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LOCTITE 3128

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
  • One component
  • Low temperature cure
  • Bonding heat sensitive components

Product Description

LOCTITE 3128 is a one part, heat curable epoxy designed to cure at low temperature and gives excellent adhesion on a wide range of materials in considerably short time. Typical applications include Memory cards, CCD/CMOS Assemblies and Lid/Cap attach for optical sensors and 3d sensing modules.

LOCTITE 3128 can be successfully used as an Edgebond underfill, particularly suited where low curing temperatures are required for heat sensitive components. This low halogen, high viscosity, heat curable epoxy has a good adhesion to a variety of surfaces and a whopping 3 weeks of pot life.

LOCTITE 3128 has a fairly low CTE and warpage and as such has also been used on finger print sensor encpasulation with positive results.

Recommended cure schedule

  • 20 minutes @ 80°C bondline temperature
  • 60 minutes @ 60 °C bondline temperature

Note: Sufficient time must be added to allow the bond location to reach the desired cure temperature. Curing profiles should be developed for each device.

Product Family
3128  
30cc Syringe 10cc Syringe

Catalog Product

Unlike other products we offer, the products listed on this page cannot currently be ordered directly from the website.
Not Available Shipping in 8 - 12 weeks

Technical Specifications

General Properties
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.
1.6
Shelf Life
Shelf Life
Shelf life is the amount of time after manufacturing that a product is guaranteed to retain its properties.

It differs vastly per product and it is based on temperature and storage conditions.

The properties can be guaranteed for the temperature and time range indicated on the TDS since those are the ones tested to be the best for the product.
Shelf Life @ -20°C 365 days
Mechanical Properties
Elongation
Elongation
Elongation is the process of lengthening something.

It is a percentage that measures the initial, unstressed, length compared to the length of the material right before it breaks.

It is commonly referred to as Ultimate Elongation or Tensile Elongation at break.
2.3 %
Viscosity
Viscosity
Viscosity is a measurement of a fluid’s resistance to flow.

Viscosity is commonly measured in centiPoise (cP). One cP is defined as
the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP.

A product like honey would have a much higher viscosity -around 10,000 cPs-
compared to water. As a result, honey would flow much slower out of a tipped glass than
water would.

The viscosity of a material can be decreased with an increase in temperature in
order to better suit an application
Viscosity 27,000 mPa.s
Hardness
Hardness
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) 88
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 22,000 N/mm2
Thermal Properties
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.
45 °C
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.
40 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.
130 ppm/°C