IPC-TM-650 EN 2022 试验方法.pdf - 第185页

1 Scope This test procedure is designed to measure the level of extractable ionic contamination on the surface of printed boards and printed board assemblies by ion chroma- tography. 2 Applicable Documents IDEMA M13-99 M…

‘‘Ionic

Cleanliness of LPISM Circuit Boards,’’ Hank Sanftle-

ben, IPC 1995 Fall Meeting Proceedings, S13-3.

6.2

IPC-HDBK-001 ‘‘Handbook and Guide to the Require-

ments for Soldered Electrical and Electronic Assemblies to

Supplement ANSI/J-STD-001’’ is another source for under-

standing ROSE testing in general.

6.3 This

method may also be known as the modified-ROSE

test. This test, due to its longer extraction time and higher

extraction temperature, has demonstrated better correlation

with the total ion determination by ion chromatography than

IPC-TM-650, Test Method 2.3.25, Detection and Measure-

ment of Ionizable Surface Contaminants by Resistivity of Sol-

vent Extract (ROSE) Method. However, as a bulk contamina-

tion measurement method, it cannot distinguish individual ion

species.

6.4

From

an analytical standpoint, the dip probe method is

preferred as more repeatable than the automated ROSE

testers and avoids many of the test inaccuracies (e.g., CO

absorption

from spray agitation) inherent in those instruments.

It should be stressed that the dip probe method is an electro-

lytic conductivity measurement and must be temperature-

compensated.

6.5

The

dip probe calibrations can be run at multiple tem-

peratures and a family of curves generated, widening the test

window for use with this method. Higher temperatures, how-

ever, will lead to a faster 2-propanol evaporation rate. The test

can also be run with more dilute concentrations, prepared by

series dilution.

6.6

Conductivity

cells have a ‘‘constant’’ value. Measured

readings must be multiplied by this constant. Exposure to

harsh chemicals may alter the constant, making a

re-calibration necessary. Do not allow the probe used for this

procedure to contact sticky, oily, or resinous liquids (e.g., flux).

6.7

This

procedure is intended to be a process control aid

and as such, no pass-fail criteria is stated. It is expected that

the fabricator/assembler will determine, with their customer,

the necessary pass-fail criteria for their product by this

method.

6.8

This

method is best suited for monitoring and control of

a previously optimized process and should not be used to

generate acceptance data unless part of a larger correlation

study. Values generated with this method should be corre-

lated to acceptable electrical performance if used for accep-

tance.

6.9

Kapak™ 500 Series Bags can be obtained from:

Kapak Corporation

5305 Parkdale Drive

Minneapolis, MN 55416

800-527-2557

www.kapak.com

A secondary source of Kapak™ or Scotchpak™ polyester

bags or pouches can be obtained from:

VWR International

1310 Goshen Parkway

West Chester, PA 19380

Orders: 1-800-932-5000

Web Orders: www.vwrsp.com

If an alternative to the Kapak™ bag or Scotchpak™ is

desired, the bag must have the following characteristics:

• No extractable ionic material in 75% 2-propanol / 25% DI

water at 80°C [176°F] for 60 minutes

• 0.01 cm [0.0039 in] wall thickness minimum

• Heat sealable or mechanical seal

6.10

There

is some concern regarding ROSE tester cell size.

Testinga2cmx2cm[0.79 in x 0.79 in] board in a 20,000

mL cell causes such a severe dilution as to cause the signal

to be lost in the noise. A recommended cell size is 5000 mL

or less. Smaller cell volumes will allow for a more measurable

result. If a smaller cell, or running with a smaller test volume,

are not an option, then the number of bare boards can be

increased, all extracted separately, and the extract solutions

all tested at once.

6.11

When

testing hybrids or microelectronics, be aware

that 2-propanol stored in glass containers can leach out

materials such as sodium, borates, and silica. 2-propanol

stored in plastic containers does not have such a leaching

problem.

IPC-TM-650

Number

2.3.25.1

Subject

Ionic

Cleanliness Testing of Bare PWBs

Date

October 2000

Revision

age4of4

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1 Scope This test procedure is designed to measure the

level of extractable ionic contamination on the surface of

printed boards and printed board assemblies by ion chroma-

tography.

2 Applicable Documents

IDEMA M13-99

Measurement of Extractable/Leachable

Anion Contamination Levels on Drive Components by Ion

Chromatography (IC)

IPC-TP-1043 Cleaning and Cleanliness Test Program, Phase

III, Water Soluble Fluxes, Part 1: B-24, lnteractions of Water

Soluble Fluxes with Metal/Substrates

IPC-TP-1044 Cleaning and Cleanliness Test Program, Phase

III, Water Soluble Fluxes, Part 2: B-36, Comparison to Phase

1 Rosin Benchmark

IPC-TR-583 An In-Depth Look at Ionic Cleanliness Testing

IPC-5701 Users Guide for Cleanliness of Unpopulated

Printed Boards

IPC-WP-008 ‘‘Setting Up Ion Chromatography Capability’’

3 Test Specimens

3.1

Printed board and/or printed board assembly for extrac-

tion

4 Apparatus and Material

4.1

Ion Chromatograph capable of accurately measuring ion

concentrations down to 0.5 parts per million (ppm). The

equipment and chemistry should be set up and standardized

per the manufacturer’s instructions. The separation column

and eluent composition should be chosen to provide baseline

resolution between the ions of interest.

