IPC-TM-650 EN 2022 试验方法.pdf - 第138页

f. Calculation of the total specimen burning time or the aver- age specimen burning time as applicable based on 10 igni- tions per set of five specimens (see Figure 3) g. Calculation of the glowing time for each specimen…

4.8

Flame Gauging Device

thin steel scale template for

gauging flame height

4.9

Burner Base

block support for use as a burner base

with a 20° incline for proper positioning of the burner flame

under the sample

Procedure

5.1 Specimen Conditioning

5.1.1

Specimen

sets should first be brought to room tem-

perature (23°C ± 2°C) for 24 hours prior to being thermal

shocked within the specifications of both the laminate and

solder mask being tested.

5.1.2

Specimen

sets shall then be divided into two groups

of 10 each. The first group shall be conditioned prior to test-

ing by exposure to standard laboratory conditions of 23°C

± 2°C and RH of 50% ± 5% for a minimum of 48 hours.

The first set shall be referred to as ‘‘as received’’ specimen.

5.1.3

The

second group shall be conditioned for a duration

of 168 hours (seven days) at 70°C ± 1°C and then cooled in

a desiccator over anhydrous calcium chloride for at least four

hours at room temperature (23°C ± 2°C) prior to testing.

This second set shall be referred to as ‘‘conditioned’’ speci-

men.

5.1.4

From

each of these groups, one half (five specimens)

will be burned for the evaluation, with the remaining five speci-

mens being held in reserve for retest if needed.

Note:

See

5.6 to determine if and when the reserve sets will

be needed.

5.2

Adjustment of Test Flame

The

burner is ignited and

adjusted to produce a blue flame 19 mm 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 high is produced. The air supply is increased slightly

by opening the air ports until only the yellow tip just disap-

pears and it forms completely blue inner and outer flame

cones. The flame is remeasured to assure correct height. The

procedure is repeated as necessary until all conditions are

met. The burner tube is vertical during the adjustment and

measuring (see Figure 1).

5.3

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 6.5 mm 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

above the top of the burner tube (see Figure 2).

5.4

Flame Test

The

test flame is placed centrally under

the lower end of the specimen. Timing begins immediately for

10 ± 0.5 seconds. The burner is withdrawn at least 152 mm

away 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 again for an addi-

tional 10 ± 0.5 seconds, then withdrawn as before.

5.5

Data to be Observed and Recorded

The

following

test data is to be recorded:

a. Duration of specimen burning to the nearest second after

the first test flame application for each specimen

b. Duration of specimen burning to the nearest second after

the second test flame application for each specimen

c. 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

d. If any specimen burns up to the holding clamp on any igni-

tion

e. If any specimen drips flaming particles, and if they ignite

the dry absorbent surgical cotton located 305 mm below

the test specimen

IPC-23101-1

Figure

1 Burner Flame

19 mm

9.5 mm

IPC-TM-650

Number

2.3.10.1

Subject

Flammability

of Soldermask on Printed Wiring Laminate

Date

8/98

Revision

age2of4

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Calculation of the total specimen burning time or the aver-

age specimen burning time as applicable based on 10 igni-

tions per set of five specimens (see Figure 3)

g. Calculation of the glowing time for each specimen if

required by the specification

5.6

Evaluation and Reporting

The

material shall be con-

sidered to be out of compliance with the specification if:

a. More than one specimen per set burns up to the holding

clamp on any ignition

b. More than one specimen per set burns for a period of time

longer than allowed by the specification for a single speci-

men

c. The total specimen burning time as applicable exceeds the

maximum allowed by the specification and is beyond the

tolerance specified in 5.6.2

d. More than one specimen glows for a period of time greater

than allowed by the specification (when applicable)

e. More than one specimen drips flaming particles, which

ignite the dry absorbent surgical cotton

5.6.2

Reporting

Each

test condition is reported separately.

The parameters outlined in 5.6 are to be reported only as

applicable.

5.6.3

Retests

only one specimen per set (five) fails to

comply with the requirements, the reserve set of specimen

shall be tested. In the case of total and/or average specimen

burning time, the reserve set shall be tested only if these cal-

culated values exceed the specification maximum by five sec-

onds or less. All specimens, their total, and their average from

the reserve set shall comply with the requirements.

6 Notes

6.1

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

flushed out during burner ignition and flame adjustment,

resulting in a false yellow flame tip. Proper flame adjustments

then become very difficult if allowed to remain.

6.2

When

the flame is correct and the specimen’s end is at

the proper height above the burner (9.5 mm), the inner blue

cone of the flame will just meet the end of the specimen. The

hottest area of the flame will then ignite the specimen.

6.3

Accurate

centering of the flame under the specimen is

essential for consistent test results.

IPC-23101-2

Figure

2 Specimen Mounted in the Test Fixture

Specimen

9.5 mm

19 mm

304 mm

y absorbant

surgical cotton

Mounting

Block

Burner

IPC-TM-650

Number

2.3.10.1

Subject

Flammability

of Soldermask on Printed Wiring Laminate

Date

8/98

Revision

age3of4

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Solder

Mask

Color

endor

Lot

Coated Thickness−Nm

Min: Max:

Laminate (ANSI type)

Color

endor

Lot

Substrate Thickness−(mm)

Min: Max:

Solder

Shock Parameters

Time (seconds)

emperature

°C

Check

One

Actual Solder

Fluidized

Alumina

Conditioning: ≥48

Hours @ 23°C ± 2°C & 50% ± 5% RH

Specimen

Number

Total

Thickness

Time of Combustion or Combustion & Glowing

Total

Flaming

Time/ea.

Total

Flaming

& Glowing

Within (W) or

Exceeds (E)

Spec. Limits

1st Flame Appli. 2nd Flame Application

Flame (sec.) Flame (sec.) Glowing (sec.)

Conditioning:

168 ± 2 Hours @ 70°C ± 1°C Desiccator Cooled

Specimen

Number

Total

Thickness

Time of Combustion or Combustion & Glowing

Total

Flaming

Time/ea.

Total

Flaming

& Glowing

Within (W) or

Exceeds (E)

Spec. Limits

1st Flame Appli. 2nd Flame Application

Flame (sec.) Flame (sec.) Glowing (sec.)

Figure

3 Vertical Burn Flammability Data

IPC-TM-650

Number

2.3.10.1

Subject

Flammability

of Soldermask on Printed Wiring Laminate

Date

8/98

Revision

age4of4

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