PHOBOS Report 99-10
Assembly of the PHOBOS spectrometer silicon modules
B.Dabrowski, M.Despet, G.van Nieuwenhuizen, M.Stodulski
PHOBOS Weekly Meeting
MIT, March 12, 1999
Mounting the silicon modules onto the cooling frames
Special jigs are designed and fabricated to allow for easier and safer mounting of the spectrometer silicon modules onto the cooling frames. Due to various configuration of the modules along the cooling frames few jigs are necessary.
Basically, two jigs (1 and 2) will be used for mounting all the modules excluding the module Type 1. The jig 1 requires several adapters (a, b, c, d) while the jig 2 does not. Each jig serves for mounting specific modules, see Table 1. The modules Type 1 will be mounted on the frames by hand. The frames are positioned horizontally on a fixture.
The jigs will be fixed to each hybrid in two points via the connector and a screw M1.6. The screw is tighten in a fixture on the bond cover. Height of the fixture should not exceeded 2.5 mm
In case of interference between the mounting jigs and cooling frame supports the latter will be moved along the frames; it requires a temporary support for the cooling frames NR 3, 4.
2. Realization
All necessary jigs are already made as well as the fixture for mounting the modules Type 1. The jigs were used to mount double- and one-sided modules on the cooling frames in different configurations. Use of the jigs allowed to pick up the module from their transport boxes, handling and assembly on the frame. Procedure of disassembly was tested, also. The tests proved functionality of the jigs, see Fig. 1. However, an individual operating with the jigs has to be excellently skill. Congratulation to Gerrit !!!
Table 1 - assignment of mounting jigs to specific modules
|
Applicable jig |
Dummy hybrid |
Shim |
Frame Number |
Silicon Module |
Comments |
|
No jig |
|
|
1 2 |
A, B C, D |
horizontal support instead. Gerrit’s decision |
|
No jig (NR 1 can be used)
|
----- |
------- |
3 4 |
E, F G, H |
will be mounted on the same support, Gerrit’s decision |
|
NR 1 (double sided) |
----- |
------ |
5 6 7 8 |
I2, J2 K4, L4 M6, N6 O9, P9 |
|
|
NR 1 a |
3 mm |
------ |
6 8 |
K1 O1, O7, P7 |
|
|
NR 1 b |
3 mm |
4 mm |
5 6 |
I1, J1 L1 |
J1 spacer to be chamfered |
|
NR 1 c |
------ |
(6+9.4) mm |
6 7 8 |
K3 M1, M3, N3, O2, O4, P3, P1 |
at cover mount only |
|
NR 1 d |
------ |
(9+9.4) mm |
7 8 |
M5 O6, O8, P8 |
at cover mount only |
|
NR 2 (one sided) |
------ |
-------- (eve. 0.8 mm) |
6 7 8 |
K2 M2, M4, N4 O3, O5, P2 |
shim seems not to be necessary |
Handling, storing and testing the modules mounted on the cooling frames
Special boxes ("blue boxes") are designed and fabricated to handle, store, test and survey the silicon modules mounted on the cooling frames. The blue boxes replace the current transport boxes foreseen for the hybrids and the modules. The modules will stay in the blue boxes until next step of the spectrometer assembly i.e. assembly of the cooling frames with the modules on the small plate.
Warning!
Blue boxes are not designed to transport the modules on the cooling frames outside of a lab space.The blue boxes feature:
- each box consists of a sub-plate (blue aluminum sandwich panel) and a cover (aluminum sheets 0.032" thick); it is intended the cover will be slid on/off the sub-plate not to be put down from above;
- light-tightness of the box will be obtained with black scotch tape,
- each sub-plate has 3 or 2 supports (aluminum channels) which a cooling frame is mounted to; the sub-plates for the cooling frames NR 3, 4 have a temporary support necessary during mounting the modules;
- each box can serve both the inner and the outer arm frames; it can require re-configuration of the supports;
- each sub-plate has handles to easy pick up from a mounting table,
- each sub-plate has a bearing bushing in the geometrical center allowing for rotation,
- each sub-plate has a strain relief to support flex cables.
2. Realization
The blue boxes are already made for eight frames. Congratulation to Marian and Bogdan!!
Assembly of the cooling frames with the modules on the small plate
1. Plans
A rigid frame is foreseen to carry the small plate with the modules. The small plate will be supported on the frame and in the experiment at the same three points. The frame has to allow for access to mounting screws from below.
A plate for assembly the cooling frames on the small plate is also necessary. That plate allows for assembly/disassembly each of the frames but one by one. It should be transparent and rigid enough to carry the heaviest frame (NR 8). The plate should precisely position a currently assembled cooling frame with respect to cooling frames already mounted on the small plate. It will be ensured by linear ball bearings built in the transparent plate and two vertical posts temporary fixed to the small plate.
2. Realization
Design of the carrying plate is based on the blue box sub-plate design. Overall dimensions of the plate were determined on the hall door size in the utility building. Raw materials are procured.
Design of the transparent plate is almost finished. Raw materials are procured, plates with precisely positioned mounting holes are machined. Proof of principle performed.