Electric discharge machining apparatus and electric discharge machining method capable of adjusting machining parameters

Abstract

To provide a device and a method for electrical discharge machining that allow adjustment of processing parameters.SOLUTION: A device for electrical discharge machining includes a placement stage and an electrical discharge machining (EDM) unit. The placement stage is used for placing a workpiece with a defined processing object area. The processing object area of a workpiece is cut along a first cutting direction applying at least one processing parameter by using an electrical discharge electrode of the electrical discharge machining (EDM) unit, and the processing parameter is adjusted according to the time at which a specified parameter of the workpiece changed to a first numerical value, and thereby, a second cutting step is implemented with respect to the processing object area of the workpiece by applying the adjusted processing parameter. The present invention provides a gradual cutting technique, and is capable of solving the problems of delayed cutting speed (Cutting speed, mm2 / min) and prolonged total cutting time, because a specified parameter of electrical discharge machining cutting changes.SELECTED DRAWING: Figure 4b

Description

[Technical field]

[0001] The present invention relates to a machining apparatus and a machining method, and more particularly to an electric discharge machining apparatus and an electric discharge machining method capable of adjusting machining parameters. [Background technology]

[0002] With the vigorous development of the semiconductor industry, electrical discharge machining technology is commonly used in the machining of ingots or wafers. Electrical Discharge Machining (EDM) is a manufacturing process that uses sparks generated by electrical discharge to shape the workpiece into the required shape. A dielectric material separates two electrodes and applies a voltage to generate a periodic, fast-changing current discharge to machine the workpiece. In electrical discharge machining technology, two electrodes are used, one electrode is called the tool electrode or discharge electrode, and the other electrode is called the work electrode and is connected to the workpiece. There is no actual contact between the discharge electrode and the work electrode during electrical discharge machining.

[0003] When the potential difference between the two electrodes becomes large, the electric field between the two electrodes also becomes large until the electric field strength becomes higher than the dielectric strength, at which time dielectric breakdown occurs, current flows through the two electrodes, and a part of the material is removed. When the current stops, new dielectric material flows into the electric field between the electrodes, and a part of the material is removed, and the insulating effect of the dielectric is provided again. After the current flows, the potential difference between the two electrodes returns to before the occurrence of dielectric breakdown, and thus a new dielectric breakdown can be repeated. However, in conventional electric discharge machining technology, the cutting thickness is large, so the cutting speed (i.e., the product of the feed speed of the discharge electrode at the workpiece during machining and the cutting thickness, mm 2 / min) slows down. Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the above, an object of the present invention is to provide an electric discharge machining apparatus and an electric discharge machining method capable of adjusting machining parameters, in order to solve the above problems of the conventional techniques. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, the present invention provides an electric discharge machining apparatus capable of adjusting machining parameters for executing a cutting procedure, comprising: a mounting stage for mounting at least one workpiece on which a machining target area is defined; and an electric discharge machining (EDM) unit for cutting the machining target area of ​​the workpiece along a first cutting direction using at least one discharge electrode with at least one machining parameter in a first cutting step of the cutting procedure, the machining parameter being adjusted in response to a specified parameter of the workpiece changing to a first numerical value, thereby executing a second cutting step on the machining target area of ​​the workpiece using the adjusted machining parameter, wherein the machining target area has a filling material therein so as to fill surface cracks formed in the machining target area in the cutting procedure.

[0006] According to the electric discharge machining apparatus capable of adjusting machining parameters of the present invention, the machining parameters include one or more of an orientation parameter, a discharge electrical parameter, a residue discharge parameter, and a movement and tension parameter.

[0007] According to the electric discharge machining apparatus capable of adjusting machining parameters of the present invention, the orientation parameter is a machining direction relative to the workpiece, the discharge electrical parameters include one or more of a peak current, a voltage when the workpiece separates from the discharge electrode, a discharge pulse duration, a discharge pulse pause time, and a servo reference voltage between the discharge electrode and the workpiece, the residue discharge parameter includes a flow rate of a residue discharge solution provided to the discharge electrode, and the movement and tension parameters include one or more of a movement speed of the discharge electrode and a tension of the discharge electrode.

[0008] According to the electric discharge machining device capable of adjusting machining parameters of the present invention, the specified parameters include a first thickness to be cut of the workpiece, and the machining parameters are adjusted in response to when the first thickness to be cut of the workpiece increases to the first numerical value, thereby performing the second cutting step on the area to be machined of the workpiece using the adjusted machining parameters.

