New energy and information technology

I. Application in the field of new energy

The core pursuit of the new energy field is higher energy density, faster charging speed, longer life and higher safety. Microsilicon powder is mainly used in lithium batteries and photovoltaic industries here.

1. Lithium battery (the most popular application direction at present)

Microsilicon powder is a star candidate for the next generation of lithium battery cathode materials.

· Core advantages: ultra-high theoretical specific capacity

· The theoretical specific capacity of the traditional graphite negative electrode is about 372 mAh/g, while the theoretical specific capacity of the silicon-based negative electrode (processed from micro-silicon powder) is as high as 4,200 mAh/g, which is more than 10 times that of graphite. This means that the use of silicon negative electrodes can greatly improve the energy density of the battery, allowing electric vehicles to run further and mobile phones to have a longer standby time.

· Technical challenges and solutions for microsilicon powder:

· Huge volume expansion: Silicon will absorb lithium ions in the process of charging and discharging, resulting in volume expansion of up to 300%, resulting in material powdering and poor battery cycle life.

· Advantages of microsilicon powder: Compared with other forms of silicon materials, microsilicon powder is a natural porous nanometer/submicron spherical particle. This structure itself can provide a certain buffer space for volume expansion. Through further carbon coating (compositing microsilicon powder with carbon materials), a stable conductive network can be built, which can not only inhibit volume expansion, but also improve conductivity.

· Function: Microsilicon powder has become the core silicon source for the preparation of silicon-carbon composite negative electrodes. Through a series of processes, the researchers purified and etched the microsilicon powder into a porous structure, and then combined it with graphite, carbon nanotubes and other carbon materials to make high-performance silicon carbon cathode materials.

Simply put: In lithium batteries, microsilicon powder is the "core raw material" for manufacturing the next generation of high-capacity cathodes.

2. Photovoltaic industry (solar cells)

Microsilicon powder is mainly used as a supplementary source of polycrystalline silicon raw materials here.

· Background: High-purity polycrystalline silicon is required to manufacture solar panels. Traditionally, polycrystalline silicon is produced through chemical processes (such as Siemens method), with high energy consumption and high cost.

· The function of microsilicon powder:

· The main component of microsilicon powder is amorphous silica, which has a relatively high purity.

· Through special metallurgical purification technology, the silicon dioxide in the microsilicon powder can be reduced and purified to obtain solar-grade polycrystalline silicon.

· This provides a potential and lower-cost process route for polycrystalline silicon production, realizing the resource utilization of industrial waste, which is in line with the concept of green circular economy.

Simply put, in the field of photovoltaics, microsilicon powder is a "potential alternative raw material" for the production of solar-grade silicon.

II. Application in the field of information technology

The field of information technology pursues faster computing speed, higher integration and more advanced semiconductor technology. Microsilicon powder mainly serves the bottom-level manufacturing of the semiconductor industry.

1. Semiconductor packaging materials

· Requirements: As the power of the chip increases, more heat is generated, which requires packaging materials to have excellent thermal conductivity to quickly dissipate heat. At the same time, the thermal expansion coefficient of the chip and the packaging material needs to be matched, otherwise thermal expansion and cold shrinkage will lead to cracking.

· The function of microsilicon powder:

· High-purity microsilicon powder is used as a functional filler for epoxy resin plastic sealing.

· Because its particle size is extremely fine and its purity is extremely high, it can be tightly stacked when filled in large quantities, forming an efficient thermal conduction pathway, which significantly improves the thermal conductivity of packaging materials.

· At the same time, by adjusting the filling ratio of the microsilicon powder, the thermal expansion coefficient of the packaging material can be accurately controlled to match the silicon chip and lead frame, and improve the reliability and life of the packaging.

Simply put: in chip packaging, microsilicon powder is an "advanced filler" to improve heat dissipation performance and stability.

2. Chemical mechanical polishing in semiconductor process

· Requirements: When manufacturing chips, it is necessary to deposit multi-layer metal (such as copper) and insulation layer (such as silicon dioxide) on the silicon wafer, and then polish it to be extremely flat and smooth before the next process can be carried out.

· The function of microsilicon powder:

· Specially treated spherical microsilicon powder with uniform particle size can be used as an abrasive in CMP polishing slurry.

· Its nanometer-level size and high hardness can achieve efficient and uniform removal of small bulges on the wafer surface, and are not easy to scratch, resulting in an ultra-high flat surface.

Simply put: In chip manufacturing, microsilicon powder is a "nanometer-level sandpaper" for ultra-precision surface polishing.

Although silicon ash is a by-product of the metallurgical industry (iron silicon and metallic silicon production), it is playing an increasingly important role in the two cutting-edge fields of new energy and information technology with its unique physical and chemical properties.

In general, its function can be summarized as: using its extremely fine particle size, high activity and high-purity silicon content as a "performance enhancer" and "structural regulator" of key materials.

Next, we will explain in detail by field: