TIBTIDNotes/TIBTIDIntNote/IntegrationProcedures.tex

\section{Integration Procedures}
\label{sec:Procedures}
TIB and TID have different integration procedures, each one being optimised
for the geometry and the best installation and test logical sequence. 
In this section the steps done to assembly a TIB shell and a TID 
ring will be described also mentioning the tests done in between and
described in detail in section~\ref{sec:Tests}. 

The integration process starts from the basic mechanical structure
already equipped with cooling pipes and the module support ledges
and fully qualified with respect to the precision mounting of the
mechanical parts and cooling performances. 

\subsection{TIB Integration Procedures}

The shell is fixed with the cylinder axis horizontal onto an
integration bench by an aluminum frame which minimizes the mechanical
stresses. The bench allows the shell to be rotated around the cylinder
axis and is also know as ``roaster''. All the internal and external strings can be 
positioned in an optimal way for access in a fast, practical and safe way.

The shell supporting structure also holds a system consisting of plastic
trays to safely arrange the AOH fibres. To easily identify each string a bar code is temporarily stick on the
structure.\\
%The string sticker is read and send to the integration database interface program
%before each mounting operation.\\
A picture of a Layer 4 mechanical structure mounted on the integration bench is shown in Fig.~\ref{fig:bench}.

\begin{figure}[!htb]
\begin{center}
  \includegraphics[width=0.85\textwidth]{Figs/bench.pdf}
\end{center}
\caption{A shell carbon fiber structure mounted on the integration bench. The cooling pipes
and ledges of inner part of the shell are visible.}
\label{fig:bench}       % Give a unique label
\end{figure}


\subsubsection{AOH Installation}
The small AOH board ($3\times 2.2 cm^2$) 
is simply screwed to a C-shaped ledge which is directly glued on the string cooling 
pipes. Due to mechanical constraints, the
fibers and their connectors should be carefully routed to the outside of the shell through a
number of ledges, holes and pipes keeping 
them as close as possible to the carbon fiber structure surface to which they are finally fixed 
using glued kapton strips. The main part of the pig-tail fibers
remains out of the shell and is temporary stored in the plastic
trays. The optical connectors are inserted 
into arrays of dummy optical plugs fixed at the far-end of the
structure to be always accessible during the various tests which
require many connect-disconnect operations.\\ 

Since the optical fibers are quite fragile, special protections have
been arranged in the most critical points. 
For example at the shell flange the fibers have to be bent and
routed with other services. There they are grouped together and
covered by a silicon rubber spiral as shown in (see
Fig.~\ref{fig:spiraline}).

The procedure resulted to be very effective: only few fibres out of
several thousand were found broken at the end of TIB/TID integration.

A layer 2 shell with AOH mounted on is shown in Fig.~\ref{fig:aoh}.


\begin{figure}[!htb]
\begin{center}
  \includegraphics[width=0.60\textwidth]{Figs/aoh.pdf}
\end{center}
\caption{A layer 2 shell with AOH mounted. The optical fiber pig-tails are also visible.}
\label{fig:aoh}       % Give a unique label
\end{figure}

\begin{figure}[!htb]
\begin{center}
  \includegraphics[width=0.60\textwidth]{Figs/spiraline2.pdf}
\end{center}
\caption{Group of optical fibers protected by siliconic ruber spirals at the flange exit.}
\label{fig:spiraline}       % Give a unique label
\end{figure}

Since the AOH is powered by the module kapton tail its test without
the corresponding module is not straightforward. So it has been choosen
not to test AOHs after their installation, despite the 
operation of changing a broken AOH when the modules are already
installed is very cumbersome and somehow risky for the nearby objects
already mounted. Eventually, the number of AOH that had to be replaced
was anyway very small, at the level of one per shell/disk.

\subsubsection{Mother Cable Installation}
The Mother Cables are put in place after the AOH
mounting and all the optical fibers have been fixed to the shell and
adequately protected where needed. The mother cable is inserted below
the ledges by sliding them on
the shell surface from the end flange. The ledges support keep the
mother cable in place (see~\ref{fig:l3detail}).  This procedure is in some cases complicated by mechanical 
constraints at the level of the shell front flange, where the mother cables are entered in the shell, 
and cooling manifolds. When the Mother Cables are inserted they 
are connected to the power cables (medusa cables) which are temporary fixed to the shell supporting 
frame. \\
The {\em medusa cable} is just a bundle of single insulated wires with
no definined envelope and geometry as a standard cable. This helps in efficiently
use the very limited available space on the TIB front flange
% allowing
%to 'distribute' the cable among the other services.  \\ 
To ease the implementation of the control ring redundancy, CCUs are
put in the ring with a defined hardware address order. So, for each
string position in the ring, care must be taken to choose the proper mother cable,
that comes with the CCUM already on it.
%,   has to be provided with a
%CCU whose address is in a fixed order with respect to its position in
%the token ring.
\begin{figure}[!htb]
\begin{center}
  \includegraphics[width=0.60\textwidth]{Figs/mc_detail_full.png}
\end{center}
\caption{A symplified detail of the $r\phi$ section of TIB L3
  mechanical drawing.}
\label{fig:l3detail}       % Give a unique label
\end{figure}


