IPC-TM-650 EN 2022 试验方法.pdf - 第660页

4.2 Power Supply Capable of producing a standing bias potential of 100 VDC with a tolerance of ± 10%. 4.3 Resistance Meter Capable of reading high resistance (10 12 ohms or greater), with a test voltage of 100 VDC. 4.4 O…

1 Scope This test method is used to determine the mois-

ture and insulation resistances of applied polymer solder mask

under two separate prescribed conditions of temperature and

humidity. One condition is described as Class T and the other

Class H. Raw material qualification testing is performed on

designated comb patterns. Production quality conformance

testing is performed on a standard ‘‘Y’’ pattern.

2 Applicable Documents

IPC-A-25A-G-KIT

Multipurpose One-Sided Test Pattern -

Gerber Format

IPC-SM-840 Qualification and Performance of Permanent

Solder Mask

J-STD-004 Requirements for Soldering Fluxes

IPC-A-600 Acceptability for Printed Boards

3 Test Specimens The IPC-A-25A-G-KIT artwork package

provides the Gerber files necessary for the fabrication of the

standard IPC-B-25A test board used with this test method.

3.1 Qualification Testing

3.1.1 Class H

Three IPC-B-25A boards using the D comb

patterns with 0.32 mm [0.0126 in] lines/spaces (see Figure 1).

Of which, two are to be coated and one uncoated with solder

mask according to the solder mask supplier’s recommenda-

tions.

3.1.2 Class T Three IPC-B-25A boards using the E and F

comb patterns with 0.41 mm [0.016 in] lines and 0.51 mm

[0.020 in] spaces (see Figure 1). Of which, two are to be

coated and one uncoated with solder mask according to the

solder mask supplier’s recommendations.

3.2 Conformance Testing IPC-B-25A board C (‘‘Y’’

shape) pattern with 0.64 mm lines/0.64 mm spacing [0.025 in

lines/0.025 in spacing] or pattern with minimum spacing on

the production board (see Figure 1), whichever has the small-

est line spacing, coated with solder mask according to the

solder mask suppliers recommendations.

4 Apparatus

4.1 Chamber

A clean chamber capable of programming

and recording an environment of 25±2°C[77±3.6°F]toat

least 65±2°C[149 ± 3.6 °F] and 90-98% relative humidity.

NOTE: This test requires a clean chamber and clean water

for repeatable test results. The following recommendations

are made:

• Incoming water purity should be between 0.5 and 0.1

micro-siemens/cm.

• Fresh deionized water should be used for each test, rather

than using a recirculating water sump.

• Chamber workspaces should be cleaned at least every six

months.

1. www.ipc.org/onlinestore

IPC-2631-1

Figure 1 IPC-B-25A Test Board

3000 Lakeside Drive, Suite 309S

Bannockburn, IL 60015-1249

IPC-TM-650

TEST METHODS MANUAL

Number

2.6.3.1

Subject

Solder Mask - Moisture and Insulation Resistance

Date

03/07

Revision

Originating Task Group

Solder Mask Performance Task Group (5-33b)

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

4.2 Power Supply Capable of producing a standing bias

potential of 100 VDC with a tolerance of ± 10%.

4.3 Resistance Meter Capable of reading high resistance

(10

ohms or greater), with a test voltage of 100 VDC.

4.4 Oven Capable of maintaining at least 120 °C [248 °F].

4.5 Timer

4.6 Solder Pot

4.7 Tongs

4.8 Soldering Iron

4.9 Flux

Water white rosin (R or RMA) with halide content

less than 0.5%, i.e., type Symbol A and B or ROL0 and ROL1

according to J-STD-004.

5 Test

5.1 Ambient Conditions

Class T and Class H: 25 +2/-5

°C [77 +3.6/-9 °F] and 40 - 50% relative humidity.

5.2 Test Conditions

5.2.1 Class T

65±2°C[149 ± 3.6 °F], with 90 ± 3% rela-

tive humidity, no bias, static, 24 hours.

5.2.2 Class H 25to65±2°C[77to149±3.6°F], with 90

+3/-5% relative humidity, 50 VDC bias, 20 cycles (160 hours

or 6

/3 days).

5.3 Specimen Preparation (Both Classes)

5.3.1

Positive, permanent and noncontaminating identifica-

tion of the test specimens is of paramount importance.

