G. De Mey, L. Rottiers, M. Driscart, E. Boone and L. Van Schoor
In this paper the temperature distribution in hybrid circuits will be studied in two different ways. First of all the results of numerical simulations obtained with the programs…
Abstract
In this paper the temperature distribution in hybrid circuits will be studied in two different ways. First of all the results of numerical simulations obtained with the programs PROMETHEE and HYBRITHERM will be shown. Secondly, experimental temperature plots obtained with infra‐red thermography will be compared with the theoretical results. The influence of the substrate material (epoxy, glass, Al2O3, AlN and BeO) on the temperature distribution will be demonstrated. Various ways of cooling will also be considered. It will be shown that using high quality substrates such as AlN or BeO is not always useful from a thermal point of view.
G. De Mey, E. Boone, G. Nachtergaele, S. Demolder and L. Rottiers
A review is given of the several heat transfer phenomena occurring in hybrid circuits. Most attention is devoted to the non‐linear properties. Some theoretical simulations and…
Abstract
A review is given of the several heat transfer phenomena occurring in hybrid circuits. Most attention is devoted to the non‐linear properties. Some theoretical simulations and experimental results are discussed.
In this contribution a linear thermal model for hybrid circuits is presented. Both the heat dissipated in screen printed resistors and in mounted components such as transistors…
Abstract
In this contribution a linear thermal model for hybrid circuits is presented. Both the heat dissipated in screen printed resistors and in mounted components such as transistors and integrated circuits is taken into account.
In this contribution a short review is given on thermal analysis of hybrid circuits using 2‐D, 3‐D and time‐dependent models. It will be shown which models are necessary to be…
Abstract
In this contribution a short review is given on thermal analysis of hybrid circuits using 2‐D, 3‐D and time‐dependent models. It will be shown which models are necessary to be included in a CAD system for hybrid circuit design.
Temperature field computations of hybrid power circuits require considerable numerical effort. This paper presents rules which show both how to limit the number of terms of the…
Abstract
Temperature field computations of hybrid power circuits require considerable numerical effort. This paper presents rules which show both how to limit the number of terms of the Fourier series and how to estimate the error which is the effect of this reduction.
The paper presents a two‐dimensional and three‐dimensional thermal model of the power hybrid circuit. Measurement of the accuracy of temperature computation using the…
Abstract
The paper presents a two‐dimensional and three‐dimensional thermal model of the power hybrid circuit. Measurement of the accuracy of temperature computation using the two‐dimensional model is carried out. Based on both models, the AUTO_T program for thermal analysis is created. This program chooses the proper model according to the required accuracy of computation. The reduction of the computational time is evident.
Computer algebra or symbolic manipulation is nothing else than performing analytical calculations with the help of a computer. This offers the advantage that lengthy and…
Abstract
Computer algebra or symbolic manipulation is nothing else than performing analytical calculations with the help of a computer. This offers the advantage that lengthy and complicated calculations can be carried out without errors in a very short time. Computer algebra techniques have also been applied to solve electrical networks. This offers particular advantages for hybrid circuit design, as will be outlined extensively in this paper.
This paper deals with the computation of thermal fields of power hybrid circuits using the finite difference method (FDM). The FDM is one of the classical methods used for…
Abstract
This paper deals with the computation of thermal fields of power hybrid circuits using the finite difference method (FDM). The FDM is one of the classical methods used for temperature calculation of microcircuits having any shape and any boundary conditions. The equation written in the matrix form, describing thermal equilibrium, is solved using Choleski's method. The need for sufficient computer memory capacity is one of the main problems when using a small personal computer. This work attempts to show how to reduce the necessary computer memory capacity as much as possible. A compromise between memory capacity and CPU time is achieved.
C. Zardini, F. Rodes, G. Duchamp and J.‐L. Aucouturier
Among the main factors to be considered for the thermal optimisation of hybrid power modules are: the thermal resistance between the power chips and the bottom of the case; the…
Abstract
Among the main factors to be considered for the thermal optimisation of hybrid power modules are: the thermal resistance between the power chips and the bottom of the case; the thermal coupling between adjacent chips; and the ability of the module to withstand the thermal overloads induced by electrical surges. In this paper, the authors show how a finite element code can be used to optimise a hybrid power assembly in both steady‐and unsteady‐state. Comparisons made between results obtained with 3D and 2D simulations show that for hybrid power modules 2D simulations are generally unreliable. However, thermal studies cannot guarantee the reliability of hybrid power assemblies. Studies relative to hybrid power circuits must be thermomechanical.
T. Kwikkers, J. Lantaires, R.B. Turnbull, H.T. Law, Barry George and Dave Savage
On 20 April ISHM‐Benelux held its 1988 Spring meeting at the Grand Hotel Heerlen. This meeting was totally devoted to implantable devices, in particular to the technologies used…
Abstract
On 20 April ISHM‐Benelux held its 1988 Spring meeting at the Grand Hotel Heerlen. This meeting was totally devoted to implantable devices, in particular to the technologies used for these high reliability, extremely demanding devices. For this meeting ISHM‐Benelux was the guest of the Kerkrade facility of Medtronic. Medtronic (headquartered in Minneapolis, USA) is the world's leading manufacturer of implantable electronic devices. Apart from the assembly of pacemakers and heart‐wires, the Kerkrade facility acts as a manufacturing technology centre for Medtronic's European facilities.