Method for constructing a device comprising interconnections

Abstract

Title: Method for manufacturing a device comprising interconnections. The invention relates to a method for manufacturing a device comprising a support (10) having a first face (100) and at least one second face (200) not parallel to the first face (100), and at least one metallic connection (21) linking said first and second faces (100, 200), said method comprising successively: Manufacturing the support (10) by additive manufacturing, providing in the support (10) at least one hole (11) opening onto the first and second faces (100, 200); Filling the at least one hole (11) with a metallic paste, said filling comprising a first filling by injecting the metallic paste into said at least one hole (11); Annealing the metallic paste so as to form the metallic connection (21). The invention also relates to a device manufactured by such a method. Figure for the abstract: Fig. 2

Description

Title of the invention: Method for making a device comprising interconnections technical field

[0001] The present invention relates, in general, to a method for forming metallic interconnections within a substrate, more particularly complex metallic interconnections within a ceramic-based substrate. PRIOR TECHNOLOGY

[0002] Ceramic metallization processes make it possible to create metallic tracks and metallic interconnections on and in ceramic supports.

[0003] The simplest way to form this type of metallic interconnection is to drill a hole through the ceramic, for example by laser, and then to apply a metallic coating to the walls of the hole, for example by chemical metallization. Another way to form the metallic interconnections is to create a hole directly during the manufacture of the ceramic support, for example during the co-sintering of the ceramic and the metallic interconnections. This process, however, remains more complex to implement.

[0004] The document “Gerges T. et al., Rapid 3D-Plastronics prototyping by selective metallization of 3D printed parts, Additive Manufacturing 73, 103673 (2023)” discloses a method based on 3D printing of supports to form metallic tracks and vias more quickly and economically. However, metallization of vias remains difficult to achieve using this method, particularly for vias with large form factors. Electrical continuity of the vias is not consistently obtained. This method is not completely reliable for forming metallic interconnects in complex supports.

[0005] There is therefore a need for a method of producing a support, in particular a ceramic support, comprising metallic interconnections, which is reliable and less complex to implement.

[0006] One objective of the present invention is to meet this need and to overcome at least partially the disadvantages mentioned above.

[0007] An objective of the present invention is to propose a method for making a device comprising a support and at least one metallic connection linking two faces of the support, which is reliable and / or which has an easy implementation.

[0008] The other objects, features, and advantages of the present invention will become apparent from an examination of the following description and accompanying drawings. It is understood that other advantages may be incorporated. SUMMARY

[0009] To achieve this objective, according to one embodiment, a method for constructing a device comprising a support having a first face and at least one second face, preferably not parallel to the first face, and at least one metallic connection linking said first and second faces of the support, said method comprising successively: - A fabrication of the support by additive manufacturing, providing in the support at least one hole opening onto the first and second faces of the support, said at least one hole being intended to accommodate at least one metallic connection, - A filling of at least one hole with a metallic paste, configured to form a continuous portion of metallic paste between an inlet orifice and an outlet orifice of the at least one hole, said filling comprising a first filling by injection of the metallic paste into said at least one hole, - Annealing the metal paste to form at least one metallic connection.

[0010] The support forms a mold into which the metal paste is injected. Machining of the support is not necessary to define the patterns of metal interconnections and metal tracks. The support directly incorporates these patterns in the form of holes and recessed reliefs after additive manufacturing.

[0011] Injection advantageously allows the metal paste to be pushed from an inlet orifice of the hole on the first face to an outlet orifice of the hole on the second face. The metal paste is thus better distributed along the hole. The process makes it possible to reliably obtain metallic interconnections exhibiting good material continuity.

[0012] The process according to the invention advantageously makes it possible to obtain a support, typically ceramic-based, comprising metallic interconnections passing through the support from one face to another of the support.

[0013] According to one aspect, the invention also relates to a device comprising a support, preferably ceramic-based, and at least one metallic connection or interconnection passing through said support and linking two non-parallel faces of the support, forming an elbow. The metallic connection(s) can link several faces of the support, for example, three faces of the support, exhibiting complex elbow shapes, for example, a T-shape. Such a device can advantageously be obtained by the method according to the invention.

