Method and apparatus for parallel extrusion of a printing medium onto a substrate

Abstract

Device and method for parallel extrusion of a printing medium onto a substrate, in particular a device for manufacturing parallel conductor tracks, having a printing head with a printing medium inlet for a printing medium, which is fluidically connected to a plurality of outlets of the printing head in order to simultaneously output the printing medium from the plurality of outlets in the form of a plurality of parallel printing medium strips, having an electrode element, a counter electrode element and a voltage source, which is configured to cooperate with the electrode element and the counter electrode element in order to form a potential difference between the electrode element and the counter electrode element and an associated electrostatic field, the electrode element being arranged and configured for supplying or discharging an electrical charge to the printing medium, so that the printing medium strips can be loaded with an electrical charge having the same polarity, and the device being configured such that the substrate can be arranged between the printing head and the counter electrode element.

Description

Technical Field

[0001] The present invention relates to a method and apparatus for parallel extrusion of printing media onto a substrate, as described in the preambles of embodiments one and ten. Background Technology

[0002] In industrial printing processes, particularly in the manufacture of semiconductor structures, such as photovoltaic solar cells, it is generally desirable to apply a printing medium onto a substrate in multiple parallel strips. Such a printing medium can be a printing paste, which in particular contains dopants for doping one or more regions of the semiconductor structure, which forms a mask structure for subsequent process steps, and / or the printing paste contains metal particles for forming metal contact structures.

[0003] A printhead is known from DE 10 2013 223 250 A1 for applying multiple parallel printing media lines to a substrate.

[0004] It is generally desirable to apply lines with the smallest possible width in order to, for example, reduce recombination losses at the metal-semiconductor interface and / or reduce shading losses due to the metal contact structure of photovoltaic solar cells.

[0005] Applying fine, parallel printing media lines to a substrate requires that the printhead output port be positioned at a small distance from the substrate surface to avoid curved lines caused by the inclined extension of the printing media lines from the output port. Such applications are known where the printhead output port moves relative to the substrate at a distance of only 50 μm.

[0006] This small pitch requires high precision in guiding the movement between the printhead and the substrate. Furthermore, problems arise when the substrate has unevenness. Reguiding the printhead to compensate for this unevenness is costly and economically impractical. Moreover, unevenness may only occur in one output port or within a group of output ports; therefore, for the remaining output ports, compensating for the aforementioned pitch may result in excessively large pitches. Summary of the Invention

[0007] Therefore, the object of the present invention is to provide an apparatus and a method that enable the application of parallel, straight printing media lines with high precision even when there is a large gap between the output port of the printhead and the substrate.

[0008] The objective is achieved by the device according to Scheme 1 and the method according to Scheme 10. Advantageous design schemes are given in the subordinate schemes.

[0009] Preferably, the device according to the invention is configured to perform the method according to the invention, particularly an advantageous embodiment of the method. Preferably, the method according to the invention is designed to be performed by the device according to the invention, particularly by a preferred embodiment of the device.

[0010] The apparatus according to the invention for extruding printing media parallel onto a substrate, particularly for producing parallel conductor lines, has a printing head having a printing media inlet for printing media, the printing media inlet being flowably connected to a plurality of output ports of the printing head so as to simultaneously output printing media from the plurality of output ports in the manner of a plurality of parallel printing media strips.

[0011] Therefore, during use, multiple printing media strips simultaneously reach the surface of the substrate, preferably perpendicular to the substrate surface. Through the relative movement between the print head and the substrate, multiple parallel lines composed of printing media are applied to the substrate.

[0012] Importantly, the printing apparatus has electrode elements, counter electrode elements, and a voltage source configured to cooperate with the electrode elements and counter electrode elements to generate a potential difference between the electrode elements and counter electrode elements and generate an associated electrostatic field. The electrode elements are arranged and configured to supply or release charge to the printing medium, thereby enabling the printing medium strip to be loaded with a charge of the same polarity. The apparatus is also configured such that a substrate can be disposed between the print head and the counter electrode elements.

