Amen, problem solved. In addition, there is slight dishdown in the fill planarization. A perfectly planar surface is preferred. Dave Simonik Process Tech. Sanmina SCI Corp. Owego NY division -----Original Message----- From: Jeffrey Bush [mailto:[log in to unmask]] Sent: Thursday, October 20, 2005 7:28 AM To: [log in to unmask] Subject: Re: Delamination at Thermal Via area? To combat this type of issue, we have implemented a panel flash after 2nd deposition to ensure the fillet was sealed - particularly important with silver/copper epoxy fillers as the dep can be spotty and the plating does not adhere to the epoxy. Jeffrey Bush Director, Quality Assurance and Technical Support VERMONT CIRCUITS INCORPORATED 76 Technology Drive - POB 1890 Brattleboro, Vermont 05302 Voice: 802.257.4571.21 Fax: 802.257.0011 http://www.vtcircuits.com -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Leo Higgins Sent: Wednesday, October 19, 2005 4:24 PM To: [log in to unmask] Subject: Re: [TN] Delamination at Thermal Via area? Hi Steve, I have enclosed two photos of a delam between the copper plated over the top of a filled via in a double sided PCB substrate for a flip chip fine pitch BGA. Hopefully you can post on your site. The substrate is approx 200um thick. The vias are not via-in-pad for flip chip solder ball attach. The solder balls are attached just adjacent to these filled vias. Via filling is insulative. You can see that the vias delaminated at some point before the flip chip underfill cured since it is thinner directly over the delam area. Since the via fill should be totally encapsulated by copper due to the via sidewall plating and the copper plating over the fill, we suspect the fill was not fully off-gassed and blew its lid with PbFree FC attach. Thanks. Best regards, Leo Director of Applications Engineering ASAT, Inc. 3755 Capital of Texas Highway, Suite 100 Austin, Texas 78704 ph 512-383-4593 fx 512-383-1590 [log in to unmask] www.asat.com The information contained in this electronic message is CUSTOMER/SUPPLIER PRIVILEGED AND CONFIDENTIAL INFORMATION intended only for the use of the individual or entity named above. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution and copying of this communication is strictly prohibited. If you have received this communication in error, please immediately notify the sender by electronic mail. Thank you. -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Steve Gregory Sent: Wednesday, October 19, 2005 12:49 PM To: [log in to unmask] Subject: Re: [TN] Delamination at Thermal Via area? Hi George! Got your pictures up! Check out: http://www.stevezeva.homestead.com/files/Delamination_Blisters-1.jpg http://www.stevezeva.homestead.com/files/Delamination_Blisters-2.jpg http://www.stevezeva.homestead.com/files/Delamination_Blisters-3.jpg Kind regards, -Steve Gregory- Senior Process Engineer LaBarge Incorporated Tulsa, Oklahoma (918) 459-2285 (918) 459-2350 FAX |---------+----------------------------> | | "Wenger, George | | | M." | | | <George.Wenger@an| | | drew.com> | | | | | | 10/19/2005 11:00 | | | AM | | | | |---------+----------------------------> >----------------------------------------------------------------------- ---- -----------------------------------| | | | To: TechNet E-Mail Forum <[log in to unmask]>@SMTP@Exchange, Stephen R Gregory/LABARGE@LABARGE | | cc: | | Subject: RE: [TN] Delamination at Thermal Via area? | >----------------------------------------------------------------------- ---- -----------------------------------| Wee Mei, I've asked Steve to post three images of delamination blistering that might be different than you are seeing but the cause is most likely the same. I do not know how many layers there are or the number of thermal vias there are in the heat spreader portion of the U2 footprint on your board but it appears that your delamination is occurring in an area of the board where the outside layers are totally covered by metal (i.e., copper). This is decrease the ability of the board to outgas in those areas if the board is heated too rapidly or to too high a temperature. I'm also assuming but can't tell because I haven't seen a cross section of your thermal vias but my guess would be that you do not have good attachment integrity of the outer-layer copper to the barrels of the thermal vias and therefore the thermal vias are not providing any mechanical strength to hole you board together when reflowed. The three images I've sent to Steve show delamination blisters on the bottom side of a 14-Layer PCB. The delamination is occurring