Adhesive materials can be applied between two join partners, e.g. dice and substrates in various ways: dispensing, stencil printing, pin transfer or as film working as intermediate connection.

Especially in the field of opto-electronically applications the proven solder materials is AuSn (80Au 20Sn) which is used in a flux less process. Layers or bumps of AuSn material located on chip and substrate are soldered together in a temperature and force process.

To attach e.g. laser bars onto sub-mounts, there are several technologies available and Indium solder has proven to be one of the better choices. The important considerations here are to limit the thermal stress to the laser bar and to reduce the oxide film of the indium solder to be as low as possible.

Using eutectic solder as bump materials is a well known technology since IBM introduced their C4 Flip Chip technology years ago. Solder is applied to the chip by ball placements or solder paste is printed to the pads. By using a reflow process the solder is melted and formed to balls.

After accurate alignment and placement of the chip to the substrate the chip and substrate are heated up to the melting temperature of the interconnect material. Simultaneously force is applied to the chip and controlled during the whole bonding process.

After accurate alignment and placement of the chip to the substrate the chip is activated by ultrasonic power. Supported by force and heat the chip bumps are scabbing on the surface of the substrate pads and create a connection between bumps and pads into a one direction oscillation (about 50 – 60 KHz).

The most popular technology of bonding of single laser or laser bars is soldering using AuSn as interconnect. The bottom of the die and the top of the sub mount are typically equipped with a AuSn layer. Within a bonding process (temperature and force) the chip is soldered to the sub mount.

Micro Assembly describes a certain range of different technologies which are used for high accurate mounting mechanical, optical or electrical parts on a micro scale to carriers. Currently two types of devices are very common: MEMS (Micro Electro Mechanical System) and MOEMS (Micro Optical Electro Mechanical System).

Vertical Cavity Surface Emitting Laser Diodes are normally bonded face up. In this case, their contacts cannot be used as alignment marks like in the case of FC bonding. Instead, indirect alignment is adopted. Characteristic structures on the VCSEL's "face" are aligned to marks on a customized glass mask tool before pick up. With the component at the tool, additional marks in the mask's peripheral area are aligned to corresponding ones on the substrate. Now, the component can be placed with it's active areas in defined position relative to the marks on the substrate.

To perform the laser bar bonding application the FINEPLACER^® femto or Lambda in motorized configuration is recommended. Especially for the necessary two point alignment of laser bars the motorized camera movement module allows the precise movement between different alignment positions. Low forces, less than 0,1N, are precise provided and controlled during the whole bonding process using the automatic bonding force module.

RFID (Radio Frequency Identification) is a new field of application for the FINEPLACER^®, used for R&D as well as pre series RFID production. The size covers a range from some mm to 0.5 mm. Low placement error becomes more and more important, as RFID dice are undergoing a continuous process of miniaturization. Flexibility and process reproducibility are further "trump cards" for quick process development.

For the evaluation of different Flip Chip process alternatives, the assembly and bonding process should be performed with an affordable and flexible piece of equipment. This should be usable as well in the research lab as in starting production runs. Most of the cooperation partners of the Flip Chip project mentioned above perform their investigations by this system. It is designed for fast and easy handling, and used now for production purposes too in big German companies as well as in Austria, Hong Kong and Singapore.