JP2708249B2 - Grinding method for ceramic members - Google Patents

Description

The present invention relates to a method for grinding a ceramic member,
For example, the present invention relates to a method of grinding a ceramic member suitable for grinding a cooling fin made of ceramics which copes with heat generated by an LSI in a large-sized computer.

[Related Art] Conventionally, cooling fins of an LSI mounted on a computer are mainly made of aluminum. However, the heat generation per LSI has increased with the sophistication of the computer and the increase in the calculation speed, and high heat conductivity has been required for the cooling fins. In addition, the density of wiring has been increased, and even a small metal powder falling on a substrate may cause an error. Therefore, use of a ceramic material that is an electrically insulating material has been studied.

The cooling fin of the LSI mounted on the large computer consists of a fin that is placed on the LSI and radiates the heat of the LSI, and a fin that is combined with it without contact and allows the heat to escape to the water cooling jacket. In order to enhance the heat transfer effect, it is necessary to increase the number of fins, and accordingly, both the groove width and the fin width are formed as narrow as 1 mm or less. Also, since each LSI has an inclination, the dimensional accuracy of the groove width, groove perpendicularity, pitch, etc. must be 10 so that the combined fins do not contact each other.
μm or less.

Groove processing of ceramic members such as cooling fins of such LSIs is mainly performed by diamond grinding. In this groove processing, a metal bond diamond having excellent strength is used because a thin grindstone is required.

However, metal-bonded diamond grindstones are susceptible to clogging and blinding. If the sharpness of the grindstone decreases, grinding resistance increases during machining such as groove grinding, resulting in reduced machining accuracy and cracks. Will be invited. Therefore, the metal bond diamond grindstone particularly requires dressing of the grindstone, that is, dressing.

Conventionally, the dressing method of a metal-bonded diamond grindstone is mainly based on electric discharge machining. However, in this method, the electrodes are intensely consumed due to electric discharge, and replacement of the electrodes is indispensable, leading to a reduction in machining efficiency.

As an alternative method, for example,
Vol. 3 (1988), "Fine Ceramics Processing Technology (2nd Report)-In-Process Electric Dressing of Metal Bond Cutting Wheel-", Keisaku Okano et al., Pp. 97-106. An electrolytic dressing method in which a bond material of a metal bond diamond grindstone is eluted and dressed using the method. However, in the conventional electrolytic dressing method, the size of the grinding liquid supply nozzle for increasing the electrolytic efficiency is increased, and the electrodes are formed so as to cover the grinding stone from both sides.

Also, without causing wear of the forming tool (electrode),
As an electrode for electrolytic processing for easily forming a grinding wheel having a desired shape, for example, a technique described in Japanese Patent Application Laid-Open No. 56-9164 is known.

This publication discloses that a plurality of electrode tips are provided in a comb-like shape, an electrolyte solution outlet is provided in a valley sandwiched between the electrode tips, and a valley sandwiched between the valleys having the electrolyte solution outlet is provided. An electrode is disclosed in which a portion is formed as a cutout portion for removing liquid stagnation caused by the collision of the electrolyte.

However, this electrode for electrolytic processing has a complicated shape, and no consideration has been given to the fact that the man-hour for manufacturing the electrode is not inexpensive.

[Problems to be Solved by the Invention] In the former electrolytic dressing method in the above-mentioned conventional technique, no consideration is given to the elution of the bonding material on the side surface of the metal bond diamond grindstone. When grooving is performed, there is a problem that the groove dimensional accuracy is deteriorated due to a decrease in the width of the grindstone, and that the life of the grindstone is reduced.

The present invention has been made in view of the above-mentioned problems in the related art, and enables a ceramic member to be ground while dressing the outer peripheral surface of the grinding wheel with high precision without deteriorating the side surface of the metal bond diamond grinding wheel, thereby achieving a highly accurate machining surface. It is another object of the present invention to provide a method for grinding a ceramic member, which can provide a high grinding performance and can prolong the life of a grindstone without wasteful removal of abrasive grains.

In particular, the present invention realizes a practical and highly reliable grinding technology capable of processing a ceramic cooling fin with high precision.

