JPH02152766A - Lapping machine with adjusting mechanism for pressurizing force - Google Patents

Abstract

PURPOSE:To make a pressurizing force constant at all times by providing an upper surface plate by hanging it on one end of the scale lever whose intermediate point is supported freely turnably, suspending a weight for setting the pressurizing force of the upper surface plate with the weight adjustable on the other end of the scale lever and attaching a wear amt. display means capable of reading the wear amt. of the upper surface place from the displacement of this scale lever. CONSTITUTION:On wearing of upper and lower surface plates 2, 3 the upper surface plate 3 is descended by those wear part, so the side suspending the upper surface plate 3 of a scale lever 15 is descended and also the side suspending a weight 14 and display means 29 is ascended and the wear amt. of the upper surface plate 3 is read in the display means 29 from the displacement amt. of the scale lever 15. Consequently, the weight of the upper surface plate 3 acting on the work is increased by reducing the weight of the weight 14 according to the wear amt. thereof and the pressurizing force can be kept constant.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lapping machine, and more specifically,
The present invention relates to a lapping machine with a pressing force adjustment mechanism that can adjust the pressing force of the upper surface plate.

[Conventional technology] A lapping machine that precisely polishes workpieces such as semiconductor wafers is
This device applies the weight of the upper surface plate directly to the workpiece as a pressing force, and laps the workpiece with abrasive grains. In such a lapping machine, it is important to select a pressure suitable for the material, shape, dimensions, etc. of the workpiece, and to process the workpiece while keeping the pressure constant at all times, in order to maintain accuracy.

However, normally, the upper and lower surface plates gradually wear out due to repeated lapping and correction operations, and their thickness decreases and they become lighter. This can easily lead to unstable lapping work.

For example, if we take a surface plate with an outer diameter of 64 hm, an inner diameter of 250 mm, a thickness of 25 mm, and a weight of 53.6 kg,
The weight decreases by 2.14 kg (4%) with 1 m of wear, and the same decreases by 6.43 kg (12
%)Decrease.

Therefore, in order to maintain machining accuracy, the weight of the upper surface plate that acts on the workpiece must be adjusted according to the amount of wear so that the pressing force can be maintained constant even if the upper surface plate wears out. It is necessary to make it possible.

[Problem to be solved by the invention] An object of the present invention is to maintain a constant pressing force by adjusting the weight of the upper surface plate that acts on the workpiece according to the amount of wear on the upper surface plate. The purpose is to provide rap discs.

[Means for Solving the Problems] In order to solve the above problems, the lapping machine of the present invention sandwiches a workpiece between a lower surface plate and an upper surface plate, and polishes the workpiece without applying pressure on the upper surface plate. In such a device, an upper surface plate is suspended from one end of a scale rod whose intermediate point is rotatably supported, and a weight is attached to the other end of the scale rod for setting the pressing force between the scale rod and the surface plate. It is characterized in that it is suspended so that its weight can be adjusted, and that it is also provided with wear amount display means that can read the amount of wear on the upper surface plate from the amount of displacement of the weighing rod.

[Function] When the upper surface plate and the lower surface plate wear out, the surface plate lowers due to the wear, so the weight and display means are suspended from the side of the scale rod where the upper surface plate is suspended. The amount of wear on the upper surface plate is read on the display means from the amount of displacement of the scale rod. Therefore, by reducing the weight of the weight according to the amount of wear, the weight of the upper surface plate acting on the workpiece can be increased and the pressing force can be kept constant.

[Example code] Embodiments of the present invention will be described in detail below with reference to the drawings.

