Quality & Reliability

The reliability of semiconductor devices must be treated not only by the device itself, but also by the operational and environmental stresses inevitably applied.
Since these stresses are closely related to each other, more important factors are explained among various factors for higher reliability.

The voltage, current, or environmental conditions applied to semiconductors are major factors that influence reliability. It is necessary to set an appropriate operating point by selecting an appropriate device and designing a circuit according to the desired circuit.
It is well known that the failure rate of an integrated circuit is greatly affected by temperature, and the failure rate increases as the temperature increases.

However, since the integrated circuit for small signals has a small applied voltage and current, it can be said that it is not necessary to worry much about temperature except for special circuits. Rather, when designing by paying attention to the application of surge voltage or variation in characteristics, if the allowable limit of characteristic variation can be identified and margined, the life of the device can be greatly extended. On the other hand, the power integrated circuit that applies a relatively large voltage and current has a higher current than the voltage, so the power consumption in the device itself is very high. Power consumption at this time causes self-heating of the integrated circuit, which is not good in terms of characteristics and reliability, so heat dissipation must be paid attention.

In order to use integrated circuits with high reliability, it is recommended to feel the voltage, current, and temperature prescribed with the maximum rating.
However, it is difficult to tell how much to feel uniformly because there is a compromise between reliability and economic feasibility, but it is usually the standard to feel as follows.

Regarding this feeling, some government offices or institutions have established usage standards or design standards to limit the scope of use.

Quality and reliability continue to improve every year due to the remarkable development of automation and improvement of manufacturing technology in the manufacturing process and the introduction of active new technologies.
Therefore, it can be said that there is little variation in quality due to the introduction of new management techniques, not to mention complete automation of the process.

However, semiconductor products are very small in shape, structure, and dimensions and are made with precision technology based on high-definition control, but even with the latest technology, it is difficult to maintain uniformity.

The case of the product is largely divided into two types: a plastic resin encapsulation type and an airtight encapsulation type made of metal.

Recently, inexpensive and highly productive plastic resin bags have become the mainstream, and the application area is expanding from small signals to large electricity.
This is due to the development of resin with high mechanical strength, excellent electrical insulation, and environmental resistance, and the development of molding technology or surface treatment technology, which enables rapid reliability improvement.

Although it is due to the market environment in terms of phenomenon, it is possible to realize the same level of reliability as a metal airtight encapsulation type except for a special environment.

However, since the plastic resin type is not an airtight encapsulation type, moisture penetrates through the resin, so if the environment in which the device or system is intended to be used is predictable in advance, it is recommended to use a metal airtight encapsulation type.
When semiconductor products are directly exposed to an atmosphere such as dust, harmful gases, salt, and radiation, they are the main causes of property instability, deterioration, and corrosion of the lead area, so it is necessary to be careful.