IPC-TM-650 EN 2022 试验方法.pdf - 第274页

1.0 Scope This test method is designed to determine the thermal integrity of unclad or metallic clad laminates using short-term solder exposure. 2.0 Applicable Documents IPC-TM-650 T est Methods Manual Method 2.1.1, Micr…

Scope

This

test method establishes and defines the pro-

cedures for determining the solder float resistance of copper

foil clad and bare flexible dielectric material.

Applicable Documents

J-STD-004

Requirements

for Soldering Fluxes

Test Specimen

3.1

Two

specimens, approximately 50 mm x 50 mm per

clad side.

3.2

For

double clad laminate, a separate specimen unit shall

be prepared and tested for each side. The copper foil shall be

etched from the reverse or nontest side of each specimen

using standard commercial practices. Bare dielectric material

shall be tested bare.

Apparatus

4.1 Test Chamber

circulating air chamber capable of

maintaining a uniform temperature of 135°C ± 10°C.

4.2

Solder Pot

electrically-heated, thermostatically-

controlled solder pot of adequate dimensions to accommo-

date the specimen and containing no less than 2.25 Kg of

solder.

4.3

Cutter

template and cutter to prepare approximately 50

mm x 50 mm specimens of copper clad dielectric material.

4.4

Solder

float test fixture as per Figure 1.

4.5

Sn60,

Sn62, or Sn63 solder conforming to J-STD-004.

Procedure

5.1

Prepare

two specimens, clean the copper foil, then pre-

condition the test specimen in an air circulating oven main-

tained at 135°C ± 10°C for one hour. Specimens may then be

held in a room temperature desiccator.

5.2

Remove

the specimens from the conditioning chamber.

5.3 Attach

the specimens to the solder float test fixture with

a thumb tack or other low mass holding device (Figure 1) prior

to floating the sample. Float the specimen, foil side down, on

the surface of the molten solder, maintained at the tempera-

ture specified in Table 1, for 10 seconds.

able 1 Solder Float Temperatures

Method

A 260°C ± 5°C

Method B 288°C ± 5°C

5.4

Float

the specimen on the surface, then remove the

specimens and tap the edges to remove excess solder.

5.5

Evaluation

Thoroughly

clean each specimen and visu-

ally examine for blistering, delamination or wrinkling. For bare

dielectric films, examine for blistering, shrinkage, distortion or

melting.

6 Notes

6.1

For

materials that absorb moisture, the preconditioning

in this method is required to remove absorbed moisture from

the materials. Absorbed moisture can volatilize and cause

delamination and blistering because of the rapid temperature

rise experienced in the solder bath. Drying may not be

required for materials with low moisture absorption character-

istics.

IPC-1412-1

Figure

1 Solder ﬂoat test ﬁxture

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.4.13

Subject

Solder

Float Resistance Flexible Printed Wiring

Materials

Date

5/98

Revision

Originating Task Group

Flex Peel Strength Test Methods Task

Group (D-13A)

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

test method is designed to determine the

thermal integrity of unclad or metallic clad laminates using

short-term solder exposure.

2.0

Applicable Documents

IPC-TM-650 Test Methods Manual

Method

2.1.1, Microsectioning

MIL-F-14256

Flux,

Soldering, Liquid (Rosin Base)

3.0

Test Specimens

3.1 Size and Configuration

Unless

otherwise specified,

specimens shall be 50.8 mm x 50.8 mm ± 0.75 mm [2.00 x

2.00 in ± 0.30 in] by the thickness of the laminate. Metallic

clad laminate shall include specimens which are completely

clad and fully etched.

3.2

Quantity and Sampling

Unless

otherwise specified,

for each clad side and for each test condition, three speci-

mens shall be used for qualification testing and two speci-

mens for lot acceptance testing. Specimens may be cut from

anywhere in the sheet of material except no specimen shall be

taken closer than 25.4 mm [1.0 in] from any edge as lami-

nated.

4.0

Apparatus or Material

4.1 Oven

Air

circulating oven capable of maintaining a tem-

perature of 125 ± 2°C [257 ± 3.6°F].

4.2

Solder Bath

Electrically

heated solder pot; thermostati-

cally controlled; containing at least 1.0 kilograms of solder;

and capable of maintaining the specified temperature. Unless

otherwise specified, the temperature shall be 288 ± 5.5°C

[550 ± 10°F]. Type Sn60 or Sn63 shall be used.

4.3

Temperature Indicator

Thermocouple

or other device

capable of measuring the solder temperature at a depth of

25.4 mm [1 in] below the surface and capable of measuring

to within ± 2°C [3.6°F] at the solder temperature specified.

