Sebastian Quednau

In situ synthesis of metallic nanowire arrays for ionization gauge electron sources

An in situ synthesis process for nanowire arrays was used to fabricate a customized field emitter array for use as a nonthermal electron source in an ionization gauge. The wire arrays fabricated with this process had a density of 1.6 × 106 cm−2 using optimized deposition of the wires in template foils on predefined electrodes. The diameter of the wires varied from 100 to 400 nm and their length ranged from 8 to 100 μm. This method can enclose with nanowires a wide area of predefined electrodes, and is possible for areas larger than 3 cm2. Further, the cylindrical shape of the nanowires was modified into a conical geometry to achieve improved thermomechanical stability.

Advanced packaging for future demands

Todays packaging is facing intensified challenges as modern electronic devices seek to combine a larger number number of functions in a tight space in various environments. This results in chip designs determined by more complex circuitries and the use of fine pitch and micro bumps, as well as challenging interconnection properties. Selecting the best suitable interconnection technology is important. This paper gives an overview of advanced connection methods, like vacuum soldering, metal to metal diffusion bonding as well as nanowire bonding, predominantly used for flip chip packaging. During different trials, various dies characterized by high bump count (more than 1 million), fine pitch (down to 15 µm) and small bump diameter (down to 4 µm) were placed on a substrate using a semi-automated flip chip bonder. This whitepaper describes test procedures for these integration technologies and provides information on utilized process parameters and results.

In-place synthesis of metallic nanowire arrays for the use in an ionization vacuum gauge

An in-place synthesis process for nanowires is used to fabricate a customized field emitter array for the use as a non-thermal electron source in an ionization gauge. The fabrication was further expanded to metallic nanocones with a density of 1.6 × 106 cm-2 using optimized deposition of the cones on predefined electrodes. This method can make the wide area of the predefined electrodes enclosed with nanowires with less standard deviation in their height.