What are SMD LEDs? Surface Mounted Device – radioelements that do not have additional mounting connections. They are attached directly to the surface of the circuit board.
This type of ultra-bright LED is widely used in lighting designs. Due to the absence of a housing, the installation density increases and the weight of the final structure is significantly reduced.
Explanation of LED markings
Consider the markings using the example of an SMD 3528 warm white light matrix.
LED-WW-SMD3528
- LED – light-emitting diode;
- WW – warm white – warm white;
- SMD – surface mount diode;
- 3528 – matrix dimensions.
Many manufacturers try to uniqueize their product with various tricks. This is how the 5636, 5736 series appear. Their characteristics are completely identical to the basic models, and the last number indicates only minor changes in the standard size.
Technical characteristics of SMD 3528 (datasheet)
SMD 3528 is a single-chip matrix with low current consumption and relatively low brightness. But precisely because of this, you can design any backlight without worrying about additional heat removal. This assembly is used in night lighting strips, in lighting systems for advertising lightboxes, and illuminated signs.
In the (RGB) version, three crystals are used in the matrix.
| LED type | Glow color | Size, mm | Luminous flux, Lm | Angle, degrees | Current, mA | Voltage, V |
|---|---|---|---|---|---|---|
| LED-WW-SMD3528 | White warm | 3.5 x 2.8 | 4,5-5,0 | 120-140 | 20 | 2,8-3,2 |
| LED-CW-SMD3528 | White | |||||
| LED-B-SMD3528 | Blue | 0,6-0,85 | ||||
| LED-G-SMD3528 | Green | 2,8-3,5 | ||||
| LED-Y-SMD3528 | Yellow | 1,2-1,6 | 1,8-2,0 | |||
| LED-R-SMD3528 | Red | |||||
| LED-RGB-SMD3528 | RGB | 0,6 | 120-140 | 20 | 2,0-2,8 | |
| 1,6 | 20 | 3,2-4,0 | ||||
| 0,3 | 20 |
SMD 3528 Dimensions
Standard sizes 3528 You can download the original datasheet SMD 3528 from the link.
Technical characteristics of SMD 5050 (datasheet)
SMD 5050 – three-crystal matrix. The power of a 5050 LED is proportional to three 3528 matrices placed in one housing. 5050 is used in surface mount systems where increased backlight brightness is required with a limited light emitter area.
| LED type | Glow color | Size, mm | Luminous flux, Lm | Angle, degrees | Current, mA | Voltage, V |
|---|---|---|---|---|---|---|
| LED-WW-SMD5050 | White warm | 5.0 x 5.0 | 10,0-12,0 | 120-140 | 3 x 20 | 3,2-3,4 |
| LED-CW-SMD5050 | White | |||||
| LED-B-SMD5050 | Blue | 2,0-2,5 | ||||
| LED-G-SMD5050 | Green | 8,0-8,5 | ||||
| LED-Y-SMD5050 | Yellow | 4,5-5,0 | 1,9-2,2 | |||
| LED-R-SMD5050 | Red | |||||
| LED-RGB-SMD5050 | RGB | 1,6 | 120-140 | 20 | 1,6-2,0 | |
| 2,5 | 20 | 2,8-3,2 | ||||
| 0,6 | 20 |
SMD 5050 Dimensions
Dimensions 5050 You can download the original datasheet SMD 5050 from the link.
Technical characteristics of SMD 5630 and 5730 (datasheet)
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Comparison tables of parameters
General table of technical characteristics 3528, 5050, 5630, 5730:
Comparison table of technical characteristics 3528, 5050, 5630, 5730 The type of LED is distinguished by crystal structure and color:
The exception is LEDs with three crystals on an LED matrix.
A three-chip SMD matrix, for example, in the 5050 series, has three anodes and three cathodes. It connects as three independent elements. For the RGB model 5050, the characteristics in the datasheet are written for each diode, since they have different power consumption parameters.
LEDs 5050 - connection diagram Such connection requirements are due to the fact that even absolutely identical crystals will have differences in the supply current and connecting without a current limiter will simply damage one of them.
REMEMBER!
- It is not recommended to connect any LED models to a power source without a resistor. When using one resistor, only one type of LED can be connected in series.
- In the case of using three-crystal diodes, each channel is connected through a separate resistor and connected to the same diode in the next module.
- Do not connect LEDs with different load characteristics. In simple words, do not connect 3528 and 5050 together.
- It is strictly contraindicated to use resistors with a resistance less than the nominal value. This will increase the load current of the LED and shorten its service life.
