After sifting through my posts, I realized that I&#;ve neglected to write something that&#;s a little more suitable for somebody who&#;s brand spankin&#; new to the world of LED COBs. This guide will serve as a short introduction to the basic elements of COB LED lighting systems, and is a good place to start if you&#;re looking to make the switch from other types of lighting, or if you&#;re new to indoor gardening altogether.
For more flip chip cob supplierinformation, please contact us. We will provide professional answers.
COB LED systems are actually quite simple &#; there are only a handful of different parts, and they all go together pretty easily. The main components of a COB LED system are:
The COB LEDs themselves
Heat sinks that the COBs are mounted to
LED drivers that power the COBs
The wires that interconnect the COBs and drivers.
Not so bad, right? Let&#;s delve a little further in.
The main component of a COB LED lighting system would obviously be the lights themselves. The term COB stands for &#;Chip On Board&#;, and refers to the fact that each unit is actually several LED (Light Emitting Diode) chips mounted together on the same substrate, which is often ceramic or metal. LEDs are semiconductors that produce photons of light when electrons flow across a junction and fill &#;electron holes&#; on the other side.
COB manufacturers release data sheets for their products that dictate each unit&#;s specifications, as well as minimum, typical, and maximum values for a number of different variables. A sample of Cree&#;s data sheet for the CXB can be found here. A few examples of a COB&#;s characteristics that can be found in the data sheet include:
Color temperature (how &#;warm&#; or &#;cool&#; is the color of the light?)
Typical forward voltage (what will the voltage be across the COB at a certain level of current?)
Maximum current (how many amps of current can you drive the LED with before it dies?)
Temperature (how does the maximum current rating change, based on the temperature of the COB case?)
Luminous Flux (how bright is the light when measured at a given current and temperature?)
Relative Spectral Distribution (what wavelengths of light are most concentrated in the light produced by the COB? Does it peak in the blue range or red range?)
So, how do these little chips get mounted? Well, if there are screw holes in the board, you can screw them down, but the better alternative is always to get a holder, if possible.
If you hate soldering or don&#;t have an iron, you&#;re in luck. Many COBs have matching holders that can be used to mount the COB to the heat sink and also offer a push-in connection for wiring to the COB terminals. The holders fit over top of the COB, and screw down into the heat sink, sandwiching the COB and forcing it to press tightly against the sink. Once it&#;s in place, you can simply push wire into the holder&#;s terminals (the white plastic pieces you see on the silver holders in the picture below), which press down on the corner contact points of the COB. Nice and simple!
If you want to focus your light more, you can add reflectors that attach to the front of the COBs (this often requires a separate adapter though). You can get reflectors in different angles, colors and materials, depending on what you need to accomplish. You can also attach glass lenses or diffusers to the reflectors to protect the COBs from dirt, water, and other garden gunk.
Despite being very energy-efficient, high-powered COB LEDs do dissipate a lot of power in the form of heat. If this heat builds, it can alter the COB&#;s characteristics and subsequently damage the unit, so it must be removed somehow. The sole purpose of heat sinks in a COB light system is to pull this heat away from the COBs and keep them running as cool as possible. Heat sinks are most often made of aluminum, which is a great conductor.
There are a number of different shapes of heat sinks, from the tested and true &#;fin&#; type, to the snazzy new &#;pin-fin&#; style. The purpose of all the fins, whether they&#;re rectangular or pins, is to increase the surface area of the heat sink as much as possible. More surface area makes it easier for heat to transfer from the COB, through the fins, and into the air.
Aside from the shape of the fins, there are 2 main types of heat sinks: active and passive.
Active heat sinks are those that use a fan to blow air over the fins to help remove the heat. If you use an actively cooled heat sink, you can get away with a much smaller unit than you could if you went passive. The risk with active cooling is that if the power supply running the fan were to ever die, the heat sink alone may not be able to cool the COB sufficiently.
