JP7094612B2 - Metal saw - Google Patents

Description

The present invention relates to a metal saw used when cutting ceramics or the like before sintering.

One of the semiconductor devices used in mobile phones and the like is a monolithic ceramic capacitor. Hundreds of these monolithic ceramic capacitors are mounted on one mobile phone, and they are mass-produced and consumed in large quantities every day.

A laminated ceramic capacitor is manufactured by first laminating a plurality of plates of raw ceramics (ceramics before sintering), dividing the plate-like material into individual chip capacitors by a cutting device, and then sintering the capacitors. If the division by the cutting device is performed after sintering, thermal deformation occurs due to the high temperature at the time of sintering, the arrangement of the chip capacitors is distorted, and precise cutting becomes difficult. Therefore, the division is performed before sintering the ceramics.

The step of dividing a plurality of plate-shaped laminates of raw ceramics into individual chip capacitors by a cutting device is performed by a cutting device equipped with a metal saw. Patent Document 1 discloses a metal saw (rotary blade) used for cutting raw ceramics and having a saw blade formed on the outer periphery thereof.

Japanese Unexamined Patent Publication No. 4-179505

By the way, when the raw ceramics are repeatedly cut using the metal saw, the saw blade on the outer circumference of the metal saw wears. In particular, the corners of both ends (the angle between the side surface of the metal saw and the cutting surface) in the thickness direction of the cutting surface of the saw blade (the surface between one side surface of the metal saw and the other side surface) have a large cutting load. The saw blade gradually changes to a shape with rounded corners due to severe wear.

When the corner portion of the saw blade of the metal saw is worn and the corner is rounded, the shape is reflected in the machined portion at the cut portion of the cut raw ceramics. Therefore, there arises a problem that the side surface of each of the chip capacitors manufactured by being divided also has a shape reflecting the shape.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a metal saw in which wear of a corner portion of a saw blade is suppressed. Then, it is to provide a metal saw in which the side surface of the formed chip capacitor does not have an abnormal shape even if it is used when dividing the raw ceramics.

According to one aspect of the present invention, the metal saw having a saw blade formed on the outer peripheral portion thereof, the first plate-shaped object, the third plate-shaped object, the first plate-shaped object, and the third plate-shaped object. The first plate-like material and the third plate-like material have an abrasive material, and the first plate-like material has a second plate-like material between the plate-like material and the plate-like material. The plate-like material, the second plate-like material, and the third plate-like material include tungsten carbide and cobalt mixed with the tungsten carbide as a binder, and the first plate-like material is contained. The ratio of cobalt contained in the tungsten carbide of the product is smaller than the ratio of cobalt contained in the tungsten carbide of the second plate-shaped product, and the first plate-shaped material and the third plate-shaped material are different from each other. The second plate-like material is more rigid than the second plate-like material, and the second plate-like material is characterized by having higher toughness than the first plate-like material and the third plate-like material. A metal saw is provided.

Further, according to another aspect of the present invention, the metal saw having a saw blade formed on the outer peripheral portion thereof is a first plate-like object, a third plate-like object, and the first plate-like object. The second plate-like material between the and the third plate-like material is integrally provided, and the first plate-like material, the second plate-like material, and the third plate-like material are integrally provided. Means: Tungsten Carbide and Cobalt mixed with the Tungsten Carbide as a Binder, and the proportion of cobalt contained in the Tungsten Carbide of the first plate-shaped product is the carbonization of the second plate-shaped product. The ratio of cobalt contained in tungsten is smaller than that of the first plate-like material, and the third plate-like material has higher rigidity than the second plate-like material, and the second plate-like material has higher rigidity. Provided is a metal saw characterized by having a higher toughness than the first plate-shaped material and the third plate-shaped material.

Further , in the metal saw according to one aspect of the present invention, the proportion of cobalt contained in the tungsten carbide of the first plate-shaped product is 5 wt%, and the proportion of cobalt contained in the tungsten carbide of the second plate-shaped product is 5 wt%. The ratio may be 30 wt% .

