Cutting device, cutting blade, and method for manufacturing electronic component

Abstract

To suppress inclining of a cutting surface in a vertical direction.SOLUTION: A member 40 to be cut is placed on a stage 10. A cutting blade 30 is formed into a thin plate shape to extend in a longitudinal direction, and cuts the member 40 to be cut. A holder 20 grips the cutting blade 30. The cutting blade 30 includes a grip part 31 gripped by the holder 20, and a blade tip part 32 extending while tapering from the end of the grip part 31 in a width direction. Tha maximum thickness of the blade tip part 32 is 10 μm-60 μm, inclusive. The cutting blade 30 is made of a hard metal. The cutting blade 30 in a state of being supported by the holder 20 bends into a projected shape on at least one side in a thickness direction and extends in the longitudinal direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a cutting device, a cutting blade, and a method for manufacturing electronic components. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2007-261116 (Patent Document 1) is a prior art document that discloses a cutting blade, a cutting device, and a method for manufacturing electronic components, which cut a green sheet laminate to produce green sheet chips. The cutting blade described in Patent Document 1 has a blade surface provided with a roughened area and a flat area, and the flat area is adjacent to the cutting edge. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-261116 A Summary of the Invention [Problem to be solved by the invention]

[0004] When a cutting blade is used to cut through a block of a laminate, a reaction force acts from the cut surface of the block on the side of the tip of the cutting blade, pushing the tip of the cutting blade laterally while also being pushed in the thickness direction of the block, which can cause the cut surface to tilt relative to the vertical.

[0005] The present invention has been made in consideration of the above problems, and aims to provide a cutting device, a cutting blade, and a method for manufacturing electronic components that can prevent the cut surface from being inclined relative to the vertical direction. [Means for solving the problem]

[0006] The cutting device according to the present invention includes a stage, a cutting blade, and a holder. A material to be cut is placed on the stage. The cutting blade is a thin plate extending along the longitudinal direction and cuts the material to be cut. The holder holds the cutting blade. The cutting blade includes a holding portion held by the holder, and a blade tip portion extending in a tapered shape from an end of the holding portion in a width direction perpendicular to the longitudinal direction. The maximum thickness of the blade tip portion is 10 μm or more and 60 μm or less. The cutting blade is made of a cemented carbide alloy. The cutting blade supported by the holder extends along the longitudinal direction while being curved convexly in at least one of thickness directions perpendicular to each of the longitudinal direction and the width direction. Effect of the Invention

[0007] According to the present invention, it is possible to prevent the cut surface from being inclined with respect to the vertical direction. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a flow diagram showing a method for manufacturing an electronic component according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view showing a configuration of a mother sheet having an internal electrode pattern. [Diagram 3] FIG. 4 is a side view showing a state in which mother sheets having internal electrode patterns are laminated. [Figure 4] 1 is a cross-sectional view showing a configuration of a cutting device according to an embodiment of the present invention. [Diagram 5] 5 is a plan view showing the positional relationship between an effective portion of an internal electrode pattern embedded in the dielectric block shown in FIG. 4 and the tip of a cutting blade. FIG. [Figure 6] FIG. 2 is a plan view showing the shape of the tip of a cutting blade according to an embodiment of the present invention. [Figure 7] FIG. 10 is a plan view showing the shape of the tip of a cutting blade according to a modified example of an embodiment of the present invention. [Figure 8] 1A to 1C are diagrams illustrating a method for evaluating a cut surface of a cutting target material cut by a cutting blade. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a cutting device, a cutting blade, and a method for manufacturing electronic components according to an embodiment of the present invention will be described with reference to the drawings. In the following description of the embodiment, the same or corresponding parts in the drawings are given the same reference numerals, and the description thereof will not be repeated.

[0010] 1 is a flow diagram showing a method for manufacturing an electronic component according to an embodiment of the present invention. In the following description of the method for manufacturing an electronic component, a method for manufacturing a multilayer ceramic capacitor will be described, but the electronic component is not limited to a multilayer ceramic capacitor and may be a multilayer ceramic coil or the like, as long as it is an electronic component made from a chip.

