IEC 60444-8:2016

Measurement of quartz crystal unit parameters - Part 8 : Test fixture for surface mounted quartz crystal units

IEC 60444-8:2016 describes test fixtures suitable for leadless surface mounted quartz crystal units in enclosures as defined in IEC 61837 (all parts). These fixtures allow the measurement of (series) resonance frequency, (series) resonance resistance, and equivalent electrical circuit parameters L1, C1 and C0 using the measurement techniques specified in IEC 60444-5 and for the determination of load resonance frequency and load resonance resistance according to IEC TR 60444-4 and IEC 60444-11.
Two test fixtures are described in this document:
1) A fixture using the p-network circuit with electrical values as described in IEC 60444-1 for measurements in transmission mode up to 500 MHz. This fixture includes optional means to add physical load capacitors for the measurement of load resonance parameters up to 30 MHz in accordance with IEC 60444-4. The range of load capacitance is 10 pF or more. Calibration of the measurement system and CL adapter board is explained hereinafter.
2) A fixture based on the reflection method, suitable for a frequency range up to 1 200 MHz. No provisions for adding a physical load capacitance are anticipated. Load resonance parameters can be measured by using the method of IEC 60444-11.
This edition includes the following significant technical changes with respect to the previous edition:
a) modification of Clause 1;
b) modification of 5.2;
c) modification of 5.3;
d) modification of 5.4;
e) 6.3 Calibration of the reflection measurement system.

Mesure des paramètres des résonateurs à quartz - Partie 8: Dispositif d'essai pour les résonateurs à quartz montés en surface

L'IEC 60444-8:2016 spécifie les dispositifs d'essai appropriés aux résonateurs à quartz sans sorties montés en surface dans des enveloppes tels que définis dans l'IEC 61837 (toutes les parties). Ces dispositifs permettent de mesurer les paramètres de fréquence de résonance (en série), de résistance de résonance (en série) et de circuit électrique équivalents L1, C1 et C0 à l'aide des techniques de mesure spécifiées dans l'IEC 60444-5. Ils permettent également de déterminer la fréquence de résonance à la charge et la résistance de résonance à la charge selon l'IEC TR 60444-4 et l'IEC 60444-11.
Deux dispositifs d'essai sont spécifiés dans le présent document:
1) Un dispositif utilisant le circuit en p avec des valeurs électriques telles que décrites dans l'IEC 60444-1 pour les mesurages en mode de transmission jusqu'à 500 MHz. Ce dispositif comprend des moyens facultatifs permettant d’ajouter des condensateurs de charge physique pour le mesurage des paramètres de résonance à la charge jusqu'à 30 MHz conformément à l'IEC 60444-4. La plage de la capacité de charge est de 10 pF ou plus. L'étalonnage du système de mesure et de la carte d'adaptateur CL est décrit ci-après.
2) Un dispositif fonctionnant selon la méthode de réflexion, approprié pour une plage de fréquences jusqu'à 1 200 MHz. Aucune disposition concernant l'ajout d'une capacité de charge physique n'est prévue. Les paramètres de résonance à la charge peuvent être mesurés en utilisant la méthode spécifiée dans l'IEC 60444-11.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) modification de l'Article 1;
b) modification du 5.2;
c) modification du 5.3;
d) modification du 5.4;
e) 6.3 Étalonnage du système de mesure de réflexion.

General Information

• Status: Published
• Publication Date: 14-Dec-2016
• ICS: 31.140 - Piezoelectric devices
• ICS: 31.180 - Printed circuits and boards
• Technical Committee: TC 49 - Piezoelectric, dielectric and electrostatic devices and associated materials for frequency control, selection and detection
• Drafting Committee: WG 11 - TC 49/WG 11
• Current Stage: PPUB - Publication issued
• Start Date: 16-Jan-2017
• Completion Date: 15-Dec-2016

Relations

• Revises: IEC 60444-8:2003 - Measurement of quartz crystal unit parameters - Part 8: Test fixture for surface mounted quartz crystal units
• Effective Date: 05-Sep-2023

Overview

IEC 60444-8:2016 specifies test fixtures and measurement guidance for leadless surface-mounted quartz crystal units (SMD quartz crystals). It defines two standardized fixture types and associated measurement practices that enable accurate determination of crystal parameters such as series resonance frequency, series resonance resistance, and the equivalent circuit parameters L1, C1 and C0. The standard is intended for use with automatic network-analyzer measurement techniques and error-correction methods described in IEC 60444-5.