According to one aspect of the present invention, there is provided a metal saw in which the first to third plate-shaped objects can be rotated as a unit. Since the metal saw according to one aspect of the present invention is formed by integrally forming three or more plate-shaped objects, the properties of each can be set independently. For example, a plate-shaped material having high rigidity and a plate-shaped material having high toughness can be formed by laminating and bonding a plurality of plates in the thickness direction.

For example, by arranging highly rigid plate-like objects on both sides, the wear resistance of the corners of the saw blade of the metal saw can be improved. Moreover, if a plate-like object having high toughness is arranged between the plate-like objects having high rigidity, the metal saw becomes strong against external force and impact, and the durability of the metal saw is enhanced.

Furthermore, when ceramics are cut with a metal saw in which a plate-shaped object with high rigidity is placed on both sides that are easily exposed to friction and a plate-shaped object with low rigidity is placed inside that is not easily exposed to friction, the cutting surface of the metal saw becomes uniform. It will be exhausted. That is, only the corners of the saw blade of the metal saw are not worn to form a rounded shape. Therefore, the side surface of the formed chip capacitor does not have an abnormal shape.

Therefore, according to one aspect of the present invention, there is provided a metal saw in which wear of the corner portion of the saw blade is suppressed. Then, a metal saw is provided in which the side surface of the chip capacitor formed even when used when dividing the raw ceramics does not have an abnormal shape.

FIG. 1 is a perspective view showing an example of a cutting device. FIG. 2 is a perspective view schematically illustrating the structure of the cutting unit. FIG. 3A is a schematic view of the metal saw viewed from the side surface, and FIG. 3B is a diagram schematically explaining the cross-sectional structure of the metal saw.

An embodiment of the present invention will be described. As an example of a cutting device using a metal saw according to the present embodiment, an external perspective view of a cutting device 2 for cutting a workpiece such as ceramics is shown in FIG. The cutting device 2 includes a main body 4 in which the cutting unit 10 having the metal saw is housed in the outer cover 8, a display monitor 6 mounted on the outer cover 8 of the main body 4, and the like.

A touch panel type display monitor 6 is arranged on the front surface of the exterior cover 8. With this display monitor 6, the operator inputs a command to the device, and the operating status of the device is displayed on the display monitor 6.

The cutting unit 10 is configured to be movable in the Y-axis direction. A holding table 12 is arranged adjacent to the cutting unit 10 so as to be movable in the X-axis direction. The holding table 12 holds the workpiece during machining. The mounting table 14 is a mounting table (elevator) for mounting a cassette capable of accommodating a plurality of workpieces inside, and is configured to be movable in the vertical direction.

When the cassette for accommodating the workpiece is placed on the mounting table 14, the cutting device 2 carries out the workpiece from the cassette and places it on the holding table 12 by a predetermined transfer mechanism. Then, the holding table 12 applies a negative pressure from a suction source (not shown) to suck and hold the workpiece on the holding table 12.

Here, a more detailed structure of the cutting unit 10 will be described with reference to FIG. FIG. 2 is an exploded view schematically explaining the structure of the cutting unit 10. As shown in FIG. 2, the cutting unit 10 includes, for example, a spindle housing 16 fixed to a moving mechanism (not shown) of the cutting device 2. Inside the spindle housing 16, a spindle 18 extending in the front-rear direction (Y-axis direction) is rotatably supported. The tip end (front end portion) of the spindle 18 projects forward from the spindle housing 16.

An opening 18a is formed at the tip of the spindle 18, and a screw groove is provided on the inner wall surface 18b of the opening 18a. A rear flange 20 made of a material containing a ferromagnet is attached to the tip of the spindle 18. The rear flange 20 includes a flange portion 22 extending outward in the radial direction and a boss portion 24 protruding forward from the surface (front surface) of the flange portion 22.

An opening 22a that penetrates the flange portion 22 back and forth is formed in the center of the flange portion 22. Further, on the back surface (rear surface) side of the flange portion 22, a fitting portion (not shown) into which the tip end portion of the spindle 18 can be fitted is formed. This fitting portion is provided at a position corresponding to the opening 22a.

If the fixing bolt 26 is tightened in the opening 22a and the opening 18a in a state where the tip portion of the spindle 18 is fitted in the fitting portion formed in the flange portion 22, the rear flange 20 is fixed to the spindle 18. The outer peripheral surface 26a of the fixing bolt 26 is provided with a thread corresponding to the thread groove of the opening 18a.

