DE102022104461A1 - Etching device and etching system - Google Patents

Abstract

The invention relates to an etching device for a workpiece to be machined by means of an etching liquid with a cavity into which the workpiece can be introduced, a supply channel for the etching liquid opening into the cavity being designed to widen at least in sections in the direction of the cavity (11). The invention also relates to an etching system with said etching device, wherein the etching device is connected to at least one etching liquid source via at least one etching liquid inlet line and to at least one etching liquid reservoir via at least one etching liquid outlet line.

Description

The invention relates to an etching device for a workpiece to be machined using an etching liquid and an etching system with the etching device.

Etching devices are used for the chemical processing of workpieces. Here, the etching liquid, which is also called pickle, is applied to a surface of the workpiece that is to be machined. A chemical reaction takes place between the etching liquid and the surface of the workpiece, whereby the surface of the workpiece is removed and a depression is formed. In this way, metallic workpieces in particular can be structured in a user-defined manner or electrical conductor paths can be formed on circuit boards in electronics production. The workpiece surface can also be contrasted with a heterogeneous structure for material testing. With so-called color etching, different layers of a workpiece surface can be selectively colored.

It is desirable to optimize the chemical reaction between the etching liquid and the workpiece surface to be machined in order to achieve high etching quality.

The known etching devices have the disadvantage that the etching of the workpiece is influenced by inhomogeneities in the etching liquid. It is therefore the object of the invention, while avoiding the disadvantages of the prior art, to develop an etching device which enables an optimized etching process. The same applies to the etching system.

The object of the invention is achieved by an etching device for a workpiece to be machined by means of an etching liquid with a cavity into which the workpiece can be introduced, with a feed channel for the etching liquid opening into the cavity being designed to widen at least in sections in the direction of the cavity. The object of the invention is also achieved by an etching system with an etching device according to the invention, the etching device being connected to at least one etching liquid source via at least one etching liquid inlet line and to at least one etching liquid reservoir via at least one etching liquid outlet line.

The invention is based on the basic idea that the widening design of the inlet channel significantly reduces the formation of air bubbles compared to an inlet channel with a constant width. The etching process is improved by the resulting homogenization of the etching liquid.

The widening section of the inlet channel preferably opens into the cavity in order to reduce the formation of air bubbles to a large extent.

Preferably, the cavity is at least partially surrounded by at least one stop of the etching device for the workpiece, with the stop and a front side of the etching device facing the stop partially surrounding a gap for introducing the etching liquid, and with the front side of the etching device facing the stop being transparent at least in regions . Due to the design, the locking provides a reproducible stop that is easy to provide for the surface of the workpiece to be machined. In addition, the surface of the workpiece to be machined is always at the same, predefined distance from the transparent end face of the etching device, especially during the etching process, which enables a particularly simple visual in situ inspection to optimize the etching process easily and effectively.

In the following, directions are described based on a cylindrical coordinate system; in this case, an axial direction corresponds to a vertical direction, with a radial direction and a circumferential direction each being aligned horizontally and thus perpendicularly to the axial direction.

In order to improve durability, the etching device can have a housing made of etching-resistant material, in particular in an area arranged adjacent to the cavity. The housing preferably has a closable opening through which the workpiece to be machined can be introduced into the cavity. The workpiece can be attachable to a workpiece holder which is made in particular of an etching-resistant material and whose dimensions are preferably adapted to the dimensions of the etching device. By introducing the workpiece into the cavity, the workpiece and/or the workpiece holder preferably comes into contact with the locking device at least in some areas and remains in a position during the subsequent etching process that can be predetermined by the position and/or the geometry of the locking device.

The at least one locking device is preferably arranged in such a way that the workpiece surface to be machined is aligned parallel to the transparent area of the end face facing the locking device in order to avoid optical aberrations.

The locking device is preferably arranged on a lateral inner wall of the cavity not. In a structurally simple embodiment of the invention, the locking device can be designed as at least one projection between the hollow space and the intermediate space. In the context of the invention, the intermediate space can in particular be a part of the cavity and/or connected to it. The locking device can be designed as a projection directed towards the cavity, in particular radially inward, it being possible for a plurality of projections to be distributed over the circumference of the inner wall. The locking device is preferably ring-shaped or frame-shaped in the circumferential direction. As a result, a workpiece arranged in the cavity and/or the workpiece holder to which the workpiece can be attached can bear against the ring-shaped or frame-shaped locking device at the edge and are reliably held on it. In such an arrangement, the detent as well as the interior wall of the cavity on which the detent may be located may partially define the clearance. At the same time, the gap can be delimited on one side by the workpiece and/or the workpiece holder, which bear against the locking device at the edge. The workpiece surface to be etched can point towards the gap. In this way, etching liquid introduced into the intermediate space can reach the surface of the workpiece to be machined, with the workpiece occupying a geometrically predefined, reproducible position and being visible through the transparent area of the front side of the etching device facing the locking device.

The transparent area of the end face facing the locking device can be designed as a glass and/or plastic insert inserted into a depression in the end face, in particular as an inserted glass pane. In particular, the glass insert can have an optical glass that differs in its chemical composition from ordinary window glass and is usually used to produce optical elements such as lenses, mirrors or prisms. The use of optical glass favors the optical monitoring of the etching process by means of the etching device according to the invention, in particular in combination with an optical sensor which is designed as a microscope, for example. For the purposes of the invention, transparent denotes a transmittance sufficient for the visual inspection of the etching process for the wavelength range actually used, which includes the optically visible wavelength range, but is not necessarily limited to this. The glass pane can have a circular configuration corresponding to the indentation and/or can be arranged radially centered on the end face. The glass pane preferably has a diameter of between 90 mm and 100 mm and/or a thickness of approximately 1 mm.

