Novel concepts in power electronics rely heavily on the availability and processability of new materials and packaging technologies to meet the requirements of increasing performance and reliability at lower form factor, weight and cost. Today’s main technological route for converter modules is still the power die soldered and wire-bonded to a DCB substrate. New applications or semiconductor technologies like e.g. SiC, however, require enhanced thermal management using standard commercial casings within the same, usually very limited thermal budget. This paper is the final of a series of publications dealing with a novel thermal management concept for power electronics enabled by the use of advanced packaging technologies as well as smart handling of power transients, making use of a TEC and a thermal buffer using a low melting BiSn eutectic as phase change material to store excess heat temporarily exploiting the PCM’s enthalpy of fusion. This concept is exemplified on a typical six-pack converter module for industrial applications (4 kW, 1200 Volts) to be integrated into a standard easyPIM casing while being able to cope with overload power pulses. This paper summarises the whole system approach, references back to literature for details finishes the series of papers with the reliability analysis of the buffer technology. Thus, all stages of product development covering design, technology and performance are finally highlighted.

Thin metal layers, especially those made of copper, are omnipresent in today's packaging applications as e.g. RDL structures, conductor traces on flexible and stretchable substrates, chip finishes or terminal metallisation, serving electrical, thermal or mechanical purposes. During operation, thermo-mechanical stress will cause failures in the Cu layers and interfaces over time. As Cu is very process and size dependent, its resistance to fatigue failure needs to be characterised with samples which have undergone identical processing steps as those in the real application. For that purpose, simple specimens and fast testing routines are necessary, some of which may need special loading stages for varying the load variables of interest such as stress amplitude and temperature. This paper addresses fatigue characterisation of thin Cu films on silicon under typical processing conditions on simple and inexpensive but industry-grade samples. Along with them, custom built test stands have been used to handle those specimens appropriately within a specimen-centred approach.

In this paper, a cooling concept for power electronics is discussed, using thermo-electric cooling in combination with a phase-change based latent heat storage module. It was designed to cope with thermal transients due to periodic overload operation phases of an IGBT power converter module. Several sub-system simulations and experiments have already been performed in previous publications leading to the current design state, which is now being tested under emulated experimental conditions. Very good results are presented, showing the feasibility of the transient cooling concept. On-going work referred to the long-term thermal stability and operation as well as a smart electrical TEC control will be motivated.

This paper deals with the system design, technology and test of a novel concept of integrating silicon power dies along with thermo-electric coolers and a phase change heat buffer in order to thermally manage transients occurring during operation. The innovative power-electronics concept features double-sided cooling as well as new materials and joining technologies to integrate the dies such as transient liquid phase bonding/soldering and sintering. To avoid a cold plate at the backside, a new low-cost, low-footprint thermal storage device has been developed and optimized by simulation to meet the requirements given by this application. Coupled-field simulations are used to predict thermal performance and are being verified by especially designed test stands.

In this paper, a new and dedicated phase change cooling concept is discussed, following the goal to buffer periodic overload operations of electric power modules and thus keeping junction temperatures constant. A top-mounted latent heat storage material (LHSM) buffer is applied, to soak the overload heat in conjunction with thermo-electric coolers (TECs), which control the temperature and phase change process. The cooling system is going to be realized within an IGBT converter module, undergoing repeated overload situations. The concept features double-sided cooling and assembling as well as new materials and joining technologies such as transient liquid phase bonding/soldering and silver sintering. One-dimensional equivalent circuit estimations and transient electro-thermal FE simulations were used to calculate the cooling performance, extract optimization guidelines and discuss potential difficulties of the concept. Furthermore, the simulations are successively refined and brought into agreement with various test stands and characterization methods of reduced complexity.

This paper deals with the system design, technology and test of a novel concept of integrating Si and SiC power dies along with thermo-electric coolers in order to thermally manage transients occurring during operation. The concept features double-sided cooling as well as new materials and joining technologies to integrate the dies such as transient liquid phase bonding/soldering and sintering. Coupled-field simulations are used to predict thermal performance and are verified by especially designed test stands to very good agreement. This paper is the second in a series of publications on the ongoing work.

In this paper, the Advanced Mixed-Mode Bending Test (AMB) is presented. The AMB is an experimental method to determine the effects on the critical crack propagation in bi-material interfaces that exist in electronic packages. Target in the development of this test rig was a quick and cost-effective data collection in addition to easier handling of samples. By two independent load components, shearing and opening of the boundary layer, a large range of the mode-angle can be determined. The test rig is designed for bimaterial beams, which are industrially manufactured, e.g. produced through laser cutting. Another preparation of the test-specimen is not necessary. It can also be used cutouts from actual products. Thus it is possible to examine influences of the production line.

This paper deals with the system design, technology and test of a novel concept of integrating Si and SiC power dies along with thermo-electric coolers in order to thermally manage transients occurring during operation, thus turning it into a smart power device. The concept features double-sided cooling as well as new materials and joining technologies to integrate the dies such as transient liquid phase bonding/soldering. Coupled-field simulations are used to predict thermal performance and are verified by especially designed test stands to very good agreement. This paper is the first in a series of planned publications on the ongoing work in the project.