Method of manufacturing thermoelectric generator

Abstract

The invention relates to a method of manufacturing a thermoelectric generator. The thermoelectric unit includes a thermoelectric film having a first surface at a cavity in the first layer of thermally conductive material. The thermoelectric film has a second surface opposite the first surface, wherein the second thermally conductive material is disposed in contact with the second surface of the thermoelectric film. The thermoelectric film includes a heat-sensitive material configured to generate a thermoelectric signal indicative of a temperature difference between the second thermally conductive material and the first thermally conductive material via a Seebeck effect. An insulating molding compound is molded onto a second thermally conductive material arranged in contact with the second surface of the thermoelectric film, wherein a mechanical stress is generated in the thermoelectric film in response to the molding. An encapsulation is provided at the second surface of the thermoelectric film. The encapsulation counteracts mechanical stresses generated in the thermoelectric film in response to molding of the insulating molding compound.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Italian Patent Application No. 102023000024078 filed on November 14, 2023, the contents of which are incorporated herein by reference in their entirety to the maximum extent permitted by law. Technical Field

[0003] This specification relates to making thermoelectric generator devices.

[0004] The solution described herein can be applied to thermoelectric generator devices operating on the basis of the Seebeck effect. Background Art

[0005] A thermoelectric generator device based on the Seebeck effect is capable of generating an electric current when a temperature difference is applied to the device. The Seebeck effect is an electromotive force (emf) generated between two points (eg, in a doped semiconductor) in response to a temperature difference between the two points.

[0006] These devices include a plurality of basic / unit cells connected in parallel and / or series in order to collect the current generated by each unit cell in the device.

[0007] The unit cell of a thermoelectric generator may comprise two differently doped (n+ and p+) electrically coupled resistors "embedded" in a structured film. Such a structured film represents the active part of the device capable of generating an electric current when a temperature difference is applied at the two surfaces of the film.

[0008] To apply a temperature difference at the two surfaces of the membrane, the membrane is arranged on a substrate (e.g., providing a back side ("cold" side)) and a thermally conductive pad is provided on the opposite surface of the membrane (e.g., providing a top / front side ("hot" side)).

[0009] In various devices, the base layer is disposed on a heat dissipation frame and the thermally conductive pad is thermally coupled to a heat source via a thermally conductive path and includes a portion of thermally conductive material and a thermally insulating cavity formed as a void area in the backside layer.

[0010] The processing of these devices involves providing the device with an insulating protective package via transfer molding. This molding step involves applying relatively strong pressure / mechanical stress to the device.

[0011] In particular, the active structured film can rupture in response to molding pressure in its most fragile portion, ie, the portion of the film just above the cavity in the base layer.

[0012] Cracking of the structured films leading to device failure and rejection has proven to be a major problem in the fabrication of such thermoelectric generator devices.

[0013] There is a need in the art for solutions to the above-mentioned problems. Summary of the invention

[0014] Embodiments herein include methods for encapsulation processing.

[0015] The solution described herein aims to reduce the mechanical stresses applied to the device during the molding step, thereby counteracting the cracking of the structured film.

[0016] In a solution as described herein, a protective encapsulation / encapsulation is provided via a multi-step encapsulation process in order to counteract rupture of the structured film (eg, at its most fragile portions).

[0017] In the solution described herein, the first encapsulation step comprises providing a protective layer on the front surface of the structured film.

[0018] In a solution as described herein, the protective layer may be provided by laminating a molded membrane or by dispensing / spin coating an insulating material so as to apply a relatively low pressure that does not cause the structured film to rupture. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] One or more embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0020] Figure 1 is a cross-sectional view illustrating the structure of a thermoelectric generator device.

[0021] Figure 2 illustrates problems that may arise when thermoelectric generator devices are processed according to conventional methods; and

[0022] FIG. 3A to FIG. 3H is a cross-sectional view illustrating a sequence of processing steps according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated.

[0024] The drawings are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale.

[0025] The edges of a feature depicted in a drawing do not necessarily indicate the end of the extent of the feature.

[0026] In the following description, one or more specific details are illustrated for the purpose of providing a deeper understanding of the examples of the embodiments of the present specification. The embodiments may be obtained without one or more specific details, or using other methods, components, materials, etc. In other cases, known structures, materials, or operations are not described or illustrated in detail so as not to obscure certain aspects of the embodiments.

