High-precision additive formation of electrical resistors

Abstract

Shown herein is a method of forming an electrical resistor comprising the steps of: forming an electrically resistive layer on a substrate; measuring an electrical resistance-related parameter of the electrically resistive layer and determining a target length of the electrically resistive layer corresponding to a target electrical resistance; and forming first and second electrically conductive terminals contacting the electrically resistive layer, said first and second electrically conductive terminals being separated by a distance corresponding to the target length.

Claims

1. A method of forming an electrical resistor having a target electrical resistance by additive manufacturing comprising the steps of: forming an electrically resistive layer on a substrate; measuring an electrical resistance-related parameter of the electrically resistive layer and determining from the electrical resistance-related parameter a target length of the electrically resistive layer corresponding to the target electrical resistance; and forming a first electrically conductive terminal and a second electrically conductive terminal contacting the electrically resistive layer, said first and second electrically conductive terminals being separated by a distance corresponding to the target length, such that an electrical resistance of a portion of the electrically resistive layer extending between the first electrically conductive terminal and the second electrically conductive terminal corresponds to the target electrical resistance.

2. The method of forming an electrical resistor of claim 1, wherein the electrically resistive layer is made of carbon, carbon composites, metal oxides, and/or mixtures thereof.

3. The method of forming an electrical resistor of claim 1, wherein forming the electrically resistive layer comprises one or more of printing, coating, vacuum coating, vacuum deposition, curing and drying.

4. The method of forming an electrical resistor of claim 1, wherein forming the first electrically conductive terminal and the second electrically conductive terminal layer comprises digital inkjet printing, digital thermo transfer printing, or digital 3-D printing.

5. The method of forming an electrical resistor of claim 1, wherein the electrical resistance-related parameter is determined by measuring an electrical resistance of a portion of the electrically resistive layer having a known length.

6. The method of forming an electrical resistor of claim 1, further comprising electrically connecting to the electrically resistive layer between the first electrically conductive terminal and the second electrically conductive terminal one or more electrically conductive elements.

7. The method of forming an electrical resistor of claim 1, further comprising measuring a final electrical resistance-related parameter of the electrically resistive layer between the first electrically conductive terminal and the second electrically conductive terminal, wherein the final electrical resistance-related parameter is indicative of an electrical resistance of the electrically resistive layer between the first electrically conductive terminal and the second electrically conductive terminal.

8. The method of forming an electrical resistor of claim 1, further comprising optically monitoring the formation of the first electrically conductive terminal and the second electrically conductive terminal.

9. The method of forming an electrical resistor of claim 1, further comprising optically monitoring the formation of the electrically isolating layer.

10. The method of forming an electrical resistor of claim 1, wherein the substrate comprises a silicon substrate, a polymer substrate, a ceramic substrate, a printed circuit board, a paper substrate or a cardboard substrate.

11. A method of forming an electrical resistor having a target electrical resistance by additive manufacturing comprising the steps of: forming an electrically resistive layer on a substrate; measuring an electrical resistance-related parameter of the electrically resistive layer and determining from the electrical resistance-related parameter a target length of the electrically resistive layer corresponding to the target electrical resistance; forming an electrically isolating layer on the electrically resistive layer having first and second ends, wherein the electrically isolating layer covers the electrically resistive layer in an overlap region extending between said first end and said second end, such that a length of the electrically resistive layer covered by the electrically isolating layer corresponds to the target length, such that an electrical resistance of a portion of the electrically resistive layer covered by the electrically isolating layer corresponds to the target electrical resistance; and forming a first electrically conductive terminal on the electrically resistive layer directly adjacent to the first end of the electrically isolating layer and forming a second electrically conductive terminal on the electrically resistive layer directly adjacent to the second end of the electrically isolating layer.

12. The method of forming an electrical resistor of claim 11, wherein the electrically isolating layer is made of a ceramic, silicon oxide, aluminum oxide or metallic oxide, paper, or an organic polymer.

13. The method of forming an electrical resistor of claim 11, wherein forming the electrically isolating layer comprises one or more of analog screen printing, analog flexo printing, analog gravure printing, analog inkjet printing, analog pad printing, analog hot stamping, analog thermo transfer printing, and analog 3-D printing.

14. The method of forming an electrical resistor of claim 11, wherein the electrically isolating layer is formed by depositing an electrically isolating element on the electrically resistive layer.