[0009] According to the electric discharge machining apparatus capable of adjusting machining parameters of the present invention, the machining parameter is an orientation parameter, and when the first thickness to be cut of the workpiece increases to the first numerical value, the electric discharge machining (EDM) unit performs the second cutting step on the area to be machined of the workpiece along the second cutting direction by changing the orientation parameter from the first cutting direction to a second cutting direction.

[0010] According to the electric discharge machining device capable of adjusting machining parameters of the present invention, there is a first included angle between the second cutting direction and the first cutting direction in a range between 0 degrees and 360 degrees.

[0011] In the electric discharge machining apparatus capable of adjusting machining parameters according to the present invention, the first included angle is 180 degrees.

[0012] According to the electric discharge machining apparatus capable of adjusting machining parameters according to the present invention, the second thickness to be cut in the second cutting step of the workpiece is smaller than the first thickness.

[0013] According to the electric discharge machining device capable of adjusting machining parameters of the present invention, the cutting speed of the workpiece by the discharge electrode in the second cutting step is greater than the cutting speed of the workpiece by the discharge electrode when the first thickness to be cut becomes the first numerical value.

[0014] According to the electric discharge machining apparatus capable of adjusting machining parameters of the present invention, when the second thickness to be cut in the second cutting step of the workpiece increases to a second value, the electric discharge machining (EDM) unit performs a third cutting step on the area to be machined of the workpiece along the third cutting direction by changing the orientation parameter from the second cutting direction to a third cutting direction, and the workpiece has a third thickness to be cut in the third cutting step.

[0015] According to the electric discharge machining device capable of adjusting machining parameters according to the present invention, there is a second included angle between 0 degrees and 360 degrees between the third cutting direction and the second cutting direction.

[0016] In the electric discharge machining apparatus capable of adjusting machining parameters according to the present invention, the second included angle is 90 degrees.

[0017] According to the electric discharge machining device capable of adjusting machining parameters of the present invention, the third thickness to be cut in the third cutting step of the workpiece is smaller than the first numerical value or the second numerical value.

[0018] According to the electric discharge machining device capable of adjusting machining parameters of the present invention, the cutting speed of the workpiece by the discharge electrode in the third cutting step is greater than the cutting speed of the workpiece by the discharge electrode when the first thickness to be cut becomes the first numerical value, or the cutting speed of the workpiece by the discharge electrode when the second thickness to be cut becomes the second numerical value.

[0019] The electric discharge machining apparatus capable of adjusting machining parameters according to the present invention further includes a heat source for heating the workpiece in the cutting step.

[0020] According to the electric discharge machining apparatus capable of adjusting machining parameters according to the present invention, the electric discharge electrode cuts the region to be machined of the workpiece in a fluid.

[0021] According to the electric discharge machining apparatus capable of adjusting machining parameters of the present invention, the area to be machined has a filling material therein so as to fill surface cracks formed in the area to be machined by the cutting step.

[0022] According to the electric discharge machining apparatus capable of adjusting machining parameters of the present invention, the filling material is formed in the area to be machined by a heat source so as to fill surface cracks formed in the area to be machined in the cutting procedure.

[0023] The electric discharge machining apparatus capable of adjusting machining parameters according to the present invention further includes an external force disturbance source for filling surface cracks in the region to be machined with a filling material in the cutting step.

[0024] According to the electric discharge machining apparatus capable of adjusting machining parameters of the present invention, the number of the workpieces is one or more.

[0025] According to the electric discharge machining apparatus capable of adjusting machining parameters of the present invention, the number of the discharge electrodes is one or more.

[0026] According to the electric discharge machining apparatus capable of adjusting machining parameters according to the present invention, the electric discharge electrode cuts the region to be machined of the workpiece in a vacuum environment.

[0027] In order to achieve the above object, the present invention provides an electric discharge machining method capable of adjusting machining parameters, characterized in that a cutting procedure is carried out using the electric discharge machining device capable of adjusting machining parameters.

[0028] In order to achieve the above-mentioned object, the present invention provides an electric discharge machining method capable of adjusting machining parameters for performing a cutting procedure, comprising the steps of: preparing at least one workpiece placed on a mounting stage and defining a machining target area; performing a first cutting step of cutting the machining target area of ​​the workpiece by applying discharge energy to the machining target area of ​​the workpiece along a first cutting direction with at least one machining parameter via at least one discharge electrode; performing a first adjustment step of adjusting the machining parameters according to when the first thickness to be cut of the workpiece increases to a first numerical value; and performing a second cutting step of cutting the machining target area of ​​the workpiece by applying the discharge energy to the machining target area of ​​the workpiece via the discharge electrode with the machining parameter adjusted in the first adjustment step.

