ALPHA SM42-120P
Harmonization Code : 3208.20.90 | Paints and varnishes that are dispersed or dissolved in a non aqueous medium
Main features
- One-component, fast-curing epoxy surface mount adhesive designed for both screen printing and dispensing.
- Non-sagging formulation with documented excellent adhesion, thermal resistance, and workability.
- Cured material provides a Tg of 110 +/- 10 °C and insulation resistance greater than 1 x 10^12 ohms after 96 hours at 85 °C/85% RH.
Product Description
ALPHA HiTech SM42-120P Surface Mount Adhesive is a one-component, fast-curing epoxy adhesive designed for screen printing and dispensing in surface mount assembly. The red paste combines non-sagging behavior with documented adhesion, thermal resistance, and workability characteristics. It can be screen printed at room temperature or applied by dispensing, with full property development using the documented thermal cure schedules. ALPHA HiTech SM42-120P is also identified as halogen-free and compliant with RoHS Directive EU/2015/863.
Key features
- Fast-curing one-component epoxy: Supplied as a ready-to-use red paste for surface mount adhesive applications.
- Screen print and dispense capable: Can be effectively screen printed at room temperature and is also suitable for dispensing.
- Non-sagging with strong functional properties: Documented features include non-sagging behavior, excellent adhesion, thermal resistance, and workability.
- Halogen-free formulation: Identified as halogen-free and compliant with RoHS Directive EU/2015/863.
Applications / Suitable for
- Surface mount adhesive applications
- Screen printing at room temperature
- Dispensing processes
TDS, SDS & Technical Documents
Technical Specifications
Physical Properties
Thixotropic index
≥ 3.0
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
55000–70000 Poise 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
General Properties
Specific Gravity
1.2–1.4
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.
Thermal Properties
Glass Transition Temperature (Tg)
110 ± 10 °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.
Additional Information
Technical properties
As-supplied / before-processing properties
Selected typical uncured material properties of ALPHA HiTech SM42-120P.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Chemistry | Epoxy | - | One-component surface mount adhesive |
| Appearance | Red paste | - | Uncured |
| Viscosity | 550 to 700 | Poise | Malcom PC-10A, 30 rpm at 25 °C |
| Specific gravity | 1.2 to 1.4 | - | Typical uncured material property |
| Thixotropic index | ≥ 3.0 | - | Typical uncured material property |
| Pot life | 7 | days | 25 °C |
Technical properties
After-processing / final-state properties
Selected typical cured material properties of ALPHA HiTech SM42-120P.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Glass transition temperature (Tg) | 110 +/- 10 | °C | DSC |
| CTE (α1), below Tg | 65 +/- 10 | ppm | TMA |
| CTE (α2), above Tg | 190 +/- 20 | ppm | TMA |
| Corrosion | None | - | 96 hours at 40 °C, 95% RH |
| Moisture absorption | < 1.0 | wt% | 24 hours, H2O at 25 °C |
| Insulation resistance | >1 x 1012 | ohms | 96 hours at 85 °C, 85% RH |
| Hardness | 80 to 90 | Shore D | Typical cured material property |
