Device for wet processing of planar work convenience, device for a cell of the device, and method for operating the device

Abstract

A device for a cell of a device for wet processing of a planar workpiece comprises a structure including first and second walls (13a,b). The workpiece is movable in a central plane (4) through a space (3) between the first and second walls (13a,b) in a first direction (y). Apertures (27) for introducing pressurized liquid between the first and second walls (13a,b) are provided on opposite sides of the central plane (4) and facing the central plane (4). The apertures (27) are distributed in a first direction (y) and a second direction (x) which is transverse to the first direction (y). Discharge openings (28a,b) for liquid exiting space (3) are defined along the extent of space (3) in the first direction (y), and on opposite sides of space (3) when viewed in the second direction (x). The first and second walls (13a,b) form barriers against liquid flow from space in the direction (z) perpendicular to the central plane (4). Channels (23a,b, 24a,b) are provided through the walls (13a,b), and each channel (23a,b, 24a,b) is arranged to guide liquid to each of the apertures (27).

Description

Technology Field

[0001] The present invention relates to a device for a cell of a device for wet processing of a planar workpiece, and said device,

[0002] It includes a structure comprising first and second walls, and

[0003] The workpiece is movable in the central plane in the first direction through the space between the first and second walls, and

[0004] Apertures for introducing pressurized liquid between the first and second walls are provided on sides opposite the central plane and facing the central plane, and

[0005] Apertures are distributed in the first direction and in the second direction which is transverse to the first direction, and

[0006] Discharge openings for liquid exiting the space are defined along the extent of the space in the first direction, on opposite sides of the space when viewed from the second direction, and

[0007] The first and second walls form barriers against liquid flow from space in a direction perpendicular to the central plane.

[0008] The present invention also relates to an apparatus for wet processing of a flat workpiece.

[0009] The present invention relates to a method for operating such a device.

[0010] The present invention also relates to such a device and at least one use of such a device. Background Technology

[0011] US 2015 / 0252488 A1 discloses a plate for wet chemical electrochemical treatment, wherein a metal is electrochemically deposited onto the surface of a material to be treated. Such a device has a bottom wall defining a treatment chamber, as well as side walls arranged on sides extending parallel to the direction of transport of the material to be treated. Additionally, the treatment chamber is closed laterally with respect to the direction of transport by additional side walls having slots for carrying through the material to be treated. Pairs of compression rollers are arranged on these slots to seal the liquid treatment chamber against a treatment liquid flowing outward, and the material to be treated is guided between them when transported into or out of the treatment chamber. The material to be treated is transported by wheels mounted on shafts at a predetermined distance from each other, and the shafts extend laterally with respect to the direction of transport. Anodes are arranged above and below the material to be treated. A transport plane extends in the direction of transport from the treatment chamber. When viewed from the transfer plane beyond the anodes, the supply devices with nozzles are positioned above and below the material to be processed. The supply devices are formed by top and bottom pen stocks, which transport the processing liquid to the surface of the material to be processed through nozzles on both sides. The nozzles and remaining components are arranged below the bath level in the processing chamber. When in use, there are no walls above the supply devices positioned above the material to be processed. The anodes do not form barriers to liquid flow in a direction perpendicular to the central plane from the space between the anodes. The wheels transporting the material to be processed come into contact with the material at locations along the entire width of the material to be processed. This is undesirable if the material to be processed is relatively vulnerable, for example, if it is covered by a photomask. If the wheels must be omitted, a relatively large distance must be maintained between the anodes and the material to be processed to prevent the material from touching the anodes.Nevertheless, undulations across the width of the material to be processed can lead to the formation of a non-uniform coating due to variations in the distance between the anode and the material.

[0012] DE 42 29 403 A1 discloses an apparatus in which thin plastic foils provided with through bores can be plated on their upper and lower surfaces and the lateral surfaces of the through bores. The plating chamber comprises a housing in which an inlet is formed by a pair of compression rollers and an outlet is formed by a pair of compression rollers. An upper anode and a lower anode extend from above and below the plastic foil at a distance parallel thereto. Each distribution space for the electrolyte is provided between the anodes and the housing of the plating chamber. The anodes are provided with a plurality of through bores inclined with respect to the direction of movement of the plastic foil, so that they converge in the direction of movement. This arrangement is configured so that the electrolyte supplied to the distribution space through conduits enters the space between the anodes and the plastic foil as a moving component parallel to the direction of movement of the plastic foil. The electrolyte flows out of the housing through lateral openings and from there flows into the sump of the apparatus. The lateral opening is provided at only one location along the length of the chamber. Plastic foil is spooled from and onto the reel at each end of the device and held tightly and flat by pairs of compression rollers. Thus, this arrangement is suitable only for processing infinite foils and requires tight contact between the foil and the compression rollers across the width of the foil.

[0013] WO 98 / 49374 A1 discloses an apparatus for electrolytically treating circuit boards and circuit foils in a horizontal continuous apparatus using direct current or pulsed current. The apparatus comprises upper and lower insoluble anodes that function as counter-electrodes. An electrolytic cell is formed by the upper anodes, the circuit board or circuit foil, and the electrolyte space between them. The anodes essentially extend across the width of the workpiece. The circuit boards and circuit foils are guided, preferably towards the center, by upper and lower guide elements between the upper and lower anodes, and are also transported by clamps that function as electrical contact elements. The guide elements are generally electrically insulated narrow spindles having perforated discs of electrically nonconductive plastic mounted thereon. Electrolyte spray devices are arranged outside the electrolyte space on the sides of the counter-electrodes facing away from the transport plane. The spray tubes are provided with holes or nozzles oriented perpendicularly or at an angle to the surface of the workpiece. Holes are provided in the anodes and positioned so that the processing liquid exiting the holes or nozzles in the spray tubes can pass through the anodes substantially or completely unhindered. However, the anodes do not form barriers that prevent liquid flow from the transfer plane in a direction perpendicular to the transfer plane. The spray tubes are positioned at a substantial distance from the upper and lower walls of the device. Therefore, a perforated disc is required to hold the circuit board or circuit foil in the transfer plane.