Key topics and requirements

• Test fixtures described
  • Transmission (π‑network) fixture: For measurements in transmission mode up to 500 MHz. Includes optional provision for adding physical load capacitors (range: 10 pF or more) to measure load-resonance parameters up to 30 MHz. Calibration procedures for the measurement system and CL adapter board are provided.
  • Reflection fixture: Based on reflection measurement technique and suitable up to 1 200 MHz. No physical load capacitance is provided; load-resonance parameters are determined using methods from IEC 60444-11.
• Measured parameters
  • Series resonance frequency and series resonance resistance
  • Equivalent electrical circuit parameters: L1, C1, C0
  • Load resonance frequency and load resonance resistance (per IEC TR 60444-4 / IEC 60444-11)
• Measurement method
  • Uses automatic network analyzers with error correction as per IEC 60444-5
  • Calibration of both transmission and reflection measurement systems is specified (including Clause 6.3 for reflection-system calibration)
• Applicability
  • Fixtures and methods apply to leadless SMD crystal enclosures as defined in IEC 61837
• Performance notes
  • Standard provides guidance to achieve high accuracy in frequency and resistance measurements; resonance resistance accuracy guidance is explicitly given as ±2 Ω or ±10%.

Applications - who should use this standard

• Crystal manufacturers for production test and specification of SMD quartz devices
• Component test laboratories ensuring repeatable, traceable crystal parameter measurements
• Oscillator and timing-device designers who need reliable equivalent-circuit data and load-resonance behavior
• Test-fixture and test-equipment manufacturers developing measurement adapters and calibration kits for SMD crystals
• Quality and compliance engineers validating component performance in oscillator designs

Related standards

• IEC 60444-1, -4, -5, -11 (other parts of the Measurement of quartz crystal unit parameters series)
• IEC 61837 (enclosure definitions for SMD crystals)
• IEC 60122-1 (equivalent circuit models referenced for crystals)

This standard helps ensure consistent, reproducible measurement of SMD quartz crystal parameters across manufacturers and test labs, supporting accurate component specification, device qualification, and oscillator design. Keywords: IEC 60444-8:2016, quartz crystal unit, SMD, test fixture, π-network, reflection method, resonance frequency, equivalent electrical parameters, calibration, network analyzer.

Standards Content (Sample)

IEC 60444-8 ®
Edition 2.0 2016-12
INTERNATIONAL
STANDARD
colour
inside
Measurement of quartz crystal unit parameters –
Part 8: Test fixture for surface mounted quartz crystal units
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: [phone]
3, rue de Varembé Fax: [phone]
CH-1211 Geneva 20 [e-mail]
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

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IEC 60444-8 ®
Edition 2.0 2016-12
INTERNATIONAL
STANDARD
colour
inside
Measurement of quartz crystal unit parameters –

Part 8: Test fixture for surface mounted quartz crystal units

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 31.140 ISBN 978-2-8322-3718-2

– 2 – IEC 60444-8:2016 © IEC 2016
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Specifications . 6
4 Leadless surface mounted quartz crystal units . 6
4.1 Enclosure . 6
4.2 Overtone and frequency range . 7
5 Specifications of measurement method, test fixture . 7
5.1 Specifications of measurement method . 7
5.2 Specifications of transmission test fixture . 7
5.3 Specifications of reflection test fixture . 10
5.4 Measuring equipment . 13
6 Calibration . 13
6.1 Calibration of the transmission test system . 13
6.2 Additional calibration of the transmission test system with C adapter board . 13
L
6.3 Calibration of the reflection measurement system . 13
Bibliography . 15

