Introduction to In-Circuit Test
Introduction Page
• Why In-Circuit Test?
• Brief history of In-Circuit Test
• 3070 History
• In-Circuit Test Fundamentals
Why In-Circuit Test?
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Solder Electrical
AXI ICT
• Shorts
• Opens • Dead Part
• Insufficient
• Invisible • Wrong Part
• Poor wetting parts
• Bad Part
• Marginal Joints
• Missing • PCB Short/Open
• Voids
• Gross Shorts •
• Excess
•
Functionally Bad
•
Lifted Leads • Inverted
Excess
• Bent Leads
• Polarity
• Bridging
• Tombstone • Missing
• Misalignment
Socketed
Parts
• Orientation
AOI • Missing Non-Elec.
ICT: In-circuit Test
• Bypass Caps, L’s
AXI: Automated X-ray Inspection • Extra Parts Placement
AOI: Automated Optical Inspection • Mark Inspection
Where to Use In-Circuit Test?
Functional test Page
AXI post wave inspection
In-circuit test
AXI solder joint
AOI post-reflow
In-Circuit Test Finds Process Defects:
AOI component Solder shorts
measurement Missing, wrong & reversed devices
AOI solder paste Open leads
Why In-Circuit Test?
TEST SHIP
MFG
GOOD
PROCESS IMPROVEMENT
Advantages of In-Circuit Test
Automated Program Generation
Fault Identification
Part of a total process test solution
combined with intelligent test & structural
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A Brief History of In-Circuit Test Page
1970’s – Analog In-circuit test developed
• Early pioneers – FaultFinders FF101; Hewlett-Packard HP3060; GenRad GR2270;
• Most boards have high manufacturing induced defects as well as poor device
quality.
- First-pass yields (FPY) < 50%.
• Principal value of ICT was to find defects on boards that failed “system” or
“functional test”
More History...
1980’s - Board ATE becomes mainstream Page
• ICT techniques mature, digital ICT(backdriving) emerges
• GR 227x/228x; HP 3065; FF303; L200; Zehntel 8xx; Marconi 80 and many others
fight for market share
• Market drive towards “combinational test” leads to new breed of testers: Teradyne
L300; Zehntel 8000; GenRad 2750; S7xx and HP 3070
More History... Page
2000s – Today
• i3070 rises to become the most popular board ATE in the world today
Agilent Board Test Innovations
Solving the Toughest Test Problems For Over 20 Years
Full ICT Coverage with as little as
50% nodal access
Tester size, reliability, Agilent MagicTest
performance 2X Faster Throughput
SMT Panels Automated Silicon
Agilent 3070 Series I Agilent Quick70
Agilent Panel Compatible High Node Nails
integrated design At-Speed Flash Programming
Test Count System Non-boundary scan
Fixturing cost, performance Agilent 3070 Series 3
Agilent 3070 Series II parts
Agilent 3070 Test Throughput Dynamic Test Access w/Flash70
1994 3070PC
Short-wire Fixturing Agilent Throughput Advanced Fixturing
Full 3070 Capability
Multiplier Agilent Quick Press Technology
SMT, Automated lines SMT opens, ASIC on PC
1992 JOT Automation
Agilent Express test development Complimentary
1998 2001
Fixturing System - Agilent TestJet vectorless opens
1989 Technology Agilent Connect Check
1993 1996
2000
Test standards Reversed electrolytics Maximize fault coverage
Analog ICT accuracy Boundary Scan Agilent Polarity Check w/lowering cost of test
6-wire measurement Test Asset Mgmt AwareTest xi
Description Language 1995
technology Agilent 3070 1999
1990 Pay-per-use
1978 Fast Test
1994
Development Faster, More Convenient
Overdriving safety Agilent Quick Basic 3070PC
Agilent Safeguard 1983 Serial bit streams (Telecom) Turn High Digital Channel
Agilent Serial Test Card 1997 Count Pin Card
1991
Large pattern sets Hybrid32 Pin Card
Agilent VPU architecture MagicTest Enhancements
1983
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3070 History: Series I
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– Introduced 1989
– Original Configuration:
• Single Density (SD) Pin Cards (72 pins/ 8 channels), 2,592 pins
maximum
• ASRU “A”
• Control Card(10 MHz 68000 Processor)
• Series 300 Controller
- 68030/68040 25MHz processor (~ 5 VAX MIPS)
- 12 MB of RAM
- 608 MB Hard Disk
– Last system sold: 1995; End of support : June 2004
Series II
– Introduced 1994 Page
– Original Configuration:
• SD Pin Cards or Double Density (DD) Pin Cards (144 pins/ 16 channels), 5,184 pins
maximum.
• ASRU “B” version
• Control-Plus Card – LAN Based, 25 MHz 68030 processor, 25 -> 50% thru put
improvement
• Series 700 Controller
- 50 MHz PA-RISC Processor (~ 62 VAX MIPS)
- 64 MB of RAM
- 2 x 1GB Hard Disk drives
– Series I systems could be upgraded to Series II capability by module-level & controller
upgrade (last System sold: 1998; End of Support : June 2005)
Series II Improvements Page
Double density – increase in max. # of pins(2,592 ->5,184)
More robust system power supplies
Enhanced DUT power supply capabilities
Faster controller (Series 700)
TestJet II
Improved discharge capability (ASRU-B)
Faster production thruput (up to 50% reduction in test time)
Approx. 2x improvement in test development time
Series 3
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– Introduced 1998
– Original Configuration:
• DD Pin Cards Supported
• Control XT( 50 MHz 68030 processor) – 2x improvement in test time
• B-Class Workstation Controller
- 180 MHz PA 7300 Processor (2.5 x faster than 725/50 for test development)
- 128 MB RAM
- 9 GB Hard drive
– Series I/II systems can upgrade to Series 3 equivalent performance(Quick 70
upgrade)
Other Series 3 Improvements
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Electrically quieter system backplane (not upgradeable from SI/SII)
Capacity for more DUT Power Supplies(ASRU-C)
Improved thermal management (blowers)
Increased capacity Power Distribution Unit (PDU)
Improved EM shielding on internal system cables
Ergonomic CRT arm
Flat-screen display
Reduced acoustic noise signature(blowers vs. fans)
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In-Circuit Test Theory - Fundamentals
What Does An In-Circuit Test Solution Consist of?