At least one clamping element is preferably provided in the cavity in such a way that the workpiece that can be introduced into the cavity and/or the workpiece holder to which the workpiece can be attached can be clamped with the locking device. For this purpose, the clamping element can be designed to act on the workpiece that can be introduced into the cavity and/or the workpiece holder with a force directed towards locking. This ensures that workpieces with different geometries always come into contact with the locking device, so that the workpiece surface to be machined is at a predefined distance from the transparent area of the end face of the etching device. For example, the clamping element can be moved, in particular linearly, in the direction of the locking.

In a particularly simple structural configuration, the clamping element has at least one spring element, it being possible for the spring element to be designed as a helical spring and/or as a metal spring. As an alternative or in addition to this, the clamping element can have a carriage that can be moved linearly in particular and that can be subjected to a force in the direction of the locking.

In an advantageous development of the invention, a workpiece holder is arranged in the cavity to accommodate the workpiece to be machined and/or the workpiece holder that can be introduced into the cavity and to which the workpiece can be attached, with the workpiece holder in particular having the clamping element.

According to the invention, the workpiece holder serves to accommodate the workpiece and/or the workpiece holder to which the workpiece can be attached, in order to be able to position them in a defined position within the cavity. The workpiece holder preferably has a stop edge for the workpiece, which delimits the bearing surface of the workpiece laterally, ie radially, and specifies the position of the workpiece. The workpiece holder can preferably have an interior space with at least one clamping element, with which the workpiece can be positioned and fixed for the etching process. The workpiece holder is preferably arranged in the cavity in such a way that the workpiece that can be arranged thereon points in the direction of the intermediate space with its workpiece surface to be machined. The workpiece holder can, in particular when the etching device is closed, be arranged completely in the cavity and/or, when the etching device is open, partially protrude from the cavity. The workpiece holder can in particular be arranged movably in the cavity by means of a bearing and/or can be fixed in a defined position by means of a locking element. In an advantageous development of the invention, the workpiece taking cylindrical, in particular designed as a hollow cylinder.

In an advantageous development of the invention, the workpiece holder is designed to be telescopic, for example as in particular two cylinder sleeves, which are preferably guided one inside the other and form a common interior space. The workpiece and/or the workpiece holder with the workpiece can be arranged in the interior of the workpiece holder via an opening on the end face. In terms of a space-saving design, the clamping element, in particular the helical spring, can be arranged in the interior of the workpiece holder and in particular can be movably guided over the inner wall of the workpiece holder. As a result, the inner wall of the workpiece holder can define an adjustment axis for the clamping element and the workpiece that can be positioned thereon and/or the workpiece holder.

The first cylinder sleeve of the workpiece holder can have a slightly larger inner diameter than the outer diameter of the second cylinder sleeve of the workpiece holder. As a result, the cylinder sleeves can in particular be guided over one another, so that they can be displaced relative to one another and along a common longitudinal axis via a common contact area. The workpiece holder is preferably made at least partially from an etch-resistant material, for example polytetrafluoroethylene (PTFE).

In an advantageous development, the inflow channel, which widens at least in sections, can be widened in the direction of the intermediate space and open into the intermediate space. In particular, the inlet channel is designed to widen continuously. For example, the side walls in the widening section of the inlet channel are not aligned parallel to one another, but enclose a finite, acute angle between them. The inlet channel is preferably designed to widen over a horizontal, in particular radial, section. According to the invention, the etching liquid reaches the intermediate space via the inlet channel and thus reaches the surface of the workpiece to be machined. The inflow channel can in particular be formed in sections between the locking device and the end face of the etching device which faces the locking device. the diameter of the inflow channel can be larger than the diameter of the outflow channel, in particular in a section directed towards the intermediate space. The inlet channel, in particular its horizontal section, most preferably its widening section, is preferably designed as a groove which is surrounded by the side walls and has a depth of 1 mm, for example.

In a preferred embodiment, the clamping element is electrically conductively connected to an electrical connection in order to make electrical contact with the workpiece that can be introduced into the cavity. This enables an electrolytic etching process with the etching device according to the invention, which is also known as electroetching. The surface of the workpiece to be machined is removed using an electric current. The workpiece can thus be electrically contacted. With this type of etching, less corrosive etchant liquids can be used to machine the workpiece compared to purely chemical etching. The etching liquid serves as an electrolyte and the workpiece electrically connected to the connection as an electrode, in particular as an anode. It is within the scope of the skilled person to immerse a second electrode, preferably made of noble metal, as a cathode at a suitable position inside or outside the etching device in the etching liquid. The cathode is preferably arranged in the cavity in such a way that the cathode is electrically conductively connected to the etching liquid during the etching process. The cathode is preferably detachably connected to the etching device so that the cathode can be replaced. A structurally simple further development of the invention can provide that the cathode is configured in a cylindrical shape.

By applying a voltage between the anode and the cathode, a current flows, whereby ions are released from the anode, in this case the workpiece, and reach the cathode through the etching liquid as the electrolyte. Said ions of the workpiece separate out or fall out of solution as a deposit on the cathode. As a result, the workpiece surface is etched at the desired points.

The cathode is preferably arranged within the cavity in such a way that it does not have any mechanical contact with the workpiece during the electrolytic etching process in order to avoid an electrical short circuit.

A heating element can preferably be arranged in particular in the cavity, which is designed to heat the etching liquid introduced into the intermediate space to a user-defined temperature. This makes it possible to also thermally etch the workpiece. Such an etching method is based on the knowledge that the result of the etching process can be decisively influenced and controlled, and therefore optimized, by a desired temperature control of the etching liquid. For this purpose, the heating element can be arranged in a simple manner in the cavity of the etching device and/or configured as a heating plate.

