LED circuit boards are being used worldwide, but how many can claim to know how they are made? Or how do they function? Hence, this article must read for anyone who intends to understand how does an LED light works. So far, we know that LEDs consist of a circuit board that allows the heat to dissipate and the light to be turned on. However, the actual mechanisms of the process are still unknown to most people. For which we will dive deep into this article to find out how do LEDs work? What is a LED PCB board? What does PCB stand for? And a lot of detail about the design and material aspects of this board.
What is an LED PCB Board?
Belonging to the classification of electroluminescent lights, LEDs abbreviated as light-emitting-diodes are semiconductor diodes. They emit light by joining charge-carrier pairs with sufficient energy gaps inside a semiconductor. These lights are either single or double-colored LEDs that emit two shades of light, white and blue.
Consequently, they act as an indicator light for the membrane switches, are much more suitable for usage underneath the polyester materials and rubber keypads. Hence, the LEDs’ soldering with a PCB that stands for “Printed Wiring Board” by a manufacturer produces light once the tiny chips are electronically charged. A ceramic base along with a thermal heat sink are the two things that bond the chip. Hence LED PCB is an essential part of the LED lighting, which we so commonly use these days, without knowing the technology that works to make these lights work. While LED PCBs are hard to cool down using traditional methods, they are easy to heat up. Hence a PCB with a metal core is used in applying the LED manufacturing process due to its ability to dissipate heat; for the same reasons, some manufacturers use aluminum to manufacture PCB LEDs. Aluminum PCB is able to produce much more significant amounts of heat as it has consisted of a dielectric material that is very thin yet dissipates more energy than the traditional PCB.
How Does the LED PCB Design?
Two significant design aspects need to be kept in mind while designing a LED PCB circuit board. Firstly, you must remember to drill holes for your LED lights’ placement, as these dilled holes are the most critical module of your design. Secondly, estimate the distance among the PCB holes. Our tip here would be to keep the distance to a minimum to accommodate the cathode and anode that will power the led lights effectively.
Once you have decided where the drills go and where the holes will be placed, ensure you save your file in a Gerber file format, the PCB standard format.
The Gerber file format can be tricky as there are so many layers to the circuit board you must be aware of what role each layer is playing. For instance, let’s take three layers of the Gerber file format; layer zero can be the PCB outline, Layer 1 can contain the copper wire structures, and layer two might have the information about the drilled holes.
LED Circuit Board Design
After you have made the Gerber file template, it is necessary to note down all the instructions and the information in a Microsoft Word Document to ensure that the manufacturers have the correct information in their hands. Certain aspects that need to be taken into consideration are mentioned below:
- Finalizing the layout of the board design:
The first and most crucial step in producing the LED PCB boards is the finalization of the circuit board’s design and layout. There are many ways to go about it; meanwhile, the constraints are there as well, much like any other business. Budgets, availability of materials, and range of the machines, these aspects will determine the design and the layout of the board. Hence, when coming to a conclusive design, these are the aspects that need to be kept in mind. As the layout of the board is the most crucial step of all.
- Orientation management:
Orientation on a LED PCB board refers to the flow in which the circuits are arranged from one point to the other. Generally speaking, all circuit boards have one or two entry points and one to two exit points. Data on the circuit board travels typically in one direction from one entry point to the exit point. The engineer’s job is to make sure that all the orientation of the entry and exit points are well synchronized and not jumbled up in a mess. All the entry and exit points need to be in one direction, which makes it much easier and cleaner.
- Component placement:
While we are on the subject of orientation, it’s worth noting that a PCB circuit board has many more components that need to be integrated into the panel. Those among us wonder what must these look like and what they are? The answer is quite simple. These are capacitors, resistors, and so much more. What do they look like? Well, have you ever disassembled a circuit board or any machine? You will find cylinders and chips and so many other structures attached to the circuit board. The point is to assemble all these components so that they are not in the way of the solder side of the circuit board.
- Manage the PCB outline:
Managing the PCB outline is a significant task. Making sure you don’t place any of the components next to the PCB outline will ensure that the circuits will not fail or any other kind of problems will not be caused due to the circuits’ placement, and they will not dislodge on their own from the board. The only elements that need to be on the edge of the panels are the sockets.
- Placing of critical components:
An effective way to ensure the industry’s best practices in the placement of all the Surface Mounted Devices to be placed on top of the LED PCB board. As per the industry’s suggested guidelines, following these guidelines will ensure that the best and best practices are applied. One of the significant aspects that the industry guidelines suggest is to place all the through-hole items or components above the board, which will further reduce assembly steps.
