...with Christian's corrections included

diff --git a/GSI_2014_MK_ProbeTests/MK_ProbeTests.tex b/GSI_2014_MK_ProbeTests/MK_ProbeTests.tex
index e92632b6b100c9889c56e4f7b8c72500ff51f524..d75e7c7c65c60ee8769a892eaa5aee419eeee051 100644 (file)
--- a/GSI_2014_MK_ProbeTests/MK_ProbeTests.tex
+++ b/GSI_2014_MK_ProbeTests/MK_ProbeTests.tex
@@ -17,6 +17,8 @@
 \author[1]{N. Bialas}
 \author[1]{M. Deveaux}
 \author[1]{B. Milanovic}
+\author[1]{J.Stroth}
+\author[1]{the CBM-MVD collaboration}
 \affil[1]{Goethe-University Frankfurt, IKF}
 
 
@@ -26,15 +28,15 @@
 
 The Compressed Baryonic Matter experiment installed at the future FAIR facility will be equipped with a high-precision micro-vertex detector aiming at an outstanding primary and secondary vertex resolution.  Highly granular, ultra-low material budget sensors, so-called Monolithic Active Pixel Sensors, manufactured at standard CMOS process, will be employed. Imperfections in CMOS process as well as further dicing and thinning procedures may reduce the final yield of sensors to be mounted in the detector stations to about 60-70$\%$. To select sensors with the best characteristics, probe-testing prior to integration is mandatory. 
 
-Such probe-tests were addressed at IKF with CMOS sensor MIMOSA-26. The  motivation to use this sensor is that the readout system \cite{1} for MIMOSA-26 already exists and it can be easily adapted to work with probe-card. Moreover, the thickens of MIMOSA-26 of 50~$\upmu$m reproduces well expected mechanical properties of final MVD device: where mechanical stability is of concern w.r.t. probe-testing.
+Such probe-tests were addressed at IKF with the CMOS sensor MIMOSA-26. The  motivation to use this sensor is that the readout system \cite{1} for MIMOSA-26 already exists and it can be easily adapted to work with probe-card. Moreover, the thickness of the MIMOSA-26 sensor of 50~$\upmu$m reproduces well expected mechanical properties of final MVD device where mechanical stability is of concern w.r.t. probe-testing.
 
-The probe-test bench shown in figure~\ref{fig:setup} was located at IKF clean room. The probe-card hots 65 tungsten needles with minimum pitch of 120 $\upmu$m. Signals from sensors are routed through the probe-card PCB to so called adapter-card. The use of additional PCB was motivated by the fact that the probe-card is made by an external company (HTT-Dresden) and any changes into that device are expensive, while an adapter-card we can design ourselves and implemented any kind of useful electronics and logic if needed. In addition, a test board hosting a wire-bonded working MIMOSA-26 sensor was manufactured. This board is used to debug all readout chain including probe-card but not sensors connected with needles, where problem with contact is of concern. To hold an ultra thin sensor, a probe-station chuck-adapter with micro-vacuum channels was manufactured.
+The probe-test bench shown in figure~\ref{fig:setup} was located at the IKF clean room. The probe-card hosts 65 tungsten needles with minimum pitch of 120 $\upmu$m. Signals from sensors are routed through the probe-card PCB to so called adapter-card. The use of this extra PCB was motivated by the fact that the probe-card is fabricated by an external company (HTT-Dresden) and any "customization" is expensive, while an adapter-card we can design ourselves and implemented any kind of useful electronics and logic if needed. In addition, a test board hosting a wire-bonded working MIMOSA-26 sensor was manufactured. This board is used to debug all readout chain including probe-card but not sensors connected with needles, where problem with contact is of concern. To hold an ultra-thin sensor, a probe-station chuck-adapter with micro-vacuum channels was manufactured.
 
-After debugging the probe-test bench with the adapter card, the first tests with 300~$\upmu$m MIMOSA-26 sensors were addressed. Sensor react to JTAG programming sequence as well as to various threshold setting providing expected data output. Next, the 50~$\upmu$m sensors were probe-tested. Here, we noticed that an overdrive allowing for proper connection between probe-card needles and sensor pads was higher than in a case of tests with thicker sensors. This was attributed to the fact that 50~$\upmu$m sensors become soft enough to adapt the surface to imperfection in a support material. Nevertheless, it was also possible to probe-test successfully the thinned sensors, but with a slightly higher over drive.  
+After debugging the probe-test bench with the adapter card, the first tests with 300~$\upmu$m MIMOSA-26 sensors were addressed. The sensor response to JTAG programming sequence as well as to various threshold setting resulted in the expected data output. Next, the 50~$\upmu$m sensors were probe-tested. Here, we noticed that an overdrive allowing for proper connection between probe-card needles and sensor pads was higher than in a case of tests with thicker sensors. This was attributed to the fact that 50~$\upmu$m sensors become soft enough to adapt the surface to imperfection in the support material. Nevertheless, it was also possible to probe-test successfully the thinned sensors.  
 
-Currently, we are working on accessing dedicated test modes of the MIMOSA-26 sensor and implementing routines allowing for more adequate and precise sensor characterization. The currently used DAQ system (TRBv2 based) will be migrated to a TRBv3 platform and some of readout chain components will be upgraded to the newest version (see Jan Michael report).   
+Currently, we are working on accessing dedicated test modes of the MIMOSA-26 sensor and implementing routines allowing for more adequate and precise sensor characterization. The currently used DAQ system (TRBv2 based) will be migrated to a TRBv3 platform and some of readout chain components will be upgraded to the newest version \cite{4}.
 
-The 50~$\upmu$m-thin precursors of a final CBM-MVD sensors were successfully tested with a probe-card. The activity reported here is also of interest by much larger community being at the stage of employing the thinned MIMOSA-26 sensor into experiment, i.e. PLUME project and upgrade pf the NA-61 experiment at CERN.  
+The 50~$\upmu$m-thin precursors of a final CBM-MVD sensors were successfully tested with a probe-card. The activity reported here is also of interest for a much larger community being at the stage of employing thinned MIMOSA-26 sensors into experimental setups, i.e. PLUME project and an upgrade of the NA-61 experiment at CERN.  
 
 
 
@@ -52,7 +54,7 @@ The 50~$\upmu$m-thin precursors of a final CBM-MVD sensors were successfully tes
 \begin{figure}[htb]
 \centering
 \includegraphics*[width=75mm]{setup.eps}
-\caption{Probe-station setup: (1) Microscope lens, (2) Adapter-card, (3) Connectivity to DAQ, (4) Probe-card, (5) Test-board hosting reference sensor and (6) chuck-adapter with one Mimosa-26 sensor.}
+\caption{Probe-station setup: (1) microscope lens, (2) adapter-card, (3) connectivity to DAQ, (4) probe-card, (5) test-board hosting the reference sensor and (6) chuck-adapter with one Mimosa-26 sensor.}
 \label{fig:setup}
 \end{figure}
 
@@ -81,6 +83,9 @@ A.Nomerotski et al., "PLUME collaboration : Ultra-light ladders for linear colli
 \bibitem{3}
 N.Abgrall for NA61/SHINE Collaboration, "Report from the NA61/SHINE experiment at the CERN SPS", CERN-SPSC-2013-028 ; SPSC-SR-124, October 2013, page 57.
 
+\bibitem{4}
+J.Michel at al., this report.
+
 
 
 \end{thebibliography}