Postdoc - Design of multi-materials electronic components for high temperature applications

We are looking for a highly motivated postdoctoral researchers for building together innovative projects to apply for Marie-Sklodowska Curie European Fellowships to the next call (September 2018). MSCA-EF are prestigious fellowships funded by the European Commission. They offer a rare opportunity to talented scientists: the chance to set up research programmes of their own. They provide an attractive grant for 1 to 2 years including salaries (around 2500€ net per month, with social care included) and allowances for mobility, family and research.

The topic and team below have been identified for welcoming you to develop your research project at UBS and helping you to write a winning proposal for the European submission in September.

General description of the project:

Keywords: Thermo-mechanical behavior; experimental mechanics; copper alloys; electronic packaging

 

Project context

The general framework of this project is the thermo-mechanical assessment of the set made of electronic packaging and metallic frame which is the core of vehicle electrification. Indeed, there is an active trend in the automotive industry to shift from mechanical to electrical power, to reduce fuel consumption. However, to intensify this trend, a higher amount of electrical power is demanded, leading to higher temperature of the functioning components. Such components are usually made of a metallic frame, in copper alloys with only one material or co-laminates [1], that integrates the electrical connections and supports the chip. Then, out of protection’s sake, a polymer packaging is injected to cover the frame, the chip and the connections. The bonding between the polymer and the metal is a key point in the performance and the durability of the electronic component, that undergoes high temperature and vibrations during service life.

 

Objectives

The aim of this project is to assess the quality of the bonding between the metallic frame and the polymer protective packaging, as a function of temperature. The metallic frame is formed in several steps, that consist of cutting and eventually bending. The surface roughness of the frame is dependent on plastic deformation [2] and can also be further modified by dedicated mechanical or chemical treatments. Moreover, the increase of temperature can lead to a degradation of the bonding properties. This project is focused on the experimental investigation and numerical simulation of the whole component, including the forming steps [3], the polymer injection step and in service behavior, especially with regards to the bonding quality. The mechanical behavior of the polymer is highly dependent on service life temperature, that tends to increase due to the technical spcecifications.

 

Approach

Several aspects are considered in this project. First of all, an experimental investigation of the surface roughness of the metallic frame must be performed, as a function of the plastic deformation. Then, the quality of the bonding metal/polymer is investigated with specific tests, as a function of temperature and surface roughness. Such a quality should be assessed both at microscopic and macroscopic scales. Indeed, micro-cracks and local delamination should affect significantly the durability of the component. And the global macroscopic characterization should give the maximum load at which failure occurs. A combined experimental-numerical approach is proposed, to lead to the development of a virtual component representative of the real one. As a broader issue, fatigue loadings and vibrations should be also taken into account.

 

Facilities

The host research laboratory has experimental facilities to investigate the mechanical behavior (tensile machines with maximum capacity ranging from  1 kN up to 500 kN, scanning electron microscope. As well as computer facilities.

 

References

[1] Fekiri H, Esin V A, Maurel V, Köster A and Bienvenu Y 2018 Mater. Design 137 68-78

[2] Phan C H, Thuillier S, Manach P Y 2015 Metall. Mater. Trans. A 46A 3502-3515

[3] Adzima F, Balan T, Manach P Y, Bonnet N and Tabourot L 2017 Int. J. Plasticity 97 171-191

MSCA-EF are prestigious fellowships funded by the European Commission. They offer a rare opportunity to talented scientists: the chance to set up research programmes of their own. They provide an attractive grant for 1 to 2 years including salaries and allowances for mobility, family and research

Applicants must be «Experienced Researchers» (i.e. by the time of the MSCA deadline, be in possession of a doctoral degree or have at least four years of full-time equivalent research experience).

Applicants can be of any nationality but must not have spent more than 12 months in France in the 3 years immediately prior to MSCA deadline.

Following the reception of your application, the eligibility of your profile for a MSCA-EF application will be checked, and then the identified supervisor will select the most promising applications regarding the excellence-based competitive conditions and evaluation criteria of the MSCA-IF programme and contact them in due course for further discussions and proposal writing until September 2018. If funded, the project proposed in September 2018 could start in May 2019.

To be crystal clear, this is the responsibility of the fellow to develop and write his/her own application proposal, but the supervisor will be deeply involved in the co-writing of the proposal and you will also receive dedicated support from the European office to write a persuasive proposal in a continuous follow-up process.