3 different PCBs :

1. Reminder: EC-front unit UV filter • 3 different PCBs: • First one (EC DYNODE board) allows to reroute half of the dynodes of 1 MAPMT so that they are aligned perpendicularly to the others. It covers the 4 MAPMTs. • Second one (EC ANODE board) covers one MAPMT but has dimensions reduced allowing a flex pcb to get out. It is used to collect signal from the anodes and send them to the ASICs. • Third one (EC HV board) covers one MAPMT. It welcomes the dynodes and supplies the HV (up to 1000 V) to the EC-dynode board which transmits it to the 4 MAPMTs. MAPMT MAPMT MAPMT • Per EC unit: • 1 EC-DYNODE board • 4 EC-ANODE boards • 1 EC-HV boards Flexible pcb toward EC-back Central column HV cables toward HV box

2. EC front assembly (dimensions) with pins of 6.6 mm EUSO-BALLOON 1mm EC-dynode (1.2 mm) 2.5 mm 5.9 mm 10.6 mm EC-anode (1.2 mm) MAPMT 8.4 mm 3.5 mm EC-HV (1.2 mm) Soldering (0.5 mm) (7) Added pins, black plastic is 2.5 mm high MAPMT Extensions of the pins

3. EC front assembly (dimensions) with pins of 5.6 mm As the pins are not long enough to reach the EC_anode, we need to add extensions on the 64 anode pins of all MAPMTs. The assembly is therefore different from EUSO Balloon. But no modifications of the pcbs look to be required, just on the assembly sequence and difficulty. It doesn’t add constraint to the mechanic. MAPMT To becutat the righlength EUSO-TA 1mm EC-dynode (1.2 mm) 10.1 mm 4.5 mm 7.9 mm EC-anode (1.2 mm) 1 mm EC-HV (1.2 mm) Soldering (0.5 mm) NB: thisis quick drawing, dimensions have to bechecked.