The VIP process is not so simple (materials, filling, curing, flatness etc.) not all the PCBs shops know how to do it right, so in order not to limit ourselves and also costs aspects (beside the reliability), I recommend up to 0.5 mm pitch to design the vias out of the bumps pads. Best Regards Reuven ROKAH Lee Parker <lee.parker@THEE To: [log in to unmask] CMG.COM> cc: Sent by: TechNet Subject: Re: [TN] VIA in Pad <[log in to unmask] > 30/06/2004 04:48 Please respond to "TechNet E-Mail Forum."; Please respond to Lee Parker I agree. Many of these materials expand during the curing process and completely fill the barrel while releasing all volatiles. Consequently after leveling and plating they become benign. Lee -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Mcmaster, Michael Sent: Tuesday, June 29, 2004 8:33 PM To: [log in to unmask] Subject: Re: [TN] VIA in Pad Reuven - I disagree with your assertion that VIP is not 100% safe. With proper selection of via fill material and a reasonable hole aspect ratio, you should have neither solderability or void issues. Mike McMaster RF Product Engineer Merix Corporation 503-992-4263 > ---------- > From: Reuven ROKAH[SMTP:[log in to unmask]] > Reply To: TechNet E-Mail Forum.;[log in to unmask] > Sent: Monday, June 28, 2004 10:08 PM > To: [log in to unmask] > Subject: Re: [TN] VIA in Pad > > I recommend to try as a first priority to layout the via out of the BGA > pad > (bump) to adjacent special micro via hole pad. > Up to 0.5 mils pitch it can be done. > The filling VIP is not 100% safe (solderability and voids aspects). > > > Best Regards > > Reuven ROKAH > > > > > "Macko, Joe @ > IEC" <joe.macko To: [log in to unmask] > Sent by: TechNet cc: > <[log in to unmask] Subject: Re: [TN] VIA in > Pad > > > > > 28/06/2004 17:35 > Please respond > to "TechNet > E-Mail Forum."; > Please respond > to "Macko, Joe @ > IEC" > > > > > > Tom, > > My experience has been that their generally a direct correlation between > voiding and VIP locations. Of course, the size of VIP has a direct > bearing > on the potential size of the void in the solder ball ..... Our current > policy is to fill all VIPs to preclude any voiding problems or > insufficient > solder conditions in leaded parts. > > I would sensitize your customer to the potential for voiding which may not > meet IPC guidelines, and the need for rework with VIPs for leaded parts. > Good luck. > > joe > > -----Original Message----- > From: Tom Parkinson [mailto:[log in to unmask]] > Sent: Friday, June 25, 2004 8:20 AM > To: [log in to unmask] > Subject: [TN] VIA in Pad > > > We're a CM. One of our customers is asking us to build a board assembly > that will be using BGAs with VIAs in pads. They are in the design stages > at > this point, and we have some concerns with having a Via in the middle of a > BGA pad. Anyone have suggestions and/or experience with this?? > > > > Thanks > > > > > > Tom Parkinson - Quality System Manager - CIT > > WinTronics, Inc. > > Ph: 724-981-5770 Ext. 235 > > Fax: 724-981-1772 > > > > > > > --------------------------------------------------- > 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 > 847-509-9700 ext.5315 > ----------------------------------------------------- > > --------------------------------------------------- > 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 > 847-509-9700 ext.5315 > ----------------------------------------------------- > > --------------------------------------------------- > 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 > 847-509-9700 ext.5315 > ----------------------------------------------------- > --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- 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 847-509-9700 ext.5315 -----------------------------------------------------