Etching equipment and etching system

Abstract

The present invention relates to an etching apparatus for a workpiece to be treated with an etching liquid, the etching apparatus comprising a cavity into which the workpiece can be introduced. The cavity is at least partially surrounded by at least one retaining member of the etching apparatus for the workpiece. The retaining member and an end face of the etching apparatus facing the retaining member partially surround a gap for introducing the etching liquid. The end face of the etching apparatus facing the retaining member is at least partially transparent. The present invention also relates to an etching system having an etching apparatus, wherein the etching apparatus is connected to at least one etching liquid source via at least one etching liquid supply conduit and to at least one etching liquid reservoir via at least one etching liquid discharge conduit.

Description

[Technical field]

[0001] The present invention relates to an apparatus for etching a workpiece with an etching liquid and an etching system including the apparatus. [Background technology]

[0002] Etching devices are used for the chemical processing of workpieces. An etching liquid, also called an etchant, is applied to the workpiece surface. A chemical reaction takes place between the etching liquid and the workpiece surface, in which the surface of the workpiece is removed and depressions are formed. In this way, particularly metal workpieces can be structured in a user-defined way or electrical conductor tracks can be formed on electronic printed circuit boards. Similarly, the workpiece surface can be contrasted with inhomogeneous structures for material testing. In so-called color etching, different layers of the workpiece surface can be selectively colored.

[0003] In order to achieve high etching quality, it is desirable to investigate the chemical reaction between the etching solution and the surface of the workpiece as accurately as possible and control it by process technology.

[0004] Known etching apparatuses have the disadvantage that the etching process cannot be reliably monitored in situ, i.e. during the etching process, and therefore the etching of the workpieces must be optimised empirically. Summary of the Invention [Problem to be solved by the invention]

[0005] The object of the present invention is therefore to develop an etching device which allows for an optimized etching process in a time- and cost-efficient manner while avoiding the disadvantages of the prior art. The same applies to etching systems. [Means for solving the problem]

[0006] The object of the present invention is achieved by an etching device for a workpiece to be processed by an etching liquid, the cavity into which the workpiece can be introduced being at least partially surrounded by at least one fastening member of the etching device for the workpiece, the fastening member and an end face of the etching device facing the fastening member partially surrounding a gap for the introduction of the etching liquid, the end face of the etching device facing the fastening member being at least partially formed transparent.Furthermore, the object of the present invention is achieved by an etching system having an etching device according to the present invention, the etching device being connected to at least one etching liquid source via at least one etching liquid supply conduit and to at least one etching liquid reservoir via at least one etching liquid discharge conduit.

[0007] The invention is based on the basic idea that a stop for the workpiece surface to be processed is provided in a simple and reproducible manner by means of a stop element, and in addition the workpiece surface to be processed is always at the same predefined distance from the transparent end face of the etching device, in particular during the etching process, which allows a particularly simple visual on-site inspection in order to simply and effectively optimize the etching process.

[0008] In the following, directional indications are described based on a cylindrical coordinate system, with the axial direction corresponding to the vertical direction, and the radial and circumferential directions each oriented horizontally and therefore perpendicular to the axial direction.

[0009] To improve durability, the etching device can have a housing made of an etching-resistant material, especially in the area adjacent to the cavity. The housing preferably has a closable opening through which the workpiece to be processed can be introduced into the cavity. The workpiece can be attached to a workpiece holder, especially made from an etching-resistant material, the dimensions of which are preferably adapted to those of the etching device. When the workpiece is introduced into the cavity, the workpiece and / or the workpiece holder preferably at least partially contact the locking member and remain in a position predetermined by the position and / or shape of the locking member during the subsequent etching process.

[0010] Preferably, at least one stop member is arranged such that the surface of the workpiece to be processed is oriented parallel to the transparent area of ​​the end face facing the stop member in order to avoid optical imaging errors.

[0011] Preferably, the locking member is arranged on the lateral inner wall of the cavity. In a structurally simple embodiment of the invention, the locking member is formed as at least one protrusion between the cavity and the gap. In the present invention, the gap may in particular be part of the cavity and / or may be connected to the cavity. The locking member may in particular be a radially inward protrusion directed towards the cavity, and a number of protrusions may be distributed around the circumference of the inner wall. Preferably, the locking member is formed in a circumferential ring- or frame-shaped manner. Thereby, the workpiece arranged in the cavity and / or the workpiece holder on which the workpiece can be mounted can abut at its edge against the ring- or frame-shaped locking member and be securely held thereon. In such a configuration, the locking member and the inner wall of the cavity in which this locking member can be arranged can partially define a gap. At the same time, the sides of the gap are limited by the workpiece and / or the workpiece holder abutting against the edge of the locking member. The surface of the workpiece to be etched can thereby face the gap. In this way, the etching liquid introduced into the gap can reach the surface of the workpiece to be processed, which takes up a geometrically defined and reproducible position and can be seen through a transparent area of ​​the end face of the etching device facing the locking member.

[0012] The transparent area of ​​the end face facing the locking member can be formed as a glass and / or plastic insert, in particular as an inserted glass plate, inserted into a recess in the end face. In particular the glass insert can comprise an optical glass, which has a different chemical composition than normal window glass and is commonly used for manufacturing optical elements such as lenses, mirrors or prisms. The use of optical glass facilitates optical monitoring of the etching process by the etching device according to the invention, in particular in combination with an optical sensor, for example formed as a microscope. The transparent means has a sufficient transmittance for visual inspection of the etching process in the particular wavelength range used, including but not necessarily limited to the optically visible wavelength range. The glass plate can correspond to the recess and can be circular and / or can be radially centered on the end face. Preferably, the glass plate has a diameter of 90 mm to 100 mm and / or a thickness of about 1 mm.