[0013] The device is based on the understanding that, because the printing media strips extend non-parallel between the printhead output port and the substrate, non-linear printing media strips appear on the substrate. However, applying a charge of the same polarity to the printing media strips results in a repulsive force between them, which, according to the applicant's research, is clearly beneficial for achieving a parallel distribution of the printing media strips.

[0014] Therefore, according to the invention, the device is configured such that a plurality of parallel printing media strips are output from the output port of the print head, and these printing media strips are charged with the same polarity, that is, each printing media strip is charged with a positive charge or each printing media strip is charged with a negative charge.

[0015] Therefore, during the printing process, the distance between the printhead output port and the substrate surface can be increased while still ensuring the parallel distribution of the printing media strips, thereby applying parallel straight printing media lines to the substrate.

[0016] The method according to the invention is used for extruding printing media parallel onto a substrate, particularly for creating parallel conductor lines. In the method according to the invention, multiple parallel strips of printing media are output from the output port of the print head onto the substrate, and the print head and the substrate are moved relative to each other. Importantly, the printing media strips are charged before being applied to the substrate, wherein all printing media strips have a charge of the same polarity.

[0017] This results in the advantages mentioned above when describing the device according to the invention.

[0018] It is advantageous for the printing medium to pass through the electrode element without being charged before the corresponding printing medium strip is output from the output port. The electrode element advantageously has multiple guide paths for the printing medium. This allows for efficient charge exchange between the electrode element and the printing medium. Particularly advantageously, the electrode element has an output port. Therefore, in this advantageous embodiment, the printing medium is output from the output port in the form of multiple parallel printing medium strips after passing through the electrode element. This avoids the printing medium being recharged due to contact with the elements of the print head after being charged, and in particular, avoids the neutralization of the printing medium.

[0019] The electrode element is advantageously disposed on the printhead. In another advantageous embodiment, the printhead is configured as an electrode element. In many applications, it is advantageous that the printhead is made of a conductive material, particularly a metal. This allows the printhead to be connected to a voltage source in a structurally simple manner, thus enabling the printhead to function as an electrode element. The large-area contact between the printing medium and the printhead ensures efficient exchange of charged particles.

[0020] Preferably, the parallel lines composed of printing media are formed on the substrate in a manner known per se, requiring only relative movement between the print head and the substrate. Within the scope of this invention, the print head moves on a stationary substrate, preferably in a linear motion. Also within the scope of this invention, the substrate moves relative to the print head, particularly preferably by means of a conveying device, such as a conveyor belt.

[0021] Therefore, the device preferably has a transport unit configured to move, particularly linearly, the substrate relative to the printhead, electrode elements, and counter electrode elements. Since only the substrate needs to move, a structurally simple design is achieved.

[0022] Also within the scope of this invention is the movement of the printhead and electrode elements relative to the substrate and counter electrode elements, or the movement of the printhead, electrode elements and counter electrode elements relative to the substrate.

[0023] Advantageously, during the relative movement between the printhead and the substrate, the distance between them remains constant. As mentioned above, compared to previously known methods, the method according to the invention allows for a larger distance between the printhead and the substrate; in particular, the distance between the printhead's output port and the substrate is preferably at least 0.75 mm, more preferably at least 1 mm, and especially at least 1.25 mm. During the application of the printing medium to the substrate, the printhead and electrode elements are disposed on one side of the substrate, particularly above the substrate, and the counter electrode is disposed on the side of the substrate opposite to the printhead and electrode elements, particularly preferably below the substrate.

[0024] The advantage of placing the printhead above the substrate is that the movement of the printing medium strip toward the substrate is aided by gravity.

[0025] The applicant's research shows that when the maximum distance between the printhead output port and the substrate surface is 3 mm, the adverse offset of the printing media strips at each edge is negligible. With a larger distance, the protruding element on the printhead can be used as a potential source, which theoretically functions as the printing media strip, guiding it in parallel.

