IPC-TM-650 EN 2022 试验方法.pdf - 第171页

1 Scope This test method provides a procedure for testing the porosity of gold electroplated from an alkaline (cyanide), acid, or neutral gold plating solution on a nickel substrate in contact with the gold deposit. 2 Ap…

5.2.7

Compress

the assembly so that the pressure between

the cadmium sulfide paper and the sample is uniform and

between 14 kg/cm2 and 18 kg/cm2.

5.2.8

While

the assembly is under compression, pass a

smooth, ripple free DC source not exceeding 12 volts

between the cathode and anode.

5.2.9 Set

the current initially at 8 mA/cm

anode area and

energize for 30 seconds.

5.2.10

Allow

the electrograms produced on the cadmium

sulfide paper to dry.

5.2.11

corresponding brown stain on the paper reveals

the presence of any defect in the plated coating.

5.2.12

Visually

examine the specimen at 10X magnification.

5.3

Gold on Nickel Method

5.3.1

Soak

the Whatman 542 filter paper for 10 minutes in a

0.8% solution of nioxime (cyclohexane 1:2 dione dioxime) and

distilled water.

5.3.2

Remove

the excess solution with blotting paper. The

paper must be hung up to dry.

5.3.3

Repeat

the steps in 5.2, except moisten the piece of

nioxime paper with distilled water and expose the ammonia

vapor.

5.3.4

Remove

the excess by blotting. The ‘‘backing pad’’ of

photographic blotting paper is to be used dry.

5.3.5 Expose

the electrograms produced on the nioxime

paper to ammonia vapor, then allow to dry.

5.3.6

corresponding purple-red stain on the paper reveals

the presence of any defects in the gold plating.

5.3.7

Visually

examine the specimens at 10X magnification.

IPC-TM-650

Number

2.3.24

Subject

Porosity

of Gold Plating

Date

2/78

Revision

age2of2

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ

Scope

This

test method provides a procedure for testing

the porosity of gold electroplated from an alkaline (cyanide),

acid, or neutral gold plating solution on a nickel substrate in

contact with the gold deposit.

Applicable Documents

None

Materials and Equipment

3.1 Materials

Acetone,

Sodium Nitrate, Reagent GD.

(NaNO

Sodium Carbonate, Anhydrous, Reagent GD.

(Na

Dimethylglyoxime, Denatured Ethyl Alcohol No. 3A,

Reagent GD. (C

OH),

Photographic Paper with Silver

Halide removed. (Kodabromide, glossy finish, single wt. pho-

tographic paper (fixed before use), Ammonium Hydroxide,

Reagent GD. (NH

OH)

3.2

Equipment

3.2.1

power supply to 0 amp to 1 amp. DC minimum, 0

volts to 10 volts

3.2.2

Milliammeter, 0 mA to 100 mA

3.2.3

Electrographic

Clamp-Press

Equipment/Apparatus

None

Procedure

5.1 Solution Make Up

5.1.1 Electrolyte

Concentration:

NaNO

(wt.) Na

Anhydr.

4% (wt.) Distilled water – balance by wt. Preparation

of 500 g (Vol. of 485 ± 10 ml.) of solution

5.1.1.1

Obtain

the tare weight of 600-ml glass beaker.

5.1.1.2

Add

400 ml of distilled water to beaker.

5.1.1.3

Using

agitation and, if necessary, heating to 48.9°C,

dissolve the following in the water:

Sodium nitrate–5g

Sodium carbonate – 20 g

5.1.1.4

After

salts are dissolved, add distilled water until the

net weight of the solution is 500 g.

5.1.1.5

Cool

the solution to room temperature before use.

5.2

Indicator Solution

The

solution is a concentration of

dimethylglyoxime – 1% (wt.) denatured ethyl alcohol No. 3A –

Balance.

Perform the preparation of 300 g (vol. of 380 ± 10 ml.) of

solution as explained in 5.2.1 through 5.2.4.

5.2.1

Obtain

the tare weight of 400-ml glass beaker.

5.2.2 Add

275 ml denatured ethyl alcohol to the beaker.

5.2.3

Using

agitation only (do not heat), dissolve3gofdim-

ethylglyoxime in the alcohol.

5.2.4

After

all additions are dissolved, add denatured ethyl

alcohol until the net weight of the solution is 300 g.

5.3

Electrographic Test

5.3.1 Cleaning Procedure

5.3.1.1

Using

a cloth, wash the contact area with alconox

solution.

