Electrical discharge machining device

Abstract

This invention discloses an electrical discharge machining (EDM) apparatus, comprising a stage and an EDM unit. The stage is equipped with a fixture, which includes a support plate for supporting a workpiece, the workpiece having a defined processing target area. The EDM unit applies discharge energy to the processing target area of ​​the workpiece via a discharge electrode with a non-uniform electric field distribution, thereby concentrating the electric field in the direction of travel. Furthermore, the support plate has an adhesive layer to adhere the workpiece, preventing vibration during the EDM process and avoiding burrs before the EDM process ends. Additionally, positioning the processing target area, for example, above the support plate, prevents the fixture from obstructing the EDM process.

Description

Technical Field

[0001] This invention relates to a processing apparatus, and more particularly to an electrical discharge machining apparatus. Background Technology

[0002] With the booming development of the semiconductor industry, electrical discharge machining (EDM) technology is commonly used to process ingots or wafers. EDM is a manufacturing process that uses electrical discharge to generate sparks, shaping the workpiece into a desired form. Two electrodes are separated by a dielectric material and a voltage is applied, generating a periodically changing, rapidly varying current discharge to process the workpiece. EDM uses two electrodes: one called the tool electrode or discharge electrode, and the other called the workpiece electrode, which is connected to the workpiece. During EDM, there is no actual contact between the discharge electrode and the workpiece electrode.

[0003] When the potential difference between two electrodes increases, the electric field between them also increases until the electric field strength exceeds the dielectric strength. At this point, dielectric collapse occurs, current flows through the electrodes, and some material is removed. When the current stops, new dielectric material flows into the electric field between the electrodes, removing the previously removed material and restoring the dielectric insulating effect. After the current flows again, the potential difference between the two electrodes returns to its state before dielectric collapse, thus allowing for a new cycle of dielectric collapse.

[0004] However, the drawbacks of electrical discharge machining (EDM) technology include poor surface roughness and numerous surface cracks on the cut surface, which can even extend along non-cutting directions, leading to unexpected cracking. Furthermore, existing EDM techniques, such as ingot cutting, use a fixture to hold the ingot's periphery, i.e., radially clamping the ingot's sides, to prevent rolling or displacement. However, since the cutting surface of the ingot is also radial, conventional techniques can only cut the ingot exposed outside the fixture, failing to cut the area where the fixture and ingot overlap. Therefore, conventional techniques require stopping the machine and readjusting the position before cutting can resume. However, regardless of the position adjustment, there will always be some overlap between the fixture and the ingot, preventing EDM from being performed. Summary of the Invention

[0005] In view of this, one or more objectives of the present invention are to provide an electrical discharge machining apparatus to solve the problems of the prior art.

[0006] To achieve the aforementioned objectives, the present invention provides an electrical discharge machining (EDM) apparatus, comprising a stage having a fixture, the fixture including a support plate for supporting at least one workpiece, wherein the workpiece defines a processing target area; and an EDM unit that applies discharge energy to the processing target area of ​​the workpiece via at least one discharge electrode in a non-uniform electric field distribution, thereby processing the workpiece along the processing target area.

[0007] The discharge electrode is covered with an electrical shielding structure on both sides, so that the discharge energy forms the non-uniform electric field distribution.

[0008] The discharge electrode has a recessed region, which allows the discharge energy to form the non-uniform electric field distribution.

[0009] The discharge electrode has a cross-sectional shape that is T-shaped, L-shaped, or elliptical, so that the discharge energy forms a non-uniform electric field distribution.

[0010] The discharge electrode has a circular cross-sectional shape, which allows the discharge energy to form a non-uniform electric field distribution.

[0011] The discharge electrode is either linear or plate-shaped.

[0012] The electrical shielding structure is a supporting structure.

[0013] The discharge electrode or the support structure has a guide bump, which corresponds to a guide groove of a pulley in the electrical discharge machining (EDM) unit, thereby guiding the guide bump using the guide groove.

[0014] The discharge electrode is a magnetic component. When the discharge electrode processes the workpiece along the processing target area, the electrical discharge machining (EDM) unit acts on the magnetic component in a non-contact manner with a magnetic attraction force to fix one orientation of the discharge electrode.

[0015] The discharge electrode system includes a first conductive line and a second conductive line, wherein the thickness of the first conductive line and / or the applied voltage are different from those of the second conductive line.

[0016] It also includes a microwave or radio frequency source for supplying microwave or radio frequency energy to the processing target area of ​​the workpiece via the discharge electrode of the electrical discharge processing (EDM) unit.

[0017] To achieve the aforementioned objectives, the present invention provides an electrical discharge machining (EDM) apparatus, comprising: a stage, the stage having a fixture, the fixture including a support plate for supporting at least one workpiece, wherein the workpiece defines a processing target area, and the processing target area of ​​the workpiece is located above the support plate; and an EDM unit for applying a discharge energy to the processing target area of ​​the workpiece via at least one discharge electrode, thereby processing the workpiece along the processing target area.