[0014] However, an arrangement similar to that described in WO 98 / 49374 A1, which does not have a perforated disc on the spindle, is used in a horizontal continuous plating apparatus currently available from the applicant. In such an apparatus, spray bars provided on opposite sides of the plane in which the workpiece is arranged to be transported are oriented in this plane. The distance from the spray bars to the plane of travel of the workpiece is relatively small. Therefore, there is a risk that thin workpieces will be undulated and touch the contact protection grids provided between the anodes and the plane of travel. In the case of dry film electroplating, the photomask may be separated from the workpiece as a result. Even if contact is avoided, the undulations may be fixed due to a relatively rigid metal layer or layers formed on the surface of the workpiece or on the surfaces. The problem to be solved

[0015] The object of the present invention is to provide a device, apparatus, and method of the types defined above in a starting phrase that allows processing of relatively thin workpieces while maintaining workpieces relatively well in a single plane. means of solving the problem

[0016] This objective is achieved according to a first aspect by a device according to the present invention, characterized in that channels are provided through walls, and each channel is arranged to guide liquid to each of the apertures.

[0017] The device may be intended to form a complete cell, or it may be configured to be positioned in a bath to form a cell. In the latter case, the space accessible to the liquid introduced between the opposite surfaces of the first and second walls will be larger than the space section between these opposite surfaces. In one embodiment, a plurality of devices may be provided in a single bath to form a cell. The types of processing may include, in particular, at least one of wet chemical processing, e.g., chemical or electrolytic metal deposition, chemical or electrolytic etching, and chemical or electrolytic cleaning. At least a portion of the liquid introduced through the apertures contains reactants, and the flow of liquid across the surfaces of the workpiece results in the replenishment of reactants and thus more efficient processing. Surface treatment of the workpiece may be only one or both surfaces of the workpiece, but there is a flow of liquid across both surfaces.

[0018] In an embodiment, the device is configured to form a cell for electroplating a workpiece, e.g., pulse plating.

[0019] The workpiece may be a plate or a foil. The workpiece may be a piece of a separate plate or foil, in contrast to a foil that is transferred from reel to reel through the device. The device is particularly suitable for processing relatively thin and relatively flexible flat workpieces, for example, having a thickness of approximately 10 to 100 μm, because these workpieces are more likely to bend. However, the device may also be used in devices for processing thicker workpieces.

[0020] The workpiece is movable in a central plane between the first and second walls in a first direction. The first direction is also referred to herein as the longitudinal direction, but is defined only by the direction of movement. The first direction does not need to correspond to the maximum dimension of the device or the space into which the liquid is introduced.

[0021] The device includes a structure comprising first and second walls. These first and second walls do not need to be joined or form part of a single assembly. However, the first and second walls are mounted to provide opposite surfaces that define at least part of the space accessible to the liquid introduced between the walls. Liquid-permeable structures may be interposed between the walls. However, except for channels, the walls are impermeable to liquid, so the walls form barriers. The first and second walls function as backflow barriers for apertures to introduce liquid into the space between the walls. Thus, the first and second walls form part of the limitation of the space accessible to the liquid introduced between the walls. While this liquid is prevented from flowing directly from the sides of the first and second walls closest to the central plane to the opposite sides of the first and second walls, the liquid can be collected and returned as pressurized liquid by a recirculation system comprising at least one pump.

[0022] Channels are provided through first and second walls, and each channel is arranged to guide liquid into each of a plurality of apertures to introduce liquid into the space between the first wall and the second wall. Apertures for introducing liquid are provided on sides opposite to the central plane and facing the central plane. Thus, the flow direction is mainly toward the discharge openings, close to the apertures, and otherwise toward the central plane. To establish this flow field, apertures can be defined on surfaces at the ends of each channel. When they are defined on the distal ends of nozzles protruding from the surface, these nozzles protrude only a relatively short distance from the surface, so that the associated wall still functions as a backflow barrier.

[0023] Because apertures are distributed in a first direction and a second or lateral direction transverse to the first direction, pressurized liquid is introduced at multiple locations across the surfaces of the walls. This accelerates the flow of the liquid in the opposite lateral direction toward the discharge openings. During operation, the discharge openings are located at the lateral edges of the workpiece moving through the device. Depending on the extent to which the space in which the workpiece moves is closed at the longitudinal ends of such space, flow in the first direction is restricted or non-existent.

[0024] Any section of a planar workpiece deviating from the center plane toward one of the opposite surfaces will locally narrow the already narrow gap between that surface and the workpiece. The flow is pinched, and as a result, the pressure increases locally. The pressure decreases locally on the opposite side of the workpiece. The resulting force will have a tendency to return the workpiece section to the center plane. This restoring effect cannot be achieved by nozzles directing branch jets toward the surfaces of the workpiece, because any section of the workpiece moving closer to the nozzle orifice receives a local impulse but does not receive a net force to return this section to the center plane. This is because there is no backflow barrier immediately behind the nozzle.

[0025] In contrast, in the present device, the workpiece is held substantially in the central plane by the flow of liquid on each side. Consequently, the space in which the workpiece can move can have a relatively small height. Thus, the amount of liquid to be circulated is relatively small, and the device becomes relatively compact. Unintended contact between the surface of the workpiece and the device is avoided. Solid guide elements in contact with the surfaces of the workpiece, far from the lateral edges of the workpiece, can be omitted at least between the longitudinal ends of the device. The workpiece does not need to be held under a second, lateral tensile force.