In Fig. 1, 1 is the body of the lapping machine, 2 is a lower surface plate arranged on the body 1 at a rotational position by a drive source (not shown), and 3 is a lower surface plate 2), which is disposed opposite to the lower surface plate 2) so as to be able to rise and fall freely. As can be seen from FIG. 3, the upper surface plate 3 is suspended from a piston rod 5a of a hydraulic cylinder 5 fixed to an arm 4a extending horizontally from a column 4. 5
As a result, the locking portion 5b at the lower end of the piston rod 5a is moved up and down to the chain line position (when not machining) and the solid line position (when machining).
When the upper surface plate 3 and the piston rod 5a are separated from each other by a distance H, the locking portion 5b is separated from the support plate 6 by a distance H, and the upper surface plate 3 and the piston rod 5a are separated from each other. The plate 7 is engaged with a driver 8 to be driven.

Therefore, when lapping the workpiece, the carrier is driven in a planetary gear-like manner by the internal gear located concentrically around the lower leg q12 and the sun gear located at the center of the internal gear.
The lower foot i2 and the bare foot l rotate the workpiece held on the carrier! 13, the workpiece is pressed by the weight of the upper surface plate 3, and then lapping is performed. In this case, the weight of the upper surface plate 3 is the weight of the upper surface plate 3 itself, plus the weight of the locking plate 7, stud 9, support plate 6, bearing box 10, etc. that are integrally attached to the upper surface plate 3. It means the total weight of the parts added together.

In order to be able to set the weight of the upper surface plate 3, that is, the pressing force that acts on the workpiece during the lapping process, and to adjust the pressing force to maintain it constant, the lapping machine is equipped with ``pressing force adjustment''. A mechanism 13 is attached. This pressurizing force adjustment mechanism 13 suspends the upper surface plate 3 and the weight 14 in a scale-like manner, so that the weight 14 of the upper surface plate 3 acting on the workpiece can be adjusted.
The specific configuration is as shown below.

That is, as shown in FIGS. 1 to 3, the arm 4a
A first scale rod 15 is rotatably disposed on the top by having an intermediate edge 15a supported by a fixed fulcrum 16,
At one fork-shaped end of the scale rod 15, a pair of hanging rods 17, 17 for suspending the upper surface plate 3 are supported by edges 15bj5b on seats 17a, +7a, respectively. The hanging rods 17, 17 are provided with a hollow shaft 18 at their lower ends, and the hollow shaft 18 is rotatably connected to the bearing box 10, which is integrated with the hill surface plate 3, via a hair link 19. The piston rod 5a passes through the inside, and when the upper surface plate 3 is raised during non-machining, the seat 1 of the hanging rods 17, 17
7a, 17a or the edge 15b of the first scale rod 15, ISb
It is designed to be separated from the

On the other hand, at the other end of the first scale rod 15, a connecting ring 22a,
A telescopic adjustment screw 21 with screws 22b screwed onto both ends is supported by the edge 15c, and a connection ring 22b at the lower end of the adjustment screw 21 has a connecting ring 22b attached to the middle point of the second balance rod 24 or the edge 24.
It is rotatably supported by a.

This second scale rod 24 is rotatably supported by an edge 24b at its base end or a fixed fulcrum 25 on the arm 4a, and a portion closer to the tip than the support position by the adjustment screw 21 is , the weight 14 is movably attached, and the weight i! A scale 26 is provided as a guide when moving the weight 14, and the weight of the weight 14 acting on the first weighing rod 15 can be adjusted by moving the weight 14. Further, a scale plate 27 equipped with a scale 28 for displaying the wear amount of both surface plates 2.3 is attached to the arm 4a, and a pointer 29 indicating the scale 28 or the tip of the second scale rod 24 is attached to the arm 4a. The scale plate 27 and the pointer 29 constitute a wear amount display means. Therefore, the scale 28 on the scale plate 27 and the scale 26 on the second scale rod 24 have a certain correspondence relationship, and the weight 14 can be moved by the scale on the scale scale 24 according to the instruction from the pointer 29. By doing so, the required weight adjustment can be made.