[0026] Therefore, in an advantageous embodiment, the electrode element has at least one edge element, preferably two edge elements. The edge elements are positioned adjacent to the output ports at the edges to avoid or at least reduce outward forces. The polarity of the charge on the edge elements corresponds to the polarity of the printed media strip at the edges. Preferably, at least one edge element is provided on each side of the plurality of output ports, and more preferably, exactly one edge element is provided on each side of the plurality of output ports, to avoid or at least reduce the corresponding outward forces acting on the printed media strip at the edges.

[0027] The counter electrode element can be designed in various shapes and configurations.

[0028] In an advantageous embodiment, the counter electrode element is configured as a planar electrode.

[0029] In another advantageous embodiment, a planar electrode is used, the width of which is greater than the width of the substrate to be processed. Here, the width corresponds to the direction of movement of the electrode perpendicular to the relative movement between the printhead and the substrate, and also perpendicular to the direction of extension of the parallel lines formed on the substrate by the printing medium.

[0030] The larger width of the electrode element compared to the width of the substrate enables the formation of favorable field lines, which facilitates the parallel distribution of the printing media strips.

[0031] Particularly advantageously, the planar electrode is configured to have a length in the direction of movement relative to the substrate, and this length also extends in the direction of the parallel printing medium lines applied to the substrate. The length of the planar electrode is at least equal to, and preferably greater than, the length of the substrate. In this advantageous embodiment, it is particularly advantageous that the print head and electrode elements move relative to the substrate and the counter electrode element. This eliminates the need for synchronized movement between the print head and electrode elements and the counter electrode element, resulting in a design with lower complexity on the device. In another advantageous embodiment, the counter electrode element has multiple sub-electrodes, in which case multiple output ports of the print head are each equipped with a sub-electrode. Particularly advantageously, each output port is equipped with at least one sub-electrode, preferably exactly one sub-electrode per output port.

[0032] This achieves the advantage that, starting from each printing medium strip, the field lines terminate at at least one sub-electrode assigned to that printing medium strip, preferably at exactly one sub-electrode assigned to that printing medium strip.

[0033] This additionally achieves calibration / alignment, as the position of the sub-electrodes affects the arrival point of the printed media strip on the substrate. The sub-electrodes are arranged at intervals corresponding to the desired spacing of the parallel lines to be applied to the substrate, thereby improving the accuracy of the resulting structure. Thus, it is advantageous, for example, when equidistant parallel printed lines are desired on the substrate, that the sub-electrodes of the counter electrode elements are correspondingly arranged at equal intervals.

[0034] Therefore, the electrode is preferably configured such that the printed media strip output from one output port extends along the direction of the electrode provided to the output port.

[0035] In an advantageous embodiment, the sub-electrodes are configured as point electrodes. This ensures the precise distribution of field lines to the corresponding point electrodes.

[0036] In another advantageous embodiment, the sub-electrodes are configured as straight linear electrodes, particularly as linear electrodes arranged parallel to each other. Therefore, the linear electrodes correspond to the desired course and desired spacing of lines composed of printing media applied parallel to the substrate.

[0037] Correspondingly, it is advantageous to move the printhead, electrode elements, and counter electrode elements relative to the substrate when the electrode is configured as a dot electrode. Conversely, it is particularly advantageous to move the printhead and electrode elements relative to the substrate and counter electrode elements when the electrode is configured as a linear electrode.

[0038] In the method according to the invention, corresponding to the device according to the invention, preferably, the printing medium strip is charged by electrode elements in a structurally simple manner, and counter electrode elements are provided on the side of the substrate facing away from the printing head, which is away from the printing head during the printing process.

[0039] Advantageously, a voltage in the range of 0.05 to 3 kV, particularly 0.3 kV, is formed between the electrode element and the counter electrode element. More preferably, there is a 1.5 mm gap between the output port of the printhead and the surface of the substrate, and Ag or Al printing paste is used.

