Introduction Mobile computing is poised to shape the way we live our lives, allowing people to generate, retrieve, and process data anywhere and at any time. The infrastructure for mobile computing is rapidly developing, as evidenced by the recent growth of cellular phone networks and a constant stream of innovations in portable electronic equipment. Mobile computing is also … [Read more...]
Conduction heat transfer in a printed circuit board
In this issue, we examine heat flow in a printed circuit board (PCB), which typically is a layered composite consisting of copper foil and a glass-reinforced polymer (FR-4). A cross-sectional view of such a laminated structure is illustrated in Figure 1. The Figure indicates the numbering system that will be used for indicating the different layers, numbered 1 through to … [Read more...]
The thermal conductivity of silicon
The most important material within the semiconductor industry is Silicon. When dealing with electro-thermal device modelling, or the interpretation of fast transient techniques for the measurement of thermal impedance, thermal conductivity of Silicon is required. For steady state thermal analyses at the board and system level, however, accurate values are not required, because … [Read more...]
Thermal interface under a plastic quad flat pack
Introduction Plastic components are designed so that the heat is dissipated by forced or natural convection. The use of plastic packages under conditions where neither cooling method is available introduces new challenges. High heat-dissipation plastic packages require a large-area solid heat sink in order to transfer the heat into the copper thermal lands on the printed … [Read more...]
The coefficient of thermal expansion
This is the second technical data feature that deals with the coefficient of thermal expansion (CTE). The first technical data feature, incorporated in the September 1997 issue, covered semiconductor materials, leadframes and solder alloys. This issue will discuss the temperature dependence of the CTE and present data on other materials that are of importance to electronic … [Read more...]
