腐蚀物包裹尘土导致手机接触失效的研究

Analysis of Corrosion Products Trapping to Contact Failure in Mobile Phones

失效手机故障触点表面污染物的微观探测表明,污染物中含有大量尘土以及腐蚀物。模型分析显示,腐蚀物包裹尘土时,触头容易在腐蚀物上爬坡导致高电阻。对浸涂NaC l溶液后再喷撒S iO2颗粒的试片进行温湿循环试验,试片表面的S iO2颗粒被腐蚀物包裹,微动试验时触头难以推开被包裹的颗粒,导致试片表面高电阻的周期性跳变。可见,污染物中的腐蚀物包裹尘土颗粒,致使连接器簧片微动时在腐蚀物上爬坡,是引起触点高电阻导致手机失效的重要原因。

Micro-investigation shows that plenty of dust particles and corrosion products were found in the contaminants on contact surface of failed mobile phones.According to the model of corrosion products trapping,the probe tends to climb up the dust particles trapped in corrosion products,which results in high contact resistance.Particles of SiO2 were scattered on the brass coupon that had immersed in the solution of NaCl.After the experimentation of temperature-humidity cycling,particles were trapped in the corrosion products.During the process of micro-motion,the probe assisted by the corrosion products had to climb up the particles,and fluctuated high resistance appeared.It is obvious that the climbing of the connector spring on the dust particles due to corrosion products trapping is an important reason for contact failure in mobile phones.