Teradyne, Inc. · NASDAQ:TER
Teradyne — Technical Presentation (May 2004)
34 slides from Teradyne's technical presentation, May 12, 2004
Slide 1: Understanding AXI Acquisition Techniques and Image Quality
“Understanding AXI Acquisition Techniques and Image Quality” Audio Dial-in Numbers International +1 706 634 5893 US/Canada +1 800 309 5939 Teradyne Assembly Test Division Website: www.teradyne.com/cbti Michael J Smith Michael.J.Smith@Teradyne.com
Slide 2: X-Ray Inspection
X-Ray Inspection AXI AOI ICT Slide 2
Slide 3: Major Components
Major Components 1. X-ray Tube Produces high resolution x-ray beam cone PCB 2. Image Intensifier / Detector Converts radiation into visible light 3. Camera Sends video signal to computer Imaging Analysis 4. Computer Analyzes Image Slide 3
Slide 4: Penetration Density and Thickness
Penetration Density and Thickness PCB’s & Solder Joint materials block x-rays based on: Material Density (Lead, Copper, Plastics, Heat Sinks, etc.) Material Thickness t Lightest - Darkest Slide 4
Slide 5: Computer prefer a gray scale (0-255)
Computer prefer a gray scale (0-255) X-ray Image 60 128 200 250 Slide 5
Slide 6: Field of View (FOV)
Field of View (FOV) FOV Influences: • Test Throughput • Resolution / Detection 1.0 in 25.4mm • Clearance .25 in 6.4 mm Smaller FOV Higher Resolution Larger FOV Low Resolution .5 in 12.7 mm Slide 6
Slide 7: Resolution
Resolution • Resolution is measured as Line Pairs .5in (12.5mm) FOV 1in (25mm) FOV – X-ray Tube spot size – Detector resolution – Field of View • Resolution Influences – Clarity of image – Measurement repeatability – Detection capabilities – False calls Slide 7
Slide 8: Types of X-ray Imaging
Types of X-ray Imaging • Transmission Imaging – Automated X-ray Inspection Systems (AXI) • Cross-Section Imaging – AXI Systems • Digital Tomosynthesis – Off-set Transmission • Laminography Slide 8
Slide 9: Automatic X-Ray Inspection Technology Evolution
Automatic X-Ray Inspection Technology Evolution ‘94 1st Digital Tomosynthesis AXI Xstation ‘86 1st Commercial AXI NIS MV6100 4000 IRT CXI-5300 ‘97 NIS CXI-5700 ‘89 1st In-line AXI ‘98 NIS CXI-3600DG IRT CXI-3300 ‘94 IRT CXI-3600 ‘ 94 4pi 5DX ‘98 HP 5DX Series 2 ‘00 Agilent 5DX Series 3 ‘89 1st Lamin
Slide 10: Transmission AXI
Transmission AXI X-ray Image Slide 10
Slide 11: Types of Cross-Section Imaging
Types of Cross-Section Imaging Tomosynthesis Laminography • Digital Image Synthesis • Mechanical Image Integration Generate Generate Off-axis Off-axis X-rays X-rays Stationary Rotating Detector Detector Slide 11
Slide 12: Principle of Laminography
Principle of Laminography * Z-Axis Mapping required Slide 12
Slide 13: Principle of Laminography
Principle of Laminography • Steer-able x-ray source and rotating detector • “Smear/Average” out objects above/below focal plane • Mechanical integration generates one slice per rotation (or acquisition) • Image acquisition and synthesis occur concurrently Off-axis images Slide 13
Slide 14: Principle of Digital Tomosynthesis
Principle of Digital Tomosynthesis Multiple Transmission Images Steer-able X-Ray Source Inspection Plane Large Area Detector Slide 14
Slide 15: Principle of Digital Tomosynthesis
Principle of Digital Tomosynthesis Digital Tomosynthesis is a Computational Technique Z= X / tan Z • Objects at different elevations move by different horizontal distances X Slide 15
Slide 16: Principle of Digital Tomosynthesis
Principle of Digital Tomosynthesis Digital Tomosynthesis is a Computational Technique Z= X / tan Z • Objects at different elevations move by different horizontal distances X Slide 16
Slide 17: Principle of Digital Tomosynthesis
Principle of Digital Tomosynthesis QFP Top Side PCB Resistor Cross Section x-ray provides the capability to generate un-obscured views of top and bottom side components Use multiple off-axis x-ray images to separate top/bottom overlapping or obscured solder connections Bottom Side Slide 17
Slide 18: Tomosynthesis vs. Laminography
