Printing stencil and printing device for forming conductive tracks on a substrate and method for manufacturing metallic contact structures of photovoltaic solar cells - Patents.com

Abstract

The present invention relates to a printing stencil (1) for forming conductive tracks on a substrate. The printing stencil (1) has a plurality of recesses in the form of printing gaps (4) for forming conductive tracks. Each printing gap (4) of the plurality of printing gaps (4) has at least one printing defined area (3) adjacent to a printing surface and at least one printing medium supply area (2) adjacent to a squeegee surface, the volume of the printing defined area (3) being smaller than the volume of the printing medium supply area. The present invention further relates to a printing device for forming conductive tracks on a substrate and a method for manufacturing metallic contact structures of photovoltaic solar cells.

Description

[Technical field]

[0001] The invention relates to a printing stencil for producing conductive tracks on a substrate according to claim 1, a printing device for producing conductive tracks on a substrate according to claim 12 and a method for producing metallic contact structures of photovoltaic solar cells according to claim 13. [Background technology]

[0002] It is known to apply a printing medium, in particular a screen printing paste, onto a substrate by forcing the printing medium through a screen printing plate using a squeegee. A typical screen printing plate has a screen printing mesh with a number of elongated mesh elements through which the printing medium can pass. To structure the printing medium passing through the screen printing mesh, a printing stencil is arranged on the screen printing mesh, which has openings such that the printing medium passes through the screen printing plate only in the area of ​​the openings of the printing stencil, making it possible to apply a structure of the printing medium, which is pre-given by the openings of the printing stencil, onto the substrate.

[0003] For semiconductor devices and especially photovoltaic solar cells, it is preferred to produce narrow linear structures of the printing medium on the substrate to form particularly narrow linear metallic contact elements, so-called contact fingers, which are preferably formed in a particularly narrow linear shape in order to minimize the shading of the incident light. It is therefore necessary to avoid variations in the cross-sectional area of ​​the structures when applying the material, since a reduction in the cross-section leads to a higher conduction resistance and thus to efficiency losses.

[0004] A screen printing plate for producing narrow, linear structures is known from DE 10 2019 122 126 A1. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] DE 102019122126 [Patent Document 2] WO 18 / 162385 Summary of the Invention [Problem to be solved by the invention]

[0006] The printing plate needs to be further optimized in order to provide a robust printing plate which, on the one hand, produces narrow, linear structures of printing medium on a substrate, and, on the other hand, allows for high throughput in manufacturing operations as well as long durability and therefore a long service life of the printing plate. [Means for solving the problem]

[0007] The problem is solved by a printing stencil for producing conductive tracks on a substrate according to claim 1, a printing device for producing conductive tracks on a substrate according to claim 12 and a method for producing metallic contact structures of photovoltaic solar cells according to claim 13. Advantageous aspects can be found in the dependent claims.

[0008] The invention is based on the recognition that it is advantageous to use a printing stencil that is formed as a plate-like printing stencil. However, in order to obtain sufficient robustness, it is desirable to form the printing stencil with a sufficient thickness. However, this necessitates the drawback that the thickness of the printing gap of the printing stencil also increases depending on the thickness of the plate-like printing stencil. This can lead to drawbacks in the supply of the printing medium and / or in the uniform output of the printing medium on the substrate. According to the invention, the drawbacks are avoided in that the printing gap has a printing medium supply area and a print definition area.

[0009] A printing stencil for forming conductive tracks on a substrate according to the present invention has a plurality of recesses in the form of printing gaps for forming conductive tracks on the substrate.

[0010] Importantly, the printing stencil is formed as a plate-like printing stencil. The printing stencil comprises a substrate surface and a squeegee surface opposite the substrate surface. Each printing gap of the plurality of printing gaps has at least one print-defining area adjacent the printing surface and at least one print-medium supply area adjacent the squeegee surface, the volume of the print-defining area being smaller than the volume of the print-medium supply area. The print-medium supply areas have a gap width that increases, preferably strictly monotonically increases, in the direction of the squeegee surface.