4.2 Hot water bath capable of maintaining 80±2°C[176 ±

3.6 °F].

4.3 Clean extraction vessels.

4.4 Clean labware (Ionic free).

4.5 Cleanroom vinyl gloves. (<3 ppm of Cl).

4.6 Deionized water with a resistivity of at least 18.0

megohm-centimeter.

4.7 IC or ACS grade chemicals for eluent and regenerant

preparation.

4.8 National standard - traceable calibration standards (e.g.,

NIST traceable).

4.9 Volumetric Flasks (Typically 25, 50, 100, and 1000ml).

4.10 Precision Pipetting Equipment (such as Eppendorf).

5 Test Procedures

5.1 Extraction Procedure

Select a low-ion extraction bag

sized to fit the board with approximately 2.5 cm [1.0 in]

excess on each side to minimize required extract solution,

with several inches at the top to allow for air expansion when

the bag is heated.

Note: See www.ipc.org/html/testmethods.htm for an IPC-

TM-650 Equipment Vendor Listing for possible vendors.

5.1.1 Use clean gloves and or tongs when handling the

samples to be tested. Place each sample in an extraction bag.

5.1.2 Prepare a 75/25 (± 5%) v/v 2-propanol/H

0 solution

for the extraction.

Note: A tolerance was added to the IC method because it is

a more specific and accurate method by comparison to the

ROSE method.

5.1.3 Add a known volume of the extraction solution to

the extraction bag covering the sample (approximately

0.5 mL/cm

of surface area).

5.1.4 Add the same volume of extraction solution to an

empty bag of the same lot for use as a blank.

5.1.5 Suspend the bags in the 80 ± 2°C [176 ± 3.6°F] water

bath allowing the water to force most of the air from the bags.

Do not allow any of the water from the water bath into the

extract solution in the bags. Fold the top of the bags over the

suspending bar and clip in place with binder clips. This will

3000 Lakeside Drive, Suite 309S

Bannockburn, IL 60015-1249

IPC-TM-650

TEST METHODS MANUAL

Number

2.3.28

Subject

Ionic Analysis of Circuit Boards, Ion

Chromatography Method

Date

11/12

Revision

Originating Task Group

Ionic Conductivity / Ion Chromatography Task

Group (5-32a)

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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minimize solvent loss during the extraction, yet not create a

sealed bag. Alternatively, the bags may be heat sealed after

forcing most of the air from the bag.

5.1.6 Allow the sample to soak for one hour (-0 min., +5

min.).

5.1.7 Remove the bags from the water bath and allow the

solution within the bag to cool to ambient temperature before

opening.

5.1.8 Gently mix the contents. Transfer solution to virgin

sample vials for analysis or pull the sample solution directly

from the bag using a clean syringe for manual injections.

5.1.9 Remove the test sample from the bag using gloved

hands or other clean device.

5.2 Analytical Procedure

5.2.1

The analysis of the extract solution should be done as

soon as possible after extraction, but shall be no longer than

four days from the extraction date.

5.2.2 Start the chromatograph per the manufacturer’s rec-

ommended method and allow it to come to a stable baseline.

5.2.3 Analyze sample solutions for anion and/or cation

content, utilizing best analytical technique and laboratory

practices.

5.3 Calculation of Results

5.3.1

Values from the chromatograms are typically reported

in parts per million (ppm, µg/mL).

5.3.2 Record the surface area of the printed board or

printed board assembly. Recommended area calculations for

the unpopulated printed board and the printed board assem-

bly are the following:

Printed Board Surface Area = Length x Width x 2

Printed Board Assembly Surface Area = (Length x Width x 2)

+ (1 x up to 50% of the printed board area)

Great caution should be taken in interpretation and compari-

son of these results as assembly surface areas will often devi-

ate by more than 10% of its’ unpopulated state.

Note: There is no standardized way for estimating the sur-

face area of components. Traditionally, values from 10 to 50%

have been used for estimating component area.

5.3.3 Results may be expressed as micrograms (µg) of ion

per square centimeter or micrograms (µg) of ion per square

inch based on the extraction volume and the calculated

sample surface area.

µg/cm

or µg/in

= (SC - BL) x Vol / Area

Where:

SC = ppm from IC (µg/mL)

BL = ppm from the bag blank

Vol = final volume (ml)

Area = surface area (cm

or in

)

Note: ‘‘ppm’’ value is actually specimen value minus blank

value.

5.3.4 Report all ions quantified.

5.3.5 Report the surface area used in the calculation and

the percentage increased in calculating the surface area of a

printed board assembly.

IPC-TM-650

Number

2.3.28

Subject

Ionic Analysis of Circuit Boards, Ion Chromatography Method

Date

11/12

Revision

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