[0029] According to the electric discharge machining method of the present invention in which the machining parameters can be adjusted, the machining parameter is an orientation parameter, and in the first cutting step, when the first thickness to be cut of the workpiece increases to the first numerical value, the orientation parameter is changed from the first cutting direction to a second cutting direction by performing the first adjustment step, and the second cutting step is performed on the area to be machined of the workpiece along the second cutting direction.

[0030] According to the electric discharge machining method capable of adjusting machining parameters according to the present invention, the second thickness to be cut in the second cutting step of the workpiece is smaller than the first thickness.

[0031] According to the electric discharge machining method of the present invention, in the second cutting step, when the second cutting thickness of the workpiece to be cut by the discharge electrode increases to a second numerical value, a second adjustment step is performed to change the orientation parameter from the second cutting direction to a third cutting direction, and a third cutting step is performed on the processing target area of ​​the workpiece along the third cutting direction.

[0032] According to the electric discharge machining method capable of adjusting machining parameters of the present invention, the third thickness to be cut in the third cutting step of the workpiece is smaller than the first numerical value or the second numerical value.

[0033] According to the electric discharge machining method capable of adjusting machining parameters of the present invention, the first adjusting step adjusts the machining parameters by changing the arrangement direction of the workpiece.

[0034] According to the electric discharge machining method capable of adjusting machining parameters of the present invention, the first adjusting step adjusts the machining parameters by changing the feed direction of the discharge electrode relative to the workpiece.

[0035] According to the electric discharge machining method capable of adjusting machining parameters of the present invention, the first adjusting step adjusts the machining parameters by changing the arrangement direction of the workpiece using the mounting stage.

[0036] The electric discharge machining method capable of adjusting machining parameters according to the present invention further includes a step of filling surface cracks formed in the machining target area in the cutting step by performing a filling step. Effect of the Invention

[0037] As described above, the electric discharge machining apparatus and the electric discharge machining method capable of adjusting machining parameters of the present invention have the following advantages.

[0038] (1) The step-by-step cutting technology can solve the problem that the total cutting time is long due to the large EDM cutting thickness.

[0039] (2) The stepwise cutting technology changes the feed direction immediately when the specified parameters change to the set values.

[0040] (3) With the step-by-step cutting technology, when the thickness to be cut is greater than the set value, the feed direction is immediately changed and the thick surface to be cut is divided into multiple cutting surfaces with smaller thicknesses, thereby solving the problem of slow cutting speed due to large EDM cutting thickness.

[0041] In order to better understand the technical features and achievable technical effects of the present invention, better embodiments and detailed descriptions are provided below. [Brief description of the drawings]

[0042] [Figure 1] FIG. 1 is a step flow chart of an electric discharge machining method capable of adjusting machining parameters according to the present invention. [Diagram 2] FIG. 2 is a schematic diagram of a first embodiment of an electric discharge machining apparatus capable of adjusting machining parameters according to the present invention. [Diagram 3] FIG. 3 is a schematic diagram of a second embodiment of an electric discharge machining apparatus capable of adjusting machining parameters according to the present invention. [Figure 4a] FIG. 4a is a front view of the workpiece when performing the first cutting step of the present invention. [Figure 4b] FIG. 4b is a cross-sectional side view of the workpiece when performing the first cutting step of the present invention. [Figure 5a] FIG. 5a is a front view of the workpiece when performing the second cutting step of the present invention. [Figure 5b] FIG. 5b is a cross-sectional side view of the workpiece when performing the second cutting step of the present invention. [Figure 6a] FIG. 6a is a front view of the workpiece when performing the third cutting step of the present invention. [Figure 6b] FIG. 6b is a cross-sectional side view of the workpiece when performing the third cutting step of the present invention. [Figure 7a] FIG. 7a is a schematic diagram of cutting multiple workpieces with a single discharge electrode according to the present invention. [Figure 7b] FIG. 7b is a schematic diagram of cutting a single workpiece with multiple discharge electrodes according to the present invention. [Figure 7c] FIG. 7c is a schematic diagram of cutting a plurality of workpieces with a plurality of discharge electrodes according to the present invention, and the viewing angle of FIG. 7a is different from that of FIG. 7b and FIG. 7c. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The ratio of each member in the drawings of the embodiment of the present invention is shown for easy understanding of the description, and is not the actual ratio. Furthermore, the dimensional ratio of the assembly shown in the drawings is for explaining each part and its structure, and the present invention is not limited thereto. Meanwhile, for convenience of understanding, the same parts in the following embodiments will be described with the same reference numerals.

[0044] Furthermore, the terms used throughout the specification and claims generally have their ordinary meanings as used in the art, the content disclosed herein, and in the particular context, unless otherwise specified. Some of the terms used to describe the present invention are explained below or elsewhere in this specification to provide those skilled in the art with additional guidance regarding the description of the present invention.