[0018] The fixture further includes two side plates located at both ends of the support plate, which are respectively positioned on both sides of the workpiece to be processed.

[0019] The fixture has an adhesive layer on the support plate, and the periphery of the workpiece is partially adhered to the adhesive layer of the fixture.

[0020] The adhesive layer is a conductive adhesive layer.

[0021] The adhesive layer is discontinuously applied to the support plate.

[0022] The adhesive layer extends upward from the support plate to at least one side of the workpiece.

[0023] The adhesive layer is incorporated into the workpiece.

[0024] The fixture has a conductive plate disposed on the support plate, and the adhesive layer is disposed on the conductive plate.

[0025] The conductive plate is a conductive metal structure with a work function of less than 4.5 eV.

[0026] The discharge electrode applies the discharge energy to the processing target area of ​​the workpiece with a non-uniform electric field distribution.

[0027] The stage adjusts the tilt of the fixture relative to the discharge electrode, or the electrical discharge machining (EDM) unit adjusts the tilt of the discharge electrode relative to the workpiece, thereby adjusting the angle between the processing target area of ​​the workpiece and the support plate of the fixture.

[0028] The workpiece and / or the fixture further have a conductive gain layer to improve the electrical contact between the workpiece and the fixture.

[0029] It also includes a heat source for heating the workpiece on the support plate, thereby improving the electrical contact between the workpiece and the fixture.

[0030] The discharge electrode is used to cut the target area of ​​the workpiece in a fluid.

[0031] The discharge electrode is used to cut the target area of ​​the workpiece in a vacuum environment.

[0032] The number of discharge electrodes is one or multiple.

[0033] The quantity of the work to be processed is one or more.

[0034] In summary, the electrical discharge machining apparatus of the present invention has the following advantages:

[0035] (1) By designing a non-uniform electric field distribution, the electric field can be concentrated in the direction of travel.

[0036] (2) By designing a non-uniform electric field distribution, the electric field distribution in the non-traveling direction can be reduced, thus reducing the surface roughness and surface cracks of the workpiece in the non-traveling direction.

[0037] (3) By setting an adhesive layer in the fixture, the shaking phenomenon of the workpiece during the electrical discharge machining process can be avoided, and the burr phenomenon before the end of the electrical discharge machining process can also be avoided.

[0038] (4) By setting an adhesive layer on the fixture, the fixture can be prevented from interfering with the workpiece in the electrical discharge machining process, thus making the electrical discharge machining process more flexible.

[0039] (5) Since the discharge electrode has multiple conductive lines, the cutting and polishing steps can be performed simultaneously, thus speeding up the overall processing procedure and obtaining a surface with low roughness.

[0040] (6) By means of the conductive gain layer of the workpiece and / or fixture, the electrical contact between the workpiece and the fixture can be improved, thereby improving the efficiency of the electrical discharge machining process.

[0041] To enable you to have a better understanding of the technical features and effects of this invention, preferred embodiments and detailed descriptions are provided below. Attached Figure Description

[0042] Figure 1 This diagram illustrates the structure of the electrical discharge machining apparatus of the present invention and is a schematic diagram obtained from the front of the fixture.

[0043] Figure 2 This is a partial schematic diagram of the structure of the electrical discharge machining apparatus of the present invention, obtained from the side of the fixture.

[0044] Figure 3 This is a partially enlarged schematic diagram of the electrical discharge machining apparatus of the present invention performing an electrical discharge machining process, wherein the discharge electrode is a single conductive line.

[0045] Figure 4This is a schematic diagram showing the structure of the electrical discharge machining apparatus of the present invention and a procedure for electrical discharge machining performed in a heated liquid tank.

[0046] Figure 5 This is a partially enlarged schematic diagram of the electrical discharge machining apparatus of the present invention performing an electrical discharge machining process, wherein the discharge electrodes are multiple conductive lines.

[0047] Figures 6a to 6g This is a schematic diagram of a discharge electrode capable of generating a non-uniform electric field distribution and its electrical shielding structure in the electrical discharge machining apparatus of the present invention.

[0048] Figures 7a to 7b This is a schematic diagram of the discharge electrode and its electrical shielding structure of the electrical discharge machining apparatus of the present invention, which have guide protrusions corresponding to the guide grooves of the pulley.

[0049] Figures 8a to 8c This is an exploded view of the workpiece, fixture, and stage of the electrical discharge machining apparatus of the present invention.

[0050] Figure 9 This is a schematic diagram showing the adhesive layer of the fixture in the electrical discharge machining apparatus of the present invention extending to the side of the workpiece.

[0051] Figure 10 This is a schematic diagram showing the adhesive layer of the fixture in the electrical discharge machining apparatus of the present invention penetrating into the workpiece.

[0052] Figure 11 This is a schematic diagram of the electrical discharge machining apparatus of the present invention, in which the orientation of the discharge electrode is fixed by a positioning unit during the electrical discharge machining process.