[0013] At least one clamping element is preferably provided in the cavity, and a workpiece and / or a workpiece holder that can be mounted in the cavity can be clamped by the locking member. For this purpose, the clamping element can be formed in such a way that the workpiece and / or the workpiece holder that can be loaded into the cavity exerts a force directed towards the locking member. This ensures that even workpieces having different shapes always abut against the locking member, so that the processing surface of the workpiece is at a defined distance from the transparent area of ​​the end face of the etching device. For example, the clamping element can be moved in the direction of the locking member, in particular linearly.

[0014] In a particularly simple constructional embodiment, the clamping element has at least one spring element, which can be configured as a coil and / or a metal spring. Alternatively or additionally, the clamping element can have a slide, which is in particular linearly movable, on which a force can be applied in the direction of the locking member.

[0015] In an advantageous development of the invention, a workpiece container is arranged in the cavity and is adapted to receive a workpiece and / or a workpiece holder to which the workpiece can be attached, in particular the workpiece container having a clamping element.

[0016] In the present invention, the workpiece container is used to hold the workpiece and / or the workpiece holder on which the workpiece is attached so that they can be positioned in a defined position in the cavity. The workpiece container preferably has a stop edge for the workpiece, which limits the resting surface of the workpiece laterally, i.e. radially, and thus predetermines the position of the workpiece. It is advantageous if the workpiece container has an interior with at least one clamping element, on which the workpiece can be positioned and fixed for the etching process. The workpiece container is preferably arranged in the cavity in such a way that the workpiece arranged thereon takes the direction of the gap at the surface of the workpiece to be processed. The workpiece container is arranged in such a way that it can be completely arranged in the cavity, in particular when the etching device is closed, and / or can partially protrude from the cavity when the etching device is open. The workpiece container can be arranged in the cavity movably, in particular by means of bearings, and / or can be fixed in place by means of fixing elements. In an advantageous development of the invention, the workpiece container is cylindrical, in particular hollow cylindrical.

[0017] In an advantageous development of the invention, the workpiece container is formed nested, for example in the form of two cylinder sleeves forming a common interior. The workpiece and / or the workpiece holder with the workpiece can be arranged inside the workpiece container via an opening in the end face. For a space-saving design, the clamping element, in particular a coil spring, is arranged inside the workpiece container and can be movably guided, in particular on the inner wall of the workpiece container. The inner wall of the workpiece container can thereby define an adjustment axis for the clamping element and for the workpiece and / or the workpiece holder which can be positioned thereon.

[0018] The first cylinder sleeve of the workpiece container can have an inner diameter that is slightly larger than the outer diameter of the second cylinder sleeve of the workpiece container, whereby the cylinder sleeves are guided in particular one above the other so that they can be displaced relative to one another and along a common longitudinal axis over a common contact area. Preferably, the workpiece container is at least partially manufactured from an etching-resistant material, for example polytetrafluoroethylene (PTFE).

[0019] In an advantageous development, the supply channel for the etching liquid, which opens into the cavity, in particular into the gap, is formed at least partially in the direction of the cavity, in particular in the direction of the gap, in particular so as to widen continuously. For example, the side walls of the widening part of the supply channel are not oriented parallel to one another but form a finite acute angle between them. Preferably, the supply channel is formed so as to widen in a horizontal, in particular radial, part. According to the invention, the etching liquid reaches the gap and thus the surface to be treated of the workpiece via the supply channel. It has been found that the widening form of the supply channel significantly reduces the formation of bubbles compared to a supply channel with a constant width. The etching process is improved by the resulting homogenization of the etching liquid. The supply channel can be formed in particular partially between the stop member and the end face of the etching device facing the stop member. The diameter of the supply channel can be larger than the diameter of the discharge channel, in particular in the part towards the gap. Preferably, the supply channel is formed as a groove, in particular in its horizontal, most preferably in its widening part, surrounded by side walls and having a depth of, for example, 1 mm.

[0020] In a preferred embodiment, the clamping element is conductively connected to an electrical terminal for electrically contacting a workpiece that can be introduced into the cavity. This allows the etching device according to the invention to carry out electrolytic etching processes (also known as electroetching). In this case, the workpiece surface is removed by using an electric current. The workpiece is then electrically contacted. This type of etching allows the workpiece to be treated using a less corrosive etching solution compared to purely chemical etching. In this case, the etching solution acts as an electrolyte and the workpiece, which is electrically connected to the terminal, acts as an electrode, in particular as an anode. In this case, according to expert knowledge, a second electrode, preferably made of a noble metal, acts as a cathode and is immersed in the etching solution at a suitable position inside or outside the etching device. Preferably, the cathode is arranged in the cavity, such that this cathode is conductively connected to the etching solution during the etching process. The cathode is preferably removably connected to the etching device so that it can be replaced. In a structurally simple embodiment of the invention, the cathode can be cylindrical.

[0021] When a voltage is applied between the anode and the cathode, a current flows, which causes ions to be released from the anode (in this case the workpiece) and migrate to the cathode through the etching solution, which acts as an electrolyte. Said ions from the workpiece are separated or precipitated from the solution as precipitates on the cathode. This causes the surface of the workpiece to be etched in the desired location.

[0022] Preferably, the cathode is positioned within the cavity such that it has no mechanical contact with the workpiece during the electrolytic etching process to avoid electrical shorts.

[0023] A heating element is preferably arranged in particular in the cavity, which is formed to heat the etching liquid introduced into the gap to a user-defined temperature. This also makes it possible to thermally etch the workpiece. Such an etching method is based on the finding that the result of the etching process can be influenced and controlled in a standard way and thus optimized by the desired temperature control of the etching liquid. For this purpose, the heating element can be simply arranged in the cavity of the etching device and / or formed as a heating plate.