[0027] References to "an embodiment" or "one embodiment" in the framework of this specification are intended to indicate that a particular configuration, structure, or characteristic described with respect to that embodiment is included in at least one embodiment. Therefore, phrases such as "in an embodiment" or "in one embodiment" that may appear in one or more points of this specification do not necessarily refer to the same embodiment.

[0028] Furthermore, in one or more embodiments, the particular formations, structures, or characteristics may be combined in any suitable manner.

[0029] The headings / references used herein are provided for convenience only, and therefore do not limit the scope of protection or the scope of the embodiments.

[0030] For simplicity and ease of explanation, throughout the specification and in the various drawings, like reference numerals are used to designate like parts or elements, and the corresponding description is not repeated for each drawing, unless the context indicates otherwise.

[0031] A thermoelectric generator device based on the Seebeck effect is a device that is able to convert a temperature difference into an electric current.

[0032] Such a device may comprise a plurality of elementary / unit cells electrically connected in parallel and / or in series in order to collect the current contribution generated by each individual unit cell.

[0033] Figure 1 The structure of a unit cell of such a thermoelectric generator device is shown in the figure.

[0034] As shown in the figure, Figure 1 The structure of the unit cell in the embodiment may include: a structured (multi-layer) film 100; a back support layer 14 supporting the structured film 100, which includes a heat conductive portion (at Figure 1 and electrically and thermally conductive pads 18 , 19 provided on the top surface of the structured film 100 .

[0035] The structured film 100 as considered herein may include, for example: a thermal oxide layer 103 having a thickness of, for example, 1.5 microns; a borophosphosilicate glass (BPSG) layer 104 having a thickness of, for example, 600 nm; two differently doped resistors (e.g., polysilicon resistors) "embedded" in the BPSG layer 104 (such as an n+ doped resistor 101 and a p+ doped resistor 102); conductive routing traces 107 (e.g., made of metals such as Al and Cu) that provide the desired electrical coupling to resistors 101 and 102, respectively; and a passivation layer 105, which may include a 500 nm TEOS layer and an approximately 500 nm SiON layer.

[0036] Get as Figure 1 The processing of the component illustrated in the example may include: providing a support layer 14 of a thermally conductive material; forming a structured film (such as Figure 1 a cavity 14B is formed in the support layer 14 at a region of the structured film 100 (indicated by reference numeral 1000 in the figure).

[0037] The process of obtaining such thermoelectric unit cells is conventional in the art, so that no more detailed description needs to be provided herein.

[0038] The structure of the film 100 will not be described in further detail in the specification and related drawings below, and it should be understood that the details of the structured film 100 presented are merely exemplary, as the embodiments of the present description can be advantageously applied to films having different structures.

[0039] like Figure 1 As shown, the backside support layer 14 (ie, the unit cells) having the structured (thermoelectric) film 100 formed thereon is arranged on a mounting location 12A of the substrate / frame.

[0040] The frame 12 discussed herein may have a plurality of unit batteries arranged at respective mounting locations 12A of the frame 12 .

[0041] The frame also includes a connection frame part (in Figure 2 12B), the connecting frame portion is configured to electrically couple (in parallel and / or in series) a plurality of cells in the device. This facilitates collection of the current generated by each individual cell.

[0042] As mentioned above, a unit cell is capable of generating an electric current in response to a temperature difference applied to its two surfaces.

[0043] In more detail: the bottom / back side is the "cold" side of the unit cell and it is in contact with the (thermally conductive) back support layer 14 arranged on the (thermally conductive) substrate / frame 12 (heat dissipation frame), and the top / front side is the "hot" side of the unit cell; a (thermally conductive) solder pad 19 is formed on the front / top surface of the structured film 100, and the solder pad 19 is configured to provide a landing point for a thermally conductive path that couples the solder pad 19 (and therefore the front / top surface of the film 100) to a heat source.

[0044] A further (conductive) pad 18 is also provided on the top surface of the film 100 to provide a landing point for a conductive path from the unit cells to the connection frame 12B for collecting the current generated by the unit cells.

[0045] In some embodiments, pads 18 and 19 may be made of the same material (eg, a metal such as copper) that is both thermally and electrically conductive.

[0046] Figure 2 The process steps of molding an insulating molding compound (eg, epoxy) onto the unit cells arranged on the substrate / frame 12 are illustrated.

