Master the core technologies of the next-generation printed circuit industry as soon as possible

 

Outstanding Entrepreneur in the National Electronic Information Industry
Expert Committee of China Service Trade Association	director
Yuncheng College of Shanxi Province	Visiting Professor	Ni Yunzhi
Jiangsu Suhang Electronics Group Company	Chairman
China Electronic Circuit Industry Association (CPCA)	director	Gong Yonglin
Printed Circuit Information	Editor in chief

 

I. Introduction

Recently, the United States has provoked a trade war with China, significantly increased tariffs on imports from China, and banned the export of high-tech products to China. The ban on China 's ZTE Corporation is an example. In April this year, the US Department of Commerce issued a ban on ZTE 's export authority, which banned US companies from selling components, goods, software and technology to ZTE for a period of 7 years. The company went into shock. Only in June did the US Department of Commerce agree to lift the ban on the condition that ZTE paid huge fines, changed its board of directors and management, and purchased more US products.ZTE Corporation is one of the world's communications equipment manufacturing giants, but the lifeblood is stuck by Yankees because of the lack of core technology and the lack of core components and integrated circuits.

Just at this time, China held the Chinese Academy of Sciences and the Chinese Academy of Engineering academician conference at the end of May this year. At the meeting, General Secretary Xi Jinping delivered an important speech, which said: "The shortcomings of China's basic science research are still outstanding, and enterprises pay insufficient attention to basic research. Lack of major original achievements, insufficient underlying technology and basic process capabilities, bottlenecks such as industrial motherboards, high-end chips, basic software and hardware, development platforms, basic algorithms, basic components, and basic materials are still prominent, and the situation where key core technologies are constrained by people is not available Radical change. "

Generally speaking, in addition to biomedicine, the core technology is material technology in the final analysis. When the product requires extremely high processing accuracy, materials are one of the biggest limitations. There are about 130 key core materials in the world. Human core technology, to some extent, refers to these 130 materials. According to data released by the Ministry of Industry and Information Technology in July 2018, 32% of them are completely blank, and 52% rely on imports, and the proportion in high-end areas is even more disparate. Although some key parts and components are domestically produced, 95% of the equipment used to produce the parts is imported

The ZTE incident in Sino-U.S. Trade is a wake-up call to China's manufacturing industry and has been deeply moved. General Secretary Xi's speech focused on the key issues and bottlenecks in the development of science and technology and industry. For our printed circuit manufacturing industry, it is also worth pondering. What are the shortcomings of our printed circuit industry? Is there a lack of core technology that will be threatened and stuck by foreign countries? Is the lifeblood of the printed circuit industry in my own hands?

 

Second, the high-performance substrate is the lifeblood of a new generation of printed circuit boards

The electronic information industry is about to enter the 5G era, and 5G is here! 5G means that the fifth generation of mobile networks is not limited to mobile phone communications. From the Internet of Things, smart cities to driverless cars, 5G is required. Almost all walks of life are struggling to cut a corner for the big cake of 5G. The same is true for printed circuit boards. 5G equipment has brought a new generation of printed circuit boards.

The key to the manufacture of printed circuit boards (PCBs) is first and foremost the raw materials-substrates. Without substrates, PCBs cannot be manufactured. PCB substrates include substrates (CCL), prepregs (pre-preg Pp), and copper foil. Many of the main properties of PCBs are determined by the substrate, such as mechanical strength, dielectric properties, dimensional stability, Heat resistance and flame resistance. For example, PCBs made of phenolic paper-based CCL with poor mechanical strength and low electrical properties can only be used in low-end consumer electronic devices. In high-performance and high-reliability electronic devices, PCBs must be made of high-performance epoxy glass cloth or polymer. The CCL of resins such as tetrafluoroethylene and liquid crystal polymer can produce good fruits only when the gene is right.

