Stacked battery structure

Abstract

Method for manufacturing a stacked battery structure (100), the method comprising: manufacturing a base substrate (102); manufacturing a battery layer (140A) formed on a support substrate (142), the battery layer comprising a protective layer (144) formed on the support substrate, a thin-film battery element (150) formed on the protective layer, and an insulator (162) covering the thin-film battery element; placing the battery layer on the base substrate, the underside of the support substrate facing upwards;at least partial removal of the support substrate from the battery layer by etching, while the thin-film battery element is protected by the protective layer, until a desired number of battery layers are stacked; an alternating repetition of: stacking an additional battery layer (140B) formed on a further support substrate, the underside of the further support substrate facing upwards, the additional battery layer comprising a protective layer, a thin-film battery element and an insulator;and one of at least partial removal of the further support substrate from the additional battery layer by etching, wherein the thin-film battery element in each battery layer contains current collectors (152, 152A, 152B) and a battery cell which is in contact with the current collectors, wherein the method further comprises: forming a through-hole (170a, 170b) in the battery layers which are stacked on the base substrate, such that it extends through at least one layer to a layer below the at least one layer, wherein the support substrates down to the layer have been removed by etching;and filling a conductive material into the through-hole or depositing a conductive material onto an inner surface of the through-hole to form a conductive path electrically connected to at least one current collector in the battery layers, wherein the formation of the through-hole comprises drilling at least one protective layer and at least one insulator in the battery layers by laser processing, leaving the current collector in place, and / or wherein the through-hole has multiple sub-sections and the multiple sub-sections have at least one horizontal dimension that is enlarged from bottom to top in the battery layers and overlap each other in a horizontal plane with respect to the base substrate, wherein the conductive path has contacts with multiple current collectors in different battery layers, with each contact being achieved on a surface of each of the multiple current collectors.

Description

TECHNICAL AREA

[0001] The present invention relates generally to a battery technology and, in particular, to a stacked battery structure and a method for manufacturing the same. The present invention further relates to a method for manufacturing a stacked structure. BACKGROUND

[0002] Recently, solid thin film batteries (STFBs) have attracted attention as a promising rechargeable battery for Internet of Things (IoT) devices due to their small footprint and safety. However, STFBs generally lack sufficient energy capacity. Since STFB capacity is limited by cathode thickness restrictions, and increasing STFB thickness is notoriously difficult, stacking (or three-dimensional assembly) is one solution for increasing STFB battery capacity. However, the thickness of the substrate on which the STFB is fabricated becomes a bottleneck in achieving a high-capacity battery.

[0003] In the field of semiconductor device manufacturing processes, back-of-wafer grinding, a process for reducing wafer thickness through mechanical grinding, is known as the most common technique for reducing wafer thickness. However, there are several disadvantages to using back-of-wafer grinding to fabricate stacked thin-film battery structures. One such disadvantage is the limit to the substrate thickness that can be reduced by mechanical grinding. Although the wafer thickness can be reduced down to 75 to 50 µm, it is still several times thicker than the thickness of the stacked thin-film battery structure (STFB), which can be less than or equal to approximately ten micrometers (~10 µm).

[0004] A multilayer thin-film battery has been proposed, comprising a first thin-film battery and a second thin-film battery, in which the cathode and anode current collectors are formed on first surfaces, and the first and second thin-film batteries are layered such that their respective first surfaces face each other (US Patent No. 9,634,334). However, the thickness of the substrate on which the thin-film battery is fabricated remains a limiting factor in achieving a high-capacity battery.

[0005] Furthermore, a monolithically integrated thin-film solid-state lithium battery unit has been proposed, containing multiple layers of electrochemical lithium cells (US patent application US2012 / 0058380). However, because the multiple layers of electrochemical lithium cells are fabricated sequentially using physical vapor deposition techniques, the materials that can be selected for the cathode in the integrated thin-film solid-state lithium battery unit are limited. Cathode materials such as LiCoO2 require a high-temperature annealing process, which cannot be applied because this complicates sequential stacking with regard to the heat resistance of other components.

[0006] Therefore, there is a need for a novel battery structure that is able to reduce the overall thickness of the battery structure while maintaining its capacity. SUMMARY

[0007] According to embodiments of the present invention, a method for manufacturing a stacked battery structure is provided. The method includes the fabrication of a base substrate. The method further includes the fabrication of a battery layer formed on a support substrate, wherein the battery layer comprises a protective layer formed on the support substrate, a thin-film battery element formed on the protective layer, and an insulator covering the thin-film battery element. The method further includes the placement of the battery layer on the base substrate, with the underside of the support substrate facing upwards. The method further includes the at least partial removal of the support substrate from the battery layer by etching, while the thin-film battery element is protected by the protective layer.

[0008] The stacked battery structure produced by the methods according to the embodiments of the present invention can have a lower overall thickness while maintaining the capacity and production costs of the stacked battery structure, which are also low, since the support substrate on which the thin-film battery element is formed can be reduced in thickness or eliminated by etching, while protecting the thin-film battery element.

[0009] In a preferred embodiment, the method further comprises alternately stacking an additional battery layer, which has a further support substrate, wherein one underside of the further support substrate faces upwards, and at least partially removing the further support substrate from the additional battery layer by etching, until a desired number of battery layers are stacked. The additional battery layer comprises a protective layer, a thin-film battery element, and an insulator. This allows the capacity of the stacked battery structure to be increased while maintaining the overall thickness of the battery structure. Since the thickness to be increased by stacking a unit of the battery layer is small, it is possible to increase the number of battery layers stacked within a given thickness.

[0010] In other preferred embodiments, the removal of the support substrate involves wet etching of the support substrate until the protective layer is reached. Since the support substrate can be completely removed by cost-effective wet etching without damaging the thin-film battery element behind the protective layer, it is possible to reduce the overall thickness as much as possible while simultaneously preventing an increase in manufacturing costs due to a reduction in substrate thickness.