[0024] The heating element can be formed as an electric heating element capable of converting supplied electrical energy into heat. In a structurally simple embodiment of the invention, the heating element is arranged in the region of the supply channel, whereby the etching liquid can be heated to a user-defined temperature when flowing through the supply channel in the direction of the workpiece to be treated and come into contact with the workpiece. The heating element can be formed as a heating plate and can in particular be arranged in the workpiece container.

[0025] If at least one temperature sensor is provided in addition to the heating element, the temperature of the etching device, in particular of the etching liquid, can be defined and monitored. Preferably, the cavity and / or the workpiece container preferably has a temperature sensor therein. A magnetic stirrer or a rotatable flow propeller, which is preferably designed to bring about a uniform wetting of the workpiece surface by the etching liquid, is provided. For this purpose, the magnetic stirrer and / or the flow propeller can be arranged in the etching liquid conduit and / or in the supply channel arranged upstream of the gap. This makes it possible to achieve a uniform and homogeneous material removal on the workpiece surface to be etched, which is called the workpiece sample within the scope of the present invention. The ions of the workpiece, which are generated as a result of the etching process under a microscope, are carried away in an optimized manner, so that static effects that interrupt the etching process are avoided and so that reproducible etching results can also be obtained. The heating element can be arranged in the cavity of the etching device, for example as a heating plate, and / or connected to a clamping element.

[0026] Preferably, the support surface of the etching device, in particular designed as at least one standoff, has a pressure sensor. In the present invention, the pressure sensor can determine the force directed at the etching device in the direction of the base on which the etching device is arranged. The pressure sensor therefore normally records the weight force of the etching device, but also the comparatively increasing force, for example when an external component is placed on the etching device or in contact with it. In particular, each standoff has a pressure sensor. The pressure sensor can be connected to an evaluation unit which reads the force determined by the pressure sensor and compares it with a defined limit value, so that, for example if the limit value is exceeded, a warning signal is output, indicating imminent damage to the etching device as a result of the forces acting on the etching device. The warning signal can be visual and / or acoustic. In this way, in particular when the optical sensor comes into contact with a transparent area of ​​the etching device during inspection of the etching process, a warning signal can be output before the optical sensor destroys the transparent area of ​​the end face and the etching liquid leaks out of the etching device.

[0027] In an advantageous development of the invention, the etching device is formed in two parts, the lower part of the etching device can in particular comprise at least a part of the cavity and / or the upper part of the etching device can comprise a stop member and / or a gap. The upper part of the etching device can be formed to close the cavity, and in the closed state of the etching device, the upper part can have an end face facing the stop member and having a transparent area. Furthermore, the stop member can be arranged on the side of the upper part facing the cavity, in particular between the cavity and the gap.

[0028] The lower part of the etching device can comprise a mounting surface, in particular at least one standing member, in a structurally simple manner. The etching device, in particular the upper part and / or the lower part, is preferably cylindrical, but can alternatively also be rectangular, in particular cuboid in shape.

[0029] The upper part can be formed as a cover element for the lower part, which can selectively close or reopen the cavity of the lower part tightly. Preferably, the upper part has an outer contour corresponding to the lower part, so that the outer side of the upper part is flat against the outer side of the lower part when the lower part is connected to the upper part, in particular when closed. This facilitates handling of the etching device according to the invention. Preferably, an etching-resistant seal, designed for example as a sealing ring, is provided in the region between the upper part and the lower part. To close the cavity, the lower part and the upper part can have corresponding closing elements arranged on their respective outer sides, so that the lower part can be releasably connected to the upper part, in particular with a frictional and / or form-fitting engagement. Preferably, at least one quick release is provided for clamping the upper part to the lower part.

[0030] Preferably, the locking members are spaced at a distance from the end face facing it, for which purpose in particular the upper portion can have at least one locking member.

[0031] In an advantageous development of the invention, the upper part has a supply channel and the lower part has an etching liquid supply conduit, which is connected to the supply channel in the closed state of the etching device. The diameter of the etching liquid supply conduit can correspond to the diameter of the supply channel, in particular the diameter of the part facing the etching liquid supply conduit. This allows the etching liquid to be guided via the etching liquid supply conduit and the supply channel to the gap of the processed surface of the workpiece. The etching liquid supply conduit can remain connected to the etching liquid source even if the upper part is removed from the lower part in order to replace the workpiece. In comparison with the supply of the etching liquid only via the upper part, the connection for conducting the etching liquid required for this is not adversely affected by the movement of the upper part, for example when the cavity is opened or closed. The etching liquid supply conduit can be at least partially formed as a glass tube or can be connected to such a glass tube.

[0032] Preferably, at least one optical sensor of the etching device is arranged such that the workpiece, which may be introduced into the cavity, can be detected by the optical sensor at least partially through the transparent area so that the etching process can be visually inspected. The optical sensor can be designed as an optically magnified system and / or can use electromagnetic radiation in the infrared, ultraviolet and / or visible spectrum for inspecting the workpiece. In an advantageous development of the invention, the optical sensor is designed in particular as a microscope, in particular as a microscope objective, which is movable in the direction of the workpiece. Furthermore, the optical sensor can have a camera, in particular a video camera, for storing and processing image information of the workpiece. The optical sensor can be arranged in particular at a variable distance from the end face facing the stop member. The optical sensor can also be designed to output a warning signal when the optical sensor falls below a predefined distance from the transparent area of ​​the end face and / or comes into contact with it.

