LED 1608 White - 1.6x0.8x0.4mm - 2.6-3.4V - 68mW - English Datasheet

1. Product Overview

1.1 General Description

This white LED is fabricated using a blue chip and phosphor to produce white light. The package dimensions are 1.6mm x 0.8mm x 0.4mm, making it suitable for compact electronic devices. It is designed for surface mount technology (SMT) assembly and is RoHS compliant.

1.2 Features

• Extremely wide viewing angle (140 degrees)
• Suitable for all SMT assembly and solder processes
• Moisture sensitivity level: Level 3
• RoHS compliant

1.3 Applications

Optical indicators, switches and symbols, displays, and general illumination purposes.

2. Technical Parameters

2.1 Electrical and Optical Characteristics (Ta=25°C)

Forward voltage (VF) at IF=5mA is binned from 2.6V to 3.4V in steps covering bins F1 (2.6-2.7V), F2 (2.7-2.8V), G1 (2.8-2.9V), G2 (2.9-3.0V), H1 (3.0-3.1V), H2 (3.1-3.2V), I1 (3.2-3.3V), I2 (3.3-3.4V). Luminous intensity (IV) at IF=5mA ranges from 90 mcd to 250 mcd across bins: 1AP (90-120 mcd), G20 (120-150 mcd), 1AW (150-200 mcd), 1AX (200-250 mcd). Viewing angle is 140 degrees (typical). Reverse current is maximum 10 µA at VR=5V. Thermal resistance from junction to solder point (RTHJ-S) is maximum 450°C/W.

2.2 Absolute Maximum Ratings

The following limits should not be exceeded: Power dissipation 68 mW; Forward current 20 mA; Reverse voltage 5 V; Peak forward current (pulse 0.1ms, 1/10 duty) 60 mA; Electrostatic discharge (HBM) 1000 V; Operating temperature -40 to +85°C; Storage temperature -40 to +85°C; Junction temperature 95°C. Care must be taken to ensure junction temperature does not exceed this rating.

3. Binning System

The LED is sorted into bins based on chromaticity (CIE 1931 coordinates) and luminous intensity. The chromaticity bins are defined in the CIE diagram with coordinates for bins B01-B06 and K01-K06. These bins cover cool white to neutral white regions. Luminous intensity bins are as described in Section 2.1. Forward voltage bins are also provided to facilitate circuit design. The bin code on the label specifies the exact VF, chromaticity, and flux rank of the device.

4. Performance Curve Analysis

4.1 Forward Voltage vs Forward Current

The typical VF-IF curve shows exponential behavior: at low currents the voltage rises rapidly, then becomes more linear. At nominal 5 mA, VF is typically in the range 2.8-3.2 V depending on bin. At 20 mA, VF increases by about 0.2-0.3 V.

4.2 Forward Current vs Relative Intensity

Relative intensity increases approximately linearly with current from 0 to 20 mA. At 5 mA, the output is around 25% of the maximum (20 mA). This curve helps in selecting drive current for desired brightness.

4.3 Temperature Effects

The relative intensity decreases with increasing ambient temperature. At 100°C, the intensity drops to about 85% of its value at 25°C. The forward current must be derated at high temperatures to avoid overheating. The Pin Temperature vs Forward Current curve shows that at 100°C, the allowable forward current is reduced to about 15 mA.

4.4 Spectrum and Radiation Pattern

The spectral distribution shows a blue peak at approximately 450 nm from the LED chip and a broad yellow emission from the phosphor, resulting in white light. The correlated color temperature (CCT) is typical of a neutral white. The radiation pattern is lambertian-like with a wide 140° viewing angle, providing uniform light distribution.

5. Mechanical and Packaging Information

5.1 Package Dimensions

The LED package measures 1.6 mm × 0.8 mm × 0.4 mm with tolerances of ±0.2 mm. The top view shows the light-emitting area, bottom view shows electrode pads, and side view shows the thin profile. Polarity is indicated by a mark on the top view. The recommended soldering pad pattern is 2.4 mm × 0.8 mm for each pad, with a spacing of 0.8 mm, as shown in Figure 1-5.

5.2 Carrier Tape and Reel Dimensions

The carrier tape is 8 mm wide with a pocket pitch of 4 mm. The reel has an outer diameter of 178 ±1 mm, hub diameter of 60 ±1 mm, and width of 13.0 ±0.5 mm. Each reel contains 4000 pieces of LEDs.

