Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-26T08:03:09.834Z Has data issue: false hasContentIssue false

Stability and properties of PET Films in Electronics Applications in Hygrothermal Environments

Published online by Cambridge University Press:  29 July 2016

Laura Frisk*
Affiliation:
Department of Electrical Engineering, Tampere University of Technology, P.O.Box 692, 33101 Tampere, Finland
Sanna Lahokallio
Affiliation:
Department of Electrical Engineering, Tampere University of Technology, P.O.Box 692, 33101 Tampere, Finland
Janne Kiilunen
Affiliation:
Department of Electrical Engineering, Tampere University of Technology, P.O.Box 692, 33101 Tampere, Finland
Kirsi Saarinen-Pulli
Affiliation:
Department of Electrical Engineering, Tampere University of Technology, P.O.Box 692, 33101 Tampere, Finland
*
Get access

Abstract

Polyethylene terephthalate (PET) is an interesting flexible substrate material for many applications in electronics since it is inexpensive and has good mechanical and electrical properties. Due to these good properties there is increasing interest in using PET in applications involving harsh environments. However, PET has relatively poor thermal properties, which may cause reliability concerns in demanding conditions. Above its glass transition temperature, Tg, PET is susceptible to hydrolysis, which may considerably restrict its use. Hydrolysis breaks the molecular structure of PET and makes the material mechanically unreliable. This paper reports the reliability of PET films in an LCD display application and in RFID tags in thermal and humid conditions. Additionally, neat PET films were studied. Several thermal cycling and humidity tests were used. The results clearly showed that above the Tg of PET the combined effect of humidity and high temperature caused PET to become brittle leading to considerable reliability problems. However, in dry thermal cycling conditions and in humid conditions below the Tg of PET, the reliability of PET was found to be excellent even under prolonged exposure.

Type
Articles
Copyright
Copyright © Materials Research Society 2016 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Chou, B. et al, “Multilayer High Density Flex Technology”, Proceedings of 49th IEEE Electronic Components and Technology Conf., San Diego, CA, USA, (1999), pp.1181–9.Google Scholar
Frisk, L. and Cumini, A.. “Effect of Substrate Material and Thickness on Reliability of ACA Bonded Flip Chip Joints”, Solder Surf MT Tech, Vol. 21, No. 3, 2009 pp. 1523.Google Scholar
Harper, C., High Performance Printed Circuit Boards, McGraw-Hill, (2000) p. 5.1-38.Google Scholar
Coombs, C., Coombs’ Printed Circuits Handbook, 5th edition, McGraw-Hill (2001), p.56.3-22Google Scholar
Sammon, C. et al. , “An FT–IR study of the effect of hydrolytic degradation on the structure of thin PET films”, Polymer Degradation and Stability, Vol. 67, No 1, (2000), pp.149–58.Google Scholar
Saarinen, K. et al. , “Reliability Analysis of RFID Tags in Changing Humid Environment” IEEE Trans. Compon. Packag. Manuf. Technol., Vol. 4 No. 1, 2014, pp. 7785.CrossRefGoogle Scholar
Saarinen, K. and Frisk, L., “Reliability Analysis of UHF RFID Tags under a Combination of Environmental Stresses”, IEEE Trans. Device Mater. Rel., Vol. 13, No.1, 2013, pp. 119–25.Google Scholar
Saarinen, K. and Frisk, L., “Reliability of UHF RFID tags in humid environments” 14th Electronics Packaging Technology Conf. (EPTC 2012), 5.-7.12.2012. Singapore.Google Scholar
Lahokallio, S. et al. , “Effects of different test profiles of temperature cycling tests on the reliability of RFID tags”, Microelectron Reliab, Vol. 55, no. 1, 2015, pp. 93100.Google Scholar
Kiilunen, J. and Frisk, L., “Hygrothermal Aging of an ACA Attached PET Flex-on-Board Assembly”, IEEE Trans. Compon. Packag. Manuf. Technol, Vol. 4 No. 2, 2014, pp. 181–9.CrossRefGoogle Scholar
Kiilunen, J. and Frisk, L., “Reliability analysis of an ACA attached flex-on-board assembly for industrial application”, Solder Surf MT Tech, Vol. 26, No.2, 2014, pp.6270.CrossRefGoogle Scholar
Lahokallio, S. et al. , “Effect of High Humidity Testing on Material Parameters of Flexible Printed Circuit Board Materials”, J. Electron. Mater., Vol. 42, No. 9, pp. 28222834, 2013.Google Scholar
Alves, N. et al. “Glass transition and structural relaxation in semi-crystalline poly(ethylene terephthalate): a DSC study”, Polymer, Vol 43, No. 15, 2002, 4111–22.Google Scholar