Figure 1 – Transmission π-network test fixture: Simplified equivalent circuit diagram,
frequency range from 1 MHz to 500 MHz . 7
Figure 2 – Transmission π-network test Fixture with physical load capacitors: simplified
equivalent circuit, frequency range from 1 MHz to 30 MHz . 7
Figure 3 – Transmission π-network test fixture: Three-dimensional projection for the test
fixture . 8
Figure 4 – Transmission π-network test fixture: Mechanical design of the test fixture . 9
Figure 5 – Transmission π-network test fixture with physical load capacitors: Structure
of the test fixture . 10
Figure 6 – Design of the reflection test fixture . 11
Figure 7 – Mechanical details of the reflection test fixture . 13
Figure 8 – Calibration technique for the reflection test fixture . 14

INTERNATIONAL ELECTROTECHNICAL COMMISSION
______________
MEASUREMENT OF QUARTZ CRYSTAL UNIT PARAMETERS –

Part 8: Test fixture for surface mounted quartz crystal units

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60444-8 has been prepared by IEC technical committee 49:
Piezoelectric, dielectric and electrostatic devices and associated materials for frequency
control, selection and detection.
This second edition cancels and replaces the first edition published in 2003. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) modification of Clause 1;
b) modification of 5.2;
c) modification of 5.3;
d) modification of 5.4;
– 4 – IEC 60444-8:2016 © IEC 2016
e) 6.3 Calibration of the reflection measurement system.
The text of this standard is based on the following documents:
CDV Report on voting
49/1126/CDV 49/1175/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60444 series, published under the general title Measurement of
quartz crystal unit parameters, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to
the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
INTRODUCTION
This document focuses on test fixtures applied to leadless surface mounted quartz crystal units.
The document is the specification for fixtures [1][2] that allow the measurement of (series)
resonance frequency, (series) resonance resistance, and equivalent electrical circuit
parameters of leadless surface mounted quartz crystal units. The measurement method using
an automatic network analyzer with error correction is described in IEC 60444-5, which also
contains proposals for test fixtures for quartz crystal units in through-hole packages.
The measuring frequency range is from 1 MHz to 1 200 MHz, and is limited to 1 MHz to
30 MHz, if a physical load capacitance is used. The use of the test fixtures in connection with
−6
error correction measurement techniques yields measurement accuracy of about 10 over of
the frequency range, and the accuracy of the resonance resistance is ±2 Ω or ±10 %.
This document forms Part 8 of a series of publications dealing with measurements of quartz
crystal unit parameters.
The IEC 60444 series consists of the following parts under the general title Measurement of
quartz crystal unit parameters:
Part 1: Basic method for the measurement of resonance frequency and resonance resistance
of quartz crystal units by zero phase technique in a π-network
Part 2: Phase offset method for measurement of motional capacitance of quartz crystal units
Part 4: Method for the measurement of the load resonance frequency f , load resonance
L
resist
...

IEC 60444-8 ®
Edition 2.0 2016-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Measurement of quartz crystal unit parameters –
Part 8: Test fixture for surface mounted quartz crystal units

Mesure des paramètres des résonateurs à quartz –
Partie 8: Dispositif d'essai pour les résonateurs à quartz montés en surface

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
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About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

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documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

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The advanced search enables to find IEC publications by a 65 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

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IEC 60444-8 ®
Edition 2.0 2016-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Measurement of quartz crystal unit parameters –

Part 8: Test fixture for surface mounted quartz crystal units

Mesure des paramètres des résonateurs à quartz –

Partie 8: Dispositif d'essai pour les résonateurs à quartz montés en surface

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 31.140 ISBN 978-2-8322-4182-0

– 2 – IEC 60444-8:2016 © IEC 2016
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Specifications . 6
4 Leadless surface mounted quartz crystal units . 6
4.1 Enclosure . 6
4.2 Overtone and frequency range . 7
5 Specifications of measurement method, test fixture . 7
5.1 Specifications of measurement method . 7
5.2 Specifications of transmission test fixture . 7
5.3 Specifications of reflection test fixture . 10
5.4 Measuring equipment . 13
6 Calibration . 13
6.1 Calibration of the transmission test system . 13
6.2 Additional calibration of the transmission test system with C adapter board . 13
L
6.3 Calibration of the reflection measurement system . 13
Bibliography . 15

