LED PLCC-2 White Specification - Size 3.5x2.75x0.7mm - Voltage 3.0-3.4V - Power 0.2W - English Technical Document

1. Product Overview

This white LED is based on a blue chip combined with phosphor conversion technology, offering high efficiency and a wide color temperature range. The package is a standard PLCC-2 (plastic leaded chip carrier) with dimensions of 3.5mm × 2.75mm × 0.7mm, suitable for automated surface mount assembly. It provides a typical luminous flux of 26-28 lumens at 60mA forward current, with a forward voltage of 3.0V to 3.4V. The device exhibits a wide viewing angle of 120 degrees, making it ideal for general illumination and indicator applications. It is RoHS compliant and has a moisture sensitivity level of 3. The LED is available in multiple color temperatures: 3000K (ERP 2780-3110K), 4000K (ERP 3770-4330K), 5700K (ANSI 5350-6050K), 6000K (ERP 5740-6530K), and 6500K (ERP 6050-6950K). The product is designed for applications such as indoor displays, tubular lights, and general lighting. Note: it is not recommended for flexible strips due to mechanical stress concerns.

2. Deep Technical Parameter Analysis

2.1 Optical and Electrical Characteristics

At a test condition of Ts=25°C and IF=60mA, the typical forward voltage is 3.12V (min 3.0V, max 3.4V). The reverse current at VR=5V is a maximum of 10μA, indicating good rectification. Luminous flux for all CCT variants is typically 26.5lm (min 26lm, max 28lm), with the 3000K version slightly lower at typical 25.5lm (min 24lm, max 28lm). The color rendering index (CRI) is typically 71.5 (min 70), which is acceptable for general lighting but not high-CRI applications. Thermal resistance from junction to solder point (RthJ-S) is 60°C/W, which must be considered in thermal design.

2.2 Absolute Maximum Ratings

Power dissipation is limited to 204mW, forward current to 65mA (peak 120mA with 1/10 duty cycle, 0.1ms pulse width). Reverse voltage maximum is 5V. ESD tolerance (HBM) is 2000V, with over 90% yield at this level. Operating temperature range is -40 to +85°C, storage -40 to +100°C, and maximum junction temperature is 110°C. These ratings must never be exceeded to ensure reliability.

3. Binning System

3.1 Forward Voltage and Luminous Flux Binning

At IF=60mA, forward voltage is binned into four groups: H1 (3.0-3.1V), H2 (3.1-3.2V), I1 (3.2-3.3V), I2 (3.3-3.4V). Luminous flux for all CCTs is binned as QIA (26-28lm). The tight binning facilitates consistent performance in application designs.

3.2 Chromaticity Binning

The CIE 1931 chromaticity diagram shows five specific bins for different color temperatures: E30 (extra warm white, ~3000K), E40 (warm white, ~4000K), A57 (neutral white, ~5700K), E60 (cool white, ~6000K), E65 (daylight white, ~6500K). Each bin is defined by four corner coordinates (X1Y1 to X4Y4) that define the acceptable color region. For example, E30 has coordinates: X1=0.4357, Y1=0.4144; X2=0.4212, Y2=0.3837; X3=0.4443, Y3=0.3916; X4=0.4588, Y4=0.4223. These bins ensure color consistency across different production batches.

4. Performance Curve Analysis

4.1 Forward Voltage vs. Forward Current

Figure 1-7 shows the exponential relationship: as forward voltage increases from 2.85V to 3.20V, current rises from near zero to 70mA. At the typical operating point of 3.12V, current is 60mA. This curve is critical for determining the appropriate series resistor in constant-voltage drive circuits.

4.2 Relative Intensity vs. Forward Current

Figure 1-8 shows a nearly linear increase in relative intensity from 0% at 0mA to 100% at 60mA, and beyond. Operating above 60mA can increase brightness but may reduce lifetime due to higher junction temperature.

4.3 Temperature Characteristics

Figure 1-9 shows relative luminous flux decreases with increasing solder point temperature: at 85°C, flux drops to about 85% of the 25°C value. Figure 1-10 shows maximum forward current derating: at 85°C, allowable current is approximately 40mA (vs 70mA at 25°C) to keep junction temperature below 110°C. Figure 1-11 shows forward voltage decreases slightly with temperature (about -2mV/°C). These curves are essential for thermal management in fixture design.

4.4 Radiation Pattern

Figure 1-12 shows a Lambertian-like radiation pattern: relative intensity is 100% at 0° angle and drops to 50% at approximately ±60°, confirming the 120° viewing angle. The pattern is symmetric, suitable for wide-area illumination.

4.5 Spectrum Distribution

Figure 1-13 shows spectral power distributions for 3000K, 4000K, and 6500K. The 3000K spectrum has a strong blue peak at ~450nm and broader yellow/red phosphor emission from 550-650nm. The 6500K spectrum has a more pronounced blue peak and less red content. These spectra comply with ERP and ANSI standards for the respective CCT bins.

5. Mechanical and Packaging Information

5.1 Package Dimensions

The top view shows a package body of 3.50mm length and 2.75mm width. Side view height is 0.70mm (excluding solder pads). The bottom view indicates two pads: anode (A) and cathode (C). Polarity is marked by a “+” symbol near the anode. A soldering pattern is provided for PCB layout: recommended pad dimensions are 2.10mm × 0.40mm for each pad (total 2.10mm × 1.10mm for rectangular area) with 2.10mm spacing between pads. All tolerances are ±0.05mm unless noted. Units are in millimeters.

5.2 Carrier Tape and Reel

The carrier tape has a width of 8mm with pocket pitch of 4.00mm. Each pocket holds one LED with polarity mark indicating direction. Feed direction is along the tape length. The reel has dimensions: A=12.4mm ±0.3mm, B=400mm ±2mm, C=100mm ±0.4mm, D=14.3mm ±0.3mm (inner hub diameter). A label on the reel specifies part number, spec number, lot number, bin codes (flux, chromaticity, voltage), wavelength (if applicable), quantity, and date.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

The recommended lead-free reflow profile: average ramp-up rate ≤3°C/s; preheat from 150°C to 200°C for 60-120 seconds; time above 217°C (TL) up to 60 seconds; peak temperature 260°C for max 10 seconds; cooling rate ≤6°C/s. Total time from 25°C to peak should be ≤8 minutes. Do not perform more than two reflow passes. Avoid mechanical stress during heating. Hand soldering: iron temperature <300°C for <3 seconds, one time only. Repairing with a double-head iron is possible but must be evaluated for LED damage.

6.2 Handling Precautions

The encapsulation is silicone, which is soft. Avoid pressure on the top surface. Do not mount on warped PCB. Avoid rapid cooling after soldering. Operating environment should limit sulfur compounds to <100PPM; bromine <900PPM; chlorine <900PPM; total Br+Cl <1500PPM. VOCs from fixture materials can discolor silicone; test compatibility. Use forceps to handle by side surfaces. Design circuit with current-limiting resistors to prevent burn-out from voltage shifts. Thermal design is critical: junction temperature must stay below 110°C.

7. Packaging and Ordering Information

7.1 Packaging Specification

Standard packaging quantity is 23,000 pcs per reel. The reel is placed in a moisture barrier bag with desiccant and humidity indicator card. The bag is then packed in a cardboard box. Moisture-sensitive level 3: after opening bag, devices must be used within 24 hours if stored at ≤30°C/60%RH. If not, baking is required: 24 hours at 60°C ±5°C.

7.2 Label Information

The label includes: Part No., Spec No., Lot No., Bin Code (for flux, chromaticity, voltage), Wavelength (if applicable), Quantity, and Date. The model naming convention is based on Refond’s internal system (shown as RF-PxxMI32DS-AF-N-Y), which encodes CCT, package type, and other features.

8. Application Recommendations

8.1 Typical Applications

This LED is suitable for optical indicators, indoor displays, tubular light applications, and general lighting. Its wide viewing angle and multiple CCT options make it flexible for ambient lighting. In tubular light designs, multiple LEDs can be placed on a linear PCB to achieve uniform light distribution.

8.2 Design Considerations

Always operate below absolute maximum ratings. Use appropriate series resistors to stabilize current. Provide adequate heat sinking, especially in high ambient temperatures. Avoid placing LEDs in high-sulfur environments. For outdoor applications, additional moisture protection may be required. The soft silicone lens may attract dust; clean with isopropyl alcohol if needed. Ultrasonic cleaning is not recommended.

9. Technology Comparison

Compared to traditional through-hole LEDs, this PLCC-2 package offers smaller footprint, lower profile, and compatibility with automated SMT processes, reducing assembly cost. Compared to other SMD packages (e.g., 2835, 3528), this 3.5×2.75mm device offers a balance between light output and thermal performance. The thermal resistance of 60°C/W is moderate, requiring careful thermal design for high-power applications. The 120° viewing angle is wider than many directional LEDs, making it suitable for uniform lighting. The CRI of 70-71 is typical for standard white LEDs; for applications needing high color rendering, other products with CRI>80 should be considered.

10. Common Questions

Q: Can this LED be driven at 65mA continuously? A: Yes, 65mA is the absolute maximum forward current at 25°C. However, derating is required at higher ambient temperatures; refer to the derating curve (Fig 1-10). For reliable long-term operation, 60mA is recommended.

Q: What is the typical lifetime? A: While not explicitly stated in the datasheet, typical white LEDs with this construction have L70 lifetimes exceeding 50,000 hours at rated current and proper thermal management, based on industry standards.

Q: Is this LED compatible with pulse-width modulation (PWM) dimming? A: Yes, the device can be dimmed via PWM if peak current does not exceed 120mA and duty cycle is limited (e.g., 1/10) to keep average current within limits. Ensure the PWM frequency is above 100Hz to avoid visible flicker.

Q: How sensitive is the color to drive current? A: White LEDs exhibit slight color shift with current due to changes in junction temperature and phosphor efficiency. For consistent color, use a constant-current driver and stable thermal environment.

11. Practical Design Case

Consider a 20W tubular light using 100 pieces of this LED. Each LED is driven at 60mA, 3.1V (typical), resulting in ~0.186W per LED, total 18.6W. The PCB is an aluminum-core board to dissipate heat. Average luminous flux per LED is 26.5lm, total 2650lm. With optical losses of 15%, the fixture output would be approximately 2250lm, achieving about 120lm/W system efficacy. Chromaticity bin E40 (4000K) is chosen for a neutral white appearance. The LEDs are placed in a linear array with 10mm pitch, and a diffuser provides uniform light distribution. Thermal simulation shows junction temperature below 85°C at 25°C ambient, ensuring long life.

12. Operating Principle

The white LED uses a blue-emitting InGaN/GaN LED chip (~450nm) that excites a yellow-emitting YAG:Ce phosphor layer. The combination of blue and yellow light produces white light. The exact color temperature is determined by the phosphor composition and thickness. This is a well-established technology for high-efficacy white LEDs. For specific CCT bins, different phosphor blends are used (e.g., adding red phosphor for warmer CCT like 3000K). The device operates under forward bias where electrons and holes recombine in the quantum well to emit photons. The wide viewing angle is achieved by the dome-shaped silicone encapsulant that acts as a lens.

13. Development Trends

The trend in white LEDs continues toward higher efficacy (>200 lm/W), improved CRI (>90), and smaller packages. New phosphor technologies (e.g., nitride phosphors) enable wider color gamut and better stability. Integration of LEDs with smart control (e.g., color tunability) is growing in demand. This PLCC-2 package may be replaced by chip-scale packages (CSP) for even smaller footprints. However, PLCC remains popular for general lighting due to its reliability and ease of handling. The use of lead-free materials and RoHS compliance is standard. Future developments may include higher current density and improved thermal resistance to reduce system cost.