Ceramics firing temperatures

Pricing as well as reliability considerations have led to an almost exclusive use of Si-based (i.e. Si and SOI) micro machined devices. Packaging and assembly has focused on ceramics (A1203, AIN, Low Temperature Co-fired Ceramics LTCC), Printed Circuit Board (PCB-) and Surface Mount Device (SMD-) technology and multichip modules (MCM s). 

LIGA lithographie, galvanoformung, abformtechnik LTCC low-temperature co-fired ceramics MEMS microelectromechanical systems... 

LTCC low-temperature co-fired ceramic (an aluminum borosilicate) Luminol 5-amino-2,3-dihydro- 1,4-phthalazinedione... 

Over the past two decades MLC technology has been progressively developed for advanced packaging, especially by main frame computer manufacturers, and it is increasingly exploited for microwave communications. Especially significant is the emergence of low temperature co-fired ceramic (LTCC) technology. 

The latter reaction can form long chain phosphates, where n is theoretically infinite. Being formed by heat treatments, these phosphates are excellent candidates for high-temperature ceramics and glasses. Because the subject of this volume is low-temperature ceramics, we will not discuss the condensed phosphates in detail, except in one case in Chapter 15, where cements for geothermal wells are discussed with sodium metaphosphate. However, bear in mind that CBPCs can be precursors to high temperature phosphates and glasses. For this reason, as we have seen in the literamre survey presented in Chapter 3, early interest in CBPCs was the formation of refractory shapes at room temperature, which were then fired to produce the final refractory components. 

Ceramics are typically made from clays (which contain silicates) that are hardened by firing at high temperatures. Ceramics are a class of nonmetallic materials that are strong, brittle, and resistant to heat and attack by chemicals. 

Figure 7. Effect of sintering time and temperature on fired density of pellets made from typical ceramic-grade oxide. (After Ref. 3.)...

Ceramics can be classified by considering the firing temperature and the resulting porosity thus high-fired stoneware (produced at above 1000°C) has porosities less than 2% and low-fired earthenware (firing between 600 and 900°C) with far more than 10% porosity are at the upper and lower ends of the scale. Porcelain (defined as white and translucent ceramic, fired up to 1400°C) can exhibit an extremely low porosity, whereas terracotta or raku (both fired below 1000°C) would be examples of high porosity. 

Figure 15.21 presents magnetization curves for a magnetic ceramic fired at two different temperatures, shown on the plot. 

High temperature ceramic heat exchangers (HX) either in tube-in-tube or plate type design are promising candidates for the use in harsh corrosive and combustion environments. In contrast to tubes, plate-lype HX with integrated flow channels can contribute to an increasing efficiency of the heat transfer. Those HX can be used for heat recovery processes, thermo chemical splitting reactions or within externally fired combined cycles. 

Pfeifer, K.B., Rumpf, A.N., Measurement of ion swarm distribution functions in miniature low-temperature co-fired ceramic ion mobility spectrometer drift mbes. Anal. Chem. 2005, 77, 5215. 

Kemethmueller S, Hagymasi M, Stiegelschmitt A, Roosen A (2007) Viscous flow as the driving force for the densification of low-temperature co-fired ceramics. J Am Ceram Soc 90 64-70... 

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