4.4

Desiccator

desiccation chamber capable of main-

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

4.5

Optical Magnification

4.5.1 Microscope

Range

100 to 200 X (for referee testing

only).

4.5.2

Magnifier

Magnifying

loupe, or equivalent, capable

of magnification of 4X to 10X.

4.6

Timer

Stop

watch, or equivalent, capable of measuring

to within 0.2 seconds.

4.7

Water White Rosin Flux

Type

R per MIL-F-14256.

4.8

Cutting Apparatus

Diamond

saw, shear or other

device capable of cutting to the specified size without exces-

sive damage or stress on the material.

4.9

Etching System

Etching

system capable of complete

removal of metallic cladding.

4.10

Flux Cleaning Solvent

Isopropyl

alcohol, flux thinner,

or equivalent.

5.0

Procedure

Specimens

shall be tested in accordance

with the following procedure.

5.1

Specimen Preparation

5.1.1 Etching

One-half

of the metallic clad laminate sam-

pling shall be completely etched in accordance with standard

industry practices.

5.1.2

Cutting

The

specimens shall be cut to size from the

unetched and etched samples by suitable means. The edges

shall be cleaned and smoothed by light sanding.

5.1.3

Conditioning

For

referee or qualification purposes,

specimens shall be placed in an air-circulating oven main-

tained at 125°±2°C [257 ± 3.6°F] for 4 to 6 hours. After

removal from the oven, place specimens in a desiccator and

allow to cool to room temperature.

5.2

Measurement

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.4.13.1

Subject

Thermal

Stress of Laminates

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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5.2.1

Fluxing

Immediately

after removal from the desicca-

tor, metal surfaces shall be cleaned by light abrasion, or other

suitable methods. Flux with rosin flux conforming to type R,

MIL- F-14256. Let drain in a vertical position.

5.2.2

Stressing

Within

10 minutes of removal from desic-

cator, float the specimen for 10 + 1, –0 seconds on the sur-

face of a solder bath maintained at the specified temperature,

measured at a depth of 25.4 mm [1.0 in] below the surface.

The specimens shall be kept in intimate contact with the sol-

der surface and agitated by gentle downward pressure using

tongs or equivalent.

Note:

Very

thin laminates, typically under 0.5 mm [0.020 in]

thick, are prone to bowing or curling upon contact with solder.

The following handling instructions apply:

a. For etched specimens, mount each specimen using

staples to a piece of corrugated board (‘‘cardboard’’)

approximately 75 x 75 mm [3.0 x 3.0 in].

b. For unetched single-clad specimens, mount each speci-

men to a 75 x 75 mm [3.0 x 3.0 in] piece of corrugated

board (‘‘cardboard’’) by slipping two opposite edges into

slits cut parallel and 38.1 mm [1.5 in] apart in the card-

board.

c. Unetched double-clad specimens including those of

unequal cladding thicknesses, do not require mounting.

5.2.3

The

specimens shall be removed from the bath and

allowed to cool to room temperature. Mounted specimens

may be removed from the supporting cardboard. Clean the

flux from the specimens using appropriate solvent.

5.3

Evaluation

5.3.1 Etched or Unclad Specimens

Examine

the speci-

mens by normal or corrected 20/20 vision, using backlighting

if necessary. Record the presence of charring, surface con-

tamination, loss of surface resin, resin softening, delamination,

blistering, weave exposure, propagation of imperfections,

measling, crazing, or voids.

Determine the number and dimension of any voids using 4X

minimum magnification; for referee purposes, 10X magnifica-

tion shall be used.

5.3.2

Clad Specimens

The

specimen shall be examined

for any evidence of blistering, delamination or other damage.

During the solder exposure, any apparent event that is evi-

dence of damage, such as the specimen exhibiting a ‘‘bump’’

felt through the tongs, shall be recorded as a sign of possible

delamination.

5.3.3

For

referee purposes, the etched or unetched speci-

mens shall then be microsectioned in accordance with IPC-

TM-650, Method 2.1.1 (except there are no plated-through

holes). The microsections shall be examined for degradation

(see 5.6.1) at a magnification of 100X and referee inspection

at 200X.

5.4

Report

Any

observed degradation to the unetched or

etched or unclad specimens shall be reported. The number

and location of voids shall be reported for each specimen.

Results of referee microsection examination will take prece-

dence over visual examination.

6.0 Note

Automatic

(gang mounting) microsectioning tech-

niques may be used.

6.1

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

2.4.13.1

Subject

Thermal

Stress of Laminates

Date

12/94

Revision

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