JP5515508B2 - Thin blade whetstone and manufacturing method thereof - Google Patents

Description

The present invention relates to a thin blade grindstone suitable for cutting hard and brittle materials such as ceramics and single crystal materials, and a method for producing the same.

2. Description of the Related Art Conventionally, a thin ring-shaped electroformed thin blade grindstone is known as a thin blade grindstone (dicing blade) for cutting a workpiece such as quartz, zirconia, and alumina with high accuracy. This thin-blade grindstone is formed by dispersing abrasive grains such as diamond and cBN in a metal binder, and the thickness thereof is formed in a thin ring shape of about several tens to several hundreds of μm. The thin-blade grindstone can hold the inner peripheral region thereof on the grindstone shaft and rotate the grindstone shaft, thereby cutting or grooving the workpiece in the outer peripheral region.

Thin blade grindstones are also required to be made thinner for reasons such as downsizing and yield improvement of electronic components in recent years. By using a metal material with high mechanical strength such as Ni as the metal binder, the thickness is reduced. An ultra-thin electroformed grindstone having a thickness of 50 μm or less is also provided. However, when the holding force of the abrasive grains by the metal binder increases, damage to the workpiece due to the abrasive grains increases, which causes a problem of increasing cracking and chipping of the workpiece called chipping during cutting.

In order to solve such a problem, Patent Document 1 discloses a thin-blade grindstone in which superabrasive grains are dispersed and arranged in a metal binder, and a thin-blade grindstone in which a large number of pores are included in the metal binder. Proposed. The pores are randomly formed in the metal binder, or are formed as pore rows penetrating in the thickness direction at random intervals in the radial direction and the circumferential direction. In this case, it is said that when the superabrasive grains are worn, the self-generated blade action is likely to occur, the sharpness is improved, and the straightness at the time of cutting is improved. Furthermore, when the pores are exposed on the cutting surface of the grindstone, chips can be accommodated in the concave portions of the pores, and clogging between superabrasive grains can be prevented to improve chip dischargeability, and coolant can be accumulated, It is said that the life can be improved by suppressing the wear and heat generation of superabrasive grains.

4A shows a cross-sectional structure of a general electroformed thin blade whetstone, and FIG. 4B shows a cross-sectional structure of a thin blade whetstone described in Patent Document 1. The abrasive grains 11 are held in a dispersed state on the metal binder 10. In the case of (b), the pores 12 are formed not only in the metal binder 10 but also in the surface layer portion.

In the case of the thin-blade grindstone having the pore structure as described above (b), the rigidity of the metal binder is lowered. Therefore, when a hard and brittle material such as lithium tantalate is processed, the metal binder is quickly worn and resistant There is concern about a decrease in wear accuracy and a decrease in cutting accuracy due to bending of the grindstone. Moreover, considering the point of machinability, there is a problem in that machinability is reduced compared to an electroformed grindstone having no pores because pores exist on the outer peripheral surface. Further, in order to form pores in the metal binder, a complicated manufacturing process is required, resulting in an increase in cost.

JP 2001-179639 A

An object of the present invention is to provide a thin blade whetstone capable of suppressing a reduction in wear resistance and bending of a whetstone while securing a chip pocket effective for discharging cutting waste and supplying coolant, and a method for manufacturing the same.

The present invention is a thin blade grindstone in which abrasive grains are dispersedly arranged in a metal binder, and the entire thickness is uniform, and recesses due to the dropping marks of the abrasive grains are formed on both side surfaces of the metal binder, The concave portion is not formed on the outer peripheral surface of the metal binder, and the density of the abrasive grains exposed on the outer peripheral surface of the metal binder is higher than the density of the abrasive grains exposed on both side surfaces. A thin blade whetstone is provided.

The first thin-blade grindstone manufacturing method according to the present invention includes a first step in which abrasive grains are dispersed and arranged in a metal binder , and a grindstone main body having a uniform overall thickness is prepared, and an outer peripheral portion of the grindstone main body. A second step of masking only the peripheral surface, and etching the surface layer portions on both sides of the metal binding material by immersing the grindstone body in an etching solution, thereby removing a part of the abrasive grains exposed on both sides A third step of dropping from the binder and forming recesses due to the dropping marks of the abrasive grains on both side surfaces of the grindstone main body; a fourth step of removing masking formed on the outer peripheral portion of the grindstone main body; With

The second thin-blade grindstone manufacturing method according to the present invention includes a first step of preparing a grindstone main body in which abrasive grains are dispersed in a metal binder, and the metal binder by immersing the grindstone main body in an etching solution. A second step of removing a part of the abrasive grains exposed to the surface layer part from the metal binder and forming a recess in the surface layer part of the grindstone body, and an outer peripheral part of the grindstone body And a third step of truing the outer peripheral portion of the grindstone main body until the concave portion of the peripheral surface can be removed.

