IPC-TM-650 EN 2022 试验方法.pdf - 第313页

1.0 Scope This method describes the method for deter- mining the time to delamination of laminates and printed boards through the use of a thermomechanical analyzer (TMA). 2.0 Applicable Documents IPC-TM-650 Method 2.4.2…

5.4.3.2

The

PTE is calculated as follows:

Percent TE = t

–t

100

Where

Initial thickness (see 5.1.5)

Thickness at Temperature D

Thickness at Temperature A

5.5

Report

5.5.1

Report

the glass transition temperature of each speci-

men.

5.5.2

Report

the TE as CTE in ppm/°C or as PTE in percent-

age, and the temperature ranges over which the TE has been

determined. If specified, report the CTE over the temperature

ranges above and below the T

(A-B

and C-D).

5.5.3

Report

the scan rate and final TE temperature if other

than that specified.

6.0 Notes

6.1

Calibration

of the TMA must be carried out according to

the manufacturer’s instructions.

6.2

The

Tg for a given material may be significantly different

when measured by DSC versus TMA. The test equipment

used should be noted after the reported glass transition value,

i.e., 136.4° (DSC) or 132.6° (TMA).

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, provided test

parameters (e.g., temperatures, edge smoothing factors, etc.)

do not conflict with the procedures specified.

6.4

improve the accuracy of the test, the thickness

should be at least 0.76 mm [0.030 in] and preferably 1.6 mm

[0.062 in]. If the material thickness to be measured is less than

0.020 inch, a specimen stack-up to at least 0.51 mm [0.020

in] may be used although the test error probability is greatly

increased. A sample of suitable thickness may be prepared

from the prepreg used in the manufacture of the base mate-

rial by laminating and curing as recommended by the supplier.

Specimen thickness should not exceed 2.36 mm [0.093 in] to

avoid variability from thermal gradients occurring within the

specimen.

6.5 Load

selection criteria. Initial load is recommended to be

5g. The load should be adjusted for differences in material

types or specimen configuration in order to assure intimate

contact between the probe, specimen, and stage. Avoid

excess load which may result in penetration or distortion of

the specimen.

6.6

Initial

temperature for starting the scan is determined by

an evaluation of the derivative of the time/temperature curve

for the equipment. Test data is not valid until the time/

temperature curve is stabilized. Refer to operating instruction

of the equipment for additional information.

6.7

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

2.4.24

Subject

Glass

Transition Temperature and Z-Axis Thermal Expansion by

TMA

Date

12/94

Revision

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1.0

Scope

This

method describes the method for deter-

mining the time to delamination of laminates and printed

boards through the use of a thermomechanical analyzer

(TMA).

2.0

Applicable Documents

IPC-TM-650

Method

2.4.24, Glass Transition Temperature

and Z-Axis Thermal Expansion by TMA.

3.0

Test Specimens

3.1 Size

Specimens

shall be approximately 6.35 mm x

6.35 mm [0.25 in x 0.25 in] by the thickness of the sample.

3.2

Quantity and Sampling

Unless

otherwise specified,

two specimens shall be tested, to be taken from random loca-

tions of the material in question.

4.0

Apparatus or Material

4.1 Drying Chamber

Air

circulating oven capable of main-

taining 105 ±2°C [221 ±3.6°F].

4.2

Cutting Equipment

Diamond

blade or wheel, sanding

equipment, or equivalent, to provide a specimen of the size

and edge quality specified.

4.3

Desiccator

Dessication

chamber capable of maintain-

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

4.4

Tester

Thermal

Mechanical Analyzer (TMA) capable of

determination of dimensional change to within ±0.0025 mm

[0.0001 in] over the specified temperature range.

5.0

Procedure

5.1 Specimen Preparation

5.1.1

Metallic

clad laminates shall be tested as is. Multilayer

printed boards may be sampled with internal conductors

present. (For determination of a multilayer board’s bond integ-

rity, presence of internal conductors is preferred.)

5.1.2

Specimens

shall be cut to the specified size using

appropriate procedures and equipment to minimize mechani-

cal stress or thermal shock.

5.1.3 The

edges shall be smooth and burr-free by means on

sanding or equivalent (to allow the specimen to rest com-

pletely flat on the mounting stage). Use care to minimize

stress or heat on the specimen.

5.1.4

The

specimen shall be preconditioned by baking for 2

hours at 105 ±2°C [221 ±3.6°F], then cooled to room tem-

perature in a dessicator.

5.2

Measurement

5.2.1

Remove

the specimen from the dessicator and place

the specimen on the stage of the TMA taking care that the

sample is centered and resting flat on the stage.

5.2.2

Lower

the TMA’s probe onto the specimen and apply

a force of 0.005 Newtons [5g]; then lower the furnace into

place around the stage.

5.2.3

Start

the temperature ramp (or scan) from an initial

temperature no higher than 35°C [95°F].

5.2.4

Maintain

the scan at the specified rate. Unless other-

wise specified, the scan rate shall be 10°C/minute (see 6.4).

5.2.5 After

the scan reaches the specified isothermal tem-

perature, hold at that temperature for 10 minutes or to failure.

Unless otherwise specified, the isothermal temperature shall

be 260°C [500°F].

If the instrument allows real time display of the data, terminate

the experiment after evidence of delamination is displayed.

5.3

Evaluation

The

time to delamination is determined as

the time from the onset of the isotherm to failure. Failure is any

event or deviation of the data plot where the thickness is

shown to have irreversibly changed. The scan in Figure 1 is

typical of an epoxy material at 260°C [500°F] isothermal tem-

perature. On occasion, some materials will delaminate before

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.4.24.1

Subject

Time

to Delamination (TMA Method)

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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the

isotherm is reached. In this case, the temperature at the

time of failure shall be recorded.

5.4

Report

5.4.1

Report

the Time to Delamination as determined in 5.3.

Report the time at which any other plot event has taken place

which was not determined to be irreversible.

5.4.2

Report

the configuration of the sample (e.g., whether

external or internal foil is present).

5.4.3 Report

the ramp rate and isothermal temperature if

other than that specified.

6.0

Notes

6.1

For

epoxy laminates and similar materials, the recom-

mended isothermal temperature is 260°C [500°F]. For polyim-

ides and other high temperature materials, the isothermal

temperature may be increased to 288°C [550°F]. For other

material types, consult with the material manufacturer.

6.2

Calibration

of the instrument should be carried out

according to the manufacturer’s instructions.

6.3

The

the material may be obtained from this test,

which is similar to Method 2.4.24. It should be noted that the

obtained is a ‘‘first pass’’ value.

6.4

faster ramp rate will decrease the time to run, provide

some greater distinction between materials, and provide a

closer equivalence to the Thermal Stress test, 2.4.13.1.

A rate of 100°C/minute [212° F/minute] is recommended for

such determinations.

Figure

IPC-TM-650

Number

2.4.24.1

Subject

Time

to Delamination (TMA Method)

Date

12/94

Revision

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