High UV-C reflective solder mask

Thanks to a unique paste formulation and CERcuits’ unique circuit mask application process, we can offer a new UV reflective mask solution on ceramic printed circuits and submounts that reflects >80% in the UVC spectrum.
As UV-C LEDs still suffer from significant side emissions and given that typical epoxy-based circuit board solder masks have a too low reflectance (see table at the bottom of this page), many UV-C modules are still underperforming and suffer from rapid degradation.
Our proprietary mask solution makes it possible sustain long and stable performances over a high load, even when using chip-on-board designs. In combination with the ceramic substrate, the modules can also be managed better thermally while being inert for environmental hazards. The combination finally enables efficient UV-C engines that meet today’s demand from curing, disinfection and other applications.
Our mask can be supplied with solderable and wire bondable finishes for both top contact, flip chip, SMT and through hole designs. (Immersion tin or silver, ENIG, ENEPIG, EPIG, DIG, …)
Typical applications include
– Ink and paint curing
– Air, water and surface disinfection
– Odor control
– Outdoor sensors
– Space applications
Characteristics & Design rules
Color | White |
Reflectivity UV-C spectrum | >80% |
Hardness (pencil test) | 4H |
Typical thickness | 30-60um (above substrate) |
Min. solder dam width | 0.2mm |
Min. soldermask opening | 0.2mm x 0.2mm |
Min. pad overlap (solder mask defined pad) | 0.05mm |
Min. pad clearance (non-solder mask defined pad) | 0.15mm |
Min. Edge spacing | 0.2mm |


How to order
Our UV relfective mask can be ordered via our C-Proto solution on both Alumina 96% (Al2O3 96%) as well as Aluminum Nitride (AlN).
Simply select the option ‘UV relfective mask’ which can be found within the quote & order form under Top Masking and/or Bottom masking.
Alternatively, you can also contact us for a quote. For example if you have a higher volume request or if you need a formal PDF quote.
Get Al2O3 96% Quote Get AlN QuoteStandard products using our UV-C reflective mask
To enable rapid and low costs prototyping and development, we developed a line a standard PCB with UV-C LED footprints that can be ordered online and held on stock.
Learn moreRequest more information & Datasheet
Reflectivity of common materials and metals
Notice the drop in most metals as soon the wavelength enters the UV ranges. Only Al remains highly reflective.
Table: Material Reflectivity under ultraviolet germicidal irradiation (UVGI) lamps
| MATERIAL | REFLECTIVITY | MATERIAL | REFLECTIVITY |
|---|---|---|---|
| % | % | ||
| ePTFE | 98.5 | Molybdenum | 25 |
| Spectralon | 95 | White botting paper | 25 |
| Smoked magnesium oxide | 93 | AZO photographic paper, unexposed | 24 |
| Evaporated aluminum | 87 | Silver | 23 |
| Alzak sheet aluminum, brightened | 87 | White water | 23 |
| Alzak sheet aluminum | 84 | White wallpaper | 22 |
| Magnesium oxide | 81 | Stainless steel | 20 |
| Aluminum -s uttered on lass | 80 | Brownish figured wallpaper | 18 |
| Pressed calcium carbonate | 78 | Tungsten | 18 |
| Pressed magnesium oxide | 77 | Linen | 17 |
| Calcium carbonate | 75 | Fluorescent lamp phosphors | 17 |
| Magnesium carbonate | 75 | Duralumin | 16 |
| Aluminum - treated surface | 74 | Kalsomine white water paint | 12 |
| Aluminum foil | 73 | Medusa cement | 11 |
| Aluminum paint | 65 | Alabastine white water paint | 10 |
| Barytes | 65 | White baked enamel | 9 |
| New plaster | 58 | White oil paint | 8 |
| Galvanized duct - smooth | 57 | Black paint | 7 |
| Galvanized duct - rough | 53 | Brass | 7 |
| Aluminum - untreated surface | 50 | Brown wrapping paper | 7 |
| White wall plaster | 46 | Titanium oxide | 6 |
| stellite | 46 | AZO photographic paper, exposed black | 6 |
| Chromium | 44 | Celluloid | 6 |
| AZO photographic paper, white back | 39 | Pongee silk | 6 |
| Chrome steel | 39 | Brown baked enamel | 6 |
| Rhodium | 38 | Casein vehicle | 6 |
| Nickel | 37 | Flat black Egyptian lacquer | 5 |
| S.W. white Decotint paint | 33 | Lithopone | 5 |
| Ivory wallpaper | 31 | Zinc oxide in clear lacquer | 5 |
| Pink figured wallpaper | 31 | Black lacquer paint | 5 |
| Speculum | 30 | White porcelain enamel | 5 |
| Bleached cotton | 30 | Zinc oxide paint | 5 |
| Tin plated steel | 28 | Lantern slide glass | 4 |
| Stainless steel | 28 | China clay | 4 |
| Tin plate | 28 | Zinc oxide casein paint | 4 |
| Ivory figured wallpaper | 26 | Pressed zinc oxide | 3 |
| The data shown is typical of commercially available material and is only offered for comparative purposes. The information shall not be interpreted as absolute material properties nor does it constitute a representation or warranty for which we assume legal liability. User shall determine the suitability of the material for the intended use and assumes all risk and liability whatsoever in connection therewith. | |||