[0047] During such a molding step, relatively high pressure (caused by Figure 2 ) is applied to the molding compound and transferred to the unit cells, and in particular to the structured film 100 .

[0048] Mechanical stress due to the applied pressure can damage the device during handling, causing failure (and therefore rejection) of the device.

[0049] In particular, it is observed that the structured film 100 is more likely to break at the portion 1000 above the empty portion or cavity 14B of the backside support layer 14 .

[0050] The solution described herein aims to reduce the mechanical stress applied to the structured thermoelectric film 100 during the molding step, thus counteracting cracking of the portion of the structured film above the void portion 14B.

[0051] In the solution as described herein, a protective encapsulation / encapsulation is provided via a multi-step encapsulation process.

[0052] In the solution as described herein, the first encapsulation step comprises providing a protective layer on the front / top surface of the structured film.

[0053] In a solution as described herein, the protective layer may be provided by laminating a molded membrane or by dispensing / spin coating an electrically insulating material so as to apply a relatively low pressure that does not cause the structured film to rupture.

[0054] In a solution as described herein, a protective layer is advantageously provided at the wafer / panel level, resulting in a more efficient assembly process.

[0055] FIG. 3A to FIG. 3H The diagram illustrates the order of processing steps according to the embodiment of the present specification.

[0056] It should also be understood that FIG. 3A to FIG. 3H The order of the steps is exemplary only to the extent that they may be omitted, performed in a different manner (e.g., using other tools), and / or replaced by other steps. 3A to 3H One or more steps may be illustrated in the figure; additional steps may be added; and one or more steps may be performed in an order different from that illustrated.

[0057] For simplicity and ease of explanation, the following description will refer to the processing of a single unit cell of a thermoelectric generator device. It should also be understood that multiple unit cells (in one or more devices) may be processed simultaneously as described herein.

[0058] Figure 3A The diagram shows a thermoelectric generator device (with a thermoelectric film 100 formed on a back side layer 14 (for simplicity, the detailed structure of the film 100 is not visible) Figure 1 The support layer includes a thermally conductive material portion 14A (such as silicon, for example) and a void portion 14B.

[0059] Figure 3A The unit cells illustrated in FIG. 4 may be part of a wafer / panel comprising a plurality of unit cells that are intended to be processed simultaneously.

[0060] Figure 3B A protective layer 200 is illustrated as being provided on the front / top surface of the unit cell in order to protect the film of the unit cell by forming a first encapsulation of the unit cell.

[0061] The protective layer 200 is advantageously provided at the wafer / panel level, i.e. by processing a plurality of unit cells simultaneously to provide them with Figure 2 The protective layer 200 is shown in FIG.

[0062] Through the method involving the application of relatively low pressure and mechanical stress to the membrane 100 of the battery, it is advantageously possible to provide Figure 3B The protective layer 200 is shown in FIG.

[0063] According to an embodiment of the present specification, the protective layer 200 may be provided by laminating a molded film on the unit cells. The laminating molded film (eg, such as an epoxy molded film) may be advantageously performed on a wafer / panel level.

[0064] Commercially available molded diaphragms (such as a molded diaphragm with a trade name of EB 4010S manufactured by Resonac, 1-13-9 Shibadaimon, Minato-ku, Tokyo 105-8518, Japan) can be used in the examples of this specification.

[0065] According to an embodiment of the present description, the protection layer 200 may be provided by dispensing or by spin coating an electrically insulating resin such as, for example, polyimide (PI).

[0066] As known to a person skilled in the art, after providing such a protective layer 200 via lamination or spin coating, a curing step of the protective layer 200 may be envisaged; this may be via a thermal treatment or via exposure of the protective layer 200 to UV light.

[0067] As discussed further below, Figure 3B The protective layer 200 illustrated in FIG. 1 protects the structured film 100 from mechanical stress and relatively high pressure generated during the molding step.

[0068] Advantageously, it is possible to provide at the wafer / panel level Figure 3B The protective layer 200 shown in FIG. 1 is provided by simultaneously providing such encapsulation to a plurality of unit cells included in an array (panel or wafer) of such unit cells. This may involve: providing a common support layer 14 of thermally conductive material; forming a common structured film 100 at the surface of the common support layer 14 (wherein the common structured film includes a plurality of parts, the plurality of parts including, for example, Figure 3A ); forming a plurality of cavities 14B at selected areas of a common support layer 14; providing (e.g., via film lamination or spin coating) a protective layer 200 at a surface of the common structured film 100; and singulating (e.g., via sawing with a blade) the common support layer 14 supporting the common structured film 100, thereby obtaining a plurality of unit cells having a (first) protective layer 200 provided at their top / front surface.