The heating element can be designed as an electrical heating element that can convert electrical energy supplied into heat. In a structurally simple embodiment of the invention, the heating element is arranged in the area of the inlet channel so that the etching liquid can be heated to a user-defined temperature as it flows through the inlet channel in the direction of the workpiece to be machined and can thus come into contact with the workpiece.

The heating element can be designed as a heating plate, which is arranged in particular in the workpiece holder.

In addition to the heating element, at least one temperature sensor can be provided in order to determine and monitor the temperature of the etching device, in particular the etching liquid. The cavity and/or the workpiece holder preferably has the temperature sensor, preferably in its interior. A magnetic stirrer or a rotatable flow propeller is preferably provided, which is designed to bring about uniform wetting of the workpiece surface with etching liquid. For this purpose, the magnetic stirrer and/or the flow propeller can be arranged in an etching liquid line arranged upstream of the intermediate space and/or in the inlet channel. As a result, a uniform and homogeneous removal of material can be achieved on the workpiece surface to be etched, which is referred to as a workpiece sample within the meaning of the invention. Viewed microscopically, the ions of the workpiece that are produced as a result of the etching process are transported away in an optimized manner, so that static effects that disrupt the etching process are avoided and, as a result, a reproducible etching result 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 the clamping element.

Preferably, a contact surface of the etching device, which is designed in particular as at least one base, has a pressure sensor. According to the invention, a pressure sensor is able to determine a force directed onto the etching device in the direction of a substrate on which the etching device is arranged. The pressure sensor thus generally registers the weight of the etching device, but also a force that is greater than this if external components are placed on the etching device, for example, or come into contact with it. In particular, each base has a pressure sensor. The pressure sensor can be connected to an evaluation unit that 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 that indicates impending damage to the etching device as a result of the force acting on it indicates. The warning signal can be optical and/or acoustic. In this way, especially when an optical sensor comes into contact with the transparent area of the etching device during the inspection of the etching process, the warning signal can be output before the optical sensor destroys the transparent area of the end face and etching liquid escapes from the etching device as a result.

In an advantageous further development of the invention, the etching device is designed in two parts, with a lower part of the etching device being able to at least partially enclose the cavity in particular and/or an upper part of the etching device being able to enclose the detent and/or the intermediate space. The upper part of the etching device can be designed to close the cavity, wherein when the etching device is in a closed state, the upper part can encompass the end face with the transparent region facing the locking device. In addition, the locking device can be arranged on a side of the upper part that faces the cavity, in particular between the cavity and the intermediate space.

The lower part of the etching device can comprise the support surface, in particular the at least one foot, in a structurally simple manner. The etching device, in particular the upper part and/or the lower part, is preferably configured in the form of a cylinder, although cuboid, in particular cubic, configurations can also be provided as an alternative.

The upper part can be designed as a cover element for the lower part, with which the cavity of the lower part can be selectively closed tightly or released again. The upper part preferably has an outer contour that corresponds to the lower part, so that the outside of the upper part lies flush against the outside of the lower part when the lower part is connected, in particular closed, to the upper part. This enables easy handling of the etching device according to the invention. An etch-resistant seal, which is in the form of a sealing ring, for example, is preferably provided in an area between the upper part and the lower part. To close the cavity, the lower part and the upper part can have locking elements arranged on their respective outer sides and corresponding to one another, so that the lower part can be releasably connected to the upper part, in particular can be connected in a non-positive and/or positive manner. At least one quick-release clamp is preferably provided for this purpose in order to clamp the upper part to the lower part.

The locking device is preferably always at a predefined distance from the end face facing the locking device, with the upper part in particular being able to have the at least one locking device for this purpose.

In an advantageous development of the invention, the upper part has the inlet channel and the lower part has an etching liquid inlet line, the etching liquid inlet line being connected to the inlet channel when the etching device is in the closed state. The diameter of the etching liquid feed line can correspond to the diameter of the feed channel, in particular in a section directed towards the etching liquid feed line. This makes it possible to conduct etching liquid via the etching liquid feed line and via the feed channel into the intermediate space to the surface of the workpiece to be machined. The etching liquid feed line can also remain connected to an etching liquid source when the upper part is removed from the lower part as a result of replacing a workpiece. Compared to supplying the etching liquid exclusively via the upper part, the connections that carry the etching liquid are not affected by the movements of the upper part, for example when the cavity is opened or closed. At least in sections, the etching liquid feed line can be configured as a glass tube or can be connected to such a glass tube.

At least one optical sensor of the etching device is preferably arranged in such a way that the workpiece that can be introduced into the cavity can be detected at least partially by the optical sensor through the transparent area in order to be able to visually inspect the etching process. The optical sensor can be designed as an optically magnifying system and/or use electromagnetic radiation in the infrared, ultraviolet and/or visible spectrum to inspect the workpiece. In an advantageous development of the invention, the optical sensor is designed as a microscope, in particular as an objective of a microscope, which can be moved in particular in the direction of the workpiece. In addition, the optical sensor can have a camera, in particular a video camera, in order to store and process image information of the workpiece. The optical sensor can be arranged at an in particular variable distance from the end face pointing to the locking device. The optical sensor can also be designed to output a warning signal if the optical sensor falls below a predefined distance from the transparent area of the end face and/or touches it.

The etching liquid source of the etching system according to the invention can be designed in a simple manner as a tightly closable container which has an etching-resistant surface and is used for storing etching liquids. The etching system preferably has a plurality of such sources of etching liquid, which can be connected to one another via a line system which can have at least one valve and at least one feed line. The at least one valve is preferably designed as a two-way valve.

