Thin and versatile backlights for miniature lighting

18x30mm and 10x20mm micropanels. A mere 1.4mm thin!

5mm and 3mm LEDs for scale

Downloadable data sheet

The problem

So you’re making small models, and you want a thin illuminated surface. An instrument panel in an airplane or spaceship, maybe. A glowing phone held by a 3D-sculpted superhero figurine. A static TV screen for a dollhouse. Or a roadside advertising sign on a model railway.

Typical solutions have problems. An LED behind a panel results in uneven hotspots, since LEDs are point light sources. A box or diffuser can help, but only if there’s room. Fibre optics are fine for glowing pushbuttons, but fibres can be hard to bend in tight spots. Electroluminescent panels are thin, but emit eerie colours and lose brightness with time. Adafruit and others sell 3-4mm thick backlight modules, but that's still pretty thick.

Wouldn’t it be great to use a super-thin illuminated panel? Well, now you can!

The solution

LCD displays often have acrylic plastic backlights. These thin yet rigid panels are edge-lit by LEDs, and use reflective and light-blocking material to transmit light efficiently. Micropanels use the same approach.

The sizes

10mm x 20mm, 10x14mm illuminated area, 1.4mm or ~1/16" thin

18mm x 30mm, 18x24mm illuminated area, 1.4mm or ~1/16" thin

35mm x 51mm, 35x45mm illuminated area, 2.4mm or ~3/32" thin (sold out; sorry)

Common applications

The 10x20mm and 18x30mm sizes were designed for the panels of the Bandai 1:72 “Perfect Grade” Millennium Falcon kit, when using the ParaGrafix brass detail set. The smaller lit area is ideal for the sidewalls of the cockpit and the corridor wall sconces. It can also be used for the back wall, though some cutting of the acrylic is obviously required.

The cool thing about using micropanels to illuminate the backwall is that it means you can open up the cockpit door, revealing the corridor. If you had a bunch of big LEDs behind the backwall for lighting you wouldn't be able to do this. At least, not without exposing the electronics!

Here's how tiny the 10x20mm panel is. It's positioned behind a ParaGrafix etched brass panel. Because it's one of the narrower sections of the cockpit, the panel will need trimming on either side.

The illuminated area

Micropanels have a working area that’s less than the full length. Each end is partly covered to reduce hotspots.

Cutting the micropanels

The panels are a sandwich. They’re clear acrylic with a dot pattern for even illumination. Each side has a white diffuser sheet. The modules can thus be cut down in size. The only bit you can’t saw down is the LED light source itself.

I recommend marking your module on the back, then slicing off the outer layers of thin diffusion film with a knife. Cut the panels using a fine-toothed razor saw. You will then need to reglue the white diffusion film.

Think about the way light will shine out of the LED before cutting - don’t cut a big hole in front of the LED itself, as that reduces light output.

Edge lighting

The edges of the panels are light-blocked by black tape, as shown above. If you want to shine light up into a narrow space you can edge-light by carefully cutting and peeling off a section of the tape. You’ll probably want to scrape or sand lightly the exposed plastic edge to give it a diffuse finish.

Colour temperature

The LEDs are available in two colour temperatures.

4500K

These panels are around 4500-5000K. This is neutral to cool white, with a slight magenta cast.

10,000K

These panels are pale blue in tone. They are more blue than regular cool white.

Micropanels are for hobbyist applications, not for cases which require precise colour.

Changing the colour

It’s easy to filter the white light to get different colours. Just apply photographic lighting gels – sheets of transparent colour-tinted polyester.

For spot detail use Tamiya clear acrylic paint. For example, the Millennium Falcon has white, blue, red, and yellow control panel lights. You can add tiny dots of colour - a drop from a toothpick works fine.

Blinkenlights

Backlighting a whole panel is great, but what about blinky lights? Flashing a panel of lights at once looks terrible, unless you’re making a BatComputer. Illuminated panels look best with static glowing lights and a few blinkers. 