[0053] Figures 12a to 12b This is a schematic diagram of the off-axis electrical discharge machining process performed by the electrical discharge machining apparatus of the present invention.

[0054] Figure 13 This is a schematic diagram of the conductive gain layer in this invention.

[0055] Figure 14 This is a schematic diagram of the conductive plate being a conductive gain layer in this invention.

[0056] Figure 15a This is a schematic diagram illustrating the present invention of cutting multiple workpieces using a single discharge electrode. Figure 15b This is a schematic diagram illustrating the present invention of cutting a single workpiece using multiple discharge electrodes. Figure 15c This is a schematic diagram illustrating the present invention of cutting multiple workpieces using multiple discharge electrodes, wherein... Figure 15a The perspective is different Figure 15b and Figure 15c .

[0057] Explanation of reference numerals in the attached figures:

[0058] 10: Electrical Discharge Machining Equipment

[0059] 20: Platform

[0060] 22: Jig

[0061] 24: Support plate

[0062] 26: Side panel

[0063] 50: Electrical Discharge Machining (EDM) Unit

[0064] 52: Discharge electrode

[0065] 52a: Depression area

[0066] 52b: Electrical shielding structure

[0067] 53a, 53b: Guide bumps

[0068] 54: Power source

[0069] 59a: Heated liquid tank

[0070] 59b: Heating liquids

[0071] 55a: First conductive line

[0072] 55b: Second conductive wire

[0073] 56a: Cable feeder and reel

[0074] 56b: Cable reel

[0075] 57a, 57b: Pulleys

[0076] 58a, 58b: Guide grooves

[0077] 60: Microwave or radio frequency source

[0078] 62: Positioning Unit

[0079] 70: Adhesive layer

[0080] 72: Conductive plate

[0081] 100: Work to be processed

[0082] 100a: Cut surface

[0083] 100b: Cut surface

[0084] 100c: Cut surface

[0085] 110: Processing target area

[0086] 80, 82, 84, 86: Conductive gain layer

[0087] 90: Heat source Detailed Implementation

[0088] To facilitate understanding of the technical features, content, advantages, and effects of this invention, the invention is described in detail below with reference to accompanying drawings and embodiments. The drawings used are for illustrative purposes only and do not necessarily represent the actual scale and precise configuration of the invention in practice. Therefore, the scale and configuration of the accompanying drawings should not be used to interpret or limit the scope of the invention in actual implementation. Furthermore, for ease of understanding, the same components in the following embodiments are indicated by the same symbols.

[0089] Furthermore, unless otherwise specified, the terms used throughout this specification and claims generally have their ordinary meaning in the context of this art, the disclosure herein, and the specific content. Certain terms used to describe the invention will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the invention.

[0090] The use of terms such as "first," "second," and "third" in this document does not specifically refer to any order or sequence, nor is it intended to limit the invention. Rather, it is merely used to distinguish components or operations described using the same technical terms.

[0091] Secondly, when this article uses terms such as "contains", "includes", "has", or "contains", these are all open-ended terms, meaning that they include but are not limited to.

[0092] Please see Figure 1 and Figure 2 , Figure 1 This diagram illustrates the structure of the electrical discharge machining apparatus of the present invention and is a schematic diagram obtained from the front of the fixture. Figure 2 This is a partial schematic diagram of the electrical discharge machining (EDM) apparatus of the present invention, taken from the side of the fixture. The EDM apparatus 10 of the present invention includes a stage 20 and an EDM unit 50 for performing electrical discharge machining (EDM) processes on a workpiece 100, such as cutting and / or electric discharge grinding (EDG). The stage 20 is equipped with a fixture 22, and the stage 20 can be a movable stage or a fixed stage. The fixture 22 includes at least a support plate 24 for placing the workpiece 100, wherein the workpiece 100 has a defined processing target area 110, and this processing target area 110 can be located at any suitable processing position within the workpiece 100. The workpiece 100 can be any conductor or semiconductor structure, such as a wafer or ingot, but the cross-section of the workpiece 100 is not limited to a circle and can be of any shape.

