LEDs are a simple invention with huge potential to change the lighting industry for the better. Don’t know much about them? what is LED? Here are some things you need to know:

What Does LED Stand For?

LED stands for light-emitting diode.

A diode is an electrical device or component with two electrodes (an anode and a cathode) through which electricity flows – characteristically in only one direction (in through the anode and out through the cathode).

Diodes are generally made from semiconductive materials such as silicon or selenium – substances that conduct electricity in some circumstances and not in others (e.g. at certain voltages, current levels, or light intensities).

Most of the material, component, parts and machine for LED strip light solution can be found in PCBontime, such as printed circuits board (including rigid and flexible PCBs), led diodes, resistors, SMD assembly, full set machines for LED soft light strip, ESD plastic reels, ESD bags etc.

What is LED?

A light-emitting diode is a semiconductor device that emits visible light when an electrical current passes through it. It is essentially the opposite of a photovoltaic cell (a device that converts visible light into electrical current).

Did You Know? There is a similar device to an LED called an IRED (Infrared Emitting Diode). Instead of visible light, IRED devices emit IR energy when electrical current is run through them.

How do LEDs Emit Light?

LEDs (Light Emitting Diodes) are semiconductor light sources that combine a P-type semiconductor (larger hole concentration) with an N-type semiconductor (larger electron concentration). Applying a sufficient forward voltage will cause the electrons and holes to recombine at the P-N junction, releasing energy in the form of light.

Compared with conventional light sources that first convert electrical energy into heat, and then into light, LEDs (Light Emitting Diodes) convert electrical energy directly into light, delivering efficient light generation with little-wasted electricity.

Types of LEDs

Two types of LEDs are available, a lamp type (leaded) and a chip type (surface mount or SMD). Users can select the ideal type based on set requirements.

SMD LEDs

The light from white LED lamps and LED strip lights is usually provided by industry standard surface-mounted device LEDs (SMD LEDs). Non-SMD types of LED lighting also exist, such as COB (chip on board) and MCOB (multi-COB).

Surface-mounted device LED modules are described by the dimensions of the LED package. A single multicolor module may have three individual LEDs within that package, one each of red, green and blue, to allow many colors or shades of white to be selected, by varying the brightness of the individual LEDs. LED brightness may be increased by using a higher driving current, at the cost of reducing the device's lifespan.

SMD LED dimension

SMD LED chips are characterised by a rectangular shape that varies in length and width depending on the model.

The size of the SMD LED is what has the greatest influence on the brightness and power consumption of the device. The larger the device, the higher the brightness level. These characteristics are easy to understand thanks to the numerical abbreviation that identifies the different types of LED.

SMD RGB LEDs - what they are

SMD RGB LED technology allows the colour of light to be changed by using three diodes: red, blue and green. In order to vary the colour of the light, these diodes are mixed according to precise intensities.

In backlighting projects, it is common to use an RGB SMD LED source to give the light profile an aesthetic and design component and at the same time a functional aspect. Each colour can be associated with a specific application status to communicate a precise function to the end-user.

SMD LEDs: the colours available

SMD RGB LEDs offer a wide variety of colours in different combinations: blue, red, yellow and many others. The RGBW LED also has a white SMD LED variant, which stands for Red Green Blue and White. In the case of white SMD LEDs, a different shade of white can be seen depending on the specific source. The colour temperature of white, which can be warm, cool or neutral, depends on a number of factors, including the bin colour of a specific LED manufacturer.

SMD LEDs application

‧ General lighting

‧ Decorative and Entertainment Lighting

‧ Indicators

‧ Illumination

‧ Switch lights

What is color temperature?

Color temperature (Correlated Color Temperature, or CCT, in lighting tech jargon) is essentially a gauge of how yellow or blue the color of light emitted from a light bulb appears. It’s measured in the Kelvin unit and is most commonly found between 2200 Kelvin degrees and 6500 Kelvin degrees.

Warm light sources, such as incandescent bulbs, have a low color temperature (2200-3000K) and feature more light in the red, orange and yellow range. When you think of a warm color temperature, think of the warm, inviting light of a fire in the fireplace or a nice high-end restaurant with classy dim lighting.

Cool light sources, such as some HID or fluorescent lamps, have a high color temperature (>4000K) and feature more light in the blue range. When you think of a cool color temperature, think of the crisp white or blue light of school hallways or hospitals.

What is Color Rendering Index (CRI)?

While color temperature dictates the hue of light, the Color Rendering Index (CRI) measures how accurately a light source displays colors compared to natural light. CRI is rated on a scale from 0 to 100, with higher values indicating better color rendering.

A light source with a high CRI (90 or above) will reveal colors more vividly and accurately, making it easier to distinguish different hues. This is particularly important in environments where color accuracy is crucial, such as in art studios, makeup areas, or kitchens.

In contrast, a lower CRI might make colors appear washed out or distorted. For example, a CRI below 80 can make it challenging to differentiate between colors, which might not be ideal for tasks requiring precise color discrimination.