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• An ICT Test System
• An ICT Test Fixture
• An ICT Test Program
!!!! 4 0 1 1047643559 0000
! Testplan for 4498-2400-2600 Wed Feb 17 19:49:50 1999
! These are the board defaults
dim BoardSet_boards_1_to_1(1:1)
dim BoardSet_boards_2_to_2(2:2)
! HP3070 STANDARD TESTMAIN Revision: "B250:1(panel)"
! PANELIZATION VERSION
!########################################################################
######
! This "main"
for Board_Num = 2 to 2
board number is Board_Num
if BoardSet(Board_Num) and dutfailed then Pins_failed_flag = 1
next Board_Num
return Pins_failed_flag
fnend
! End of Testplan Writer Generated Testplan.
What Does ICT Test?
ICT Systems automatically generate tests for the following devices:
resistors comparators SSI
capacitors voltage regulators MSI
inductors voltage references LSI
parallel R and C current sources VLSI
parallel R and L jumpers TTL/CMOS/ECL/ACT
diodes fuses custom IC's
zener diodes resistor packs custom analog IC's
transistors opto-isolators custom mixed IC's
JFETs RS-232 transceivers switches
potentiometers clock oscillators connectors
operational amplifies delay lines sockets
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What Is an ICT System? Page
• All In-Circuit Test Systems consist of the following hardware components
• Analog Stimulus/Measurement Sub-system – performs tests
• Switching Sub-system – connects the Device-Under-Test (DUT) to the test
system
• Computer/Testhead Controller, usually a PC.
• Systems that consist of ONLY the above components are usually referred to
as Manufacturing Defect Analyzers (MDA). In Asia they may be called “ICT”
systems.
Basic ICT/MDA Block Diagram
DUT/UUT/BUT Page
Simple to use
Low cost
Passive (no power) tests only
Test Fixture Very popular in Asia (1000s in use)
Limited capability, poor coverage for
Analog Stim/Measure complex PCBAs
Controller
Switching Sub-System
Advanced or “True” ICT Systems Page
• Advanced ICT systems, like the Agilent 3070 have capabilities beyond that of
the MDA systems.
• Digital Stimulus Response Sub-systems – Provide powered on tests of digital
devices to verify functionality
• Programmable DUT Power Supplies – Provide power to the DUT for actual
performance tests
• Systems with these enhancements are considered “true” ICT systems or in
Asia they are called “ATE”
“True” In-Circuit Test Systems Page
DUT/UUT/BUT
Test Fixture
Switching Sub-System
DUT P.S.
DUT P.S.
Controller
Digital Sim/Response
Analog Stim/Response
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Why Was Boundary-Scan Created?
Why Was Boundary-Scan Created? Page
Integrated Circuits (IC) complexity
– Microprocessors
– ASICs
– MCMs
Loss of Node Access
– Surface Mount Technology (SMT)
– MCMs
Larger pin count devices
– 14 to 24 (older IC's)
– 100 to 400 (newer IC's)
Why Was Boundary-Scan Created? Page
Improve Fault Coverage - less escapes
Reduce Repair Time - better diagnostics
(e.g. fix joint vs. replace 300 pin IC)
Reduce Test Development Time - no need to understand internal logic
Use at Board Prototype Stage - don't need ASIC Patterns
Chip Cost Increase - Offset by lower mfg/test/repair
costs and increased quality of product shipped
Evolution Of Boundary-Scan Page
1985 : Joint European Test Action Group (JETAG)
1988 : Joint Test Action Group (JTAG)
1989 : IEEE Committee and Balloting
1990 : IEEE 1149.1-1990 Standard
1994 : 1149.1a (corrections and improvements)
1149.1b - BSDL Standard (HP/Agilent contribution)
2003 - 1149.6 (AC Extest) - Major drivers included Cisco & Agilent
Typical IC
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Test Challenges:
Traditional test vectors are difficult and
time-consuming to create
Not all pins can be accessed
Core Most faults are not internal to
Logic device(connection)
Hard to create test libraries for all
possible modes of use
Typical IC with Boundary-Scan
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Boundary
Cells
Core
Logic
The device can be controlled
and tested through TDI, TCK,
TMS, & TDO
TEST ACCESS PORT
CONTROLLER
Test Data (TAP) Test Data
In (TDI) Out (TDO)
Test Mode Test Clock
Select (TMS) (TCK)
Arrows denote access points
What Is ICT+? Page
• Extending the use of the 3070 beyond “In-Circuit Test”
• Limited functional tests
• Parametric measurements
• Intent is to reduce time/steps to test product
• Usually NOT a replacement for functional test stage
How Does the Agilent 3070 Support ICT+? Page
• Hardware:
• PC Controller – allows for 3rd party instruments, cards, etc.
• Performance Port – Integrates external access to UUT via fixture
• Serial, USB, GPIB ports – allows connection to external peripherals
• Software:
• External program calls
• Applications library for many applications
• Full feature BT-Basic language vs. spreadsheet only
For more product information on In-Circuit Test, visit
www.keysight.com/find/ict
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