[0026] Since the discharge openings for the liquid are defined on opposite sides of space when viewed in the second direction and provided along the range in the first direction of space, the flow of the liquid is directed outward from the middle in both lateral directions. If the flow were to exist in the second direction only from one edge of the workpiece to the opposite edge, the thin workpiece would start to flutter like a flag when the wind blows, especially if it is supported only on one of its edges.

[0027] As mentioned, in an embodiment of the device, apertures are defined on the surfaces of the first and second walls at the ends of each channel.

[0028] That is, the channels are essentially through bores of the first and second walls. The channel ends at the apertures are at least coplanar with the wall surface. This helps, first, to establish the desired flow field. Second, the first and second walls can be positioned closer together.

[0029] The embodiment includes first and second liquid dispensing devices, the first and second walls each include the walls of the first and second liquid dispensing devices, and the liquid dispensing devices are mounted such that the space extends between the liquid dispensing devices.

[0030] This embodiment has relatively few parts.

[0031] In an embodiment of the devices, at least one liquid distribution space extending in a second direction across the inlets of the channels is defined on the opposite side of at least one of the first and second walls with respect to the space.

[0032] In particular, a first liquid distribution space may exist on the side opposite the first wall facing the direction of the central plane, and a second liquid distribution space may exist on the side opposite the second wall facing the direction of the central plane. If the device includes first and second liquid distribution devices, the liquid distribution spaces may be defined in the respective chambers of the liquid distribution devices. The liquid distribution space equalizes the liquid pressure on the upstream side of the channels through the first and second walls. Accordingly, each liquid distribution space generally extends in the first and second directions across the inlets of a plurality of channels. Each liquid distribution space may, for example, extend substantially across the first and / or second directional range of the wall on the side where such liquid distribution space is defined.

[0033] In a specific example of the present embodiment, the liquid distribution space is defined by a barrier inclined toward the wall, and the liquid distribution space tapers toward the edge of the wall.

[0034] The effect is that the liquid is required to be introduced into the liquid distribution space only on one side of the liquid distribution space. The liquid may be introduced through one or more elongated apertures extending in a first or second direction at or near the edge of the liquid distribution space and generally parallel thereto. The height of the liquid distribution space decreases toward the opposite edge (relative to the first or second wall). As a result, a relatively uniform exit velocity of the liquid across the apertures is achieved without providing liquid inlets for pumping the liquid into the liquid distribution space along multiple edges of the liquid distribution space.

[0035] An example of an embodiment of a device in which a liquid distribution space is defined on the opposite side of at least one of the first and second walls with respect to the space includes at least one branch liquid conduit that widens toward the opposite side, having an inlet connectable to a liquid supply conduit on one side and communicating with the liquid distribution space at a plurality of locations along the width of the branch liquid conduit.

[0036] This embodiment requires only a limited number of connections to tubular conduits carrying liquid from the pump. Nevertheless, uniform flow is achieved along the edges of the liquid distribution space. In the embodiment, flow guides may be provided along at least a portion of the length of the branch conduit, for example, at the wider end of the branch conduit. This helps to avoid turbulence. Liquid communication with the liquid distribution space at multiple locations along the width of the branch liquid conduit may be through multiple distinct apertures distributed along the width of the branch liquid conduit. Alternatively, a single aperture may extend along most of the width of the branch liquid conduit, for example, substantially the entire width, corresponding to at least 90% or at least 95% of the width of the branch liquid conduit.

[0037] In an example of this embodiment of a device comprising first and second liquid dispensing devices, the first and second walls each comprise the walls of the first and second liquid dispensing devices, the liquid dispensing devices are mounted such that a space extends between the liquid dispensing devices, and the branch liquid conduit and liquid dispensing space are defined within a chamber in the housing of one of the first and second liquid dispensing devices by a barrier extending within the chamber.

[0038] This results in a compact configuration with relatively few sealed connections between different components, and thus results in a relatively low risk of leakage.

[0039] In an embodiment of the device, at least one of the discharge openings is formed by a single gap extending along a range in a first direction of space to opposite liquid-impermeable parts, for example, between the edges of the first and second walls.

[0040] The effect is that the edge section of the workpiece can be extended through the discharge opening and held outside the space between the first and second walls, or at least a portion of the conveying device for holding the workpiece at the edge of the workpiece can be extended into such a space through the discharge opening. In the latter case, the part holding the workpiece can be effective in moving the workpiece longitudinally through the device. In the former case, the parts holding the workpiece can at least support the workpiece as it moves through the device, but they can also move the workpiece through the device.

[0041] In the examples, each discharge opening has a height of up to 100 mm, for example, up to 50 mm or even less than 40 mm.

[0042] In this regard, the term height refers to a dimension in the transverse direction relative to the central plane.

[0043] The relatively small height allows the sections of the workpiece to return to the center plane when moving from such a plane so that a flow rate of up to 10 m / s, for example less than 8 m / s or even less than 5 m / s, is achieved. The minimum flow rate can be, for example, 0.1 or 0.5 m / s.

[0044] The embodiment further includes at least one liquid-permeable electrode, for example, a planar electrode, extending into a plane between the central plane and one of the first and second walls.

[0045] The present embodiment is for an electroplating cell. In particular, there may be a first liquid-permeable electrode, e.g., a first planar electrode, extending into the plane between the central plane and the first wall, and a second liquid-permeable electrode, e.g., a planar electrode, extending into the plane between the central plane and the second wall. Even relatively thin workpieces have a relatively low risk of coming too close to the electrodes or electrodes due to undulations. This not only reduces the risk of damage from physical contact but also reliably produces a uniform plating thickness. In one embodiment, the electrode may include meshes. Each electrode may be subdivided into mutually electrically isolated segments located in the plane of the electrode. Examples of such configurations and their effects are described, for example, in WO 2003 / 018878 A2.

