ASTM F1995-12
(Test Method)Standard Test Method for Determining the Shear Force of a Surface Mount Device (SMD) in a Membrane Switch
Standard Test Method for Determining the Shear Force of a Surface Mount Device (SMD) in a Membrane Switch
SIGNIFICANCE AND USE
The different combinations of SMD types, attachment medias, circuit substrates, plating options, and process variation can account for significant variation in test outcome.
The SMD shear strength test is useful to manufacturers and users for determining the bond strength of the component to the membrane switch circuit.
SCOPE
1.1 This test method covers the determination of the shear integrity of materials and procedures used to attach surface mount devices (SMD) to a membrane switch circuit.
1.2 This test method is typically used to indicate the sufficient cure of conductive adhesive or underfill, or both. In general, this test method should be used prior to encapsulant. This test may also be used to demonstrate the Shear Force with encapsulation.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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.
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Designation: F1995 − 12
StandardTest Method for
Determining the Shear Force of a Surface Mount Device
1
(SMD) in a Membrane Switch
This standard is issued under the fixed designation F1995; 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. Significance and Use
1.1 This test method covers the determination of the shear 3.1 The different combinations of SMD types, attachment
integrity of materials and procedures used to attach surface medias, circuit substrates, plating options, and process varia-
mount devices (SMD) to a membrane switch circuit. tion can account for significant variation in test outcome.
1.2 This test method is typically used to indicate the 3.2 The SMD shear strength test is useful to manufacturers
sufficient cure of conductive adhesive or underfill, or both. In and users for determining the bond strength of the component
general, this test method should be used prior to encapsulant. to the membrane switch circuit.
This test may also be used to demonstrate the Shear Force with
4. Interferences
encapsulation.
4.1 The following parameters may affect the results of this
1.3 The values stated in SI units are to be regarded as
test:
standard. No other units of measurement are included in this
4.1.1 Temperature and humidity, and
standard.
4.1.2 Substrate movement during test.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5. Apparatus
responsibility of the user of this standard to establish appro-
5.1 Device, shall consist of a load-applying instrument with
priate safety and health practices and determine the applica-
an accuracy of 6 5 % of full scale capable of indicating peak
bility of regulatory limitations prior to use.
hold.
2. Terminology
5.2 Mounting Fixture, method to secure specimen to insure
stability during test.
2.1 Definitions:
2.1.1 membrane switch—A momentary switching device in
5.3 SMD Contact Tool, suitable to apply a uniform distri-
which at least one contact is on (or made of) a flexible
bution of force to an edge of the SMD.
substrate.
5.4 Magnification Device, suitable to facilitate visual obser-
2.1.2 shear load—A force applied parallel to the mounting
vation of the SMD and contact tool interface during testing
surface sufficient to shear the SMD from its mounting.
(optional).
2.1.3 SMD—Abbreviation for surface mount device (for
example, light emitting diode (LED), resistor)
6. Procedure
2.1.4 attachment media—A mounting adhesive used for
6.1 Pretest Setup:
electrical or mechanical bonding, or both, of the SMD to the
6.1.1 Attach specimen to the test base to minimize move-
substrate.
ment of the substrate during test. Ensure that no damage occurs
during attachment to the test base that could affect bond
2.1.5 plating—A thin metallic coating (that is, gold, nickel)
performance.
covering the leads of the SMD or circuit, or both, in the
6.1.2 Thedirectionofappliedforceshallbeparallelwiththe
electrical interface area.
plane of the circuit substrate.
6.1.3 The SMD contact tool shall load against an edge of the
component, which most closely approximates a
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:F1995–00(Reapproved2005) Designation:F1995–12
Standard Test Method for
Determining the Bond Strength of a Surface Mount Device
(SMD) on a Membrane Switch by Applying Shear Force
Determining the Shear Force of a Surface Mount Device
1
(SMD) in a Membrane Switch
This standard is issued under the fixed designation F1995; 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
1.1 This test method covers the determination of the shear integrity of materials and procedures used to attach surface mount
devices (SMD) to a membrane switch circuit.
1.2
1.2 This test method is typically used to indicate the sufficient cure of conductive adhesive or underfill, or both. In general, this
test method should be used prior to encapsulant. This test may also be used to demonstrate the Shear Force with encapsulation.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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.
2. Terminology
2.1 Definitions:
2.1.1 membrane switch—A momentary switching device in which at least one contact is on (or made of) a flexible substrate.
2.1.2 shear load—A force applied parallel to the mounting surface sufficient to shear the SMD from its mounting.
2.1.3 SMD—Abbreviation for surface mount device (that is,(for example, light emitting diode (LED), resistor)
2.1.4 attachment media—Amounting adhesive used for electrical or mechanical bonding, or both, of the SMD to the substrate.
2.1.5 plating—A thin metallic coating (that is, gold, nickel) covering the leads of the SMD or circuit, or both, in the electrical
interface area.
3. Significance and Use
3.1 The different combinations of SMD types, attachment medias, circuit substrates, plating options, and process variation can
account for significant variation in test outcome.
3.2 The SMD shear strength test is useful to manufacturers and users for determining the bond strength of the component to
the membrane switch circuit.
4. Interferences
4.1 The following parameters may affect the results of this test:
4.1.1 Temperature and humidity, and
4.1.2 Substrate movement during test.
5. Apparatus
5.1 Device, shall consist of a load-applying instrument with an accuracy of 6 5 % of full scale capable of indicating peak hold.
5.2 Mounting Fixture, method to secure specimen to insure stability during test.
5.3 SMD Contact Tool, suitable to apply a uniform distribution of force to an edge of the SMD.
5.4 Magnification Device, suitable to facilitate visual observation of the SMD and contact tool interface during testing
(optional).
1
This test method is under the jurisdiction of ASTM Committee F01 on Electronics , and is the direct responsibility of Subcommittee F01.18 on Membrane Switches .
Current edition approved May 1, 2005. Published June 2005. Originally approved in 1999. Last previous edition approved in 2000 as F1995–00. DOI:
10.1520/F1995-00R05.Membrane Switches.
Current edition approved Feb. 1, 2012. Published March 2012. Originally approved in 1999. Last previous edition approved in 2005 as F1995–00(2005). DOI:
10.1520/F1995-12.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
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F1995–12
6. Procedure
6.1 Pretest Setup:
6.1.1 Attach specimen to the test base to minimize movement of the substrate during test. Ensure that no damage occurs during
attachment to the test base that could affect bond performance.
6.1.2 The direction of applied force shall be parallel with the plane of the circuit substrate.
6.1.3 The SMD contact tool shall load against an edge of the component, which most closely approximates a 90° angle with
1
the base of the circuit substrate. Contact tool should make contact to SMD at a point equal to or less than ⁄2 the total SMD height,
(see Fig. 1).
6.2 In-Process Test:
6.2.1 Bring contact tool into contact with SMD specimen.
6.2.2 Gradually increase force, not to exceed 225 g/s, until bond failure.
6.2.3 After initial
...
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