The Effect of Encapsulation Geometry on the Performance of Stretchable Interconnects

The stretchability of electronic devices is typically obtained by tailoring the stretchable interconnects that link the functional units together. The durability of the interconnects against environmental conditions, such as deformation and chemicals, is therefore important to take into account. Dif...

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Main Authors: Mahmoud Mosallaei, Jarno Jokinen, Mikko Kanerva, Matti Mäntysalo
Format: Article
Language:English
Published: MDPI AG 2018-12-01
Series:Micromachines
Subjects:
Online Access:https://www.mdpi.com/2072-666X/9/12/645
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author Mahmoud Mosallaei
Jarno Jokinen
Mikko Kanerva
Matti Mäntysalo
author_facet Mahmoud Mosallaei
Jarno Jokinen
Mikko Kanerva
Matti Mäntysalo
author_sort Mahmoud Mosallaei
collection DOAJ
description The stretchability of electronic devices is typically obtained by tailoring the stretchable interconnects that link the functional units together. The durability of the interconnects against environmental conditions, such as deformation and chemicals, is therefore important to take into account. Different approaches, including encapsulation, are commonly used to improve the endurance of stretchable interconnects. In this paper, the geometry of encapsulation layer is initially investigated using finite element analysis. Then, the stretchable interconnects with a narrow-to-wide layout are screen-printed using silver flake ink as a conductor on a thermoplastic polyurethane (TPU) substrate. Printed ultraviolet (UV)-curable screen-printed dielectric ink and heat-laminated TPU film are used for the encapsulation of the samples. The electromechanical tests reveal a noticeable improvement in performance of encapsulated samples compared to non-protected counterparts in the case of TPU encapsulation. The improvement is even greater with partial coverage of the encapsulation layer. A device with a modified encapsulation layer can survive for 10,000 repetitive cycles at 20% strain, while maintaining the electrical and mechanical performance.
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spelling doaj.art-11974eeb0c474ed78832dc48b4218e742022-12-22T00:05:00ZengMDPI AGMicromachines2072-666X2018-12-0191264510.3390/mi9120645mi9120645The Effect of Encapsulation Geometry on the Performance of Stretchable InterconnectsMahmoud Mosallaei0Jarno Jokinen1Mikko Kanerva2Matti Mäntysalo3Laboratory of Electronics and Communications Engineering, Faculty of Computing and Electrical Engineering, Tampere University of Technology, 33720 Tampere, FinlandLaboratory of Materials Science, Faculty of Engineering Sciences, Tampere University of Technology, 33720 Tampere, FinlandLaboratory of Materials Science, Faculty of Engineering Sciences, Tampere University of Technology, 33720 Tampere, FinlandLaboratory of Electronics and Communications Engineering, Faculty of Computing and Electrical Engineering, Tampere University of Technology, 33720 Tampere, FinlandThe stretchability of electronic devices is typically obtained by tailoring the stretchable interconnects that link the functional units together. The durability of the interconnects against environmental conditions, such as deformation and chemicals, is therefore important to take into account. Different approaches, including encapsulation, are commonly used to improve the endurance of stretchable interconnects. In this paper, the geometry of encapsulation layer is initially investigated using finite element analysis. Then, the stretchable interconnects with a narrow-to-wide layout are screen-printed using silver flake ink as a conductor on a thermoplastic polyurethane (TPU) substrate. Printed ultraviolet (UV)-curable screen-printed dielectric ink and heat-laminated TPU film are used for the encapsulation of the samples. The electromechanical tests reveal a noticeable improvement in performance of encapsulated samples compared to non-protected counterparts in the case of TPU encapsulation. The improvement is even greater with partial coverage of the encapsulation layer. A device with a modified encapsulation layer can survive for 10,000 repetitive cycles at 20% strain, while maintaining the electrical and mechanical performance.https://www.mdpi.com/2072-666X/9/12/645encapsulationfinite element analysisprinted electronicsscreen printingstretchable interconnects
spellingShingle Mahmoud Mosallaei
Jarno Jokinen
Mikko Kanerva
Matti Mäntysalo
The Effect of Encapsulation Geometry on the Performance of Stretchable Interconnects
Micromachines
encapsulation
finite element analysis
printed electronics
screen printing
stretchable interconnects
title The Effect of Encapsulation Geometry on the Performance of Stretchable Interconnects
title_full The Effect of Encapsulation Geometry on the Performance of Stretchable Interconnects
title_fullStr The Effect of Encapsulation Geometry on the Performance of Stretchable Interconnects
title_full_unstemmed The Effect of Encapsulation Geometry on the Performance of Stretchable Interconnects
title_short The Effect of Encapsulation Geometry on the Performance of Stretchable Interconnects
title_sort effect of encapsulation geometry on the performance of stretchable interconnects
topic encapsulation
finite element analysis
printed electronics
screen printing
stretchable interconnects
url https://www.mdpi.com/2072-666X/9/12/645
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