[0046] The embodiment further includes at least one liquid-permeable shielding structure, for example, a planar shielding structure, extending into a plane between a central plane and one of the first and second walls.

[0047] In the embodiments, such shielding structures are provided on each side of the central plane. When electrodes are provided on each side of the plane, the shielding structures are positioned between the central plane and such electrodes. Thus, contact between the workpiece surface and the electrodes is prevented in all situations. Such contact would otherwise lead to a short circuit, because one of the workpiece and the electrode typically forms the anode and the other the cathode. Each shielding structure will generally be the solid structure closest to the central plane on the side of the central plane where such shielding structures are provided. Each shielding structure may be manufactured from an electrical insulating material, for example, a polymer material. One method of implementing the shielding structure is to provide a relatively large number of relatively small diameter throughgoing channels in a plate of the electrical insulating material. The surface density of these channels will be at least an order of magnitude greater than the scale of the apertures for the first and second walls. The diameters of the channels will be correspondingly smaller. To achieve uniform current densities, two or more adjacent channels at specific locations may be linked by severing a material that would otherwise separate them. Alternatively, or additionally, one or more channels may be plugged together. In the example, the distance between the central plane and the shielding structure is 2 mm to 15 mm, for example, less than 10 mm or even less than 8 mm, in a device intended for use with workpieces having a thickness of less than 1 mm, e.g., less than 10 µm or even less than 50 µm. The shielding structure or structures are particularly used when processing distinct planar workpieces (i.e., sheets such as those in contrast to continuous webs) because they enter a cell having an essentially unsupported free edge. The cross-section of the workpiece at such an edge may be curved in the direction of travel.

[0048] In an embodiment of the device, nozzles extending into apertures are provided on the first and second walls.

[0049] Generally, each nozzle will be provided for each aperture. The nozzles may be formed in the wall, or the nozzles may be separate devices inserted into the bores from the wall and fixed in place against the wall. Generally, the apertures will correspond to the exit orifices of the nozzles. However, in the embodiments, the exit orifices of the nozzle devices may be set back somewhat with respect to the apertures formed on the wall surface. The nozzle devices may protrude slightly from the bore in which they are arranged. However, separate nozzle devices will completely fill the bores in the wall into which they are inserted. Therefore, if separate nozzle devices are provided, the liquid cannot bypass these nozzle devices through the first and second walls. The nozzles allow streams of liquid entering the space to be formed in such a way that the nozzles are separated from the circular-cylindrical channels.

[0050] In a specific example of the present embodiment, the orifices of the nozzles are provided with an elongated shape having a larger dimension in the second direction than in the first direction.

[0051] This has the effect of providing the required tangential flow field (along the surface of the workpiece from the center outward to the discharge opening) without the need to reduce the mutual spacing between the apertures to an extreme degree, particularly in the first direction. Relatively uniform coverage of the workpiece surface by the liquid is achieved. The nozzles may be, for example, fan nozzles, i.e., nozzles having a slit-shaped orifice. In a specific example of the present embodiment, in which the device also comprises at least one liquid-permeable electrode, for example, a planar electrode, extending into the plane between the central plane and one of the first and second walls, the electrode is provided with elongated liquid-permeable windows, for example, apertures, aligned with each nozzle orifice. The liquid-permeable windows in the electrode may have a relatively small area in the present embodiment. Since the electrodes are non-conductive where the windows are provided, fewer compensation measurements are required due to the non-conductive windows. In particular, if a shielding structure is also provided between the electrode and the central plane, the shielding structure requires less adjustment to achieve a uniform current density across the area of ​​the workpiece.

[0052] In an embodiment of the device, the apertures are arranged in rows extending at least approximately in a second direction.

[0053] This contributes to providing a uniform flow from the center to the discharge openings. Generally, there will be at least three, for example, at least five or at least ten apertures in each row. Because the apertures are aligned, each row extends in a straight line. Because the apertures are essentially aligned into rows extending in a second direction (within customary manufacturing tolerances), the rows extend parallel to each other.

[0054] In an example of an embodiment in which apertures are aligned into rows extending in at least a second direction, the apertures are uniformly distributed within each row.

[0055] That is, the spacing between apertures is at least approximately the same for all apertures in a row, and there are at least three apertures in each row. In an embodiment, the spacing is the same for a plurality, for example, a plurality of rows.

[0056] In a specific example of an embodiment in which apertures are aligned into rows extending in at least a second direction and apertures are uniformly distributed within each row, the apertures of each row are offset in the second direction with respect to the apertures of at least one other row.

[0057] This helps avoid streaks in the first direction if the workpiece undergoes electrochemical processing.

[0058] In a specific example of an embodiment in which apertures are aligned into rows extending in at least approximately a second direction, the apertures are uniformly distributed within each row, the apertures of each row are offset in a second direction with respect to at least one other row's apertures, and the apertures are aligned into columns extending at an acute angle with respect to a first direction.

[0059] Therefore, a compromise is achieved between establishing a roughly uniform flow field and preventing streaks on the workpiece.

[0060] In an embodiment of the device, the first and second walls are provided with apertures at at least one of (i) a surface density of at least 460 apertures per m² and (ii) a linear density of at least 16 apertures per m in the second direction (x).

[0061] The effect is that relatively thin, distinct workpieces (i.e., sheets as opposed to continuous webs) with a thickness of approximately 1-100 µm, for example, approximately 5-50 µm, can be processed while being held relatively well in the central plane. This is particularly true for devices configured so that the central plane—which is the transport plane—becomes an inherently horizontal plane.

