IPC-TM-650 EN 2022 试验方法.pdf - 第283页

1 Scope This method covers the determination of the force necessary to propagate a tear in flexible insulating mate- rials that range between the thicknesses of approx.12 µm to 100 µm [approx. 0.0005 in to 0.004 in]. Thi…

1.0

Scope

This

method is to determine the average force in

grams required to propagate tearing through a specific length

of the constant radius specimen. Because of the variation of

materials and orientation of fibers, the method has been

designed to compensate and derive acceptable data.

2.0

Applicable Documents

ASTM-D-689

Tear

Strength

3.0

Test Specimens

least five specimens from each

direction are required to obtain an average result. They shall

be cut as per Fig. 1. A Thwing-Albert Co. TA63 Sample Cut-

ter, Catalog No. 98 may be used.

4.0

Apparatus

Pendulum Impluse Tester from Thwing-

Albert Co., or equal, having: stationary clamp, moveable

clamp, stop catch, pointer and scale.

5.0

Procedure

5.1 Preparation

5.1.1

Cut

specimens, adjust and calibrate apparatus paying

particular attention to the pendulum to be certain it swings

freely.

5.1.2

Separate

clamps 0-10 in. apart and align the speci-

men in the plate perpendicular to the plane of the oscillation

of the pendulum, with the edges of the jaws gripping the

specimen in a horizontal line.

5.1.3

The

clamping surface of the jaws must be at least 1 in.

in width and 0.5 in. in depth.

5.2

Test

5.2.1

Raise

the pendulum to its top position, place speci-

men midway in the clamps so that its upper edge is parallel to

the top of the clamps and the precut initial slit is at the bottom

of and between the clamps at right angles to their top.

5.2.2

Release

the stop latch and tear the specimen.

5.2.3

the pendulum section completes its swing, catch it,

being careful not to disturb the position of the pointer.

5.3

Evaluation

Examine

specimen carefully. If torn through

the constant-radius section within approximately 60° on either

side of the vertical line of intended tear, record the pointer

reading to the nearest 0.5 unit. If torn outside the 60°, disre-

gard specimen and test a new piece. Calculate the tearing

resistance in grams (R), as follows:

R =

SxC

= Corrected scale reading

S = Machine capacity in grams

n = Number of sheets torn

6.0 Notes Thwing-Albert

Instrument Co. is located in Phila-

delphia, Pennsylvania.

Figure

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.4.17

Subject

Tear

Strength (Propagation)

Date

4/73

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.

age1of1

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1 Scope This method covers the determination of the force

necessary to propagate a tear in flexible insulating mate-

rials that range between the thicknesses of approx.12 µm to

100 µm [approx. 0.0005 in to 0.004 in]. This test method is

based on ASTM D 1938.

2 Applicable Documents

ASTM D 1938

Standard Test method for Tear propagation

Resistance (Trouser Tear) of Plastic Film and Thin Sheeting by

a Single Tear Method

3 Test Specimen Preparations

3.1

If the specimens to be tested are clad flexible dielectric

materials, the copper foil shall be fully etched (removed) using

standard commercial practices. If the dielectric material to be

tested is unclad, use the material as it exists for this test

method. If the specimens are flexible insulating bonding mate-

rial that inherently has an adhesive that is not fully cured, full

curing of this adhesive shall be accomplished before the

material is tested.

3.2 The specimens shall be of the single-tear type and

shall consist (see Figure 1) of strips 75 mm [approx. 3 in] long

by 25 mm [approx. 1 in] wide and shall have a clean longitu-

dinal slit 50 mm [approx. 2 in] long cut with a sharp razor

blade or the equivalent (Note: All dimensions shall be mea-

sured to within a 0.5% tolerance.)

3.3 If the specimen is composed of a base dielectric plus

adhesive coated on one or both sides, the thickness of the

base dielectric needs to be measured, either via cross-

sectional analysis or if feasible, removal of the adhesive lay-

er(s). The thickness of the specimen below the slit (see Figure

1) shall be measured in three places and recorded in millime-

ters or microns [in]. This provides the user of this test method

with knowledge of only the base dielectric film thickness.

3.4 Sufficient specimens shall be cut to provide a minimum

of five specimens in both transverse and longitudinal axes and

identified. Specimens shall be free of nicks or other defects

that might cause premature test failure. Verification of lack of

defects in the slit shall be done using a minimum magnifica-

tion of 3X.

