LT3004WH-A-GL White LED Specification - Size 3.0x0.85x0.42mm - Voltage 3.0V - Power 60mW

1. Product Overview

The LT3004WH-A-GL is a white surface-mount LED designed for general illumination and backlight applications. It utilizes a blue InGaN chip combined with a yellow phosphor to produce white light. The package is a PLCC (Plastic Leaded Chip Carrier) type with dimensions of 3.0mm × 0.85mm × 0.42mm, making it suitable for compact designs. This LED offers a wide viewing angle of 120°, high luminous intensity up to 3250mcd, and excellent reliability. It is RoHS compliant and has moisture sensitivity level 3. Key applications include LCD backlighting and mobile phone backlighting.

2. Technical Parameter Analysis

2.1 Electrical Characteristics

At a test condition of IF=20mA and Ts=25°C, the forward voltage (VF) is typically 3.0V with a range from 2.7V to 3.3V depending on bin. The reverse current (IR) at VR=5V is less than 1µA. Absolute maximum forward current is 30mA, and peak forward current (1/10 duty, 0.1ms pulse) is 100mA. Maximum reverse voltage is 5V. Electrostatic discharge (HBM) rating is 2000V. The LED junction temperature (Tj) must not exceed 105°C.

2.2 Optical Characteristics

Luminous intensity (Iv) at IF=20mA is typically 2650mcd, ranging from 2150mcd to 3450mcd depending on bin. Viewing angle (2θ1/2) is 120 degrees. The color coordinates are defined in the CIE 1931 chromaticity diagram, with multiple bin groups (N0 to N4, M0 to M4, and MN groups) for precise color control. The spectrum distribution shows a peak wavelength around 450nm from the blue chip and a broad yellow emission from the phosphor, resulting in white light.

2.3 Thermal Characteristics

The LED junction temperature must be kept below 105°C. The forward current derating curve (Fig. 1-9) shows that as solder temperature increases, the maximum allowable forward current decreases to ensure Tj ≤ 105°C. Proper thermal management, such as adequate PCB copper area and heat sinking, is essential for reliable operation.

3. Binning System

3.1 Luminous Intensity Binning

At IF=20mA, the luminous intensity is divided into bins from 30 to 42, each covering a range of 100mcd. For example, bin 30 covers 2150-2250mcd, bin 36 covers 2750-2850mcd, and bin 42 covers 3350-3450mcd. Equivalent luminous flux (in lumens) is also provided for each bin.

3.2 Forward Voltage Binning

Forward voltage is binned from V0 (2.7-2.8V) to V5 (3.2-3.3V) in 0.1V steps. All measurements are at IF=20mA, Ta=25°C, with tolerance ±0.03V.

3.3 Chromaticity Binning

The CIE 1931 chromaticity coordinates are divided into multiple groups (N0 to N4, M0 to M4, and MN groups) for precise color consistency. Each group defines a small rectangular region in the chromaticity diagram, ensuring tight color control for backlight and display applications.

4. Performance Curves

4.1 Forward Voltage vs. Forward Current (Fig. 1-7)

The VF-IF curve shows a typical exponential diode characteristic. At 20mA, VF is approximately 3.0V. The curve helps designers predict voltage drop at different drive currents.

4.2 Forward Current vs. Relative Intensity (Fig. 1-8)

The relative luminous intensity increases almost linearly with forward current up to 50mA. This linearity is useful for dimming applications.

4.3 Spectrum Distribution (Fig. 1-10)

The spectral power distribution shows a blue peak at about 450nm and a broad yellow phosphor emission from 500nm to 700nm. The white light has a high color rendering index suitable for general illumination.

5. Mechanical and Packaging Information

5.1 Package Dimensions

The LED has a PLCC package with dimensions 3.0mm × 0.85mm × 0.42mm. Tolerances are ±0.1mm unless otherwise noted. The package has a silicone lens on top, which is soft and requires careful handling.

5.2 Carrier Tape Dimensions

The LEDs are supplied on 12mm wide carrier tape with pocket dimensions A0=0.95mm, B0=3.15mm, K0=0.55mm. Pitch P1=4.00mm, P2=2.00mm, P0=4.00mm. Reel diameter is 178mm with 5000pcs per reel.

5.3 Polarity and Marking

The LED has a cathode mark (typically a notch or dot) on one side. Refer to the package drawing for polarity orientation.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

The recommended reflow soldering profile follows JEDEC standards: preheat from 160°C to 260°C over 60-120 seconds; time above 217°C (TL) should be 60-120 seconds; peak temperature 260°C for a maximum of 10 seconds (within 5°C of peak). The cooling rate should not exceed 6°C/s. The total time from 25°C to peak should be less than 8 minutes. Do not perform more than two reflow passes, and if the interval between passes exceeds 24 hours, the LEDs may be damaged due to moisture absorption.

6.2 Hand Soldering

For manual soldering, the iron temperature must be below 300°C, and the contact time should be less than 3 seconds. Only one hand soldering operation is allowed.

