The Software And Hardware Design In Laser Micro-Fabrication Control System

During the last ten years of 20^th century, due to the research and application of Micro Electric Mechanical System, a new branch of laser fabrication which named laser micro-fabrication is rising. Generally speaking, the laser micro-fabrication means that processing length is smaller than 100um. The main methods of fabrication contain: laser bean fabrication,aeolotropism etching fabrication,laser chemistry fabrication and so on. This fabrication method has obvious advantages, for example, it could accurately process organic,crystals,ceram and metal, it could process material in three dimensionals, another excellence is that it could manufacture in a big scale. The control system of laser micro-fabrication means: 1 for getting some specifical shapes, the light beam and the material which needed to be fabricated made relative motion; 2 the control equipments realize this relative motion.In this paper, we research a control system of the laser micro-fabrication. Through data conversion, the graphic data of the material to be processed can be transformed to be distinguished by the system. By controlling the turn of the tilting mirror, we can do the fabrication of the material in a tiny range (100um×100um) and Z direction by piezo-electricity flatform. In this way, we realize the 3D-fabrication. After the fabrication in this range, by the stepper motor, we could control the flatform (the material is on it) in a bigger range in x-y plane , repeat the course just like we had said before, so the system could fabricate in a bigger range than ever before. By the speediness shutter, we could exactly control the time of fabrication. The first chapter can be divided into three parts: introduces the history, the actuality, the characteristic and the application field of the laser micro-fabrication; analyses the function and the design request in the control system; confirm what need to do in this design.The second chapter introduces the function of every element in this control system; it contains electronic element and the optics element, emphasizes what need to be payed attention to in construsting the system, in this chapter, we mainly emphasize the phonetic notation in optics field ; according to the practice, analyse the good and the bad aspect, finally, choose the elements that we will use in this design. We choose the computer and the single chip to control the shutter, the reason is that the precisions of the computer and the single chip are different, in this condition, we could satisfy various fabrication requests. In the aspect of how to control the tilting mirror, we choose the high performance analog output multi-function cards. The command comes from the computer, through the card, controls the tilting mirror, and then makes the focus move on the material, so we realize the fabrication. But the range of this method is very small, so we use the stepper motor and the stepper motor drive to control it. In the aspect of software, we choose C language and VB language.The third chapter researches the hardware design, in this part, we introduce the theory, the characteristic and the function of the hardware; it contains the single chip,the tilting mirror,the cards,the stepper motor and its driver.we also design the control circuits of the speediness shutter, the stepper motor and the tilting mirror. Then we introduce the hardware of the inspect system and the theory of CCD.In the forth chapter, we program the code of the control system to make the hardware work as we want. The graphic data which drawed by Auto CAD can be transformed to the control tilting mirror and piezoelectricity platform movement order code through data conversion program, thus the processing to the material according to the request can be realized. The data conversion procedure can can swith the graphic data file DXF in AutoCAD to the data file LIN used in processing system. At first the tilting mirror control software design is to use the simple point output DA mode of the data acquisition card to control the rotation of tilting mirror, but as the PC machine operating system timeliness is not good and the control precision can only achieve a millisecond level, the machined surface woule be roughly because of the difficulty of the public time to be controled accurately. So we used double cushion outputs DA mode of the data acquisition card to control the rotation of tilting mirror, as the storaging and sending out the data can be carried on at the same time, the above question could be eliminated and we obtained a good processing image. The control is simple and the control scope of tilting mirror is small, the partial that not be processed exposured in the scope which can be controled by tilting mirror, in this way we realized the wide range processing. The C language can make the single chip produce the narrow pulse, so we could control the time of the state of the shutter. By the VB language ,we gain a simple and pellucid interface to control the shutter,the stepper motor,the tilting mirror. In the final chapter, by an example that we do in this control system, analyses the quality of this control system. Finally, we accomplish the target. The control system we did can make the laser micro-fabrication in a bigger range and we can accurately control the distance of the movement of the stepper motor and the interval time of speediness shutter. In the end, according to the questions in the examination process, we summarize the advantages of the control system and the parts to be improved in the future. This is a fabrication control system which can fabricate material according to different requirements. After lots of fabrications had be done, as the codes of every fabrication were saved, we can use it to do some fabrication without setup parameters in advance. The difference between this design and the former design is that this software is programed by VB language, the interface is more friendly, so even not familiar with the program, he also can use this system to fabricate material.