[0011] More importantly, the walls of the print defined area enclose a first opening angle that is smaller than a second opening angle enclosed by the walls of the print medium supply area and / or the print defined area has a gap width that increases, preferably strictly monotonically increases, in the direction of the substrate surface.

[0012] The printing stencil according to the invention allows for the formation of structures of print medium on a substrate by means of print gaps, where the print defined areas cause the print medium to be applied through a shape defined by the print defined areas, with the application of structures of small dimensions requiring print gaps of correspondingly narrow widths.

[0013] In the prior art, the printing gaps in the printing plates used in screen printing have vertically extending side walls. If the printing gap width is narrow in the known printing plates due to the small dimensions of the printing gap, there is a problem that a sufficient amount of printing medium cannot be added. To prevent this problem, in the prior art, the printing stencils are manufactured as thin as possible. However, thin printing stencils lead to reduced durability and therefore need to be replaced more frequently in the manufacturing operation and / or require a support structure, such as a screen printing mesh, on which the printing stencil is placed.

[0014] In the case of the printing stencil according to the invention, the printing medium supply area has a larger volume than the printing definition area, which allows the use of a printing stencil with a greater thickness and therefore a greater robustness compared to the prior art, since the larger volume of the printing medium supply area allows a greater flow of printing medium to the printing medium supply area, which makes it possible to omit support structures in the area of ​​the printing gap, in particular a screen printing mesh, also in the printing stencil according to the invention, due to the greater robustness.

[0015] The print medium feed area of ​​the printing stencil according to the invention has a gap width that increases, preferably strictly monotonically increases, in the direction of the squeegee surface, which facilitates feeding of the print medium in the squeegee surface.

[0016] Additionally, in a printing stencil according to the present invention, the increased gap width advantageously prevents build-up of the printing medium.

[0017] The printing stencil according to the invention is particularly suitable for producing metallic contact structures of photovoltaic solar cells, where such contact structures, in particular the contact fingers, of such solar cells are generally shaped in a straight line, so that the printing gaps of the plurality of printing gaps are advantageously shaped as straight printing gaps.

[0018] It is within the scope of the invention that the first opening angle formed by the walls of the print-defined area and the second opening angle formed by the walls of the print-medium supply area have the same orientation, in which case the print-defined area also has a gap width that increases, preferably strictly monotonically increases, in the direction of the squeegee surface, but in which the first opening angle is smaller than the second opening angle so as to allow a large volume in the print-medium supply area and an accurate definition of narrow print structures in the print-defined area.

[0019] Thus, in an advantageous embodiment, the printing stencil has a print defining area with a smaller opening angle than the print medium supply area, in particular by 10 degrees, preferably by 20 degrees, in particular by 30 degrees smaller.

[0020] It is also within the scope of the invention for the first opening angle to have an opposite orientation to the second opening angle. In this advantageous embodiment, the print definition area has a gap width that increases in the direction of the substrate surface, preferably strictly monotonically increasing. This also allows for a precise definition of the structure to be printed.

[0021] In this case, the opening angle of the print definition area is advantageously greater than 30 degrees, preferably greater than 40 degrees, particularly preferably greater than 60 degrees.

[0022] Advantageously, in this embodiment, on the one hand a large inflow of printing medium in the printing medium supply area and on the other hand a precise definition of the structures to be printed is facilitated.

[0023] Configurations are obtained which are advantageous in embodiments in which the printing stencil has a thickness of more than 50 μm, in particular more than 100 μm, preferably more than 500 μm.

[0024] An advantage of this configuration is its robustness, which increases with stencil thickness.

[0025] Advantageous configurations are obtained in embodiments in which the print-defined areas have a thickness of less than 250 μm, in particular less than 50 μm, preferably less than 25 μm.

[0026] An advantage of this arrangement is that it allows achieving a target height of the structures formed from the print medium of less than 250 μm, in particular less than 50 μm, preferably less than 25 μm.

[0027] Advantageous embodiments are obtained where the stencil body is formed from one of the following materials: glass, silicon or stainless steel, preferably glass.

