IPC-TM-650 EN 2022 试验方法.pdf - 第163页

5.3 Method B 5.3.1 Apply mold release to the alligator clips on the appa- ratus shown in Figure 1 and allow to air dry. 5.3.2 Weigh each specimen to the nearest milligram [0.001 gram]. Record as W1. 5.3.3 Secure each spe…

1.0

Scope

This

test method is designed to measure the

volatile content of prepreg used as bonding plies in the manu-

facture of laminate and printed boards.

2.0

Applicable Documents

None

3.0

Test Specimens

3.1 Specimen Size

The

test specimen shall be a ply of

prepreg cut with its diagonal parallel to the X or Y axis of the

prepreg. The specimen shall be approximately 101.6 x 101.6

mm [4 in x 4 in]. A hole approximately 3.18 mm [0.125 in] in

diameter shall be punched in one corner of the specimen.

3.2

Quantity and Sampling

Unless

otherwise specified,

for each material tested, three specimens shall be prepared;

one specimen shall be cut from the center of the width and

one each from each edge of the sheet of prepreg. Specimens

shall be cut no closer than 25.4 mm [1 in] from the edge of the

prepreg sheet.

4.0

Apparatus or Material

4.1 Analytical Balance

Analytical

balance capable of

weighing to the nearest milligram [0.001 gram].

4.2

Oven

Air

circulating oven capable of maintaining ±

2.8°C[±5°F] at the specified test temperature (see Table 1).

4.3

Desiccator

Desiccation

chamber capable of maintain-

ing an atmosphere less than 30% R.H. at 23°C [73.4°F].

Vacuum drying systems, or equivalent, that could absorb or

remove organic components shall not be used.

4.4

Hanging Device to Support Prepreg

4.4.1

Paper

clip, alligator clip, or equivalent (Method A)

4.4.2

Clip

jig, as shown in Figure 1. (Method B)

5.0

Procedure

5.1 Specimen Preparation

5.1.1

The

prepreg shall be cut to conform with the speci-

men size and configuration as per 3.1.

5.1.2

Preconditioning

Unless

the prepreg is tested within

10 minutes of manufacture, specimens shall be desiccated for

24 ± 2 hours before testing. Specimens tested as part of

manufacturing control procedures are exempt from desicca-

tion. For referee testing, desiccation shall be performed. (See

6.1.)

5.2

Method A

5.2.1

Apply

mold release to the hanging device and allow to

air dry.

5.2.2

Weigh

the hanging device to the nearest milligram

[0.001 gram]. Record as W

5.2.3

Weigh

each specimen with a hanging device to the

nearest milligram [0.001 gram]. Record as W

5.2.4

Place

each specimen and hanging device in the air

circulating oven at the temperature and for the time specified

in Table 1 or by the governing document.

5.2.5

Remove

each specimen with the hanging device and

weigh within two minutes to the nearest milligram [0.001

gram]. Record as W

5.2.6

Calculate

and record the volatile content as follows:

Volatile content (%) =

(

− W

)

100

(see 5.2.2)

(see 5.2.3)

(see 5.2.5)

able 1

Prepreg

(1)

Material

Type

Oven

(1)

emperature

Test

(1)

ime

Difunctional Epoxy,

Tetrafunctional Epoxy,

Multifunctional Epoxy,

Polyimide Blend

163°C (325°F) 15 ± 1 minute

Polyimide 225°C (437°F) 30 ± 1 minute

Cyanate Ester 145°C (293°F) 15 ± 1 minute

(1) For material types that do not conform to the types listed,

follow the manufacturer’s instructions for temperature and

time.

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.3.19

Subject

Volatile

Content of Prepreg

Date

12/94

Revision

Originating Task Group

MIL-P-13949 Test Methods Task Group (7-11b)

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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5.3

Method B

5.3.1

Apply

mold release to the alligator clips on the appa-

ratus shown in Figure 1 and allow to air dry.

5.3.2

Weigh

each specimen to the nearest milligram [0.001

gram]. Record as W1.

5.3.3

Secure

each specimen at diagonally opposite corners

from the metal hanging apparatus as shown in Figure 1.

5.3.4

Place

the apparatus with specimens in the air circulat-

ing oven at the temperature and for the time specified in Table

1 or by the governing document.

5.3.5 Remove

the specimens from the oven and from the

holding apparatus and weigh each specimen within two min-

utes to the nearest milligram [0.001 gram]. Record as W2.

5.4

Calculation

Calculate

and record the volatile content

as follows:

Volatile Content (%) =

(

− W

)

100

5.5

Report

The

results should be reported and shall con-

tain the following:

(1) Identification of prepreg material type tested.

(2) Percent volatile content for each specimen tested and the

average.

(3) Test temperature and time in oven.

Figure

1 Method of holding device

IPC-TM-650

Number

2.3.19

Subject

Volatile

Content of Prepreg

Date

12/94

Revision

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6.0 Notes

6.1

Moisture Content

6.1.1 Exclusion of Moisture Content

Desiccation

of the

specimens is performed for the following reasons.

6.1.1.1

This

test method is based on the understanding that

‘‘Volatile Content’’ refers to organic solvents and other ingre-

dients of the prepreg that may remain in the material after

curing. Water or moisture content is not considered as a

‘‘Volatile’’ for purposes of this test, and therefore desiccation

is a fundamental step to exclude H

from the data. It is not

possible to remove all H

from material that is hygroscopic,

but the most significant content is removed.

6.1.1.2 This

method has a high intrinsic variability potential,

and since moisture content is extremely variable and depen-

dent on the storage environment, meaningful data is best

achieved by removing the moisture.

6.1.2

Moisture Content Determination

This

method can

be performed in an alternative manner, in which the specimen

is weighed before it is desiccated. The difference between the

‘‘As Is Weight’’ and the ‘‘Weight After Desiccation’’ (but

before oven drying) is the moisture content.

6.2

Alternate Specimen Holder

Method B has been

designed to minimize the problem of specimens flopping

around in the air circulating oven.

6.3

Desiccator Conditions

The

Test Methods Task Group

determined that a great majority of test laboratories are unable

to consistently hold the Relative Humidity in a desiccator to

less than 20%. Based on data from participating company lab

management, the lowest practically feasible RH for use with

the affected IPC Test Methods is 30% maximum.

IPC-TM-650

Number

2.3.19

Subject

Volatile

Content of Prepreg

Date

12/94

Revision

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