Application of response surface method for optimal transfer conditions of multi-layer ceramic capacitor alignment system

The multi-layer ceramic capacitor (MLCC) alignment system aims at the inter-process automation between the first and the second plastic processes.As a result of testing performance verification of MLCC alignment system,the average alignment rates are 95% for 3216 chip,88.5% for 2012 chip and 90.8% for 3818 chip.The MLCC alignment system can be accepted for practical use because the average manual alignment is just 80%.In other words,the developed MLCC alignment system has been upgraded to a great extent,compared with manual alignment.Based on the successfully developed MLCC alignment system,the optimal transfer conditions have been explored by using RSM.The simulations using ADAMS has been performed according to the cube model of CCD.By using MiniTAB,the model of response surface has been established based on the simulation results.The optimal conditions resulted from the response optimization tool of MiniTAB has been verified by being assigned to the prototype of MLCC alignment system.

Influence of Composition on Properties of Medium Temperature Sintering (Ba,Sr)TiO_3 Series Capacitor Ceramics

The influence of the composition （Yb2O3, MgO, CeO2, Li2CO3） on the dielectric properties of medium temperature sintering （Ba, Sr）TiO3 （BST） series capacitor ceramics was investigated by means of conventional technology process and orthogonal design experiments. The major secondary influencing factors and the influencing tendency of various factor＇s levels for the dielectric properties of BST ceramics were obtained. The optimum formula for maximum dielectric constant （ε） and for minimum dielectric loss （tanδ） was obtained under the experimental conditions. The BST ceramics with optimum comprehensive properties was obtained by means of orthogonal design experiments, with the sintering temperature at 1200 ℃, the dielectric constant 5239, the dielectric loss 0.0097, withstand electric voltage over 6 MV·m^-1, capacitance temperature changing ence of various components on the providing the basis for preparation rate （△C/C） - 75.67%, and suited for Y5V character. The mechanism of the infludielectric properties of medium temperature sintering BST ceramics was studied, thus of multilayer capacitor ceramics and single-chip capacitor ceramics.

Dopant Behaviours of Sm_2O_3 on Microstructure and Properties of Barium Zirconium Titanate Ceramics

The effect of Sm 2O 3 dopant on the sintering characteristics and dielectric properties of barium zirconium titanate ceramics (BaZr x Ti 1- x O 3) was investigated. It is shown that trace amount of Sm 2O 3 can greatly affect the grain growth and densification of barium zirconium titanate ceramics during sintering. At the same time, the dielectric peak at high temperature shifts to lower temperature and that at low temperature shifts to higher temperature. The two dielectric peaks overlap with each other when the Sm 2O 3 dopant content varies from 0 25% to 1%, and the maximum relative dielectric constant is greatly enhanced. These effects may be attributed to the substitution actions of the rare earth element in perovskite lattice. At the doping content of 0 75%, the dielectric constant maximum of 23570 can be obtained. By adopting some proper additives, an excellent Y5V dielective material is obtained, and the room temperature properties are as follows: relative dielectric constant ε RT ≥23,000, dielectric loss tgδ≤0 0075 and the breakdown strength under alternating field E b≥5 kV·mm -1 .

Effect of SiO_2 addition on the dielectric properties and microstructure of BaTiO_3-based ceramics in reducing sintering

The effect of SiO2 doping on the sintering behavior, microstructure, and dielectric properties of BaTiO3-based ceramics has been investigated. Silica was added to the BaTiO3-based powder prepared by the solid state method with 0.075mol%, 0.15mol%, and 0.3mol%, respectively. The SiO2-doped BaTiO3-based ceramic with high density and uniform grain size were obtained, which were sintered in reducing atmosphere. A scanning electron microscope, X-ray diffraction, and LCR meter were used to determine the microstructure as well as the dielectric properties. SiO2 can form a liquid phase belonging to the ternary system of BaO-TiO2-SiO2, leading to the formation of BaTiO3 ceramics with high density at a lower sintering temperature. The SiO2-doped BaTiO3-based ceramics can be sintered to a theoretical density higher than 95% at 1220℃ with a soaking time of 2 h. The dielectric constants of the sample with 0.15mol% SiO2 addition sintered at 1220℃ is about 9000. Doping with a small amount of silica can improve the sintering and dielectric properties of BaTiO3-based ceramics.

