JPH0295574A - Grinding method for electrolytic dressing and method and device for compound working of polishing method serving conductive grindstone for tool as well - Google Patents

Abstract

PURPOSE:To facilitate a stabilized mirrorface grinding by serving the conductive grindstone used for electrolytic dressing grinding for the tool for polishing as well after the electrolytic dressing grinding and performing finishing efficiently. CONSTITUTION:A highly efficient mirror face finish grinding is performed by the conductive grindstone fixed with a fine abrasive grain. Then finally only the small cutting streak which can not be ground even by this fine fixed abrasive grain is removed at high speed and completely by the electrolytic polishing method and free abrasive grain utilized auxiliarily.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a processing method and apparatus used in grinding and polishing in the field of machining, and particularly relates to a method and an apparatus for grinding and polishing in the field of machining. This invention relates to a composite machining method and device that utilizes the characteristics of a cast iron fiber bonded grindstone as a grindstone and can also be used as a grinding tool.

(Prior art) The conventionally common method for finishing workpiece materials, especially mirror finishing, is a polishing method called lapping or polishing, in which free abrasive grains and the workpiece are rubbed against each other to gradually eliminate irregularities. It was an extremely simple but time-consuming method. This finishing method takes a long time to process each workpiece, so by building a large-scale laboratory device and processing multiple workpieces at the same time, the apparent machining efficiency is increased and a single shape is achieved. It can be said that this method is suitable for producing large quantities of products with

However, the era of mass production of a small number of products, which began with the industrial revolution, which can be considered a symbol of modern civilization, is coming to an end, and modern industry is now demanding high-mix, low-volume production and high processing precision that were previously unimaginable. As time progressed, various drawbacks of polishing, which had never been a problem in the past, became a hindrance to high production efficiency. Among them, the drawbacks of difficulty in full automation and low finishing efficiency are fundamental disadvantages of the polishing method that uses free abrasive grains, and there is no way to solve these problems other than changing the processing principle itself. It has been said that there is no such thing.

Assuming that this polishing method using free abrasive grains is changed to a grinding method that uses fixed fine abrasive grains, that is, a grinding wheel with fine abrasive grains, the low machining efficiency that was a problem with co-locating the abrasive grains will naturally be reduced. Although it is thought that it can be easily solved,
It is possible that no measures were taken to maintain high-precision grinding over a long period of time. In fact, many studies have revealed that it is difficult to make a grindstone that retains fine abrasive grains, and that it is almost impossible to maintain a mirror surface using conventional grinding methods.

Therefore, in conventional processing technology, especially finishing processing technology, polishing (lapping, lapping,
(polishing) method, or first grind it with a whetstone with relatively coarse abrasive grains to obtain a certain degree of smoothness, then transfer the workpiece to another processing machine and move on to polishing with free abrasive grains. It can be said that the conventional technology had no choice but to take such complicated processing steps.

(Problems to be Solved by the Invention) The present invention is said to be completely unachievable by conventional polishing techniques using loose abrasives such as lapping (1)
) High finishing efficiency, (2) High machining accuracy, (3) Full automation of finishing machining, (4) Compactness of finishing machining equipment, (
5) We anticipate that we will be able to easily and reliably solve problems that are essential for future industrial development, such as increasing the flexibility of finishing processes. In particular, according to the present invention, which successively performs grinding processing to obtain high processing efficiency and polishing processing to obtain high processing accuracy, it is possible to consolidate almost all processing steps into one, and especially (1), (2), and (3) are considered to have a large effect on problem solving.

(Means for Solving the Problems) The present invention improves the conventional polishing method using loose abrasive grains such as lapping, and achieves highly efficient mirror finish grinding using a conductive grindstone fixed with fine abrasive grains (particle size: several μm). After significantly shortening the finishing machining time by doing this, in the end, only the fine grinding marks that could not be removed even with fine fixed abrasive grains were removed at high speed and using the electrolytic polishing method and free abrasive grains used as an auxiliary method. Take steps to completely remove it.

