低盒形件的工艺计算及模具设计

本文介绍低盒形件的工艺计算及模具设计。在工艺计算中,介绍了影响低盒形件毛坯尺寸的因素及低盒件不需修边和需要修边高度毛坯尺寸的计算。在模具设计中,介绍我公司低盒形件典型零件的形状和尺寸精度,重点介绍低盒形件不需修边及需要修边的模具结构特点及设计中的有关问题,本文对低盒形件的设计制造等方面有指导意义。长文根据我公司生产实践总结而写成,可能有不妥之处,请同行指正。     

高质高效盒形件的切边工艺方法

一、前言在冷冲压生产中切边工艺被广泛应用,对盒形件的切边多数应用冲压切边方法。在带凸缘的盒形件切边中,其方法均已熟练掌握,本文盒形件的切边系指对无凸缘的盒形件口部的切边。由于盒形件是非轴对称的形状,因此造成切边方法较为复杂,尤其想要     

中国电子学会生产技术学会金属塑性加工学组盒形件成型学术讨论会在太原召开

中国电子学会生产技术学会塑性加工学组首届年会决定召开的盒形件成型学术讨论会,一九八二年十月十五日至十九日在太原举行。来自全国十三个省(市)自治区44个单位的55名代表参加了会议。会议共收到论文23篇,其中宣读20篇。它涉及盒形件毛坯展开尺寸的确定;一次成型极限;多次拉深的工艺计算;不同盒形件拉深模具的设计;盒形件的修边以及改善盒     

高方盒形件拉深工艺计算与模具设计

高盒形件拉深时变形复杂,材料沿其毛坯周边变形是不均匀的。目前各种冲压手册给出的工艺计算方法均是罗氏的计算方法。此计算方法公式繁锁,计算数据不可靠,给模具设计带来一定的困难。七九年哈工大发表了“高盒形件多次拉深变形的分析与工艺     

方盒形件多次拉深成形极限图

本文在分析高盒形件多次拉深变形特点的基础上,通过实验研究提出了高方盒形件多次拉深成形极限图的概念,并根据相当数量的实验数据绘出了这个图形。同时也给出了关于高盒形件多次拉深模具设计的要点。     

低盒形件拉深变形与成形极限

盒形件是一种非旋转体零件,拉深时它的变形与圆筒形件拉深相比,变形区都是受一拉一压应力状态作用下所产生的拉深变形,变形性质同属于压缩类成形。但与圆筒形拉深又有着很大差别。盒形件本身几何     

提高盒形件拉深质量探讨

盒形件拉深经常出现法兰、侧壁和球底皱纹,侧壁回弹、凹陷、叉口、底部鼓起、凹瘪等弊病,影响零件表面质量和配合尺寸精度。因此,很有必要进行探讨研究,以提高盒形件拉深质量。     

带圆凸缘盒形拉深件模具设计

一、引言带圆凸缘盒形拉深件一次不能成形时,则需要进行多次拉深,其拉深的变形特点既不同于带凸缘的圆筒形零件的拉深,也不同于盒形件的一次拉深。对于拉深的次数、工     

盒形件的冲压变形分析

盒形件——各种高度的直壁方形盒与矩形盒的冲压变形,和直壁圆筒形零件的冲压变形的性质基本上是一样的,其变形区都是在径向拉应力与切向压应力的作用下产生拉深变形,而且也存在着变形区所需的拉应力与传力区的承载能力之间的关系问题。但是,由于在这两种零件的冲压变形之间也存在着很大的差别,因而使许多实际问题,如工艺设计,工艺参数及其确定、模具设计等     

高盒形件洗衣机内桶拉深工艺

前言洗衣机内桶是一种高盒形件,整体成形需要多道拉深工序。我厂一九八○年开始研制以反拉法生产的内桶,去年已形成专业生产线,仅去年下半年的产量约为六万件,预计今年年产量约为三十万件。对于这种高盒     

Why do people purchase virtual goods? A uses and gratification (U&G) theory perspective

Few literature studies have investigated the relationships between different uses and gratifications (U&Gs) of mobile instant messaging (MIM) apps, continuation, and purchase intentions. To address this gap, the researchers aimed to examine the influence of the content, social, process, and technology U&Gs of MIM on continuation intentions toward MIMs, and purchase intentions toward virtual goods available on MIMs. A comprehensive research model was developed based on the U&G theory, which was tested using cross-sectional data from 309 Japanese MIM users. The study considered six different U&Gs of MIM as independent variables and purchase intentions towards stickers and continuation intentions towards MIM as dependent variables. The study results suggest that exposure U&G has a significant positive association with MIM sticker purchase intentions. The entertainment and affection U&G are positively associated with continuation intentions towards MIM use. The study contributes to the literature by investigating U&Gs that motivate MIM users to have both positive purchase intentions toward virtual goods, such as stickers, and continuation intentions toward MIMs. The study has significant theoretical and practical implications for both researchers and practitioners who are interested in virtual goods, the virtual economy, MIM apps, social media, new media, and the service economy.     