[0069] Thus, the singulated unit cells are arranged on the support frame. As mentioned above, the support frame 12 includes a thermally conductive mounting location 12A (also referred to as a heat dissipation frame) and a connection frame 12B configured to be electrically coupled to the unit cells.

[0070] Both the heat sink portion 12A and the connection portion 12B of the substrate / frame 12 may be made of the same thermally and electrically conductive material, for example a metal such as copper.

[0071] Figure 3C The unit cells are illustrated arranged at a mounting location 12A of a support frame 12. As illustrated, the support frame 12 may be arranged on a temporary (and possibly sacrificial) carrier S to facilitate further processing.

[0072] like Figure 3C As shown in , a molding step is performed to provide an electrically insulating protective encapsulation to the device. An electrically insulating molding compound 20, such as an epoxy resin, is (pressure) molded over the unit cells arranged on the support frame 12. As discussed below, the electrically insulating molding compound 20 may be a molding compound suitable for laser direct structuring (LDS).

[0073] As mentioned, the protective layer 200 provided on the top / front surface of the structured film 100 reduces the mechanical stress applied thereto during the molding step.

[0074] It has been found that a protective layer 200, such as a molded film laminated on the cell or an electrically insulating material (e.g., polyimide (PI)) provided at the top / front surface of the membrane 100, effectively counteracts cracking of the membrane 100, thereby facilitating the manufacturing process of the thermoelectric generator device as described herein.

[0075] Advantageously, a suitable material for protective layer 200 has sufficient rigidity (hardness) to counteract cracking of structured film 100 at the portion 1000 thereof over cavity 14B during the molding step.

[0076] In order to effectively counteract the mechanical stress generated in the film 100 in response to the molding step, a protective layer 200 may be provided at a portion of the top / front surface that extends beyond (and includes) the portion 1000 of the film 100 above the cavity 14B. In other words, the protective layer 200 provides an encapsulation of the pad 19 formed at the region 1000 of the film 100, wherein the encapsulation contacts the top / front surface of the film 100 at the portion of the film 100 surrounding the region 1000. As will be appreciated by those skilled in the art, as Figure 3C As illustrated in , the protective layer 200 provided on the wafer / panel level (eg, via lamination or spin coating) may be such that the protective layer 200 covers the entire top / front surface of the film 100 .

[0077] As mentioned, the protective layer 200 comprises a material having a hardness / rigidity sufficient (in the molded condition) to counteract cracking of the film 100. In general, in addition to the materials already mentioned, (electrically insulating) encapsulating materials having a Young's modulus (in the molded condition) greater than 0.7 GPa (preferably greater than 1.0 GPa) have been found to effectively counteract cracking of the structured film 100 during the molding step.

[0078] According to some embodiments, the protective layer 200 may be formed by providing a (thermosetting) resin at the top / front surface of the film 100 (eg via lamination or spin coating). The curing may be performed at a temperature higher than the glass transition temperature of the (curing) resin. Figure 3C. Therefore, a suitable resin material for the protective layer 200 is a resin having a Young's modulus greater than 0.7 GPa (preferably greater than 1.0 GPa) at a temperature higher than its glass transition temperature. It has been found that for a large class of such resins, this can correspond to a Young's modulus greater than 10 GPa (preferably greater than 15 GPa) at a temperature lower than its glass transition temperature.

[0079] Figure 3C The molding step illustrated in the figure can be considered as the second encapsulation step in a multi-step encapsulation process, which is intended to reduce mechanical stress (and risk of rupture) on fragile parts of the device under processing (such as part 1000 of the membrane 100 illustrated in the figure).

[0080] Figure 3D and Figure 3E The processing steps for providing electrical and thermal conductive paths onto pads 18 and 19 that land on the top / front surface of structured film 100 are illustrated.

[0081] Similar to what was discussed with respect to pads 18, 19, the coupling paths falling thereon may be made of the same electrically and thermally conductive material, eg, a metal such as copper.

