The Development of China High Permeability MnZN Ferrite

Soft ferrite material is a very important national resource, the basis of functional materials, which are widely used in all kinds of electronic products, such as: communications equipment, household appliances, computers, cars and so on. In recent years, the development directions of electronic products are light, thin, short and small, the high performance of soft ferrite materials meet higher requirements. High permeability Mn-Zn materials are developed fast with the development of the market, and become one of the best materials of the market prospects.

High permeability Mn-Zn ferrite material is mainly used in electronic circuits, broadband transformer, Integrated Services Digital Network (ISDN), local area network (LAN), wide area network (WAN), the background lighting and other areas of pulse transformer, anti-electromagnetic wave filters and other fields. In these areas, as core is essentially to work in the weak field, materials with high permeability will show a unique advantage.

First of all, the higher the permeability of materials, the fewer the number of turns of the coil inductance can get the demand, thus it can effectively reduce the coil's DC resistance and the consequent loss; Secondly, the use of high permeability material can significantly reduce the size of the transformer, so as to conduct to miniaturization of devices and systems, and reduce weight. These features conform to the development trend of electronic products, at present its production accounts for more than 25% output of total ferrite.

In the communications, computer, network and other electronic information industries, the rapid development of market demand reaches an annual average rate of over 20% of high-speed growth. Therefore, the domestic and export-oriented enterprise have started the studies on high permeability MnZn ferrite and the procurements of great important research results continue to emerge. Research progress in the development of early high-conductivity material is only one-sided pursuit of high permeability and some Curie temperature. However, this material is very limited in practical application, the application needs of the market demand that a lot of materials should not only have high initial permeability, but also good in temperature resistance characteristics, high frequency characteristics, low loss, high impedance and good superposition properties. This requires improvment of magnetic permeability and other performance parameters at the same time, and the material properties should achieve a good balance. The research of high permeability area has moved from the simple pursuit of high permeability rate of transfer to the improvment of overall performance, which is the current development trends of high permeability ferrite. The market demand has the following notable features:

  1. Wide temperature application requirements are generally presented: the market demand for many material properties have been raised to wide temperature requirements
    • Stable characteristics of the magnetic permeability in wide temperature range
    • Modern communication equipment, outdoor facilities, such as repeaters, microwave relay stations, submarine cables, fiber optic cable, underwater equipment, etc. require not only working in high temperature environment, but could also bear the cold, especially communication equipments are required to have a reliable and stable working status. As a result, many customers require material to reach -40 ~ +80 °C, and even to 125 °C for extended temperature range, inductance can meet the requirements, which requires materials from low to high temperatures have a high permeability. TDK Corporation H5C4, is a typical representative of such materials.

    • Has a Curie point. Such materials are mainly used in automotive electronics. Due to the special conditions of the car, which requires the working temperature of -50 ~ +150 °C, generally for high permeability materials, the Curie temperature is difficult to achieve such a high level to fill the piece of Siemens blank. But the T39 and other specially developed materials' Curie temperature is higher than 160 °C
    • The impedance has a wide temperature characteristics. The most important indicator of the common-mode choke used for anti-electromagnetic interference device is the impedance of a component, a number of customized materials in a wide temperature range of resistance can meet the requirements. T39 mentioned above is one of the materials in this regard
    • Low harmonic distortion (THD) has a wide temperature characteristic. With the rapid development of network technology, xDSL modem transformer has been widely used. The core of such materials requires a low THD. Now a lot of business-to-core THD downstream requirements are no longer confined to room temperature. Materials are often required to work within -20 °C, and even within a wider temperature range to meet the requirements
    • High DC superimposed with a wide temperature characteristics. TDK has developed DNW45 material within the -40 ~ +85 °C temperature range with good stacking properties in this respect to meet market demand
  2. Low harmonic distortion (THD) requirements are widely used in recent years with the rapid development of communications technology and xDSL (includes asymmetric digital subscriber line ADSL and Symmetric Digital Subscriber Line SDSL) technology
  3. Pairs are used to achieve isolation, impedance matching, and high and low pass filtering function of the high permeability ferrite cores and increasing demand, while ferrite core is made of higher demands. In order to reduce the transmission process the signal waveform distortion, reduce transmission errors and to extend the transmission distance, transformers are required with a low total harmonic distortion. Total harmonic distortion and the core materials performance, and core geometry are directly related to the design of transformer. One with the core indicators of performance-related material than the hysteresis loss coefficient ηB is characterized by ferrite materials. Magnetic flux density changes in a certain context of loss characteristics. Domestic and foreign manufacturers have realized great importance to this market, and given positive response, and have developed their own materials, the corresponding low THD. Typical grades are EPCOS company's new T38, magnetic permeability rate of 10000 ± 30%, ηB <0.3 '10-6 / mT; Nicera the company's 10TB, magnetic permeability rate of 10000 ± 30%, ηB <0.12 '10-6 / mT; Taiwan CROSS Electronics A101, permeability rate of 10000 ± 30%, ηB <0.5 '10-6 / mT; TDK Corporation DN40, DN70, permeability, respectively 4000 ± 25%, 7000 ± 25%, ηB were <0.8 '10-6 / mT, and <0.2 '10-6 / mT; days pass the TH10, permeability of 10000 ± 30%, ηB <0.3 '10-6 / mT

