SU1346408A1 - Device for polishing planar surfaces - Google Patents

Abstract

The invention relates to abrasive machining and can be used to polish wafers. The purpose of the invention is to increase the processing accuracy by ensuring uniform removal of material from the polished plate. The device contains a lapping disk 4 mounted for rotation around its axis, and a faceplate 6 for securing the plates 5. At the same time the Lapping disk 4 is made with a collar 8 and installed at an angle of 20-50 ° C. to a horizontal surface. During the processing of the faceplate 6, the increased friction force between the plates 5 and the surface of the finishing disk 4, is affected by the rolling force equal to the component of the weight of the plate 6, directed parallel to the surface of the finishing disk 4. At the same time, on the faceplate 6, located on the rotatable finishing disk, 4, centrifugal forces act, pressing it against the collar 8. As a result of the action of these rims, the faceplate rolls uniformly along the inner side of the collar 8. I Il, 1 tab. (L CO 4 about: 4 O 00

Description

The invention relates to abrasive processing and can be used for polishing wafers, in particular in the manufacture of semiconductor radiation detectors.

The purpose of the invention is to increase the machining accuracy by ensuring uniform removal of material from the polished surface.

The drawing schematically shows the proposed device.

The device comprises a frame I with a mounted drive 2 with an axis of rotation 3, on which a finishing disk D, inclined at an angle of 20-50 relative to the horizontal plane, is fixed. The plates 5 are attached to the faceplate 6 and pressed with the help of the load 7 to the working surface of the finishing disk 45 having a shoulder 8.

The device works as follows.

The surface of the rotating finishing disc 4 at the expense of friction forces carries the faceplate 6 on it, on which the plates 5 are fixed, as the finishing disc 4 is inclined, there is a component of the faceplate gravity parallel to the surface of the finishing disc. Simultaneously on the faceplate; rotating spinning disc, centrifugal forces act, pressing it against the collar 8 °. With the help of the hoop 9, relative angular velocities are selected. At the same time, by selecting the weight 7, pressing the faceplate with the plates to the surface of the finishing disk, the viscosity of the working mixture applied to the surface of the finishing disk, the speed of the finishing disk, the outer diameter of the hoop and the angle of inclination of the finishing disk are selected under which the faceplate rolls evenly along the inside side of the collar. Experiments have shown that a very uniform removal of material from the plate takes place and the surfaces to be processed are obtained with a high accuracy of parallelism of the working surface. The processing of silicon wafers 0-21 mm has been carried out. After processing, the plate parameters are: thickness 10 µm, thickness difference in a batch of one

face plate. The angle of inclination of the finishing disc has a plate value that has been repetitively processed. With the increase of it. 0.2 μm, equal thickness of each decreases the component strength of the hard plate O, 1 μm, the flatness of the stand, the perpendicular working surface of the plates is 0.05 μm, the angle between the finishing disk, which leads to the plane of the surface Togo,

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reduce the removal rate of the material of the machined plates. At small angles of inclination the rotation of the faceplate is unstable or completely absent due to

reducing the component of the body weight;

perpendicular to the axis of rotation, with the removal of material completely stopped. The optimum angle of inclination of the pre-vodka disc, as established experimentally, is 20-50.

After finishing, the samples are detached from the faceplate, turned over and fixed again on the surface.

5 planes, now processed side (strictly parallel to the faceplate surface). The other side is treated in the same way, and as a result, the plate may have a high plane-parallelism of the sides. In that there are no forces in the device, there is no need for additional nodes, parts that would compensate for them.

Example. The adjustment disc with a diameter of 360 mm is made of duralumin and installed at an angle to the horizon. The deviation of the plane of its surface does not exceed i 2 μm. On the surface of the finishing disk, you can find a nut nut batist. The diamond paste is coated with diamond paste of the required grain size. The necessary friction conditions between the surface of the finishing disk and the samples attached to the faceplate are achieved by adjusting the viscosity of the diamond paste. Viscosity is controlled by applying vasels of first oil to the surface of the finishing disc.

The washer is a glass plate with a diameter of 75 mm and a thickness of 23 mm with a curvature of surfaces of 0.030 µm. On the faceplate goes with the 5th ebony hoop. Loads are a set of brass disks.

Rotation of the finishing disc is carried out via a belt drive with adjustable speed.

0 rotation

Processing of silicon wafers 0 21 mm. After processing, the plate parameters are: thickness 10 µm, thickness difference in a batch of once-processed plates 0.2 µm, equal thickness of each plate O, 1 µm, flatness of the sides of the plates 0.05 µm, angle between the plane of the surfaces of the parts and working plane faceplate 0.4.

The parameters of the plates, depending on the angle of inclination of the finishing disc are given in the table.

Claims (1)

The invention of the device for polishing flat surfaces containing mounted 20–50 to the horizon. ten 0.00020 0.00020 0.00020. 0,0010 0,00010 0,00010 0,00010 0,0005 VNIIPI Order .5078 / 13 Random polygons pr-tie, Uzhgorod, st. Project, 4 The finishing disk with the collar and the faceplate for fastening the parts rotatable around its axis with the possibility of rotation, characterized in that, in order to increase the accuracy of surface treatment by providing a rasplomerny material removal, the finishing disk is set at an angle There is no material removal, because with such a small angle of inclination of the finishing disk, the rolling force acting on the faceplate is less than the frictional force between the working surface of the finishing disk and the plate surface to be treated with any combination of load, viscosity of the working mixture, speed of the finishing disk and hoop diameter. The processing accuracy deteriorated sharply due to the unfavorable ratio of the rolling force acting on the faceplate and the force pressing the faceplate to the surface of the finishing disc. Circulation 714 Subscription