In the present invention, we have changed the conventional method of changing the processing tool and processing machine several times for each process, and even if the process changes from mirror grinding to mirror polishing, the conductive grindstone itself used for the initial mirror grinding can be changed. By using it as a polishing tool,
It is possible to obtain a quality that can almost be used as a final finished product using the same processing machine. In the present invention, the conductive grindstone is used because it generates an electrolytic dressing effect during grinding, which facilitates the removal of abrasive grains and grinding debris, which are problems when achieving stable mirror grinding using a fine abrasive grindstone. This is to ensure that this is achieved.

Moreover, after mirror grinding using electrolytic dressing, the conductive grinding wheel can be used as an electrolytic polishing tool by simply controlling the electrical conditions, and by making some improvements to the same grinding wheel, it can be used for conventional final polishing. The great novelty of the present invention is that it can also be used as a tool.

(Function) Below, the mirror grinding process using the electrolytic dressing action in the composite processing method of the present invention and the polishing action by the conductive grindstone used for grinding will be described in detail.

First, we will discuss the mirror grinding mechanism using electrolytic dressing in the early stage of the composite processing method according to the present invention. Not only metal-bond grindstones but also conductive grindstones can already have an effect of sharpening the abrasive grains and removing grinding debris (usually referred to as electrolytic dressing) due to electrolytic action. It has become clear. Grinding methods using electrolytic dressing are said to be most effective, especially for metal-bond rigid grindstones that have extremely high abrasive grain retention, such as cast iron fiber-bond grindstones. When cast iron fiber bonded grinding wheels with fine abrasive grains (diamond or CBN abrasive grains) are used in conventional grinding methods, the grinding performance is quite poor, and because the bond is a rigid bond, the abrasive grains are separated from the bond. This is because it is difficult to make it protrude, and stable mirror grinding cannot be achieved. However, according to the electrolytic dressing grinding method of the early stage of the present invention, the initial stage of using the grinding wheel (immediately after truing: Fig. 1A
), the abrasive grains covered with cast iron fiber bond are
It gradually becomes more prominent with the time of electrolytic dressing. This situation is shown in FIG. 1A→FIG. 1B→FIG. 1C.

In the early stages of the composite machining method according to the present invention, the focus is on protruding abrasive grains from this cast iron fiber bonded grinding wheel and maintaining it, and the grinding wheel itself is set as the (+) pole, and the metal plate electrode facing the grinding wheel surface is set as the (-) pole.
) As a pole, mirror grinding is achieved by supplying conductive grinding fluid to the gap between the two. In the grinding process, which is the initial process of the present invention, when a fine abrasive cast iron fiber bond grinding wheel is used, the finished surface roughness is already on the order of a mirror surface.
It can be improved to F (86820-4 Qnm), which can be said to be a finished surface accuracy that cannot be achieved by normal grinding.

Therefore, since a surface quality comparable to that of a conventional grinding surface has already been obtained in the initial grinding stage of the present invention, the surface precision can be further improved in a very short period of time in the later polishing process of this combined processing method. It will be possible.