Figure 1 – Transmission π-network test fixture: Simplified equivalent circuit diagram,
frequency range from 1 MHz to 500 MHz . 7
Figure 2 – Transmission π-network test Fixture with physical load capacitors: simplified
equivalent circuit, frequency range from 1 MHz to 30 MHz . 7
Figure 3 – Transmission π-network test fixture: Three-dimensional projection for the test
fixture . 8
Figure 4 – Transmission π-network test fixture: Mechanical design of the test fixture . 9
Figure 5 – Transmission π-network test fixture with physical load capacitors: Structure
of the test fixture . 10
Figure 6 – Design of the reflection test fixture . 11
Figure 7 – Mechanical details of the reflection test fixture . 13
Figure 8 – Calibration technique for the reflection test fixture . 14

INTERNATIONAL ELECTROTECHNICAL COMMISSION
______________
MEASUREMENT OF QUARTZ CRYSTAL UNIT PARAMETERS –

Part 8: Test fixture for surface mounted quartz crystal units

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60444-8 has been prepared by IEC technical committee 49:
Piezoelectric, dielectric and electrostatic devices and associated materials for frequency
control, selection and detection.
This bilingual version (2017-04) corresponds to the monolingual English version, published in
2016-12.
This second edition cancels and replaces the first edition published in 2003. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) modification of Clause 1;
b) modification of 5.2;
– 4 – IEC 60444-8:2016 © IEC 2016
c) modification of 5.3;
d) modification of 5.4;
e) 6.3 Calibration of the reflection measurement system.
The text of this standard is based on the following documents:
CDV Report on voting
49/1126/CDV 49/1175/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
The French version of this standard has not been voted upon.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60444 series, published under the general title Measurement of
quartz crystal unit parameters, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to
the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
INTRODUCTION
This document focuses on test fixtures applied to leadless surface mounted quartz crystal units.
The document is the specification for fixtures [1][2] that allow the measurement of (series)
resonance frequency, (series) resonance resistance, and equivalent electrical circuit
parameters of leadless surface mounted quartz crystal units. The measurement method using
an automatic network analyzer with error correction is described in IEC 60444-5, which also
contains proposals for test fixtures for quartz crystal units in through-hole packages.
The measuring frequency range is from 1 MHz to 1 200 MHz, and is limited to 1 MHz to
30 MHz, if a physical load capacitance is used. The use of the test fixtures in connection with
−6
error correction measurement techniques yields measurement accuracy of about 10 over of
the frequency range, and the accuracy of the resonance resistance is ±2 Ω or ±10 %.
This document forms Part 8 of a series of publications dealing with measurements of quartz
crystal unit parameters.
The IEC 60444 series consists of the following parts under the general title Measurement of
quartz crystal unit parameters:
Part 1: Basic method for the measurement of resonance frequency and resonance resistance
of quartz crystal units by zero phase technique in a π-network
Part 2: Phase offset method for measurement of motional capacitance of quartz crystal units
Part 4: Method for the measurement of the load resonance frequency f , load resonance
L
resistance R and the calculation of other derived values of quartz crystal units, up to
L
30 MHz
Part 5: Methods for the determination of equivalent electrical parameters using automatic
network analyzer techniques and error correction
Part 6: Measurement of drive level dependence (DLD)
Part 7: Measurement of activity and frequency dips of quartz crystal units
Part 8 Text fixture for surface mounted quartz crystal units
Part 11 Standard method for the determination of the load resonance frequency f and the
L
effective load capacitance C using automatic network analyzer techniques and
Leff
error correction.
___________
Numbers in square brackets refer to the Bibliography.