\subsubsection{Module Mounting}\label{sect:tibmodules}
Both single modules and double sided module assemblies are mounted on the shell by hand. 
The module  is supported below the front-end
hybrid and on the opposite side by two ledges support that precisely
define the module position and act as heat sink
%for the front-end hybrid and the sensor generated power
being in contact with the cooling pipes. 
The shape of the ledges is different for the single sided modules and
for the double-sided module assemblies. In the latter case the
``stereo'' module sits on the structure upside-down and the ledge
below the hybrid has a milled slot to ensure enough room to the
front-end hybrid. The ledge on the opposite side has two different
shapes reflecting the two orientations of the ``stereo'' modules. 
Each ledge has two M1 threaded holes. One is concentric with a 2mm
diameter socket. 
The module features one precision pin on both short sides that fits
into the socket (Fig. \ref{fig:insets} c). The milling of the socket and the glueing of the
ledge onto the shell is done by using the same reference, i.e. the
ledge edges, so to ensure an accurate positioning.
The module pin at the hybrid side is glued onto the module frame. The
one at the opposite side, however, fits into an 'U'-shaped
slot a design that allows for movements along the module long side. In
a device that will be affected to huge temperature changes, this is an
essential feature to compensate for thermal variations while ensuring
mechanical precision.

Before mounting a module on the shell the structure is rotated to place
the corresponding string in a confortable and horizontal
position. Then the module inventory database is queried for an
appropriate module. The answer depends on module type and availability
at the integration centre and on the module depletion 
voltage (see par.~\ref{sec:biasandvdepl}). \\

The module identified for mounting then undergoes an optical
inspection to check for obvious damages and the temporary labels used
during the production are removed. Finally the module and ledges
contact surfaces are inspected and cleaned to ensure an optimal heat
exchange with the cooling circuit. The operations that imply the
handling of the modules are very delicate and account for 
a considarable fraction of the time spent into module mounting.\\

The single sided module or the double side modules assembly is mounted
on the structure by hand. It is first leaned onto the ledges and then is 
gently slit until the pin at the hybrid side enters into the precision
socket. Now can only the rotation around the pin axis is possible. 
The mounting is completed by inserting in the corresponding precision
socket the T-shaped aluminum pin placed in the U-shaped slot
(Fig. \ref{fig:insets} b) located on the frame short side opposite to
the hybrid. The module is finally tighetned by the four M1 screws by
using a limited-torque screw driver.

\begin{figure}[tbh]
\centering
\includegraphics[width=.7\textwidth]{Figs/collage.pdf}
\caption{TIB single-sided module insets:
\textbf{a:} The U-shaped slot glued on the carbon fiber module frame;
\textbf{b:} the T-shaped pin inserted in the slot (seen from below);
\textbf{c:} front-end hybrid side precision insertion pin (seen from below).}
\label{fig:insets}
\end{figure}

The clearance between the module most fragile parts (bondings)
and the other surrounding structures when the operation is performed (cooling pipes and ledges of the 
adjacent strings and modules already mounted) are, in case of single-sided modules, 
sufficiently large for a safe operation. For the double-sided module
assemblies the cleareances are much reduced, of the order or less than a millimeter. 
In this case, to ease the mounting, a simple mechanical guidance 
template has been designed to further reduce the risk of possible
accidental damage of the microbonds or the sensor.

Once a module or a double sided assembly is mounted its basic
functionality is tested by feeding low voltages and checking I$^2$C
communications with the various devices present on the hybrid, the CCU
on the mother cable and the AOH. This also allows the module identity
to be certified by using the DCU hardware ID. 
Once a string of three or six modules is completed the I$^2$C
communications are checked again and a pedestal and noise run is taken
with a HV bias at 400V. For the tests complete description see
section~\ref{sec:Tests}.