[0093] The electrical discharge machining (EDM) unit 50 has a discharge electrode 52, which may be, for example, a linear conductive wire, a plate-shaped conductive plate, or other conductive structure. Taking the workpiece 100 as an example of a cylindrical ingot, the processing target area 110 is defined, for example, on the radial side of the ingot. Figure 2 The dotted line indicates the location. However, the location of the processing target area 110 described above is merely an example and is not intended to limit the invention. Figure 3 As shown, a gap exists between the surface of the discharge electrode 52 and the workpiece 100 on both the surface in the traveling direction (cutting surface 100a) and the surface in the non-traveling direction (cutting surfaces 100b, 100c). This gap is filled with an insulating material such as air, deionized water, or oil, or other suitable insulating substances, to serve as a dielectric material. For example, if the discharge processing step is performed in deionized water, the deionized water will fill the aforementioned gap. Similarly, if the discharge processing step is performed in an atmospheric environment, air will fill the aforementioned gap. Furthermore, as... Figure 4 As shown, if the electrical discharge machining (EDM) step is performed in the heating liquid tank 59a, the heating liquid 59b will fill the aforementioned gap. Furthermore, the heating liquid 59b in the heating liquid tank 59a, such as hot oil, can reduce thermal shock or increase thermal uniformity. In addition, during the EDM process, the present invention uses liquid pressure to reduce vibration in the workpiece 100, reducing the surface roughness of the cut surfaces 100b and 100c, thus helping to improve the quality of the EDM. As described above, the present invention is illustrated by using a single discharge electrode 52 (a single conductive structure) to cut a workpiece 100 (i.e., a single solid structure). Figure 2 As shown, however, the present invention is not limited thereto. The discharge electrode 52 of the present invention can also, for example, simultaneously perform discharge processing on multiple workpieces 100 (i.e., multiple solid structures), such as... Figure 15a As shown, the discharge electrode 52 can simultaneously cut multiple workpieces 100. Similarly, the present invention can also use multiple separate discharge electrodes 52 (multiple conductive structures) to simultaneously process a single workpiece 100 (such as...). Figure 15b (as shown) or multiple items to be processed (such as...) Figure 15cThe cutting process is performed as shown. Furthermore, the electrical discharge machining process of the present invention is not limited to being performed in the aforementioned liquid or gaseous fluids; it can also be performed in a vacuum environment. In other words, the electrical discharge machining process of the present invention can perform wet cutting of the workpiece 100 by the discharge electrode 52 (i.e., in a liquid tank or heated liquid tank 59a) and dry cutting of the workpiece 100 by the discharge electrode 52 (i.e., in air or a vacuum environment). During the dry cutting of the workpiece 100 by the discharge electrode 52, the present invention can selectively cool the discharge electrode 52. For example, a cooling fluid such as a liquid or gas can be used to cool or maintain the temperature of the discharge electrode 52, or the discharge electrode 52 can be heated by the discharge energy, i.e., without using a cooling fluid such as a liquid or gas.

[0094] Please continue reading. Figures 1 to 3 As shown, the electrical 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. When the value of this voltage difference is greater than the insulation strength provided by the aforementioned gap, discharge energy is generated and provided to the processing target area 110 of the workpiece 100, thereby processing the workpiece 100 along the processing target area 110. Furthermore, taking a linear conductive wire as an example, the discharge electrode 52 of the present invention can be a single conductive wire (e.g., a linear conductive wire). Figure 3 (This can be either a series of conductive lines or multiple conductive lines. Taking two conductive lines as an example, such as...) Figure 5As shown, the thickness (diameter) and / or applied voltage of the first conductive wire 55a may be the same as or different from that of the second conductive wire 55b. For example, the thickness of the second conductive wire 55b is substantially greater than the thickness of the first conductive wire 55a, thereby allowing the first conductive wire 55a to be used to cut the cutting surface 100a of the workpiece 100 located in the travel direction (front side), while the second conductive wire 55b can be used to polish the cutting surfaces 100b and 100c of the workpiece 100 located in a direction other than the travel direction. The thickness of the first conductive wire 55a and the second conductive wire 55b and / or the applied voltage can be determined according to the desired surface roughness, and therefore no further examples are given. The present invention may also optionally include a microwave or radio frequency source 60 for supplying microwave or radio frequency energy to the processing target area 110 of the workpiece 100 via, for example, a first conductive line 55a and / or a second conductive line 55b, thereby providing heating, annealing, or polishing effects, effectively reducing surface roughness and avoiding the need for subsequent mechanical or chemical polishing steps. Similarly, if the discharge electrode 52 of the present invention is only a single conductive line, the microwave or radio frequency source 60 of the present invention can also supply microwave or radio frequency energy to the processing target area 110 of the workpiece 100 via this single conductive line. Taking microwave or radio frequency source 60 as an example, the wavelength range of the microwave of the present invention is from about 1 mm to about 1 m, the frequency range is from about 300 GHz to about 0.3 GHz, and the power range is, for example, from about 200 watts to about 5,000 watts. The material of the discharge electrode 52 can be selected from, for example, a group consisting of copper, brass, molybdenum, tungsten, graphite, steel, aluminum, and zinc. The thickness of the discharge electrode 52 is approximately less than 300 μm, preferably ranging from approximately 30 μm to approximately 300 μm.

[0095] In one embodiment, the discharge energy provided by the discharge electrode 52 of the present invention preferably has a non-uniform electric field distribution, and the electric field of the discharge energy provided by the discharge electrode 52 is preferably concentrated in the travel direction of the discharge electrode 52. That is, the electric field distribution in the travel direction (cutting direction) of the discharge electrode 52 is larger, while the electric field distribution in the lateral direction perpendicular to its travel direction is smaller. In other words, the discharge energy provided by the discharge electrode 52 is preferably concentrated on the workpiece 100 in the travel direction (front side), while the discharge energy applied to the workpiece 100 in the non-travel direction (both sides) is reduced. Therefore, the surface roughness of the cut surfaces 100b and 100c of the workpiece 100 in the non-travel direction can be reduced, for example, the Ra and Rz values ​​can be reduced, as well as the surface cracks of the cut surfaces 100b and 100c.