[0082] Figure 3D The diagram shows vias 180', 190' opened (by molding) in the mold compound 20 toward the pads 18, 19 and the portion 12B of the support frame 12 (e.g., via laser machining LB). The vias 180' to the pads 18 and the connection frame 12B are indicated with the same reference numerals in the figure because they are configured to form one conductive path from the pads 18 to the connection frame 12B.

[0083] As illustrated, vias 180 ′, 190 ′ to pads 18 , 19 extend through protective layer 200 in order to expose pads 18 , 19 and thereby facilitate subsequent processing.

[0084] Figure 3E The figure shows a growth / deposition step in which a conductive material (e.g., a metal such as copper) is deposited / grown to provide electrical and thermal vias 180, 190 between the pads 19 and the front / top surface of the encapsulation 20 and between the connection frame 12B and the pads 18 (no emphasis is given to indicate that appropriate electrical and thermal vias have been formed). As illustrated, the electrical coupling between the connection frame 12B and the pads 18 may include a conductive trace 181 extending on the front / top surface of the encapsulation 20.

[0085] The vias 180 , 190 and traces 181 may be provided via any method known to those skilled in the art.

[0086] For example, the conductive vias 180 , 190 and traces 181 may be formed using conventional electrochemical deposition / growth processes.

[0087] According to an embodiment, vias 180 , 190 and traces 181 may be formed via laser direct structuring (LDS).

[0088] LDS is a laser-based processing technology that involves transferring ("structuring") the desired conductive pattern onto a plastic molding suitable for LDS (i.e., having additives suitable for the LDS process embedded therein), which can then undergo metallization to complete the desired conductive pattern.

[0089] Laser processing of a mold compound suitable for LDS "activates" the additive particles embedded therein, thus facilitating the subsequent metallization step.

[0090] Metallization can involve electroless plating followed by electroplating. Electroless plating, also known as chemical plating, is a class of industrial chemical processes that produce metal coatings on various materials by autocatalytic chemical reduction of metal cations in a liquid bath. In electroplating, an electric field between the anode and the workpiece, which acts as the cathode, forces positively charged metal ions to move to the cathode, where they release their charge and deposit themselves as metal on the surface of the workpiece.

[0091] Reference is made to U.S. patent application publication numbers 2018 / 0342453, 2019 / 0115287, 2020 / 0203264, 2020 / 0321274, 2021 / 0050226, 2021 / 0050299, 2021 / 0183748, or 2021 / 0305203 as examples of the possibility of applying LDS technology in manufacturing semiconductor devices.

[0092] Where the conductive vias 180 , 190 and traces 181 are provided via LDS, the mould compound is selected as a suitable compound for LDS and metal material is grown / deposited to form the electrically and thermally conductive vias 181 , 191 and traces 182 are completed via electroless plating followed by electrolytic deposition.

[0093] Figure 3F A second layer of encapsulation compound 22 (such as epoxy, for example, possibly with an LDS additive embedded therein) is illustrated transfer molded onto the top / front surface of the first encapsulation layer 20 .

[0094] Figure 3G and Figure 3H The processing steps of growing / depositing thermally conductive material (eg, metal such as copper) from the top / front surface of the device (top / front surface of encapsulation layer 22 ) through molded via 191 to the topmost portion of via 190 are illustrated.

[0095] Can be about Figure 3D and Figure 3E The process of forming the via 191 is performed to provide the vias 180 , 190 , for example via electrochemical deposition and / or laser direct structuring; in the latter case, the molding compound 22 is a compound suitable for LDS, in which LDS additive particles are embedded.

[0096] The vias 190 , 191 and the pads 19 form a thermally conductive path extending from the top / front surface of the device through the mold compounds 20 , 22 to the structured film 100 .

[0097] The vias 180 and traces 181 form conductive paths that extend from the top / front surface of the structured film 100 through the mold compounds 20 , 22 to the connection portion 12B of the frame 12 .

[0098] In short, about FIG. 3A to FIG. 3F The processing steps described include providing a thermoelectric unit including a thermoelectric film 100 having a first surface at a cavity 14B in a first layer 14 of thermally conductive material.

[0099] The thermoelectric film 100 has a second surface opposite to the first surface, wherein the second heat conductive material 19 is arranged in contact with the second surface of the thermoelectric film 100 .

[0100] Thermoelectric film 100 includes a thermosensitive material (eg, two differently doped resistors 101 , 102 ) configured to generate a thermoelectric signal indicative of a temperature difference between second thermally conductive material 19 and first thermally conductive material 14 via the Seebeck effect.

