Why is FPCB an important part of LED strips?
The PCB boards are classified as different types including single layer PCB, double layer PCB, multiple layers PCB, and rigid PCB, flexible PCB, rigid-flex PCB, and Aluminum circuit boards. In order to better understand the soft light strip, here we first analyze its material FPCB.
With the advancement of technology, LED light strips are becoming more and more popular. The addition of flexible PCB further makes LED strips provide great convenience in home lighting and decoration. The following will take you to a comprehensive understanding of the structure of the flexible PCB and its role in the LED strip.
What is Flexible PCB?
Flexible printed circuit board, also known as flexible printing or flexible circuit, is a special type of PCB which you can bend to any shape you want. They are mostly used in high temperature applications,as well as high density applications. The flexible design pcb is composed of polyimide(PI) or transparent polyester film as the substrate material, which has high heat resistance and is very suitable for welding installation components. For more PCB substrate properties, please refer to “Introduction To The Material Properties Of PCB CCL“
What Does It Act On The LED Strip?
LED strips are basically circuit boards that are connected to each other. SMT (Surface Mount Technology)refer to make SMD LEDs and other components such as connectors mounted on flexible PCBs. In other words, the FPCB acts as a substrate on which the manufacturer mounts the LED chips.
Besides being its structure, another main function of a circuit board is to dissipate heat. Click to learn more about the features and applications of flexible PCBs.
Structure of a flexible PCB.
Flexible electronics are with good plasticity and perfect for LED strip lights. The 5-meter reel is the most common flexible substrate setup for LED strips.
Like rigid pcb, FPC can be classified into single-layer, double-layer or multi-layer PCB circuits.
Single layer FPCB
A single-layer circuit board consists of a base layer and a conductive layer. Solder mask oil and silkscreen protect these layers. It has no circuitry on the back.
They have a thin structure, only 1 oz thick. You feel very light when you hold them.
Double layer FPCB
Compared to a one-side PCB, a two-side PCB has two copper layers, which makes it thicker and heavier because it has a conductive layer on both sides.
They are also more durable because the board can handle higher currents and dissipate heat better.
In the current lighting market, we can find that both single-layer PCB and double-layer PCB are used for LED strips. After removing the tape on the back of the LED strip, the difference between the two PCBs can be clearly seen.
Some led strip lighting manufacturers select single layer PCB to reduce cost. Although double-layer PCBs are more expensive, LED strips made from them have higher lumens and better heat dissipation, which significantly improves their stability and longer lifespan.
The main components of a single-layer flexible printed circuit are as below:
- Dielectric Substrate Film: The substrate of printed circuit boards. The most widely used material is polyimide (PI), which is characterized by high resistance to traction and temperature;
- Electrical Conductors: consist of copper, which represent the traces of an electrical circuit;
- Protective Finish: made from overlays or cover-lays;
- Adhesive Material (Polyethylene Or Epoxy Resin): used for connecting the various layers of the FPCB together.
The main elements of a two-layers flexible printed circuit as in photo:
Copper weight in FPCB:
A key aspect of any electronic circuit is the choice of copper. The quality and purity of copper used in electronic circuits is largely standardized, but its thickness can vary widely. Although a unit of measurement for thickness, ounces (oz) are often used to describe the thickness of a copper layer (the technical definition is based on the amount of copper, measured in ounces, required to achieve a specific thickness in excess of 1 square foot).
Copper thickness may be something you need to pay attention to when choosing an LED strip light. Especially for higher power LED strips, we advise at least 2.0 oz, preferably 3.0 oz or above. Other conditions being same, thick copper is better for the several reasons:
1) Thicker copper refer to bigger current can go through the circuit of the LED strip. Thinner copper can lead to higher resistance and heat build-up, which can eventually lead to voltage drops and even early led failure.
2) The thicker the copper, the faster the heat dissipation. The faster the heat generated by the LED is transferred to the surrounding environment, the better the performance and lifespan of the LED. Copper is an excellent conductor of heat, so having a thicker layer of copper will go a long way in facilitating heat transfer away from the LED.
Click to see more heavy copper pcb performance and advantages.
Application, material and performance of LED Strip Lights.
It is a newly designed LED strip product that can be applied not only to curved surfaces, but also nonlinear surfaces. Your LED strip runs can now make turns with ease, without needing to cut up segments and rejoin them using connectors.
LED Strip Lights Applications:
Flexfire LED strip lights are very popular in many applications of lighting design because of their high brightness,compact size,and low power consumption. Homeowners, bars, architects, restaurants and countless others which use them in every imaginable way have demonstrated their versatility.
