Flexible Compounds for Clear Optical Device Assembly

A customer manufacturing mini-display systems is seeking an optically clear flexible compound. It is also essential that the product has a very low viscosity as it will be used for potting in a novel product developed by the manufacturer.

Determining the Answers to the Problem

Masterbond was approached by the customer and the following questions were answered.

• Is it required that the material has to quickly cure?
• Is it possible to add heat for curing?
• What are the potting dimensions?
• Is there a refractive index requirement?
• Is there a hardness value for the material?

The Solution

Master Bond has a wide range of optically clear, flexible potting compounds. The experts from Master Bond made a number of recommendations that met the viscosity, clarity and flexibility requirements of the customer.

These recommendations include the following:

• UV15-7SP4 - In case the main concern is a rapid cure, Master Bond UV15- 7SP4 is the right fit that cures in a time frame of 10-30 s when exposed to an ultraviolet light source that emits at a wavelength of 320-365 nm. It is very convenient to handle this single part UV system and can be cured in sections of ¼ inch thickness.
• MasterSil 151 - The MasterSil 151 will be suitable for a deeper cure as it can cure in thicknesses more than 1 inch. As it is a silicone system, high-temperature resistance and exceptional flexibility is offered. It is an addition cured system and there is no need to be exposed to moisture for complete cross-linking.
• Super Gel 9 - Master Bond also has alternatives in cases where a UV or silicon system will not be suitable. Super Gel 9 is a two component, urethane modified epoxy system that readily cures at room temperature to form a resilient, soft, gel-like system with dimensional stability. It has a very low viscosity and exotherm, enabling casting in larger sections. The combination of properties enables its use for the encapsulation of sensitive electronic parts and for sealing delicate optical components.
• EP37-3FLF – This is also an excellent optically clear potting, encapsulating and casting system. It has a very low viscosity and is low in exotherm, which is another consideration for relatively large castings. As with the other compounds, it possesses superior electrical insulation properties. This two component epoxy has a convenient one to one mix ratio by volume or weight and has a longer working life.

Summary of Products

The product summary is provided in the table below.

This information has been sourced, reviewed and adapted from materials provided by Master Bond Inc.

For more information on this source, please visit Master Bond Inc.