\subsubsection{Control Ring Installation}
The control electronics that supervises the control ring, i.e. the
DOHM boards and in case the AUXs, are located on a carbon fiber skin
are mounted on the shell external surface just above the modules by carbon fiber pillars and aluminum supports (Fig. \ref{fig:dohm}). 
A thin aluminum foil has been glued on the skin and electrically grounded 
to reduce possible interference between the logical control signals and
the module analog electronics. All mother cables are then connected to
the DOHM (and AUX) ports by using a set of appropriately terminated
flat-cables that have been preprared before, on the empty structure,
by using dummy replicas of the DOHS/AUX boards and mother cables.

Each shell needs of three to six Control Rings, generally
differing also withinh the same shell with respect to the number of
served strings and the geographical distribution of these strings
into the shell. 
For example, Layer 1 and 2, which are equipped with 
double sided modules, have control rings of 3 to 5
strings, while Layer three and four have 13 to 15 single sided strings.\\
\begin{figure}[!htb]
\begin{center}
  \includegraphics[width=0.60\textwidth]{Figs/dohm.pdf}
\end{center}
\caption{A Layer 3 control ring circuitry during the cable preparation
  witha DOHM and an AUX (the smaller board) with control ring cables
  connected the mother cable heads (not visible).}
\label{fig:dohm}       % Give a unique label
\end{figure}

As can be seen in Fig.~\ref{fig:dohm}, due to the variable number of strings connected and their 
different positions with respect to the support
mechanics and cooling, each control cable have a different length and shape and
should be tailored in-situ to minimize the path satisfying all the mechanical constraints.
Each control cable path has been optimized as a consequence of the
very limited room available for services.
For layer three and four the part of the control cables
which is not protected by the carbon fiber plate
is shielded using a thin Aluminum foil.\\
The $4 \times 2$ optical fibers, which connect the two DOH to the FEC,
are cerefully routed and protected at the flange. In fact the
redundancy architecture allows the ring to work also if the connection
to the master DOH fails, but the price to pay if both DOH connections
fail is of the order of 1-2\% of the entire TIB.\\
The DOHM cabling is completed by the power cable, very similar to the
mother cable 'medusas', and by the wiring of two PT1000 temperature
probes per control ring that comes already glued on the cooling manifolds. 
The four probe wires are in fact routed through the DOHM via the Control
Ring power cable up to the power supply racks where the interlock
boards are also located. The four-wire resistance measurement
of the PT1000 is necessary to avoid the contribution of the 
40 meter long power cable.
Also a humidity meter is hosted on the DOHM board; it is read out
through dedicated wires on the Control Ring power cable.

A thinner carbon fiber skin is used as a protecting cover. Electrical
shielding is ensured by an aluminum foil glued to the cover and
grounded (Fig. \ref{fig:dohml1}). Finally the control ring is tested (see section \ref{sec:Tests}).\\ .

\begin{figure}[tbh]
\centering
\includegraphics[width=.7\textwidth]{Figs/L1DOHM.pdf}
\caption{A Layer 1 completed with its control rings. The DOHM and cable area is covered with
aa aluminum shielded carbon fiber plate.}
\label{fig:dohml1}
\end{figure}


\subsection{TID Integration }
The integration of the TID rings has required the design of a handling tool that 
allows safe and easy manipulation of the mechanical structure, allows access and integration
on both side and provide support for the long optical fibers associated with the AOH and the DOH
of the DOHM. Moreover it should allow the assembly of rings into a full disk.

The handling tool is based on a aluminum crow plate with different mounting positions for: ring 
holding towers (4 to hold each ring) to adapt to any of the three different rings; U-shape
feets to allow the placing of the ring  front side upwards or downwards; stocking cylinder where to 
place and hold the long fibers; aligning jigs with pillar to allow to pair together two crowns
and join pairs of rings together to allow the assembly of ring into a disk. The handling tool will be called
 in the following as {\it integration crown} and it is shown in Fig.~\ref{fig:ringbench} for different configuration:
for a R1, R3 rings on the front side and a R1 for both sides.

