Electrical Contact Behavior Of Carbon Pasteboard During Fretting Experiment And Concentration Effect Of Sodium Lactate As "Adhesive" For Particle Contamination On Electrical Contacts

Electrical contact is widely used in telecommunication and electronic industry and its reliability has vital effect. The performance of Electrical contact material decides the ability and reliability of wiring and connector. This paper contains two parts: one is the electrical contact behavior of carbon pasteboard on electrical contact, the other one is the concentration effect of sodium lactate as "adhesive" for particle contamination on electrical contact.As it is known, carbon pasteboard is very popular of use since it has low price and inhibited character from chemical corrosion. There is a possibility for this kind of contact to be used in tiny electronic equipment such as mobile facility. An experiment for carbon pasteboard is set up to investigate the electric contact behavior during fretting. The result shows that contact resistance is increasing after some number of micro motions. X-ray energy spectroscopy shows that there is no change for the amount of carbon and oxygen nor is their ratio before and after the experiment. Furthermore, there is very little heat energy generated during the motion which is unable to produce new material. Therefore, surface material is kept as is. Scanning Electronic microscopy illustrates the wear out part of material. The wear debris while becoming various kinds of sheet under pressure piled up at the end or in the middle of the track. When testing probe passing the piled sheets, contact resistance may increase. For practical application, it depends on how high the resistance can be accepted.Sodium lactate may act as "adhesive" for gathering the dust particles. An experiment set up for showing the concentration of lactate may play an important role. With a high concentration such as 20% of lactate coated on contact surface, particles are pushed away during micro motion. However, with a 10% of lactate coated on the contact surface, particles are adhered together and thus caused an increase of contact resistance. A comparison is also made, if no lactate is coated, dust particles are split away during micro motion. As a result, concentration of lactate around 10% may cause the lactate to act as "adhesive" for particles and that may lead to contact failure.