Next, the polishing effect in the latter stage of the composite processing method of the present invention will be described. The most novel part of the present invention is
This can be said to be due to the continuity between the polishing process performed in the latter stage and the mirror polishing process in the early stage. That is, the polishing tool used in the later polishing process can be realized as an initial conductive grindstone. Now, even though the ground surface of the workpiece obtained by the initial mirror grinding is mirror polished, microscopically it still has a cross-sectional shape as shown in FIG. 2A. To this grinding surface, a conductive grindstone, for example, a cast iron Faberbond grindstone similar to the one described above, is used as an electrolytic Shinreki tool with the (-) pole and the workpiece side as the (+) pole while applying voltage. When moved, the grinding surface, which initially had a cross section as shown in Figure 2, shows that the electrolytic polishing effect occurs between the gap between the conductive cast iron fiber bond and the workpiece (in other words, the amount of protrusion of fine abrasive grains). This results in reduction of grinding marks (FIG. 2B). Naturally, in this step, the machining path used during initial grinding will be passed through again. In order to reliably obtain the electrolytic polishing effect at this stage, the amount of abrasive grain protrusion after electrolytic dressing grinding in the early stage of the composite processing method of the present invention must be appropriately controlled, and the electrolytic dressing effect is extremely small in the microscopic space. It is no exaggeration to say that it produces the effect of reliably producing the electrolytic polishing effect. Furthermore, in the present invention, free abrasive grains are also used as an auxiliary, which maintains the electropolishing effect by extremely finely removing the fine nonconductor film that forms on the finished surface as electropolishing progresses. fulfill the role of This situation is shown in FIG. 2C. Normally, one electropolishing effect is expected to reduce the roughness of the mirror-ground surface by almost half, so it is possible to obtain a mirror-finished workpiece that cannot be obtained even by mirror-finishing in an extremely short time. Furthermore, in order to obtain a super mirror surface with an R18 of several nm or less, for example, by providing a part of the cast iron fiber bonded grinding wheel with a non-grinding part (Fig. 3A), the tool can be further pressed against the workpiece under constant pressure. (FIG. 3B), it is possible to increase the roughness of the mirror-ground surface.

(Effects of the Invention) The present invention not only makes it possible to easily realize stable mirror polishing, which has been considered difficult to put into practical use, but also enables processing of silicon, ferrite, ceramics, cemented carbide, steel materials, and other conductive materials. It has become possible to easily and efficiently finish even the final product of materials, where even minute scratches caused by mirror grinding can be easily achieved. The composite machining method according to the present invention can achieve even a fairly precise mirror finish on the same machine tool, so it will play a major role in automating finishing work, which has been a problem in the past. In particular, the most important point in reducing mold production costs and improving processing accuracy in the future is how to eliminate human intervention and automate work such as mold polishing, which has been considered a craft since ancient times. However, it can be said that the present invention has a great effect on various basic industries such as the electronic industry, as well as the mold industry regardless of the purpose.

Further, assuming that the present invention is put into practical use, it can be said that the fact that no complicated or extremely special equipment is required will give a great advantage in its widespread use. In other words, according to the configuration of the multi-processing device according to the present invention, it is not difficult to configure the conductive grindstone, electrolytic dressing device, electrolytic polishing device, machining fluid supply device, workpiece, etc., and all of these are attached. Since it can be attached to conventional processing machines using this method, machines that are incorporated into current production processes can be used almost as-is.

Naturally, there are no particular restrictions on the conductive grindstone shape, f-cover, Asahi workpiece shape, and processing machine type. This is a fact that demonstrates the novelty and great versatility of the present invention.
By adopting the present invention in the near future, we can expect innovations in production methods that have never been seen before.

(Example) Hereinafter, the present invention will be explained in detail based on examples.

Table 1 shows the specifications of the mirror grinding/electrolytic finishing combined processing system used to carry out the present invention. This example was carried out to confirm the basic effects of the composite processing method according to the present invention, and the workpiece used was a silicon wafer, which is a typical electronic material. In the combined machining experiment system shown in Table 1, two types of processing machines are used to clarify the combined machining effect of the present invention. In other words, in order to confirm the combined effect of mirror grinding and subsequent spark-out (grinding wheel movement without cutting), we used a precision rotary flat surface equipped with a hydrostatic (oil) specification spindle. Use a grinder. In addition, in the second experiment, in the present invention, a non-grinding part was set up in a part of the tool, and a system was constructed in a simulated manner to realize an electrolytic calendar near a constant pressure. Check the combined effect of grains. This system uses a commonly used, inexpensive horizontal infeed grinder as a processing machine.