[Means for Solving the Problems] In order to achieve the above object, in a method of grinding a ceramic member according to the present invention, a metal plate is provided at a position facing a metal bond diamond grindstone mounted on a grinding machine. Applying while supplying a working liquid between the metal bond diamond grindstone and the metal plate that are driven to rotate,
In the method of grinding a ceramic member, wherein a ceramic member is processed while dressing the metal bond diamond grindstone, a thickness of the metal plate controls a range in which a working liquid hits the metal bond diamond grindstone, And the amount of the bond material eluted by the electrolytic dressing of the metal bond diamond grinding wheel is fed back to the amount of cut in the groove processing of the ceramic member.

In addition, technical means are described as follows according to the technical idea that developed the present invention.

When grinding a ceramic member, it is necessary to suppress the elution of the bonding material on the side surface of the metal bond diamond grindstone, and to grind it with a grindstone whose amount of elution on the outer peripheral surface is grasped. In view of the above, the present invention provides a plate-shaped electrode, supplies a processing liquid in a film form to the outer peripheral surface of the grindstone, and controls the thickness of the electrode, the grindstone, the distance between the electrodes, and the applied voltage to control the grinding wheel and the electrode. It controls the strength distribution of electrolysis during the process, suppresses the elution of the bonding material on the side surface of the grinding wheel, and optimizes the elution amount on the outer peripheral surface.

[Operation] The operation of the above technical means is as follows.

In the electrolytic dressing, since the electrolysis is performed via the grinding fluid, only the portion where the machining fluid is supplied undergoes electrolysis in proportion to the electrolysis strength. When the width of the flow in the axial direction of the grindstone when the flow of the machining fluid hits the grindstone is equal to the grindstone thickness, the machining fluid is also supplied to the R portion of the corner of the end face of the grindstone, so that the bonding material on the side face of the grindstone is also eluted. When the machining fluid is supplied to the center side of the grinding wheel end surface R, the machining fluid that hits the grinding wheel is shaken outward by centrifugal force. Only the material elutes.

Therefore, the thickness of the metal plate to be the electrode is changed to [Whetstone width-2R]
By providing the metal plate as a thinner one in front of the grinding fluid supply port, the working fluid flows in a film shape following the metal plate and hits the outer peripheral surface of the grindstone.

In addition, the strength of the electrolysis between the grindstone and the electrode is proportional to the current density and is affected by the distance between the two electrodes. Therefore, by measuring the value of the current flowing between the grindstone and the current, the position of the electrode is always appropriate. And the elution amount of the bonding material on the outer peripheral surface is calculated. The results are fed back to the amount of cut in the grinding of the ceramic member, for example, the groove processing of the ceramic cooling fins, so that a constant groove depth can be maintained and the processing accuracy can be improved.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5.

FIG. 1 is a schematic configuration diagram of an electrolytic dressing apparatus used for processing a ceramic cooling fin according to one embodiment of the present invention, and FIG. 2 is a diagram illustrating electrode thickness and elution amount of pound material on the side surface of the grinding wheel during electrolytic dressing. And FIG. 3 is an enlarged sectional view taken along the line AA of FIG.

In FIG. 1, reference numeral 1 denotes a spindle of a grinding machine (not shown);
Is a metal-bonded diamond grindstone mounted on the spindle 1. This metal-bonded diamond grindstone 2 is made of a metal base 2b and an abrasive 2c made of a hard material such as diamond on the outer peripheral surface of the metal base 2b. And the like, and are integrally formed by being contained in a metal such as a metal, and rotate in the direction of the arrow.

Reference numeral 3 denotes a processing liquid supply device which is considered to face the metal bond diamond grinding stone 2. Reference numeral 4 denotes a metal plate provided at the tip of the processing liquid supply device 3, and the metal plate 4 has a predetermined thickness. And a metal electrode plate made of copper or the like having excellent conductivity. A grinding fluid 11 is supplied from the rear of the metal plate 4 toward the outer peripheral surface of the metal bond diamond grindstone 2 as a working fluid (electrolyte).

5 is a carbon plate.
Is strongly pressed by a spring 7 against a grindstone flange 6 which fixes the metal bond diamond grindstone 2 to the main shaft 1.

Reference numeral 9 denotes a DC voltage supply device applied between the metal bond diamond grinding wheel 2 and the metal plate 4. The carbon plate 5 is connected to the positive electrode side of the DC voltage supply device 9 via a feeder line 8, The metal plate 4 of the working fluid supply device 3 is connected to the side via a feeder wire 10.

