IPC-TM-650 EN 2022 试验方法.pdf - 第222页

The measurement location can then be observed on the video camera image and adjusted if necessary. The collimator area indicated on the video image should fit entirely within the test area of the sample specimen as seen …

5 Procedure

5.1 Instrument Setup

Prior to the purchase of the Certi-

fied Reference Materials (CRMs), confirm with the XRF

manufacturer that the instrument is capable of measuring

phosphorus content and obtain details of the recommended

machine set-up and operational procedures.

Instrument setups usually contain a product file that contains

the required measurement specific hardware and software

settings for the application. In addition, the product file con-

tains a calibration file which defines the calibration settings

and certified reference material to be used.

5.2 Typical Instrument setup conditions and measuring

ranges are as follows:

• Aperture Size: 1 mm for both 10kV and 50kV applications.

• Anode Current (I): I=1 mA for 10kV and I=0.15 mA for 50kV

(Anode current setup maximizing achievable instrument

count rates will yield best instrument repeatability, reference

5.3).

• Primary Beam Filter: NO filter for 10 kV and Ni Filter for

50 kV.

• Measurement Time: 120 s for 10kV and 20 s for 50kV.

5.3 Instrument Calibration Calibration shall be per-

formed with CRM’s according to the instrument manufacturer

instructions. The CRM’s shall be traceable to national labora-

tories. The structure of the reference material shall be similar

to the samples under investigation, i.e., NiP/Cu/PCB, Au/NiP/

Cu/PCB or Au/Pd/NiP/Cu/PCB. Individual calibration foils

shall not be used for multilayer coatings. The certified refer-

ence standards shall have compositions and thicknesses

similar to the samples to be measured. If desired, it is possible

to calibrate an instrument over the full (low to high) phospho-

rous range. However, optimum accuracy can be achieved by

calibrating each phosphorous range (low, mid, and high)

separately. Each phosphorous content range should be cali-

brated with no less than 4 standards per range. No less than

3 measurements per calibration standard shall be performed.

Calibration checks should be performed after each calibration

and periodically by re-measuring the calibration standards. If

the results are within the measurement uncertainty of the

standards and the uncertainty of the measurement itself, no

action is required. If not, a recalibration of the instrument is

required. Typical CRM standards used and results obtained

are summarized in Table 1.

5.4 Sample Placement There are some basic rules for

positioning specimens. For each measurement, it shall be

ensured that the X-ray fluorescence radiation can reach the

detector without obstruction. For flat, unpopulated PCB

boards, this is not a problem.

If populated boards are being measured, the operator shall

note the position of the detector and position the sample such

that no components are present in locations that would

prevent the radiation emanating from the measurement loca-

tion from reaching the detector, as illustrated schematically in

Figure 2.

The area measured should be flat and not tilted.

5.5 Measurement XRF equipment operation is instrument

specific and shall be in accordance with the instrument

manufacturer’s instructions. Always ensure that the correct

measurement file is selected for the application to be mea-

sured. Typically, instruments will slide the measuring stage out

of the instrument when the measurement chamber is opened.

The test sample is then positioned on the programmable X-Y

stage such that the laser pointer points at the measurement

location. When the measurement chamber is closed, the

stage will automatically retract into the chamber.

IPC-2344-2

Figure 2 Sample Placement with Respect to Detector

IPC-TM-650

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

Page3of4

The measurement location can then be observed on the video

camera image and adjusted if necessary. The collimator area

indicated on the video image should fit entirely within the test

area of the sample specimen as seen in Figure 3. The sample

image is then focused with the autofocus feature of the instru-

ment.

A minimum of 5 measurements shall be made per measure-

ment location (0.060 in x 0.060 in pad). Using a polycapillary

instrument, the 5 measurements shall be made at different

locations on the pad or the instrument should be used in a

scanning mode across the pad. On each side of the test

specimen on which an electroless nickel coating has been

applied, three pads shall be measured. The Measurement

Report shall include as a minimum:

• Instrument used

• Size of the collimator

• Measurement time

• Excitation conditions

• Individual measurement results

• Statistical measurement parameters such as mean, stan-

dard deviation and relative standard deviation

• Specification Limits as required

• Operator, time and date

6 Notes

6.1 Measurement Results:

Table 2 demonstrates the excellent standard deviation

achievable (0.4 wt.-% for 60 s measuring time) for measure-

ment of P-concentration. It should be noted that a high total

spectral intensity of more than 50,000 cps is the result of very

high flux excitation by an instrument using a polycapillary X-ray

optic emitted from a relatively small measuring spot of less

than 50 µm Ø.

