IPC-TM-650 EN 2022 试验方法.pdf - 第320页

5.1.2 Specimens shall be cut to the specified size using appropriate procedures and equipment to minimize thermal shock and mechanical stress. Method A specimens shall have their edges smooth and burr-free by means of sa…

Scope

This

test is designed to determine the glass tran-

sition temperature (T

)

and room temperature storage modu-

lus (E’) of dielectric materials used in High Density Intercon-

nect (HDI) and Microvias by the use of dynamic mechanical

analysis (DMA).

When testing a stand alone HDI dielectric layer, DMA will pro-

vide modulus as a function of temperature and glass transition

for this layer. When DMA is used on built-up constructions,

the data will be a complex curve representing the composite

moduli and glass transitions.

Two methods are presented:

• Method A for thick specimens

• Method B for thin specimens (recommended for HDIS and

Microvia dielectric layers).

For anisotropic materials (reinforced dielectrics), the x and y

directions will have different modulus vs. temperature behav-

ior. Anisotropic materials shall be tested in both the x and y

directions.

Applicable Documents

2.1 ASTM Documents

E 1640

Test

Method for Assignment of the Glass Transition

Temperature by Dynamic Mechanical Analysis

4065

Standard

Practice for Determining and Reporting

Dynamic Mechanical Properties for Plastics

4092

Standard

Terminology Relating to Dynamic Mechani-

cal Measurements on Plastics

Test Specimen

3.1 Size

Method A

Flexural

bending geometry – thick specimens

(>0.5 mm): Specimens shall be approximately 8 mm to 12

mm wide, 20 mm to 40 mm long, and 1 mm to 2 mm thick.

The thickness shall be a minimum of 0.5 mm; for thicknesses

<0.50 mm, use Method B. An aspect ratio of length/thickness

= 10/1 or greater should be maintained. Exact specimen

dimensions should be determined by the apparatus used.

Method

Thin

film tension geometry – thin specimens

(<0.50 mm): Specimens shall be approximately 15 mm to 20

mm long and 2 mm wide. The minimum thickness is deter-

mined by the strength of the material; it should not break dur-

ing testing. Exact specimen dimensions may be determined

by the apparatus used.

3.2

All

specimens should be fully cured according to manu-

facturer’s recommendations. Thick specimens may be made

by use of multiple lamination/cure cycles if required.

3.3

Unless

otherwise specified, one specimen shall be

tested, to be taken from a random location in the material in

question.

Apparatus or Material

4.1

DMA capable of determination of modulus to +1%

precision and tan δ resolution of 0.01 over the specified tem-

perature range. The DMA will preferably have computer data

acquisition and analysis. The DMA must have an environmen-

tal chamber capable of having inert flush gas and capable of

heating the specimen to at least 310°C.

4.2

Diamond

blade or saw, sanding equipment, or equiva-

lent to provide specimens of the size and edge quality

required for Method A

4.3

Scissors,

razor blades, or equivalent to provide speci-

mens of size and edge quality for Method B

4.4

Air

circulating oven capable of maintaining 105°C ± 2°C

4.5

Dessicator

capable of an atmosphere <30% RH at 23°C

4.6

Etching

system capable of complete removal of metallic

cladding

Procedure

5.1.1

Metallic

clad specimens shall be tested without the

cladding. Etch and dry using appropriate procedures and

equipment.

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.4.24.4

Subject

Glass

Transition and Modulus of Materials Used in

High Density Interconnection (HDI) and Microvias -

DMA Method

Date

11/98

Revision

Originating Task Group

HDI Test Methods Task Group (D-42a)

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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5.1.2

Specimens

shall be cut to the specified size using

appropriate procedures and equipment to minimize thermal

shock and mechanical stress. Method A specimens shall have

their edges smooth and burr-free by means of sanding or

equivalent (to allow the specimen to rest flat on the mounting

stage). Method B specimens shall be rectangular, with their

long edges parallel (to ensure good mounting in the film fix-

ture). Method B specimens shall have smooth edges without

nicks or tears.

5.1.3 Specimens

shall be preconditioned by baking for one

hour ± 15 minutes at 105°C, then cooled to room temperature

in a dessicator.

5.2

Measurement

5.2.1 Apparatus Set-up

5.2.1.1 Install the Required DMA Clamp

Method A

Install

and calibrate the DMA with a bending

geometry fixture/clamp.

