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Precision Part Inspection System

0.2-micron fixture repeatability provides ability to take 500 measurements across 9 process steps.

automated precision inspection system

DWFritz developed a unique, 6-point kinematic fixture with a very low friction design and an automated loading procedure for a challenging part (encased in a plastic frame) to achieve 0.2-micron fixturing repeatability. As a result, parts were measured, processed, and re-measured with excellent Gage R&R.

This system provides an automated platform for high-resolution part inspection. Components are manually loaded into custom-built nests installed on Primatics .02 micron X-Y table stacks. Viewing custom screens and navigating via standard computer keyboard, the operator selects a recipe and then activates the cycle-start command. As the nests are moved into the inspection area, part I.D. is automatically verified by an onboard barcode reader. Vision inspections are performed by either of two Cognex digital cameras, with height inspections completed by a Class II Laser device. Machine guarding is via a light curtain designed to immediately halt or prevent machine movement whenever the light beam is interrupted.

 

Technical Specifications
Specifications:
  • Machine Vision: Two Cognex digital cameras, 1024 X 1280.
  • Control System: Custom design, Windows-based.
  • Operator Interface: Custom screens created with Visual Basic.
  • Throughput: Typically 90–120 per hour.
  • Repeatability: better than 0.2 microns when evaluated using Cognex Vision Pro 4.0.
Key Attributes:
  • Automatically locates and zeros on existing fiducials (or any other feature) on test part.
  • Normal pass/fail optical comparator inspections can be performed with actual data as the result.
  • Recipe-based inspection of parts with user interface for developing recipes for new parts.
  • Self-contained automated system with custom software running on standard Windows platform.
SERVO CONTROL:

Galil 1820.
OPERATOR INTERFACE:

Custom Graphical User Interface written in Visual Basic 6.0
ENVIRONMENT:

Designed for cleanroom operation.
MACHINE VISION:

Cognex Vision Pro 4.0
DISCRETE I/O:

16 inputs and 16 outputs
XY STAGE:

Primatics 0.02 µm X-Y table
ACCURACY:

± 3µm X-axis, ± 2µm Y-axis
THROUGHPUT:

90–120 parts per hour
INSPECTION:

Over 100 different measurements performed at 6 distinct steps in the assembly process.
REPEATABILITY:

Better than 0.2 µm High Mag, 1 µm low mag
RELIABILITY:

Monthly calibration to NIST standard
SAFETY:

Keyence Light Curtain

 

automation equipment for precision inspection

 

© 2012 DWFritz Automation Inc., All rights reserved.