电声器件用胶黏剂的粘接原理及应用技术

电声器件中扬声器、传声器的装配过程是一个使用各种不同种类和性能的胶黏剂,把其零件粘接起来的过程。着重介绍了电声器件用胶黏剂的粘接原理、影响粘接强度的因素以及扬声器、传声器用粘黏剂的特点和实际应用。     

大功率扬声器音圈断线的失效分析及改善

结合扬声器音圈(Voice?Coil,VC)线材材质及补强胶特性,分析功率试验时音圈断线失效的原因.扬声器工作时,随着音圈温度的升高,环氧型补强胶由于耐温不足会逐渐产生疲劳及补强失效现象.随着补强胶对铜包铝(Copper?Clad?Aluminium?Wire,CCAW)音圈线的粘合力下降以及音圈的持续往复振动,线径较细且韧性较差的CCAW线在补强较弱的位置产生裂纹,在电流的持续作用下,裂纹位置发生尖端放电现象并击穿线体,熔点较低的铝芯发生了熔融后凝固的现象,最终造成音圈线的断路失效.经理论分析和试验验证,使用耐温更高的聚酰胺型补强胶可以改善失效问题.     

彩色电视机用扬声器述评

彩色电视机已进入千家万户,彩色电视机元器件国产化工作已取得可喜成绩。扬声器是电视机伴音系统的重要器件。由于彩色电视机多项性能优于黑白电视机,再加上彩色电视机本身结构的特点,又对彩电用扬声器提出一些新的要求。近年来国内各扬声器工厂都致力于彩电用扬声器研制工作,为国内各电视机厂配套试制彩电用扬声器。不少产品已在国内彩电中批量使用。部分还出口供国外彩色电视机使用。我们对日本等国各公司彩电用扬声器进行了广泛调查研究,测试分析其特点。三十年来,国内扬声器工业不断发展,不论在理论研究上、还是工艺技术方面皆有长足的进步。尽管彩电用扬声器质量标准严格,但我们还是在较短时间内试制出众多规格的扬声器,满足了彩电配套要求,达到了国外同类产品的质量指标,扬声器已成为电子工业部1986年10月宣布的、已经认定、限制进口的彩电用元器件之一。在此我们将有关问题叙述如下。     

适用于扬声器制造的新型胶粘剂

)1 引言 现代扬声器的各类非常多,制作扬声器的材料也是五花八门,涉及磁性材料(铁氧体、钕铁硼等)、金属材料(镀锌铁、铝、钛、铜等)和非金属材料(纸、橡胶、PVC,PP、聚酯、聚酰亚胺、尼龙、碳纤维、聚氨酯、酚醛、丝绸、布等),品种非常繁多。 为了把这些不同材质的零件组合到一起,选择适当的胶粘剂是很重要的。现代扬声器制造业受行业竞争和环境保护的双重压力,而且用户对扬声器品质的要求越来越高,从而对胶粘剂的要求也越来越高,例如,室温快速固化、工艺简单可靠、尽量无公害等。图1表示扬声器各粘接部位的用胶情况。     

电视机中的电声设计(四)

４扬声器的设计要求与整机测量４．１概论随着市场的需要，材料性能的提高，电视机用扬声器在可靠性、物理性能等方面取得了长足的进步。几年前，电视机采用的扬声器的额定功率都很低，只有２～３W，而现在可以用到１０W左右，甚至达２０～３０W。但还是有一些声性能不合格的彩色电视机归因到扬声器的性能方面，这可能和电视机与扬声器厂家产品开发生产脱离有关，很多扬声器配件厂对彩色电视机的声性能要求了解不多，造成配合上的问题，这就要求电视机生产厂家对扬声器的设计提出要求。表１是１份典型的彩电用扬声器规格书。４．２扬声器…     