SMD LEDs are modern lighting devices that are installed as additional lighting. They have become basic components in LCD panel indicators, emergency and general lighting systems. The most popular modification has become, used to decorate apartments and commercial enterprises.
Marking features
Each SMD LED has a symbolic designation, with which you can find out the overall dimensions of the chip. This means that if the size is 4.5x2.0, then the marking accordingly is SMD 4520. The most popular standard sizes for modern LED strips are considered to be 3528, 5050 and 5630, you can also add 5730 to this list. With their help, complete lighting of residential and commercial premises. They practically replace standard incandescent lamps.
Among all these, the brightest is considered to be the 5630 type, which is often used in rooms with large windows. Each SMD diode has its own parameters:
Brightness and lighting power;
Energy consumption;
Dispersive power;
Lifetime;
Lighting temperature.
All these aspects are taken into account when purchasing LED strip or diodes separately. Particularly important are the parameters of temperature and scattering, which significantly affect the amount of light and its color. Cheaper models have an unpleasant yellow tint, while more expensive ones have cool, light tones.
Varieties
Pioneer: SMD 3528
SMD 3528 can be called one of the first diodes that marked the beginning of the development of such lighting technology. Their dimensions are 3.5 by 2.8 (as can be found from the markings), height – 1.4 mm. There are two contacts on both sides, and a key on the cathode side. The top is covered with phosphor luminous powder.
The standard operating current is 20 mA and affects the color of the lighting. The performance of the diode also depends on the overall temperature: when it reaches 80C, the indicator drops by almost a third. Luminous flux is 7.0 lm.
Updated: 5050
New technology has made it possible to implement multi-colored LEDs and the ability to adjust their color separately. The case size is 5x5, inside of which there are 3 crystals similar to the model described above.
It is not recommended to increase the maximum power more than 60 mA due to loss of quality. Operating temperature is: from -45 to +65 C. Luminous flux is no more than 18 Lm.
Latest development: SMD 5630X
The characteristics of SMD LEDs have been improved with this variation. New dimensions and semiconductor were implemented in a small 5.6x3.0 package. Compared to previous versions, it shows high efficiency and light output.
Dispersion can reach 58 lm, with a power of 150 mA. The voltage level directly depends on the level of white light. Thanks to the small substrate, heat removal is much faster and easier. It has four pins located next to the first contact mark.
An analogue of this option can be called 5730, operating in a pulsed current network. It has lower light resistance and increased flux, reaching 110 Lm.
With minimal consumption
They are considered the most effective and easy to use. SMD LEDs of this format have a reduced housing size, which significantly affects the ability to place them more densely on boards. The maximum dispersion is up to 13 lm, and the minimum is only 8 lm. Using them allows you to achieve brighter light, but also significantly reduce the energy consumption of the entire tape.
Conclusion
LED formats can be very different: those used in backlighting screens, for illuminating entire rooms or individual objects. Their main characteristics affect the overall energy consumption, and the dissipation ability affects the ability to organize proper lighting using LED strips. Modern technologies do not stand still and you can already notice new, ultra-bright options used in electronic equipment or a certain category of equipment.
LED lighting products are known for their performance, power, efficiency and durability. In recent years, SMD LEDs have begun to gain popularity. Thanks to better heat dissipation, the elements can be mounted on any surface.
SMD LEDs - what are they?
LED SMD – surface mount LED lamps. Their main difference from conventional diodes is the installation method, which determines the design features. The standard output version has long leads for installing the lamp through holes in the board. An SMD device has only contact pads - planer leads, so the product is attached directly to the board. This method is called surface mounting. Installation of diodes is very simple and can be done by a non-specialist.
This solution has another significant advantage. The characteristics of SMD LEDs include high light output with low electricity consumption. However, the realization of this advantage requires very good heat dissipation. Massive short leads are more efficient and dissipate heat better. In addition, the diode practically sits on the board and transfers heat to it.
SMD LEDs are more resistant to vibrations and mechanical damage due to their tighter fit.
Explanation of SMD LED markings
LED brands are designated in order to make their use more convenient. Only 4 digits are used for this, so it’s not difficult to “unravel” the designation.
Devices are classified by size, and the marking essentially indicates the size of the product. The numbers indicate the length and width in millimeters. For example, model 3528 has dimensions of 3.5 * 2.8 mm. Other information about the device can be obtained from the instructions.
Important! It is useful to study the instructions, since many Chinese manufacturers install lower-power chips in a typical case. At the same time, it is easy to purchase an LED with a power of 0.1 W instead of 1 W.
SMD LED Dimensions
The standard sizes of SMD LEDs to some extent determine the parameters of the product. There are many types of them, but the following 6 are among the most popular.
