IPC-TM-650 EN 2022 试验方法.pdf - 第795页

1.0 Scope 1.1 To determine the effects of a controlled salt laden atmo- sphere on connector components, finishes and mechanisms. This test is intended to explore the corrosion resisting proper- ties of various materials …

IPC-3-8-4

Figure 4 Tolerances for Terminal-Peak Sawtooth Shock Pulse

IPC-3-8-5

Figure 5 Tolerance Limits for Measuring System Frequency Response

IPC-TM-650

Number

3.8

Subject

Mechanical Shock, Connectors

Date

7/75

Revision

Page5of5

1.0 Scope

1.1

To determine the effects of a controlled salt laden atmo-

sphere on connector components, finishes and mechanisms.

This test is intended to explore the corrosion resisting proper-

ties of various materials and finishes and not to simulate cli-

matic conditions of a seacoast or shipboard environment.

2.0 Reference Documents

2.1

Information in this section is intended to parallel the test

method described in EIA-RS-364/TP-26.

3.0 Test Specimen

3.1

A connector (plug and receptacle) complete with appli-

cable guide, keying, and engaging hardware or a card-edge

receptacle and mating printed circuit board (if required by the

individual connector specification). The connector or recep-

tacle shall be mated unless otherwise specified in the indi-

vidual connector specification.

3.2 Neither the plug nor receptacle shall be mounted or ter-

minated during this test, unless such mounting (or termination)

is necessary (1) to insure the mechanical integrity of the com-

ponent, (2) to measure the specified electrical characteristic(s),

(3) was a requirement of previously imposed environmental or

functional tests.

3.3 Printed circuit boards and electrical connections to the

test specimen, except those connections considered under

test, may be coated with a suitable wax to inhibit corrosion.

The coating shall not be applied to any termination or portion

of the connector under test.

3.4 The plug, receptacle, or mated connector shall be sus-

pended or supported within the test chamber in a normal (or

typical) mounting attitude using non-corrosive material (e.g.,

plastic rods, hooks, waxed string, etc.). The test specimens

shall be positioned so that they do not shield each other from

the freely settling fog, and so that corrosion products and

condensate from one specimen do not fall upon another.

4.0 Apparatus

4.1

A chamber capable of maintaining a dry bulb tempera-

ture of +35°C (+1.1, -1.7°C) within the exposure zone. Satis-

factory methods for controlling the temperature are: (1) hous-

ing the chamber in a properly controlled constant-

temperature room; (2) insulating the chamber and pre-heating

the air to the proper temperature prior to atomization; (3) jack-

eting the chamber and controlling the temperature of the

water or air within the jacket.

NOTE:

The use of immersion heaters within the exposure

zone to maintain temperature is prohibited.

The chamber and all accessories exposed to the salt fog

atmosphere shall be constructed of non-reactive material

(e.g., glass, hard rubber, plastic, or wood other than ply-

wood). The exposure zone shall be vented to prevent a pres-

sure build-up affecting test conditions.

4.2 A compressed air supply free from all impurities such as

oil and dirt. Means shall be provided to humidify and warm the

compressed air as required to meet the operating conditions.

The air pressure shall be suitable to produce a finely divided

dense fog with the atomizer(s) used. To insure against clog-

ging of the atomizer(s) by salt deposition, the air should have

a relative humidity at the point of release from the nozzle

greater than 85 percent for the 20 percent solution and

greater than 95 percent for the 5 percent solution. A satisfac-

tory method of humidification is to pass the air in very fine

bubbles through a tower containing heated water. The tem-

perature of the water should be 35°C or higher, as necessi-

tated by increasing volume of air flow or increasing heat loss

through the chamber walls; it should not exceed a value

above which an excess of moisture is introduced into the

chamber or a value which makes it impossible to maintain the

operating temperature.

