AVX固体钽电容漏电流分析.doc

固体钽电容漏电流分析ANALYSIS OF SOLID TANTALUM CAPACITOR LEAKAGE CURRENT固体钽电容漏电流分析Abstract:摘要The leakage current of a solid tantalum capacitor is the sum of several independent factors. From measurements of leakage over a range of test conditions some degree of separation of these components of the current can be achieved and so the relative importance of factors leading to high leakage can be assessed. There is a background level present directly related to dielectric absorption and it contributes to the loss factor of the capacitor. It is not a true leakage. On top of this absorption current there are other components, most of which are essentially by-passing the bulk of the dielectric. These can be moisture or manganese dioxide tracks or breakdown sites in the dielectric layer. These typical behavior patterns are described in detail.固体钽电容器的漏电流是几个独立因素之和，对各种条件下漏电流的测量，可以一定程度将这些漏电流成分分开，因此相对重要的大漏电流因素可以评估出来。

有直接的背景涉及到介质吸收，它对电容器的损耗因子有贡献它不是真正的漏电流另外，紧接着吸收电流的是其它成分，大多数在本质上是介质本体的旁路电流这些可能是潮汽或二氧化锰轨迹或介质层的击穿点造成的这些典型的行为方式也会详细介绍The leakage current of a solid tantalum capacitor is the sum of several independent factors. From measurements of leakage over a range of test conditions some degree of separation of these components of the current can be achieved and so the relative importance of factors leading to high leakage can be assessed.固体钽电容的漏电流是几个独立因素的总和， 在一定测试条件范围内对漏电流可以得到某种程度的分开的量值，所以，可以对导致漏电流大的重要因素进行评估There is a background level present equivalent to a dielectric resistivity of about 1016 ohm cm. This background is directly related to dielectric absorption and it contributes to the loss factor of the capacitor. It is not a true leakage insofar as it can be recovered when the capacitor is discharged. It is proportional to voltage and, over the period usually employed for leakage current measurements, is inversely proportional to time.这里有一个大约为1016Ωcm介质电阻率的参考背景。

此背景直接与介质吸收相联系，并对电容器的损耗因子有贡献它并不是真正意义上的漏电流，因为在电容器放电时可以恢复它与电压成正比，并在测量漏电流期间与时间成反比On top of this absorption current there are other components, most of which are essentially by-passing thebulk of the dielectric. These can be moisture or manganese dioxide tracks or breakdown sites in the dielectric layer. The dependence of these on the measuring voltage ranges from ohmic to an extreme sensitivity. Moisture tracks can be identified by their behavior at high and low temperatures. Leakage at breakdown sites usually exhibit a strong dependence on voltage. On the other hand manganese dioxide tracks are normally ohmic.在吸收电流的最大值中，存在其它的成分，绝大多数情况下主要是电介质体的旁路电流。

这些情况可能是潮气或二氧化锰轨迹或介质层有穿破点这决定于测量电压，范围从欧姆级到极端敏感的值潮湿的原因可以通过在高低温时，电容器的行为特性鉴别出来介质层有穿破点发生的漏电流很大程度上地决定于电压另一方面二氧化锰轨道一般为欧姆级的电流Some typical behavior patterns are described in detail.下面会详细介绍一些漏电流典型的表现模式Introduction简介The leakage current of a solid tantalum capacitor is normally expressed as a single value measured at room temperature, at rated voltage, and after 3 or 5 minutes. This value is classed as high or low in comparison with a selection limit of typically 10nA/μFV (e.g., 3.3μA for a 33μF 10V capacitor). The capability limit of a low leakage solid capacitor is in the region of 0.01nA/μFV; in terms of insulation resistance this equates to 100,000 megohm microfarads and in terms of resistivity to higher than 1016 ohm cm.钽电容的漏电流测量一般在室温、额定电压、3-5分钟后以专一的值表示。

与选定的一般极限10nA/μFV(例如：33μF10V为3.3μA) 做比较，可以分类为高漏电流或低漏电流低漏电流电容的能力极限在0. 01nA/μFV的范围内用绝缘电阻的话，等于1000，000兆欧微法，相当于高于1016欧姆厘米电阻率In any production batch there is a range of leakage current values extending from the region of 0.1nA/μFV or lower, up through the selection limit. Those near or above this limit are removed on final test. The manufacturer needs a procedure for analyzing the causes of these rejects as well as for improving the general level of performance and for examining failures on life test and in the field. This paper outlines results obtained in such analyses.在任何一个产品批中，漏电流值的范围从0. 1nA/μFV或更低，高到选定的极限值。

那些接近或超过此极限值的产品在最后的测试中被剔除制造商需要分析剔除的原因，并改善一般产品的性能，以及为寿命故障试验和生产现场制定一个程序这篇文章概括了从这样的分析中得到的结果Leakage Distribution漏电流分布情况A typical distribution of leakage currents within a production batch is shown in Fig. 1.在一个产品批内典型的；漏电流分布情况见图1：批能力极限选定的极限一批中的数量短路漏电流10nA/μFV10.010.01 ∫∫Figure 1. Batch distribution图1：批分布There is a lower limit below which no values occur; this is the capability limit for that particular anodedesign and production process. In a perfect batch all the leakage currents would cluster close to that limit. In practice there is a tail to the distribution, some capacitors being only slightly above the normal levels and others with values extending through to short circuits with resistance values down to below 10 ohms.漏电流有一个低的不能更低的极限值，这是具体阳极设计和生产工艺能力的极限。

在一个理想的生产批中，所有漏电流会集中在此极限的周围实际上，分布有一个尾状形，一些电容器只是稍高于正常水平，另一些的值扩大到电阻值低于10欧姆的短路In order to understand leakage current behavior 。