- Placement of the VIAs:
Vertical interconnect access is a system of circuit boards that can be placed between multiple layers vertically. Some cases can be identified where the circuit goes from the surface to the interior, which can be seen in the case of multi-layered PCBs; in other cases, one course may be extended from one edge of the board to the other. Copper designed; these are placed inside the board once the holes are drilled in the PCB. Surface Mounted Technology “SMT” is the method used to integrate the SMD “Surface Mounted Devices” onto the circuit board. Mentioning all of this information is critical in understanding the importance of the placement of the VIAS as it cannot be placed near the SMT pads since that may migrate the solder away. This may cause a faulty joint as the pad can enter the via space. The best idea would be to keep a distance of 0.025 inches or more among the SMT pad and Via.
- Widths definition and design:
The circuit board may require a lot of varying current flows. This variability may require larger size circuit boards as the net width of the circuit board may vary. Generally, for the size of the low digital and analog signals a wire, width of 0.010 inches is recommended. However, those circuit boards carrying 0.3 A electricity need to be more comprehensive.
What are LED PCB Materials?
Depending on the usage of the circuit board, the manufacturing of these circuit boards involves the usage of a number of materials, setups, and designs. The most crucial aspect of the circuit board is the composition of the material used.
Following are some of the most common core materials used:
- FR-4:FR stands for Fire Retardant, and it does what the name suggests. It is mainly made of glass and epoxy, and it’s the most widely used core material. However, it is not as efficient in transferring heat.
- Epoxies:Another one of the most common options used in PCB Circuit boards. However, they are not as durable as compared to the rest of the core materials. Since they aren’t as durable, the cost of the epoxies is lesser than its competitors.
- Metal-Core:PCBs with metalcore often comprise aluminum fused with a lamination of copper along with different metals. For electrical insulation, heat transfer, and thermal conductivity, all of these materials offer excellent results.
Since heat transfer plays the most vital role in the LED PCB usage, aluminum, among all the other metals, is the most durable and commonly used LED PCB Material.
Aluminum Sheet Material
Aluminum Circuit Board:
The most commonly used LED PCB is the Aluminum PCBs. These boards are placed on an aluminum alloy base consisting of magnesium, aluminum, and silicon. Altering the properties of materials used to assist in meeting the needs of each usage, hence these LED PCB boards are so effective.
Layers of Aluminum PCBs:
- Base layer:An alloy Aluminum sheet is used as a base layer, and it is the base layer that the whole PCB is laid upon.
- A layer of Thermal Insulation:A ceramic polymer layer is placed in the thermal insulation layer that allows the board to remain protected from mechanical and thermal damage. Since the electricity travels through the board, the thermal insulation layer is responsible for absorbing the heat and transferring it directly to the aluminum layer, from where it is dispersed.
- Circuit layer:This is the layer where all the components are laid out based on the LED PCB circuit design that is shared with the manufacturers.
The number of layers may vary depending on the design of the board.
There is a large variety available in aluminum material. All of these options and varieties offer different characteristics, making them ideal for multiple purposes.
Flexible Aluminum: As the name suggests, these LED PCBs consist of polyimide, aluminum, ceramic fillers, and resin, providing increased insulation and flexibility while containing the thermal conductivity of the aluminum. These PCBs can be flexed, eliminating the need to attach connectors, fixtures, and other wires. However, the cables are designed to be bent once and be put into place; repeating the flexing process is impossible. These PCBs are different from conventional boards that are rigid and do not bend.
Hybrid Aluminum: Hybrids are made by combining aluminum and non-thermal metals such as the conventional FR-4 board. While it may benefit in reducing the cost of the board, it also increases rigidity. However, it does deliver superb heat dissipation.
Multi-layered Aluminum: These PCBs are made of more layers than two and are made of thermally conductive dielectrics. These boards are capable of dissipating heat effectively and do provide high performance. However, as compared to the other boards, these boards are less effective in transferring heat.
LED PCB Assembly:
When assembling a LED PCB pitch, you can use various techniques to design your board.
The Pitch is a unique design method that can be used on various parts of the board. Also, there are many effective ways of achieving this if you are working with a copper layer, which is why it is necessary to cover one of the board’s sides with pads arranged in the style of a matrix.
An assembled LED’s components generally are arranged on the driver’s side, and it usually has four pads. In the case of a smaller LED pitch, it is essential that the large size of the LED must be avoided, as it may affect the resolution and display.
While developing a pitch, always keep in mind the range that should be used in assembly. For the LED Pitch, the range lies between 1.0 to 4.0 (mm). For the SMT pitch, the range lies between 0.45 to 1.6 (mm).