The operation of processing the cooling fins 12 made of ceramics while dressing the metal-bonded diamond grindstone 2 by the dressing apparatus thus configured will be described.

Rotate the metal bond diamond wheel 2 to remove the grinding fluid
When a predetermined DC voltage is applied between the grinding wheel 2 and the metal plate 4 by the DC voltage supply device 9 while supplying the grinding wheel 11, a current flows between the metal bond diamond grinding wheel 2 and the metal plate 4 via the grinding fluid 11. Flows.

FIG. 3 is a view of the state of the metal bond diamond grindstone 2 and the metal plate 4 as an electrode during dressing as viewed from above.

As shown in FIG. 3, when the thickness t of the metal plate 4 is smaller than the thickness T of the metal bond diamond grindstone 2 by R at the corner of the grindstone, the grinding fluid supplied from the machining fluid supply device 3 Since 11 flows along the metal plate 4, the strength of the electrolysis at the portion where the grinding fluid 11 is applied on the outer peripheral surface of the grindstone becomes the highest, and the electrolysis is actively performed in this portion.

FIG. 2 is a diagram showing the selection of the grinding wheel thickness by taking the electrode thickness (mm) on the horizontal axis and the elution amount of the bonding material on the grinding wheel side surface on the vertical axis, where the grinding wheel thickness is 0.6 mm and R is 0.2. An example of the relationship between the thickness of the metal plate 4 (electrode) and the amount of the bond material eluted on the side of the grinding wheel when a thin blade grinding wheel having a thickness of 1.0 mm and a grinding wheel thickness of 1.0 mm and a radius of 0.2 mm are used. It is shown.

As is apparent from the figure, when the thickness t of the metal plate 4 is smaller than the thickness T of the metal bond diamond grinding wheel 2 by 2R or more, the elution of the bonding material on the side surface of the grinding wheel is not observed, and the thickness t of the electrode plate 4 is reduced. When it becomes larger, the amount of the bond material eluted on the side surface of the grinding wheel sharply increases.

In the apparatus of the present embodiment, the thickness t of the metal plate 4 is set to be smaller than the thickness T of the metal bond diamond grinding wheel 2 by 2R or more, and the processing liquid is supplied from the processing liquid supply nozzle 13 to the grinding point of the ceramic member. By performing the groove processing on the ceramic cooling fins 12 while performing the above-mentioned electrolytic dressing, there is no elution of the bonding material on the side surface of the grindstone, and the variation in the groove width, the perpendicularity of the groove, and the variation in the groove depth are 10 μm.
The following high-precision ceramic cooling fins can be obtained.

According to this embodiment, the outer peripheral surface of the grindstone can be dressed by a predetermined amount without deteriorating the side surface of the metal bond diamond grindstone.Therefore, there is no useless removal of abrasive grains, without reducing the life of the metal bond diamond grindstone. There is an effect that a cooling fin made of ceramics having a groove processed with high precision and having an excellent cooling effect can be obtained.

Further, the metal plate (electrode) in this embodiment has a simple shape, and the dressing apparatus can be manufactured with relatively low man-hours.

Needless to say, the technique of the present embodiment can be applied not only to the cooling fins but also to the overall grinding of the ceramic member.

Next, FIG. 4 is a schematic configuration diagram of an electrolytic dressing apparatus according to another embodiment of the present invention. In the figure, components having the same reference numerals as those in FIG. 1 are the same as those in the previous embodiment, and the description thereof will be omitted. In FIG. 4, illustration of the processing part of the ceramic part is omitted.

In the embodiment shown in FIG. 4, the metal plate 4 (electrode) is provided independently of the working fluid supply device 14 for electrolysis.

Since the machining fluid supply port of the machining fluid supply device 14 is located near the upper portion of the metal plate 4, the grinding fluid 11 flows along the metal plate 4 and is supplied onto the outer peripheral surface of the metal bond diamond grindstone 2. The same effects as in the embodiment described with reference to FIGS. 1 and 3 are expected.

Next, FIG. 5 is a control system diagram of an electrolytic dressing apparatus according to still another embodiment of the present invention. In the figure, those having the same reference numerals as those in FIG. 1 are the same as those in the previous embodiment.
The description is omitted. Further, in FIG. 5, illustration of a processed part of the ceramic part is omitted.