适用于扬声器制作的新型胶粘剂

１引言 现代扬声器的各类非常多，制作扬声器的材料也是五花八门，涉及磁性材料（铁氧体、钕铁硼等）、金属材料（镀锌铁、铝、钛、铜等）和非金属材料（纸、橡胶、ＰＶＣ，ＰＰ、聚酯、聚酰亚胺、尼龙、碳纤维、聚氨酯、酚醛、丝绸、布等），品种非常繁多。 为了把这些不同材质的零件组合到一起，选择适当的胶粘剂是很重要的。现代扬声器制造业受行业竞争和环境保护的双重压力，而且用户对扬声器品质的要求越来越高，从而对胶粘剂的要求也越来越高，例如，室温快速固化、工艺简单可靠、尽量无公害等。图１表示扬声器各粘接部位的用胶情况。…     

大功率扬声器与功率有关的若干问题

在大功率扬声器设计中音圈线径设计是关键。从介绍音圈线径与功率的关系开始,谈到最大振幅(位移)及各注意要点,最后介绍了大功率扬声器用胶粘剂的一些使用问题。     

低谐振频率布边音盆扬声器的研制

采用聚氨酯胶粘剂与聚丙烯酸酯类胶粘剂共混改性，得到性能更好的阻尼胶，刮涂到棉布上，模压成音盆弹边。测定音盆的谐振频率，发现具有较低的F0，并且热稳定性能比只使用聚丙烯酸酯胶粘剂的音盆好；用这种布边音盆制得扬声器样品，其频响曲线和阻抗曲线与Philips公司提供的泡沫边扬声器的频响曲线和阻抗曲线类似。     

低臭型磁路胶ZA—2

改性丙烯酸酯胶已广泛应用于扬声器磁路系统的胶接,但目前的改性丙烯酸酯胶均以甲基丙烯酸甲酯(MMA)为主要原料,有刺激性臭味,减轻其臭味是近年各国研究的主要方向。本文简述了磁路胶的最新发展趋势,介绍了作者采用低臭气、低挥发性的甲基丙烯酸酯类单体,代替MMA,研制的低臭型改性丙烯酸酯胶ZA-2的主要性能和实用考核结果。     

扬声器灵敏度与气候条件的关系

扬声器灵敏度,是考核扬声器电声转换效率的一个重要指标。电视机、收音机和录音机都用扬声器放声,所以整机声灵敏度的好坏,与扬声器有直接关系。这样,对扬声器灵敏度的准确测量,就显得非常重要了。扬声器生产厂和大量使用扬声器的整机厂,都有这样的经验,扬声器的灵敏度是随季节而变化的。在夏天时偏低,冬天时偏高。这种感性的认识是否正确呢?有否确定的规律,能否对扬声器灵敏度进行修正呢?这就是本文所要讨论的问题。实验表明,温度、湿度和大气压力的变化,都能引起扬声器灵敏度测量值的变化。这是有规律可循,并且能够做出定量修正的。     

Sensorless Force Control for Injection Molding Machine Using Reaction Torque Observer Considering Torsion Phenomenon

Recently, many plastic products have been produced and used. These plastic products are mostly manufactured using injection molding machines. The quality of plastic products depends on the injection force. Therefore, it is important to develop a fine force-control system. Generally, in force-control systems, the force information from the environment is detected by a force sensor. However, control systems using force sensors present problems related to signal noise, sensor cost, narrow bandwidth, and other factors. To overcome these problems, this paper presents a proposal for a new sensorless force-control method using a reaction torque observer. The injection molding machine, which uses a ball screw, has a resonance frequency that is affected by the torsion phenomenon. This new reaction torque observer considers the torsion phenomenon and friction phenomena.      

The effect of patterns on thermal stress during rapid thermalprocessing of silicon wafers

The presence of patterns can lead to temperature nonuniformity and undesirable levels of thermal stress in silicon wafers during rapid thermal processing (RTP). Plastic deformation of the wafer can lead to production problems such as photolithography overlay errors and degraded device performance. In this work, the transient temperature fields in patterned wafers are simulated using a detailed finite-element-based reactor transport model coupled with a thin film optics model for predicting the effect of patterns on the wafer radiative properties. The temperature distributions are then used to predict the stress fields in the wafer and the onset of plastic deformation. Results show that pattern-induced temperature nonuniformity can cause plastic deformation during RTP, and that the problem is exacerbated by single-side heating, increased processing temperature, and increased ramp rate. Pattern effects can be mitigated by stepping the die pattern out to the edge of the wafer or by altering the thin film stack on the wafer periphery to make the radiative properties across the wafer more uniform     