[0033] The etching liquid source of the etching system according to the invention can be simply designed as a sealable container having an etching-resistant surface and used for storing the etching liquid. Preferably, the etching system has a plurality of such etching liquid sources, which can be connected to each other via a conduit system, which can in particular have at least one valve and at least one supply conduit. The at least one valve is preferably designed as a two-way valve.

[0034] The etching system according to the invention may comprise at least one pump device and / or at least one valve device, which are at least indirectly connected to the etching liquid supply conduit and / or to the etching liquid discharge conduit for directing the etching liquid into and / or out of the gap, in particular at a predefined flow rate, by means of the pump device and / or the valve device, the flow of the etching liquid can be controlled in a user-defined manner, for example to start and / or to end the etching process.

[0035] The pumping device comprises at least one pump and is connected, in particular via a valve device, to at least one etching liquid source as well as to the supply channel and the etching liquid supply conduit, for conveying the etching liquid from the etching liquid source through the etching liquid supply conduit and the supply channel into the gap. In addition, the pumping device may be connected to the supply channel, the discharge conduit and the etching liquid reservoir for directing the etching liquid from the gap towards the etching liquid reservoir in a user-defined manner after the etching process. The pumping device may in particular be formed to be electrically controllable, allowing the setting of a volumetrically and / or pressure-controlled flow of the etching liquid.

[0036] The valve arrangement comprises at least one controllable valve, in particular a solenoid valve, which may be formed as a shut-off valve, a directional valve or a mixing valve. The at least one controllable valve is preferably provided as a two-way valve. The valve arrangement is electrically controllable. By means of this valve arrangement, the flow of the etching liquid can be opened or blocked by an electrical signal in a simple manner, in particular user-defined, in order to start, interrupt and / or terminate the etching process of the etching apparatus.

[0037] In an advantageous development of the invention, a valve device and / or a pump device are connected to a plurality of etching liquid sources for conveying the etching liquid into the gap in a user-defined mixing ratio. For this purpose, at least one mixing valve can be provided. In addition, a cleaning liquid source can be provided, in which the cleaning liquid can be guided into the gap in a user-defined manner, in particular by means of a pump device and / or a valve device, and the etching process can be interrupted and the etching liquid can be removed from the gap in a controlled manner.

[0038] Preferably, the pumping device and / or the valve device are connected to the control unit so that the etching liquid can be introduced into the etching apparatus at user-defined process parameters, the process parameters including at least one parameter from the group of: composition of the etching liquid, flow rate of the etching liquid, density of the etching liquid, supply time of the etching liquid to the gap, drain time of the etching liquid from the gap.

[0039] The control unit can be configured to control the pumping and / or valving devices at a predefined clock frequency. Preferably, the composition of the etching liquid led to the gap can be user-defined by the control unit, in particular by the above-mentioned mixing valve. Furthermore, the control unit can be connected to electrical terminals and / or heating elements for controlling the electrical and / or thermal etching process.

[0040] According to an advantageous development of the invention, the heating element can be arranged outside the etching apparatus as part of the etching apparatus, so that the temperature of the etching liquid is controlled before and / or during its entry into the etching liquid supply conduit and / or supply channel.

[0041] At least one component of the etching apparatus and / or etching system may be placed in a drip tray to prevent possible leakage into the environment in the event of a leak. [Brief description of the drawings]

[0042] Additional advantages and features of the present invention are apparent from the claims and the following description, which set forth in detail exemplary embodiments of the invention. [Figure 1] 1 shows a front view of a first embodiment of an etching apparatus according to the present invention, in which a lower part and an upper part of the etching apparatus are shown separated from each other. [Diagram 2] 2 shows the etching apparatus according to FIG. 1 with the lower and upper parts combined. [Diagram 3] 2 shows a cross-sectional view of the etching apparatus of FIG. [Figure 4] 3 shows a cross-sectional view of the etching apparatus of FIG. 2. [Diagram 5] 2 shows a top view of the upper part of the etching apparatus in FIG. 1. [Figure 6] 6 shows a view of the upper part of FIG. 5 seen from below. [Figure 7]2 shows a top view of the lower part of the etching apparatus of FIG. 1. [Figure 8] 2A and 2B show the workpiece container of the etching apparatus of FIG. 1, as viewed from the front and from above, respectively. [Figure 9] 2 shows a cross-sectional front view of a second embodiment of an etching apparatus according to the invention with an optical sensor; [Figure 10] 3 shows a third embodiment of an etching apparatus according to the invention for electrolytic etching. [Figure 11] 4 shows a fourth embodiment of an etching apparatus according to the invention for thermal etching. [Figure 12] 1 illustrates a side view of a portion of an etching system. [Figure 13] 13 shows a partial cross-sectional view of the etching system according to FIG. [Figure 14] 13 shows a top view of a part of the etching system according to FIG. 12. [Figure 15] 13 shows a rear view of a portion of the etching apparatus shown in FIG. 12. [Figure 16] FIG. 13 shows a side view of a fourth embodiment of an etching apparatus according to the present invention. [Figure 17] 17 shows a cross-sectional view of the etching apparatus shown in FIG. 16. [Figure 18] The etching system shown in FIGS. 13 to 15 has an etching agent circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] Figure 1 shows a first embodiment of an etching device 1 according to the invention, which is used for chemical processing of a workpiece 16 by means of an etching liquid. The etching device 1 is made in two parts, is substantially cylindrical in shape and comprises a lower part 2 and an upper part 3, the upper part 3 being made so as to close a cavity 11 formed in the lower part 2 (see Figures 3 and 4). The etching device 1 has a quick release fastener 4 with a clamping clip 5 and a corresponding protrusion 6. The clamping clip 5 is arranged on a radial side 2a of the lower part 2, while the protrusion 6 is arranged on a radial side 3a of the upper part 3.

