IPC-TM-650 EN 2022 试验方法.pdf - 第134页

[257 ± 3.6 ° F], then cooled in a desiccator for 4 hours mini- mum prior to testing. 5.2.3 Reserve sets of specimens may also be conditioned concurrently for failure verification purposes. 5.3 Preparation for Testing 5.3…

1.0

Scope

This

test method is designed to determine the

degree of flame resistance of metal-clad or unclad laminate. It

is intended for use on laminate of thicknesses 0.51 mm [0.020

in] and greater.

2.0

Applicable Documents

IPC-TM-650

Method

2.3.6, Etching, Ammonium Persulfate Method

Method 2.3.7, Etching, Ferric Chloride Method

Method 2.3.7.1, Cupric Chloride Etching Method

Method 2.3.7.2, Alkaline Etching

UL-STD-94, Flammability

3.0

Test Specimens

3.1 Size

Test

specimens shall be 127± 0.64 mm [5.0 ±

0.025 in] in length and 12.7 ± 0.51 mm [0.5 ± 0.020 in] in

width by the thickness being tested. Edges shall be smoothed

after cutting; any radius imparted to the corners shall not

exceed 1.27 mm [0.05 in].

3.2 Quantity and Sampling

Specimens

may be taken par-

allel to either grain direction, unless otherwise specified. Five

specimens shall be prepared for each condition required.

Reserve sets of five specimens should also be prepared in the

event a retest is necessary.

4.0

Apparatus or Material

4.1 Test Chamber

laboratory hood, totally enclosed,

with a heat-resistance glass window for observing the test,

shall be used. The exhaust fan shall be turned off during the

test, but may be turned on periodically to clear out the fumes

between tests.

4.2

Specimen Holder

Clamping

device adjustable for ver-

tical positioning of the test specimen shall be provided within

the test chamber so that the specimen will hang with its length

in a vertical position approximately coincident with the central

vertical axis of the test chamber.

4.3

Laboratory burner

Bunsen or Tirrill Burner shall be

used having a tube length of 101.6 mm [4.0 in] and an inside

diameter of 9.4 mm [0.370 in]. The burner shall not be

equipped with end attachments.

4.4

Gas supply

The

gas supply shall be regulated and

metered for uniform flow. The standard gas shall be Technical

Grade methane. Natural gas or other fuel gases such as

butane, propane and acetylene may be used, provided they

have a nominal heat content of 1000 BTU per cubic foot.

Technical grade methane shall be used for referee testing.

4.5

Timer

Stopwatch

or other suitable timing device with a

precision of 0.5 seconds minimum.

4.6

Desiccator

Desiccation

chamber capable of maintain-

ing an atmosphere of less than 30% RH at 23°C [73°F].

4.7

Conditioning

oven of circulating draft type capable of

maintaining 125 ± 2°C [257 ± 3.6°F].

4.8

Thin

steel scale or template for gauging flame height.

4.9 Etching

system capable of removing metal-cladding

from the laminate.

4.10

Cutting and edge smoothing apparatus such as

shears, diamond blade saw, or other equipment, and sanding

or routing equipment for smoothing.

5.0

Procedure

5.1 Specimen Preparation

Metal-clad

laminates shall be

completely etched using standard industry practices (see IPC-

TM-650, Methods 2.3.7, 2.3.7.1, or 2.3.7.2). Unclad lami-

nates shall be tested in the as-is condition. Specimens shall

be cut to size and the edges smoothed, in accordance with

3.1.

5.2

Specimen Conditioning

5.2.1

Specimen

sets shall be conditioned prior to testing by

exposure to standard laboratory conditions of 23 ± 2°C

[73 ± 3.6°F] and relative humidity of 50 ± 5% for 24 hours

minimum.

5.2.2 If

specified, a second set of specimens shall be

conditioned for 24 ± 2 hours at a temperature of 125 ± 2°C

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.3.10

Subject

Flammability

of Laminate

Date

12/94

Revision

Originating Task Group

MIL-P-13949 Test Methods Task Group (7-11b)

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

[257 ± 3.6°F],

then cooled in a desiccator for 4 hours mini-

mum prior to testing.

