The role of adhesion layers on the interfacial reliability of multilayer insulators
Research output: Thesis › Master's Thesis
Flexible metal-polymer multilayer structures are essential components in present and future space applications such as multilayer insulators (MLI). The metal-polymer interfaces represent a weak interface in these materials as they connect the adjacent materials that exhibit vastly different physical and chemical properties. Adhesion is therefore, strongly tied to the overall reliability of the material system and its lifetime. 200 nm and 900 nm Ag films on Kapton and polyethylene naphthalate substrates with and without Ti adhesion interlayers were studied with regards to the Ag thickness, substrate and Ti-interlayer effect on adhesion strength and damage evolution. Before adhesion testing, a pre-characterization of the material with in-situ fragmentation in order to assess damage evolution showed primarily thickness effects. Thicker (900 nm) Ag layers resulted in less damage than thinner Ag layers (200 nm). For adhesion tensile induced delamination, a method with a Mo stressed overlayer was used. The results of adhesion testing revealed the detrimental effect of a Ti interlayer on the adhesion energy of 200 nm Ag films on both Kapton and polyethylene naphthalate. X-ray Photoelectron Spectroscopy interface chemistry characterization was used to quantitatively assess the chemical composition of interface of 200 nm Ag films on PEN substrates with and without Ti interlayer. The findings of this thesis show that the presence of adhesion interlayers does not necessarily improve the adhesion and that interlayers can be excluded from future MLIs. The findings also have further implications for flexible electronics and other metal-polymer systems.
|Translated title of the contribution||Die Rolle von Adhäsionsschichten bezüglich der Interface auf die Zuverlässigkeit von Multischicht-Isolatoren|
|Award date||28 Jun 2019|
|Publication status||Published - 2019|