IPC-TM-650 EN 2022 试验方法--.pdf - 第754页
APPENDIX A Additional C AF Resistance Factors Checklist Test board part number and revision level. Drilled H ole Size fo r each Hole-Hole and Hole-Plane spacing tested (a lso recommend drilling feed rate, speed of ro tat…
e)
A surface finish for fine pitch featured PCBs that are often
assembled using surface mount components (SMCs). The
OSP surface finish provides very flat/co-planar land areas
for the placement and attachment of SMC devices.
f)
This phrase alludes to the manufacturing of a bare printed
circuit board that is not populated (assembled) with any
discrete components.
6.2 Reference Documents
Electrochemical Migration: Electrically Induced
Failures in Printed Wiring Assemblies
Electrochemical Migration
Resistance Test (note: covers only surface electrochemical
migration)
Surface Insulation Resistance Handbook
Number
2.6.25
Subject
Conductive Anodic Filament (CAF) Resistance Test: X-Y Axis
Date
02/21
Revision
C
IPC-TM-650
—
Organic
Solderability
Preservative
(OSP):
Printed
Circuit
Board
Fabrication
(PCB
Fab):
IPC-TR-476
IPC-TM-650,
Method
2.6.14.1
IPC-9201
Page
9
of
11
APPENDIX A
Additional CAF Resistance Factors Checklist
Test board part number and revision level.
Drilled Hole Size for each Hole-Hole and Hole-Plane spacing tested (also
recommend drilling feed rate, speed of rotation, chip loading data, backup
material type, etc.).
Desmear & Cleaning Process (ex: permanganate, plasma).
Whether glass microetch was used (and if so, the controlling process
parameters).
Board finish type (HASL or specific OSP, immersion silver, immersion tin,
ENIG, etc.).
Laminate material type that was used (manufacturer and material name or
number).
Woven Glass Manufacturer (silane treatment application).
Type of soldermask (if used).
PCB Fab manufacturer and facility.
Method of separating test board from working panel.
Number of circuit layers in test board.
Copper thickness in plated through holes in test board.
Dielectric Thickness and Construction (same construction throughout is
recommended for CAF testing). Examples:
Core 2/2 3.0 mils thick 1 ply 1080, Prepreg 1 ply 1080
Core 1/1 4.3 mils thick 1-106/1-1080, Prepreg 1-106/1-1080
Core H/H 5.0 mils thick 1-2113, Prepreg 1-2113
Failure Location (with examples)
Glass-Resin Boundary
Migration Between Glass Fibers
Migration Between Fiber Bundles
Void within Fiber Bundle
Incomplete Wetting Against Fiber
Hollow Fiber (report glass cloth supplier name, name of fiber source)
Test Interruptions:
Cause (example: power interruption)
Length of Interruption
Test Re-Start Parameters
Frequency of Measurement. Examples:
24 Hours
20 Minutes
6 Minutes
Time of Failure: Examples
200 Hours (hollow fiber)
300 Hours (void within fiber bundle)
21 Hours (migration between fiber bundles)
Number
2.6.25
Subject
Conductive Anodic Filament (CAF) Resistance Test: X-Y Axis
Date
02/21
Revision
C
IPC-TM-650
Document
for
every
CAF
resistance
test
the
several
additional
factors
that
can
affect
C4F
resistance.
These
critical
factors
include:
Parameters
Comments
Page
10
of
11
Failure Type & Distance (between drilled hole walls, or hole wall to plane
edge). Examples:
PTH-PTH, 11.0 mils, Nelco 4000-11
PTH-Plane (GND), 15.0 mils, FR406 (dicy-cured)
Current Limiting Resistor Value (default is 1.0 meg-ohm or 10
6
ohms)
Assembly Process Simulation: Examples
No Bake, No Preconditioning
Bake (specify), No Preconditioning
Bake (specify), 3X @ 260 °C Preconditioning (specify profile)
Bake (specify), 6X @ 260 °C Preconditioning (specify profile)
Bake (specify), 6X @ 230 °C Preconditioning (specify profile)
Bake (specify), 5X @ 245 °C Preconditioning (specify profile)
CAF Test Parameters: Examples
15 Vdc, 50 °C, 80% RH, drilled hole wall to hole wall spacings
100 Vdc, 65 °C, 87% RH, drilled hole wall to hole wall spacings
10 Vdc, 65 °C, 85% RH, drilled hole wall to hole wall spacings
Material(s) Tested: Examples
FR406 (dicy-cured)
Nelco 4000-11
Reporting Dates: Examples
Date Tested: August 2006
Date CAF Test Coupon Manufactured: February 2006
Number
2.6.25
Subject
Conductive Anodic Filament (CAF) Resistance Test: X-Y Axis
Date
02/21
Revision
C
IPC-TM-650
Parameters
Comments
Page
11
of
11