JPH0871915A - Lap correction method and device therefor - Google Patents

Abstract

PURPOSE: To provide a correction carrier which can correct an irregular worn lap easily so as to perform the correction in a short time in a correction device of a rotary flat lapping machine. CONSTITUTION: A correction device is provided with a rectangular correction carrier 24 which is thin and long in the radial direction of a lap and a reciprocating device 7, 9 which reciprocates the correction carrier 24 within a surface parallel with a correction surface of the lap. The dimension S in the longitudinal direction of the correction carrier 24 is wider than width L in the radial direction of the lap 18, and the reciprocating stroke of the correction carrier 24 is such stroke that the correction carrier does not come off from the correction surface of the lap 18. Preferably, the correction carrier 24 reciprocates in the radial direction of the lap 18. It is desirable to use such correction carrier 24 that has a structure in which diamond abrasive particles are electrodeposited on its abrasive particle face, that is, diamond abrasive particles are held on a working face of the correction carrier by means of a nickel plated layer, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lap repair device installed on a rotary type flat lapping machine, and more particularly to the shape and structure of a repair carrier of the repair device.

[0002]

2. Description of the Related Art Lapping is a technique in which a loose abrasive is interposed between a tool called a lap and a workpiece to machine the workpiece by relative movement between the lap and the workpiece. Of these, it is a processing method with extremely high surface accuracy,
It is used for the finest processing such as block gauges and VLSI wafers.

FIG. 10 is a perspective view of a rotary type flat lapping machine used for lapping. The flat lapping machine 1
It has an opening in its upper surface 4 and a vertical axis 17
An annular wrap 18 that rotates around the front faces. Lapping is a processing method in which the surface shape of the lap 18 is transferred to the workpiece, so the surface accuracy of the product processed by the flat lapping machine depends on the surface accuracy of the lap.

Since the lap 18 is unevenly worn by the loose abrasive supplied from the slurry supply device during the lapping process, a correction process (dressing) is performed at regular time intervals in order to maintain the surface accuracy of the lap. There must be. Lapping correction processing includes cutting, grinding,
Three-sided sliding etc. are known. Among them, the grinding type correction device using the correction carrier is the mainstream of the correction processing because it has an advantage that it does not require any other special device and can easily cope with a large lap.

FIG. 10 shows a conventional correction device attached to a flat lapping machine. Conventional device is wrap 1
A circular correction carrier 51 is pressed against the upper surface of 8. The correction carrier 51 is rotatably provided around a vertical axis at the tip of a support arm 52 that cantilevers from the upper surface 4 of the flat lapping machine. L on the front side wall 2 of the lapping machine
A motor 7 is mounted via a bracket 5, and a pulley 53 fixed to a drive shaft 8 of the motor and a pinch roller 54 pressed against the outer peripheral surface of the correction carrier 51 are connected by a belt 55. . The rotation of the motor 7 is transmitted to the correction carrier 51 by this pinch roller 54.

In the correction processing by the conventional apparatus, the lap 18 is rotated around the vertical axis 17 at a constant speed, the loose abrasive is flown on the surface of the lap by the slurry supplying device 20, and the correction carrier 51 is made to move at a constant speed by the motor 7. It is performed by pressing the surface of the lap with a constant pressure while rotating it, and rubbing the loose abrasive and the lap. From the viewpoint of the correction carrier, the correction carrier 51 revolves around the surface of the wrap 18 while revolving around the surface of the wrap 18, and the free abrasive material and the lap are rubbed with each other to flatten the surface shape of the lap.

The reason why the correction carrier is rotated is to prevent the correction carrier 51 from being unevenly worn and to increase the friction distance per unit time to increase the amount of correction processing. However, the amount of wear of the correction carrier itself also increases.

[0008]

It is generally known that the amount of correction work of the lap is proportional to the friction distance and the pressing force of the correction carrier. It is also known that the use of a carrier having reverse wear characteristics for a lap that is unevenly worn in a concave or convex shape can correct the surface shape to a substantially flat surface. Therefore, the operator visually confirms the uneven wear state of the lap to select the correction carrier having the opposite wear characteristics, and sets the pressing force and other correction conditions to perform the correction processing.