[0028] The advantage of using the aforementioned materials, and especially glass, as opposed to conventional materials is that glass is more scratch resistant. Furthermore, glass has a high modulus of elasticity and also a lower coefficient of thermal expansion.

[0029] An advantageous configuration is obtained in an embodiment in which the width of each of the plurality of print gaps at the end of the print-defined area facing the squeegee surface is less than 50 μm, in particular less than 25 μm, preferably less than 15 μm.

[0030] In this embodiment, it is advantageous that the flow behavior of the print medium is thereby significantly influenced, so that the dimensions of the printed structures have a high degree of homogeneity.

[0031] A further advantageous configuration is obtained in an embodiment in which the width of each of the multiple printing gaps at the end facing the substrate surface of the print-defined area is less than 50 μm, in particular less than 25 μm, preferably less than 15 μm and / or in the range of 15 μm to 25 μm.

[0032] In this embodiment, it is advantageous that the flow behavior of the print medium is thereby significantly influenced, so that the dimensions of the printed structures have a high degree of homogeneity.

[0033] A further advantageous configuration is obtained in an embodiment in which the width of each of the plurality of print gaps at the end facing the squeegee surface of the print-defining area is greater than 15 μm, in particular greater than 25 μm, preferably greater than 50 μm.

[0034] Advantageously, in this embodiment, this provides sufficient print media supply, and the width of the print gap at the end opposite the squeegee surface is important to the volume formed in the print media supply area, which is the print media reservoir from which additional media is dispensed.

[0035] A further advantageous configuration is obtained in which the print medium supply area terminates directly at the squeegee surface and the print definition area terminates directly at the substrate surface, particularly in embodiments in which the print medium supply area and the print definition area are adjacent to one another.

[0036] A further advantageous configuration is obtained in embodiments in which the print defining area tapers in the direction of the squeegee surface and the print medium supply area diverges in the direction of the squeegee surface.

[0037] In this embodiment, with sides resembling an hourglass shape, the configuration advantageously creates an open volume facing the substrate, which can receive the print medium by providing it therethrough, allowing a larger volume of print medium to be ejected onto the substrate, similar to the previous embodiment.

[0038] It is a further object of the present invention to provide a printing plate, a printing apparatus and a method for forming conductive tracks on a substrate.

[0039] A printing plate according to the invention comprises a printing stencil according to the invention, which is arranged in a frame, preferably under tensile stress.

[0040] The advantage of mounting in a frame is that the fixed printing stencil is placed in the frame in a rigid yet slightly flexible manner due to tensile stress.

[0041] An advantageous configuration of the printing plate according to the invention is obtained in an embodiment in which no carrier structure, in particular a mesh-like carrier structure, is formed at the opening of the printing gap, in particular no screen printing mesh is arranged.

[0042] In conventional screen printing plates, a carrier material, in particular a mesh-like carrier material with a mesh width, is arranged over the entire surface of the stencil. However, in particular in the case of a screen mesh, there is a disadvantage that in the case of very small structures, it is necessary to use a carrier material with wires having a diameter that is basically smaller than the structure to be printed. The carrier material leads to a decrease in robustness and a deterioration in the dimensional accuracy of the printing stencil. The aforementioned disadvantages are avoided by omitting the carrier structure when using a plate-shaped printing stencil. In this embodiment, it is possible to omit the carrier material because the printing stencil can be designed to have a thickness that is sufficient for the inherent robustness of the printing stencil as described above, so that the robustness of the printing stencil does not have to be achieved by a mesh-like carrier structure.

[0043] A printing medium, in particular a screen printing paste, is applied onto a substrate via a printing apparatus according to the invention, which comprises a printing stencil, in particular a preferred embodiment of a printing stencil, according to the invention, and at least one squeegee, by means of which the printing medium is passed over the printing plate and applied onto the substrate.

[0044] The printing device according to the invention, when using a highly durable printing stencil, makes it possible to form structures, in particular linear structures, on a substrate using a printing medium by means of the printing gaps of the printing stencil.

