Publications

Abstract not provided.

As electronic and optical components reach the micro- and nanoscales, efficient assembly and packaging require the use of adhesive bonds. This work focuses on resolving several fundamental issues in the transition from macro- to micro- to nanobonding. A primary issue is that, as bondline thicknesses decrease, knowledge of the stability and dewetting dynamics of thin adhesive films is important to obtain robust, void-free adhesive bonds. While researchers have studied dewetting dynamics of thin films of model, non-polar polymers, little experimental work has been done regarding dewetting dynamics of thin adhesive films, which exhibit much more complex behaviors. In this work, the areas of dispensing small volumes of viscous materials, capillary fluid flow, surface energetics, and wetting have all been investigated. By resolving these adhesive-bonding issues, we are allowing significantly smaller devices to be designed and fabricated. Simultaneously, we are increasing the manufacturability and reliability of these devices.

Silane adhesion promoters are commonly used to improve the adhesion, durability, and corrosion resistance of polymer-oxide interfaces. The current study investigates a model interface consisting of the natural oxide of 100 Si and an epoxy cured from diglycidyl ether of bisphenol A (DGEBA) and triethylenetetraamine (TETA). The thickness of (3-glycidoxypropyl)trimethoxysilane (GPS) films placed between the two materials provided the structural variable. Five surface treatments were investigated: a bare interface, a rough monolayer film, a smooth monolayer film, a 5 nm thick film, and a 10 nm thick film. Previous neutron reflection experiments revealed large extension ratios (>2) when the 5 and 10 nm thick GPS films were exposed to deuterated nitrobenzene vapor. Despite the larger extension ratio for the 5 nm thick film, the epoxy/Si fracture energy (G{sub c}) was equal to that of the 10 nm thick film under ambient conditions. Even the smooth monolayer exhibited the same G{sub c}. Only when the monolayer included a significant number of agglomerates did the G{sub c} drop to levels closer to that of the bare interface. When immersed in water at room temperature for 1 week, the threshold energy release rate (G{sub th}) was nearly equal to G{sub c} for the smooth monolayer, 5 nm thick film, and 10 nm thick film. While the G{sub th} for all three films decreased with increasing water temperature, the G{sub th} of the smooth monolayer decreased more rapidly. The bare interface was similarly sensitive to temperature; however, the G{sub th} of the rough monolayer did not change significantly as the temperature was raised. Despite the influence of pH on hydrolysis, the G{sub th} was insensitive to the pH of the water for all surface treatments.

Abstract not provided.

Abstract not provided.