IPC-TM-650 EN 2022 试验方法.pdf - 第231页

1.0 Scope With this test method the flexural fatigue life for any given bend radius, the flexural fatigue behavior and the ductility in percent deformation after tensile failure can be determined. Note: The indirect dete…

5.3.4

The

flexural fatigue life at bend radii other than man-

drel radius can also be obtained by evaluating the ductility for-

mula for the flex life in cycles-to-failure using the fatigue duc-

tility determined in 5.3.1.2 and the desired bend radius.

6.0 Notes

For

further technical details, reference the mate-

rial shown below.

6.1 Document

in paragraph 2.0 (IPC-TP-204).

6.2 Engelmaier,

W., ‘‘Fatigue Ductility for Foils and Flexible

Printed Wiring,’’ Program No. 1883D HP-67/97 User’s

Library, Hewlett Packard Co., Corvallis, Oregon, 1978.

6.3

Engelmaier,

W., ‘‘Fatigue Ductility Flex Tester,’’ Drawing

L520163, Bell Telephone Laboratories, Inc., Whippany, New

Jersey, 1978.

6.4

Test Equipment Sources

The

equipment sources

described below represent those currently known to the

industry. Users of this test method are urged to submit addi-

tional source names as they become available, so that this list

can be kept as current as possible.

6.4.1

Fatigue

Ductility Flex Tester, Universal Tool & Machine

Inc., 171 Coit St., Irvington, NJ 07111; 201-374-4400.

6.4.2

JDC

Precision Sample Cutter, Model JDC 125-N or

equal.

IPC-TM-650

Number

2.4.2.1

Subject

Flexural

Fatigue and Ductility, Foil

Date

3/91

Revision

age3of3

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ

1.0

Scope

With

this test method the flexural fatigue life for

any given bend radius, the flexural fatigue behavior and the

ductility in percent deformation after tensile failure can be

determined.

Note:

The

indirect determination of foil ductility by using a

fatigue test is made necessary by the geometry and dimen-

sions of foil samples which make tensile elongation and rup-

ture tests inadequate for ductility determination.

2.0

Applicable Documents

IPC-TM-650

Method

2.1.1, Microsectioning

Method 2.4.18, Tensile Strength and Elongation, Copper Foils

3.0

Test Specimen

Foil

of sufficient size to permit cutting

of three 3.2 mm [1/8 inch] wide specimens of at least 50.8

mm [2 inches] in length. Specimens must be clean cut and

free of burrs and nicks.

4.0

Apparatus

4.1

Ductility

Flex Tester, Universal Mfg., Model FDF or 2FDF

or equal (see 6.4 and Figure 2).

4.2

Sample

cutter, punch or tensile cut router. Note 6.4.

4.3

Micrometer

tool capable of measurement to the nearest

0.0025 mm [0.0001 inch].

4.4

Programmable

Calculator, Hewlett-Packard HP-67, or

equivalent.

4.5

Sample

holders, 203.2 x 12.7 mm [8 x 1/2 inch], of very

flexible but durable material, e.g., epoxy-impregnated glass

cloth, paper, etc.

4.6

Microscope

5.0 Procedure

5.1 Preparation of Samples

5.1.1

The

samples should be smooth and undistorted

(wrinkle free).

5.1.2

Use

the sample cutter to cut the 3.2 mm [1/8 inch]

wide test specimen. Examine each specimen for nicks, cuts,

or curled edges. Discard any specimen with defects.

5.1.3

Use

the micrometer to determine the specimen thick-

ness, t, in center of each specimen to the nearest 0.0025 mm

[0.0001 inch]. If one or both specimen surfaces are rough, it

is necessary to determine the core thickness, t

from

a micro-

section (see Figure 1).

Note:

Thickness

is a critical parameter in the determination of

fatigue ductility. A 10% error in t

results

in a 14% error in D

Note:

The

core thickness, t

is preferably determined as a

fraction of the specimen thickness, t, from a microsection pre-

pared per IPC-TM-650, method 2.1.1 and measured with a

metallurgical microscope at 200X minimum with a suitable filar

eyepiece or reticle. The measurement is to be made from the

valley of the rough surface to the smooth surface, or valley to

valley, where both surfaces are rough. The t

to be made

once on a batch or lot basis, and this fractional value of t

then multiplied by all other micrometer, t, values to achieve

core values for all samples.

Note:

Care

must be taken that during thickness measure-

ments the specimens are not compressed or surface rough-

ness crushed, producing false low thickness readings.

5.1.4

Attach

test specimen to the ends of 2 sample holders

with adhesive tape and clamp 84 grams [3 ounce] foil weight

(not the 8 ounce weight shown in Figure 2) to the free ends of

the sample holders to form a loop (See Figure 2).

IPC-2421-1

Figure

1 Smooth and rough foil

▼

t = t

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.4.2.1

Subject

Flexural

Fatigue and Ductility, Foil

Date

3/91

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.

age1of3

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ

1 Scope To determine the number of flexes to conductor

failure of etched flexible printed board conductor patterns.

2 Applicable Documents None

3 Test Specimen The test specimen shall consist of an

etched conductor pattern in accordance with Figure 1. A mini-

mum of six specimens with the long dimension of the conduc-

tors oriented in the transverse direction of the base material

shall be prepared using standard commercial practices.

For double-sided clad constructions, a separate sample

specimen shall be prepared for each side. The opposite

(untested) side shall be completely etched of copper.

4 Apparatus Flexural Endurance Tester (see Figure 2) or

equivalent.

5 Procedures

5.1

Examine the etched conductor specimen for any pre-

existing fractures and look for evidence of process anomalies

(such as pin holes and nicks), which could cause premature

fracture. If such fractures or anomalies are found, the speci-

men shall be discarded and a new specimen selected.

5.2 Attach (solder, clamp, etc.) a short length of insulated

wire to the extreme ends of the conductor pattern of each of

the six specimens.

5.3 Using the flexure test equipment as seen in Figure 2,

mount the specimen so that the inside diameter of the loop is

6mm±1mm[approximately, 0.25 in ± 0.04 in] and connect

the two wires to the relay. The horizontal oscillation of the

reciprocating bar causes the flexible test specimen to move in

what can be described as a rolling, flexible action.

5.4 Test three specimens per clad side with the conductor

on the inside of the loop. The reciprocating travel should not

exceed 10 cycles per minute. The loop shall travel 25 mm ±

5 mm [effectively, 1 in ± 0.2 in].

5.5 The number of cycles to failure is when electrical discon-

tinuity of the conductor occurs.

5.6 Report the average number of cycles to failure for the

three specimens tested per clad side.

6 Note Master set of drawings of a similar test fixture as

seen in Figure 2 is available from the IPC office. This fixture is

not commercially available.

IPC-243-1

Figure 1 Flexural Endurance Test Pattern.

(NOTE: Conductors are 1.5 mm ± 0.1 mm [approximately, 0.059 in ±

0.004 in] wide on 2.5 mm ± 0.1 mm [approximately, 0.01 in ± 0.004 in]

centers.)

IPC-243-2

Figure 2 Typical Flexural Endurance Test Fixture Equipment

3000 Lakeside Drive, Suite 309S

Bannockburn, IL 60015-1249

IPC-TM-650

TEST METHODS MANUAL

Number

2.4.3

Subject

Flexural Endurance, Flexible Printed Board

Materials

Date

6/11

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.

Page1of1