Metallic Materials Technology | Materials Technology | Murata technology platform

Summary

Generally, metallic material technology is utilized across a wide range of fields, including structural materials that leverage mechanical properties-such as those found in automobile bodies-and catalytic materials that utilize chemical properties. In the electronics field as well, diverse metal materials are employed for the purpose of utilizing electric currents and electromagnetism; electrical conductors that transmit electrical signals and power are prime examples.
Murata's metallic material technology consists of techniques to extract the performance of metal materials, techniques to composite metal materials, and techniques to process metal materials.
These technologies contribute to enhancing product reliability. The thickness of internal electrodes in ceramic capacitors has been reduced to 0.2µm (micrometers) due to component miniaturization. The smoothness of the electrodes and their adhesion to the ceramics are now required at levels incomparable to the past.
Additionally, these technologies help unlock the performance of functional metal materials like magnetic core materials. As electronic components continue to shrink, there is a growing need to extract more energy from limited material volumes. It is crucial not only to prevent performance degradation caused by mechanical or thermal processing but also to achieve effects unattainable with individual materials by combining them with different materials.

Technical Explanation
Technological Strengths
Technological Advancement
Application examples for this technology

Murata's Metallic Materials Technology

Technical Explanation

Murata's metallic materials technology enables the realization of compact, high-performance, and highly reliable electronic components. We develop our own electrodes and magnetic core materials, maximizing their performance through advanced control. This technology comprises techniques for extracting performance from metallic materials, techniques for compositing metallic materials, and techniques for processing metallic materials.

Technology for Unlocking the Performance of Metallic Materials: This technology alters metal microstructures through processes such as heat treatment to obtain desired properties. Metallic materials exhibit diverse structures beyond regular crystalline structures, including solid solutions where solids dissolve into each other and irregular amorphous structures. These structures significantly influence the material's properties.
Specifically, in forming internal electrodes for electronic components, this technology precisely controls and optimizes sintering behavior when integrating metal materials like nickel, silver, and copper with ceramics during simultaneous firing. This involves optimizing factors such as metal particle size, surface condition, crystallinity, and trace additives. Technologies like uniform mixing, grinding, and classification are also essential for forming high-precision, homogeneous electrodes.

Metallic Material Composite Technology: This technology forms composite structures by coating metal particle surfaces or mixing metals with resins. Composite formation enables the realization of new or enhanced functionalities. Achieving homogeneous, high-quality composite structures requires deep understanding of chemical properties and precise powder handling techniques. Examples include controlling coating types and thicknesses, designing novel combinations of metal materials and resins, and developing processes for homogeneous mixing.

Metallic Material Processing Technology: This technology enables the precise forming of materials into product shapes. For instance, when manufacturing a 2mm diameter inductor, raw powder must be filled into a small die hole and subjected to uniform, precise pressure. Both excessive and insufficient pressure degrade performance, demanding delicate adjustments and ingenuity.

Technological Strengths

Murata's strength in metal material design technology lies in its ability to precisely design material compositions tailored to specific applications and performance requirements. This capability is built upon years of accumulated expertise in materials science and advanced processing and control technologies. In particular, by closely observing, analyzing, and controlling the state of metal materials from their pre-processing condition through to intermediate stages until they become final products, we refine them into materials possessing ideal performance.

Strengths of the Technology for Unlocking the Performance of Metallic Materials: Its key strength lies in the ability to design electrodes with optimal electrical properties and high reliability for each application, leveraging our unique powder control and mixing technologies. Drawing on a wealth of knowledge accumulated over many years, we comprehensively control everything from material selection to processing conditions to maximize product performance. One example is the LC filter. Within a single product, we incorporate four distinct copper electrodes:

Capacitive electrodes forming the capacitor
Line electrodes forming the inductor
Via electrodes connecting between layers
External electrodes connecting the product to the substrate

We adjust the design principles according to function. For instance, the capacitive electrode employs a thin, smooth design with high adhesion to glass ceramics, while the line electrode uses a thin, thick design capable of withstanding high currents.
Since these metal materials with different functions have varying sintering temperatures, we control the process to achieve sintering at similar temperatures through composition adjustments using trace additives and surface coatings. Furthermore, electrode material design is optimized considering manufacturing process stability.
This same optimization applies not only to LC filters but to all Murata ceramic electronic components. The foundation of our technology for unlocking the full potential of metal materials lies in the collective experience and technical expertise accumulated over many years in this process.

Strengths of Metallic Material–Resin Composite Technology: This technology enables the creation of functions and performance unattainable with a single material, creating functions and performance unattainable with a single material. To achieve this, we thoroughly analyze material changes occurring during the manufacturing process, clarify the interface state between the metal material and the resin, and control the invisible microstructure.
A prime example is the metal alloy power inductor used in power electronics circuits. By applying heat and pressure to a composite material combining metallic magnetic powder and insulating resin, we increase the packing density and enhance performance. For high-performance magnetic cores, uniformly coating metal particles with highly reliable resin is crucial. Product characteristics degrade if the coating is too thin or too thick. We focus on resin material selection, interface control methods, and improving mixing techniques.
Leveraging our cultivated design expertise, we provide highly efficient and reliable metal composite material products.

Structure and Appearance of Metallic Material Alloy Winding

Cross-sectional view of winding Metal Alloy

Technology for Metallic Material Composites

Source of inserted image: Power Inductor Basic Course - Chapter 1

Technological Advancement

Evolution of the Technology for Unlocking the Performance of Metallic Materials: This technology has evolved in step with the ongoing miniaturization and increasing reliability requirements and enhanced reliability of electronic components. When multilayer ceramic capacitors were first commercialized in 1970, the thickness of the internal electrodes was 10 to 20µm. Today, the thinnest have been miniaturized to less than 0.2µm. Furthermore, to reduce transmission loss in high-frequency bands, internal electrodes require high conductivity and surface smoothness. Consequently, internal electrode material technology continues to evolve by minimizing coarse particles and impurities and precisely controlling finer metal powders.
Additionally, reducing the environmental impact of electrode materials is an unavoidable challenge for achieving a sustainable society. We are working to utilize metal materials derived from recycled raw materials and to design electrode materials using chemicals with low environmental impact, aiming to balance performance and sustainability.

Challenges	Technological Advancements
Internal electrode thickness	From 0–20 µm to a minimum thickness of 0.2 µm or less
High-frequency transmission loss	Reduction of Coarse Particles and Impurities Precise control of fine metal powders
Reduction of environmental impact	Utilization of metal materials derived from recycled raw materials Electrode material design using chemicals with low environmental impact

Technological evolution aiming to balance performance and sustainability

Evolution of Metallic Material Composite Technology: This technology supports the advancement of metal alloy power inductors used in DC-DC converters.
Metal magnetic powders become magnetized and store energy in the magnetic field created by current, releasing it when the current decreases. However, excessive current causes increased losses and magnetic saturation, preventing sufficient energy storage. To address this, efforts have focused on suppressing magnetic saturation through adopting low-loss materials, improving surface insulation, and optimizing particle size distribution. Specifically, combining large and small particle sizes enhances packing efficiency and improves magnetic flux paths, increasing the current capacity.
Through these innovations, metal alloy power inductors have evolved into highly efficient components capable of handling large currents. As the advancement of AI (Artificial Intelligence) makes the energy consumption of electronics an increasingly critical challenge, Murata will further advance metallic materials technology for power inductors to contribute to the realization of a sustainable society.