Flexible LED Strip categories:
According to correlated color temperature (CCT)—Cool White, Natural White, Warm White, Tunable White;
Other different Single Color of LED Light Strips:
Changing Color of LED Strip Lights:
Material Of LED Strip:
Starting with a layer of copper as the base circuit, a core layer and two layers of PI polymer are applied on both sides using a special flexible adhesive. This outer PI substrate is commonly referred to as a “coverlay” and can come in a different kinds of colors. Usually, the white color is used mostly because of its high reflectivity.
Three layers of PI provide protection and structural integrity to the copper layers. However, in some small areas, the copper must be exposed so that the LEDs and other components can make electrical connect.
Finally, attach a layer of double-sided tape to the back of the LED strip. 3M 200MP double-sided adhesive used for it.
The LED belt with clear coverlay and 3M adhesive is visible.
Characteristics of LED strips:
The excellent flexibility of LED strips can be applied to a variety of complex environments. The variable ductility of the flexible PCB helps the light bar to change the angle at any corner.
Light Weight And Small Size:
Since FPCs are lighter than rigid PCBs, and can be designed in smaller sizes for greater flexibility. Therefore, the LED strip made of flexible PCB is smaller than the LED light of rigid PCB.
Relatively Poor Cooling:
The marked disadvantage to flexible LED strip attribute to their poor thermal performance. A significant disadvantage of flexible LED strip substrates is their poor thermal performance compared to rigid PCBs such as aluminum substrates and thick copper PCBs. If we look at thermal conductivity numbers, Kapton (polyimide) is 0.12 W/m-K, and the 3M adhesive material is 0.18 W/m-K.
Get To Know COB LED Strip Light Comprehensively.
What is COB?
COB refer to Chip On Board. The method is to package the chip on the PCB board directly. It is a kind of integrated package technology for LED.
What is COB LED Strip Light?
COB led strip is a high-density led strip encapsulated by COB, which can reduce the thermal resistance of the circuit system of the high-density strip, vastly improve low glare, the service life of the led,uniform light, high luminous flux density,and no dark space. So this is a spotless led strip light.
There is much different between the latest COB LED technology and traditional SMD LED chips because instead of soldering a single LED chip to a flexible PCB and then mounting it on an aluminum profile; the light-emitting wafer is cut into hundreds of smaller chips. These small and virtually invisible wafers of semiconductor crystals are bonded directly to the PCB circuit board by a special bonding way, that allows for solder-free manufacturing and maximum heat dissipation. Beam angle up to 180°.
Difference between SMD LED and COB LED?
1) The yellow coating in the middle of the COB chip is just the phosphor coating, giving full control over the color temperature and CRI. This type of LED technology enables chip densities of up to 840 chips per meter and is expected to offer greater flexibility and better brightness than other LED technologies.
2) COB LEDs have better brightness and greater uniform appearance than their predecessors. COB technology provides a higher level of light dispersion, eliminating the dark and bright spots created by narrow beam fittings, eliminating the need to install in aluminum channels and removing light spots with a PMMA diffuser. In addition, COB has higher reliability and longer life than SMD LED, with 3M tape on the back, high color efficiency and uniform illumination.
3) COB led strip has the big advantages of high CRI, high flexibility, high density, low power consumption, high efficiency, no spot, long life,high beam angle, etc., and will be the most important product in the future led low-voltage lighting market.
Advantages of COB LED Flex Strips.
Uniform light, High Color Rendering Index, Good flexibility, Wide emitting angle 180 degree, Can be cut, Ultra-thin, Variety of colors, Dimmable, High Brightness, Energy saving, Environmental protectionFeature, Easy install, WaterproofFeature, Low heat, More Efficient, Less Heat;
Color Temperature Of COB Flex Strips.
COB Flex strips of standard white outputs divided into 3000K Warm White, 4000K Neutral White and 6000K Cool White.
There are also available for RGB,Dual color, Red, Blue and Green which all look wonderfully.
JHD has 10+ years of experience in flexible PCB production. We have been using high standard mass production lines to manufacture flexible PCBs that maintain stable performance under special conditions. This makes it perfect for LED lighting, medical or military applications. The excellent substrate remains flexible after heat curing, and the fine pad layout and surface treatment process help to provide high performance lighting effects. If you have other questions or needs about flexible PCB, please feel free to contact us, we will use our professionalism and ingenuity to solve your doubts.