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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
Both sides of a PCB circuit board and above will require copper to be sunk into the holes, making the holes have copper and become electrical holes. However, during the production process, the manufacturer may occasionally discover that there is no copper or copper is unsaturated in the hole after copper deposition. Now, our company briefly describes several reasons. The reason for the absence of copper in the pores is nothing more than: 1. Drill dust plug holes or holes with coarse diameter. 2. When depositing copper, there are bubbles in the solution and no copper is deposited in the hole 3. There is circuit ink inside the hole, no protective layer is applied, and there is no copper in the hole after etching. 4. If the acid and alkali solution in the hole is not cleaned thoroughly after copper deposition or plate electrification, and the parking time is too long, slow bite corrosion will occur. 5. Improper operation and prolonged residence time during micro etching process.
1、 Introduction: With the continuous improvement of human requirements for living environment, the environmental issues involved in the production process of PCB circuit boards are particularly prominent. The topic of lead and bromine is currently the most popular; Lead-free and halogen-free technologies will affect the development of PCB circuit boards in many ways. Although at present, the changes in the surface treatment process of circuit boards are not significant and may seem distant, it should be noted that long-term slow changes will lead to significant changes. With the increasing demand for environmental protection, the surface treatment process of PCB circuit boards is bound to undergo significant changes in the future. 2、 The purpose of surface treatment is to ensure good weldability or electrical performance, which is the most basic purpose of surface treatment. Due to the tendency of copper in nature to exist in the form of oxides in the air, it is unlikely to remai
The holes on a circuit board are generally divided into copper holes and non copper holes. Non copper holes are mainly used for positioning and installation, and generally belong to larger holes with a diameter of 0.8mm or more. A through hole usually belongs to a plug-in or via hole, and the most common hole on a PCB board should be a via hole (conduction hole). The aperture of the plug-in hole is larger than the size of the via hole, usually above 0.5, based on the installation of capacitors, resistors, sockets, and other components. The main function of the electric hole is to conduct electricity, and the aperture is generally small, with a common aperture of less than 0.3. With the increase of precision boards, the functional requirements of the product increase, and the number of circuit board layers increases, the aperture is also getting smaller and smaller, with the minimum aperture of 0.1mm. Laser drilling is required. The through-hole needs to have a conductive effect, an
1. The surface of the welding area is contaminated, coated with flux, or metal compounds are generated on the surface of the SMT component. It can cause poor wetting. Sulfides on the surface of silver and oxides on the surface of tin can cause poor wetting. 2. When the residual metal in the solder exceeds 0.005%, the activity of the solder decreases and poor wetting occurs. 3. During wave soldering, there is gas on the surface of the substrate, which can also lead to poor wetting. The methods to solve poor wetting include: 1. Strictly implement the corresponding welding process. 2. PCB circuit boards and component surfaces should be cleaned properly. 3. Select the appropriate solder and set a reasonable welding temperature and time.
(1) Determine the variation pattern of the longitude and latitude direction and compensate it on the negative film according to the shrinkage rate (this work is carried out before photogrammetry). When cutting at the same time, process according to the fiber direction or according to the character markings provided by the manufacturer on the substrate (usually the vertical direction of the characters is the vertical direction of the substrate). When designing the circuit, it is important to ensure that the entire board surface is evenly distributed as much as possible. If it is not possible, it is necessary to leave a transition section in the space (without affecting the circuit position). This is due to the difference in warp and weft yarn density in the glass fabric structure of the board, resulting in differences in the warp and weft strength of the board. ⑶ Trial brushing should be used to keep the process parameters in a state, and then the rigid plate should be carried out
1. Preparation for welding: Preparation before welding includes cleaning of the welding area, installation of components, and preparation of solder, flux, and tools. Solder wire with the left hand and hold an electric soldering iron with the right hand (keep the soldering iron head clean and keep the soldering head in a welding state at all times). 2. Heating welding parts: Pay attention to heating the entire welding part evenly. 3. Feeding welding wire: After heating the weldment to a certain temperature, the welding wire and soldering iron come into contact with the weldment from the opposite side. 4. Remove the welding wire: When the welding wire melts a certain amount, immediately remove the welding wire. 5. Remove the soldering iron: After the soldering tin has moistened the welding pad or the welding part, remove the soldering iron. Manual soldering of PCB circuit boards is very simple for engineers who often weld them, but for those who have not welded them before, it m
Some people have a strong interest in debugging PCB circuit boards, just like programmers solving bugs. There are many common PCB circuit board problems, including circuit board design, damage to electronic components, circuit shorts, component quality, and PCB circuit board wire breakage. Common PCB board failures mainly focus on components, such as capacitors, resistors, inductors, diodes, triodes, Field-effect transistor, etc. The integrated chips and crystal oscillators are obviously damaged, and the more intuitive way to judge these component failures can be observed through the eyes. There are obvious burning marks on the surface of electronic components with obvious damage. For faults like this, simply replacing the faulty component with a new one can solve the problem. Of course, not all electronic component damage can be observed with the naked eye, such as resistors, capacitors, transistors, etc. In some cases, the damage cannot be seen from the surface and requires the
