AL-3249 Encapsulation Gel For plastic optics and display elements

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1 AL-3249 Encapsulation Gel For plastic optics and display elements AL-2233 is a high purity transparent polymer coating product ÅngströmLink designed specifically KEY FEATURES for coating of optical and photonic components. It may be applied by spin coating, or dip Low coating, temperature or may be curing used to gel form a thin sheet of coating Long material pot life, by ultra-clear casting on a flat substrate or in a mold. The low 1.49 refractive index for index matching of AL-2233 silicamakes it ideal for enhancement of total internal reflection at grazing incidence optical interfaces where unintentionally applied layers of organic hydrocarbons might otherwise cause ray leakage ÅngströmLink AL-3249 is a 1:1 mix ratio encapsulation material from designed the lightpath. especially Suitable for protection applications of sensitive for AL-2233 photonics are as assemblies a lightguide from cladding, mechanical an shock, anti-reflection thermal (AR) shock, coating dust, and on lenses, ambient a atmosphere. planar polymer The product waveguide is a two-part cladding room and temperature overcoat, curing a gel mold which release remains for precision fluid for at plastic least five optics, hours and of pot an optically and then clear cures low to surface a non-flowable energy barrier soft gel film consistency for preventing within life, migration twenty-four of hours adhesives at room on temperature. optical substrates. Moderately The product elevated is temperatures available in (50ºC) several accelerate standard the concentrations, time required to allowing reach a full a choice cure. The of mild a range heat of cure coating of AL-3249 thicknesses enables per room coat. temperature AL-2233 offers mixing a and service application, temperature and quick range setting up to of +110 C the gel without (up to the +300 C high temperatures for transient that soldering can be damaging operations). to plastic optics. The product is supplied in a ready-to-use cartridge which mixes the material automatically as it is dispensed without need for vacuum degassing. AL-3249 offers a service temperature range of -40 C to +200 C (+260 C for 1 to 2 minutes for soldering operations). Applications Encapsulation for flat panel displays Matrix medium for suspension of plastic microspheres, switch elements, etc. Index matching between optical glasses, crystals, and plastics Pigtailing or joining of plastic optical fiber (POF) or fiber arrays Backlight encapsulation and light pipes Benefits Long pot life Allows time for encapsulation of multiple or large assemblies Low viscosity before cure Allows faster dispensing speeds for filling flat panel volumes Low temperature cure Eliminates damage to adjoining plastic optics during heat bake Low modulus gel Offers large strain relief without delamination in touch screens & flexible displays Ultra-clear Allows efficient optical coupling down to the near UV High refractive index of 1.52 Improves brightness & contrast with acrylic display covers High purity composition Low ionics for sensitive semiconductors, metals Wide temperature service Suitable for outdoor use; Permits solderability

2 Property (at 25 c unless noted) test Method typical Value cure Processing characteristics Uncured mixed viscosity ASTM D cp Pot Life (2X viscosity) ASTM D hours min Gelled & Non-flowable at 25 C visual 24 hours Full Cure Time at 25 C visual 72 hours Full Cure Time at 75 C visual 1 hour Full Cure Time at 100 C visual 15 min cured Mechanical Properties Cure shrinkage, by volume ASTM D % Physical Consistency visual Soft, self-healing gel Durometer, Type 000 ASTM D Specific Gravity ASTM D cured thermal Properties Glass Transition TMA < -50 C, est. Thermal Expansion by Volume TMA 8 x 10-4 cc/cc/ C, est. Thermal Conductivity ASTM C watt/meter-ºk, est. Evaporation Rate (24hrs, 100 C) ASTM D-972 < 0.1%, est. TGA Take-off (1% wt.loss, 10ºC/min. in air) TGA > 250ºC, est. cured Electro-Optical Properties Appearance visual Clear Ionics (K, Na, P, Ag, Cu, Sn) ICP < 10 ppm, each, est. Volume Resistivity ASTM D-257 > ohm-cm, est. Dielectric Strength ASTM D-149 > 10 kv/mm, est. Refractive Index, 589 nm ASTM D Refractive Index vs. Temperature, 589 nm ASTM D x 10-4 / C Refractive Index vs. Wavelength prism coupler see chart Optical Absorption spectrophotometer see chart control of cure rate and Pot Life The cure rate for AL-3249 may be increased by heating, and decreased by cooling. The pot life, defined as the time from initial mixing to the time at which the viscosity has doubled from its initial value, varies with temperature as does the gel time (non-flowable) and time for full cure (final durometer) temperature c ( F) Pot Life Gel time Full cure 25 (77) 5 hours 48 hours min 72 hours 50 (122) ½ hour 1½ hours 5 hours 100 (212) < 5 minutes 7 minutes 1 hour Deaeration If air bubbles become trapped in the dispensed fluid volume during the dispensing process, the assembly should self-deaerate due to the product s long room temperature pot life and low viscosity as long as no pockets of air are trapped beneath mechanical parts. If accelerated deaeration is required, the assembly may be vacuum deaerated using a pressure of 635 mmhg (25 inhg) or greater. Apply the vacuum while observing the uncured fluid for presence of bubble formation and increase vacuum slowly enough to avoid rapid foaming. Hold vacuum until bubbles at the fluid surface collapse and are no longer visible.