[0096] In order to provide discharge energy with a non-uniform electric field distribution via discharge electrode 52, such as Figures 6a to 6gAs shown, the discharge electrode 52 of the present invention may have a recessed region 52a around it (e.g., on the left and right sides or one side) or an electrical shielding structure 52b around it (e.g., on the left and right sides or one side), which is, for example, an insulating material or other suitable material. Both the recessed region 52a and the electrical shielding structure 52b can reduce the outward spread of the electric field of the discharge electrode 52, thus reducing the surface roughness of the cut surfaces 100b and 100c of the workpiece 100. For example, the cross-sectional shape of the discharge electrode 52 may be, for example, a T-shape with a recessed region 52a (e.g., ...). Figure 6a Alternatively, the discharge electrode 52 may be surrounded by an electrical shielding structure 52b (e.g., on the left and right sides or one side), and the cross-sectional shape of the discharge electrode 52 may also be, for example, T-shaped (e.g., ...). Figure 6b ), l-shaped (such as) Figure 6e , Figure 6f , Figure 6g ), round (such as) Figure 6c ), oval (such as) Figure 6d The recessed area 52a can be shaped as described above, or preferably only exposes the front side (in the direction of travel) of the discharge electrode 52, so that the electric field of the discharge energy provided by the discharge electrode 52 is concentrated in the direction of travel of the discharge electrode 52. In the discharge machining process, the recessed area 52a can fix the discharge electrode 52 to reduce the shaking or rotation of the discharge electrode 52 during the cutting process, and can also provide drainage through the hole.

[0097] In addition, such as Figure 1 and Figure 4 As shown, the electrical discharge machining (EDM) unit 50 of the present invention may optionally include a wire feeder 56a and a wire take-up reel 56b, wherein the two ends of the discharge electrode 52 are respectively connected to the wire feeder 56a and the wire take-up reel 56b, and the wire feeder 56a and the wire take-up reel 56b can respectively use pulleys 57a and 57b to engage the discharge electrode 52, thereby positioning the discharge electrode 52 and, for example, adjusting the tension of the discharge electrode 52. Therefore, the discharge electrode 52 of the electrical discharge machining (EDM) unit 50 of the present invention may optionally include a guide bump 53a (such as...). Figure 6g (As shown) the guide grooves 58a and 58b corresponding to pulleys 57a and 57b (e.g.) Figure 7a As shown), and / or, the electrical shielding structure 52b may not only cover the area around the discharge electrode 52, but may also selectively have conductive bumps 53b (as shown). Figure 6d (As shown) the guide grooves 58a and 58b corresponding to pulleys 57a and 57b (e.g.) Figure 7b As shown in the figure, it is used as a supporting structure at the same time.

[0098] In addition, please see Figures 1 to 12bTo prevent the workpiece 100 from shaking during the discharge machining process by the discharge electrode 52, or to prevent burrs from forming before the end of the discharge machining process, the fixture 22 of the present invention selectively provides an adhesive layer 70 on the support plate 24. The periphery of the workpiece 100 is partially adhered to the adhesive layer 70, thereby ensuring that the workpiece 100 is firmly adhered to the support plate 24 of the fixture 20. The adhesive layer 70 is not limited to a continuous type (e.g., ...). Figure 8b (as shown) or discontinuous (such as) Figure 8c (As shown) is disposed on the support plate. Taking a discontinuous type as an example, the adhesive layer 70 is disposed intermittently on the support plate 24 of the fixture 22, and its position corresponds to the processing target area 110, that is, the position of the adhesive layer 70 is located below the processing target area 110. The position of the adhesive layer 70 is not limited to being located directly below the processing target area 110; as long as it can adhere to the workpiece 100, it is applicable to the present invention.

