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Have you noticed that now more and more of our lighting is using led lighting.What is LED? Compared to the traditional light bulbs, LEDs have lower power consumption, longer lifetime and higher energy efficiency. In the PCB industry,when we say LED PCB, it refers to the pcb used for LED lighting, if you are looking for a suitable LED PCB for your lighting system, this article may bring you something. WHAT ARE LEDS COMPOSED OF?LED is an initial light-emitting diode that produces light when an electric current passes through. LEDs typically have negative and positive electrodes, which generate light in the visible light region.The LEDS are glued to the PCB by soldering process and have electrical connections for lighting.Since light-emitting diodes dissipate a lot of heat when they are in use, when you are designing LED, the metal core is usually the best choice for LED PCB, it is because that it dissipates heat more faster. Among them, the metal material aluminum is the most widely used
PCB (Printed Circuit Board), the Chinese name is a printed circuit board, also known as the printing circuit board, is an important electronic component, a supporting body for electronic components, and a carrier for electronic components. Because it is made of electronic printing, it is called a "print" circuit board. Act After the electronic equipment uses the printed board, due to the consistency of similar printed boards, it avoids the errors of artificial wiring, and can realize the automatic installation or paste, automatic welding, and automatic detection of electronic components, which ensures the quality of electronic equipment , Increase labor productivity, reduce costs, and facilitate maintenance. Classification (1) Single panel Single-Sided Boards is on the most basic PCB, parts of the parts on one side, and the wires are concentrated on the other side (when there is a patch component, the wire is the same side, and the plug-in device is another). (2) Double -panel
Due to the lack of one layer of dielectric and foil, the cost of raw materials for odd numbered PCBs is slightly lower than that for even numbered PCBs. However, the processing cost of odd layer PCBs is significantly higher than that of even layer PCBs. The processing cost of the inner layer is the same; But the foil/core structure significantly increases the processing cost of the outer layer. Odd layer PCBs require the addition of non-standard stacked core bonding processes on the basis of core structure technology. Compared to the nuclear structure, the production efficiency of factories that add foil outside the nuclear structure will decrease. Before laminating and bonding, the outer core requires additional processing, which increases the risk of scratches and etching errors on the outer layer. The best reason for not designing PCBs with odd layers is that odd layer circuit boards are prone to bending. When the PCB is cooled after the multi-layer circuit bonding process, th
The current boards are rarely that kind of rectangular or other. They are all irregular, but there are several kinds of line drawing outer frames, which are unable to choose from. In addition, now because of the use of the equipment (such as SMT), now They all have to spell V-CUT, but the spacing spacing is different, some have spacing, and some have no distance. It is okay to do a batch for the first factory. It is not possible to fight according to the first factory, and the steel net cannot be set. Therefore, there is no special case, it is best not to have a spacing; in addition, some file design may draw a small cubic hole to draw a small cubic hole on the shape layer. Compared to PADS, it is better to put it on the appearance layer. It is easy to misunderstand the manufacturer as to rush out this hole or make the NPTH attribute. For some PTH attributes, it is easy to have problems.