[0045] The method for manufacturing a metallic contact structure of a photovoltaic solar cell according to the invention comprises the following steps: - applying a print medium to a squeegee surface of a print stencil; - pushing the print media through the print gap of the print stencil with at least one squeegee to apply a print media structure onto the solar cell substrate at a substrate side of the print stencil opposite the squeegee side.

[0046] What is important is that the printing stencil is formed as a plate-like printing stencil having a substrate surface and a squeegee surface facing the substrate surface; Each print gap of the plurality of print gaps has at least one print defining area adjacent to the print surface and at least one print medium supply area adjacent to the squeegee surface, the volume of the print defining area being smaller than the volume of the print medium supply area; The print medium supply area has a gap width that increases, preferably strictly monotonically increasing, towards the squeegee surface.

[0047] More importantly, the walls of the print defined area enclose a first opening angle that is smaller than a second opening angle enclosed by the walls of the print medium supply area and / or the print defined area has a gap width that increases, preferably strictly monotonically increases, in the direction of the substrate surface.

[0048] The method according to the invention makes it possible to form structures, in particular linear structures, on a substrate with a printing medium by means of the printing gaps of the printing stencil, the printing medium being applied in a shape defined by the printing defined areas.

[0049] The problem mentioned at the beginning is furthermore solved according to the invention by using the printing stencil according to the invention to produce metallic conductive tracks of a photovoltaic solar cell, in particular on the front side facing the light incidence of the photovoltaic solar cell.

[0050] The so-called LIDE (laser induced deep etching) method is particularly suitable for producing the printing stencil according to the invention. This method makes it possible to produce the printing gap and the defined opening angle required for the stencil according to the invention. Such a method is described in WO 18 / 162385. It is particularly advantageous to produce the printing stencil using glass.

[0051] It is within the scope of the invention that the printing device is structurally configured in a known manner and has a drive unit for driving the squeegee and a supply unit for supplying the printing medium to the squeegee surface, which are known per se.

[0052] It is within the scope of the present invention for the printing stencil to have other printing gaps or recesses with different structural configurations in addition to the aforementioned printing gaps, in particular to provide one or more printing gaps with a larger width in order to connect the contact fingers generated with the printing gaps by a connector, a so-called bus bar.

[0053] The volume of the printing medium supply area is preferably defined by the walls of the printing gap in the area of ​​the printing medium supply area and the squeegee surface of the printing stencil, in particular the squeegee surface of the printing stencil continuing as a flat surface. The volume is further preferably defined in the direction of the substrate surface by the printing defining area.

[0054] The volume of the print-defined area is preferably defined by the walls of the print gap in the print-defined area and the substrate surface of the print stencil, in particular the substrate surface of the print stencil continuing as a flat surface. The volume is further preferably defined in the direction of the squeegee surface by the print medium supply area.

[0055] The plurality of printing gaps of the printing stencil according to the invention preferably comprises at least 5, particularly preferably at least 10, and even more preferably at least 15 printing gaps.

[0056] Further preferred features and embodiments are explained below with reference to example embodiments and drawings: Figures 1 and 2 respectively show example embodiments of a printing gap of a printing stencil according to the invention; Figure 3 shows an example embodiment of a printing stencil according to the invention; and Figure 4 shows an example embodiment of a printing device according to the invention.

[0057] The drawings are shown in a schematic and not to scale representation, in which identical symbols indicate elements having the same or identical function.

[0058] The embodiment of the printing stencil according to the invention shown in FIG. 1 is illustrated in cross section, showing a partial cross section of the printing stencil with printing gaps. The printing stencil continues in the same way on the left and right. The printing stencil here has a total of 19 parallel arranged printing gaps of equal size.

[0059] The plate-shaped printing stencil 1 has an opening with an opening angle β on the squeegee surface R, which is the upper side in the drawing. The printing stencil 1 has an opening with an opening angle α on the substrate surface S, which is the lower side in the drawing. The opening angle β on the squeegee side is larger than the opening angle α on the substrate side. Both opening angles are oriented in the same direction.

