+86 755 2794 4155 
sales@knownpcb.com
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
1. High precision: CCD automatic alignment, automatic expansion and contraction to ensure printing accuracy. The maximum printing resolution is 1440dpi. 2. Fine text: Using well-known brand inkjet printing heads for more precise printing quality. Minimum text size 500 μ M/400 μ m. Minimum line width 75 μ M/60 μ M. 3. High efficiency: The multi line inkjet printing head has a higher printing speed. 4. Short cycle: No need to make screen printing, three steps in place, shortening the production cycle. 5. The spray printing area has strong inclusivity: the maximum spray printing area is 610 * 762mm, and the thickness range of the circuit board is 0.1-10mm, with strong inclusivity. 6. Multi spray printing mode: mass production, high-precision, and custom mode. 7. Cost saving: Eliminating various equipment and material costs, as well as labor costs, in the wire mesh process. 8. More environmentally friendly: It does not produce pollutants and is friendly to the environment and op
In recent years, people have increasingly attached importance to environmental protection, so while demanding steady economic development, there are also more requirements for environmental protection construction. Building an "environmentally friendly" society has increasingly become an urgent need for people. The country has also increased its efforts to regulate environmental protection to meet the needs of the times. In 2017, China comprehensively strengthened environmental emission restrictions and conducted inspections on the manufacturing industry, forcing nearly a hundred enterprises to suspend trading for rectification. In 2018, the implementation of the "Environmental Protection Tax" resulted in an increase in environmental protection costs for PCB manufacturers. After a round of rectification, some PCB manufacturers who could not meet environmental requirements were forced to withdraw from the market, and those fortunate enough to survive also had higher requirements fo
If two holes are too close during drilling operation, it will affect the efficiency of PCB drilling process. Due to the fact that after drilling the first hole, the material in one direction is too thin when drilling the second hole, resulting in uneven stress on the drilling nozzle and uneven heat dissipation of the drilling nozzle, leading to the breakage of the drilling nozzle, resulting in unsightly PCB hole collapse or incomplete drilling. 2. In PC multilayer boards, vias have hole rings on each layer of the circuit, and the environment around each layer of the hole ring varies, with and without wire clips. When optimizing files in PCB factory CAM engineers, they will cut off a portion of the hole ring in cases where the clamping wire is too close or the hole is too close to the hole, to ensure a safe distance of 3mil between the welding ring and different network copper/wire. 3. The hole position tolerance for drilling is ≤ 0.05mm. When the tolerance reaches the upper limit
The first level is relatively simple, and the process and process are easy to control. The second order problem starts to get troublesome, one is the alignment problem, and the other is the punching and copper plating problem. There are various second-order designs, one of which is to stagger the positions of each stage and connect the secondary layers through wires in the middle layer, which is equivalent to two first-order HDIs. The second method is to overlap two first order holes and achieve second order through superposition. The processing is also similar to two first order holes, but there are many process points that need to be specially controlled, which is mentioned above. The third method is to directly drill holes from the outer layer to the third layer (or N-2 layer), with many different processes and greater difficulty in drilling. For the third order, the second order analogy is.