Dimensions, mm | Number of crystals | Power, W | Luminous flux, Lm | Operating temperature, C |
||
The table includes only the basic parameters, but allows you to compare the luminous flux and power of the device.
Important! The power of the luminous flux depends on the color of the LED.
In addition to those listed, they also produce a variety of 3 and 6 volt LEDs, which are used to backlight LED TVs, computer monitors, tablets, and smartphones.
Characteristics of SMD LEDs
Each type of SMD LED is characterized not only by the amount of radiation and the amount of current consumed, but also by other parameters. The type of product determines the application of the device and installation features.
3528 LED Specifications
As can be seen from the table, the SMD 3528 LED can be single-chip or triple-chip. In the first case, it can generate white neutral and warm light, as well as yellow, blue, green and red. In the second, it serves several flowers at once. The single-chip version is equipped with 2 terminals for connection, and the three-chip version is equipped with 4 (1 cathode and 3 anodes). To prevent environmental influences, the crystals are filled with a transparent compound. The material may include a phosphor: this is how the color parameters of the device are equalized.
The luminous flux that the device emits is small. But SMD 3528 has miniature dimensions and regenerates different colors. Due to this, LEDs are used in lighting strips and inexpensive decorative lamps.
5050 LED Specifications
The SMD 5050 LED can include 3 or 4 crystals. For a single-color lamp, crystals of the same or similar shade are chosen. 5050 has a higher brightness - 3 times more than 3528. The diodes provide the same protection: a transparent compound or phosphor.
The device has the best power-to-price ratio and provides any color of light output. As a rule, 5050 is installed on decorative lighting strips - single-channel, RGB, RGBW. If you increase the mounting density - up to 60 pieces per 1 m, the LED strip can be used not only as decoration, but also to illuminate interior elements. The strips are equipped with controllers that allow you to adjust the shade and intensity of the light.
5630 LED Specifications
Element 5630 has only a single-chip design, but is distinguished by high power: it generates a luminous flux of 57 lumens. The color is white, with different temperatures: cold, daytime, warm. The device is protected by 2 antistasors and can withstand a current pulse of up to 400 mA.
The LED has 4 pins, but only 2 provide operation of the element. The other 2, together with the substrate, are required for heat removal. Diodes are used in the manufacture of powerful lamps and spotlights.
Important! The brightness of the diode depends on the air temperature. At +85 degrees the indicator drops by 25%.
5730 LED Specifications
The single-chip version has the same power as the 5630, but the three-chip SMD LED 5730 is three times more powerful: it produces light with a brightness of up to 158 lumens. Also designed to produce a white luminous flux, but with different color temperatures.
The modification has a very low thermal resistance, which makes it possible to do without two additional pins, as in the 5630. At the same time, it can also withstand pulse current.
The element is characterized by high performance and is used in the same way as 5630 - in the production of high-power LED lamps.
Characteristics of LED 3014
Single-chip element of moderate power - up to 11 lumens, and very small sizes. A compound is used as protection. The LED produces white light - warm, cool, primary colors, as well as orange. This relatively recently appeared modification is classified as low-current.
When installing the product, you need to take into account its peculiarity: its leads are atypically long and reach the bottom of the case. Thus, heat dissipation is improved.
The main purpose of 3014 is modules and strips of decorative lighting. Diodes are often used in the production of automobile lamps and tabletop devices.
2835 LED Specifications
Of all types of SMD LEDs, this model is the most powerful: it emits about 20% more light than 5730. This can reduce power consumption. The single-chip device is produced in three versions of different power. It emits white light of different temperatures. It is similar in size to element 3528, but has a round lens.
This option is the most popular, as it is used in the manufacture of literally any lighting fixtures: outdoor lamps, spotlights, household LED lamps. And this means a large number of fakes, where instead of a one-watt diode they install an element of lower power.
Application of SMD LEDs
LED lamps are used so widely that it is impossible to list all areas of application.
Most often, devices of this kind are found in the following products:
- pocket and tactical flashlights - 6 volt LED lamps are installed here;
- lamps and turn signals on cars;
- household lighting products of various types;
- decorative lighting, mounted both inside and outside the building, uses crystals that generate different colors;
- signs, indicators, traffic lights, billboards;
- SMD LEDs are extremely popular in landscape design; the elements are not afraid of vibration and low temperature, which allows you to organize the most interesting lighting options;
- Low-current modifications are actively used for indication.
In each case, diodes of the required power are selected. In this case, the color of the light flux is taken into account.