[0062] For devices configured for use in a device in which the central plane is essentially a vertical plane, the first and second walls are provided with apertures at at least one of (i) a surface density of at least 230 apertures per m² and (ii) a linear density of at least 8 apertures per m in the second direction (x). A smaller number of apertures reduces the manufacturing cost of the device. When the central plane, i.e., the transport plane, is essentially a vertical plane, gravity will support the return of sections of the workpiece moved from the plane back into the plane. Thus, fewer apertures are required for a workpiece of a given thickness.

[0063] According to another aspect, an apparatus for wet processing of a planar workpiece according to the present invention comprises at least one device according to any one of the prior claims.

[0064] The device includes one or more cells. At least one cell includes one or more devices according to the present invention. The type of process executed may differ between the cells.

[0065] The device may include at least one pump for pumping liquid into the apertures of the device or each device according to the present invention. Thus, the pump(s) serve as a source of pressurized liquid. The device may be configured to drive the pump or each pump to achieve a specific minimum flow rate at the discharge openings of the device or each device.

[0066] In an embodiment of the device in which at least one of the discharge openings is formed by a single gap extending between the edges of the opposite liquid-impermeable parts, e.g., first and second walls, along a range in a first direction of the space between the surfaces, the device further comprises a conveying device including at least one clamp for disengaging with a workpiece at an edge of the workpiece, which is guided for movement along the length of the gap, and at least one drive for driving the movement of the conveying device.

[0067] Accordingly, the workpiece needs to be contacted only at one or both of its lateral edges to move the workpiece through the device. In one embodiment, the device may include a series of two or more devices of the aforementioned type and a single transfer device for moving the workpiece through the entire series of devices. The transfer device is guided for movement in a first direction.

[0068] According to another aspect, a method for operating a device according to the present invention comprises the step of pumping liquid through apertures and discharge openings while moving a workpiece through the device in a central plane.

[0069] The workpiece is essentially maintained in a central plane as it moves through the device by the action of a liquid flowing along the surfaces of the workpiece. In particular, the liquid is pumped through at a rate sufficient to ensure that any section of the workpiece moving from the central plane toward one of the first and second walls generates a local force that tends to return such section toward the central plane. The workpiece is a separate workpiece, namely a sheet, rather than a continuous or semi-continuous web. The workpiece may generally be a panel or a foil.

[0070] According to another aspect, the present invention provides a use of a device and / or apparatus according to the present invention for manufacturing semiconductor devices, e.g., photoelectric devices.

[0071] The device and / or apparatus may be used, in particular, to manufacture optoelectronic devices. These devices may be flexible devices. The device and / or apparatus may also be used, for example, to manufacture interconnects in a damascene electroplating process and / or to fill at least one of trenches and vias, for example.

[0072] In certain embodiments, the device and / or apparatus is used to deposit one or more device layers or precursor layers on a substrate, e.g., a silicon substrate, a glass substrate coated with a transparent conductive oxide, a TCO, e.g., a tin oxide (e.g., fluorine-doped tin oxide, FTO, indium tin oxide, ITO), or a molybdenum-coated stainless steel substrate. When the device and / or apparatus is used to deposit a device layer or a precursor layer, the workpiece may subsequently undergo additional processing steps in a controlled atmosphere, e.g., annealing, laser scribing, photoresist patterning, etc. In this regard, it is advantageous for the workpiece to be relatively thin but distinct. Roll-to-roll processing for depositing the device layer or the precursor layer for forming the device layer is not essential.

[0073] Absorbent layers (or their precursors) and rear contact layers can be deposited.

[0074] Optoelectronic devices that can be manufactured in this manner include CdS / CdTe-based solar cell devices, solar cell substrates incorporating ZnTe, ZnSe, ZnS, or ZnO, and doped silicon surfaces having a plating base based on CuInSe2, Cu2ZnSnS4, or CuInGaSe2, or indium-doped tin oxide. These and further embodiments are disclosed, for example, in EP 2 709 160 B1.

[0075] The present invention will be described in more detail with reference to the attached drawings. Brief explanation of the drawing

[0076] Figure 1 is a cross-sectional view of a part of a cell for electroplating a planar workpiece. FIG. 2 is a detailed schematic cross-sectional view illustrating a part of the cell and the flow direction of the electrolyte circulating in the cell. Figure 3 is a plan view of one of two walls through which the workpiece can move between the cells. Figure 4 is a planar cross-sectional view of one of two liquid distribution devices forming part of the cell. Specific details for implementing the invention

[0077] A device (1) for forming part of a cell of a device for wet processing of a planar workpiece includes first and second liquid dispensing devices (2a,b).

[0078] It is also convenient to define a first direction (y), referred to herein as the longitudinal direction, and a second direction (x), which is transverse to the longitudinal direction (y) and referred herein as the lateral direction (Fig. 4). In use, the planar workpiece is guided in the first direction (y) (Fig. 4) through the space (3) (Fig. 1) between the liquid dispensing devices (2a, b). The workpiece essentially extends to a central plane (4) (Fig. 2) midway between the first and second liquid dispensing devices (2a, b). In the example, the central plane (4) is generally a horizontal plane.

[0079] In the illustrated example, the device (1) is intended to form part of an electroplating cell. Accordingly, the device (1) further includes first and second anodes (5a,b) and first and second shielding structures (6a,b).

[0080] The shielding structures (6a,b) may include a grid made of, for example, an electrical insulating material, for example, a polymer material. The shielding structures (6a,b) are liquid permeable. The anodes (5a,b) may be electrically conductive, for example, made of a metal, mesh, or other grid structure. Thus, the anodes (5a,b) are also liquid permeable.

[0081] Although two anodes (5a,b) are shown in the drawings, these anodes (5a,b) do not need to extend across the range of space (3) in the first direction (y). Instead, a series of anodes may exist in a single plane alternately in the first direction (y). Additionally, each anode (5a,b) may be subdivided into mutually electrically insulated segments in the second direction (x).

