Introduction to Conformal Coating I

Class meets on Tuesday and Thursday. 

Conformal coatings are used to protect electronic assemblies from the end-use environment, but training courses on coating application and cure are rare. Introduction to Conformal Coating I is taught by an industry-subject-matter expert with 40+ years of experience in coatings and electronic assembly. This program is designed to provide process engineers/professionals with knowledge of conformal coating materials and practical tips for running and maintaining a robust, high-quality conformal coating (CC) operation.

WEEK 1
SESSION 1: CONFORMAL COATING OVERVIEW
This session covers the basics to provide the learner with a solid foundation.
Topics Include:
• What coatings are (and are not), and what is expected of them
• Types of coating – advantages and disadvantages
• Conformal Coating Standards and how they apply
o MIL-I-46058
o IPC-CC-830
o UL746
o IEC Specifications
o J-STD-001 and IPC-A-610
o Other pertinent specifications
• Common Issues with Drawings and Call-outs
SESSION 2: PREPARING FOR CONFORMAL COATING
Topics Include:
• Discussion of homework from Session 1
• Facilities Parameters which can impact CC
• Common Upstream Contributors to Coating Issues
• Equipment Setups
• Tools
• Masking Materials
• Masking/Demasking Methods
• Cleaning Processes
• Drying prior to coating
• Maintenance

WEEK 2
SESSION 3: APPLYING CONFORMAL COATINGS
Topics Include:
• Discussion of Questions/Issues from Session 2
• Components that are not / should not be coated
• Safety / PPE
• Applying by Brush
• Applying by Manual Spray
• Applying by Automated Spray
• Applying by Dip Coating
• Applying by Chemical Vapor Deposition
• Process Control Methodologies
• Common process issues during application
• Building thicker layers and associated hazards
SESSION 4: DRYING/CURING CONFORMAL COATINGS
Topics Include:
• Discussion of Questions/Issues from Session 3
• Air drying
• Vacuum drying
• Air quality (floaties)
• Common issues and process problems with hand coating
• Common issues and process problems with manual spraying
• Common issues and process problems with automated spraying
• Common issues and process problems with dip coating
• Process Control Methodologies
• Common process issues in manufacturing for drying Assignment:
• Review your coating operations for potential negative impacts, compile a list for discussion. How are you applying coatings now, and how do you know the coating job is adequate?
• What curing processes are you currently using, and how do you know they are adequate?

WEEK 3
SESSION 5: COMMON COATING ISSUES IN PROCESSING
Topics Include:
• Discussion of Questions/Issues from Session 4
• Dewetting
• Cotton Candy and webbing
• Coating Cracking
• Coating sharp points
• Coating on and around adhesives
• Missed steps
• Press-fit connectors
• Incompatible materials
• Adhesives and Coatings
• Shelf Life and Working Life
SESSION 6: INSPECTING CONFORMAL COATINGS
Topics Include:
• Discussion of Questions/Issues from Session 5
• Inspection Equipment
• Inspection practices – good and bad
• Tolerances on Keep Outs
• Cosmetics
• Bubbles and Voids
• Non-uniform coating
• IPC-TR-587 Review
• Delamination
• Fisheyes and orange peel
• Corrosion and Tarnish under the coating
• Transparency
• Defects induced by Climatic Testing
• Conformal Coating Automated Optical Inspection

WEEK 4
SESSION 7: REWORKING CONFORMAL COATINGS
Topics Include:
• Discussion of Questions/Issues from Session 6
• Chemical rework methods
• Thermal Rework Methods
• Mechanical Methods
• Laser Oblation
• Post rework cleaning
• Recoating
• Patch Coating
SESSION 8: DISCUSSION AND NEXT STEPS
Topics Include:
• Discussion of Questions/Issues from Session 7
• Overall discussion on items not covered in the course or where more detail is desired
• IPC Resources
• IPC Committees
• SMTA Resources
• SMTA Activities
• Reading Materials and Beneficial Websites
• Other sources of Knowledge