Application of LTCC Technology from the Development of Mobile Phones

In the future, handsets are moving toward lightweight, multi-functional, digital, high-reliability, and high-performance, and the requirements for miniaturization, integration, and modularization of components are becoming more and more urgent. Low Temperature Co-fired Ceramic (LTCC) is a remarkable interdisciplinary integrated component technology that has emerged in recent years. It has played a huge role in the changes in the volume and functionality of mobile phones. The role is a powerful means to achieve the future development goals of mobile phones. This technology was first developed by Hughes of the United States in 1982. The specific process is to make low-temperature sintered ceramic powder into a precise and dense green tape, which is used as a circuit board material and is used on green tape. Laser drilling, micro-hole grouting, precision conductive paste printing and other processes to produce the required circuit patterns, and embedded a number of passive components (such as capacitors, resistors, filters, impedance converters, couplers, etc.) , Then laminated together, sintered at 900 °C, made passive integrated components of the three-dimensional circuit network, can also be made into a three-dimensional circuit substrate with built-in passive components, on the surface can be mounted IC and active devices, made Passive/active integrated functional modules.

Seeing such a complicated and professional explanation as above, many people may already begin to feel confused. In fact, from a literal point of view, "low-temperature co-fired ceramics" has already taught everyone its basic meaning. First, it is made of ceramic materials; Secondly, the so-called “low-temperature co-firing” is to stack multiple layers of different functional ceramics at a relatively low sintering temperature (below 1000° C.) to finally obtain the required components. There has been an image metaphor that compares components made of low-temperature co-fired ceramics to a single building, each layer having different functions, but they are all one.

The usage of LTCC in mobile phones is more than 80%. The LTCC products used in mobile phones include LC filters, duplexers, function modules, and transceiver switching modules. The most commonly touched people are mobile phones, telephones, and cordless phones. Nowadays, the most used antenna is the Bluetooth headset. As long as the volume is small, the wireless receiving device must use filters and antennas, which are inseparable from LTCC. The LTCC device is very small, the smallest is only 1mm × 0.5mm, in the hands, a sneeze may disappear.

2 The advantages of LTCC Compared with other integrated technologies, LTCC has many advantages:

First, ceramic materials have excellent high-frequency, high-speed transmission, and wide-band characteristics. According to the different ingredients, the dielectric constant of LTCC materials can be varied within a wide range. In combination with the use of high-conductivity metal materials as the conductor material, the quality factor of the circuit system is improved, and the circuit design flexibility is increased.

Second, it can meet the requirements of large current and high temperature resistance, and has better thermal conductivity than ordinary PCB circuit boards, greatly optimizing the thermal design of electronic equipment, high reliability, and can be applied to harsh environments, prolonging its use. life;

Thirdly, a circuit board with a very high number of layers can be manufactured, and a plurality of passive components can be embedded therein, thereby eliminating the cost of the package assembly and realizing passive and active on a three-dimensional circuit substrate with a high number of layers. Integration will help improve the assembly density of the circuit and further reduce the volume and weight;

Fourth, it has good compatibility with other multilayer wiring technologies. For example, the combination of LTCC and thin-film wiring technology can achieve higher packing density and better performance in mixed multilayer substrates and hybrid multi-chip modules.

Fifth, the discontinuous production process facilitates the quality inspection of each layer of wiring and interconnection vias before the finished product is finished, which is conducive to improving the yield and quality of multilayer substrates, shortening the production cycle, and reducing costs.

Sixth, energy saving, material saving, greening, and environmental protection have become unstoppable trends in the development of the component industry. LTCC has also catered to this development demand and has minimized the environmental pollution brought about by raw materials, scrap, and production processes.

LTCC's application prospects In addition to its application in mobile phones, LTCC has become the preferred method for the integration and modularization of electronic components in the future with its excellent electronic, mechanical, and thermal characteristics. It is used in military, aerospace, automotive, computer and medical applications. LTCC can be used more widely. Although most of the current LTCC manufacturers are foreign companies, including Murata, Kyocera, TDK, Taiyo Yuden, CTS Corp, and Robert of Europe. Bosch, C-MAC MicroTechnology, and Screp-Erulec, etc., however, are not without competition in terms of the technological development status of China's LTCC. The State Council issued the "Electronic Information" in 2009. The contents of the Industrial Restructuring and Revitalization Plan outline clearly stated that it will vigorously support independent research and development of electronic components and set it as a key research area. Low-temperature co-fired ceramic technology will become a major development trend of China's electronics manufacturing industry in the coming years. . Some domestic manufacturers have begun to install advanced LTCC equipment and have adopted new types of raw materials developed independently to speed up the manufacturing of finished products. There are a number of such series of products that have been developed, such as Zhejiang Zhengyuan Electric Co., Ltd. and Shenzhen Nanpo Electronics Co., Ltd. LTCC related products company with international advanced level. As a result, we believe that LTCC technology will have a revolutionary impact on China's electronic components industry.