[0101] The insulating mold compound 20, 22 is molded onto the second thermally conductive material 19 arranged to be in contact with the second surface of the thermoelectric film 100. In response to the molding of the insulating mold compound 20, 22, mechanical stress is generated in the thermoelectric film 100.

[0102] An encapsulation 200 (eg a molded membrane) of a second thermally conductive material 19 is provided at a second surface of the thermoelectric film 100 .

[0103] The encapsulation 200 counteracts mechanical stress generated in the thermoelectric film 100 in response to molding of the insulating mold compounds 20 , 22 .

[0104] The above process is performed (advantageously) at the wafer / panel level by providing an array of thermoelectric units sharing a common thermoelectric film 100. The common thermoelectric film (100) has a first surface at the cavity 14B in the first thermally conductive material layer 14 and a second surface opposite the first surface at each thermoelectric unit in the array, wherein the second thermally conductive material 19 is arranged in contact with the second surface of the common thermoelectric film 100.

[0105] An encapsulation 200 is provided at the second surface of the common thermoelectric film (eg via film lamination or spin coating).

[0106] The thermoelectric cells in the array of thermoelectric cells are singulated, and a plurality of individual thermoelectric cells (with respective encapsulations 200 provided) result from the singulation.

[0107] The individual units are arranged onto a common support substrate / frame 12 , and the insulating mold compounds 20 , 22 are molded onto the individual units arranged on the common support substrate 12 .

[0108] Advantageously, the encapsulation 200 provided at the second surface of the thermoelectric film 100 comprises an encapsulation material having a Young's modulus greater than 0.7 GPa (preferably greater than 1.0 GPa) at the molding temperature.

[0109] Without prejudice to the essential principles, the details and embodiments may vary, even significantly, with respect to what is described merely by way of example, without departing from the scope of protection.

[0110] The claims are an integral part of the technical teaching provided with respect to the embodiments.

[0111] The scope of protection is determined by the appended claims.

Claims

1. A method comprising: Providing a thermoelectric unit including a thermoelectric film, the thermoelectric film having a first surface at a cavity in a first thermally conductive material layer, wherein the thermoelectric film has a second surface opposite the first surface, wherein a second thermally conductive material is arranged in contact with the second surface of the thermoelectric film, wherein the thermoelectric film includes a thermosensitive material, the thermosensitive material being configured to generate a thermoelectric signal via a Seebeck effect, the thermoelectric signal being indicative of a temperature difference between the second thermally conductive material and the first thermally conductive material; molding an insulating mold compound onto the second thermally conductive material disposed in contact with the second surface of the thermoelectric film, wherein the molding creates mechanical stress in the thermoelectric film; as well as An encapsulation of the second thermally conductive material arranged in contact with the second surface of the thermoelectric film is provided at the second surface of the thermoelectric film, wherein the encapsulation counteracts mechanical stress generated in the thermoelectric film. 2 . The method of claim 1 , wherein the molding is performed at a molding temperature, and wherein the encapsulation provided at the second surface of the thermoelectric film comprises an encapsulation material having a Young's modulus greater than 0.7 GPa at the molding temperature. 3 . The method of claim 1 , wherein the encapsulation provided at the second surface of the thermoelectric film comprises a resin encapsulation material having a Young's modulus greater than 0.7 GPa at a temperature higher than a glass transition temperature of the resin encapsulation material. 4 . The method of claim 1 , wherein the encapsulation provided at the second surface of the thermoelectric film comprises a resin encapsulation material having a Young's modulus greater than 10 GPa at a temperature lower than a glass transition temperature of the resin encapsulation material.

5. The method according to claim 1, comprising: The encapsulation of the second thermally conductive material is provided, wherein the second thermally conductive material is disposed between the encapsulation and the second surface of the thermoelectric film.

6. The method according to claim 1, comprising: The second thermally conductive material is provided as a thermally conductive pad, the thermally conductive pad being arranged to contact the second surface of the thermoelectric film at the cavity.

7. The method according to claim 6, comprising: The encapsulation is provided onto the thermally conductive pad, and the encapsulation is provided onto the second surface of the thermoelectric film around the cavity.

8. The method according to claim 1, comprising: The encapsulation is provided by dispensing or spin coating an encapsulation material at the second surface of the thermoelectric film.