[0011] In further preferred embodiments, the support substrate is made of a glass material, the wet etching process may include etching using a buffered hydrofluoric acid (BHF) solution, the protective layer acts as an etch stopper against the BHF solution, and the base substrate is made of a material resistant to the BHF solution. In this way, the throughput of the support substrate removal can be increased, and a tool or material for protecting the base substrate may become unnecessary.

[0012] In further preferred embodiments, the base substrate is equipped with a base battery layer formed on it, which contains a thin-film battery element formed on the base substrate and an insulator that covers the thin-film battery element formed on the base substrate. When placing the battery layer on the base substrate, the battery layer is placed on the insulator of the base battery layer. This makes the manufacturing process more efficient.

[0013] In other preferred embodiments, the thin-film battery element contains current collectors and a battery cell in each battery layer, which is in contact with the current collectors. The method further includes forming a through-hole in the battery layers such that it extends through at least one layer to a layer below the at least one layer, wherein the support substrates down to the layer have been removed by etching. The method further includes filling the through-hole with a conductive material or depositing a conductive material onto an inner surface of the through-hole to form a conductive path that is electrically connected to at least one current collector in the battery layers. Since the through-hole, which extends over at least two battery layers, can be manufactured jointly, the manufacturing process for the conductive path can be simplified.

[0014] In other preferred embodiments, forming the through-hole involves drilling at least one protective layer and at least one insulator in the battery layers by laser processing, while the current collector remains. Therefore, the manufacturing costs for the conductive path can be reduced.

[0015] In other preferred embodiments, the through-hole has multiple sub-sections, and these sub-sections have at least one horizontal dimension that is enlarged from bottom to top in the battery layers stacked on the base substrate, and overlap each other in a horizontal plane with respect to the base substrate. The conductive path has contacts with multiple current collectors in different battery layers, with each contact being made on an area of ​​each of the multiple current collectors. The reliability of the contacts between the conductive path and the current collectors can therefore be improved.

[0016] According to other embodiments of the present invention, a stacked battery structure is provided comprising a base substrate and two or more battery layers on the base substrate. Each battery layer includes a protective layer; a thin-film battery element formed on the protective layer; and an insulator covering the thin-film battery element. In the stacked battery structure, the battery layers are stacked inverted with respect to the base substrate, such that each insulator is located on one side of the base substrate, each protective layer is located on a side opposite the base substrate, and the insulator of an upper battery layer is connected to a lower battery layer.

[0017] The stacked battery structure according to the embodiments of the present invention can have a smaller overall thickness while maintaining its capacity, or it can have a larger capacity while maintaining the overall thickness of the battery structure. Since the thickness to be increased by stacking a unit of the battery layer is small, it is possible to increase the number of battery layers stacked within a given thickness.

[0018] In other preferred embodiments, the insulator of the upper battery layers has a surface bond to the protective layer of the lower battery layers. In yet another preferred embodiment, no rigid material is inserted between the insulator of the upper layer and the protective layer of the lower layer. This makes it possible to reduce the overall thickness.

[0019] According to further embodiments of the present invention, an electronic unit is provided comprising an electronic component and a stacked battery structure. The stacked battery structure includes a base substrate, two or more battery layers on the base substrate, and a wiring layer for connecting the stacked battery structure to the electronic component. Each battery layer includes a protective layer. Each battery layer also includes a thin-film battery element formed on the protective layer, which is used to supply power to the electronic component through the wiring layer. Each battery layer further includes an insulator covering the thin-film battery element.In the electronic unit, the battery layers are stacked in reverse with respect to the base substrate, so that each insulator is located on one side of the base substrate, each protective layer is located on one side opposite the base substrate, and the insulator of an upper battery layer connects with a lower battery layer.

[0020] The electronic unit according to a further embodiment of the present invention can have a large-capacity battery while maintaining a small battery footprint.

[0021] According to further embodiments of the present invention, a stacked battery structure is provided. The stacked battery structure is manufactured by placing a battery layer comprising a support substrate onto a base substrate, the underside of the support substrate facing upwards, the battery layer comprising a protective layer formed on the support substrate, a thin-film battery element formed on the protective layer, and an insulator covering the thin-film battery element. The stacked battery structure is further manufactured by at least partially removing the support substrate from the battery layer by etching, while the thin-film battery element is protected by the protective layer.

[0022] The stacked battery structure according to the embodiments of the present invention can have a lower overall thickness while maintaining its capacity, since the thickness of the support substrate on which the thin-film battery element is formed can be reduced or eliminated while protecting the thin-film battery element.

[0023] According to a further embodiment of the present invention, a method for fabricating a stacked structure is provided. The method includes fabricating a base substrate. The method includes fabricating a unit element layer comprising a support substrate, a protective layer formed on the support substrate, a unit element formed on the protective layer, and an adhesive material covering the unit element. The method includes placing the unit element layer onto the base substrate with the underside of the support substrate facing upwards. The method further includes etching the support substrate from the underside of the support substrate until the protective layer of the unit element layer is reached.

[0024] The stacked structure according to the embodiments of the present invention can have a lower overall thickness while maintaining the number of stacked unit layers in the stacked structure, since the support substrate on which the units are formed is eliminated while protecting the unit element.