[0011] As shown in FIG. 1, when manufacturing a multilayer ceramic capacitor, first, a ceramic dielectric slurry is prepared (step S1). Specifically, a ceramic dielectric powder, an additive powder, a binder resin, a dissolving liquid, and the like are dispersed and mixed, and thus a ceramic dielectric slurry is prepared. The ceramic dielectric powder is, for example, a dielectric particle having a perovskite structure such as BaTiO3, CaTiO3, SrTiO3, CaZrO3, or CaHfO3. The additive powder is, for example, at least one of a Si compound, an Mg compound, an Mn compound, an Fe compound, a Cr compound, an Ni compound, and a Co compound. As the binder resin, a polyurethane resin, a urea resin, a melamine resin, an epoxy resin, a vinyl acetate resin, an acrylic resin, or an aqueous polymer such as polyvinyl alcohol (PVA) or polyvinyl butyral (PVB) can be used. These may be used alone or in a mixture of two or more kinds. The ceramic dielectric slurry may be either a solvent-based or water-based. When the ceramic dielectric slurry is a water-based paint, the ceramic dielectric slurry is prepared by mixing a water-soluble binder, a dispersant, etc. with a dielectric raw material dissolved in water.

[0012] Next, a ceramic dielectric sheet is formed (step S2). Specifically, the ceramic dielectric slurry is formed into a sheet shape on a carrier film using a die coater, gravure coater, or microgravure coater, and then dried to form a ceramic dielectric sheet. From the viewpoint of miniaturization and high capacity of the multilayer ceramic capacitor, the thickness of the ceramic dielectric sheet is preferably 0.2 μm or more and 10 μm or less.

[0013] Next, a mother sheet is formed (step S3). FIG. 2 is a plan view showing the configuration of a mother sheet having an internal electrode pattern. As shown in FIG. 2, a ceramic dielectric sheet 41 is coated with a conductive paste so as to have a predetermined pattern, thereby forming a mother sheet having a predetermined internal electrode pattern 42 on the ceramic dielectric sheet 41. The conductive paste contains Ni powder, a solvent, a dispersant, a binder, and the like, and is prepared so as to have a constant viscosity. As the binder, polyvinyl butyral (PVB) or polyvinyl alcohol (PVA), or the like, is used. As a method for coating the conductive paste, a screen printing method, an inkjet method, a gravure printing method, or the like can be used. From the viewpoint of miniaturization and high capacity of the multilayer ceramic capacitor, the thickness of the internal electrode pattern 42 is preferably 0.2 μm or more and 10 μm or less. In addition to the mother sheet having the internal electrode pattern 42, a ceramic dielectric sheet 41 that has not been subjected to the above step S3 is also prepared as the mother sheet.

[0014] Next, a plurality of mother sheets are laminated (step S4). Specifically, a predetermined number of mother sheets, each of which does not have an internal electrode pattern 42 and is made of only ceramic dielectric sheets 41, are laminated so as to have a thickness of, for example, 0.5 μm or more and 5 μm or less. A predetermined number of mother sheets, each of which has an internal electrode pattern 42, are laminated thereon. FIG. 3 is a side view showing a state in which the mother sheets having an internal electrode pattern are laminated. As shown in FIG. 3, the mother sheets are laminated so that the internal electrode patterns 42 are alternately shifted by half a pitch. The number of mother sheets, each of which has an internal electrode pattern 42, that are laminated is, for example, 10 sheets or more and 1000 sheets or less. A predetermined number of mother sheets, each of which does not have an internal electrode pattern 42 and is made of only ceramic dielectric sheets 41, are laminated thereon so as to have a thickness of, for example, 0.5 μm or more and 10 μm or less. In this way, a group of mother sheets is formed.

[0015] Next, the group of mother sheets is pressed together to form a dielectric block (step S5). Specifically, the group of mother sheets is pressed in the stacking direction by a hydrostatic press or a rigid press to form a dielectric block. At this time, the ceramic dielectric sheets 41 are pressed at a predetermined temperature, so that the ceramic dielectric sheets 41 come into close contact with each other. In addition, by arranging a ceramic dielectric sheet 41 of a certain thickness as the outermost layer in the stacking direction and pressing it, the ceramic dielectric sheet 41 on which the internal electrode pattern 42 is formed can be protected.

[0016] Next, the dielectric block is cut to form chips (step S6). Here, the configuration of a cutting device according to one embodiment of the present invention used for cutting the dielectric block will be described. FIG. 4 is a cross-sectional view showing the configuration of a cutting device according to one embodiment of the present invention. FIG. 5 is a plan view showing the positional relationship between the effective portion of the internal electrode pattern embedded in the dielectric block shown in FIG. 4 and the cutting edge of the cutting blade. FIG. 6 is a plan view showing the shape of the cutting edge of the cutting blade according to one embodiment of the present invention.

