OLS-1000HF | Liquid Encapsulant - Two part Epoxy

Harmonization Code : 3907.30.00.90 |   Polyacetals, other polyethers and epoxide resins, in primary forms; polycarbonates, alkyd resins, polyallyl esters and other polyesters, in primary forms : Epoxide resins : Other
Main features
  • Liquid epoxy encapsulant
  • LED applications
  • Low Halogen

Product Description

OPTOLINQ OLS-1000HF is a two-part (Part A & Part B), optically clear epoxy casting compound designed for the encapsulation of LED lamps and displays. It features excellent UV resistance, high optical transmittance, good adhesion to a range of substrates, and good thermal shock resistance. It is geared specifically for applications that will not be exposed to temperatures above 125 °C, and where the cost of the encapsulation material is a large percentage of the final part cost. The OLS-1000HF is the Low Halogen version of OLS-1000.

OPTOLINQ OLS-1000HF has been used extensively for low-power LED encapsulation, automatic LED casting, and potting of large optoelectronic modules. Each of these applications relies on the high clarity and other optical properties of the OLS-1000HF as well as its excellent mechanical properties. The OLS-1000 can be colored and diffused by the addition of specific dye concentrates and diffusant concentrates. This product is not made for SMD encapsulation but mainly for DIP packages.


Product Family
5 kg
Part A Part B

Catalog Product

Unlike other products we offer, the products listed on this page cannot currently be ordered directly from the website.

Technical Specifications

General Properties
Pot Life
Pot Life
Pot life is the amount of time it takes for the viscosity of a material to double (or quadruple for lower viscosity materials) in room temperature after a material is mixed.

It is closely related to work life but it is not application dependent, less precise and more of a general indication of how fast a system is going to cure.
4 hours
Refractive index
Refractive index
The refractive index determines how much the path of light is bent, or refracted, when entering a material. It is calculated by taking into account the velocity of light in vacuum compared to the velocity of light in the material.

The refractive index calculation can be affected by the wavelength of light and the temperature of the material. Even though it is usually reported on standard wavelengths it is advised to check the TDS for the precise test parameters.
Chemical Properties
Water Absorption 0.3 %
Electrical Properties
Dielectric Strength
Dielectric Strength
Dielectric strength is measured in kV per mm and is calculated by the Breakdown voltage divided by the thickness of the tested material.

Those two properties go hand in hand and while Breakdown voltage is always thickness dependent, dielectric strength is a general material property.

As an example, the dielectric strength of Polyimide is 236 kV/mm. If we place 1mm of Polyimide between two electrodes, it will act as an insulator until the voltage between the electrodes reaches 236 kV. At this point it will start acting as a good conductor, causing sparks, potential punctures and current flow.
20 kV/mm
Visible Light Transmission 98 %
Volume Resistivity
Volume Resistivity
Volume resistivity, also called volume resistance, bulk resistance or bulk resistivity is a thickness dependent measurement of the resistivity of a material perpendicular to the plane of the surface.
6.4x1015 Ohms⋅cm
Mechanical Properties
Hardness is a dimensionless quantity. There is no direct relationship between measurements in one scale and their equivalent in another scale or another hardness test.
Durometer (Shore D) 85±5
Flexural Modulus
Flexural Modulus @ 25°C 3407 N/mm2
Flexural Strength
Flexural Strength @ 25°C
Flexural Strength @ 25°C
Flexural strength, also known as modulus of rupture, or bend strength, or transverse rupture strength is a material property, defined as the stress in a material just before it yields in a flexure test. This is the flexural strength tested at Room Temperature, 25°C
145 N/mm2
Tensile Modulus
Tensile Modulus
Tensile modulus is a mechanical property that measures the stiffness of an elastic material. It is the slope of stress / strain curve of a material under direct tensile loading.

It can be used to predict the elongation or elastic deformation of an object as long as the stress is less than the tensile strength of the material. Elastic deformation is caused by stretching the bonds between atoms and the deformation can be reversed when the load is removed.

Tensile modulus is affected by temperature and is an important engineering attribute since we generally want to keep elastic deformation as small as possible.
Tensile Modulus @25°C 1519.5 N/mm2
Tensile Strength
Tensile Strength
The tensile strength of a material is the maximum amount of tensile stress that it can withstand while being stretched or pulled before failure.

Some materials break very sharply, without plastic deformation, in what is called a brittle failure. Others, which are more ductile, including most metals, experience some plastic deformation and possibly necking before fracture.
Tensile Strength
Tensile Strength
Tensile strength determines the resistance of a material to break under tension and it measures how much elongating load (or tensile stress) it can handle before fracture.

To make it simple, it measures how much force we have to apply when pulling apart a material before it breaks.
59.2 MPa
Thermal Properties
Coefficient of Thermal Expansion (CTE)
Coefficient of Thermal Expansion (CTE)
CTE (Coefficient of thermal expansion) is a material property that is indicative of the extent to which a material expands with a change in temperature. This can be a change in length, area or volume, depending on the material.

