ASTM B885-09(2015)

Standard Test Method for Presence of Foreign Matter on Printed Wiring Board Contacts

SIGNIFICANCE AND USE
5.1 This test method provides a way to detect contamination on printed wiring board fingers that affects the electrical performance of such fingers. Such contamination may arise during PWB manufacture, circuit assembly, or service life and may include solder mask, solder flux, hardened lubricants, dust, or other materials. This test method provides a nondestructive method of inspecting such fingers at any point in the life of the product including after original manufacture, after assembly of circuit components to the PWB, and after time in service such as when returned for repair. Because this test method uses two probes to finger contacts in series, it provides a sensitive test for contaminants that may increase electrical resistance when the fingers are plugged into an edgecard connector that typically makes contact to the finger through only one contact to finger interface.  
5.2 Practice B667 describes a more general procedure for measuring contact resistance of any solid material in practically any geometrical form. The method in Practice B667 should be used for general studies and fundamental studies of electrical contact materials.
SCOPE
1.1 This test method defines a resistance probing test for detecting the presence of foreign matter on Printed Wiring Board (PWB) contacts or fingers that adversely affects electrical performance. This test method is defined specifically for such fingers coated with gold. Application of this test method to other types of electrical contacts or to fingers coated with other materials may be possible and desirable but may require some changes in fixturing, procedures, or failure criteria.  
1.2 Practice B667 describes another contact resistance probe method that has more general application to electrical contacts of various materials and shapes. Practice B667 should be used for more fundamental studies. This test method provides a fast inspection method for printed wiring board fingers.  
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 become familiar will all hazards including those identified in the appropriate Material Safety Data Sheet (MSDS) for this product/material as provided by the manufacturer, to establish appropriate safety and health practices, and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Apr-2015
• ICS: 31.180 - Printed circuits and boards
• Technical Committee: B02 - Nonferrous Metals and Alloys
• Drafting Committee: B02.11 - Electrical Contact Test Methods

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: B885 − 09 (Reapproved 2015)
Standard Test Method for
Presence of Foreign Matter on Printed Wiring Board
Contacts
This standard is issued under the fixed designation B885; 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 B542 Terminology Relating to Electrical Contacts and Their
Use
1.1 This test method defines a resistance probing test for
B667 Practice for Construction and Use of a Probe for
detecting the presence of foreign matter on Printed Wiring
Measuring Electrical Contact Resistance
Board (PWB) contacts or fingers that adversely affects electri-
cal performance. This test method is defined specifically for
3. Terminology
such fingers coated with gold. Application of this test method
3.1 Definitions—Terms used in this test method related to
to other types of electrical contacts or to fingers coated with
electrical contacts are defined in accordance with Terminology
other materials may be possible and desirable but may require
B542.
some changes in fixturing, procedures, or failure criteria.
3.2 Definitions of Terms Specific to This Standard:
1.2 Practice B667 describes another contact resistance
3.2.1 edgecard connector, n—an electrical connector de-
probe method that has more general application to electrical
signed to connect physically and electrically with a compatible
contacts of various materials and shapes. Practice B667 should
PWB equipped with gold fingers.
be used for more fundamental studies. This test method
provides a fast inspection method for printed wiring board 3.2.2 printed wiring board (PWB) contacts, PWB fingers,
fingers. n—areas near the edge of a printed wiring board coated with
gold and designed to function as electrical contacts when the
1.3 The values stated in SI units are to be regarded as
board is plugged into a compatible edgecard connector.
standard. No other units of measurement are included in this
standard.
4. Summary of Test Method
1.4 This standard does not purport to address all of the
4.1 Two closely spaced electrodes are brought into contact
safety concerns, if any, associated with its use. It is the
withasinglePWBfingerinsuchamannerthattheycontactthe
responsibility of the user of this standard to become familiar
surface with a minimum of wipe.Afixture loads each electrode
will all hazards including those identified in the appropriate
to apply a force in the range of 0.5 to 0.7 N to the surface of
Material Safety Data Sheet (MSDS) for this product/material
the finger. Two electrical leads attached to each electrode are
as provided by the manufacturer, to establish appropriate
used to make a four–wire resistance measurement to detect
safety and health practices, and determine the applicability of
elevated resistance indicative of the presence of a film or other
regulatory limitations prior to use.
contaminant on the finger.
2. Referenced Documents
5. Significance and Use
2.1 ASTM Standards:
5.1 This test method provides a way to detect contamination
B539 Test Methods for Measuring Resistance of Electrical
on printed wiring board fingers that affects the electrical
Connections (Static Contacts)
performance of such fingers. Such contamination may arise
during PWB manufacture, circuit assembly, or service life and
may include solder mask, solder flux, hardened lubricants,
This test method is under the jurisdiction of ASTM Committee B02 on
dust, or other materials. This test method provides a nonde-
Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee
structive method of inspecting such fingers at any point in the
B02.11 on Electrical Contact Test Methods.
life of the product including after original manufacture, after
Current edition approved May 1, 2015. Published May 2015. Originally
assembly of circuit components to the PWB, and after time in
approved in 1997. Last previous edition approved in 2009 as B885 – 09. DOI:
10.1520/B0885-09R15.
service such as when returned for repair. Because this test
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
method uses two probes to finger contacts in series, it provides
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
a sensitive test for contaminants that may increase electrical
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. resistance when the fingers are plugged into an edgecard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B885 − 09 (2015)
connector that typically makes contact to the finger through this fixture to minimize shock and vibration reaching the
only one contact to finger interface. probes. Placement on a foam pad on a bench top has been
found suitable.
5.2 Practice B667 describes a more general procedure for
measuring contact resistance of any solid material in practi- 6.4 Two Springs, one for each electrode, having a spring
cally any geometrical form. The method in Practice B667 constant and a pretension that will apply a load in the range of
should be used for general studies and fundamental studies of 0.5 to 0.7 N when the electrode is brought to rest on the finger
electrical contact materials. being tested. Other mechanisms that achieve the same result
are acceptable.
6. Apparatus
6.5 Mechanism, that will move the electrode fixture from an
6.1 Four-Wire mΩ Meter, with a resolution of 0.0001Ω or
open position to the closed position on the finger in such a
better, capable of performing dry circuit resistance measure- manner that the electrodes meet the surface of the contact with
ments in accordance with Test Method
...

