Abstract: In FIGS. 5 and 7, a temperature chamber 4 encloses a centrifugal-fan wheel 8 that is mounted concentric with a test ring 2 such that the fan's radially expelled air, indicated by arrows 12, flows across the ring in parallel with the test ring surfaces and is circulated via heating/cooling elements back to the fan inlet. The test ring includes guide holes 36 and electronic components 32 with terminals 34. It can be rotated via a pin wheel 22 with drive pins 24 that engage in guide holes 36 . A vertically mobile contact head 26 includes guide pins 28 and contact pins 42 that are connected with an external test instrument 51. Each time the ring is rotated a step, the contact head moves down to first engage guide pins 28 with the guide holes 36—thereby accurately aligning the contact pins 42 with the terminals 34—and, upon further down movement, connecting the contact pins 42 with terminals 34.

Abstract: In FIGS. 5 and 7, a temperature chamber 4 encloses a centrifugal-fan wheel 8 that is mounted concentric with a test ring 2 such that the fan's radially expelled air, indicated by arrows 12, flows across the ring in parallel with the test ring surfaces and is circulated via heating/cooling elements back to the fan inlet. The test ring includes guide holes 36 and electronic components 32 with terminals 34. It can be rotated via a pin wheel 22 with drive pins 24 that engage in guide holes 36 . A vertically mobile contact head 26 includes guide pins 28 and contact pins 42 that are connected with an external test instrument 51. Each time the ring is rotated a step, the contact head moves down to first engage guide pins 28 with the guide holes 36—thereby accurately aligning the contact pins 42 with the terminals 34—and, upon further down movement, connecting the contact pins 42 with terminals 34.

Abstract: Method for identifying, monitoring, and controlling the blank frequencies in each separate carrier of a planetary lap machine, based on measuring blank frequency signals via an electrode imbedded in a lap plate, analyzing the time frequency pattern of these signals as they pass the electrode, correlating it with the sequence of carriers passing the electrode, and from that identifying and correlating groups of signals with the loads of blanks in each carrier, then monitoring the frequencies and the frequency spread in each carrier and, optionally, terminating lapping when frequencies and spread in a carrier exceed a target value.

Abstract: The present application describes apparatus and method for monitoring and controlling the etching of quartz crystals to a desired target frequency by means of monitoring the frequency of a monitor blank that is immersed in the etchant simultaneously with the etch load. Since during etching the thickness removal is the same for monitor and etch load, one can predetermine a monitor target frequency in terms of the load target frequency. The process is terminated upon reaching the monitor target.

Abstract: Method and apparatus for adjusting the electrical parameters of monolithic crystal filters having an electrode pattern that includes resonator electrodes and inter-resonator gap and constitutes two coupled resonators, based on thin-film deposition on the electrode pattern of one side of the filter through a single-aperture mask, with mask and filter movable relatively to each other during the adjustment process, such as to be able to guide said deposition in response to measurements of said electrical parameters to any area of said electrode pattern for the purpose of adjusting said parameters to their target values.

Abstract: A carriage or dielectric disk (40) has a series of electrical contacts (46, 48) defined by conventional circuit board techniques on upper and lower surfaces around a peripheral edge. Sockets (42, 44) are wave soldered in electrical connection with the electrical contacts. At least the electrical contacts are plated with a hard, dense metal, such as nickel. When components have been frictionally inserted into the sockets, the carriage is placed in a cooling chamber (18). Air of a selected temperature is blown through a central port (22) and directed to flow over the surface of the carriage and the supported components (10). A motor (60) rotates the carriage to move the electrical contacts (46, 48) successively into electrical communication with relatively soft electrical contact springs (58) connected with a test instrument (32). The test circuit measures electrical characteristics or properties of each component at each of a plurality of preselected temperatures.

Abstract: Method and apparatus for measuring the characteristic frequencies of a monolithic crystal filter and for adjusting them to predetermined values, based on selectively transmitting two balanced decoupled signals through the filter to an output signal detector for exciting and measuring the characteristic frequencies.

Abstract: Method for fine tuning center frequency and bandwidth of a monolithic crystal filter by means of adjusting its two resonator frequencies and its symmetric frequency to predetermined values. The three frequencies are preferably measured in a network that provides two balanced signals and is able to apply them alternately (for the measurement of the two resonator frequencies) and simultaneously (for the measurement of the symmetric frequency) to the two filter ports. The frequencies are adjusted by changing the mass distribution on the crystal wafer in sequential steps.

Abstract: Apparatus for automatic lapping control, based on imbedding an electrode in a lap plate of a lap machine and including at least one piezoelectric wafer in the lap load. Connected with the electrode is an automatic control circuit used for sensing the resonance frequency of the piezoelectric wafer and for terminating lapping when the resonance frequency reaches a presetable target frequency. Also connected with the electrode is an impedance comparator circuit used for sensing the presence and absence of a piezoelectric wafer at the electrode face and for activating the automatic control circuit in the presence of a wafer and deactivating the control circuit in the absence of a wafer.

Abstract: Apparatus for automatic lapping control, based on imbedding an electrode of special construction in a lapping plate of a lapping machine, including at least one piezoelectric wafer in the lapping load, sensing the resonance frequency of the piezoelectric wafers as they pass by the electrode, and automatically terminating the lapping when the resonance frequency equals or exceeds a target frequency; the special electrode construction comprising a facing of a dielectric material with a high dielectric constant and surrounded by an insulator having a low dielectric constant and an average wall thickness larger than its wall thickness at the surface of the lapping plate.

Abstract: Apparatus for automatic lapping control, based on imbedding an electrode of special construction in a lapping plate of a lapping machine, including at least one piezoelectric wafer in the lapping load, sensing the resonance frequency of the piezoelectric wafers as they pass by the electrode, and automatically terminating the lapping when the resonance frequency equals or exceeds a target frequency; the special electrode construction comprising a facing of a dielectric material with a high dielectric constant and surrounded by an insulator having a low dielectric constant and an average wall thickness larger than its wall thickness at the surface of the lapping plate.