[0014] Such a device can be advantageously used in the field of microelectronics or power electronics for mounting and assembling electronic chips on the substrate. The invention also relates to an electronic system comprising such a device and at least one electronic chip connected to the device's metallic connections. The length of the through-hole metallic connections according to the invention is minimized. These through-hole metallic connections thus advantageously limit electrical oscillations or fluctuations of a signal, for example, a radio frequency signal emitted or received by a power electronic component. Different faces of the substrate can be connected via the metallic connections running through the device according to the invention. This allows for an expanded range of connections within the device. BRIEF DESCRIPTION OF THE FIGURES

[0015] The aims, objects, features and advantages of the invention will become clearer from the detailed description of embodiments thereof, which are illustrated by the following accompanying drawings in which:

[0016] [Fig.1] [Fig.2] Figures 1 and 2 schematically illustrate in perspective the manufacturing steps of a device comprising metallic connections linking two non-parallel faces of the support, and through metallic connections, according to an embodiment of the present invention.

[0017] [Fig.3] Fig.3 schematically illustrates the device along the section plane AA' illustrated in [Fig.2], according to one embodiment of the present invention.

[0018] [Fig.4] Fig.4 illustrates an annealing diagram for forming the connections metallic parts of the device, according to an embodiment of the present invention.

[0019] [Fig. 5] Fig. 5 schematically illustrates a support comprising holes presenting a T-shape, according to an embodiment of the present invention.

[0020] [Fig. 6] Fig. 6 schematically illustrates in perspective a device comprising the support illustrated in [Fig.5], in which metallic connections are formed at the T-holes, according to an embodiment of the present invention.

[0021] The drawings are given by way of example and are not limiting of the invention. They constitute schematic representations of the principle intended to facilitate understanding of the invention and are not necessarily to scale with practical applications. In particular, in the schematic diagrams, the thicknesses of the different layers and portions, and the dimensions of the patterns and holes are not necessarily representative of reality. DETAILED DESCRIPTION

[0022] Before proceeding with a detailed review of embodiments of the invention, optional features that may be used in combination or alternatively are listed below:

[0023] According to one example, the embodiment of the support is configured so that at least one hole has an elbow within the support.

[0024] In one example, at least one hole has a first cross-section on one side of the bend and a second cross-section on the other side of the bend, the first cross-section being larger than the second. In another example, the inlet for filling is chosen on the first side of the bend. This optimizes the injection filling process. The continuity of the injected material is improved.

[0025] According to one example, the support is configured so that at least one hole has a diameter strictly less than or equal to 1 mm, and / or a longitudinal dimension greater than 15 mm.

[0026] According to one example, the support has a third face substantially parallel to the first face and substantially orthogonal to the second face, and the support is configured such that at least one hole has a T-shape opening onto the first, second, and third faces of the support. Such a configuration expands the device's connection possibilities. This configuration is simpler to implement using additive manufacturing and less expensive than drilling or engraving the support, for example.

[0027] In one example, the support is configured to include at least one second hole opening onto the first and third faces of the support. In this example, two types of holes coexist within the support: a first type of hole connecting two non-parallel faces of the support, and a second type of hole, also called a "through hole," connecting two parallel faces of the support. This expands the device's connection possibilities.

[0028] According to one example, the first filling by injection of at least one hole is configured to also fill said at least a second hole.

[0029] According to one example, the process further comprises a second screen-printing filling of at least a second hole with a second metal paste. The filling of the different types of holes can be done by different techniques, or in a hybrid manner. The filling may comprise a first injection filling of the first type of hole and a second screen-printing filling of the second type of hole. Alternatively or in combination, the filling may comprise a first injection filling of the first type of hole and a second injection filling of the second type of hole. The first and second fillings may be carried out simultaneously or successively. The first and second types of holes may be pre-filled during the first The holes are filled by injection molding and then completely filled during a second filling by screen printing. The second filling can complete the first filling for a given type of hole. The first type of hole, joining two non-parallel faces of the substrate, is systematically filled at least partially by injection molding.

[0030] According to one example, the second screen-printing filling is carried out after the first injection filling of at least one hole. The second screen-printing filling may also complete the first injection filling.

[0031] According to one example, the second filling of at least one second hole occurs during the simultaneous scraping of the first and / or second faces of the substrate. A scraper is typically used to spread the metal paste and to scrape and level the metal paste in at least one second hole. A front of metal paste moves in front of the scraper and is partially deposited in at least one second hole, and possibly in at least one hole that was partially filled by injection. The metal paste is removed from the substrate face at the rear of the scraper. The metal paste remains only in the holes of the substrate.