5.3 Label Information

Each reel is labeled with part number, specification number, lot number, bin code (including flux code, chromaticity bin, VF bin, wavelength code), quantity, and date code.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

The recommended reflow profile follows JEDEC standards. Preheat from 150°C to 200°C for 60-120 seconds. Ramp-up rate should not exceed 3°C/s. The time above 217°C (liquidus) is 60-150 seconds. The peak temperature is 260°C with a maximum dwell time of 10 seconds (within 5°C of peak). Cooling rate should be ≤6°C/s. Total time from 25°C to peak is maximum 8 minutes. Do not perform reflow soldering more than twice.

6.2 Hand Soldering and Repair

If hand soldering is necessary, use a soldering iron at ≤300°C for less than 3 seconds per pad. Only one hand soldering operation is permitted. Repair after reflow is not recommended; if unavoidable, use a double-head soldering iron and pre-qualify the process.

6.3 Precautions

Avoid mounting on warped PCB; do not apply mechanical stress or vibration during cooling; do not cool rapidly after soldering.

7. Packaging and Ordering Information

The LEDs are packaged in moisture barrier bags with desiccant and humidity indicator. Storage conditions before opening: ≤30°C, ≤75% RH, valid within 1 year from date of packaging. After opening: ≤30°C, ≤60% RH, must be used within 24 hours. If the storage time is exceeded or the desiccant has changed color, bake the LEDs at 60±5°C for at least 24 hours before use. The outer packaging is a standard cardboard box suitable for shipment.

8. Application Suggestions

Due to its small size, this LED is ideal for dense PCB layouts. Use current-limiting resistors to ensure the forward current does not exceed 20 mA. Consider thermal design: the LED should be mounted with adequate copper area to assist heat dissipation. Avoid exposing the LED to sulfur-containing environments (>100 ppm) or halogenated compounds (Br>900 ppm, Cl>900 ppm, total >1500 ppm) as they can cause corrosion and discoloration. For cleaning, use isopropyl alcohol; do not use ultrasonic cleaning as it may damage the LED.

9. Technical Comparison

Compared to larger SMD packages like 2835 (2.8×3.5 mm) or 3528, the 1608 package offers a 75% smaller footprint while still providing sufficient brightness for indicator applications (up to 250 mcd). Its wide 140° viewing angle is advantageous for applications where uniform light distribution is needed. However, its maximum forward current is limited to 20 mA, resulting in lower total flux compared to high-power LEDs. It is best suited for low-power, space-constrained designs.

10. Frequently Asked Questions

10.1 How should I handle ESD sensitive devices?

Always use grounded workstations, wear anti-static wrist straps, and store LEDs in anti-static packaging.

10.2 What if the moisture barrier bag is damaged?

If the bag is damaged or if the humidity indicator shows >30%, the LEDs must be baked at 60±5°C for 24 hours before use.

10.3 Can I use different drive currents for dimming?

Yes, the LED can be driven with currents from 0 to 20 mA. Note that chromaticity may shift slightly with current. Pulse operation with low duty cycle is possible up to 60 mA peak.

10.4 Is this LED suitable for outdoor use?

The operating temperature range (-40 to +85°C) is suitable for many outdoor applications, but proper encapsulation and protection from humidity and contaminants are required.

11. Application Cases

Case 1: Smart home thermostat backlighting - the small footprint fits on a compact PCB, providing white status indication. Case 2: Automotive interior button illumination - wide viewing angle ensures visibility from multiple angles. Case 3: Battery level indicator on portable electronics - low power consumption extends battery life.

12. Operating Principle

This white LED utilizes a blue-emitting InGaN chip that emits light at ~450 nm. The chip is coated with a yellow-emitting phosphor (typically Ce-doped YAG). The blue light partially excites the phosphor to emit yellow light; the combination of blue and yellow light appears white to the human eye. The ratio of blue to yellow determines the correlated color temperature.

13. Development Trends

The trend in the LED industry is toward smaller packages with higher efficacy. Chip-scale packaging (CSP) and flip-chip architectures are gaining popularity for better thermal performance and reduced size. This 1608 package represents a mature technology that remains widely used for indicator and display applications. Future developments include higher brightness per unit area and improved color stability over temperature.