PCB heat dissipation. For electronic devices, a certain amount of heat will generate during work, so that the internal temperature of the equipment will rise rapidly. If the heat is not distributed in time, the equipment will continue to heat up, and the device will fail due to overheating. Electronics will fail. Electronics will fail. Electronics will fail. Electronics will be invalidated. The reliability of the device will decrease. Therefore, it is very important to carry out a good heat dissipation treatment on the circuit board. The heat dissipation of the PCB circuit board is a very important link, so what are the cooling skills of the PCB circuit board? Let's discuss it together. 1. PCB plates that are widely used through the PCB board itself are copper -covered/epoxy glass cloth substrates or phenolic resin glass cloth substrates, as well as a small amount of paper base covering copper plate. Although these substrates have excellent electrical performance and processing p
1. Crystal foil phenolic glass layer pressure plate: It is a layer of pressure products made of epoxy phenolic resin through the heat pressure of epoxy phenol. Good performance and convenient processing. Its plate surface is pale yellow. If the triamine is used as a curing agent, the surface of the plate is pale green and has good transparency. It is mainly used as printed circuit boards in radio equipment with high working temperature and frequency. 2. Copper foil phenolic paper layer pressure plate: It is a layer pressure product made of phenolic resin perfume with phenolic resin through the heat pressure of phenolic resin. Comes with a single -alkali glass soaked tape, and it is applied to copper foil. It is mainly used as a printed circuit board in radio equipment. 3. Soft polyester copper film: It is a band -shaped material made of polyester film and copper thermal, and it curls into spiral shape inside the device in the application. In order to reinforce or moisture -proof,
1. Layout The layout, line width, and line spacing of printed wires and pads shall be in accordance with the provisions of the design drawings. But our company will handle the following: compensate for the line width and PAD ring width appropriately according to the process requirements, and generally increase the PAD for single panels as much as possible to enhance the reliability of customer welding. When the design line spacing does not meet the process requirements (if it is too dense, it may affect performance and manufacturability), our company will make appropriate adjustments according to the pre production design specifications. ★ In principle, it is recommended that customers design double or multi-layer boards with a through hole (VIA) inner diameter of 0.3mm or more and an outer diameter of 0.6mm or more. The component pad should be greater than 50% of the aperture, and the minimum plate thickness to aperture ratio should be ≤ 6:1. The design of the width and spacing o
1. The various design elements that make up a PCB should be described in the design drawings. The appearance is represented by Mechanical 1-16 layers (priority) or Keep out layer. If used simultaneously in the design file, generally keep out layer is used to prohibit wiring without opening holes, and mechanical 1 is used to indicate forming. In the design pattern, indicate a long SLOT hole or hollow, and use Mechanical 1 layer to draw the corresponding shape. 2. Dimensional tolerances for PCB board samples The overall dimensions of the PCB should comply with the provisions of the design drawings. When there is no specification in the drawing, the tolerance of the external dimensions is ± 0.2mm. 3. Flatness (warpage) 0.7% (4) The concept of layers 1. If a single panel draws a signal layer on the top layer, it indicates that the circuit on that layer is the front view. 2. If a single panel draws a signal layer on the bottom layer, it indicates that the circuit on that layer is
PCB (Printed Circuit Board), also known as Printed Circuit Board or Printed Circuit Board in Chinese, is an important electronic component that supports electronic components and provides electrical connections for electronic components. Due to its use of electronic printing technology, it is called a "printed" circuit board. The early 20th century to the late 1940s was the embryonic stage of the development of PCB substrate materials industry. Its development characteristics are mainly reflected in the emergence of a large number of resin, reinforcement materials, and insulation substrates used by professional PCB manufacturers for substrate materials during this period, and preliminary technological exploration has been made. All of these have created necessary conditions for the emergence and development of the most typical substrate material for printed circuit boards - copper-clad board. On the other hand, the mainstream PCB manufacturing technology, which uses metal foil etc
PCB (Printed Circuit Board), also known as Printed Circuit Board or Printed Circuit Board in Chinese, is an important electronic component that supports electronic components and provides electrical connections for electronic components. Due to its use of electronic printing technology, it is called a "printed" circuit board. The early 20th century to the late 1940s was the embryonic stage of the development of PCB substrate materials industry. Its development characteristics are mainly reflected in the emergence of a large number of resin, reinforcement materials, and insulation substrates used by professional PCB manufacturers for substrate materials during this period, and preliminary technological exploration has been made. All of these have created necessary conditions for the emergence and development of the most typical substrate material for printed circuit boards - copper-clad board. On the other hand, the mainstream PCB manufacturing technology, which uses metal foil etc
