This document provides an overview of conformal coatings, including what they are, why they are used, common types, and how to select, apply, and test them. Conformal coatings are thin protective films that conform to electronic circuit assemblies to provide moisture, heat, corrosion and other environmental protections. They are available in acrylic, epoxy, polyurethane, silicone and other types, and can be applied through brushing, dipping, spraying or other methods. Proper surface cleaning and achieving the recommended coating thickness are important to avoid application issues.

1. Conformal Coating Training

2. Conformal Coating What is a conformal coating? What does it do? Why coat? What types are there? How to select? How to apply? How to test?

5. Moisture

6. Heat

7. Corrosion

8. Fungus

9. Dust, Conductive particlesIMPROVED CIRCUIT RELIABILITY

11. Good dielectric properties

12. Good moisture resistance

13. Good flexibility so as not to stress components...

16. IPC-CC-830B

18. Conformal Coating Epoxy Strengths and Weaknesses

19. Conformal Coating Polyurethanes Strengths and Weaknesses

20. Conformal Coating Silicone Strengths and Weaknesses

22. Dipping – Manual / Automated

23. Spraying – Aerosol / Manual / Automated

25. Keep the brush “loaded”

26. Flow the coating - DO NOT PAINT!BRUSH Application

28. Slower Removal Rate - < 10cm/min (4”/min)– The slower the speed, the thinner the coating

29. ALWAYS dip board in vertical position, not horizontalDIP Application

31. Coating is applied to both sides simultaneously

32. Coating thickness controlled by dipping speed & viscosity control

33. Can be done by hand for small assemblies but best done by machineDIP Application

35. Double Dip Solves this ProblemApplication

37. Maximizes coverage

38. Reduces waste

39. Minimizes Evaporation of Coating BathDIP Application

41. Hand Spray

42. HumiSeal Aerosol products

43. Automated Equipment

44. Asymtek / Nordson

45. PVASPRAY Application

47. Need multiple passes each at 90 degrees and multiple coats, 2 to 3 minimum

48. Always spray assembly in horizontal with spray gun at ~45 degree angle to board surfaceSPRAY Application

50. 2-Part Materials may be used

51. Better Tip and Edge Coverage

52. Reduced MaskingSPRAY Application

54. Packaged in 12-oz cans

55. Good for small users and rework

56. Lower solids content than liquid productsSPRAY Application

57. Conformal Coating Selective Spray Equipment SPRAY Application

58. Conformal Coating Automated Atomized Spray SPRAY Application

59. Conformal Coating FLOW Application

62. > 50 years experience

63. Greatest pool of technical knowledge

64. ISO 9001 Registered

65. Mil-I-46058C, IPC-CC-830 and UL746E compliant products

67. Most forgiving of contamination

68. Dry at room temperatures

69. Have desirable electrical and physical properties

70. Fungus resistant

71. Long pot life

72. No exotherm during drying- heat sensitive components

73. Does not shrink

74. EASY TO REPAIR

75. VOC and VOC HAPS-free versions availableHumiSealAcrylic (AR) Products

77. Outstanding dielectric properties for extended periods

78. Excellent chemical resistance

79. Available as single - or two-component

80. Variety of cure types

81. Moderately repairable

82. Chemical strippers

83. Heat

84. VOC and VOC HAPS-free versions availableHumiSealUrethane (UR) Products

86. Good thermal endurance – heat generating devices

87. Humidity and corrosion resistance

88. One component, 100% solids – no VOC issues

89. Thermal or moisture cure

90. Lower abrasion resistance- softer

91. High CTE

92. Mechanically repairable

93. Not solvent-soluble / Do not vaporize with heat

94. New Silicone DigestersHumiSealSilicone (SR) Products

96. High abrasion and chemical resistance

97. Might be considered “indestructible”

98. Good electrical properties

99. Good component anchoring

100. Very Difficult to Repair

101. Hard to physically remove

102. Not removed by solvent

103. Chemical strippers will attack substratesHumiSealEpoxy (ER) 2A53

105. High flexibility

106. Excellent electrical properties

107. High humidity & corrosion resistance

108. Good thermal stability, low outgassing

109. High cohesive strength – tough

110. Low CTE

111. Stabile Modulus at lower temps

112. Must be repaired mechanically

113. Not solvent soluble / requires aggressive stripper

114. Does not vaporize with heatHumiSeal1B51 Series (Synthetic Rubber)

116. Strippers

117. ThinnersHumiSealAncillary Products

120. Adhesion loss

121. Electrical failures

122. Coating voids

123. IPC specifications recommend ionic cleanliness level of < 1.5 g/cm2NaCl equivalenceTroubleshooting Surface Cleanliness

125. Too Thick

126. Incomplete drying / solvent entrapment

127. Bubbles

128. Longer cure times

129. Shrinking or cracking

130. Decreased coating properties

131. Too Thin

132. Inadequate Protection!Troubleshooting Coating Thickness