In FIG. 5, 15 is an ammeter provided in a DC voltage supply system, 16 is an electrode position control device relating to a means for positioning the metal plate 4 (electrode), and 17 is a metal bond diamond grinding wheel 2.
Is a grindstone position control device according to the position adjusting means.

In the embodiment of FIG. 5, for example, as the groove processing of the ceramic cooling fin progresses, the outer peripheral surface of the metal bond diamond grindstone 2 is mechanically worn and receded by the elution of the bonding material by electrolytic dressing, and the distance between the grindstone and the electrode is reduced. In order to prevent the electrolysis efficiency from dropping
The current flowing in the device is constantly monitored by the ammeter 15.

When the current value decreases, the electrode plate 4 is moved to an appropriate position by the current position control device 16 so that the amount of the bond material eluted on the outer peripheral surface of the metal bond diamond grinding wheel 2 is always constant, and the information is transmitted to the grinding wheel position control device. Feedback to 17 and metal bond diamond wheel 2
Increase the depth of cut. Furthermore, the side of the whetstone and the metal plate 4
Is detected by a light projection method or a stylus gauge, and the position of the electrode plate 4 with respect to the thickness direction of the grindstone is accurately positioned.

According to the embodiment shown in FIG. 5, the effects described in each of the above embodiments can be further ensured, and the reliability of the device can be improved.

[Effects of the Invention] As described above in detail, according to the present invention, without deteriorating the side surface of the metal bond diamond grindstone,
A ceramic member grinding method that can grind ceramic members while dressing the grinding wheel outer surface with high precision, obtains a high-precision machined surface, eliminates useless removal of abrasive grains, and extends the life of the grinding wheel Can be provided.

In particular, a practical and highly reliable grinding technology capable of processing ceramic cooling fins with high precision can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electrolytic dressing apparatus used for processing a ceramic cooling fin according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating electrode thickness and elution of a bonding material on a side surface of a grindstone during electrolytic dressing. Diagram showing the relationship between quantities, the third
FIG. 1 is an enlarged sectional view taken along the line AA of FIG. 1, FIG. 4 is a schematic configuration diagram of an electrolytic dressing apparatus according to another embodiment of the present invention, and FIG. 5 is still another embodiment of the present invention. It is a control system diagram of the electrolytic dressing apparatus concerning an example. 2 ... Metal bond diamond grinding wheel, 3,14 ... Working fluid supply device, 4 ... Metal plate, 5 ... Carbon plate, 8,
10 feeder wire, 9 DC voltage supply device, 11 grinding fluid, 12 cooling fins made of ceramics, 15 ammeter, 16 electrode position control device, 17 wheel position control device.

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-1-121172 (JP, A) JP-A-60-33006 (JP, A) JP-A-58-501623 (JP, A) JP-A-3-301 170266 (JP, A) Hira 1-84963 (JP, U)

Claims (3)

(57) [Claims] 1. A metal plate is provided at a position facing a metal bond diamond wheel mounted on a grinding machine, and a machining liquid is applied between the metal bond diamond wheel driven by rotation and the metal plate while supplying a processing liquid. A method of grinding a ceramic member while dressing the metal bond diamond grindstone, wherein a thickness of the metal plate controls a range in which a working fluid hits the metal bond diamond grindstone; A grinding method for a ceramic member, comprising: dressing an outer peripheral surface of a grindstone; and feeding back an elution amount of a bond material by electrolytic dressing of the metal bond diamond grindstone to a cut amount of a groove processing of the ceramic member. 2. The electrolytic dressing of the method for grinding a ceramic member according to claim 1, wherein the thickness of the metal plate is equal to or less than a value obtained by subtracting R dimensions of both side surfaces of the grinding wheel from the thickness of the metal bond diamond grinding wheel. A grinding method for a ceramic member having an electrolytic dressing, characterized in that: 3. The electrolytic dressing of the method for grinding a ceramic member according to claim 1, wherein a wear amount of the metal bond diamond grindstone and an elution amount of a bond material by the electrolytic dressing are controlled to control the metal bond diamond grindstone. A method for grinding a ceramic member having electrolytic dressing, wherein the outer peripheral surface is flattened.