[0040] As described above, the method and apparatus according to the invention achieve high precision when applying multiple parallel lines composed of printing media onto a substrate. Thus, in an advantageous improvement, a multi-stage printing method can be implemented, having at least two printing steps, through the method and apparatus according to the invention:

[0041] In an advantageous embodiment, in a first printing step, a first structure is applied, the first structure consisting of parallel lines, the lines being composed of the aforementioned printing medium, which serves as the first printing medium. In a second printing step, a second structure is applied to the first structure consisting of parallel lines, the second structure consisting of parallel lines, preferably composed of a second printing medium different from the first printing medium.

[0042] In this way, a large aspect ratio can be achieved because a large height can be achieved by printing at least two lines composed of printing media overlapping each other without increasing the line width, or at least by increasing the line width to a small extent.

[0043] Alternatively or additionally, it is preferable to use two different printing media so that different functions can be achieved in the following process steps:

[0044] In many applications, and particularly in the fabrication of localized contact structures and / or localized doped structures in semiconductor components (especially photovoltaic solar cells), the surface of a substrate is typically covered with an electrically insulating layer consisting of parallel lines formed by printed media. In the case of silicon-based photovoltaic solar cells, the substrate typically has an insulating layer in the form of a silicon oxide layer or a silicon nitride layer. It is desirable for the printed media to penetrate the insulating layer to induce doping in the semiconductor substrate through dopants contained within the printed media, and / or to form electrical contacts with the semiconductor substrate using metal particles from the printed media.

[0045] Therefore, it is known that a heat treatment step is performed after the application of the printing medium, in which at least the printing medium is heated, preferably the entire substrate with the printing medium. Typically, the printing medium contains glass powder to allow penetration of the electrical insulating layer during the heat treatment step.

[0046] Advantageously, the above-described at least two-stage implementation of the printing method is designed such that the first printing medium passes through the electrical insulating layer, but the second printing medium does not pass through the electrical insulating layer.

[0047] This can be achieved in an advantageous embodiment by having a first printing medium configured to penetrate an electrically insulating layer, for example, the first printing medium having glass powder, but a second printing medium not configured to penetrate the electrically insulating layer in the subsequent heat treatment step, in particular the second printing medium not having glass powder.

[0048] Similarly, in another advantageous embodiment, a first printing medium is first applied and penetrated through the electrical insulating layer by thermal action. Following this step, in a second printing process, a second printing medium is applied onto the lines of the first printing medium that have previously penetrated the electrical insulating layer. The method and apparatus according to the invention also offer significant advantages because precise calibration is achieved through the high accuracy of the method and apparatus, that is, overlapping application of the printing lines applied in the first printing process and the printing lines applied in the second printing process is realized, while side-by-side application is avoided.

[0049] Preferably, the plurality of output ports are arranged in a straight line. Attached Figure Description

[0050] Other advantageous features and implementations are described below with reference to embodiments and accompanying drawings. Here:

[0051] Figures 1a-1c Two embodiments of the device according to the invention are shown, having planar electrodes as counter electrode elements;

[0052] Figures 2a-2c Two embodiments with a counter electrode element are shown, the counter electrode element having a split electrode; and

[0053] Figures 3a-3c The method steps for manufacturing a metal contact structure for photovoltaic solar cells are shown.

[0054] Explanation of reference numerals in the attached figures

[0055] A Spacing

[0056] 1 Print head

[0057] 1a Printing Media Inlet

[0058] 2. Printing media storage container

[0059] 3. Printing media strip

[0060] 4. Matrix

[0061] 4a Insulation layer

[0062] 5. Voltage source

[0063] 6 Electrode Elements

[0064] 6a, 6b Edge elements

[0065] Electrode elements 7a, 7b, 7c, and 7d

[0066] P-point electrode

[0067] L-shaped wire electrode

[0068] 8. Printed Media Lines Detailed Implementation

[0069] The accompanying drawings are schematic diagrams that are not to scale. The same reference numerals in the drawings denote the same or equivalent elements.

