IPC-TM-650 EN 2022 试验方法.pdf - 第378页

1.0 Scope This test is carried out to determine the reflow properties of the solder paste. The ability of the prealloyed solder particles in the paste to reflow into a sphere on a non- wettable substrate is determined un…

1.0

Scope

The

object of this test is to determine the com-

ponent hold-down capability of the adhesive material at wave

soldering temperatures due to material softening or degrada-

tion. Test coupons are assembled using the adhesive material

and 1206 size chip resistors. The test coupons are preheated

then floated on a solder pot, after which the loss of any com-

ponents is noted.

2.0

Applicable Documents

MIL-F-14256

Flux,

Soldering, Liquid (Rosin based)

QQ-S-571

Solder,

Tin Alloy, Tin-lead Alloy, and Lead Alloy

3.0

Test Specimens

Bare FR-4 Test Coupon-approximately 50.8 mm [2.0 in ]

square

2. 1206 sized surface mount chip resistors

4.0

Apparatus

Solder

pot Sn 60 Sn 62 Sn 63 per QQ-S-

571—temperature controlled to provide 260 ± 5°C.

5.0

Procedures

5.1 Test Coupon Fabrication

single test coupon is

made by applying 20 adhesive dots or rectangles on to a bare

FR-4 coupon. The thermal cure adhesive dots shall be sten-

ciled providing a dot 0.1 mm [0.004 in] thick and 1.27 mm

[0.050 in] in diameter. The ultraviolet cured adhesive deposits

shall be stenciled into a 2.0 x 0.76 mm [0.080 x 0.030 in]

rectangular slit of 0.1 mm [0.004 in] thickness.

The chip resistors are first centered over then securely

pressed into the adhesive deposits. The resistors are aligned

over the UV adhesive rectangles such that equal adhesive

volumes are observed at both component sides.

The assembly is then cured per manufacturers recommended

conditions.

5.2

Solder Float

The

test coupon is fluxed with a type R

per MIL-F-l4256 flux and excess drained off. The coupon is

then held approximately 12.7 mm [0.5 in] above the dross-free

solder pot surface for 60 ±5 seconds with the component side

facing the solder surface. The coupon is then brought into

contact with the clean solder surface and allowed to float for

10 + 1-0 seconds while being lightly but continuously agi-

tated.

After cooling, the remaining flux residue is cleaned from the

surface and the coupon examined for severely displaced

components. A component is severely displaced if:

1. No longer on the test coupon.

2. It is rotated more than 30 degrees from its original posi-

tion.

3. It is lifted or tilted away from the board’s surface leaving

a gap between either component termination and the

board of more than 1 mm [0.040 in]. A suitable thickness

shim may be used in this determination.

5.3

Evacuation

Any

evidence of severely displaced com-

ponents on the processed test coupons shall be noted.

6.0 Notes

None

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.4.42.1

Subject

High

Temperature Mechanical Strength Retention

of Adhesives

Date

3/88

Revision

Originating Task Group

N/A

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 is carried out to determine the reflow

properties of the solder paste. The ability of the prealloyed

solder particles in the paste to reflow into a sphere on a non-

wettable substrate is determined under defined test condi-

tions.

2.0

Applicable Documents

None

3.0

Test Specimen

Frosted

glass microscope slide, alu-

mina substrate or glass/epoxy printed circuit board with a

thickness of 0.60 to 0.80 mm and a minimum length and

width dimension of 76 mm and 25 mm, respectively.

4.0

Equipment/Apparatus

4.1

Metal

Stencils

4.1.1

Stencil for Type 1-4

Stencil

76 mm x 25 mm x 0.2

mm provided with at least 3 round holes of 6.5 mm diameter

apertures with a minimum distance between centers of 10

mm.

4.1.2

Stencil for Type 5-6

Stencil

76 mm x 25 mm x 0.1

mm provided with at least 3 round holes of 1.5 mm diameter

apertures with a minimum distance between centers of 10

mm.

4.2

Spatula

4.3

Solder

bath not less than 100 mm x 100 mm x 75 mm

deep containing solder suitable to maintain a temperature of

25°C above the liquidus temperature of the solder paste being

evaluated.

4.4

Flat

hot plate

4.5

Surface

temperature thermometer

4.6 Magnifying

glass with a 10 to 20 times magnification.

5.0

Procedure

5.1 Preparation

5.1.1

Set

the temperature of the solder bath or hot plate at

a temperature of 25°C +/–3°C above the liquidus temperature

of the solder alloy.

5.1.2 Homogenize

the solder paste by hand stirring with a

spatula.

5.1.3

Condition

the paste to uniform temperature of 25° C

+/–2°C.

5.1.4

Prepare

two test specimens with either/or both sten-

cils listed above (4.1.1 and 4.1.2). The solder paste should be

squeeged with the spatula to fill and level each hole.

5.2

Test

5.2.1 Test Conditions

5.2.1.1

Test

one specimen within 15 +/–5 minutes after

placement of solder paste on test coupon.

5.2.1.2

Test

the second specimen 4 hours +/–15 minutes

after placement of solder paste on test coupon. Storage for 4

hours shall be at 25°C +/–3°C and 50 +/–10% RH.

5.2.2

Conditioning Heating Equipment

5.2.2.1

Clean

the surface of the solder bath with the

scraper.

5.2.2.2 Remove

all foreign material from the surface of the

hot plate to ensure proper control.

5.2.3

Solder Reflow

Reflow

specimens by one of the fol-

lowing two methods.

5.2.3.1

Lower

the substrate, in a horizontal position with the

paste deposit on top, into the solder bath at a speed of 25 +/–

2 mm/second until the substrate is 50% submerged. It is

important that good thermal contact is achieved between the

molten solder and the substrate. As soon as the solder has

melted, withdraw the substrate from the solder bath maintain-

ing it in a horizontal position. The total time on the solder bath

shall not exceed 20 seconds.

The

Institute for Interconnecting and Packaging Electronic Circuits

2215 Sanders Road • Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.4.43

Subject

Solder

Paste—Solder Ball Test

Date

1/95

Revision

Originating Task Group

Solder Paste Task Group (5-24b)

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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5.2.3.2

Place

the substrate on the hot plate. As soon as the

solder has melted, withdraw the substrate from the hot plate

maintaining a horizontal position. The reflow shall occur within

20 seconds after the specimen is placed in contact with the

hot plate.

5.3 Evaluation

5.3.1

Examine

the reflowed specimens under 10X to 20X

magnification.

5.3.2

Solder

ball size and number should be compared with

Figure 1.

5.3.3

Record

the degree of reflow in comparison with Figure

1 for the 6.5 cm and 1.5 cm acceptance/reject conditions,

respectively.

IPC-TM-650

Number

2.4.43

Subject

Solder

Paste—Solder Ball Test

Date

1/95

Revision

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