Investigations of solder joint damage potentials for board-level chip-scale packages subjected to consecutive drops

Transient structural responses of a board-level chip-scale package subjected to consecutive drops are investigated in this paper using a numerical methodology based on the support excitation scheme and incorporated with the implicit time integration scheme. Evolutions of stresses, plastic strains, and plastic strain energies in the solder joints under repetitive drop impacts are examined and correlated with actual experimental observations. Effects of isotropic hardening and kinematic hardening presumed for the solder alloy are examined and compared. The numerical results indicate that under kinematic hardening, during the course of repetitive drop impacts, maximum and residual stresses remain nearly constant while plastic strains and plastic strain energies increase almost linearly. On the other hand, under isotropic hardening, as the drop count increases, maximum stresses increase while the incremental plastic strain energy decreases.     

Compact generic multi-channel plastic joint for surgical instrumentation

With the progress of the miniaturisation, we can expect to integrate new embedded micro-systems such as micro-sensors and micro-actuators into surgical instruments to assist surgeons during minimally invasive surgery (MIS). This paper presents a compact plastic joint with several channels to integrate wires and optical fibres. These wires and fibres will be used to supply and send data from micro-devices inside surgical tools. The aim of our study is to design a biocompatible compact joint with two degrees of freedom and a mobility range close to ±90°. The architecture of this new joint is based on a generic design with biocompatible plastic and super-elastic NiTi wires. Analytical simulation allows to readily suggest different solutions for different scales. Because the surgeon works with a visual feedback, the articulated joint is controlled in an open-loop configuration. Finally, this paper presents two kinds of applications that use the plastic joint: a tele-operated surgical robot and a hand-held surgical instrument.     

当前陶瓷-金属封接及其相关技术的新进展

本文综述了最近十年来国内外陶瓷 -金属封接及其相关技术的新进展 ,指出了我国该技术领域存在的问题及其解决办法。     

Shear‐Band Dynamics in Metallic Glasses

The future of metallic glasses as an advanced structural and functional material will to a great extent depend on the understanding and control of their mesoscopic flow defects called shear bands. These defects are sweet‐and‐sour; sweet because they mediate macroscopic plasticity at room temperature, and sour because they quickly promote failure. In the past decade, fundamental research generated great progress in characterizing the role that shear bands play during plastic deformation of disordered systems, including metallic glasses. Similar to those in many other materials, shear bands in metallic glasses are only active for a very short time, which directed research focus towards topological, structural, chemical, and thermal properties of formed, but inactive shear bands. In this paper, recent progress in directly characterizing the shear‐band dynamics in situ during straining experiments is presented. Various shear‐banding stages are outlined, including formation, propagation, and arrest, as well as shear‐band creep and aging. The results are discussed in a more general context of disordered materials, concluding with a summarizing overview of time‐scales involved in shear banding, and describing future research directions that may lead to controlled shear‐band plasticity in metallic glasses.     

TD-LTE接入失败问题分析及解决

本文对TD-LTE无线接入问题进行了研究,简要阐述接入过程及在接入过程中常见的问题表现,通过对各类问题提出解决每类问题的思路方案,形成了一套解决接入问题的优化流程。     

稀土有机配合物电致发光器件的研究进展

概述了稀土有机配合物电致发光薄膜器件的材料、结构、发光机理以及目前研究的状况、出现的问题和研究的发展趋势.     

研讨特种塑封管的再后固化效果

塑封器件的后固化，早巳被确认为固定工艺。通常是侧重于解决器件环境试验中存在的问题。我们意外发现它对于某种特殊器件有着神奇般的补救作用。     

Technology 1993-medical electronics

Developments during 1992 are reviewed. Much progress was made in developing a variety of innovative devices that diagnose and treat health problems or aid basic biomedical research, but unprecedented delays were experienced in approving medical devices in the US. A particularly active area of medical electronics has been implantable defibrillators. Another promising area is the development of ophthalmic lasers that correct vision by reshaping the eye. Commercial products based on biosensors are emerging, owing to advances in a number of areas and the demand that products using biosensors be more efficient and cost less than current approaches