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