LED lighting
Flame Barriers for LED Luminaire Lighting Systems
LEDs are popular with lighting design engineers because they provide:
• Enhanced reliability and durability
• Reduced power consumption
• Compact form factor
• Improved contrast and color accuracy
• Illumination at greater distances
• Full brightness within nanoseconds
As anticipated cost improvements and higher performance become
a reality, LED lighting is expected to gain an ever increasing share of
the global lighting market. Lighting manufacturers are moving into
LED luminaires, LED-based light fixtures with an integrated source,
to achieve the highest efficiency at the lowest cost.
LED lighting luminaires depend on high-performance LEDs
and good thermal management.
LED luminaires depend on high-performance LEDs, good thermal
management, and low optical loss. In addition to the use of heat sinks
and thermal interface materials (TIMs) for thermal management at
the component level, new materials are providing solutions at the
luminaire/light fixture housing level. A typical design might include a
polymeric housing, heat sink, thermal interface material (TIM),
LED PCB light engine, flame barrier material, and optics.
Using new materials and new approaches, design engineers can
create integrated luminaire designs on a modular basis, with a common
footprint that can be easily incorporated into similar light fixtures.
This type of modular design enhances the design-for-manufacturability
of the product.
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Innovative Flame Barrier Materials
Polymeric enclosures with flame barrier materials are becoming
popular in LED luminaire design. There’s a wide variety of flame
barrier materials with different dielectric strengths, flammability
ratings, arc and track resistance, thermal ratings, dimensional
stability, and convertibility. Newer flame barrier materials have
been developed
specifically for LED lighting applications, for
Cleavage Load
example, a Flame Barrier FRB Series from 3M™.
This new type of electrical flame barrier allows Isolated
Non-Class 2 and Direct Connected designs to meet UL 8750
enclosure requirements. A Class 1 luminaire requires UL 94
5VA rated housing materials to safely contain the high voltages
associated with Class 1.
The UL94 test method classifies materials based on results from
specified small-scale flame tests. Classifications run from
5VA, 5VB, V-0, V-1, V-2, to HB in decreasing order of flame
resistance. A material classified as 5VA or 5VB is subjected
to a flame ignition source that is approximately five times
more severe than that used in the other tests. Specimens tested
in 5VA or 5VB may not drip any flaming particles and 5VA
rated materials may not develop any burn-through holes
during testing.
One approach involves creating a 5VA enclosure for a Class 1
luminaire with 3M’s flexible flame barrier insulation material and
LED with 5VA primary lenses. The flame barrier material would
be a thin, flexible insulation composed primarily of inorganic
materials. The material provides:
• High resistance to flammability and ignitability
• Excellent arc and track resistance
• Good dielectric strength
• Ease of convertibility
Housing and Heat Sink
Thermal Pad
LED PC Board Light Engine
3M™ Flexible Insulation
with or without adhesive
Optics
A flame barrier material provides thin, flexible insulation that eliminates the need
for flame retardants in the fixture’s optics.
Using this material would eliminate the need for flame retardants
in the optics that reduce lighting efficiency. Using an optical
sheet with an array of LED lenses also simplifies the sealing
and assembly of the luminaire.
In this approach, the flame barrier material is placed between
the circuit board light engine and secondary optical lens.
The voltage in this area may be greater than 60V. The material
can be die-cut to meet the shape of the fixture housing and
accommodate the LEDs. By using this design, LED luminaire
efficiency is significantly increased, as both a separate glass
plate and flame retardant fillers in the plastic optical lens plate
can be eliminated. Without a separate glass plate, weight and
cost are reduced.
Working with an Experienced
Converter/Materials Supplier
Lighting manufacturers are looking to materials converters for:
• Precision die-cutting, multi-layer laminating, and slitting to
tight tolerances;
• Access to a range of thermal management solutions;
• Testing capabilities.
Working with an experienced converter and materials supplier
like Fabrico is critical to successful thermal management for
LED applications.
From identification and selection of the appropriate materials
and adhesives, to slitting, layering, laminating, precision
die-cutting, and packaging of the finished product, Fabrico
provides the design, prototyping, testing, and manufacturing
knowledge to complete advanced LED luminaire designs.
When working with customers who are designing with thermal
management in mind, finding the right thermal management
approach and material is often a process of elimination.
The more knowledge of how much heat the component
generates, its place within the overall product, and other
thermal management details, the shorter the process of
selecting and matching appropriate substrates, TIMs,
and flame barrier materials.
Fabrico selects from servo driven rotary die-cutting, CNC
die-cutting, laser cutting, and water jet cutting to meet the
complex specifications of thermal management for LED lighting
systems. For example, a servo driven rotary die-cutter can
maintain tight tolerances ranging from 0.015” to +/-0.005”
at speeds up to 500 fpm, and is ideal for the complex,
multi-layer die-cutting and lamination that a thermal interface
pad or tape may require.
For complex foam tape converting, water jet technology
provides clean edges with no distortion. Laser cutting,
kiss-cutting, slitting, and laminating can also be used in
converting applications.
3M Flame Barrier FRB Series allows engineers to design more powerful and
brighter direct connected LED arrays.
Fabrico’s fully equipped test laboratory ensures that customer
materials meet designed-in specifications before they move to
the factory floor, often eliminating the need to test materials at
the customer’s facility. A complete test lab offers:
• Accurate and precise part dimension measurement
and verification;
• Adhesive/release liner testing to determine converting
properties and high speed application characteristics;
• Material strength measured to ensure that material meets
application requirements;
• Static shear testing to measure the cohesive strength of
the adhesive to withstand a fixed load over time;
• Material weight measurement to determine adhesive
coating weight;
• Microscopic imaging to determine differences between
adhesive and material over time;
• Dielectric testing to determine a material’s electrical
insulation properties;
• Thermal testing for materials and adhesives;
• Resistance and voltage testing to provide a complete profile
of the electrical properties of a material or adhesive.
From identification and selection of materials and adhesives, to precision die-cutting, slitting,
laminating, and packaging, Fabrico offers solution based on advanced assembly technology.
About Fabrico
Fabrico’s material converting capabilities include: custom design
solutions for applications that require slitting, laminating,
and die-cutting. Laser cutting, kiss-cutting, and water
jet cutting are available depending on the application
and materials being used.
With more than 30 years of materials experience, Fabrico
engineers also understand the impact of material selection
on the overall manufacturing process, and design material
systems that optimize production efficiency and improve
overall cost-effectiveness.
Fabrico Headquarters
4175 Royal Drive, Suite 800, Kennesaw, GA 30144
Phone: 678-202-2700 | Fax: 678-202-2702
Toll Free: 800-351-8273 | E-mail: info@fabrico.com
Material Partners
Fabrico has strategic relationships with world-class materials
suppliers, such as 3M, Loctite, Adhesives Research, DuPont,
ITW Formex, and others, to assist its customers in selecting
the best material for the intended use and to expedite materials
sourcing. Whether adhesive films or liquid, all critical material
properties are considered in any Fabrico project, including
chemical, thermal, and moisture resistance.
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Fabrico is a trademark of EIS, Inc.; 3M is a trademark of the 3M Company.
Loctite is a Registered Trademark of Henkel AG & Co. KGaA.