MINIATURE THIN FILM INDUCTORS (MODIFICATION NO. 2).
Abstract
Work continued on fabricating miniature thinfilm inductors using flat conducting spirals deposited on ferrite substrates and encapsulated with a ferrite-film deposit. The period covered is from 1 September 1963 to 1 December 1963. Gold spiral coils of 0.67 and 1.58 microhenry air-core inductance have been fabricated on Ceramag 9 ferrite substrates. These coils were fabricated by electro-plating a gold spiral pattern which was vacuum deposited on the substrate in two steps through two properly oriented masks. The methods used to solve the problems of adjacent turn shorting during electro-plating and poor adhesion of the pattern to the substrate are described. Samples of the gold spirals have been encapsulated in ferrite film deposited at 800 C to thicknesses of 150 microns. An inductance increase over air-core value of only four times was obtained, although the permeability of the films has been measured to be seventy or more. The reason for this small inductance increase is not known at this time. Because of the low inductance increase, no Q-value measurements at 1 mc were made. Ferrite films deposited at temperatures of 400 to 700C were also studied. This investigation was initiated in case it was necessary to deposit ferrite on coils that could not survive at 800 C temperature. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 20, 1963
- Accession Number
- AD0426183
Entities
People
- F. R. Gleason
Organizations
- Motorola Mobility