PhD in a project called Advanced Laser Induced Subsurface Separation ALISS

Chair

The chair of Applied Laser Technology at Twente University is focusing on machines for the lasering of Materials. The physical aspects of laser material interaction with ultra short pulses are studied and processes are improved by sensoring and automation. The production of micro- and nano-structured surfaces with femto- and pico-second pulsed laser ablation is an emerging and promising technique for which continuously new applications are encountered that may result in completely new devices. It is e.g. applied to metal master surfaces that are subsequently reproduced by injection moulding, rolling or imprint methods. In general the results will contribute to bridging the micro-nano manufacturing gap. In addition to processes for material removal, mainly by ablation, attention is given to laser assisted material deposition of layers on a micro-scale.

Within this group there is a position for a

PhD in a project called Advanced Laser Induced Subsurface Separation ALISS

Background

As electronic packages shrink in size, integrated circuit packaged devices must be reduced both in footprint and thickness. The main motivation for the development of smaller packages is the demand for portable communication devices, such as memory cards, smart cards, cellular telephones and portable computing. One of the aspects of this tendency is that semiconductor dies and consequently wafers will be thinner, down to 20 µm. Below 200 µm separation introduces so much mechanical and thermal stress that the yield reduces to below economical acceptable levels. For efficiency of the use of silicium the sawing kerf-width should be reduced to 10-20 µm, a requirement that cannot be met by mechanical separation technologies. A possible direction for solving these problems is the use of laser modification of the semiconductor material in such a way that internal material modifications will act as breaking lines for the actual separation of the dies in the wafer. The first experiments in this direction have been done by industry and have shown that active laser control and focus control is essential to achieve precisely located material modifications. To further diminish the thermal and mechanical stress the use of ultra short laser pulses must be developed and the separation of the single dies must be developed to obtain good die strength and kerf edge quality

Project

The project focuses on research of a new cutting machine for cutting silicium with laser beams. The project is a cooperation between the University of Twente, Philips, TNO, CCM, Sioux, ALSI and VDL. The research of the group is mainly aimed at the possibilities of ultra short laser pulses. The ALISS project will develop the necessary technologies to make internal modification by multiple laser beams an enabling technology for the use of very thin and low–k wafers. As such the project will deliver a breadboard environment that will show that laser dicing is possible and that the technology can be transferred to an industrial production environment. The required laser and breaking processes will be developed as well as pre-prototypes for the execution of the processes

The ALISS project will show that material modification in semiconductor material can be effectively done with a multi-beam approach. This is essential as this unique feature will have a one on one relation with the productivity of the final system. Current approaches only use single beams and need to process dicing streets several times. The possibility to align dicing streets on the dice in stead of on the global wafer markers will make the ALISS concept robust to cope with the developments in assembly.

Profile

You have completed a master study in mechanical engineering, materials science, physics or equivalent You are proficient in spoken and written English. Background in laser technology is a plus. You have well developed social skills to co-operatively work in our research group as well as with the other partners in the project

Appointment and salary

We offer a challenging position at the interface between Applied Laser Technology and Mechanical Automation. You are offered a position for a period of 4 years. Your salary will be €2042.- gross per month for the first year, leading up to €2612,-gross per month in the 4^th year, according to the Collective Labour Agreement for Dutch Universities. In addition, we offer our employees a broad package of secondary benefits.

Information and application

For further information about this position you can contact Prof.dr.ir. A.J. Huis in ‘t Veld, telephone number: 053-4892527, or e- mail:a.j.huisintveld@utwente.nl

You are invited to send your application together with curriculum vitae topersoneelszaken@ctw.utwente.nl, with reference to vacancy number 09/206. Applications should be received by 30^th of November 2009 .