High bond reliability wire

Ag/Pd ratio 70/30 TR-4865 (fired at 850°C) 25-35 pf2 cm Excellent wire bondability High reliable wiring Wire bonding pad Lead terminal... 

Epoxy molding compounds, used to encapsulate microelectronic devices, contain bromine to provide flame retardancy to the package. This bromine, typically added as tetrabromo bisphenol-A or its epoxy derivative, has been found to contain many hydrolyzable bromides. These bromides, along with the presence of chloride impurities, are detrimental to the life of the electronic component. Bromine especially has been suspected (proven) to cause wire bond failure when subjected to moisture and/or high temperatures. With the addition of a more thermally and hydrolytic stable bromine compound, flame retardancy does not have to be compromised to increase the device reliability. Stable brominated cresol epoxy novolac, when formulated into a microelectronic encapsulant, increases the reliability of the device without sacrificing any of the beneficial properties of present-day molding compounds. 

FIGURE 1.1.11 Solder joint reliability by TCT (—40 to 123°C) for wire bonded chip assembly type CSP made of the high TCE ceramic materials. 

Gold pastes have been commercially used for highly reliable electrodes in electronic devices and circuits, in particular for applications such as medical, space, and military equipment. Figure 12.5 shows a gold wire bonded to such an electrode. 

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