POWER MODULOS Pressing Home the Advantages

EXCELENTE ARTIGO DA REVISTA BODOPOWER SYSTEM
Pressing Home the Advantages
Press-Fit pin for solder-less assembly
Solder pins have been the interface of choice for power modules for many years. The new
press-fit pin developed by Vincotech takes the assembly properties of Vincotech power
modules a step further: the solder-less assembly of the modules, equally easy on both
sides of the PCB, leads to higher reliability and design flexibility and drastically reduces
production costs.
By Peter Sontheimer, Vincotech

The target: faster and easier assembly
Common inverter construction today features large Through The Hole
(TTH) components along with smaller SMD devices on one side of
the PCB, with the power module mounted on the other side and connected
to the heat sink (see fig 1). Only in exceptional cases, where
space allows and where special heat sink shapes are possible, the
power module is mounted on the same side as all other components.
This means that wave-soldering of the power module is not possible.
The solution most usually adopted in these cases is either a manual
solder process, which immediately raises questions regarding reliability
and production efficiency, or selective robot soldering, entailing the
same production efficiency issues as well as higher costs.

Simulation software to calculate heatsink.

SemiSimV1 is a Powerful simulation and calculation program for power electronics.
The simulation program consists of the following modules:
Mod1: power loss calculation for buck and boost converters, 3-phase inverters and Indirect Matrix Converter.
Customer-specific adaptations are possible.
Mod2: temperature of the silicon and lifetime calculations for defined load cycles
Mod3: Thermal resistance and thermal conductivity of VIA's and PCBs in different lay-out
Mod4: Heatsink calculation, heat resistance and heat transfer coefficient calculation of heat sinks in natural convection and active.
Mod5: 2-D simulation of heat sink temperature in accordance with the heat spreading and thermal conductivity of heat sink.
Heat sink temperature calculated
Database for the collection of IGBT, MOSFET, diode and thyristor data

Be determined for a long life and reliable operation of power electronics, the semiconductor temperature. In many cases, a heat sink is used for cooling. Be known for the determination of the semiconductor temperature, the temperature of the heatsink.
The heat sources are usually not distributed homogeneously on the heatsink. Thus, the heat distribution as a function of the position of the heat sources can be simulated.
There are excellent simulation programs to perform the calculation based on the finite element method. This is often drawn a 3-Dimensional Model of the heat sink. The model is divided into a corresponding number of elements. The result deserting method is very accurate.
The disadvantage is the high complexity and high cost of such programs.
Another important point is the correct value for the thermal resistance (heat resistance) of the heatsink. This value is dependent on the geometry, imprinted on the type of cooling or dissipation of the heat sink is. This value is not found in the data sheets of manufacturers, as it depends on the previously described parameters.
SemiSimV1 the Modul4 and Modul5 is a very inexpensive program that allows a first estimation of the temperature distribution and heat sink temperature. The required thermal resistance of heat sink can be calculated quickly and easily.
The program does not provide the exact dates of a "Finite Element Simulation", however, allows the developer from the beginning of the heat sink to calculate and simulate the temperature of the heat sink.

Thermal Analysis of Semiconductors

Thermal simulation predicts the junction temperature
and life time of semiconductors.

The design of power converter includes necessarily the calculation of power loss and
temperature rise in the semiconductors and heat sink. This article shows the procedure of
evaluation junction temperature and life time of semiconductors.
By Tobias Hofer, Negal Engineering GmbH Switzerland.

The design of power converter includes necessarily the calculation of
power loss and temperature rise in the semiconductors and heat
sink. For a reliable design the temperature ripple of the silicon should
also be considered. The temperature ripple mainly determines the life
time of the semiconductor (number of cycles to failure). The junction
temperature is related to the heat sink temperature. Mostly the heat
sources are not homogenous distributed over the heat sink. Therefore,
the heat distribution on the heat sink must be known.

