There are seven different types of ceramic substrates named after different technologies. Today, we elaborate on the principles of these seven technologies, preparation principles, process flow, technical characteristics and specific applications and development trends.
Background of Ceramic Substrate Development
The first generation of semiconductors represented by silicon (Si), germanium (Ge) materials, mainly used in the field of data computing, laid the foundation of the microelectronics industry. The second generation of semiconductors represented by gallium arsenide (GaAs), indium phosphide (InP), mainly used in the field of communications, for the production of high-performance microwave, millimeter wave and light-emitting devices, laid the foundation of the information industry. With the development of technology and the extension of application needs, the limitations of the two gradually manifested themselves, making it difficult to meet the needs of high frequency, high temperature, high power, high energy efficiency, resistance to harsh environments and lightweight miniaturization. The third generation semiconductor materials represented by silicon carbide (SiC) and gallium nitride (GaN) are characterized by large forbidden band width, high critical breakdown voltage, high thermal conductivity, and high carrier saturation drift speed, etc. The electronic devices made by them can work stably at 300°C or even higher temperature (also called power semiconductors or high temperature semiconductors). electronics (such as IGBT), focused photovoltaic (CPV), microwave radio frequency (RF) devices such as the "core", in semiconductor lighting, automotive electronics, a new generation of mobile communications (5G), new energy and new energy vehicles, high-speed rail transportation, consumer electronics and other fields with broad application prospects, is expected to break through the traditional Semiconductor technology bottleneck, and the first generation, the second generation of complementary semiconductor technology, in the optoelectronic devices, power electronics, automotive electronics, aerospace, deep well drilling and other fields have important application value, energy saving and emission reduction, industrial transformation and upgrading, to give rise to new economic growth points will play an important role.
With the continuous development of power devices (including LED, LD, IGBT, CPV, etc.), heat dissipation has become a key technology affecting device performance and reliability. For electronic devices, the effective life of the device is usually reduced by 30% to 50% for every 10°C increase in temperature. Therefore, the selection of suitable packaging materials and processes, improve the device heat dissipation capacity has become a technical bottleneck in the development of power devices. Take high-power LED package as an example, because 70% ~ 80% of the input power into heat (only about 20% ~ 30% into light energy), and the LED chip area is small, device power density is very large (more than 100 W/cm2), so heat dissipation has become a key problem of high-power LED package must be solved. If the chip heat is not timely exported and dissipated, a large amount of heat will be gathered in the LED internal, chip junction temperature will gradually increase, on the one hand, the LED performance degradation (such as reduced luminous efficiency, wavelength red shift, etc.), on the other hand, will generate thermal stress inside the LED device, leading to a series of reliability problems (such as service life, color temperature changes, etc.).
Seven technology types of ceramic substrates
With the rise and application of power devices, especially the third-generation semiconductors, semiconductor devices are gradually developing in the direction of high power, miniaturization, integration and multi-function, which also put forward higher requirements for the performance of packaging substrates. Ceramic substrates (also known as ceramic circuit boards) have high thermal conductivity, good heat resistance, low coefficient of thermal expansion, high mechanical strength, good insulation, corrosion resistance, radiation resistance, and other characteristics, and are widely used in the packaging of electronic devices. In this paper, we analyze the physical properties of commonly used ceramic substrate materials (including Al2O3, AlN, Si3N4, BeO, SiC and BN, etc.) and focus on various ceramic substrates (including thin film ceramic substrate TFC, thick film printed ceramic substrate TPC, direct bonded ceramic substrate DBC, direct plated ceramic substrate DPC, reactive metal welded ceramic substrate AMB, laser activated metal ceramic substrate LAM and various 3D ceramic substrates). LAM and various 3D ceramic substrates).
Ceramic substrate preparation technology
Ceramic substrates, also known as ceramic circuit boards, include ceramic substrates and metal circuit layers. For electronic packaging, the substrate plays a key role in connecting the internal and external heat dissipation channels, as well as electrical interconnection and mechanical support. Ceramics have the advantages of high thermal conductivity, good heat resistance, high mechanical strength, and low coefficient of thermal expansion, and are commonly used as substrate materials for power semiconductor device packaging. According to the package structure and application requirements, ceramic substrates can be divided into two categories: flat ceramic substrates and three-dimensional ceramic substrates.
2.1 Planar Ceramic Substrates
According to the preparation principle and process, flat ceramic substrate can be divided into Thin Film Ceramic Substrate (TFC), ThickPrinting Ceramic Substrate (TPC), Direct Bonded Copper Ceramic Substrate (DBC), Active Metal Brazing Ceramic Substrate (AMB), Direct Plated Copper Ceramic Substrate (DPC), and LaserActivated LaserActivated Metallization Ceramic Substrate (LAM), etc.
Thin Film Ceramic Substrate (TFC) Preparation Principle, Process Flow and Technical Characteristics
Thin-film ceramic substrates generally use a sputtering process to deposit metal layers directly on the surface of the ceramic substrate. If assisted with lithography, development, etching and other processes, the metal layer can also be prepared graphically as a line, as shown in Figure 6. Due to the low sputtering deposition speed (generally less than 1 μm/h), the thickness of the metal layer on the surface of TFC substrates is small (generally less than 1 μm), and high graphic accuracy (line width/line spacing less than 10 μm) can be prepared for ceramic substrates, which are mainly used in the field of laser and optical communication for the packaging of small-current devices.
Thick film printed ceramic substrate (TPC) technology process and features
The TPC substrate is prepared by screen printing the metallic paste onto the ceramic substrate, and then sintering it at high temperature (generally 850°C ~ 900°C) after drying, as shown in Figure 7. Depending on the viscosity of the metal paste and the size of the screen aperture, the thickness of the prepared metal line layer is generally 10 μm ~ 20 μm (increasing the thickness of the metal layer can be achieved by multiple screen printing). However, due to the limitations of the screen printing process, TFC substrates are not able to obtain high precision lines (minimum line width/line spacing is generally greater than 100 μm). In addition, in order to reduce the sintering temperature and improve the bonding strength of the metal layer to the ceramic substrate, a small amount of glass phase is usually added to the metal paste, which will reduce the electrical and thermal conductivity of the metal layer. The TPC substrate samples and their cross-sections are shown in Figure 8.
was established in June 2001, is a national high-tech enterprise specializing in the research and development, production and operation of ultra-precision grinding and polishing materials in China, and is a pioneer in the industry with a number of international and domestic independent intellectual property rights, many years of experience in product technology development and many customer applications.
GRISH provides customers with specialized and customized grinding and polishing solutions, as well as a variety of complementary and serialized precision grinding and polishing material products, processes and equipment, focusing on solving customers' high-end needs of ultra-precision grinding and polishing, and helping customers succeed!
Its ultra-precision polishing film & polishing tape, electrostatic flocking abrasive tape & polishing tape, 3D three-dimensional bump abrasive, single crystal & polycrystalline & polycrystalline like - diamond micro powder and corresponding abrasive solution, CMP polishing solution, abrasive additives and other ultra-precision polishing consumables developed and produced by GRISH are widely used in optical communication, automotive, semiconductor, LED, sapphire, ceramics, LCD, 3C electronics, rollers, oral medicine and other industries, and have been exported to many countries and regions such as USA, UK, Germany, Russia, Japan, Korea, India, Brazil, etc.
Welcome to visit and consult us ！！！
With specialized, serialized and
matching and customized products.
Precise service to help customers succeed!
【Precision Polishing Nano Material Expert--Grish 】
【Specializing in precision grinding & polishing for 20 years】