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:
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.
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.
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