However, such selection and setting of correction conditions depend on the skill level of the operator, and there is a problem that variations occur depending on the operator and the surface accuracy of the lap after the correction processing cannot be kept constant. . Further, in the conventional device, there is a problem that the amount of correction processing per unit time is small and the correction carrier must be frequently exchanged, which requires a long time for the correction processing.

A first object of the present invention is to provide a correction carrier which can always be corrected to be flat regardless of the uneven wear state of the lap, and a second object of the present invention is to provide a correction carrier for a short time. It is to provide a means capable of making correction processing.

[0011]

According to the present invention, the contact surface of the correction carrier 24 with the wrap 18 is a rectangular shape elongated in the radial direction of the wrap, and the wrap 18 is corrected while reciprocating. The correction device for performing the correction process includes a rectangular correction carrier 24 and reciprocating devices 7 and 9 for reciprocating the correction carrier 24 in a plane parallel to the correction surface of the lap. The longitudinal dimension S of the correction carrier 24 is larger than the radial width L of the wrap 18, and the reciprocating stroke of the correction carrier 24 is a stroke in which the correction carrier does not deviate from the correction surface of the wrap 18.

The correction carrier 24 is preferably a wrap 18.
Reciprocate in the radial direction. The reciprocating speed (average speed) of the correction carrier 24 is preferably higher than the peripheral speed of the lap 18 during correction processing. When the reciprocating speed of the correction carrier 24 is high, the correction carrier 24 may be a precise rectangle. The reciprocating speed of the correction carrier 24 is the lap 18
When it is smaller than the peripheral velocity of the wrap 18, the correction carrier 24 preferably has a shape in which the inner diameter side of the wrap 18 is slightly narrower.

It is further preferable that the repair carrier 24 has a structure in which diamond abrasive grains 25 are electrodeposited on the abrasive grain surface, that is, the diamond abrasive grains 25 are held on the processed surface of the repair carrier by a nickel plating layer 26 or the like. .

[0014]

Since the correction carrier 24 used in the method and apparatus of the present invention is rectangular and the short side thereof is the circumferential direction of the wrap 18, the width C (length of the short side) C of the correction carrier 24 is the wrap 18. Small enough compared to the radius of. Further, since the correction carrier 24 is reciprocated within a range that does not come off the lapping surface, the correction carrier 24 always crosses the lapping surface of the lap 18 in the width direction. The lap 18 passes through the machining surface of the correction carrier 24 in the width direction (short side direction) while drawing an arc locus by its rotation, and the length of the arc locus at the time of passing is the inner diameter side and the outer diameter side of the lap. Does not make a big difference.

Further, since the motion of the correction carrier 24 is a reciprocating motion, the wrap 18 and the correction carrier 24 are thereby reciprocated.
The relative sliding contact distance with and is constant at all points.
Therefore, according to the present invention, the friction distance of the correction carrier 24 with respect to the lapping surface of the wrap 18 is uniform over the entire lapping surface, and therefore the surface of the wrap is modified into a flat surface shape without any special consideration by the operator. it can.

When the reciprocating speed of the correction carrier 24 is increased, the ratio of the friction distance based on the reciprocating motion is increased. Therefore, the influence of the difference in distance between the inner diameter side and the outer diameter side of the arc locus traversing the correction carrier 24. Is relatively small, so it is preferred that the correction carrier 24 be of a precise rectangular shape.
On the other hand, when the reciprocating speed is low, the influence of the distance difference between the inner circumference side and the outer circumference side of the arc locus traversing the correction carrier 24 becomes relatively large, so the correction is made by an amount corresponding to the distance difference of the arc locus. A shape in which the inner peripheral side of the carrier is slightly narrower is more preferable. By reciprocating the correction carrier 24, the friction distance per unit time can be increased and the correction processing time can be shortened.

Further, abrasive grains 2 are formed on the processed surface of the correction carrier 24.
When the electrodeposited No. 5 is used, the lapping liquid containing fine loose abrasive grains stays in the recesses between the abrasive grains, so that the correction processing amount per unit time can be increased and the correction carrier Wear of 24 is reduced, and replacement of the correction carrier 24 during lapping becomes unnecessary.

