As an indispensable device in electronic links, connectors are one of the key exhibition areas of Munich Shanghai Railway Station, attracting powerful connector leading enterprises at home and abroad, such as AVIC Optoelectronics, Guang Lai Electric, Sumitomo Electric and Rosemburg. With the advent of the 5G era, the requirements of "high speed and high efficiency" are put forward for signal and power transmission, and the materials, performance and design of connectors are challenged. At the connector innovation forum held in Munich recently, I learned the views of connector industry experts such as AVIC Optoelectronics, Weber Alloy and KMD on the opportunities and challenges of connectors in the 5G era.
Weber alloy: smart materials continue to create value for customers
Weber Alloy is a leading advanced manufacturing enterprise in China's materials industry, and it is the main unit that formulates national and industrial standards for new nonferrous alloy materials in China. At present, it owns 185+ patent and 17+ national standard. At the forum, the theme brought by Weber Alloy is: intelligent materials, creating value for customers continuously, and sharing connector material selection.
The function of connector is to act as a bridge in the circuit and realize the low-loss connection between electrical signals and signals. The contact resistance of the connector itself is obviously higher than that of the two connecting parts, which is the weak part of the whole link. This is a bottleneck of connector development at present.
The application of 5G has the characteristics of "high current and high voltage". The current connector is equivalent to gathering power signals from the "fast lane" at the "intersection", which hinders the transmission speed. In order to change this situation, many factors need to be considered when designing connectors. Weber alloy analyzed this from the point of view of material selection.
Weber alloy thinks that electrical conductivity and thermal conductivity are the main materials. The higher the thermal conductivity of the material, the lower the contact resistance and the lower the temperature rise of the connector, while the higher the thermal conductivity of the material, the better the heat transfer ability and the lower the temperature rise of the connector.
Secondly, the mechanical properties of materials should be considered when selecting materials. The mechanical properties of connectors include yield strength and elastic modulus, which will affect the retention of connectors. If the clamping force is too large, it will affect the separable characteristics of the connector, and plugging and unplugging will lead to additional wear of the connector; If the holding force is too small, the contact resistance of the connector will increase and its reliability will decrease.
Finally, heat resistance, corrosion resistance, welding performance, material cost, processing and molding cost should be considered. According to the use environment of the connector, we need to find a balance point from many characteristics of the material.
Weber alloy mentioned that most connector materials use copper alloy at present, because copper has excellent electrical and thermal conductivity, availability and cost, but its strength is poor, so copper alloy is used. But in fact, the conductivity and strength of bronze, white copper and brass we use at present cannot be both.
In order to cope with the development of 5G applications, connector materials must meet the requirements of high strength and high conductivity. Therefore, Weber alloy is constantly developing balanced alloys covering high conductivity, high strength and both conductivity and strength. At present, the solutions of Boway alloy are copper-chromium-zirconium alloy boway 18 150, boway 18 160, Boway18400; Cu-Ni-Si alloy boway70250, boway70260, boway 190 10, Boway19005; Tellurium copper alloy PW 14500, etc. It has better strength, conductivity and high temperature resistance, and is suitable for industries such as automobiles and high-speed backplane connectors for 5G communication.
KMD: Ensuring a stable and efficient connection in the 5G era
KMD (Cameron) is a global company specializing in providing connector tapes and an international supplier of communication connector materials. Its customers include Huawei, Amphenol, MOSS, SCI and other large enterprises. The theme brought by KMD is how to ensure a stable and efficient connection in the 5G era. Share connector changes and new manufacturing requirements brought about by the 5G era.
The 5G era is an era of high-speed interconnection, and everything is connected. Compared with the 4G era, it has new characteristics: high frequency, high speed and high stability; Storage and transmission of big data; Multi-terminal input and output in transmission mode, etc. Among them, the high-speed and stable storage and transmission of big data has become an increasingly critical technical challenge in the 5G era, requiring connectors with higher conductivity and strength to ensure stable connection. In addition, micro connectors are becoming the general trend.
In the 5G era, the number and data volume of personal intelligent consumer terminals are increasing. According to the prediction of consulting organizations such as Cisco, the data volume will increase by 20% every year in the next 5- 10 years, and the data volume generated by personal consumption terminals will gradually increase, and it is expected to reach 53% of the total data volume in 2030. This means that in the future, consumer terminal products such as smart phones, tablets, smart wear and VR/AR devices will be greatly developed, and at the same time, higher requirements will be put forward for data transmission and storage. It is predicted that from 2017 to 2022, the growth of personal intelligent terminal equipment will reach 10%, and the data growth will reach 30%.
At the same time, the vigorous development of global big data high-speed processing centers will become an inevitable trend. It is predicted that in 2065,438+06-2024, the market size of big data centers will grow at a compound annual growth rate of 65,438+07.2%, and in 2065,438+06-2022, emerging markets in Asia-Pacific will grow rapidly at a rate of 24%, becoming a fast-growing region in the world.
Facing the rapid growth of data, how to realize the stable, high-speed and reliable transmission of connectors? KMD answers from the perspective of materials. KMD pointed out that copper alloy with high electrical conductivity and high thermal conductivity is the most suitable connector material, and the 5G era put forward new requirements for copper alloy strip: high strength/low elongation/high toughness/high conductivity; Excellent stamping performance and surface quality; Proper insertion force.
Taking KDM as an example, a new connector terminal-fisheye terminal is widely used in the field of communication connectors because it can keep stable connection without welding, but it requires high design and manufacturing technology of raw materials: 1. Because long-term positive pressure and stable contact are needed, the yield strength is required to be higher than 700MPa and the stress relaxation resistance is excellent (≥80%,120 C/). 2. In the manufacturing process, the thickness of 0.23-0.25mm needs to be reduced to 0. 15-0. 18mm, so it needs high bending performance (toughness) (r/t = 2,180); 3. The data transmission speed is required to be higher, so the conductivity needs to be increased from 40%IACS to 45-60% IACS; 4. Due to the miniaturization of terminals, the future forming direction may be parallel to the rolling direction of copper strip, so the requirements for material isotropy are getting higher and higher.
To sum up, new alloy materials should have higher strength, toughness and electrical conductivity, and at the same time, special requirements such as low roughness coefficient, high hardness, low resistance and long-term stability are put forward for surface requirements. The solutions brought by KMD include bare strip of C7025 alloy with high strength, high conductivity and high toughness, and Sn 13 (hot tin) and Sn28M(SnAg) coatings with special properties.
Avic optoelectronics: discussion on the development of high-speed interconnection technology
AVIC Optoelectronic is a leading connector enterprise and a "nationally recognized enterprise technology center" in China. Its products are widely used in aerospace, military electronics, new energy vehicles, communication and data centers, rail transit and other fields. The theme brought by AVIC Optoelectronics is the development of high-speed interconnection technology, sharing the development trend of high-speed interconnection and the design technology of high-speed connectors.
According to the forecast of IDC, an IT information consulting company, the global data will reach 35zb (1zb =109tb =10/2gb =10/5mb) in 2020, and it is expected to reach 2025. The demand for high-speed connectors will increase by more than 20% every year.
In the past, high-speed connectors were monopolized by international connector giants. Domestic connectors began to contact in 2000, and the real beginning was 20 10. With the development of 5G communication technology, the proportion of high-speed connectors used in major projects in China is gradually increasing, such as quantum communication and quantum computer, cloud computing, national cyberspace security, 5G/ Beidou navigation and so on.
Compared with 3/4G, the transmission rate and capacity of 5G are increased by more than 10 times. With the support of the 5G architecture, the future Internet of Vehicles, Internet of Things and autonomous driving are all possible. Following the pace of 5G, various technical fields are developing in the direction of high speed, and the original high-speed interconnection products can no longer bear such a large amount of data transmission.
AVIC optoelectronics compares "high-speed interconnection" to "expressway", and the changes made by expressway to increase traffic volume are to increase the number of lanes and increase the speed of bicycles. Compared with high-speed interconnection products, the development of 3G-5G is a process of increasing the number of channels. The number of stations in 5G base stations is 1000 times that of 3G and 10 times that of 4G. Secondly, the transmission speed of 5G data signals is faster, and a single signal level carries more data.
The breakthrough of high-speed connectors is the foundation of sustainable development of 5G. AVIC Optoelectronic pointed out that it has achieved a single channel of 25Gpbs.
Links, but also encountered bottlenecks: backboards above 25Gpbs are facing problems such as increased link loss, difficult heat dissipation and high cost. The development of 25Gpb requires the use of more advanced and higher-end plates, and the material cost and processing cost are relatively high. At the same time, the backboard with 25Gpb is perforated, and it will be more difficult for the backboard above 25 GPB to dissipate heat.
At the forum, AVIC Optoelectronics brought three solutions:
First, the development from traditional backboard to orthogonal backboard.
That is, there are fewer midplanes and two mainboards are interconnected. Advantages: The orthogonal architecture greatly reduces the high-speed signal transmission distance between the service card and the switching matrix card (reducing the distance of a backplane), and then the attenuation of link transmission will also be reduced, which provides a hardware architecture foundation for the stable transmission of high-speed signals.
Second, the transition from traditional backboard to cable backboard:
That is, replace the backplane with a high-speed line. Advantages: the manufacturing process of the cable itself is very mature, the loss of the high-speed cable itself is much less than that of PCB, and the high-speed cable can realize short-distance interconnection communication, so it will be a cost-effective and efficient interconnection solution. Disadvantages: the cable processing efficiency is low, and the welding efficiency is much lower than the compression efficiency.
Thirdly, the traditional backplane turns to the orthogonal cable backplane scheme.
AVIC Optoelectronic has developed 56/ 1 12Gpbs in the above three schemes, and thinks that the third scheme will be the mainstream in the future. At present, AVIC Optoelectronic has 56Gpbs high-speed connection products, including GF5 high-speed backplane connector, GF5Z high-speed mezzanine self-plugging connector, BGA high-speed mezzanine self-plugging connector and so on. 1 12Gpbs high-speed connection products are GF6 series high-speed backplane connectors and GF6 series high-speed orthogonal (OD) connectors.
abstract
With the acceleration of new infrastructure, 5G empowers all walks of life. The future world will be intelligent, digital and scientific, and a huge amount of data will be generated every day, which requires stable and high-speed transmission through connectors, which challenges the material, performance and the whole design and manufacturing process of connectors. Therefore, enterprises in the connector industry chain should keep up with the pace of 5G, predict and lay out the future direction of connectors in advance, and realize that the future products are mainly personalized, and both material manufacturers and connector manufacturers need to carry out digital transformation, cooperate intelligently with customers, and gradually transform from connector manufacturers to application solution providers to provide better products.