[0044] The lower part 2 has an etching solution supply conduit 7 and an etching solution discharge conduit 8. The etching solution supply conduit 7 enters radially from the side surface 2a of the lower part 2 and opens into a vertical glass tube 7a which penetrates the cavity 11 and projects beyond the upper end surface 2b of the lower part 2 towards the upper part 3 as shown in Figure 1. The etching solution discharge conduit 8 similarly penetrates the side surface 2a of the lower part 2 and opens into the cavity 11. A leg 9 having a support surface is provided on the lower side surface 2c of the lower part 2 opposite the upper part 3.

[0045] The upper part 3 has a centering member 10 on its lower side 3b facing the lower part 2, by which the upper part 3 is arranged radially centered on the lower part 2 and is fitted tightly into the lower part. For this purpose, the centering member 10 has a diameter slightly smaller than the inner diameter of the cavity 11. The centering member 10 has a chemically corrosion-resistant packing member arranged radially transversely thereto, which is not shown in FIG. 1. For simplicity of illustration, the centering member 10 is not shown in the other figures.

[0046] The etching apparatus 1 shown in Figure 1 is in a loaded state, in which a workpiece 16 can be positioned on a coil spring 13 in a cylindrical etch-resistant workpiece container 12 in the lower part 2. This state is explained with the aid of Figure 3.

[0047] Figure 2 shows the etching device 1 of Figure 1 in a state where the lower part 2 and the upper part 3 are assembled, and the clamp clips 5 and the protrusions 6 are clamped together. Figure 2 shows the etching device 1 in an operating state, which will be explained with reference to Figure 4.

[0048] Figure 3 shows a cross-sectional view of the etching device 1 shown in Figure 1 in the loaded state. According to Figure 1, the upper part 3 is shown removed and lifted off the lower part 2. The lower part 2 has a cavity 11 in its upper end face 2b. As already mentioned, the workpiece container 12 is arranged in the cavity 11, is hollow in this embodiment and has an opening 24 in its upper end face facing the upper part 3 for receiving the workpiece 16.

[0049] Within the workpiece container 12 there is a clamping element in the form of a metallic coil spring 13, on which a workpiece 16 can be placed. At its end opposite the top 3, the coil spring 13 is rigidly connected to the workpiece container 12. The workpiece container 12 is shown in more detail in Figure 8 and will be described individually below.

[0050] The upper part 3 has on its axial upper end face 14a a transparent area 14 formed as optical glass 14b, which is arranged flush with the end face 14a of the upper part 3 as a fitting and rests on the upper part 3 on an area which in this respect serves as a support surface. An annular locking member 15 is formed in the upper part 3. When the cavity 11 is open, the etching device 1 is in the loading state and the workpiece 16 to be etched together with the workpiece sample 16a to be etched and inspected is positioned in the workpiece container 12 and on the coil spring 13. The upper part 3 is then placed on the lower part 2 in order to close the cavity 11 and is clamped thereto. The locking member 15 then mechanically abuts against the edge of the workpiece 16. The closing movement of the upper part 3 is transmitted by the locking member 15 to the workpiece 16 and to the coil spring 13, whereby the spring is mechanically loaded and serves as a clamping element. When the cavity 11 is closed, the etching apparatus 1 enters an operating state, so that the workpiece 16 is clamped between the coil spring 13 and the stop member 15 and is subjected to an axially upward force towards the stop member 15. This is shown in FIG.

[0051] The stop element 15 is formed as an annular circumferential radial protrusion 15a, so that when the cavity 11 is closed, a gap 17 is formed in the axial direction between the transparent area 14 of the upper part 3 and the surface of the workpiece 16, and the protrusion 15 is arranged between the cavity 11 and the gap 17, so that the surface of the workpiece 16 is oriented parallel to the end face 14a, in particular parallel to the surface of the inserted glass 14b. This is advantageous because the surface of the workpiece 16, in particular the surface of the workpiece sample 16a to be inspected, can be uniformly and clearly seen through the transparent area 14 and the microscope can be used as an optical sensor 26 for monitoring the workpiece 16 during the etching process. Due to the clamping element 13 formed as a coil spring 13, the workpiece surface to be processed is always at a structurally predetermined - axial - distance from the glass 14b. This allows a reliable inspection of the workpiece 16 in situ even during the etching process. The optical axis of the optical sensor 26 corresponds to the axial direction.

[0052] According to FIG. 4, when the etching device 1 is closed, i.e. in particular when the cavity 11 is closed by the upper part 3, the etching liquid supply conduit 7 opens via the glass tube 7a into the supply channel 18 of the upper part 3. The diameter of the etching liquid supply conduit 7 and the diameter of the glass tube 7a respectively correspond to the diameter of the part of the supply channel 18 facing it. The supply channel 18 runs through the upper part 3 and opens into the gap 17. This allows the etching liquid to reach the surface to be etched of the workpiece 16. The etching liquid is led via the discharge channel 19 from the gap 17 into the cavity 11 and from the etching device 1 via the etching liquid discharge conduit 8 of the lower part 2 together with the dissolved components of the workpiece 16.

