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14 SMT007 MAGAZINE I AUGUST 2019 spray applications, significantly reducing coat- ing cycle times. What Types of Products Feature Within the 2K Range? Electrolube's 2K conformal coating range fundamentally combines the tough, resis- tant properties of an encapsulation resin with the easy application of a coating. Examples of products within the range include 2K550, 2K850, and 2K750 conformal coatings. 2K550 is a flexible, high-performance coat- ing, which has excellent clarity and resistance to discolouration, humidity, and condensation. The UL94V-0 compliant polyurethane coat- ing is characterised by greater coating thick- ness and enhanced edge coverage, and shows improved adhesion, hardness, and scratch resistance. 2K550 also features a fluorescent trace to aid inspection. The 2K850 UV cure coating combines the speed and convenience of UV cure with the benefits of Electrolube's 2K system. The 2K850 offers a faster processing time while still deliv- ering high levels of protection. The polyure- thane coating is a significant development to help speed up production, providing an imme- diate tack-free coating and enabling complete cure at room temperature within 24 hours compared to the industry moisture cure aver- age of 8–14 days. Fea- turing a wide operating temperature range of -40 to +130°C with good thermal shock perfor- mance, 2K850 provides a consistent chemical cure and strong protection against water, moisture, salt mist, and condensa- tion, making it ideal for tough electronic applica- tions exposed to harsh conditions. Electrolube has also developed a new sili- cone 2K conformal coat- ing, 2K750. The UL94V-0 compliant coating pro- vides a wide operating temperature range of -40 to +220°C with a high continuous use temperature of 200°C. The tough, low-stress coating has an extremely fast thermal cure time of 10 minutes at 80°C, in addition to curing at ambient temperature, and provides excellent adhesion to most solder resists and metals. The transition to implementing Elec- trolube's 2K conformal coatings range couldn't be simpler with a straightforward valve mod- ification, such as PVA's VPX-2KS or Nordson ASYMTEK's AM range. What Testing Procedures Have the 2K Products Been Through, and What Are the Results? All of the 2K materials have been tested to comply with the BMW GS95011-5 automo- tive standard and meet the requirements of the IPC-CC-830. The testing procedures for the BMW GS95011-5 automotive standard includes sequential thermal shock, salt spray, corro- sive gas, temperature, and humidity cycling. In addition to the BMW standard, the mate- rials have been subjected to a minimum of 1,000 thermal shock cycles (-40° to +130°C) on populated, no-clean assemblies to ensure there is no tendency to cracking at the higher film builds (Figure 4). Figure 4: 2K850 thermal shock performance (-40° to +130°C).