The influence of the single chip production process on the single chip yield is very important. These factors can be refined to the number of single-chip microcomputer chip process steps, the single-chip production process cycle, as well as packaging and final testing, all of which affect the single-chip process yield.
The influence of single-chip manufacturing process technology on chip yield
Explain the impact of the above three points on the performance of the microcontroller.
The influence of single-chip microcomputer chip manufacturing process technology on chip yield
The number of manufacturing steps of the single-chip microcomputer chip process. The number of process steps is considered a limiting factor for the CUM yield of the fab. The more steps, the greater the possibility of breaking the wafer or mishandling the wafer. This conclusion also applies to the wafer electrical test yield rate. As the number of process steps increases, unless corresponding measures are taken to reduce the impact, the density of wafer background defects will increase. The increased background defect density will affect more chips, making the wafer electrical test yield lower.
The single-chip technology process cycle. The actual processing time of wafers in production can be calculated in days. However, due to the temporary slowdown caused by waiting in line at various process stations and process problems, the wafers usually stay in the production area for several weeks. The longer the wafer wait time, the greater the possibility that the electrical test yield will decrease due to contamination. The shift to just-in-time production is an attempt to increase the yield rate and reduce the related costs caused by the increase in production line inventory.
SCM chip packaging and final test yield rate. After completing the wafer electrical test, the single chip wafer enters the packaging process, is cut into individual chips, and is packaged in a protective casing. A series of steps also include multiple visual inspections and quality inspections of the packaging process.
After the packaging process is completed, the packaged chip will undergo a series of physical, environmental, and electrical tests, collectively referred to as the final test. After the final test, the third main yield rate is calculated, which is the ratio of the number of qualified chips in the final test to the number of qualified chips in the electrical test of the wafer.
To sum up, the yield rate of single-chip microcomputers is guaranteed through various production links, and the processing technology of single-chip microcomputer chips is rigorous.