| 摘要 |
PROBLEM TO BE SOLVED: To effectively prevent the parasitic oscillation, noise and crosstalk due to the element-element coupling by providing metal protrusions at specified period or less on the back of the cap. SOLUTION: Many conical protrusions 12 are formed on the cap back. A metal base plate 10 is made by etching an FeNiCo alloy, Kovar and its surface is plated with Ni/Au. The protrusion interval L meets L<c/2vε<1/2> where c is light velocity, E specific dielectric const. of a board, and v signal frequency. The protrusions 12 are made by die-casting an Al alloy and plate parts of them are adhered to the back of a cap plate 10 through a quickdrying Ag paste. A thin plate collecting the protrusions 12 is cut thin to 0.2 mm. The repetition frequency is less than a half the wavelength of a max. frequency signal. |
