Extended thermal cycling of ATLAS ITk strip modules with and without stress mitigating interposers

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Fomin, Nikolai, Hommels, Bart, Ivison, Thomas, Kariyapperuma, Kosala, Liu, Jesse
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866911172873158656
author Fomin, Nikolai
Hommels, Bart
Ivison, Thomas
Kariyapperuma, Kosala
Liu, Jesse
author_facet Fomin, Nikolai
Hommels, Bart
Ivison, Thomas
Kariyapperuma, Kosala
Liu, Jesse
contents This paper investigates critical mechanical failures during stand-alone thermocycling of ATLAS Inner Tracker strip pre-production modules. Five modules undergo extended thermocycling after adequately levelling thermal chucks and introducing interlocks for unattended operation. Module bow evolution is tracked via regular sensor metrology. All five modules exhibit bow increases with a mean of $146\pm 27~μ$m when raising maximum cycling temperatures from $20^\circ$C to $40^\circ$C. Four such modules exhibit sensor fractures when cycled to $-44^\circ$C. A stress-mitigating layer of silicone gel and Kapton film interposer is introduced to three further modules, with detailed quality control data establishing electromechanical viability. No significant bow change of $1\pm 10~μ$m is observed after ten cycles between $[+40, -44]^\circ$C relative to $[+20, -44]^\circ$C. Two interposer modules undergo 200 thermocycles up to $[+56, -44]^\circ$C without fracturing. This decreased sensor deformation and fracturing is interpreted as evidence for reduced thermal stress.
format Preprint
id arxiv_https___arxiv_org_abs_2507_12586
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Extended thermal cycling of ATLAS ITk strip modules with and without stress mitigating interposers
Fomin, Nikolai
Hommels, Bart
Ivison, Thomas
Kariyapperuma, Kosala
Liu, Jesse
Instrumentation and Detectors
High Energy Physics - Experiment
This paper investigates critical mechanical failures during stand-alone thermocycling of ATLAS Inner Tracker strip pre-production modules. Five modules undergo extended thermocycling after adequately levelling thermal chucks and introducing interlocks for unattended operation. Module bow evolution is tracked via regular sensor metrology. All five modules exhibit bow increases with a mean of $146\pm 27~μ$m when raising maximum cycling temperatures from $20^\circ$C to $40^\circ$C. Four such modules exhibit sensor fractures when cycled to $-44^\circ$C. A stress-mitigating layer of silicone gel and Kapton film interposer is introduced to three further modules, with detailed quality control data establishing electromechanical viability. No significant bow change of $1\pm 10~μ$m is observed after ten cycles between $[+40, -44]^\circ$C relative to $[+20, -44]^\circ$C. Two interposer modules undergo 200 thermocycles up to $[+56, -44]^\circ$C without fracturing. This decreased sensor deformation and fracturing is interpreted as evidence for reduced thermal stress.
title Extended thermal cycling of ATLAS ITk strip modules with and without stress mitigating interposers
topic Instrumentation and Detectors
High Energy Physics - Experiment
url https://arxiv.org/abs/2507.12586