Circuit-bearing substrate

These papers and others " show the efficiency of CVD diamond substrates in removing heat from high-power modules. Its use as a heat sink or heat spreader seems to be feasible in most situations. Problems may occur because of its exceptionally low CTE, since it will eventually interface with a metal or printed wiring board having much higher CTE. It also would usually need to be pohshed before use as a circuit-bearing substrate, as opposed to... 

The mechanical properties, especially the internal stresses set up by interaction of substrate and deposit, have a close bearing on the behavior of metallic interconnects (electrical conductors) in integrated circuits. Such interconnects suffer from more diseases than does a drink-sodden and tobacco-crazed invalid, and stress-states play roughly the role of nicotine poisoning. A very good review specifically of stresses in films is by Nix (1989). 

Use Electron and microwave tubes, optical elements in radiation detectors, substrate for thin-film components and integrated circuits, abrasive, record needles, precision instrument bearings, aluminum composites, micromortars for hand-pulverizing chemicals. 

The thermoplastics used for MID are neither as rigid nor as strong as the glass-reinforced themosets routinely used for printed-circuit boards. The layer of metal deposited on the substrate is typically hard and compensates for the poor wirebonding properties of the soft substrate material. This is why bondability is largely independent of the polymer used. It is important to bear in mind, however, that there is a minimum thickness specification for plating (Table 5.7). The thicker the metallization, the more dependable the wire-bonding process becomes. [182]... 

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