Дизайн светодиодной печатной платы: примеры использования светодиодов и приложения

LEDs sound like a trivial technology. We often hear them and see them in our daily lives. LED PCBs are nothing new, and you probably heard about them dozen times. However, compared to previous lighting technology, they are innovative and efficient – enabling hundreds of industries worldwide to provide light-related services efficiently and safely.

Traditional light technology was power hungry due to high power (heat) discharge. Conventional light bulbs were more expensive and had a shorter life span than the new LEDs we use today.

In this article, we will cover what LED PCBs is and how LED PCBs are manufactured. This article will also explain, step by step, how to make an LED PCB board and the techniques involved in the PCB fabrication process. If you or your company is designing a brand new LED PCB, this article will benefit you throughout your journey.

What are LEDs and LED PCB designs?

LEDs stand for Light emitting diodes. Those diodes are solid-state semiconductors that turn electric current and voltage into light.

You might be wondering, What is so unique in LEDs technology? The answer would be a highly efficient and compact design. The LEDs can fit in PCB designs with different shapes and forms.

Back then, Traditional light bulbs were designed in a very particular way. They were power-hungry and expensive to produce. The semiconductors diode emitters, however, can fit in any PCB design. They enable companies to create many applications for hundreds of different industries. The led materials mainly consist of silicon, similar to many other products based on semiconducting materials.

LED PCB comes in many variations and designs. Each one has its pros and cons. Different LED PCB design techniques shall apply according to each company and product needs.

PCB LED structure

LED PCB board structures changes based on the application and requirements. The central concept of PCB manufacturing stays the same. Here are some of the materials used in custom LED PCB designs:

1. "FR-4", is one of the most common materials used in PCB production. It consists of glass, epoxy, and copper. The material is simple and cheap to produce and does an excellent job regarding industrial applications and heat resistance. However, this material has a disadvantage which is heat dispensing inefficiency. Heat dispensing should always be the priority be during the LED PCB design process.
2. Aluminum PCB – often consists of Aluminum and other types of metals, this kind of material is precious when it comes to efficient heat dispensing and insulation of electrical circuits. Aluminum PCB for LEDs is very common and considered the first choice when producing your LED PCB.
3. Epoxy PCB – a material often used in PCB production but isn't very common for LED PCB board designs. The reason is that epoxy is fragile. Other options, such as FR-4 and aluminum PCB are often recommended for LED PCB fabrication.

LED PCBs emit light which results in heat. In that case, the best material for heat dissipation would be Aluminum.

Because of the vital role of heat transfer in LED PCB applications, metals, especially Aluminum, are the most common LED PCB materials. Aluminum's low-cost and efficient PCB manufacturing process results in great manufactured products. Most manufacturers will recommend it for LED-related productions depending on the application's needs.

Aluminum PCB for LED

Aluminum PCBs, when used correctly, are highly efficient, brilliant heat dispensers and provide excellent signal connectivity. The PCB boards mainly consist of Aluminum but might also contain other materials such as silicon, magnesium, and different types of metal. When Aluminium PCB is produced, it has multiple layers, each with its function and use:

• The First layer – this layer consist, you guessed it, of Aluminum! As the first layer, it must be solid and durable. The other layers will base on top of the aluminum layer.
• The second layer consists of thermal insulation material, a material made out of ceramic polymer. The polymer prevents external PCB damage due to mechanical moving parts or heat dispensed on and around the board.
• LED circuit layer, The third and last layer. This layer consists of the custom design layout and schematic wiring. This layer contains mostly copper, similar to other PCB-designed boards.

The printed circuit boards are produced in multiple layers. Whenever it's 4 or 16 layers, the base, middle and final layer structure continues to persist. Multi-layer PCB is defined as having a multilayer of circuits. This might also increase the complexity and might produce more heat than expected.

