Conformal Coating Uv Curing Technical Bulletin June 09

     

 

Technical Bulletin June 09 UV Conformal Coatings and UV Curing  

UV cure conformal coatings are solvent-free 100% solids materials, which, when exposed to the correct wavelengths and intensities of Ultra violet (UV) light, cure quickly creating a tough, durable conformal coating. All of the liquid conformal coating is converted into solid coating, unlike traditional solvent and water based acrylic and polyurethane conformal coatings, which rely on evaporation of the solvent or water, before any cross-linking mechanism can occur. UV Curing of UV Conformal Coating

Humiseal UV40 Conformal Coating

UV curing of conformal coatings is becoming increasingly important for high volume users in fields such as automotive and consumer electronics.

HumiSeal’s new UV40 conformal coating is an exciting innovation in UV curable chemistry that provides performance superiority over traditional UV curable conformal coating products.

This increase in the popularity of UV curable conformal coating is due to its rapid cure speed, level of processing ease, environmental friendliness and thermal cycling resistance, which have never before been achieved with UV conformal coating materials. The super fast curing times of UV conformal coatings mean that productivity in the conformal coating process can be massively increased.

Being 100% solventless, the NEW UV40 UV curing conformal coating not only maintains the speed of cure and environment-friendly nature that is popular in today’s electronic fabrication, it also offers advantages not found in existing UV curable conformal coating products.

To take advantage of these benefits with products such as Humiseal UV40 you need a conveyorised UV curing system like the example below.

  HumiSeal UV40 conformal coating provides: • Higher IR (insulation resistance) and MIR (moisture insulation resistance) • Greater adhesion to a wide range of commonly used solder resists • Resistance to a wider range of solvents The UV100 UV conveyor shown is an inline conveyor with SMEMA capability. It can utilise both top and bottom side curing and uses pin or chain edge conveyance. SCH Technologies is a Trading Name of SCH Services Limited  Newburgh Building, McLintock Way, Barnsley, South Yorkshire. S70 6BF    Tel: +44 (0)1226 297711 Fax: +44 (0)1226 297733  www.conformalcoating.co.uk 

• Greater flexibility at a wide range of temperatures • Does not become brittle at low temperatures • A truly reliable secondary (shadow area) moisture activated cure mechanism!

SCH Technologies are ISO9001 and ISO14001 certified

          Lamps: Microwave & Arc Lamp Technology UV Curing

UV Microwave Lamps

The two types of UV lamps available for curing UV   curable conformal coatings are UV Arc Lamps and UV Microwave Lamps.

The UV Microwave lamp bulb will last much longer than UV Arc lamp technology. Depending on the model, lifetime of the bulb can be quoted between 4000-8000 hours and one model guarantees 9000 hours. During this time there is very little power degradation. The UV lamp will not extinguish until the end of its life in this time period and the cost for the bulbs are similar.

UV Curing Arc Lamps The UV Arc Lamps are much lower in capital cost compared to the UV Microwave Lamp systems. The life time of a UV bulb is approx 500-1000 hours, depending how the UV lamp system is used, and, after this time the output power will degrade to be about 60% of the initial value. This drop in power can be critical if the speed of the UV conveyor is approaching the limit of the UV cure ability of the lamp and the UV conformal coating and may need to be monitored. If the UV system is run slow enough this may not be an issue (relative to heat cure a slow speed is still pretty fast!).

Generally, if cost is an issue then UV Arc lamps are recommended, especially if there is low volume use and high speed is not critical. For high volume, high speed applications, UV Microwave Lamps are recommended since it is more economic over time and no maintenance is involved in monitoring the UV output.

SCH Technologies offer Typical Arc Lamp for curing conformal coating

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Conformal coating Subcontract Services

The cost for replacement of UV bulbs is typically low depending upon the lamp fill, and a similar price to the microwave bulbs.

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Global supply of Conformal Coating Application Equipment

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Humiseal Conformal Coatings

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Conformal Coating Training courses Consultation & troubleshooting

It must also be noted that UV Arc Lamps also run a little hotter than the UV Microwave Lamps.

PLEASE CHECK OUR WEBSITE FOR DETAILS

Future Bulletins

www.conformalcoating.co.uk

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Automated Conformal coating inspection. How effective is it?

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Conformal coating CTI (Comparative Tracking Index).

SCH Technologies is a Trading Name of SCH Services Limited  Newburgh Building, McLintock Way, Barnsley, South Yorkshire. S70 6BF    Tel: +44 (0)1226 297711 Fax: +44 (0)1226 297733  www.conformalcoating.co.uk 

SCH Technologies are ISO9001 and ISO14001 certified