[0099] The fixture 22 may optionally include a conductive plate 72 disposed on the support plate 24, and the aforementioned adhesive layer 70 is disposed on the conductive plate 72, thereby serving as a buffer layer to prevent damage to the fixture 22 during the electrical discharge machining process. The conductive plate 72 is, for example, but not limited to, a material layer with a work function of approximately 4.5 eV or less, such as zinc, titanium, aluminum, or other suitable conductive metal structures. The adhesive layer 70 also provides conductivity, fixation, and protection for the conductive plate 72, and has the advantage of being easy to remove. Furthermore, in addition to the aforementioned adhesive layer 70 disposed on the support plate 24 of the fixture 22, the fixture 22 of the present invention may optionally include two side plates 26 disposed at both ends of the support plate 24 (e.g., ...). Figure 8a As shown in the diagram, the two side plates 26 are located on both sides of the workpiece 100, and preferably hold the workpiece 100 in place, for example, axially holding the ingot. This prevents the workpiece 100 from sliding or tipping over when the processing angle is tilted, and also allows the side plates 26 to be staggered from the travel path of the discharge electrodes 52, thereby hindering the discharge processing procedure. In addition, the adhesive layer 70 can be omitted in this invention, that is, the workpiece 100 can be placed directly on the conductive plate 72 of the fixture 22. If the adhesive layer 70 is omitted, the workpiece 100 can also be selectively held directly by the two side plates 26 of the fixture 22, which can prevent the workpiece 100 from sliding or tipping over. The adhesive layer 70 can be a non-conductive or conductive adhesive layer. As long as it can adhere the workpiece 100 to the support plate 24 of the fixture 20 or to the conductive plate 72, it is applicable to the present invention. Furthermore, there is no limitation on the adhesion area between the adhesive layer 70 and the workpiece 100. As long as it can make the workpiece 100 electrically connected to the support plate 24 or the conductive plate 72 below it to form an electrical circuit, it is applicable to the present invention.

[0100] like Figure 9As shown, the adhesive layer 70 is not limited to adhering only to the bottom of the workpiece 100; the adhesive layer 70 may also selectively extend upwards from the support plate 24 (i.e., the bottom of the workpiece 100) to at least one side of the workpiece 100, as long as it can securely adhere to the workpiece 100, it is applicable to the present invention. Furthermore, as... Figure 10 As shown, before adhering to the adhesive layer 70, the present invention may, for example, pre-process the workpiece 100 to create a rough surface or gaps in the area of ​​the workpiece 100 to which the adhesive layer 70 is to be adhered. Therefore, the adhesive layer 70 can further penetrate the workpiece 100 from its surface, improving adhesion. Furthermore, if the adhesive layer 70 is a conductive adhesive, it can also enhance conductivity. The adhesive layer 70 can be any suitable material, such as commercially available conductive or non-conductive adhesives.

[0101] In addition, such as Figures 2 to 3 and Figure 8a As shown, the processing target area 110 of the workpiece 100 in this invention is preferably located above the support plate 24, that is, the projection line of the processing target area 110 falls between the two side plates 26, rather than the conventional technique where the processing target area is located outside the side plates of the support plate. This invention reduces vibration of the workpiece 100 during the electrical discharge machining process and prevents burrs from forming on the cut surfaces 100b and 100c of the workpiece 100 before the end of the electrical discharge machining process. Furthermore, by positioning the processing target area 110 of the workpiece 100 above the support plate 24, that is, between the two side plates 26, the discharge electrode 52 will only perform the electrical discharge machining process between the two side plates 26. The position of the processing target area 110 of the workpiece 100 is not limited to being directly above the support plate 24; any location suitable for machining is applicable to this invention. Therefore, the present invention can perform electrical discharge machining (EDM) on the entire workpiece 100, avoiding the disadvantage of conventional techniques where the side plate 26 obstructs the process and limits EDM to the target area located outside the side plate of the support plate. Figure 8b and Figure 8c As shown, since the present invention has provided an adhesive layer 70 on the support plate 24 of the fixture 22, and the position of the support plate 24 is located below the processing target area 110, it can reliably support the entire workpiece 100. Therefore, even if the above-mentioned side plates 26 are omitted, the present invention can still achieve the effect of reducing vibration and burr phenomena, and the electrical discharge machining process will not be hindered by the side plates 26 at all.

[0102] Because when the overlap length between the discharge electrode 52 and the workpiece 100 is too long, the discharge electrode 52 between the pulleys 57a and 57b is prone to vibration during the cutting process of the workpiece 100, causing the cutting surface to shift or become skewed. Moreover, the further away from the pulleys 57a and 57b the position is, the greater the vibration amplitude of the discharge electrode 52. Therefore, the present invention may also selectively include a positioning unit 62 for non-contact fixing of the orientation of the discharge electrode 52. For example, the discharge electrode 52 or the electrical shielding structure 52b is, for example, a magnetic component, such as a magnet or an iron-containing material, while the positioning unit 62 is, for example, a component that can generate magnetic attraction, such as a magnet or an electromagnet. The discharge electrode 52 and the positioning unit 62 are respectively located on opposite sides of the processing target area 110, so that the magnetic attraction acts on the aforementioned magnetic component, allowing the discharge electrode 52 to maintain a fixed orientation during the discharge processing procedure.

[0103] Furthermore, the present invention can, for example, adjust the angle between the processing target area 110 of the workpiece 100 and the support plate 24 of the fixture 22 to perform an off-axis electrical discharge machining (EDM) procedure. For example, such as... Figure 1 and Figure 12a As shown, the stage 20 of the present invention can be, for example, a movable stage with multi-axis (e.g., 2-axis, 3-axis or more) motors, thereby achieving positional movement and even adjusting the tilt of the fixture 22 relative to the discharge electrode 52, or as... Figure 1 and Figure 12b As shown, the wire feeder 56a and the wire take-up reel of the electrical discharge machining (EDM) unit 50 of the present invention may, for example, be a multi-axis (e.g., 2-axis, 3-axis or more) motor. By adjusting the wire feed direction of the electrical discharge machining (EDM) unit 50, the tilt of the discharge electrode 52 relative to the workpiece 100 can be adjusted.