[0045] The use of "first," "second," "third," etc. in this article is not intended to denote a specific order or sequence, nor is it used to limit the invention, but is merely used to distinguish between components or operations that are described with the same terminology.

[0046] Secondly, when terms such as "including," "comprising," "having," and "containing" are used in this article, they are all open terms, meaning including but not limited to.

[0047] The present invention provides a stepwise cutting technique, preferably by adjusting machining parameters when the designated parameters change to corresponding set values ​​(first value, second value, third value, ...), thereby solving the problem of slower cutting speed and longer total cutting time due to changes in the designated parameters during the EDM procedure. The specified parameters are, for example, the thickness to be cut of the workpiece or the cutting speed. Taking as an example the specified parameter being the thickness to be cut of the workpiece, in a first cutting step of an electric discharge machining procedure, when the first thickness to be cut of the workpiece increases to a corresponding set value, such as a first value, the machining parameters are adjusted, and a subsequent second cutting step is performed with the adjusted machining parameters, and so on. Taking the specified parameter as an example being the cutting speed of the workpiece, in a first cutting step of an electric discharge machining procedure, when the first cutting speed of the workpiece drops to a corresponding set value (e.g., a first value), the machining parameters are adjusted, and a subsequent second cutting step is performed with the adjusted machining parameters, and so on.

[0048] Please refer to FIG. 1 and FIG. 2. FIG. 1 is a step flow chart of the electric discharge machining method capable of adjusting machining parameters of the present invention. FIG. 2 is a schematic diagram of a first embodiment of an electric discharge machining apparatus capable of adjusting machining parameters according to the present invention. The present invention provides a stepwise cutting technique, which can solve the problem that the cutting speed is slow and the total cutting time is long due to the large EDM cutting thickness by adjusting the machining parameters when the designated parameters change to the corresponding set values. In a first embodiment of the present invention, the electric discharge machining apparatus 10 of the present invention includes a mounting stage 20 and an electric discharge machining (EDM) unit 50, and is used to perform an electric discharge machining procedure, such as a cutting procedure, on a workpiece 100 to achieve a slicing or thinning effect. The mounting stage 20 is provided with, for example, a jig 22, and the mounting stage 20 may be a movable mounting stage or a fixed mounting stage.

[0049] First, in the electric discharge machining method of the present invention, a workpiece 100 is prepared (step S10), and the workpiece 100 is placed on a mounting stage 20 using a jig 22. A machining area 110 is defined on the workpiece 100, and the machining area 110 may be located at any suitable machining position on the workpiece 100. Workpiece 100 may be any conductive or semiconductive structure, such as a wafer or ingot, although the cross section of workpiece 100 is not limited to being circular and may be any shape.

[0050] The electric discharge machining (EDM) unit 50 of the electric discharge machining apparatus 10 of the present invention has at least a discharge electrode 52, which is, for example, a linear conductive wire, a plate-shaped conductive plate, or a conductive structure having another shape. The electric discharge machining (EDM) unit 50 of the present invention may further optionally have a supply reel 56a and a take-up reel 56b, and both ends of the discharge electrode 52 are respectively connected to the supply reel 56a and the take-up reel 56b, and the supply reel 56a and the take-up reel 56b are optionally fitted to the discharge electrode 52 using pulleys 57a, 57b, respectively, to position the discharge electrode 52 and, for example, adjust the tension of the discharge electrode 52.

[0051] Continuing to refer to FIG. 2, the electric discharge machining (EDM) unit 50 of the present invention further includes a power source 54, which is connected to the discharge electrode 52 via an electrical circuit to generate a voltage difference between the discharge electrode 52 and the workpiece 100, and provides discharge energy to the machining target area 110 of the workpiece 100 to cut the workpiece 100 along the machining target area 110 (step S20).

[0052] The present invention may optionally include a microwave or high frequency source 60 for supplying microwave or high frequency energy to the region 110 to be processed of the workpiece 100 to provide a heating, annealing or polishing effect, which can effectively reduce surface roughness and avoid the need to perform a subsequent mechanical or chemical polishing step. Similarly, the microwave or radio frequency source 60 of the present invention may supply microwave or radio frequency energy to the area 110 to be machined of the workpiece 100 via the discharge electrode 52 . For example, the microwave or high frequency source 60 is a microwave, the wavelength range of the microwave of the present invention is about 1 mm to about 1 m, the frequency range is about 300 GHz to about 0.3 GHz, and the power range is about 200 watts to about 5,000 watts. The material of the discharge electrode 52 may be selected from the group consisting of, for example, copper, brass, molybdenum, tungsten, graphite, steel, aluminum, and zinc. The thickness range of the discharge electrode 52 is less than about 300 μm, and preferably about 30 μm to 300 μm.