6.3 Handling and Storage

Moisture sensitivity level is 3. Before opening the sealed bag, storage conditions: ≤30°C, ≤75% RH, shelf life 1 year from date of sealing. After opening, the LEDs must be used within 24 hours (≤30°C, ≤60% RH). If the storage conditions are exceeded or the desiccant has faded, baking is required at 60±5°C for ≥24 hours.

6.4 Handling Precautions

Avoid applying mechanical stress or pressure on the silicone lens during pick-and-place. Use vacuum nozzles with proper force. Do not warp the PCB after soldering. Avoid ultrasonic cleaning which can damage the LED. Use isopropyl alcohol for cleaning if needed.

7. Packaging and Ordering

7.1 Packaging Details

Each reel contains 5000 pieces. The reel diameter is 178mm, width 12.8mm. The carrier tape is sealed with a cover tape. The labeled information includes part number, bin code, luminous intensity (Iv), forward voltage (VF), wavelength code (WL), quantity, date code, and lot number.

7.2 Moisture Resistant Packing

The reels are vacuum-sealed in a moisture barrier bag with desiccant and a humidity indicator card. The bag is then packed in a cardboard box.

7.3 Ordering Information

Customers should specify the desired bin codes for luminous intensity, forward voltage, and chromaticity when ordering. The standard product is LT3004WH-A-GL.

8. Application Recommendations

The LT3004WH-A-GL is ideal for LCD backlighting (especially small to medium size), mobile phone keypad and display backlight, indicator lights, and decorative lighting. Its compact size allows high-density mounting. For uniform backlighting, multiple LEDs can be used in arrays with appropriate diffusers. The wide 120° viewing angle provides good off-axis brightness. In circuit design, a current-limiting resistor is essential to prevent overcurrent. For dimming, PWM (pulse width modulation) at frequencies above 1kHz is recommended to avoid flicker. When using the LED in series/parallel strings, ensure balanced current distribution using ballast resistors or constant-current drivers.

9. Reliability Test and Failure Criteria

The LED has passed reliability tests including reflow soldering (260°C max, 10s), thermal shock (-40°C to 100°C, 100 cycles), high temperature storage (100°C, 1000h), low temperature storage (-40°C, 1000h), life test (Ta=25°C, IF=20mA, 1000h), high temperature/humidity storage (60°C/90%RH, 1000h), and high temperature/humidity operation (60°C/90%RH, IF=15mA, 500h). Acceptance criterion is 0 failures out of 20 samples for each test. Failure is defined as VF > USL×1.1, IR > USL×2.0, or luminous flux < LSL×0.7.

10. Frequently Asked Questions

Q1: What is the typical forward voltage at 20mA? A: Typically 3.0V, with bin range 2.7V-3.3V.

Q2: Can I drive the LED at 30mA continuously? A: Yes, 30mA is the absolute maximum forward current, but careful thermal management is needed to keep junction temperature below 105°C. For long life, consider derating to 20mA.

Q3: How do I select the correct bin for my application? A: Choose luminous intensity bin according to required brightness, voltage bin according to driver voltage compliance, and chromaticity bin for color consistency. Typical backlight applications use bins in the N or M groups.

Q4: Can the LED be used in outdoor environments? A: The operating temperature range is -30°C to +85°C, but the silicone encapsulant may degrade under prolonged UV exposure. For outdoor use, ensure additional protection from direct sunlight and moisture.

11. Design Case Study

Case: LCD Backlight for 7-inch Display A 7-inch display requires uniform backlighting with a luminance of 300cd/m². Using 30 pieces of LT3004WH-A-GL arranged in 5 rows × 6 columns, each driven at 20mA, the total current is 600mA. With a light guide plate and diffuser, the system can achieve the required brightness. The forward voltage per LED is approximately 3.0V, so a 12V supply with series resistors (e.g., 330Ω per row of 6 LEDs) will work. The PCB layout should include thermal vias to dissipate heat. Reliability testing confirms the LEDs maintain >90% lumen maintenance after 10,000 hours at 25°C ambient.

12. Working Principle

The white LED uses a blue-emitting InGaN (indium gallium nitride) semiconductor chip. When forward current passes through the chip, electrons and holes recombine radiatively, emitting blue light (peak ~450nm). This blue light partially excites a yellow-emitting phosphor (typically YAG:Ce) coated on the chip. The combination of the blue light and the yellow phosphor emission results in white light. The exact color temperature and color rendering index depend on the phosphor composition and coating thickness. The PLCC package provides mechanical protection and a reflective cavity for efficient light extraction.

13. Technology Trends

The LED industry is moving towards higher efficacy (lumens per watt), smaller packages (e.g., 1.6x0.8mm chip-scale packages), and better color consistency (narrow binning). The LT3004WH-A-GL represents a compact PLCC solution with good performance for current applications. Future trends include integration of multiple LEDs in a single package (e.g., RGB white), improved thermal management, and use of quantum dots for enhanced color gamut. For backlighting, mini-LED and micro-LED technologies are emerging, but PLCC LEDs remain cost-effective for medium-volume products.