Abstract In this filter, each one of two coupled resonators is formed on a different crystal wafer. Each wafer is accurately positioned with respect to one longitudinal groove in the periphery of a ceramic ring. The wafer is supported in the central opening in the ring with wires which are soldered to metalized areas of the ring and to resonator lead patterns on the wafer to form a resonator assembly. Each resonator is tuned to operate at a predetermined frequency by locating the associated resonator assembly in a masking jig with respect to the one groove on the ring to accurately align the resonator electrode patterns with holes in the jig. A metal film is evaporated onto a resonator electrode to adjust the resonant frequency of the associated resonator to be equal to the predetermined frequency. In a packaged filter the resonator assemblies and electrically conductive spacers are alternately stacked on a header having a pair of posts protruding therefrom that are located in longitudinal grooves in the ceramic rings and openings in the spacers for supporting the stacked elements. Extensions and tabs on the spacers are soldered to the alignment posts and metalized areas on the rings, respectively, to ground the resonators and spacers to the header. The spacer sandwiched between the rings provides isolation between the resonators on adjacent wafers. A discrete chip capacitor is connected to a resonator electrode and a metalized area on a ring which is grounded to the header. The resonator electrodes are also selectively interconnected and connected to insulated lead pins in the header to produce a filter structure. The packaged filter is hermetically sealed by cold welding a cover to the header.
THE METHOD OF FABRICATING STACKABLE RESONATOR ASSEMBLIES, EACH ASSEMBLY INCLUDNG A PIEZOELECTRIC CRYSTAL BODY HAVING A CONDUCTIVE PATTERN FORMED ON EACH OF THE TWO OPPOSING MAJORS FACES THEREOF WITH OVERLAPPING BODY PATTERNS AND HAVING LEAD PATTERNS CONNECTED TO THE BODY PATTERNS, THE PATTERNS BEING FORMED ON THE CRYSTAL FACES WITH RESPECT TO A FIRST REFERENCE POINT ON HE CRYSTAL FACES BY LOCATING THE CRYSTAL BODY ON THE CIRCUMFENERCE THEREOF AND A DIELECTRIC FRAME HAVING AN OPENING THERETHROUGH FOR RECEIVING THE CRYSTAL BODY, HAVING A SECOND REFERENCE POINT THEREON THAT IS SPACED FROM THE OPENING, AND HAVING PLURALITY OF METALLIC ELECTRODES FORMED ON THE END OF THE FRAME ADJACENT THE OPENING THERETHROUGH: COMPRISING THE STEPS OF PLACING A CRYSTAL BODY IN THE OPENING THROUGH AN ASSOCIATED FRAME WITH THE CRYSTAL SPACED FROM THE FRAME TO EXPOSE THE CONDUCTIVE PATTERNS ON BOTH SIDES OF THE CRYSTAL, POSITIONING THE FIRST REFERENCE POINT ON EACH CRYSTAL BODY WHICH IS IN THE OPENING IN EACH ASSOCIATED DIELECTRIC FRAME TO BE AT THE SAME DISTANCE FROM THE SECOND REFERENCE POINT, AND POSITIONING EACH CRYSTAL BODY IN THE OPENING TO MAKE THE CONDUCTIVE PATTERNS THEREON HAVE THE SAME ORIENTATION WITH RESPECT TO THE SECOND REFERENCE POINT ON THE FRAME.
Claim 2
Independent Claim
202 words
THE METHOD OF FABRICATING STACKABLE RESONATOR ASSEMBLIES, EACH ASSEMBLY INCLUDNG A PIEZOELECTRIC CRYSTAL BODY HAVING A CONDUCTIVE PATTERN FORMED ON EACH OF THE TWO OPPOSING MAJORS FACES THEREOF WITH OVERLAPPING BODY PATTERNS AND HAVING LEAD PATTERNS CONNECTED TO THE BODY PATTERNS, THE PATTERNS BEING FORMED ON THE CRYSTAL FACES WITH RESPECT TO A FIRST REFERENCE POINT ON HE CRYSTAL FACES BY LOCATING THE CRYSTAL BODY ON THE CIRCUMFENERCE THEREOF AND A DIELECTRIC FRAME HAVING AN OPENING THERETHROUGH FOR RECEIVING THE CRYSTAL BODY, HAVING A SECOND REFERENCE POINT THEREON THAT IS SPACED FROM THE OPENING, AND HAVING PLURALITY OF METALLIC ELECTRODES FORMED ON THE END OF THE FRAME ADJACENT THE OPENING THERETHROUGH: COMPRISING THE STEPS OF PLACING A CRYSTAL BODY IN THE OPENING THROUGH AN ASSOCIATED FRAME WITH THE CRYSTAL SPACED FROM THE FRAME TO EXPOSE THE CONDUCTIVE PATTERNS ON BOTH SIDES OF THE CRYSTAL, POSITIONING THE FIRST REFERENCE POINT ON EACH CRYSTAL BODY WHICH IS IN THE OPENING IN EACH ASSOCIATED DIELECTRIC FRAME TO BE AT THE SAME DISTANCE FROM THE SECOND REFERENCE POINT, AND POSITIONING EACH CRYSTAL BODY IN THE OPENING TO MAKE THE CONDUCTIVE PATTERNS THEREON HAVE THE SAME ORIENTATION WITH RESPECT TO THE SECOND REFERENCE POINT ON THE FRAME.
Claim 3
Dependent Claim
30 words
The method according to claim 1 including the additional step of registering on the circumference of the crystal body for orienting the conductive patterns in the opening in the frame.