15. The method of claim 14, further comprising adjusting the length of the electrically resistive layer covered by the electrically isolating element by positioning the electrically isolating element with respect to the electrically resistive layer.

16. The method of forming an electrical resistor of claim 11, wherein forming the first electrically conductive terminal and the second electrically conductive terminal comprises forming an electrically conductive layer on the electrically isolating layer and on parts of the electrically resistive layer not covered by the electrically isolating layer, wherein the electrically conductive layer has a discontinuity that electrically isolates the first electrically conductive terminal from the second electrically conductive terminal.

17. Arrangement for forming an electrical resistor having a target electrical resistance by additive manufacturing, wherein the arrangement comprises: a first deposition device configured for depositing an electrically resistive material for forming an electrically resistive layer; a processing unit configured for measuring an electrical resistance-related parameter of an electrically resistive layer formed by the first deposition device and determining from the electrical resistance-related parameter a target length of the electrically resistive layer corresponding to the target electrical resistance; and a second deposition device configured for depositing an electrically conductive material for forming electrically conductive terminals; wherein the processing unit is further configured for controlling the second deposition device to form a first electrically conductive terminal and a second electrically conductive terminal such as to contact an electrically resistive layer formed by the first deposition device, said first and second electrically conductive terminals being separated by a distance corresponding to the target length, such that an electrical resistance of a portion of the electrically resistive layer extending between the first electrically conductive terminal and the second electrically conductive terminal corresponds to the target electrical resistance.

18. The arrangement of claim 17, wherein the second deposition device comprises a printing device configured for printing the first electrically conductive terminal and the second electrically conductive terminal by means of inkjet printing, thermo transfer printing, or 3-D printing.

19. The arrangement of claim 17, further comprising an optical device configured for optically monitoring the formation of the first electrically conductive terminal and the second electrically conductive terminal by the second deposition device and/or for optically monitoring the formation of the electrically isolating layer by the third deposition device.

20. The arrangement of claim 17, further comprising a measuring device suitable for measuring an electrical resistance-related parameter of the electrically resistive layer.

21. Arrangement for forming an electrical resistor having a target electrical resistance by additive manufacturing, wherein the arrangement comprises: a first deposition device configured for depositing an electrically resistive material for forming an electrically resistive layer; a processing unit configured for measuring an electrical resistance-related parameter of an electrically resistive layer formed by the first deposition device and determining from the electrical resistance-related parameter a target length of the electrically resistive layer corresponding to the target electrical resistance; a second deposition device configured for depositing an electrically conductive material for forming electrically conductive terminals; and a third deposition device configured for depositing an electrically isolating material for forming an electrically isolating layer; wherein the processing unit is further configured for controlling the third deposition device to form the electrically isolating layer on an electrically resistive layer formed by the first deposition device, such that the electrically isolating layer extends from a first end to a second end, wherein the electrically isolating layer covers the electrically resistive layer in an overlap region extending between said first end and said second end, such that a length of the electrically resistive layer covered by the electrically isolating layer corresponds to the target length; and wherein the processing unit is further configured for controlling the second deposition device to form a first electrically conductive terminal on the electrically resistive layer directly adjacent to the first end of the electrically isolating layer and to form a second electrically conductive terminal on the electrically resistive layer directly adjacent to the second end of the electrically isolating layer.

22. The arrangement of forming an electrical resistor of claim 21, wherein the third deposition device comprises a robot device configured for depositing a prefabricated electrically isolating element on an electrically resistive layer formed by the first deposition device, wherein the electrically isolating element extends from a first end to a second end, wherein a distance between the first end and the second end corresponds to the target length, such that an electrical resistance of a portion of the electrically resistive layer covered by the electrically isolating element corresponds to the target electrical resistance.

23. The arrangement of forming an electrical resistor of claim 21, wherein the third deposition device comprises a printing device configured for printing the electrically isolating layer by means of analog screen printing, analog flexo printing, analog gravure printing, analog inkjet printing, analog pad printing, hot stamping, and analog thermo transfer printing.

24. The arrangement of claim 21, wherein the third deposition device comprises a printing device configured for printing the electrically isolating layer by means of digital inkjet printing, digital thermo transfer printing, or digital 3-D printing.

