In the previous article, we have mentioned EMI shielding, EMC testing and other topics more than once. Today, the editor combines the previous discussion and the summary of actual experience, and summarizes the content of today's article. You can get the core blood. The editor will not repeat the tear gas, the most complete introduction of EMI shielding materials will start here.
Brief introduction of main materials:
1. The fiber cloth (generally commonly used polyester fiber cloth) is pre-treated and then electroplated with metal plating to make it have metallic characteristics and become conductive fiber cloth. Can be divided into: nickel-plated conductive cloth, carbon-plated conductive cloth, nickel-plated copper conductive cloth, aluminum foil fiber composite cloth. There is a distinction between plain weave and grid in appearance;
2. The most basic layer is highly conductive copper, and the outer layer combined with nickel has corrosion resistance;
3. The nickel/copper/nickel coated polyester fiber cloth provides excellent conductivity, shielding effectiveness and corrosion resistance, which can meet the requirements of various ranges, and the shielding range is 100K-3GHz.
Conductive cloth of various substrates
It can be used for professional shielding work clothes for electronic, electromagnetic and other high radiation work, and special shielding cloth for shielding room;
IT industry shielding special cloth, touch screen gloves, anti-radiation curtains, etc. It is widely used in PDA handheld computers, PDP plasma display screens, LCD displays, notebook computers, copiers and other electronic products where electromagnetic shielding is required.
Conductive cloth fiber close-up conductive cloth pad:
The conductive cloth liner is made of highly conductive and anti-corrosive conductive cloth, and is composed of a highly compressed and highly elastic foam core, which is formed by precision processing. The conductive cloth liner has a good electromagnetic wave shielding effect. Various shapes and sizes can be processed according to customer requirements, and are widely used in EMI shielding materials/EMC prevention of various electronic products.
Conductive cloth liner is suitable for electromagnetic shielding, anti-static (ESD) and grounding of various electronic equipment. It can be widely used in electronic enclosures, cabinets, indoor enclosures, industrial designs, notebook computers, mobile communication equipment, and so on.
Conductive rubber (adhesive strip)
Conductive rubber is a kind of rubber material filled with metal fillers, which provides the functions of high conductivity, electromagnetic shielding, and moisture-proof sealing. This material can be shaped into sheet, molded, extruded and film-like shapes as required.
Conductive rubber is used in parts that require long-term stability of excellent electromagnetic shielding and high conductivity. It is widely used in communication equipment, information technology equipment, medical equipment, industrial electronic equipment market.
STM patch foam
SMT patch foam is a ground terminal that can be used in surface mount technology and is one of the surface mount components. In electrical/electronic equipment, in order to avoid malfunction due to unnecessary electromagnetic waves or reduce the noise of EMI shielding materials, the EMC countermeasure parts can be used by soldering the ground terminal on the PCB.
High-speed surface assembly, suitable electrical conductivity, excellent heat resistance and grounding characteristics, conductive elastic terminals for PCB grounding with excellent durability and reliability, when electrical/electronic equipment is exposed to external shocks or dropped SMT patch foam has excellent shock absorption characteristics and has the function of protecting internal accessories and cushioning.
Conductive silica gel
1. Conductive silica gel is a paste-like material, divided into single/two-component packaging and room temperature/high temperature curing conductive silica gel. At present, the commonly used materials on the market mainly require silver/copper, silver/nickel, nickel/carbon, etc.;
2. It is suitable for FIP (Form In Place) on-site molding process, used for precision dispensing machine to dispense, it can dispense into D-shaped, triangular, and wavy shapes;
3. Excellent shielding effectiveness and mechanical effectiveness;
4. Lower viscosity shortens the dispensing cycle and improves production efficiency;
5. It has good adhesion on most metal surfaces;
6. The curing time of normal temperature conductive adhesive is 12~24 hours, and the curing temperature of high temperature conductive adhesive is 30 minutes at 150 degrees Celsius;
7. Conductive silica gel has been proved to have good reliability and good resistance to electrolytic corrosion in strict outdoor environment tests, and is more suitable for use in harsh outdoor environments for long periods of heat, cold, humidity, ultraviolet light, ozone and locks. It can also ensure its performance is very stable in tight and severe environments;
8. The working temperature range is between -55 degrees Celsius and +125 degrees Celsius.
Conductive silica gel is mainly used in the communications, electronics, military, security, and automotive industries. It can be widely used in wireless base stations, repeaters, filters, mobile phones, handheld computers, notebooks, automotive central controls, cameras, walkie-talkies, security equipment and other wireless equipment Electromagnetic shielding on the case. It has better shielding effectiveness when used on die castings such as aluminum alloy.
Electromagnetic wave absorbing material
1. The absorbing material is a kind of magnetic material, a composite soft magnetic material that can conduct magnetism;
2. High-performance sheet-shaped wave absorbing material, which is suitable for design in narrow spaces;
3. Non-conductive voltage acrylic adhesive and high adhesive strength make the installation reliable;
4. It can be cut to suppress any electromagnetic wave noise that occurs on the PCB, such as electromagnetic wave/harmonic noise/serial station, etc. surrounding consumer electronic equipment;
5. It is usually suitable for the absorption of electromagnetic waves in the range of 13.56MHZ to several 8GHZ, especially suitable for the absorption of discrete noise generated by PCB and RF signal sheets and FFC (flexible flat)/FPC (flexible) cable signal stations, etc.;
6. Thin or flexible materials can be used in portable devices;
7. It can be made into various shapes and sizes to adapt to a wide range of applications;
8. Suppress electromagnetic resonance;
9. Electromagnetic wave anti-interference;
10. Suppress electromagnetic noise of all types of electronic equipment;
Absorbing materials are mainly used in communications, electronics, aerospace, military, navigation, medical, environmental protection and many industrial sectors that use microwave and high frequency. They are widely used in electronic digital products, wireless charging, RFID radio frequency identification, mobile communication equipment, wireless equipment , Office automation equipment (personal computer, TFT LCD, etc.), audio/video communication equipment terminal, digital switch, flexible circuit board, high-speed CPU chip, image processor, oscillator chip, storage chip, high-speed signal line speed, shielding case inner shell , High-speed microprocessors, etc.