In addition to electronic components and chassis connections the size and shape, the conductive elastomer is usually in the application of the design of several design elements should also consider the following:
Design should be considered sources of interference intensity and frequency, electric field or magnetic field of dominant position and the system power and signal attenuation requirements and materials, some of the properties and thickness requirements.
Entity conductive elastomer material is well tolerated in a higher closing force and pressure on the environment and to meet the repeated opening and closure requirements. It is by changing its own shape, rather than volume to adapt to the pressures, so as to achieve sealing. Therefore, the design must take into account the physical conductive elastomer in the case of heat or pressure to change the shape of the potential space needed. Because of the required sealing requirements are different, the size of the required closing force will be different, for example, require only electromagnetic seal, only needed 6 lbs / in the force can be, if the magnetic seal is also necessary to waterproof, you need to impose 8 pounds / in before the force could meet the requirements. Also, if the closure imposed by a smaller force, the cross-sectional area can be used for the extrusion hollow shape conductive adhesive tape, such as the O-shaped hollow, or hollow D-shaped and so on, you can save a lot of raw materials.
For most static sealing applications, we must calculate the volume of sealing and sealing tape will occupy much space in order to determine whether the latter can accommodate ring, so the design of the volume filling factor becomes very important. Been filled and filled less than failure could, in a sealed.
Amount of compression available to the designer a cross-section of different shapes of conductive elastic deformation capacity of qualitative comparison. It is the conductive elastomer material hardness and cross-sectional shape functions.
In the design of sealing tape, the tape with the mating surface between the electrochemical compatibility must also be given due attention. Electrochemical corrosion can occur to three conditions are indispensable. They are: 1) contact with each other in two different conductive materials, or conductor connection; 2) they exist between the conductive environment, such as electrolytic solution, salt spray, water vapor, etc.; 3) EMF gap between the two materials. Only when these three conditions will occur simultaneously with the electrochemical corrosion, affecting sealing performance. In addition, the permeability of polymer materials also affect the electrochemical corrosion. By limiting the conductive elastic body immersed in electrolyte solution, while preventing the occurrence of electrochemical corrosion.
1) In the assembly process, to avoid the conductive strip stretching more than 5%. Because the stretch is too long, resulting in rubber particles can be made between the internal conductive enough to turn the formation of conductive pathways will affect the electrical properties also affected the effectiveness of the shielding strip. 2) If there is shear stress, then do not use cross-sectional area for conductive elastomer O-shaped section, should be selected for the D-shaped cross section, P-shaped or C-shaped. 3) The conductive elastomer used in permanent deformation of the compression the smaller the better, the general control of 30% or less (to ASTM D395 method B).