9. The method according to claim 1, comprising: The encapsulation is provided by laminating a molded film of encapsulation material at the second surface of the thermoelectric film.

10. The method of claim 1, wherein the insulating mold compound has an outer surface opposite the second surface of the thermoelectric film, and wherein the method comprises: At least one thermally conductive formation is provided by the insulating mold compound molded onto the second thermally conductive material, wherein the at least one thermally conductive formation provides a thermally conductive path between the outer surface of the insulating mold compound and the second thermally conductive material.

11. The method according to claim 10, further comprising: The at least one thermally conductive formation is provided via deposition of a metallic material.

12. The method of claim 11, wherein the insulating molding compound molded onto the second thermally conductive material comprises a laser direct structuring (LDS) molding compound, and the method further comprises: The at least one thermally conductive formation is provided via laser direct structuring of the LDS molding compound.

13. The method according to claim 1, comprising: providing an array of thermoelectric units sharing a common thermoelectric film, wherein the common thermoelectric film has a first surface and a second surface at each thermoelectric unit in the array, the first surface being at a cavity in the first thermally conductive material layer, the second surface being opposite the first surface, wherein the second thermally conductive material is arranged in contact with the second surface of the common thermoelectric film; as well as The method comprises: providing an envelope of the second thermally conductive material at the second surface of the common thermoelectric film arranged in contact with the second surface of the common thermoelectric film; performing singulation on the thermoelectric cells in the array of thermoelectric cells, wherein a plurality of individual thermoelectric cells result from the singulation; and The insulating mold compound is molded onto the individual thermoelectric units resulting from singulation, wherein the encapsulation of the second thermally conductive material counteracts mechanical stresses generated in response to molding the insulating mold compound onto the individual thermoelectric units resulting from singulation.

14. The method according to claim 13, comprising: arranging the individual thermoelectric units resulting from singulation onto a common supporting substrate; as well as The insulating molding compound is molded onto the individual thermoelectric units resulting from singulation arranged on the common support substrate.

15. The method of claim 14, wherein the common support substrate includes a thermally conductive portion in heat exchange relationship with the first layer of thermally conductive material.

16. The method of claim 14, wherein the common support substrate comprises a conductive portion, and the method comprises: An electrical coupling formation is provided, the electrical coupling formation coupling the conductive portion in the common support substrate with a thermosensitive material in the thermoelectric film, the thermosensitive material being configured to generate the thermoelectric signal via the Seebeck effect.

17. The method according to claim 16, comprising: The electrical coupling formation is provided via deposition of a metallic material.

18. The method of claim 17, wherein the insulating molding compound molded onto the second thermally conductive material comprises a laser direct structuring (LDS) molding compound, and the method comprises: The electrical coupling formation is provided via laser direct structuring of the LDS molding compound.

19. A method comprising: providing a thermoelectric unit including a thermoelectric film, the thermoelectric film including a thermosensitive material, the thermosensitive material configured to generate a thermoelectric signal via a Seebeck effect, the thermoelectric signal being indicative of a temperature difference between a first thermally conductive material and a second thermally conductive material; Covering the thermoelectric film and the first conductive material and the second thermal conductive material with an encapsulation layer; molding a first insulating molding compound over the encapsulation layer; forming a first through hole through the first insulating mold compound and the encapsulation layer to reach the first thermally conductive material; forming a second through hole through the first insulating mold compound and the encapsulation layer to reach the second thermally conductive material; covering the first insulating mold compound with a second insulating mold compound; as well as A third through hole is formed, the third through hole penetrating the second insulating mold compound to reach the second through hole.

20. The method of claim 19, wherein the first insulating mold compound and the second insulating mold compound are laser direct structured (LDS) mold compounds.

21. The method of claim 19, wherein the encapsulation layer comprises a resin encapsulation material having a Young's modulus greater than 0.7 GPa at a temperature higher than a glass transition temperature of the resin encapsulation material.

22. The method of claim 19, wherein the encapsulation layer comprises a resin encapsulation material having a Young's modulus greater than 10 GPa at a temperature lower than a glass transition temperature of the resin encapsulation material.

23. The method according to claim 19, further comprising: mounting the thermoelectric unit to a support; as well as A fourth through hole is formed, the fourth through hole penetrating the first insulating mold compound and the encapsulation layer to reach the support member.

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