Micro press forming and assembling of micro parts in a progressive die Abstract A micro press forming and in-process assembly technology were developed and applied to fabrication of metal parts and units. Technologies based on high-energy beams, such as ion and short pulse laser were developed for fabrication of features of dies in micro scale and finishing surface in nano scale. In addition, DLC coating on surface of the die was developed in order to improve wear-resistance and reduce friction. A micro gear with diameter of 0.2 mm was produced using sheet metals. Furthermore, a unit part with three components was fabricated in a precise progressive die using the micro press system. The results show that the micro metal forming could be a new technology for fabrication of micro devices, such as MEMS, bio-chips in low cost and with large quantities.24097
1. Introduction
MEMS (Micro Mechanical Electro system) and Biochips attract attention in this decade. These kinds of micro devices are mainly made of silicon or glass, and fabricated by using micro machining technique, which usually costs very high. Fabrication technology for providing the MEMS stably in lower cost is an important issue. Since the micro machining technique is based on photolithography that processes features in 2 dimensions or 2.5 dimensions, MEMS can only have restricted structures with fragile materials. On the contrary, metals have the properties of ductility, conductivity so that MEMS fabricated based on metal forming could have more freedom in structure with high strength and ductile materials. On the other hand, metal forming in sub-millimeter or micrometer scales also becomes a very important issue for the audio-video or information technological devices due to miniaturization of the structure parts [1,2].
The authors have been working on a novel micro metal forming technology in which micro parts or units are fabricated by micro press forming and automatic assembly processes in a progressive die [3]. Several kinds of sheet metals are supplied into the die by feeders and formed simultaneously in several steps and then, assembled together to a unit in the progressive die. We also introduced high-energy beams for the fabrication of micro die with feature of several micrometers and using DLC (Diamond Liked Carbon) coating technique to form film on the surface of the die for improving the wear-resistance [4].
In this study, we attempt to develop several kinds of die for punching and deep drawing, and utilize to press forming in a progressive die to produce some micro metallic parts and units.
2. Micro press forming for fabrication of mems
Press forming is one of most significant metal forming process for fabrication of complicated parts in a press machine. Most of parts used in Audio Video (AY) and Information Technological (IT) devices are fabricated by the press forming. The feature of these parts became smaller and smaller these years. Furthermore, MEMS and Biochips consist of multi-parts constructing a system or a unit with complicated structure. Fabrication of parts/units with feature of sub-millimeters using press forming could be important in next few years. The issues for forming parts with sub-millimeters features are:
- Development of new method for fabrication and evaluation of die with feature of sub-millimeters,
- Surface treatment of die for protection from wear and breakage,
- Development and evaluation of metallic materials with fine grains,
- Handling and assembly of micro parts.
In this study. we proposed a micro fabrication system by using press forming to form micro parts in multi-steps and then, to assemble parts into a unit in a progressive die. Fig. I shows conception of the micro fabrication system. Several kinds of materials supplied into the progressive die by feeders, respectively, and formed simultaneously in the progressive die in several steps and then, assembled together in the same die. As the result, a unit part could be formed as an output of the press forming. In order to establish the micro fabrication system, accuracy of each element of dies in dimensions and of alignment is challengeable. The issues are shown as follows: 微冲压成型级进模英文文献和中文翻译:http://www.youerw.com/fanyi/lunwen_17439.html