Review of the EC-Front
P. Barrillon on behalf of all the people involved (and they are many !)
March 1st 2012 - LAL
Dimensions of the PDM frame:167mm x 167mm x 28.7mm
PDM structure: reminder
• 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 to the EC-dynode board which transmits it to the 4 MAPMTs.
EC unit description: front part
Per EC unit:• 1 EC-DYNODE board• 4 EC-ANODE boards• 1 EC-HV boards
UV filter
MAPMTMAPMT MAPMT
Flexible pcb toward EC-back
HV cables toward HV box3
EC-Unit: side view
MAPMT MAPMT
EC ANODE BOARD
EC DYNODE BOARD
EC HV BOARD
dynode
anode
EC-ASIC board welcomes ASICs as well as connectors.
Data out are then transmitted to the PDM board.
Toward PDM board
4
From EC-front to EC-back
5
The flex and second rigid parts of the EC-anode boards have to go through the mechanical structure to reach the EC-ASIC board.
PDM mechanical structure, with cross and hole.
Front view
6.1 mm outer diameter 3.1 mm inner diameter
Radius of the corner : R2.2
55 mm
Thickness: 1 mm
11 mm6 mm
17 mm
Outer and inner diameters10 and 6 mm
19.62 mm 19.62 mm
53 mm51 mm Thickness: 3 mm
9.3 mm
17 mm
~2 mm
Dimensions from schematic (Frascati)
• EC-dynode needs to be < 55 mm long/large 54.5 mm
• EC-dynode central hole needs to welcome a screw of 2.5-3 mm
• EC-anode flex and 2nd rigid parts needs to be < 19 mm large 16 mm
• EC-anode flex needs to be 4-5 cm long depending on the type
• The central hole of the mechanical structure can be removed
Conclusions from schematic
• PCB used to transmit HV signals to the dynodes pins of each MAPMT.
• Rerouting will have to be done (inside the pcb) for 7 pins (GR and Dy7 to Dy12) of MAPMT 3
• For the MAPMTs with no rerouting (1, 2 and 4): all 14 pins (K, GR and Dy1 to Dy12) will be cut and soldered on this pcb
• For the MAPMT with rerouting (3): the 6 dynodes with lowest voltages and GR will be rerouted, new pins will be soldered on the. These 7 pins and the 7 other ones (Dy1 to Dy6 and K pin) will have extensions added
The EC-dynode board
64 anodes pins going through the pcb (no soldering/connection)Rerouting of 6 HV
pins and GR
Pins with extensions
1 2
3 4
EC-dynode schematic
Top view
• 54.5 x 54. mm• 1.5 mm thickness (can be reduced to 1.2 mm)• 8 layers pcb• 3.2 mm hole in the middle• 3 areas 16.5 x 2.5 mm added to ease potting spread• bottom right MAPMT print corresponds to the one with the pins extended
EC-dynode: dimensions and pins positions
Top layer Layer 2 Layer 3 Layer 4
Layer 5 Layer 6 Layer 7 Bottom layer
EC-dynode: routing
The EC-anode board (1/3)
EC-ANODE corresponding to the MAPMT with rerouted pins at the level of the EC-dynode board.
Bigger holes because of extensions
Same PCBs (holes for dynodes are not represented)
Extensions
Areas gained for flexes
12
• Allows the routing of the 64 signals toward the connector.• Choice of the connector is the critical part. It shouldn’t be too
high, too large or too long but has to allow a feasible routing.
The EC-anode board (2/3)
13
Flexible pcb
Rigid pcbRigid pcb
As long as neededAs long as needed
connector23.7 mm
~ 24 mm
< 19 cm
• 2 types of pcbs are foreseen:• 1 with a straight flexible part• 1 with a curved flexible part
• similar routing• same orientation• One with a connector on top
layer, the other with the connector on bottom layer• Easier assembly
The EC-anode board (3/3)
14
CONNECTOR
conn
ecto
r
CONNECTOR
connector
EC-anode schematic
• First rigid: 24 x 23.7 x 1.5 mm• Flex: 16 x 50 x ? mm• Second rigid: 16 x 55 x 1.5 mm• Rigid parts thickness can be reduced to 1.2 mm• Rigid parts: 6 layers pcb• Flex: 4 layers pcb• Holes for the 14 extensions coming from the EC-dynode: 2 mm large.
EC-anode: dimensions and pins positions
Top layer (gnd)
EC-anode straight: routing
Layer 2
Layer 3
EC-anode straight : routingLayer 4
Layer 5
Bottom layer (gnd)
EC-anode curved : routing
Top layer(gnd)
Layer 2 Layer 3
EC-anode curved : routing
Layer 4 Layer 5 Bottom layer(gnd)
EC-HV
See Andreas Ebersoldt’s review
MAPMT MAPMT
ScrewsColumn
2 options to fixe the EC front to the PDM mechanical structure:• 2 screws and a column (colonnette in French) in between• 1 screw long enough (~ 20 mm)
In both options the initial central column would be removed. This would ease the assembly and potting of the EC front by postponing the fixation of it on the mechanical structure after the potting. But this central column is part of the initial design which stiffness was proved…
Screws would have 2.5 or 3 mm diameter.
EC-front on the mechanical structure
MAPMT
EC-dynode (1.5 mm)
EC-anode (1.5 mm)
EC-HV (1.5 mm)
2.5 mm
~ 3 mm
1mm
(7) Added pins, black plastic is 2.5 mm high
Extensions of the pins
Soldering (0.5 mm)
11 mm
8.5 mm
6.5 mm
NB: PCBs thickness could be reduced to 1.2 mm
MAPMT
EC front assembly
MAPMT
EC-dynode (1.5 mm)
EC-anode (1.5 mm)
EC-HV (1.5 mm)
Soldering (0.5 mm)
EC front assembly sequence
1. Added pins are soldered to the EC-dynode2. MAPMT dynodes cut and soldered to the EC-dynode3. Extensions added to the 14 HV pins coming out of the EC-dynode4. Anode pins cut (if needed) and soldered to the EC-anode5. Extensions pins cut and soldered to the EC-HV
The MAPMT (reminder)
25
• R11265-M64 MAPMT from Hamamatsu.– 64 channels (Anodes)– 12 Dynodes (Dy1 – Dy12), 1 cathode (K) and 1 Guard Ring (GR)
• It is a photo-detector used to sense the UV photons arriving through the lenses. Each one should be equipped with a UV filter bonded with an optical glue
Potting area
Potting must surround the 3 pcbs of the EC-front and the MAPMTs but shouldn’t cover the front of the filters.Potting area
Front part of the filters. They must not be covered with potting.
Cables going out of the potting
MAPMT MAPMT