The conventional porous hole grindstone is effective in suppressing chipping and the like because it can form a chip pocket effective for discharging cutting waste and supplying coolant. However, since the strength of the metal binder is reduced due to the presence of pores, when cutting a hard and brittle material, there is a concern about wear resistance and also a concern about bending of the grindstone during processing. The pores are effective on the side of the grinding wheel that contributes to the discharge of cutting scraps and the supply of coolant, but the effect is low on the outer peripheral surface of the grinding wheel that contributes to the cutting of the work material. Rather, it is desirable that there are no pores. Therefore, in the present invention, by forming a recess only on the side of the grindstone that contributes to the discharge of cutting waste and the supply of coolant, chipping is suppressed, and no recess is provided on the outer peripheral surface, and the outer peripheral surface is provided with no recess. By making the density of the exposed abrasive grains higher than the density of the abrasive grains exposed on both side surfaces, the machinability is improved, the wear resistance is lowered, and the bending of the grindstone is suppressed.

Various methods can be considered as the method of forming the recess, but by removing a part of the abrasive grains exposed on the surface layer portion on both sides of the metal binder from the metal binder, the recess is formed by the dropped abrasive grain marks. It is good to do. In this case, it is possible to easily form a recess having an appropriate depth and opening area as a chip pocket, and it is easy to form the recess as compared with the conventional case because it only drops the abrasive grains on the surface layer. It is.

In the case of an electroformed thin-blade grindstone, since abrasive grains are embedded in the metal binder, even the surface layer abrasive grains do not fall off easily. Thus, as a method for promoting the removal of the abrasive grains on the surface layer portion, for example, there is a method of immersing a grindstone in an etching solution and etching a metal binder present around the abrasive grains. In this case, the surface of the metal binder is etched, and the protruding length of the abrasive grains is increased. At the same time, the holding strength of the abrasive grains is reduced, so that the abrasive grains on the surface layer portion can be removed with relative ease. The etching thickness is not particularly limited, but is preferably about 1/3 to 2/3 times the average grain size of the abrasive grains.

When the entire grindstone is immersed in the etching solution, not only the both side surfaces of the grindstone but also the peripheral surface of the outer peripheral portion are etched, so that the abrasive grains on the peripheral surface of the outer peripheral portion are dropped and a recess is formed. Therefore, by masking the outer peripheral surface of the grindstone before etching and immersing in the etching solution in this state, only the abrasive grains on the surface layer portions on both side surfaces may be dropped to form the recesses. If the masking is removed after the etching, the abrasive grains on the peripheral surface of the outer peripheral surface do not fall off, so that a grindstone having no recess on the peripheral surface of the outer peripheral portion can be created. In addition, even when a concave portion is formed on the outer peripheral portion peripheral surface by etching, by truing the outer peripheral portion of the grindstone main body until the concave portion on the peripheral peripheral surface of the grindstone main body can be removed (by an amount corresponding to the etching thickness), A grindstone having no recess on the outer peripheral surface can be created.

In order to drop off the abrasive grains on both sides, for example, an adhesive tape may be attached to both sides of the grindstone, and the attached tape may be peeled off to remove the abrasive grains together with the tape. If it is attempted to drop the abrasive grains on the surface layer only by etching, it is necessary to etch deeply, which may reduce the strength of the metal binder. Therefore, when an adhesive tape is applied to both sides of the grindstone body after the etching process and the adhesive tape is peeled off, the abrasive grains whose holding strength has been lowered by etching are removed from the metal binder together with the adhesive tape. Since they can be separated, it is not necessary to etch deeply, and the abrasive grains can be dropped without reducing the strength of the metal binder. The concentration of abrasive grains on both sides can be easily adjusted by the etching time and the adhesive strength of the adhesive tape.

