IPC J-STD-003B.pdf - 第19页

0.08 in]. The dwell time in the molten solder shall be 3.0 ± 0.5 seconds. Immersion and emersion rates shall be 25 ± 2 mm [0.984 ± 0.08 in] per second. After withdrawal, the solder shall be allowed to solidify by air coo…

27.5 mm

[1.081 in]

2.0 mm

[0.0787 in]

22.5 mm

[0.8858 in]

7.5 mm [0.295 in]

2.5 mm [0.0984 in]

Land Size 1.5 mm [0.0591 in]

40 Plated Through-Holes

0.8 ± 0.0125 mm [0.031 ± 0.0004921 in]

3.0 mm

[0.118 in]

2.5 mm

[0.0984 in]

9 Spaces @

Layer 1 Only

Appropriate

Specimen

Number

IPC-003b-4-2

Figure 4-2 Suggested Test Specimen for Plated-Through Holes

COMPONENT SIDE VIEW

Test Coupon size = 25 mm x 15 mm [0.984 in x 0.591 in]

SMD Pad Size = 3.18 mm x 4.52 mm [0.1250 in x 0.1780 in]

Pads are extended 0.51 mm [0.020 in] beyond the edge

Pad to pad pitch = 4.0 mm [0.157 in]

Mask clearance = 3.58 mm x 4.94 mm [0.1410 in x 0.1945 in]

Both sides

2.54 mm [0.1000 in]

0.94 mm [0.0370 in]

Pad Size (dia.) = 1.9 mm [0.0748 in]

Pad to pad pitch = 4.0 mm [0.157 in]

PTH size = 1.15 mm [0.0453 in] finished

Mask clearance = 2.31 mm [0.0909 in]

Both sides

IPC-003b-4-3

Figure 4-3 Suggested Test Specimen for Surface Mount Features

IPC J-STD-003B March 2007

Provided by IHS under license with IPC

Not for Resale

No reproduction or networking permitted without license from IHS

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0.08 in]. The dwell time in the molten solder shall be 3.0

± 0.5 seconds. Immersion and emersion rates shall be 25 ±

2 mm [0.984 ± 0.08 in] per second. After withdrawal, the

solder shall be allowed to solidify by air cooling while the

board is maintained in a vertical position. Prior to exami-

nation, all test specimens shall have the ﬂux removed using

a cleaning agent in accordance with 3.2.3.

4.2.1.4 Evaluation

4.2.1.4.1 Magnification

Test specimens shall be exam-

ined at 10X using the equipment speciﬁed in 3.3.3.

4.2.1.4.2 Surface Evaluation – Accept/Reject Criteria

A minimum of 95% of each of the surfaces (i.e., each pad)

being tested shall exhibit good wetting. The balance of the

surface may contain only small pin holes, dewetted areas,

and rough spots provided such defects are not concentrated

in one area. For less critical applications, a smaller percent

coverage may be determined between vendor and user.

There shall be no nonwetting or exposed base metal within

the evaluated area. An area of 3.2 mm [0.126 in] width

from the bottom edge of each test specimen shall not

be evaluated. Areas contacted by ﬁxtures shall not be

evaluated.

4.2.2 Test B – Rotary Dip Test Tin/Lead Solder This

test is for rotary dip testing of plated-through holes, surface

conductors and attachment lands.

4.2.2.1 Apparatus A device shall be used to move the

test specimen in a circular path so that the ﬂat surface of

the test specimen will contact the solder at a constant speed

without stopping. The distance between the center of rota-

tion and the center of the test specimen shall be 100 mm

[3.937 in] minimum. An example of a test specimen holder

is shown in Figure 4-4. Those parts of the holder including

the retaining spring (if ﬁtted) which come into contact with

the test specimen and/or the solder should have low ther-

mal capacity and conductivity. The time of contact between

any point of the test face of the test specimen and the mol-

ten solder shall be determined by a timer. The timer shall

start when the face of the test piece is parallel to the solder

surface. A strip of 50 mm [1.97 in] wide polytetraﬂuoroet-

hylene (PTFE) or equivalent shall precede the test speci-

men in the test cycle in order to remove oxide or ﬂux resi-

due from the solder surface immediately before the test

specimen is introduced.