25. The arrangement of claim 21, further comprising a subtractive device suitable for forming a discontinuity in an electrically conductive layer formed by the second deposition device on the electrically isolating layer to thereby form the first electrically conductive terminal and the second electrically conductive terminal, such that the first electrically conductive terminal and the second electrically conductive terminal are electrically isolated from each other.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 is a flow diagram representing a method for forming an electrical resistor according to an embodiment of the invention.

(2) FIG. 2 shows an electrical resistor formed by a method according to an embodiment of the invention.

(3) FIG. 3 shows an electrical resistor formed by a method according to an embodiment of the invention.

(4) FIG. 4 shows an electrical resistor formed by a method according to another embodiment of the invention.

(5) FIG. 5 is a flow diagram representing a method for forming an electrical resistor according to another embodiment of the invention.

(6) FIG. 6 illustrates a method for forming an electrical resistor according to an embodiment of the invention.

(7) FIG. 7 illustrates a method for forming an electrical resistor according to another embodiment of the invention.

(8) FIG. 8 illustrates an exemplary use of electrically conductive elements for reducing the length of the electrical path between the first and second electrically conductive terminals according to an embodiment of the invention.

(9) FIG. 9 illustrates another exemplary use of an electrically conductive element for reducing the length of the electrical path between the first and second electrically conductive terminals according to an embodiment of the invention.

(10) FIG. 10 illustrates an operation of adjusting the length of an electrically resistive layer covered by an electrically isolating element according to an embodiment of the invention.

(11) FIG. 11 shows an arrangement for forming an electrical resistor according to an embodiment of the invention.

(12) FIG. 12 shows an arrangement for forming an electrical resistor according to another embodiment of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

(13) Certain embodiments of the present invention are described in detail herein below with reference to the accompanying drawings, wherein the features of the embodiments can be freely combined with each other unless otherwise described. However, it is to be expressly understood that the description of certain embodiments is given by way of example only, and that it should not be understood to limit the invention.

(14) FIG. 1 is a flow diagram illustrating a method 50 of forming an electrical resistor having a target electrical resistance by additive manufacturing according to an embodiment of the invention. Exemplary electrical resistors to formed by the method 50 illustrated in FIG. 1 are shown in FIGS. 2 and 3. Thus, FIGS. 1 to 3 may be considered in combination for a better understanding of the invention. The method 50 comprises a step 52 of forming an electrically resistive layer 14 on a substrate 12. In the embodiment shown, the step 52 comprises printing an electrically resistive layer 14 of carbon having a thickness of 15 m on a substrate 12 that corresponds to a PCB of PET having a thickness of 75 m.

(15) The method 50 further comprises a step 54 of measuring an electrical resistance-related parameter of the electrically resistive layer 14 along a first direction and determining from the electrical resistance-related parameter a target length L of the electrically resistive layer 14 along the first direction corresponding to the target electrical resistance. In FIGS. 2 and 3, the first direction corresponds to a horizontal direction in the paper plane. In the embodiment shown, the electrical resistance-related parameter is determined by measuring the electrical resistance of a portion of the electrically resistive layer 14 having (not shown) a known length, for example a fixed distance between two measuring terminals of a measuring device suitable for electrical resistance measurements. However, said known length may also be obtained as a result of a direct length measurement of the distance between two points of the electrically resistive layer 14 along the first direction at which the electrical resistance-related parameter is measured.

(16) The measurement of the electrical resistance-related parameter allows determining an electrical resistance to length ratio of the electrically resistive layer 14 and hence using a desired target electrical resistance as an input variable for determining, in view of said ratio, a target length L of the electrically resistive layer 14 along the first direction corresponding to the target electrical resistance.

(17) The method 50 further comprises a step 56 of forming a first electrically conductive terminal 16a and a second electrically conductive terminal 16b on the electrically resistive layer 14 separated by a distance along the first direction corresponding to the target length L. This way, an electrical resistance of a portion of the electrically resistive layer 14 extending between the first electrically conductive terminal 16a and the second electrically conductive terminal 16b along the first direction corresponds to the target electrical resistance. In the embodiment shown, the first electrically conductive terminal 16a and the second electrically conductive terminal 16b are inkjet printed on the electrically resistive layer 14 with a high degree of spatial accuracy such that the distance between the first electrically conductive terminal 16a and the second electrically conductive terminal 16b precisely corresponds to the target length L.