[0053] In detail, as shown in Figures 2 and 4a, in step S20, the discharge electrode 52 cuts the machining target area 110 of the workpiece 100 by applying discharge energy to the machining target area 110 of the workpiece 100 along a first cutting direction D1 with at least one machining parameter. For example, assuming that the workpiece 100 is a cylindrical ingot, the processing area 110 is defined in the radial direction of the ingot, for example, as shown by the dotted lines in Figures 4b and 5b, where the dotted lines represent the uncut processing area 110 and the solid lines represent the cut processing area 110. The thickness to which the ingot is to be cut is not a fixed value but varies; for example, when the discharge electrode 52 cuts the ingot in parallel from top to bottom, the thickness to be cut at the top of the ingot is the minimum value, and the maximum thickness to be cut of the ingot is its diameter length. Furthermore, typically, when the thickness of the ingot to be cut exceeds a certain value, the cutting speed of the ingot decreases non-linearly with the increase in the thickness to be cut. Therefore, the specified parameters in the stepwise cutting technique provided by the present invention are exemplified by the thickness to be cut, i.e., the processing parameters are adjusted according to the thickness of the workpiece 100 to be cut. For example, when the overlap length between the discharge electrode 52 and the workpiece 100 (i.e., the thickness of the workpiece 100 to be cut) reaches a set value, the processing parameters can be changed, for example, by changing the feed direction relative to the workpiece 100, so that the thickness of the workpiece 100 to be subsequently cut is made smaller than this set value, thereby achieving the effect of optimizing the total cutting time of the entire workpiece. For example, the present invention can adjust the processing parameters according to the first cutting thickness T1 in the first cutting step S20 of the workpiece 100 (step S30), that is, it is determined whether the first cutting thickness T1 in the first cutting step S20 of the workpiece 100 becomes the set numerical value (first numerical value), and if the answer is "yes," the processing parameters can be adjusted, and then the second cutting step S40 is performed on the processing target area 110 of the workpiece 100 using the adjusted processing parameters.

[0054] For example, assuming that the processing parameter is an orientation parameter (i.e., a processing direction relative to the workpiece), in the first cutting step S20, the discharge electrode 52 cuts the workpiece 100 along a first cutting direction D1 by applying discharge energy to the processing target area 110 of the workpiece 100 with at least one processing parameter. However, when the first cutting thickness T1 of the workpiece 100 increases to a set value (first value), the present invention changes the above orientation parameter from the first cutting direction D1 to the second cutting direction D2 by performing a first adjustment step S30. Then, a second cutting step S40 is performed. There is a first included angle, such as 180 degrees, between the second cutting direction D2 and the first cutting direction D1. However, the present invention is not limited to this, and the first included angle is, for example, in the range between 0 degrees and 360 degrees.

[0055] Similarly, in the second cutting step S40, the discharge electrode 52 cuts the workpiece 100 in a second cutting direction D2. In the second cutting step S40, when the second cutting thickness T2 of the workpiece 100 to be cut by the discharge electrode 52 increases to a second numerical value, the electric discharge machining (EDM) unit 50 changes the orientation parameter from the second cutting direction D2 to a third cutting direction D3 by readjusting (S50) the orientation parameter, and performs a third cutting step S60 on the processing target area 110 of the workpiece 100 along the third cutting direction D3, and in the third cutting step S60, the third cutting thickness T3 of the workpiece 100 in the third cutting direction D3 has a third numerical value. The second number may be, for example, less than, greater than, or equal to the first number. The third numerical value may be, for example, less than, greater than, or equal to the first numerical value or the second numerical value. In one embodiment of the present invention, the second number is equal to the first number and the third number is less than the first number (the second number). There is a second included angle between the third cutting direction D3 and the second cutting direction D2, and the second included angle is between 0 degrees and 360 degrees, for example, 90 degrees, but the present invention is not limited thereto, and the second included angle is, for example, in the range between 0 degrees and 360 degrees. However, in another embodiment of the present invention, taking two-stage cutting as an example, when the second numerical value is equal to the first numerical value and the second to-be-cut thickness T2 in the second cutting step S40 of the workpiece 100 cut by the discharge electrode 52 has not all increased to the second numerical value (first numerical value), the present invention can cut the workpiece 100 in the second cutting direction D2 until the cutting is completed. In the two-stage cutting, since the second thicknesses T2 to be cut of the present invention are all smaller than the diameter of the ingot, the cutting speed of the workpiece 100 of the present invention is still faster than the conventional non-stage cutting technique, and the total cutting time required is shorter.