PCB (Printed Circuit Board), also known as Printed Circuit Board in Chinese, is an important electronic component that supports electronic components and serves as the carrier for electrical connections of electronic components. Due to its use of electronic printing technology, it is called a "printed" circuit board. Its main function is to avoid manual wiring errors due to the consistency of similar printed boards in electronic equipment, and to achieve automatic insertion or installation of electronic components, automatic soldering, and automatic detection, ensuring the quality of electronic equipment, improving labor productivity, reducing costs, and facilitating maintenance. HDI boards refer to high-density interconnect circuit boards. The boards with blind hole electroplating and secondary pressing are all HDI boards, which are divided into first, second, third, fourth, and fifth order HDIs. For example, the motherboard of the iPhone 6 is a fifth order HDI. Simply burying
HDI board (High Density Interconnector), also known as high-density interconnect board, is a circuit board that uses micro blind buried hole technology and has a relatively high line distribution density. The HDI board has both inner and outer circuits, which are connected internally by drilling and metallization processes. HDI boards are generally manufactured using the stacking method, and the more times they are stacked, the higher the technical level of the board. Ordinary HDI boards are basically stacked once, while higher-order HDI uses two or more layers of technology, as well as advanced PCB technologies such as hole stacking, electroplating filling, and laser direct drilling. When the density of PCBs increases beyond eight layers, manufacturing with HDI will result in lower costs compared to traditional complex pressing processes. HDI boards are conducive to the use of advanced assembly technology, and their electrical performance and signal accuracy are higher than trad
Answer: (1) Solder resist oil is generally composed of a mixture of the main agent, curing agent, and diluent of the ink. During the mixing and stirring of the ink, there will be some air left in the liquid. When the ink is squeezed by a scraper or screen, it flows onto the board surface. In a short period of time, when it encounters strong light or equivalent temperature, the gas inside the ink will flow rapidly with the accelerated flow of the ink, and evaporate outward. (2) The spacing between the lines is too narrow, and the lines are too high. During screen printing, the solder mask ink cannot print onto the substrate, resulting in the presence of air or moisture between the solder mask ink and the substrate. During curing and exposure, the gas expands and causes bubbles due to heat. (3) Single lines are mainly caused by high lines. When the scraper contacts the line, the angle between the scraper and the line increases, making the solder mask ink unable to print to the bottom
The signal integrity problem is not caused by a single factor, but by multiple factors in board level design. The main signal integrity problems include reflection, ringing, ground bounce, crosstalk, etc. The following mainly introduces the solutions to crosstalk and reflection. Cross talk refers to the unwanted voltage noise interference caused by electromagnetic coupling on adjacent transmission lines when a signal propagates on the transmission line. Excessive crosstalk may cause false triggering of the circuit, resulting in the system not functioning properly. Due to the inverse ratio between crosstalk and line spacing, it is proportional to the parallel length of the lines. Crosstalk varies with the load of the circuit, and for the same topology and wiring situation, the larger the load, the greater the crosstalk. Crosstalk is directly proportional to the signal frequency. In digital circuits, the edge change of the signal has the greatest impact on crosstalk. The faster the
Signal integrity refers to the ability of a signal to respond with the correct timing and voltage in a circuit. It is a state in which the signal is undamaged and represents the quality of the signal on the signal line. 1 Delay Delay refers to the limited speed at which a signal is transmitted on the wires of a PCB board, and there is a transmission delay between the signal being sent from the sending end to the receiving end. The delay of the signal will have an impact on the timing of the system, and the transmission delay mainly depends on the length of the wire and the dielectric constant of the surrounding medium. In high-speed digital systems, the length of signal transmission lines is the most direct factor affecting the phase difference of clock pulses. Clock pulse phase difference refers to the asynchronous arrival of two clock signals at the receiving end. The phase difference of clock pulses reduces the predictability of signal arrival. If the phase difference of clo