The PCB manufacturing process technology is not weak in mainland China. With the diligence and intelligence of the Chinese people, as long as the relevant materials and equipment are available, the company has skilled craftsmen, and even complex PCB products can be manufactured. At present, domestic enterprises have manufactured a variety of high-performance special PCBs, including embedded components, embedded copper blocks, metal-based heat dissipation, and high-frequency mixed pressure PCBs that have reached international advanced levels. However, the high-performance substrates used in the new generation of high-performance PCBs still rely on foreign imports, highlighting high-frequency and high-speed substrates and high thermal conductivity substrates. A number of domestic PCB manufacturing companies have produced a variety of special PCBs, such as "56Gbps ultra-high-speed printed circuit boards suitable for 5G communications" and "5G connected high-density interconnected modules for vehicle networking". The achievements of PCB products, unfortunately, they use foreign materials. At present, China is already the world's largest producer of PCB substrates in terms of output, but some high-performance substrates still lack domestic production and rely on foreign imports.

Electronic equipment has different design requirements at different frequencies, and circuit substrates with different characteristics are required to support circuits that are most suitable for different frequencies. When looking for circuit materials for microwave and millimeter-wave power amplifiers suitable for 5G applications, in addition to the substrate must be low dielectric loss (Df) and low dielectric constant (Dk), there are circuit materials that can perform effective thermal management. There are two parameters for evaluating the thermal properties of materials: thermal conductivity and temperature coefficient of dielectric constant (TCDk). For amplifiers and other circuits in 5G systems, circuit substrates are required to have low Dk, Df, and low TCDk values, as well as high thermal conductivity, in order to produce high-quality, high-performance, high-frequency power amplifiers.

Factors affecting insertion loss on microstrip circuits In addition to the insulation, copper conductors have become more critical. This is mainly determined by the smoothness of the copper surface. Because the skin effect will occur in a very high frequency environment, the roughness of the copper foil is also an important factor. In addition, the thinning of the circuit requires thin copper foil and ultra-thin copper foil. .

The new generation PCB focuses on 5G communication and automotive electronics, and it exhibits high-frequency high-speed characteristics and high heat dissipation characteristics on the PCB. To meet the requirements of high-frequency, high-speed, and high heat dissipation performance, PCBs are particularly important in addition to design and manufacturing factors. Therefore, the substrate should be regarded as the core technology of PCB, especially the high-performance substrate is the lifeblood of high-performance PCB.

 

Third, the gap between high-performance substrates

The main requirements of high-frequency materials are low dielectric constant (Dk) and low dielectric loss factor (Df). At present, mainstream high-frequency products are achieved by using polytetrafluoroethylene (PTFE) and hydrocarbon resin materials.

Check the product technical information of some PCB substrate manufacturing companies such as copper clad laminate (CCL). International advanced CCL manufacturers include Rogers, Isola, Park Electrochemica, Taikangike (Taconic), Tenghui (ventec), Panasonic (Panasonic) and so on. For example, Panasonic's ultra-low-loss multilayer board substrate MEGTRON7 is a multilayer circuit board material with the lowest industrial transmission loss, which meets the requirements of high-capacity and high-speed transmission of high-end network equipment.

Rogers has a series of high frequency, high speed and high thermal conductivity substrates. The composition of its CCL includes polytetrafluoroene (PTFE) glass cloth reinforcement, PTFE resin filled ceramics, PTFE resin filled ceramic glass cloth reinforcement, modified epoxy. Resin-filled ceramics, hydrocarbon-resin-filled ceramics, hydrocarbon-resin-filled ceramic glass cloth reinforcements, ceramic-filled thermosetting polymers, polyetheretherketone (PEEK) resin glass cloth reinforcements, etc. In particular, it should be noted that Rogers does not simply provide high-performance substrates, but rather provides advanced connectivity solutions (ACS). Not only does it launch a variety of high-performance CCL and Pp products, it also introduces the specific performance and application areas of various products. , And PCB design and processing technology guide. Their new substrate development combined with PCB users is highly targeted and clear-cut. Rogers's approach is also a factor in their substrate selection by more PCB manufacturers.

In terms of high thermal conductivity substrates, Tenghui's products are more prominent. For example, metal-based copper clad laminates can choose different substrates and insulation layers. The thermal conductivity is from 1W / m · K to 10W / m · K. There are various specifications, there are Ceramic-filled high thermal conductivity laminates and prepregs for multilayer PCBs have a thermal conductivity of 2.2 W / m · K which is 8 times that of FR-4.