The etching system according to the invention can have at least one pump device and/or at least one valve device, which is connected at least indirectly to the etching liquid inlet line and/or to the etching liquid outlet line in order to direct etching liquid at a particularly predefined flow rate to the intermediate space and/or to drain it away from the intermediate space. The flow of the etching liquid can be controlled in a user-defined manner by means of the pump device and/or the valve device, for example in order to start and/or end the etching process in a user-defined manner.

The pumping device comprises at least one pump and is connected in particular via the valve device to the at least one etching liquid source and to the inflow channel and to the etching liquid inflow line in order to convey etching liquid from the etching liquid source via the etching liquid inflow line and the inflow channel into the intermediate space. In addition, the pump device can be connected to the inflow channel, the outflow line and the etching liquid reservoir in order to guide the etching liquid out of the intermediate space to the etching liquid reservoir in a user-defined manner after the etching process. The pumping device is in particular designed to be electrically controllable and can allow the setting of a volume- and/or pressure-regulated flow of etching liquid.

The valve device comprises at least one controllable valve, in particular a solenoid valve, which can be designed as a blocking, directional or mixing valve. The at least one controllable valve is preferably designed as a two-way valve. The valve device can be electrically controllable. The valve device allows the flow of etching liquid to be released or blocked in a simple manner by means of an electrical signal, in particular in a user-defined manner, in order to start, interrupt and/or end the etching process of the etching device.

In an advantageous development of the invention, the valve device and/or the pump device is connected to a plurality of etching liquid sources in order to inject the etching liquid into the intermediate zones in a user-defined mixing ratio to promote chin space. At least one mixing valve can be provided for this purpose. In addition, a rinsing liquid source can be provided in order to direct a rinsing liquid in the rinsing liquid source into the intermediate space in a user-defined manner, in particular by means of the pump device and/or the valve device, in order to interrupt the etching process and pump the etching liquid out of the intermediate space in a controlled manner.

The pump device and/or the valve device is preferably connected to a control unit in such a way that the etching liquid can be introduced into the etching device with a user-defined process parameter, the process parameter comprising at least one parameter from the following group: composition of the etching liquid, flow rate of the etching liquid, density of the etching liquid , Timing of the inflow of the etchant into the gap, Timing of the outflow of the etchant from the gap.

The control unit can be designed to control the pump device and/or the valve device with a predetermined clock frequency. The composition of the etching liquid routed to the intermediate space can preferably be controlled in a user-defined manner by means of the control unit, in particular by means of the mixing valves mentioned. In addition, the control unit can be connected to the electrical connection and/or to the heating element in order to control the electrical and/or the thermal etching process.

An advantageous development of the invention can provide for the heating element to be arranged as part of the etching system outside the etching device in such a way that the temperature of the etching liquid is controlled before and/or while it enters the etching liquid feed line and/or the feed channel.

The etching device and/or at least one component of the etching system can be arranged in a collecting trough in order to protect the environment from any escaping etching liquid in the event of a leak.

• 1 ein erstes Ausführungsbeispiel einer erfindungsgemäßen Ätzvorrichtung in einer Frontansicht, wobei ein Unterteil und ein Oberteil der Ätzvorrichtung voneinander gelöst dargestellt sind;
• 2 die Ätzvorrichtung gemäß 1 mit zusammengesetztem Unterteil und Oberteil;
• 3 die Ätzvorrichtung gemäß 1 in einem Schnitt;
• 4 die Ätzvorrichtung gemäß 2 in einem Schnitt;
• 5 das Oberteil der Ätzvorrichtung gemäß 1 einer Aufsicht;
• 6 das Oberteil gemäß 5 in einer Unteransicht;
• 7 das Unterteil der Ätzvorrichtung gemäß 1 in einer Aufsicht;
• 8 eine Werkstückaufnahme der Ätzvorrichtung gemäß 1 in a) einer Frontansicht und b) einer Aufsicht;
• 9 ein zweites Ausführungsbeispiel einer erfindungsgemäßen Ätzvorrichtung mit einem optischen Sensor in einer geschnittenen Frontansicht;
• 10 ein drittes Ausführungsbeispiel einer erfindungsgemäßen Ätzvorrichtung zum elektrolytischen Ätzen;
• 11 ein viertes Ausführungsbeispiel einer erfindungsgemäßen Ätzvorrichtung zum thermischen Ätzen;
• 12 einen Teil eines Ätzsystems in Seitenansicht;
• 13 der Teil des Ätzsystems gemäß 12 in einem Schnitt;
• 14 der Teil des Ätzsystems gemäß 12 in Aufsicht;
• 15 der Teil des Ätzsystems gemäß 12 in Hinteransicht;
• 16 ein viertes Ausführungsbeispiel der erfindungsgemäßen Ätzvorrichtung in einer Seitenansicht;
• 17 die Ätzvorrichtung gemäß 16 in einem Schnitt und
• 18 das Ätzsystem gemäß 13 bis 15, das einen Ätzmittelkreislauf aufweist.

Further advantages and features of the invention result from the claims and the following description, in which exemplary embodiments of the invention are explained in detail. show:

• 1 a first embodiment of an etching device according to the invention in a front view, wherein a lower part and an upper part of the etching device are shown detached from each other;
• 2 the etching device according to 1 with assembled lower part and upper part;
• 3 the etching device according to 1 in one cut;
• 4 the etching device according to 2 in one cut;
• 5 the upper part of the etching device according to 1 a supervisor;
• 6 the upper part according to 5 in a bottom view;
• 7 the lower part of the etching device according to FIG 1 in a supervision;
• 8th a workpiece holder of the etching device according to FIG 1 in a) a front view and b) a top view;
• 9 a second embodiment of an etching device according to the invention with an optical sensor in a sectional front view;
• 10 a third embodiment of an etching apparatus for electrolytic etching according to the present invention;
• 11 a fourth embodiment of an etching device according to the invention for thermal etching;
• 12 a part of an etching system in side view;
• 13 the part of the etching system according to 12 in one cut;
• 14 the part of the etching system according to 12 in supervision;
• 15 the part of the etching system according to 12 in rear view;
• 16 a fourth embodiment of the etching device according to the invention in a side view;
• 17 the etching device according to 16 in a cut and
• 18 the etching system according to 13 until 15 , which has an etchant circuit.

