IPC-TM-650 EN 2022 试验方法--.pdf - 第219页

1 Scope The purpose of this test me thod is to measure the thickness and phosphorous (P) concentration of chemically (electroless) deposited nickel (Ni) coatings by ( energy disper- sive) X-ray fluorescence ( XRF) analys…

1 Scope

This test method is used to determine the ability of

a solder mask to resist degradation by solvents and cleaning

agents.

2 Applicable Documents

Qualification and Performance of Permanent

Solder Mask

Multipurpose One-Sided Test Pattern

3 Test Specimens

Six (6) IPC-B-25A boards coated with

solder mask on the top side. Five are to be tested and one is

to be held as a control.

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.

4 Apparatus and Reagents

4.1

Reagent Grade 2-Propanol (Isopropyl Alcohol)

4.2

Deionized Water (DI Water) with resistivity ≥2 MΩ-cm

and ≤10 MΩ-cm

4.3

10% Alkaline Detergent [by volume], which shall be

comprised of

• 5% alkanolamine

• 2.5% 2-butoxyethanol

• 2.5% glycol ether

• 90% DI Water

4.4

Monoethanolamine

4.5

Miscellaneous laboratory-ware (e.g., beakers, funnels,

storage bottles, graduated cylinders) including:

1) A hot plate capable of heating up to 65 °C [149 °F]

2) A thermometer capable of measuring accurately up to 100

°C [212 °F]

3) A vent hood, or performed with adequate ventilation

4.6

Thermometer with measurement uncertainty less than 2

°C [3.6 °F] and precision better than 1 °C [1.8 °F].

5 Procedures

5.1 Chemical Exposure

5.1.1

Prepare the solvents and cleaning agents as outlined

in Section 4 and Table 1.

5.1.2

Completely immerse one test specimen in each of the

solutions shown in Table 1. A new specimen is to be used for

each chemical.

5.1.3

After immersion, hang the specimens to dry for ten

minutes at ambient laboratory conditions.

5.2 Visual Examination

5.2.1

Visually examine each printed board with corrected

20/20 vision without magnification for delamination or surface

degradation such as cracks, tackiness, blisters or swelling of

the solder mask.

6 Notes

6.1 Safety

Operator should be trained and familiar with the

hazards inherent to the chemicals being used and analyzed.

Proper personal safety equipment, such as safety glasses,

gloves and splash apron, and adequate ventilation shall be

used.

1. www.ipc.org/onlinestore

Isopropanol

Ambient

Laboratory Conditions

75% isopropanol/

25% deionized water

46 ± 2 °C [115 ± 3.6 °F] 15

10% Alkaline detergent 57 ± 2 °C [135 ± °F] 2

Monoethanolamine 57 ± 2 °C [135 ± °F] 2

Deionized water 60 ± 2 °C [140 ± °F] 5

D-Limonene

Ambient

Laboratory Conditions

3000 Lakeside Drive, Suite 309S

Bannockburn, IL 60015-1219

IPC-TM-650

TEST METHODS MANUAL

Number

2.3.42

Subject

Solder Mask - Resistance to Solvents and

Cleaning Agents

Date

03/07

Revision

Originating Task Group

Solder Mask Performance Task Group (5-33b)

ASSOCIATION CONNECTING

ELECTRONICS INDUSTRIES

IPC-SM-840

IPC-A-25A-G-KIT1

Table

Exposure

Solder

Mask

Solvents/Cleaning

Agents

Solvent/

Cleaning

Agent

Temperature

(

℃)

[°F]

Time

(Minutes)

Note:

Record

the

ambient

temperature

and

temperature

measurement

uncertainty

℃

Material

this

Test

Methods

Manual

was

voluntarily

established

Technical

Committees

PC.

This

material

advisory

only

and

use

adaptation

，

entirely

voluntary.

IPC

disclaims

all

liability

any

kind

the

use,

application,

adaptation

this

material.

Users

are

also

wholly

responsible

for

protecting

themselves

against

all

claims

liabilities

for

patent

infringement.

Equipment

referenced

for

the

convenience

the

user

and

does

not

imply

endorsement

IPC.

Page

1 Scope

The purpose of this test method is to measure the

thickness and phosphorous (P) concentration of chemically

(electroless) deposited nickel (Ni) coatings by (energy disper-

sive) X-ray fluorescence (XRF) analysis.

The measurement is nondestructive and noncontact, and can

be performed either in ambient atmosphere or under vacuum.

Measurements

be made on a defined feature (equi-

valent to a typical SMT pad) of 1.5 mm x 1.5 mm [0.060 in x

0.060 in] or equivalent area, using a 0.6 mm diameter collima-

tor. This equates to a measuring spot size (analysis area) of

1 mm diameter.

This test method is designed primarily for failure analysis, pro-

cess qualification and process auditing. It is not intended for

daily production control, due to the complexity and cost of the

equipment required.

