Moisture Protection Coatings for Printed Circuit Boards and Electronic Components

1. Significance of Moisture-Proof Coatings for Printed Circuit Boards

(1) Prevention of short circuits caused by ionic migration

Halogen ions present on printed circuit boards, in combination with moisture, cause metal ion migration.
The migrated metal ions recombine with electrons and are metallized again, forming new conductive paths that can result in short circuits.

Reference:
Toshifumi Fujishiro, “Ionic Migration of Printed Circuit Boards and Reliability Analysis”

(2) Prevention of metal corrosion caused by moisture, acidic gases, battery electrolytes, etc.

(3) Prevention of malfunction caused by condensation, water ingress, battery electrolyte leakage, etc.

(Leakage prevention)

1-1. Application Overview

Moisture Protection Coatings for Printed Circuit Boards and Components

Current application examples:

• Automotive electronic control unit (ECU) circuit boards

• Control circuit boards for electric water heaters

• Outdoor unit circuit boards for air conditioners

• Traffic signal control circuit boards

• Mobile phone base station circuit boards

Suitable for outdoor equipment and circuit boards requiring high reliability.

1-2. Features of Fluorinated Moisture Protection Coating

FLuoro Surf FG-3000 Series – Feature Set 1 (Performance Advantages)

• Excellent moisture resistance:
  3–4 times higher moisture barrier performance than polyurethane or acrylic coatings at the same film thickness
  (Ideal for lightweight equipment)

• High electrical insulation:
  High volume resistivity and surface resistivity

• Water and oil repellency / anti-fouling:
  Water contact angle: 115–119°

• Excellent chemical resistance:
  Resistant to acids and lithium battery electrolytes

• Low dielectric constant:
  2.25 (at 1 GHz)
  (Ideal for high-frequency circuit boards)

1-3. Features of Fluorinated Moisture Protection Coating

FLuoro Surf FG-3000 Series – Feature Set 2 (Advantages in Practical Use)

• Safety:
  Uses non-flammable fluorinated solvents; not subject to PRTR regulations or Fire Service Act regulations, and does not require explosion-proof equipment

• Multiple drying options:
  Fast-drying and slow-drying types available to match different coating systems

• Multiple film thickness (concentration) options:
  Concentrations available: 2%, 4%, 8%, 20%, 30%
  Can be selected according to application and required performance

• Customization available:
  Custom formulations available based on customer requirements