1 shows a first exemplary embodiment of an etching device 1 according to the invention, which is used for the chemical processing of a workpiece 16 by means of an etching liquid. The etching device 1 is designed in two parts and is approximately cylindrical and comprises a lower part 2 and an upper part 3, with the upper part 3 being designed to have a cavity 11 formed in the lower part 2 (see FIG 3 and 4 ) to close. The etching device 1 has a quick-release fastener 4 which includes a clamp 5 and a projection 6 corresponding thereto. The clamp 5 is on the radial lateral surface 2a of the lower part 2 arranged, while the projection 6 is arranged on the radial lateral surface 3a of the upper part 3.

The lower part 2 has an etching liquid inlet line 7 and an etching liquid outlet line 8 . Etching liquid feed line 7 runs radially through lateral surface 2a of lower part 2 and opens into a vertically oriented glass tube 7a, which extends through cavity 11, protrudes from an upper end face 2b of lower part 2, and according to FIG 1 is directed to the upper part 3. The etchant discharge line 8 also runs through the lateral surface 2a of the lower part 2 and opens into its cavity 11. Feet 9 with contact surfaces are provided on an underside 2c of the lower part 2 facing away from the upper part 3.

On the underside 3b facing the lower part 2, the upper part 3 has a centering 10, by means of which the upper part 3 can be positioned radially centered on the lower part 2 and inserted into it with a tight fit. For this purpose, the centering 10 has a slightly smaller diameter than the inside diameter of the cavity 11 . The centering 10 has an in 1 manner not shown on a radially laterally arranged, chemically and corrosively resistant seal. For better clarity, the centering 10 is no longer shown in the following figures.

In the 1 The etching device 1 shown is in a loading state in which a workpiece 16 can be positioned within the lower part 2 on a coil spring 13 in a cylindrical, etch-resistant workpiece holder 12 of the lower part 2 . This condition is in relation to 3 explained.

2 shows the etching device 1 according to FIG 1 with the lower part 2 and the upper part 3 in an assembled state, the clamp 5 and the projection 6 being clamped together. According to 2 is the etching device 1 in an operating state, which with respect to 4 is explained.

3 shows the etching device 1 according to FIG 1 , i.e. in the loaded state, in one cut. According to the representation in 1 the upper part 3 is shown detached from the lower part 2 and raised. The lower part 2 has the cavity 11 on the upper end face 2b. As already mentioned, the workpiece holder 12 is arranged in the cavity 11 , which in the exemplary embodiment shown here is hollow and has an opening 24 on its upper end face on a side facing the upper part 3 in order to accommodate the workpiece 16 .

A clamping element in the form of a metallic helical spring 13 is arranged inside the workpiece holder 12, on which the workpiece 16 can be positioned. The helical spring 13 is rigidly connected to the workpiece holder 12 at an end remote from the upper part 3 . The workpiece holder 12 is in 8th shown in detail and will be described in more detail below.

On its axially upper end face 14a, the upper part 3 has a transparent area 14, which is designed here as optical glass 14b, which is arranged as an insert part flush with the end face 14a of the upper part 3 and rests on the upper part 3 in an area that is serves as a support surface. On the upper part 3 here an annular locking device 15 is formed. With the cavity 11 open—the etching device 1 is in the loading state—a workpiece 16 to be etched and a workpiece sample 16a to be etched and examined is positioned in the workpiece holder 12 and on the helical spring 13 . The upper part 3 is then placed on the lower part 2 and braced with it in order to close the cavity 11 . Here, the locking device 15 comes into mechanical contact with an edge area of the workpiece 16 . The closing movement of the upper part 3 is transmitted to the workpiece 16 and to the helical spring 13 by means of the locking device 15, as a result of which the latter is tensioned mechanically and serves as a clamping element. When the cavity 11 is closed—the etching device 1 is in the operating state—the workpiece 16 is thus clamped between the helical spring 13 and the locking device 15 and subjected to an axially upward force directed toward the locking device 15 . this is in 4 shown.

The detent 15 is designed as a ring-shaped circumferential radial projection 15a; when the cavity 11 is closed, an intermediate space 17 is formed axially between the transparent region 14 of the upper part 3 and the surface of the workpiece 16, with the projection 15 being arranged between the cavity 11 and the intermediate space 17 and the surface of the workpiece 16 being parallel to the end face 14a, is aligned in particular parallel to the surface of the glass 14b used. This is advantageous since the surface of the workpiece 16, in particular the surface of the workpiece sample 16a to be examined, can be seen uniformly well through the transparent area 14 and a microscope can be used as an optical sensor 26 to monitor the workpiece 16 during the etching process. Due to the clamping element 13, which is designed as a helical spring 13, the workpiece surface to be machined is always at a constructively predefined—axial—distance from the glass 14b. This enables reliable inspection of the movement piece 16 also in situ during the etching process. The optical axis of the optical sensor 26 corresponds to the axial direction.

The etching liquid feed line 7 opens according to FIG 4 in the closed state of the etching device 1, i.e. in particular when the cavity 11 is closed by the upper part 3, via the glass tube 7a into an inlet channel 18 of the upper part 3. The diameter of the etching liquid inlet line 7 and the diameter of the glass tube 7a each correspond to the diameter of the line directed towards it Section of the inlet channel 18. The inlet channel 18 extends through the upper part 3 and opens into the intermediate space 17. The etching liquid thus reaches the surface of the workpiece 16 to be etched the space 17 into the cavity 11 and via the etching liquid discharge line 8 of the lower part 2 from the etching device 1.

