In terms of the current development status and trends of international electronic circuits, the development prospects of PCBs are very broad, but we inevitably encounter some mistakes in the design process. This article will take you to see the development prospects of PCBs and several common mistakes. , do you make these mistakes? Knowing these mistakes before they affect the overall functionality of the board is a great way to avoid costly production delays.
First look at the development prospects and trends of PCB:
1. Chip-scale packaging CSP will gradually replace TSOP and ordinary BGA
CSP is a chip-scale package. It is not a separate form of packaging, but a chip-scale package when the chip area is comparable to the package area. The CSP package can make the ratio of chip area to package area exceed 1:1.14, which is quite close to the ideal situation of 1:1, which is about 1/3 of the ordinary BGA; the center pin form of the CSP package chip is effectively shortened. The transmission distance of the signal reduces the attenuation, and the anti-interference and anti-noise performance of the chip can also be greatly improved. In the CSP packaging method, the chip particles are soldered to the PCB board one by one through solder balls. The contact area of the PCB board is large, so the heat generated by the chip during operation can be easily conducted to the PCB board and dissipated.
Development prospects: Chip-scale packaging developed in response to the lightness, thinness, shortness and smallness of electronic products is a new generation of packaging methods. According to the development trend of electronic products, chip-scale packaging will continue to develop rapidly and gradually replace TSOP (ThinSmallOutlinePackage) packaging and Ordinary B GA package.
2. By 2010, the output value of photovoltaic panels will increase by 14%
Photoelectric board, or photoelectric backplane, is a special printed circuit board with a built-in optical path, and it is also a kind of backplane, mainly used in the field of communication. Main advantages of optoelectronic backplanes: low signal distortion; avoidance of noise; very low crosstalk; loss independent of frequency; dense wavelength demultiplexing technology; 12-6 channel multiplex connectors; waveguide multichannel connectors; improved discrete The reliability of the cable; the number of layers of the photoelectric board can reach 20 layers, more than 20,000 lines, and 1,000 pins of the connector; the bandwidth of the traditional backplane is limited due to the use of copper wires.
Development prospects: Due to the growth of bandwidth and distance, the transmission line of copper material will reach the limit of bandwidth and distance, while optoelectronic transmission can meet the needs of increased bandwidth and distance. Photoelectric backplanes are mainly used in communication exchange and data exchange, and will be applied to workstations and servers in the future. According to forecasts, by 2010, the global output value of optoelectronic backplanes will reach 200 million US dollars, with an annual growth rate of about 14%.
3. The development prospect of rigid-flex board is very promising
In the past, the name of flexible board FPC was very messy. It was first called a soft board, and later it was also called a flexible board, a flexible printed circuit board, etc.
Rigid-flex printed board refers to a printed board containing one or more rigid areas and one or more flexible areas, which are composed of rigid boards and flexible boards laminated together in an orderly manner and formed with metallized holes Electrical connections. Rigid-flex printed boards can not only provide the support function of rigid printed boards, but also have the flexibility of flexible boards, which can meet the requirements of three-dimensional assembly. In recent years, the demand is increasing. The traditional rigid-flex board design idea is to save space, facilitate assembly and improve reliability; the new rigid-flex board integrating traditional rigid-flex board design and micro-blind hole technology provides a new solution for the interconnection field. Its advantages are: suitable for folding mechanisms, such as flip phones, cameras, notebook computers; improve product reliability; apply traditional assembly methods, but can simplify assembly and be suitable for 3D assembly; combine with micro-via technology to provide better Design convenience and use of smaller components; use lighter materials in place of traditional FR-4.
Rigid-flex boards for mobile phones are generally composed of two-layer flexible boards and rigid boards.
Development prospects: Rigid-flex board is a type of PCB that has grown very rapidly in recent years. It is widely used in computers, aerospace, military electronic equipment, mobile phones, digital (camera) cameras, communication equipment, analytical instruments, etc. It is predicted that the average annual growth rate from 2005 to 2010 is more than 20% in terms of output value, and the average annual growth rate in terms of area is more than 37%, which greatly exceeds the growth rate of ordinary PCBs. So far, there are very few manufacturers that can produce rigid-flex boards, and almost no manufacturers have experience in mass production, so their development prospects are very promising.
