IPC-TM-650 EN 2022 试验方法.pdf - 第813页

5.2 Evaluation 5.2.1 Record and report resistance vs. number of rocking cycles. 6 Notes 6.1 Keithley Model 503 Milliohmmeter may be purchased from: KEITHLEY INSTRUMENTS, INC. 28775 Aurora Road Cleveland, Ohio 44139 (216)…

1 Scope The purpose of this test method is to determine

the susceptibility of non-noble metal contact interfaces to the

phenomena of fretting corrosion. Fretting corrosion is an

accelerated oxidation of contact surfaces brought about by

small amplitude cyclic relative motions between mating con-

tacts. In this test, a driving motion is imposed, which tends to

cause relative motion at the contact surfaces. From contact

resistance measurements, one determines whether the result-

ing contact motion, if any, generates significant or detrimental

films in the contact interface.

2 Applicable Documents None

3 Test Specimens

3.1

Any pre-production or production connectors

4 Equipment/Apparatus

4.1

Clamping fixture for test connector(s) and test boards to

mate with test connectors or, in the case of post receptacles,

postheaders

4.2 A motorized cam, crank, or other mechanism, with

appropriate linkage, must be provided to physically attach to

the movable connector, test board, or post and rock this half

back and forth as illustrated in Figure 1. The rocking motion

shall be approximately 10 cycles per minute, but no faster

than 30 cycles per minute.

4.3 The mechanism must be adjustable so as to restrict the

amplitude of motion to one, which, in the case of a PCB sys-

tem, just lets the board touch the card slot in the connector

on each side.

4.4 A counter to record the number of rocking cycles should

be provided.

4.5 A means of measuring contact resistance must be pro-

vided. Dry circuit measuring conditions are to be maintained,

with open-circuit voltages of 50mv or less and test currents of

100 ma or less. A Keithley Model 503 milliohmmeter or its

equivalent may be used.

5 Procedure

5.1 Test

5.1.1

Contacts are to be assembled in their housings as in

normal intended usage.

5.1.2 New test connectors, boards, or posts are to be used

in each test.

5.1.3 Measure and record initial resistance after inserting

test connector(s), board(s), or post(s).

5.1.4 Attach and adjust rocking mechanism, then begin

rocking cycles.

5.1.5 Stop the rocking motion and measure contact resis-

tance after 10, 20, 50, 100, 200, 300, 400, and 500 cycles.

Individual contacts are to be measured separately (see Figure

2).

Note: A millohmmeter having separate current and voltage

leads may be used instead, with leads positioned as shown in

Figure 2.

IPC-3-16-1

Figure 1 Fretting Motion to be Applied to PCB

Connectors

2215 Sanders Road

Northbrook, IL 60062-6135

IPC-TM-650

TEST METHODS MANUAL

Number

3.16

Subject

Fretting Corrosion, Connectors

Date

2/78

Revision

Originating Task Group

Material in this Test Methods Manual was voluntarily established by Technical Committees of the IPC. This material is advisory only

and its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the use, application, or adaptation of this

material. Users are also wholly responsible for protecting themselves against all claims or liabilities for patent infringement.

Equipment referenced is for the convenience of the user and does not imply endorsement by the IPC.

Page1of2

ASSOCIATION CONNECTING

ELECTRONICS INDUSTRIES

5.2 Evaluation

5.2.1

Record and report resistance vs. number of rocking

cycles.

6 Notes

6.1

Keithley Model 503 Milliohmmeter may be purchased

from:

KEITHLEY INSTRUMENTS, INC.

28775 Aurora Road

Cleveland, Ohio 44139

(216) 248-0400

IPC-3-16-2

Figure 2 Method of Making Contact Resistance Measurements

IPC-TM-650

Number

3.16

Subject

Fretting Corrosion, Connectors

Date

2/78

Revision

Page2of2

1 Scope This test method is used to determine the effects

of long term operation of components in atmospheres con-

taining industrial gaseous pollutants. It consists of exposure to

a flowing-gas humid atmosphere containing SO

S, and

in concentrations of 200 parts per billion (ppb). This cor-

responds to a worst-case polluted atmosphere, and is an

accelerated exposure to normal, average pollutant level atmo-

sphere. An acceleration factor of 30-40 is associated with this

test.

1.2 To further simulate and accelerate conditions obtained

in operating environments, the test also involves temperature

and humidity cycling, so as to cause breathing and moisture

condensation on the test samples.

2 Applicable Documents None

3 Test Specimen

3.1

Any pre-production or production samples wired and

mated as intended for actual use

4 Apparatus

4.1

Test chamber and its associated control equipment

capable of producing and maintaining the conditions of 4.1.1

and 4.1.2

4.1.1 Capable of cycling the temperature between 68°C

and 26°C with the following schedule:

Eight hours at 68°C

One hour transition to 26°C

Two hours at 26°C

One hour transition to 68°C

These 12-hour cycles are to be repeated continuously for the

duration of time specified for the exposure.

4.1.2 Capable of maintaining 80% RH ± 5% RH during the

68°C dwell time. Uncontrolled during temperature transitions

so as to allow condensation on the samples.

4.2 Gaseous Atmospheric Pollutants Concentrations of

200 ppb in normal air (N

- 20% O

) of the following pollutants

shall be maintained in the exposure chamber at all times:

S (200 ppb)

(200 ppb)

A convenient and satisfactory way of producing this environ-

ment is the ‘‘Battelle Flowing Gas System.’’ In this system, the

pollutant concentrations are maintained through the use of

permeation tubes, which are small Teflon tubing sections,

about 2 cm long, sealed at both ends, and containing the pol-

lutant of interest as a liquid at room temperature. These per-

meation tubes are placed in the main air stream, which feeds

the exposure chamber, and the concentrations of the pollut-

ants are determined by the diffusion rates of the gas out of the

permeation tubes. At a constant flow rate and temperature of

the main air stream, the concentration of pollutants will be

constant. Periodic weighing of the permeation tubes may do

pollutant gas ‘‘analysis.’’

The flow rate of the main air stream is such that the exposure

chamber volume is exchanged approximately every 30 min-

utes.

5 Procedure

5.1

Wire and mate the test specimen as in normal intended

operation during exposure in this test.

5.2 The duration of this test is generally calculated from the

expected service lifetime of the product.

5.3 The actual duration of this exposure is to be determined

between vendor and user and/or is a part of the applicable

product specification. A 60-day exposure in this test corre-

sponds to approximately six years of exposure in normal

industrial environments.

6 Notes

6.1 Reference

Abbott, W. H., Effects of Industrial Air Pol-

lutants on Electrical Contact Materials, Holm Seminar on Elec-

tric Contact Phenomena, November 1973.

2215 Sanders Road

Northbrook, IL 60062-6135

IPC-TM-650

TEST METHODS MANUAL

Number

3.17

Subject

Industrial Gas Test (Battelle Method), Connectors

Date

2/78

Revision

Originating Task Group

Material in this Test Methods Manual was voluntarily established by Technical Committees of the IPC. This material is advisory only

and its use or adaptation is entirely voluntary. IPC disclaims all liability of any kind as to the use, application, or adaptation of this

material. Users are also wholly responsible for protecting themselves against all claims or liabilities for patent infringement.

Equipment referenced is for the convenience of the user and does not imply endorsement by the IPC.

Page1of1

ASSOCIATION CONNECTING

ELECTRONICS INDUSTRIES