Connection requirements
You can install diodes on any surface: on a concrete ceiling covered with wallpaper, on a plastic panel, next to tension films. Thanks to good heat dissipation, the possibility of damaging the material is eliminated. But although the installation of devices is very simple compared to output devices, installation requires the implementation of several recommendations:
- to connect the product to a power source, you need to use a driver, otherwise the LED may fail or operate incorrectly;
- if only 1 resistor is used, the elements should be connected in series to avoid variations in parameters;
- It is forbidden to connect diodes with different operating current values in series, in this case some of the elements will glow dimly;
- if the current is too high, the LED overheats and burns out; accordingly, it is permissible to install a resistor only with sufficient resistance.
If you plan to install garden lighting, you should choose products that are protected from moisture and dust.
Conclusion
SMD LEDs are distinguished by very good heat dissipation, which, on the one hand, ensures their operation at fairly high temperatures, and on the other hand, allows them to be mounted on any surface. There are a lot of types of elements, so for any case - from a spotlight to an indication, you can choose the appropriate modification.
LED is a semiconductor device that converts electric current into light radiation. Unlike incandescent and energy-saving lamps, they are more durable and energy efficient. Based on their design, they are divided into two main types – DIP and SMD.
They differ in housing design and contact arrangement. In this article we will talk about SMD diodes.
Surface Mounted Device (SMD) – a device mounted on a surface. In other words, if a DIP LED has long contact legs and is mounted through holes in the electrical board, then SMD analogs are mounted directly on the board or in the LED strip, since they have small contacts.
Japan is a leader in the development of LED technology, SMD diodes in particular. That's why they have the best products.
SMD element housings
The main type is a rectangular plastic case.
Mass production has been established specifically for this type. If we take ordinary diodes, and not light sources, then there is also a cylindrical metal-glass housing. For the needs of lighting specifically, there is no point in such a design.
The dimensions of the SMD LED element are more important. They can be identified by their markings.
SMD semiconductor marking
The four numbers in the marking indicate the length and width in hundredths of a millimeter. For example, a 1206 diode is 12 mm long and 6 mm wide.
The annotation RGB means that the LED can produce one of three colors - red, green or blue.
For a radio amateur, knowledge of these two parameters in the marking of SMD diodes is usually sufficient.
Brief technical characteristics and application
SMD LEDs with markings 5050, 3528 and 5630 (5730) are popular. It is in the LED strip that such SMD crystals are used, which is why they have become widespread.
But there are quite a lot of other standard sizes. Here are the main ones (brief descriptions and areas of application, the most common of them):
0603. Power 1.9 - 2.3 watts. Commonly used in car dashboards and screen backlights in some mobile phones.
2835. Power 0, 2 – 1. Used in LED lamps, pocket and tactical flashlights. Good energy savers. But mostly only white.
Not to be confused with the 3528, which is older and not as energy efficient.
3528. Appeared a long time ago. Unlike 2835, it is available in different colors: warm and cool white, red, green, yellow and blue.
3014. Power 0.1 W. Modern LEDs. It is difficult to name a specific area of application; there is little information on the Internet.
3030. 1.5 - 2.2 W. For repair of LCD and LED TVs.
3535. 1-3 W. They have taken a firm place in the market due to their high heat output. They are actively used in street lighting and in production.
5050. 0.2 or 0.26 Watt. It's basically just three 3528 diodes in one package. Used for beautiful general lighting - bars, restaurants, hotels, etc.
5630. 0.5 Watt. The best application is in LED strips. They require good cooling, which is why they are almost never used in other areas.
0805 and 1206 are not very common. They are mainly used by radio amateurs or for illuminating phones (smartphones).
5730. Power from 0.5 to 1 watt. Average characteristics and low price. It is found in lamps of all types: from decorative lighting to street and industrial lighting. One of the most common crystals.
LEDs are becoming increasingly popular in modern lighting systems. They are actively used in design, decoration, and other areas. LED sources emit pure light, are economical and safe. Nowadays, SMD LEDs are increasingly used, known as surface mounted devices, which means a surface-mounted device. Their power and luminous flux are constantly increasing, just like traditional light bulbs with long stems and a round plastic lens.
General structure and principle of operation of SMD LEDs
The main advantage of such LEDs is their maximum proximity of the crystal relative to the heat sink. This factor is important when emitting a powerful light flux with the release of a large amount of heat. The power of one SMD LED is in the range of 0.01-0.2 W, and from 1 to 3 crystals can be installed on a separate ceramic substrate.