The integration crown was made as light as possible, but rigid enough not to add mechanical stress to the 
ring or the disk, during the manipulation, specially during rotation  
of the structure (made manually using two handles) and the 
assembly of rings into a disk.  Weight????????

\begin{figure}[!htb]
\begin{center}
%  \includegraphics[width=0.49\textwidth]{Figs/R1-front.pdf}
%  \includegraphics[width=0.49\textwidth]{Figs/R2-front.pdf}
%  \includegraphics[width=0.49\textwidth]{Figs/R1-back.pdf}
%  \includegraphics[width=0.49\textwidth]{Figs/R3-front.pdf}

  \includegraphics[width=0.7\textwidth]{Figs/R1-front.pdf}
%  \includegraphics[width=0.49\textwidth]{Figs/R2-front.pdf}
  \includegraphics[width=0.7\textwidth]{Figs/R1-back.pdf}
%  \includegraphics[width=0.49\textwidth]{Figs/R3-front.pdf}
\end{center}
\caption{ The TID integration crown  holding R1 rings in front (top) and back (bottom) positions.}
\label{fig:ringbench}       % Give a unique label
\end{figure}
Once a new ring structure arrived, it was mounted on an integration crown. In order to identify easily the mother cable positions
during the integration bar code stickers were temporarelly glued to the ring. The integration work was made
 in parallel on several rings and disks at different steps of integration, therefore several integration crowns were used. 

TID cooling ledges for the AOH could arrived with a bending angle outside specification, due to manipulations 
of the ring and some touching that do not compromise the mechanical integrity of the cooling pipe. 
The clearance between parts in a disk is very small, in particular silicon sensors have a minimal distance of 2mm between 
AOH cooling ledges between ring 3 and ring 1, therefore mechanical checks were made and adjustment applied if needed.

\subsubsection{Services Installation }
The first step of integration was the installation of the services. For the TID a problem to be solved was the routing out of the optical fibers of the DOHs and  AOHs: all fibers have to exit from the TID at specific positions relative to  holes on Service Cylinder. 
To do that,  a set of AOHs associated to each mother cable was found,  all fibers were prepared to form a unique bundle that 
could be easily routed in the ring, holding together fibers using silicon rubber spirals. The same was done for pairs of DOHs going to the same DOHM.

All mother cables were prelimanarly tested in a dedicated test bench.  The ring integration begin installing all four
mother cables on each side of the ring: they were placed and screwed to the ring and equipped with 
CCU with the proper  $I^2C$ address. The connector of the mother cables reach the outermost radius of the ring to allow the connection to the power cables.  

Then the DOHM was fixed: for R2 and R3 the addition of a cable was needed in order to allow power connection at the outer radius of the ring. The ground of the DOHM was connected to a cable to reach the outer ring radius and will be used to make a unique grounding line for all TID+/-.  Then the DOHM  was equipped with a proper CCU and with the needed two DOHs:  their fiber were routed out properly and attached to integration crown via the stocking cylinder. 

 The control ring cables that connect DOHM to the mother cables were pre-formed in advance and were mounted and adapted into the ring. A 
complete functionality test of the control ring was then performed to verify that the  main control ring and the redundancy were working
fine. 

Two temperature sensors PT1000 were finally glued to the cooling manifold and  connected to the DOHM.


Details of the DOHM integration can be seen in the Fig.~ref{fig:tiddohms}.
\begin{figure}[!htb]
\begin{center}
  \includegraphics[width=0.4\textwidth,angle=90]{Figs/dohm-r1.pdf}
  \includegraphics[width=0.4\textwidth,angle=90]{Figs/dohm-r2.pdf}
  \includegraphics[width=0.4\textwidth,angle=90]{Figs/dohm-r3.pdf}
\end{center}
\caption{Integration of DOHM in the TID rings, from left to right R1, R2 and R3.}
\label{fig:tiddohms}       % Give a unique label
\end{figure}


Mounting of the AOH followed, screwing them temporarelly to the cooling ledge. The fiber lenght closes to the module was hold in place using foil of kapton properly shaped and glued to the ring. Then fiber bundle was routed up to the outmost ring radius at the position where the mother cables connectors are, and they are mechanical hold there by a kapton foil screwed to the ring: the remaining lenght was then fixed to the stocking cylinders. Some of these working solutions are in shown in Fig.~\ref{fig:tidfibers}. All

\begin{figure}[!htb]
\begin{center}
  \includegraphics[width=0.4\textwidth,angle=90]{Figs/Fiber-kapton1.pdf}
  \includegraphics[width=0.4\textwidth,angle=90]{Figs/Fiber-kapton3.pdf}
  \includegraphics[height=0.4\textwidth]{Figs/Fiber-kapton2.pdf} 
\end{center}
\caption{Few examples of solutions found for routing, bind together and fix the AOH fibers in the rings.}
\label{fig:tidfibers}       % Give a unique label
\end{figure}

\subsubsection{Module Mounting }
The mounting of TID modules follow exactly the same procedure explained in the TIB section~\ref{sect:tibmodules}.
Module mounting in rings is easier than in shells, since modules with following azimuthal angle are placed in opposite sides
of the ring. Neverthelss a lot of care was still needed: the precision pin was often very tight and the 
module cometa was placed on the U-shaped slot and hold down by the side precision insertion pin. Sistamatic
checks were made  on the electrical connection of the module ground with the carbon fiber. 

