LOCTITE 3515

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

Cornerbond
Fast cure
Self alignment of SMT components

Product Description

LOCTITE 3515 is a one component epoxy adhesive, designed to allow self-alignment of SMT components during the reflow operation. The adhesive is pre-applied to the board at the corners of the CSP pad site using a standard SMA dispenser, a process that speeds assembly by eliminating post-reflow underfill dispense and cure steps.

LOCTITE 3515 cures during the solder reflow phase to form a reliable bond, and contributes to improvements in handheld device reliability. LOCTITE 3515 cornerbond has excellent dispensing characteristics, good dot profile, and good on-board electrical characteristics. Reinforcement of CSPs with interposers or comerless arrays in portable electronic devices.

Cure Schedule

30 minutes @ 150 °C
5 minutes @ 180 °C
30 seconds @ 200 °C
15 seconds @ 220 °C

Specifications

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.

1.23

Chemical Properties

Ionic Content
Chloride (Cl-) Chloride (Cl-) The amount of Chloride (Cl-) ion extracted from the product in parts per million (ppm)	110 ppm
Potassium (K+) Potassium (K+) The amount of Potassium (K+) ion extracted from the product in parts per million (ppm)	24 ppm
Sodium (Na+) Sodium (Na+) The amount of Sodium (Na+) ion extracted from the product in parts per million (ppm)	55 ppm

Mechanical Properties

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

2,300 N/mm2

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.	49 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.	183 ppm/°C

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.

73 °C

Thermal Conductivity

Thermal Conductivity
Thermal conductivity describes the ability of a material to conduct heat. It is required by power packages in order to dissipate heat and maintain stable electrical performance.

Thermal conductivity units are [W/(m K)] in the SI system and [Btu/(hr ft °F)] in the Imperial system.

0.28 W/m.K