Table 2 Classification of processing steps carried out in the examples of the present invention (■10■: No.-
In other words, in the processing experiment conducted in this example, each process was conveniently divided into ■+■ (first process) and ■ (second process) as shown in Table 2. This is done using a separate processing machine system. In this way, although the processing machines are separated for convenience of testing in this example,
The concept of the composite processing method according to the present invention shows that by modifying a part of the conductive grindstone, the processing machines of this embodiment can be integrated into one unit.

First, in the first step described above, a fine abrasive cast iron fiber pond diamond grinding wheel (#4000: average abrasive grain diameter of about 4 μm) is used.
is used as a grinding and electropolishing process. In the grinding system using the grinding machine, a positive (+) voltage is applied to the grinding wheel to achieve mirror polishing of the silicon wafer. Of course, the voltage application on the grinding wheel side (+) is the purpose of electrolytic in-process dressing. The power supply device used at this time was an electrolytic dressing electric iN device whose specifications were designed for this mirror surface grinding. This power supply automatically executes processes such as supplying a relatively strong electrolytic current during the abrasive grain ejection process in the initial stage of mirror grinding, and supplying a weak current sufficient to contribute to the removal of grinding debris after the abrasive grain ejects. It also has a built-in mechanism.

In this system, after mirror grinding with a fine abrasive grindstone, the voltage polarity of the electrolytic power supply is reversed, and a (+) voltage is applied to the workpiece and a (-) voltage is applied to the grindstone. In this case, the grindstone essentially serves as a tool (electrode) for electrolysis. When transitioning from mirror grinding to electrolytic polishing, a holder is required that not only changes the applied polarity but also sets the electrolytic conditions and supplies the (+) pole to the workpiece itself. The researchers used a conductive vacuum chuck that directly supplies power to thin workpieces such as silicon wafers. The processing fluid used in this grinding machine was a commercially available water-soluble grinding fluid diluted 50 times with tap water, and the same processing fluid was used as is in the subsequent electrolytic polishing process. Since both electrolytic dressing and electrolytic polishing have a sufficient strength to flow a weak current, a sufficient combined effect of both can be obtained.

In addition, the features of this grinding machine include good rotational accuracy and main shaft rigidity, and the machining fluid supplied from the grinding wheel center shaft can be expected to be highly effective in removing grinding debris.

FIG. 4A is a configuration diagram of an apparatus for carrying out mirror polishing in the first step of the present invention. The figure mainly consists of a main part 41 of a precision rotary surface grinder and a power supply device 42 for electrolytic dressing. In the figure, a silicon wafer 43 as a workpiece is fixed on a holder 45 on a rotary table 44 and mirror-ground while a grinding fluid 46 for processing is supplied by centrifugal force from the center of the grindstone.

In addition, the electrolytic dressing device in the surface grinder is equipped with a grinding wheel 4.
7 A power supply brush closely attached to the outer periphery of the (+) electrode 48 and a (=) electrode plate 4 installed parallel to the grinding wheel surface with a certain gap.
9, and realizes in-process dressing by supplying the same grinding fluid used during machining between the grindstone and the (-) electrode. In the example, smoothing (truing) of the cast iron fiber bond grinding wheel 47 used before mirror grinding,
This was done by grinding with a W^stick grindstone (#80), followed by polishing by electrolytic dressing for 10 minutes.

After performing mirror polishing of the silicon wafer with this configuration, a polishing process using electrolytic action is started while supplying current to the silicon wafer. At this stage, a (-) voltage is applied to the grinding wheel 47, and a (+) voltage is applied to the silicon wafer through the conductive holder 45, and electrolytic polishing is performed while the grinding wheel is passed over the silicon wafer. The system configuration diagram during electrolytic polishing is shown in Figure 4B.Of course, the grinding devices in Figures 4A and 4B are the same, and the current supply method was manually switched by the operator, but this is not done automatically. It is easy to apply a switching device.When mirror grinding and mirror electrolytic finishing were carried out using this processing process, initial electrolytic in-process dressing grinding (electrolytic draining was performed in-process and fine abrasive cast iron fiber bond A good mirror surface wafer with Rsax of 44 nm and Ra of 5 nm was obtained by grinding using a diamond grinding wheel, and furthermore, due to the electrolytic polishing effect, R + aa
x26nm.

