SkyBeam: Applications & adhesives, every question, answered
55 answers below, written from the manufacturer's manuals and our own bench experience. Prefer to tap through them? The same answers power the live chat in the corner. Ready to buy? See the SkyBeam or request a quote.
Which LED wavelength matches my adhesive?
Your adhesive datasheet lists the spectral range its photoinitiator needs - match the light guide to it. SkyBeam guides come in 365, 385, 395 and 405 nm.
365 nm is the workhorse for many medical-grade and legacy chemistries; 385-405 nm suits most modern formulations and penetrates deeper into thick layers.
Will narrowband LED light cure my adhesive?
Yes, as long as its photoinitiator absorbs inside the 365-405 nm band the SkyBeam guides cover. If the datasheet calls for UVB/UVC or broad visible content, a broad-spectrum arc source like the SunSpot 2 is the better fit.
Best wavelength for deep or through cures?
Longer wavelengths - 395 or 405 nm - penetrate thick adhesive layers best, because UV attenuation increases as wavelength gets shorter.
The manual notes that deep cures through thick, opaque or colored adhesives call for the longer UV-A and visible-edge wavelengths for maximum penetration.
Can it cure tinted or opaque adhesives?
Colored or opaque adhesives attenuate UV, so pick a longer wavelength guide - 405 nm gives the best penetration - and confirm full cure during your process qualification.
Can UV pass through glass or plastic parts?
Only partially - UV is easily attenuated by any material that is not extremely transparent or optically pure, and even window glass blocks most UV wavelengths. Attenuation is worse at shorter wavelengths, so if you must cure through a substrate, use a longer wavelength and verify the material transmits it.
Does doubling intensity halve cure time?
Not always - for some adhesive types the relationship is not linear. A short exposure at high peak intensity can cure faster and more completely than the same, or even a higher, dose spread over a longer time.
Why is my thin coating tacky on the surface?
Surface tack on thin films is traditionally removed with short UVB/UVC wavelengths, which LEDs do not emit. Very high LED irradiance can also cure thin layers tack-free - run a small spot near full power - or move the job to a broad-spectrum arc source.
Is SkyBeam right for PCB wire tacking?
Yes - dispense a small dot of UV acrylate over the wire, bring a 3-8 mm spot onto it, and it reaches handling strength in a 1-4 second timed burst.
On automated lines the four channels stake up to four joints per index with PLC handshaking.
Can I stake parts on populated boards?
Yes - a spot cure puts energy only where the adhesive is, so neighboring components stay at ambient temperature. There is no bulk heat, no reflow risk, and no board warp.
Can UV staking replace an oven cure?
For tacking and staking work, yes. A UV acrylate dot reaches handling strength in seconds, versus a 30-minute oven pass that thermal-cycles every joint on the assembly.
Is it used for medical device bonding?
Yes - needle bonding, catheter assembly, lens fixing, and fiber termination are the core uses. Per-channel timers, intensity settings, and life logs make the dose a programmed parameter instead of an operator skill.
Can the cure recipe be locked for production?
Yes. Each channel stores its mode, power, and exposure time, and the front-panel security key switch prevents anyone from changing parameters without the key.
Turn the key off and remove it after setup - settings can only be edited with the key switched on.
Why LED spot cure for optical assembly?
LED spots deliver a timed, regulated dose with virtually no infrared, so optical alignment does not shift as the joint warms. That matters for lens fixing and fiber work where microns count.
Can it bond fiber-optic terminations?
Yes - fiber termination is a standard SkyBeam application. Small 2-5 mm spots and 1-5 second per-channel timed exposures give each ferrule the same validated dose.
How does it speed multi-point PCB work?
Four independent channels each drive their own light guide with their own power and timer, so up to four joints cure per cycle instead of one.
Can it cure parts in-line on a conveyor?
Yes. LEDs are instant on/off with no warm-up, so a PLC can trigger a timed exposure at every index and read BUSY/READY feedback between cycles.
What output at 385, 395 and 405 nm?
With the 4 mm lens: 10/12/14 W/cm2 at 5 mm. With the 6 mm lens: 5.3/6.3/7.4 W/cm2 at 11 mm. With the 12 mm lens: 1.7/2.0/2.3 W/cm2 at 26 mm, and the 15 mm lens gives 1.4/1.6/1.9 W/cm2 at 28 mm (385/395/405 nm respectively).