According to Anxin Securities. Southern Fortune.com: High-frequency substrates are basically occupied by US and Japanese manufacturers. Rogers (55%), Park / Nelco (22%), Isola (9%), and ZTE Chemicals (5%) occupy major global markets. Share, of which PTFE market share Rogers is more than 90%. Whether these percentage values ​​are accurate or not, and engineers who manufacture high-performance PCBs say that the substrate must be a foreign company's product. At present, almost all of the high-frequency and high-speed PCB substrates in China use the specifications of foreign companies. These are facts.

Let's look at our domestic leading CCL manufacturing companies, such as the top five domestic CCL output companies listed in the 17th (2017) China Electronic Circuit Industry Ranking of CPCA: Guangdong Shengyi Technology, Jinan Guoji Technology, Shandong Jinbao Electronics , Nanya New Materials Technology, Zhejiang Huazheng New Materials. Checking the websites of these companies, in addition to Shandong Jinbao Electronics only paper-based copper clad laminates, the other four companies have or are launching new high-performance CCL and Pp substrates.

For example, Guangdong Shengyi Technology Co., Ltd., which ranks top in China, has high-speed circuit substrates: S7045G / S7045GB. Application areas: communication, server, base station, backplane, line card, high-performance computer, office router, etc .; RF & microwave circuit substrate: S7136H Application areas: high-frequency wireless communications, high-speed computers, satellite signal transmission equipment, microstrip and cellular base stations, antennas and power amplifiers. The dielectric properties of these substrates are only close to the low loss range.

Nanya New Materials Technology Co., Ltd. has high-speed circuits and microwave / RF CCLs. Zhejiang Huazheng New Materials Co., Ltd. has high-frequency materials, which are said to be suitable for base station antennas, airborne, ground, and surface radar systems. These products are only based on test data. I wonder if they are commercialized and what are the specifications when commercialized? These high-speed and high-frequency circuit substrates in China all have extremely wide application fields. They list a lot of applications, but they are not targeted. It is usually difficult to cure a disease by including all kinds of medicines.

In terms of thermally conductive substrates, Guangdong Shengyi Technology Co., Ltd. has high thermal conductivity FR-4, thermally conductive adhesive sheet, thermal conductivity 1.5W / m · K; aluminum-based copper-clad board, thermal conductivity 2.0W / m • K. Jinan Guoji Technology Co., Ltd. has aluminum-based copper clad laminates, with a thermal conductivity of 2.0W / m • K. Huazheng New Materials also has heat-dissipating metal-based copper clad laminates and adhesive sheets. Compared with Tenghui's highly thermally conductive substrate, the domestic company's indicators are still far from perfect.

For the requirements of high-performance substrates, in addition to the indicators of dielectric constant and dielectric loss, there are related indicators such as heat resistance, heat dissipation, thermal expansion coefficient, and water absorption to be considered. There are also some high-performance substrate materials, such as substrates for integrated circuit packaging substrates, liquid crystal polymer (LCP) resin substrates for flexible PCBs, HDI board laminated adhesive sheets, etc., which have not yet seen such domestic commercialized substrates. material. Of course, to achieve high performance of the substrate requires corresponding resins and fillers, glass cloth, copper foil and other materials to match, how the material source of these substrates is worth pondering.

 

Fourth, grasp the core technology of the industry

We regard PCB substrate technology as the core technology of PCB. Especially for high-performance PCB, the core position of high-performance substrate is more important. It is the lifeblood of new generation PCB.

The above made a brief comparison of the existing advanced high-performance substrates at home and abroad. We may be ignorant and omit the domestic advanced level of substrate products, or write it wrongly and depreciate it. At present, the high-performance substrates of foreign companies occupy the vast majority of China's high-end PCBs, which everyone can perceive in the industry. This fact illustrates the gap between domestic and international advanced substrates. This is a "critical core technology subject to people's situation" .