[0082] The conveying device (7) (Fig. 1) is illustrated only very schematically. The conveying device (7) includes a clamp (8) for holding a workpiece at one of its lateral edges. A plurality of such conveying devices (7) may be provided to hold the workpiece. A drive (9) is arranged to move the conveying device (7) in a first direction (y). The drive (9) may be, for example, an infinite belt or an infinite chain. In the electroplating process, the workpiece functions as a cathode. The clamp (8) or each of the above is arranged to make electrical contact with the workpiece to establish a voltage difference between the workpiece and the anodes (5a,b).

[0083] In the illustrated embodiment, the workpiece is held at only one edge. In other embodiments, the workpiece may be held at opposite edges when viewed from the second direction (x). In particular, the workpiece may extend into the second direction (x) beyond the space (3) and may be driven by wheels or belts that contact the workpiece at the edges of the workpiece.

[0084] Each liquid dispensing device (2a,b) includes a housing having a liquid inlet (10a,b) for connection to each liquid supply conduit (11a,b). One or more pumps (not shown) are provided to pump liquid through the liquid supply conduits (11a,b).

[0085] The chamber (12a,b) is defined by the housing. Each composite wall (13a,b) includes a housing wall (14a,b) of each housing and an additional wall (15a,b) positioned relative to the housing wall (14a,b). At least the facing surfaces of the walls (13a,b) are essentially parallel to the central plane (4), which are the anodes (5a,b) and shielding structures (6a,b). The component walls (14, 15) of each composite wall (13a,b) may be manufactured from different materials. For example, the additional walls (15a,b) may be manufactured from an electrically insulating material. The housing wall (14a,b) may be manufactured from a mechanically stronger material. In an alternative embodiment, the additional walls (15a,b) are omitted. As long as the composite walls (13a,b) form a barrier to liquid flow from the central plane (4) toward the liquid distribution devices (2a,b), only one of the component walls (14,15) of each composite wall (13a,b) needs to be impermeable to liquid.

[0086] Each chamber (12a,b) is subdivided by an inner wall (16a,b) (Fig. 1) into a third direction (z) (Fig. 1 and Fig. 2) that is transverse to the first and second directions (x,y). Each inner wall (16a,b) is inclined toward walls (13a,b) between which a space (3) is defined. A liquid distribution space (17a,b) is defined between the inner wall (16a,b) and the wall (13a,b) closest to the space (3). In one embodiment, the liquid distribution space (17a,b) extends in the first direction (y) over essentially the entire range of the wall (13a,b) toward the first direction (y). In another embodiment, a plurality of adjacent liquid distribution spaces (17a,b) may be provided side by side in a first direction (y) and each may extend in a second direction (x) from one lateral edge of the wall (13a,b) to the opposite lateral edge.

[0087] The liquid distribution space (17) is closed at one lateral end and has an inlet at the opposite lateral end. The liquid distribution space (17) is tapered so that the height of the liquid distribution space (17) decreases toward the closed end.

[0088] At least one gap (18a-f) (Fig. 1 and Fig. 4) exists between the free end of the inner wall (16a,b) and the chamber side wall (19a,b). At least one gap (18a-f) extends together along the range of the chamber (12a,b) in the first direction (y). Each gap (18a-f) provides liquid communication between the liquid distribution space (17) and the branch liquid conduit (20a,b) defined in the chamber (12a,b). The inlet side of the branch liquid conduit (20a,b) is connected to the liquid inlet (10a,b). The outlet side is located in the gaps (18a-f). In the illustrated embodiment, flow guides (21a-c) (Fig. 3) are provided on the outlet side. The flow guides (21a-c) subdivide the branch liquid conduit (20a,b) into parallel channels, in this example, four channels. The side walls (22a,b) of the branch liquid conduit (20) are straight in the illustrated example, but can alternatively be curved.

[0089] In the space (3) between the liquid dispensing devices (2a,b), each wall (13a) located therebetween is provided with a plurality of channels (23a,b, 24a,b) (Fig. 2) that terminate at apertures for introducing liquid into the space (3). In the illustrated embodiment, the longitudinal axes of the channels (23a,b, 24a,b) are oriented substantially perpendicular to the central plane (4).

[0090] In the illustrated embodiment, the additional walls (15a,b) are support walls made, for example, of plastic. Threaded through bores are provided in the additional walls (15a,b) into which nozzle devices (25a-d) (Fig. 2) are inserted. Alternatively, the nozzle devices (25a-d) can be pressurized into the through bores. The nozzle devices (25a-d) completely fill the through bores, allowing liquid to pass only through the additional walls (15a,b) via the nozzle devices (25a-d). Thus, the section of each channel (23a,b, 24a,b) is defined by one of the nozzle devices (25a-d).

[0091] The nozzle devices (25a-b) are fan nozzle devices (25a-d) that shape the stream of liquid coming out of each nozzle device (25a-d). To this end, the constriction forms an orifice (26) (Fig. 3) having an elongated shape with larger dimensions in the second direction (x) than in the first direction (y). The same applies to the exit aperture (27) through which the liquid enters the space (3). In the illustrated embodiment, this exit aperture (27) is slit-shaped.

[0092] The gaps (28a,b) are defined between the walls (13a,b) at the lateral edges of the walls (13a,b). These gaps (28a,b) essentially extend along the range of the walls (13a,b) in the first direction (y).

[0093] Therefore, when in use, the liquid flows outward from the center in a second direction (x). The liquid distribution space (17) and the branch liquid conduit (20) ensure that the liquid is introduced into the space (3) at a relatively uniform rate so that the flow accelerates toward the lateral edges of the workpiece. As a result, a self-centering effect is achieved by keeping the workpiece in a central plane without the need for supports in contact with the workpiece. Nevertheless, the shielding structures (6a,b) ensure that contact with the anodes (5a,b) is prevented in all situations.