[0018]

1 to 3 are perspective views of a rotary type flat lapping machine provided with a correction carrier of the present invention. Brackets 5 and 6 extending on the same plane as the upper surface 4 of the lapping machine are provided on the front side wall 2 and the rear side wall 3 of the rotary type flat lapping machine 1 in the figure. A motor 7 is fixed to the lower surface of the bracket 5 on the front side. Drive shaft 8 of motor 7
Protrudes upward from below the bracket 5 through the through hole, and the base end of the rotary lever 9 is fixed to the tip of the drive shaft. A base end of a connecting link 12 having the same length as that of the rotary lever 9 is pivotally attached to the front end of the rotary lever 9 via a pivot pin 11. On the other hand, the rear end of the bracket 6 is pivotally attached to the base end of an arm 14 having a fulcrum pin 13 provided on the upper surface as a swing center. It is connected. Motor 7
When is driven, the arm 14 swings around the fulcrum pin 13 via the rotary lever 9 and the connecting link 12. The swing width of the arm 14 is the rotation lever 9 and the connecting link 1.
It can be freely set by changing the length of 2.

The arm 14 extends in the tangential direction of an annular wrap 18 which rotates about a vertical axis 17 (see FIG. 3), and a rectangular holder 19 in a plan view is provided in an area where the arm 14 and the wrap 18 overlap. It is provided. The holder 19 is
As shown in FIG. 2, a rod 21 is provided upright at a position separated in the rotational direction of the wrap 18, and the upper portion of the rod 21 is a guide fixed to the arm 14 via linear motion bearings 22 and 22. It is guided by a cylinder 23. A rectangular bottom correction carrier 24 is fixed to the lower surface of the holder 19.
The correction carrier 24 is held horizontally by the holder 19 regardless of the uneven wear state of the wrap.

FIG. 4 and FIG. 5 show the surface shape of the lap which is unevenly worn by the lapping process and is corrected by the above apparatus. The lap used for the measurement is a cast iron one (FC300), which has an inner diameter of 99 mm and an outer diameter of 1
A 54 mm one was used and rotated at 4.82 rad / s. The correction carrier was also cast iron (FC300), and had a width of 50 mm and a pressing force of 5 kPa. In order to increase the amount of correction processing per unit time, the motor 7 is rotated and the correction carrier has an amplitude of 5 mm and a frequency of 31.4 rad.
A rocking vibration of / s was added. The working fluid has a particle size of GC
# 600 of 35 wt% was used, and was continuously supplied to the surface of the wrap by the processing liquid supply device 20. Also,
To keep the surface shape of the correction carrier flat, 30
Every minute, the carrier was replaced with a modified carrier with good surface accuracy.

The vertical axis in FIGS. 4 and 5 represents the corrected machining amount,
The horizontal axis shows the distance from the center of the wrap. The line a in FIG. 4 is
The surface shape of the lap which is unevenly worn in a concave shape is shown, and the line b shows the surface shape of the lap after the correction processing. As is clear from the line b in FIG. 4, the surface shape of the lap after the correction process was almost flat. A line c in FIG. 5 shows the surface shape of the lap that is unevenly worn in a convex shape, and a line d shows the surface shape of the lap after the correction processing. The surface shape of the lap after the correction processing is slightly convex. It is considered that this is because the correction carrier could not move horizontally with respect to the lap because the effect of the bending moment of the support portion of the correction carrier could not be suppressed due to insufficient rigidity of the device that applies the oscillating vibration.
In this case, a flat profile can be obtained by performing non-vibration processing, but the correction processing time increases.

As the correction carrier, fixed abrasive grains can also be used. FIG. 6 shows an example of a repair carrier on which fixed abrasive grains are electrodeposited. Electrodeposition correction carrier 24 of FIG.
Is the average particle size # 14 on the bottom surface 24a of the rectangular correction carrier.
The diamond abrasive grains 25 of 0 to 170 are fixed by the nickel plating layer 26.

FIG. 7 is a schematic view of a plating apparatus used for plating the modified carrier shown in FIG. The plating apparatus includes an outer tank 28 containing a plating solution 33 and an intermediate tank 2 housed in the outer tank.
9 and the inner tank 30 accommodated in the intermediate tank. The upper side of the intermediate tank 29 is attached to the lower surface of the lid 32 of the outer tank, and the bottom surface thereof is separated from the bottom surface of the outer tank 28. The side wall of the intermediate tank is provided with a through hole 31 through which the plating solution flows in and out. The inner tank 30 is placed on the bottom surface of the intermediate tank 29. The rectangular correction carrier 24 is placed on the inner tank 30 via an insulating material with the bottom surface 24a facing upward, and the average particle size # 140 to 1 is set so as to cover the bottom surface of the correction carrier.
70 diamond abrasive grains 25 are filled in the inner tank.