[0017] As shown in FIG. 4, a cutting device 100 according to an embodiment of the present invention includes a stage 10, a cutting blade 30, and a holder 20.

[0018] The stage 10 has a flat plate shape. A heating mechanism is provided inside the stage 10. The heating mechanism is, for example, a heating wire, a cartridge heater, or a Peltier element. The heating mechanism is capable of heating the upper surface of the stage 10 to a temperature in the range of 100° C. to 140° C., for example.

[0019] An adsorption mechanism is provided on the upper surface of the stage 10. The adsorption mechanism can hold the material to be cut by vacuum suction or electrostatic adsorption. The stage 10 is configured to be movable in the Y-axis direction and rotatable within the XY plane. A dielectric block 40, which is the material to be cut, is placed on the stage 10.

[0020] The holder 20 holds the cutting blade 30. Specifically, the holder 20 holds the cutting blade 30 from both sides in the Y-axis direction. The holder 20 extends along the longitudinal direction (X-axis direction) while having a pair of curved holding surfaces such that the cutting blade 30 held by the holder 20 has a convex curved shape in the thickness direction (Y-axis direction) as described below. The holder 20 is configured to be movable in the Z-axis direction.

[0021] The cutting blade 30 is a thin plate extending along the longitudinal direction (X-axis direction) and cuts the material to be cut. The cutting blade 30 includes a gripping portion 31 that is gripped by the holder 20, and a blade tip portion 32 that extends in a tapered shape from the end of the gripping portion 31 in the width direction (Z-axis direction) perpendicular to the longitudinal direction (X-axis direction). The cutting blade 30 has a blade tip 33 located at the tip of the blade tip portion 32.

[0022] The maximum thickness Tm of the cutting edge portion 32 is 10 μm or more and 60 μm or less. In this embodiment, the maximum thickness of the grip portion 31 is the same as the maximum thickness Tm of the cutting edge portion 32, but is not limited to this, and the maximum thickness of the grip portion 31 may be thicker than the maximum thickness Tm of the cutting edge portion 32. In this case, the maximum thickness of the grip portion 31 is, for example, 50 μm or more and 100 μm or less.

[0023] In this embodiment, the cutting blade 30 is double-edged, but is not limited thereto, and may be a single-edged blade, a clamshell blade, or a stepped blade having a step at the boundary between the gripping portion 31 and the cutting edge portion 32. The cutting blade 30 is made of a cemented carbide alloy. The cutting blade 30 is made of a bonded metal mainly composed of tungsten carbide and cobalt.

[0024] As shown in Figures 5 and 6, the cutting blade 30 supported by the holder 20 extends along the longitudinal direction (X-axis direction) while being curved convexly in at least one of the thickness directions (Y-axis direction) perpendicular to each of the longitudinal direction (X-axis direction) and the width direction (Z-axis direction). In this embodiment, the cutting blade 30 supported by the holder 20 extends along the longitudinal direction (X-axis direction) while being curved convexly in one of the thickness directions (Y-axis direction). As shown in Figure 6, the maximum displacement Lm of the cutting blade 30 in the thickness direction (Y-axis direction) when supported by the holder 20 is 10 µm or more and 40 µm or less.

[0025] As shown in FIG. 5, in the dielectric block 40, the effective portions 42a where the stacked internal electrode patterns 42 face each other are located along an imaginary line L that extends in the X-axis direction while being curved convexly to one side in the Y-axis direction due to distortion during compression bonding or the like.

[0026] The cutting blade 30 cuts the dielectric block 40 at a position between the effective portions 42a adjacent to each other in the Y-axis direction. Specifically, while the dielectric block 40 is held by the suction mechanism of the stage 10, the heating mechanism heats and softens the dielectric block 40. In this state, the holder 20 is lowered as shown by the arrow B1 in FIG. 4, and the cutting blade 30 cuts the dielectric block 40 at a position between the effective portions 42a adjacent to each other in the Y-axis direction as shown in FIGS. 4 and 5. Thereafter, the holder 20 is raised, and the stage 10 is moved in the Y-axis direction by one pitch of the effective portions 42a of the dielectric block 40, and the holder 20 is lowered again to cut the dielectric block 40 by the cutting blade 30. By repeating this operation, the dielectric block 40 is cut into a plurality of strips extending in the X-axis direction. Thereafter, the stage 10 is rotated by 90°, and the plurality of strip-shaped dielectric blocks 40 are repeatedly cut by the cutting blade 30 to be divided into a plurality of chips.

