Good observation, yes. Once everyone gets the concept it is remarkable how many opportunities there are to optimize. Suppliers are certainly part of the equation. Smart suppliers often have new products that provide huge opportunities, though reliability can be an unknown. Guy -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Frederick Miller Sent: Wednesday, December 21, 2011 8:22 AM To: [log in to unmask] Subject: Re: [TN] QFP center slug over signal vias How about bring the suppliers into the class? I have run classes with suppliers and designers and you should see the engineers defending their designs. The idea is to have an open mind and understand the bigger picture. The supplier may be able to reduce the total assembled cost even if his part will cost more. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Guy Ramsey Sent: Wednesday, December 21, 2011 8:04 AM To: [log in to unmask] Subject: Re: [TN] QFP center slug over signal vias A related "other salt mine" story. I once taught a three day a DFM / DFA seminar for a large maker of radar equipment. Top management selected a team of PCB designers to attend. Two hours in to the first lecture portion of the program, before the first break I asked for questions. One of the designers raised his hand, "Not really a question, just a comment . . . and perhaps a rhetorical one," he said. "You are preaching to the choir. Where are the program managers, system engineers, buyers, manufacturing engineers?" In response, during the subsequent break, I called the guy who had signed the PO. We spent the next two hours rearranging the class roster. Reconvened after lunch, and had an dynamic and much better two and one have day seminar. Guy -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Mike Fenner Sent: Wednesday, December 21, 2011 6:13 AM To: [log in to unmask] Subject: Re: [TN] QFP center slug over signal vias HI One of my aphorisms/sayings is "You can never plumb the depths of other people's ignorance, but lack of knowledge isn't stupidity". And another is "Just because you know something, doesn't mean the other guy does". I think what we are looking at is a symptom of our specialized and dispersed age, where manufacturing , design, marketing/sales etc may never even meet let alone talk. What does one engineering discipline really know about another? In a former salt mine we tried to address this 1) by making people into product teams, even if only virtual and meeting by conference call. This gave them all a stake in the product. 2) by swapping people interdepartmentally for a month. 3) by taking designers , quality people etc to customers/shows so they could see stuff and ask questions. I will always remember one of our designers saying: So THAT's what a printer looks like, I had imagined something much smaller. Now I finally understand what you have been telling me...... It was difficult to keep doing this, as once it started working managers could only see the short term disruption and not the long term benefit. So we stopped untill someone said " I've got this great idea, why don't we..." And us older timers would catch each others' eyes and... MERRY CHRISTMAS Regards Mike -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Joyce Koo Sent: Tuesday, December 20, 2011 10:58 PM To: [log in to unmask] Subject: Re: [TN] QFP center slug over signal vias Frank, I have all the respect for designer. Part of the problem is the product cycle is getting shorter: a designer never got chance to see (1) MFG data - production yield, can do and can't do stuff (new machine capability matrix for example) and (2) reliability data of his-her own design and (3) market data - field return and touch and feel feed back: all etc,etc, you would expect a design to learn, mature, refine. The fast product cycle produce someone hand over a hot potato before jump into another "newer, better, bigger" thing. The designer didn't got chance to face his own music, that is why many poor design come out. Not totally designer's fault. The current environment "promote" bad designer and many get away with it. Sad (don't get me start "good old days" rap). -------------------------- Sent using BlackBerry ----- Original Message ----- From: Frank Kimmey [mailto:[log in to unmask]] Sent: Tuesday, December 20, 2011 03:43 PM To: [log in to unmask] <[log in to unmask]> Subject: Re: [TN] QFP center slug over signal vias I think you would be surprised to see how many Designers would agree. As a Designer, I want to have the best possible understanding of how things are made and/or repaired. Surprisingly, or not it seems Management does not see any value add in allowing Designers to better understand what they are trying to do. Since we seem not to be allowed on the floor, then the best we can hope for is good communication between Assembly, Fab and Design. Unfortunately, most of that communication never reaches the Designer (it tends to get stopped at the Design Engineer, Quality Engineer or Process Engineer, etc.) Try inviting the Designer in for a tour and I bet you will get Engineers whose jobs are to tell the PCB Designer what to do. I can't speak for all PCB Designers but I know that