ASTM F2750-08

Standard Test Method for Determining the Effects of Bending a Membrane Switch or Assembly

SIGNIFICANCE AND USE
Bending of membrane switches or their components can affect their visual appearance, mechanical integrity or electrical functionality. This test method simulates conditions that may be seen during manufacture, installation or use.
Bend testing may be destructive, therefore any samples tested should be considered unfit for future use.
Specific areas of testing include, but are not limited to:
Membrane switch flex tails, and
Any component of a membrane switch that may be subjected to bending.
SCOPE
1.1 This test method establishes a method for the bending of any part of a membrane switch with conductive circuits.
1.1.1 The values given in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.2 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.

General Information

• Status: Historical
• Publication Date: 31-Oct-2008
• ICS: 29.120.40 - Switches
• Technical Committee: F01 - Electronics
• Drafting Committee: F01.18 - Printed Electronics

Relations

• Replaced By: ASTM F2750-09 - Standard Test Method for Determining the Effects of Bending a Membrane Switch or Assembly
• Effective Date: 15-Jun-2009
• Referred By: ASTM F3290-17 - Standard Guide for Handling and Application of a Membrane Switch or Printed Electronic Device to its Final Support Structure (Withdrawn 2023)
• Effective Date: 01-Nov-2008
• Referred By: ASTM F3147-15 - Standard Test Method for Evaluating the Reliability of Surface Mounted Device (SMD) Joints on a Flexible Circuit by a Rolling Mandrel Bend (Withdrawn 2024)
• Effective Date: 01-Nov-2008

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:F2750–08
Standard Test Method for
Determining the Effects of Bending a Membrane Switch or
Assembly
This standard is issued under the fixed designation F 2750; 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 3.2 Bend testing may be destructive, therefore any samples
tested should be considered unfit for future use.
1.1 This test method establishes a method for the bending of
3.3 Specific areas of testing include, but are not limited to:
any part of a membrane switch with conductive circuits.
3.3.1 Membrane switch flex tails, and
1.1.1 The values given in SI units are to be regarded as the
3.3.2 Any component of a membrane switch that may be
standard. The values given in parentheses are for information
subjected to bending.
only.
1.2 This standard does not purport to address all of the
4. Interferences
safety concerns, if any, associated with its use. It is the
4.1 The following parameters may affect the results of this
responsibility of the user of this standard to establish appro-
test:
priate safety and health practices and determine the applica-
4.1.1 temperature,
bility of regulatory limitations prior to use.
4.1.2 humidity, and
2. Terminology 4.1.3 orientation of the conductor (either extension or com-
pression) could have significant impact on the results.
2.1 Definitions:
2.1.1 bend—to force from a straight form into a different
5. Apparatus
and especially a curved one.
5.1 Mandrel, allowed to rotate smoothly around its longitu-
2.1.1.1 Discussion—In this case, no “hard” or angled crease
dinal axis, rigid, low friction smooth surface. Diameter to be
or fold is to occur. The substrate will only be formed into a
specified.
radius.
5.2 Fixture to hold test sample securely in place in a vertical
2.1.2 bend cycle—a bend of a sample around a specified
manner (refer to Fig. 1).
mandrel which is “rolled” in one direction, followed by rolling
5.3 Mechanism capable of providing a consistent force and
in the opposite direction, returning the sample to its original
rate of pull to the sample.
position (see Fig. 1).
5.4 Equipment for the monitoring and recording of resis-
2.1.3 mandrel—a cylindrically shaped metal rod, such as a
tance.
brazing or drill rod.
2.1.4 membrane switch—a momentary switching device in
6. Test Samples
which at least one contact is on, or made of, a flexible
6.1 The test samples may be components, tail assembles or
substrate.
finished switches. If the sample length is too short for the test
2.1.5 membrane switch tail—a flexible portion of a mem-
fixture, a sample coupon of the same construction (layer to
brane switch used for input/output connection.
layer) must be provided (minimum; 250 mm length by 25 mm
width).
3. Significance and Use
6.2 The width of the test sample must not exceed the length
3.1 Bending of membrane switches or their components can
of the mandrel.
affecttheirvisualappearance,mechanicalintegrityorelectrical
functionality. This test method simulates conditions that may
7. Procedure
be seen during manufacture, installation or use.
7.1 Clamponeendofthetestsampletothetestfixture–this
is the static end of the test sample.
7.1.1 Compression Conductor Testing—conductor side of
This test method is under the jurisdiction of ASTM Committee F01 on
the test sample faces the mandrel.
Electronics and is the direct responsibility of Subcommittee F01.18 on Membrane
7.1.2 Extension Conductor Testing—conductor side of the
Switches.
Current edition approved Nov. 1, 200
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