Everlight Electronics Co. Ltd. is a Taiwanese company which is the world’s seventh largest LED (light-emitting diodes) manufacturer. Its headquarters are in the city of Taipei. Everlight Electronics is a leading Optoelectronics provider of LEDs, LED Displays, Optical Sensors, Fiber Optic, Infrared, and Optocoupler components serving various applications in the consumer, computing, automotive, telecommunication and industrial market segments. In addition to offering a broad portfolio of products and high installed manufacturing capacities, Everlight Electronics is also vertically integrated by investing in LED optical chip manufacturing to maintain a stable supply of chips.

There are some other LED chips are also doing well in the market. Just like Citizen, Sharp, LG, Luxeon, GE, Togialed etc....LED lighting market is growing, good companies will have more opportunity in this market.

Top Quality SMD LED Chips Manufacturer

In led lighting business, the most important is the led chips. Most of the damage is from the led chips. So PCBontime Limited always deliver the top best quality led chips to ensure long life time of your LED lighting products.

Manufactured in the USA, CREE is one of the leading LED chip brands in the world with SMD LED chips ranging from 0.1W up to 5W and COB from 5W up to 200W. CREE manufacture LEDs for almost all kind of luminaries either it is a Bulb or a 1000W flood light. CREE high power LEDs are extremely efficient, with a luminous efficacy up to 200 Lm/W.

NICHIA is a Japanese LED brand, offering a broad range of SMD LEDs for general lighting applications with high colour rendering index, long lifetime and high lumens efficacy. NICHIA research designing of LED chips, the manufacture and markets LED all over the world used in all types of lighting applications. NICHIA standard LED is designed and developed as calibration standard of luminous and radiant quantities for LED products in collaboration with National Institute of Advanced Industrial Science and Technology (AIST). It has uniform spatial distribution, and has achieved excellent temperature stability and lighting reproducibility.

The Japanese manufacturer is one of the best-LED chips manufacturers when it comes to quality of light. As Toyoda Gosei used the same phosphor as Nichia, they can deliver superior light quality. The latest innovation from Toyoda Gosei is the Development of LEDs with light that reproduces natural sunlight based on proprietary technology which comes from mixing red, blue, and green phosphor. This new technology with proved a new level of a comfortable environment for the human, and with highest CRI it will allow people to see colour as if under sunlight. This new technology will fit perfectly within many lighting applications such as fashion retail, art and museum, and inspection process.

Based in Germany, OSRAM is one of the leading LED chip manufacturers in the world. OSRAM is also world’s largest optoelectronic semiconductors maker after Nichia.

Lumileds is one of the most selling LED chip brand in the world. Philips lighting using Lumileds in the manufacturing of most of their lighting products. Lumileds launches new 2835 LED which achieves 170lm/W. All Philips LED lighting products using the Lumileds chip which makes it one of the most selling LED chip brand. It is an excellent choice for LED indoor lighting. Lumileds was a joint venture between Agilent Technologies and Philips Lighting, but Later Philips acquired the company, and now it is known as Philips Lumileds Lighting Company.

Bridgelux is a USA LED brand. Our patented light source technology produces clean, white LEDs used as the core of commercial and industrial lighting. It’s a rapidly growing market, and everything we do is focused on understanding light’s impact on human behavior, and delivering products that create better environments and experiences. That’s why Bridgelux products are backed by research, world-class engineering, and human intuition.

South Korean LED manufacturer, Seoul Semiconductor develops LED chips for general lighting, automotive lighting and backlighting. Seoul Semiconductor developed world’s first high voltage AC driven LED.

As a forefront pioneer of LED technology, Samsung LEDs marks a new era in a global industry. SAMSUNG delivers a product line that comprises core components for LED lighting systems including modules for various uses in displays, mobile devices, automotive, and smart lighting solutions.

​​​​​One of the global leading high power LED chip manufacturer. From Taiwan, Edison Opto product range includes SMD LED chip in all packages, i.e. 3030, 2835, 5050, 5630 etc. and high power SMD LED chips in 3535 package. Edison is also manufacturing COB for high power applications up to 200W. Edison major products are a high power LED chips used in lighting equipment, such as indoor lighting, e.g. Bulbs, down lights, panel lights etc., special lighting, and outdoor lighting, e.g. Street lighting applications. Edison also manufactures individual LEDs for Automobile applications.

EPISTAR is a wafer manufacturer; different companies buy wafer which using for LED manufacturing. You can find different Epistar LEDs available in the market from different vendors/manufacturers.Epistar LEDs chips is a good affordable selection for in indoor lighting applications, e.g. LED Bulbs, LED downlights etc., while most of the COB chips are used in outdoor applications, e.g. Floodlights, street lights, tunnel lights etc. Epistar LEDs chips are available in all regular dimensions and packages, i.e. 3535, 5050, 5630 and most commonly used 2835.

Based in China, San’an is the leading, and most selling LED chip brand in China. Most of the LED lighting products manufactured in China uses San’an Chips in them. San’an produce LED chips of all packages that can be used in indoor, outdoor and all general lighting applications.