A nickel plate 34 is arranged in parallel with the correction carrier 24 accommodated in the inner tank 30, and this nickel plate is fixed to the lower surface of a support plate 35 which is installed in the intermediate tank 29 through an insulating material. ing. The correction carrier 24 is connected to the cathode of the DC power supply 36, and the nickel plate 34 is connected to the anode. The plating solution 33 is supplied to the intermediate tank 29 by a stirring blade 38 driven by a motor 37 connected to a power source 36.
And flowing in the inner tank 30. Further, the temperature of the plating liquid is adjusted by blinking the heater 39 hanging from the lid 32. The temperature of the plating solution is monitored by the sensor 41, and the controller 42 controls the heater 39 by the signal from the sensor.
Turn on and off.

The pH of the plating solution is measured using a pH meter. The current density is set according to the electrodeposition conditions using a variable DC voltage constant current power supply. The composition of the plating solution is nickel sulfate, nickel chloride, and boric acid. The pH is 4.2, the bath temperature is 60 ° C., and the current density is 2 A / dm ² . The energization time is 80 minutes.

Next, a method of manufacturing the electrodeposition correction carrier will be described. The manufacturing process is divided into four steps of pretreatment, pre-plating, abrasive grain electrodeposition, and post-plating. The pretreatment is performed in order to remove chips, oils and fats adhering to the surface of the repair carrier in order to obtain a plating layer having good adhesion. First, the side surface of the modified carrier having good surface accuracy is subjected to an insulation treatment using a silicon caulking agent. This is soaked in acetone for 10 minutes to degrease it, and then soaked in 10% hydrochloric acid for 10 minutes to activate the electrodeposited surface. After activation, the modified carrier is rinsed with distilled water to complete the pretreatment.

The modified carrier that has undergone the pretreatment is set in the plating apparatus. Then, in order to increase the adhesive force of the plating layer holding the abrasive grains, nickel plating is preliminarily plated on the bottom surface of the repair carrier for 20 minutes.

After the preliminary plating is performed, the diamond abrasive grains 25 are uniformly precipitated in the inner tank 30 and the electricity is supplied. afterwards,
Nickel plating is performed as post-plating to remove excess abrasive grains and to properly fill the shallowly-grounded abrasive grains.

FIG. 8 shows the amount of correction processing per unit time of the electrodeposited correction carrier. The circular correction in which the conventional circular correction carrier shown in FIG. 10 and diamond abrasive grains of grain size # 140 to 170 are electrodeposited. 10 laps with the carrier
It is a comparison of the correction processing amount when the time correction processing. The comparison was performed by changing the particle size of the loose abrasive (particle size # 28
In 0, he changed to a new modified carrier once on the way. ). In the figure, the shaded bars indicate the amount of correction processing in the conventional correction carrier, and the white bars indicate the amount of correction processing in the electrodeposition carrier. The conventional circular correction carrier is 2
It was exchanged every hour and processed for 10 hours.

The conventional circular correction carrier and the electrodeposited circular correction carrier show a tendency that the amount of correction processing decreases as the particle size decreases (particle size increases). Compared to the conventional circular correction carrier, the electrodeposited circular correction carrier has a particle size of 55 microns to 7.5 microns,
1.5 times, 3 times, 6 as the particle size decreases
It can be seen that the amount of correction processing is increased to double or 16 times.

It is considered that this is because the number of free abrasives held in the chip pockets generated between the electrodeposited diamond abrasive grains increased and the ratio of the scratching action by the free abrasives increased. Even when the circular correction carrier is electrodeposited, the processing characteristics of the lap are flat as in the case without electrodeposition, and when the free abrasive having a particle size of 25 microns (particle size GC # 600) is used, The amount of correction processing is about three times that of conventional correction carriers.

