Reliability issues in low temperature screening of components

wacy0607@

Reliability issues in low temperature screening of components [Copy link]

Hello, the chips I choose are generally industrial grade, and the low temperature range of the processor or memory is above -40℃. However, due to product requirements, it is necessary to use -45℃ for screening. Will this over-temperature screening cause hard damage to the device? If there is no problem with the screening, how will it affect the reliability of the subsequent use of the device?

maychang

Low temperatures are generally not destructive and will not damage the chip. At most, the chip will not work properly. After the temperature returns to the normal range, the chip can still work normally, and generally there is not much impact on reliability.

wsmysyn

Generally, the impact is not significant. Before the chip leaves the factory, the wafer may be tested in a low temperature environment, such as in a -40 degree low temperature box. We have done this before, and the wafer is screened at 25 degrees, -40 degrees and 85 degrees. After packaging, a reliability test is also required, such as 300 hours of high or low temperature, etc. The temperature is lower. Generally, it only affects the transistor parameters of the chip, such as reduced power consumption, some communication interfaces, or internal logic, clock frequency or signal edge changes, which generally will not damage the chip. Just pay attention to some timing changes. Generally, the change from -40 degrees to -45 degrees is not so obvious. . If it only supports 0-70 degrees, the parameters may change greatly when it is placed at a low temperature of -45. It is mainly related to the chip design process. For example, some chips have an internal clock of 10kHz at normal temperature, and the clock may be 15kHz at -40 degrees. At a high temperature of 85 degrees, it is only 7kHz. . .

chunyang

A slight over-limit of low temperature will not have any effect on the device, but the manufacturer cannot guarantee that the device will work normally under the over-limit. When the temperature recovers, the parameters will recover. The screening pass rate of slightly over-limit should be higher, and generally there is a margin.

qwqwqw2088

Considering the temperature standards of components, the operating temperature range of commercial-grade components is generally 0℃~+70℃, that of industrial-grade components is -40℃~+85℃, and that of military-grade components is -55℃~+125℃. Currently, almost all ICs are made of the same silicon wafer, but the temperature difference is caused by different packaging.

qwqwqw2088

Military grade is ceramic packaging, which can achieve a wide operating temperature range. The OP selects by temperature, -45℃ is industrial grade, and the chips of major manufacturers should be able to reach the industrial grade limit. As for the follow-up, it will not affect the device.