[0053] FIG. 5 shows the upper part 3 from above, where it can be seen that the upper part 3 has an approximately circular outer contour and on its radial side surface 3a a total of three projections 6 are arranged evenly distributed around the circumference. The transparent area 14 likewise has an approximately circular outer contour and is inserted into the upper part 3 as optical glass 14b, as already explained. Due to the transparency of the optical glass 14b forming the transparent area 14, a supply channel 18 formed axially below the transparent area 14 is visible from above in FIG. 5. The supply channel 18 has a portion that extends approximately axially below the optical glass 14b and is laterally delimited by two walls 20, 21. In this portion, the supply channel 18 is designed as a groove with a depth of 1 mm surrounded by the walls 20, 21. The walls 20, 21 are spaced apart from one another at a distance that increases in the direction of the gap 17 and thereby forms an acute angle between them, so that the supply channel 18 widens in the direction of the gap 17. As a result, the flow characteristics of the etching solution flowing through the supply channel 18 to the workpiece 16 are improved and in particular the formation of bubbles in the gap 17 is avoided. The discharge channel 19 of the upper part 3 is also seen in Figure 5 and has a constant diameter which is smaller than the diameter of the supply channel 18 in the region seen in Figure 5.

[0054] FIG. 6 is a bottom view of the upper portion 3 of FIG. 5. The supply channel 18 is arranged to communicate the glass tube 7a with the etching liquid supply conduit 7 of the lower portion 2 when the cavity 11 of the lower portion 2 is closed. The discharge channel 19 opens into the cavity 11 of the lower portion 2 that is closed by the upper portion 3. In FIG. 6, only the portion of the optical glass 14b surrounded by the annular protrusion 15a of the locking member 15 is shown. The underside of the upper portion 3 of FIG. 6 has an annular groove 3c approximately in the center in the radial direction between the locking member 15 and the side surface 3a, and a seal ring 3d is inserted into this groove to seal the cavity 11 of the lower portion 2 from the outside when the etching apparatus 1 is assembled.

[0055] FIG. 7 shows the lower part 2 of the etching device 1, which has a cylindrical side surface 2a corresponding to the upper part 3, on which three clamping clips 5 are evenly distributed around the circumference. The clamping clips 5 are formed to correspond to the projections 6 of the upper part 3. The cavity 11 of the lower part 2 is exposed in the plan view of FIG. 7. As already explained, the etching liquid supply conduit 7 serves to convey the etching liquid in the supply channel 18 of the upper part 3. The etching liquid discharge conduit 8 serves to guide the etching liquid emerging from the discharge channel 18 of the upper part 3 out of the cavity 11 of the lower part 2. As can be seen from FIG. 7, the discharge channel 8 of the etching liquid is formed partly as a groove 8a, which is formed in the bottom 11a of the cavity 11 and which extends through the side surface 2a of the lower part 2. The upper side of the lower part 2 shown in FIG. 7 has an annular groove 2d corresponding to the annular groove 3c of the upper part 3, and is therefore also formed to receive a sealing ring 3d when the etching device 1 is closed.

[0056] In an alternative embodiment of the etching apparatus 1, the discharge channel 19 in the upper part 3 opens directly into the etching liquid discharge conduit 8 in the lower part 2, which in that case, like the etching liquid supply conduit 7, can partially comprise or be connected to a glass or plastic tube.

[0057] 8 a) shows a view from the front and b) shows a view from above of the workpiece container 12. The workpiece container 12 has a stepped hollow cylindrical shape with a lower cylindrical part 22 and an upper cylindrical part 23, the latter having a smaller diameter than the lower cylindrical part 22. Both cylindrical parts 22 and 23 are formed as sleeves and define an interior 12a shown in FIG. 3, in which the previously described clamping element in the form of a coil spring 13 can be arranged. The upper cylindrical part 23 has an opening 24 on its end side, in which the workpiece 16 can be inserted and placed on the coil spring 13 arranged in the workpiece container 12. The cylindrical parts 22, 23 are made from polytetrafluoroethylene (PTFE).

[0058] The lower cylindrical part 22 has an opening 25 on its side 22a, which opens into the interior 12a of the workpiece container 12. The etching liquid led from the discharge channel 19 into the cavity 11 of the lower part 2 can reach the interior 12a of the workpiece container 12 through the opening 25 and flow out of the workpiece container 12 again through the opening 25. Therefore, the interior 12a of the workpiece container 12 is not sealed off from the cavity 11 of the lower part 2.

[0059] Fig. 9 shows a second embodiment of the etching apparatus 1 according to the present invention, which has substantially the same structure as the first embodiment of the etching apparatus 1, and has corresponding components configured in the same manner (see Figs. 1 to 8). Note that the same technical components in Fig. 9 are denoted by the same reference numerals as in Figs. 1 to 8, and the corresponding descriptions are to be referred to.

[0060] The etching device 1 according to FIG. 9 has an optical sensor 26 arranged axially above the glass 14b for visual inspection of the etching process, which in the illustrated embodiment is formed as a diagrammatically represented microscope 26, FIG. 9 showing an axially movable objective lens 26a of the microscope 26 for visual inspection of the etching process in particular in situ. During the axial movement of the objective lens 26a, there is a risk that the objective lens 26a comes into contact with the glass 14b and, if the movement continues, in particular the etching liquid will leak out, causing serious damage. In order to avoid damage to the etching device 1, its feet 9 each have a pressure sensor 9a. The pressure sensors 9a are formed to measure a force directed towards the base. This force corresponds to the weight force of the etching device 1 during normal operation. However, if the objective lens 26a comes into contact with the glass 14b, the force measured by the pressure sensor 9a increases. In this case, a warning signal can be emitted to warn the user of impending damage to the etching device 1.

