Whiskers overview

Apart from manifold structures, carbons can have various shapes, forms, and textures, including powders with different particle size distributions, foams, whiskers, foils, felts, papers, fibers [76, 77], spherical particles [76] such as mesocarbon microbeads (MCMB s) [78], etc. Comprehensive overviews are given, for example in [67, 71, 72], Further information on the synthesis and structures of carbonaceous materials can be found in [67, 70, 72, 75, 79]. Details of the surface composition and surface chemistry of carbons are reviewed in Chapter II, Sec. 8, and in Chapter III, Sec. 6, of this handbook. Some aspects of surface chemistry of lithiated carbons will also be discussed in Sec. 5.2.2.3. 

Fig. 8.5. SEM pictures of activated tungsten wire emitters (a) overview showing the thin tungsten wire close to the holders and the whisker-bearing middle section, (b) detail of the middle with the whiskers resolved. By courtesy of Carbotec, Bergisch Gladbach, Germany.

Figure 9 Overview of copper whisker array prepared by electrodeposition in the membrane with micropores, and dissolution of the polymer matrix by a solvent.

Recently Schwetz [169] gave an overview of the different mechanisms forming SiC whiskers. One of the processes technically used for SiC whisker production has been mentioned before in Sect. 4.1.2, the pyrolysis of rice husks. This process counts among the type VS (Vapor-Solid mechanism) since the dominating reaction responsible for the whisker growth is the second step of the reaction sequence ... 

Zeng JB, He YS, Li SL, Wang YZ. Chitin whiskers an overview. Biomacromolecules... 

FIG. 21 An FIB cross-sectional micrograph of a whisker grown on satin-tin deposited on a copper substrate showing (a) overview of an intermetallic SnCu particle at the root of the whisker. (From Ref. 48.)... 

Solder joints must be capable of meeting stringent reliability requirements discussed in detail in Chaps. 19 (Reliability), 20 (Thermomigration/Electromigration), and 21 (Tin Whiskers). Some of these issues are discussed briefly in this section for convenience of providing an overview. 

---