5.2.3

Reserve

sets of specimens may also be conditioned

concurrently for failure verification purposes.

5.3

Preparation for Testing

5.3.1 Adjustment of Test Flame

The

burner is ignited and

adjusted to produce a blue flame 19 mm [0.75 in] high. The

correct flame is obtained by adjusting the gas supply and the

air ports of the burner until a blue flame with a yellow- tipped

outer cone 19 mm [0.75 in] high is produced. The air supply

is increased slightly by opening the air ports only until the yel-

low tip just disappears and completely blue inner and outer

flame cones are formed. The flame is remeasured for correct

height. The procedure is repeated as necessary until all con-

ditions are met. The burner tube is vertical during adjustment

and testing. (See 6.2, 6.3, and 6.4.)

5.3.2

Specimen Mounting

Each

specimen is mounted in

the test fixture with its longitudinal axis vertical. The clamp

used shall cover no more than the upper 6.4 mm [0.25 in] of

the specimen. The vertical position of the test fixture/

specimen assembly is adjusted so that the lower end of the

specimen is 9.5 mm [0.375 in] above the top of the burner

tube.

5.4

Measurement

5.4.1

The

test flame is placed centrally under the lower end

of the specimen for 10 ± 0.5 seconds. The burner is with-

drawn from the specimen. If active combustion ceases prior

to the specimen being completely consumed, the test flame is

to be immediately placed under the specimen for an additional

10 ± 0.5 seconds, then withdrawn as before.

5.4.2

Evaluation and Report

Steps

5.5.1, 5.5.2, and

5.5.3 shall be performed for each test condition.

5.5

Recording Data

The

following data is to be observed

and recorded.

5.5.1

Duration

of specimen burning to the nearest second

after the first test flame application for each specimen.

5.5.2

Duration

of specimen burning to the nearest second

after the second test flame application for each specimen.

5.5.3

Duration

of specimen burning plus glowing to the

nearest second after the second test flame application for

each specimen, only if required by the specification.

5.5.4 If any specimen burns up to the holding clamp on any

ignition.

5.6

Calculation

5.6.1

Calculate

the total specimen burning time and the

average burning time based on ten ignitions per set of five

specimens.

5.6.2

Calculation

of the glowing time for each specimen, if

required by the specification.

5.7

Report

The

material shall be reported as out of compli-

ance for one or more of the following test results, unless oth-

erwise specified.

5.7.1

than one specimen per set burns up to the hold-

ing clamp on any ignition.

5.7.2

than one specimen per set burns for a period of

time longer than allowed by the specification for a single

specimen.

5.7.3

The

total specimen burning time or the average speci-

men burning time as applicable exceeds the maximum

allowed by the specification and is beyond the tolerance

specified in 5.5.4.

5.7.4

than one specimen glows for a period of time

greater than allowed by the specification (when applicable).

5.8

Retest

only one specimen per set fails to comply with

the requirements, the reserve set of specimens shall be

tested. In the case of total or average specimen burning time,

the reserve set shall be tested only if these calculated values

exceed the specification maximum by five seconds or less. All

specimens from the reserve set shall comply with the require-

ments.

6.0 Notes

6.1

Most

laminates covered by this test method do not drip

molten

or flaming material, and therefore provisions for this evalu-

ation have not been described. If necessary, refer to UL-STD-94.

6.2 The

inside of the burner barrel should be cleaned fre-

quently. Specimen combustion by-products can collect

around and inside the barrel tip. These deposits can be

IPC-TM-650

Number

2.3.10

Subject

Flammability

of Laminate

Date

12/94

Revision

age2of3

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ

flushed

out

during

burner ignition and flame adjustment resulting

in a false yellow flame tip. Proper flame adjustment becomes very

difficult.

6.3

When

the flame is correct and the specimens end is at

the proper height above the burner 9.5 mm [0.375 in], the

inner blue come of the flame will just meet the end of the

specimen. The specimen will then be ignited by the hottest

area of the flame.

6.4

Accurate

centering of the flame under the specimen is

essential for consistent testing.

6.5

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

2.3.10

Subject

Flammability

of Laminate

Date

12/94

Revision

age3of3

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