[0094] An example of device (1) is configured for workpieces having a thickness of up to 100 μm, e.g., up to 60 μm, up to 50 μm, or even up to 10 μm. Typical dimensions for the height of the gaps (28a,b) range from 2 to 50 mm. The liquid is pumped at a rate such that the velocity in the gaps (28a,b) is at least 0.1 m / s, e.g., at least 0.5 m / s. The velocity will generally be less than 10 m / s and may be less than 5 m / s.

[0095] The shielding structures (6a,b) are spaced apart by at least 5 mm and up to 25 mm, for example up to 20 mm or even less than 15 mm (in a direction perpendicular to the central plane (4)). The distance from each anode (5a,b) to the central plane (4) is at least 8 mm, for example at least 10 mm, and generally up to 15 mm, for example up to 12 mm.

[0096] In the illustrated embodiment, the nozzle devices (25a-d) are arranged in rows that essentially extend parallel to the second direction (x). The mutual spacing between the apertures and, therefore, the nozzle devices (25a-d) is equal within each row. In the illustrated embodiment, this spacing is also the same for all rows. However, the nozzle devices (25a-d) of each subsequent row in the first direction (y) are offset in the second direction (x) relative to the nozzle devices (25a-d) in the previous row. The offset is the same for each pair of rows, and the spacing between rows in the first direction (y) is also uniform. As a result, it can be said that the nozzle devices (25a-d) are arranged in columns that exist at a slight angle (α) with respect to the first direction (y) (Fig. 3). An additional result is that the number of nozzle devices (25a-d) can be 10 or 11. The spacing is equivalent to achieving a linear density of at least 16 apertures (27) per m in the second direction (x). In the illustrated embodiment, the surface density is at least 460 per m², for example, at least 600 per m². Accordingly, the dimensions of the walls (13a,b) in the first direction (y) are at most 500 mm, for example, 400 to 450 mm. The dimensions in the second direction (x) are at most 700 mm, for example, 600 to 650 mm. For these dimensions, there are at least 120 apertures (27) per wall (13a,b).

[0097] The present invention is not limited to the embodiments described above and may be modified and varied within the scope of the appended claims. For example, although the device of the present example has a horizontal transport plane (referred to herein as the central plane (4)), the same effect can be achieved in a device having a vertical transport plane. In such a device, the flow field described herein can be achieved by immersing the device (1) in a liquid bath for a relatively long time so that liquid coming from the upper gap of the gaps (28a,b) does not eject into free space. In embodiments having a vertical transport plane, the dimension in the first direction (x) may be larger, for example, up to 1300 mm. The minimum number of nozzle devices (25a-d) per unit area, as well as the minimum linear density in the second direction (x), may be about half of the values ​​given above for the embodiment having a horizontal transport plane without sacrificing the effect of holding the workpiece relatively well in the central plane.

[0098] In a device comprising a plurality of devices (1) arranged in a row, the spacing between shielding structures (6a,b) can be reduced in a first direction (y).

[0099] The space accessible to the liquid does not need to be completely empty as long as it can be penetrated by the liquid. Therefore, sections of such space may be filled with a porous structure, for example, foam. This can serve as a spacer, for example, between the walls (13a,b) and the anodes (5a,b) and / or between the anodes (5a,b) and the shielding structure (6a,b). Explanation of the symbols

[0100] 1- Device 2a,b - Liquid distribution devices 3 - Space 4 - Central Plane 5a,b - Anodes 6a,b - Shielding structures 7- Transport device 8 - Clamp 9 - Drive 10a,b - Liquid inlets 11a,b - Liquid supply conduit 12a,b - Chamber 13a,b - First and second composite walls 14a,b - Housing walls 15a,b - Additional walls 16a,b - Interior walls 17a,b - Liquid distribution space 18a-f - Gaps in the chambers 19a,b - Chamber side walls 20a,b - Branch liquid conduit 21a-c - Flow Guides 22a,b - Branch conduit side walls 23a,b - 1st channels 24a,b - 2nd channels 25a b - Nozzle devices 26 - Orifice 27 - Exit Aperture 28a,b - Gaps