Furthermore, a grindstone body that does not have a concave portion on the surface is prepared, and an adhesive tape is applied to both sides of the grindstone body without etching the grindstone body, and the adhesive tape is peeled off to expose both sides. A part of the abrasive grains may be dropped together with the adhesive tape, and a recess may be formed in the surface layer portion of the grindstone body by the dropped abrasive grain traces. In the case where the thickness of the grindstone main body is thin, the strength of the grindstone main body may be reduced by the etching process. In this case, a part of the abrasive grains exposed on both side surfaces can be dropped together with the adhesive tape by applying the adhesive tape to both side surfaces without performing the etching process and peeling off the adhesive tape.

As the metal binder, in addition to Ni, an alloy of Ni and another metal (such as Co), or a metal other than Ni may be used, but an alloy having mechanical strength and wear resistance equivalent to Ni is used. desirable. When the metal binder is made of Ni, a mixed solution of hydrochloric acid and nitric acid, a ferric chloride solution, or the like can be used as the etching solution. Workpieces that can be cut with the thin-blade grindstone of the present invention include alumina, zirconia, silicon-glass composites, silicon carbide, etc., LiTaO ₃ single crystals, piezoelectric ceramics such as PZT, quartz, dielectrics, etc. Includes hard materials.

According to the present invention, since the concave portion is formed only on the side surface of the grindstone, the concave portion can be used as a chip pocket that contributes to discharge of cutting waste and supply of coolant, and chipping can be suppressed. In addition, since the outer peripheral surface is not provided with a recess, the density of the abrasive grains exposed on the outer peripheral surface of the metal binder is made higher than the density of the abrasive grains exposed on both side surfaces. The same machinability as that of a cast grindstone can be maintained, and a decrease in wear resistance and bending of the grindstone can be suppressed. Therefore, an effective thin blade grindstone can be realized even when a hard and brittle material such as lithium tantalate is cut.

According to the manufacturing method of the present invention, the outer peripheral surface of the thin-blade grindstone is masked and etched, or after the entire surface is etched, the concave portion is removed by truing only the outer peripheral surface, or on both side surfaces of the grindstone main body. By attaching the adhesive tape and peeling off the part of the abrasive grains exposed on both sides when the adhesive tape is peeled off together with the adhesive tape, it is possible to easily create a grindstone having recesses only on both sides. . In particular, when the etching process is used, the holding strength of the abrasive grains in the surface layer portion of the metal binding material is lowered, so that the abrasive grains are relatively easily dropped, and a recess can be formed by the dropped abrasive grain traces.

It is the front view and AA sectional view taken on the line of 1st Embodiment of the thin-blade grindstone concerning this invention. It is sectional drawing which shows the manufacturing process of the thin blade grindstone which concerns on this invention. It is sectional drawing which shows an example of the dropping method of the abrasive grain from the thin blade grindstone concerning this invention. It is an expanded sectional view of the conventional single layer whetstone and the whetstone described in patent documents 1.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. 1A and 1B show a first embodiment of a thin-blade grindstone according to the present invention, in which FIG. 1A is a front view of the thin-blade grindstone, and FIG. The thin blade whetstone 1 of this embodiment is a ring-shaped electroformed thin blade whetstone, and is formed by dispersing abrasive grains 2 such as diamond and cBN in a metal binder 3 made of Ni. The thickness of the grindstone 1 is set to about several tens of μm to several hundreds of μm, desirably 50 μm or less, and the particle size of the abrasive grains 2 is set to about 3 to 20 μm. FIG. 1 is a principle diagram for simplifying the explanation, and the particle diameter of the abrasive grains 2 with respect to the thickness of the metal binder 3 is actually smaller than that in FIG.

A part of the abrasive grains 2 exposed on both side surfaces 1a of the thin-blade grindstone 1 has fallen off from the metal binder 3, and a plurality of recesses 4 are formed by the dropped abrasive grain marks. The abrasive grains 2 exposed on the outer peripheral surface 1b of the thin-blade grindstone 1 are not dropped and no recess is formed. Therefore, the density of the abrasive grains 2 exposed on the outer peripheral surface 1b of the metal binder 3 is higher than the density of the abrasive grains 2 exposed on both side faces 1a.

As shown in FIG. 1 (b), since the concave portions 4 corresponding to the size of the abrasive grains 2 are formed on both side surfaces 1a of the grindstone 1, these concave portions 4 are used for discharging cutting waste and supplying coolant. An effective chip pocket can be formed and chipping can be effectively suppressed. Moreover, since the recessed part 4 is not formed in the outer peripheral part peripheral surface 1b of the grindstone 1, the abrasive grain density of the outer peripheral surface which contributes most to cutting is high, even when cutting a hard-brittle material like lithium tantalate. Good machinability can be obtained. For this reason, it is possible to effectively suppress the deterioration of wear resistance and the bending of the grindstone, which were the disadvantages of the porous hole grindstone.