The outer peripheral surface of the flange portion 22 is a contact surface 22b that abuts on the back side surface of the metal saw 28. The contact surface 22b is formed in an annular shape when viewed from the axial center direction (Y-axis direction) of the spindle 18. The boss portion 24 is formed in a cylindrical shape, and a thread is provided on the outer peripheral surface 24a thereof.

A circular opening 28a through which the boss portion 24 is inserted is formed in the center of the metal saw 28, and the metal saw 28 is attached to the rear flange 20 by inserting the boss portion 24 through the opening 28a.

With the metal saw 28 attached to the rear flange 20, an annular front flange 30 is attached to the front side surface of the metal saw 28. An opening 30a is formed in the center of the front flange 30, and the boss portion 24 of the rear flange 20 is fitted into the opening 30a. The back surface on the outer peripheral side of the front flange 30 is a contact surface (not shown) that abuts on the front side surface of the metal saw 28. This contact surface is provided at a position corresponding to the contact surface 22b of the rear flange 20.

After mounting the front flange 30, an annular fixing nut 32 is tightened to the tip of the boss portion 24. As a result, the front flange 30 is pressed against the rear flange 20, and the metal saw 28 is sandwiched between the rear flange 20 and the front flange 30. The fixing nut 32 is formed with an opening 32a, and a screw groove is provided on the inner wall surface 32b of the opening 32a.

A blade cover 34 for accommodating a metal saw 28 or the like mounted on the spindle 18 is provided on the front surface of the spindle housing 16. The blade cover 34 is composed of a blade cover main body 36 fixed to the front surface of the spindle housing 16 and a slide cover 38 slidable in the left-right direction (X-axis direction) with respect to the blade cover main body 36.

The slide cover 38 is connected to the blade cover main body 36 via an air cylinder 40, and slides with the air supplied through the connector 42. After the metal saw 28 is attached to the spindle 18, the slide cover 38 is slid to close the blade cover 34, so that the metal saw 28 can be accommodated inside the blade cover 34.

A pair of substantially L-shaped nozzles 44 that sandwich the lower portion of the metal saw 28 back and forth are fixed to the slide cover 38. Cutting water is supplied to the nozzle 44 through a connector 46 provided on the slide cover 38. A plurality of slits (not shown) are formed on the tip end side of the nozzle 44 so as to face the metal saw 28. Cutting water is supplied through the plurality of slits.

On the other hand, the blade cover main body 36 is provided with a supply hole (not shown) for supplying cutting water to the metal saw 28. This supply hole is connected to a connecting tool 48 provided in the blade cover main body 36, and the metal saw 28 is cooled and washed by the cutting water supplied from the supply hole through the connecting tool 48.

Next, the structure of the metal saw 28 will be described with reference to FIGS. 3 (A) and 3 (B). FIG. 3A is a schematic view when the metal saw is viewed from the side surface, and FIG. 3B is a diagram schematically explaining a cross-sectional structure of the metal saw in the thickness direction.

As shown in FIG. 3A, a circular opening 28a inserted through the above-mentioned boss portion 24 is formed in the center of the metal saw 28. A saw blade 28b is formed on the outer periphery of the metal saw 28. When the spindle 18 of the cutting unit 10 rotates, the metal saw 28 mounted on the cutting unit 10 rotates along with the rotation. When the rotating metal saw 28 reaches the workpiece, the saw blade 28b cuts the raw ceramics.

The saw blade 28b has a plurality of cutting edge portions (rake surfaces) and a plurality of back portions (relief surfaces) of the plurality of cutting edge portions on the rear side in the rotation direction of the metal saw 28, respectively. Each cutting edge portion has a shape protruding in the outer peripheral direction of the metal saw 28 from the adjacent back portion, and cuts the workpiece. Each back portion has a shape cut in the center direction of the metal saw 28 from the adjacent cutting edge portion, and secures a space for efficiently discharging cutting chips generated by cutting.