[0032] For example, the metal paste used for injection molding and the second metal paste used for screen printing are identical, and preferably correspond to the same silver-based metal paste. Such metal pastes are commercially available as standard. This reduces the cost of the process. The viscosity of the metal paste can be chosen according to the dimensions of the holes, their shape factor, and / or the flatness of the substrate surfaces.

[0033] According to one example, the method further comprises at least one scraping of the first face of the support and / or the second face of the support, so as to equalize the level of metal paste in the at least one hole with said first and / or second faces of the support bordering said at least one hole. This makes it possible to obtain connections flush with the face(s) of the support. The compactness of the device is improved. The integration of the device is improved.

[0034] According to one example, the method further comprises at least one polishing step, for example, a chemical-mechanical polishing step, of the first face of the substrate and / or the second face of the substrate, after annealing the metal paste. This improves the flatness of the substrate face(s) and / or the leveling of the metal paste with the adjacent substrate face(s). This improves the surface finish of the substrate faces and / or the exposed surfaces of the metal paste, for example, in preparation for subsequent soldering of an electronic chip to the metal connections.

[0035] According to one example, the support is made of ceramic.

[0036] According to one example, the realization of the ceramic-based support is completely performed before filling at least one hole, without any subsequent filling steps. Additive manufacturing of the ceramic support does not require any other manufacturing steps are performed after the holes have been filled. Unlike processes involving co-manufacturing or co-sintering steps, such as those used in the production of LTCC (low-temperature co-fired ceramic) supports, there is no need to manage support formation steps during or after the holes have been filled with metal paste. The process according to the invention is easier to implement.

[0037] According to one example, filling at least one hole and / or at least a second hole comprises a first filling step by injection followed by a second filling step by screen printing, which includes squeegeeing the first and / or second faces of the substrate. The filling is completed during the second step. This completion is typically achieved during the squeegeeing, by pushing the front of the metal paste into the holes partially filled by injection. This improves the filling of the holes and forms flush metal connections.

[0038] According to one example, at least one face of the substrate has a curved surface, and the scraping of said face of the substrate is configured to follow this curved surface. The face may have a continuous curvature, a linear slope, or a break in slope. The scraping can advantageously be adapted to different substrate profiles, for example, to create three-dimensional devices.

[0039] According to one example, the metallic connections are configured to be connected to one or more electronic chips. The electronic chips are typically surface-mounted on the substrate.

[0040] According to one example, the device comprises a support having a first face and at least one second face not parallel to the first face, and at least one metallic connection linking said first and second faces of the support. Advantageously, the at least one metallic connection has an elbow within the support. This allows for versatile linking of different non-parallel faces of the support.

[0041] According to one example, the support has a third face substantially parallel to the first face and substantially orthogonal to the second face, and at least one metallic connection has a T-shape opening onto the first, second and third faces of the support.

[0042] Except in cases of incompatibility, it is understood that all the above optional features can be combined to form an embodiment that is not necessarily illustrated or described. Such an embodiment is obviously not excluded from the invention. The features and advantages of the method according to the invention can be applied, mutatis mutandis, to the features and advantages of the device or system according to the invention, and vice versa.

[0043] It is specified that, within the framework of the present invention, the terms "on", "overcomes", "covers", "underlying", "opposite" and their equivalents do not necessarily mean "in contact with". Thus, for example, the deposition or formation of a first layer on a second layer does not necessarily mean that the two layers are directly in contact with each other, but means that the first layer at least partially covers the second layer by being either directly in contact with it, or by being separated from it by at least one other layer or at least one other element.

[0044] A layer may also be composed of several sub-layers of the same material or of different materials.

[0045] A substrate, stack, layer, element "based" on a material A is understood to mean a substrate, stack, layer, element comprising only this material A or this material A and possibly other materials, for example alloying elements and / or dopant elements.

[0046] A preferably orthonormal coordinate system, comprising the x, y, z axes, is shown in the attached figures.

[0047] In the present patent application, the thickness of a layer is taken along a direction normal to the principal extension plane of the layer. Thus, a layer typically has a thickness along z. The relative terms "on", "overlies", "under", "sub-", "intercalated" refer to positions taken along the z direction.

[0048] The terms "vertical" and "vertically" refer to a direction along the z-axis. The terms "horizontally" and "laterally" refer to a direction in the xy plane. Unless explicitly stated otherwise, thickness, height, and depth are measured along the z-axis.

[0049] An element located "in line" or "directly" with another element means that these two elements are both located on the same line perpendicular to a plane in which extends mainly a lower or upper face of a substrate, that is to say on the same line oriented vertically in the figures.

