IEC 60444-8-2003 pdf – Measurement of quartz crystal unit parameters – Part 8: Test fixture for surface mounted quartz crystal units.
1 Scope This part of IEC 60444 explains the test fixture that allows the accurate measurement of resonance frequency, resonance resistance, and equivalent electrical circuit parameters of a leadless surface mounted quartz crystal units using zero phase technique as specified in IEC 60444-4 and IEC 60444-5. An equivalent circuit constant and the application frequency range obtained by using the test fixture are then shown. In addition, this is applied to the enclosure shown in IEC 61240 as a crystal unit without lead wires. An equivalent circuit of the test fixture and an electric values are based on IEC 60444-1 and IEC 60444-4. The range of load capacitance is 10 pF or more. Calibration of the measurement system and C L adapter board is explained hereinafter. This document applies to the test fixture that allows the accurate measurement of resonance frequency, resonance resistance, parallel capacitance C 0 , motional capacitance C 1 , and motional inductance L 1 of the crystal unit over the frequency range from 1 MHz to 150 MHz using an automatic network analyzer, based on IEC 60444-5. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60444-1:1986, Measurement of quartz crystal unit parameters by zero phase technique in a pi-network – Part 1: Basic method for the measurement of resonance frequency and resonance resistance of quartz crystal units by zero phase technique in a pi-network IEC 60444-2:1980, Measurement of quartz crystal unit parameters by zero phase technique in a pi-network – Part 2: Phase offset method for measurement of motional capacitance of quartz crystal units IEC 60444-5:1995, Measurement of quartz crystal units parameters – Part 5: Methods for the determination of equivalent electrical parameters using automatic network analyzer techniques and error correction
3 General issue The test fixture and the method for measuring the resonance frequency, resonance resistance, and equivalent electrical circuit parameters must be specified in the contract between the crystal unit supplier and the user. The crystal unit requires special consideration as it has no lead wires. 4 Leadless surface mounted quartz crystal units 4.1 Enclosure No particular specification shall be made regarding the enclosure type. However, it is recommended that enclosures such as those shown in IEC 61240, be used. 4.2 Overtone and frequency range No particular specification shall be made regarding the overtone, because the measurement is made using the zero phase technique. The frequency range is from 1 MHz to 150 MHz when the load capacitance is not used, and is from 1 MHz to 30 MHz when the load capacitance is used. 5 Specifications of measurement method, test fixture 5.1 Specifications of measurement method The measurement method is according to IEC 60444-5. The method uses the admittance circle technique. 5.2 Specifications of test fixture An equivalent circuit of the test fixture and electric values are based on IEC 60444-1. The size and the structure are different in this document from those of IEC 60444-1. The size and the structure suit leadless crystal units. The test fixture configuration is as specified in IEC 60444-1. Figure 1 and Figure 2 show the test fixture, but stray capacitances between measurement terminals such as C t1 and C t2 in Figure 2 of IEC 60444-1 are not specified. Figure 3 and Figure 4 show 3-D and design of the test fixture. No specifications shall be made as to the structures of the test fixture to be used, except that they must secure the mechanical contact of the electrode performing the same function as the lead wire of an ordinary quartz crystal unit and the measurement terminals of the test fixture.