In the lapping machine having the above configuration, when processing a workpiece, the optimum pressing force of the upper surface plate 3 is determined according to the type, shape, dimensions, etc. of the workpiece. 14, and the adjustment screw 21 is set so that the pointer 29 points to zero with the upper and lower surface plates 2 and 3 in direct contact with each other.
Zero point adjustment is performed by expansion and contraction of the upper and lower surface plates 2.
．． 3, the workpiece is lapped.

At this time, the pressing force P of the upper surface plate 3 acting on the workpiece is calculated from the middle edge 15a of the first scale rod 15 to the upper surface plate, where the weight of the upper surface plate 3 is 1 and the weight of the #21 weight 14 is W5. The distance to the edge ISb that supports 3.3. middle edge 15
The distance from a to the edge 15c supporting the adjustment screw 21 is 1.2, and the distance from the edge 24b at the base end of the second weighing rod 24 to the middle edge 24a supported by the adjustment screw 21 is L. Yu, heavy i from the proximal edge 24b! When the distance to the center of 14 is L4 (variable), it is expressed as.

Here, the upper and lower surface plates 2.3 gradually wear out due to repeated lapping work and correction work, and by reducing the weight, the pressing force of the upper surface plate 3 decreases, but by the amount of wear, the soil foot 513 that acts on the workpiece The pressing force can be kept constant by increasing the weight as follows. In other words, when the upper and lower surface plates 2 and 3 are brought into direct contact with each other, both surface plates 2 and 3
, 3 wear and the shoes will be lowered by the amount of wear @ 3, so
The first scale rod 15 rotates and the end of the second scale rod 24 on the pointer 29 side is lifted by the adjustment screw 21, and the pointer 29
indicates the scale 28 corresponding to the total amount of wear on both surface plates 2.3. In this case, the scale 28 corresponds to the total amount of wear on the scale plate 27.
Since the amount of wear on the foot g13 can be immediately known by adding a scale indicating the amount of wear on the weight 14, the amount of wear on the second weighing rod 24 corresponds to the amount of wear. By moving P to the fixed fulcrum 25 side and reducing L4, the weight of the weight 14 acting on the first weighing rod 15 is reduced, and the weight of the upper surface plate 3 acting on the workpiece in the above equation, that is, the pressing force P can be increased. Furthermore, after the pressing force is adjusted in this manner, the zero point of the pointer 29 is adjusted to prepare for the first lapping operation.

In the above embodiment, the pressure force is manually adjusted by moving the single weight 14, or the amount of wear on the upper surface plate 3 displayed on the display means is automatically read and the amount of wear on the upper surface plate 3 is adjusted accordingly. By automatically displacing the weight 14, the pressure force can be automatically adjusted.

[Effects of the Invention] As described above, according to the present invention, by adjusting the weight of the weight, it is possible to easily set the most suitable pressing force for the material, shape, dimensions, etc. of the workpiece, and also to Even if the pressing force shows a tendency to decrease due to wear of the surface plate, the pressing force can always be kept constant by adjusting the weight of the above-mentioned weight and increasing the weight of the upper surface plate that acts on the workpiece. can.

[Brief explanation of the drawing]

Fig. 1 is a side view showing one embodiment of the lapping machine of the present invention, Fig. 2 is an enlarged partial sectional view showing only the main parts, and Fig. 3
The figure is an enlarged sectional view of FIG. 2 viewed from the front. 2. Lower surface plate, 3. Upper surface plate, 14.. Weight, 15.. Scale rod, 27.. Scale plate, 29.. Pointer.

Claims (1)

[Scope of Claims] 1. A workpiece is sandwiched between a lower surface plate and an upper surface plate, and the workpiece is polished without being pressurized by the weight of the upper surface plate, the intermediate point being freely rotatable. An upper surface plate is suspended from one end of a scale rod supported by a scale rod, and a weight for setting the pressing force of the upper surface plate is suspended from the other end of the scale rod so that the weight can be adjusted. A lapping machine with a pressurizing force adjustment mechanism, characterized in that it is equipped with a wear amount display means that can read the amount of wear on the upper surface plate from the amount of wear on the upper surface plate.