Tomosynthesis vs. Laminography Tomosynthesis Laminography [Max Value Method] [Average Method] Some Digital Blurring Compared to Transmission AXI Slide 18
Slide 19: Imaging Performance Examples
Imaging Performance Examples • Transmission AXI – Resolution • ~ 20 lp/mm at 1.21 Sq-in FOV • Image noise 4.5% • Laminography AXI – resolution • ~ 8lp/mm at 0.64 Sq-in FOV • Image noise 7.5% Slide 19
Slide 20: Imaging Performance
Imaging Performance Laminography AXI Transmission AXI Better image quality and lower noise reduce false fails and increases fault detection. Slide 20
Slide 21: Tomosynthesis vs. Laminography
Tomosynthesis vs. Laminography • Tomosynthesis – Multiple Cross-sections per Acquisition: ‘infinite slicing’ 1 • Laminography – Laser Mapping to focus on layer – 1 Cross-section per Acquisition 1 2 • board warp 3 • board bounce & vibration 4 • laser map repeatability Slide 21
Slide 22: Flat to a 3D representation
Flat to a 3D representation GULLWING SOLDER JOINT X-RAY IMAGE Heel Fillet Transmission Solder Joint Histogram Slide 22
Slide 23: Adoption of Standards - IPC 7-32
Adoption of Standards - IPC 7-32 • IPC 610 – Human Inspection Solder Joint Acceptability • IPC 7-32 Subcommittee (Automated Inspection Technologies) – Working with the IPC 610 Subcommittee – Translate the IPC 610 solder joint acceptability into language that is directly measurable by automatic inspe
Slide 24: Void Measurement
Void Measurement A potential problem with Lead Free manufacturing process Slide 24
Slide 25: Void Measurement Calculations can vary
Void Measurement Calculations can vary – Void Area = 31 pixels – Radius = 12 pixels – ( 12 * 12 ) * π = 452.4 = 6.85% – Void Area = 60 pixels – Narrow Radius = 12 pixels – Wide Radius = 16 pixels – Circle = ( 12 * 12 ) * π = 452.16 = 13.26% – Oval = ( 12 * 16 ) * π = 603 = 9.85% Slide 25
Slide 26: Void Issues Related to Ball Shape
Void Issues Related to Ball Shape X-ray source Similarly sized voids in may appear to vary in size •Side voids appear brighter and thus larger because rays travel thru a shorter distance through the ball •Voids at mid-ball appear darker or smaller as x-rays travel through more solder than at the sid
Slide 27: Issues with Voids
Issues with Voids Multiple small and misshaped voids looks similar Slide 27
Slide 28: Measure Void Accuracy
Measure Void Accuracy • Use real voids from production boards and grind the ball to detail actual void size. • Correlation between actual and void measurements were made. Slide 28
Slide 29: Transmission AXI Graphed Results
Transmission AXI Graphed Results Slide 29
Slide 30: Technology Summary
Technology Summary AXI • AXI Vs other inspection techniques – Hidden joints Vs Visible Joints AOI – 2D Vs Shape and Volume. Hidden Joint Trend (package volume) For All High Pin Count Packages With IO >50 30000 80.00% 70.00% ICT 25000 60.00% 30 mm 20000 50.00% millions of units 15000 40.00% Visible Q
Slide 31: Technology Summary
Technology Summary • Transmission – Sharpe images • Reduces False Pass/Failure. – Can measure relative shape and volume – Large FOV • High Throughput – Can not easily resolve obscured solder joint • Solder joints on both sides of the board Slide 31
Slide 32: Technology Summary
Technology Summary • Laminography – Resolve most obscured solder joints – Averaging produces “smeared” images • Increases False Pass/Fail – Mechanical tolerances “smearing” effect • Increases False Pass/Fail – Smaller FOV or larger pixel detector can help reduce “smearing” • But Reduces throughput –
Slide 33: Technology Summary
Technology Summary • Digital Tomosynthesis – Resolve most obscured solder joints – Most of the advantages of Transmission AXI – Maximum image values produces sharper images • Minimise false pass/fail – Can have long image acquisition times • Reduce Throughput – Image processing has to take advantage
Slide 34: Understanding AXI Acquisition Techniques and Image Quality
“Understanding AXI Acquisition Techniques and Image Quality” Teradyne Assembly Test Division Website: www.teradyne.com/cbti Michael J Smith Michael.J.Smith@Teradyne.com