Next, an example of the manufacturing method of the thin blade whetstone 1 which consists of the said structure is demonstrated with reference to FIG. First, an electrolytic plating solution containing Ni in which abrasive grains 2 such as diamond are dispersed is prepared, a substrate such as stainless steel and an anode plate are disposed facing each other in this plating solution, and the substrate is connected to the cathode. When a current is applied between the cathode and the anode, a Ni alloy plating layer is deposited on the substrate, and the metal binder 3 in which the abrasive grains 2 are uniformly dispersed is formed. When the metal binding material 3 reaches several tens of μm to several hundreds of μm, the plating is finished, the substrate on which the metal binding material 3 is formed is taken out of the plating solution, and the metal binding material 3 is peeled off from the substrate. The peeled metal binder 3 is formed into a ring shape to obtain a single-layer grindstone 1A shown in FIG. The process so far is the same as the manufacturing method of a general electroformed thin blade grindstone. Masking 5 is applied only to the outer peripheral surface 1b of the obtained single-layer grindstone 1A.

Next, the protrusion length of the abrasive grains 2 exposed from both side surfaces 1a is increased as shown in FIG. 2B by immersing the single-layer grindstone 1A in an etching solution and etching the surface of the metal binder 3. A single-layer grindstone 1B is obtained. In addition, since the outer peripheral surface 1b is covered with the masking 5, it is not etched and the protrusion length of the abrasive grain 2 exposed from the outer peripheral surface 1b remains as it is.

Next, while removing the masking 5 on the outer peripheral surface 1b, a part of the abrasive grains 2 exposed from the both side faces 1a of the single-layer grindstone 1B are dropped off, and the recesses 4 are formed by the dropped abrasive grain traces. To do. Note that the abrasive grains 2 fall off naturally only when the abrasive grains 2 have a large protruding length and a low holding power when immersed in an etching solution or after cleaning after etching. In this way, the thin blade grindstone 1 having the recesses 4 on both side surfaces as shown in FIG. 2C is obtained.

In FIG. 2, only the both side surfaces are etched by immersing them in an etching solution in a state where the outer peripheral surface of the single-layer grindstone 1 </ b> A is masked 5, but the entire surface of the single-layer grindstone 1 </ b> A is etched without performing the masking 5. After that, the grindstone may be attached to a dicer, and the outer peripheral surface may be scraped off by an amount corresponding to the etching thickness by truing to remove the concave portion of the grindstone outer peripheral surface. In a general cutting grindstone, since truing is always performed before cutting, there is an advantage that special processing such as masking is not required by scraping off the concave portion of the outer peripheral surface during the truing.

FIG. 3 shows another method for dropping the abrasive grains 2 exposed on both side surfaces 1a of the single-layer grindstone 1B. (A) shows the state which affixed the adhesive tape 6 on the both sides | surfaces of the etched single-layer grindstone 1B. At this time, the abrasive grains 2 whose protrusion length has increased by etching are bonded to the adhesive tape 6 in a wide area.

Next, when the adhesive tape 6 is peeled off as shown in (b), a part of the abrasive grains 2a whose protruding length is increased (holding force is reduced) is dropped from the metal binder 3 together with the adhesive tape 6. The recess 4 is formed by the dropped abrasive grain trace. Since the abrasive grains 2a are forcibly separated from the metal binder 3 in this manner, it is not necessary to etch deeply to the extent that the abrasive grains 2a naturally fall off, and the strength reduction of the metal binder 3 can be suppressed.

In addition, in FIG. 3, although the example which removes the abrasive grain 2 with the adhesive tape 6 from the both sides | surfaces of the single-layer grindstone 1B after an etching was shown, an adhesive tape is affixed on the both sides | surfaces of the single-layer grindstone 1A before an etching, A part of the abrasive grains on both side surfaces may be removed by peeling off. As is well known, an electroforming grindstone (single-layer grindstone 1A) is grown by plating in a plating bath in which abrasive grains are dispersed, but a large number of abrasive grains are exposed on both side surfaces, and some of the abrasive grains are Drop off with a little load. By peeling off these abrasive grains by the adhesive force of the tape, a concave portion can be formed by the dropped abrasive mark.