How do I cure heat-sensitive substrates?
Turn the channel power down - it adjusts from 10 to 100% - or back the guide tip off to reduce intensity at the part. The manual specifically recommends reduced intensity for temperature-sensitive curing substrates.
Adhesive too reactive at full power?
Very reactive adhesives can be run at reduced intensity - each channel's UV power is adjustable from 10% to 100% from the front panel, and increasing working distance lowers intensity further.
Does the LED spot heat the part?
There is virtually no infrared like an arc lamp produces, but at high output the guide tip can still deliver significant heat to a surface it is aimed at up close. Cure on a metallic or non-flammable surface and keep the tip away from flammables.
What is step (16ST) exposure mode for?
Step mode programs 1-16 sequential steps, each with its own UV power and time, and repeats the sequence 1-99 times via the PS setting. It is handy for staged exposures - for example a gentle gel step followed by a full-power finish cure.
Can it do dam-and-fill encapsulation?
Yes for shallow fills: gel the dispensed dam with a short exposure, fill, then cure. For pots deeper than about 5 mm, plan two fill-and-cure passes, specify a dual-cure chemistry, or use the broad-spectrum SunSpot 2 for better depth penetration.
How do I handle shadowed adhesive?
UV cures are line-of-sight, so any adhesive the light cannot see stays wet. Fixture so the guide tip sees every fillet, angle two guides at opposing 45-degree positions around vertical walls, or use a dual-cure chemistry for hidden regions.
How deep can a UV spot cure reach?
Roughly 5 mm is the practical depth for typical encapsulants. Beyond that, fill and cure in two passes or specify a dual-cure (UV plus moisture or heat) chemistry, and verify the dose at depth during qualification.
How do I inspect cure coverage quickly?
Fluorescing adhesives make coverage checks a two-second look under a UV lamp. Back that up with pull or shear tests on first articles each shift.
Do plastics need prep before bonding?
Yes - solvent-wipe both substrates, and abrade or plasma-treat low-energy plastics for reliable adhesion before dispensing.
Which chemistry for fine-pitch boards?
Pick a low-shrinkage UV acrylate rated for tacking and staking. High-shrink chemistries can lift fine-pitch pads or stress solder joints as they cure.
Can it cure UV inks and paints?
Yes - the SkyBeam is designed for photo-initiated inks, coatings and paints as well as adhesives. Thin layers benefit from its high irradiance, which can cure them without surface tack.
How fast are typical spot cures?
PCB tacking runs 1-4 seconds per joint, medical bond points 1-5 seconds, and structural or encapsulation zones 2-10 seconds. Actual times depend on your adhesive's required dose and the irradiance at the part.
How should I verify dose in production?
Measure intensity at the guide tip with a radiometer on a fixed schedule and log the readings - a roughly 20% drop means it is time to service or replace the guide.
The LEDCure radiometer (UV4006 series) is offered in 365, 385, 395 and 405 nm versions with a 0.4-40 W/cm2 range.
How far should the tip sit from the joint?
Use the lens table as your anchor - for example the 6 mm 365 nm lens is rated 5.6 W/cm2 at 13 mm. Moving closer raises irradiance and shortens cure; a typical PCB fixture holds the tip 8-12 mm above the joint for a 5 mm spot.
Where do I get exposure settings from?
Start with the exposure time and intensity on your adhesive's datasheet, then fine-tune on your own parts - the manual notes optimum settings may need to be determined experimentally.
Can each channel cure a different adhesive?
Yes - every channel has its own mode, power (10-100%) and timer, so four different products or bond types can run side by side on one controller.
Is it suited to glass-to-metal bonds?
Yes - UV spot curing fixtures the part for seconds instead of the hours a clamps-and-oven epoxy cycle takes, and dissimilar-material joints avoid the stress built up during oven cool-down.
Why choose spot cure over flood cure?
A spot puts energy only where the adhesive is, so the rest of the part stays at ambient and no masking is needed. Because the light is delivered to a small area, scatter is minimal and shielding is much simpler to build.
What is a photoinitiator?
