IPC-TM-650 EN 2022 试验方法.pdf - 第329页

1 Scope This test method establishes a procedure for determining the thermal decomposition temperature (T d )o f base laminate materials using thermogravimetric analysis (TGA). Use of this test method for printed wiring …

6.2

There

are several methods for determining the T

organic material:

• Differential scanning calorimetry (DSC)

• TMA

• DMA

in organic materials is a broad transition, which arises when

molecular mobility greatly increases in the specimen as a

result of heating. No one method is superior to another; they

each measure different physical changes that occur in a

specimen near and around T

DSC

measures the heat capacity of a specimen. TMA mea-

sures the expansion of a specimen and DMA (dynamic

mechanical analysis) measures the stiffness of the specimen.

The T

determined

from TMA, DSC, and DMA may vary sig-

nificantly (up to 10°C) because they are measuring different

physical properties, which change differently as the specimen

goes through T

As a result, the test equipment used should

be noted after the reported T

value

(i.e., 136°C; DSC, TMA,

or DMA).

6.3

Most

thermal analysis equipment have the software

capability to determine T

and

CTE values; it is recommended

that this approach be used for consistency.

6.4

improve the accuracy of this test:

Method

Increase

the thickness to 0.76 mm or higher. Do

not stack single layers of thinner materials to achieve the mini-

mum thickness; this greatly increases test error.

Method

sure the specimen is mounted in the clamps

correctly and that any clamp expansion is corrected properly

by calibration of the probe. Method B clamps and specimens

may have more difficulty reaching thermal equilibrium.

6.5

Load Selection Criteria

Method A

The

initial load is 2 g. The load may be adjusted

for differences in material types or specimen configuration in

order to assure intimate contact between the probe, speci-

men, and stage. Avoid an excess load (15 g), which may

result in penetration or distortion of the specimen.

Method

The

initial load is5goftension (approximately

50 mN). The load (or force) may be adjusted for differences in

material types or specimen configuration in order to assure

that the specimen is being held without slack. Avoid an exces-

sive load (or force), which may result in elongation of the

specimen due to the applied tension. Specimens above T

may

become so soft as to be stretched.

Examine all specimens after the test to look for signs of exces-

sive loads, distortions, tears, and other defects.

IPC-TM-650

Number

2.4.24.5

Subject

Glass

Transition Temperature and Thermal Expansion of

Materials Used in High Density Interconnection (HDI) and

Microvias - TMA Method

Date

11/98

Revision

age5of5

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1 Scope This test method establishes a procedure for

determining the thermal decomposition temperature (T

)of

base laminate materials using thermogravimetric analysis

(TGA). Use of this test method for printed wiring boards or

other composites may not yield comparative results.

2 Applicable Documents All terms and definitions in this

document conform to IPC-T-50, Terms and Definitions for

Interconnecting and Packaging Electronic Circuitry.

3 Test Samples

3.1 Sample Construction

The sample may be an unclad

laminate material or laminate material with copper completely

removed and that has been cut (using water cooling/cleaning

only, no oil) approximately square to fit into the TGA sample

pan. Typical sample mass (weight) is 10 mg to 30 mg.

Samples shall be cut to the specified size using appropriate

procedures and equipment to minimize mechanical stress

and/or thermal shock.

Note: Samples of the same mass but with a smaller surface

area may lose mass at a slower rate.

3.2 Surface Preparation All edges of the sample shall be

finished smooth and burr-free by sanding or equivalent (to

allow the sample to rest completely flat on the sample pan).

Use care to minimize the introduction of mechanical stress or

heat to the sample.

3.3 Mass Measurement The accuracy of the mass mea-

surements shall be within ± 0.01 mg.

4 Equipment/Apparatus or Material

4.1 Thermogravimetric Analyzer (TGA)

Thermal gravi-

metric analysis instrument shall comprise the following:

4.1.1 Microbalance, null type, sensitive to 0.001 mg.

4.1.2 Furnace equipped with dry (dew point below -68°C

[-90°F], moisture less than 3.5 ppm) nitrogen (less than

20 ppm oxygen) purge.

4.1.3 Temperature programmer capable of providing con-

trolled 10°C ± 0.1°C [18°F ± 0.18°F] per minute heating rate

from ambient to 800°C [1472°F].

4.2 Mass Measurement Capability The TGA shall be

capable of measuring mass to within 0.01 mg of actual value.

5 Procedure

5.1 Test Sample Preparation

The test samples should be

baked at 110°C ± 2°C [230.0°F ± 3.6°F] for 24 hr and placed

in a desiccator for cooling to room temperature (equilibration)

prior to testing. In standard lab conditions, the TGA test

should be started within 15 minutes of removing test sample

from the dessicator because samples may gain mass due to

moisture absorption.

5.2 Equipment Startup and Calibration (Follow Manu-

facturer’s Recommendations.)

5.2.1 Calibrate the balance to within ± 0.01 mg.

5.2.2 Calibrate the temperature sensor to within ± 1.0°C

[1.8°F].

5.2.3 Set the purge rate of 55 cc/min (0.9 mL/s). Run the

TGA gas purge for 30 minutes before inserting a sample. The

rate of flow of the gas in the cell will have a significant effect

on the calibration, therefore, the instrument must be calibrated

with the same flow rate as is used during the test. The tem-

perature sensor should be positioned so that it does not come

into contact with sample at any time. After the temperature

sensor has been correctly positioned, the instrument can be

calibrated. Neither the sensor position nor the flow rate should

be subsequently changed.

5.3 Heating Sample

5.3.1

Place the sample in the TGA and measure its mass.

5.3.2 Heat the sample at a rate of 10°C/min from ambient

(not to exceed 50°C) to 550°C.

3000 Lakeside Drive, Suite 309S

Bannockburn, IL 60015-1219

IPC-TM-650

TEST METHODS MANUAL

Number

2.4.24.6

Subject

Decomposition Temperature (T

) of Laminate

Material Using TGA

Date

4/06

Revision

Originating Task Group

Laminate/Prepreg Materials Subcommittee (3-11)

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.

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ASSOCIATION CONNECTING

ELECTRONICS INDUSTRIES

5.3.3 Record the temperature, T

(2%), at which the mass

of the sample is 2.0% less than its mass measured at 50°C.

5.3.4 Record the temperature, T

(5%), at which the mass

of the sample is 5.0% less than its mass measured at 50°C.

6 Results Report the following information:

a) The initial mass of the sample.

b) The room temperature and relative humidity under which

testing was conducted.

c) The thermal decomposition temperature, T

(2%).

d) The thermal decomposition temperature, T

(5%).

7 References

IPC-TM-650

Method 2.3.40, Thermal Stability

ASTM D-3850 Standard Test Method for Rapid Thermal

Degradation of Solid Electrical Insulating Materials by Thermo-

gravimetric Analysis

IPC-TM-650

Number

2.4.24.6

Subject

Decomposition Temperature (T

) of Laminate Material Using TGA

Date

4/06

Revision

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