Passive heat sinks are just chunks of metal and nothing else. As mentioned above, passive heat sinks must be much larger than their active counterparts in order to dissipate the same heat. What&#;s great about passive sinks is that you don&#;t have to worry about the fan dying and your COB overheating, as there are no moving parts.
If you were to try and mount your COB directly to your heat sink with nothing in between, you wouldn&#;t get very good contact between the two. When mounting to the heat sink, It&#;s imperative that 100% of the COB is making solid contact. Every minuscule pore and scratch that isn&#;t making contact is a spot that heat will build up and cause problems. For this reason, you need to use a thermal interface like a thermal pad, or thermal paste on the back of the COB to ensure the best connection possible.
LED drivers are the handy little boxes that take the power from your electrical outlet and convert it to a form that the COBs can use. The electricity coming from your outlet is alternating current (AC), and this does not work for COB LEDs &#; they require direct current (DC) instead.
LED drivers often come unterminated, which means you will have to wire an AC power plug to the end of the power cable (out of the box, it&#;s simply 3 bare wires). You will also need to terminate the positive and negative wires that connect to the COB LED circuit, as well as the 2 wires that control the dimming of the unit (some drivers come with a dimming knob built into the unit, but others simply come with 2 leads that you must attach a potentiometer to).
When purchasing an LED driver, you need to make sure that it is capable of producing enough power (in watts) to run all of your COBs. You also need to make sure it can produce this power at a certain current (in amps) and voltage (in volts). LED drivers come in 2 types: constant voltage drivers and constant current drivers. Constant voltage drivers hold their rated voltage steady and vary their current output, whereas constant current drivers hold their rated current steady, and vary their output voltage. C.V. drivers are typically used in parallel wired systems, while C.C. drivers are typically used in series wired systems.
If you&#;re new to LED, I&#;d suggest starting with constant current drivers as they are far easier to work with and are generally better-suited for most LED applications. Constant voltage drivers work wonderfully too, but can be trickier to set up and less forgiving if you mismatch the driver and COBs.
I would suggest reading these posts on selecting LED COBS and matching drivers, wiring LED COBs in series and parallel, and constant current vs. constant voltage drivers for a more detailed explanation.
This is the simplest part of the system &#; everyone has worked with wire in some capacity or another. You won&#;t need a lot of wire but you should definitely try to find the right stuff. You will need to connect all the COBs to one another and then connect the COBs back to the driver for power. See the post on wiring LED COBs in series and parallel for more information on how to hook up the COBs, and this post for help choosing wire for your system. In most cases, 18 gauge solid core cable should do the trick, but it&#;s best to check nonetheless.
Well, that&#;s it for the basics of a COB LED system! As always, you should definitely exercise caution when assembling these systems. It really helps to have some working knowledge of electricity, as there are certainly risks involved. I would suggest enlisting the help of a knowledgeable friend for the electrical stuff if it&#;s not your forte.
If you&#;re ready to get into the finer details, check out the DIY Guides section for a number of builds, articles, and calculators to help you build your own LED grow light.
If you&#;ve got a question, head on over to the forum and start a topic! Our community is happy to help, no matter what skill level you&#;re at.
Share
What do you know about COB LEDs? You may say, now all spotlights are COB LEDs. And you may also say, COB LED lights are manufactured by grouping many light-emitting diodes on a circuit board. Here is a more specific explanation of COB LEDs:
COB, or chip on board, is an LED packaging technology to directly bond/attach multiple LED chips on a printed circuit board. The chips are covered and sealed in thermally conductive epoxy resin (usually adding silver). And the printed circuit boards used for COB LED modules are usually ceramic PCBs. Sometimes, the circuit boards can be copper substrate PCBs and aluminum substrate PCBs.
The essence of a COB LED module is a PCBA. But the components - LED chips are so tiny, and they are assembled on the PCBs by operators with the help of the microscope. And the chips are so fragile from heat, moisture, and dust, so they are protected by sealing in the thermally conductive epoxy resin.
Compared with the SMD LED lights, COB LEDs have these advantages:
A COB LED light's luminous efficacy can reach 80Lm/W;
COB LEDs have multiple color temperature options and high color rendering index;
COB LEDs have a uniform and soft light emission, with no ghosting/flaring.
