IPC-TM-650 EN 2022 试验方法.pdf - 第744页

IPC-3408-fig4 Figure 3 Four Probe Interconnect Resistance Measurement T echnique for Flex to PWB and Flex to ITO Glass VI Ih, Vh I1 R1= AV/I 6th trace IPC-3408-fig3 Figure 2 Interconnection Resistance T est Assembly; Fle…

IPC-3408-3-1

Figure

1 Interconnection Resistance Test Assembly; Flex to ITO Glass

0.4 mm Flex, 9 x 25 mm

9.0 mm x 2.5 mm nom.

ZAF, 0.025 mm, 3.2 x 10 mm

Bonded Test Sample

0.2 mm line/space

Pitch Flex-ITO Glass

Test Sample Clamped

to 0.4 mm Pitch Test Board

Clamp

IPC-TM-650

Number

2.6.24

Subject

Junction

Stability Under Environmental Conditions

Date

11/98

Revision

age2of3

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ

IPC-3408-fig4

Figure

3 Four Probe Interconnect Resistance Measurement Technique for

Flex to PWB and Flex to ITO Glass

Ih, Vh

R1= AV/I

6th trace

IPC-3408-fig3

Figure

2 Interconnection Resistance Test Assembly; Flex to PWB

0.4 mm Flex, Shortened on End

17 Traces, 9 mm x 25 mm

ZAF, 0.050 mm, 3.2 mm x 10 mm

Bonded Test Sample

0.2 mm line/space

Pitch Flex Board

IPC-TM-650

Number

2.6.24

Subject

Junction

Stability Under Environmental Conditions

Date

11/98

Revision

age3of3

电子技术应用　　　　　　　ｗｗｗ．ＣｈｉｎａＡＥＴ．ｃｏｍ

1 Scope

This test method provides a means to assess the propensity

for conductive anodic filament (CAF) growth and other forms

of electrochemical migration failure modes within a printed

board (PB). This test method can be used to assess PB lami-

nate materials, PB design and application parameters, PB

manufacturing process changes and other applications such

as press-fit connectors.

Warning 1: This IPC test method has not been designed for

use with voltages exceeding 100 Vdc bias, however higher

voltage bias testing is being routinely required to be per-

formed, such as for electric vehicle electronics. Note that at

100 Vdc using 20 mA cut-off means 2 watts of power being

dissipated per channel, so using a much lower cut-off current

is recommended for better root cause failure analysis.

Warning 2: As voltage bias is increased, the wiring insulation

required needs to change in order to ensure operator safety.

2 Applicable Documents

2.1 IPC

IPC-9253

CAF Test Board Design (Available in the ‘‘Drafts’’

section of the 5-32e Task Group Home Page)

IPC-9254 CAF Test Board Design (Available in the ‘‘Drafts’’

section of the 5-32e Task Group Home Page)

IPC-9255 CAF Test Board Design (Available in Free Down-

loads in IPC Home Page)

IPC-9256 CAF Test Board Design (Available in Free Down-

loads in IPC Home Page)

IPC-9691 CAF Test Method User Guide for the IPC-TM-650,

Method 2.6.25

IPC J-STD-001 Requirements for Soldered Electrical and

Electronic Assemblies

IPC J-STD-004 Requirements for Soldering Fluxes

IPC J-STD-006 Requirements for Electronic Grade Solder

Alloys and Fluxed and Non-Fluxed Solid Solders for Electronic

Soldering Applications

IPC-TM-650 Test Methods

2.3.25 Detection and Measurement of Ionizable Surface

Contaminants by Resistivity of Solvent Extract

2.6.27 Thermal Stress, Convection Reflow Assembly

Simulation

2.2 American Society for Testing and Materials (ASTM)

ASTM D-257

Standard Test Methods for DC Resistance or

Conductance of Insulating Materials

3 Test Specimens

The IPC-9254 CAF test board design is the older coupon and

has been superseded by the IPC-9253. The new smaller CAF

test coupons are IPC-9255 and IPC-9256 and are used for

evaluating PTH-PTH spacings only. These smaller CAF test

coupons allow users to put a CAF test coupon at the perim-

eter of their panels for testing. All IPC CAF test coupon design

Gerber files are down-loadable and are available on the IPC

committee and free download web sites.

3.1 CAF Test Board Designs The IPC-9253 and IPC-

9254 have 10 layers and dimensions are approximately

125x175 mm [nominally 5x7 in]. Test board designs for evalu-

ating CAF resistance shall have varying drilled hole wall to

drilled hole wall distances for plated holes. These distances

can range from as low as 0.15 mm [0.00591 in] separation for

alternate laminate materials expected to have very high CAF

resistance and minimal copper wicking out from the plated-

through hole (PTH), to as high as 0.89 mm [0.0350 in] sepa-

ration for evaluating press-fit connector applications. The

drilled hole size, rather than the finished hole size, is specified

in the chart on the bare board fabrication drawing to ensure

consistent spacing. Internal layer thieving may be added to

plane layers around the perimeter. Test boards should be

manufactured so that the machine/grain direction of the

woven fiber reinforcement is perpendicular to the rows of

same-net daisy chain vias for A1-A4 (machine/grain direction

tends to fail first). Test board designs shall have sufficient

minimum spacings on outer layers to ensure that surface insu-

lation resistance failures do not occur. Layouts of the IPC-

9253 and IPC-9254 test board structures (CAF Test Boards)

are shown in Figure 1.

3000 Lakeside Drive, Suite 105N

Bannockburn, IL 60015-1249

IPC-TM-650

TEST METHODS MANUAL

Number

2.6.25

Subject

Conductive Anodic Filament (CAF) Resistance Test:

X-Y Axis

Date

02/21

Revision

Originating Task Group

Electrochemical Migration Task Group (5-32e)

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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