Claims

Claim 1 A device for a cell of a device for wet processing of a planar workpiece, comprising a structure including first and second walls (13a,b), wherein the workpiece is movable in a central plane (4) through an internal space (3) between the first and second walls (13a,b) in a first direction (y), and apertures (27) for introducing pressurized liquid between the first and second walls (13a,b) are provided on opposite sides of the central plane (4) and facing the central plane (4), wherein the apertures (27) are distributed in the first direction (y) and in a second direction (x) which is transverse to the first direction (y), and discharge openings (28a,b) for liquid exiting the space (3) are provided along the extent of the space (3) in the first direction (y). When viewed from the second direction (x), defined on opposite sides of the space (3), the first and second walls (13a,b) form barriers against liquid flow from the space in a direction (z) perpendicular to the central plane (4), channels (23a,b) are provided penetrating the first wall (13a), channels (24a,b) are provided penetrating the second wall (13b), each channel (23a,b, 24a,b) is arranged to guide liquid to each of the apertures (27), and at least one liquid distribution space (17a,b) extending in the second direction (x) across the inlets of the channels (23a,b, 24a,b) is, in a direction away from the space (3), the first and second walls (13a,b) The liquid distribution space (17a,b) is defined by a barrier (16a,b) disposed on the outer side of at least one opposite side of the first and second walls (13a,b) and on the opposite side of at least one of the first and second walls (13a,b), and the liquid distribution space (17a,b) has a height defined by the barrier (16a,b),A device for a cell of a device for wet processing of a planar workpiece, wherein the height decreases along the second direction (x) from one lateral edge of the first and second walls (13a,b) to the opposite lateral edge for at least one of the first and second walls (13a,b) and forms a closed end of the liquid distribution space (17a,b). Claim 2 In claim 1, the apertures (27) are defined at the ends of each channel (23a,b, 24a,b) and on the surfaces of the first and second walls (13a,b), for a device for a cell of a planar workpiece for wet processing. Claim 3 A device for a cell of a device for wet processing of a planar workpiece, wherein, in claim 1, the device further comprises first and second liquid dispensing devices (2a,b), wherein the first and second walls (13a,b) each comprise walls (14a,b) of the housing of the first and second liquid dispensing devices (2a,b), and the first and second liquid dispensing devices (2a,b) are mounted such that the space (3) extends between the liquid dispensing devices (2a,b). Claim 4 A device for a cell of a device for wet processing of a planar workpiece, wherein, in claim 2, the device further comprises first and second liquid dispensing devices (2a,b), wherein the first and second walls (13a,b) each comprise walls (14a,b) of the housing of the first and second liquid dispensing devices (2a,b), and the first and second liquid dispensing devices (2a,b) are mounted such that the space (3) extends between the liquid dispensing devices (2a,b). Claim 5 A device for a cell of a device for wet processing of a planar workpiece, wherein, in claim 1, an inlet (10a,b) connectable to a liquid supply conduit (11a,b) on one side, and further comprising at least one branch liquid conduit (20a,b) that widens toward the opposite side in liquid communication with the liquid distribution space (17a,b) at a plurality of locations along the width of the branch liquid conduit (20a,b). Claim 6 A device for a cell of a device for wet processing of a planar workpiece, wherein, in claim 5, the branch liquid conduit (20a,b) and the liquid distribution space (17a,b) are separated within the chamber (12a,b) in the housing of one of the first and second liquid distribution devices (2a,b) by a barrier (16a,b) extending within the chamber (12a,b). Claim 7 A device for a cell of a device for wet processing of a planar workpiece, wherein at least one of the discharge openings (28a,b) is formed by a single gap extending between opposite liquid-impermeable parts or the edges of the first and second walls (13a,b) along the range in the first direction (y) of the space (3). Claim 8 A device for a cell of a device for wet processing of a planar workpiece according to claim 1, further comprising at least one of at least one liquid-permeable electrode (5a,b) and at least one liquid-permeable shielding structure (6a,b) extending into a plane between the central plane (4) and one of the first and second walls (13a,b). Claim 9 A device for a cell of a device for wet processing of a planar workpiece, further comprising at least one liquid-permeable shielding structure (6a,b) extending into a plane between the central plane (4) and one of the first and second walls (13a,b) in claim 1. Claim 10 A device for a cell of a device for wet processing of a planar workpiece, wherein the first and second walls (13a,b) further comprise additional walls (15a,b) disposed on the space (3) side of the walls (14a,b), and nozzles (25a-d) extending to the apertures (27) are provided penetrating the additional walls (15a,b). Claim 11 A device for a cell of a device for wet processing of a planar workpiece, wherein the orifices (26) formed at the ends of the nozzles (25a-d) are provided with an elongated shape having a larger dimension in the second direction than in the first direction (y), and the orifices (26) are positioned at a position corresponding to the apertures (27) or at a position set back relative to the apertures (27). Claim 12 In claim 1, the apertures (27) are aligned in rows extending in at least the second direction (x), for a device for a cell of a planar workpiece for wet processing. Claim 13 In claim 12, the apertures (27) are a device for a cell of a device for wet processing of a planar workpiece, which is uniformly distributed within each row. Claim 14 In claim 13, the apertures (27) of each row are offset in the second direction relative to at least one other row aperture, for a device for a cell of a planar workpiece for wet processing. Claim 15 In claim 14, the apertures (27) are aligned in columns extending at an acute angle (α) with respect to the first direction (y), for a device for a cell of a planar workpiece for wet processing. Claim 16 A device for a cell of a device for wet processing of a planar workpiece, wherein the first and second walls (13a,b) are provided with apertures (27) at least one of (i) a surface density of at least 460 apertures (27) per m² and (ii) a linear density of at least 16 apertures (27) in the second direction (x) per m. Claim 17 An apparatus for wet processing of a planar workpiece, comprising at least one device (1) according to any one of claims 1 to 16. Claim 18 An apparatus for wet processing of a flat workpiece according to claim 17, further comprising at least one pump for pumping liquid into apertures (27). Claim 19 In claim 17, the device (1) is a device (1) formed by a single gap extending between opposite liquid impermeable parts or the edges of the first and second walls (13a,b) along a range in the first direction (y) of the space (3), wherein at least one of the discharge openings (28a,b) is formed by a single gap extending along a range in the first direction (y) of the space (3), and the device further comprises a conveying device (7) comprising at least one clamp (8) for disengaging with the workpiece at the edge of the workpiece, which is guided for movement along a range in the first direction (y), and at least one drive (9) for driving the movement of the conveying device (7), for wet processing of a planar workpiece. Claim 20 A method of operating a device according to claim 17, comprising the step of pumping liquid through apertures (27) and discharge openings (28a,b) while moving a workpiece through the device in a central plane (4). Claim 21 A method of operating the device, wherein the liquid is pumped through at a rate sufficient to ensure that any section of the workpiece moving from the central plane (4) toward one of the first and second walls (13a,b) generates a local force that tends to return the section toward the central plane (4). Claim 22 In any one of claims 1 to 16, at least one of the devices is a device for a cell of a device for wet processing of a planar workpiece used to manufacture semiconductor devices or optoelectronic devices. Claim 23 In claim 17, the device is a device for wet processing of a planar workpiece used to manufacture semiconductor devices or optoelectronic devices. Claim 24 A device for a cell of a device for wet processing of a planar workpiece, wherein the barrier (16a,b) contacts the first and second walls (13a,b) only at one end of the first and second walls (13a,b).

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