Warpage of FC-PBGA Packages Flip chip technology has emerged as an important chip-level package solution to meet the ever-increasing demand of high I/O requirements. The flip chip technology was implemented originally for a multi-layer ceramic substrate. In the ceramic flip chip package, a shear strain in each bump, produced by the mismatch of the coefficient of thermal … [Read more...]
Thermal joint conductance for graphite materials
The heat flow across a metal/interstitial elastic-layer/metal joint is a very important problem in many microelectronic applications. It is generally known that when two surfaces are brought together, intimate solid-to-solid contact occurs only at discrete parts of the interface. Therefore, the actual contact area of pressed surfaces represents a very small fraction of the … [Read more...]
Flash Diffusivity Method: A Survey of Capabilities
The development, specification, and quality control of materials used in electronics packaging and thermal management often require the measurement of thermophysical properties.This data can be critical to a successful design, especially with the rapidly increasing cooling requirements that result from the packaging of higher performance devices. A variety of methods, involving … [Read more...]
Understanding Phase Change Materials
Although phase change materials (PCM) were introduced nearly twenty years ago, it was not until the development of the high-powered Pentium processor that this class of interface material gained widespread acceptance. The large quantities of heat produced by these processors necessitated a carefully designed thermal path where all of the thermal resistances were minimized. For … [Read more...]
The Role of Natural Graphite in Electronics Cooling
Graphite is available as a variety of different material forms, the most useful in the electronics cooling market being pyrolytic graphite, graphite fiber reinforced carbon and polymer matrix composites, graphite foams and, the subject of this brief, natural graphite. The basic structure of graphite is shown in Figure 1. Figure 1. Structure of graphite crystal. The … [Read more...]