Case temperature
The lifetime of the power module not only depends on the temperature
difference ΔTj but also on the average junction temperature of
the semiconductor. It makes a difference whether the temperature
swing of 30K is between 60°C and 90°C or between 80°C and
110°C. It takes a much smaller number of cycles to failure if the
absolute temperature is higher. The junction temperature is relative to
the case temperature of the semiconductor module. The fact that the
heat sources (semiconductors) are not evenly spread over the heat
sink, the heat distribution of the heat sink must be simulated. The
simulation tool used for the simulation in this paper represents the
heat sink as a rectangular plate. One side is cooled by convection.
On the other side rectangular heat sources are placed. The top of the
heat sources and heat sink is isothermal.

For a reliable design of the power converter it is important to calculate
the semiconductors temperature. The significance of simulating
the temperature distribution on the heat sink was shown. Taking the
temperature ripple and the average temperature of the semiconductor
in account leads to safer designs. With adequate simulation software
it is possible to optimize the design during the development
process in an early stage. All simulations in this paper were performed
with SemiSimV1 [3].

EL ARTIGO COMPLETO ESTA HOSPEDADO EM MINHA PAGINA PERSONAL

References
[1] Realistic benchmarking of IGBT-modules with the help of fast and
easy to use simulation-tool
R.Schnell, U.Schlapbach; ABB Switzerland
[2] Power Cycling Lifetime of Advanced Power Modules for Different
Temperature Swings U.Scheuermann, U.Hecht; SEMIKRON
[3] SemisSimV1, www.negal.ch

Ceramic Heatsink Provides Innovative ThermalManagement

A new ceramic technology offers an innovative solution for thermally sensitive components and circuits,
thanks to its excellent thermal conductivity and stability characteristics and its compact form. CeramCool is
the ideal heatsink for high-power semiconductors where it demonstrates its ability to handle high power
peaks. Alfred Thimm, Service Center Design, CeramTec AG, Plochingen, Germany

ENTREVISTA AL MATEMATICO PERUANO PROF. SR. CESAR CAMACHO

REPRODUZCO UNA PARTE DEL ARTICULO DEL BLOG. DEL PROF. CARLOS TORRES,SOBRE LA VIDA DE UNO DE LOS MAYORES MATEMATICOS PERUANOS DE LA ACTUALIDAD,PUBLICADO EN EL DIARIO EL COMERCIO EN SETIEMBRE DEL 2008,PIENSO QUE ES UN TEMA PARA REFLEXION Y DE ACTUALIDAD,SI QUIERE VER EL TEXTO COMPLETO SOLAMENTE CLICKAR EN ESTE ENLACE.
El día sábado 6 de septiembre se publicó, en el diario El Comercio, una entrevista realizada al matemático César Camacho. El tema de la entrevista versó sobre la ciencia en el Perú, específicamente la matemática. El doctor Camacho, con la gran trayectoria ganada en todo el mundo, nos presenta su visión acerca de la fuga de cerebros que viene padeciendo nuestro país. En este blog ya comentamos un poco de esta problemática. Asimismo, acerca de la vida de este gran matemático que ahora labora en el IMPA.
Les anexo la entrevista y espero dejen sus comentarios.
“El Perú exporta talento y eso es una insensatez, un absurdo”
El matemático más importante del Perú afirma que mil científicos peruanos de nivel de excelencia aportan al desarrollo de otros países. Es necesario una clara política de Estado
LA FICHA
Nombre: César Leopoldo Camacho Manco.Nació: Barranco, abril de 1943.Estudios: GUE Alfonso Ugarte. Ingeniería de minas y matemática pura en la UNI. Doctorado en matemática en la Universidad de Berkeley.Trayectoria: Director del Instituto Nacional de Matemática Pura (IMPA) de Brasil. Tiene 40 trabajos y 9 libros publicados. La PUCP le otorgó en el 2006 el Premio Southern Perú y la medalla Cristóbal de Lozada y Puga a la creatividad humana. Mundialmente se le reconoce la solución a un problema clásico propuesto en el año 1856 y que hoy se conoce como teorema de la separatriz de Camacho-Sad.
Fuente: El Comercio