A Novel Approach to Assembly and Interconnection for Micromachines.

目前的微电子或微机械制造技术是基于硅大规模集成电路技术的基本工艺步骤的表面微加工技术。然而，制造真正的智能微系统不仅需要微机械加工技术的实质性进步，还需要能够集成和组装微部件以获得所需的三维结构。传统键合方法的主要缺点是工艺温度较高，不需要使用耐热性较差的部件或前处理设备。在本研究中，我们获得了一种新开发的微装配装置，在该装置中，微部件可以在室温下通过SAB方法进行精确定位和相互连接。微装配装置由两个超高压室组成，其中一个用于将安装在圆盘上的样品送入装配室。然后，一个样本被拿起…通过机械手将更多的样品从圆盘上分离出来，并将其保持在另一个试件上方的所需位置，该试件放置在一个12个自由度的多轴工作台上。可以通过机械手和多轴工作台的组合操作来获得所需的接合位置。简单地说，机械手由形状记忆合金(SMA)弹簧驱动，多轴工作台由11个步进电机和3个压电致动器操作，样品的位置由扫描电子显微镜(SEM)监测，该扫描电子显微镜也在特高压条件下运行。然后用1.5keV左右的Ar快原子束(FAB)照射几分钟，对要粘合的试件表面进行溅射清洁。去除金属表面的自然氧化膜或受污染的表面层后，它们在轻微的压力下接触。由于FAB源是差动泵浦的，整个过程都是在低于10^&lt；-7&gt；Pa的超高电压下进行的。我们用SAB方法研究了室温下锡焊料(Phi340um)与铝或铜板的微连接。锡焊料与铝或铜的结合强度高达40MPa.用透射电子显微镜研究了这些界面结构.在铜和锡的界面处有约5 nm的过渡层，这是Cu6Sn5金属间化合物。在铝与锡的界面上，铝和锡原子直接结合，没有夹层和晶格扭曲。较少

Current fabrication technology for microelectronics or micromachines is based on the surface micromachining techniques for the basic processing steps of silicon-LSI technology. However, fabrication of real intelligent microsystems requires not only substantial progresses in the micromachining technology but also the ability to integrate and assemble the microcomponents to get a requisite three-dimensional structure. The main drawback of the conventional bonding methods is their rather high process temperatures which exclude the use of less heat-resisting components or preprocessed devices.In this study we obtained a newly developed microassembly apparatus, in which microcomponents can be positioned precisely and bonded to each other via the SAB method at room temperature. The microassembly apparatus consists of two UHV chambers, one of which is used for the feed-through of the specimens which are mounted on a disc and transferred into the assembly chamber. A specimen is then picked up … More from the disc by a manipulator and held at a desired position above the other specimen which is set on a multi-axial stage of twelve degrees of freedom of motion. The desired bonding positions may be derived the combining operations of the manipulator and the multi-axial stage. Briefly, the manipulator is driven by a SMA (shape memory alloy) spring and the multi-axial stage is operated by eleven stepping motors and three piezo-acturators.The positions of the specimens are monitored by a SEM (scanning electron microscope) which is operated also in UHV conditions. The surface of the specimens to be bonded are then sputter-cleaned by Ar fast atom beam (FAB) irradiation of about 1.5keV for several minutes. After native oxide film on metal surface or contaminated surface layr is removed, they are brought into contact under a slight pressure. Since the FAB source is pumped differentially, the whole processes are going on at an UHV lower than 10^<-7> Pa at this time.We investigated on the microbonding of Sn solder (phi340mum) and Al or Cu plates by means of the SAB method at room temperature. The bond strength of Sn solder to Al or Cu reached as high as 40MPa.These interface structures were investigated by transmission electron microscopy (TEM). At interface between Cu and Sn, there is inter-layr of about 5nm, which is Cu_6Sn_5 intermetallic compound. At interface between Al and Sn, Al and Sn atoms bonded directry without inter-layr and lattice distortion. Less