[0056] Taking the workpiece 100 as an example, a feature of the present invention is that the numerical values ​​of the specified parameters (such as the first cutting thickness T1, the second cutting thickness T2, and the third cutting thickness T3) are all smaller than the diameter of the ingot, thereby solving the problem of slow cutting speed due to the large cutting thickness in conventional electric discharge machining technology. Furthermore, taking the three-stage cutting listed above as an example, the third numerical value of the third cutting thickness T3 of the present invention is smaller than the first numerical value of the first cutting thickness T1 (i.e., the second numerical value of the second cutting thickness T2), and of course is smaller than the diameter of the ingot, so that when the ingot is completely cut along the third cutting direction D3 (from left to right), the cutting speed of the workpiece 100 of the present invention is faster than that of the conventional non-stage cutting technology, and the total cutting time required is shorter.

[0057] The set values ​​mentioned above may be calculated, for example. For example, the user first measures the size of the workpiece to obtain values ​​that satisfy the condition that the first value of the first thickness to be cut T1 is greater than the third value of the third thickness to be cut T3, and then manually inputs these values ​​into the electric discharge machining (EDM) unit 50, so that the electric discharge machining (EDM) unit 50 adjusts the machining parameters for different thicknesses to be cut, and the setting of the set values ​​can find an optimal solution according to the relationship between the thickness to be cut and the cutting speed. Alternatively, the numerical values ​​of the first cutting thickness T1, the second cutting thickness T2, and the third cutting thickness T3 may be learned, for example, by a learning algorithm. For example, a database is created according to multiple actual cutting data, and the processing parameters optimized by the learning algorithm are provided, so that the processing parameters for different thicknesses can be automatically adjusted. Alternatively, the present invention may not take into account the numerical relationship between the first cutting thickness T1, the second cutting thickness T2 and the third cutting thickness T3, but the user may directly specify, for example, a first numerical value of the first cutting thickness T1 and / or a second numerical value of the second cutting thickness T2, and the first numerical value and / or the second numerical value may be any numerical value greater than 0 and less than the diameter of the ingot. For example, if the radial cross section of the workpiece 100 is a perfect circle, the set value (first value) may be between the side length of the square within the circle and the diameter of the circle. However, in other embodiments, the set value (first value) may be, for example, equal to or less than the side length of the square within the circle. That is, as long as the second thickness to be cut T2 or the third thickness to be cut T3 is smaller than the diameter of the ingot, it contributes to improving the overall cutting speed. For example, in another embodiment, when the discharge electrode 52 partially cuts the processing target area 110 of the workpiece 100 along a first cutting direction D1 in the first cutting step S20, the present invention can, for example, change the processing direction for the workpiece 100 from the first cutting direction D1 to a second cutting direction D2 and perform a second cutting step S40 along the second cutting direction D2. Similarly, when the discharge electrode 52 partially cuts the processing target area 110 of the workpiece 100 along the second cutting direction D2 in the second cutting step S40, the present invention can, for example, change the processing direction for the workpiece 100 from the second cutting direction D2 to a third cutting direction D3, and perform a third cutting step S60 along the third cutting direction D3, and so on. Furthermore, although the stepwise cutting technique of the present invention is exemplified by three-step cutting, the present invention is not limited to the above-listed three-step cutting, the present invention may also perform two-step cutting, four-step cutting or even multi-step cutting, all of which are applicable to the present invention as long as the overall cutting speed is faster than the conventional non-stepwise cutting technique.

[0058] Next, taking the processing parameter as an example, namely, the processing direction relative to the workpiece, the present invention can achieve the effect of changing the feed direction, for example, by adjusting the placement direction of the workpiece 100. As an example of automatically changing the placement direction of the workpiece 100, as shown in FIG. 2, the mounting stage 20 of the present invention may be, for example, a movable mounting stage equipped with a multi-axis (two-axis, three-axis or more) motor, thereby changing the machining direction relative to the discharge electrode 52 of the jig 22 so that the discharge electrode 52 cuts the workpiece 100 from the first cutting direction D1, the second cutting direction D2, the third cutting direction D3 or another direction. Alternatively, as shown in FIG. 2, the electric discharge machining (EDM) unit 50 of the present invention, such as the supply reel 56a and the take-up reel 56b, may be equipped with, for example, a multi-axis (two-axis, three-axis or more, etc.) motor, and by adjusting the feed direction of the electric discharge machining (EDM) unit 50 to change the machining direction of the discharge electrode 52 relative to the workpiece 100, the discharge electrode 52 can cut the workpiece 100 from the first cutting direction D1, the second cutting direction D2, the third cutting direction D3, or another direction. As an example of manually changing the placement direction of the workpiece 100, a user can manually change the placement direction of the workpiece 100 on the mounting stage 20, for example, so that the discharge electrode 52 cuts the workpiece 100 from the first cutting direction D1, the second cutting direction D2, the third cutting direction D3 or another direction.