[0025] Additional features and advantages are implemented through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered part of the claimed invention. List of characters

[0026] The subject matter considered to be the invention is precisely set out and expressly claimed in the claims at the end of the description. The above and other features and advantages of the invention will become apparent from the following detailed description in conjunction with the accompanying drawings. It should be noted that the sizes and relative positions of elements and layers in the drawings are not necessarily drawn to scale. Some of these elements or layers have been enlarged and positioned arbitrarily to improve the legibility of the drawing. Fig. Figure 1 illustrates a cross-sectional view of a stacked battery structure according to an exemplary embodiment of the present invention. Fig. 2A, Fig. 2B, Fig. 2C, Fig. 2D and Fig. Figure 2E illustrates cross-sectional views of structures obtained at each step in a first third of the manufacturing process of a stacked battery structure according to an exemplary embodiment of the present invention. Fig. 3A, Fig. 3B and Fig. Figure 3C illustrates cross-sectional views of structures obtained at each step in a middle third of the manufacturing process of the stacked battery structure according to the exemplary embodiment of the present invention. Fig. 4A, Fig. 4B and Fig. Figure 4C illustrates cross-sectional views of structures obtained at each step in the last third of the manufacturing process of the stacked battery structure according to the exemplary embodiment of the present invention. Fig. Figure 5 shows a representation of connected current collectors in the stacked battery structure according to an exemplary embodiment of the present invention. Fig. 6A, Fig. 6B, Fig. 6C, Fig. 6D, Fig. 6E and Fig. Figure 6F illustrates a process for manufacturing a through-hole connection with a step-like structure according to exemplary embodiments of the present invention. Fig. 7A and Fig. Figure 7B illustrates cross-sectional views of stacked battery structures according to other embodiments of the present invention. Fig. 8A and Fig. 8B represent electronic units that contain a stacked battery structure according to one or more exemplary embodiments of the present invention. Fig. 9A and Fig. 9B describe a comparison between stacked battery structures with and without the application of a novel process for removing a support substrate according to exemplary embodiments of the present invention. DETAILED DESCRIPTION

[0027] The present invention is described below with reference to certain embodiments, and it is understood that the embodiments described below are merely examples and are not intended to limit the scope of the present invention.

[0028] One or more embodiments according to the present invention relate to a stacked battery structure, a method for manufacturing the stacked battery structure, a stacked battery structure manufactured by the method, and an electronic unit containing the stacked battery structure, wherein a large battery capacity can be achieved in a volume-efficient manner.

[0029] The following refers to Fig. 1 a stacked battery structure according to an exemplary embodiment of the present invention is described.

[0030] Fig. Figure 1 illustrates a schematic representation of a stacked battery structure. 100 A cross-sectional view of the stacked battery structure 100 will be in Fig. 1 shown. As in Fig. Figure 1 shows the stacked battery structure. 100 a base substrate 102; a plurality of battery layers 110 , 140 , which are based on the base substrate 102 are stacked, each containing at least one thin-film battery cell; a pair of vias 172 , 174 , which are in the stacked battery layers 110 , 140 are formed; and a wiring layer 180 , located on top of the stacked battery layers 110 , 140 is trained.

[0031] In the described embodiment, the substrate can be used. 102 stacked battery layers, an upward-facing base battery layer 110 , whose thin-film battery element is facing upwards, and two or more downward-facing battery layers 140 contained, whose thin-film battery cell is facing downwards. In the in Fig. 1. Stacked battery structure shown 100There is an upward-facing base battery layer 110 and two downward-facing battery layers 140A , 140B , which are located on the upward-facing base battery layer 110 are stacked.

[0032] The upward-facing base battery layer 110 can be applied to the base substrate 102 be formed. The upward-facing base battery layer 110 can a thin-film battery cell 120 , which is based on the base substrate 102 is trained, and an insulator 132 containing the thin-film battery cell 120 covered. The downward-facing battery layers 140 can on the insulator 132 the upward-facing base battery layer 110 be arranged.

[0033] Each downward-facing battery layer 140 contains a protective layer 144 , a thin-film battery cell 150, which is on the protective layer 144 is trained, and an insulator 162 , which is the thin-film battery cell 150 covered.

[0034] It should be noted that the orientation of the thin-film battery cell 150 in the downward-facing battery layer 140 those of the upward-facing base battery layer 110 is the opposite. Each downward-facing battery layer 140 is on its underlying battery layer ( 110 or 140 ) with regard to the base substrate 102 arranged in reverse, so that each insulator 162 on the side of the base substrate 102 is located and each protective layer 144 located on one side opposite the base substrate. The downward-facing battery layers 140 are stacked in such a way that the insulator of one of the upper battery layers (e.g. 162B) with one of the lower battery layers (e.g. 140A ) connects and the insulator of the lowest downward-facing battery layer (i.e., 162A in Fig. 1) with the upward-facing base battery layer 110 connects.

[0035] The base substrate 102 It can be made from any rigid material, such as silicon, aluminum oxide ceramic, glass, mica, etc., to name just a few. Since the manufacturing process of the thin-film battery cell 120 However, it may contain a heating process for a cathode material; the basic substrate 102 preferably made from heat-resistant materials that can withstand the heating process for the cathode material.

[0036] The protective layer 144can be made from a chemically resistant material that can be used as an etch stopper against wet etching in the manufacturing process of the stacked battery structure 100 This can be carried out. The manufacturing process is described below. In a specific embodiment, the protective layer 144 Made from a chemically inert material, it can be used as an etch stopper against wet etching using a buffered hydrofluoric acid (BHF) solution. The protective layer 144 Furthermore, it can prevent moisture or a liquid such as an electrolyte from entering components of the thin-film battery cell. 150 penetrates. In view of the manufacturing process of the thin-film battery element. 150 is the protective layer 144 , on which the thin-film battery cell 150It is manufactured preferably from heat-resistant materials that can withstand the heating process of the cathode material. Considering the manufacturing process of the vias 172 , 174 is the protective layer 144 , through which through holes are produced, preferably made of a material with relatively lower dry etch resistance that can be laser-machined. Such materials include, but are not limited to, silicon nitrides SiN (e.g., Si3N4). In other embodiments, however, other inorganic materials such as polysilicon can also be used, provided that the material does not impair the production of through holes and exhibits etch and heat resistance. The material of the protective layer 144 It can be deposited by virtually any standard method, including vapor deposition techniques. The thickness of the protective layer 144can range from approximately 0.1 to approximately 1.0 µm.

[0037] The insulators 132 , 162 They can be made from an adhesive material, such as a resin with a specific curing temperature, which might be in the range of 150 to 250 degrees Celsius, for example. Any laser-machinable adhesive resin that can be drilled by a laser can be used as the insulator material. 132 , 162 They can be used. Such a resin could include BCB (benzocyclobutene) resin, etc., to name just a few.

