Hi, I found an article where they have described 106-LD and 1080-LD, for laser drilling. They were more tight than the normal 106 and 1080, but only in one direction. The no-glass-hole was more or less eliminated, but they still had 1layer-2layer waves on them. For 0deg/90deg routing, the difference is that you don't have no_glass-1layer wave-s in the weave, only the 1layer-2layer, and for 45deg routing the no_glass-2layer wave was eliminated. Another article from dielectricsolutions.com describes spread-weave as they manufacture their NovaSpeed glass-fabrics. These are tight in both directions (as opposing to the above 106-LD). Their article describes the glass coverage with 3 numbers, the portion covered by 2 layer glass, 1 layer glass and no-glass. For example 77-22-1. Something like this would perfectly specify the glass for high-speed design purposes, so then the design engineer could decide what is good enough and what is not, without requesting vendor specific photos (that are impossible to get) of the glass fabric, or without gambling. IPC and the industry should pick this up. It would be nice to know which material manufacturers put this NovaSpeed glass fabric into their prepregs/laminates. NanYa claims to have 1067,1086 glas styles in the glass fabric section, but their NPLDII/NPLDIII laminate (these ones have low enough loss) datasheets don't have these glass styles listed only the traditional ones. This IPC committee develops the glass fabric/style standard (IPC-4412A): http://www.ipc.org/CommitteeDetail.aspx?Committee=3-12D If you check their meeting minutes, the spread glass was on their agenda years ago, but somehow they did not discuss it properly and did not add this into the standard. Regards, Istvan Nagy -----Original Message----- From: Lee Sent: Friday, January 18, 2013 9:46 AM To: jeff.loyer@xxxxxxxxx ; Alexander.Ippich@xxxxxxxxxxxxx ; buenos@xxxxxxxxxxx ; si-list Subject: [SI-LIST] Re: Fiber Weave Effect My experiences are similar to those outlined below. IPC standards always lag the industry. Isn't that what standards do- document the past! From what I can tell, spreading is done to improve the quality of laser drilled blind vias, not for signal integrity reasons. For that reason, spread glass will be most available where that kind of PCB is being manufactured. The laminate suppliers who cater to the "high speed" market are gradually adding these glasses for reasons that I discuss in my upcoming paper at DesignCon. True, there are no standards yet. 3313 is available mechanically spread in both direction or in only one. You can see that in the test results we got. I have been a proponent of 3313 glass for fast diff pairs. The glass I used when we got the best results was from Matsushita. Turns out that not all laminate suppliers were using the same glass supplier, so we found two very different results. Maybe some of us need to step in at IPC and get these standards updated. If it isn't one thing, it is another! Plenty of challenges to keep us busy! -----Original Message----- From: Loyer, Jeff Sent: Friday, January 18, 2013 8:05 AM To: Alexander.Ippich@xxxxxxxxxxxxx ; buenos@xxxxxxxxxxx ; si-list Subject: [SI-LIST] Re: Fiber Weave Effect My experience matches Alexander's - there is a lot of ambiguity in the term "spread glass"; it can mean different things, depending on the vendor. The best definitions I have seen came from an Isola presentation ("Glass Fabric", July 2012) with the following definitions: ". Expanded Weave - Glass Spread More than Standard in one Direction . Open Weave - Same as Expanded . Open Filament - Same as Expanded . Spread Glass - Glass Spread by a # of Different Ways . Mechanically Spread (MS) Glass - Glass is Mechanically Spread in both the warp and fill directions. . Square Weave - Glass that has a Balanced Density and/or Yarn Counts in Warp and Fill Directions. . Flat Glass - Glass is made from fibers with little or no twist. Isola does not offer Flat Glass. Spread Glass is "Flatter" but not truly a Flat Glass." In the presentation, they (Isola) offer "Square", "Expanded", Spread", and "MS Spread". I've never seen totally Flat Glass, except perhaps RCC (which has no glass) or Thermount (which is not woven). I've also seen presentations which show: Nanya offers "Spread Weave" Rogers offers "Spread Glass" Lee Ritchey advocates a 3313 style glass, though I don't know what materials that's available for Compunetics and Dielectric Solutions had some early solutions (NovaSpeed 1080, see "Advanced Glass Reinforcement Technology for Improved Signal Integrity") Thermount offers non-woven products This is a compilation of the data I currently have - I welcome others adding to it. Note: this list in no way represents endorsement of any product. Regarding how to distinguish 1080 from spread glass 1080 - it should specifically say it is spread glass (or some other term) in the vendor's stackup drawing; it may not have a unique number designation. I hope this helps, Jeff Loyer -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Alexander Ippich Sent: Thursday, January 17, 2013 11:01 PM To: buenos@xxxxxxxxxxx; si-list Cc: Alexander Ippich Subject: [SI-LIST] Re: Fiber Weave Effect Istvan, this is another issue, where the standardization of for example IPC lags behind the needs of the industry quite a bit... You are absolutely right, looking at the IPC 4412 does not tell you, if this is a "spread" glass or not. I have put "spread" in double quotes, because this term is not specified itself yet (to my knowledge). Terms like square weave only adds to this confusion. These are terms coined by individual manufacturers. In the case of square weave, this