We were able to obtain an extremely good mirror surface wafer with an R of 4 nm. These changes in surface properties are shown in FIGS. 5 (after mirror grinding) and B (after electrolytic finishing). Judging from the surface texture and surface roughness measurement results obtained by microscopic observation, it can be seen that a sufficient effect of reducing grinding marks has been obtained. The mirror grinding conditions are: grinding wheel circumferential speed 1000 m/min (rotation speed 159 orpm), rotary table feed speed 1
00 s/min and a cutting depth of 2 μm/pass, followed by electrolytic polishing finishing at a cutting depth of 0 and the same feed rate. Therefore, immediately after slicing, the silicon wafer is mounted on a holder and the surface is smoothed with a coarse grindstone.
If the mai is set to about 0.40 μm, it will only be 2 Pa.
A mirror surface with Raax of 26nm and Ra of 4nm can be achieved in a 5s process. This actual processing can be accomplished in just over two minutes if silicon wafers are fed continuously.

Note that the electrolytic conditions in this step are ε. 60V (no load voltage), 1plOA (peak current), T2μ5ec (
In addition to the low on-time/off-time conditions, the actual machining current value ultimately decreases to less than IA.
It can be considered that there is no impact on the processing machine itself or the operator. The processing fluid itself does not contain any special electrolyte,
There is no possibility of problems with corrosion of processing machines or any impact on workers. Conventionally, the mirror surface properties obtained in this example have not been achieved by lapping for 30 to 40 minutes. In fact, efficiency is increased by more than 10 times.

On the other hand, in the second step of the embodiment of the present invention, a configuration as shown in FIG. system. The configuration of the apparatus used in this embodiment is roughly composed of a main part 61 of a horizontal infeed grinding machine and an electrolytic power supply device 62. In this grinding machine, the silicon wafer 63 and the tool 64 approach each other while rotating around the horizontal axis, and when they are in contact, a constant pressure cutting method is performed. Here, it is possible to use a method similar to the combined processing method implemented with the rotary surface grinder described above, but since the combined effect of continuous processing of mirror grinding and electrolytic polishing has already been implemented, this method In the second stage of the example, the tool 64 is mainly provided with a conductive part that contributes to electrolytic polishing and a non-conductive part that contributes to polishing with auxiliary free abrasive particles, and the tool 64 and the silicon wafer 6 are heated at a constant pressure.
A combined machining experiment of electrolytic polishing and free abrasive @polishing was carried out while 3 was brought into close contact. At this time, a (-) pole voltage was applied to the tool side via the power supply brush 65, and a (10) pole voltage was applied to the silicon wafer 63 side via a similar power supply brush 66. Due to the nature of the infeed grinder, the tool shaft and work shaft were insulated from each other using an insulating jig 67. In addition, a conductive holder 68 is attached to the work shaft.
A silicon wafer is mounted through the tool and the silicon wafer is processed while a conductive processing liquid 69 containing free abrasive grains is supplied between the tool and the silicon wafer. The structure of the "electrolytic polishing tool" used in this example is shown in FIG.
2, the former contributes to the electrolytic polishing effect, and the latter contributes to the polishing effect using free abrasive grains. When this tool and the silicon wafer are brought into close contact with each other under constant pressure, the non-conductive portion 72 is deformed according to the applied pressure, and the distance between the conductive portion and the silicon wafer is appropriately set, resulting in an effective polishing effect. I can expect it. Of course, the conductive part 7 of this tool
If 1 is a cast iron fiber bonded grinding wheel part with fixed abrasive grains, the non-conductive part 72 retreats from the grinding wheel part due to forced cutting in the early stage of machining, and mirror grinding with fixed abrasive grains (
For electrolytic dressing, the grinding wheel side is set as the (+) pole), and if the feeding method is then changed to constant pressure control, the grinding wheel portion is retracted from the non-conductive portion, and the polishing effect of this example can be achieved. The composite processing method of the present invention can be implemented with one processing machine. In this example, a CW (silicon wafer after etching treatment) was used as the workpiece in order to confirm the basic composite polishing effect. This C
The initial surface roughness of W is R,0,68μm, R,0,l O
μm, but as a result of this processing R-0.37 μm
It was confirmed that the surface roughness improved by yRa 0.06 μm (Figure 8 A (initial surface) and B ("! after puff finishing)). From the changes in the processed surface properties and finished surface roughness pattern. If we infer it, we can see that even with a highly electrically resistive material such as a silicon wafer, the effect of composite research is definitely occurring.In this case, such an improvement can be obtained in about 10 minutes of processing time. Therefore, it is expected that if CW is performed instead of mirror-ground wafers, the mirror surface roughness can be improved with considerable efficiency.When this process was actually performed, mirror-finished silicon wafers were easily obtained. Therefore, in the future, it will be possible to create a completely new mirror-finishing tool by using a cast-iron fiber-bond grinding wheel with a non-conductive part used in this example (Fig. 9). It can be said that r4 was recognized.The reason why free abrasive grains (average grain size 0.6 μm: γ alumina abrasive grains) were used as an auxiliary in this process is that in conventional electrolytic polishing, as electrolysis progresses, This is to suppress the phenomenon where an oxide film is formed on the surface of the workpiece and electrolytic polishing stops.Therefore, it is known that it is effective even if the concentration of free abrasive particles that should be mixed into the conductive processing fluid is low. .This is also advantageous from the viewpoint of machine maintenance.