(18) Thus, the electrical resistor 10 is suitable for being connected to external electronic components through the first electrically conductive terminal 16a and the second electrically conductive terminal 16b and for working as a passive circuit element having an electrical resistance corresponding to the target electrical resistance.

(19) In the embodiment shown in FIG. 2, the first electrically conductive terminal 16a and the second electrically conductive terminal 16b have outermost ends along the first direction that coincide with the outermost ends along the first direction of the electrically resistive layer 14, so that neither the first electrically conductive terminal 16a nor the second electrically conductive terminal 16b extend along the first direction beyond the electrically resistive layer 14. However, in other embodiments of the invention, as e.g. that shown in FIG. 3, the first electrically conductive terminal 16a and the second electrically conductive terminal 16 be may extend along the first direction beyond the electrically resistive layer 14. It will be hence clear to those skilled in the art that the present invention is not restricted to any particular geometrical configuration of the first electrically conductive terminal 16a and the second electrically conductive terminal 16b with respect to the electrically resistive layer 14, as long as the separation between the first electrically conductive terminal 16a and the second electrically conductive terminal 16b along the first direction corresponds to the target length L.

(20) FIG. 5 is a flow diagram illustrating a method 60 of forming an electrical resistor having a target electrical resistance by additive manufacturing according to an embodiment of the invention. An exemplary electrical resistor 10 formed by the method 60 illustrated in FIG. 5 is shown in FIG. 4. Thus, FIGS. 4 and 5 may be considered in combination for a better understanding of the invention. The method 60 comprises a step 62 of forming an electrically resistive layer 14 on a substrate 12. In the embodiment shown, the step 62 comprises coating an electrically resistive layer 14 of carbon having a thickness of 15 m on the substrate 12, which in the embodiment shown corresponds to a ceramic substrate 12, and subsequently drying the electrically resistive layer 14.

(21) The method 60 further comprises a step 64 of measuring an electrical resistance-related parameter of the electrically resistive layer 14 along a first direction and determining from the electrical resistance-related parameter a target length L of the electrically resistive layer 14 along the first direction corresponding to the target electrical resistance. Method step 64 of the method 60 illustrated in FIG. 5 is analogous to method step 54 of the method 50 illustrated in FIG. 1.

(22) The method 60 further comprises a step 66 of forming an electrically isolating layer 20 on the electrically resistive layer 14 that extends along the first direction between a first end 20a and a second end 20b of the electrically isolating layer 20, wherein a distance between the first end 20a and the second end 20b along the first direction corresponds to the target length L. Therefore, an electrical resistance of a portion of the electrically resistive layer 14 covered by the electrically isolating layer 20 along the first direction corresponds to the target electrical resistance. In the embodiment shown, the electrically isolating layer 20 is formed on the electrically resistive layer 14 by means of screen printing using a printing screen or mask corresponding to a negative image of the electrically isolating layer 20 having a length precisely corresponding to the target length L. For example, an electrically resistive printing polymer fluid can be pressed though the printing screen onto the electrically resistive layer 14 so that an electrically isolating layer 20 made of a polymer is formed on the electrically resistive layer 14 having a length along the first direction precisely corresponding to the target length L.

(23) The method 68 further comprises a step 68 of forming a first electrically conductive terminal 16a on the electrically resistive layer 14 directly adjacent to the first end 20a of the electrically isolating layer 20 and forming a second electrically conductive terminal 16b on the electrically resistive layer 14 directly adjacent to the second end 20b of the electrically isolating layer 20. The first electrically conductive terminal 16a and the second electrically conductive terminal 16b are separated along the first direction by the electrically isolating layer 20, which has a length that corresponds to the target length L. Consequently, an electrical path joining the first electrically conductive terminal 16a and the second electrically conductive terminal 16b extends through a portion of the electrically resistive layer 14 having a length corresponding to the target length L and hence an electrical resistance corresponding to the target electrical resistance. Thus, the electrical resistor 10 is suitable for being connected to external electronic components through the first electrically conductive terminal 16a and the second electrically conductive terminal 16b and for working as a passive circuit element having an electrical resistance corresponding to the target electrical resistance.

