It is very common for PCB factories to have no inventory, even for many conventional FR4 boards. At this time, in order to meet the delivery time, many board factories or marketing personnel will negotiate with customers, "can we change materials with the same performance level?" The customer will ask back, "which one to change?…
The electromagnetic interference produced by switching power supply often affects the normal work of electronic products. The correct PCB layout of switching power supply becomes very important. In many cases, a power supply designed perfectly on paper may not work properly during the initial debugging because of many problems in the PCB layout of the…
Digital signal processing chip (DSP) has high-performance CPU (clock performance over 100MHz) and high-speed advanced peripheral equipment. With CMOS processing technology, DSP chip power consumption is getting lower and lower. These great progress increases the complexity of DSP circuit board design, and compared with simple digital circuit design, it faces more similar problems. The following…
PCB board design needs to provide information: (1) Schematic diagram: a complete electronic document format, which can generate correct netlist; (2) Mechanical size: provide the specific position and direction identification of positioning device, as well as the identification of specific height limit position area; (3) BOM list: it mainly determines and checks the specified package…
1. IDE (parallel port hard disk) The full name of IDE is "integrated drive electronics", that is, "electronic integrated drive". The transmission speed of IDE is 100 or 133mb / s. its original meaning is the hard disk drive that integrates "hard disk controller" and "disk body". By integrating the disk body with the…
Via is one of the most important parts of PCB, and the cost of drilling usually accounts for 30% to 40% of PCB board making cost. From the design point of view, a via is mainly composed of two parts, one is the middle drill hole, the other is the pad area around the drill…
VENTEC electronics is a professional copper clad laminate manufacturer. Its business scope includes: R & D, production and processing of epoxy resin glass cloth copper clad laminate for single and double and multi-layer PCB, epoxy resin glass cloth PP for multi-layer PCB, and new instrument components and materials and related products for flexible circuit board.…
Polytetrafluoroethylene is referred to as PTFE, which has a wide range of use temperature, excellent chemical stability, electrical insulation, self-lubricating, aging resistance and other excellent properties. It is widely used in many fields. However, the application of polytetrafluoroethylene in device manufacturing often encounters problems related to its surface properties. Poor surface wettability can lead to…
1. What back drill? In fact, back drilling is a special kind of depth control drilling. In the production of multi-layer pcb boards, such as the production of 12-layer pcb, we need to connect the first layer to the ninth layer. Usually, we drill via holes (once drilling), and then aging copper. In this…
Why the bare copper pad on the side of QFN device and pad on the back side of SMT welding do not climb tin or the height of tin climbing can not meet the standard requirements in IPC, which is a knotty and headache problem. How to solve this problem, today we will talk about…
What are the pins and voltages of DDR, DDR2 and DDR3? In DDR memory, there are 92 single-sided gold finger pins (184 on both sides), 52 pins on the left side of the notch and 40 pins on the right side of the product; DDR2 Memory has 120 gold fingers on one side (240 on…
Beginners must know: what is the difference between ARM and MCU? 1. Software This should be the biggest difference. The operating system is introduced. Why introduce operating system? What's the benefit? 1) Convenient. It is mainly reflected in the later development, that is to develop the application program directly on the operating…
Recognizing diodes and detecting their characteristics is an essential skill for anyone working with electronics. Diodes are semiconductor devices that allow current to flow in one direction while blocking it in the other, and they come in various types. Here are some key skills and methods for recognizing and detecting diodes: Visual Inspection: The most…
EDA tools emerge in an endless stream. At present, EDA software that has entered China and has a wide influence include EWB, PSpice, OrCAD, PCAD, PROTEL, viewlogic, mentor, graphics, Synopsys, lsilogic, cadence, Microsim, etc. These tools have strong functions and can be used in several aspects. For example, many software can be used for circuit…
1. How to choose PCB material for high frequency PCB? For PCB board selection, it is necessary to strike a balance between meeting design requirements and mass production and cost. Design requirements include electrical and mechanical parts. In general, when designing very high-speed PCB board (frequency higher than GHz), this material problem will be more…
1. Component layout When doing stacking, it is necessary to consider the layout of structural parts and main components, such as I / O connector, SIM card, battery connector, T card, camera, speaker, receiver, RF part, baseband part, GSM antenna part, Bluetooth antenna part and mobile TV antenna part. The placement of these parts…