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4 Substrate Preparation Substrates should be free of dust, oil, and fingerprint soils. Clean substrates using suitable industrial techniques for cleaning electro-optics. If hydrocarbon solvent cleaning (e.g. acetone, toluene) is used, a final rinse with reagent grade isopropanol is recommended. If aqueous detergent cleaning is used, multiple final rinses with de-ionized water or a single rinse with reagent grade isopropanol is recommended. Adhesion to fluoroplastic substrates is generally poor but may be improved with chemical etching or plasma etching of the substrate. Mix ratio and Mixing In order to achieve the final cure properties indicated on the product bulletin, it is recommended that the proportions be held to the prescribed 50:50 ratio by weight within +/- 2%. When mixing small quantities, more precise metering of the proportions is usually achieved by measuring out the components by weight, rather than by volume. Mixing may be accomplished by hand, use of a static mixer tip, or automated centrifugal mixer. For hand mixing, combine the materials in a properly cleaned beaker and stir steadily with a stainless steel utensil for at least two minutes. Regardless of the mixing technique used, thorough mixing of the gel components is critical for obtaining repeatable optical and mechanical properties. cure Inhibition AL-3249 will cure in contact with most properly cleaned substrate materials including optical glasses, optical plastics, and photonic semiconductors. Adhesion to fluoroplastic substrates is generally poor but may be improved with chemical etching or plasma etching of the substrate. Substrates to avoid include certain butyl, nitrile, chlorinated, and EPDM elastomers, certain plastics with leachable plasticizers, and the cure residues of certain adhesives including UV-cured epoxies and amine-cured epoxies. cleanup AL-3249 may be removed from surfaces by first wiping off excess gel with a suitable dry lint-free wipe and then by wiping down the surface with a lint-free wipe soaked with acetone. If the surface material is incompatible with acetone - acetone can soften or crack some plastics use isopropanol. If acetone residues are undesirable, the clean-up process should be completed with a final rinse with reagent grade isopropanol. The user is responsible for compliance with all applicable regulations governing disposal of waste materials as indicated in the MSDS. Shelf Life AL-3249 has a limited shelf life (6 months from date of manufacture when stored in its unopened original container under the storage temperature range noted on the product label). Use of a product after the expiration date shown on the package, or use of a product which has been improperly stored, may result in improperly cured material. Packaging Package Size Use compatible Dispenser 50cc Double Barrel Cartridge Prototyping, small production batches Fiber Optic Center p/n DMA gram kit Prototyping, small production batches Not applicable - Measured weight by user 2 pint kit Large volume users Not applicable - Measured weight by user Other container options are also available for use with automated dispensing equipment. Contact Fiber Optic Center.

5 Specifications The typical properties quoted on this product data sheet should not be used as a basis for preparation of product specifications. Consult Fiber Optic Center for assistance. Warranty AL-3249 has a limited shelf life (6 months from date of manufacture when stored in its unopened original container under the storage temperature range noted on the product label). Use of a product after the expiration date shown on the package, or use of a product which has been improperly stored, may result in improperly cured material. Safety Consult the Material Safety Data Sheet (MSDS) for AL-3249 before use. AL-3249 is an industrial product, designed for use only by qualified laboratory or production personnel. For Special Quotes and technical consultations Randall Elgin / Optical Polymers Fiber Optic center Tel: Mobile: randalle@focenter.com