Study On Manufacture Technique Optimize For Tire Pressure Monitor Sensor

Direct tire pressure sensor module needs batteries as power supplier, the battery itself cannot be disassembled, so the discharge life judged service life of the whole product. Therefore, reducing the internal circuit loss, improve the service life of the product, is of great significance for the development and promotion of tire pressure monitoring system.At present, the research direction in industry to extend the service life of the tire pressure sensor are mainly to reduce power consumption, using alternative energy sources, and so on. But such cutting-edge researches are very difficult into practical application. Optimization of the existing manufacturing processes for mature products, is easy to implement in practical application, but also can effectively reduce the failure occurred during the production process of products, so it is an product life level upgrade research direction..This article summarized the failure reason based on the L company short time field failure tire pressure sensor. The tire pressure sensor which using the 3V button type lithium battery as the power supplier, the self discharge caused by battery internal short circuit, and PCB ion pollution to short are induced cell fast discharge, they are all important reason leading to shorter product life, and expounds the basic principles of failure.This article also analyzes three process may be introduced into the ion pollution in the tire pressure sensor manufacturing process, they are bare board manufacturing and cleaning processes, assembly circuit board reflow soldering process and product assembly process. By analysis the source and harm of pollution ions, and the test methods, confirmed the process optimization scheme.This article verifying the optimization of process by experiment, instead of tap water to clean PCB bare board with deionized water, chloride ion content in the residue from the manufacturing process will be reduced from 4.2μg/in2 to 0.95μg/in2; sulfate ion content decreased from 4.2μg/in2 to 2.4μg/in2. While the reflow profile and the product assembly process optimization, WOA content decreased from 37.8μg/in2 to 3.57μg/in2; sodium and ammonium ions are decreased from 6μg/in2 levels to about 1μg/in2, and also decreased chloride ion contentThrough the manufacturing process optimization, to solve the problem of high field failure rate, improve the level of product quality and service life, and also reduces the product process failure rate and scrap rate, improve the competitiveness of the company.