[0104] Furthermore, to improve the efficiency of the electrical discharge machining process, this invention can also enhance the electrical contact between the workpiece 100 and the fixture 22 through a conductive gain layer. For example, such as Figure 13 As shown, a conductive gain layer 80 can be formed on the workpiece 100 by surface modification, such as using the aforementioned electrical discharge machining (EDM) unit 50 or laser. The composition of the conductive gain layer 80 is determined according to the composition of the workpiece 100, and the conductive gain layer 80 is located adjacent to the support plate 24 of the fixture 22 or directly connected to the support plate 24. This invention improves the electrical contact between the fixture 22 and the workpiece 100 by surface modification of the workpiece 100. Alternatively, this invention can also form conductive gain layers 82 and / or 84 on the support plate 24 and / or the side plates 26 of the fixture 22 through coating or other methods to provide good electrical contact. Even the conductive plate 72 can be coated with a conductive gain layer 86 or is itself a conductive gain layer 86 (e.g., Figure 14As shown), to provide good electrical contact, the conductive gain layers 82 and 84 can be positioned adjacent to or in direct contact with the workpiece 100. The materials of the conductive gain layers 82 and / or 84 can be, for example, the same or different conductive materials, as long as good electrical contact is provided, they are suitable for this invention. Furthermore, the conductive plate 72, the support plate 24 of the fixture 22, and / or the side plates 26 themselves can also be, for example, constructed from the conductive gain materials of the aforementioned conductive gain layers 82, 84, and / or 86. The conductive gain materials can be, for example, different or the same conductive materials, such as different or the same metal materials, as long as good electrical contact is provided, they are suitable for this invention. Alternatively, during the electrical discharge machining process, materials that aid conductivity can be added to the heating liquid 59b of the aforementioned heating liquid tank 59a to facilitate the electrical discharge machining process, especially to improve the electrical discharge machining efficiency of the workpiece 100 awaiting processing, whether it is a semiconductor or a defective conductor. The work function of the aforementioned conductive gain layers 82, 84 and / or 86 is, for example, less than about 4.5 eV, but is not limited thereto; any layer that helps to improve electrical contact is applicable to the present invention.

[0105] In addition, the present invention can also heat the workpiece 100 on the support plate 24 using a heat source 90 to improve the electrical contact between the workpiece 100 and the fixture 22. The heat source 90 can be, for example, the aforementioned heating liquid tank 59a, a microwave or radio frequency source 60, or a laser source and / or an infrared light source. After the workpiece 100 comes into contact with the fixture 22, heat treatment using the heat source 90 can improve the electrical contact, thereby improving the efficiency of the subsequent electrical discharge machining process.

[0106] In summary, the electrical discharge machining apparatus of the present invention has the following advantages:

[0107] (1) By designing a non-uniform electric field distribution, the electric field can be concentrated in the direction of travel.

[0108] (2) By designing a non-uniform electric field distribution, the electric field distribution in the non-traveling direction can be reduced, thus reducing the surface roughness and surface cracks of the workpiece in the non-traveling direction.

[0109] (3) By setting an adhesive layer in the fixture, the shaking phenomenon of the workpiece during the electrical discharge machining process can be avoided, and the burr phenomenon before the end of the electrical discharge machining process can also be avoided.

[0110] (4) By setting an adhesive layer on the fixture, the fixture can be prevented from interfering with the workpiece in the electrical discharge machining process, thus making the electrical discharge machining process more flexible.

[0111] (5) Since the discharge electrode has multiple conductive lines, the cutting and polishing steps can be performed simultaneously, thus speeding up the overall processing procedure and obtaining a surface with low roughness.

[0112] (6) By means of the conductive gain layer of the workpiece and / or fixture, the electrical contact between the workpiece and the fixture can be improved, thereby improving the efficiency of the electrical discharge machining process.

[0113] The above description is merely illustrative and not restrictive. Any equivalent modifications or alterations made without departing from the spirit and scope of this invention should be included in the appended claims.

Claims

1. An electrical discharge machining apparatus, characterized in that, Include: A platform, the platform being equipped with a fixture, the fixture including a support plate for supporting at least one workpiece to be processed, wherein the workpiece to be processed defines a processing target area; and A discharge machining unit applies discharge energy to the processing target area of ​​the workpiece via at least one discharge electrode in a non-uniform electric field distribution, thereby processing the workpiece along the processing target area, wherein the discharge electrode has a recessed area, so that the discharge energy forms the non-uniform electric field distribution.

2. The electrical discharge machining apparatus as described in claim 1, characterized in that, The discharge electrode is covered with an electrical shielding structure on both sides, so that the discharge energy forms the non-uniform electric field distribution.