[0038] The upward-facing base battery layer 110 and the lowest downward-facing battery layers 140A can pass through the insulators 132 , 162A the battery layers 110 , 140A be connected. The lower and upper downward-facing battery layers (e.g. 140A , 140B ) can pass through the upper insulator (e.g.162B ) be connected, which is provided in between.

[0039] Hardening can improve the insulation properties. 132 the upward-facing base battery layer 110 and the insulator 162A the lowest downward-facing battery layers 140A be integrally attached to one another. The insulator of the upper battery layer (e.g. 162B ) may have a surface that is compatible with the protective layer of the lower battery layer (e.g. 144A ) connects. In the in Fig. 1 shown final stacked battery structure 100 is no rigid material between the insulator of the upper (e.g. 162B ) and the protective layer of the lower (e.g. 144A ) added.

[0040] Each thin-film battery cell 150 in the downward-facing battery layer 140 can have a cathode current collector (CCC) 152; a cathode 154, which are connected to the cathode current collector 152 is connected; an electrolyte 156 , which forms an interface with the cathode 154 features; an anode 158 , which form an interface with the electrolyte 156 features; and include an anode current collector (ACC) 160 connected to the anode 158 is connected. The cathode 154 , the electrolyte 156 and the anode 158 form a battery cell that connects to the current collectors 152 , 160 is in contact. The thin-film battery cell 120 in the upward-facing base battery layer 110 can have a structure similar to that of the thin-film battery cell 150 in the downward-facing battery layer 170 matches or is similar to it, and may also have a cathode current collector 122 , an anode current collector 130and contain a battery cell that connects to the current collectors 122 , 130 is in contact with a cathode 124 , an electrolyte 126 and an anode 128 may contain.

[0041] The cathode current collectors 122 , 152A , 152B and the anode current collectors 130 , 160A , 160B can be made from any of the metals (e.g. Cu, Pt, Al, Au etc.) and other conductive materials (e.g. graphite, carbon nanotubes etc.), provided it is suitable for the respective cathode material 124 , 154 and the anode 128 , 158 is suitable. The cathode current collector 122 and the anode current collector 130 can be applied to the base substrate 102 be trained. The cathode current collectors 152A , 152B and the anode current collectors 160A , 160B can be found on the respective protective layers 144A, 144B be trained.

[0042] It should be noted that if the protective layer 144 made of a conductive material, an additional, non-conductive layer between the current collectors 152 , 160 and the protective layer 144 It may also be added. Furthermore, it should be noted that if the base substrate 102 made of a conductive material, an additional, non-conductive layer between the current collectors 122 , 130 and the base substrate 102 may be joined.

[0043] The cathode 124 , 154 It can be made from crystalline or nanocrystalline lithium intercalation compounds such as LiCoO2, LiMn2O4, to name just a few. The cathode material 124 , 154It can be deposited by virtually any standard method, including gas-phase deposition techniques such as sputtering, and the thin film obtained by low-temperature deposition can be annealed at a predetermined temperature (usually in the range of 500 to 700 degrees Celsius) to obtain fully crystalline phases. Alternatively, the cathode material can be 124 , 154 can be deposited by virtually any standard method, including vapor deposition techniques, while the substrate is heated to a predetermined deposition temperature. Other unheated cathode materials, such as nanocrystalline Li, are not suitable. x Mn 2-x O4 must not be excluded from the candidates for the cathode material.

[0044] Regarding the electrolyte 126 , 156It can be any solid electrolyte, such as a ceramic electrolyte, which includes lithium oxide-based electrolytes (e.g., lithium phosphooxynitride (LiPON), lithium lanthanum titanium oxide (LLTO), etc.), lithium sulfide-based electrolytes, and other lithium phosphate-based electrolytes such as lithium boron phosphate (LiBP). The electrolyte 126 , 156 can be deposited by virtually any standard method, including gas-phase deposition techniques such as sputtering. In the Fig. In the embodiment shown in 1, the electrolyte 126 , 156 so on the cathode 124 , 154 to be deposited so that it covers the surface and edges of the cathode 124 , 154 completely covered.

[0045] The anode 128 , 158can be made from any silicon and materials that have a melting point higher than the curing temperature of the insulator. 132 , 162 is. In particular, the anode can be 128 , 158 to be a lithium-free anode, wherein the anode is formed by electroplating metallic lithium or by lithiation at the interface between the electrolyte 126 , 156 and the anode current collector 130 , 160 is formed during the first charging. Alternatively, it can be the anode. 130 , 160 This involves a lithium-ion anode such as silicon tin oxynitride (SiTON), tin nitride, and zinc nitride. By inserting the aforementioned anode material, the anode can be... 130 Temperatures for hardening the insulator 132 , 162withstand. In other embodiments, however, a metallic lithium having a melting point of 180 degrees Celsius may not be excluded from candidates for the anode material, provided that the anode material can withstand the hardening temperature required to harden the insulator. 132 , 162 can withstand.

[0046] In a preferred embodiment, each thin-film battery cell can 120 , 150 It can be manufactured as an all-solid-state thin-film battery, more precisely as an all-solid-state lithium-ion thin-film battery. In a specific embodiment, the overall thickness of the thin-film battery element can be reduced. 120 , 150 less than or equal to approximately ten micrometers (e.g. ~10 µm).

[0047] The vias 172 , 174 This allows within the stacked battery layers 110 , 140They are trained to create a conductive path between an external unit and the thin-film battery elements. 120 , 150 in the stacked battery layers 110 , 140 Provide. Note that the vias 172 , 174 in the described embodiment by at least one battery layer ( 140B , 140A in Fig. 1) up to a layer below at least one battery layer ( 110 in Fig. 1) can extend, which include one or more protective layers ( 144B , 144A in Fig. 1) and one or more insulators ( 162B , 162A , 132 in Fig. 1) contains.