5.3.1.2

Rinse

the contact area in tap water.

5.3.1.3

Rinse

the contact area in deionized water.

5.3.1.4 Rinse

the contact area with acetone and air dry.

5.4

Cut

a piece of silver halide-free photographic paper to a

size slightly larger than the area of the sample or part of the

sample being tested. The dimensions of the photographic

paper should not exceed the dimension of that part of the

sample being porosity tested by more than 0.79375 mm in

any one direction.

5.5 Wet

the photographic paper, cut in 5.2 with the electro-

lyte solution prepared in 5.1.1. The photographic paper is

immersed for 30 minutes or more in the electrolyte.

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.3.24.1

Subject

Porosity

Testing of Gold Electrodeposited on a Nickel

Plated Copper Substrate Electrographic Method

Date

10/85

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.

age1of3

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ

After

saturating the photographic paper with electrolyte, press

the paper between two paper towels to ensure any excess

electrolyte is removed from the photographic paper.

5.6

Assemble

the sample being tested for porosity and the

photographic paper of 5.5 in the electrographic clamp-press

as explained in 5.6.1 through 5.6.6.

5.6.1 Place

a piece of Teflon or equivalent insulating mate-

rial on the platform of the compression spring and piston

device on the clamp-press.

5.6.2 Place

the back of the sample or area of sample being

tested on top of and in contact with the Teflon.

5.6.3

Place

the silver halide-free photographic paper satu-

rated with electrolyte in 5.5 on top of and in contact with the

face of the sample or area of the sample being tested. The

emulsion side of the paper should be in contact with the test

sample.

5.6.4

Place

a piece of pure gold or gold-clad copper on top

of the photographic paper so the gold surface is in contact

with the photographic paper.

The gold or gold-clad material placed on the photographic

paper is to have the same maximum dimensions as that part

of the sample being porosity tested. The minimum dimensions

of the gold or gold-clad material is to be not more than

0.79375 mm shorter than the dimensions of the area being

tested in any one direction. Attach a lead wire to the gold or

gold-clad material in order to make electrical contact.

5.6.5

Place

a piece of Teflon or equivalent insulating mate-

rial on the back of the gold or gold-clad material.

5.6.6

Lower

the screw of the clamping and screw the

device until the pressure end of the screw is just in contact

with the back of the Teflon and holds the assembly in place.

Do not apply force at this time. See 5.11 for a schematic dia-

gram of assembly.

5.7

Compress

the spring of the clamp-press by tightening

the screw device until a pressure is exerted on the assembly

as in 5.6.6.

5.8

Connect

a DC power source so the positive (+) voltage

contacts the sample being tested and the negative (-) voltage

is connected to the lead of the gold or gold-clad material of

5.6.6. Apply a current, such that the current density is 250 mA

± 50 mA per square inch of surface in contact with the pho-

tographic paper. Applied voltage should not exceed 10 volts.

If the current density of 250 ± 50 mA/sq. in. cannot be

obtained at ≤10 volts, then the time of current flow should be

increased while holding the potential at 10 volts. The

increased time of current flow can be calculated by the follow-

ing formula.

Time of current flow (sec) =

250 mA/sq. in. of surface in contact with paper

Current

density in mA/sq. in. at 10 volts

x 60 sec

The time of the current flow should be 60 ± 1 sec.

5.9

Unclamp

the assembly and remove the silver halide-free

photographic paper.

5.10

Apply

one to two drops of the indiicator solution from

5.2. to the photographic paper.

5.11

Develop

the photographic paper containing indicator

solution by holding the paper over an ammonium hydroxide

solution.

5.12

Dry

the photographic paper to which indicator solution

was added and read the test results.

5.13

Observe

the porosity test schematic, as shown in Fig-

ure 1.

5.14

Test Results

5.15

Nickel

exposure through the gold will show up on the

indicating photographic paper as a red stain. Copper expo-

sure will show up as green stains. This exposure is caused by

pores, cracking, or unplated areas. These stains should be

examined under 10X min, 15X max.

5.15.1

Pores

will show up as fine dots.

5.15.2

Cracking

Cracks

will show up as continuous fine

lines.

5.15.3

Unplated Areas

Unplated

areas will show up as

large blots or red lines.

IPC-TM-650

Number

2.3.24.1

Subject

Porosity

Testing of Gold Electrodeposited on a Nickel Plated Copper

Substrate Electrographic Method

Date

10/85

Revision

age2of3

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