FIG. 3B is a schematic view showing a cross-sectional structure when the metal saw 28 shown in FIG. 3A is cut at a plane perpendicular to the side surface and passing through the alternate long and short dash line AA'. As shown in FIG. 3B, the metal saw 28 is sandwiched between the first plate-shaped object 50a, the third plate-shaped object 50c, and the first plate-shaped object 50a and the third plate-shaped object 50c. It has a second plate-like object 50b and the like.

The method of forming the metal saw 28 will be described. First, a metal powder is placed in a ring-shaped molding die and cold-pressed to form a ring-shaped compaction body. Next, three ring-shaped pressure powders formed are laminated, sintered, and integrated. When the outer peripheral portion of the obtained sintered body is ground to the cutting edge, a metal saw 28 is formed.

The physical characteristics of each plate-shaped material can be adjusted by adjusting the constituent materials, composition, and the like of the metal powder as each raw material at the time of producing the first to third plate-shaped materials. By adjusting the physical characteristics of the first to third plate-shaped objects, the physical characteristics of the metal saw 28 formed by sintering can be adjusted.

For example, in the metal saw 28 according to the present embodiment, the physical properties of the first to third plate-shaped objects are adjusted to obtain the rigidity of the first plate-shaped object 50a and the rigidity of the third plate-shaped object 50c. Each can be made higher than the rigidity of the second plate-shaped object 50b.

Generally, when cutting is repeated using a metal saw, the corners of both ends in the thickness direction are worn at the cutting edge of the saw blade, and the corners of the saw blade 28b on the outer circumference of the metal saw gradually change to a rounded shape. Tend to do.

Therefore, in the metal saw 28 according to the present embodiment, the rigidity of the first plate-shaped object 50a and the third plate-shaped object 50c is first higher than the rigidity of the inner second plate-shaped object 50b. -Adjust the constituent materials, composition, etc. of the third plate-shaped material. Then, since both side surfaces of the metal saw 28 are plate-like objects having high rigidity, the wear resistance of the metal saw 28 is improved. Therefore, the shape of the metal saw 28 is unlikely to change due to wear, and the shape of the side surface of the chip capacitor formed by cutting with the metal saw 28 is also unlikely to be in an abnormal state.

By the way, in general, when the rigidity of the metal saw is increased, the hardness is increased but the metal saw tends to be brittle, and the possibility of damage due to impact or the like increases. Therefore, simply increasing the hardness of the metal saw in order to realize a metal saw having excellent wear resistance causes a problem of impact resistance.

Therefore, in the metal saw 28 according to the present embodiment, the toughness of the second plate-shaped material 50b sandwiched between the first plate-shaped material 50a and the third plate-shaped material 50c is increased. Adjust the constituent materials and composition of the plate-shaped material. The plate-like material with high toughness has improved impact resistance and cushions the impact received from the outside.

When the toughness of the second plate-shaped object 50b is higher than that of the first and third plate-shaped objects, the second plate-shaped object 50b is impacted when an external impact is applied to the metal saw 28. To alleviate. Then, it is possible to prevent the first plate-shaped object and the third plate-shaped object having high rigidity from being damaged by the impact. Since the second plate-shaped material 50b has high toughness and low wear resistance, it is easily worn when cutting with the metal saw 28 is repeated, but the second plate-shaped material 50b is not located at both ends where wear is particularly likely to occur. Can withstand long-term use.

That is, since the metal saw 28 according to the present embodiment is provided with the first plate-shaped object 50a and the third plate-shaped object 50c on the side surface side where wear is likely to occur, the shape change due to the wear of the side surface of the saw blade 28b can be suppressed. On the other hand, since the second plate-shaped object 50b having high toughness is provided inside, the occurrence of damage or the like can be suppressed even if an impact is applied to the metal saw 28. Therefore, the life of the metal saw 28 is extended.

The rigidity and toughness of the plate-shaped material are adjusted by the constituent elements of the plate-shaped material and their ratios (content ratios) and the like. Then, for example, the constituent elements of the first plate-shaped material and its content ratio are set to be different from the constituent elements of the second plate-shaped material and their ratios, and the respective rigidity and toughness are adjusted. For each plate-shaped material used in the metal saw 28, for example, a material in which cobalt is mixed with tungsten carbide (tungsten carbide) as a binder is used, and the rigidity and toughness of the plate-shaped material can be adjusted by the content of cobalt. ..