[0070] In Figure 1, partial illustrations in sub-figures b and c are provided to depict an embodiment of the device according to the invention in a top view. Figure 1b and Figure 1c The side views of the embodiments shown are the same and Figure 1a The text shows:

[0071] Both embodiments have a printhead 1 with a print media inlet 1a. The print media inlet 1a is connected to a print media storage container 2 via a pipe. The print media storage container contains a pump, which allows print media to be introduced from the print media storage container 2 into the printhead 1 through the print media inlet 1a.

[0072] exist Figure 1a In the figure, on the side below the print head 1, the print head has multiple output ports for printing media. Eleven output ports are shown in the schematic diagram of the accompanying drawing, from which printing media strips 3 flow. Here, for clarity, only the printing media strip on the right is labeled with reference numeral 3. Thus, eleven parallel printing media strips 3 are guided through the print head 1 to the substrate 4 disposed below the print head 1, such that the printing media strips 3 reach the substrate 4 vertically from above. In practical embodiments, a larger number of parallel printing lines are printed, particularly in the range of 100 to 200 printing lines. For better illustration, eleven parallel lines are shown in the figure.

[0073] Substrate 4 constitutes a precursor in the manufacture of photovoltaic solar cells. Substrate 4 is based on a silicon wafer that has already undergone base doping and front-side emitter doping, and has a substrate applied to the substrate 4. Figure 1a An insulating layer is located on the upper front side, and the insulating layer is constructed as a silicon oxide layer.

[0074] In the example shown in Figure 1, the printhead 1 is positioned relative to the substrate 4 according to... Figure 1a The diagram in the figure moves perpendicular to the plane of the figure. In this way, eleven parallel printing media lines can be formed on the surface of the substrate 4.

[0075] Furthermore, the printing apparatus according to the embodiment shown in FIG1 has a voltage source 5. The printhead 1 is made of metal and thus constitutes an electrode element 6.

[0076] Counter electrode elements 7a or 7b are disposed below the substrate 4, and the counter electrode elements are respectively configured as planar electrodes.

[0077] Voltage source 5 is connected to electrode element 6, that is, to printhead 1, and to counter electrode elements 7a and 7b, so as to generate a potential difference (voltage) of up to 2kV between these elements, which in the present case generates a potential difference (voltage) of 1.5kV.

[0078] As described above, the printhead 1, acting as electrode element 6, is made of metal and thus configured to be conductive, thereby drawing electrons from the printing medium via the voltage source 5. Consequently, each of the eleven printing medium strips 3 carries a positive charge and therefore has the same polarity. This creates a repulsive force between the printing medium strips 3, which reduces the risk of the printing medium strips 3 deviating from their parallel distribution. Figure 1a As shown.

[0079] The charge q is at position i. i The printed media strips are subjected to forces according to the principle of electrostatics based on the surrounding charges.

[0080] An imbalance in the total charge on the left or right side of the printed media strip i will not cause a deviation from parallelism because the force decreases with the square power of the distance between the corresponding charges. Therefore, the main part of the force is applied to directly adjacent printed media strips, ensuring the parallelism (self-alignment characteristic) of the printed media strips to each other.

[0081] Therefore, in the two embodiments shown in FIG1, the electrode element 6 configured as the printhead 1 has a plurality of output ports for the printing medium.

[0082] exist Figure 1b and Figure 1cThe image shows a top view of the corresponding embodiment as seen from above.