[0061] FIG. 10 shows an etching device 1 in a third embodiment of the invention, which is similar to the embodiment according to FIG. 9 and therefore has some identically constructed components. The same reference numerals as in FIG. 9 are therefore used for the technical components identical to those in FIG. 10 and reference is made to the corresponding description. In contrast to the embodiment of FIG. 9, the coil spring 13 is electrically conductive and is in contact with the electrically conductive metal plate 27a of the lower part 2. On the side facing the workpiece 16, the coil spring 13 has an electrical contact 27b which is in contact with the workpiece 16 and serves to electrically contact the workpiece 16. The workpiece container 12 is also electrically conductive and can be electrically contacted via a second connection terminal 27c, so that a voltage can be applied to the workpiece 16 to be etched. This makes the etching device of FIG. 10 suitable for electrolytic etching of the workpiece 16.

[0062] FIG. 11 shows a fourth embodiment of the etching device 1 according to the invention, which is structurally similar to the embodiment of FIG. 10 and therefore has some identically constructed components. Therefore, the same reference numerals as in FIG. 10 are used for the technical components that are the same as in FIG. 11, and reference is made to the corresponding description. Unlike the etching device 1 shown in FIG. 10, the etching device 1 of FIG. 11 has a heating plate 28 as a heating element arranged in the workpiece container 12 of the lower part 2 and a temperature sensor 29 that radially penetrates the lower part 2 at the axial height of the workpiece 16 and protrudes into the cavity 11. The heating plate 28 converts the supplied electrical energy into heat and is electrically connected to the electrical terminal 27 of the lower part 2. In the embodiment shown here, the heating plate 28 is thermally conductively connected to the etching liquid in the gap 17 via the spring element 13 and the workpiece 16 in order to control and adjust the temperature of the etching liquid in a user-specified manner.

[0063] Figure 12 shows a part of an etching system 30 according to the invention, which, in addition to the etching apparatus 1 (not shown in Figure 12) and the etching liquid reservoir 48 (not shown in Figure 12), has four etching liquid sources 31, only one of which is shown in schematic form in Figure 12. The etching liquid sources 31 are disposed inside the reservoirs 32, so that in the event of leakage from the etching liquid sources 31, the leaked etching liquid is collected in the reservoirs 32 to avoid damage to the environment.

[0064] The etching liquid source 31 is connected via an etching liquid conduit 33 to a housing 34 in which a pumping device 38 and a valve device 39 are arranged, the pumping device 38 and the valve device 39 being not shown in FIG. 12. The housing 34 further comprises a control unit 37 (not shown in FIG. 12) by means of which the pumping device 38 and the valve device 39 can be controlled in order to convey the etching liquid from the etching liquid source 31 to the etching device 1. The housing 34 comprises a cover 35 in which an input unit 36 ​​designed as a control panel (not shown in FIG. 12) is integrated. The input unit 36 ​​is connected for signal transmission to the control unit 37 and makes it possible to control the components arranged in the housing 34 in order to operate the etching device 1.

[0065] FIG. 13 shows in schematic cross section a part of the etching system 30 shown in FIG. 12, in which a pumping device 38 and a valve device 39 arranged in the housing 34 can be seen. In the embodiment shown here, the valve device 39 is a directional valve, which directs the etching liquid from at least one of the four etching liquid sources 31 to the pumping device 38. A control panel 36 is arranged on the side of the cover 35 opposite the housing and is connected to a control unit 37 having a microcontroller. Signal connections of the control unit 37 with the pumping device 38 and the valve device 39 make it possible to control them. This control can be performed in a time-controlled manner, so that the etching process can be started and ended at user-defined times. The pumping device 38 is connected to the etching liquid supply conduit 7 (not shown in FIG. 13) of the etching device 1 according to the invention.

[0066] In another embodiment, the valve device 39 is designed as a mixing valve, by means of which the etching liquid present in the etching liquid source 31 can be conveyed in a predefinable ratio to the etching device 1, in particular to the gap 17 therebetween. The mixing ratio can be set via the control panel 36. Likewise, the time sequence of the etching process can also be set via the control panel 36. One of the etching liquid sources 31 can be filled with a cleaning liquid, which can be user-definedly controlled via the control unit 37 in order to feed the cleaning liquid into the gap 17 of the etching device 1, in particular to facilitate the etching process in a user-defined manner. In this way the etching process can be terminated in a controlled manner.

[0067] Figure 14 shows a view from above of part of the etching system 30 according to Figures 12 and 13, from which four etching liquid sources 31 can be seen, which are, as already mentioned, respectively connected via etching liquid conduits 33 to valve devices 39 in the housing 34 of the etching system 30. The etching liquid can be conveyed to the etching device 1 according to the invention via supply conduits 40. Figure 15 shows a view from the rear of part of the etching system 30 of Figures 12 to 14, from which the arrangement of the etching liquid sources 31 in the tank 32 can be seen in particular.

[0068] Figure 16 shows a fourth embodiment of the etching device 1 according to the invention in a side view, in which the etching device 1 is arranged in a drip tray 41, which itself is arranged on a base 42. In the embodiment shown, the base 42 is designed as a microscope table. Figure 17 shows the etching device 1 from Figure 16 in a schematic cross section, in which it can be seen that the etching device is in contact with the drip tray 41 via the already described feet 9.

[0069] FIG. 18 shows an etching system 30 already partially described with reference to FIGS. 12 to 15, which is operated in an etching liquid circuit using an etching device 1 according to the invention according to FIGS.

[0070] 18, a part of the etching system 30 shown in FIGS. 12 to 15 is connected to an etching liquid supply conduit 7 via a supply conduit 40. The flow rate, time or temperature of the etching liquid transported into the etching apparatus 1 via the etching liquid supply conduit 7 can be set by the control unit 43 or the input unit 36.

