| 摘要 |
1,215,340. Ladder network. ANGSTROHM PRECISION Inc. 12 March, 1969 [12 March, 1968], No. 13146/69. Heading G4H. [Also in Divisions H1 and H3] A ladder network formed of two groups of resistive films 15 . . . 20 and 10 . . . 14, Fig. 1, deposited on an insulating substrate is constructed in such a manner that after manufacture the values of the films 15 . . . 20 may be adjusted individually by grinding, this grinding causing some unavoidable grinding of the films 10 . . . 14; however, the values of films 10 . . . 14 may be individually adjusted by a final grinding operation which does not at all affect the films 15 . . . 20. For analogue-digital conversion, the films 10 . . . 14 may each have a value R and the films 15 . . . 20 a value 2R. In the construction shown in Figs. 2, 3 the films 15 . . . 20 are formed by sinuous paths 31 1 . . . 31 6 and the films 10 . . . 14 by U-shaped paths 34 1 . . . 34 5 . These paths 31, 34 are constructed by depositing resistive material 72 on the walls of similarlyshaped V-section grooves formed in a ceramic substrate 30. The grooves are defined by lands. Thus the groove forming path 31, is defined by lands 50 . . . 53 and these lands are ground to adjust the resistance of path 31; similarly, lands 55 . . . 58 define the path 31 2 . However, lands 55, 58 partly define the paths 34 1 , 34 2 and thus grinding of these lands affects the resistance value of these paths. Final adjustment of the paths 34 1 , 34 2 is made by grinding lands 60, 62, respectively. Recesses 32 1 . . . 32 6 and 31 1 . . . 33 6 constituting terminals for the resistive paths are formed along the two edges of the substrate 30 and are coated with a conducting film 70, e.g. of gold. Thus the ends of path 31, make contact with terminals 32 1 , 33 1 and the ends of path 34 1 make contact with terminals 33 1 , 33 2 . The network may be encapsulated, the connections to the terminals being made through wires 36 having heads 37 contacting the film 70. |