(24) As shown in FIG. 4, the first electrically conductive terminal 16a and the second electrically conductive terminal 16b need not have a regular form nor be coplanar with the underlying electrically isolating layer 20 and electrically resistive layer 14. For example, the first electrically conductive terminal 16a and the second electrically conductive terminal 16b of the embodiment shown in FIG. 4 have an irregular form, extend over parts of the electrically resistive layer 14 not covered by the electrically isolating layer 20, and partly extend over the electrically isolating layer 20. In the embodiment of FIG. 4, the first and second electrically conductive terminals 16a, 16b are formed on the electrically resistive layer directly adjacent to the first and second ends 20a, 20b of the electrically isolating layer 20 by having them overlap with the ends 20a, 20b of the electrically isolating layer 20. Accordingly, the electrically isolating layer 20 provides for the precise location where the electrically conductive terminals 16a, 16b contact the electrically resistive layer 14 without requiring a correspondingly precise positioning of the electrically conductive terminals 16a, 16b themselves. Accordingly, the only method step that needs to be carried out with high precision in this embodiment is the formation of the electrically isolating layer 20. Manufacturing imperfections e.g. with regard to the cross-section or electrical resistivity of the electrically resistive layer 14 are absorbed in the proper choice of the target length, and a high precision with regard to forming the electrically conductive terminals 16a, 16b is likewise not necessary, since they may simply be formed such as to overlap with the corresponding end of the electrically isolating layer 20, which automatically ensures that they are formed on the electrically resistive layer 20 directly adjacent to the respective end of the electrically isolating layer 20.

(25) FIG. 6 illustrates different stages of a method for forming an electrical resistor 10 according to an embodiment of the invention. As shown in FIG. 6a, an electrically resistive layer 14 of carbon is coated on a substrate 12 and subsequently dried. The electrically resistive layer 14 can however also be made of metal oxides as tin oxide, PeDot and/or of mixtures thereof. In the embodiment shown, the electrically resistive layer 14 is conformably formed over the substrate 12 such that the electrically resistive layer 14 is coplanar with the substrate 12.

(26) As shown in FIG. 6b, an electrically isolating layer 20 is formed on the electrically resistive layer 14. In the embodiment shown, the electrically isolating layer 20 is made of an organic polymer and is formed by screen printing. As shown in the figure, the electrically isolating layer 20 need not have a regular shape as long as it has a length along the first direction that precisely corresponds to the target length L. For example, in the embodiment shown, the electrically isolating layer 20 has a curved top surface that is not coplanar with the underlying electrically resistive layer 14.

(27) As shown in FIG. 6c, an electrically conductive layer 16 is formed on the electrically isolating layer 20 and on parts of the electrically resistive layer 14 not covered by the electrically isolating layer 20. In the embodiment shown, the electrically conductive layer 16 is made of copper and is conformably formed over the electrically isolating layer 20 and on parts of the electrically resistive layer 14 not covered by the electrically isolating layer 20 by means of coating and subsequent drying.

(28) As shown in FIG. 6d, an opening 18 is formed in the electrically conductive layer 16 that forms a discontinuity in the electrically conductive layer 16 and exposes the electrically isolating layer 20 through the electrically conductive layer 16. The electrically conductive layer 16 is thereby divided in a first electrically conductive terminal 16a and a second electrically conductive terminal 16b that are electrically isolated from each other, such that an electrical path between the first electrically conductive terminal 16a and the second electrically conductive terminal 16b extends through the electrically resistive layer 14. The process of forming the opening 18 does not require high precision, since the separation between the first electrically conductive terminal 16a and the second electrically conductive terminal 16b through the electrically resistive layer 14, i.e. the electrical path joining the first electrically conductive terminal 16a and the second electrically conductive terminal 16b, corresponds to the target length L irrespectively of a form or dimension of the opening 18. Thus a quality of the formation process of the opening 18 does not affect the accuracy with which the electrical resistor 10 achieves the target electrical resistance. In the embodiment shown, the opening 18 is formed by means of a fast mechanical erosion, like e.g. sawing, although other erosive processes can be used.

(29) FIG. 7 illustrates different stages of a method for forming an electrical resistor 10 according to a further embodiment of the invention. As shown in FIG. 7a, an electrically resistive layer 14 is formed on a substrate 12. In the embodiment shown, the electrically resistive layer 14 is made of a polymer, like e.g. PE, PP, PET, OPA, PC or PVC, and is conformably printed on the substrate 12 by means of screen printing.