In the case of standard aperture beam collimation, the total

measuring time for similar precision is expected to be a factor

of 2-3 X longer.

IPC-2344-2

Figure 3 Positioning ofa1mmØCollimator on a 1.5 mm

x 1.5 mm [0.060 in x 0.060 in] ENEPIG Pad

Table 1 Measurement of Coating

Thickness and Phosphorus Content:

Typical achievable results for NiP/Cu/PCB samples

(1 mm collimator; measuring time 120 s)

CRM

Speciﬁed Values Measured Values

d (µm) %P d (µm) %P

CRM 1 5.20 (0.1) 0 5.29 (0.1) 0.0 (0.3)

CRM 2 7.35 (0.2) 0 7.43 (0.1) 0.1 (0.3)

CRM 3 1.2 (0.1) 8 (0.4) 1.2 (0.1) 7.7 (0.3)

CRM 6 2.89 (0.1) 10.6 (0.4) 2.88 (0.1) 10.7 (0.4)

CRM 4 6.9 (0.2) 9.0 (0.4) 6.5 (0.1) 8.9 (0.3)

CRM 5 5.90 (0.2) 11.2 (0.4) 5.7 (0.1) 11.1 (0.3)

CRM 7 11.20 (0.2) 11.3 (0.4) 11.2 (0.1) 11.4 (0.3)

Table 2 Evaluation of Measurement

Repeatability using a Polycapillary XRF:

5 Readings of the ENEPIG Sample shown in Figure 3.

Au Pd NiP wt-%P

Mean 0.049 µm 0.096 µm 3.2 µm 9.3

Standard

deviation

0.002 µm 0.002 µm 0.026 µm 0.413

50 nm Au/96 nm Pd/3.2 µm NiP9.3/Cu/PCB

(Small spot polycapillary instrument, measuring time 60 s)

IPC-TM-650

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

Page4of4

Scope

This

test method uses pressure sensitive tape to

determine the adhesion quality of platings, marking inks or

paints, and other materials used in conjunction with Printed

Boards.

Applicable Documents

Commercial Item Description (CID) A-A-113

Tape,

Pres-

sure Sensitive, Adhesive.

Test Specimens

Any

preproduction, first article, or pro-

duction printed board. A minimum of three tests should be

performed for each evaluation.

Apparatus or Material

4.1 Tape

roll of pressure sensitive tape 3M Brand 600

1/2 inch wide or a tape as described in (CID AA-113), Type 1,

Class B, except that the tape may be clear. The shelf life of

the tape is one year.

Procedure

5.1 Test

Press

a strip of pressure sensitive tape, 50 mm

[2.0 in] minimum in length, firmly across the surface of the test

area removing all air entrapment. The time between applica-

tion and removal of tape shall be less than one minute.

Remove the tape by a rapid pull force applied approximately

perpendicular (right angle) to the test area. An unused strip of

tape must be used for each test.

5.2

Evaluation

Visually

examine tape and test area for evi-

dence of any portion of the material tested having been

removed from the specimen.

5.3

Report

The

report should note any evidence of material

removed by this test.

6 Notes

6.1

plating overhang breaks off (slivers) and adheres to the

tape, it is evidence of overhang but not an adhesion failure.

6.2

foreign material (oil, grease, etc.) is present on the test

surface the results may be affected.

6.3

Certification

of 3M Brand 600 1/2 inch tape to CID-A-A-

113 is not required. The 3M Brand 600 1/2 inch tape is avail-

able through most office supply stores.

2215

Sanders Road

Northbrook, IL 60062-6135

IPC-TM-650

TEST

METHODS MANUAL

Number

2.4.1

Subject

Adhesion,

Tape Testing

Date

05/04

Revision

Originating Task Group

Rigid Printed Board Performance Task Group

(D-33a)

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.

age1of1

ASSOCIA

TION CONNECTING

ELECTRONICS INDUSTRIES

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