Shenzhen Xin Jie Jia Electronic Film Switch Co., Ltd. is a research and development, production, sales of membrane switches, film panels in one of the professional manufacturers, the company cited from abroad advanced membrane switch production technology, is committed to the core components of electronic materials, , Structural research and development, and achieved fruitful results. Now for everyone to explain the film switch circuit screen version of the production.
Circuit is the most important factor in evaluating the intrinsic quality of the membrane switch. The circuit should be constrained by parameters such as current, resistance, withstand voltage, insulation, life, etc. It is also the screen printing products to the multi-functional, high-tech field penetration Concrete manifestation. To ensure the function of the circuit, first of all to ensure that the printing of silver paste circuit quality of the screen.
Before making the network version of the network, we must first consider the circuit parameters and circuit elements of the screen on the production requirements.
① the thickness of the conductive conductor of the same conductor wire, the size of the resistance and the cross-sectional area of the wire is inversely proportional to the current through the cross-sectional area is proportional to, it can be seen, the film switch printed circuit thickness is to ensure that the switch performance Basic conditions. So in the process of making the screen must choose the appropriate thickness of the screen layer, so as to ensure adequate access to the conductor circuit graphics. ② The life of the conductive pattern The conductive pattern has a sufficient thickness not only to provide favorable conditions for the passage of current, to reduce the resistance, but also to improve the high wear resistance of the switch contacts in the drawing.
③ in the membrane switch metal silver contacts, should be printed on the conductive carbon paste protective layer. Due to the physical properties of the carbon paste layer can constitute the following effects: carbon paste is a non-metallic conductor, not with the oxygen in the air, thus protecting the bottom metal silver contacts from oxidation; carbon has a small coefficient of friction, is a Solid lubricants, when it acts on the switch contacts, is conducive to the rapid closure of the contact after the separation; carbon has a high wear resistance, can improve the wear resistance of the switch contacts to ensure that the switch contacts can withstand the number of Million tons of contact; dense carbon coating can hinder the migration of silver ions, thus effectively protecting the stability of the switching performance; when the carbon coating on the wire jack, can be conducive to the connection of wire and wiring terminals. Due to the thick carbon coating is prone to peeling tendencies, so the printed conductive carbon paste screen should not be too thick.
④ The density of the conductive pattern The thickness of the conductive pattern is the basis for setting the switching performance parameters. However, since the circuit pattern printed by the membrane switch is formed by the aggregation of the particles of the conductive metal (usually silver particles) Silver paste), the barrier between the resin connection to the particles, the barrier of the impurity to the conductor particles, and the barrier formed by the wire mesh on the metal particles during the screen printing process affect the compactness of the conductor pattern, thereby affecting Performance of electrical parameters. For the above reasons, in order to allow conductive printed materials, especially silver paste in the silver tablets through the smooth, you need to choose a slightly lower mesh screen, and requires a smaller wire diameter, hole width is relatively large.
⑤ conductive pattern of the smoothness of the circuit graphics is clean refers to the edge of the sharpness, it is not only for the appearance of consideration, more important is to take into account the impact of electrical parameters. It is possible to reduce the edge impedance of adjacent wires, especially in high temperature and high humidity conditions, which may lead to the migration of silver ions along the edge of the wire to produce silver ions migration, resulting in short circuit between lines and failure of membrane switch.