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Optically Clear
Silicone Rubber Encapsulant
- Optically clear
- Compliant
- Room or low temperature cure
- Non-yellowing
- Low shrinkage
Description
Opti-tec 7020 is a 2 part, clear liquid silicone which will cure at room
temperature or can be accelerated at elevated temperatures. Its combination
of transparency, non-yellowing and compliance makes it suitable for encapsulation
of sensitive electronic or opto-electronic parts (e.g. LEDs), protecting
the components from vibration, moisture and atmospheric contaminants.
Applications
- Optical assembly
- Opto-electronics, photonics, LEDs
- Optical encapsulation & glob topping, casting, potting
- Solar panels
- Electronics potting
Opti-tec 7020 provides clear, non-yellowing encapsulation for electronics and opto-electronics
Features
- Opti-tec 7020 has a convenient 10:1 mixing ratio for use in automatic dispensing equipment or hand mixing
- Opti-tec 7020 has a low viscosity which allows for ease of flow around complex parts, providing electrical insulation and shock resistance
- Opti-tec 7020 contains no solvents
- Opti-tec 7020 has a non-yellowing catalyst system
- Opti-tec 7020 has a chemical composition which provides hydrolytic stability and reversion resistance. It is an addition cure silicone
| Typical Properties | |
| Uncured properties | |
| Colour | Part A - clear Part B - clear Mixed - clear, colourless |
| Viscosity (cps) | Part A - 4000 Part B - 500 Mixed - easily pourable |
| Specific gravity | Part A - 1.02 Part B - 1.00 |
| Mix ratio | 10:1 Part A to Part B |
| Pot life | 4 hours |
| Cured properties (1 hour @ 100°C) | |
| Hardness, Shore A | 40 |
| Temperature range | -60 to 200°C |
| Tensile strength | 750 psi |
| Elongation at break | 100% |
| Linear shrinkage | ~0.1% |
| CTE (ppm/°C) | 275 |
| Refractive index | 1.406 |
| Dielectric strength (kV/mm) | 20 |
| Dielectric constant @ 1000Hz | 2.69 |
| Dissipation factor @ 1000Hz | 0.0006 |
| Volume resistivity (ohm-cm ) | 1.7 x 1015 |
| Thermal conductivity (W/m K) | 0.18 |
| Specific heat (kJ/kg) | 1.255 |
Packaging
Opti-tec 7020 is supplied in matched kits in a 10 to 1 ratio of Part A to Part B - standard size is 1.1kg total. Unopened containers have a shelf life of 12 months at ambient temperatures. Alternatively, Opti-tec 7020 is supplied in pre-weighed 250 gram twinpacks.
Instructions
Weigh 10 parts of Part A to 1 part of Part B. The mixing container should
be 4 to 5 times larger than the volume of silicone. Use stainless steel,
HDPE, polypropylene, etc. Using clean tools, thoroughly mix the A and B components.
The twinpack is a clear film sachet, with Part A and Part B separated by a removable clip and rail divider. To mix the adhesive, remove the divider and massage the two parts together within the twinpack. The two parts are mixed until they appear uniform, which usually takes about 2 to 3 minutes. Cut off one corner of the twinpack, and dispense to required area, or to syringe for more precise application.
Care should be taken to avoid excessive aeration. For many applications, natural degassing will be sufficient. If degassing is required, intermittently evacuate at 20-40 mbar for 15-30 minutes. Leave for a few minutes after releasing the vacuum to allow surface bubbles to collapse.
Cure begins as soon as the components are mixed in the recommended ratio. Complete cure is normally achieved in 16 to 24 hours at ambient temperatures of 20-30°C. Cure can be accelerated by heating to 50-120°C.
| Part number | Description |
| OPT7020-1100G | 1.1kg kit |
| OPT7020-250G | 250g twinpack |
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January 2007
Version 1.2
17 Station Field Industrial Estate, Banbury Road
KIDLINGTON, Oxfordshire, OX5 1JD, ENGLAND
Tel: +44 1865 842842 Fax: +44 1865 842172 info@intertronics.co.uk