OPTOLINQ GT-W170MG | White Epoxy Mold Compound

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
  • High light reflectance and excellent light shielding
  • Low yellowing at high temperature
  • High MSL performance

Product Description

OPTOLINQ GT-W170MG is a premium white epoxy molding compound designed for the encapsulation of optical and optoelectronic semiconductor devices. It delivers exceptional photoelectric performance through outstanding light reflectance, shielding properties, and high-temperature stability. GT-W170MG is the non-green version of GT-W170.

OPTOLINQ GT-W170MG complies with the stringent safety standards for voltage isolation and flammability. With its low moisture absorption and excellent anti-solderability, GT-W170MG enables devices to achieve high moisture sensitivity levels (MSL). It ensures optimal device performance and reliability in diverse applications, and is compatible with a wide range of packages, such as dual in-line packages (DIP), small outline integrated circuits (SOIC), and plastic leaded chip carriers (PLCC).

Product Family
1 kg
14 mm 16 mm 18 mm
4.3 gr 10.6 gr 11.3 gr

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
Appearance at room temperature.
Specific Gravity
Specific Gravity
Specific gravity (SG) is the ratio of the density of a substance to the density of a reference substance; equivalently, it is the ratio of the mass of a substance to the mass of a reference substance for the same given volume.

For liquids, the reference substance is almost always water (1), while for gases, it is air (1.18) at room temperature. Specific gravity is unitless.
Physical Properties
Spiral Flow @ 175°C 71 cm
Mechanical Properties
Flexural Modulus
Flexural Modulus @ 25°C 16000 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
115 N/mm2
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.
Hot Hardness, Shore D @ 175°C 83
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.
23.5 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.
80 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 @ 160°C / 320°F 27 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.
165 °C
UL 94 Rating
UL 94 Rating
Flammability rating classification.
It determines how fast a material burns or extinguishes once it is ignited.

HB: slow burning on a horizontal specimen; burning rate less than 76 mm/min for thickness less than 3 mm or burning stops before 100 mm
V-2: burning stops within 30 seconds on a vertical specimen; drips of flaming particles are allowed.
V-1: burning stops within 30 seconds on a vertical specimen; drips of particles allowed as long as they are not inflamed.
V-0: burning stops within 10 seconds on a vertical specimen; drips of particles allowed as long as they are not inflamed.
5VB: burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimens may develop a hole.
5VA: burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimens may not develop a hole
Curing Conditions
Curing Schedule
Curing Schedule
Curing schedule is the time and temperature required for a mixed material to fully cure. While this applies to materials that cure with heat, there are also other materials that can be cured with UV.

Even though some materials can cure on ambient temperatures, others will require elevated temperature conditions to properly cure.

There are various curing schedules depending on the material type and application. For heat curing, the most common ones are Snap cure, Low temperature cure, Step cure and Staged cure.

Recommended cure type, schedule, time and temperature can always be found on the Technical data sheets.
Mold Temperature 160-180 °C
Preheat Temperature 85-95 °C
Post Mold Cure
Post Mold Cure @ 150°C / 302°F 4-6 hrs
Transfer Pressure 40-90 kg/cm2
Transfer Time 15-20 s

Additional Information

OPTOLINQ GT-W170MG Properties


Reflectance Curve of Optolinq GT-W170MG

Reflectance Curve of GT-W170MG

Viscosity Curve of Optolinq GT-W170MG at 175 °C

Viscosity Curve of Optolinq GT-W170MG at 175 °C

TMA Curve of Optolinq GT-W170MG

TMA Curve of Optolinq GT-W170MG

DSC Curve of Optolinq GT-W170MG

DSC Curve of Optolinq GT-W170MG


TGA Chart of Optolinq GT-W170MG



Adhesion Strenght of Optolinq GT-W170MG



Dielectric Strength and Breadown Voltage of Optolinq GT-W170MG

Test Method: GB/T 1408.1-2016 

Sample No. Thickness [mm] Breakdown Voltage [kV] Dielectric Strength [kV/mm]
1 1.09 21.71 19.92
2 1.07 20.89 19.52
3 1.10 21.32 19.38
4 1.06 21.50 20.28
5 1.08 21.45 19.86
Average / 21.45 19.86


Before Testing

Before Dielectric Strength Test GT-W170MG
During Testing

During Dielectric Strength Test GT-W170MG
After Testing

After Dielectric Strength Test GT-W170MG


Processing Instructions

  • Be sure to keep the product dry as moisture can lead to curing failures or affect the electrical integrity of compounds.
  • Before use, thaw GT-W170MG for 16–24 hours at 20–25 °C with the package sealed. Keep the packaging unopened to prevent moisture contamination.

Storage and Handling

To ensure the integrity of OPTOLINQ GT-W170MG, keep it away from oxidizing materials. Avoid exposure to heat sources like molding dies and lead-frame preheating panels, as prolonged heat exposure can lead to the degradation of the molding compound. Transport the product at or below 10°C for best results. For extended storage, maintain a cold environment, ideally at 5 °C or lower. Under proper conditions, the shelf life of the product is 9 months from the manufacturing date. The pot life is 72 hours when unpacked at room temperature after removal from the cold room, including thawing time.


Please note that the provided information is based on available data and typical conditions. For specific applications and detailed test results, refer to the actual test data and conduct appropriate certifications.