High-temperature storage device

These molding compounds were also used to encapsulate electronic devices for reliability testing. In Figures 4, 5, and 6, stable bromine CEN outperformed "state-of-the-art" resins in the bias pressure cooker device test (BPC), high temperature storage device test (HTS), and the highly accelerated stress test (HAST). 

Figure 5 shows the performance of encapsulated devices under the high temperature storage device test. The conditions of this test are as follows storage in standard convection oven 0 200°C, no induced humidity, and no bias. Test results indicate that the encapsulant based on the stable bromine CEN took greater than 52 weeks to reach 50% failure that is, 50% of the initial number of devices have failed, in contrast to the standard high purity resin encapsulant which failed at 14 weeks. 

Figure 5. High Temperature Storage Device Test 200 C, No Induced Humidity, and No Bias...

The electronics industry desires improved flame suppressant additives for microelectronic encapsulants due to bromine induced failure. Epoxy derivatives of novolacs containing meta-bromo phenol have exhibited exceptional hydrolytic and thermal stability in contrast to standard CEN resins with conventional TBBA epoxy resins. When formulated into a microelectronic encapsulant, this stable bromine epoxy novolac contributes to significant enhancements in device reliability over standard resins. The stable bromine CEN encapsulant took about 30% more time to reach 50% failure than the bias pressure cooker device test. In the high temperature storage device test, the stable bromine CEN encapsulant took about 400% more time to reach 50% failure than the standard compound. Finally, the replacement of the standard resins with stable bromine CEN does not adversely affect the desirable reactivity, mechanical, flame retardance or thermal properties of standard molding compounds. 

Recently, a new failure mode has been found in the accelerated testing of high temperature storage It shows an increase in the resistance of the bonding pad, or in severe cases disconnection, when a device is stored at high temperatures around 200 C. It is due to the formation of an aluminum-gold intermetallic compound Its formation seems to be accelerated by free bromine or chlorine it may be... 

On the other hand, since most of these reactions are thermally activated, their kinetics are accelerated by the rise in temperature in an Arrhenius-like manner. Therefore, within a much shorter time scale, the adverse effect of these reactions could become rather significant during the storage or operation of the cells at elevated temperatures. In this sense, the long-term and the thermal stability of electrolytes can actually be considered as two independent issues that are closely intertwined. The study of temperature effects on electrolyte stability is made necessary by the concerns over the aging of electrolytes in lithium-based devices, which in practical applications are expected to tolerate certain high-temperature environments. The ability of an electrolyte to remain operative at elevated temperatures is especially important for applications that are military/space-related or traction-related (e.g., electric or hybrid electric vehicles). On the other hand, elevated tem-... 

Barium titanate has many important commercial apphcations. It has both ferroelectric and piezoelectric properties. Also, it has a very high dielectric constant (about 1,000 times that of water). The compound has five crystalline modifications, each of which is stable over a particular temperature range. Ceramic bodies of barium titanate find wide applications in dielectric amplifiers, magnetic amplifiers, and capacitors. These storage devices are used in digital calculators, radio and television sets, ultrasonic apparatus, crystal microphone and telephone, sonar equipment, and many other electronic devices. 

Electrical heating requires power supply by an interim storage device, i.e. a battery. Even though batteries exist as buffer devices in most fuel cell system concepts, their size would need to increase considerably to meet the demands for start-up. Therefore, battery power is a less viable option especially for hydrocarbon reforming systems, where high operating temperatures of the reformer exceeding 600 °C need to be achieved. 

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