Method

Install

and calibrate the DMA with a thin film

fixture/clamp.

5.2.1.2

Start the Experiment

Method A

Measure

the length, width, and thickness of the

specimen to within at least +0.01 mm or preferably +0.005

mm. Clamp the specimen in the DMA fixture. Set the sample

strain amplitude to operate within the linear viscoelastic range

of the material. Strains <1% are recommended and are typi-

cally 0.1%. Program the sample temperature range. Enclose

the specimen and fixture in the environmental chamber (fur-

nace).

Method

Measure

the length, width, and thickness of the

specimen to within at least +0.01 mm or preferably +0.005

mm. Sample lengths of 10 mm to 20 mm are typical. Mount

the specimen in the clamps of the film fixture according to the

manufacturer’s instructions. Apply tension force between 10 g

and 50 g. A typical base force would be 20 g (see 6.5 for an

explanation of the load criteria). Enclose the specimen and

probe in the environmental chamber.

5.2.1.3

Provide

an inert gas purge (helium or nitrogen) to the

environmental chamber. Temperature calibration of the DMA

must be performed under the same gas conditions.

5.2.2

Running the DMA Temperature Scan

5.2.2.1 Initial Temperature (T

initial

)

For specimens with T

below

or near room temperature,

start the scan at least 20°C below the anticipated transi-

tion. This may require a DMA with subambitent cooling

control of the environmental chamber.

b. For specimens with T

greater

than room temperature,

start the scan at 30°C.

5.2.2.2

Sample Heating and Deformation Rate

The

specimen

shall be run at 2°C/min and an oscillation frequency

of 1 Hz.

5.2.2.3

Temperature Excursion

Heat

the specimen to at

least 20°C greater than the T

This test is general in nature

and data may be taken above T

required. There is no

required upper temperature.

5.3

Evaluation

5.3.1

The

DMA storage modulus should resemble the plot

shown in Figure 1.

5.3.2

idealized DMA curve has a linear section below the

transition (glassy region below the temperature of T

)

and a

stepwise drop through the glass transition region. These linear

sections are used in calculating T

onset of the modulus

drop (see Figure 1).

IPC-24244-1

Figure

1 DMA Modulus Plot

IPC-TM-650

Number

2.4.24.4

Subject

Glass

Transition and Modulus of Materials Used in High Density

Interconnection (HDI) and Microvias - DMA Method

Date

11/98

Revision

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5.3.3

Examine

all specimens after the test to look for signs

of excessive loads, distortions, tears, and other defects. If any

defects or sample irregularities are found, discard the sample

and the data, rerun another specimen, or pick a different

method for determining T

and

storage modulus.

5.4

Calculations

5.4.1 Glass Transition Temperature (T

)

Construct

tangent line to the curve below the transition temperature in

the modulus curve. Construct a tangent to the storage modu-

lus curve at or near the inflection point approximately midway

through the step change in the transition. The temperature

where these tangents intersect is the reported T

for

the

material. For consistency it is recommended that the DMA

computer analysis software be used for this calculation. See

Figure 1 for an example of this tangent intersection method.

5.4.2

Storage Modulus (E’)

The

sample storage modulus

(E’) shall be calculated at room temperature (22°C) and

reported in units of Pa (N/m

For consistency it is recom-

mended that the DMA computer analysis software be used for

this geometry specific calculation.

5.4.3

Alternative

thermal transitions may be reported as the

transition peak temperature in the sample loss modulus (T

tan δ plots (T

)

(see Figure 2 and Figure 3).

5.5

Report

5.5.1

Report

the glass transition temperature 22°C (room

temperature) for each specimen, rounding to the nearest

whole number.

5.5.2

Report

the modulus in units of Pa (N/m

)

at 22°C.

5.5.3

For

anisotropic (reinforced) samples report the both

the x and y direction modulus.

5.6

Plot

5.6.1

Plot

the storage modulus vs. temperature (°C) for the

specimen. If using computer-based analysis, include the T

IPC-24244-2

Figure

2 DMA Tan Delta Plot

Note: T

the transition peak temperature.

IPC-24244-3

Figure

3 DMA Loss Modulus Plot

Note: T

the transition peak temperature.

IPC-TM-650

Number

2.4.24.4

Subject

Glass

Transition and Modulus of Materials Used in High Density

Interconnection (HDI) and Microvias - DMA Method

Date

11/98

Revision

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