1. The multi-layer PCB board has good sampling quality and strong wear resistance. The surface of the PCB board sample is clearly and aesthetically pleasing, and can be marked with various logos, patterns, QR codes, and text. The patterns are directly engraved on the material, which highlights the wear resistance; 2. High machining accuracy. The minimum spot diameter of the laser beam emitted by the laser can reach 10um (UV laser) after being focused, which is of great help in processing complex graphics and precision machining; 3. High efficiency, simple operation, and cost reduction. Users only need to set the parameters on the computer to directly mark the material surface, which can be completed in just a few seconds to more than ten seconds; 4. Non destructive marking. Laser marking adopts non-contact processing, and the laser head does not need to contact the surface of the material, so there is no need to consider damage to the material; 5. Wide range of use, safe and en
1. Substrate ★ FR4: Glass cloth epoxy resin copper-clad foil plate (Tg: 130 °). ★ CEM-1: Paper core glass cloth surface - epoxy resin copper-clad foil board. ★ 94V0: Flame retardant cardboard. ★ Aluminum substrate: Thermal conductivity coefficient of 100. 2. Copper foil: 99.9% or more electrolytic copper, surface copper foil thickness of finished product: 18 μ M (H/HOZ), 35 μ M (1OZ), 70 μ M (2OZ). 3. Plate thickness: ★ Thickness of single and double-sided boards: 0.4mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.6mm, 2.0mm, 2.5mm The minimum thickness of multi-layer printed boards: 4 layers ≥ 0.6mm, 6 layers ≥ 1.0mm, and 8 layers ≥ 1.6mm, with a finished board thickness tolerance of ± 10%.
1. The less bending the leads between the pins of high-speed electronic devices, the better. It is best to use full straight leads for high-frequency circuit wiring, and if a bend is needed, a 45 degree bend or arc bend can be used. This requirement is only used to improve the bonding strength of copper foil in low-frequency circuits, while in high-frequency circuits, meeting this requirement can reduce the external emission and mutual coupling of high-frequency signals. 2. The less interlayer alternation between the pins of high-frequency circuit devices, the better. The so-called "less interlayer alternation of the leads, the better" refers to the use of fewer via (Via) during the component connection process. A through-hole can bring about a distributed capacitance of about 0.5pF, reducing the number of through-holes can significantly improve speed and reduce the possibility of data errors. 3. The shorter the lead between the pins of high-frequency circuit devices, the better.
The resistance encountered during the propagation of high-frequency signals or electromagnetic waves in electronic device transmission signal lines is called "impedance". Why do some boards require impedance during the production process, and what are the advantages of impedance PCB circuit boards! 1. It is necessary to consider the installation of electronic components through plug connections, and later SMT patch connections also need to consider issues such as conductivity and signal transmission performance, so the lower the impedance, the better. 2. During the production process, the materials used must have low electrical resistivity to ensure that the overall impedance value of the circuit board meets the product quality requirements and can operate normally. 3. PCB tin plating is the most common problem in the production of the entire circuit board, and it is a key link that affects impedance; Its biggest defects are easy oxidation or deliquescence, poor solderability, mak
The origin of PCB circuit board printing in China probably dates back to the middle and late 1990s. The research on automatic optical detection systems for circuit board printing defects is still at a relatively early level. With the continuous maturity of process technology in the later stage, there has been progress in express delivery in the field of printed circuit boards. With the rapid development of the electronics industry, the application scope of circuit boards has also increased, So how do we distinguish the quality and sincerity of finished circuit boards! 1: Board thickness control standards: Different factories have limited printable process capabilities when printing circuit boards. The standard accuracy of the manufacturer can be determined based on the board thickness. The smaller the control tolerance, the stronger the printing ability, while the larger the control tolerance, the smaller the printing ability. 2: The glossiness of the solder mask color on the boa
The shape of circuit board pads can be divided into 7 categories: 1. Square solder pads: commonly used when the components on a printed circuit board are large but few, and the printed wires are simple. 2. Circular solder pads: widely used in single and double-sided printed boards with regular component arrangement. 3. Island pad: The connection between pads is integrated and is commonly used in vertical irregular arrangement installation. 4. Teardrop solder pads: often used when connecting thin wires, commonly used in high-frequency circuits. 5. Polygonal pads: Used to distinguish pads with similar outer diameters but different apertures, making it easy to process and assemble. 6. Elliptical pad: This type of pad has sufficient area to enhance peel resistance and is commonly used in dual inline devices. 7. Open solder pads: commonly used to ensure that the holes of manually repaired solder pads are not sealed by solder after wave soldering.