between layer 13 and layer 14 in areas that have a copper ground plane on Layer 14. There acre also not PTH's in these areas to hold the board together when internal moisture is driven off too fast. There are no blisters where ever there are PTH's. We're not sure there was a single cause for our delamination or multiple causes. These boards were over 1 year old and could have and probably did absorb moisture from the environment. We believe the reflow profile that caused these blisters had too fast a ramp and too hot a peak temperature. If we baked the boards prior to the reflow they didn't delamination or if we didn't bake the boards and used a correct profile they didn't blister. I hope this information helps you find the root cause for you delamination. My suggestion is to examine your reflow profile and cross section thermal vias in the blistered area. Regards, George George M. Wenger Reliability / FMA Engineer Base Station and Subsystems Group Andrew Corporation, 40 Technology Drive, Warren, NJ 07059 (908) 546-4531 [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory Sent: Wednesday, October 19, 2005 10:30 AM To: [log in to unmask] Subject: Re: [TN] Delamination at Thermal Via area? Hi Wee Mei! I've got your pictures posted. Go to: http://www.stevezeva.homestead.com/files/U2_top.JPG http://www.stevezeva.homestead.com/files/U2_bottom.JPG http://www.stevezeva.homestead.com/files/U2_delamination.JPG Are the vias filled? Are you seeing this delamination on very many PCB's? Are you seeing it only on the bottom of the PCB? Kind regards, -Steve Gregory- Senior Process Engineer LaBarge Incorporated Tulsa, Oklahoma (918) 459-2285 (918) 459-2350 FAX |---------+----------------------------> | | Wee Mei | | | <[log in to unmask] | | SG> | | | Sent by: TechNet | | | <[log in to unmask]>| | | | | | | | | 10/19/2005 03:47 | | | AM | | | Please respond to| | | TechNet E-Mail | | | Forum | | | <[log in to unmask]>| | | ; Please respond | | | to Wee Mei | | | <[log in to unmask] | | SG> | | | | |---------+----------------------------> >----------------------------------------------------------------------- ---------------------------------------| | | | To: [log in to unmask]@SMTP@Exchange | | cc: (bcc: Stephen R Gregory/LABARGE) | | Subject: [TN] Delamination at Thermal Via area? | >----------------------------------------------------------------------- ---------------------------------------| Hello, Just asked Steve to download 3 pictures on the defects. Kindly take a look at them and would appreciate some feedback on the possible root cause. Steve : Thanks for the downloading. Regards, Wee Mei --------------------------------------------------- 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 ----------------------------------------------------- __________________________________________________________________ This message may contain information that is privileged and confidential to LaBarge, Inc. 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In such event, you should destroy the message and kindly notify the sender by reply e-mail. --------------------------------------------------- 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 ----------------------------------------------------- ------------------------------------------------------------------------ ---- -------------------- This message is for the designated recipient only and may contain privileged, proprietary, or otherwise private information. If you have received it in error, please notify the sender immediately and delete the original. Any unauthorized use of this email is prohibited. ------------------------------------------------------------------------ ---- -------------------- [mf2] __________________________________________________________________ This message may contain information that is privileged and confidential to LaBarge, Inc. It is for use only by the individual or entity named above. If you are not the intended recipient, you may not copy, use or deliver this message to anyone. In such event, you should destroy the message and kindly notify the sender by reply e-mail. --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 ----------------------------------------------------- ____________________________________________________________________________ _ Scanned by Sanmina-SCI eShield ____________________________________________________________________________ _ --------------------------------------------------- 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 -----------------------------------------------------