[0083] exist Figure 1b In the first embodiment shown, the electrode element 7a is configured as a planar electrode, which has an area larger than that of the substrate 4. In this embodiment, the printhead 1 is moved by a transport unit (not shown) in... Figure 1b The direction shown in the diagram is from bottom to top; therefore, as mentioned earlier, in Figure 1a In the side view, the movement is perpendicular to the plane of the drawing, thereby forming eleven parallel printing media lines on the upper side of the base 4. For clarity, only the printing media lines on the right are labeled with reference numeral 8. Figure 1b In the first embodiment shown, the printhead 1, that is, the electrode element 6, moves relative to the substrate 4 and the counter electrode element 7a.

[0084] exist Figure 1c In the second embodiment shown, the counter electrode element 7b is also configured as a planar electrode. Like the counter electrode element 7a, the counter electrode element 7b also has a width greater than that of the substrate 4 (in...). Figure 1b and Figure 1c (The extension dimension is at a medium level). However, unlike the first embodiment, in... Figure 1c The length of the counter electrode element 7b in the second embodiment shown in the figure (in) Figure 1b and Figure 1c The vertical extension dimension in the middle is not greater than 4 of the base.

[0085] In the second embodiment, the printhead 1, the electrode element 6, and the counter electrode element 7b all move relative to the substrate 4.

[0086] As mentioned at the beginning, the two embodiments described in Figure 1, in particular, allow for a spacing A of 1.2 mm between the printhead 1 and the substrate 4 in the current case. However, since the charge polarity of the printing media strips 3 is the same, finer, parallel printing media lines 8 (with a width ranging from 15 μm to 80 μm in the current case, and 30 μm in the current case) can be applied, which have high precision in terms of straightness and parallelism.

[0087] In particular, in multi-stage printing methods, the embodiment shown in Figure 2 provides higher accuracy and additionally enables the possibility of calibration.

[0088] This is similar to Figure 1, in Figure 2a The side view is also shown in the middle, which is for the purpose of... Figure 2b Neutralization Figure 2c The embodiments shown are the same.

[0089] The structures of the third and fourth embodiments are basically the same as those of the first and second embodiments, except that the electrode elements are different.

[0090] Therefore, in Figure 2b In the diagram, only the counter electrode element 7c of the third embodiment is shown, and correspondingly in Figure 2c The counter electrode element 7d of the fourth embodiment is shown.

[0091] like Figure 2a As shown, in the third and fourth embodiments of the device according to the invention, printing medium is supplied from the printing medium storage container 2 to the print head 1, which is configured as an electrode element 6, through the printing medium inlet 1a, so that parallel strips of printing medium 3 are output from the output port of the print head 1 onto a substrate 4, the substrate 4 being disposed at a distance A from the print head 1. A potential is generated between the electrode element 6 and the counter electrode elements 7c and 7d by a voltage source 5. However, the counter electrode elements 7d and 7c are not configured as planar electrodes, but rather each have multiple sub-electrodes, as shown in the top view of the counter electrode elements 7c and 7d. Figure 2b and Figure 2c As can be seen in:

[0092] according to Figure 2b The counter electrode element 7c has multiple dot electrodes, of which only one dot electrode is labeled P for clarity. The number of dot electrodes corresponds to the number of output ports of the printhead 1. Therefore, there are eleven dot electrodes P in the current simplified illustration. The dot electrodes P are disposed on the non-conductive substrate of the counter electrode element 7c and are interconnected only by cables and by laterally disposed terminals to conductively connect the dot electrodes P to the voltage source 5.

[0093] In the fourth embodiment, it is configured similarly to the counter electrode element 7c, but instead of the dot electrode P, the counter electrode element has linear electrodes L. The linear electrodes L are each constructed as a straight line, and these straight lines are arranged parallel to each other. The number of linear electrodes here also corresponds to the number of output ports of the printhead 1; therefore, in the present case, it is eleven.

[0094] The spacing between the dot electrode P and the line electrode L also corresponds to the spacing of the output port of the print head 1, and also corresponds to the desired spacing of the printing medium strip 3 output from the print head 1, and corresponds to the spacing of the parallel printing medium lines 8 to be formed on the substrate 4.