4. High multi-layer boards bring opportunities to the Chinese industry
A multi-layer board refers to a PCB board with an independent wiring layer greater than two layers. Generally, multiple double-sided boards are laminated by lamination, and each layer of the board is laminated to form a whole board through a layer of insulation. High multi-layer boards generally refer to multi-layer boards with more than 10 layers, mainly used in switches, routers, servers and large computers. Some supercomputers use more than 40 layers.
Development prospects: Ordinary multi-layer boards are mature products, and the future growth is relatively stable; but high-level multi-layer boards have high technical content, and countries such as Europe and the United States have basically abandoned conventional PCB production, bringing some opportunities to the Chinese industry. It is predicted that the high multi-layer board (backplane) will grow by about 13% in the future.
5. 3G boards improve the technical level of PCB products
Printed boards for third-generation mobile communication products (3G). 3G board generally refers to 3G mobile phone board. It is a high-end printed circuit board. It is manufactured by advanced secondary lamination process. The circuit grade is 3mil (75μm). A series of cutting-edge technologies for printed boards. 3G technology is significantly improved over existing products.
Development prospects: 3G is the next-generation mobile communication technology. Currently, developed countries such as Europe, America and Japan have begun to apply it. 3G will eventually replace the existing 2G and 2.5G communications. By the end of 2005, the number of 3G users worldwide has increased by 57.4%. The total number has reached 237 million. In 2005, a total of 122 million 3G mobile phones of various standards were sold, and the future development will still maintain a growth rate of more than 20%. The matching printed board, ie 3G board, maintains the same growth rate. 3G board is an upgrade of existing products, which makes the overall level of the PCB industry step into a higher level.
6. HDI board will grow rapidly in the future
HDI is the abbreviation of HighDensity Interconnect. It is a (technology) for producing printed boards. It is currently widely used in mobile phones, digital (camera) cameras, MP3, MP4, etc. The more times, the higher the technical grade of the board. Ordinary HDI boards are basically one-time buildup, and high-end HDI uses two or more buildup technologies, while using advanced PCB technologies such as stacking, electroplating, and laser direct drilling. High-end HDI boards are mainly used in 3G mobile phones, advanced digital cameras, IC carrier boards, etc.
Development prospects: According to the use of high-end HDI boards - 3G boards or IC substrates, its future growth is very rapid: the world's 3G mobile phone growth will exceed 30% in the next few years, and China will soon issue 3G licenses; IC substrate industry consulting Institution Prismark predicts that China's forecast growth rate from 2005 to 2010 is 80%, which represents the technical development direction of PCB.
The development is really fast, but the errors we will encounter when designing are as follows:
6.1. Landing Mode
While most PCB design software includes a library of common electrical components, their associated schematic symbols and landing patterns, some boards will require the designer to draw them manually. If the error is less than half a millimeter, engineers must be very strict to ensure proper spacing between pads. Mistakes made during this production phase will make welding difficult or impossible. The necessary rework will result in costly delays.
6.2. Using blind/buried vias
In today's market of devices accustomed to IoT, smaller and smaller products continue to make the biggest impact. When smaller devices require a smaller PCB, many engineers choose to utilize blind vias and buried vias to reduce the board footprint to connect internal and external layers. While effectively reducing the area of a PCB, vias reduce routing space and can become complex as the number of additions increases, making some boards expensive and impossible to manufacture.
6.3. Trace width
To keep the board size small and compact, engineers aim to keep the traces as narrow as possible. Determining the PCB trace width involves many variables, making it difficult, so it is imperative to have a comprehensive knowledge of how many milliamps will be required. In most cases, the minimum width requirement is not sufficient. We recommend using a width calculator to determine proper thickness and ensure design accuracy.
Opportunities are also challenges, we should take our chances and avoid mistakes.
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