用于有源矩阵液晶显示的Ta-Ta2O5-Ta MIM薄膜二极管

本文介绍了一种用于有源矩阵液晶显示、具有对称结构的ＭＩＭ薄膜二极管,其中Ｔａ２Ｏ５膜采用溅射／阳极氧化两步法制成。实验结果表明,用此法制备的氧化钽膜作绝缘层的ＭＩＭ二极管,具有良好的开关特性,较大的通断比和较好的伏安特性对称性     

MIM隧道二极管的发光机理

本文介绍金属－绝缘体－金属（ＭＩＮ）结的基本结构以及发光机理，根据电流波动理论计算得到的表面等离子极化激元（ＳＰＰ）慢模能量分布与测量光谱的比较，得出发光中慢模起主要作用的结论，并以此来说明ＭＩＭ结Ｉ－Ｖ特性的负阻现象。     

光刻返工引起的MIM电容失效机理和解决方案

针对由金属-绝缘体-金属(MIM)电容金属层光刻返工引起的产品成品率下降10％的问题,开展了一系列工艺实验,分析了引起失效的机理并提出了改进措施.采用扫描电子显微镜对失效样品进行了分析和表征,发现失效样品的氮化硅介电层有空洞,而未经MIM光刻返工的样品均未发现介质层有异常.由于MIM金属层光刻返工时,经过等离子体去胶和EKC溶液清洗表面易对电容介质层造成损伤,引起极板间短路,进而影响器件性能.实验结果表明,采用有机显影溶剂去胶来取代等离子体去胶,可有效改善光刻返工引起的电介质层损伤.采用该方法返工两次以内的成品率均不受影响.同时发现MIM电容层上的钨塞孔链密度在一定程度上影响失效率,分析认为高孔链密度样品更易受到后续孔刻蚀工艺的强电场影响.     

High-density MIM capacitors using Al2O3 andAlTiOx dielectrics

We have investigated the electrical characteristics of Al₂ O₃ and AlTiO_x MIM capacitors from the IF (100 KHz) to RF (20 GHz) frequency range. Record high capacitance density of 0.5 and 1.0 μF/cm² are obtained for Al₂ O₃ and AlTiO_x MIM capacitors, respectively, and the fabrication process is compatible to existing VLSI backend integration. However, the AlTiO_x MIM capacitor has very large capacitance reduction at increasing frequencies. In contrast, good device integrity has been obtained for the Al₂O₃ MIM capacitor as evidenced from the small frequency dependence, low leakage current, good reliability, small temperature coefficient, and low loss tangent     

Nanostructured metal–insulator–metal capacitor with anodic titania

This paper presents fabrication and electrical characterization of barrier type TiO₂ metal–insulator–metal (MIM) capacitor using anodization. Polarization process, conduction mechanisms, and structural properties are studied in detail. We found that the anodization voltage played a major role in electrical and structural properties of the thin film. The barrier type anodic TiO₂ is suggested as a dielectric material for high-performance MIM capacitors.     

Stability Improvement of 60 GHz Narrowband Amplifier Using Microstrip Coupled Lines

We present an analysis of microstrip coupled lines (MCLs) used to improve the stability of a 60 GHz narrowband amplifier. The circuit has a 4‐stage structure implementing MCLs instead of metal‐insulator‐metal (MIM) capacitors for the unconditional stability of the amplifier and yield enhancement. The stability parameter, U, is used to compare the stability of MCLs with that of MIM capacitors. Experimental results show that MCLs are more stable than MIM capacitors with the same capacitances as MCLs because the parasitic parallel resistances of MCLs are lower than those of MIM capacitors. Moreover, the bandwidth of an amplifier using MCLs is narrower than one using MIM capacitors because the parasitic series inductances of MCLs are higher than those of MIM capacitors.     

MIM隧道发光结的光谱分析及负阻现象

在MIM隧道发光结的研究过程中,结的发光是SPP快模还是慢模起主要作用,一直是许多学者争论的主题。本文利用扫描电子显微镜估计MIM隧道结的表面粗糙度,然后根据对结的发光光谱的数据分析,得出快模在发光中占主要地位的结论,并以此解释MIM结I—V特性中的负阻现象。     

Electron emission from MIM systems and discontinuous metal films

The review reports results of experimental and theoretical study of electrical properties, especially electron emission from both sandwich (MIM cathodes) and planar (discontinuous metal films) metal-insulator-metal systems. Experimental dependencies—I—V characteristics of leakage and emission current, distributions of emitted electrons before and after the forming process—are summed up. Some attention is devoted to various hypotheses about the physical processes which take part during the electron emission from sandwich and planar MIM systems.     

Effect of deposition conditions on charging processes in SiNx: Application to RF-MEMS capacitive switches

The paper presents a systematic investigation of dielectric charging in low temperature silicon nitride for RF-MEMS capacitive switches. The dielectric charging is investigated with the aid of Metal-Insulator-Metal (MIM) capacitors with different thickness dielectric film and symmetric and asymmetric metal contacts. The experimental results demonstrate that the charging process is almost symmetric in low temperature deposited silicon nitride. Experiments performed in both MIM and MEMS reveal that the charging process is strongly affected by temperature. Specifically at high temperatures the charging rate increases exponentially with temperature.