Now you know what an LED COB is and its benefits. As an engineer or solutions company, you may want to develop your own brand of LED COB lights. You may also want to know how LED COBs are manufactured.
PCBONLINE, a one-stop COB LED manufacturer, will guide you through the complete manufacturing process of COB LED modules. Let's go!
Step 1: ceramic PCB manufacturing
The first step is to manufacture the substrate boards for LED packaging. Ceramic PCBs are often the PCB option for COB LEDs because alumina and aluminum nitride have good thermal conductivity and do not need an electric insulation layer. PCBONLINE manufactures ceramic PCBs, aluminum PCBs, and copper substrate PCBs according to clients' designs. PCBONLINE adopts the DPC technology to manufacture ceramic PCBs that can achieve 3D design for high-power LED packaging.
Step 2: expanding the LED chip film
The LED chips are arranged on a film. Technicians evenly expand the LED chip film to separate them using the expansion machine.
Note
Integrated circuits are in short supply in the world. Buy LED chips and ICs before you have the COB LEDs manufactured. If you can purchase LED chips/ICs at a lower price than PCBONLINE does, purchase them.
Step 3: doping silver paste on the PCB pads
Like solder paste printing in the SMD production process, silver paste is applied on the PCB pads. The only difference is that there is no need for a PCB stencil, and the silver paste is doped on the PCB pads using a dispensing machine.
Step 4: LED chips pick-and-place
The LED chips are microchips, and assembling them on the PCBs is operated under the microscope. PCBONLINE's experienced operators pick and place the LED chips on the PCB pads using a die bonder.
Step 5: PCBA baking
This step is similar to reflow soldering in the SMT assembly process. The assembled printed circuit board is baked in a thermal cycle oven to melt and solidify the silver paste. In this way, the LED chips are attached to PCB pads tightly. When the solder paste solidifies, take the PCBA out.
Step 6: die bonding
If the COB LEDs have ICs (dies) that need assembling, this step and step 7 happen. Operators use the dispensing machine to dop red or black glue on the IC pads and use anti-static equipment (vacuum suction pen or sub) to pick and place the dies on the glue.
Step 7: baking
Put the PCBA assembled with IC dies in the thermal cycle oven to bake. The glue melts to connect the ICs with the circuit board. When the glue solidifies, take the PCBA out.
Step 8: wire bonding
Operators at PCBONLINE use the gold wire or aluminum wire to connect the PCB pads by the wire bonding machine.
Note
Another connecting method is the flip-chip (pad to pad). This method requires no gold/aluminum wires to connect the PCB pads.
Step 9: pre-testing
The COB LEDs can't be repaired once sealed with glue. So before sealing, technicians test the electrical characteristics of the PCBAs. Only the qualified PCBAs can enter the next step. The not-good PCBAs are returned to fix.
Step 10: glue sealing
LED chips are sealed with AB glue, and IC dies are sealed with black glue. And then PCBONLINE finished the appearance packaging according to customers' requirements.
Step 11: glue solidifying
The PCBA covered with glue is placed in the thermal cycle oven to bake again to dry up the glue.
Step 12: post-testing
Finally, the COB LED is assembled. Technicians at PCBONLINE test the electrical performance of the COB LED to check whether it is qualified or not.
Voila! The COB LEDs are manufactured. You may find that the whole production process is similar to turnkey PCB manufacturing. Yes, they are!
After the testings, PCBONLINE can adjust the RGB (green, red, and blue) LEDs' color according to the client's requirements.
Are you developing a COB LED project? Want a one-stop COB LED manufacturing solution? PCBONLINE, a turnkey COB LED PCB manufacturer, provides you with the one-stop COB LED manufacturing solution. PCBONLINE has decades of manufacturing experience in ceramic, aluminum, and copper substrate PCBs. And it has complete COB LED production lines to complete the above steps.