4.2.2.2 Test Specimen The test specimen shall be in

accordance with 1.7. The test specimen shall either be a

full board, a section of a board, or a suggested test speci-

men (see Figures 4-2 and 4-3). The test specimen shall be

of such a width as to allow 13 mm [0.512 in] clearance

from the solder pot sides. The minimum number of termi-

nations (plated-through holes or attachment lands) per test

specimen shall be six. If plated-through holes are to be

tested, then the minimum number of holes to be tested is

30 per test lot. This would require a minimum of ﬁve test

specimens (six holes per test specimen, 30 holes total). The

test specimen shall be representative of the product. The

exposed length of test specimen test face in the direction of

travel shall be25±5mm[0.984 ± 0.20 in]. Test specimen

preparation shall be in accordance with 3.4.

4.2.2.3 Procedure Dross and burned/residual ﬂux shall

be completely removed from the surface of the molten sol-

der immediately prior to dipping. After ﬂuxing and drain-

ing, per 4.1, mount the test specimen to be tested in the test

equipment test specimen holder. Adjust the test equipment

to immerse the test specimen into the solder bath to a

maximum of 50% of the test specimen thickness unless

otherwise speciﬁed. Activate the test equipment to expose

the test specimen to solder. After the test specimen has

cleared the solder bath, allow all the solder to solidify in

the position in which the machine stops before removing

from the test specimen holder. Care must be taken so

that solder does not ﬂow over the upper face of the test

specimen. This may be impacted by the width of the test

specimen. Dwell time at the maximum depth shall be 3.0

± 0.5 seconds. Prior to examination, all test specimens

shall have the ﬂux removed using a cleaning agent in

accordance with 3.2.3.

4.2.2.4 Evaluation

4.2.2.4.1 Magnification

Test specimens shall be exam-

ined at 10X using the equipment speciﬁed in 3.3.3.

1) Dwell timer set at 3.0 ± 0.5 seconds

2) Adjustable speed control on 100.0 mm

[3.9370 in] radius on solder station

3) Dwell at end of 100.0 mm [3.9370 in]

radius swing to allow solder to solidify

Solder

Coupon

Dross

Wiper

IPC-003b-4-4

Figure 4-4 Rotary Dip Test

March 2007 IPC J-STD-003B

Provided by IHS under license with IPC

Not for Resale

No reproduction or networking permitted without license from IHS

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4.2.2.4.2 Surface Evaluation – Accept/Reject Criteria

An area of 3.0 mm [0.118 in] width from the trailing edge

of each test specimen shall not be evaluated. Areas con-

tacted by ﬁxtures shall not be evaluated. A minimum of

95% of each of the surfaces (i.e., each pad) being tested

shall exhibit good wetting. The balance of the surface may

contain only small pin holes, dewetted areas, and rough

spots provided such defects are not concentrated in one

area. For less critical applications, a smaller percent cover-

age may be determined between vendor and user. There-

shall be no nonwetting or exposed base metal within the

evaluated area.

4.2.2.4.3 Plated-Through Hole Evaluation Only plated-

through holes that are at least 5.0 mm [0.197 in] from any

surface or ﬁxturing structure supporting the test specimen

during the test will be evaluated. An area of 3.0 mm [0.118

in] width from the trailing edge of each test specimen shall

not be evaluated. Areas contacted by ﬁxtures shall not be

evaluated.

Accept/Reject Criteria:

• Class 1 and 2 Product – Solder shall fully wet the wall

area of the plated-through holes, and plug holes less than

1.5 mm [0.0591 in] diameter (complete ﬁlling is not

necessary).

• Class 3 Product – The test specimen has soldered

successfully if solder has risen in all plated-through holes.

The solder shall have fully wetted the walls of the hole.

There shall be no nonwetting or exposed base metal on

any plated-through hole.

Accept/reject criteria for boards thickness <3.0 mm

[<0.118 in] shall be in accordance with 5.2 and Figures 4-5

and 4-6. The solder must have wet over the knee of the

hole and out onto the land around the top of the hole,

except for boards whose thickness exceeds 3.0 mm [0.118

in].

On thick boards, i.e., greater than 3.0 mm [0.118 in] the

capillary forces due to surface tension may not be large

Target Condition

Acceptable Condition

(for PCBs > 3.0 mm thk)

Nonacceptable Condition

IPC-003b-4-5

Figure 4-5 Effectiveness of Solder Wetting of Plated-Through Holes - Class 3

Figure 4-6 Examples of Solder Wetting of Plated-Through Holes - Class 3

Acceptable Condition Nonacceptable Condition

IPC J-STD-003B March 2007

Provided by IHS under license with IPC

Not for Resale

No reproduction or networking permitted without license from IHS

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