leave the
theoretical spacing between the solder joints become 15 mil. However for some reason the
package that used may have balls that off the true position which may result the two solder
joints come very close together after reflow.
What would be the minimum allowable spacing between the two joints?
Thanks,
Alex
"Stephen R. Gregory" wrote:
> Hi Alex!
>
> Do you really mean .005"? Sounds pretty 'friggen tight to me. Here's a page
> that talks about ball pitch on uBga packages and chip scale packages:
>
> http://www.ednmag.com/ednmag/reg/1995/052595/11df1.htm
>
> No where are they getting that tight...I just want to say, I see you're from
> Alcatel, so you're in the packaging business, have a heart on us assembly
> guys, you may design a package that works, but then leave it up to
> "floor-rats" like us to figure out how to put these things together. A BGA
> package that goes down to .005" spacing is asking too friggen' much!!! I
> don't think I'm alone in that observation....I could be wrong...(it hasn't
> been the first time)
>
> Geeze, you designers need to get down on the manufacturing floor...don't mean
> that badly, just a necessary requirement before you push the limits...
>
> -Steve Gregory-
>
> << Hi,
>
> Do anyone have any literature referring to what is the minimum spacing
> between two BGA solder joints? From talking to many people, 0.005" seem
>
> to be the most commonly use number. Do people agree with this number?
> Why?
>
> Thanks,
> Alex >>
>
> ---------------------------------------------------------------------------------
> Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
> 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 delivery of Technet send the following message: SET Technet NOMAIL
> Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
> information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
> ---------------------------------------------------------------------------------
---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
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 delivery of Technet send the following message: SET Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------
|