As described above, the present invention particularly provides a combined processing method of an electrolytic in-process dressing grinding method using a conductive grinding wheel such as a cast iron fiber bonded grinding wheel and a Kenbo method using the same grinding wheel as a Shinreki tool on the same processing machine. By performing the steps sequentially, it was possible to easily create a mirror-finished silicon wafer with high processing efficiency and high surface precision, which was previously impossible.

If the present invention is fully put into practical use, processing efficiency that is on a different order from conventional methods will be realized, as was confirmed in this example, and production costs will be reduced as well as high added value and high This means that quality improvement can be easily achieved. In this example, the present invention was implemented using a silicon wafer, an electronic material that is considered to have a major impact on the modern electronic industry, but the present invention can be widely applied to any conductive work material. It goes without saying that it is possible.

It is highly anticipated that the present invention will be applied as a basic technology that will shed light on the production industry, where competition to lower costs is becoming increasingly heated.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram showing the state of the abrasive grains of the grindstone due to electrolytic dressing at the initial stage of the complex machining of the present invention. Fig. 2 shows the mirror grinding of the complex machining of the present invention and the polishing effect using the whetstone as a tool. A schematic explanatory diagram showing the principle; FIG. 3 is a schematic diagram showing a composite polishing effect using a tool that shares a non-conductive part with a cast iron fiber bond grinding wheel; FIG. 4A is a diagram for mirror grinding in an embodiment of the present invention. FIG. 4B is a configuration diagram of an apparatus for performing composite polishing using a grindstone as a tool in an embodiment of the present invention, and FIG.
Graphs showing changes in the processed surface properties of silicon wafers when processing is carried out using the combined processing apparatus shown in FIGS. 4B and 4B, and FIG. A block diagram of the apparatus used to confirm the composite polishing effect utilized, and FIGS. 7A and 7B are a side view and a plan view showing the tool used to confirm the electrolytic composite polishing effect in the example of the present invention. , FIG. 8 is a graph showing changes in finished surface properties observed as a result of polishing a CW (silicon wafer) using the apparatus and tools shown in FIGS. 6 and 7. FIGS. 9A and 9B are a side view and a plan view schematically showing a Shinreki tool that shares a non-conductive part with a cast iron fiber bond grindstone, which has a high possibility of being put to practical use. (Explanation of symbols) Items related to Fig. 4 41 Main parts of precision rotary surface grinder 4
2...Power supply device for electrolysis (dressing/ken@)
43... Silicon wafer (work material) 44...
... Rotary table 45 ... Conductive holder (silicon wafer suction plate) 46 ... Processing coolant 47 ... 9 Iron fiber bond grindstone 48 ...
・・Whetstone part power supply brush 49 ・・・Things related to electrode for electrolytic dressing shown in Fig. 6 61 ・・・Main part of horizontal infeed grinding machine 62 ・・・
...Power supply device for electrolysis (dressing/Kenreki) 63
...Silicon wafer (work material) 64...