The COB LED manufacturer PCBONLINE has competitiveness for:
One-stop COB LED manufacturing, from 3D ceramic PCBs fabrication, chip sourcing, and PCB assembly, to the COB LED box build assembly.
PCBONLINE has mature techniques of COB LED wire bonding and flip-chip assembly.
PCBONLINE can adjust the LED light wavelength according to the specified optical parameters.
Apart from LED chips, PCBONLINE can also assemble capacitors, resistors, and control modules to extend LED lights' smart functions.
Free one-on-one engineering support (DFX) and customer service for COB LED projects.
PCB manufacturing is IPC-A-600 compliant, and COB LED assembly is IPC-A-610 Class 3 compliant.
The one-stop COB LED solution provider PCBONLINE can manufacture the COB on both rigid and flexible substrate boards. If you are looking for COB LED manufacturing for your brand, PCBONLINE can provide one-stop contract manufacturing and co-R&D with you!
Online register and get $100 coupons for COB LED manufacturing online purchases now!
Want more information on 200w cob led chip? Feel free to contact us.
This COB LED module produced by PCBONLINE is used for spotlights. The module has a composite structure: its bottom layer is a copper substrate PCB; the white part is an embedded ceramic substrate light-emitting module; the yellow part is a light source (manufactured in the flip-chip method).
This article tells what a COB LED is and its advantages. And it mainly illustrates the complete steps of COB LED manufacturing. If you want to develop COB LEDs in your own brand, PCBONLINE will provide you with a one-stop COB LED manufacturing solution.
What is a COB LED?
How Long Do COB LEDs Last?
When Using Battery Power, Why are COB LEDs So Important?
What are the Differences between Normal Led and COB LED?
Differences between COB LEDs and SMD LEDs
Why Choose the COB LED?
The Advantages and Disadvantages of COB LED
Multiple Uses of COB LED
Conclusion
LED lights are continually being upgraded to increase their usability, adaptability, and energy efficiency. When compared to standard incandescent lights, LED lights are extremely popular since they may last up to 25 times longer while using less power.
COB and SMD LED lights are two types of LED lights available, which are the two primary sources of light these days. Both of these components create high-quality illumination and have a lengthy life expectancy, as well as the highest efficiency to date.
In this case, we will talk about COB LEDs, which are the latest in the LED industry and provide a number of advantages over the previous options.
One of the most recent developments in the world of LEDs is "Chip on Board" (COB) technology. When contrasted to other standards, we can consider it quite recent and innovative.
COB lights are made up of an arrangement of LED chips that are tightly packed and attached to a silicon carbide base. As a result, one huge LED chip with outstanding illumination uniformity is created, making it perfect for many professionals such as filmmakers and photographers.
Generally, COB chips feature nine or even more diodes. Irrespective of the number of diodes, COB chips only have two contacts and one circuit. On a big chip, this can result in more powerful lighting of up to 250 lumens (at 20mA). The panel-like aspect of COB LED lights is due to the chip's basic circuit design.
COB LED lights, unlike SMD LED lights, cannot be utilized to make color-changing lamps or lights. That is due to the fact that there are only two contacts and one circuit. To achieve the color-changing illusion, several modification channels are needed. COB LED lights are hence effective in single-color applications.
The longevity of a COB LED is determined by how they are used as well as how much heat they are exposed to. A COB LED has an average rated lifetime of 50,000 hours. That is assuming a person uses them for 12 hours a day on average.
There has always been a trade-off between both the amount of high-quality lumen output (brightness) and the duration of runtime through battery operation when building a battery-powered lighting system. If you utilize the same size battery, the more high-quality illumination you want, the shorter the runtime will be. That has become considerably less of a concern with the emergence of COB LED tech.
COB LEDs with little power can produce exceedingly high-quality, ultra-bright light. As a consequence, a COB LED-based lighting system may be powered for extended periods of time using a relatively tiny and lightweight lithium-ion battery pack.
To begin, a basic understanding of Surface-Mounted Device (SMD) LEDs is required. They are by far the most widely used LEDs on the market today. The LED chip is firmly fused to a printed circuit board and is widely utilized due to its adaptability, even in the notification light on the smartphone. The amount of diodes and contacts on SMD LED chips is one of their most distinguishing features.
