— 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 cm 2

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 cm 2 each for adjustment of bonding head Standard ERNI 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 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 100 mm pad 10 x 10 mm 2 copper with chemical gold opening for detector legs bias pads SMD 1 M , 4 x total

15.6 mm "balcony" 15.6 mm 15.0 mm 1.6 mm 15.6 mm PCB bond wire "balcony" PCB glue 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 Dual row, male, type B Pins: 68 (unused pins marked red) Height: 8.2 mm Size: ~(6.3×46.3) mm 2 Pin pitch: 1.27 mm (both x and y) Four 1MΩ resistors

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 glue bond wire

PCB Layout Layout made by P. Skott

Metal support structure to support PCB and sensor during bonding

Conclusions & work plan Design finished, Layout finished ILFA, Hannover: ongoing (incl. gold plating, machining of hole) Weeks 8, 9, Al bonding fixture: to be manufactured Setup of testing station in C27 (Power supply, etc.)