Sometimes we find the photolithography isn’t that successful. The reason might be the exposure. Normally the UV intensity of the EVG 620 Aligner is 12 mW/cm2. However, it varies overusing.
Therefore, it’s necessary to know the current UV intensity.
This post shows how to measure the UV intensity instructed by Bill.
1.”UNIF” Icon
![](https://sites.utexas.edu/xiaoyuniu/files/2021/07/Picture1-1024x768.png)
2.assemble the chuck for measuring UV intensity
![](https://sites.utexas.edu/xiaoyuniu/files/2021/07/IMG_1338-1024x768.jpeg)
3.set up the UV meter
![](https://sites.utexas.edu/xiaoyuniu/files/2021/07/IMG_1339-768x1024.jpeg)
4.”continue”
![](https://sites.utexas.edu/xiaoyuniu/files/2021/07/IMG_1337-1024x768.jpeg)
5.Aligner works at the mode of UV measuring. So, the UV meter reads the intensity of the UV light of the EVG 620 aligner.
![](https://sites.utexas.edu/xiaoyuniu/files/2021/07/IMG_1340-768x1024.jpeg)
6.Put back the UV meter to its box.
![](https://sites.utexas.edu/xiaoyuniu/files/2021/07/IMG_1341-1024x768.jpeg)
7.the UV meter should be put below the MJB4 aligner.
![](https://sites.utexas.edu/xiaoyuniu/files/2021/07/IMG_1342-768x1024.jpeg)