those who I work with would love a chance to learn how to do better designs. Also, we are seeing more Engineers designing PCB, this is another issue as they are not specialists who have that extra pride in being a PCB Designer. And as we all know, they are smarter than us so we need to just do as we are told whether we agree or not as to the proper way to design a PCB. Just a PCB Designer's opinion, FNK Frank N Kimmey CID+ Manager - PCB Design Powerwave Technologies Inc. Mobile - 916-670-0645 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory Sent: Tuesday, December 20, 2011 12:03 PM To: [log in to unmask] Subject: Re: [TN] QFP center slug over signal vias I think there should be some sort of requirement for a designer to spend at least a few weeks on the manufacturing floor before they start laying out boards... -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Phil Bavaro Sent: Tuesday, December 20, 2011 2:52 PM To: [log in to unmask] Subject: Re: [TN] QFP center slug over signal vias I agree completely. Sharing the pain always is a good learning experience. -----Original Message----- From: Joyce Koo [mailto:[log in to unmask]] Sent: Tuesday, December 20, 2011 11:10 AM To: Bavaro, Phillip @ MWG - TW; TechNet E-Mail Forum Subject: RE: QFP center slug over signal vias If you ask the designer to (1) tape the kapton tape on a piece of clean glass (cleaned using IPA and DI, followed by IPA rinse and dry)(2) cut into small pieces of the size using knife - under microscope if it is necessary, (3) put the piece on to the PWB at desired location using tweezers with proper ESD protection/with ionized gas blow on his hands. I am sure you will never, ever see the same mistake again from the whole design group (the words get around very very quickly ;-). My 1.92 cents. Joyce Koo Materials Researcher - Materials Interconnect Lab Research In Motion Limited Office: (519) 888-7465 79945 Mobile: (226) 220-4760 -----Original Message----- From: [log in to unmask] [mailto:[log in to unmask]] Sent: Tuesday, December 20, 2011 1:39 PM To: Joyce Koo; TechNet E-Mail Forum Subject: RE: QFP center slug over signal vias Yeah, that was my first solution but unfortunately it is too small to put Kapton on reliably (.006" x .015"). I tried to get it die cut but could not get a quote. -----Original Message----- From: Joyce Koo [mailto:[log in to unmask]] Sent: Tuesday, December 20, 2011 10:32 AM To: 'TechNet E-Mail Forum'; Bavaro, Phillip @ MWG - TW Subject: RE: QFP center slug over signal vias Based on my book, solder mask is not consider as valid dielectric for signal. (Kapton tape would be). Joyce Koo Materials Researcher - Materials Interconnect Lab Research In Motion Limited Office: (519) 888-7465 79945 Mobile: (226) 220-4760 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Phil Bavaro Sent: Tuesday, December 20, 2011 1:26 PM To: [log in to unmask] Subject: [TN] QFP center slug over signal vias We found an existing design which has a device (QFP with center slug) that has too small of a center slug pad on the PWB. Within the corresponding area where the center slug pad should have been, the designer put some signal vias. Therefore the only thing preventing the signal via from shorting out to the center slug (ground) is the solder mask. No failures to date have been reported, even after a 20g vibe test. Is this a violation of J-STD-001 or perhaps IPC-2221 -6.3.4 regarding minimum electrical spacing? ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------------------------- This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful. --------------------------------------------------------------------- This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful. ------------------------------------------------------------------------ ---- -- This message and any attachments are solely for the use of the addressee and may contain L-3 proprietary information that may also be defined as USG export controlled technical data. If you are not the intended recipient, any disclosure, use or distribution of its content is prohibited. Please notify the sender by reply e-mail and immediately delete this message and any attachments. ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- Click the following link to report this email as spam: https://www.mailcontrol.com/sr/Nhv+0oxNgE3TndxI!oX7UpBF13olpmG!kPIRAJYlw wEHH NRytg1VxHVWsae6Oy8ZGRTWn85OBaiFfmYpsSvVwQ== ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------------------------- This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful. ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- This e-mail message and any attachments may contain confidential information from Astrolab Inc. If you are not the intended recipient, you are hereby notified that disclosure, printing, copying, distribution, or the taking of any action in reliance on the contents of this electronic information is strictly prohibited. If you have received this e-mail message in error, please immediately notify the sender by reply message and then delete the electronic message and any attachments. Thank you for your cooperation. ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------