ASTM F1681-14

Standard Test Method for Determining Current Carrying Capacity of a Membrane Switch Circuit (Withdrawn 2023)

SIGNIFICANCE AND USE
4.1 Current carrying capacity is used by designers and manufacturers of electronic interface circuitry to ensure that the membrane switch can reliably handle the loads occurring in normal use and under extreme circumstances. A thorough understanding of CCC allows manufacturers to take it into account when developing design rules for membrane switches.  
4.2 Failures due to exceeding the CCC of a circuit may take the form of a significant change in conductor resistance, insulation breakdown (shorts), or conductor breakdown (opens).  
4.3 Since a number of design parameters, such as trace width, ink film thickness, and heat transfer (mounting substrates, active cooling such as fans) affect the final test results, any conclusions should only be applied to specific designs, rather than to a general combination of materials.  
4.4 Current carrying capacity tests may be destructive and units that have been tested should be considered unreliable for future use.  
4.5 Current carrying capacity may be significantly different for static loads and dynamic (that is, cycling) loads. Failure modes are also generally different.  
4.6 The use of a thermocouple to monitor the temperature of the UUT may be helpful to monitor the progress of the test.  
4.7 Initial expected starting current should be calculated in advance to prevent damage to test equipment.
SCOPE
1.1 This test method covers the determination of the current carrying capacity of a conductor as part of a membrane switch.  
1.2 This test method may be used to test a circuit to destruction, that is, to determine its maximum current carrying capacity, or it may be used to test the ability of a circuit to withstand a desired current level.  
1.3 This test method applies only to static conditions, and does not apply to contact closure cycling of a membrane switch under current load (test method forthcoming).  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
WITHDRAWN RATIONALE
This test method covers the determination of the current carrying capacity of a conductor as part of a membrane switch.
Formerly under the jurisdiction of Committee F01 on Electronics, this test method was withdrawn in January 2023 in accordance with section 10.6.3 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.

General Information

• Status: Withdrawn
• Publication Date: 31-Dec-2013
• Withdrawal Date: 09-Jan-2023
• ICS: 19.080 - Electrical and electronic testing
• ICS: 29.120.40 - Switches
• Technical Committee: F01 - Electronics
• Drafting Committee: F01.18 - Printed Electronics

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: F1681 − 14
Standard Test Method for
Determining Current Carrying Capacity of a Membrane
1
Switch Circuit
This standard is issued under the fixed designation F1681; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.4 membrane switch—a momentary switching device in
which at least one contact is on, or made of, a flexible
1.1 This test method covers the determination of the current
substrate.
carrying capacity of a conductor as part of a membrane switch.
3.1.5 power capacity—electrical power is defined as cur-
1.2 This test method may be used to test a circuit to
rent × voltage=V×I (watts).
destruction, that is, to determine its maximum current carrying
3.1.6 test points—two preselected conductive points in a
capacity, or it may be used to test the ability of a circuit to
circuit loop, possibly including a switch.
withstand a desired current level.
1.3 This test method applies only to static conditions, and
4. Significance and Use
doesnotapplytocontactclosurecyclingofamembraneswitch
4.1 Current carrying capacity is used by designers and
under current load (test method forthcoming).
manufacturers of electronic interface circuitry to ensure that
1.4 This standard does not purport to address all of the
themembraneswitchcanreliablyhandletheloadsoccurringin
safety concerns, if any, associated with its use. It is the
normal use and under extreme circumstances. A thorough
responsibility of the user of this standard to establish appro-
understanding of CCC allows manufacturers to take it into
priate safety and health practices and determine the applica-
account when developing design rules for membrane switches.
bility of regulatory limitations prior to use.
4.2 Failures due to exceeding the CCC of a circuit may take
2. Referenced Documents
the form of a significant change in conductor resistance,
2
insulation breakdown (shorts), or conductor breakdown
2.1 ASTM Standards:
(opens).
F1578 Test Method for Contact Closure Cycling of a Mem-
brane Switch
4.3 Since a number of design parameters, such as trace
F1680 Test Method for Determining Circuit Resistance of a
width, ink film thickness, and heat transfer (mounting
Membrane Switch
substrates, active cooling such as fans) affect the final test
results, any conclusions should only be applied to specific
3. Terminology
designs, rather than to a general combination of materials.
3.1 Definitions:
4.4 Current carrying capacity tests may be destructive and
3.1.1 conductor resistance—the measured electrical resis-
units that have been tested should be considered unreliable for
tance through a circuit loop between two test points.
future use.
3.1.2 Discussion—When a switch is included in that loop, it
4.5 Current carrying capacity may be significantly different
shall be ''closed” in accordance with Test Method F1680.
for static loads and dynamic (that is, cycling) loads. Failure
3.1.3 current carrying capacity (CCC)—themaximumlevel
modes are also generally different.
of electrical current that a circuit can conduct without sustain-
4.6 Theuseofathermocoupletomonitorthetemperatureof
ing damage.
the UUT may be helpful to monitor the progress of the test.
1
4.7 Initial expected starting current should be calculated in
This test method is under the jurisdiction of ASTM Committee F01 on
Electronics and is the direct responsibility of Subcommittee F01.18 on Membrane
advance to prevent damage to test equipment.
Switches.
Current edition approved Jan. 1, 2014. Published January 2014. Originally
5. Interferences
approved in 1996. Last previous edition approved in 2007 as F1681–07a. DOI:
10.1520/F1681-14.
5.1 The following parameters may affect the results of this
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
test:
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
5.1.1 Temperature,
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 5.1.2 Relative humidity,
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F1681 − 14
5.1.3 Heat transfer characteristics of mounting substrates, 8.2.4 If the test is intended to go to destruction, and no
5.1.4 Active cooling, degradation occurs at the maximum level, the test may be
5.1.5 Imperfection or variation in conductor deposition, repeated using a higher power (voltage and current) level, a
5.1.6 Inconsistencies in the homogeneity of the conductor. change in the voltage range is permissible.
8.2.5 At the con
...