Knowing the CTE of the layers is helpful in analyzing stresses that might occur when a
system consists of an adhesive plus some other solid component.
Coefficient of Thermal Expansion (CTE), α1
Coefficient of Thermal Expansion (CTE), α1
CTE α1 (alpha 1) is the slope of the Coefficient of thermal expansion in a temperature range below the Glass transition temperature (Tg).

It explains how much a material will expand until it reaches Tg.
65 ppm/°C
Coefficient of Thermal Expansion (CTE), α2
Coefficient of Thermal Expansion (CTE), α2
CTE α2 (alpha 2) is the slope of the Coefficient of thermal expansion in a temperature range above the Glass transition temperature (Tg).

It explains the extent to which a material will expand after it passes Tg.
179 ppm/°C
Gel Time
Gel Time
Gel time is the time it takes for a material to reach such a high viscosity (gel like) that it is no longer workable.

It is usually measured for different temperature conditions and even though it does not refer to full cure it is advisable to never move or manipulate the material after it reached its gel time since it can lose its desired end properties.
Gel time @ 150°C 120-220 Sec
Glass Transition Temperature (Tg)
Glass Transition Temperature (Tg)
The glass transition temperature for organic adhesives is a temperature region where the polymers change from glassy and brittle to soft and rubbery. Increasing the temperature further continues the softening process as the viscosity drops too. Temperatures between the glass transition temperature and below the decomposition point of the adhesive are the best region for bonding.

The glass-transition temperature Tg of a material characterizes the range of temperatures over which this glass transition occurs.
159 °C

Additional Information

Processing Instructions

Pre-heat agent A at 45–60 °C for a maximum of 4 h, depending on the temperature and season.

Mix components A and B in a certain proportion and stir uniformly.

Defoam the mixture.

Curing conditions :

  • Size Φ3:            First cure at 130–135 °C/1 h, followed by post cure at 130–135 °C/6–8 h.
  • Size Φ5:            First cure at 125–130 °C/1 h, followed by post cure at 130–135 °C/6–8 h.
  • Sizes Φ8, Φ10: First cure at 105–120 °C/1 h, followed by post cure at 130–135 °C/6–8 h.


 Degree of Cure after First Curing
TMA Chart
DSC Curve (Partially Cured and Liquid OLS-1000HF)


OLS-1000HF Transmittance Curve
DSC Curve of Fully Cured OLS-1000HF

Using Additives

Optolinq OLS-1000HF can be mixed with diffusing agents or color pastes to achieve customer-specific purposes.

Recommended quantity (in weight %) of various diffusing agents and color pastes to be used with OLS-1000HF:

  • OCP01-R Red Color Paste: 2-5% by weight
  • OCP01-B Blue Color Paste: 1-3% by weight
  • OCP01-G Green Color Paste: 2-4% by weight
  • ODF-10 Diffusing Agent: 2-5% by weight

Values with our latest pastes and agents TBD.

Storage and Handling

OPTOLINQ OLS-1000HF is supplied in cans and jars and should be kept in a cool (10°C – 25°C) dry place (40% – 75% humidity) away from direct sunlight or temperature extremes. Part B is particularly sensitive to moisture, so be sure to remove moisture after using and to keep the lid of the container tightly sealed after use.

Under these conditions, the shelf life of Part A is 6 months and the shelf life of Part B is 3 months. The data contained herein may be reported as typical value and/or range values based on actual test data and are verified on a periodic basis.


OLS-1000HF Beta Site Performance in E*

Material Properties



delta CTE

Curing temperature

Refractive Index

Halogen Content




Water absorption






Optically clear

Fl, Br, I = < 50 ppm

Cl ~696 ppm

Electrically non-conducting

> 88

 to follow

< 0.35


Initial Assessment



Shore D

PASSED – Shore D measurements were consistent w/ expected values in TDS

Transmission Test

PASSED – High transmittance at ~905 nm and comparable w/ current material

Degree of cure

PASSED - >90% degree of cure obtained from DSC (also consistent w/ Shore D readings)


PASSED – Tg values obtained from DSC were close (+/- 20C) from the declared Tg in TDS

Ease of Dispensing

PASSED – Can be dispensed using current tapered plastic dispense needle and current dispensing machine

Curing Profile

PASSED – Compatible w/ current conventional convection oven in the production line

Material Preparation

PASSED – No problems encountered in 1:1 mixing and Thinky Mixer procedure to mix

Sample build using dummy units

  • No other visual defects observed post-cure.
  • No cracks, no delamination (time zero), no voids and bubbles, no leak, no cloudy encapsulation.

Good units build for WHTOL

  • No issues encountered during production build for WHTOL.