[0048] Each via 172 (or 174 ) can be formed in a through hole that passes through at least one of the stacked battery layers 110 , 140is open. The through-hole can pass through one or more battery layers. 110 , 140 be trained. The through holes 172 , 1744 They are made conductive by filling their inner surfaces with a conductive material (e.g., solder paste) or by depositing a conductive material (e.g., metal) on them, in order to enable the vias. 172 , 174 to train.

[0049] Each via 172 (or 174 ) is connected to at least one of the current consumers 122 , 152 (or 130 , 160 ) in the stacked battery layers 110 , 140 electrically connected. In one or more embodiments, each via has contacts with multiple current collectors in different battery layers, with each contact being achieved on a surface of each of the multiple current collectors.

[0050] In the Fig. In the embodiment shown and described in section 1, the through-hole connection can be made. 172 Contacts on the respective surfaces of the cathode current collectors (e.g. 122 , 152A , 152B ) exhibit. The vias 174 can make contacts on the respective surfaces of the anode current collectors (e.g. 130 , 160A , 160B exhibit.

[0051] It should be noted that according to Fig. 1 looks as if the via 172 (or 174 ) not with the current collectors 152A , 152B ( 160A , 160B ) the downward-facing battery layers 140A , 140B would be in contact. The through-contacts 172 (or 174 ) however, they are connected to the current collectors 152A , 152B (or 160A , 160B ) each in contact at different cross-sections. The outlines of the pantographs 152 , 160Various cross-sections are marked by dashed lines in Fig. 1 indicated.

[0052] The wiring layer 180 , located on top of the stacked battery layers 110 , 140 It is formed, may have a conductive element (a wiring pattern) that connects the vias 172 , 174 connects to external ports that can be connected to the external unit, such as a CPU (Central Processing Unit), memory, etc. The wiring layer 180 Furthermore, it can be made from a resin as an insulator for the wiring layer. The resin can be any BCB (benzocyclobutene) resin, a polyimide, or other polymers.

[0053] The structure of the stacked battery structure 100 is possibly not based on the in Fig. 1 specific embodiment shown. Although this is limited in Fig. 1 is not shown, it can be found in the stacked battery structure 100 An additional layer may be present. For example, the thin-film battery cell 120 , 150 prior to the deposition of a resin from the insulator 132 , 162 are covered by other protective coatings.

[0054] Furthermore, the layout of the thin-film battery elements 120 , 150 within the stacked battery structure 100 possibly not on the in Fig. 1 specific embodiments shown, in which all thin-film battery elements 120 , 150 through the via 172 , 174 are connected in parallel.

[0055] In other embodiments, such a layout can be used in which at least two of the thin-film battery elements 120 , 150 using vias and / or a surface wiring layer such as the wiring layer 180 They are connected in series. Connecting the thin-film battery cells. 120 , 150 In series, a connection voltage of the stacked battery structure can be achieved. 100 This increases the capacity while maintaining a small footprint for the stacked battery structure. Since electrode materials that have previously been practically unused due to their lower potential difference can be employed by connecting the elements in series, the design possibilities for electrode materials can be expanded. Furthermore, suitable series connections allow for a wider range of connection voltages for the stacked battery structure.100 to be won.

[0056] In a specific embodiment, connections between multiple layers can be made not only by a via, but also by another surface wiring layer, such as the wiring layer. 180 This is achieved after each electrical path from each current collector has been routed through a suitable via structure to the top of the stack. The via can be open through all layers, including the layers from top to bottom, or it can be open through a portion of the layers, with the hole terminating at a current collector in the middle layer. Even if the via is open through all layers from top to bottom, it may not need to be connected to all current collectors.

[0057] The following will refer to a number of Fig. 2A to Fig. 2E, Fig. 3A to Fig. 3C and Fig. 4A to Fig. 4C is a process for manufacturing a stacked battery structure. 100 described according to an exemplary embodiment of the present invention.

[0058] Fig. 2A to Fig. 2E, Fig. 3A to Fig. 3C and Fig. 4A to Fig. 4C illustrates cross-sectional views of structures present at each step of the stacked battery structure manufacturing process. 100 to be won.

[0059] As in Fig. As shown in 2A, the manufacturing process can be a step towards producing a base substrate. 102 containing a thin-film battery cell 120 is manufactured. In a specific embodiment, the base substrate produced by this step is 102Made from bulk silicon, which exhibits resistance to BHF solution and heat. The thin-film battery cell 120 , which is a cathode current collector 122 , a cathode 124 , an electrolyte 126 , an anode 128 and an anode current collector 130 contains, can be processed by virtually any standard process on the base substrate 102 manufactured, as described below with regard to the thin-film battery element 150 for the downward-facing battery layer 140 is described using an example.

[0060] As in Fig. As shown in Figure 2B, the manufacturing process can also include a step to form an insulator. 132 above the thin-film battery cell 120 and the base substrate 102 included to form a basic battery layer 110 to gain, which are based on the substrate 102is designed. In a specific embodiment, this step can be a partial step for depositing an insulating material over the thin-film battery cell. 120 ; and a subsequent step to level the insulation material to create a flat surface 132a to be achieved by a suitable method, include, as below with regard to the downward-facing battery layer 140 is described using an example.

[0061] As in Fig. As shown in 2C, the manufacturing process can further include a step to produce a carrier substrate. 142 containing a protective layer 144 is formed. The carrier substrate 142 , on which the thin-film battery cell 150 It is preferably manufactured from heat-resistant materials that can withstand the heating process for the cathode. 154can withstand. In a specific embodiment, the support substrate produced by this step 142 Made from a glass material that exhibits a relatively high etching rate in the BHF solution and, furthermore, heat resistance. The protective layer 144 It can be made from a chemically resistant material that can be used as an etch stop against wet etching using the BHF solution. In a specific embodiment, the protective layer 144 Made from silicon nitrides SiN (e.g., Si3N4), which exhibit a low etching rate in the BHF solution and also heat resistance. The protective layer 144can be formed on the glass substrate by virtually any standard agent, including a vapor deposition technique such as RF magnetron sputtering, plasma-enhanced chemical vapor deposition (PECVD), low-pressure chemical vapor deposition (LPCVD), to name just a few.