[0050] A longitudinal dimension of a hole is taken along a direction normal to the cross-section of the hole. When a hole has several straight or curved portions, its longitudinal dimension corresponds to the sum of the longitudinal dimensions of each portion.

[0051] Additive manufacturing is also referred to as 3D printing in the following, as a synonym.

[0052] In the context of the present invention, the metal paste has a viscosity compatible with the implementation of a standard injection and / or screen printing process. As such, the metal paste can also be considered as a Metallic ink, for example, screen printing ink. In the following, "metallic ink" and "metallic paste" are used interchangeably, as synonyms.

[0053] In the context of the present invention, the term "inject" means "forcing, with a pressure greater than atmospheric pressure," a metallic paste or ink into the holes formed by 3D printing. The injection is typically carried out using a nozzle or injector from an inlet orifice of the hole to an outlet orifice of the hole. The injection filling of the holes is configured to obtain a continuous flow of injected material. The continuous portion of injected material extends between the inlet and outlet orifices, preferably from the inlet orifice of the hole to the outlet orifice of the hole.

[0054] In the context of the present invention, the term "level" means "bring to the same level." The level of paste or metallic ink in at least one hole typically, after leveling, is substantially the same level as the surface of the substrate bordering said at least one hole. The free surface of the metallic ink then extends as a continuation of the surrounding substrate face. Leveling is understood to be within manufacturing tolerances. Thus, depending on the surface tension of the metallic ink, the free surface of the metallic ink may exhibit a slight curvature, either protruding or recessed from the substrate face. This free surface may also change during subsequent annealing. Those skilled in the art understand that scraping typically allows for leveling the levels as the scraper passes over the surface, without prejudging the actual ink level after scraping.

[0055] Similarly, the term "flush" is understood within manufacturing tolerances, and encompasses slight variations in levels between the face of the support and the surface of the metallic connection formed after annealing.

[0056] The terms "approximately", "around", "in the order of" mean within 10%, and preferably within 5%. Furthermore, the terms "between ... and ..." and equivalents mean that the bounds are inclusive, unless otherwise stated.

[0057] Figure 1 illustrates a ceramic support manufactured by 3D printing according to one embodiment of the process. This support 10 has a first face 100, a second face 200 substantially orthogonal to the first face 100, and a third face 300 substantially parallel to the first face 100. The support 10 includes first holes 11 connecting the first face 100 and the second face 200, and second holes 12 connecting the first face 100 and the third face 300. The first holes 11 thus connect two non-parallel faces 100, 200 of the support 10 and form a first type of hole. The second holes 12 thus connect two parallel faces 100, 300 of the support 10 and form a second type of hole. The first holes 11 have a first orifice 111 on the first face 100, typically an inlet orifice for injection, and a second orifice 112 on the second face 200, Typically, an outlet port for injection. Each first hole 11 typically has, starting from the inlet port, a first straight section, a bend, and a second straight section leading to the outlet port. The bend is located within the support 10. The support can be ceramic-based, for example, alumina- or aluminum nitride-based. 3D printing advantageously allows the holes 11, 12 to be created directly in the support 10, typically without removing any material. First holes 11 of complex shapes, including, for example, several bends and / or several straight sections of different orientations, can be advantageously produced.

[0058] The holes 12 may have transverse dimensions, taken here in the xy plane, on the order of several millimeters, or even a few tens of millimeters. The holes 11 may have a diameter of a few millimeters or less, for example, a diameter less than 1 mm. The diameter or cross-section of the hole 11 is not necessarily constant along its length. The inlet orifice 111 typically has a cross-section, taken here in the xy plane, greater than the cross-section of the outlet orifice 112, taken here in the yz plane. This improves the injection of material into the hole 11. The support 10, manufactured by 3D printing, advantageously forms a mold into which a metal paste is injected to create complex metallic patterns or connections within the support 10.