3. The electrical discharge machining apparatus as described in claim 1 or 2, characterized in that, The cross-sectional shape of the discharge electrode is T-shaped, L-shaped, or elliptical with the recessed area, so that the discharge energy forms the non-uniform electric field distribution.

4. The electrical discharge machining apparatus as described in claim 2, characterized in that, The discharge electrode has a circular cross-sectional shape, which allows the discharge energy to form a non-uniform electric field distribution.

5. The electrical discharge machining apparatus as described in claim 1, characterized in that, The discharge electrode can be linear or plate-shaped.

6. The electrical discharge machining apparatus as described in claim 2, characterized in that, The electrical shielding structure is a supporting structure.

7. The electrical discharge machining apparatus as described in claim 6, characterized in that, The discharge electrode or the support structure has a guide bump, which corresponds to a guide groove of a pulley in the electrical discharge machining unit, thereby guiding the guide bump using the guide groove.

8. The electrical discharge machining apparatus as described in claim 1, characterized in that, The discharge electrode is a magnetic component. When the discharge electrode processes the workpiece along the processing target area, the discharge processing unit acts on the magnetic component in a non-contact manner with a magnetic attraction force to fix one orientation of the discharge electrode.

9. The electrical discharge machining apparatus as described in claim 1, characterized in that, The discharge electrode system includes a first conductive line and a second conductive line, wherein the thickness of the first conductive line and / or the applied voltage is different from that of the second conductive line.

10. The electrical discharge machining apparatus as described in claim 1, characterized in that, It also includes a microwave or radio frequency source for supplying microwave or radio frequency energy to the processing target area of ​​the workpiece via the discharge electrode of the electrical discharge processing unit.

11. An electrical discharge machining apparatus, characterized in that, Include: A platform, the platform having a fixture, the fixture including a support plate for supporting at least one workpiece, wherein the workpiece defines a processing target area, and the processing target area of ​​the workpiece is located above the support plate; and A discharge machining unit is used to apply discharge energy to the processing target area of ​​the workpiece via at least one discharge electrode, thereby processing the workpiece along the processing target area, wherein the discharge electrode applies the discharge energy to the processing target area of ​​the workpiece with a non-uniform electric field distribution, wherein the discharge electrode has a recessed area, thereby causing the discharge energy to form the non-uniform electric field distribution.

12. The electrical discharge machining apparatus as described in claim 11, characterized in that, The fixture further has two side plates located at both ends of the support plate, which are respectively positioned on both sides of the workpiece to be processed.

13. The electrical discharge machining apparatus as described in claim 11, characterized in that, The fixture has an adhesive layer on the support plate, and the periphery of the workpiece is partially adhered to the adhesive layer of the fixture.

14. The electrical discharge machining apparatus as described in claim 13, characterized in that, The adhesive layer is a conductive adhesive layer.

15. The electrical discharge machining apparatus as described in claim 13, characterized in that, The adhesive layer is discontinuously applied to the support plate.

16. The electrical discharge machining apparatus as described in claim 13, characterized in that, The adhesive layer extends upward from the support plate to at least one side of the workpiece.

17. The electrical discharge machining apparatus as described in claim 13, characterized in that, The adhesive layer is incorporated into the workpiece.

18. The electrical discharge machining apparatus as described in claim 11, characterized in that, The fixture has a conductive plate disposed on the support plate.

19. The electrical discharge machining apparatus as described in claim 13, 14, 15, 16 or 17, characterized in that, The fixture has a conductive plate disposed on the support plate, and the adhesive layer is disposed on the conductive plate.

20. The electrical discharge machining apparatus as described in claim 18, characterized in that, The conductive plate is a conductive metal structure with a work function of less than 4.5 eV.

21. The electrical discharge machining apparatus as described in claim 11, characterized in that, The stage adjusts the tilt of the fixture relative to the discharge electrode, or the discharge machining unit adjusts the tilt of the discharge electrode relative to the workpiece, thereby adjusting the angle between the processing target area of ​​the workpiece and the support plate of the fixture.

22. The electrical discharge machining apparatus as described in claim 1 or 11, characterized in that, The workpiece and / or the fixture further have a conductive gain layer to improve the electrical contact between the workpiece and the fixture.

23. The electrical discharge machining apparatus as described in claim 1 or 11, characterized in that, It also includes a heat source for heating the workpiece on the support plate, thereby improving the electrical contact between the workpiece and the fixture.

24. The electrical discharge machining apparatus as described in claim 1 or 11, characterized in that, The discharge electrode is used to cut the target area of ​​the workpiece in a fluid.

25. The electrical discharge machining apparatus as described in claim 1 or 11, characterized in that, The discharge electrode is used to cut the target area of ​​the workpiece in a vacuum environment.

26. The electrical discharge machining apparatus as described in claim 1 or 11, characterized in that, The number of these discharge electrodes is one or multiple.

27. The electrical discharge machining apparatus as described in claim 1 or 11, characterized in that, The quantity of the work to be processed is one or more.

Images