5 shows the upper part 3 in a plan view, in which it can be seen that the upper part 3 has an essentially circular outer contour, on the radially outer lateral surface 3a of which a total of three projections 6 are arranged distributed evenly over the circumference. The transparent area 14 also has an essentially circular outer contour and is inserted into the upper part 3 in the manner already explained—as optical glass 14b. Due to the transparency of the optical glass 14b forming the transparent portion 14, is in the top view 5 the inlet channel 18 can be seen, which is formed axially below the transparent area 14 . The inlet channel 18 has a section which runs essentially axially below the optical glass 14b and is delimited laterally by two walls 20, 21. In this section, the inlet channel 18 is designed as a 1 mm deep groove surrounded by the walls 20,21. The walls 20 , 21 are at a distance from one another that increases in the direction of the intermediate space 17 and thereby enclose an acute angle between them, so that the inlet channel 18 is designed to widen in the direction of the intermediate space 17 . As a result, the flow properties of the etching liquid flowing through the inlet channel 18 to the workpiece 16 are improved and, in particular, the formation of air bubbles in the intermediate space 17 is avoided. The drain channel 19 of the upper part 3 is also in 5 visible and points out in the in 5 visible area has a constant diameter which is smaller than the diameter of the inlet channel 18 .

6 shows the upper part 3 of 5 in a bottom view. The inlet channel 18 is arranged in such a way that when the cavity 11 of the lower part 2 is closed, it communicates with the glass tube 7a and with the etching liquid inlet line 7 of the lower part 2 . The drain channel 19 opens into the cavity 11 of the lower part 2, which is closed by the upper part 3. In 6 only the portion of the optical glass 14b bordered by the annular projection 15a of the detent 15 can be seen. The bottom of the shell 3 of the 6 has an annular groove 3c radially approximately centrally between the detent 15 and the lateral surface 3a, into which a sealing ring 3d is inserted in order to seal the cavity 11 of the lower part 2 from the outside when the etching device 1 is assembled.

7 shows the lower part 2 of the etching device 1, which has the cylindrical lateral surface 2a corresponding to the upper part 3, on which three clamps 5 are arranged distributed evenly over the circumference. The clamps 5 are designed to correspond to the projections 6 of the upper part 3 . In the supervision of 7 the cavity 11 of the lower part 2 is released. In the manner already explained, the etching liquid feed line 7 serves to convey etching liquid into the feed channel 18 of the upper part 3 . Etching liquid discharge line 8 serves to guide the etching liquid emerging from discharge channel 18 of upper part 3 out of cavity 11 of lower part 2 . How based on 7 As can be seen, the etchant discharge channel 8 is partially designed as a groove 8a which is formed in a bottom 11a of the cavity 11 and runs through the lateral surface 2a of the lower part 2 . The top of the base 2 according to 7 has an annular groove 2d, which corresponds to the annular groove 3c of the upper part 3, and is therefore also designed to accommodate the sealing ring 3d when the etching device 1 is closed.

In an alternative embodiment of the etching device 1, the discharge channel 19 of the upper part 3 can open directly into the etchant discharge line 8 of the lower part 2, wherein the etchant discharge line 8, like the etchant feed line 7, can partially have a glass or plastic tube or be connected to a glass or plastic tube can.

8th shows in view a) a front view and in view b) a top view of the workpiece holder 12. The workpiece holder 12 has a stepped hollow cylindrical shape with a lower cylinder part 22 and an upper cylinder part 23, with the upper cylinder part 23 having a smaller diameter than the lower cylinder part 22 has. Both cylinder parts 22 and 23 are designed as sleeves and delimit the interior space 12a, which 3 is shown and in which the clamping element already described in the form of the coil spring 13 can be arranged. The upper cylinder part 23 has the opening 24 on the front side, through which the Workpiece 16 can be introduced and placed on the coil spring 13 positioned in the workpiece holder 12 . The cylinder parts 22, 23 are made of polytetrafluoroethylene (PTFE).

The lower cylinder part 22 has an opening 25 on its lateral surface 22a, which opens up the interior space 12a of the workpiece holder 12 . The etching liquid conducted from the discharge channel 19 into the cavity 11 of the lower part 2 can reach the interior 12a of the workpiece holder 12 via the opening 25 and can flow out of the workpiece holder 12 again through the opening 25 . The interior 12a of the workpiece holder 12 is therefore not sealed off from the cavity 11 of the lower part 2 .

9 shows a second exemplary embodiment of the etching device 1 according to the invention, which is essentially identical in structure to the first exemplary embodiment of the etching device 1 and has correspondingly identically structured components (cf. 1 until 8th ). For the same technical components, in 9 the same reference numerals as in FIGS 1 until 8th used and reference is made to the corresponding explanations.

The etching device 1 according to FIG 9 has, for the visual inspection of an etching process, an optical sensor 26 which is arranged axially above the glass 14b and which is designed as a schematically illustrated microscope 26 in the exemplary embodiment shown, wherein 9 an axially displaceable lens 26a of the microscope 26 shows in order to inspect the etching process visually, in particular in situ. During the axial movement of the objective lens 26a, there is a risk that the objective lens 26a will come into contact with the glass 14b and, if the movement continues, break it, which would cause serious damage, in particular because of the etching liquid then escaping. To avoid damaging the etching device 1, its adjustable feet 9 each have a pressure sensor 9a. The pressure sensors 9a are designed to determine a force directed against the ground. In normal operation, this force corresponds to the weight of the etching device 1. However, if the lens 26a comes into contact with the glass 14b, the force determined by the pressure sensors 9a increases. In this case, provision is made for a warning signal to be output in order to inform a user that etching device 1 is about to be damaged.