[0059] Figure 2 illustrates the device obtained after filling the holes 11, 12 of the support 10 with a metal paste. The metal paste preferably fills each hole 11, 12 completely. It is flush with the faces 100, 200, 300 into which the holes 11, 12 open. The holes 11 are at least partially filled by injecting the metal paste from the inlet ports 111 during a first filling step. This makes it possible to obtain a continuous portion of metal paste between the inlet port 111 and the outlet port 112. The holes 12 can also be filled, at least partially during the first filling step, by injecting the metal paste. Alternatively or in addition, the holes 12 can be filled by screen printing during the first filling step, using a squeegee.If necessary, when holes 11 or 12 are not completely filled, a second filling step can be carried out in addition to the first filling step by injection and / or screen printing. The second filling step is typically done with metallic paste or metallic ink spread using a squeegee, by screen printing. The ink or metallic paste is accumulated at the beveled end of the squeegee and pushed into the empty spaces of holes 11, 12 as the squeegee moves, for example along the x-axis. The metallic ink front flows into the empty spaces as the squeegee moves, for example along the x-axis, on the first face 100 of the substrate. The end of the squeegee is then... typically in contact with face 100. This prevents the metallic ink from remaining on face 100 of the substrate. The scraper allows both the completion of the filling of holes 11, 12 and the removal of excess metallic ink. After the scraper has passed, the surface of the metallic paste filling holes 11, 12 is approximately level with the corresponding face. The filling of holes 11, 12 during the first filling step and / or during the second filling step can be done simultaneously.

[0060] The metallic paste has fluidic properties, typically viscosity and surface tension, compatible with dispensing by injection, via a nozzle or injector. Preferably, the metallic paste also has fluidic properties compatible with squeegee application. Furthermore, it exhibits good adhesion to the substrate 10, typically ceramics. It may include metallic nanoparticles, for example, silver nanoparticles. The metallic ink can be selected from standard screen-printing metallic inks, for example, a silver-based metallic ink from Dycotec references DM-SIP-14001S or DM-SIP-14033. Other metallic ink formulations are possible, depending on the intended applications.

[0061] After filling the holes 11, 12, and preferably after equalizing the levels of metallic ink with the faces 100, 200, 300 of the substrate, a densification heat treatment is typically performed. This heat treatment allows the solvents of the metallic ink to evaporate and / or the metallic nanoparticles to sinter to form the metallic connections 21, 22 ([Fig. 2]). The metallic connections 22 are through-holes, between the faces 100 and 300. The metallic connections 21 typically have, starting from the face 100 (inlet orifice), a first straight portion, a bend, and a second straight portion opening onto the face 200 (outlet orifice).

[0062] Figure 3 is a cross-section of the device along a median xy plane, referenced AA' in Figure 2. The second straight portion of the metal connections 21 is visible in this section along AA'. Part of the bend in the metal connections 21 is also visible in this section along AA'. The diameter at the bend is greater than the diameter of the second straight portion. Continuing from the bend, the diameter of the first straight portion (not shown) is greater than the diameter of the second straight portion.

[0063] Figure 4 illustrates an example of a recommended heat treatment for Dycotec metallic ink references. This heat treatment typically consists of stabilized annealing at approximately 850°C for ten minutes, with controlled temperature rise and fall.

[0064] After annealing, an optional polishing step can be carried out on faces 100 and / or 200 and / or 300 of the substrate, for example a chemical-mechanical polish or a Polishing with a diamond disc. This polishing can advantageously flatten face(s) 100, 200, 300 of the substrate when these are not perfectly flat. Polishing can also remove any silver paste residue outside the defined holes and / or flush the metal connections 21, 22. A perfectly flat surface, with well-defined, flush metal connections, is thus advantageously obtained. Other post-annealing steps can also be carried out, for example, to prepare the surface of the metal connections for subsequent soldering of components onto said metal connections. Chemical etching or plasma etching can, for example, be performed.

[0065] Figures 5 and 6 illustrate another embodiment based on another support configuration 10 manufactured by 3D printing.

[0066] Fig. 5 illustrates a support 10 comprising holes 11 of the first type and holes 12 of the second type, as before. The holes 11 are T-shaped and connect the first, second, and third faces 100, 200, and 300. The holes 11 have a first orifice 111 at the first face 100, a second orifice 112 at the second face 200, and a third orifice 113 at the third face 300. For injecting the metal paste into the holes 11, at least one inlet orifice will be chosen from these three orifices 111, 112, and 113, and preferably at least one outlet orifice from these three orifices 111, 112, and 113. A second inlet or outlet orifice may be chosen from these three orifices 111, 112, and 113. One of these three orifices 111, 112, and 113 may optionally be plugged during the injection of metallic paste.The holes 12 connect the parallel faces 100, 300 of the support 10, as before. Reinforcements 123 are provided within the holes 12. These reinforcements 123 improve the mechanical strength of the support 10. These reinforcements 123 also stabilize the metal paste spread in the holes 12. The retention of the metal paste in the holes 12 is thus improved.

