EPOTEK H20E
Harmonization Code : 3810.10.00 | Soldering, brazing or welding powders and pastes consisting of metal and other materials
Main features
- Electrically Conductive Die Attach
- 2.5-Day Mixed Pot Life
- Dispensable, Printable Silver Paste
Product Description
EPO-TEK H20E Silver-Filled Epoxy is a two-component, silver-filled electrically conductive epoxy for die attach and microelectronic interconnection. The smooth thixotropic paste mixes 1:1 by weight, has a 2.5-day pot life, and can be dispensed, stamped, or screen printed. A recommended cure of one hour at 150 deg C produces typical volume resistivity of no more than 0.0004 ohm cm and thermal conductivity of 2.5 W/(m K) by laser flash. Supported applications include attaching semiconductor die to lead frames, solderless flip-chip assembly, fine-pitch SMD printing, and hybrid microelectronics.
Key features
- Electrically conductive die attach: Typical cured volume resistivity is no more than 0.0004 ohm cm at 23 deg C.
- Long mixed-material window: The system provides a 2.5-day pot life.
- Flexible deposition methods: The thixotropic paste supports dispensing, stamping, and screen printing.
Applications
- Semiconductor die attach to lead frames
- Si and MEMS chip attachment
- Solderless flip-chip assembly
- Fine-pitch SMD printing
- Hybrid microelectronics
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Component System
Two Part
Describes the number of components that must be supplied, mixed, or activated before application or cure.
Physical Properties
Thixotropic index
4.6
Thixotropic Index is a ratio of a material s viscosity at two different speeds in Ambient temperature, generally different by a factor of ten.
A thixotropic material s viscosity will decrease as agitation or pressure is increased. It indicates the capability of a material to hold its shape. Mayonnaise is a great example of this. It holds its shape very well, but when a shear stress is applied, the material easily spreads.
It helps in choosing a material in accordance to the application, dispense method and viscosity of a material.
Viscosity
2,200 - 3,200 mPa.s
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
Thermal Properties
Glass Transition Temperature (Tg)
≥ 80 °C
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.
Operating Temperature
< 300 °C
Thermal Conductivity
2.5 W/m.K
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.
Electrical Properties
Volume Resistivity
≤ 0.0004 Ohms⋅cm
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.
Additional Information
Technical properties
As-supplied / before-processing properties
Typical as-supplied values for the silver-filled two-component system and frozen syringe format where stated.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Mix ratio by weight | 1:1 | - | Part A:Part B |
| Specific gravity | Part A 2.03; Part B 3.07; syringe 2.67 | - | As supplied |
| Pot life | 2.5 | days | Mixed system |
| Shelf life - bulk | 1 | year | At room temperature |
| Shelf life - syringe | 1 | year | At -40 deg C |
| Color | Part A silver; Part B silver | - | Before cure |
| Consistency | Smooth thixotropic paste | - | Before cure |
| Viscosity | 2,200 to 3,200 | cP | At 23 deg C and 100 rpm |
| Particle size | <= 45 | microns | Lot-acceptance property |
Technical properties
After-processing / final-state properties
Typical cured values retain the stated cure, test method, and die-attach context; the two thermal-conductivity values use different bases.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Recommended cure | 1 | h | At 150 deg C |
| Alternative cure | 5 min at 150 deg C; 15 min at 120 deg C; 3 h at 80 deg C | - | Minimum alternative cures may not achieve all listed properties |
| Glass transition temperature | >= 80 | deg C | Dynamic cure: 20 to 200 deg C; ISO 25 min; ramp -10 to 200 deg C at 20 deg C/min |
| Shore D hardness | 75 | - | Typical cured value |
| Lap shear strength | 1,475 | psi | At 23 deg C |
| Die shear strength | >= 10 kg / 3,556 | psi | At 23 deg C |
| Thermal conductivity | 2.5 | W/(m K) | Laser-flash method |
| Calculated thermal conductivity | 29 | W/(m K) | Derived from thermal-resistance data; method basis retained separately |
| Volume resistivity | <= 0.0004 | ohm cm | At 23 deg C |