  4. DC superimposed request with the local area network (LAN) large-scale development, 100Mbps transmission speed into the mainstream, in order to make device miniaturization and thinner to meet the case of DC bias inductor requirements, a good overlay performance of a large number of ferrite cores are needed. In this regard, the first TDK Corporation has developed a DN45 material, µi = 4500 ± 25%, its application temperature is between 0 ~ 70 °C, compared with the traditional HP5 material (5000 ± 25%), the DC-superimposed characteristics increase by 30% or more. Then, with a claim of wide temperature range, the company has developed a new material DNW45, which can work in -40 ~ 85 °C, µi = 4200 ± 25%, compared with the DN45, its DC-superimposed characteristics also increase by 23%. Steward company also developed a similar 46 material
  5. High-impedance required. The rapid development of electronic technology is making electromagnetic pollution problems becoming increasingly prominent
  6. In order to limit the harm of electromagnetic interference, many countries have developed electronic product electromagnetic compatibility standards, asking their own anti-electromagnetic interference electronic equipment to meet a certain standard, while the surrounding electromagnetic interference must be limited to a certain extent. This requires a lot of anti-electromagnetic interference core, and the most important indicator is the impedance of the components. EPCOS, Germany's new T38 and Japanese TDK Corporation HS52, HS72, HS10 and other materials are mainly targeted at this part of the market. In addition, a growing number of customers have also requested materials with high stability, including:

    1. Stress stability, the requirement that materials in the as winding, packaging, compression spring such as the use of the process to produce stress drop after the inductor should be small
    2. Time stability of the requirement that materials cut off the coefficient is smaller
    3. Temperature stability, required temperature coefficient, thermal shock resistance and so on to meet the requirements
    4. The magnetic field stability, including a weak magnetic field value and the quality factor Q than the hysteresis loss coefficient ηB of stability
    5. The current produced by the world's major high permeability Mn-Zn materials, the typical type and number of representative grades, including:

      Type 1) only the requirement that materials with high permeability and a certain degree of Curie temperature. A typical representative of Japan's TDK Corporation H5C5, whose initial permeability of 30000 ± 30%, the highest current level of international trade. There are also German EPCOS Inc. T56, its initial permeability of 20000 ± 30%; Netherlands Ferroxcube company's 3E8 and 3E9, its initial permeability were 18000 ± 20% and 20000 ± 20%.

      Type 2) require material with high permeability characteristics of wide temperature range. Typical materials for the TDK Corporation H5C4, whose initial permeability of 12000 ± 25%, -20 °C, when, µi3 9000. In addition, there FDK's 2H15B, its initial permeability of 10000 ± 20%, at -40 ~ 85 °C have a high magnetic permeability

      Type 3) stressed that the material has broadband characteristics. Typical representatives of Steward's 40 material, the permeability of 10000 can be maintained to 250kHz or more

      Type 4) stressed that the low harmonic distortion (THD), a typical material for the above-mentioned TDK Corporation DN40, DN70, Taiwan CROSS of the A101, to win Sierra's 10TB

      Type 5) stressed that the material has good overlay performance. Typical materials for the above-mentioned TDK Corporation DN45

      Type 6) request the material also has high permeability and high Bs features. Typical materials for the TDK Corporation DN50, its initial permeability of 5200 ± 20%, Bs = 550mT (25 °C), 380mT (100 °C)

      Type 7) stressed that the good superposition of the material properties, and can be achieved in a wide temperature. Typical materials for the above-mentioned TDK Corporation DNW45, Steward's 46 material

      Type 8) stressed that the temperature characteristics and high impedance characteristics. Typical materials for the above-mentioned EPCOS Inc. T39, its Curie temperature is higher than 160 °C, and in range from -40 ~ 150 °C has a good impedance characteristics

      Type 9) stressed that the material characteristics of both broadband and high impedance characteristics. Typical material grades for the TDK Corporation HS52, HS72, HS10

      Type 10) stressed that the material also has broadband characteristics, high impedance and low harmonic distortion. EPCOS typical representatives of the company's new T38, its initial permeability of 10000 ± 30%, impedance peak at 700kHz and above, and the hysteresis loss coefficient than the ηB <0.3 '10-6 / mT