Types of Aluminum boards

While the layer consistency of aluminum PCB stays the same, there are multiple options when it comes to the PCB type and its flexibility:

1. Flex aluminum PCB – as with any other PCB, flex PCB is always a great option. This type of PCB is often used in applications that might need some "bending" due to tight space or particular environment needs. The Flex aluminum PCB persists on its excellent insulation with added flexibility by design. The most significant disadvantage of the Flex board is the complexity of replacing damaged components. Flex PCBs are more fragile than rigid PCBs, which might be a problem in specific applications that often move or are exposed to harsh environmental conditions.
2. Hybrid PCBs with Aluminum – This type of PCB combines a rigid FR-4 PCB and an aluminum design. Combining both types can increase the PCB's durability and heat dissipation abilities. Hybrid PCBs come at a low and affordable cost which results. This allows LED designs to be manufactured and mass-produced with ease.
3. Multilayer PCBs – when it comes to multilayer PCB designs, aluminum material plays a crucial role. The board would provide efficient conductivity and performance if the multilayer LED PCB design consisted of over two layers. However, an essential part is its excellent heat dissipation ability. Multilayer PCBs are the most common types as they provide complex circuits with the necessary flexibility and capability.

The type of aluminum board used by the LED PCB design will likely depend on the project application needs. The critical points of LED PCB design include the heat dispensing ability and the insulation between the layers. To ensure the design functions properly, it's crucial to consider other factors such as the enclosure and environment.

Light PCB assembly

When it comes to LED PCB assembly, there are multiple options. The PCB might have a single or dual layout (single side or double side assembly). The community itself is done by two standard techniques – SMT and DIP:

• SMT PCB assembly – SMT stands for Surface-mount and is the most common way to assemble a PCB, and LED PCB is no different. We can archive this by mounting the components on top of the PCB using a pick-and-place machine. Once the details are mounted on the printed circuit board, the PCB is inserted into an oven. The oven will regulate the temperature and safely join the solder paste with the components. An efficient LED PCB assembly machine can paste thousands of PCBs a day. They are making this process highly efficient for mass production.
• DIP assembly – called through-hole PCB assembly, DIP components are inserted manually into designated holes. The PCB will then enter a wave-soldering machine that will solder the components in place. This process is less efficient than SMT. It has a higher fault rate due to the manual work involved in placing the details manually.
• Hybrid LED PCB assembly – some designs can't be either SMT or DIP and require both. In such a case, SMT will be done first, and the DIP components will be soldered by hand.

Regardless of the assembly technique used during the LED PCB manufacturing process, the LED PCB factories producing the board will ensure the board functions properly by using visual inspection and advanced machinery.

PCB LED applications and use cases

There are many benefits and use cases of LED designs. We often see them in LCDs, light bulbs, and consumer goods, but there are complex and critical applications which less known to us:

• Medical and hospital use – In surgery rooms or simple dentist checks, doctors use LED tech to save lives. LED is crucial because it doesn't emit high heat. It's bright and power efficient.
• Telecommunication and networking – Ever seen a server room? It's full of blinking LEDs! The telecommunication industry uses LEDs for indication purposes. Those indicators notify the staff if anything goes wrong in a timely matter. This is crucial, especially for server farms that must be consistently up to provide service at all times.
• Aviation industry – cockpits come with a bunch of LEDs and indicators, enabling the air commanders to know if anything goes wrong. Visual indicators are crucial in industrial applications where lives stand on the line. Also, have you ever noticed the passenger light goes on and off automatically mid-flight? This is due to an intelligent LED light circuit. By controlling the light timing and intensity, passengers can avoid having jetlags at the landing.

Summary

PCBs can be complex, but they don't have to. At PCBasic, we ensure your LED PCB design is manufactured with consistency, quality, and according to your specific design needs.

PCBasic, One of the Leading LED circuit board manufacturers, has over 15 years of experience in LED PCB board manufacturing and assembly, producing light board designs for top brands across the globe. Our factory is based in Shenzhen, China – the silicon valley of hardware.

This enables us to get the best quality of components for your light-emitting PCB design with ease. We only cooperate with authorized distributors and suppliers, ensuring the light components function properly.

LED components that are sensitive and fragile should be handled with extra care. We take extra precautions to ensure your production goes as smoothly as possible with as minimal risk.

For more information or inquiry regarding PCB, PCBA, and LED custom design – do not hesitate to contact us.