[0095] The field lines of the electrostatic field to be formed terminate perpendicularly at the counter electrode. In an embodiment where the counter electrode has mutually separated sub-electrodes, each printable medium strip is subjected to a force along the field lines, which causes the printable medium strip to deviate from its position relative to the sub-electrode perpendicular to the dispensing direction.

[0096] Similar to the second embodiment, in having according to Figure 2b In the third embodiment of the counter electrode element 7c, the printhead 1, the electrode element 6, and the counter electrode element 7c are moved relative to the substrate 4. Similar to the first embodiment, in the case of having... Figure 2c In the fourth embodiment of the counter electrode element 7d, the printhead 1 and the electrode element 6 are moved relative to the substrate 4 and the counter electrode element 7d.

[0097] Figure 3 shows different method steps for forming a metal contact structure on substrate 4 using a two-stage printing method.

[0098] The substrate 4 is shown in side views in sub-figures a and b of Figure 3, while the substrate 4 is shown in top view from above in sub-figure c of Figure 3.

[0099] The substrate 4 has an insulating layer 4a on its surface, which is electrically insulating and composed of a silicon oxide layer. Similarly, in a variant of this embodiment, the insulating layer can be constructed differently, for example, as a silicon nitride layer. Using the apparatus according to the third embodiment or alternatively the fourth embodiment, firstly in a first printing step, a first printing medium is printed onto the insulating layer 4a of the substrate 4 in fine lines with a width ranging from 15 μm to 80 μm, currently 40 μm. Next, in a second printing step, a second printing medium, different from the first printing medium, is similarly printed onto the printing medium lines of the first step in printing medium lines, thereby applying it to the first printing medium. The first printing medium contains glass powder, which is more corrosive, while the second printing medium does not contain glass powder. On the other hand, both printing media contain metal particles.

[0100] In the heat treatment step where both printing media act together, the substrate 4 is heated (to approximately 700°C to 850°C, and in the present case to approximately 780°C) for 20 to 40 seconds, and in the present case for 30 seconds, so that the printing media lines of the first printing media penetrate the insulating layer 4a and form a conductive contact with the substrate 4. Conversely, the printing media lines of the second printing media do not penetrate the insulating layer 4a.

[0101] In the current embodiment, compared to the width of the printed media lines of the second printed medium (having a width in the range of 20 μm to 80 μm, currently 60 μm), the first printed medium applies printed media lines with a smaller width (in the range of 15 μm to 70 μm, currently 20 μm), so that the printed media lines of the second printed medium remaining on the insulating layer 4a have sufficient width to ensure a small lateral conduction resistance. Conversely, the main function of the finer printed media lines of the first printed medium is to achieve a conductive connection between the printed media lines of the second printed medium and the substrate 4.

[0102] Thus, on the one hand, sufficient lateral conductivity is achieved on the surface of the insulating layer 4a through the printed dielectric lines of the second printed dielectric, and on the other hand, recombination at the metal / semiconductor contacts is reduced due to the smaller width of the printed dielectric lines of the first printed dielectric. Also within the scope of the invention is the selection of different width relationships, particularly the application of two printed dielectric lines with the same width.

[0103] Furthermore, Figure 1 also shows an improvement to the previously described embodiment: in this improvement, the electrode element 6 has two edge elements 6a and 6b, shown in shaded lines. The edge elements 6a and 6b are also constructed of metal and are electrically connected to the electrode element 6 configured as the printhead 1, such that the edge elements 6a and 6b have the same potential difference as the counter electrode element 7a as the potential difference between the electrode element 1 and the counter electrode element. This can compensate for or at least reduce forces that may act outwards (i.e., to the left at the left edge of the printhead strip 3 in Figure 1, and to the right at the right edge of the printhead strip 3).

