IPC-TM-650 EN 2022 试验方法.pdf - 第81页

1.0 Scope This method provides a technique for determin- ing the overall thickness of treated or untreated copper foils and for determining the profile factor on foils used for the manufacture of electrical grade laminat…

1.0

Scope

This

method of test covers the procedure for

determining weight (average thickness - by weight measure-

ment) of copper foil for printed circuits.

2.0

Applicable Documents

None.

3.0

Test Specimen

Use

template described below to cut

three samples of copper. Samples should be taken from near

the left and right edges and the center across the width of the

roll.

4.0

Apparatus

4.1

Balance

capable of weighing accurately to ±0.1 grams.

4.2

Knife

suitable for cutting copper.

4.3

Template

precut to 254 sq. in. (0.164 sq. meters) [12 in

±1/32 in by 21-3/16 in ±1/32 in] (304.8mm by 538.2

+0.079mm).

5.0

Procedure

5.1

Identify

the samples (left, center and right); weigh sec-

tions singly and record values.

5.2

Evaluation

(1)

One ounce copper foil (nominal 0.0014 in.) should weigh

50 grams ±5.

(2) Two ounce copper foil (nominal 0.0028 in.) should weigh

100 grams ±10.

(3) ‘‘X’’ ounce copper foil should weigh 50X grams ±10%.

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062

IPC-TM-650

TEST

METHODS MANUAL

Number

2.2.12

Subject

Thickness

of Copper By Weight

Date

3/76

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.

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1.0

Scope

This

method provides a technique for determin-

ing the overall thickness of treated or untreated copper foils

and for determining the profile factor on foils used for the

manufacture of electrical grade laminates and multilayer circuit

boards.

The profile factor is the difference between the actual

mechanical thickness of the foil and the calculated effective

thickness based on the weight and density. This method will

define the profile factor to about 0.00025 mm [0.01 mil], how-

ever, due to variations within the foil the use of values of incre-

ments less than 0.00125 mm [0.05 mil] is seldom necessary

on treated foils. This method easily achieves this level of pre-

cision.

A. Background: While for a sample with perfectly flat sur-

faces the theoretical and actual thickness would be equal,

in practice virtually all foils used in such applications are

manufactured with one rough surface to enhance adhe-

sion to the substrate. Since this irregular surface reduces

the effective electrical thickness of the substrate material

and may affect other electrical and mechanical properties,

it is often useful to quantify the degree of variation from the

theoretical thickness. The technique described herein pro-

vides a measure of this variation, which on normal foil

generally runs from 0.0025 to 0.025 mm [0.1 mil to 1 mil]

and may represent over a 50% increase to the foils theo-

retical thickness.

B. Applications: The effective minimum electrical thickness of

a double-sided laminate may be readily determined by

subtracting the overall mechanical thickness of the foil

(both sides) from the overall thickness of the laminate at a

particular location.

The actual mechanical thickness of the base material may

be estimated by subtracting the effective thickness of the

copper foil from the overall mechanical laminate thickness.

The Profile Factor may be used to monitor variations of

incoming foils of a particular type without time consuming

microsectioning. Comparison of different foil types may be

made but judgment or performance should be made

using the actual criteria of interest.

2.0

Applicable Documents

None.

3.0

Apparatus

3.1 Paper cutter

3.2

25.4

mm [1 inch] precision cutter, 324 mm [12 inches]

long minimum.

3.3

Analytical

balance 1 mg. resolution.

3.4

Standard

25.4 mm [1 inch] ratchet micrometer with

0.0025 mm [0.0001 inch] resolution (or better), 25 psi pres-

sure, 6.4 mm [0.25 inch] anvil.

3.5

Parallel

jaw pliers.

4.0

Specimen

4.1

Number:

4.2 Form:

324 x 25.4 mm [12.00 x 1.00 inches].

4.3

Location

4.3.1

Roll:

Specimens shall cut across the width of the foil

from the center and both edges of the roll.

