How to write a better technical background when applying for a patent?

Background: It refers to technologies that are helpful for understanding, searching and examining utility models, and documents reflecting these background technologies can be cited. Background technology is the description of the closest existing technology, and it is the basis for formulating new technical schemes of practical technology. In addition, it is necessary to objectively point out the problems and shortcomings in the background technology, and if the literature is cited, the source should be explained.