空封光电耦合器内部多余物颗粒PIND检出概率研究

空封光电耦合器内部残留的多余物颗粒对其可靠性有严重影响,粒子碰撞噪声检测(PIND)是多余物颗粒检测的主要手段,但是存在一定的漏检。基于PIND试验中的电压采样数据建立了检出概率的模型,并利用该模型研究了同等质量下典型颗粒的分布区域、试验频率与检出概率的关系,结果表明陶瓷颗粒和导电胶颗粒分别受到碰撞对象硬度和颗粒粘附性的较大影响,使其在不同区域的检出概率具有明显差异,其中导电胶颗粒的检出概率因颗粒弹性弱而整体偏小,但在试验频率上升后有明显改善,而短金丝因粘附性弱、弹性强,检出概率大且稳定。据此提出了对典型多余物颗粒的控制与检测方法,采用该方法能够有效地提高光电耦合器的可靠性。所用模型和研究方法可推广至其他空封元器件的类似研究中。

Research on PIND Detection Probability of Remainder Particles in Empty Sealed Optocoupler

The remainder particles in empty-sealed optocoupler will seriously affect its reliability. Particle impact noise detection (PIND) is the main method for detecting the remainder particles, but it presents an undetected error rate. Based on the voltage sampling data in PIND test, the detection probability model is established in this paper. The effects of distribution region and test frequency on the detection probability of typical kinds of particles with the same mass were studied by using the model. The results show that the detection probability of ceramic particles and conducting resin particles are greatly affected by hardness of impact object and particle adhesion, which makes the detection probability in different regions present obvious differences, and the overall detection probability of the latter is small due to the weak elasticity of particles, but will obviously improve after the test frequency rises. The results also show that the detection probability of short gold wire is large and stable due to its weak adhesion and strong elasticity. Based on this, the control and detection method for typical remainder particles is proposed, which will effectively improve the reliability level of the optocoupler. The model and research method in this paper can be extended to similar research on other empty sealed components.