MCMDCsG < DetDev

---++ Measurement of capacitance between strip and GND plane

*Measurements performed by Alex Chilingarov at Lancaster University*
---+++ Introduction

The impedance between the bias rail and the ground plane was measured with an LCR meter in RsCs mode for a range of frequencies. For reasonably low frequencies, the measured Rs is all the bias resistances in parallel. And the measured Cs is all the strip to ground plane couplings in parallel. The measurements were done with the sensor biased for at least one sensor of each ground plane type.
---+++ Results for w14, 6 um BCB under the GND plane

Capacitive coupling between bias rail and GND plane versus bias voltage

<img width="590" alt="CsG vs bias voltage w14" src="%ATTACHURL%/w14CsG10kHzUp.gif" height="368" />

Capacitive coupling between bias rail and GND plane versus time

<img width="590" alt="Cs vs time" src="%ATTACHURL%/w14CsG10kHzHold.gif" height="368" />

Summary plot of all measured sensors on w14 and all measured frequencies

<img width="590" alt="Cs for all sensors and all frequencies" src="%ATTACHURL%/w14CsGvsFreq.gif" height="368" />

Table with calculated strip to GND plane capacitance for w14 at 10 kHz <table width="428" height="94" border="0"><tbody><tr><td align="left" valign="middle" style="width: 150px">GND plane type <br /></td><td align="center" valign="middle" style="width: 150px"># strip covered <br /></td><td align="center" valign="middle" style="width: 100px">Cs/strip <br /></td><td align="center" valign="middle" style="width: 100px">Rs/strip <br /></td></tr><tr><td align="left" valign="middle" style="width: 100px"> Solid</td><td align="center" valign="middle" style="width: 100px"> 129</td><td align="center" valign="middle" style="width: 100px"> 1.85 pF</td><td align="center" valign="middle" style="width: 100px"> </td></tr><tr><td align="left" valign="middle" style="width: 100px"> Mesh 50%/30um<br /></td><td align="center" valign="middle" style="width: 100px"> 128.5</td><td align="center" valign="middle" style="width: 100px"> 1.30 pF<br /></td><td align="center" valign="middle" style="width: 100px"> </td></tr><tr><td align="left" valign="middle" style="width: 100px"> Mesh 50%/80um</td><td align="center" valign="middle" style="width: 100px"> 126</td><td align="center" valign="middle" style="width: 100px"> 1.5 pF<br /></td><td align="center" valign="middle" style="width: 100px"> </td></tr><tr><td align="left" valign="middle" style="width: 100px"> Mesh 25%/30um</td><td align="center" valign="middle" style="width: 100px"> 126.5</td><td align="center" valign="middle" style="width: 100px"> 0.76 pF<br /></td><td align="center" valign="middle" style="width: 100px"> </td></tr></tbody></table>
---+++ Results for w09, 12 um BCB under the GND plane

-- Main.LarsEklund - 02 Apr 2009

Attachments

Topic attachments
I	Attachment	History	Action	Size	Date	Who
gif	w14CsG10kHzHold.gif	r1	manage	8.3 K	2009-04-02 - 07:47	LarsEklund
gif	w14CsG10kHzUp.gif	r1	manage	9.8 K	2009-04-02 - 07:47	LarsEklund
gif	w14CsGvsFreq.gif	r1	manage	9.9 K	2009-04-02 - 07:47	LarsEklund

This topic: DetDev > ResearchResults > MCMD > MCMDCsG
Topic revision: r3 - 2009-04-06 - LarsEklund