It is the reactive ingredient added to adhesive, coating and ink resins that absorbs a specific range of light wavelengths and drives the liquid to polymerize into a solid. Its absorption range determines which LED wavelength you need.
How do light-cure resins differ from epoxies?
Two-part epoxies must be measured, mixed, and then cure on their own clock. Light-curing resins are single-component, ready to use as received, and cure on demand only when exposed to UV.
What dose do adhesives typically need?
There is no universal number - manufacturers specify either the energy (J/cm2) required or an intensity plus duration, and reactivity varies by product. Use cure time = energy / intensity to translate their spec into a SkyBeam timer setting.
Is 365 nm right for medical adhesives?
365 nm is the workhorse wavelength for medical-grade adhesives, and it is the standard recommendation for needle bonding, catheter work and lens fixing. Always confirm against your specific adhesive's datasheet.
What ambient conditions does curing need?
The controller is rated +10 to +40 C at 20-90% non-condensing humidity, and the light guides should work below 40 C. Keep the area clean - vapors, dust and airborne particles can contaminate lenses or clog cooling and cut light output.
Can it tack magnet wire on coils?
Yes - coil terminations are a classic use. A staked dot of UV acrylate keeps fine magnet wire from shifting during depaneling, conformal coating and test.
Does staking help connectors under flex?
Yes - connectors and tall electrolytics that see board flex need reinforcement at exactly one point. A spot-cured dot at the connector shoulder adds that strength without a bulk cure of the whole board.
How do I pick the right spot size?
Use the smallest lens that still covers the bond area - smaller spots concentrate the same LED output into higher irradiance and faster cures. Larger 12-15 mm spots trade intensity for coverage.
Can four bond points cure simultaneously?
Yes - each of the four channels drives its own guide, and you can fire them together by turning the LINK parameter on or wiring their trigger inputs in parallel.
Part of my bead stays wet - why?
Usually shadowing or attenuation: the light is not reaching that section at sufficient intensity. Reposition the guide or add a second channel at another angle, check the lens is clean, and confirm the LED wavelength matches the adhesive's spectral requirement.
Which radiometer works with SkyBeam?
The LEDCure UV4006 series, offered in 365, 385, 395 and 405 nm versions with a 0.4-40 W/cm2 dynamic range. The UV4244-12 fixture positions a spot guide over an EIT radiometer for repeatable readings.
Can you help match a system to my adhesive?
Yes - send a quote request with your adhesive, substrate and cycle time, and our US-based team will recommend the right system, wavelength, light guide and exposure settings from the datasheet values.
What if my cure area is larger than 15 mm?
Spot systems are meant for localized cures. Cover longer bond lines by fixturing multiple guides across the four channels, or index the part through sequential timed exposures.
Datasheet says 320-390 nm UVA - which guide?
The 365 nm guide sits squarely inside that band and is the right choice. It is also the default wavelength included with the system unless you specify otherwise at order.
My adhesive needs UVB - can SkyBeam cure it?
No - SkyBeam LEDs emit narrowband light at 365, 385, 395 or 405 nm only, all in the UVA/visible-edge range. For UVB/UVC-dependent chemistries, the SunSpot 2 arc covers 275-650 nm.
How strong are LED spot cures?
The SkyBeam's very high power-density output produces rapid, high-bond-strength cures. Tightly regulated switch-mode supplies keep intensity consistent so strength is repeatable part to part.
How repeatable is the dose part to part?
LED current is regulated to plus/minus 1% over line and load, timers resolve to 0.1 seconds, and each channel stores its own settings - so every part sees the same energy once the recipe is set.
Does a dirty lens slow curing?
Yes - adhesive deposits and condensed vapors on the glass lens cut UV transmission and curing efficiency. Clean it with a soft cloth dampened with isopropyl alcohol; never use abrasives or steel wool, and avoid touching the lens with bare fingers.
Do all adhesive brands cure the same?
No - products from different manufacturers have different reactivity levels and need their exposure adjusted accordingly. Consult the adhesive manufacturer for the appropriate cure time for each material.
Curing got slower - what do I check?
Work through the manual's checklist: LED intensity set too low, guide tip too far from the part, lens needing cleaning, an adhesive whose spectral needs do not match the LED type, or aged LEDs. Increase power, move closer, clean the glass, and verify output with a radiometer.