LED Installing holes:
The LED holes are non-infiltrating, and they consist of the individual specification. Keeping that in mind, the board thickness should be -0.5mm. Also, the drilling angle must be 1300. At the same time, the depth tolerance should be no more than 30.2mm. However, the tolerance of the diameter should be 30.5mm. If it’s seen that some of the holes consist of an inadequate distance at a copper-less area, you will be required to plate through the holes. This way, the copper will not be bare at the margin of Vias.
Blinding Laser Drilling Vias:
If you have a board with at least two layers, and in case you stack your design in a laser drilling style, then blind electrical soldering is safe to use with the filling method. However, you need to know that applying this method is expensive and may cause some complications. Also, in case you have more than two layers, then it’s better to design your laser drilling blind vias.
Solder Mask Opening Pad:
Opting for this technique, you will have to ensure that your pads are placed in a highly consistent way. This way, you can utilize copper on the pads, ensuring you will be able to ensure the peeling of the solder mask doesn’t happen.
Space between Outer Margins and Outer Pads:
Maintaining some distance between the outer margin and pads is necessary. That’s because if there is a lack of space, you may end up experiencing issues such as milling detections and copper exposure.
Mounting an SMD on PCB LED
SMD stands for surface-mounted devices that are used on the LED PCB. All of the SMDs placed above the board work in complete unison in order for it to function properly. The sizes of SMDs are becoming smaller as the technology improves. This means that the complexity of the assembling of these products is also increasing. The SMD LEDs are really small light-emitting diodes that are placed on the PCB, with great perfection and hard work.
- Put the PCB on a level and dry surface with the component side facing upwards.
- Recognize the places where the LEDs are to be fastened on the PCB utilizing the circuit board chart. Make careful notice of the extremity of the pads, such as the positive and negative terminals of the LED.
- Using tweezers, position the first LED between the respective pads on the PCB. After putting the LED between the two pads, verify that about half of the pads are visible and that the polarity is right.
- Set the soldering iron to 450 degrees Celsius and turn it on. Before proceeding to the next stage, wait until the temperature reaches this level.
- Touch the tip of the solder wire to the tip of the soldering iron for a few seconds. Any of the solders will melt and build upon the iron’s tip. Using the tip of tweezers, gently click the LED. With the tip of the soldering iron, strike the interface of one of the LED terminals and corresponding pad. The weld motion will stream to the pad and will cover a piece of the LED terminal too. Rehash this interaction on the opposite finish of the LED.
- Patch the following LED utilizing a similar strategy. Spot the binding iron tip once again into its holder and turn off the welding iron.
The Benefits of LED PCB:
Aluminum PCBs have become the new norm in the LED industry for many businesses. This is due to the numerous advantages and features that aluminum PCBs offer. The following are some of the advantages:
Less Expensive: Aluminum can be found in mines all over the world, making it relatively inexpensive to obtain and refine as opposed to other metals. Aluminum is much less costly than other rare metals due to its abundance. As a result, aluminum manufacturing is less costly, especially when it comes to aluminum PCBs.
As compared to the heat transfer methods, such as heat sinks, aluminum-based circuit boards are often less costly. Heat sinks are marginally more efficient at transmitting heat than aluminum bases, but they are considerably more expensive to include in the PCB.
Environmentally friendly: Aluminum Soda Cans and aluminum boards are also recyclable, as well all know. Since aluminum PCBs are recyclable and non-toxic, they are relatively simple to dispose of and are suitable for the environment.
Improved durability: Aluminum is much more durable than ceramic and fiberglass. This solid, long-lasting material resists breakage and can withstand the stresses of the manufacturing process. This also means that the final PCB is more damage resistant from normal handling, particularly in environments where there is a lot of impacts.
Lightweight: Aluminum is extremely light, despite its durability. This means that a PCB’s stability can be enhanced without adding weight, which is n essential factor in manufacturing. It results in a lighter finished product, but it also reduces the cost of shipping and storing circuit boards and the end products in bulk quantities.
Better heat transfer: Consistently high temperatures in electronics can cause severe damage and impair functionality. As a result, heat transfer is the most critical aspect of a completed PCB.
The word “heat transfer” refers to how well thermal energy transmits from one location to another. The efficacy of a material’s conduction, evaporation, and radiation are the determining factors by material’s conduction, evaporation, and radiation. Conduction is the transferring of thermal energy from one region to another by a liquid. At the same time, convection means transferring thermal energy from a metal to a fluid, and radiation is the quantity of thermal energy released by a material.
The Lighting Industry:
LEDs with PCBs that are aluminum-based are very suitable for a variety of applications and industries due to the advantages mentioned above. Aluminum LEDs are used in a variety of applications, including:
Telecommunication: Telecommunication hardware often makes use of LED indicators and screens, and the enhanced heat transfer capacity of LED PCBs with aluminum base is very useful in application due to surrounding machinery. These aluminum PCB LEDs are also ideal for telecommunication applications due to their increased durability and reduced weight. Furthermore, aluminum PCBs are widely used for other telecommunication parts, such as high-frequency amplifiers and filtering appliances.