More than two contacts are possible on SMD LED chips. On a single chip, up to three diodes can be found, each with its own circuit. An anode and cathode would be used in each circuit, resulting in 2, 4, or 6 connections on a chip.
SMD LED chips can include up to three diodes on a single chip, each with its own circuit. In a chip of this type, each circuitry contains a single anode and one cathode, resulting in 2, 4, or 6 connections. COB chips typically have nine or even more diodes. Furthermore, irrespective of the number of diodes, COB chips have two contacts and one circuit. COB LED lights have a panel-like appearance, whereas SMD LED lights would seem like a collection of smaller lights due to this straightforward circuit design.
The SMD LED chip could have a red, green, and blue diode. By employing those three diodes, you can generate any hue simply by altering the output level. But there are just two contacts and one circuitry on COB LED lights. They can't be utilized to create color-changing lights or bulbs. To achieve the color-changing appearance, multiple channel modifications are needed. As a result, COB LED lights are effective in single-color applications but not in multi-color uses.
The luminosity of SMD chips is well known, and they may generate 50 to 100 lumens per watt. COB is noted for its high heat efficiency and lumens per watt ratio. With a minimum number of 80 lumens per watt, COB chips could emit more lumens with less power. It can be found in a variety of bulbs and applications, such as a point-and-shoot camera or your 's flash.
In SMD LED chips, a smaller current capacity is necessary; however, in COB LED chips, a large current capacity external energy source is needed.
COB LED lights, as a basic guideline, are higher-quality light emitters. This is due to the fact that they use reflectors to create concentrated and regulated light. They also lack the frosted lens that comes standard with SMD LED lights.
COB LEDs are a higher-end LED that has a more structural look. In case you intend to live with your LED bulbs for a long time, a COB is a way to go; if you are located in an investment property, SMD will suffice.
You should expect brighter, clearer lighting. COB LED lights, for example, are useful in high-ceiling areas.
* Because of the multi-diode incorporation, there is a lot of light.
* It produces more lumens while using less energy.
* Due to the limited light emission zone, the device is small in size. As a consequence, the lumen per square centimeter/inch has grown significantly.
* To active the many diode chips housed in COB LEDs, a single circuitry with only two connections is used. As a result, there are fewer parts per LED chip that are necessary for proper performance. Furthermore, by reducing the number of components and eliminating the standard LED chip architecture packing, the heat created by each LED chip can be decreased.
* Due to the extreme ease of installation in an outside heat sink, the entire temperature range of the entire assembly is lower. When you keep things at a set temperature, they last longer and are more reliable, which saves you money.
* Clarity is improved, and efficiency is boosted.
* Since it can cover a big area with one chip, it has a huge focusing area.
* Excellent anti-vibration properties
* A well-engineered outside power source. That occurs since it requires a steady current and voltage to avoid damaging the diodes.
* A well-designed heat sink is very important. If the heating element is not properly placed, the diode will be destroyed due to overheating. Due to the highly focused light waves emitted from a limited area, a considerable amount of heat is created.
* Lighting fixtures with cob chips have a lower repairability. That is because in case one of the solitary diodes in a COB is damaged as a result of a mechanical malfunction, the entire COB led must be substituted with a newer one. In the case of SMD LED, however, if one fails, it is simple to change it and get it back to operate at a lower cost.
* Color selection is limited.
* More expensive than SMD chips.
COB LEDs have a wide range of applications, extending from residential to industrial utility, with some of them being:
* COB LEDs would be used primarily as solid-state lighting (SSL) substitutes for metal-halide bulbs in street lighting, high-bay lighting, downlights, and high-output track lights.
* They are useful in LED lighting fixtures for placement in living rooms and huge halls because of their wide-angle beam.
* High lumens at night time are required in spaces such as a playground, gardens, or a large stadium.
