cleanliness in control: filmic contamination

Inspection technology for quality control after cleaning and activationCleanliness in Control – Filmic Contamination| André Lohse Online Seminar | 1
André Lohse, Head of Applications
SITA Messtechnik GmbH www.sita-process.com | www.sita-lab.com
Cleanliness in Control: Filmic Contamination
Cleanliness in Control – Filmic Contamination| André Lohse Online Seminar | 2
Process Chain – The Source of Filmic Contamination
Starting Point:
Use of oils, grease, coolants, separation agent is essential for machining and casting processes
Processes like bonding, coating, welding, … require clean surfaces
Consequence:
Contaminations like oil, grease, coolants, separating agents, … have to be removed in the cleaning process
The surface has to be clean enough for the specific gluing, welding, … process (requirement/tolerance)
machining coating bonding welding
Cleanliness is Crucial – Impact of Filmic Contamination
Pores in the weld seam
Further examples Soft spot formation in gas nitriding processes Defects in coating (electroplating, PVD, CVD) Bad electrical contact when soldering or bonding
Example Image Source: www.loctite.de
Example Image Source: wwww.besserlackieren.de
Example Image Source: ww.profabricationtechniques.com
Task of Cleanliness Inspection
Aim: Check the cleanliness before painting to ensure good quality and avoid discarding or reworking parts
Clean enough for painting?
Common Techniques for Cleanliness Inspection
For Process Control Visual inspection Wipe test Water break test Dyne test inks Contact angle measurement Fluorescence measurement
For (Failure) Analysis in Laboratory Extraction/gravimetry of non-volatile residues (NVR) Total organic carbon (TOC) IR spectroscopy (FT-IR) Electron microscopy/X-ray spectroscopy (SEM/EDX) X-ray photoelectron spectroscopy (XPS) Gas chromatography with mass spectrometry (GC-MS) Residual gas analysis (RGA) Time of flight – Secondary ion mass spectrometry (ToF-SIMS)
Guideline „Filmic Contamination in Control“ (see appendix)
Measure Contact Angle – Test Wetting Behaviour
Wettability is sensitive to changes in surface condition Wetting inhibiting and promoting substances, Oxidation and adsorption layers, Chemical or physical activation/passivation SITA SurfaSpector Mobile water contact angle measurement to check
wettability Patented method – easy handling on complex geometries Allows quality inspection directly in production
environment Calibration standards for device verification Use for: Cleanliness Inspection Surface Treatment Monitoring
Liquid
Surface
Application: Analysis and Process Control in Electronics Manufacturing
Application:
Starting point:
Solution:
1. Laboratory analysis XPS: residues of fluoropolymer interfere with coating adhesion
2. Removal of fluorine residues by plasma cleaning
3. Contact angle measurement for process control of plasma cleaning
Example Image Source: Plasmatreat
Example Image Source: www.ilh.uni-stuttgart.de
Measure Fluorescence – Inspect Cleanliness
Fluorescence signal increases with film thickness/contamination quantity
The lower the reading in RFU, the cleaner the surface
Standardised with SITA calibration standards
Contact free, non-destructive, in-line capable, thickness sensitive
Use for:
Value in unit RFU (Relative Fluorescence Unit)
Contamination
Example Applications
Sealing of Aluminium Housings Laser Beam Welding of Gears Parts
Application: Bonding of Gas Meter Housings
Application: Starting point: Solution:
Bonding of gas meter housings, optimisation of cleaning process Limit value gas tightness of the bond increased, consequence: 58 % rejects Optimisation of cleaning process, monitoring effect with fluorescence measurement After optimisation: 0.1 % Rejects
Application: Process Design and Optimization
Benchmark wet-chemical cleaning processes Laser cleaning/stripping
CO2 snow blast cleaning Plasma cleaning
uncleaned cleaning machine
Example Image Source: Trumpf Laser Application Center
Application: Coating Thickness Inspection of Anti-Corrosion Oil
Application:
Starting point:
Solution: Inspection using fluorescence measurement
(quantity, even distribution)
Further Information
„Filmic Contamination in Control“ Publisher: German professional association of industrial parts cleaning (FIT – Fachverband industrielle Teilereinigung) Target group: Users of measurement and testing technology, process chain managers and plant operators
Download: 2019_10_JOT_Optimised_inspection_technology_for_quality _control_after_cleaning_and_activation.pdf
https://www.youtube.com/watch?v=LDuXGDaG8QQ https://www.fit-online.org/publikationen/richtlinien
2019_JOT_Special_Defining_limit_values_for_sufficient_part s_cleanliness.pdf
https://www.youtube.com/watch?v=W0HO51ZBUPM
SITA CleanoSpector
SITA SurfaSpector
Solutions for Quality-assuring Process Control
Measure Concentration.
Monitor Contamination.
Task of Cleanliness Inspection
Measure Contact Angle – Test Wetting Behaviour
Application: Analysis and Process Control in Electronics Manufacturing
Measure Fluorescence – Inspect Cleanliness
Application: Process Design and Optimization
Application: Coating Thickness Inspection of Anti-Corrosion Oil
Further Information

cleanliness in control: filmic contamination

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