(30) As shown in FIG. 7b, a prefabricated electrically isolating element 22 is deposited on the electrically resistive layer 14. The prefabricated electrically isolating element 22 extends from a first end 22a to a second end 22b along the first direction, wherein a distance between the first end 22a and a second end 22b corresponds to the target length L. In the embodiment shown, the prefabricated electrically isolating element 22 is a stripe made of an organic polymer that has a length corresponding to the target length L. The prefabricated electrically isolating element 22 is glued on the electrically resistive layer 14 and covers a portion of the electrically resistive layer 14 having a length corresponding to the target length L and hence having an electrical resistance corresponding to the target electrical resistance.

(31) As shown in FIG. 7c, an electrically conductive layer 16 is formed on the prefabricated electrically isolating element 22 and parts of the electrically resistive layer 14 not covered by the prefabricated electrically isolating element 22. In the embodiment shown, the electrically conductive layer 16 is made of silver and is printed on the prefabricated electrically isolating element 22 and part of the electrically resistive layer 14 not covered by the prefabricated electrically isolating element 22 by means of inkjet printing. When printing the electrically conductive layer 16, the printing process is momentarily interrupted such that a discontinuity 24 is formed in the electrically conductive layer 16. Consequently, a first electrically conductive terminal 16a is formed adjacent to the first end 22a of the prefabricated electrically isolating element 22 and a second electrically conductive terminal 16b is formed adjacent to the second end 22b of the prefabricated electrically isolating element 22. Notably, the interruption of the printing process of the electrically conductive layer 16 for forming the discontinuity 24 does not require high precision, since the separation between the first electrically conductive terminal 16a and the second electrically conductive terminal 16b through the electrically resistive layer 14, i.e. the electrical path joining the first electrically conductive terminal 16a and the second electrically conductive terminal 16b, corresponds to the target length L irrespectively of a form or dimension of the discontinuity 24. Thus a quality of the interruption, like e.g. a spatial or time resolution thereof, does not affect the accuracy with which the electrical resistor 10 achieves the target electrical resistance.

(32) FIG. 8 schematically shows how an electrically conductive element 25 may be used for reducing the length of the electrical path between the first and second electrically conductive terminals 16a, 16b according to an embodiment of the invention. As shown in the figure, an electrically conductive element 25 is electrically connected to the electrically resistive layer 14 between the first and second electrically conductive terminals 16a, 16b. Although only one electrically conductive element 25 is exemplarily shown in the figure, it is understood that more than one electrically conductive element 25 may be used. The electrically conductive element 25 is, in the embodiment shown, of the same material as the first and second electrically conductive terminals 16a, 16b, for example of copper. As a result, the electrically conductive element 25 allows for an electric current to flow through its interior with a negligible electrical resistance and hence shortcuts an electrical path joining the first and second electrically conductive terminal 16a, 16b such that the effective length of said electrical path is reduced as compared to a situation in which the electrically conductive element 25 would not be present, like for example that shown in FIG. 2. Consequently, the length of the electrical path through the electrically resistive layer 14 between the first and second electrically conductive terminals 16a, 16b does no longer correspond to a separation distance L between first and second electrically conductive terminals 16a, 16b (cf. FIG. 2) but instead to the sum of a length L1 between the first electrically conductive terminal 16a and the electrically conductive element 25 and a length L2 between the second electrically conductive terminal 16b and the electrically conductive element 25, which sum is smaller than the length L of FIG. 2, wherein the difference between the length L and the sum of the lengths L1 and L2 correspond to a length of the electrically conductive element 25. Thus, one or more electrically conductive elements 25 may be used for reducing an electrical resistance value of the electrical resistor 10.

(33) FIG. 9 schematically illustrates another exemplary use of an electrically conductive element 25 for reducing the length of the electrical path between the first and second electrically conductive terminals 16a, 16b according to an embodiment of the invention. In this case, the electrically resistive layer 14 has a folded U-shape and so has the electrical path joining the first and second electrically conductive terminals 16a, 16b. The electrically conductive element 25 shortcuts this path such that the portion of the electrically resistive layer 14 illustrated in the figure to the right of the electrically conductive element 25 does no longer contribute to an effective length of the aforesaid electrical path. Thus the effective length of the electrical path between the first and second electrically conductive terminals 16a, 16b can be adjusted by conveniently positioning the electrically conductive element 25.

