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NEA141 |
NEA141 is a medium viscosity, thixotropic paste which
cures under UV light. This adhesive was designed for coil terminating.
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NEA155 |
NEA155 is a red, thixotropic paste that cures in minutes
at high temperatures to form an electrically insulating polymer.
This adhesive can be readily applied by syringe, screen printing
or pin transfer techniques. It is ideal for bonding SMT devices
to printed circuit boards so that they can pass through the solder
bath without shifting.
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Norland UV Sealant 91 |
This is a screenable paste adhesive specifically designed to
seal the perimeter of liquid crystal displays. It provides the
ultimate solution for manufacturing displays because it is a
single component, solventless sealant that cures quickly at room
temperature when exposed to UV light.
Norland Electronic Adhesive 121&
123
NEA121 is a clear, low viscosity adhesive that cures when
exposed to UV light and / or heat. Applications include tacking,
filling and sealing precision components, and tamper proofing
adjustable components. NEA121 is ideal for spot curing small
areas.
NEA123 is a thixotropic paste that cures under UV light and
/ or heat. This fast curing adhesive is ideal for wire tacking,
capacitor bonding and coil terminating. NEA123 contains a latent
heat catalyst that can quickly cure areas that are not exposed
to ultraviolet light. The heat cure is not required if all the
adhesive receives proper exposure to UV light.
Norland Electronic Adhesives 121 and 123 ("NEA 121 and
123") are single component adhesives that cure tack free
in seconds to a tough, resilient polymer when exposed to ultraviolet
light. NEA 121 is a low viscosity liquid, and NEA 123 is a thixotropic
paste. They are recommended as an extremely fast and efficient
way to tack, fill, seal or bond precision components or wires
in place. With this system, a drop of adhesive is used to form
a bridge between the component or wire, and the substrate. Exposure
to UV light quickly cures them, and holds the component in place.
Useful applications for NEA 121 and 123 include wire tacking,
chip capacitor bonding, coil termination, bonding of head gimbal
assemblies and tamper proofing adjustable components.
The unique advantage of these adhesives is that even though they
cure in seconds, they are extremely stable when not exposed to
ultraviolet light. Norland 121 and 123 are sensitive to the whole
range of UV light from 320 to 380 nanometres with peak sensitivity
around 365 nanometres. Cure time is dependent on light intensity
and thickness of adhesive layer. The adhesives have been designed
to be spot cured in small areas with hand held or desk top UV
light sources that are safe and easy to use.
Recommended Light Sources
|
Hand Held |
Manufacturer |
Approximate Cure Time |
|
RC-250 |
Xenon Corp. |
5-30 seconds at 1/2 inch |
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|
Wilmington, MA |
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Opticure Light Gun |
Norland Products |
10-60 seconds at 1/2 inch |
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Available from Tech Optics |
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Desk Top |
Manufacturer |
Approximate Cure Time |
|
Portascan 100 |
American Ultraviolet |
5-30 seconds at 6 inches |
|
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Chatham, NJ |
|
Faster cure times are possible with medium pressure vapour lamps
(typically 200 watts/linear inch). These are most commonly used
in conveyorized applications because the light must be shielded
from the operator. These types of lights are available from companies
such as American Ultraviolet or Fusion UV Curing Systems.
In addition to the UV cure, Norland 121 and 123 contain a
latent heat catalyst that can quickly cure areas that do not
see the ultraviolet light. The catalyst allows the adhesive to
cure in 10 minutes at 125° C in a convection oven, or 3 hours
at 80°C. Faster cure times are possible with infrared ovens.
Temperatures less than 60° C will not appreciably activate
the adhesive. The advantage of the heat cure is to bring partially
cured adhesive to full cure to get the maximum physical properties
of the adhesive. The heat cure is not required if all the adhesive
receives proper exposure to UV light.
NEA 121 and 123 have very good adhesion to glass, metals,
printed circuit boards and many plastics. Since the cure is very
exothermic, the adhesive should be allowed to cool back to room
temperature before adhesive testing begins. Components bonded
with NEA 121 and NEA 123 can withstand temperature conditions
from -150° C to 150°C.
|
Typical Properties |
NEA 121 |
NEA 123 |
|
Viscosity at 25° C |
300 cps |
200,000 cps |
|
Elongation at Failure |
30% |
60% |
|
Modulus of Elasticity (psi) |
160,000 |
50,000 |
|
Tensile Strength (psi) |
3,500 |
3,000 |
|
Hardness - Shore D |
85 |
60 |
|
Total Mass Loss (TML) |
3.14% |
3.89% |
|
Collected Volatile Condensable Material (CVCM) |
0.41% |
0.21% |
|
Dielectric Constant (1 MHz) |
4.04 |
4 |
|
Dissipation Factor (1 MHz) |
0.045 |
0.044 |
|
Volume Resistivity (ohm-cm) |
1.0x10 to power 15 |
1.0x10 to power 12 |
|
Surface Resistivity (Megohms) |
10x10 to power 9 |
1.0x10 to power 9 |
|
Dielectric Strength (volts) |
980 |
980 |
|
Arc Resistance (sec) |
95 |
92 |
To remove uncured adhesive from substrate use an acetone or
alcohol moistened cloth. The cured adhesive can be removed by
prying the drop with a knife edge or soaking in a solvent combination
of 90 parts methylene chloride and 10 part methanol.
Handling and Storage Precautions
CAUTION: Norland Electronic
Adhesive 121 and 123 may cause skin irritation and prolonged
contact with skin should be avoided. If contact occurs wash well
with soap and water. Use in well ventilated area.
Store in a cool dark place. CAUTION:Do
not freeze material. Never expose the bulk material to high heat
or ultraviolet light. It can generate an extremely exothermic
reaction.
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