Once a full mother cable was ready, several test as exaplined later in the paper. To perform the noise test,
the entire ring was darken and measurements were done, first without bias and then with bias up to 100V to check 
good high voltage connection and that no evident physical damage was done to the silicon module. 


\subsubsection{Assembly of rings into a disk }

Integration crown equipped with alignment cylinder, also alignment ring pieces
put on place.  

Slow manual movement going down, rotating a pair of distance screws. 

Lot of care in last millimiter about fitting fixing holes between rings and about parallelism of rings
and critical point of very close parts. Then, unfix the top ring from the integration crown and
screwing down the rings.

Passing fibers from one integration crown to the other one. 

Detaching the integration crown

Disk assembly proceed for R1 on a R3, then R2 on R1-R3 structure.


\begin{figure}[!htb]
\begin{center}
  \includegraphics[height=0.6\textwidth]{Figs/Disk-assembly.pdf} 
\end{center}
\caption{Disk assembly.}
\label{fig:tidassembly}       % Give a unique label
\end{figure}


\begin{figure}[!htb]
\begin{center}
  \includegraphics[height=0.6\textwidth]{Figs/DISK.pdf} 
\end{center}
\caption{Disk assembled.}
\label{fig:tidassembly}       % Give a unique label
\end{figure}


\subsection{Integration Database}

Each active element, cables included, 
of the CMS experiment is identified by a bi-dimensional, radiation resistant,
bar code which is glued on the component itself redundantly coding a 14-digit number.
For the tracker the registered components are: 
detector modules, AOHs, DOHMs, DOHs, CCUs, Mother Cables,
optical fibres and ribbons, power and control cables. 
Using this code the object characteristics and the results of the tests previously performed
during the production phase, can be retrievied from 
the Tracker construction database~\cite{ref:database}.
Of equal, or even more, importance are the component
mounting locations and the connections between them.
This information is stored on the integration database at integration time.
Moreover the integration database acts also as an inventory to locate the components among
the various integration centers managing the shipping procedures.
It also contains a subset of the test data of all the 
devices and their functional status (good, broken, mounted, dismounted, etc...).\\
Along with module tests results also an important number is stored for each module:
the hardware identifier of the DCU chip
embedded with the module (or DcuHardId). This code can be retrieved during data acquisition, 
allowing for an unambiguous identification of a module.\\
A TIB/TID specific key was defined to store the location of mounted devices (named Geographical
Identifier, or GeoId): it is a string
composed of numerical fields separated by dots, as described in Table~\ref{tab:geoids}.
Bar code stickers with the GeoId are glued on the mechanical structure 
before the integration starts (Fig. \ref{fig:stickers}).

\begin{figure}[t]
\centering
\includegraphics[width=.6\textwidth]{Figs/stickers.pdf}
\caption{An empty shell with the bar code stickers identifying the strings.}
\label{fig:stickers}
\end{figure}

The first 7 numbers in a GeoId identify the string to which a device belongs, while the last
part of this code represents the physical location where the device is placed.

\begin{table}[h!]
\begin{center}
\begin{tabular}{l|ccc}
    & 1               & 2     & free value  \\
    \hline
  a & TIB             & TID              &             \\
  b & Forward ($z>0$) & Backward ($z<0$) &             \\
  c & Up ($y>0$)      & Down ($y<0$)     &             \\
  d &                 &                  & Layer \#    \\
  e & Inner           & Outer            &             \\
  f &                 &                  & Manifold \# \\
  g &                 &                  & String \#   \\
\end{tabular}
\caption[smallcaption]
{A generic $a.b.c.d.e.f.g$ GeoId identifies a string and  must be interpreted according
to this table. For example of GeoId 1.1.2.4.1.3.2 identifies the second string, of the
third manifold placed in the inner surface of the Layer 4 Down Forward TIB shell.}
\label{tab:geoids}
\end{center}
\end{table}

%The first number identifies TIB (1) against TID (2),
%the second number marks the forward part (1) vs. the backward (2). Hence TIB and TID codes become
%different. For TIB the third number identifies the upper/lower shell (1,2) and the fourth is
%the layer index (1-4).
%The following numbers represent if a device is placed on the inner or outer surface of a shell, 
%the cooling manifold a device belongs to and the string index insidethe same manifold.
Revision:	1.4
Committed:	Mon Mar 9 15:41:05 2009 UTC (16 years, 1 month ago) by sguazz
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