As the etching solution, a mixed solution of hydrochloric acid and nitric acid, a ferric chloride solution, or the like can be used. By appropriately setting the concentration, temperature, and time of the etching solution, it is possible to promote the removal of the abrasive grains. The etching thickness is about 1/3 to 2/3 times the average grain size of the abrasive grains, preferably about half the average grain size of the abrasive grains.

Here, an example of the thin blade grindstone concerning the present invention is shown. First, a commercially available single-layer grindstone with the following conditions was prepared.
Wheel thickness: 70 μm
Grinding wheel dimensions: 52mm outer diameter, 40mm inner diameter
Metal binding material: Ni
Abrasive: # 600 (average particle size about 25 μm) to # 1200 (average particle size 7.5 μm to 12 μm) diamond The above single-layer grindstone is etched using ferric chloride solution, hydrochloric acid + nitric acid, etc., and etched The thickness was 3 μm (the total thickness of the single-layer grindstone 70−6 = 64 μm). Thereby, a part of the abrasive grains on the side surface of the grindstone dropped off, and a thin blade grindstone in which the concentration of abrasive grains was reduced from 50% to 25% was created.

It processed on the following processing conditions using the above thin blade grindstones.
Workpiece: Composite material of ceramic and metal (thickness: 0.75mm)
Spindle speed: 30000rpm
Cut speed: 1-60mm / s
Cutting method: Upcutting When processed under the above conditions, the chipping of the workpiece was less than that of the Ni single-layer grindstone, and the machining quality could be maintained for a long time.

As a method of removing the abrasive grains on both sides, a method of dipping a grindstone in an etching solution and a method using an adhesive tape were mentioned, but it is also possible to immerse the grindstone in a medium to give ultrasonic vibrations. It is. As the medium, water, ethanol, IPA, a detergent dedicated to ultrasonic cleaning, or the like can be used.

1 Thin blade whetstone 2 Abrasive grain 3 Metal binding material (Ni plating layer)
4 Recess 5 Masking material 6 Adhesive tape

Claims (6)

In the thin blade grindstone where the abrasive grains are dispersed and arranged in the metal binder, and the entire thickness is uniform ,
On both side surfaces of the metal binding material, recesses due to the falling marks of the abrasive grains are formed, and on the outer peripheral surface of the metal binding material, the recesses are not formed,
A thin blade grindstone characterized in that the density of the abrasive grains exposed on the outer peripheral surface of the metal binder is higher than the density of the abrasive grains exposed on both side faces. A part of the abrasive grains exposed to the surface layer portions on both side surfaces of the metal binder is dropped from the metal binder, and the recess is formed by the dropped abrasive mark. The thin blade grindstone according to 1. A first step of dispersing and arranging abrasive grains in a metal binder and preparing a grindstone body having a uniform overall thickness ;
A second step of masking only the outer peripheral surface of the grindstone body;
By immersing the grindstone body in an etching solution and etching the surface layer portions on both side surfaces of the metal binding material, a part of the abrasive grains exposed on both side surfaces fall off from the metal binding material, and both side surfaces of the grindstone body A third step of forming a recess due to a drop mark of the abrasive grains ,
And a fourth step of removing masking formed on the outer peripheral portion of the grindstone main body. A first step of preparing a grindstone main body in which abrasive grains are dispersed in a metal binder;
By immersing the grindstone main body in an etching solution and etching the surface layer portion of the metal binder, a part of the abrasive grains exposed to the surface layer portion is dropped from the metal binder, and a recess is formed in the surface layer portion of the grindstone body. A second step of forming;
And a third step of truing the outer peripheral portion of the grindstone main body until the concave portion of the peripheral surface of the outer peripheral portion of the grindstone main body can be removed. In forming a recess by dropping a part of the abrasive grains from the metal binder,
A first sub-step of attaching an adhesive tape to both sides of the grindstone body;
A second sub-step of stripping off the adhesive tape, wherein a part of the abrasive grains exposed on both sides when the adhesive tape is peeled off is dropped together with the adhesive tape. The manufacturing method of the thin blade grindstone of Claim 3 or 4 to do. A first step of preparing a grindstone main body in which abrasive grains are dispersed in a metal binder;
A second step of attaching an adhesive tape to both sides of the grindstone body;
In the step of peeling off the adhesive tape, when the adhesive tape is peeled off, a part of the abrasive grains exposed on both sides is dropped together with the adhesive tape, and the surface layer portion of the grindstone main body by the dropped abrasive grain traces And a third step of forming a recess in the thin-blade grindstone manufacturing method.

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