・Composite polishing tool 65... Tool part power supply brush 66... Work part power supply brush 67... Tool part insulating plate 68... Conductive suction plate 69 ... Conductive machining fluid related to Figure 7 71 ... Conductive portion of polishing tool 72 ...
・Non-conductive part of the polishing tool Fig. Grinding wheel-like layer immediately after truing → Grinding wheel state in the middle of setting up the non-grinding power → Condition change of 18 iron fiber bond grinding wheel with insufficient grinding Fig. U Constant-pressure polishing effect due to conductive part and non-conductive part Tool that shares non-conductive part with cast iron fiber 17F grinding wheel Diagram: Schematic diagram of cross-section of rigid material after Jail grinding M Electrolysis occurs in the gap Electrolytic polishing effect by the grindstone Polishing effect by the non-conductive part of the tool 11 Smoothing effect by the polishing action after surface grinding Cylindrical 4A Diagram Rotation direction of the grindstone 0 46→・・・・・・ Mirror grinding device using electrolytic in-process doref sink Fig. 4B Grinding wheel rotation direction O. Polishing device that uses the grinding wheel as a tool. Fig. Electrolytic polishing tool diagram Finishing effect cylinder diagram made only with electrolytic polishing tools

Claims (1)

[Scope of Claims] (1) An electrolytic dressing grinding method and a conductive electrolytic dressing characterized in that after the electrolytic dressing grinding, the conductive grindstone used for the electrolytic dressing grinding is also used as a polishing tool to perform finishing processing efficiently. A combined polishing method that uses a grindstone as a tool. (2) In the early stage of the combined processing method, grinding is performed while applying a (+) voltage to the grinding wheel side for electrolytic dressing of the conductive grinding wheel, and in the latter stage of the combined processing method, the grinding Because it can also be used as an electrolytic polishing tool (-)
2. The composite machining method according to claim 1, wherein a (+) voltage is applied to the workpiece side. (3) The composite processing method according to claim (1), characterized in that in the polishing method that also uses the conductive grindstone, which is performed in the later stage of the composite processing method, polishing using free abrasive grains is performed auxiliary. . (4) Claim (1) characterized in that the conductive grindstone comprises an abrasive part that contributes to grinding in the early stage of the composite processing method, and a conductive part that contributes to electrolytic polishing in the latter stage of the composite processing method. Combined processing method described. (5) The composite processing method according to claim 1, wherein the conductive grindstone includes a non-grindstone portion that contributes to polishing using free abrasive grains that is performed auxiliary in the later stage of the composite processing method. (6) The composite machining method according to claim 1, wherein the machining fluid in the composite machining method contains a conductive grinding fluid effective for energization and fine free abrasive grains effective for polishing. Method. (7) An electrolysis device comprising: a conductive grindstone; an electrolytic dressing device for the conductive grindstone; and a power supply device that applies a voltage between the conductive grindstone and the workpiece in a state where machining fluid is supplied. A complex processing device that combines dressing grinding and polishing using a conductive grindstone as a tool.