Thermal conduction module

The most advanced implementation of cofired-ceramic-packaging technology is the thermal conduction module (TCM) used in large-scale computers (IBM) (4, 72, 74). This package can accommodate over 100 flip-chip-bonded ICs on a 90 by 90 mm cofired ceramic substrate. The multilayer ceramic substrate contains 33 metal layers for chip pad redistribution, signal interconnection, and power distribution (Figure 14). Each chip contains 120 bonding pads, and 1800 pins are brazed to the bottom of the substrate for connection to a PWB. 

Fig. 5.26 Multilayer ceramic thermal conduction module (a) underside showing connector pads - substrate size 90 x 90 x 6 mm (b) multilayer construction (c) silicon chip mounting positions (d) schematic diagram illustrating buried interconnections (e) thermal conduction module. (Courtesy of IBM Corp., East Fishkill.)...

We consider shaping in Chapter 23, but mention some additional features here. The method used depends on the material. Either brute force or a plasticizer should be used. The classic example is pottery—we mold the clay. Then we have the alumina thermal conduction module (TCM), cordierite honeycombs, Si3N4 fishhooks, and carbide blades for kitchen knives. 

Tummala, R.R. and Ahmed, S. 1992. Overview of packaging of the IBM enterprise system/9000 based on the glass-ceramic copper/thin film thermal conduction module. IEEE Trans. Comp., Hybrids, and... 

Lead as a coating material for the thermal conduction module c-ring... 

R. R. Tummala and S. Ahmed, Overview of Packaging for the IBM Enterprise System 9000 Based on the Glass-Ceramic Copper/Thin Film Thermal Conduction Module, 7EEE Trans, on Comp., Hybrids and Mfg. Tech., Vol. 14, No. 4, Dec. 1991, pp. 426-431. 

Single-crystal sUicon has also been employed as substrate material, particularly in multichip module (MGM)-Si appUcations. As a substrate, sUicon offers good thermal conductivity and matches the GTE of the devices mounted on it it does, however, have a relatively high dielectric constant and is very britde. 

On the other hand, following the development of hybrid combustor configurations that prevent operation of the catalyst module at temperatures above 900-1000 °C, the major drawback of metallic monoliths, namely the limited maximum operating temperature, has been overcome. Accordingly, honeycombs made of metal foils have been adopted in GT catalytic combustors in view of their excellent thermal shock resistance and thermal conductivity properties [9]. In addition, metallic substrates are a promising option for the fabrication of microcombustors. 

ASTM E1952, 2001. Standard test method for thermal conductivity and thermal diffusivity by modulated temperature differential scanning calorimetry. 

The Seebeck coefficients Qa and <2b are material constants of conductors A and B, respectively. They depend primarily on two parameters their work function (see Appendix C) and their thermal conductivity. There are many combinations of electronic conductors producing V of few mV °C 1. It is interesting to note that direct modulation of one or both Seebeck coefficients by chemical interaction with an electron acceptor or electron donor gas is possible. It has been demonstrated as a sensing principle for detection of gaseous NO2 with an ti Oj/Au thermocouple junction (Liess and Steffes, 2000). 

A similar problem can arise in any of the correlations that relate the properties of a mixture to the pure component properties at the temperature and pressure of the mixture. In this module these included the viscosity and thermal conductivity of both liquids and gases. 

High thermal conductivity He it sinks for semiconductor lasers, power ICs, and multi-yip modules, heater for inkjet head, flow sensors... 

A gas chromatograph (Yanaco G-3810) was equipped with a thermal conductivity detector (TCD) and a flame ionization detector (FID). Molecular Sieve 5A and Porapak Q were used for CO and Hj analysis in the TCD and CH4 and C2H4 analysis in the FID, respectively. Soluble products such as CH3OH, CH3CHO, and CjHjOH were analyzed by the FID after electrolysis for 5 h. Formate ions and other anions in the solution were analyzed by means of an ion chromatograph (Dionex DX-lOO) equipped with an anion exchange column (lonPac ICE-ASl), an anion exchange micromembrane suppressor, and a conductivity detector module. 

A 5ul thermal conductivity cell has been discussed by Craven and Clouser (15,16) which Is modulated at 10 cycles per second. Here the analytical and reference gas flows are alternately switched to flow through a single detection cell. An advantage of the modulated TCD Is that the cell remains nearly constant for sequential pulses, and thus the modulated detection removes the low frequency components of the TCD signal. This effectively eliminates any problems that are associated with drifting baselines. 

The modulated TCD retains the limitations Imposed on conventional thermal conductivity detectors with respect to stability of the reference and analytical flows, detector wall temperature stability, and make-up flows being required to... 

The main bottleneck in this case will be in relaxation on the Y-Z plane (perpendicular to gradient), since there will be the most property mismatch and restricted movement of the parts of the whole specimen. Interesting, that relative anisotropy in elastic module between X and Y/Z components is not large (2-3%), but depends on temperature and anisotropy coefficient in a complicated way (Fig.4a and b). On the other hand, differences in values of thermal conductivity between X and Y/Z are almost the same for different anisotropy, but change strongly with the temperature (Fig.4c and d). The results for Y/Z-plane could be summarised in Table 1. 

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