10 shows the etching device 1 according to the invention in a third exemplary embodiment, which is similar to the embodiment according to FIG 9 is and accordingly partially identically constructed components. Therefore, for the same technical components in 10 the same reference numerals as in 9 used and reference is made to the corresponding explanations. In contrast to the design of 9 the coil spring 13 is designed to be electrically conductive and is in contact with the electrically conductive metal plate 27a of the lower part 2 . On its side facing the workpiece 16, the helical 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 holder 12 is also designed to be electrically conductive and can also be electrically contacted via a second connection 27c, so that the workpiece 16 to be etched can be subjected to an electrical voltage. This makes the etching device suitable 10 for electrolytic etching of the workpiece 16.

11 shows a fourth embodiment of the etching device 1 according to the invention, which is similar in structure to the configuration of FIG 10 is and accordingly partially identically constructed components. Therefore, for the same technical components in 11 the same reference numerals as in 10 used and reference is made to the corresponding explanations. In contrast to the in 10 Etching device 1 shown has the etching device 1 of 11 an electric heating plate 28 arranged on the lower part 2 and inside the workpiece holder 12 as a heating element, and a temperature sensor 29 which radially extends through the lower part 2 at the axial height of the workpiece 16 and protrudes into the cavity 11 . The heating plate 28 converts supplied electrical energy into heat and is electrically connected to the electrical connection 27 of the lower part 2 . In the exemplary embodiment shown here, the heating plate 28 is thermally conductively connected to the etching liquid in the intermediate space 17 via the spring element 13 and the workpiece 16 in order to control the temperature of the etching liquid in a user-defined manner and to regulate its temperature.

12 shows part of an etching system 30 according to the invention, which, in addition to the in 12 Etching device 1, not shown, and an in 12 Etching liquid reservoir 48 not shown has four etching liquid sources 31, of which in 12 due to the perspective, only one source of etching liquid 31 can be seen. Etching liquid sources 31 are arranged within a trough 32, so that in the event of a leak, etchant escaping from etching liquid sources 31 is collected in trough 32 and further damage to the environment is avoided.

The etching liquid sources 31 are each connected via an etching liquid line 33 to a housing 34 in which a pump device device 38 and a valve device 39 are arranged, the pump device 38 and the valve device 39 in 12 are not shown. The housing 34 also includes a also in 12 non-visible control unit 37, with which the pump device 38 and the valve device 39 can be controlled in order to convey etching liquid from the etching liquid source 31 to the etching device 1. The housing 34 includes a cover 35, in which a control panel designed and 12 input unit 36, not shown, is integrated. The input unit 36 is connected to the control unit 37 in terms of signals and allows the components arranged in the housing 34 to operate the etching device 1 to be controlled.

13 shows the in 12 part of the etching system 30 shown in a schematic section, according to which the pump device 38 arranged in the housing 34 and the valve device 39 can be seen. In the exemplary embodiment shown here, the valve device 39 is a directional control valve, by means of which etching liquid is routed from at least one of the four etching liquid sources 31 to the pumping device 38 . The control panel 36 is arranged on a side of the cover 35 facing away from the housing and is connected to the control unit 37, which has a microcontroller. It is possible to control the pump device 38 and the valve device 39 via the signal connections between the control unit 37 and the pump device 38 . The control can be timed so that the etching process can be started and stopped at user-defined times. The pump device 38 is connected to the etchant supply line 7 of the etching device 1 according to the invention, which is 13 is not shown.

In an alternative embodiment, the valve device 39 is designed as a mixing valve, with which it is possible to convey the etching liquids in the etching liquid sources 31 in a definable ratio to the etching device 1, in particular into the intermediate space 17 thereof. The mixing ratio can be set using the control panel 36. A time sequence for the etching process can also be set via the control panel 36 . One of the etching liquid sources 31 can be filled with a rinsing liquid that can be controlled in a user-defined manner via the control unit 37 in such a way that the etching process is promoted in a user-defined manner by feeding the rinsing liquid into the intermediate space 17 of the etching device 1 . In this way, the etching process can be completed in a controlled manner.

14 shows the part of the etching system 30 according to FIGS 12 and 13 in top view, from which the four etching liquid sources 31 can be seen, which, as already mentioned, are each connected to the valve device 39 within the housing 34 of the etching system 30 via an etching liquid line 33 . Etching liquid can be conveyed to the etching device 1 according to the invention via feed lines 40 . 15 shows the portion of the etching system 30 of FIG 12 until 14 in rear view, from which in particular the arrangement of the etching liquid sources 31 in the tub 32 can be seen.

16 shows a fourth exemplary embodiment of the etching device 1 according to the invention in a side view, with the etching device 1 being arranged in a collecting pan 41 and the collecting pan 41 itself being arranged on a base 42 . In the exemplary embodiment shown, the base 42 is designed as a microscope table. 17 shows the etching device 1 of FIG 16 in a schematic section, from which it can be seen that the etching device is in contact with the collecting trough 41 via the feet 9 already described.

18 shows the etching system 30, which is partially already in relation to the 12 until 15 was explained, and with an etching device 1 according to the invention according to the 1 until 11 , is operated in an etchant circuit.

According to 18 is the in the 12 until 15 The part of the etching system 30 shown is connected to the etching liquid feed line 7 via one of the feed lines 40 . A remote control 43 or the input unit 36 can be used, as already explained, to set the volume flow, at what time or at what temperature an etching liquid is to be conveyed through the etching liquid feed line 7 into the etching device 1 .