[0059] Additionally, the processing parameters of the present invention are exemplified by orientation parameters, but are not intended to limit the present invention. The processing parameters may be, for example, one or more of an orientation parameter, a discharge electrical parameter, a residue evacuation parameter, and a movement and tension parameter. In detail, the orientation parameter is, for example, a machining direction relative to the workpiece, the discharge electrical parameters include one or more of the peak current (the maximum current flowing between the two poles of the discharge electrode during discharge), the voltage when the workpiece leaves the discharge electrode, the discharge pulse duration, the discharge pulse rest time, and the servo reference voltage between the discharge electrode and the workpiece, the residue drainage parameters include a flow rate of a residue drainage solution provided to the discharge electrode, the residue drainage solution being, for example, water, preferably deionized water, and the residue drainage solution being provided, for example, between both end points of the discharge electrode, and the movement and tension parameters include one or more of the movement speed of the discharge electrode and the tension of the discharge electrode. The inter-electrode voltage (the voltage between the discharge electrode and the work electrode) is in the range of about 0 to about 300 V, the discharge pulse duration is in the range of about 5 μs to about 2400 μs, and the discharge pulse rest time is in the range of about 5 μs to about 2400 μs. In other words, the present invention is not limited to adjusting one or more of the processing parameters, which may include, for example, various electric discharge processing parameters. Furthermore, the present invention may preferably adjust the processing parameters according to different thicknesses to be cut.

[0060] Also, as shown in Figures 3 and 4b, there is a gap between the surface of the discharge electrode 52 and the surface of the workpiece 100 in the traveling direction (cutting surface 100a) and the surface in the non-traveling direction (cutting surfaces 100b, 100c), and this gap is filled with an insulating material such as air, deionized water or oil as a dielectric material or other suitable insulating substance. For example, if the EDM step is carried out in deionized water, the deionized water will fill the gap. Similarly, if the EDM step is carried out in an atmospheric environment, air will fill the gap. Also, as shown in FIG. 3, in the second embodiment of the present invention, when the EDM step is performed in the liquid tank 59a, the liquid 59b fills the above-mentioned gap, and the liquid 59b in the liquid tank 59a is a heatable liquid, such as oil, which can reduce thermal shock or improve thermal uniformity. In addition, during the EDM procedure, the present invention can reduce the run-out of the workpiece 100 by the liquid pressure, and reduce the surface roughness of the cutting surfaces 100b, 100c, thereby contributing to improving the EDM quality. As described above, as shown in FIG. 4a, the present invention will be described by way of example with one discharge electrode 52 (single conductive structure) cutting one workpiece (i.e., a single solid structure), but the present invention is not limited thereto. As shown in FIG. 7a, the discharge electrode 52 of the present invention may, for example, perform an electric discharge machining procedure on multiple workpieces 100 (i.e., multiple solid structures) simultaneously, i.e., the discharge electrode 52 can cut multiple workpieces 100 simultaneously. Similarly, the present invention may perform cutting procedures simultaneously on one workpiece 100 (as shown in FIG. 7b) or multiple workpieces (as shown in FIG. 7c) with multiple separated discharge electrodes 52 (multiple conductive structures). Furthermore, the electrical discharge machining procedure of the present invention is not limited to being performed in a fluid, such as a liquid or gas, as described above, but may also be performed in a vacuum environment. In other words, the electric discharge machining procedure of the present invention can wet cut the workpiece 100 with the electric discharge electrode 52 (i.e., performed in a liquid tank 59a) as well as dry cut the workpiece 100 with the electric discharge electrode 52 (i.e., performed in an air or vacuum environment). In the present invention, the temperature of the discharge electrode 52 may be selectively lowered during dry cutting of the workpiece 100 by the discharge electrode 52. For example, the temperature of the discharge electrode 52 may be lowered or maintained at the temperature by using a temperature-lowering fluid such as liquid or gas, or the temperature of the discharge electrode 52 may be raised by discharge energy without using a temperature-lowering fluid such as liquid or gas.