[0027] As shown in Fig. 1, the chip is then fired (step S7). Specifically, the chip is heated, and the dielectric material and conductive material contained in the chip are fired to form a laminate. The firing temperature is appropriately set according to the dielectric material and conductive material.

[0028] Next, external electrodes are formed (step S8). For example, the laminate is plated with Ni and then with Sn in this order to form plating layers, thereby forming external electrodes on the outer surfaces of the laminate.

[0029] Through the above-mentioned series of steps, a multilayer ceramic capacitor can be manufactured.

[0030] Here, a cutting blade according to a modified example of one embodiment of the present invention will be described. Fig. 7 is a plan view showing the shape of the tip of the cutting blade according to a modified example of one embodiment of the present invention. As shown in Fig. 7, in the modified example of one embodiment of the present invention, the cutting blade supported by the holder 20 extends in a meandering manner along the longitudinal direction (X-axis direction) while being curved in a convex shape alternately in both thickness directions (Y-axis direction). The maximum displacement Lm of the tip 33a of the cutting blade according to the modified example of one embodiment of the present invention is 10 μm or more and 40 μm or less.

[0031] In this modified example, the cutting blade is convexly curved in both thickness directions (Y-axis direction), and therefore the rigidity of the cutting edge of the cutting blade is increased compared to when the cutting blade is convexly curved in only one thickness direction (Y-axis direction), thereby effectively preventing the cutting surface from tilting relative to the vertical direction.

[0032] (Experimental Example) Below, an experimental example will be described that examines the influence of the maximum thickness of the cutting edge and the maximum amount of displacement of the cutting blade in the thickness direction on the effect of suppressing the inclination of the cutting surface with respect to the vertical direction.

[0033] In sample 1, the width of the cutting edge portion 32 in the Z-axis direction was 50 μm, the maximum thickness Tm of the cutting edge portion 32 was 10 μm, and the maximum displacement amount Lm of the cutting edge tip 33 shown in Figure 6 was seven types: 0 μm, 1 μm, 10 μm, 20 μm, 30 μm, 40 μm, and 100 μm.

[0034] In sample 2, the width of the cutting edge portion 32 in the Z-axis direction was 50 μm, the maximum thickness Tm of the cutting edge portion 32 was 60 μm, and the maximum displacement amount Lm of the cutting edge tip 33 shown in Figure 6 was seven types: 0 μm, 1 μm, 10 μm, 20 μm, 30 μm, 40 μm, and 100 μm.

[0035] Fig. 8 is a diagram showing a method for evaluating the cut surface of a cutting target material cut with a cutting blade. As shown in Fig. 8, a dielectric block having a thickness dimension T was cut, and if the horizontal distance Lh from the blade tip penetration position on the upper surface of the dielectric block to the end of the cut surface located on the lower surface of the dielectric block was 1 / 10 of the thickness T of the dielectric block or less, it was determined that the inclination suppression effect of the cut surface was recognized. In this experimental example, the thickness T of the dielectric block 40 was set to 500 μm, and if the horizontal distance Lh was 50 μm or less, it was determined that the inclination suppression effect of the cut surface was recognized.

[0036] [Table 1]

[0037] The experimental results are summarized in Table 1. As shown in Table 1, in Sample 1, in which the maximum thickness Tm of the cutting edge 32 is 10 μm, the effect of suppressing the inclination of the cut surface was observed when the maximum displacement Lm of the cutting edge 32 was in the range of 20 μm to 40 μm. When the maximum displacement Lm of the cutting edge 32 was 100 μm, the dielectric block 40 could not be cut at the desired position.

[0038] In sample 1, in which the maximum thickness Tm of the cutting edge 32 was 60 μm, the effect of suppressing the inclination of the cut surface was observed when the maximum displacement Lm of the cutting edge 32 was in the range of 10 μm to 40 μm. When the maximum displacement Lm of the cutting edge 32 was 100 μm, the dielectric block 40 could not be cut at the desired position.

[0039] From the above experimental results, it was confirmed that by using the cutting blade 30 according to this embodiment, it is possible to prevent the cut surface from being inclined relative to the vertical direction.

