Technical - Information on Specifications

 

At E Wave, we welcome customer LED enquiries. After understanding our customer's requirements, E Wave will propose our ' best match' specification, which all deliveries will adhere to. The notes on this page explain some of the background in what determines our specifications.

Wavelength (nm) Customer's can either give us their wavelength requirement as (i) a specific wavelength with precise tolerances, or (ii) a wavelength range. For example, if our customer required a wavelength (dominant) of 518 nm +- 2 nm, E Wave could offer 515.0 ~ 520.0 nm, or 517.5 ~ 520.0 nm. E Wave can measure every LED chip for wavelength (dominant or peak) and offer very precise tolerance if necessary. In LED chip delivery, E Wave provides wavelength data including: minimum, average, maximum and standard deviation.

LED Intensity (mcd) or Power (mW) This is normally the most important specification for customers. Depending on the volume of LEDs required by a customer, E Wave may undertake custom growth of the LED chips, or custom probing and sorting of the LED chips, to meet customers' requirements.

Forward Voltage (V) E Wave can measure forward voltage for every LED chip and in delivery, provide data including: minimum, average, maximum and standard deviation. E Wave can undertake voltage sorting to provide batches of LED chips within 0.1 mV voltage ranges. This can be very useful for customers placing multiple LED chips in series.

Electro-Optic Specifications (LED chips and packaged parts)

Visible Wavelengths (420 ~ 680 nm)

Term
units
  Description

Dominant

Wavelength

nm
nanometre Sometimes called the hue, the dominant wavelength is calculated from the CIE graph. It is the best specification to ensure colour repeatability between orders. Depending on the wavelength, tolerances of +- 2.5 nm and better can be guaranteed on low and high volume deliveries.
Intensity

mcd

cd

millicandella

1 candella = 1 lm/sr.

Sometimes called the brightness, the intensity refers to the amount of visible power (lumens) emitted by an LED, into a given solid angle (steradian, sr). NB: 1 sr is equal to a solid angle of 65.5 degrees, a hemisphere has a solid angle of 2 pie sr.

Intensity values are the normal specification for comparing LED chip grades. However, for packaged LEDs, the beam angle has to be considered when comparing intensity. Eg, a LED chip producing an intensity of 100 mcd, can be packaged as a 300 mcd LED with a 5 degree beam angl, or packaged as a 50 mcd LED with a 100 degree beam angle.

Luminous Flux
lm
lumen This is the total amount of visible power emitted by the LED. This value is becoming more important for LEDs as they are used as alternatives to incandescent and other traditional lights.

Non-Visible Wavelengths (350~400 and > 680 nm)

Term
units
  Description
Peak Wavelength
nm
nanometre  
Radiant Intensity
mW/sr
milliwatts per steradian A useful measure of how much radiation is being emitted in a particular direction. Particulary important for packaged LEDs, where the application needs a certain amount of radiation in a target area.
Radiant Flux

mW

W

milliwatt

watt

Also called the radiant power, this is the total amount of radiant power emitted by the LED. This can be measured in an integrating sphere, or with a calibrated photometer.

 

 

 

 

 

 

 

 

 

 

RoHS Compliant products

Copyright E Wave Corporation

 

 

 

 

LED Products

 

 

 

 

 

Contact

T:44(0)20
8123 7843
E Wave Corporation
Building 3, North London Business Park
Oakleigh Road South
London N11 1GN
United Kingdom