FIG. 9 is a view showing a case where a rectangular correction carrier is electrodeposited with diamond abrasive grains having a grain size of # 140 to 170 by the plating apparatus shown in FIG. Is. The conditions for correction processing are shown in FIGS.
The processing liquid used was a free abrasive having a particle size of # 600 (particle size of 25 microns) of 35 wt%. Line e in the figure shows the surface shape of the wrap, line f has an amplitude of 5 mm,
The surface shape of the lap when the correction processing is performed for 1 hour under the condition of the oscillation frequency of 0.8 Hz is shown, and the line g shows the surface shape of the lap when the correction processing is further performed for 4 hours thereafter. No modification carrier is exchanged during the processing time.

It can be seen from FIG. 9 that the outer surface shape of the lap after the correction processing for one hour is substantially flat. 4 more
It can be seen that even after the correction processing for a total of 5 hours, only the amount of processing increases while the surface shape of the lap remains flat. As described above, by using the electrodeposited rectangular correction carrier, highly efficient and highly accurate correction processing can be performed without depending on the surface shape of the unevenly worn lap. Although the above embodiment is for the correction processing on one side of the wrap, it goes without saying that it can be applied to the correction processing for both sides.

[0034]

As described above, since the correction carrier used in the method and apparatus of the present invention is rectangular, the surface texture of the lap can be corrected to be flat regardless of the uneven wear state of the lap. Further, since the abrasive grains are electrodeposited on the rectangular correction carrier, they have wear resistance and do not need to be replaced during the correction process. Further, it is possible to increase the processing amount as compared with the ordinary lapping processing. It is possible to perform correction processing with higher efficiency by using loose abrasive grains that are finer than the electrodeposited abrasive grains, and the smaller the free abrasive grain size, the shorter the time required for correction machining compared to normal lapping. it can.

[Brief description of drawings]

FIG. 1 is a perspective view of a correction carrier of the present invention shown attached to a rotary type flat lapping machine.

FIG. 2 is a perspective view of a correction carrier.

FIG. 3 is a plan view showing a relative position between a lap and a correction carrier.

FIG. 4 is a graph of correction processing of a lap that is unevenly worn in a concave shape.

FIG. 5 is a graph of correction processing of a lap that is unevenly worn in a convex shape.

FIG. 6 is an enlarged sectional view of an electrodeposited repair carrier.

FIG. 7 is a schematic diagram of a plating device.

FIG. 8 is a graph showing the relationship between the loose abrasive material and the amount of correction processing.

FIG. 9 is a graph of correction processing using a rectangular electrodeposition correction carrier.

FIG. 10 is a perspective view of a conventional correction carrier shown attached to a rotary type flat lapping machine.

[Explanation of symbols]

 7 Motor 9 Rotating Lever 18 Lap 24 Correction Carrier 25 Diamond Abrasive Grain 26 Nickel Plating Layer C Width of Correction Carrier L Radial Width of Wrap S Longitudinal Dimension of Correction Carrier

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takehiko Noto 1-161 Taiheiji Temple, Nonoichi-cho, Ishikawa-gun, Ishikawa Prefecture B203 Dormitory B203 (72) Inventor, Naoto Sunagawa 2-8-11 Izuminode, Kanazawa-shi, Ishikawa Prefecture 201 (72) Inventor Norihiko Moriya 3-31 Sumiyoshi-cho, Nonoichi-machi, Ishikawa-gun, Ishikawa Sugimori Apartment

Claims (3)

[Claims] 1. A method of repairing a wrap in which a repair carrier (24) is pressed against a wrapping surface while rotating the wrap (18) having a ring-shaped planar wrapping surface around the central axis of the ring. Wrap a rectangular modified carrier (24) with a long side longer than the radial width (L) around the long side.
(18) is pressed against the lapping surface in the radial direction, and the wrap (18) is rotated while reciprocating the correction carrier (24) with a stroke in which the correction carrier (24) does not come off the lapping surface. How to fix laps. 2. In a wrap repairing device, a rectangular repair carrier (24) having a long side longer than the radial width (L) of the wrap (18) to be repaired is wrapped around the long side.
And is equipped with a reciprocating device (7, 9) for reciprocating the correction carrier (24) in a plane parallel to the plane of the wrap (18). , Lap fixer. 3. The lap correcting device according to claim 2, wherein abrasive particles (25) are electrodeposited on the processing surface of the correction carrier (24).