1. High heating device with heat sink and heat conduction plate When there are a few components in the PCB that have a high heat output (less than 3), a heat sink or heat transfer tube can be added to the heating device. When the temperature cannot be lowered, a heat sink with a fan can be used to enhance the heat dissipation effect. When there are a large number of heating devices (more than 3), a large heat dissipation cover (board) can be used. It is a specialized heat sink customized according to the position and height of the heating devices on the PCB board, or different component high and low positions can be cut out on a large flat heat sink. Snap the heat dissipation cover onto the surface of each component as a whole and dissipate heat by contacting each component. However, due to poor consistency in height during component assembly and welding, the heat dissipation effect is not good. Generally, soft thermal phase change Thermally conductive pad is added on the surface
The direct reason for the temperature rise of printed boards is due to the presence of circuit power consuming devices. Electronic devices have varying degrees of power consumption, and the heating intensity varies with the size of power consumption. Two phenomena of temperature rise in printed boards: (1) Local or large-scale temperature rise; (2) Short term or prolonged temperature rise. When analyzing the thermal power consumption of PCB circuit boards, it is generally analyzed from the following aspects. 1. Electrical power consumption (1) Analyze the power consumption per unit area; (2) Analyze the distribution of power consumption on PCB circuit boards. 2. Structure of printed boards (1) The size of the printed board; (2) The material of the printed board. 3. Installation method of printed boards (1) Installation method (such as vertical installation, horizontal installation); (2) Sealing condition and distance from the casing.
As pcb design is more and more commonly used in existing development boards, and sub boards are used to drive hydraulic devices and servo motors or perform tasks according to light, motion and sound, the design trend of printed circuit boards gradually tends to Open-source hardware mode and control system. Another major trend in PCB design is the explosive growth of development boards. In October 2013, a survey was conducted on PCB designers from around the world, including professional engineers from 42 different countries. The survey results show that nearly two-thirds of the respondents (64%) believe that the development board has to some extent reduced their demand for customized PCB design. On the surface, this result poses a threat to the development of PCB design, but in reality, printed circuit board design tools are being increasingly applied in development board design. However, since its inception, the design of printed circuit boards has not undergone fundamental chang
These electronic products aim to save space and make them lighter and more compact. Durable and to achieve good performance, it is necessary to cancel the previous wire connection and switch to a printed circuit board. PCB meets the requirements of space, performance, and reliability. Not every electrical appliance requires a circuit board, simple appliances may not require a circuit, such as an electric motor. However, electrical appliances with specific functions typically require circuit boards to be implemented, such as televisions, radios, computers, etc. There is also a PCB at the bottom of the Rice cooker and a governor in the fan. PCB board usually refers to a hard circuit board, mainly used for computer motherboards, mouse boards, graphics cards, office equipment, printers, copiers, remote controls, various chargers, calculators, digital cameras, radios, TV motherboards for household appliances, limited TV amplifiers, mobile phones, washing machines, electronic scales, t
Single sided PCB sample delivery time: Normal delivery time is 2-3 days, and can be expedited within 12 or 24 hours Sample delivery time for double-sided PCB board: Normal delivery time is 2-3 days, and can be expedited within 12 or 24 hours Sample delivery time for the fourth layer circuit board: normal delivery time 4-5 days, with 12, 24, and 72 hours for expedited delivery Six layer circuit board sample delivery time: normal delivery time of 6-7 days, with 72 hours for expedited delivery LED aluminum substrate sample lead time: Normal lead time 3-4 days, can be expedited within 72 hours Delivery time for small batch sampling of PCB circuit boards: 5-6 days within 5 square meters; 6-7 days within 10 square meters; Over 10 square meters for 8-9 days Kind reminder: 1. Except for matte black, matte green, and purple, all other colors are free of charge! 2. Place an order for payment before 18:00 on the same day, and the PCB sample delivery time will be calculated from the ne
In the PCB production process, the reservation of process edges is of great significance for subsequent SMT chip placement processing. The process side is to assist in the welding of the PCB board on both sides or on all four sides of the PCB board. It is mainly used to assist production and is not a part of the PCB board. It can be removed after the completion of PCBA manufacturing and production. Due to the fact that process edges consume more PCB boards, which increases the overall cost of the PCB, it is necessary to balance economy and manufacturability when designing PCB process edges. For some special shaped PCB boards, the original PCB boards with 2 or 4 process edges can be cleverly simplified by splicing. When designing the splicing method in SMT mounting processing, it is necessary to fully consider the track width of the SMT mounting machine. For splicing exceeding 350mm in width, it is necessary to communicate with the SMT supplier's process engineer. The main reason
