Master’s Thesis: Phase-Contrast X-ray Imaging of Advanced Semiconductor Packages

Do you want to help reveal what conventional X-ray imaging cannot see? Excillum develops the world’s brightest laboratory X-ray

sources, and we are looking for a master’s student in physics, electrical engineering, applied mathematics or a similar field who

is excited about X-ray phase-contrast imaging, advanced semiconductor packaging and experimentation.

About Excillum

At Excillum, we push the boundaries of X-ray technology to enable breakthroughs in manufacturing, medicine and science. Our

advanced X-ray sources enhance the manufacturing of semiconductors, batteries, electronics and aerospace components, as well as

enable new biomedical and material sciences. They make our customers’ X-ray systems faster and better with lower cost of

operation.

Founded in 2007 by researchers from KTH, Excillum has grown into a global leader in advanced microfocus and nanofocus X-ray

sources. Today, our products are used by leading industrial companies, instrument manufacturers and research institutions around

the world.

About the project

X-ray phase-contrast imaging can improve the visibility of low-density features that produce weak absorption contrast. Used in

fields such as medical soft-tissue imaging and materials science, it exploits phase shifts caused by the refractive index of

different materials in the sample, complementing conventional absorption-based contrast.

Advanced packaging is a key technique improving the performance of modern electronic components. Next-generation high-end chips

incorporate co-packaged optics, silicon photonics and waveguides for data transmission, as well as glass substrates.

Thermal-interface materials are another important type of low-density feature in advanced packages. Non-destructive inspection of

these structures remains challenging, and high-resolution phase-contrast imaging may offer a solution. However, metal layers and

interconnects can strongly attenuate the low-energy X-rays required for phase contrast, creating a trade-off between sensitivity

to low-density features and penetration through the package.

This thesis will evaluate the feasibility of using 3D X-ray phase-contrast imaging with nano-CT and/or laminography to inspect

low-density structures in advanced electronic packages. Simulations will first assess feasibility and optimise our in-house

imaging system. The most promising conditions will then be tested in a proof-of-concept experiment, with the possibility to

perform further measurements if time permits.

What you will do

• Review the benefits and limitations of different X-ray phase-contrast imaging methods

Who you are

You are a master’s student in physics, electrical engineering, applied mathematics or a similar field, with a genuine interest in

X-ray physics and simulation. You enjoy turning physics into models, and models into tools that others can use. To succeed in this

project, we believe you have:

• Compensation: SEK 15,000 halfway through the project and an additional SEK 15,000 upon successful completion. Excillum also

covers project-related expenses such as travel and materials.

Apply

To apply, please submit your CV, a cover letter and a copy of your academic transcripts.

We look forward to your application! If you have any questions regarding the thesis, do not hesitate to contact Hugo Högberg West

at hugo.hogberg@excillum.com.