Patent ID: 7947600
Filing Date: 2011-05-24
Classification: H01F,H01L

Abstract:
1. A micro-transformer manufacturing method comprising the steps of: forming a primary coil by: forming an impurity-diffused region selectively on the surface of a semiconductor substrate, depositing a first insulating film on the surface of the semiconductor substrate having the impurity-diffused region, forming a first opening and a second opening in the first insulating film, wherein the first opening and the second opening reach the impurity-diffused region, depositing a first conductive film on the first insulating film, working the first conductive film into a desired shape around the portion of the first conductive film over the first opening, depositing a second insulating film on the first insulating film and the first conductive film, and removing a portion of the second insulating film to expose the portion of the first conductive film over the second opening; and forming a secondary coil by: forming a second conductive film on the surface of an insulator material, which is sized to have a smaller area than an area of the second insulating film; working the second conductive film into a desired shape; and adhering the secondary coil onto the second insulating film of the primary coil with the insulator material being positioned between the secondary coil and above the second insulating film, while maintaining the portion of the first conductive film over the second opening exposed, and without electrically connecting the exposed portion of the first conductive film over the second opening with the second conductive film.