IPC-TM-650 EN 2022 试验方法.pdf - 第285页

1.0 Scope To determine the tensile strength (in PSI) and the elongation (in percentage) of copper foil at ambient and elevated temperatures by mechanical force testing. 2.0 Applicable Documents ASTM-E-345 Tensile Strengt…

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

Page2of2

1.0

Scope

determine the tensile strength (in PSI) and

the elongation (in percentage) of copper foil at ambient and

elevated temperatures by mechanical force testing.

2.0

Applicable Documents

ASTM-E-345

Tensile

Strength

3.0

Test Specimens

Copper

foil sufficient in size to permit

cutting or etching of five specimens 10 inches x

⁄

inch.

Specimens

must be clean cut and free of burrs and nicks.

4.0

Apparatus

4.1

Constant

strain rate tensile tester capable of pulling at

rate of 0.050 and 2.0 inches/minute.

4.2

JDC

#50 sample cutter

⁄

inch

wide x 10 inches long.

4.3

shear to cut 10 inches long sample to 6 inches long.

4.4

Mettler

Balance type P120 or equivalent.

4.5

Elevated

temperature chamber or fixture, attachable to

the tensile tester, capable of reaching and maintaining a tem-

perature of 180°C ±10°C during sample testing.

5.0

Procedure

5.1 Preparation of Samples

5.1.1

The

sample should be smooth and undistorted

(wrinkle free).

5.1.2

Use

the JDC #50 to cut five tensile specimens.

5.1.3

Cut

the five 10 inches long specimens to 6 inches

long.

Note: Accuracy is important in the

⁄

inch

x 6 inches dimen-

sions because it is used to determine foil thickness and cross-

sectional area.

5.2

Weighing Samples

5.2.1

Weigh

tensile sample to at least three places beyond

the decimal point, in grams.

5.2.2

Record

the weight and calculate the mean average

cross-sectional area.

Note: The density of electrodeposited copper is 8.909 gm/cc

(16.389 cc/in

8.909 gm/cc = 146 gm/in

The

density of rolled copper is 8.93 gm/cc (16.389 cc/in

8.93

gm/cc = 146.35 gm/in

Mean

average thickness =

Weight

of tensile sample in grams

Area of Tensile

sample in sq.

inches

The density

of copper in

gm/in

Mean

avg. cross-sectional area =

Weight

of tensile sample in grams

Area of Tensile

sample in sq.

inches

The density

of copper in

gm/in

5.3

General Test Information

5.3.1

the tensile tester is equipped with an area compen-

sator, dial the mean average cross-sectional area into it. If not

then the cross-sectional area has to be used to compute the

tensile strength.

Note:

Tensile Strength

lbs/in

Load

used to break sample in lbs.

Mean

average cross−sectional area

If Tensile Tester is equipped with area compensator after the

test is complete, the Tensile Strength can be read directly

from the chart.

5.3.2

Ambient Temperature Testing

5.3.2.1

Select

load range.

5.3.2.2

Place

the sample in the jaws of the Tensile Tester

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.4.18

Subject

Tensile

Strength and Elongation, Copper Foil

Date

8/80

Revision

Originating Task Group

Printed Board Test Methods (7-11d)

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.

age1of2

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ

being

careful that it is properly centered and the axis aligned

with the jaws.

5.3.2.3

Test Conditions

(1) Gage length 2.0 inches

(2) Crosshead speed 2.0 inches/min.

(3) Chart speed 20 inches/min.

Note: At a chart speed of 20 inches/min., a gage length of

2.0 inches and a crosshead speed of 2.0 inches/min. each

one inch of chart paper equals 5.0% linear elongation.

5.3.3

Elevated Temperature Testing

5.3.3.1

Select

load range.

5.3.3.2

Bring

temperature chamber or fixture up to 180°C

±10°C.

5.3.3.3

Open

temperature chamber and clamp foil sample

between tensile jaws. (Note: Caution must be exercised to

avoid excessive clamping pressures and to provide good

sample alignment for testing.)

5.3.3.4

temperature chamber and monitor sample

temperature with a thermocouple. Permit foil sample to dwell

at 180°C temperature for 5 minutes prior to tensile test. Maxi-

mum time at temperature should not exceed 10 minutes.

5.3.3.5

Test Conditions

(1)

Gage length 2.0 inches

(2) Crosshead speed 0.050 inches/min.

(3) Chart speed 20 inches/min.

Note: At a chart speed of 20 inches/min., a gage length of

2.0 inches and a crosshead speed of 0.050 inches/min., each

one inch of chart paper equals 0.125% linear elongation.

Note: Temperature chamber contains normal ambient air.

Inert gas atmosphere is not necessary, but may be used.

5.4

Evaluation

5.4.1

Activate

crosshead to break sample and make calcu-

lations of tensile strength in pounds/in

and

elongation in %.

5.4.2

Percent

elongation may be determined by fitting the

ends of the fractured specimen together carefully and mea-

suring the distance between the original gage marks to the

nearest 0.01 inch. Elongation is the increase in length of the

gage length, expressed as a percentage of the original gage

length.

Percent elongation =

length at break −original gage length X 100

original

gage length

5.4.3

Average

all five elongation readings.

6.0 Notes

6.1

For

guidance, typical values for tensile strength and

elongation are:

TENSILE

STRENGTH

Oz/ft

Electrodeposited

Standard

or high ductility As rolled

Light cold

rolled Annealed

lb/in

1/2

15,000 50,000 — 15,000

1 30,000 50,000 — 25,000

2 & over 30,000 50,000 25,000 25,000

ELONGATION

Oz/ft

Electrodeposited

rolled

Light cold

rolled AnnealedStandard High ductility

percent

percent min. percent min. percent min. percent

1/2 2 5 1/2 — 5

1 3 10 1/2 — 10

23151520

IPC-TM-650

Number

2.4.18

Subject

Tensile

Strength and Elongation, Copper Foil

Date

8/80

Revision

age2of2

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