– 6 – IEC 60444-8:2016 © IEC 2016
MEASUREMENT OF QUARTZ CRYSTAL UNIT PARAMETERS –

Part 8: Test fixture for surface mounted quartz crystal units

1 Scope
This part of IEC 60444 describes test fixtures suitable for leadless surface mounted quartz
crystal units in enclosures as defined in IEC 61837 (all parts). These fixtures allow the
measurement of (series) resonance frequency, (series) resonance resistance, and equivalent
electrical circuit parameters L , C and C using the measurement techniques specified in
1 1 0
IEC 60444-5 and for the determination of load resonance frequency and load resonance
resistance according to IEC TR 60444-4 and IEC 60444-11.
Two test fixtures are described in this document:
1) A fixture using the π-network circuit with electrical values as described in IEC 60444-1 for
measurements in transmission mode up to 500 MHz. This fixture includes optional means
to add physical load capacitors for the measurement of load resonance parameters up to
30 MHz in accordance with IEC 60444-4. The range of load capacitance is 10 pF or more.
Calibration of the measurement system and C adapter board is explained hereinafter.
L
2) A fixture based on the reflection method, suitable for a frequency range up to 1 200 MHz.
No provisions for adding a physical load capacitance are anticipated. Load resonance
parameters can be measured by using the method of IEC 60444-11.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements 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 60444-5, 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 Specifications
The test fixture and the method for measuring the (series) resonance frequency, (series)
resonance resistance, and equivalent electrical circuit parameters shall 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, in particular if load resonance parameters are to be
determined [3].
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 61837, be used.

4.2 Overtone and frequency range
No particular specification shall be made regarding the overtone. The frequency range is from
1 MHz to 500 MHz for the described transmission fixture when the physical load capacitance is
not used, and from 1 MHz to 30 MHz when the physical load capacitance is used. The
frequency range for the reflection fixture is up to 1 200 MHz.
5 Specifications of measurement method, test fixture
5.1 Specifications of measurement method
The basic measurement method is IEC 60444-5. The model of equivalent circuit of the quartz
crystal unit is shown in IEC 60122-1. It could be necessary to use a more advanced model for
the housed crystal in the high frequency range above several hundred MHz. Depending on the
construction of the SMD enclosure, different results may occur between grounded and
ungrounded measurements, namely for the measurement of load resonance parameters [3], [4].
If the crystal is grounded in the application, the working frequency may depend on the
orientation of the crystal in the circuit. It is therefore recommended to make use of the
orientation mark on the crystal (for example pad 1) when correlating the working frequency in
the oscillator with the load resonance measurement according to IEC 60444-5.
5.2 Specifications of transmission test fixture
The equivalent circuit of the π-network test fixture and its electric values are based on
IEC 60444-1. To match the leadless crystal packages, the size and the structure are different
in this document from those of IEC 60444-1 and IEC 60444-5. The test fixture configuration is
similar to that in IEC 60444-1. Figure 1 and Figure 2 show the test fixture, but stray
capacitances between measurement terminals such as C and C in IEC 60444-1:1986,
t1 t2
Figure 2, are not specified. Figure 3 and Figure 4 show a 3-D view and the mechanical design
of the test fixture.
Crystal Crystal
Load
Input Output
Input capacitance Output
IEC IEC
Figure 1 – Transmission π-network test Figure 2 – Transmission π-network test
fixture: Simplified equivalent circuit Fixture with physical load capacitors:
diagram, frequency range from 1 MHz to simplified equivalent circuit, frequency
500 MHz range from 1 MHz to 30 MHz

– 8 – IEC 60444-8:2016 © IEC 2016

IEC
Figure 3 – Transmission π-network test fixture:
Three-dimensional projection for the test fixture

Dimensions in millimetres
IEC
Figure 4 – Transmission π-network test fixture: Mechanical design of the test fixture
No specifications need to be made as to the detail structures of the test fixture to be used,
except that it shall secure a reliable mechanical contact of the electrodes performing the same
function as the lead wire of a through-hole quartz crystal unit and the measurement terminals
of the test fixture. The reference plane of the measurement is the plane of the SMD pads. The
necessary mechanical force to assure a reliable contact is 2 N.
Figure 5 shows the structure of the π-network test fixture with physical load capacitors.

49,9
7,4
11,4
– 10 – IEC 60444-8:2016 © IEC 2016
Crystal unit positioning board
Shorting plate
50 Ω Crystal unit
C Adapter board
L
C Adjustment
L
Contact board
IEC
Figure 5 – Transmission π-network test fixture with physical load capacitors:
Structure of the test fixture
5.3 Specifications of reflection test fixture
The mechanical design of the reflection test fixture is shown in Figures 6, and its usable
frequency range is from 1 MHz to 1 200 MHz [2]. It is the SMD version of the one-port
reflection test fixture shown in IEC 60444-5.

