Hi, Mickey A 3/3mil width/spacing trace needs a 9mil via2via airgap, so the via pad needs to be 17mil with an 8mil hole size. Anyway, the balance of PCB layer adding and the using of blind vias is an interesting matter, consider the power will not be isolated. B.R. Li Yi Causion: This e-mail and its attachments contain confidential information from H3C, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it! ----- Original Message ----- From: "weiner, mickey" <[log in to unmask]> To: <[log in to unmask]> Sent: Tuesday, August 04, 2009 3:18 PM Subject: Re: [TN] Looking for a fabricator for a .65mm bga brd Barbara, A Via pad is required in the center of every 4 pads. The diagonal space between 2 bga pads with .25 mm dia. leaves 0.67 mm. Minimum via pad dia. - see also Dwight response- would be .46 mm leaving 0.1 mm (4 mils) via2bgapad distance. This can be done - but highly not recommended . With Inner via pad the same size you get 7.5 mils between 2 adjacent via pads - enough for 1 trace 3 mils wide only.You should calculate the escapes for all your signals + plane layers to find how many layers you'll need. I suggest you search the Amkor web site they have good design application notes. Mickey _____ From: Barbara Burcham [mailto:[log in to unmask]] Sent: Monday, August 03, 2009 7:17 PM To: weiner, mickey Subject: Re: [TN] Looking for a fabricator for a .65mm bga brd Hi Mickey, The matrix is full. Pad size recommended is .3mm and am considering a .25mm pad...the balls on the part are collapsible so that makes me a smidge nervous. Should I be? Thanks for any suggestions, Barbara On Mon, Aug 3, 2009 at 10:05 AM, weiner, mickey <[log in to unmask]> wrote: Barbara, Is 0.65 mm the pitch? Is it a full matrix ? what's the recommended pad size I doubt if under 0.8 mm pitch you'll manage without blind vias Mickey r -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Barbara Burcham Sent: Monday, August 03, 2009 5:23 PM To: [log in to unmask] Subject: [TN] Looking for a fabricator for a .65mm bga brd I am working on a layout that has a 0.65mm 14x14 matrix bga on an 0.062 thick board. I have to be able to place through hole vias between the pads. Would love to use 3 and 3 spacing. Who out there can advise me about this? Yes, the board HAS to be 0.062 thk...has a card edge connector...but can be on the low side of that. Yes, we really want to use through hole vias. We can use 1/2 oz copper on all 8 layers. The board is small and can easily be run on a smaller production panel to improve tolerances. So, how small a capture pad and hole can be done in a production environment, reliably? Need to get this nailed down today. Barbara Burcham, C.I.D. pcb Trace Design 281-341-7539 Wk/Hm 713-249-7718 Cell [log in to unmask] --------------------------------------------------- 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 ----------------------------------------------------- CONFIDENTIALITY This e-mail message and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail message, you are hereby notified that any dissemination, distribution or copying of this e-mail message, and any attachments thereto, is strictly prohibited. If you have received this e-mail message in error, please immediately notify the sender and permanently delete the original and any copies of this email and any prints thereof. ABSENT AN EXPRESS STATEMENT TO THE CONTRARY HEREINABOVE, THIS E-MAIL IS NOT INTENDED AS A SUBSTITUTE FOR A WRITING. Notwithstanding the Uniform Electronic Transactions Act or the applicability of any other law of similar substance and effect, absent an express statement to the contrary hereinabove, this e-mail message its contents, and any attachments hereto are not intended to represent an offer or acceptance to enter into a contract and are not otherwise intended to bind the sender, Sanmina-SCI Corporation (or any of its subsidiaries), or any other person or entity. -- Barbara Burcham, C.I.D. pcb Trace Design 281-341-7539 Wk/Hm 713-249-7718 Cell [log in to unmask] CONFIDENTIALITY This e-mail message and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail message, you are hereby notified that any dissemination, distribution or copying of this e-mail message, and any attachments thereto, is strictly prohibited. If you have received this e-mail message in error, please immediately notify the sender and permanently delete the original and any copies of this email and any prints thereof. ABSENT AN EXPRESS STATEMENT TO THE CONTRARY HEREINABOVE, THIS E-MAIL IS NOT INTENDED AS A SUBSTITUTE FOR A WRITING. Notwithstanding the Uniform Electronic Transactions Act or the applicability of any other law of similar substance and effect, absent an express statement to the contrary hereinabove, this e-mail message its contents, and any attachments hereto are not intended to represent an offer or acceptance to enter into a contract and are not otherwise intended to bind the sender, Sanmina-SCI Corporation (or any of its subsidiaries), or any other person or entity. --------------------------------------------------- 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 -----------------------------------------------------