Backlight Modules & Bars for Signage — Complete Guide
LED backlight systems — both modules and bars — are essential for creating bright, even, and durable signage. Whether you’re building a shallow lightbox, a deep channel letter, or a wide-format flex-face sign, choosing the right solution is key.
This guide covers:
- Types of modules and bars
- Lens options and beam angles
- Spacing and depth guidelines
- Power and control considerations
- Installation and mounting tips
💡 What Are Backlight Modules and Bars?
Backlight modules are compact LED units with lenses, typically connected in a chain.
Backlight bars are linear LED assemblies, often rigid or semi-rigid, designed to cover wider areas or edges.
🧱 Where They’re Used:
- Channel letters (front-lit, halo-lit)
- Lightboxes (shallow, medium, or deep)
- Fabric boxes and stretch signage
- Flex-face signs and billboards
- Double-sided signs or edge lighting
🔠 Types of LED Backlight Systems
| Type | Description | Best For |
|---|---|---|
| Standard Modules | Compact, general-purpose modules | Channel letters, 80–150mm |
| Wide-Angle Modules | 160–180° lens for shallow signs | 30–80mm depth |
| Linear Modules | Strip-style, flexible or rigid | Fabric/flex-face backlighting |
| High-Power Modules | Powerful LEDs for deep signs | Cabinets, 150mm+ |
| Backlight Bars | Rigid strips with evenly spaced LEDs | Medium/deep boxes, large areas |
| Edge-Lit Bars | Side-mounted bars for ultra-thin boxes | Slim lightboxes <60mm |
🔭 Lens Optics & Beam Angles
Most modules and bars use optical lenses to spread light across a wide area.
| Lens Angle | Spread Type | Notes |
|---|---|---|
| 120° | Standard | Ideal for 100mm+ depth |
| 160–180° | Wide beam | Perfect for shallow signs |
| Asymmetric / Elliptical | Directed throw | Bars placed at edges (side-lit) |
📏 Spacing & Depth Guidelines
> Always follow the spacing chart provided by your supplier. General recommendations:
| Type | Sign Depth | Spacing / Layout |
|---|---|---|
| Wide-angle module | 30–60mm | 60–100mm spacing |
| Standard module | 80–120mm | 100–150mm spacing |
| High-power module | 120–200mm+ | 200–300mm spacing |
| Backlight bar | 60–150mm | 100–200mm between bars |
| Edge-lit bar | <60mm | Mounted on sides, throw across surface |
🧠 Pro Tip: Backlight bars often require fewer units and faster installation — but plan around depth and reflective backing for optimal performance.
⚙️ Voltage & Power Options
| Voltage | Usage |
|---|---|
| 12V | Short runs, small signs |
| 24V | Common choice, efficient |
| 48V | Ideal for long backlight bars |
Power range:
- Modules: 0.3W to 3W per unit
- Bars: 6W to 20W+ per bar
Use constant voltage drivers with appropriate wattage and allow 20–30% safety margin.
🎛 Control Options
- PWM Dimmers — Smooth brightness control
- 0–10V Dimming — Great for larger commercial signs
- DMX Control — Addressable or multi-zone control
- SPI Pixel — For animated or digital signage (mostly modules)
💧 IP Ratings & Outdoor Use
| IP Rating | Description | Best For |
|---|---|---|
| IP20 | No protection | Indoor lightboxes |
| IP65 | Splash-proof | Covered outdoor use |
| IP67 | Fully sealed modules | Exterior signs |
| IP68 | Waterproof bars/modules | Long-term outdoor use |
🛠 Installation Tips
✅ Recommended:
- Use reflective back panels (white or aluminum)
- Test layout before permanent mounting
- Observe spacing charts
- Inject power for long runs (every 3–5 meters)
❌ Avoid:
- Shadows from poor spacing or module angle
- Loose wires or poor waterproofing
- Overloading drivers
⚡️ Use aluminum profiles or brackets for bars to ensure alignment and heat management.
🧪 Quality & Reliability Features
Premium backlighting products often include:
- LM-80 or TM-21 tested LEDs
- Optical PMMA lenses (non-yellowing)
- Sealed injection-molded housing
- Heat-tested, salt-spray, and UV-tested units
🧠 Module vs Bar — Quick Comparison
| Feature | Modules | Bars |
|---|---|---|
| Form Factor | Small, flexible | Long, rigid or semi-rigid |
| Best For | Letters, curved signs | Boxes, wide or rectangular signs |
| Mounting | Peel/stick, screw-in | Clip-in brackets or channels |
| Speed of Install | Slower (more units) | Faster, fewer points |
| Cost Efficiency | Great for small jobs | Better for large installations |
🧰 Example System — Medium Lightbox
- Box Depth: 120mm
- Size: 1.5m × 2.5m
- Option A: 24V wide-angle modules every 10cm
- Option B: 3 rows of 1000mm backlight bars
- Power Supply: 150W CV 24V driver (with dimming)
📦 When to Use Bars Over Modules
Use backlight bars if:
- You're lighting large format signs
- You need a cleaner install with fewer components
- The sign has sufficient depth for beam spread (60mm+)
- You want faster install times and uniform brightness
🛠 Still Need Help?
Send us your sign dimensions, depth, material, and lighting goals — we’ll suggest a complete setup including layout, power plan, and control.