1. The minimum diameter on one side of all solder pads shall not be less than 0.25mm, and the maximum diameter of the entire solder pad shall not exceed three times the aperture of the component. 2. Efforts should be made to ensure that the distance between the edges of two solder pads is greater than 0.4mm. 3. In cases of dense wiring, it is recommended to use elliptical and elongated solder pads. 4. For plug-in components, in order to avoid copper foil breakage during welding, the single-sided connecting plate should be completely covered with copper foil, and the minimum requirement for double panels should be to fill in tears. 5. All machine insertion parts should be designed as drip solder pads along the bending direction to ensure full solder joints at the bending position. 6. Daisy shaped solder pads should be used on large-area copper sheets to avoid virtual soldering.
(1) Protective post-treatment Except for chrome plating, all other protective coatings used as surface coatings must undergo appropriate post-treatment to maintain or enhance their protective performance. The most commonly used post-processing method is passivation. For those with high protection requirements, surface coating treatment should be carried out, such as glossy coating treatment. From the perspective of environmental protection and cost, water-based transparent coating can be used. (2) Decorative post-treatment Decorative post-treatment is a common treatment process in non-metallic electroplating. For example, imitation gold, imitation silver, imitation antique copper plating, brushing, coloring or dyeing, and other artistic treatments. Most of these treatments also require the surface to be coated with transparent gloss coating. Sometimes it is necessary to use colored transparent coatings, such as imitation gold, red, green, purple and other colors. (3) Functional
1、 Decanting method Decanting method is actually a filtration method, which is a physical method in the wastewater treatment of PCB board industry. The flushing water containing copper shavings discharged by the deburring machine can be filtered and removed after being treated by a decanter. The effluent filtered by the decanter can be reused as cleaning water from the burr machine. 2、 Chemical method Chemical methods include redox method and chemical precipitation method. The oxidation-reduction method is the use of oxidants or reducing agents to convert harmful substances into harmless or easily precipitated substances. The cyanide containing wastewater and chromium containing wastewater in circuit boards are often treated using the oxidation-reduction method, as explained later. Chemical precipitation method is the use of one or several chemical agents to convert harmful substances into easily separable precipitates or precipitates. There are various chemical agents used for
1. The solderability of circuit board holes affects welding quality Poor solderability of circuit board holes will result in virtual soldering defects, affecting the parameters of components in the circuit, leading to unstable conduction of multi-layer board components and inner wires, and causing the entire circuit function to fail. The so-called weldability refers to the property of the metal surface being wetted by molten solder, that is, the formation of a relatively uniform and continuous smooth attached film on the metal surface where the solder is located. The main factors affecting the solderability of printed circuit boards are: (1) the composition of the solder and the properties of the soldered material. Solder is an important component of the welding chemical treatment process, which is composed of chemical materials containing flux. The commonly used low melting point eutectic metals are Sn-Pb or Sn-Pb-Ag. The impurity content should be controlled in a certain proport
PCB wastewater is polychlorinated biphenyl wastewater, which is a type of wastewater in the printing industry and circuit board factories. Nowadays, the world produces 300 million to 400 million tons of toxic and harmful chemical waste annually, among which persistent organic pollutants (POPs) are of great ecological harm and the most widely spread on Earth. In addition, PCB wastewater is divided into cleaning wastewater, ink wastewater, complexation wastewater, concentrated acid wastewater, concentrated alkali wastewater, etc. The production of printed circuit boards (PCBs) requires a large amount of water, and there are many types of pollutants in the wastewater with complex components. Reasonable classification, collection, and treatment of wastewater based on the characteristics of different PCB manufacturers are key to ensuring that wastewater treatment meets standards. For the treatment of wastewater in the PCB board industry, there are chemical methods (chemical precipitatio
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