* Additional applications incorporate basic lighting for passageways and corridors, fluorescent lighting replacement, LED lamps, light strips, smartphone camera flash, and so on.
COB LEDs are becoming more popular in lighting applications as designers discover the advantages of employing them over typical standard LEDs. It's difficult not to take into account them for any led light application structure because of:
* Their ability to cram more LED sources into a smaller area, resulting in higher lumen output
* Their ability to transmit heat to a heat sink more efficiently
* Their wider field of view
* Their lower light loss
* Their lower failure rates are due to their more straightforward construction
COB LEDs are the most recent and advanced tech available today. Simply said, they are brighter, use less electricity, and provide a higher-quality beam of light than previous LED technology now used in most trade show illumination.
Our well-equipped facilities and excellent management throughout all stages of creation enable us to guarantee total buyer satisfaction with COB chip
Common forms of CSP Several forms include: flip chip, non-flip chip, wire bonding, ball grid array, and leaded. These five forms will be introduced one by one next.
Flip-chip CSP (FCCSP):
Flip-chip refers to turning the chip upside down and attaching it to the substrate or lead frame. Compared with general CSP, the difference is that it uses bumps such as solder or copper pillars for interconnection instead of traditional wire bonding. I/O pads can be distributed over the entire surface of the chip, allowing chip size to be reduced through optimized circuit paths. The absence of bond wires also helps reduce signal inductance. FCCSP (Flip Chip CSP Package) provides chip scale capacity for approximately 200 I/Os or less. FCCSP offers better chip protection and better solder joint reliability than Direct Attachment (DCA) or Attachment-on-Board (COB). FCCSP features a low-profile, small-profile, and lightweight package. FCCSP is over molded in two ways: one using capillary underfill (CUF) and the other using epoxy molding compound instead of underfill (MUF) to reduce cost, improve thermal performance and secondary reliability .
Non-flip-chip:
Non-flip chip, also known as front mount chip, is the earliest chip structure. From top to bottom, the structure is: electrode, P-type semiconductor layer, light emitting layer, N-type semiconductor layer and substrate. In this structure, the heat generated by the PN junction needs to be conducted to the heat sink through the sapphire substrate. The poor thermal conductivity of the sapphire substrate leads to poor thermal conductivity of the structure, thereby reducing the luminous efficiency and reliability of the chip. In the positive chip structure, both the p-electrode and the n-electrode are located on the light-emitting surface of the chip, and the shielding of the electrodes will affect the luminous efficiency of the chip, resulting in a low luminous efficiency of the chip; the positive and negative electrodes are located on the same side of the chip, which is prone to current congestion and reduces Luminous efficiency; In addition, factors such as temperature and humidity may also cause electrode metal migration. As the chip size shrinks and the spacing between positive and negative electrodes decreases, electrode migration may cause short circuit problems.
Wire-bonded:
Wire bonding is the process of creating electrical interconnections between semiconductors (or other integrated circuits) and silicon chips using bonding wires, which are thin wires made of materials such as gold and aluminum. Although less common, wire bonding is used to connect ICs to other electronic devices or to connect one printed circuit board (PCB) to another. Wire bonding is generally considered the most cost-effective and flexible interconnection technique used to assemble the vast majority of semiconductor packages. Wire bonding can be used for frequencies above 100 GHz. The two most common processes are gold ball bonding and aluminum wedge bonding.
Ball Grid Array:
A Ball Grid Array (BGA) is a surface mount package (chip carrier) for integrated circuits. BGA packages are used to permanently mount devices such as microprocessors. BGAs can provide more interconnect pins than dual in-line or flat packs. The entire underside of the device can be used, not just the perimeter. The traces connecting the package&#;s leads to the wires or the die to the package&#;s balls are also shorter on average than perimeter-only types, enabling better performance at high speeds.
Leaded:
Chip-On-Lead (COL) is a technology that mounts a die or crystal on the leads of a lead frame instead of pads. To complicate matters further, unlike conventional leadframes, this leadframe has no tape for support during wire bonding.
If you want to learn more, please visit our website are cob lights better than led.