High Frequency Flex minutes -102215

Minutes of Oct 22, 2015 Meeting

(10:00 AM Central)


Project Leader:  Martyn Gaudion, Polar Instruments.


Project Facilitator:    John Davignon, HDP


Present on the call:


Joe Smetana, Alcatel-Lucent

Glenn Oliver, DuPont

John Davignon, HDP

Geoffrey Hazelett, Polar


Next Meeting:  Nov 5, 2015 @ 10 AM CT


Next Meeting Agenda:


·         Neil to supply the cross hatch designs he would like to see on the panel and what would give us the most information. Need these before we can modify coupons

·         Discuss what help maybe provided by Microconnex (Geoffrey/Microconnex)

·         Discuss getting CAD support.

Action items:


·         Glenn will review the MRT-6 test coupons on the website and see if the SPP coupon is Ok for our use with some modification, See below for modification discussions

·         Farhad volunteered to do the X-hatch simulation.

·         Farhad volunteered to do the panelization, all he needs is the Gerber files. Neil will work with Farhad to get him the Gerber files and panelize them.



TV/coupon Design discussions:


Glenn is concerned with what structures do we want on this TV.  We need a prioritized list of what structures we want to build on the panel.

Glenn has a modified S3 coupon design for flex that he shared with the team. He sent this to Joe for review and we can send to Scott H at Cisco if we feel a need.  Scott is aware of this modified version of Glenn's.  The differential lengths are >16" and have been adapted for flex.

NOTE: What do we need to do to this coupon in order to use it? Is it ready for the cross hatch designs to be added?


Joe stated that the connectorless SPP coupon design can be found on the HDP website under the MRT-6 TV. This is not designed for flex so we will have to modify it.  Joe has sent this MRT-6 TV to Glenn and the team who will review the MRT-6 test coupons.

·         The impedance should be OK as a drop in

·         The trace angles have been skewed for fiber filled epoxy laminates and will most probably have to be straighten for the X-Hatch designs

·         Use the microvias to reduce reflection

·         Use the 3 different line widths and lengths to get best data

NOTE: SPP does not care about impedance, it can measure it but it does not matter what it is. (Frequency domain TRL) With connectorless pads we can measure (Impedance/Loss/Dielectric constant)


Cross Hatching Discussions:


We need Polar to help with the Cross hatching and what we think we will get.

We should start with Gerber’s of the coupons that we have and add cross hatching.

The team would like ask Neil what the cross hatch designs he would like to see on the panel and what would give us the most information. How many crosshatch levels do we want on the panel?

It was suggested that we could do a 6 level factorial design. Polar has a way to model this and we want their inputs.

S3 and SPP are the baseline with below:

·         Cross hatching lines on simple lines (short/long) that will give us the variation we are looking for.

·         3 x 2 matrix on the cross hatch - copper area (open-closed) / how fine the mesh ( wide open, nominal, closed) - big and small pitch ( 1:1 and 1:5)

·         Using both a microstrip and stripline configuration

Glenn said that we need the connectors we will use and the footprint in order to do the 3D modeling. 

50 ohms impedance is best because the test equipment is calibrated for it. The line widths may not be able to do this, but that is the target. The fabrication factors will change the real data compared to the model. Glenn's feedback is that the models and measurements do not match and that is why we are doing the project.


Glenn said that if we can wait until Dec he might have a new hire to help with the project.


Glenn said to look at Freedom CAD to help with the coupon modification.  Would anyone be willing to help pay for this service if we cannot source it from the team/membership?


Plan to date:

·         The team decided to do the baseline study with the thicker laminates as designed by Neil Chamberlain stack-up construction posted to the website.

·         Farhad volunteered M-Flex to help with the simulation of the X-hatch design.

·         Glenn said that TTM Santa Clara will build the TV

·         Polar can do the connectorless SPP testing

·         Glenn can do the S3 testing (he will have to put on connectors for this)


NOTE: We need to think about the X-hatch designs and how the fabricator can fabricate them. Concerns about the alignment of the differential pairs and the X-hatch designs. Must be manufacturable for us to be successful.


Next Meeting:  Nov 5, 2015 @ 10AM CT