[0040] (Additional Note) It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0041] <1> a stage on which a workpiece to be cut is placed; A thin cutting blade extending along a longitudinal direction for cutting the cutting target material; a holder for holding the cutting blade; The cutting blade includes a gripping portion that is gripped by the holder, and a blade tip portion that extends in a tapered shape from an end of the gripping portion in a width direction perpendicular to the longitudinal direction, The maximum thickness of the cutting edge is 10 μm or more and 60 μm or less, The cutting blade is made of a cemented carbide alloy, A cutting device in which the cutting blade supported by the holder extends along the longitudinal direction while being convexly curved in at least one of a thickness direction perpendicular to each of the longitudinal direction and the width direction.

[0042] <2> The maximum displacement of the cutting blade in the thickness direction when supported by the holder is 10 μm or more and 40 μm or less. <1> The cutting device according to claim 1 .

[0043] <3> The cutting blade supported by the holder extends in a meandering manner along the longitudinal direction while being curved in a convex shape alternately in both directions in the thickness direction. <1> or <2> The cutting device according to claim 1 .

[0044] <4> A thin plate-shaped cutting blade extending along a longitudinal direction for cutting a cutting target material, A gripping portion that is gripped by the holder; A cutting edge portion extending in a tapered shape from an end of the grip portion in a width direction perpendicular to the longitudinal direction, The maximum thickness of the cutting edge is 10 μm or more and 60 μm or less, The cutting blade is made of a cemented carbide alloy, The cutting blade extends along the longitudinal direction while being curved convexly in at least one of a thickness direction perpendicular to each of the longitudinal direction and the width direction.

[0045] <5> The maximum displacement in the thickness direction is 10 μm or more and 40 μm or less. <4> The cutting blade according to claim 1.

[0046] <6> The wire extends in a meandering manner along the longitudinal direction while alternately curving convexly in both directions in the thickness direction. <4> or <5> The cutting blade according to claim 1.

[0047] <7> preparing a dielectric block having an internal electrode pattern embedded therein; <1> from <6> and cutting the dielectric block, which is the material to be cut, using the cutting blade according to any one of claims 1 to 5.

[0048] In the above-described embodiment, the combinable configurations may be combined with each other. The above-described curved shape of the cutting blade may be realized in a state where the cutting blade is held by the holder 20, but the cutting blade before being held by the holder 20 may have the above-described curved shape.

[0049] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0050] 10 stage, 20 holder, 30 cutting blade, 31 gripping portion, 32 cutting edge portion, 33, 33a cutting edge tip, 40 dielectric block, 41 ceramic dielectric sheet, 42 internal electrode pattern, 42a effective portion, 100 cutting device.

Claims

1. a stage on which a workpiece to be cut is placed; A thin cutting blade extending along a longitudinal direction for cutting the cutting target material; a holder for holding the cutting blade; The cutting blade includes a gripping portion that is gripped by the holder, and a blade tip portion that extends in a tapered shape from an end of the gripping portion in a width direction perpendicular to the longitudinal direction, The maximum thickness of the cutting edge is 10 μm or more and 60 μm or less, The cutting blade is made of a cemented carbide alloy, A cutting device in which the cutting blade supported by the holder extends along the longitudinal direction while being convexly curved in at least one of a thickness direction perpendicular to each of the longitudinal direction and the width direction.

2. 2. The cutting device according to claim 1, wherein a maximum displacement of the cutting blade in the thickness direction while supported by the holder is 10 μm or more and 40 μm or less.

3. 3. The cutting device according to claim 1, wherein the cutting blade supported by the holder extends in a serpentine manner along the longitudinal direction while being curved in a convex shape alternately in both directions in the thickness direction.

4. A thin plate-shaped cutting blade extending along a longitudinal direction for cutting a cutting target material, A gripping portion that is gripped by the holder; A cutting edge portion extending in a tapered shape from an end of the grip portion in a width direction perpendicular to the longitudinal direction, The maximum thickness of the cutting edge is 10 μm or more and 60 μm or less, The cutting blade is made of a cemented carbide alloy, The cutting blade extends along the longitudinal direction while being curved convexly in at least one of a thickness direction perpendicular to each of the longitudinal direction and the width direction.

5. The cutting blade according to claim 4 , wherein the maximum displacement in the thickness direction is 10 μm or more and 40 μm or less.

6. The cutting blade according to claim 4 or 5, wherein the cutting blade extends in a serpentine manner along the longitudinal direction while curving alternately in convex shapes in both directions in the thickness direction.

7. preparing a dielectric block having an internal electrode pattern embedded therein; and cutting the dielectric block, which is the material to be cut, with the cutting blade according to claim 1 or 4.

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