HV boards

1.FIRST ASDBLR HV PROTO BOARD: leakage currents on 100nA CH, humidity at cern.

2. TRIAL 1Encapsulate caps in Printed Circuit Board 20-80 C schock, Ileak 1nA, (later increase) 3 broken caps Sparking under cap’s Test cycles 10-80C for 2 weeks,

3. TRIAL 2 improved casting, pick and place paste, no cleaning slurryStill broken capacitors (not HV but mechanical) Curved boards

4. TRIAL 3 Still broken capsNow thermal shocks -40 to +120 CMost probably Rework solder problem

5. TRIAL 4Now better mounting on flat bad, ‘no rework’ , capacitor monitorring

6. If failing “open Boards” with vac casting

Status HV boards

New HV board without fuses

Capacitor monitoring checklist