— Test board for CBM01B2 baby detectors —

Anton Lymanets & Johann Heuser

CBM collaboration meeting

GSI, 27 February 2008

Microstrip detector testing at GSI

Detector CBM01B2

256 256

orthogonal strips;

50.7 µm pitch;

AC readout;

285 µm thick

Dimensions:

1.56 1.56 cm2

test global detector characteristics

e.g. IV, CV

access both detector sides

contact a few strips for detailed measurements, including n-XYTER readout

do all this as quickly and as simple as possible

Let’s make a test board

Read-out CBM01B2 sensor (“small baby”, 50.7 μm pitch)

Read-out 32 strips in the middle of sensor on both sides

Ultrasonic wedge bonding PCB → sensor

Ordinary line density

Two test zones 1 cm2 each for adjustment of bonding head

Standard ERNI 114805 connector to n-XYTER kit

Test board

PCB: • Standard manufacturing limits • in particular the pitch size of the bonding pads: 200 µm line pitch

Wire bonding: • Max. recommended bond wire

length @ 50 µm pitch: ~ 2.5 mm

• Fan-out bond pattern required.

Max. opening angle: ~ 40 deg

Advice from:

H. Deppe (bonding, PCB)R. Lalik (connection to n-XYTER board)

PCB top side PCB bottom side

100 mm

70 mm

70 m

m

100

mm

pad 10 x 10 mm2

copper with chemical gold

opening for detectorlegs bias pads

SMD 1 M, 4 x total

15.6 mm

"balcony"

15.6

mm

15.0

mm

15.0 mm

1.6 mm

15.6 mm

PCB

bond wire

"balcony"

PCBglue

0.3 mm

detector

0.6

mm

1.0

mm

Opening in PCB for detector mounting

Top view

Side view

4 bias pads

Connector:ERNI model 114805 Dual row, male, type BPins: 68 (unused pins marked red) Height: 8.2 mmSize: ~(6.3×46.3) mm2

Pin pitch: 1.27 mm (both x and y)

Four 1MΩ resistors

http://www.erni.com/smc.htd?gID=4654590

PCB to Si sensor bonding

Pads layout at PCB:Line width: 100 μm 2

(no pads)Pitch: 200 μm

PCB

CBM01B2

Max angle: 51°Max bond length: 3.3 mm

Mechanical mounting of the detector

"balcony"

~ 1.6 mm

~ 1.5 cm

~ 300 µm

"balcony"

PCB PCBglue

bond wire

PCB Layout

Layout made by

P. Skott

Metal support structure to support PCB and sensor during bonding

100

12 50

120

Conclusions & work plan

Design finished, Layout finished

Production @ ILFA, Hannover: ongoing

(incl. gold plating, machining of hole) Weeks 8, 9, 10 2008

Al bonding fixture: to be manufactured

Setup of testing station in C27 (Power supply, etc.)