Bachelorthesis/Masterthesis/Project with seminar

Topic: Development and investigation of two-layer “LTCC-sol-gel thin film” structures

The methods for preparing LTCC after sintering are based on the processes of polishing and lapping. These processes are used to create the required thickness tolerance and parallelism for thin film processes. However, at the same time, polishing / lapping led to the opening of the pores contained in the bulk of the ceramic substrates. In order to remove pores and smooth the surface, inorganic layers with a dense structure are applied to the substrates.

In this work, the effect of sol-gel coating of LTCC on the quality of its surface will be investigated.

The basic research steps:

  1. Preparation of substrates before sol-gel spin-coating process:
    1. Cleaning process
    2. investigation of physical parameters of pure substrate before coating (LSM, AFM, SEM)
  2. Application variation of spin-coating method, and sintering parameters to optimize the layer quality
  3. Study of physical parameters of obtained composite structures (LSM, AFM, SEM)
 

Contact:Dr. Kateryna Soloviova, Tel. 03677 69-3440


 
 

Topic: Creating an ordered array of Si nanopillars (Project with seminar/Bachelor or Master thesis)

Lithography and etching are two main procedures in creating microstructures. The task here is to create defined arrays of Si nanopillars with a MLA150 maskless aligner and reactive ion etching (RIE). Different densities and heights of the pillars must be planned and produced. A good documentation is mandatory. These structures shall later be used for reaction tests with Al/Ni multilayer.

  1. Preparing masks in AutoCad, Klayout or similar program, with three different structure densities
  2. Etching the masked wafer with RIE
    - Testing different process times - Measuring structure height with scanning electron microscope

Contact: M. Sc. Konrad Jaekel, ZMN206, Tel. 03677 69-3429


 

Topic: Investigation of the stability of a black silicon process (Project with seminar)

Silicon etching can result in creating a surface modification called black silicon, which is mostly used in the photovoltaic industry. Here these structures are already produced and scanning electron microscope (SEM) images from top-view and cross-section are already present. The task is the analysis of the images with image pre-processing and different image processing tools, searching for knowledge of the process reliability.

  1. Pre-processing SEM images
  2. Using image segmentation like watershed method in e.g.: MatLab, python or gwyddeon
  3. Visualization and analysis of the results
  4. Final statement about the process deviation
 

Contact: M. Sc. Konrad Jaekel, ZMN206, Tel. 03677 69-3429


 

The electrical and geometrical investigation of through ceramic micro-via (TCµV) (Project with seminar)

The fabrication of multilayered high-resolution structures requires the development of miniaturized conductive vias to electrically connect the structures in different ceramic layers.

The creation of lasered miniaturized vias is simple, however, the challenge is presented in succeeding a high density filled microvias on different stacking levels. The aim of this project with seminar is the electrical and geometrical investigation of stacked micro-vias.

For this purpose, the following subtasks are to be solved:

  • The alignment and stacking of levelled microvias in different subsequential layers
  • The geometrical analysis of miniaturized conductive vias in LTCC substrates
  • The electrical investigation of the filled vias (comparing the electrical behaviour of the through ceramic conductive vias to a patterned in ceramic conductors)
 

We expect very good professional performance in studies, above-average commitment and willingness to learn.

We offer an interesting job in a motivated, interdisciplinary team. If you are curious, I look forward to a personal conversation.

 

Contact: M. Sc. Nesrine Jaziri, Kirchhoffbau room 1051, Tel. 03677 69-1117


 

The fabrication and characterization of thick/thin films-based thermoelectric generators under LTCC technology (Project with Seminar/Master Thesis)

Thermoelectric generators (TEGs) are presenting an outstanding performance for converting thermal into electrical energy. TEGs are used in many sectors from low to high power applications. Low temperature cofired ceramics (LTCC) technology presents aplenty of advantages for the TEG systemsfrom manufacturing multilayered TEGs to presenting low thermal conductivity of the ceramic tapes, the ability of coherent packaging, and the high-volume integration of complex systems. LTCC technology is also known for its reliability, good compatibility with integrated passive devices, and working in high temperatures compared to other technologies. The aim of this project with seminar, that can also be a master thesis with further tasks, is the fabrication and characterization of a thick/thin films-based thermoelectric generators under LTCC technology. For this purpose, the following subtasks are to be solved:

  • Characterization of Boron thermal and electrical properties for different doping rates using Scanning Electron Microscope (SEM), Laser Scanning Microscope (LSM) and Thin Film Analyzer (TFA) from LINSEIS.
  • The creation of two points measurements structures to electrically characterize the doped Boron (second approach than TFA).
  • The geometrical characterization and electrical measurements of the Silver/Boron planar thermoelectric generators
 

We expect very good professional performance in studies, above-average commitment and willingness to learn.

We offer an interesting job in a motivated, interdisciplinary team. If you are curious, I look forward to a personal conversation.

 

Contact: M. Sc. Nesrine Jaziri,Kirchhoffbau room 1051,Tel. 03677 69-1117


 

Development of an alignment technique for combining miniaturized conductor lines and vias (Project with seminar/Master thesis)

LTCC are used in several applications such as microwave, RF and satellite communications, which can involve composite miniaturized systems [1]. For this purpose, the conducting patterns and vias are miniaturised, however a suitable technique for their alignment is crucial. In this work, a combination of high-resolution patterns with laser drilled miniaturized vias will be developed. The tasks are divided in the following steps:

  • Design optimization of thick/thin film technologies for miniaturized conductor lines and vias using AutoCAD
  • Identifying and investigating a technique for aligning the lines to the vias
  • Inspecting the accuracy and precision of the alignment of the vias to the lines using (SEM/optical microscope/ LSM)

[1] Schulz, A., Gutzeit, N., Stöpel, D., Welker, T., Hein, M. and Müller, J., 2016, March. High resolution patterning of LTCC based microwave structures for Q/V-band satellite applications. In 2016 German Microwave Conference (GeMiC)(pp. 19-22). IEEE.

Contact: Dr.-Ing. Shraddha Supreeti, Kirchhoffbau room 1052, Tel. 03677 69-3650


Design, modelling and simulation of heat dissipation structures for VCSEL array (Project with seminar/Master thesis)

Vertical-cavity surface-emitting laser (VCSEL) arrays have been gaining interest in different areas such as space communication, biomedical and gas sensing, gesture recognition and more, due to several advantages [1]. The dissipation of heat generated by the VCSEL arrays play a crucial role in effective and efficient functioning of the arrays. In this work, the effect of heat dissipation structures for VCSEL array, on a LTCC carrier will be analysed. It will consist of the following tasks:

  • Study different methods/structures for heat dissipation on LTCC
  • Design, model and simulate the heat dissipation components using FEM (ANSYS/COMSOL)
  • Analyse and summarise the simulation results of the different structures

[1] Wang, C., Li, C., Dai, J., Lan, T., Zhou, G., Meng, J. and Wang, Z., 2019. Thermal analysis of VCSEL arrays based on first principle theory and finite element method. Optical and Quantum Electronics, 51(6), pp.1-14.

Contact: Dr.-Ing. Shraddha Supreeti, Kirchhoffbau room 1052, Tel. 03677 69-3650