101seminartopics.com INTRODUCTION In power electronics, solid-state electronics is used for the control and conversion of electric power .The goal of power electronics is to realize power conversion from electrical source to an electrical load in a highly efficient, highly reliable and cost effective way. Power electronics modules are key units in a power electronics system. These modules contain integration of power switches and associated electronic circuitry for drive control and protection and other passive components. During the past decades, power devices underwent generation-by- generation improvements and can now handle significant power density. On the other hand power electronics packaging has not kept pace with the development of semiconductor devices. This is due to the limitations ofpower electronics circuits. The integration of power electronics circuit is quite different from that of other electronics circuits. The objective of power electronics circuits is electronics energy processing and hence require high power handling capability and proper thermal management. Most of the currently used power electronic modules are made by using wire-bonding technology [1,2]. In these packages power semi conductor dies are mounted on a common substrate and interconnected with wire bonds. Other associated electronic circuitries are mounted on a multi layer PCB and connected to the power devices by vertical pins. These wire bonds are prone to resistance, parasitic and fatigue failure. Due to its two dimensional structure the package has large size. Another disadvantage is the ringing produced by parasitic associated with the wire bonds.
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In order to integrate the electromagnetic power passive components used
in power electronic converters in to modules, we use spiral integration technology.
This integration technology for power passives can best be described by first
considering a simple bifilar spiral winding as shown in figure 6.
Fig:6 Spiral Integrated LC structure
This structure consists of two windings (A-C and B-D), separated by a
dielectric material. This resultant structure has distributed inductance and
capacitance and is best described as an electro magnetically integrated LC
resonant structure for which equivalent circuit characteristics depends on theexternal connections. Even more complex integrated structures can be realized by
adding more winding layers.
Design of these structures requires deliberate increase and modification of
naturally existing structural impedances, like intra winding capacitance, to realize
a particular equivalent circuit function. These models will provide power densities
of 29W/cm3 at frequencies up to 1MHz. In our example of DPS system the
passive part contains decoupling capacitor, current doubler inductors and isolation
transformer. Because of the current doubler configuration, passive IPEM can be
realized by stacking two transformers and using only one DC blocking capacitor
The performance of IPEM can be evaluated using various parameters. A
comparison of IPEM and wire bonding technology is given in table 2. As given inthe table, IPEM has achieved 35% reduction of foot print area as compared to the
wire-bonding version. The planar interconnects in IPEM reduces the structural
inductance by a factor of three when compared to the wire bonding. But the
structural capacitance is increased by a factor of five.
There are several advantages for integrating power electronics system
using the IPEM concept. The main advantages are
1. Modular approach:
This modular approach reduces the design and implementation time cycles as
well as simplifies the assembly process.
2. Improved usage of space
The reduction in volume increases the power density and reduces the profile
of the system.
3. Reduction of components and inter connects.
This improves the system reliability and also increases the speed.
4. Reduction in structural packaging inductance.
It leads to improved electrical performance, which in turn leads to reduced
voltage ringing across the power switches. It increases the switching
frequency.
The main disadvantage of this system is that it is very complex comparedto other 2-D modules. Also it requires efficient combination of a large number of
different technologies.
APPLICATIONS
IPEM can be used for most of the power electronic circuits. Hence it has a