3-Dimensional Shop Floor Measurements To Improve Yield Dr. r. E Eri rik N Novak
Good Metrology Saves Significant Money • According to Quality Digest, poor quality control costs an average of $2M/year over the 100 companies they surveyed. • NIST performed 16 economic studies since 2000, showing average benefit of metrology investment is 47:1 10/2/2018 2
Consequences of Poor Quality Control Are Severe Internal Failure Costs External Failure Costs – Waste – Repair and service – Scrap – Warranty claims – Rework – Complaints – Additional failure analysis – Returns – Reinspection – Travel and Return time – Downgrading – Throughput – Shortages – Downtime – Post-warranty costs – Dissatisfaction – Customer perception 10/2/2018 3
The Modern Take on ‘An Ounce of Prevention…’ 10/2/2018 4
Effects on Measurement Capability Are Interrelated Operator 10/2/2018 5
Micro-Scale Defects Are Critical To Understand • Performance – Pitting/porosity, scratches, affect efficiency – Nicks and dents can cause leaks – Burrs can cause damage to other parts • Longevity – Defects can lead to excessive wear – Imperfections can initiate corrosion – Structural integrity is compromised by voids • Perception – The human eye is excellent at seeing small flaws – The human eye is terrible at estimating their size – Customers will reject parts they suspect 10/2/2018 6
Metrology Tradeoffs Must Be Balanced Standoff Distance Field of View Vertical Resolution Max. Feature Height Lateral Resolution Flexible Ease Software Depth Range of Use • Major Goals: • Quantify anything an operator can readily see • Quantify anything a scribe gauge or ‘calibrated fingernail’ can feel • Meet current and next-gen part spec drawings • Instant results • Future Proof – Automation Capability, Customizable, Cloud-enabled… 10/2/2018 7
Traditional Shop-Floor Inspection Methods Are Insufficient Visual / Finger Test Operator dependent Non-gage capable Comparison Test Plate Replication combined with surface profiler High material costs 30+ mins/measurement Operator and material dependent ***When in doubt – reject or rework… Expensive!!! 10/2/2018 8
Test: Which Pit Is Deepest? 2 3 1 6 5 4 10/2/2018 9
Test: Which Pit Is Deepest? 80 um 25 um .0032” 150 um .001” .006” 20 um .0008” 150 um < 5 um .006” 20 um <.0002” .0008” 10/2/2018 10
Most Portable Tools Are 2D and Lack Resolution Laser Scanners and Stereoscopes Limited lateral resolution >2mil (50um) Non-gage capable for micro-defects <10mils Single line doesn’t capture full defect (i.e. deepest point) Sensitive to material finish, reflectivity and slope 2D Stylus Profilers Limited vertical range Give PV value only Can’t measure edges, corners across steps ***Portable and convenient but not capable of measuring micro-defects 10/2/2018 11
Pit Measurement Using 2D Trace Varies .0030” (76 um) 10/2/2018 12
Pit Measurement Using 2D Trace Varies .0025” (63 um) 10/2/2018 13
Pit Measurement Using 2D Trace Varies .0022” (56 um) 10/2/2018 14
Automated 3D Results Eliminate Uncertainty .0028” (71 um) 10/2/2018 15
Large Defects Are Even Harder To Assess .0023” (58 um) 10/2/2018 16
Large Defects Are Even Harder To Assess .0009” (23 um) 10/2/2018 17
Large Defects Are Even Harder To Assess .0017” (43 um) 10/2/2018 18
Large Defects Are Even Harder To Assess .0013” (33 um) 10/2/2018 19
Analysis of Entire Defect Eliminates Uncertainty .0029” (74 um) 10/2/2018 20
3D Lab-Based Metrology Is Impractical 3D Optical Profilers $75-200K Limited to small parts Requires dedicated, trained operator Slow feedback due to measurement turnaround time 3D Stylus Profilers $25-150K Limited to small parts Limited to single trace – can’t measure full feature Measurements take several minutes Slow feedback due to measurement turnaround time ***Lab-based metrology provides adequate resolution but is not practical for shop-floor inspection 10/2/2018 21
What Are Critical Criteria For Success? • Easy To Use • Non-Destructive • Sufficient Resolution • Sufficient Range • Field of View • Correlation – Between Units – With other techniques • Robustness • Extensible 10/2/2018 22
3D Shop Floor Measurements Provide Instant Feature Analysis 10/2/2018 23
