n-XYTER Hybrid Developments Christian J. Schmidt et al., GSI Darmstadt JINR, Dubna, Oct. 15 th 2008

C.J. Schmidt at the 12th CBM Collaboration Meeting, Dubna, Oct. 15th 2008 n-XYTER, current workhorse chip for prototyping workhorse readout chip for detector prototyping architectural example front-end for DAQ development (self triggered, data driven) sample ASIC for technological front-end electronics hybrid developments bonding technology, circuit board technology thermal management, active cooling concepts power management (integraly high currents, low voltage, high B-fields, high rad. environment) very dense mechanical boundary conditions

C.J. Schmidt at the 12th CBM Collaboration Meeting, Dubna, Oct. 15th 2008 "Simple" FEB for the n-XYTER Starter Kit A simple hybrid PCB with signal fan-in, ADC and interconnect to SysCore DAQ chain Allow development of the DAQ chain Allow the readout of various detector prototypes Allow to explore the challenges of hybrid development The September beam time has shown the whole signal chain operative! Silicon Strip / GEM Gas Detectors --- n-XYTER --- SysCore DAQ System

C.J. Schmidt at the 12th CBM Collaboration Meeting, Dubna, Oct. 15th 2008 n-XYTER FEB: At the limits of PCB-technology Chip-In-Board solution avoids space eating vias allows pitch adaptation: 50,7 µm on chip to PCB side 101,4 µm on two levels Interference point of many technologies, each imposing limiting boundary conditions:

C.J. Schmidt at the 12th CBM Collaboration Meeting, Dubna, Oct. 15th 2008 n-XYTER FEB: At the limits of PCB-technology 100 µm pitch on PCB is at the limit of PCB technology! landing area for bonds comes out much smaller than 50 µm high yield wire bonding technology finds limits at ~65 µm landing space Chip-In-Board technologically impeeds use of cooling vias Unplugged vias spoil bonding structures Plugged vias spoil bonding surface quality Current Solution: Macroscopic metal inlay underneath the chip realized after PCB manufacturing will give thermal link to cooling infrastructure FEB-Rev B FEB-Rev C  Realize 125 µm pitch on PCB at the expense of more complicated fan-out bonding with Chip-In-Board, two layer bonding and metal in-lay cooling contact  FEB-Rev D

C.J. Schmidt at the 12th CBM Collaboration Meeting, Dubna, Oct. 15th 2008 It is all a question of yield! PCB-Technology 50µ / 50µ shatteres yield close contact to manufacturer special solutions (Chip in Board) metal inlay solution Wire Bonding Technology: Maximum bond length ~ 4 mm Staggered fan-out complicates bonding Bonding machine determines specs on dimensions of landing space Home made issues: -- Cooling strategy: Wire bonds demand cooling from below Flip-Chip bump bonds may allow cooling from either side -- Limitations on Orcad layout tool -- On Chip bond-pad layout

C.J. Schmidt at the 12th CBM Collaboration Meeting, Dubna, Oct. 15th 2008 n-XYTER FEB Prototype - GEM-TPC for PANDA  Dimensions: 265 x 103 mm  8 layers Board status: in production Slide by Rafal Lalik Application foreign to CBM, but high density gas detector read-out, just like CBM-MUCH First large scale application of n-XYTER: 92 chips on 46 boards. Beam time for the TPC at FoPi: End of 2009

C.J. Schmidt at the 12th CBM Collaboration Meeting, Dubna, Oct. 15th 2008 n-XYTER Quattro  4 n-XYTERs on one PCB  100 x 100 mm 2  8 layers  SysCore read-out  complicated mechanical milling scheme Status: In production at ILFA ! Integrated double sided Silicon Baby Sensor Readout Slide by Rafal Lalik

C.J. Schmidt at the 12th CBM Collaboration Meeting, Dubna, Oct. 15th 2008 STS specific hybrid developments Hybrid for STS Ladder Modules Combined challenges with high density chip assembly needs sensitive microcable detector interconnect integrated cooling integrated powering scheeme in high magnetic fields and rad. env. Temptatively, a completly different technology comes into play: Silicon based circuit board flip chip assembly of XYTERs high efficiency cooling contacts and hybrid stackability tap bonding for micro-cables (V. Pugatch, Kiev) separated potential domain for upper and lower side det. readout

C.J. Schmidt at the 12th CBM Collaboration Meeting, Dubna, Oct. 15th 2008 Two development lines to be discussed: STS module based on n-XYTER and PCB technology primarily to show micro cable performance 4 to 8 chip hybrid, preferably dual side readout STS module based on n-XYTER and compact flip-chip technology, Silicon circuit board serves as efficient cooling contact (cooling from both sides) pitch adapter to the micro cables Precise project definition and distribution of workpackages still to be done, GSI Detectorlab signed up for hybrid development (we will have a new electronics engineer starting in December) so we should now start this discussion

C.J. Schmidt at the 12th CBM Collaboration Meeting, Dubna, Oct. 15th 2008

C.J. Schmidt at the 12th CBM Collaboration Meeting, Dubna, Oct. 15th 2008