is something Isola has a patent to. Regarding "spread" glass, there are the newer glass styles, like 1067, 1086, 3313,.. that are woven in a way to minimize the gaps between the glass strands right from the beginning. But be careful, this does not mean, that the glass is totally homogenous - it still has gaps (high resin content) and conglomeration of glass fibres (low resin content). Then there are base material manufacturers, that still use the traditional glass styles (like 106, 1080), but use a process like water spreading or air spreading to open up the strands of glass to get to a more homogenous distribution of the glass fibres. Again, since there is no standard yet, you can not put a number to the "degree of spread". You need to look at sample pictures (and yes, very likely the nicer ones will be shown around). Bottom line, since all of these glass styles do not result in a "100% tight fabric", they will never solve the fibre weave effect completely. So at the end of the day, you will need to do actual measurements on actual prototypes. Best regards, alex _______________________________________________________________ Alexander Ippich Sr. Signal Integrity Engineer Multilayer Technology GmbH & Co. KG Herrenberger Strasse 110 71034 Boeblingen - Germany Email alexander.ippich@xxxxxxxxxxxxx Pers. haftender Gesellschafter: Multilayer Technology Geschäftsführungs GmbH, Geschäftsführer: Werner Widmann Sitz der Gesellschaft: Böblingen, Amtsgericht Böblingen HRA242264 http://www.multek.com Endless innovation creates changes for tomorrow -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Istvan Nagy Sent: Friday, January 18, 2013 5:10 AM To: si-list Subject: [SI-LIST] Re: Fiber Weave Effect Hi all, I would like to join this conversation. I am trying to find out about a possibly complete list of available spread-glass materials. Who makes these, and which products, which glass styles? From different sources what I have found is not consistent. - For example some people say new glass styles were invented to have thin materials with spread-glass fabric, so we can distinguish. - I think I have read somewhere (don't remember where) that existing glass styles (like 1080) have traditional and also spread-glass option. If both are called 1080, then how to distinguish? I found an IPC spec (IPC-xxx amendment 1) That lists glass styles, but how to find out which is a loose fabric and which ones are tight spread-glass fabrics? Some Isola datasheets mention spread-glass and square-weave glass (what's that?) as option, while some other Isola datasheets only mention standard E-glass option. Most material manufacturer datasheets don't mention anything about this. For example someone said 1067 is spread-glass. Is it guaranteed that if we get 1067 anywhere it will be 99% tight spread-glass fabric? I also saw photo examples of spread glass fabrics in technical papers, but I guess those have shown the nicest ones. How does an 1067 or 1086 really look like? Do they completely solve the fiber weave effect (100% tight fabric) or they just improve on it (littlebit smaller holes than usual)? Does anyone have a list of specific existing materials and glass styles with spread-glass? I mean not just 1-2 examples, but a longer list if possible. Regards, Istvan Nagy -----Original Message----- From: Scott McMorrow Sent: Sunday, January 06, 2013 10:41 AM To: dudi@xxxxxxxxxxxxxxxxx Cc: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Fiber Weave Effect Here is our paper on laminate weave skew from 7 years ago. http://www.teraspeed.com/papers/The%20Impact%20of%20PCB%20Laminate%20Weave%20paper.pdf http://www.teraspeed.com/papers/Laminate%20Weave_DesignCon%20Slides.pdf -- Scott McMorrow Teraspeed Consulting Group LLC 16 Stormy Brook Road Falmouth, ME 04105 (401) 284-1827 Business http://www.teraspeed.com Teraspeed® is the registered service mark of Teraspeed Consulting Group LLC On Sun, Jan 6, 2013 at 9:52 AM, Dudi Tash <dudi@xxxxxxxxxxxxxxxxx> wrote: > Hi All, > I'm looking for some books regarding the Fiber Weave Effect. Good > articles are welcomed as well. I've read the Altera and PCISIG papers > > Please advise > > Best Regards, > Dgtronix Ltd. I Founder & CEO I Dudi Tash > eFax: +972-3-7256490 I Mobile: +972-54-6345629 I Office: > +972-9-9660967 www.dgtronix-tech.com<http://www.dgtronix-tech.com/> > > [cid:image001.jpg@01CDEC2E.48C05F30]<http://www.dgtronix-tech.com/> > [cid:image002.jpg@01CDEC2E.48C05F30] > > [cid:image003.jpg@01CDEC2E.48C05F30] > > > *This email contains confidential and proprietary information of > Dgtronix > Ltd.* > > > > ------------------------------------------------------------------ > 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 forum is accessible at: > http://tech.groups.yahoo.com/group/si-list > > List archives are viewable at: > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > > -- Scott McMorrow Teraspeed Consulting Group LLC 16 Stormy Brook Road Falmouth, ME 04105 (401) 284-1827 Business http://www.teraspeed.com Teraspeed® is the registered service mark of Teraspeed Consulting Group LLC ------------------------------------------------------------------ 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 forum is accessible at: http://tech.groups.yahoo.com/group/si-list List archives are viewable at: //www.freelists.org/archives/si-list 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 forum is accessible at: http://tech.groups.yahoo.com/group/si-list List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu Legal Disclaimer: The information contained in this message may be privileged and confidential. 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