If you have the space then fibre optics are ideal! Drill holes in the acrylic and run thin fibres for tiny pinpoints of light as required. Feed these fibres with red or some other contrasting colour.

To eliminate light leaks make the hole slightly bigger than the fibre, and add black or silver paint around the hole edges. Use Tulip black fabric paint or similar - it’ll both hold the fibre in place, and block light leaks. And never use superglue/ACC on fibre optics – it destroys the fibres!

Simulating TVs and monitors

Micropanels are perfect for simulating static TV sets, monitors, miniature cell phones and tablets. Just put a transparent graphic over the acrylic.

True photographic slides are the best for this sort of thing, since they have a good density of black and darker colours, compared to inkjet and laser printouts.

Note: 18x30mm panels have visible diffuser dots compared to the smaller sizes.

Wiring the micropanels

The panels use standard 0603 LEDs, presoldered to nice flexible wires. This makes them way easier to use than individual SMDs. Wires are polarized red and black, for your positive and negative convenience.

They have a reverse voltage of 2.8-3.2 volts DC. In other words, 3.2 volts is the maximum you can use. I would recommend using a 2.8 volt supply.

If you’ve never used LEDs before, please consult my article on the Age of Plastic website. It’s really easy to burn LEDs out if you apply too much current! They also don’t light up if wired backwards because LEDs are polarized devices.

The micropanels are rated at 15 mA of current. They work fine at 10mA, which is what I recommend if you’re using a bunch of lights. They won’t be quite as bright but will last longer, and will use less power.

Reducing the brightness is often a good idea. Control panels, for example, call for careful touches of lighting. You don’t want your cockpit to look like it’s lit by welding torches. That isn’t realistic!

The 10x20mm and 18x30mm micropanels contain one LED each. The 35x51mm micropanel contains two LEDs each. However, the larger panel isn’t quite as bright, on average, owing to the increased area. It’s easy to cut back the light-blocking tape on the edge of the panel and glue in an additional LED if you need it to be brighter.

Current regulators

I really like current regulators. These are tiny devices that always produce an LED-safe current regardless of what you feed it. There’s no need to calculate resistor values. You just select the regulator that produces the desired output current, and solder it inline (series) with the LED. 5 mA, 10 mA, 15 mA, and 20 mA regulators are commonly available.

I’m sure some electronic experts will turn their noses up at these things. And they’re not cheap. But the reason I like them, aside from their ease of use, is their input voltage flexibility. You’ve got 5 volts from a USB adapter? Great - the regulator just works! You’ve got a 9 volt battery battery? Cool - just plug it in. Resistors, by contrast, are fixed and can’t adjust automatically to varying input voltages.

I use 10 mA current regulators from German supplier kokkologo. US supplier Lighthouse LEDs also sells regulators, but only 20 mA versions.

Where micropanels aren’t useful

Nothing's perfect. Here are some ways that micropanels won't help you.

• Where there's no room. Even 1.4mm thin is too thick for some models. In that case just glue in some 0201 or 0402 SMD LEDs.

• If you need an enormous yet thin panel. A COB panel is best for that, though they do consume much more power.

• If you need really bright light. A micropanel is a diffuser and so is always less bright than a bare LED. That said, you can always peel off some of the side material and glue your own extra SMD LEDs in place for increased output.

• If you need focused spotlight-type light. In which case use a normal LED, or a COB LED with a reflector. Micropanels produce diffused soft light.

• If you have tons of room behind whatever it is you're lighting. In that case, just use regular LEDs, or thick LED panels, or whatever – it'll be cheaper.

• If the colour output doesn't work for you. Of course, if it's too cool just glue on a thin polyester sheet of “warming” filter material and you're good to go.

• If you need precise colour. If you care about CRI numbers or whatever you're probably not making model spaceships and planes.

• If you can't supply power to a bunch of LEDs.