For some friends who are new to aluminum substrates, there are still questions about the difference between aluminum substrates and PCB boards. Today, the editor will talk to you specifically about this question. Aluminum substrate is a metal-based copper-clad laminate with good heat dissipation function. Generally, a single panel is composed of a three-layer structure, which is a circuit layer (copper foil), an insulating layer and a metal base layer. PCB board, also called printed circuit board, is a provider of electrical connections for electronic components. PCB board is a big category, aluminum substrate is only one of the types, and the design is designed in accordance with the requirements of pcb board. The aluminum substrate we generally call is a single-sided aluminum-based PCB board with good thermal conductivity and is generally used in the LED industry. At present, the commonly used LED aluminum substrate has two sides, the white side is for soldering the LED pins, a
Everyone knows that aluminum is a kind of metal and has conductivity. How can it be used as a PCB material? This is because the aluminum substrate is composed of three layers: copper foil, insulating layer and metal aluminum. Since there is an insulating layer, can the metal layer be made of other materials besides aluminum? Such as copper plate, stainless steel, iron plate, silicon steel plate and so on. What kind of material is used for the metal substrate, in addition to considering the heat dissipation performance, but also consider the thermal expansion coefficient, thermal conductivity, strength, hardness, weight, surface condition and cost of the metal substrate. Under normal circumstances, considering the cost and technical performance, aluminum plate is an ideal choice. Available aluminum plates are 6061, 5052, 1060, etc. If there are higher thermal conductivity, mechanical properties, electrical properties and other special performance requirements, copper plates, stain
Copper foil is a kind of negative electrolytic material, a thin, continuous metal foil deposited on the base layer of the circuit board, which acts as the conductor of the PCB. It easily adheres to the insulating layer, accepts the printed protective layer, and forms a circuit pattern after corrosion. What is the role of the copper foil of the aluminum substrate? The copper foil of the aluminum substrate is also called the circuit layer of the aluminum substrate. It is the conductor of the aluminum-based circuit board and also a kind of cathode electrolytic material, which is generally deposited on the base layer of the circuit board. Thin, continuous metal foil. Copper foil has low surface oxygen characteristics and can be attached to various substrates, such as metals, insulating materials, etc., and has a wide temperature range. The copper foil of the aluminum substrate is easily adhered to the insulating layer and accepts the printed protective layer. After corrosion, the patt
The good heat dissipation performance of the aluminum substrate makes it widely used. Let the aluminum substrate manufacturers introduce the aluminum substrate in detail below. 1. Features of aluminum substrate 1. Using surface mount technology (SMT); 2. In the circuit design scheme, the heat dissipation is extremely effective treatment; 3. Reduce the operating temperature of the product, improve the power density and reliability of the product, and extend the service life of the product; 4. Reduce product volume, reduce hardware and assembly costs; 5. Replace the fragile ceramic substrate to obtain the best mechanical durability. 2, the structure of the aluminum substrate Aluminum-based copper clad laminate is a metal circuit board material, composed of copper foil, thermally conductive insulating layer and metal substrate: Copper foil: the copper clad laminate equivalent to ordinary PCB, the thickness of the circuit copper foil is loz to 10oz. Thermally conductive insul
1. Enter the PCB design system and set relevant parameters Set the environmental parameters of the design system based on personal habits, such as the size and type of grid points, the size and type of cursors, etc. Generally, the default values of the system can be used. In addition, parameters such as the size and number of layers of the circuit board need to be set. 2. Generate Import Network Table The network table is a crucial bridge and link between circuit schematic design and printed circuit board design. Network tables can be generated from circuit schematics or extracted from existing electronic circuit board files. When introducing network tables, it is necessary to check and correct errors in the circuit schematic design. 3. Arrange the packaging positions of each component The automatic layout function of the system can be utilized, but it is not very complete and requires manual adjustment of the packaging position of each component. 4. Wiring the circuit board
1. There are many factors to consider when determining the stacking structure of multi-layer PCB boards. In terms of wiring, the more layers there are, the more advantageous it is for wiring, but the cost and difficulty of making boards will also increase accordingly. For manufacturers, the symmetry of the stacked structure is the focus of attention when manufacturing PCB boards, so the selection of the number of layers needs to consider various needs to achieve the best balance. For experienced designers, after completing the pre layout of components, they will focus on analyzing the wiring bottlenecks of PCBs. Analyze the wiring density of the circuit board with other EDA tools; Determine the number and type of signal layers by synthesizing the number and types of signal lines with special wiring requirements, such as differential lines and sensitive signal lines; And then based on Determine the number of internal electrical layers based on the type of power supply, isolation, a
Previously, I worked in a small electronics factory to manually attach PCB board components, which required hundreds of pieces to be attached in a day. The efficiency was very low and could not match that of a mounting machine. Because it is a small factory, there is not enough manpower, and basically every step has been done, so I have some understanding. Firstly, the engineer uses AD software to draw the PCB. After the layout is manually completed, the drawings are handed over to the manufacturer for sampling. Generally, the PCB board and its corresponding steel mesh can be sampled within 7 working days. Then, the device is purchased according to the circuit diagram provided by the engineer. Then, it is the production line. We scrape solder paste on the screen printing table. Align the silk screen of the PCB board with the steel mesh, then fix the steel mesh, and then scrape tin on the steel mesh. Apply the solder paste onto the silk screen on the surface of the PCB board, so tha
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