(34) FIG. 10 schematically illustrates an operation of adjusting the length of an electrically resistive layer 14 covered by an electrically isolating element 22 acting as an electrically isolating layer 20 according to an embodiment of the invention. In the embodiment shown, the electrically resistive layer 14 is formed having an angled shape, more precisely an L-shape. The electrically isolating element 22 is then deposited on the electrically resistive layer 14 such that a length of the electrically resistive layer 14 covered by the electrically isolating element 22 corresponds to the target length L which has previously been determined. The aforesaid length, which is L-shaped according to the form of the electrically resistive layer 14 can be adjusted by positioning the electrically isolating element 22 with respect to the electrically resistive layer 14, for example by shifting the electrically isolating element 22 along the direction corresponding to the horizontal direction in the figure.

(35) The electrically isolating element 22 then covers the electrically resistive layer 14 in an overlapping region, which is correspondingly L-shaped and extends between a first end 22a and a second end 22b of the electrically isolating element 22. Subsequently, the first electrically conductive terminal 16a is formed adjacent to the first end 22a of the electrically isolating element 22 and the second electrically conductive terminal 16b is formed adjacent to the second end 22b of the electrically isolating element 22. The first and second electrically conductive terminals 16a, 16b partly overlap the electrically isolating element 22.

(36) FIG. 11 shows a schematic view of an arrangement 100 according to an embodiment of the invention for forming an electrical resistor having a target electrical resistance by additive manufacturing. The arrangement 100 comprises a first deposition device 140 and a second deposition device 160 that are integrated in a combined deposition device 180. In the embodiment shown, the first deposition device 140 comprises a printing device configured for forming an electrically resistive layer 14 by screen printing, and the second deposition device 160 comprises a further printing device configured for inkjet printing a first electrically conductive terminal 16a and a second electrically conductive terminal 16b or an electrically conductive layer 16 according to the embodiments described above on the electrically resistive layer 14 formed by the first deposition device 140.

(37) The arrangement 100 further comprises a processing unit 300 that is configured for measuring an electrical resistance-related parameter of an electrically resistive layer 14 formed by the first deposition device 140 along a first direction and for determining from the electrical resistance-related parameter a target length L of the electrically resistive layer 14 along the first direction corresponding to the target electrical resistance. In the embodiment shown, the processing unit 300 comprises a software tool configured for accurately controlling the printing of the first electrically conductive terminal 16a and the second electrically conductive terminal 16a by the second deposition device 160 such that a distance between them precisely corresponds to the target length L. Further, the processing unit 300 comprises a measuring device 310 suitable for measuring the electrical resistance-related parameter. For example, the measuring device 310 may comprise an ohmmeter and/or means for determining a length of the electrically resistive layer 14 along the first direction. In the embodiment shown, the measuring device 310 is suitable for measuring a final electrical resistance-related parameter.

(38) The arrangement 100 further comprises an optical device 400, which in the embodiment shown comprises a photographic camera. The optical device 400 is configured for monitoring and tracking the formation of the first electrically conductive terminal 16a and the second electrically conductive terminal 16b by the second deposition device 160 and for providing information about the corresponding formation process to the processing unit 300.

(39) FIG. 12 shows a schematic view of an arrangement 100 according to another embodiment of the invention for forming an electrical resistor having a target electrical resistance by additive manufacturing. The arrangement 100 comprises a first deposition device 140, a second position device 160, and a third deposition device 200. The first deposition device 140 and the second deposition device 160 correspond to the first deposition device 140 and the second deposition device 160 of the embodiment shown in FIG. 11. The third deposition device 200 comprises a robot device 210 configured for depositing a prefabricated electrically isolating element 22 on an electrically resistive layer 14 formed by the first deposition device 140 according to corresponding embodiments of the invention described above. The arrangement 100 further comprises a processing unit 300 controlling all of its components.

(40) The arrangement 100 further comprises a subtractive device 240 configured for forming an opening in an electrically conductive layer 16 formed by the second deposition device 160 according to corresponding embodiments of the invention described above.

(41) Although preferred exemplary embodiments are shown and specified in detail in the drawings and the preceding specification, these should be viewed as purely exemplary and not as limiting the invention. It is noted in this regard that only the preferred exemplary embodiments are shown and specified, and all variations and modifications should be protected that presently or in the future lie within the scope of protection of the invention as defined in the claims.