The Bandai “Perfect Grade” Millennium Falcon

Here are the LEDs you need to light the PG Falcon's cockpit interior and corridor, assuming you're using the Paragrafix etched brass kit, and the Age of Plastic cockpit corridor parts.

Note that the micropanels are not a plug and play solution! It will take some work to cut and trim each panel to fit, especially on the sidewalls where there's almost no clearance. You'll likely have to file the corners down as well to match the curvature of the tunnel interior. The micropanels will let you light parts of the Falcon kit that you'd never be able to otherwise, but it's definitely a solution for more advanced or patient model makers!

Cockpit sidewalls

8x 10x20mm

Note: all will need trimming, but the bottom two will need to be trimmed down considerably

Cockpit backwall

2x 18x30mm

Note: Cut into L shapes. Ideally will require additional 0402 or 0601 LEDs added to the top of each panel for more even lighting over the door.

Corridor sconces

2x 18x30mm

1x 10x20mm

Note: this will not illuminate the final sconce in the corridor, though fortunately that isn't visible from the cockpit.

Corridor floor

3x 18x30mm

Note: the corridor floor wasn’t designed to take micropanels, so a lot of cutting of the panels is required. Because there’s enough room under there the corridor was intended to be lit by normal techniques - small groups of regular LEDs with diffusing material, or reflective metal tape, shining up. Because that's cheaper! You can of course use micropanels if you wish.

Gunbay

4x 18x30mm

Note: Medium panels will not fully illuminate the ends. There’s enough space around the gunbays to illuminate the sides using normal techniques - groups of LEDs lighting diffusing material. Again, it's the cheaper option!

Factory specifications

This is the luminance for the LED, not for the whole panel. The diffusion of the white plastic reduces light output. The factory does not publish MTBF data, but offers an expected lifespan of 50,000 hours at 15 mA. Personally I drive them at 10mA since I care more about working lifespan than I do about brightness.

Pricing

If you're interested in obtaining some, please drop me a line.

Prices in pounds sterling. Please send PayPal payments in UK currency; the service will automatically convert from your local currency. That's a lot easier than posting various other currency costs, given fluctuating exchange rates. Please send the full amount and cover all fees; note that PayPal may deduct fees at my end, which I can't absorb because I'm not a big business with hefty margins.

10mm x 20mm x 1.4mm micropanel, 4500K

per panel: £0.75 GBP

18mm x 30mm x 1.4mm micropanel, 4500K

per panel: £0.75 GBP

10mm x 20mm x 1.4mm micropanel, 10,000K

per panel: £0.75 GBP

18mm x 30mm x 1.4mm micropanel, 10,000K

per panel: £0.75 GBP

35mm x 51mm x 2.4mm micropanel, 4500K (SOLD OUT)

per panel: £1.50 GBP

SK6812 mini-E smart LEDs (limited supply)

These are tiny 3.2mm x 2.8mm x 1.8mm Neopixel-type smart RGB LEDs. They're similar to the popular SK6812 and SK6812 mini LEDs, but these ones come in flat housings with four protruding solder tabs, so it is possible (though challenging) to solder these by hand!

per set of 10: £5 GBP

Postage and packing for regular orders

Within the UK: £4
to other countries: £11

As of 3/2023. Parcels are shipped in a padded envelope at letter rates, and are sent with tracking. Signature required when available (eg: Canada doesn't support signatures from the UK). I don't support sending PayPal invoices; sorry.

Specific set Pricing

PG Falcon Set A: cockpit only
8x 10x20mm, 2x 18x30mm
£7.50 plus appropriate shipping

PG Falcon Set B: cockpit, corridor
9x 10x20mm, 7x 18x30mm
£12 plus appropriate shipping

PG Falcon Set C: cockpit, corridor, gunbay
9x 10x20mm, 11x 18x30mm
£15 plus appropriate shipping

CONTACT

theageofplastic.info

contact@theageofplastic.info

Unit 34652
PO Box 6945
London W1A 6US
UK

Light up your models with LED micropanels!