Silicon dioxide (SiO2) is one of the most common and also one of the most important materials in the world as it is the basis for our windows, beaches and wine glasses. It is also a source of silicon, of course. As such, the thermal conductivity (TC) of the bulk material is well documented. However, in many cases of interest to the thermal management of semiconductors (for … [Read more...]
Thermal Vias – A Packaging Engineer's Best Friend
Introduction In the 1990's, with the advent of surface mounting of semiconductor packages, multilayer printed circuit boards and multilayer substrates for Ball Grid Array packages were introduced. In order to create electrical interconnections between the different metal layers, vias are fabricated [1]. In most cases vias are hollow cylinders of copper, created by plating a … [Read more...]
Opto-electronic Transceiver Modules, a System Design Perspective
Introduction Small Form Factor (SFF) optical transceiver packages for use at 1-2 Gbits/s data rates have been described by several authors [1-5]. These rely on dual miniature optical connectors such as the MT-RJ or the LC to provide optical-component case widths as small as one centimeter. Passive alignment of the optical fibers with the active optical devices is achieved with … [Read more...]
Modeling Heat Conduction in Printed Circuit Boards Using Finite Element Analysis
Introduction Heat transfer in and around a printed circuit board (PCB) is generally very complex. Some of the heat generated in components is conducted away through the multiple conducting (trace) layers, vias, and dielectric layers of the board; and some is dissipated by convection and radiation from the exposed surfaces. There has long been a focus on characterizing the … [Read more...]
Surface Flatness
Surface flatness is an important issue for thermal designers as it is directly related to thermal contact resistance between surfaces. In this column, the definitions of surface flatness related parameters are discussed. These definitions are presented here as in the ASME B46.1-1995 standard [1]. Surfaces are characterized by three main parameters: roughness, waviness, and … [Read more...]
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