After the etching process, the etching liquid exits the etching device 1 again through the etchant discharge line 8 and reaches a first two-way valve 46. This is designed to be electrically controllable and is connected to the control unit 37 in terms of signals in a manner not shown here. By means of an electrical control signal, the etching liquid emerging from the etching device 1 can optionally be routed via a discharge line 47 into an etching agent reservoir 48 . Etching agent reservoir 48 allows an amount of etching liquid contaminated by the etching process to be removed from etching system 30 . It is within the in 18 shown embodiment that the contaminated etching liquid is performed as needed and depending on a user input via the remote control 43 from the etching system 30 or automated and at regular time intervals.

Alternatively, the first two-way valve 46 can be activated via an electrical control signal in such a way that the etching liquid is routed into a return line 49 . Via the return line 49 the etching liquid reaches a second two-way valve 50, which is also designed to be electrically controllable and is connected to the control unit 43 in terms of signals in a manner not shown here.

The etching liquid in the return line 49 can be fed back to one of the etching agent sources 31 via the second two-way valve 50 so that it can then be used further. Alternatively, the etchant can be conducted directly into the etchant feed line 7 via the bypass line 52 without having to be fed to an etchant source 31 beforehand. In this case, the etching liquid can circulate via the lines 7, 8 and 49 and, when the first two-way valve 46 is actuated in a suitable manner, can finally be conducted into the etching agent reservoir 48.

How regarding 13 already explained, one of the etching liquid sources 31 can contain rinsing agent, for example in the form of alcohol, which can be fed into the etching device 1 via the etching liquid feed line 7 in the manner already described above, in order to influence the etching process taking place therein. The rinsing agent can then circulate in the etching liquid outlet line 8 in a manner also already described via the first two-way valve 46, the return line 49, the second two-way valve 50 and the bypass line 52 for rinsing purposes in the etching system 30. After completion of such a rinsing process, the rinsing agent can be discharged into the etchant reservoir 48 or another rinsing agent reservoir, not shown here, by actuating the first two-way valve 46 . Etching device 1 can be cleaned in a corresponding manner in that, when control unit 37 is actuated accordingly, air flows from it via etching liquid inlet line 7 into etching device 1 and from there via etching liquid outlet line 8, the first two-way valve 46, outlet line 47 and finally to the Etching liquid reservoir 48 is passed, from where the air can get into the outside environment.

Claims (15)

Etching device (1) for a workpiece (16) to be processed by means of an etching liquid with a cavity (11) into which the workpiece (16) can be introduced, with an inlet channel (18) for the etching liquid opening out into the cavity (11), at least in sections is designed widening in the direction of the cavity (11). Etching device after claim 1 , characterized in that the cavity (11) is surrounded at least in regions by at least one detent (15) of the etching device (1) for the workpiece (16), the detent (15) and an end face (14a ) of the etching device (1) partially enclosing an intermediate space (17) for introducing the etching liquid and wherein the end face (14a) of the etching device (1) facing the locking device (15) is designed transparent at least in regions. Etching device after claim 2 , characterized in that the detent (15) is formed as at least one projection (15a) between the cavity (11) and the intermediate space (17), which is in particular ring-shaped. Etching device according to one of claims 2 or 3 , characterized in that at least one clamping element (13) is provided in the cavity (11) in such a way that the workpiece (16) that can be introduced into the cavity (11) and/or a workpiece holder that can be introduced into the cavity (11) on which the workpiece (19) can be attached, with the lock (15) can be clamped. Etching device after claim 4 , characterized in that the clamping element (13) has a spring element (13), in particular a metal spring (13a). Etching device according to one of Claims 1 until 5 , characterized in that a workpiece holder (12) is arranged in the cavity (11) in order to hold the workpiece (16) to be machined and/or the workpiece holder which can be introduced into the cavity (11) and to which the workpiece (19) can be attached, record, in particular the valuables receptacle (12) having the clamping element (13). Etching device according to one of claims 2 until 6 , characterized in that the at least partially widening inflow channel (18) is widened in the direction of the intermediate space (17) and opens into the intermediate space (17). Etching device according to one of Claims 4 until 7 , characterized in that the clamping element (13) is electrically conductively connected to an electrical connection (27). Etching device according to one of Claims 1 until 8th , characterized in that a heating element (28) is preferably arranged in the cavity (11) and is designed to heat the etching liquid introduced into the cavity (11), in particular into the intermediate space (17), to a user-defined temperature. Etching device according to one of Claims 1 until 9 , characterized in that a bearing surface (9) of the etching device, in particular as at least one base is formed, has a pressure sensor (9a). Etching device according to one of Claims 1 until 10 , characterized in that the etching device (1) is designed in two parts, with a lower part (2) of the etching device (1) in particular the cavity (11) at least partially and/or an upper part (3) of the etching device (1) the locking device (15 ) and/or the intermediate space (17). Etching device according to one of Claims 1 until 11 , characterized in that an optical sensor (26) is arranged in such a way that the workpiece (16) that can be introduced into the cavity (11) can be detected at least partially by the optical sensor (26) through the transparent region (14). Etching system (30) with an etching device (1) according to one of Claims 1 until 12 wherein the etching device (1) is connected to at least one etching liquid source (30) via at least one etching liquid inlet line (7) and to at least one etching liquid reservoir (46) via at least one etching liquid outlet line (8). etching system Claim 13 , characterized in that a pump device (38) and/or a valve device (39) are connected to the etching liquid inlet line (7) and/or to the etching liquid outlet line (8). etching system Claim 14 , characterized in that the pump device (38) and/or the valve device (39) are connected to a control unit (37) in such a way that the etching liquid can be introduced into the etching device (1) with a user-defined process parameter, the process parameter being at least one parameter of the following group: composition of the etchant, flow rate of the etchant, density of the etchant, time of inflow of the etchant into the gap (17), time of outflow of the etchant into the gap (17).

Images