[0060] In this embodiment, the print medium supply area 2 is formed by a volume defined by the upper surface of the printing stencil on the squeegee side and the opening edge of the flow passage wall of the opening defined by the opening angle β.

[0061] In this embodiment, the print defined area 3 is formed by the volume defined by the lower surface S of the printing stencil facing the substrate and the opening edge of the opening of the print gap, which is defined by the opening angle α.

[0062] Thus, the print medium supply area 2 terminates directly at the squeegee surface, whereas the print definition area 3 terminates directly at the substrate surface.

[0063] In the configuration, the print medium supply area and the print definition area are adjacent to each other. In the present embodiment, the height H2 of the print medium supply area is selected to be larger than the height H3 of the print definition area. Furthermore, the volume of the print medium supply area 2 is larger than the volume of the print definition area 3, which makes it easy to add sufficient print medium.

[0064] The embodiment of the printing stencil according to the invention shown in Fig. 2 is shown in cross section, showing a partial cross section of the printing stencil with printing gaps. The printing stencil continues in the same way on the left and right. The printing stencil here has a total of 19 parallel arranged printing gaps of equal size.

[0065] The plate-shaped printing stencil 1 has an opening with an opening angle β on the squeegee surface R, which is the upper side in the drawing. The printing stencil 1 has an opening with an opening angle α on the substrate surface S, which is the lower side in the drawing. The opening angle β on the squeegee side is larger than the opening angle α on the substrate side. The two opening angles are oriented opposite each other, so that both areas have an hourglass shape.

[0066] In this embodiment, the print medium supply area 2 is formed by a volume defined by the upper surface of the printing stencil on the squeegee side and the opening edge of the flow passage wall of the opening defined by the opening angle β.

[0067] In this embodiment, the print defined area 3 is formed by a volume defined by the lower surface S of the printing stencil facing the substrate and the opening edge of the opening of the print gap, which is defined by the opening angle α.

[0068] Thus, the print medium supply area 2 terminates directly at the squeegee surface, whereas the print definition area 3 terminates directly at the substrate surface.

[0069] In the configuration, the print medium supply area 2 and the print definition area 3 are adjacent to each other. In the present embodiment, the height H2 of the print medium supply area is selected to be larger than the height H3 of the print definition area. Furthermore, the volume of the print medium supply area 2 is larger than the volume of the print definition area 3, which makes it easy to add sufficient print medium.

[0070] In Fig. 3 an embodiment of a printing stencil 1 according to the invention is shown in a top view. The printing stencil 1 is configured to be rectangular, in which it has 19 parallel arranged printing gaps of equal dimensions. In this embodiment the printing gaps 4 are arranged parallel to each other and parallel to the edges of the printing stencil 1. The printing gaps 4 make it possible to generate linear structures of printing medium on the substrate. The structures are metallic contact elements.

[0071] The view shown in FIG. 3 also corresponds to a top view of the example embodiment shown in FIGS.

[0072] In Fig. 4 an embodiment of a printing device according to the invention is diagrammatically shown. The printing device comprises a printing plate formed from a printing stencil 1 according to the embodiment embodiment shown in Fig. 1 and a frame 5. The printing stencil 1 is arranged in the frame 5. The printing plate comprising the printing stencil 1 and the frame 5 thus constitutes a printing plate according to the invention which does not have a carrier structure, in particular a screen printing mesh, at the opening of the printing gap 4.

[0073] Above the printing plate a squeegee 6 is arranged in a drive unit 7. The drive unit 7 and the frame 5 are arranged in a holder of the printing apparatus, not shown, which further comprises a support for a substrate 8. The substrate 8 is a precursor of a silicon solar cell, on which metallic contact fingers 10 are applied. A printing paste 9 containing metal particles is applied to the squeegee surface on top of the printing stencil 1 by means of a printing medium supply unit of the printing apparatus, also not shown.

[0074] A squeegee 6 is moved over the printing stencil 1 using a drive unit 7, thereby forcing the printing paste 9 through the printing gap 4 of the printing stencil 1 and onto the substrate 8, so that the printing paste is applied onto the substrate 8 in the form of thin, parallel-arranged, linear contact fingers 10.

