ECCOBOND FP4546
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others
Main features
- Low-CTE Flip-Chip Underfill
- Toughened Crack-Resistant Epoxy
- 32-Hour Pot Life at 25 deg C
Product Description
LOCTITE ECCOBOND FP4546 is a black, heat-curing liquid epoxy encapsulant developed for semiconductor underfill and flip-chip devices. Its high-purity, filled formulation combines a low coefficient of thermal expansion with improved toughness and is specially suited to assemblies requiring improved crack and fracture resistance. After cure, it forms a rigid, low-stress seal that dissipates stress on solder joints. The material supports capillary underfill processing, with a typical viscosity of 12,000 mPa·s at 25 °C and a recommended cure of 30 minutes at 165 °C or 90 minutes at 150 °C.
Key features
- Low thermal expansion: Typical cured CTE is 35 ppm/°C below the glass transition temperature.
- Toughened encapsulation: Developed for improved crack and fracture resistance in flip-chip devices.
- Controlled heat cure: Recommended cure is 30 minutes at 165 °C, with an alternate schedule of 90 minutes at 150 °C.
Applications / Suitable for
- Flip-chip device underfill
- Semiconductor encapsulation
- Capillary underfill processes
TDS, SDS & Technical Documents
Technical Specifications
Physical Properties
General Properties
Thermal Properties
Additional Information
As-supplied / before-processing properties
Typical uncured-material and storage values provided for product evaluation. These values are reference data and are not guaranteed specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Black liquid | — | As supplied |
| Viscosity | 12,000 | mPa·s | Brookfield cone and plate, CP52, 25 °C, 20 rpm |
| Filler content | 60 | % | Ignition method |
| Flow time | 30 | s | 90 °C, 3 mil gap, 500 mil flow |
| Pot life | 32 | h | 25 °C; time to double viscosity |
| Gel time | 10 | min | 121 °C |
| Shelf life | 270 | days | Stored at −40 °C |
After-processing / final-state properties
Typical cured-material values provided for technical evaluation. Cure and test conditions are retained where supplied; values are not guaranteed specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Coefficient of linear thermal expansion below Tg | 35 | ppm/°C | Sample cured 7 minutes at 160 °C |
| Coefficient of linear thermal expansion above Tg | 100 | ppm/°C | Sample cured 7 minutes at 160 °C |
| Glass transition temperature | 130 | °C | Typical cured-material value |
| Flexural modulus | 7,500 | N/mm² | Equivalent to 1.09 × 106 psi |
| Extractable chloride | 20 | ppm | Extractable ionic content |
| Extractable sodium | 5 | ppm | Extractable ionic content |
