IEC PAS 61747-5-3:2007

PUBLICLY
IEC
AVAILABLE
PAS 61747-5-3
SPECIFICATION
First edition
Pre-Standard
2007-05
Liquid crystal display devices –
Part 5-3:
Liquid crystal display devices –
Glass strength and reliability
measurement method
Reference number
IEC/PAS 61747-5-3:2007(E)
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PUBLICLY
IEC
AVAILABLE
PAS 61747-5-3
SPECIFICATION
First edition
Pre-Standard
2007-05
Liquid crystal display devices –
Part 5-3:
Liquid crystal display devices –
Glass strength and reliability
measurement method
PRICE CODE
Commission Electrotechnique Internationale Q

International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue

– 2 – PAS 61747-5-3 © IEC:2007(E)

CONTENTS
FOREWORD.3

INTRODUCTION.4

1 Scope and object.5

2 Normative references .5

3 Terms and definitions .5

4 Abbreviated terms .6
5 Apparatus.6
5.1 Method A: Quasistatic biaxial strength.6
5.2 Method B: Quasistatic edge strength (parent glass).7
5.3 Method C: Quasistatic strength (module).8
5.4 Method D: Fatigue constant.8
6 Test sample.9
6.1 Parent glass .9
6.2 Full-size module .9
7 Procedure: Quasistatic loading .9
8 Stress calculations .9
8.1 Quasistatic biaxial strength (parent glass) .9
8.2 Quasistatic edge strength (parent glass) .10
8.3 Quasistatic failure load (LCD module) .10
9 Fatigue and reliability calculations .10
9.1 Fatigue constant calculation .11
9.2 Weibull parameter calculation from dynamic failure stress data .11
9.3 Static fatigue failure probability calculation.11
10 Reporting requirements .12
Annex A (informative)  Worked test example.13
Annex B (informative)  Bibliography .16

Figure 1 – Schematic of ROR test fixture for measuring biaxial strength of parent
glass.7
Figure 2 – Vertical bend test fixture for measuring the edge strength of parent glass .7

Figure 3 – Schematic of strength measurement for full-size LCD module .8
Figure A.1 – Weibull plot of biaxial strength of abraded glass with different
thicknesses.13
Figure A.2 – Fracture surface of parent glass with 0,089 mm mirror radius .14
Figure A.3 – Plot of calculated strength versus 1/square root of mirror radius .14
Figure A.4 – Weibull distribution of the strength of 17” module.15

Table A.1 – Strength data before and after abrasion .13
Table A.2 – Strength data and Weibull parameters .15

PAS 61747-5-3 © IEC:2007(E) – 3 –

INTERNATIONAL ELECTROTECHNICAL COMMISSION

___________
LIQUID CRYSTAL DISPLAY DEVICES –

Part 5-3: Liquid crystal display devices – Glass strength

and reliability measurement method

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
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
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A PAS is a technical specification not fulfilling the requirements for a standard but made
available to the public.
IEC-PAS 61747-5-3 has been processed by IEC technical committee 110: Flat panel display devices.
The text of this PAS is based on the This PAS was approved for
following document: publication by the P-members of the
committee concerned as indicated in
the following document:
Draft PAS Report on voting
110/85/NP 110/103/RVN
Following publication of this PAS, which is a pre-standard publication, the technical committee
or subcommittee concerned will transform it into an International Standard.
This PAS shall remain valid for an initial maximum period of three years starting from
2007-05. The validity may be extended for a single three-year period, following which it shall
be revised to become another type of normative document or shall be withdrawn.

– 4 – PAS 61747-5-3 © IEC:2007(E)

INTRODUCTION
This PAS is devoted to the mechanical reliability of liquid crystal display (LCD) devices. This

PAS is restricted to transmissive or reflective LCD modules using either segment, passive or

active matrix and achromatic or colour-type LCDs that are equipped with their own integrated

source of illumination or without their own source of illumination. Analysis and testing are

performed on LCD module component glass as well as finished on LCD modules. Statistics of

the mechanical strength of the modules are determined, allowing a prediction of module

failure probability at a given stress level, or, for a given probability of failure, the maximum

recommended safe loading stress for the module.

PAS 61747-5-3 © IEC:2007(E) – 5 –

LIQUID CRYSTAL DISPLAY DEVICES –

Part 5-3: Liquid crystal display devices – Glass strength

and reliability measurement method

1 Scope and object
This PAS applies to commercially available liquid crystal displays (LCDs).
This PAS applies to all LCD types, including transmissive, reflective or transflective LCD
modules using either segment, passive or active matrix and achromatic or colour-type LCDs
that are equipped with their own integrated source of illumination or without their own source
of illumination.
The object of this PAS is to establish uniform requirements for accurate and reliable
measurements of the following LCD parameters, as defined herein:
a) quasistatic strength;
b) quasistatic fatigue.
The methods described in this PAS apply to all sizes, small and large, of LCDs.
Methods for measuring the fatigue constant are described in this PAS and are taken from the
referenced literature [13-20]. The primary results are formulae for estimated allowable stress
for the specified lifetime or estimated failure rate for the specified stress level. By way of an
example, limited data for strength and fatigue behaviour of LCD glass are included in an
informative annex to this PAS. Similarly, limited data for the static strength of LCD modules is
also included and compared with that of parent glass
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 61747-5, Liquid crystal display devices – Part 5: Environmental, endurance and
mechanical test methods
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
strength
stress at which a sample fails for a given loading condition
3.2
LCD surface strength
biaxial strength wherein surface flaws with different orientations are subjected to uniform
tension during measurement [1-4]
3.3
LCD edge strength
uniaxial strength wherein edge flaws are subjected to tension during measurement [5-8]

– 6 – PAS 61747-5-3 © IEC:2007(E)

3.4
LCD (mechanical) reliability
Reliability expressed as either an estimated allowable stress which the LCDs can sustain for a

speci
...