As the speed of integrated circuit output switches increases and the density of PCB boards increases, Signal Integrity has become one of the essential issues in high-speed digital PCB design. Factors such as the parameters of components and PCB boards, the layout of components on the PCB board, and the layout of high-speed signal lines can all cause signal integrity issues. For PCB layout, signal integrity requires providing a circuit board layout that does not affect signal timing or voltage, while for circuit wiring, signal integrity requires providing termination components, layout strategies, and wiring information. High signal speed, incorrect layout of termination components, or incorrect wiring of high-speed signals on a PCB can all cause signal integrity issues, which may result in incorrect system output, abnormal circuit operation, or even complete failure. How to fully consider signal integrity factors and take effective control measures in the PCB design process has b
Answer: 1. The circuit board surface includes a foil coated substrate and a pre copper plated substrate after hole metallization. To ensure a firm adhesion between the dry film and the substrate surface, it is required that the substrate surface be free of oxide layers, oil stains, fingerprints, and other dirt, drilling burrs, and rough coatings. To increase the contact area between the dry film and the substrate surface, it is also required that the substrate have a micro rough surface. To meet the above two requirements, the substrate must be carefully treated before applying the film. The treatment methods can be summarized into two categories: mechanical cleaning and chemical cleaning. 2. The same principle applies to resistance welding. Before resistance welding, grinding the plate is to remove some oxidation layers, oil stains, fingerprints, and other dirt from the plate surface. In order to increase the contact area between the resistance welding ink and the plate surface and
With the continuous enhancement of mobile terminal functions and the continuous development of thinness and lightness, the design of HDI boards is more towards third-order or even any layer HDI boards. Apple has adopted any layer of HDI for the first time in iPhone 4 and iPad 2, significantly improving the product's lightness and thinness. Subsequently, the Android camp quickly followed suit, and any layer of HDI became the standard motherboard for current mid to high-end smartphones. According to statistics, changing from first-order HDI to any layer HDI can reduce the volume by about 40%. It is expected that any layer of HDI will be applied in an increasing number of high-end smartphones and tablets in the future. At present, the adoption rate of third-order HDI and any layer HDI for smartphones is about 30%, while the adoption rate for tablets is even higher at over 80%. We believe that mobile terminals represented by smartphones will continue to drive the development of HDI boa
In addition to mobile terminals, high-end servers will also drive up the overall demand level for HDI. Currently, PCBs with layers below 8 are mainly used for household appliances, PCs, desktop computers, etc., while high-end applications such as high-performance multi-channel servers and aerospace require PCBs with layers above 10. Taking servers as an example, on single or dual channel servers, PCB boards are generally between 4-8 layers, while high-end servers such as 4-way and 8-way require 16 layers or more on the motherboard and 20 layers or more on the backplane. Therefore, HDI boards are more commonly used. The development of the domestic cloud computing market and the rapid expansion of mobile internet such as mobile payments, OTO applications, and social networks have driven the steady growth of the Chinese server market, becoming the main driving force for global shipment growth, and the growth rate is constantly increasing. In 2015, the sales revenue was 49.82 billion
1. Why do I need to plug holes when BGA is in resistance welding? What are the acceptance criteria? Answer: Firstly, the solder plug hole is to protect the service life of the through hole. The hole diameter required for the BGA position plug is generally relatively small, ranging from 0.2 to 0.35mm. During the subsequent processing, some of the medicine in the hole is not easy to dry or evaporate, and it is easy to leave residue. If the solder plug hole is not plugged or not full during the solder plug, there will be residual foreign objects or solder beads in the subsequent processing such as tin spraying and gold deposition, which will be heated when the customer installs the component for high-temperature welding, Foreign objects or tin beads inside the hole will flow out and adhere to the component, causing defects in the performance of the component, such as open circuit or short circuit. BGA is located in the solder plug hole A. Be sure to plug it fully. B. There should be
After several waves of upward momentum, PCB factories have already reached their limits in terms of affordability. It is understood that in the past six months, the average price of CCL materials has increased by about 20-30%. Therefore, most PCB manufacturers, especially traditional hard board manufacturers, can no longer withstand the pressure and have started price negotiations with customers, hoping that customers can understand the pressure from PCB factories and help absorb some costs. The end customers, ODM and OEM factories that are in contact with PCB factories have seen a real shortage of materials, and the pressure to rush out far outweighs the cost pressure. Recently, their attitudes have indeed softened. It is widely believed that although the magnitude of the price increase cannot be determined, the cost transfer negotiations among PCB factories are expected to achieve certain results. Even if the price increase is only 5-10%, it can be considered as a small supplemen