5.0

Procedure

5.1 Test

5.1.1

Fold

the specimen around itself into a 10 ply 25.4 mm

[1 inch] long sample maintaining the treated side out so that

there are no treated side to treated side interfaces.

5.1.2

Weigh

the specimen on the analytical balance to the

nearest 0.001 gram and record as WI.

5.1.3 Compress

the outer 3.2 mm [1/8 inch] of the speci-

men using a pair of pliers with parallel jaws or equivalent

device.

5.1.4

Using

the micrometer, measure the thickness of the

specimen to the nearest 0.0025 mm [0.0001 inch] or better in

four locations around the center at least 3.2 mm [1/8 inch]

from the compressed edges. Use three clicks of a properly

calibrated ratchet micrometer (providing a force of 25 psi ±5

psi on the sample).

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062

IPC-TM-650

TEST

METHODS MANUAL

Number

2.2.12.1

Subject

Overall

Thickness and Profile Factor of Copper

Foils Treated and Untreated

Date

9/87

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.

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5.2

Calculation

5.2.1

Calculate

the effective thickness of the foil in mils by

multiplying the weight of the 324 x 25.4 mm [12 x 1 inch]

specimen by 0.572 mil/g.

Te (mil)=0.572

mil

xW(g)

= Thickness Equivalent

Sample calculation:

W = 2.16 g

Te = 0.572 mil/g x 2.16 g = 0.0031 [1.236 mil]

5.2.2

Calculate

the average mechanical thickness microme-

ter of each 10 ply specimen from the four values taken on

each sample.

5.2.3

Calculate

the average overall thickness (Tm) for each

sample by dividing the average thickness of the specimen by

the number of plies.

5.2.4

Calculate

the average profile factor of the foil for each

specimen by subtracting the effective thickness from the aver-

age mechanical thickness.

PF=Tm−Te

5.2.5

Average

the three values of profile factor.

5.3

Report

5.3.1

Report

the average profile factor for the three speci-

mens tested.

5.3.2

Report

the average mechanical thickness for the three

specimens tested.

6.0 Notes

Thickness

of Specimen: The thickness of the specimen used

must be at least 100 times the precision of the thickness

measuring device. More plies may be required for lighter foil,

e.g. 0.5 ounce per square foot foil if the micrometer precision

is 0.0025 mm [0.0001 inch] since a minimum of 0.25 mm [10

mils] is required to fulfill the 1% requirement. If a precision

25.4 mm [1 inch] cutter is not available a paper cutter or

punch and die set may be used for sample preparation, how-

ever, the areas of the sample used for weight determination

must be known to 1% or better and the thickness sample

must be free from wrinkles or creases.

Precision: A study of various 1 oz./ft copper foils resulted in

reproducibility between testers using a hand micrometer with

0.0013 mm [0.00005 inch] resolution.

Comparison to Other Methods: The profile factor determined

by this test may vary slightly from the actual profile height as

estimated from other methods, such as microsectioning or

profilometery. The denser the treatment structure the more

this technique will underestimate the true profile height. The

precision of this method between testers was about 50% bet-

ter than microsectioning in determining the amount of profile

on low profile treated ED copper using the same number of

determinations using a single microsection as the test vehicle.

The time required by this method is under 5 minutes.

Thickness

Mean

(mils)

Microns

Standard

Deviation

(mils) Microns

Proﬁle

Factor

Mean

(mils) Microns

Standard

Deviation

(mils) Microns

Treated ED Foil Class 1

1 oz.ft

1.61

40.9 0.015 0.38 0.350 8.89 0.015 0.38

Treated ED Foil Class 3

1 oz./ft

1.62 41.2 0.013 0.33 0.251 6.38 0.013 0.33

Untreated RA Foil Class 7

3/4 oz./ft

1.06

26.4 0.010 0.25 0.061 1.55 0.011 0.28

IPC-TM-650

Number

2.2.12.1

Subject

Overall

Thickness and Profile Factor of Copper Foils Treated and

Untreated

Date

9/87

Revision

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