[0067] Figure 6 illustrates the device obtained after filling the holes 11, 12 of the support 10 with a metallic paste. The filling is carried out as before, at least partially by injection into the holes 11 of the first type, and by injection and / or screen printing into the holes 12 of the second type. The metallic paste preferably fills each hole 11, 12 completely. It is flush with the faces 100, 200, 300 onto which the holes 11, 12 open. The through-hole metallic connections 22 are typically dedicated to supplying power to an electronic chip and may correspond to a positive electrode V+, a negative electrode V-, and a phase. The T-shaped metallic connections 21 are typically dedicated to controlling the gate(s) of an electronic chip. The metallic connections 21, 22 running within the ceramic support 10 advantageously have a reduced length, by This relates to metallic tracks running along the substrate, for example. This helps to limit parasitic elements and thus reduce oscillations during switching.

[0068] It is clear from the foregoing that the method according to the invention advantageously makes it possible to produce a device comprising a support and metallic connections of complex shapes within said support. Such a device is particularly advantageous for limiting electrical signal oscillations or partial discharges in power electronics modules. Such a device also requires less material for manufacturing and less energy for operation. The energy and environmental impact of such a device is therefore advantageously reduced.

[0069] Other applications are conceivable, particularly in the field of ceramic metallization. Watchmaking or jewelry systems can advantageously benefit from such a device. The invention is not limited to the embodiments described above.

Claims

Demands

1. A method for making a device comprising a support (10) having a first face (100) and at least one second face (200) not parallel to the first face (100), and at least one metallic connection (21) linking said first and second faces (100, 200) of the support (10), said method comprising successively: • Fabrication of the support (10) by additive manufacturing, providing in the support (10) at least one hole (11) opening onto the first and second faces (100, 200) of the support (10), said at least one hole (11) being intended to receive the at least one metallic connection (21), • Filling of the at least one hole (11) with a metallic paste, configured to form a continuous portion of metallic paste between an inlet orifice (111) and an outlet orifice (112) of the at least one hole (11), said filling comprising a first filling by injection of the metallic paste in said at least one hole (H),• Annealing of the metal paste so as to form at least one metallic connection (21).

2. A method according to the preceding claim in which the embodiment of the support (10) is configured so that at least one hole (11) has a bend within the support (10).

3. A method according to the preceding claim in which the at least one hole (11) has a first section on a first side of the bend, and a second section on a second side of the bend, the first section being larger than the second section, and in which the inlet orifice (111) for filling is chosen from the first side of the bend.

4. A method according to any one of the preceding claims in which the support (10) has a third face (300) substantially parallel to the first face (100) and substantially orthogonal to the second face (200), and the embodiment of the support (10) is configured so that at least one hole (11) has a T-shape opening onto the first, second and third faces (100, 200, 300) of the support (10).

5. Method according to the preceding claim in which the embodiment of the support (10) is configured so as to provide at least one second hole (12) opening onto the first and third faces (100, 300) of the support (10).

6. Method according to the preceding claim wherein the first filling by injection of at least one hole (11) is configured to also fill said at least a second hole (12).

7. Method according to claim 5 further comprising a second filling by screen printing of at least a second hole (12), with a second metallic paste.

8. Method according to the preceding claim wherein the second filling by screen printing is carried out after the first filling by injection of at least one hole (11).

9. A method according to any one of the two preceding claims wherein the metal paste used for injection and the second metal paste used for screen printing are identical, and preferably correspond to the same silver-based metal paste.

10. A method according to any one of the preceding claims in which the embodiment of the support (10) is configured so that at least one hole (11) has a diameter strictly less than or equal to 1 mm, and a longitudinal dimension greater than 15 mm.

11. A method according to any one of the preceding claims further comprising at least one scraping of the first face (100) of the support (10) and / or the second face (200) of the support (10), so as to equalize a level of metallic paste in the at least one hole (11) with said first and / or second faces (100, 200) of the support (10) bordering said at least one hole (11).

12. A method according to any one of the preceding claims further comprising at least one polishing of the first face (100) of the support (10) and / or of the second face (200) of the support (10), after annealing of the metal paste.

13. A method according to any one of the preceding claims in which the support (10) is made of ceramic.

14. A method according to the preceding claim in which the fabrication of the ceramic-based support (10) is completely carried out before filling at least one hole (11), without any subsequent filling step.

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