[0075] 4 shows a schematic diagram: in a practical arrangement the printing stencil 1 is slightly curved, typically in the area of ​​the squeegee 6 in the direction of the substrate 8 . [Explanation of symbols]

[0076] 1 Printing stencil 2 Print media supply area 3 Printing area 4 Print Gap 5 Frames 6 Squeegee 7. Drive unit 8 Substrate 9 Printing paste 10 Contact Finger R Squeegee surface S board surface α, β opening angle

Claims

1. A printed stencil (1) for forming a conductive path on a substrate, The printing stencil (1) is a printing stencil having a plurality of recesses in the shape of printing gaps (4) for forming the conductive path on the substrate, The printing stencil (1) is formed as a plate-shaped printing stencil (1) having a substrate surface (S) and a squeegee surface (R) facing the substrate surface (S). Each of the plurality of printing gaps (4) has at least one printing definition area (3) adjacent to the printing surface and at least one printing medium supply area (2) adjacent to the squeegee surface (R), and the volume of the printing definition area (3) is smaller than the volume of the printing medium supply area (2). The printing medium supply area (2) has a gap width that increases in the direction of the squeegee surface (R), and further - The wall of the print definition area (3) surrounds a first opening angle (α) that is smaller than the second opening angle (β) surrounded by the wall of the print medium supply area (2) and / or - The printable area (3) is a printable stencil (1) having a gap width that increases in the direction of the substrate surface (S).

2. The printing stencil (1) according to claim 1, wherein the gap width of the printing medium supply area (2) increases densely and monotonically.

3. The printing stencil (1) according to claim 1, wherein the gap width of the printing area (3) increases densely and monotonically.

4. The printing stencil (1) according to claim 1, characterized in that the wall of the printing definition area (3) surrounds an opening angle (α) that is 10 degrees smaller than the wall of the printing medium supply area (2).

5. The printing stencil (1) according to claim 4, characterized in that the wall of the printing definition area (3) surrounds an opening angle (α) that is 20 degrees smaller than the wall of the printing medium supply area (2).

6. The printing stencil (1) according to claim 4, characterized in that the wall of the printing definition area (3) surrounds an opening angle (α) that is 30 degrees smaller than the wall of the printing medium supply area (2).

7. The printing stencil (1) according to any one of claims 1 to 6, characterized in that the printing stencil (1) has a thickness greater than 50 μm.

8. The printing stencil (1) according to claim 7, characterized in that the printing stencil (1) has a thickness greater than 100 μm.

9. The printing stencil (1) according to claim 7, characterized in that the printing stencil (1) has a thickness greater than 500 μm.

10. The printing stencil (1) according to any one of claims 1 to 6, characterized in that the printing area (3) has a thickness less than 250 μm.

11. The printing stencil (1) according to claim 10, characterized in that the printing area (3) has a thickness less than 50 μm.

12. The printing stencil (1) according to claim 10, characterized in that the printing area (3) has a thickness less than 25 μm.

13. A printing stencil (1) according to any one of claims 1 to 6, characterized in that the stencil body is formed from one of the materials of glass, stainless steel, and silicon.

14. The printing stencil (1) according to claim 13, characterized in that the stencil body is formed from glass.

15. The printing stencil (1) according to any one of claims 1 to 6, characterized in that the width of each of the plurality of printing gaps (4) at the end of the printing definition area (3) facing the squeegee surface (R) is less than 50 μm.

16. The printing stencil (1) according to claim 15, characterized in that the width of each of the plurality of printing gaps (4) at the end of the printing defining area (3) facing the squeegee surface (R) is less than 25 μm.

17. The printing stencil (1) according to claim 15, characterized in that the width of each of the plurality of printing gaps (4) at the end of the printing definition area (3) facing the squeegee surface (R) is less than 15 μm.

18. The printing stencil (1) according to any one of claims 1 to 6, characterized in that the width of each of the plurality of printing gaps (4) at the end of the printing definition area (3) facing the substrate surface (S) is less than 50 μm.