[0062] As in Fig. In 2D representation, the manufacturing process can be a step towards producing the thin-film battery element. 150 on the carrier substrate 142 contained, with the protective layer 144 The thin-film battery cell is inserted in between. 150 It can be manufactured on the substrate using any conventional process. For example, the thin-film battery cell can be 150 They are manufactured through a series of gas phase deposition processes.

[0063] The exemplary process for manufacturing the thin-film battery element 150 can (a) take a step to deposit an anode and a cathode current collector 152 , 160 on the protective layer 144 ; (b) a step towards depositing a cathode 154 on the cathode current collector 152 at low temperature; (c) a step to anneal the cathode 154 at a predetermined annealing temperature (e.g. in a range of 500 to 700 degrees Celsius) to obtain a fully crystalline phase; (d) a step to deposit an electrolyte 156 , which is the cathode 154 completely covered; and (e) a step to deposit an anode 158 on the electrolyte 156 and the anode current collector 160 In another embodiment, process (f) may include a step for depositing the cathode. 154 on the cathode current collector 152at a predetermined deposition temperature, while the support substrate 142 is heated, instead of steps (b) and (c).

[0064] As in Fig. As shown in 2C, the manufacturing process can further include a step towards forming the insulator. 162 above the thin-film battery cell 150 and the protective layer 144 included to form a battery layer 140 to obtain those on the carrier substrate 142 is formed, whereby the protective layer 144 is inserted in between.

[0065] In a specific embodiment, the step to form the insulator can be 162 a partial step in the deposition of an insulating material over the thin-film battery cell 150 ; and a subsequent step to level the insulation material to create a flat surface 162ato obtain, by pressing the insulation material, by fly-cutting the insulation material, or by chemical and mechanical polishing of the insulation material. Alternatively, the leveling step can be carried out using a spin-on glass technique, in which the carrier substrate 142 , which holds the deposited insulating material, is rotated at high speeds to distribute the insulating material evenly over an upper surface of the protective layer 144 to distribute.

[0066] By being in the ranks of Fig. 2C to Fig. By repeating the steps described in 2E with a predetermined frequency, the desired number of battery layers can be achieved. 140 , which are on the respective carrier substrate 142 The training is carried out separately. It should be noted that the [products] in the series of Fig. 2C to Fig. The steps described in section 2E can be repeated in parallel or sequentially and can be performed after or before the steps described in the series of Fig. 2A to Fig. have been described in section 2B.

[0067] As in Fig. As shown in 3A, the manufacturing process can include a step towards placing the battery layer. 140A with the carrier substrate 142A on the base substrate 102 included, wherein the underside of the carrier substrate 142A is upward-facing. Since, in the described embodiment, the base substrate 102 with the base battery layer formed on it 110 equipped, the battery layer 140 upside down, so on the insulator 132 the base battery layer 110 arranged so that the insulator 162 on the side of the base substrate 102 is located and the protective layer 144 (and the carrier substrate) 142A), on which the thin-film battery cell 150A is manufactured on a side opposite the side of the base substrate.

[0068] As in Fig. As shown in 3B, the manufacturing process can include a step to remove the support substrate. 142A from the battery layer 140A contained through etching, while the thin-film battery cell 150A through the protective layer 144A is protected. The etching can be chemical etching. In the described embodiment, the carrier substrate can be 142 by wet etching the carrier substrate 142 , until the protective layer 144 is achieved completely from the battery layer 140 be eliminated, as in Fig. 3B illustrates this, while its underlying structure remains untouched. If the support substrate 142 is made from a glass material and is the base substrate 102If the material is made of silicon, wet etching using a BHF solution can be employed, as it exhibits high selectivity for silicon dioxide (SiO2) over silicon. The protective layer 144 acts as an etching stopper against BHF wet sets.

[0069] If the base substrate 102 If it is made from a material that exhibits resistance to BHF, such as silicon, the back of the base substrate must be 102 The substrate cannot be protected during wet setting. Therefore, a special tool or material can be used to protect the base substrate. 102 This may be unnecessary. However, in other embodiments, a material that does not exhibit resistance to BHF is used as the base substrate material. 102 not excluded, provided the reverse side of the base substrate 102can be protected by any known tool such as a wafer chuck or a chemically resistant material such as silicon nitride, thus enabling protection of the back side during wet forming.

[0070] It should be noted that the carrier substrate 142 in Fig. 3B completely from the battery layer 140 This is illustrated as eliminated. However, an alternative embodiment can be considered in which the support substrate 142 by etching, partially removing the battery layer 140A is removed.

[0071] As in Fig. As shown in 3C, the manufacturing process can include a step of repeatedly stacking the additional battery layer (e.g. 140B ) contained until the desired number of battery layers is reached 140 is stacked. The step to repeatedly stacking the additional battery layer. 140can be achieved by alternately performing a sub-step to stack the additional battery layer 140 with another carrier substrate 142 and a partial step for removing the carrier substrate 142 from the additional battery layer 140 Included. In each repeating cycle, the additional battery layer is 140 with the carrier substrate 142 stacked, with the underside of the support substrate 142 is oriented upwards. The carrier substrate is then applied. 142 by etching in the same manner as described above Fig. 3B described, at least in part by the additional battery layer 140 removed.

[0072] In a particular embodiment, after the desired number of battery layers are selected, 140 The insulators have been stacked. 132 , 162A , 162B , which occur after each stacking of the battery layer 140can be partially cured, fully cured by the resin of the insulator. 132 , 162A , 162B is exposed to the curing temperature. Through complete curing of the insulator. 132 , 162A , 162B upper and lower layers are formed in the stacked battery layers. 110 , 140A , 140B each one firmly attached to the other.

