Conductive Sponge: Composite Process Upgrade Empowers Electromagnetic Protection of Electronic Devices

Electromagnetic interference has become a key factor affecting the stable operation of electronic devices. As a low-cost and easy-to-process electromagnetic shielding material, conductive sponge is expanding its application boundaries through production process upgrades. Traditional conductive sponge has problems such as weak adhesion of conductive layers and unstable shielding effectiveness. The new generation of products has achieved comprehensive performance optimization through composite process innovation.​

The core breakthrough in the production and manufacturing process lies in the "substrate modification + multi-layer conductive composite" technology. High-density polyurethane sponge is selected as the substrate, and the pore size (10-50μm) is precisely controlled through physical foaming process to improve the elastic recovery rate and structural stability of the sponge; then, chemical plating and vacuum sputtering composite processes are adopted to sequentially deposit copper and nickel layers on the sponge surface. The copper layer ensures high conductivity, and the nickel layer enhances oxidation resistance and wear resistance. The thickness of the conductive layer is controlled at 0.5-2μm. By optimizing the plating process, the peel strength between the conductive layer and the substrate is increased by more than 40%, avoiding delamination during long-term use. In addition, precision cutting technology is introduced in the production process to customize products of different shapes and sizes according to needs, with a minimum tolerance of ±0.1mm.​

In terms of performance characteristics, the upgraded conductive sponge has three advantages: "high shielding effectiveness, high elasticity, and wide frequency adaptation". In the frequency range of 30MHz-1GHz, the electromagnetic shielding effectiveness can reach 60-80dB, which can effectively block electromagnetic signal leakage and external interference; the Shore hardness is controlled at 15-30 degrees, with excellent compression and rebound performance, and the compression deformation rate is less than 10%, which can adapt to the long-term extrusion environment after equipment assembly; it is also compatible with high and low temperature environments (-40℃~+85℃) and can maintain stable performance under extreme conditions.​

Application fields have expanded from traditional consumer electronics to multiple scenarios: in smartphones and laptops, it is used for electromagnetic sealing of chassis gaps and interfaces; in communication base station equipment, it adapts to the shielding needs of antenna modules and cabinets; in the field of medical equipment, such as nuclear magnetic resonance instruments and ultrasonic equipment, it ensures the electromagnetic compatibility of equipment during operation and avoids interfering with surrounding instruments; in addition, it is widely used in automotive electronics, industrial control equipment and other fields to provide protection for the stable operation of electronic devices.​

In the future, with the development of 5G and IoT technologies, conductive sponge will further optimize high-frequency shielding performance, develop ultra-thin (thickness <1mm) and high flame-retardant grade products, and explore environmentally friendly conductive plating processes to reduce environmental impact during production, continuously adapting to the miniaturization and high-performance development needs of electronic devices.