SMT (3.5 x 2.8 x 1.8)

SMT Series

Our SMT series represents Marubeni’s low-power surface-mount LEDs, optimized for compact size and efficient performance. These SMT LEDs come in a 3.5 mm × 2.8 mm package (often referred to as “3528” footprint) with a low profile, making them ideal for indicators, small illumination tasks, and high-density LED arrays. Despite their “low-power” designation, the SMT family can accommodate multiple chips and various lens options to tailor output. Each SMT LED is built on a ceramic substrate for stability, with optional epoxy or silicone lenses molded on top to achieve the desired beam angle. This series offers single-color versions in the UV, visible, and NIR ranges, as well as bi-color options and multi-chip combinations for more complex functionality.

Features of Marubeni SMT LEDs

• Compact 3.5×2.8 mm Footprint: The SMT package is a standard 3528 surface-mount LED form factor, which is widely used and easy to design into PCBs. Its small size allows close spacing of LEDs – beneficial for creating LED matrices or multi-element sensors. At only 1.8 mm high, these LEDs occupy minimal vertical space, enabling slim device designs.
• Multiple Chip Capability: Unlike typical low-power SMD LEDs that contain a single die, our SMT package can integrate up to 3 LED chips (depending on chip size) within the 3.5×2.8 mm form. This means you can have higher light output by driving three dice in unison, or combine different wavelengths in one package. For example, we can place a red, green, and blue chip together to form an SMT RGB LED, or an IR + red chip for a medical sensor LED. The internal design supports both 300 µm class chips and even up to 1 mm chips (for single-color high output) with proper thermal management.
• Lens and Beam Options: The SMT family offers a variety of integrated lens geometries. Versions are available with flat encapsulation for a wide 120° viewing angle, as well as domed lenses that collimate light into narrower beams (e.g. 30° or 60° full-width). There are even extremely narrow SMT versions with engineered lenses achieving ±10° (20° full angle) beams, useful for sensing or long-throw illumination. This flexibility lets you choose an SMT LED that either broadly illuminates a target or focuses light as needed without external optics.
• Energy Efficient: The low-power SMT series is designed for use at standard LED currents (20–30 mA nominal), offering high efficacy at these drive levels. Using advanced LED chips (AlInGaP for red/amber, InGaN for blue/green, etc.), our SMT LEDs achieve bright output with minimal power consumption. Thermal dissipation through the ceramic body and PCB pads ensures the LED junction stays cool, preserving efficiency. These characteristics make SMT LEDs suitable for battery-powered devices and dense arrays where power and heat must be managed.
• Full Spectrum Availability: Marubeni provides the SMT series in wavelengths from 365 nm UV through 940 nm IR. This includes all primary visible colors and specialty wavelengths like 365 nm, 375 nm, 395 nm in UV (popular for counterfeit detection and UV curing), 525 nm green and 590 nm yellow for indicators, and 850/880/940 nm infrared for remote control or sensing. We also offer 760–810 nm far-red SMT LEDs for biomedical uses. Precise binning ensures color consistency and matching for multi-LED projects.

Applications of SMT (Low-Power) LEDs

Given their balance of size and output, SMT series LEDs excel in applications like status indicators, small-scale lighting, and sensor illumination. Many consumer electronics use our SMT LEDs as indicator lights – for instance, the standby LED on a TV or the notification LED on a smartphone can be a tiny SMT package that fits on a crowded PCB. The availability of different colors (including bi-color packages that can show two colors) allows designers to convey device status in an elegant, low-profile way.

In medical devices, SMT LEDs are used for indicators on instruments and as light sources in medical research devices. A cluster of SMT deep-red (660 nm) LEDs, for example, can serve as the light source in handheld medical and wellness devices. The compact size means multiple LEDs can be arranged in an array to increase coverage while keeping the device portable.

Our SMT infrared LEDs are widely used in proximity sensors and small IR data links. For example, a reflective optical sensor in an industrial or automotive context might use an SMT 850 nm IR LED paired with a photodiode to detect object presence. Because the SMT LED is low-power, it can be continuously driven or pulsed at high frequency with little heat, which is perfect for sensors that need constant IR emission. Additionally, SMT 940 nm LEDs serve in short-range IR communication (e.g. old-style IRDA ports or custom wireless links between devices) – their surface-mount nature allows integration directly next to ICs and other components.

Wearable technology and IoT devices benefit from SMT LEDs for both indication and sensing. Smart rings, hearing aids, and fitness bands have extremely limited space, and our 3.5×2.8 mm or smaller LEDs can provide visual feedback (like a tiny RGB LED for notifications) or emit light for sensors (like an IR LED shining into skin for heart-rate monitoring) without making the device bulky. The low power draw also helps maximize battery life in these wearables.

Another area is LED arrays and displays with fine pixel pitch. For moving message signs or small LED dot-matrix displays, the SMT LED’s consistent sizing and easy PCB mounting allow tight packing. Our SMT LEDs have been used in high-resolution LED matrices where dozens or hundreds of LEDs form patterns or characters. Because they can be placed by automated machines at precise intervals, achieving an even and closely spaced array is straightforward.

In summary, the SMT low-power series provides an optimal solution when you need a small, efficient, and versatile LED. From consumer gadgets and medical sensors to automotive indicators and beyond, these LEDs deliver reliable light output in a miniature form. Marubeni’s ability to offer custom configurations (multi-chip, special wavelengths, unique lensing) within this family means you can tailor the SMT LED to your exact application requirements, enjoying both the convenience of surface-mount technology and the performance of Marubeni’s high-quality emitters.