Papers by Jaroslaw Kaczynski
Proceedings of the ... International Symposium on Microelectronics, Mar 7, 2024
TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk, 1998
ECS Journal of Solid State Science and Technology
Bump-less copper (Cu) bonding is currently the most attractive approach for fine-pitch (< 20 µ... more Bump-less copper (Cu) bonding is currently the most attractive approach for fine-pitch (< 20 µm) 3D integration due to its compatibility with the wafer back-end-of-the-line fabrication process. In this study, themocompression bonding of bump-less Cu pads with a diameter of 4 µm and a pitch size of 10 µm was pursued, while chemical mechanical polishing (CMP)-processed Cu pads enclosed in SiO2 were employed with both protruded and recessed topographies. The effects of Cu topography (protruded or recessed) and bonding temperature on the electrical and microstructural properties of the die bonds as well as mechanical bonding strength were investigated. It was found that thermocompression bonding of CMP-processed Cu can be realized at shorter processing times, lower bonding temperatures, and pressures than standard electroplated Cu bonding. The bonding yield of the three configurations, i.e. protruded-protruded, protruded-recessed, and recessed-recessed Cu pads was also compared.
Flexible and Printed Electronics
Stretchable printed electronics have recently opened up new opportunities and applications, inclu... more Stretchable printed electronics have recently opened up new opportunities and applications, including soft robotics, electronic skins, human-machine interfaces, and healthcare monitoring. Stretchable Hybrid systems (SHS) leverage the benefits of low-cost fabrication of printed electronics with high-performance silicon technologies. However, direct integration of silicon-based devices on conventional stretchable substrates such as thermoplastic polyurethane (TPU) and polydimethylsiloxane (PDMS) is extremely challenging due to their restricted low-temperature processing. In this study, a recently developed thermoset, stretchable substrate (BeyolexTM) with superior thermal and mechanical properties was employed to realize HSS via direct flip chip bonding. Here, ultra-thin chips (UTC) with a fine-pitch, daisy-chain structure was flip-chip bonded by using anisotropic conductive adhesives, while the complementary circuitry was facilitated via screen-printed, stretchable silver tracks. The...
Transactions of the Institute of Fluid-Flow Machinery, 2017
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
A good thermal performance of a PCB depends on the amount of copper planes in a stack and the num... more A good thermal performance of a PCB depends on the amount of copper planes in a stack and the number of thermal vias used in a thermal pad underneath a power device. The PCB designer has the task to develop a layout that works properly and also is as cheap as possible in the production process. At the starting point often it is not known how many layers will be necessary, but based on the knowledge of power dissipation and the thermal specifications of the assembled components a rough estimation on the thermal performance of the whole module is given. To give the engineer the possibility to get an idea how many layers or thermal vias are necessary in advance, a 3D simulation model is developed and presented in this paper. It shows the influence on the thermal resistance of the PCB if making different adjustments and also points out which reduction can be achieved with each step. Finally the strategy is described how to start optimizing such a design and what to do next.
Sensors and Actuators A-physical, 2020
In this work an analytical model for the flow resistance for viscous air damping in a MEMS struct... more In this work an analytical model for the flow resistance for viscous air damping in a MEMS structure comprising a perforated plate in close proximity to a solid plate is developed. Such a configuration is widely used for oscillating MEMS sensors and actuators. It was shown that in addition to the resistance caused by the perforation hole and by squeeze film damping between the two plates, an additional resistance in the intermediate region caused by the redirection of the flow between the perforation hole region and the squeeze film region also has to be considered. The overall flow resistance is the sum of the flow resistance of several regions. The models for the individual regions have been derived analytically for the squeeze film damping and using numerical solutions of the Navier-Stokes equation for the perforation hole and the intermediate region. The validity of the derived damping model is limited to cases where the Knudsen number is smaller than 0.1 , the porosity is small...
Introduction Condensation particle counters (CPC) are widely used in science and industry for mea... more Introduction Condensation particle counters (CPC) are widely used in science and industry for measuring particle number concentrations. The condensation nuclei magnifier (CNM) is the part of the CPC where the actual particle growth happens. This work deals with an approach for a CNM operating at around 150 200 °C (HT-CNM) for engine exhaust. On one hand this concept prevents formation of artefacts in the aerosol stream caused by dilution and heating and on the other hand the effort of aerosol preconditioning will be minimized. The main application field are defiled aerosols, in particular automotive exhaust gases, but such devices are also of interest for interference-free measurement of aerosols e.g. in highly humid environments.
Energies, 2021
Copper sinter paste has been recently established as a robust die-attach material for high -power... more Copper sinter paste has been recently established as a robust die-attach material for high -power electronic packaging. This paper proposes and studies the implementation of copper sinter paste materials to create top-side interconnects, which can substitute wire bonds in power packages. Here, copper sinter paste was exploited as a fully printed interconnect and, additionally, as a copper clip-attach. The electrical and thermal performances of the copper-sinter paste interconnections (“sinterconnects”) were compared to a system with wire bonds. The results indicate comparable characteristics of the sinterconnect structures to the wire-bonded ones. Moreover, the performance of copper sinterconnects in a power module was further quantified at higher load currents via finite element analysis. It was identified that the full-area thermal and electrical contact facilitated by the planar sinterconnects can reduce ohmic losses and enhance the thermal management of the power packages.
2021 23rd European Microelectronics and Packaging Conference & Exhibition (EMPC)
Microelectronic Engineering
Microelectronic Engineering
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Papers by Jaroslaw Kaczynski