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: B885 − 09 B885 − 09 (Reapproved 2015)
Standard Test Method for
Presence of Foreign Matter on Printed Wiring Board
Contacts
This standard is issued under the fixed designation B885; 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 defines a resistance probing test for detecting the presence of foreign matter on Printed Wiring Board
(PWB) contacts or fingers that adversely affects electrical performance. This test method is defined specifically for such fingers
coated with gold. Application of this test method to other types of electrical contacts or to fingers coated with other materials may
be possible and desirable but may require some changes in fixturing, procedures, or failure criteria.
1.2 Practice B667 describes another contact resistance probe method that has more general application to electrical contacts of
various materials and shapes. Practice B667 should be used for more fundamental studies. This test method provides a fast
inspection method for printed wiring board fingers.
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 become familiar will all hazards including those identified in the appropriate Material Safety Data
Sheet (MSDS) for this product/material as provided by the manufacturer, to establish appropriate safety and health practices, and
determine the applicability of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
B539 Test Methods for Measuring Resistance of Electrical Connections (Static Contacts)
B542 Terminology Relating to Electrical Contacts and Their Use
B667 Practice for Construction and Use of a Probe for Measuring Electrical Contact Resistance
3. Terminology
3.1 Definitions—Terms used in this test method related to electrical contacts are defined in accordance with Terminology B542.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 edgecard connector, n—an electrical connector designed to connect physically and electrically with a compatible PWB
equipped with gold fingers.
3.2.2 printed wiring board (PWB) contacts, PWB fingers, n—areas near the edge of a printed wiring board coated with gold and
designed to function as electrical contacts when the board is plugged into a compatible edgecard connector.
4. Summary of Test Method
4.1 Two closely spaced electrodes are brought into contact with a single PWB finger in such a manner that they contact the
surface with a minimum of wipe. A fixture loads each electrode to apply a force in the range of 0.5 to 0.7 N to the surface of the
finger. Two electrical leads attached to each electrode are used to make a four–wire resistance measurement to detect elevated
resistance indicative of the presence of a film or other contaminant on the finger.
This test method is under the jurisdiction of ASTM Committee B02 on Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee B02.11 on
Electrical Contact Test Methods.
Current edition approved April 15, 2009May 1, 2015. Published May 2009May 2015. Originally approved in 1997. Last previous edition approved in 20032009 as
B885 - 97 (2003).B885 – 09. DOI: 10.1520/B0885-09.10.1520/B0885-09R15.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’sstandard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B885 − 09 (2015)
5. Significance and Use
5.1 This test method provides a way to detect contamination on printed wiring board fingers that affects the electrical
performance of such fingers. Such contamination may arise during PWB manufacture, circuit assembly, or service life and may
include solder mask, solder flux, hardened lubricants, dust, or other materials. This test method provides a nondestructive method
of inspecting such fingers at any point in the life of the product including after original manufacture, after assembly of circuit
components to the PWB, and after time in service such as when returned for repair. Because this test method uses two probes to
finger contacts in series, it provides a sensitive test for contaminants that may increase electrical resistance when the fingers are
plugged into an edgecard connector that typically makes contact to the finger through only one contact to finger interface.
5.2 Practice B667 describes a more general procedure for measuring contact resistance of any solid material in practically any
geometrical form. The method in Practice B667 should be used for general studies and fundamental studies of electrical contact
materials.
6. Apparatus
6.1 Four-Wire mΩ Meter, with a resolution of 0.0001 Ω or better, capable of performing dry circuit resistance measurements
in accordance with Test Methods B539, Test Method C.
6.2 Two Gold-Tipped Electrodes (Probes), with a radius not less than 3.0 mm at the tips. Each electrode shall have two wires
attached. One wire, the voltage lead, shall be attached within 2 mm of the tip end. The other wire, the current lead, shall be attached
at any convenient location that is at least 0.5 mm farther away from the tip than the attachment point of the voltage lead.
6.3 Fixture, to hold the PWB securely
...