Components

  • Mechanics: Front panel, back panel, cooling block and screws.  
  • EpixHR250M carrier, P&CB, and Digital boards


  • 24-channel Fiber optics cable, MTP adapter, on-board transceiver and optical fiber clip


  • On-board transceiver mounting tool and hex keys (3/32'' and 5/64'') 


  • Power cable


Thermal padding

Position two layers of thermal pad on top of the surface of the P&CB that is in contact with the cooling block (large connector side). Two inductors on this side will be visibly coming out from under the thermal pad. These chips have enough height to be in direct contact with the cooling block, and there is no margin for a thermal pad there. Gently remove the thermal pad from the top of the inductors until the inductor becomes visible. 



As for the carrier and the digital board, in some regions it is recommended to use one layer while in others it is recommended to use two layers of thermal pads. See image below

1 layer regions:

  • On top of the FPGA
  • On the full upper side of the digital board
  • On the bottom region of the cooling block designated for the carrier board

In every other place 2 layers would do. Bear in mind that some of the component part on the bottom side of the digital board have significant height. It can be observed on the left side the pressure that these component exerted on the thermal padding. If bulging is observed when screwing, then unscrew and manually compress the thermal pad in these regions or remove the second layer of the thermal pad.


Fastening the boards on the cooling block

Using the short 3/32'' screws and key to fasten both the P&CB and the digital boards to the cooling block. Pay attention to board bulging. If you see it bulging, remove the screws and examine the thermal pad. They should look as follows



Use the back and/or front covers when necessary to position the detector without damaging the PCB pins, connectors and components.

Connecting transceiver


The transceiver is extremely fragile, and the OBT Mounting manual can be referenced in order to mount it to the board. Nonetheless, the essence is captured here, so follow strictly these instructions

  1.  Set your Micro ESD pre-set adjustable torque screwdriver to a torque of 3.5 Ncm
  2. Remove the black cover from the transceiver based mounted on the board by simply pulling it out
  3. Unscrew the black cap off of the transceiver bottom and remove it
  4. Position the transceiver on the transceiver base on the P&CB. Pay attention to the unique shapes on the base defining the orientation of the transceiver.
  5. While positioning your fingers on top of the transceiver, apply pressure gradually to the screw and rotate three turns
  6. Then move to the next corner in the following order
  7. Repeat the process until all your screws are screwed in with the configure torque
  8. You are done with fastening the transceiver. This is how it should look like.

Connecting the transceiver cable

Remove the socket protection plug, and while positioning the small brown square upwards, plug it in the transceiver. Do not invert it, and make sure the small brown square is on top. Then position the two hooks on the fiber optics cable, and pull the other side using a screw driver until it hooks to the transceiver pressuring the cable in. 



This is how it should look like



Now as a final step, position a kapton tape on the fragile fiber optics cable so it holds the cable from moving, and hence, breaking to small wires within. This is how it should look like.

Hooking up the carrier


This is the most delicate step of them all. The carrier wire bonds are exposed, and something as little as a strong breeze or a light touch may damage them, so proceed with extreme caution. 

You will need both sides of the cooling block exposed and the carrier cannot be installed with any of the covers assembled.

The following image shows how your setup needs to look like before installing the carrier. You can make holes in the carrier single layer thermal pad using a screw driver or your hex key. 4 long 3/32 '' screws will be used to fasten the carrier. They will go in the cooling block from the side of the P&CB , pass through the cooling block all the way to the other side holding the carrier.



With extreme caution, remove the cover on the carrier by unscrewing the lateral screws using a 3/32'' hex key.  



To get some leverage holding the carrier, you may want to insert of screws laterally in the aluminum block of the carrier as follows



With extreme caution grab the carrier from the sides without touching the wirebond, and raise it vertically. You will see 4 screws in the back. With a 3/32'' hex key unscrew them one by one until the carrier is unfixed from the cover base.

Now position the carrier on the cooling block on the side of the digital board, and with one hand hold the carrier while with another hand carefully apply some pressure on the connector. 



Now you can proceed to screwing the carrier on to the cooling block by inserting 3/32'' screws in the 4 holes in the bottom side of the cooling block, through the cooling block and fastening the carrier using your 3/32'' key.



Once all four screws are fastened, you can unscrew the lateral leverage screws on the aluminum of the carrier.

Proceed at once to position the upper side cover with extreme caution to protect the carrier wire bonds from getting damaged.

Screw the lateral screws with a 5/64'' hex key and screws. You should have a setup like the one shown above.

Hooking up the MTP adapter and the power cable to the lower cover


Pass the small side of the power cable through the socket hole in the lower cover of the detector. Make sure that the asymmetric orientation of the connector hole is similar to that of the connector. 



Now use a 3/32'' screw to fasten the connector to the cover.

Now from the external side of the cover, slide in the MTP adapter from the clipper side into the cover. Use 5/64'' screws to fasten the fiber optics MTP adapter to the cover as well. Any orientation should be ok.  You final work should look like this.


Now gently insert the other side of the power cable in the P&CB. Orientation matters. The connector extrusion should be to the upper side. Now connect the Fiber optics cable to the MTP adapter. Orientation also matters. This is how your setting should look like now


As a final step, you need to close the cover without jeopardizing the cables. The covers may be stuck due to fitting issues, but another possible reason is that the cables are trapped somewhere, so proceed with extreme caution. The thick cable can be extended in all the available space. The Fiber optics can be rotated in a circle under the cover. Your final setup should now look like this.


Congratulations. You are done.

References


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