Due to its design, the contact pads of the LED substrate are directly connected to the circuit board. A wide lighting angle and other parameters are possible with a standard base. These LEDs are widely used in various displays and scoreboards due to their small housing sizes. They are easily mounted on boards, combined into strips and rulers, convenient for subsequent separation and installation. A wide range of housing sizes significantly expands the scope of use of SMD LEDs.
To grow crystals, a standard technology is used, which is metal-organic epitaxy. The thickness of each grown layer is constantly measured and strictly controlled. Special impurities are added to individual layers - acceptors or donors, which ensure the formation of a p-n transition, when electrons are concentrated in the n-region and holes in the p-region.
At a certain stage, the films are etched, contacts are created to the transition layers, and the contact leads are covered with a metal film. Such a film is grown on a common substrate, after which it is cut into many chips with an area of 0.06-1.0 mm. These chips are later used to make LEDs.
Finished crystals are installed in special cases. Then contacts are made to them, and at the end an optical coating is mounted on the crystal to reflect radiation or, conversely, to brighten the surface. For example, when producing a white LED, phosphor is applied uniformly. At the next stage, heat is removed from the housing with the crystal, and then it is covered with a plastic dome to focus the light at the desired angle. Manufacturing LEDs in this way involves the use of new technologies, which account for about half the cost of the entire light source.
There is a special technology for placing SMD LEDs on a single substrate. In short, it is called COB, which means chip-on-board or chip on a board. When using this technology, several crystals are placed on the board at once, which do not have ceramic substrates and cases. The installed crystals are subsequently covered with a common layer of phosphor, which can significantly improve the characteristics and reduce the overall cost of the entire matrix.
Regardless of the manufacturing technology, all SMD LEDs are mounted on a common metal substrate, which often performs a cooling function. If the LED assembly has increased power, additional cooling is arranged using a radiator and fan.
Thus, low-power SMD LEDs, installed in large quantities in the lamp, make it possible to obtain high-quality diffused light without using any special optical systems. In this case, only protective glass is installed, absorbing only 8% of the light flux.
Pros and cons of SMD LEDs
Despite their lower power compared to fluorescent lamps, LEDs of this type are among the most promising. Due to white radiation, high accuracy of color and shade reproduction is ensured. SMD LEDs, due to their excellent luminous efficiency, reaching 146 lumens per W, are suitable for use in lighting systems.
The designs of these LED light sources are characterized by increased resistance to vibration and mechanical stress. Therefore, they are actively used in industrial and street lighting. The service life of such LEDs is about 30 thousand hours, with daily operation of at least 8 hours. All types of devices, including SMD 3528, SMD 5050 and others, can withstand any number of on and off cycles.
SMD lamps are distinguished by a wide range of colors, which includes not only radiation intensity, but also shades. In this regard, there is no need to use light filters. Many LEDs, for example, SMD 5630 and SMD 5730, have low inertia, that is, they immediately begin to work at full power. There is no need to wait for heating and subsequent glow, as is the case with conventional lamps.
LEDs SMD 3014, SMD 2835 and other similar elements have different emission angles. During operation, a directed light flux is generated, illuminating a specific area, and not the entire surrounding space. The undoubted advantage of such lamps is their absolute insensitivity to cold weather.
Disadvantages include intolerance to high temperatures, which requires additional measures for ventilation and heat removal. It should be noted the high cost of these devices, which fully pays off during further operation.
Characteristics of SMD elements
LEDs of this type differ from other products due to their own specific characteristics. First of all, their entire design is designed for surface mounting, eliminating the need for soldering, fastening and assembly. Most SMD LEDs have low thermal resistance, that is, they do not heat up and can be placed on any surface - ceilings, plastic panels, near tension fabrics, etc.
Depending on the brand, the sizes of SMD LEDs can be very different, and therefore they are successfully used in any place. During operation, the radiation power of these elements remains unchanged.
Many LEDs have a silicone coating to promote sealing and improved heat dissipation. In order to correctly select the right product, special markings of SMD LEDs are used, which display all the main parameters.
The technical characteristics are displayed more clearly in the table:
|
Options |
3528 |
5050 |
5630 |
5730 |
2835 |
|
Luminous Flux (Lm) |
100 |
||||
|
Power, W) |
0,06 |
0,2 |
0,5 |
1,0 |
0,2 |
|
Temperature (0 C) |
|||||
|
Current (A) |
0,02 |
0,06 |
0,15 |
0,3 |
0,18 |
|
Voltage (V) |
3,3 |
3,3 |
3,3 |
3,4 |
3,3 |
|
Dimensions (mm) |
3.3x2.8 |
5.0 x 5.0 |
5.6x3.0 |
5.7x3.0 |
2.8x3.5 |