19. The printing stencil (1) according to claim 18, characterized in that the width of each of the plurality of printing gaps (4) at the end of the printing defined area (3) facing the substrate surface (S) is less than 25 μm.

20. The printing stencil (1) according to claim 18, characterized in that the width of each of the plurality of printing gaps (4) at the end of the printing defining area (3) facing the substrate surface (S) is less than 15 μm.

21. The printing stencil (1) according to claim 18, characterized in that the width of each of the plurality of printing gaps (4) at the end of the printing definition area (3) facing the substrate surface (S) is in the range of 15 μm to 25 μm.

22. The printing stencil (1) according to any one of claims 1 to 6, characterized in that the width of each of the plurality of printing gaps (4) at the end of the printing medium supply area (2) facing the squeegee surface (R) is greater than 15 μm.

23. The printing stencil (1) according to claim 22, characterized in that the width of each of the plurality of printing gaps (4) at the end of the printing medium supply area (2) facing the squeegee surface (R) is greater than 25 μm.

24. The printing stencil (1) according to claim 22, characterized in that the width of each of the plurality of printing gaps (4) at the end of the printing medium supply area (2) facing the squeegee surface (R) is greater than 50 μm.

25. The printing stencil (1) according to any one of claims 1 to 6, characterized in that the printing medium supply area (2) terminates directly on the squeegee surface (R), and the printing definition area (3) terminates directly on the substrate surface (S).

26. The printing stencil (1) according to claim 25, characterized in that the printing medium supply area (2) and the printing definition area (3) are adjacent to each other.

27. A printing plate having a printing stencil (1) according to any one of claims 1 to 6, characterized in that the printing stencil is arranged within a frame.

28. A printing plate having the printing stencil (1) described in Claim 27, wherein the printing stencil is arranged within the frame under tensile stress.

29. The printing plate according to claim 27, characterized in that a support structure is not formed in the opening of the printing gap (4).

30. The printing plate according to claim 29, characterized in that a mesh-like support structure is not formed.

31. The printing plate according to claim 29, characterized in that a screen printing mesh is not arranged on it.

32. A printing apparatus for forming a conductive path on a substrate, comprising a printing stencil (1) according to any one of claims 1 to 6 and at least one squeegee, wherein the screen printing apparatus is configured to apply a printing medium to the substrate by passing it through a screen printing plate using the squeegee.

33. A method for manufacturing a metallic contact structure for a photovoltaic solar cell, - Apply the printing medium to the squeegee surface (R) of the printing stencil (1). - A method comprising the step of using at least one squeegee to press the printing medium through the printing gap (4) of the printing stencil (1) in order to apply a printing medium structure onto a solar cell substrate on the substrate surface (S) of the printing stencil facing the squeegee surface (R), The printing stencil (1) is formed as a plate-shaped printing stencil (1) having a substrate surface (S) and a squeegee surface (R) facing the substrate surface (S). Each of the multiple printing gaps (4) has at least one printing definition area (3) adjacent to the printing surface and at least one printing medium supply area (2) adjacent to the squeegee surface (R), and the volume of the printing definition area (3) is smaller than the volume of the printing medium supply area (2). The printing medium supply area (2) has a gap width that increases in the direction of the squeegee surface (R), and further - The wall of the print definition area (3) surrounds a first opening angle (α) that is smaller than the second opening angle (β) surrounded by the wall of the print medium supply area (2), and / or - The method is characterized in that the printed defined area (3) has a gap width that increases in the direction of the substrate surface (S).

34. The method according to claim 33, wherein the gap width of the printing medium supply area (2) increases densely and monotonically.

35. The method according to claim 33, wherein the gap width of the printable area (3) increases densely and monotonically.

36. Use of the printed stencil (1) according to any one of claims 1 to 6 for forming a metallic conductive path in a photovoltaic solar cell.

37. The use according to claim 36, characterized in that the metallic conductive path is formed on the front surface facing the light incidence of the photovoltaic solar cell.

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