Summary form only given. For thermal management one has to distinguish between two categories: the heating of electronic components by their environment and heating due to power dissipation in the electronics. In the first case thermal insulation is essential for component protection. The authors show the limits of cooling mechanisms using liquids (liquid coolers and heat pipes) as well as electrothermal cooling. Furthermore, possibilities of passive cooling (heat spreading) are discussed. From the viewpoint of thermomechanical aspects, high temperature applications are complicated, because large temperature intervals drastically increase thermal mismatch in comparison to normal conditions. Effective cooling and equalizing temperature distributions are suitable to lower thermal mismatch by avoiding excessive temperature gradients. Thermomechanical principles like CTE matching or applying ductile intermediate layers, well known from low temperature packaging, become extremely more important. Some aspects of mechanical stresses on the acceleration of diffusion processes are discussed.

High performance aluminium nitride water cooled heat sinks were fabricated and characterized. A variety of fabrication processes were employed to meet different cooling requirements. They include laser cut microchannel coolers for chip and multichip heat sinks as well as dry pressed pin fin heat sinks for power electronics. Thermal simulation was used to optimize the heat sink design.

Due to the demand for short signal running times the HF-technology requires high integration densities of active components. This results in considerable thermal problems additionally enlarged by the steady rising tact frequencies (up to 80 Gbits/s). Thus usual layouts for telecommunication purposes show hot spots with high temperature gradients. A consequence of local temperature elevations is a drastically reduced component life time. Thermally induced stresses caused by the high temperature gradients are a further failure source. In combination with more thermal cycles per time unit these mechanical strains and stresses cause a considerable reduction of life time, too. Numerical parameter studies of various board materials have shown, that a properly heat conducting and efficiently cooled board is a promising measure to reduce the component stresses by decreasing and equalizing the component temperatures. Using aluminium as the board material under the same conditions a lower operation temperature can be achieved with the effect of increasing the life time. Otherwise, the integration density can be increased to get better HF-properties. The dielectric is an anodic oxide (Eloxal). The thickness ratio between it and the aluminium substrate has been optimized numerically. The presentation deals with the choice of the new board material from thermal, thermomechanical and environmental viewpoints. A first demonstrator for the interconnection technology on anodically oxidized aluminium already exists and is presented

We introduce a new packaging concept for high power laser bars using Au(80)Sn(20)-solder on different heatsinks e.g. CVD-diamond and CuW. First the optimal thermal concept and design with the lowest possible thermal resistance is described. The thermal simulations were done by an inhouse made computer program based on FFT (Fast-Fourier-Transformation). The results of the 3D- and 2D-FEM-simulations for the thermomechanical design show a solution with low bonding stress. Design rules based on the discussion of these results including the technological limitations are described, which were used to define different alternative packaging concepts. The technological realization of these concepts is described and presented. The electro-optical characterization of such bonded laser bars gave first indications about maximum power, thermal resistance, bonding stress and reliability

The integration of electronic, acoustic, mechanical, thermal, optical and magnetic functions within one product is one of the great challenges for future microelectromechanical systems (MEMS) today. The development of advanced materials plays a key role for the design and development of new MEMS. Application fields and examples as well as future visions of microsystem technology are highlighted in this article. Additionally, some of the borders and requirements of today's MEMS design are also pointed out

The integration of electronic, acoustic, mechanical, thermal, optical and magnetic functions within one product is one of the great challenges for future MEMS today. The development of advanced materials plays a key role for the design and development of new MEMS. Application fields and examples as well as future visions of microsystem technology will be highlighted in this article. Additionally, some of the borders and requirements of today's MEMS design will be pointed out.

Laser bars typically have a size of 10/spl times/0.6/spl times/0.1 mm/sup 3/ and an optical output power of more than 10 watt. Commercially these bars are bonded using soft solders like In or eutectic PbSn-solder. Soft solders lead to migration, whiskers at the bond and an increasing of the thermal resistance. Commercial manufactures using such packaging technique only guarantee a lifetime in the range of 5,000 hours. Instead we use a highly reliable and fluxless contact can be achieved by using the eutectic Au(80)Sn(20)-solder.

Chipanordnung bestehend aus einem ersten Chip (10), einer Verbindungsvorrichtung (12) und zumindest einem zweiten Chip oder einem Substrat (14), wobei die Verbindungsvorrichtung aus einer Mehrzahl einzelner voneinander beabstandet angeordneter Diamantteile (12) besteht, die zwischen den Chips (10) oder zwischen dem ersten Chip (10) und dem Substrat (14) angeordnet und mit denselben derart verbunden sind, das die Chips oder der Chip und das Substrat ausschlieslich uber die Diamantteile miteinander verbunden sind.