4 Test Equipment

4.1 Constant Strain Rate Tensile Test Machine

This

test machine shall have a weighing head that can measure

the load applied to tear the specimen. It should be equipped

with a device for recording the load carried by the specimen

and amount of separation of the grips during the test. The

testing machine shall be essentially free from inertia lag at

the specified rate of testing and shall indicate the load with

an accuracy of ± 2% of the indicated value, or better. A

device shall be included to control the grip separation rate at

250 mm [approx.10 in] ± 5% per minute.

4.2 Thickness Measuring Devices Suitable micrometers,

or thickness gages, reading to 2.5 µm [approx. 0.10 in] or less

shall be used for measuring the thickness of the specimens.

4.3 Cutter The cutter shall be a sharp razor blade or the

equivalent.

5 Conditioning

5.1 Conditioning

Condition the specimens at 23°C ± 2°C

[73.4°F ± 3.6°F] and 50% ± 5% relative humidity for not less

than 24 hours prior to test.

5.2 Test Conditions Conduct tests in the Standard Labo-

ratory Conditions of 23°C ± 2°C [73.4°F ± 3.6°F] and 50% ±

5% relative humidity.

6 Procedure

6.1

Secure tongue A (Figure 1) in one grip and tongue B in

the other grip of the tensile testing machine using an initial grip

separation of 50 mm [approx. 2 in]. Align the specimen so that

its major axis coincides with an imaginary line joining the cen-

ters of the grips.

6.2 Using a grip separation speed of 250 mm [approx. 10 in]

/ minute, start the tensile test machine and record the load

necessary to propagate the tear through the entire unslit

25 mm [approx. l in] portion.

6.3 Test not less than five (5) specimens in each of the

transverse and longitudinal directions.

3000 Lakeside Drive, Suite 309S

Bannockburn, IL 60015-1249

IPC-TM-650

TEST METHODS MANUAL

Number

2.4.17.1

Subject

Propagation Tear Strength, Flexible Insulating

Material

Date

1/13

Revision

Originating Task Group

Flexible Circuits Test Methods Subcommittee

(D-15)

Material in this Test Methods Manual was voluntarily established by Technical Committees of 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 IPC.

Page1of2

7 Calculations

7.1 Low Extensible Films

For base dielectric films that

have load-time charts characterized by Figure 2, the average

tear propagation force in grams [ounces] is obtained by aver-

aging the load indicated on the chart over the time period,

disregarding the initial and final portions of the curve. Record

the average load value reading from the tensile testing

machine. The average resistance to tearing shall be calcu-

lated from all specimens tested in each of the transverse and

longitudinal directions.

7.2 High Extensible Films For base dielectric films that

have load-time charts characterized by Figure 3, the initial

force to continue the propagation of the slit and the maximum

force attained are obtained from the chart and reported in

grams [ounces]. The initial force may be more readily detected

by placing a dot approximately 3 mm [1/8 in] in diameter at

the base of the razor blade slit with a wax pencil. As the load

is applied to the sample, the dot area is observed. When the

load is just sufficient to begin the extension of the slit, a ‘‘blip’’

is introduced on the chart (see Figure 3) by pushing the

appropriate button on the recorder or the equivalent to mark

this point. The maximum load is the highest reading on the

chart as indicated. Calculate the average of the five initial tear-

propagation forces and the average of the five maximum tear-

propagation forces in grams [ounces] for the transverse and

longitudinal directions of the material test specimens.

8 Report

8.1

Report the average base dielectric film thickness only of

the specimens tested. This provides the user of this test

method with the base dielectric film thickness only, if required,

by the flexible circuitry material specifications.

8.2 For low extensible base dielectric films described in 7.1,

report the average of the five average tear propagation deter-

minations in grams [ounces] for the transverse and longitudi-

nal specimens.

8.3 For high extensible base dielectric films described in 7.2,

report the average of the five initial tear-propagation forces

and the average of the five maximum tear-propagation forces

in grams [ounces] for the transverse and longitudinal

specimens.

IPC-24171-1

Figure 1 Single-tear specimens

IPC-24171-2

Figure 2 Load-time chart for low-extensible base

dielectric ﬁlms

IPC-24171-3

Figure 3 Load-time chart for high extensible base

dielectric ﬁlms

IPC-TM-650

Number

2.4.17.1

Subject

Propagation Tear Strength, Flexible Insulating Material

Date

1/13

Revision

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