Automotive: Aluminum PCB LEDs can be used in cars, such as on indicators, headlights, and brake lights, among other places. Aluminum PCBs are suitable for the automotive sector because of their reliability, low cost, and longevity. Aluminum PCBs can also widely be used in power controllers and electronic regulators, so their uses are limited to LEDs.
LED Display: LED displays and pointers have become very popular in computer appliances, and because of the heat sensitivity of the computer machinery, aluminum PCB LEDs are one of the best options. The usage of Aluminum PCBs is widely common in computer parts such as power devices, CPU boards, and floppy drives because they are able to transfer and handle the heat.
Medical: High-powered LED lights are widely used in surgical and medical examination rooms, and these LED lights often use Aluminum PCBs. This is due to the reliability and heat transferability of aluminum PCB LED, which ensures that medical equipment continues to operate correctly, no matter how many patients go through the facility. Aluminum PCBs are often used in medical scanning technology, along with lighting instruments.
Aluminum PCB Types:
The layers can be modified in a variety of ways to build new PCB designs. Each of these modifications results in slightly different characteristics, making it ideally suited to some industries more than others.
Aluminum PCBs come in a variety of shapes and sizes:
Polyimide resin and ceramic fillers are used in flexible aluminum to provide outstanding flexibility and insulation while preserving aluminum’s excellent thermal conductivity. These PCBs can be shaped to bind directly with points where needed. This removes the need for wires, plugs, and fixtures that may increase the final product cost. These PCBs aren’t built to flex multiple times, so once bent, they are supposed to stay in that shape.
Hybrid aluminum is created by fusing a non-thermal material into an aluminum base metal. This material’s usage is more common in circuit boards made of FR-4. The board can disperse heat more efficiently and improve the rigidity by joining the layers together. These hybrids are also less costly than items made entirely of aluminum. The disadvantage is that versatility is lost.
Multilayer aluminum PCBs are typically the best in case of high performance and high-power supply usage. These PCBs are made up of thermally conductive dielectric layers. While these multilayer approaches are capable of high efficiency, it is inefficient in the matter of transferring heat. However, in more intricate designs, these PCBs are usually helpful for simple heat dissipation.
A PCB’s aluminum base can be either pre-drilled or back-filled with dielectric before it gets laminated with thermal materials for more advanced construction. These are very challenging projects that require a lot of time and effort, and they are usually reserved for the most difficult or specialized jobs.
How to Choose the Best LED PCB Board Manufacturer:
One of the top leaders of the market is PCBMay. Since LED lights are sensitive to heat temperature and LED PCBs can be complicated, you’ll need a company with experience and top-of-the-line equipment to bring them together. EMSG has been dealing with LED lighting from the beginning of the technology, so we have the experience and the expertise to help you achieve your requirements.
The consistency in quality of the goods comes first. It is probably an inferior product if the illumination isn’t very bright, flickers, or the brightness of the light looks off.
Such consistency aspects include:
- Does the manufacturer’s substance meet or exceed the requirement of the regulatory body? Underwriter Laboratories and the American National Standard Institute are two such organizations in the United States.
- Is there a warranty available? Be sure you understand what is insured in the warranty and what it does not.
- What is the energy consumption of the LED? After all, one of the most significant advantages of LEDs is that they are Energy Efficient. If a product from one company uses far more resources than similar products from another manufacturer, you should generally cross that manufacturer off the list.
- Has the LED’s success been independently verified? What parameters were included in the testing, and how was it performed?
Even if the quality is superior, you don’t want to purchase anything you cant afford. A trustworthy and customer service-oriented producer, on the other hand, can direct you to solutions that will fulfill your objectives while remaining within budget.
Yes, the materials used, how the LEDs are manufactured, and the company’s standards are significant factors to consider. However, you should get more from your seller than just a decent product.
What is their customer service, for example? Do they answer immediately and courteously to your queries and requests? Will they cooperate with you? They should have the ability to assist you with everything related to LED purchases. After all, you are probably unaware of the construction procedure. What licenses are you going to need? Would your project necessitate the use of subcontractors, and when do they begin and finish?
You might also need assistance with staff preparation and assessing where and how much your LED lighting or monitor needs to be serviced. Strong project management covers both of these points, and this service is extremely beneficial to the business.
These are some of the key factors about the LED PCB construction and assembly. Also, be careful while choosing a manufacturer. Please leave feedback down below.