      Type 11) request the material also has broadband characteristics, low loss characteristics, low harmonic distortion and excellent temperature characteristics. Typical in this regard material is EPCOS, introduced in 2003 T66 material, its initial permeability of 13000 ± 30%, can be maintained to 100kHz, 10kHz than loss of less than 1×10-6, than the hysteresis loss is less than 0.3×10-6/mT, and in -40 °C ~ +80 °C between the µ-T curve has good linearity. All types of material is a balance between the various properties, thereby highlighting the results of some of these features. With the changes in market demand, will continue to produce new material. Trend of industrial development in recent years, Western developed countries, the transfer of magnetic material industries to China one after another. The main foreign high permeability MnZn material related businesses, such as Japan's TDK, FDK, win Sierra, Europe Ferroxcube, EPCOS and so have invested in mainland China, the creation of wholly-owned or joint-venture company, set up production bases, production year by year significant growth. And this shift will continue. This is mainly due to the reasons below:

      1. The low-cost of labor
      2. The rich resources of raw materials
      3. a huge domestic market

      And these features in the future would still exist for a long period of time. For one hand, this shift to enhance the total production of China's magnetic materials and products, grades, expand the ranks of China's magnetic materials industry has accelerated the production base in China become the world's magnetic materials and sales markets; for the other hand, makes the Chinese market in magnetic materials competition has become more intense. As these enterprises have a technological advantage, while access to the domestic low-cost labor resources and raw materials resources, domestic enterprises to create a very large pressure.

      To meet the challenge, and enhance their competitive ability, you can start from the following aspects:

      1. Magnetic material to further expand the operation scale industrial development in China at an alarming rate, and now basically formed its own industrial system, while there a number of industry leading enterprises. High permeability Mn-Zn ferrite, and Rui Tiantonggufen tech related companies entered the market, days pass and the East magnetic, the output is already ranked in the world. However, when compared with the large foreign companies, business scale is still too small. For example, fiscal year 2005, China's biggest magnetic material manufacturer with annual sales of 2.52 billion; and Xiamen TDK's sales reached 2.76 billion, Japan's TDK's annual net sales revenue of about 6.148 billion U.S. dollars (49.63 billion yuan). Chinese companies only need to further expand the scale of magnetic material, powerful alliances, complementary advantages, doing a good job under the premise of the main business, to diversify operations, in order to further enhance their ability to resist risks. At the same time, expand the scale of an enterprise to the strength of the high-end product development and more investment, improve product margins, increase their competitive advantage. TDK Corporation of Japan leading the industry in fiscal year 2005 funding for the research and development has reached ¥ 36,300,000,000 (25.5 billion RMB), compared with China's biggest magnetic material manufacturer's sales even more
      2. Enhance product development capabilities, the implementation of intellectual property strategy in the past, China's magnetic materials industry basically is taking the low-cost expansion strategy, the product is mainly middle and low grade. Now, with the technological advantages of foreign enterprises to enter China, and equal access to cheap labor, low-cost advantage of Chinese enterprises will no longer be obvious, this led to magnetic materials companies at a disadvantage in the competition, many enterprises will be eliminated. In this case, the Chinese high permeability Mn-Zn ferrite-related businesses must focus on technological progress to enhance R & D capabilities, so that product performance keeping up the international market, and develop their own unique advantages, access to proprietary intellectual property rights, so that other companies can not be replaced, so as to stand in the market competition unbeaten. In this context, China's high permeability Mn-Zn ferrite-related enterprises begin to attach importance to technological progress, increase the technological input. Large companies began to self-built research institute, pay attention to talent introduction, cultivation and use, many businesses employ domestic and foreign experts to guide research and development and participate in production management, and to strengthen cooperation with universities, research institutes, cooperation, industry technical standards have been great rate increase. Future high permeability Mn-Zn ferrite-related enterprises in technological progress, greater efforts, in order to obtain advantages in international competition
      3. Emphasis on upstream and downstream industries, upstream and downstream industries, the joint alliance is an important way to develop their own enterprises. Companies with upstream raw materials, a stable supply of raw materials can be combined on the one hand, to ensure consistency of product performance; the other hand, can reduce the impact of price increases of raw materials, improve enterprise anti-market risks. Do a good job communicating with the downstream customers to carry out joint development, according to customer requirements, timely feedback to develop new materials that meet market needs, is the enterprise to improve product profitability, market-an important way. This requires a number of enterprises in the middle of high-quality talent, it is necessary to understand the materials, components, and also to understand the downstream devices, machine. Good communication in order to provide good service, build customer confidence in the enterprise, constantly expand its strengths in the same industry. In addition, China's high permeability Mn-Zn ferrite-related enterprises also need to improve the management level and the level of information and to resolve corporate self-regulation within the industry is poor, vicious competition and so on, can we truly gain a competitive advantage in the market