Dimensions in millimetres
ø62
ø88,8
M5 screw × 4
36,5
IEC
a) Top view
ø12
APC 3,5 mm connector (FEMALE)
APC 3,5 mm connector (MALE)
Coaxial semi-rigid cable
IEC
b) Cross section view
Figure 6 – Design of the reflection test fixture
The test fixture is to be connected with the s port of the network analyser through a high
quality coaxial cable with an APC 3,5 precision coaxial connector at the test fixture side. For
higher frequencies, the use of semi-rigid or rigid coaxial cable is recommended.

60,3
– 12 – IEC 60444-8:2016 © IEC 2016
The device under test (DUT) is fixed to the measurement adapter as shown in Figure 7. A
guide plate to fix the DUT shall be designed in accordance with IN-OUT terminals of the DUT.
A contact pin is inserted into the central conductor of the coaxial connector at the DUT side.
Care shall be taken during the insertion to avoid deformation due to excessive force.
A holding clamp is screwed and fixed to the base unit. The depth of the screw motion shall be
adjusted in accordance with the mechanical conditions. If the clamp is screwed too tightly, the
coaxial connector or DUT may be damaged. Adjust the length of the M5 screw such that it will
not penetrate too deeply into the measurement unit.
Measurement adapter
(Stainless steel)
Guide plate for crystal
(Gold finish on brass)
4-M3 screw
Contact terminal
Device mounted area
GND terminal
IEC
a) Top view
Knurled knob
(Rotated to fix the device)
Positioning lever
Crystal device
IEC
b) Cross section view
Figure 7 – Mechanical details of the reflection test fixture

5.4 Measuring equipment
The vector network analyzer shall provide an error-correction-feature using internal
mathematical processing of the measurement values, and shall be able to effectively eliminate
the causes of errors via the connection of the S-parameter equipment with the test fixture.
6 Calibration
6.1 Calibration of the transmission test system
The calibration is done in accordance with IEC 60444-5 by the use of three reliable standard
impedance elements for calibration. These are: a short element, an open element and a load
element of 25 Ω or 50 Ω.
The specification of the load element of 25 Ω or 50 Ω has to be prescribed in the range from
1 MHz to 500 MHz. For low frequencies < 150 MHz, it is sufficient if the resistance value is
50 Ω ± 5 % and the phase is 0,2° maximum. For higher frequencies, the calibration elements
shall be described by the elements for their equivalent electric circuit (see IEC 60444-5 for
details).
adapter board
6.2 Additional calibration of the transmission test system with C
L
A precision capacitance meter is used for the calibration of the C adapter board. The
L
measurement shall be done at 1 MHz. The permissible tolerance is ±0,02 pF.
6.3 Calibration of the reflection measurement system
A 3-term calibration of the measurement system shall be performed before connecting the test
fixture to the end of a coaxial cable. Precise APC 3,5 calibration devices (Open, Short,
Termination) shall be used, which have a guaranteed characteristics in the measurement
frequency band. After connecting the cable to the test fixture without a crystal unit inserted, the

– 14 – IEC 60444-8:2016 © IEC 2016
measured phase will rotate in the Open condition. For compensation of the phase error, an
electrical length shall be added. See Figure 8 for details.
OPEN
Instrument side
SHORT
Coaxial cable
Termination
Reference plane
(50 Ω)
Standard devices
IEC
a) Calibration method
IEC
b) Compensation for electrical length
Figure 8 – Calibration technique for the reflection test fixture

Bibliography
[1] M. Koyama, Y. Watanabe, Y. Oomura, Results of the quartz crystal measurement data
obtained at the leadless resonator measurement workshop held in Japan, in
th
Annual Symposium on Frequency Control, May 1993, p. 614-
Proceedings of the 47
[2] Y. Watanabe, M. Wada, Y. Sakuta, M.Hattori, O. Takahashi, Precision Test Fixture for
Measuring Equivalent Circuit Parameters of GHz Surface-Mounted Quarts Crystal Units,
Japanese Journal of Applied Physics 51 (2012) 07GC09
[3] M.van Herwijnen, F.Sohre, Load-Resonance Measurement Accuracy of Ceramic
th
Surface Mount Quartz Crystals 14 EFTF 2000 p. 285
th
[4] E. Seydel Measurement method for high frequency quartz crystals, 11 EFTF 1997
p. 453
[5] IEC 60122-1, Quartz crystal units of assessed quality – Part 1: Generic specification
[6]
...