4.3 Atomizer(s) capable of an approximate atomization rate

of 3 quarts of salt solution per 10 cubic feet of exposure zone

volume per 24-hour period of test. The atomization and dis-

persion shall be such that a suitable receptacle at any point in

the exposure zone will collect 0.5 to 3.0 milliliters of solution

per hour for each 80 square centimeters of horizontal collect-

ing area (10 centimeters diameter) based on a minimum col-

lection period of 16 hours. The specific gravity of collected

solution shall meet the specified requirements of paragraph

4.4.

2215 Sanders Road

Northbrook, IL 60062-6135

IPC-TM-650

TEST METHODS MANUAL

Number

3.9

Subject

Salt Spray, Connectors

Date

7/75

Revision

Originating Task Group

N/A

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.

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ASSOCIATION CONNECTING

ELECTRONICS INDUSTRIES

4.4 Salt solution of 20 percent or 5 percent concentration as

specified in the individual connector specification. The salt

used shall be sodium chloride, and in the dry state must be

equal to USP purity or purer. The distilled or deionized water

shall not contain more than 200 parts per million of total sol-

ids. The solution shall be kept free from solids by filtration or

decantation. The 20 percent solution shall be prepared by

dissolving 20 ± 2 parts (by weight) of salt in 80 parts (by

weight) of distilled or deionized water. The 5 percent solution

shall be prepared by dissolving5±1parts (by weight) of salt

in 95 parts (by weight) of distilled or deionized water. The

specific gravity of the prepared solutions shall be 1.126 to or

deionized water. The specific gravity of the prepared solutions

shall be 1.126 to 1.157 for the 20 percent solution and 1.0268

to 1.0413 for the 5 percent solution when measured at a tem-

perature of 35°C ± 1.1°C. The pH of the solutions shall be

adjusted to within 6.5 to 7.2 at the same temperature. Only cp

grade hydrochloric acid or sodium hydroxide shall be used to

adjust the pH.

4.5 Hydrometer of appropriate range

4.6 pH meter capable of electrometrically measuring the pH

of the prepared or collected solutions using a glass electrode

with a saturated potassium chloride bridge.

5.0 Procedure

5.1 Pre-Cleaning

Specimens soiled with oil, dirt, or grease

shall be cleaned as necessary. The cleaning method shall not

include the use of corrosive solvents nor solvents which

deposit either corrosive or protective films, nor the use of

abrasives other than a paste of pure magnesium oxide. Speci-

mens having an organic coating shall not be solvent cleaned.

Cleaned specimens shall be given a minimum of handling,

particularly on the significant surfaces.

5.2 The test specimen shall be continuously exposed to the

salt fog atmosphere for a period of time corresponding to one

of the test conditions shown in Table 1. Unless otherwise

specified, Test Condition 8 shall apply.

Table I Test Duration

Condition Length of Test (Hours)

A96

B48

5.3 Post-Cleaning

Immediately after exposure, the test

specimen shall be dipped in running tap water not warmer

than 37.8°C for a period not to exceed 5 minutes and dried

for 12 hours (maximum) in a circulating air oven at a tempera-

ture of 38°C ± 3°C.

NOTE:

If measurement of contact resistance or low level cir-

cuit resistance is specified as part of the post-test evaluation,

the test specimen shall not be unmated prior to measurement

of these parameters.

If closer examination of a plated or treated surface is required,

the corrosion products may be removed using any method

which will not affect the integrity of the plating or finish.

6.0 Notes

6.1

Acceptance criteria shall be established in terms of one,

or any combination, of the following:

A. The maximum low level circuit resistance after the test or

the maximum change in this parameter as a result of the

exposure.

NOTE:

When low level circuit resistance is specified as

an acceptance criterion, its measurement shall precede

any other evaluation.

B. The maximum contact resistance after the test or the

maximum change in this parameter as a result of the

exposure.

C. Pitting, porosity, or other defects in the plating or finish.

D. Corrosion products sufficient to interfere with normal con-

nector mating.

E. If a contact resistance failure occurs when a connector is

mated to a printed circuit board, care must be taken to

determine whether the failure was of the connector or of

the printed circuit pads deteriorating.

IPC-TM-650

Number

3.9

Subject

Salt Spray, Connectors

Date

7/75

Revision

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