[0061] In addition, the present invention may further selectively perform a filling step, for example by providing ultrasonic waves using an external force disturbance source such as an ultrasonic unit 95 to fill the surface cracks on the cut surfaces 100b, 100c of the processing area 110 with filling material, thereby avoiding the continuous expansion of these excess surface cracks, and not only strengthening the structure but also achieving the effect of performing the cutting steps S20, S40 or S60 at high speed (even accelerated). The composition of the filling material may be, for example, but is not limited to, materials such as Si, SiC, SiGe, Ge, GaAs, GaN, or InP, and any material suitable for filling cracks, such as a filler or adhesive, is applicable to the present invention. The frequency range of the ultrasonic waves is, for example, from about 15 KHz to about 30 KHz, but is not limited to this. This filling step is preferably carried out in a fluid, for example a liquid 59b such as oil or water or a conductive medium such as air, and the ultrasound generates fluid droplets and impact pressure waves in the fluid such that the material particles of the filling material are embedded into surface cracks in the cut or thinned surface of the area to be machined 110. In addition, the present invention is not limited to a specific structure of the ultrasonic unit 95, and the direction in which the ultrasonic unit 95 provides ultrasonic waves is not particularly limited; any direction may be used, and as long as the filling effect can be achieved, it is applicable to the present invention. The present invention may utilize a heat source 70 to heat the workpiece during the cutting procedure. Heat source 70 may be, for example, the liquid tank 59a, a microwave or radio frequency source 60, or a laser source, and / or an infrared light source. The present invention also provides that the thermal energy provided by the heat source 70 can oxidize or cause other chemical reactions on the surface of the separated or cut solid structure (such as the first half structure 100a) or its modified layer 120 to form a filler material such as silicon oxide or oxide, which can further fill surface cracks and prevent the propagation of the surface cracks.

[0062] As described above, the electric discharge machining apparatus and the electric discharge machining method capable of adjusting machining parameters of the present invention have the following advantages.

[0063] (1) The step-by-step cutting technology can solve the problem that the total cutting time is long due to the large EDM cutting thickness.

[0064] (2) The stepwise cutting technology changes the feed direction immediately when the specified parameters change to the set values.

[0065] (3) With the step-by-step cutting technology, when the thickness to be cut is greater than the set value, the feed direction is immediately changed and the thick surface to be cut is divided into multiple cutting surfaces with smaller thicknesses, thereby solving the problem of slow cutting speed due to large EDM cutting thickness.

[0066] The above description is given by way of example only and is not limiting. Any equivalent modifications or variations thereto that do not depart from the spirit and scope of the present invention are intended to be encompassed within the scope of the appended claims. [Explanation of symbols]

[0067] 10: Electrical discharge machining equipment 20: Mounting stage 22: Jig 50: Electrical discharge machining (EDM) unit 52:Discharge electrode 54: Power source 56a: Supply reel 56b: Winding reel 57a, 57b: Pulley 59a: Liquid tank 59b:Liquid 60: Microwave or radio frequency source 70:Heat source 95: Ultrasonic unit 100: Workpiece 100a, 100b, 100c: Cut surface 110: Processing area S10, S20, S30, S40, S50, S60: Step D1: First cutting direction D2: Second cutting direction D3: The third cutting direction T1: First cutting thickness T2: Second cutting thickness T3: The third cutting thickness

Claims

1. 1. An electric discharge machining apparatus capable of adjusting machining parameters for performing a cutting procedure, comprising: a mounting stage for mounting at least one workpiece having a region to be processed defined thereon; an electric discharge machining (EDM) unit for cutting the workpiece region to be machined along a first cutting direction with at least one machining parameter using at least one electric discharge electrode in a first cutting step of the cutting procedure, the machining parameter being adjusted in response to a change in a specified parameter of the workpiece to a first value, thereby performing a second cutting step on the workpiece region to be machined using the adjusted machining parameter; a filler material is provided in the processing area to fill surface cracks formed in the processing area by the cutting step; the specified parameters include a thickness of the workpiece to be cut; the processing parameters are adjusted in response to a time when the first thickness to be cut of the workpiece is increased to the first value, thereby performing the second cutting step on the processing target area of ​​the workpiece using the adjusted processing parameters; The electric discharge machining apparatus capable of adjusting machining parameters, characterized in that the machining parameter is an orientation parameter, and when the first thickness to be cut of the workpiece increases to the first numerical value, the electric discharge machining (EDM) unit performs the second cutting step on the area to be machined of the workpiece along the second cutting direction by changing the orientation parameter from the first cutting direction to a second cutting direction.

2. The electric discharge machining apparatus capable of adjusting machining parameters according to claim 1 , wherein the filling material is formed in the area to be machined by a heat source so as to fill surface cracks formed in the area to be machined in the cutting step.

3. The electric discharge machining apparatus capable of adjusting machining parameters according to claim 1 , further comprising an external force disturbance source that causes surface cracks in the area to be machined to be filled with the filler material in the cutting step.

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