IPC-TM-650 EN 2022 试验方法.pdf - 第797页

1.0 Scope 1.1 To determine the solderability of electrical contacts intended for such termination. 2.0 Reference Documents 2.1 Information in this section is intended to parallel the test method described in EIA-RS-178A.…

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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1.0 Scope

1.1

To determine the solderability of electrical contacts

intended for such termination.

2.0 Reference Documents

2.1

Information in this section is intended to parallel the test

method described in EIA-RS-178A.

2.2 QQ-S-571 Solder; Lead Alloy, Tin Alloy, Tin-Lead Alloy;

Flux Cored Ribbon and Wire, and Solid Form.

2.3 LLL-R-626 Rosin, Gum; Rosin, Wood; Rosin, Tall Oil.

3.0 Test Specimen

3.1

The contacts of a connector or individual contacts.

NOTE:

For wire-hole contacts, it is desirable that a short

length of solid copper wire of appropriate size be affixed as

shown in Figure 1.

3.2 Unless otherwise specified in the individual contact or

connector specification, the test samples shall not be cleaned

by any means prior to the test. Care shall be exercised to

avoid contamination (grease, perspirants, etc.) of the surface

to be tested.

4.0 Apparatus and Materials

4.1

Solder pot, having a minimum capacity of 2 pounds,

electrically heated, and thermostatically controlled to provide

and maintain the solder temperatures required.

4.2 A temperature measuring device of suitable range for

the specified test condition and an appropriate stainless steel

jacketed thermocouple.

4.3 Dipping device similar to that shown in Figure 2.

4.4 Solder (Sn 60) conforming to Federal Specification

QQ-S-571.

4.5 Flux of non-corrosive type, composed of 25 percent (by

weight) rosin and 75 percent (by weight) alcohol. The rosin

shall be Class A, Type 1, Grade WW in accordance with Fed-

eral Specification LLL-R-626. The alcohol shall be 99 percent

isopropyl alcohol. The flux shall be free of additional activators.

5.0 Procedure

5.1

The solder pot temperature shall be adjusted to, and

maintained at, the specified test temperature shown in Table

1 for a minimum period of 2 hours prior to test.

Table I Test Temperatures

Condition Temperature

1 232 ± 5°C

2 271 ± 5°C

5.2

The portion of the contact to be soldered shall be

immersed in flux for a minimum period of 5 seconds and then

allowed to drain for a minimum period of 60 seconds prior to

test.

IPC-3-10-1

Figure 1 Wire Hole Termination

2215 Sanders Road

Northbrook, IL 60062-6135

IPC-TM-650

TEST METHODS MANUAL

Number

3.10

Subject

Solderability, 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

5.3 The solder bath shall be occasionally stirred with a clean

stainless steel paddle to ensure that it is of uniform composi-

tion and temperature throughout. The surface of the bath shall

be skimmed immediately prior to each test to remove any

dross or residual unburned flux from previous tests.

5.4 The sample shall be affixed to the dipping device shown

in Figure 2 and oriented so that the contact termination will

enter the solder bath to the specified depth.

5.5 The sample shall be immersed in the solder bath at a

rate of 1.00 ± 0.25 inches per second and withdrawn at the

same rate. The dwell time in the solder shall be 5.0 ± 0.5 sec-

onds.

5.6 The sample shall not be removed from the dipping

device or otherwise disturbed until the solder has solidified.

5.7 The sample shall be thoroughly cleaned of residual flux

and examined under 10X magnification for evidence of the

following:

A. Dewetting of areas to be soldered.

B. Pinholes or voids in the solder coat.

C. Incomplete fill of solder well or hole.

6.0 Notes

6.1

Acceptance criteria shall be established in terms of one,

or any combination, of the following:

A. Less than 95% coverage of flat surfaces.

B. Pinholes or small voids or solder surface roughness con-

centrated in any one area of the contact.

C. Poor filleting around wire or incomplete fill of solder well.

IPC-3-10-2

Figure 2 Suggested Dipping Device for Solderability Test

IPC-TM-650

Number

3.10

Subject

Solderability, Connectors

Date

7/75

Revision

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