[SI-LIST] Re: AW: Multi-Giga-Hertz Rigid-Flex Feasibility
- From: Hirshtal Itzhak <ihirshtal@xxxxxxxxxx>
- To: leeritchey@xxxxxxxxxxxxx, Gert Havermann <Gert.Havermann@xxxxxxxxxxx>, si-list@xxxxxxxxxxxxx
- Date: Mon, 30 Nov 2009 18:18:15 +0200
Thank you, Lee
Can you please refer specifically to my question as to the flex impedance
tolerance? Assuming I will use 3-4 mil width traces with 3-mil Polyamide based
material thickness, what is the impedance that manufacturers regularly commit
to? Is it regular to have +/-10% (on the flex section alone)?
Thanks
Itzhak
-----Original Message-----
From: Lee Ritchey [mailto:leeritchey@xxxxxxxxxxxxx]
Sent: Monday, November 30, 2009 6:04 PM
To: Hirshtal Itzhak; Gert Havermann; si-list@xxxxxxxxxxxxx
Subject: RE: [SI-LIST] Re: AW: Multi-Giga-Hertz Rigid-Flex Feasibility
Itzhtal,
I use both polyamide based flex material and Liquid Crystal Polymer from
Rogers. Both work well. LCP has lower loss.
The reason that stripline is usually not used in flex circuits is that
makes a 3 layer assembly which is not very flexible. There is nothing
wrong with microstrip. Works fine.
Lee Ritchey
> [Original Message]
> From: Hirshtal Itzhak <ihirshtal@xxxxxxxxxx>
> To: Havermann, Gert <Gert.Havermann@xxxxxxxxxxx>; <si-list@xxxxxxxxxxxxx>
> Date: 11/29/2009 4:00:51 AM
> Subject: [SI-LIST] Re: AW: Multi-Giga-Hertz Rigid-Flex Feasibility
>
> Hello Gert
>
> First - thank you for your contribution.
>
> I have a few questions regarding your email:
>
> 1) You refer to a trace width of 0.8mm as "small". This is a 31.5mil
width, which I hardly call "small"! I regularly use 3-4 mil trace widths in
my designs. Is there something different in Flex circuits, which enforces
me to use such LARGE traces (compared to my regular traces)?
>
> 2) I see the problem you mention for the Microstrip configuration. Is it
common to use Stripline on a flex circuit? I was told this is impractical,
although I'm not sure what the reason is.
>
> Thanks
>
> Itzhak Hirshtal
> Elta
>
> -----Original Message-----
> From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]
On Behalf Of Havermann, Gert
> Sent: Tuesday, November 24, 2009 4:19 PM
> To: si-list@xxxxxxxxxxxxx
> Subject: [SI-LIST] AW: Multi-Giga-Hertz Rigid-Flex Feasibility
>
> Hello Itzhak ,
>
> All Polimide (Kapton) materials will do the job from a loss and
dispersion prospective. The tolerance you mention seems to be unreasonable
high for an etching tolerance. I did Flex designs with impedance control,
100Ohm +/-10Ohm, 0.8mm tracewidth without problems (of corse I had to pay
extra for the small trace width).
> If you refer to an impedance tolerance due to bending and surrounding
material, thats another story. If you design it in microstrip (as you are
planning it), then everithing touching the flex might change your
impedance. Designing it in stripline decreases the flexibility of the flex
and increases cost.
>
> Look for Dupont, Grace Electron or Shengyi Flex materials for more info.
>
> BR
> Gert
>
>
> --------------------------------------------------------------------------
> Absender ist HARTING Electronics GmbH & Co. KG; Sitz der Gesellschaft:
Espelkamp; Registergericht: Bad Oeynhausen; Register-Nr.: HRA 5596;
persצnlich haftende Gesellschafterin: HARTING Electronics Management GmbH;
Sitz der Komplementהr-GmbH: Espelkamp; Registergericht der
Komplementהr-GmbH: Bad Oeynhausen; Register-Nr. der Komplementהr-GmbH: HRB
8808; Geschהftsfhrer: Torsten Ratzmann
> -----Ursprngliche Nachricht-----
>
> Von: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]
Im Auftrag von Hirshtal Itzhak
> Gesendet: Dienstag, 24. November 2009 14:21
> An: si-list@xxxxxxxxxxxxx
> Betreff: [SI-LIST] Multi-Giga-Hertz Rigid-Flex Feasibility
>
> Hello All
>
>
> My project manager intends to use a rigid-flex design in our next
high-speed board.
>
>
>
> He wants to route a few pairs of 3.125GHz from a rigid section to another
one through a flex section.
>
>
>
> Does anyone know if this is feasible? I found out that the 2 sections,
although spec'd to be 100-Ohm diff impedance, can still differ
substantially - as much as 30%, because the tolerance of the flex section
is +/-20%. Can such a design work for a substantial trace length? Should I
restrict the trace length on the flex section to be no more than an inch or
so, in order to reduce the impact of the supposed non-uniform impedance?
>
>
>
> I intend to use a 2-layer flexible laminate with the pairs on one layer
and a Ground reference on the other one.
>
>
>
> Any advice on this matter would be helpful
>
>
>
> Thanks
>
>
>
> Itzhak hirshtal
>
>
>
>
>
> The information contained in this communication is proprietary to Israel
Aerospace Industries Ltd., ELTA Systems Ltd.
> and/or third parties, may contain classified or privileged information,
and is intended only for the use of the intended addressee thereof. If you
are not the intended addressee, please be aware that any use, disclosure,
distribution and/or copying of this communication is strictly prohibited.
> If you receive this communication in error, please notify the sender
immediately and delete it from your computer. Thank you.
>
>
> This message is processed by the PrivaWall Email Security Server.
>
>
>
>
> ------------------------------------------------------------------
> 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.net
>
> 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
>
>
>
>
> http://www.mesago.de/de/SPS/main.htm
> Besuchen Sie uns auf der SPS/IPC/Drives 2009
> vom 24. - 26. November 2009 in Nrnberg, in Halle 10 am Stand 130.
>
> ------------------------------------------------------------------
> 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.net
>
> 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
>
>
>
> This message is processed by the PrivaWall Email Security Server.
>
>
>
>
> The information contained in this communication is proprietary to Israel
Aerospace Industries Ltd., ELTA Systems Ltd.
> and/or third parties, may contain classified or privileged information,
and is intended only for
> the use of the intended addressee thereof. If you are not the intended
addressee, please be aware
> that any use, disclosure, distribution and/or copying of this
communication is strictly prohibited.
> If you receive this communication in error, please notify the sender
immediately and delete it from
> your computer. Thank you.
>
>
> This message is processed by the PrivaWall Email Security Server.
>
>
>
> ------------------------------------------------------------------
> 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.net
>
> 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
>
This message is processed by the PrivaWall Email Security Server.
The information contained in this communication is proprietary to Israel
Aerospace Industries Ltd., ELTA Systems Ltd.
and/or third parties, may contain classified or privileged information, and is
intended only for
the use of the intended addressee thereof. If you are not the intended
addressee, please be aware
that any use, disclosure, distribution and/or copying of this communication is
strictly prohibited.
If you receive this communication in error, please notify the sender
immediately and delete it from
your computer. Thank you.
This message is processed by the PrivaWall Email Security Server.
------------------------------------------------------------------
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.net
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
Other related posts:
