KR100980750B1 - Micro pattern machining of difficult to cut material using powder blasting process - Google Patents

Abstract

PURPOSE: A micro pattern machining method of difficult-to-cut materials using powder blasting is provided to reduce chipping and cracks and improve accuracy by a precision-machining process due to the collision of micro abrasive. CONSTITUTION: A micro pattern machining method of difficult-to-cut materials using powder blasting comprises a masking process, a powder-blasting process, and a cleaning process. The masking process is composed of laminating, exposure, and developing. In the powder-blasting process, micro abrasive accelerated by high-speed air or gas collides against a specimen at high-speed density. In the powder-blasting process, material is machined when a nozzle passes by an X direction route or a lengthwise route.

Description

MICRO PATTERN MACHINING OF DIFFICULT TO CUT MATERIAL USING POWDER BLASTING PROCESS}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to powder blasting, and more particularly to fine pattern processing of difficult materials using powder blasting, which designs and manufactures stamps as a method for providing a basis for mass production in the production of fine patterns. Difficult materials here refer to materials that are difficult to process depending on the purpose of use, the mechanical and chemical properties and processing methods of the material to be processed, and the tools used for processing.

Until now, the spraying process has been used for relatively rough primary processing such as descaling of castings and forgings, removing burrs, cleaning or surface finishing, and there is little concept of improving precision. However, in the spray processing for the purpose of fine processing, the time variation of the processing amount directly affects the processing quality and processing efficiency. In order to overcome this problem, the spray processing method which introduces the concept of precision is powder blasting technique. The powder blasting can be divided into chemical etching processing and mechanical etching processing. The chemical etching methods include a lithography method and a MEMS processing method, and the mechanical etching processing method is not a widely used processing method, but is continuously studied. . Powder blasting described herein below refers to a mechanical etching process.

Powder blasting (hereinafter referred to as powder blasting), which is a mechanical etching process, is a method in which fine particles of several micrometers to several tens of micrometers accelerated by high speed air or gas collide with a specimen at a high speed of 0.1 to 0.5 MPA at a high density. The micro-machining process is basically performed by mechanical etching, and the processing is performed by the front and rear or left and right scanning of the nozzle while the workpiece (the material at the time of processing and the workpiece) is covered with the mask film. .

At this time, the processing condition variables include the injection pressure, the feed speed, the material and size of the injection material (the powder powder used in the powder blasting equipment), the injection amount per minute, the number of injections, the distance between the nozzle and the workpiece. Appropriate conditions must be selected for improved precision and processing efficiency. Since this processing method is an integrated form of micromachining by the impact of the respective fine abrasives, it is a machining method suitable for precision micromachining due to less chipping and cracks.

The powder blasting is a random process, but when a shape processing having a specific pattern is required, a mask is applied to the workpiece. This process is called a masking process, and the masking process is largely performed by laminating, exposure, and developing. It consists of three steps. At this time, the precision of the masking process is known to significantly affect the pattern precision of the material during powder blasting.

The spraying material used for the powder blasting process includes artificial and natural mineral particles, vegetable particles, synthetic resin particles, and metal particles. Among them, artificial and natural mineral particles are used the most, and depending on the hardness of the injection material used for processing, it is divided into hard particles and soft particles, and depending on the shape of the injection material, fine particles, obtuse polygonal particles, and spherical particles are used. Classified as

Among them, the hard spray material is the most widely used, and silicon carbide, fused alumina, and Japanese quartzite are fine grains, and Novacurite, Arkansas, USA is an obtuse polygonal grain. As a general requirement of the spraying material used for the powder blasting process, the mechanical strength is not easily crushed against impacts, and the grinding particles mainly have a sharp angle, and are round and have water and water-soluble chemicals and gases. In addition to being stable against, the particle size should be even and cheap.

      An object of the present invention is to design and manufacture a stamp of a difficult-to-work material combined with a fine pattern as a method for preparing a mass production base in the production of a fine pattern.

In other words, as a conventional mechanical processing method for processing a fine pattern, a sudden plastic deformation occurs and an unstable state occurs, and thermal insulation shear occurs. This is a thermal diffusion rate of the workpiece (not a powder blasting method but generally using a machine tool). Since the mechanical processing method is a method of rotating and processing the tool on the material, heat is generated, which means that the heat generated at this time is low.

In addition, when machining difficult materials, vibration occurs due to the mechanical properties and the rigidity of the cutting system, which causes problems in precision machining, and cutting is difficult due to the extremely high cutting temperature and rapid tool wear. There is this.

In addition, the processing method using the powder blasting of the present invention is an integrated form of micro-processing due to the impact of the respective fine abrasives, so that the chipping or cracking process is bonded to the fine fine processing, powder blasting is not a general machining method of difficult materials It is a fine pattern processing method of a difficult material using.

In order to solve the above problems, the conventional spraying process has been used for relatively rough primary processing, such as descaling of cast or forged products, deburring, cleaning or surface finishing, and thus there is little concept of precision machining. However, for the purpose of micromachining, powder blasting can be used because a large amount of processing and a large sized material are not required. Powder blasting is a random process, but when a shape with a specific pattern is required, the workpiece is masked. This process is called a masking process.

If the powder blasting process after the masking process has a more precise processing result than the general machining, there is an advantage that the mass production is possible mechanically.

Accordingly, the fine pattern processing of the difficult material using the powder blasting of the present invention is characterized in that it comprises a masking process consisting of a laminating treatment, exposure treatment, development treatment, powder blasting process, washing process.

       In addition, the powder blasting process of the present invention is characterized in that the fine particles of several micrometers to several tens of micrometers accelerated by high-speed air or gas impinge on the specimen at high speed and high density of 0.1 to 0.5MPA, characterized in that the process of fine processing .

In addition, the processing conditions of the powder blasting process of the present invention is controlled by controlling the injection pressure, the feed rate, the material and size of the injection material, the injection amount per minute, the frequency of injection, the distance between the nozzle and the workpiece to improve the processing precision and processing efficiency It is characterized by.

The micropattern processing method using powder blasting, which is the processing method of the present invention, can be effectively used for the development of precision manufacturing technology such as semiconductor, electronic, nano, etc. based on the existing MEMS technology, mass production technology, and convergence technology such as IT, BT, NT, etc. .

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1A is a diagram illustrating a masking operation on a specimen for an evaluation pattern, in which a pattern to be evaluated is masked on the specimen in order to evaluate the workability of a workpiece. As shown in FIG. 1A, the mask has a Y-shaped and serpentine shape having a width of 200 μm & 300 μm on the left side of the specimen and an intaglio pattern similar to the comb pattern on the right side. have. The shape precision of the masking pattern was measured using a vision system equipped with a microscope. FIG. 1B is a diagram illustrating a pattern photographed using a microscopic vision system (MVS). As a result of the measurement, an error of up to 5 μm was observed for the large pattern on the left side, but an error of up to 10 μm for the fine pattern on the right side.

FIG. 2 is a view for explaining a processing progress direction of the upper plate stamp. Since the pattern processing direction of the upper plate stamp is processed while passing through a path having a “d” shape as shown in FIG. 2, the Y-axis direction is pitch. ) Will be overlapped and processed. Therefore, it is important to set the pitch appropriately in the Y-axis direction. For this purpose, the pitch in the Y-axis direction was set to 2.5 mm based on the data and nozzle diameter previously studied.

In addition, when the spray direction is bent in the vertical direction, the processing path is sufficiently large compared to the size of the specimen to prevent excessive overlapping of the injection material even though the Y-axis nozzle speed is increased. It is set to process only when passing the path of).

In addition, Figure 3 is a view showing the pattern processing direction of the lower plate stamp, the pattern processing direction of the lower plate stamp (Stamp) in the case of ①, ② as shown in Figure 3 to increase the processing efficiency and to prevent the unintended portion is processed In the axial direction, the pitch was changed to 1 mm, and most of the machining parts were overlapped. In the case of ③, the Y-axis direction was processed to 2.5 mm in the pitch.
FIG. 4 is a diagram illustrating the spraying material by taping around the pattern. As shown in FIG. 4, the spraying material is taped around the pattern to concentrate the spraying material on the pattern. In actual processing, the processing time was reduced by about 30% compared to the front spraying, and it is thought that the result of the spraying material being concentrated on the pattern by taping.

Next, the pattern processing shape will be analyzed.

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In the case of the embossed shape of the upper plate stamp, the spraying area to be processed is wide and the size of the pattern is large, so that it is easier to process than the negative mixer pattern. As shown in Table 1, processing experiments and various analytical work were carried out with emphasis on the intaglio pattern rather than the embossed pattern. The results are shown in Table 2, and the detailed sections are described by dividing by the type of the spraying material.

Table 1-1 Experimental condition

Table 1-2 Experimental result

       On the other hand, after processing, it was cleaned for 10 minutes by using an ultrasonic cleaner to remove fine dust or particles on the surface of the specimen, and a non-contact three-dimensional shape measuring instrument (WYKO NT-100 and MVS (Microscope Vision System)) for fine measurement of the overall shape. WYKO Vision 32 and MVS-1000 were used for the shape analysis program.

As a result of the measurement, each pattern was measured to have an error of about 1 to 2 μm. However, considering that the actual pattern is a few hundred micrometers pattern size, it is a small enough negligible error, and therefore, it is considered to be suitable for fine precision machining.

The fine pattern processing method using the powder blasting of the present invention can be used in the field of metal materials, mechanical / electronic parts material technology and precision production machinery.

FIG. 1A is a diagram illustrating a specimen in which a masking operation is completed on a specimen for an evaluation pattern, and FIG. 1B is a diagram illustrating a masking state of a specimen photographed using a microscope vision system (MVS).

It is a figure for demonstrating the processing progress direction of a top plate stamp.

3 is a view showing a pattern processing direction of a lower plate stamp.

Figure 4 is a state of the specimen taken by using a microscope vision system (MVS) to further overlap the injection material by taping around the pattern.

Claims (3)

In the fine pattern processing of difficult materials using powder blasting, A masking process consisting of laminating, exposure, and developing processes; Powder blasting process in which fine particles of several micrometers to several tens of micrometers accelerated by high speed air or gas, which are accelerated by mechanical etching, collide with the specimen at a high density of 0.1 to 0.5 MPA, In the fine pattern processing of the difficult material using powder blasting including a washing process, In the powder blasting process, the processing direction of the nozzle is processed while passing through the path of the '-' direction, and the Y-axis direction is overlapped according to the pitch, and the nozzle is set so as to be processed only when passing through the longitudinal X-direction path. Fine pattern processing of difficult materials using powder blasting. delete delete

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