Department Mounting and Assembling, Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik
Various laser types and modules are being developed at the Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik for applications in fields such as space, spectroscopy, medicine, communication and entertainment. This results in different requirements in terms of chip bonding and placement. In this work, the challenges in the bonding process will be discussed for two general types of modules.
The first type is for high power applications, i.e. a fiber coupled pump module for solid state lasers with an output power of about 6 kW. A module consists of a large number of single laser chips mounted in stacks together, e.g. 2 x 28 laser chips. This type addresses a high throughput in chip assembly with higher demands on reproducibility and placement accuracy.
The second type of module that will be discussed is a master oscillator with power amplifier (MOPA) which is used with slight variations, in applications for laser metrology, laser sensors, and laser systems for second harmonic generation. The main challenges at FBH are despite the individuality of modules meet the demands on the die bonding process, e.g. for space applications, and placement accuracy, e.g. two chips need to be placed at a distance of up to 40 mm with a placement accuracy of less than 10 μm.
DieFab Senior Engineer, Prima Electro S.p.A.
Performances and lifetime of high power laser diodes (from tens watts for a single diode to hundreds watts for laser bars) are strongly affected by mounting process. The high total heat generated by laser active region must be carefully managed in order to prevent performances degradation and device failures as catastrophically optical damage at the emission facet. A p-side down attach process is needed and bond-line between laser diode and sub-mount must ensure, among others, low thermal resistance, control of induced stress, precision and accuracy of placement, repeatability.
Here we review the development and characterization of mounting processes on manual and automating assembly machines in the production of high power laser diodes and multi emitter laser modules for industrial laser cutting applications.
Main achievements are a thermal resistance as low as 1.5°C/watt and diode facet/sub-mount edge overhang values of 3±1um. Positive reliability results have been obtained so far: 480k devices per hour on 137 devices, 9k hours accumulated on first prototype samples.
Product Manager, Finetech
In recent years, the semiconductor assembly equipment market has seen unprecedented growth rates resulting in a shortage of packaging capacity – especially for new and very high end applications and products in smaller to midsize volumes. In order to ease the pressure more and more manufacturers have started to build up or increase capacity. Some of them now even develop their new products on production machines in order to bypass the problems associated when moving a new product from lab to fab.
Having realized this trend, Finetech has started to develop and introduce automatic production systems in parallel to its well-known lab and R&D table top bonders. Being a global oriented company with worldwide operations, we have learned the requirements of European customers may differ significantly from those of e.g. Asian and American customers.
In this presentation we take a look at the requirements of European customers when it comes to automatic production systems.
Rony Jose James
Senior R&D Engineer, Optics and Packaging, CSEM
The need for more functionality and for miniaturization in the microelectronics and optoelectronics areas has led to a diversified strategy to achieve the goal in different niche application fields. CSEM offers a technology portfolio and is active in R&D projects to develop custom-designed prototypes, assembled with specific constraints coming from the industry, from space institutions and other players requiring dedicated packaging solutions.
In this presentation, the hybrid integration of a chip on wafer with flip-chip thermosonic bonding is presented with underfilling to achieve high-density chip-stacking and thermo-cycling up to 150°C. A second topic shall be presented about more standard chip die-attach processes, where the key aspect is the selection of adhesive material to survive harsh environment DI-water immersion tests. At last a miniature optoelectronic package comprising a VCSEL array will be shown with dimensions below 0.6x0.6x1.5 mm3. This component was developed targeting an exciting new application for optical stimulation of hair cells in the cochlea.
Process Engineer, Sicoya
The need for more bandwidth in worldwide communications is constantly increasing. Sicoya GmbH offers energy and cost-effective optical transceiver solutions for intra data center connections based on Silicon Photonics.
In silicon photonics, optical components are integrated into Silicon using standard CMOS technology. An additional laser source is required because a laser source cannot be integrated directly into silicon. To combine single-mode-optics with semiconductor assembly technologies an improved alignment accuracy is needed to meet the requirements for the optical interfaces.
In this talk, the hybrid integration of a semiconductor laser as a flip-chip component to an electrical and photonic co-integrated chip (ePIC) with an accuracy of half a micrometer is presented.
Head of Design, Finetech
Based on rapid progress of semiconductor technology, Finetech is improving its machines and modules permanently in order to be able to mount newest products by means of the newest technologies. At first, parameter expansions are introduced (higher bonding forces, faster heating ramps etc.); besides, new bonding technologies are being constantly integrated (such as vacuum die bonding and laser soldering).
A special challenge in the recent past has been µBump interconnections, where hundreds of thousands of smallest bumps have to be securely connected. In these cases it is not enough to pre-adjust substrate fixture to the tool plane once or to use a passive mechanism to compensate non-parallelism.
That’s why new modules were developed to measure and correct distances and parallelism before and within mounting processes. These new capabilities are presented and described for the first time within this presentation.
Product Manager, Finetech
What does it mean to achieve precision and what does it actually need to get there? Both FINEPLACER® family-members sigma and femto 2 stand for sub-micron accuracy and wide flexibility – and sharing quite some features in common, they represent the equipment range from manual to automatic bonders. And accuracy does not only mean the well-known terms of optical resolution and placement accuracy. There are more ingredients which together form a solution in complexity that grows. Software though is everything to keep control of the system. Hear about the latest improvements and features driving us now and for the future, being prepared in facing the application needs you will bring to us.
Product Manager, Finetech
During this year's Micro Assembly Day we will introduce our ongoing development of the FINEPLACER® lambda, standing in line with the equipment concept of FINEPLACER® systems femto 2 and sigma. New options make it possible to adapt the system and make it even more flexible in response to the challenges of different micro assembly and packaging applications. Here we combine the well-known FINEPLACER® lambda options with the new electronics and IPM2 software to optimize the system’s productivity and usability.
Head of Semiconductor Integration Technologies, Institut für Mikroelektronik Stuttgart (IMS CHIPS)
Flexible, thin and bendable electronics have the potential to enable many applications by integrating digital and non-digital functionalities on flexible substrates. The desired system performance often requires the integration of different components such as thin and flexible silicon ICs, sensors and thin-film large-area components. Adequate integration technologies for chip handling and placement, embedding and interconnect are a key issue for these Hybrid Systems in Foil (HySiF).
Chip-Film Patch (CFP) is an embedding technology for chip thicknesses ranging from a few microns up to 50 μm using wafer based processes. Fine pitch interconnects and multichip patches are feasible by semiconductor processing technologies and adaptive layout techniques. CFP technology is used for single devices such as smart sensor patches or as an interposer for multichip modules in a large area foil systems. Applications ranging from embedded multichip modules for industry 4.0 solutions to bendable sensor foils for robotic gripper fingers are presented.
System Packaging Department, Fraunhofer-Institut für Elektronische Nanosysteme ENAS
In this contribution, several investigations on the development of induction heating for bonding of microsystems are presented. Induction technology allows for significantly more efficient heating of the bonding area by using the mechanism of eddy current heating instead of lossy and time consuming convective heat transfer through the component. The influence of coating material, coil design and frequency on the desired temperature distribution in common bonding areas will be discussed. The findings have been verified by finite element method (FEM) and IR thermography. By optimizing the induction coil and choosing a suitable frequency of the high frequency power supply, selective and homogeneous induction heating for wafer and chip bonding has been achieved. The presented technology can be applied in MEMS and IC packaging such as diffusion bonding, eutectic bonding, solder bonding or sintering of metallic particle pastes.