Claims

1. An apparatus for extruding printing media parallel onto a substrate, the apparatus having a print head (1) having a print media inlet (1a) for the printing media, the print media inlet (1a) being flowably connected to a plurality of output ports of the print head (1) so as to simultaneously output the printing media from the plurality of output ports in the manner of a plurality of parallel print media strips. Its features are, The device has an electrode element (6), counter electrode elements (7a, 7b, 7c, 7d), and a voltage source configured to cooperate with the electrode element (6) and the counter electrode elements (7a, 7b, 7c, 7d) to create a potential difference and an associated electrostatic field between the electrode element (6) and the counter electrode elements (7a, 7b, 7c, 7d). The electrode element (6) is arranged and configured to supply or release charge to the printing medium, thereby loading the printing medium strips with charges of the same polarity. The device is configured such that a substrate (4) can be disposed between the printhead (1) and the counter electrode elements (7a, 7b, 7c, 7d), the counter electrode elements (7a, 7b, 7c, 7d) having a plurality of sub-electrodes, the sub-electrodes being assigned to a plurality of output ports of the printhead (1), the sub-electrodes being configured as linear electrodes (L), the sub-electrodes being configured such that the print media strip (3) output from the output port extends along the direction of the sub-electrode assigned to the output port, the sub-electrodes being configured as linear electrodes (L) arranged parallel to each other.

2. The device according to claim 1, characterized in that, The electrode element (6) has multiple guide paths for the printing medium.

3. The device according to any one of the preceding claims, characterized in that, The electrode element (6) is disposed on the printhead (1).

4. The device according to claim 1, characterized in that, The counter electrode elements (7a, 7b, 7c, 7d) are configured as planar electrodes, and the device has a transport unit configured to move the print head (1) and the electrode elements (6) relative to the counter electrode elements (7a, 7b, 7c, 7d).

5. The device according to claim 1, characterized in that, The device has a transport unit configured to move the substrate (4) relative to the printhead (1), the electrode element (6), and the counter electrode elements (7a, 7b, 7c, 7d).

6. The device according to claim 1, characterized in that, Assign at least one of the aforementioned sub-electrodes to each output port.

7. A method for extruding a printing medium parallel onto a substrate, wherein, Multiple parallel printing media strips are output from the output port of the print head (1) onto the substrate (4), and the print head (1) and the substrate (4) move relative to each other. The print head (1) and the substrate (4) are characterized in that, before the printing media strips are applied to the substrate (4), a charge is applied to the printing media strips, all of which have the same polarity of charge; the charge is applied to the printing media strips via electrode elements (6), and during the printing process, counter electrode elements (7a, 7b, 7c, 7d) are provided on the side of the substrate (4) facing away from the print head (1), wherein, in the electrode elements (6) and A potential difference is formed between the counter electrode elements (7a, 7b, 7c, 7d) and an associated electrostatic field is formed, the electrostatic field being in the range of 0.05kV to 3kV. The counter electrode elements (7a, 7b, 7c, 7d) have multiple sub-electrodes, and the sub-electrodes are assigned to multiple output ports of the printhead (1). The sub-electrodes are constructed as linear electrodes (L) that are straight. The sub-electrodes are configured such that the print media strip (3) output from the output port extends along the direction of the sub-electrode assigned to the output port. The sub-electrodes are constructed as linear electrodes (L) that are arranged parallel to each other.

8. The method according to claim 7, characterized in that, During the printing process, the distance (A) between the print head (1) and the substrate (4) is greater than 0.75 mm.

9. The method according to any one of claims 7 to 8, characterized in that, A two-stage printing process is implemented. In the first printing process, a first structure is applied, which consists of parallel lines composed of a printing medium serving as a first printing medium. In the second printing process, a second structure is applied to the first structure, which consists of parallel lines composed of a second printing medium different from the first printing medium.

10. The method according to claim 9, characterized in that, The substrate (4) has an electrically insulating layer (4a) on the side facing the print head (1), and the first printing medium includes a substance that penetrates the insulating layer (4a) under thermal action.

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