The main purpose of PCB baking is to remove moisture and moisture, removing moisture inside or absorbed from the outside of the PCB, as some PCBs themselves use materials that easily form water molecules. In addition, after PCB production and placement for a period of time, there is also a chance to absorb moisture from the environment, and water is one of the main culprits causing PCB explosion or delamination. Because when the PCB is placed in an environment with a temperature exceeding 100 ℃, such as a reflow furnace, wave soldering furnace, hot air leveling, or manual welding process, water will become water vapor and quickly expand its volume. The faster the heating speed on the PCB, the faster the expansion of water vapor; The higher the temperature, the larger the volume of water vapor; When water vapor cannot escape from the PCB in a timely manner, there is a good chance of expanding the PCB. Especially the Z direction of a PCB is the most fragile, sometimes it may brea
At present, the formation process of refined circuits includes laser imaging (pattern transfer) and pattern etching forming. Laser direct imaging (LDI) technology is the process of obtaining refined circuit patterns directly by laser scanning on the surface of copper clad plates coated with photoresist. Laser imaging technology greatly simplifies the process flow and has become the mainstream technology in HDI PCB plate making. The application of semi additive method (SAP) and improved semi additive method (mSAP), namely graphic etching method, is increasing nowadays. This technology process can also achieve conductive circuits with a line width of 5um. How to improve electroplating uniformity and deep hole plating ability in PCB manufacturing, and improve the reliability of the board. This depends on the continuous improvement of the electroplating process, starting from various aspects such as the proportion of electroplating solution, equipment allocation, and operating proce
With the development of technology, some high-tech devices are becoming increasingly miniaturized and precise, which puts higher demands on the HDI boards they use. The line width/spacing of HDI circuit boards for some devices has evolved from early 0.13 mm (5 mils) to 0.075 mm (3 mils) and has become a mainstream standard. As a leading enterprise in the HDI fast board industry, Shenzhen Benqiang Circuit Co., Ltd. has achieved a production process of 38 μ M (1.5 mil) is approaching the limit of the industry. The increasingly high requirements for line width/distance have brought the most direct challenge to graphic imaging in the PCB manufacturing process. So how are the copper wires on these precision boards processed and formed? The important feature of HDI circuit boards is the presence of micro through holes (aperture ≤ 0.10 mm), all of which belong to buried blind hole structures. The buried blind holes on HDI boards are currently mainly processed by laser, but there are a
PCB circuit board impedance refers to the parameters of resistance and reactance, which hinder AC power. In the production of PCB circuit boards, impedance processing is essential. The reasons are as follows: 1. PCB circuits (bottom of the board) should consider the installation of electronic components by plugging, and after plugging, issues such as conductivity and signal transmission performance should be considered. Therefore, it is required that the impedance should be as low as possible, and the resistivity should be less than 1&TIMes per square centimeter; Below 10-6. 2. During the production process of PCB circuit boards, they need to go through processes such as copper deposition, electroplating tin (or chemical plating, or thermal spraying tin), and connector soldering. The materials used in these processes must ensure a low resistivity to ensure that the overall impedance of the circuit board meets product quality requirements and can operate normally. 3. The tin plat
For the electronics industry, according to industry surveys, the most fatal weaknesses of chemical tin plating are its susceptibility to discoloration (i.e. oxidation or deliquescence), poor solderability leading to difficulty in soldering, high impedance leading to poor conductivity or unstable overall board performance, and susceptibility to tin growth, which can lead to short circuits in PCB circuits and even burning or ignition events. It is reported that Kunming University of Technology in the early 1990s was the first to study chemical tin plating in China, followed by Guangzhou Tongqian Chemical (Enterprise) in the late 1990s. It has been recognized in the industry for the past 10 years that these two institutions are doing the best. Among them, according to our contact screening investigations, experimental observations, and long-term endurance tests of numerous enterprises, it has been confirmed that the tin coating of Tongqian Chemical is a pure tin layer with low resist
About Us Product Center Capabilities&Applications Quality Assurance News Contact Us flexible printed circuit board
ISO 9001:2008 registered © 2022 Shenzhen Knownpcb Technology Co., Ltd. All Rights
Reserved ICP: 粤ICP备08036040
Inquiry Now
EN
CN
中文
Home > 