More specifically, when forming a plate-like material having high rigidity, the ratio of cobalt contained in tungsten carbide is about 5 wt%. When forming a plate-like material having high toughness, the proportion of cobalt contained in tungsten carbide is about 30 wt%. However, the metal saw according to the present embodiment is not limited to this. Rigidity and toughness are determined along with the thickness of each plate-like object according to the desired properties of the metal saw and the type of the object to be processed.

Further, in the metal saw according to the present embodiment, a high hardness abrasive material (particles) made of a material such as diamond or alumina is mixed into the first plate-shaped material and the third plate-shaped material. When the abrasive material (particles) is mixed in the first plate-shaped material and the third plate-shaped material, the wear resistance is improved as compared with the other materials constituting each plate-shaped material. When the abrasive material (particles) is mixed into the first plate-shaped object and the third plate-shaped object which are both side surfaces of the metal saw, the wear of the metal saw can be reduced and the life of the metal saw can be extended. However, the metal saw according to the present embodiment is not limited to the case where the abrasive material is included.

The present invention is not limited to the description of the above embodiment, and can be modified in various ways. For example, in the above embodiment, the case where the number of plate-shaped objects constituting the metal saw is three has been mainly described. However, the plate-shaped material constituting the metal saw may be composed of four or more pieces, and in that case, the rigidity of the plate-shaped material on both side surfaces of the metal saw may be higher than the rigidity of the inner plate-shaped material.

In addition, the structure, method, and the like according to the above-described embodiment can be appropriately modified and implemented as long as they do not deviate from the scope of the object of the present invention.

2 Cutting equipment 4 Main body 6 Display monitor 8 Exterior cover 10 Cutting unit 12 Holding table 14 Mounting table 16 Spindle housing 18 Spindle 18a Opening 20 Rear flange 22 Flange part 22a Opening 22b Contact surface 24 Boss part 26 Fixing bolt 26a Outer surface 28 Metal saw 28a Opening 30 Front flange 30a Opening 32 Fixing nut 32a Opening 32b Inner wall surface 34 Blade cover 36 Blade cover body 38 Slide cover 40 Air cylinder 42 Connecting tool 44 Nozzle 46 Connecting tool 48 Connecting tool 50a First plate-like object 50b Second Plate 50c Third plate 52a Opening of first plate 52b Opening of second plate 52c Opening of third plate

Claims (3)

A metal saw with a saw blade formed on the outer circumference.
It integrally has a first plate-like object, a third plate-like object, and a second plate-like object between the first plate-like object and the third plate-like object.
The first plate-like object and the third plate-like object have an abrasive material and have an abrasive material.
The first plate-like material, the second plate-like material, and the third plate-like material include tungsten carbide and cobalt mixed with the tungsten carbide as a binder .
The proportion of cobalt contained in the tungsten carbide of the first plate-shaped product is smaller than the proportion of cobalt contained in the tungsten carbide of the second plate-shaped product.
The first plate-shaped object and the third plate-shaped object have higher rigidity than the second plate-shaped object.
The second plate-like material is a metal saw characterized by having higher toughness than the first plate-like material and the third plate-like material. A metal saw with a saw blade formed on the outer circumference.
It integrally has a first plate-like object, a third plate-like object, and a second plate-like object between the first plate-like object and the third plate-like object.
The first plate-like material, the second plate-like material, and the third plate-like material include tungsten carbide and cobalt mixed with the tungsten carbide as a binder .
The proportion of cobalt contained in the tungsten carbide of the first plate-shaped product is smaller than the proportion of cobalt contained in the tungsten carbide of the second plate-shaped product.
The first plate-shaped object and the third plate-shaped object have higher rigidity than the second plate-shaped object.
The second plate-like material is a metal saw characterized by having higher toughness than the first plate-like material and the third plate-like material. The proportion of cobalt contained in the tungsten carbide of the first plate-like substance is 5 wt%.
The metal saw according to claim 1 or 2, wherein the proportion of cobalt contained in the tungsten carbide of the second plate-like substance is 30 wt%.

Images