Can someone comment on the impact of assymetrical stackup on PCB yield ? Thanks Perry Michael Khusid wrote: > Alexander, > > Unless I miscounted, I can see 27 layers in your stackup. An odd number of > layers will get you an assymetrical stackup and will cause PCB warpage. > > Michael > > -----Original Message----- > From: Nosovitski, Alexander (Contr) > To: si-list@xxxxxxxxxxxxx > Sent: 1/21/04 4:02 PM > Subject: [SI-LIST] PCB STACKUP > > Hello si-list, > > The design I am working on has a dense placement. > > The proposed stack up looks as follow: > > TOP > POWER_ANALOG > DIFF_SIGNAL (Gb/s signals) > AGND > > GND > POWER > S > S > GND > POWER > S > S > GND > SPLIT_POWER > GND > S > S > POWER > GND > S > S > GND > > AGND > DIFF_SIGNAL_ANALOG (Gb/s signals) > POWER ANALOG > > BOTTOM > > All signal layers are 0.5 Oz copper and > > All planes are solid ( except one in the middle) with 0.5 Oz copper. > > The diff. signals are running at 2.5Gb/s. > > There are different opinions about analog plane location. > > Could the arrangement above cause a problem? > > What else should I be concern about? > > Any help or suggestion is appreciated! > > Regards, > > Alexander Nosovitski > > > > > > -----Original Message----- > From: Salkow, Steven [mailto:steven.salkow@xxxxxxxx] > Sent: Wednesday, January 21, 2004 1:57 PM > To: weirsp@xxxxxxxxxx; fred@xxxxxxxxxxxxx; kar_thik_v1@xxxxxxxxx > Cc: si-list@xxxxxxxxxxxxx > Subject: [SI-LIST] Re: Looking for thin dielectric tape > > 4 mil prepreg (pcb laminate) is generally available from anyone doing > multilayer PCB. You may also get samples from laminate vendors (dupont, > Norplex) (sprayed with Scotch 444 adhesive for cold adhesion to copper > foils) > 3M (tape division) have exactly what your looking for up to 36" wide > slit to any width but they have minimum qtys > > see > http://products3.3m.com/catalog/us/en001/utilities_telecom/oem_electrica > l/node_R5MTBSFVGPbe/root_GST1T4S9TCgv/vroot_GSHBRQT7DVge/gvel_BBGZX3B1QG > gl/theme_us_oemeletrical_3_0/command_AbcPageHandler/output_html > > Catalog on the above page for download > > Steve Salkow > Lockheed Martin > 3200 Zanker Road > San Jose, CA 95134 > (408) 473-4058 (san Jose) > (408) 742-4162 (Sunnyvale) > steven.salkow@xxxxxxxx > salkow@xxxxxxxxxxxx > (925) 462-1075 Home > (925-) 487-5946 Cell > (408) 468-7271 Numeric Pager > > -----Original Message----- > From: si-list-bounce@xxxxxxxxxxxxx > [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of steve weir > Sent: Tuesday, January 20, 2004 11:17 PM > To: fred@xxxxxxxxxxxxx; kar_thik_v1@xxxxxxxxx > Cc: si-list@xxxxxxxxxxxxx > Subject: [SI-LIST] Re: Looking for thin dielectric tape > > If you want to lay out a board, onesy, twosy, Express PCB is not a bad > way > to go. www.expresspcb.com It sure beats the Bishop Graphics adhesive > backed Cu tape, or a bathroom full of ferric chloride. > > Steve. > At 01:44 PM 1/20/2004 -0800, Fred Townsend wrote: > >The last time I check you could still get mylar sheeting at most > >drafting and staionary stores. You would to apply your own adhesive. > >Comes in 4 and 7 mil thicknesses. You can also get polyester sheeting > >frosted one side and adhesive on the other for making labels. Failing > >that how about 3M's double sticky magic tape? > > > >Fred Townsend > > > >Karthik V wrote: > > > > >Hello, > > > > > > I am a student at the State University of New York. I am > > looking for a double sided sticky dielectric tape (more like a sheet ) > of > > thickness about 4mils (0.1mm) and with a dielectric constant of > > around 4, to use between copper sheets - to make a "temporary board". > I > > tried things like epoxy, but it's almost impossible to get it so thin > and > > still provide infinite DC resistance. > > > > > > Could anyone point me to places where I could look for this > > > kind of stuff. Is there anything else I could try to get the > dielectric > > (with Dk around 4) so thin ( apart from elaborate processes ) . > > > > > >thanks in advance, > > >Karthik, > > > > > >--------------------------------- > > >Do you Yahoo!? > > >Yahoo! Hotjobs: Enter the "Signing Bonus" Sweepstakes > > > > > >------------------------------------------------------------------ > > >To unsubscribe from si-list: > > >si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > > > > >or to administer your membership from a web page, go to: > > >//www.freelists.org/webpage/si-list > > > > > >For help: > > >si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > > > >List technical documents are available at: > > > http://www.si-list.org > > > > > >List archives are viewable at: > > > //www.freelists.org/archives/si-list > > >or at our remote archives: > > > http://groups.yahoo.com/group/si-list/messages > > >Old (prior to June 6, 2001) list archives are viewable at: > > > http://www.qsl.net/wb6tpu > > > > > > > > > > > > > > > > > > > > > > >------------------------------------------------------------------ > >To unsubscribe from si-list: > >si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > > >or to administer your membership from a web page, go to: > >//www.freelists.org/webpage/si-list > > > >For help: > >si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > >List technical documents are available at: > > http://www.si-list.org > > > >List archives are viewable at: > > //www.freelists.org/archives/si-list > >or at our remote archives: > > http://groups.yahoo.com/group/si-list/messages > >Old (prior to June 6, 2001) list archives are viewable at: > > http://www.qsl.net/wb6tpu > > > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > List technical documents are available at: > http://www.si-list.org > > List archives are viewable at: > //www.freelists.org/archives/si-list > or at our remote archives: > http://groups.yahoo.com/group/si-list/messages > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > List technical documents are available at: > http://www.si-list.org > > List archives are viewable at: > //www.freelists.org/archives/si-list > or at our remote archives: > http://groups.yahoo.com/group/si-list/messages > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > List technical documents are available at: > http://www.si-list.org > > List archives are viewable at: > //www.freelists.org/archives/si-list > or at our remote archives: > http://groups.yahoo.com/group/si-list/messages > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field > > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > List technical documents are available at: > http://www.si-list.org > > List archives are viewable at: > //www.freelists.org/archives/si-list > or at our remote archives: > http://groups.yahoo.com/group/si-list/messages > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > -- Perry Qu Design & Qualification | 600 March Road Alcatel Canada | Ottawa, ON K2K 2E6, Canada DID: (613) 7846720 | FAX: (613) 5993642 ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu