7070 White LED Datasheet - Package 7.0x7.0x0.8mm - Forward Voltage 37.7V - Power 10.6W - English Technical Document

1. Product Overview

This document details the specifications for the T7C series of high-power white light-emitting diodes (LEDs) in a 7070 package. This product is designed for general and architectural lighting applications requiring high luminous output and reliability.

1.1 Core Advantages

The LED features a thermally enhanced package design, which is critical for managing heat in high-power applications, thereby improving longevity and maintaining consistent light output. It offers high luminous flux output and is capable of operating at high forward currents. The package is compact with a wide viewing angle, making it suitable for a variety of lighting fixtures. It is compatible with lead-free (Pb-free) reflow soldering processes and is designed to comply with RoHS environmental standards.

1.2 Target Applications

• Interior lighting fixtures.
• Retrofit lamps for replacing traditional light sources.
• General illumination purposes.
• Architectural and decorative lighting.

2. Technical Parameter Analysis

2.1 Electro-Optical Characteristics

The primary electro-optical performance is measured at a forward current (IF) of 280mA and a junction temperature (Tj) of 25°C. The luminous flux varies with correlated color temperature (CCT). For a CCT of 2700K with a Color Rendering Index (CRI or Ra) of 80, the typical luminous flux is 1160 lumens (lm), with a minimum of 1000 lm. For CCTs from 3000K to 6500K (Ra80), the typical luminous flux is 1300 lm, with a minimum of 1100-1200 lm depending on the CCT. The tolerance for luminous flux measurement is ±7%, and for CRI measurement, it is ±2.

2.2 Absolute Maximum Ratings

These ratings define the limits beyond which permanent damage to the device may occur. The absolute maximum forward current (IF) is 350 mA. The pulse forward current (IFP) can reach 525 mA under specific conditions (pulse width ≤100μs, duty cycle ≤1/10). The maximum power dissipation (PD) is 14000 mW. The reverse voltage (VR) should not exceed 5 V. The operating temperature range (Topr) is from -40°C to +105°C. The storage temperature range (Tstg) is from -40°C to +85°C. The maximum junction temperature (Tj) is 120°C. The soldering temperature (Tsld) for reflow is specified as 230°C or 260°C for a maximum of 10 seconds.

2.3 Electrical/Optical Characteristics

Under standard test conditions (Tj=25°C), the typical forward voltage (VF) at 280mA is 37.7V, with a range from 36V (min) to 40V (max) and a tolerance of ±3%. The reverse current (IR) is a maximum of 10 μA at 5V reverse bias. The viewing angle (2θ1/2), defined as the full angle where intensity drops to half of the peak, is typically 120°. The thermal resistance from the junction to the solder point (Rth j-sp) is typically 1.8 °C/W. The device has an electrostatic discharge (ESD) withstand capability of 1000V (Human Body Model).

3. Binning System Explanation

3.1 Part Numbering System

The part number follows the structure: T [X1][X2][X3][X4][X5][X6] – [X7][X8][X9][X10]. Key codes include: X1 (Type code: 7C for 7070 package), X2 (CCT code: e.g., 27 for 2700K, 30 for 3000K), X3 (Color Rendering: 8 for Ra80), X4 (Number of serial chips), X5 (Number of parallel chips), X6 (Component code), X7 (Color Code: e.g., R for 85°C ANSI standard).

3.2 Luminous Flux Binning

The LEDs are sorted into luminous flux bins. For example, for a 4000K, Ra80 LED, bin 3C covers 1200-1300 lm, bin 3D covers 1300-1400 lm, and bin 3E covers 1400-1500 lm. Similar binning exists for other CCTs, allowing for selection based on required brightness levels.

3.3 Forward Voltage Binning

Forward voltage is also binned. Code 6L covers a VF range of 36-38V, and code 6M covers 38-40V, both at IF=280mA.

3.4 Chromaticity Binning

The color consistency is defined by 5-step MacAdam ellipses on the CIE chromaticity diagram. The document provides center coordinates (x, y) at both 25°C and 85°C, along with ellipse parameters (a, b, Φ) for various CCTs (27R5 for 2700K, 30R5 for 3000K, etc.), indicating tight color control. Energy Star binning is applied for CCTs between 2600K and 7000K. The tolerance for chromaticity coordinates is ±0.005.

4. Performance Curve Analysis

The datasheet references several key performance graphs (Fig 1 to Fig 6). These typically illustrate the relationship between operational parameters and device performance. Fig 1: Color Spectrum shows the spectral power distribution at 25°C. Fig 2: Viewing Angle Distribution depicts the spatial radiation pattern. Fig 3: Forward Current vs. Relative Intensity shows how light output changes with drive current. Fig 4: Forward Current vs. Forward Voltage is the IV characteristic curve. Fig 5: Ambient Temperature vs. Relative Luminous Flux illustrates the thermal derating of light output. Fig 6: Ambient Temperature vs. Relative Forward Voltage shows how the forward voltage changes with temperature. These curves are essential for circuit design and thermal management.

5. Mechanical and Package Information

5.1 Package Dimensions

The LED uses a 7070 surface-mount device (SMD) package. The overall dimensions are 7.00 mm in length and width. The package height is 0.80 mm. The document includes a detailed dimensional drawing showing the pad layout, with two anode and two cathode pads for the 2-series, 2-parallel internal chip configuration. Key pad dimensions include a width of 2.80 mm and spacing. The polarity is clearly marked. Unless otherwise specified, the dimensional tolerance is ±0.1 mm.

6. Soldering and Assembly Guidelines

6.1 Reflow Soldering Profile

A detailed reflow soldering profile is provided to ensure reliable assembly without damaging the LED. Key parameters include: Preheat from 150°C to 200°C over 60-120 seconds. Maximum ramp-up rate to peak temperature is 3°C/second. The time above liquidous temperature (TL=217°C) should be 60-150 seconds. The peak package body temperature (Tp) must not exceed 260°C. The time within 5°C of this peak temperature (tp) should be a maximum of 30 seconds. The maximum ramp-down rate is 6°C/second. The total time from 25°C to peak temperature should not exceed 8 minutes.

7. Application Notes and Design Considerations

7.1 Thermal Management

Given the high power dissipation (up to 10.6W at 280mA, 37.7V), effective thermal management is paramount. The low thermal resistance (1.8 °C/W) is beneficial but requires a well-designed metal-core printed circuit board (MCPCB) or other heatsinking solution to keep the junction temperature within safe limits, especially considering the derating of luminous flux with temperature (Fig 5). Exceeding the maximum junction temperature (120°C) will significantly reduce lifespan and reliability.

7.2 Electrical Drive Considerations

The LED should be driven with a constant current source, not a constant voltage source, due to the exponential IV relationship (Fig 4). The driver must be rated for the high forward voltage (typical 37.7V). Care must be taken to avoid voltage spikes or reverse bias exceeding 5V. The pulse current capability allows for potential dimming via pulse-width modulation (PWM), but the specified duty cycle and pulse width limits must be observed.

7.3 Optical Design

The wide 120° viewing angle makes this LED suitable for applications requiring broad, even illumination without secondary optics. For focused beams, appropriate lenses or reflectors will be needed. Designers should account for the binning selections (flux, CCT, Vf) to ensure consistency in the final product's brightness and color.

8. Frequently Asked Questions (Based on Technical Parameters)

8.1 What is the actual power consumption?

At the typical operating point of 280mA and 37.7V, the electrical power input is approximately 10.56 Watts (0.28A * 37.7V). Design the power supply and thermal system accordingly.

8.2 How do I select the right bin?

Choose the CCT bin (X2) based on the desired light color (warm white, cool white, etc.). Select the luminous flux bin (e.g., 3C, 3D) based on the required light output level for your application. The voltage bin (6L, 6M) may be important for driver design, especially in multi-LED arrays, to ensure current matching.

8.3 Can I drive it at the absolute maximum current of 350mA?

While possible, driving at the absolute maximum rating will generate more heat (approximately 13.2W, assuming VF~37.7V), pushing the junction temperature higher and accelerating lumen depreciation. It is generally recommended to operate below the absolute maximum, perhaps at the test current of 280mA, for optimal lifetime and reliability, unless the thermal design is exceptionally robust.

8.4 What does \"Pb-free Reflow Soldering Application\" mean?

It means the materials used in the LED package are compatible with high-temperature soldering processes that use lead-free solder alloys, which typically have higher melting points than traditional tin-lead solder. The provided reflow profile is designed for such processes.

9. Technical Principles and Trends

9.1 Operating Principle

A white LED typically uses a blue-emitting indium gallium nitride (InGaN) semiconductor chip. Part of the blue light is converted to longer wavelengths (yellow, red) by a phosphor layer coating the chip. The mixture of blue and converted light is perceived as white by the human eye. The correlated color temperature (CCT) and color rendering index (CRI) are controlled by the phosphor composition and concentration.

9.2 Industry Trends

The lighting industry continues to demand higher efficacy (lumens per watt), improved color quality (higher CRI, better R9 for red rendering), and greater reliability. Packages like the 7070 are part of a trend towards standardized, high-power SMD LEDs that offer good thermal performance and simplify manufacturing compared to older through-hole or COB (Chip-on-Board) packages for certain applications. There is also a focus on precise binning and tighter tolerances to ensure color and brightness consistency in finished luminaires.