[0071] After the etching process, the etching liquid leaves the etching device 1 again through the etching liquid discharge conduit 8 and reaches a first two-way valve 46, which is designed to be electrically controllable and is connected to the control unit 37 for signal transmission in a manner not shown here. By means of an electrical control signal, the etching liquid emerging from the etching device 1 can be selectively led via a discharge line 47 into an etching liquid reservoir 48. The etching liquid reservoir 48 makes it possible to lead off an amount of etching liquid contaminated by the etching process from the etching system 30. It is within the scope of the embodiment shown in FIG. 18 that the contaminated etching liquid is led off from the etching system 30 as required, depending on a user input via the control unit 43 or automatically and at regular intervals.

[0072] Alternatively, the first two-way valve 46 can be controlled via an electrical control signal, such that the etching liquid is directed to a return conduit 49. The etching liquid reaches a second two-way valve 50, which is designed to be electrically controllable via the return conduit 49 and is connected to the control unit 43 for signal transmission in a manner not shown here.

[0073] The etching solution in the return conduit 49 can be returned to one of the etching solution sources 31 via the second two-way valve 50 for later reuse. Alternatively, the etching solution can be conducted directly to the etching solution supply conduit 7 via a bypass conduit 52 without first having to be supplied to the etching solution source 31. In this case, the etching solution can be circulated via the conduits 7, 8, and 49 and ultimately conducted into the etching solution reservoir 48 by appropriately operating the first two-way valve 46.

[0074] As already explained with reference to FIG. 13, one of the etching liquid sources 31 may contain a cleaning agent, for example in the form of an alcohol, which may be introduced into the etching device 1 via the etching liquid supply conduit 7 and influence the etching process occurring there. The cleaning agent may then be circulated in the etching system 30 for cleaning purposes via the etching liquid discharge conduit 8 in the manner already explained, via the first two-way valve 46, the return conduit 49, the second two-way valve 50 and the bypass conduit 52. After completion of such a cleaning process, the cleaning agent may be discharged into the etching liquid reservoir 48 or into another cleaning agent reservoir (not shown here) by activating the first two-way valve 46. In a corresponding manner, cleaning of the etching device 1 may be performed by correspondingly activating the control unit 37, allowing air to be led from this control unit via the etching liquid supply conduit 7 to the etching device 1, from where it may be led via the etching liquid discharge conduit 8, the first two-way valve 46, the discharge conduit 47 and finally to the etching liquid reservoir 48, from where the air may be discharged to the external environment.

Claims

1. An etching device (1) for a workpiece (16) to be treated by an etching solution, comprising: A cavity (11) in which the workpiece (16) can be loaded, the cavity (11) is at least partially surrounded by at least one fastening member (15) of the etching device (1) for the workpiece (16), the fastening member (15) and an end face (14a) of the etching device (1) facing the fastening member (15) partially surround a gap (17) for introducing the etching liquid; The end surface (14a) of the etching device (1) facing the engaging member (15) is formed to be at least partially transparent. Etching equipment.

2. 2. The etching device according to claim 1, characterized in that the stop (15) is formed as at least one projection (15a), in particular annular, between the cavity (11) and the gap (17).

3. An etching apparatus as claimed in claim 1 or 2, characterized in that at least one clamping element (13) is provided in the cavity (11), and the workpiece (16) introduced into the cavity (11) and / or a workpiece holder which can be introduced into the cavity (11) and to which a workpiece (19) can be attached is clamped by the locking member (15).

4. 4. The etching device according to claim 3, characterized in that the clamping element (13) comprises a spring element (13), in particular a metal spring (13a).

5. 5. The etching apparatus according to claim 1, characterized in that in the cavity (11) a workpiece container (12) is arranged for accommodating the workpiece (16) and / or the workpiece (19) which can be introduced into the cavity (11), in particular the workpiece container (12) having the clamping element (13).

6. 6. The etching apparatus according to claim 1, wherein the etching liquid supply channel (18) opening into the gap (17) is formed so as to at least partially expand in the direction of the gap (17).

7. 7. An etching apparatus according to any one of claims 3 to 6, characterized in that the clamping element (13) is electrically conductively connected to an electrical terminal (27).

8. The etching apparatus according to any one of claims 1 to 7, characterized in that a heating element (28) is arranged in the cavity (11), the heating element (28) being configured to heat the etching liquid introduced in the gap (17) to a user-specified temperature.

9. characterised in that the support surface (9) of the etching device is in particular formed as at least one leg and has a pressure sensor (9a), The etching apparatus according to any one of claims 1 to 8.

10. The etching device (1) is formed in two parts, characterised in that the lower part (2) of the etching device (1) in particular at least partially comprises a cavity (11) and / or the upper part (3) of the etching device (1) comprises the stop member (15) and / or the gap (17), The etching apparatus according to any one of claims 1 to 9.

11. 11. The etching apparatus according to claim 1, further comprising an optical sensor (26) arranged such that the workpiece (16) introduced into the cavity (11) is detected by the optical sensor (26) at least partially via the transparent area (14).

12. the etching device (1) is connected to at least one etching solution source (30) via at least one etching solution supply conduit (7) and to at least one etching solution reservoir (46) via at least one etching solution discharge conduit (8); An etching system (30) comprising an etching device (1) according to any one of claims 1 to 11.

13. 13. The etching system according to claim 12, characterized in that a pump device (38) and / or a valve device (39) are connected to the etching liquid supply conduit (7) and / or to the etching liquid discharge conduit (8).

14. said pump arrangement (38) and / or said valve arrangement (39) being connected to a control unit (37) such that said etching solution is introduced into said etching apparatus (1) using user-defined process parameters; 14. The etching system according to claim 13, characterized in that the process parameters include at least one parameter from the following group: composition of the etching liquid, flow rate of the etching liquid, density of the etching liquid, supply time of the etching liquid to the gap (17), drain time of the etching liquid to the gap (17).

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