5.3.2 Visually inspect the test specimens for any obvious

defects, as described in IPC-A-600. If there is any doubt

about the overall quality of any test specimen, the test speci-

men shall be discarded.

5.3.3 One uncoated specimen subjected to the same pro-

cessing (except solder mask coating) as the coated speci-

mens shall be supplied with each set of coated samples for

testing as a control.

5.3.4 Subject one solder mask coated IPC-B-25A board to

solder in accordance with J-STD-004. Clean any residual flux

residue from the board surface using the following procedure:

1) Rinse with deionized or distilled water (30 seconds

minimum).

2) Immerse the board in 2-propanol and agitate (30 seconds

maximum). Gently scrub the board using a soft bristled

brush while submersed.

3) Spray the board with clean 2-propanol.

4) Bake in an oven at 50 °C [122 °F] for three hours minimum.

5.4 Electrical Connections (Both Classes)

5.4.1

For qualification purposes, single stranded PTFE

coated wire or some equivalent should be used to attach the

appropriate test pads (designated in 3.1) to the power supply

used for biasing and/or insulation resistance testing. When

soldering the wires onto the pads care should be taken to

ensure that the flux does not splatter onto the combs. A

simple noncontact shield fixture should be used to protect the

test patterns from flux splattering during soldering.

Note: An alternate method is to use gold plated alligator

clips.

5.4.2 For quality conformance purposes, single stranded

PTFE coated wire or an equivalent should be used to attach

the appropriate test pads of pattern C to the power supply for

insulation resistance testing.

5.5 Soldering Flux The flux shall not be removed.

Note: If the flux has contaminated the pattern on the control,

the sample shall be discarded and a new one used. It cannot

be cleaned because it will not represent the cleaning process

that was used prior to solder mask application.

5.6 Specimen Handling For the remainder of the test, the

surface of the test specimens either uncoated or coated with

solder mask shall not be handled or exposed to any other

contaminating influence. Handle all test specimens by the

edges only.

5.7 Class H Procedures

5.7.1 Class H Testing

IPC-TM-650

Number

2.6.3.1

Subject

Solder Mask - Moisture and Insulation Resistance

Date

03/07

Revision

Page2of5

5.7.1.1 Place specimens in a chamber, in a vertical position

and under a condensation drip shield. Condition the speci-

mensat50±2°C[122 ± 3.6 °F] with no added humidity, for

a period of 24 hours.

5.7.1.2 Allow the specimens to cool, measure and record

the initial insulation resistance measurements at ambient labo-

ratory conditions. Apply 100 VDC on the specimen’s test

points as specified in 3.1.1 or 3.2 with the resistance meter

and take the reading after one minute. See 6.2.

5.7.1.3 Connect the 50 VDC voltage source to each of the

specimens test points as indicated in 3.1.1 or 3.2. Each

chamber load shall contain at least one uncoated control

board that is representative of the cleaning process used prior

to solder mask application for each solder mask tested.

5.7.1.4 The test points for qualification tests are 1 to 2, 3 to

2, 3 to 4 and 5 to 4 on the D comb pattern. On the D comb

pattern, test points 1, 3 and 5 are connected to the positive

terminal and test points 2 and 4 are connected to the nega-

tive terminal of the resistance meter. For quality conformance,

the pair of test points is 1 to 2 on the C pattern. One side of

the C pattern should be connected to the negative terminal

and the other side to the positive.

5.7.1.5 Close chamber door and apply a 50 volt bias to all

comb patterns (D or C patterns) tested.

5.7.1.6 Expose test specimens to 20 cycles of temperature

and humidity (see Figure 2). The bias voltage shall be main-

tained throughout the entire 20-cycle period. Humidity shall be

maintained at 85% minimum through the cycles except when

going to low temperature (see step c below), in which case

the humidity may temporarily drop to 80% minimum.

One cycle is as follows:

a. Start test at 25±2°C[77±3.6°F]andraise the tempera-

ture to 65±2°C[149 °F] over a time span of 2.5 hours ±

5 minutes

Figure 2 Moisture and Insulation Resistance Test Graph

8 16 24 32 40 48 56 64 72 80 88 96 104 112 120 128 136 144 152 160 168

Elapsed Time (hour)

Temperature (Degree C)

Optional Measurement Made

Mandatory Measurement Made

IPC-TM-650

Number

2.6.3.1

Subject

Solder Mask - Moisture and Insulation Resistance

Date

03/07

Revision

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