Influence of doped Ag^+ on multifunction characteristics in SrTiO_3 ceramics

SrTiO 3 capacitor varistor multifunction ceramics is fabricated by a single sintering process. The research is carried out, mainly aimed at the influence of the doped Ag + on multifunction characteristics in SrTiO 3 ceramics and its mechanism. The results show that the density of grain boundary acceptor state increases effectively due to the fact that Sr 2+ on grain surface is substituted by doped Ag distributing at grain boundary in form of Ag + during the course of oxidizing annealing, which is proposed to be the fundamental reason for understanding the significant difference of both the dielectric properties and varistor properties in SrTiO 3 ceramics samples with various Ag + contents.

Dielectric Properties and Structure of Yb_2O_3-Doped (Ba,Sr)TiO_3 Ceramics

The effect of Yb2O3 doping amount on the dielectric properties of (Ba, Sr)TiO3 (BST) series capacitor ceramics prepared using solid state reaction method were studied. With the increasing of Yb2O3 doping amount, the dielectric constant(ε) of materials increased, the dielectric loss(tanδ) of materials decreased to minimum when w(Yb2O3) was 0.9%. The BST ceramics with high ε(10000), low tanδ(0.0213) and high DC breakdown voltage(7.2 kV·mm-1) were obtained. The influence of Yb2O3 doping amount on the structure of BST ceramics was studied by means of X-ray diffraction(XRD) and scanning electron microscope. The influencing mechanism of Yb2O3 on the dielectric properties of BST ceramics was studied. The results showed that Yb2O3 doping influenced the properties and structure of BST ceramics by means of forming defect solid solution, but did not influence crystal grain size,the crystal phase was single perovskite structure, did not influence XRD data of BST and did not improve capacitance temperature property greatly, but increase dielectric constant greatly. These results provided the basis for Yb2O3-doped BST series capacitor ceramics.

Effect of Au film pre-deposited at different durations as inner electrode on the electrical properties and interface microstructures of Na_2O-PbO-Nb_2O_5-SiO_2 multi-layer glass-ceramic capacitors

To further study the effect of sputtered Au film as transition electrode layer on the electrical properties and interface microstructures of Na20-PbO-Nb2O5-SiO2 multilayer glass-ceramic capacitors, Au films pre-deposited at different time were prepared by DC magnetron sputtering. Compared with the single paste electrode structure, samples with Au films pre-deposited from 6 to 18 min have the consistent perfor- mance to effectively improve the electrical properties of the capacitors, resulting in the doubled breakdown strength, an increase of equivalent capacitance by 22% and a decrease of leakage current by an order of magnitude. SEM observations indicate that the Au films with deposition time from 6 to 18 min would all help the formation of a dense electrode/dielectric interface and inhibit the diffusion of Ag. The results reveal that Au film pre-deposited for 6 min as inner electrode was sufficient to improve the interface microstructure and therefore to inhibit the Ag diffusion and enhance the overall performance of the multi-layer glass-ceramic capacitors.

BaTiO_(3)基超薄层BME MLCC的可靠性机理

多层陶瓷电容器(Multilayer ceramic capacitors,MLCC)作为市场占有率最高的无源电子元器件,是基础电子元件产业中需要突破关键技术的重点产品之一,在汽车电子、5G通讯、电网调频、航空航天等领域有广泛的应用。在小型化、薄层化发展趋势下,MLCC的介质层厚度不断降低,单层介质在相同电压下的电场显著增大,尤其是中高压超薄层MLCC。因此,MLCC的可靠性愈发成为一项关键的产品质量指标。本文结合加速老化测试、高温阻抗谱、漏电流测试,系统研究超薄层MLCC的劣化机理,揭示抑制氧空位的迁移与富集是保证超薄层MLCC可靠性的重中之重。为此,应减小介质层内部的氧空位浓度,增大其迁移所需的激活能,提高界面肖特基势垒,从而提升超薄层MLCC的可靠性。本文的研究成果为超薄层MLCC介质材料的设计提供了有力指导。