[0073] As in Fig. As shown in 4A, the manufacturing process can include a step towards forming through holes. 170a , 170b in the stacked battery layers 110 , 140A , 140B Included. The through holes 170a , 170b can extend through at least one layer to the layer below it, if the support substrates 142 down to the layer that has been removed by etching. Fig. 4A are the carrier substrates 142B , 142Adown to the battery layer 140A removed by etching, and the through holes 170a , 170b extend through two battery layers 140B , 140A down to the layer below it 110 The through holes 170a , 170 can be arranged perpendicular or at an angle to the base substrate in the stacked battery layers 102 be trained.

[0074] If a laser-machinable insulator material is used for the insulator 132 , 162A , 162B When used, the through holes can 170a , 170b by directly drilling through both the insulators 162B , 162A , 132 as well as the protective layer 144B , 144A in the stacked battery layers by laser processing and can simultaneously be the current collector 122 , 130 , 152 , 160remain. The hole can have dimensions of several tens of micrometers (e.g. 50 µm diameter / width).

[0075] As in Fig. As shown in Figure 4B, the manufacturing process can include a step to fill the through-holes with a conductive material. 170a , 170b exhibit the vias 172 , 174 to form conductive paths. The filling of the conductive material can be carried out by virtually any standard means, such as filling with solder paste. In the described embodiment, each via is 172 (or 174 ) with the respective current consumers 122 , 152A , 152B (or 130 , 160A , 160B) in the stacked battery layers are electrically connected. In an alternative embodiment, the manufacturing process can include a step for depositing a conductive material on the inner surface of the through-holes. 170a , 170b instead of filling with the conductive material.

[0076] By performing the described steps in a series of Fig. 4A to Fig. 4B can be the conductive paths, each connected to the corresponding current collectors, within the stacked battery layers. 110 , 140 They will be trained. The process for creating the guiding path is described in more detail below.

[0077] As in Fig. As shown in 4C, the manufacturing process can be a step towards forming the wiring layer. 180 on the top side of the battery layers 110 , 140A , 140B Included. The wiring layer180 may contain a conductive element that connects the vias 172 , 174 It connects to external terminals used to connect to an external unit such as a CPU or memory. A resin can be applied over the conductive element to act as an insulator.

[0078] Although the above description focuses on a single stacked battery structure 100 Once the design is complete, the manufacturing process can be carried out not only at the chip or package level, but also at the wafer or plate level. In a specific embodiment, the base substrate can be 102 and the carrier substrate 142 have a wafer or plate form, and the base substrate 102 and the carrier substrate 142 A majority of the thin-film battery cells trained on it can 120 , 150included. After connecting, the majority of the battery layers can be... 110 , 140 , which may be in the form of a wafer or a plate, are divided into a plurality of chips, each having a structure that corresponds to the one in Fig. 1. Stacked battery structure shown 100 agrees.

[0079] According to the in Fig. 2A to Fig. 2E, Fig. 3A to Fig. 3C and Fig. 4A to Fig. 4C shown exemplary embodiment would, since each battery layer 110 , 140 , which is manufactured for stacking, the thin-film battery cell 120 , 150 exhibits that has already been manufactured separately, other components of the stacked battery structure 100 due to the heating process for the cathode 124 , 154not damaged, unlike sequential stacking, where multiple layers of electrochemical cells are manufactured one after the other, and where previously formed components, such as an anode for a lower layer, must withstand the heating process for the cathode that is subsequently formed for an upper layer. In other words, the cathode material 124 , 154 can be converted into a crystalline phase without damaging the other components.

[0080] Since the most likely thermal process after stacking is hardening of the insulator. 132 , 162 and the wiring layer 180 This would mean that the other components would not be damaged during the entire manufacturing process, provided the components of the stacked battery structure are not damaged. 100 be able to withstand the curing temperature.

[0081] Referring to a number of Fig. 5 and Fig. 6A to Fig. Section 6E describes a process for manufacturing a through-hole connection with a step-shaped structure according to the exemplary embodiment of the present invention.

[0082] Fig. Figure 5 shows a schematic representation of the through-hole connection. 172 in the stacked battery structure 100 connected current consumers 122 , 152 In Fig. 5 are a cross-sectional view 200 the stacked battery structure 100 , top views 210 , 220 , 230 on three battery layers 110 , 140A , 140B on a section around the cathode current collector 122 , 152A , 152B (as seen through a dashed circle P in Fig. 5) before stacking. A relationship between the cross-sectional view 200 and the top views210 , 220 , 230 is indicated by arrows and labels in Fig. 5 shown. The cross-sectional view 200 corresponds to a cross-section that passes through the “ X “ in the top views 210 , 220 , 230 from Fig. 5 is indicated. It should be noted that the outlines of the pantographs 152 , 160 , which are in the cross-section of the cross-sectional view 200 do not appear, through dashed lines in Fig. 5 will be specified.

[0083] In Fig. 5 are further top views 240 , 250 , 260 the stacked battery layers immediately after the stacking step, immediately after the step to form the through-hole or immediately after the filling step. Fig. 6A to Fig. Figure 6E illustrates a process for manufacturing the through-hole plating. 172 with the stepped structure. The in Fig. 6A to Fig. The cross-sectional views shown in Figure 6E correspond to an enlarged view of a section indicated by a dashed circle P together with cross-sections indicated by the “ V “ in Fig. 5 will be specified.

[0084] As seen from above 210 for the first layer (i.e., the base battery layer) 110 ) shown, are the basic substrate 102 , the cathode current collector 122 , which is defined by a dashed rectangle in the top view 210 is specified, and the insulator 132 layered. As shown in the top views. 220 , 230 The insulator is shown. 162 , the cathode current collector 152 , which is also represented by dashed rectangles in the top view 220 , 230 is specified, and the protective layer 144 each for the second and third layer (i.e., the battery layers) 140A , 140B)layered. It should be noted that the positions of the cathode current collectors 122 , 152A , 152B (possibly together with the entire structure of the thin-film battery cell) 120 , 150A , 150B) together with a direction in a horizontal plane of the base substrate 102 will be relocated.

