Conductive Silicone Sheet
Conductive Silicone Sheet, also called Conductivity Silicone Gasket, or Electrically Conductive Elastomeric Washer, which is made of transparent silicone rubber materials with conductive particale like graphite, nickel, glass silvering, sliver-plate aluminum, copper etc, in aim to reduces or eliminates the EMI/RFI (electromagnetic interference and radio frequency interference) noise that is often associated with electronics. Generally, Silicone Rubber Conductive Sheet forming ways: Die Cutting Tooling and Rubber Compression Mold Tooling. Conductive Silicone Sheet refers to any rubberized material washer with conductive properties, such as glass silvering, silver-plat aluminum, silver, etc. These kind of conductive particle are well-dispersed in the silicone rubber. Conductive network forms when the neighboring conductive particles contact under pressure. It reduces or eliminates the EMI/RFI (electromagnetic interference and radio frequency interference) noise that is often associated with electronics.
Conduction Silicone Sheet has electromagnetic shielding function, when the volume resistance is less than 10 ohm.cm. Mainly applied in electromagnetic shielding occasion, also used in the chassis, cabinets, shelter electronic and microwave waveguide system, connector pad, etc.
Conductive Silicone Sheet：Generally, the lower the resistance, the higher the hardness. When the resistance is below 10ohm.cm, the hardness mostly over 70 shore A.
If conduction silicone rubber sheet made by compression mold tool, the surface of rubber compression mold tooling should electroplate coating for easily release conduction rubber sheets from mold tooling.
Conductive Rubber includes following several major types:
CONSIL-NC (graphite nickel plating filled in silicone rubber)
CONSIL-V (silver filling silicone rubber extrusion padding)
CONSIL-A silicone rubber (aluminum silver)
CONSIL-N (nickel plated silver filled in silicone rubber)
CONSIL-C silicone rubber (copper plating silver)
SC-CONSIL(graphite filled in silicone rubber)
CONSIL-R silicone rubber (fine silver)
CONSIL-II (silver filled in silicone rubber molded gasket)
Conductive Silicone Rubber Sheet with Backing Adhesive Tape
Backing Ahesive Conductivity Silicone Sheet, which made of rear gummed glue by die cutting tooling after finished rubber compression tooling production. Backing Adhesive Conductive Sheet is widely used in electric products and PCB products
Conductive Silicone Sheet Applications
Conductive silicone Sheet often refers to o ring in rubber material, whose volume resistance is within 10^9 ohm.cm. Conductive rubber can provide a good electrical conductivity (Inhibition of frequency 40 GHZ) with its good electromagnetic sealing and water vapor sealing ability. Its volume resistivity can be 0.004 ohm. cm, with good stability.
Conductive Silicon Sheet is used in both military and commerce. Main function is to seal and electromagnetic shield. Products can adopt compression molding or extrusion molding. It is on chip or other cutting shape. Shielding performance is as high as 120 dB (10 GHz). Conductivity silica gel Sheet is also used in medical electrode. Volume resistance of conductive rubber is bigger compared with that of metal, based on volume resistance is proportional to the distance, the longer the distance, the greater the resistance. Conductive Elastomeric Sheet has been widely used on the medical electrode. Electrode is thinner, generally below 1 mm, conductive rubber is completely electrified in this case.
Conductive Silicone Sheet Main Principles
Conductive particles filled inside the conductive silicone gasket reach a certain volume number, and contact one another, finally form electron continuous state. When strong electromagnetic wave in external electromagnetic field hits free electrons in conductive particles, forming an opposite electromagnetic field, internal and external electromagnetic field offset each other to weaken the effect of electromagnetic interference wave.
Determining the right filler is dependent on the level of shielding needed for a specific application, the more conductive the filler the higher the level of shielding achieved.
Conductive Silicon Sheet another principle is energy transformation, in other word, law of conservation of energy. When electromagnetic wave hits free electrons, conductive particles generate heat in the process of electrons movement, which is electromagnetic interference wave - free electron movement kinetic energy-thermal energy, in order to weaken the electromagnetic interference.
Conductive Silicone Sheet Structure
Conductive Silicone Sheet must be subject to certain compression force to good electrical conductivity, Therefore, the structure must be designed to ensure proper pressure. Optimal amount of compression plates is in height from 7 to 15% ; solid round , D -shaped highly compressed optimum amount of 12 to 30% ; tubular , P-shaped highly compressed form optimum amount of 20 to 60%.
Conductive Silicone Sheet Material Choice
When working with conductive Silicone Sheet , it’s important to remember that galvanic compatibility will also have an effect on which wire type or filler should be used. in this case, a conductive wire type or filler choice needs to be made where the difference in voltage potential between the dissimilar metals are as small as possible.
A widely popular form of conductive rubber is conductive Silicon Sheet. In conductive Silica Gel Sheet the base rubber is usually comprised of compounds such as silicone, fluorosilicone, or EPDM (ethylene propylene diene monomer). For example, silicone is used for general weather sealing and high temperatures to 400 deg. Fluorosilicone is used for applications where exposure to jet fuel, gasoline, and alcohols are present. EPDM is used for applications where exposure to coolants, steam, phosphate ester.
After choosing a specific rubber suited for the intended environment, a conductive filler must be determined. Some of the most common conductive metal fillers used are silver aluminum, silver glass, silver copper, and nickel graphite.