China's communication equipment manufacturers Huawei and ZTE are leading pioneers in the 5G era and have strong advanced technology capabilities. However, the United States imposed a ban on ZTE, letting ZTE lie down, and thought that it would overtake the curve in the 5G era, which turned into a rollover. The reason is also very simple: ZTE ’s communication equipment integrated circuit chips are from American companies. ZTE does not have its own chip, nor does it have high-performance chips in the country. The lifeblood is in the hands of others. Now that the chip is stuck in the United States, there is no way for ZTE to survive. Advanced products do not have their own core technology, as if high-rise buildings have no solid foundation, they will overturn whenever there is wind and grass.

General Secretary Xi also said at this year ’s two-house conference: “Practice has repeatedly told us that key core technologies are not available, ca n’t be bought, and ca n’t be obtained. Only by mastering the key core technologies in one ’s own hands can we fundamentally To safeguard national economic security, national defense security and other security. "

If the United States also comes to the ban on high-performance substrates that are not allowed to export to China, then what substrates are used for our 5G high-performance PCB production? In a free world and market economy environment, such assumptions may be completely worrying and alarmist. However, in the current "White House Blind Trade Activism" situation, caution is still needed. We see things as dialectics, divided into two, bad things will become good things, and the US imperial sanctions will become an impetus for struggle! The Outline for the Development of the Integrated Circuit Industry issued by the State Council clearly stated: "The main links of the integrated circuit industry chain will reach the international advanced level in 2030, and a number of companies will enter the first international echelon, and the industry will achieve leapfrog development."

Domestic PCB substrate manufacturers are working hard to develop and launch high-performance substrates, which are approaching the international advanced level. There are national electronic circuit substrate engineering technology research centers and several provincial and municipal substrate technology research and development centers in China, and they have also received government awards or funding. In short, China's road to basic science and technology has a long way to go. There are no corners to overtake, but it is still necessary to step up from basic education and theoretical research. It is believed that superior authorities will give full play to the advantages of the system, make timely decisions, further integrate resources, and guide them to develop advanced high-performance substrates. We sincerely hope to realize the localization of high-performance substrates at an early date, master the core technology of the industry and the initiative of industrial development, so that the printed circuit industry in China will continue to develop safely.

 

 

[references]

 

[1] Securities Times. Can ZTE lift the fine of 1 billion US dollars and 300,000 shareholders? (N / OL). Sina. 2018-06-08,

[2] Prismark Partners LLC. Excerpts from Prismark's Presentation at CPCA 2018 (J / OL). PCB magazine 2018/05

[3] I-Connect007 Editorial Team .Experts Discussion: What Does 5G Mean to Materials and EDA Tools? (J / OL) .PCB magazine 2018/05

[4] John Coonrod. Making the Most of PCB Materials for 5G Microwave and mmWave Amps (J / OL). PCB design 2018/05

[5] Anxin Securities. South Fortune Network (OL). Http://www.southmoney.com/gupiao/cpbd/201806/2359020.html 2018/6/21

[6] Matrix Electronics (OL). Http://www.matrixelectronics.com/   2018/06/05

[7] Panasonic news (OL). Https://news.panasonic.com/global/press/data/2018/05/en180529 .2018 / 05/29

[8] Rogers. Product Selection Guide (OL). Http://www.rogerscorp.com/acs/index.aspx . 2018-06-20

[9] Ventec International Group (OL). Http://www.ventec-group.com/products/thermal-management/ .2018-06-20

[10] The 17th (2017) China Electronic Circuit Industry Ranking. (N) Printed Circuit Information. 599 Issue 2018.05.25

[11] Shengyi Technology Network (OL). Http://www.syst.com.cn/cn/product . 2018-06-16

[12] South Asia New Materials Technology Network (OL). Http://www.ccl-china.com/ .2018-06-16

[13] Huazheng New Materials Network (OL). Http://www.wazam.com.cn/ .2018-06-16

[14] Jinan Guoji Technology (OL). Http://www.goldenmax.cn/a/gdm/products/brand/ .2018-06-16

[15] Chaoshun Electronic Technology Network (OL). Http://www.csdztech.com/about/?119.html .2018-07-06

[16] Wangling Insulation Material Network (OL). Http://www.wang-ling.com.cn/products_view .2018-07-06