Interferometry/Structured Light/Fringe Projection: Scalable Surface Metrology Resolution depends primarily on the wavelength of fringes White Light Interferometry: Micro-Roughness Fringe Projection: Large Irregular Shape Laser Interferometry: Optic Shape Optical Coherence Tomography: Retina Phase Contrast Microscopy (DIC): Spyrogira Cell 10/2/2018 4D Technology Corporation 10/2/2018 24 24 24
Polarization Combined With Structured Light Allows Fast 3D Measurements Array of micro-polarizers Array of color filters matched to detector matched to detector α= 45, φ =90 α= 0, φ =0 Unit Cel α= 135, φ =270 α= 90, φ =180 • Uses 4 pixels to reconstruct phase • Uses 4 pixels to reconstruct color • Color image in one frame • 3D image in one frame • Slight loss in lateral resolution • Slight loss in lateral resolution US Patent 7,230,719 10/2/2018 4D Technology Corporation 10/2/2018 25 25
Polarized Structured Light (PSL) Enables Precision Hand-Held Metrology • Structured light uses the bending of projected lines to compute 3D shape • Generally requires multiple patterns, colors, or angles so is not vibration-immune • High-resolution difficult to achieve, especially on metal surfaces • Polarization enables both single-frame and high- resolution measurements 10/2/2018 26
4D InSpec Designed Specifically for Shop Floor Metrology Specification 4D InSpec 4D InSpec XL Vertical Resolution 2.5 um (0.0001”) 2.5 um (0.0001”) Depth Range 2.5mm (0.1000”) 9mm (0.35”) Standoff distance 35mm (1.3”) 60mm (2.3”) Field of View 8 x 8mm (0.3”x0.3”) 15x15mm (0.6”x0.6”) Lateral Sampling 3.5 um (0.00015”) 7.0 um (0.0003”) Meas+Analysis time <1sec <1sec 10/2/2018 27
PSL Measures Many Materials and Finishes • Carbon Fiber • Ultra-finish • Composites • Matte • Glass • Rough Ultra-finished Blades • Plastics • Cast Iron • Flat • Metals • Curved • Silicon • Corners • Rubber • Paper • Textiles • Semi-transparent/cloudy Surfaces Paint Layer Thickness Spline Gear 10/2/2018 28
PSL Provides High Repeatability • Measured 0.00075” (19um) defect 30 times • Results Shown Below • Standard deviation = .00002” (0.5um) 0.0009 0.0008 0.0007 Pit Depth (inches) 0.0006 0.0005 0.0004 0.0003 0.0002 0.0001 0 0 5 10 15 20 25 30 35 Measurement # 10/2/2018 29
Cross Platform Correlation Is Important • Range of pit depths observed on field hardware (25-75 um, 0.001 to 0.003”) • Results are within ± 2.5um (0.0001”) on average • FRT white light profilometer and 4D InSpec are statistically indistinguishable 10/2/2018 30
3 System Correlation Data Shows Excellent Agreement IS161201 vs. Demo • Feature range from .0008 y = 0.9989x - 6E-05 R² = 0.9973 0.00000 -0.016 -0.014 -0.012 -0.01 -0.008 -0.006 -0.004 -0.002 0 -0.00200 to .014” (20 um to 355 um) -0.00400 • Offset <.00009” (2 um) -0.00600 -0.00800 -0.01000 • Slope <1.2% different -0.01200 -0.01400 • R^2 >.996 -0.01600 IS171104 vs. Demo y = 0.9986x - 6E-05 IS171104 vs. IS161201 y = 1.0125x + 9E-05 R² = 0.9975 R² = 0.9961 0.00000 0 -0.016 -0.014 -0.012 -0.01 -0.008 -0.006 -0.004 -0.002 0 -0.01600 -0.01400 -0.01200 -0.01000 -0.00800 -0.00600 -0.00400 -0.00200 0.00000 -0.00200 -0.002 -0.00400 -0.004 -0.00600 -0.006 -0.00800 -0.008 -0.01000 -0.01 -0.01200 -0.012 -0.01400 -0.014 -0.01600 -0.016 10/2/2018 31
InSpec Vs. 3D Microscope Shows Excellent Correlation on Shot Peened Roughness Ra (micrometer) 25 y = 1.0048x + 0.5809 R² = 0.9978 20 15 10 5 0 0 5 10 15 20 25 10/2/2018 4D Technology Corporation Confidential Info 32
Reliability Can Matter as Much as Capability 10/2/2018 33
Optics Allow Fold Mirror To Access Tight Spaces 34 10/2/2018
Custom Fixturing Makes Specific Part Measurements Simple Corner Flat Blade 45º Edge 10/2/2018 35
Key Shop Floor Measurement Applications • • Part Types Types of Measurements : – Turbine blades – Porosity – Pipes – Corrosion depth, volume, areal coverage – Shafts – Rivet depth and planarity – Gears and transmissions – Radius of curvature – Solder joints and connectors – Pit and scratch depth, area, aspect – Rivets and fasteners ratios, volume – Solar panels – Die peen, laser mark depth, uniformity, and planarity – 3D printed metals and plastics – Cooling hole geometry 10/2/2018 36
Intuitive, Touchscreen Interface Provides Instant Results Analyses Results Live Video History 10/2/2018 37
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