2 Applicable Documents

Specification for Electroless Nickel/Electroless

Palladium/Immersion Gold (ENEPIG) Plating for Printed Circuit

Boards

Specification for Electroless Nickel/Immersion

Gold (ENIG) Plating for Printed Circuit Boards

3 Test Specimen

This test method is primarily designed

for measurement of the phosphorus content in ‘‘as plated’’

ENIG PWBs. Other ENIG or electroless nickel (EN) plated sub-

strate materials may also be tested using this method, includ-

ing flexible circuits, silicon wafers, aluminum or steel. The typi-

cal thickness range of the NiP layer on PWB substrates is 3 to

6 µm [118.1 to 236.2 µin]. The Phosphorous content can

range from 0 % to 14% by weight. Minimum and maximum

thickness for single layers of electroless nickel required for

accurate determination of the P content is 0.5 µm to 25 µm

[19.7 µin to 984 µin]. The maximum thickness of gold present

on the surface of the specimen when tested

be less

than 0.10 µm [0.004 µin]. For samples with thicker gold, the

gold must be removed by chemical stripping or Ion milling

prior to evaluation.

While this test method is also suitable for evaluating phospho-

rus content in ENEPIG samples, the thickness of both the

gold (Au) and palladium (Pd) layers needs to be considered.

The maximum thicknesses of the layers over the electroless

nickel on ENEPIG specimens when tested

exceed

0.05 µm [0.002 µin] of Au and 0.10 µm [0.004 µin] of Pd on

top of the EN layer. This constraint will impact measurement

of ENEPIG samples plated on the higher side of the current

IPC-4556 specification. For samples with gold thicknesses

above 0.05 µm [0.002 µin], chemical or Ion milling stripping

may be carried out prior to evaluation. With the gold removed,

the maximum thickness of palladium on a specimen when

tested

be 0.25 µm [0.0098 µin].

Electroless palladium deposits may also contain phos-

phorus and its contribution to the total phosphorus content

must be taken into account when reporting the phosphorus

content of the deposit.

The sample to be tested should be flat and ideally not popu-

lated with components in the area of measurement. If testing

is done on populated boards, consideration has to be given to

measurement location, such that none of the electronic com-

ponents block the fluorescent radiation from reaching the

detector, as described in Section 5.4.

The test specimen requires no other sample preparation.

4 Apparatus

An X-ray fluorescence spectrometer consist-

ing of the following:

• A radiation source (X-ray tube with adjustable HV power

supply from 10 kV to 50 kV).

• A primary beam filter and safety shutter assembly.

• A video camera.

• An X-ray collimator or a polycapillary X-ray optic.

• An energy dispersive Silicon Drift Detector SDD (a device in

which charge carriers created by the incidence of X-ray pho-

tons on a high purity silicon substrate are directed to a mea-

suring electrode by an applied transverse electric field),

including electronics.

• Evaluation software capable of simultaneously measuring

coating thickness and composition of multiple layers. The

software of the instrument

have the capability of mul-

tiple excitation modes. It is necessary to apply different exci-

tation conditions; a soft excitation for the excitation of P-K at

10 kV and a hard excitation for Ni-K at 50 kV.

• A programmable X-Y positioning stage (accurate positioning

is required especially if small areas are to be analyzed).

• The instrument must be able to record the Intensities of the

individual radiation components of the Phosphorous K

energy line (I

P-K

) and the Nickel K energy line (I

Ni-K

) with suf-

ficient precision.

3000 Lakeside Drive, Suite 105N

Bannockburn, IL 60015-1249

IPC-TM-650

TEST METHODS MANUAL

Number

2.3.44

Subject

Determination of Thickness and Phosphorus

Content in Electroless Nickel (EN) Layers by X-Ray

Fluorescence (XRF) Spectrometry

Date

03/16

Revision

Originating Task Group

Plating Processes Subcommittee (4-14)

Association

Connecting

Electronics

Industries

shall

Note:

IPC-4556

IPC-4552

shall

not

Material

this

Test

Methods

Manual

was

voluntarily

established

Technical

Committees

PC.

This

material

advisory

only

and

use

adaptation

entirely

voluntary.

IPC

disclaims

all

liability

any

kind

the

use,

application,

adaptation

this

material.

Users

are

also

wholly

responsible

for

protecting

themselves

against

all

claims

liabilities

for

patent

infringement.

Equipment

referenced

for

the

convenience

the

user

and

does

not

imply

endorsement

IPC.

Page

A Certified Reference Material (CRM) covering the measuring

range of the application as described in 5.2.

A typical instrument layout is shown in Figure 1.

IPC-2344-1

Number

2.3.44

Subject

Determination of Thickness and Phosphorus Content in

Electroless Nickel (EN) Layers by X-Ray Fluorescence (XRF)

Spectrometry

Date

03/16

Revision

IPC-TM-650

—

Anode

Primary

filter

Shutter

3749

Primary

x-radiation

Spectrum

Mirror

Detector

Aperture

(Collimator)

Primary

X-rodiation

Coating

laye

Electron

Base

material

X-ray

tube

Cathode

Video

camera

X<ay

fluorescence

radiation

WinFTM

main

window

Figure

XRF

Instrument

Layout

Page