[0085] The top view 240 in Fig. 5 represents the top surface of the stacked battery layers 110 , 140A , 140B immediately after the stacking steps of the desired number of battery layers 110 , 140 dar. Fig. Figure 6A shows a cross-sectional view of the stacked battery layers. 110 , 140A , 140B immediately after the stacking steps. As shown in the top view. 240 from Fig. As shown in 5, the upper surface of the protective layer is shown. 144B the third battery layer 140Bimmediately visible after the stacking steps.

[0086] The top view 250 in Fig. 5 represents the top surface of the stacked battery layers 110 , 140A immediately after the step to form the through-hole. Fig. Figure 6B shows a cross-sectional view of the stacked battery layers. 110 , 140A , 140B This is the step immediately following the creation of the through-hole. By drilling through the protective layers. 144B , 144A and the insulators 162B , 162A , 132 The through hole is cut from top to bottom. 170a through the stacked battery layers 110 , 140A , 140B manufactured. It should be noted that the current collector 152B , 152A , 122 It can act as a stopper for laser drilling; accordingly, the current collector would 152B , 152A , 122after laser processing on the insulator 162B , 162A , 102 remain, and their underlying structures remained untouched.

[0087] As in Fig. As shown in 6B, the through hole 170a at least one respective horizontal dimension, enlarged from bottom to top, in the stacked battery layers 110 , 140A , 140B exhibit, and all subsections can be located in a horizontal plane of the base substrate. 102 overlap. As seen in the top view. 250 from Fig. Figure 5 shows the surfaces of all cathode current collectors after the step of forming the through-hole. 122 , 152A , 152B through the through hole 170a to see when they are in relation to the base substrate 102 viewed from a normal direction.

[0088] Fig. 6C to Fig. 6E represents the process of manufacturing a through-hole after creating the through-hole. 170a with cross-sectional views of the structure. Fig. 6F represents the alternative process of manufacturing a through-hole after creating the through-hole. 170a with a cross-sectional view of the structure.

[0089] As in Fig. As shown in 6C, an inner surface of the through-hole can be 170a with an insulating material (e.g. a polymer) 176 The insulating material can be coated. Coating can be carried out using any standard method, such as gas-phase deposition polymerization.

[0090] As in Fig. Once displayed in 6D, sections of the insulation material can then be removed. 176 , which are on the cathode current collectors 122 , 152A , 154BThe deposited areas are etched back by an anisotropic standard etching process so that the surfaces of the cathode current collectors 122 , 152A , 152B be exposed. At this point, the through-hole can be opened. 170a several subsections, each with a step that includes the cathode current collector (e.g., the cathode current collectors) 152A , 152B ) exposes, or has an internal bottom surface that exposes the cathode current collector (e.g. the cathode current collector) 122 ) exposes.

[0091] As in Fig. As shown in 6E, the conductive material is placed in the hole. 170a filled to allow for through-hole contact 172 to train. The top view 260 in Fig. 5 represents the top surface of the stacked battery layers 110 , 140A immediately after the filling step. As shown in the top view. 260 As shown, after the filling step, the upper end of the via is shown.172 , which is located on the upper surface of the protective layer 144B the third battery layer 140B exposed, to be seen when it is in relation to the base substrate 102 viewed from the normal direction, whereas all cathode current collectors 122 , 152A , 152B are covered by the conductive material. Alternatively, the conductive material can be applied to the inner surface of the through-hole. 170a to be separated to enable through-contacting 172 to train, as in Fig. 6F is shown.

[0092] It should be noted that the step involves coating the inner surface of the through-hole. 170a and a step towards etching back the sections of the insulation material 176 can be omitted if no other conductive material besides the current collectors is used. 152 , 122 is present on the inner surface of the through-hole 170ais exposed. In a specific embodiment, where the protective layer 144 is made from an insulating material such as silicon nitride and the carrier substrates 142 are completely removed by etching or the carrier substrates 142 are made from an insulating material such as glass, can, if the support substrates 142 Since some of the material is still present, the coating step and the etching step can be omitted.

[0093] Such in Fig. 6E and Fig. The stepped structure shown in 6F would allow for the stepped battery structure 100 reliable contacts between the via 172 and the electricity consumers 122 , 152A , 152B in the stacked battery structure 100 exhibits.

[0094] The following will refer to Fig. 7A and Fig. 7B Variants of the stacked battery structure according to one or more exemplary embodiments of the present invention are described.

[0095] In the embodiment described above, three battery layers are shown for illustration purposes. 110 , 140A , 140B in the stacked battery structure 100 available. The number of battery layers 110 , 140 in the stacked battery structure 100 However, it may not be limited to the specific embodiment described above. In one or more embodiments, two or more than three battery layers are possible. 110 , 140 to be stacked to form the stacked battery structure 100 to train.

[0096] Fig. 7A represents a stacked battery structure 200 that represents an upward-facing base battery layer 210 and eight downward-facing battery layers240A until 240H , a total of nine on the base substrate 202 features stacked battery layers, each containing a thin-film battery element 220 , 250 exhibit.

[0097] Furthermore, in the embodiment mentioned above, the downward-facing battery layers are 140 described as being based on the base substrate 102 are formed, with the base battery layer 110 in between. In other embodiments, the downward-facing battery layers can 140 however, directly on the base substrate 102 be formed without the base battery layer 110 is inserted in between.

[0098] Fig. 7B represents a stacked battery structure 300 that the nine on the base substrate 302 stacked, downward-facing battery layers 340A until 3401each contains a thin-film battery cell 350 exhibit.

[0099] It is only necessary to perform eight stacking steps to create the stacked battery structure. 200 to manufacture, whereas nine executions are required to create the stacked battery structure. 300 to manufacture, therefore the stacked battery structure 200 with the base battery layer 210 more advantageous than the stacked battery structure 300 .

[0100] The following will refer to Fig. 8A and Fig. 8B schematic representations of an electronic unit described which has a stacked battery structure 100 according to one or more exemplary embodiments of the present invention. The electronic unit can be used for an IoT unit.

[0101] Fig. