IPC-TM-650 EN 2022 试验方法.pdf - 第165页

1.0 Scope 1.1 The Hull Cell is a miniature plating unit designed to pro- duce cathode deposits on a panel that correlates the charac- teristics of the plating unit being evaluated. Interpretation of the ‘‘as plated’’ cat…

6.0 Notes

6.1

Moisture Content

6.1.1 Exclusion of Moisture Content

Desiccation

of the

specimens is performed for the following reasons.

6.1.1.1

This

test method is based on the understanding that

‘‘Volatile Content’’ refers to organic solvents and other ingre-

dients of the prepreg that may remain in the material after

curing. Water or moisture content is not considered as a

‘‘Volatile’’ for purposes of this test, and therefore desiccation

is a fundamental step to exclude H

from the data. It is not

possible to remove all H

from material that is hygroscopic,

but the most significant content is removed.

6.1.1.2 This

method has a high intrinsic variability potential,

and since moisture content is extremely variable and depen-

dent on the storage environment, meaningful data is best

achieved by removing the moisture.

6.1.2

Moisture Content Determination

This

method can

be performed in an alternative manner, in which the specimen

is weighed before it is desiccated. The difference between the

‘‘As Is Weight’’ and the ‘‘Weight After Desiccation’’ (but

before oven drying) is the moisture content.

6.2

Alternate Specimen Holder

Method B has been

designed to minimize the problem of specimens flopping

around in the air circulating oven.

6.3

Desiccator Conditions

The

Test Methods Task Group

determined that a great majority of test laboratories are unable

to consistently hold the Relative Humidity in a desiccator to

less than 20%. Based on data from participating company lab

management, the lowest practically feasible RH for use with

the affected IPC Test Methods is 30% maximum.

IPC-TM-650

Number

2.3.19

Subject

Volatile

Content of Prepreg

Date

12/94

Revision

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1.0

Scope

1.1

The

Hull Cell is a miniature plating unit designed to pro-

duce cathode deposits on a panel that correlates the charac-

teristics of the plating unit being evaluated. Interpretation of

the ‘‘as plated’’ cathode panel give rapid information about

brightness levels, irregular plate deposits, uniformity of depos-

its, coverage, throwing power, impurities, and plating bath

chemistry.

1.2

Theory:

Within the parameters of recommended operat-

ing characteristics of a particular plating solution, the HULL

CELL will duplicate what is actually occurring in the plating

unit proper.

Correlation of the ‘‘as plated’’ panel and the HULL CELL

SCALE allows rapid, nondestructive testing of plating solu-

tions for research, preventative maintenance, troubleshooting,

and quality control.

2.0

Applicable Documents

O. Technical Bulletin No. 404

The Hull Cell, by Sedusky and Mohler

3.0

Test Specimen

3.1 Description of Specimen

representative sample

from the plating unit to be evaluated is withdrawn and should

be a composite sampling from various areas in the plating

tank and from various depths within these areas.

3.2

Specimen Preparation

The

representative sample

should be analyzed chemically for those critical components

recommended by the supplier of the plating bath. Correlation

of Hull Cell panels without the information on the bath chem-

istry can be very misleading.

3.3

Operating Conditions

Particular

attention shall be

given to the physical conditions of the plating unit at the time

of sampling and these operating conditions should be dupli-

cated during Hull Cell testing. If this is not done, interpretation

will be meaningless. Example: temperature, cathode agitation,

air agitation.

4.0

Apparatus

4.1 Description of Equipment

bench or portable minia-

ture plating cell is employed using the following components.

a. A rectifier (D.C. power source) with variable controls for

amperage from 0-10 amps, 0-12 volts. This power source

should have less than 5% ripple.

b. Hull Cell Anode ‘‘+’’ chemistry of the anode the same as

is in the plating unit or as recommended by the chemical

supplier. Example: zinc anode for zinc plating bath.

c. Color coded coated cables capable of carrying the current

required with an alligator clip soldered to cell end. Color

code recognized universally is as follows: anode ‘‘+’’

black; cathode ‘‘–’’ red.

d. Hull Cell Cathode Panels—two most widely used are zinc

plated steel and thin plastic protected brass panels.

e. Hull Cell—with scribed solution level line, 267 ml, 524 ml,

or 1000 ml size. The most commonly used size is the 267

ml. Hull Cells are available in Lucite, Polypropylene, and

Porcelain.

f. Hull Cell Scale—a calibrated ruler for interpretation of 1, 2,

3, and 5 amp panels to determine current densities.

g. Hull Cell Agitator—optional motor driven arm and panel

assembly for duplicating solution and/or cathode agita-

tion.

h. Air Agitation Hull Cell—specially designed for introducing

air into the miniature plating unit to duplicate air agitation

operations.

i. Timer—separate or built into the DC power unit depend-

ing upon the sophistication desired.

5.0

Procedure

5.1 Preparation

(It

is recommended that panels be

handled with tweezers and gloves to prevent misleading

results.)

5.1.1

Pre-clean

cathode test panel.

5.1.2

For

zinc plated steel panels: immerse in 50% by vol-

ume C.P. Hydrochloric acid to strip off protective zinc film.

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.3.21

Subject

Plating

Quality Hull Cell Method

Date

8/97

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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5.1.3

Cold

water rinse.

5.1.4

Wipe

surface with Hull Cell sponge that has been

soaked in D.I. water.

5.1.5

Observe

panel for water break free condition. Repeat

5.1.4 and 5.1.5 as necessary.

5.1.6

For

plastic coated brass panels-remove plastic film by

peeling it off.

5.1.7

Soak

in mild soak cleaner.

5.1.8 Reserve

current clean at 2 amps for one minute.

5.1.9

Cold

water rinse.

5.1.10

Acid

dip 10% C.P. Hydrochloric Acid for 5 seconds.

5.1.11

Cold

water rinse.

5.1.12

Observe

for water break free surface; repeat steps

5.1.7 through 5.2.11 if necessary.

5.2

Test

Insert

cathode test panel along the slanted side of

the Hull Cell (it just fits), which has solution to scribed line.

5.2.1

Hook

red cable to anode (+).

5.2.2

Hook

black cable to cathode (–).

5.2.3

Set

timer to prescribed time (see tech bulletin).

5.2.4

Turn

on power source.

5.2.5

Adjust

power to described amperage.

5.2.6

Start

time.

5.2.7 At

prescribed time, shut off power.

5.2.8

Disconnect

cathode cable.

5.2.9

Remove

cathode panel.

5.2.10

Cold

water rinse.

5.2.11

Complete

desired post plate treatment if any-

example: dipping panel in 1/4 to 1/2 of 1% by volume. Nitric

Acid (C.P. Grade) for 3-5 seconds enhances the ability to

interpret the panel on zinc and cadmium plating solutions.

5.2.12

Warm

Water Rinse.

5.2.13

Dry, forced air or even wiping with a water absorbent

paper towel.

5.2.14

alternate method of drying the panels is to water

rinse followed by an alcohol rinse to drive off the water. Also,

a method of preserving samples is to spray them immediately

with a clear lacquer to prevent oxidation.

5.3

Evaluation

5.3.1

See

Bulletin ‘‘The Hull Cell’’ or proprietors data sheets

utilizing the Hull Cell Scale appropriate for the amperage used

as the guide to current densities.

5.3.2 Hull

Scale use: place the bottom edge of the ‘‘as

plated’’ on the line that matches the amperage plating was

performed. The areas on the panel above these numbers are

the area of that number’s current density.

IPC-2321-1

Figure

1 Hull Cell Hook Up

IPC-TM-650

Number

2.3.21

Subject

Plating

Quality Hull Cell Method

Date

8/97

Revision

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