MgO掺杂对NBT-SBT陶瓷电容材料介电及储能性能影响

为提升钛酸铋钠(NBT)基无铅陶瓷电容材料的储能性能,以A位掺杂方式向0.65[Na_(0.5)Bi_(0.5)TiO_(3)]-0.35Sr_(0.7)Bi_(0.2)TiO_(3)中引入MgO,并采用固相烧结法制备了不同摩尔含量(x=0.01~0.06)的0.65[(Na1-x,Mgx)0.5Bi_(0.5)TiO_(3)]-0.35Sr_(0.7)Bi_(0.2)TiO_(3)(NBT-SBT)陶瓷样品。通过SEM观察和XRD表征,发现随着Mg^(2+)含量的增加,NBT-SBT陶瓷的晶粒尺寸呈先减小后增大的变化,在Mg^(2+)掺入量(x)为0.025时,陶瓷晶粒尺寸最小。介电温谱和电滞回线测试表明该陶瓷为典型的铁电弛豫体,具有较高的介电常数(εr)和电极化强度(Pmax)。在100 k V/cm电场下,(Na0.94,Mg0.06)BT-SBT的可释放能量密度Wrec高达1.65 J/cm^(3),储能效率η为75%,综合性能优于同类NBT基陶瓷样品。结果表明,MgO掺杂的(Na1-x,Mgx)BT-SBT陶瓷具有优异的储能密度和效率,可为电子电力设备等领域的高功率储能电容器件的研究提供参考。

基于陶瓷电容绝缘子的能量采集方法

提出了一种利用电容分压器原理将陶瓷电容器封装在绝缘体内部并进行在线能量提取的方法。通过现场测试,得分为4 nF/80 nF的陶瓷电容绝缘体可以获得2W的最大输出功率,验证了该方法的可行性。通过搭建10kV电路仿真平台,发现当隔离变压器二次侧串联电感或两台隔离变压器串联时,输出功率比单台隔离变压器大,隔离变压器串联电感二次侧输出功率较高。

大容量多层陶瓷电容器的充测特性与测试方法研究

智能驾驶时代的到来使得新能源汽车得到了巨大发展,大容量、高耐压、多层陶瓷电容的市场需求与日俱增。这类电容属于Ⅱ类陶瓷电容,具有介电常数大、充放电时间长的特点,测试分选这类电容需提出更高要求。为满足这类电容的测试分选需求,为相关行业研发人员解惑,分析了电容的介电特性、吸收电特性、充放电特性、双峰现象以及在线测试等。通过相关产品测试得出:在额定电压电流条件下,改变充电时间、充电次数、空位间隔等相关参数,可延长充电时间和充电后空置时间,减小漏电流。

Superior energy storage efficiency through tailoring relaxor behavior and band energy gap in KNN-based ferroelectric ceramic capacitors

With the increasing demand of high-power and pulsed power electronic devices,environmental-friendly potassium sodium niobate((Na_(0.5)K_(0.5))NbO_(3),KNN)ceramic-based capacitors have attracted much attention in recent years owning to the boosted energy storage density(W_(rec)).Nevertheless,the dielectric loss also increases as the external electric field increases,which will generate much dissipated energy and raise the temperature of ceramic capacitors.Thus,an effective strategy is proposed to enhance the energy storage efficiency(η)via tailoring relaxor behavior and bad gap energy in the ferroelectric 0.9(Na_(0.5)K_(0.5))-NbO_(3)-0.1Bi(Zn_(2/3)(Nb_(x)Ta_(1−x))1/3)O_(3) ceramics.On the one hand,the more diverse ions in the B-sites owing to introducing the Ta could further disturb the long-range ferroelectric polar order to form the short−range polar nanoregions(PNRs),resulting in the highη.On the other hand,the introduction of Ta ions could boost the intrinsic band energy gap and thus improve the Eb.As a result,high Wrec of 3.29 J/cm^(3) and ultrahighηof 90.1%at the high external electric field of 310 kV/cm are achieved in x=0.5 sample.These results reveal that the KNN-based ceramics are promising lead-free candidate for high-power electronic devices.

