Right-Angle Bent-Lead LED: Side-Emitting Indicator Structure & Custom Guide
Product designers often run into this problem: the PCB mounts horizontally, but the indicator needs to emit through the side of the enclosure. Redesigning with a vertical daughter board costs too much — so the most common solution is bending the leads of a through-hole LED 90°, laying the diode body "flat" so it shines sideways. This is the bent-lead LED (also called 90° bent-lead or side-bent LED).
1. What Problem Does a Bent-Lead LED Solve?
A standard through-hole LED (F3/F5) stands vertically on the PCB and shines upward. Use a 90° bent-lead LED when the product requires:
- The PCB flat against the enclosure bottom, with light exiting through a side-wall aperture;
- The diode reaching past the PCB edge to align with a front-panel opening;
- Stacked boards where the diode must clear the structure above.
In all these cases, a 90° bent-lead LED forms the solution in one step — cheaper than adapter boards or side-view SMD parts, with the proven reliability of through-hole wave soldering.
2. Three Process Essentials for Lead Forming
- Bend position: the bend point must be at least 2mm from the epoxy body, or bending stress travels into the package and risks breaking the bond wire. Hongcheng Optoelectronics forms all bent leads at a standard 3mm from the body.
- Pitch and dimensional tolerance: after forming, the lead pitch and the height from the diode center to the mounting face determine whether the diode aligns with the panel hole. Hongcheng holds bent-lead dimensions to ±0.1mm and supports custom bend angles (30°/45°/90°) and dimensions to drawing.
- Forming equipment: hand-bent leads are inconsistent — volume production must use tooling dies for one-shot forming, avoiding root cracks and plating damage.
3. Bent-Lead LED vs Side-View SMD: How to Choose?
| Comparison | 90° Bent-Lead Through-Hole LED | Side-View SMD LED |
|---|---|---|
| Soldering process | Wave / hand soldering | Reflow |
| Mechanical strength | High (through-hole anchored) | Moderate (pad-mounted) |
| Light exit height | Customizable (set by lead forming) | Fixed (at board level) |
| Unit cost | Low | Slightly higher |
| Batch friendliness | Small-batch friendly, no tooling fee | Must match the PCB design |
4. What to Provide for a Custom Bent-Lead LED?
The custom process is simple: ① send a structural drawing or sample (marking bend angle, segment dimensions, and lead pitch); ② Hongcheng delivers samples within 3 days; ③ after fit confirmation, volume supply begins. All F3 and F5 colors (including dual-color) can be bend-formed — red-green dual-color bent-lead versions are a frequent request for industrial control panels.
Hongcheng Optoelectronics (HC-LED) stocks standard 90° F3/F5 bent-lead versions, with special angles and dimensions available to drawing — samples ship in 3 days. Engineers working on side-emitting structures are welcome to contact our engineering team directly with drawings for evaluation.
