Functional failure means that a function point is not implemented. This is often caused by design. Usually, it is verified by simulation before the design stage, so usually a chip is designed and the simulation verification takes about 80% of the time. . Performance is not qualified, a performance indicator requires no clearance, such as 2G cpu can only run to 1.5G, digital-to-analog converter under the required conversion speed and bandwidth conditions, the effective number of eeno to reach 12, but only 10 , and lna’s noise figure indicator is not up to standard and so on. This kind of problem is usually caused by two problems. One is that there is not enough space in the design of the system in the early stage, and the other is that the physical implementation layout is too bad. This type of problem is usually verified by post-simulation. Production failed. The reason for this problem is to mention the production of monocrystalline silicon. Those who have studied semiconductor physics know that monocrystalline silicon is a regular face-centered cubic structure. It has several crystal orientations. Usually, we grow single crystals by pulling in the 111 crystal orientation. However, due to various external factors, such as temperature, pulling speed, and various randomness of quantum mechanics, misalignment occurs during the growth process. This is called a defect.

Another cause of chip defect generation is the irregular structure caused by ion implantation, which cannot be corrected even by annealing. These problems in the semiconductor can lead to device failure, which in turn affects the entire chip. Therefore, in order to be able to pull out the failed or semi-failed chip after production, special test circuits will be added at the time of design, such as the test inside the simulation, the logic in the digital, and the storage to ensure delivery to the customer. It is ok chip. Products that fail or are semi-failed are either discarded or sold at the low end after castration.

When running the chip test system, if the chip in the chip test system is found to be unqualified, it needs to be removed in time to continuously improve the operating efficiency of the chip. (This article is from the source network, if there is any infringement, please contact Lneya to delete, thank you.)