多层瓷介电容器手工焊接质量提升

手工焊接后的多层瓷介电容器在温度循环试验过程中发生烧毁故障,故障原因为焊接过程中热应力较大导致器件本体生成裂纹。设计手工焊接试验,并经验证得出结论:在手工焊接过程中,通过降低手工焊接温度,增加焊接前印制电路板(PCB)的预热,可以避免器件本体产生裂纹;在产品设计阶段,避免选用较大尺寸封装,为PCB设计非接地焊盘,可以提高手工焊接的工艺窗口,从而提升多层瓷介电容器手工焊接质量。

Ni–MgO核–壳纳米粉体的制备

采用包覆热分解烧结法,制备了多层陶瓷电容器内部电极用MgO包覆Ni纳米粉体,讨论了反应物浓度和分散剂含量对包覆纳米镍盐前驱体颗粒大小和均匀性的影响,分析了还原烧结温度对包覆纳米Ni粉球形度和分散性的影响,并利用X射线衍射仪、扫描电镜、透射电镜、热机械分析仪对MgO包覆纳米Ni粉进行了表征分析。结果表明:反应物浓度达到足以引起反应爆炸成核时,能够获得纳米镍盐颗粒;添加适量的分散剂,可以得到分散良好的纳米镍盐前驱体颗粒;还原烧结温度700℃时,可以获得球形度和分散性良好的MgO包覆纳米Ni粉;MgO包覆在纳米Ni粉表面,形成了核壳结构,该纳米Ni粉具有良好的收缩延迟效果。

基于异丙醇溶剂热合成四方相BaTiO_(3)工艺探索及机理研究

以Ba(OH)_(2)·8H_(2)O和Ti(OC_(4)H_(9))_(4)为原料、异丙醇(IPA)为溶剂,通过溶剂热法合成富四方相纳米钛酸钡(BTO)粉体,研究了钡钛比、体系pH值、溶剂热温度及时间等因素对制备高四方性纳米BTO粉体的影响,利用X射线衍射和扫描电镜等表征方法研究了IPA在溶剂热制备BTO过程中的作用机理。结果表明,溶剂热工艺合成过程中,IPA会优先提供一定的—OH以促进Ti(OC_(4)H_(9))_(4)的水解,生成TiO_(6)八面体并与Ba^(2+)连接。在低碱度环境中,经相转变、小颗粒溶解与重结晶等过程逐步转变为形貌规整的四方相BTO。钡钛比1.6、体系pH值10、溶剂热温度220℃、时间24 h、煅烧温度950℃、煅烧时间2 h时制备的富四方相纳米BTO粉体分散均匀、形貌规整,呈四方形或近四方形,c/a值达1.009 4,平均粒径为124 nm。

柔性电子制造技术在叠压机设计中的应用研究

介绍了柔性电子制造技术,对R2R制造工艺的单元技术进行研究并应用于MLCC叠压机的柔性基板传输系统设计,包括放/收卷单元、纠偏控制单元、进给单元、张力控制单元,取得了较好的实际应用效果。

基于机器学习的小容值MLCC容量模型的研究

小容值多层瓷介电容器(MLCC)容易出现容量命中率低的问题,本文通过机器学习算法建立小容值MLCC容量模型,采用MSE、R2、拟合精度和预测精度评估各模型的准确度。最后选择采用线性回归模型表达小容值MLCC的印刷层数和电容量之间的关系,并通过实际投产验证,证明该模型可以用于指导小容值MLCC的实际生产,提高小容值MLCC容量命中率。

多层陶瓷电容器BaTiO_(3)材料的研究前景与展望

本文从BaTiO_(3)基介质材料的设计出发,阐述了发展高体积效率和高电容MLCC的关键问题和最新进展。本文在简要介绍MLCC和介电材料的基础上,总结了目前开发高性能可靠的BaTiO_(3)基介电材料存在的问题,并阐述了形貌调控、化学改性和掺杂改性等提高介电性能的策略。最后,对MLCC的发展和未来应用进行了展望。

MLCC电容环境失效案例解析

MLCC电容的全称为多层片式陶瓷电容器(Multi-layer Ceramic Capacitor,英文缩写MLCC),是由陶瓷介质薄膜与内电极以层层错位的方法交替叠合,经过高温一次性烧结制成陶瓷芯片,最后在陶瓷芯片的两端涂覆外电极浆料而制成的电容器。因此,MLCC的内应力复杂,耐环境应力的能力有限。在实际的复杂使用环境中,MLCC往往会由于经受机械应力、电应力以及温度应力的综合作用导致MLCC出现裂纹或金属电极错位而失效。本文通过对MLCC电容典型失效案例的解析,总结了常见MLCC的失效原因,对复杂工况下PCBA的可靠性设计有一定参考意义。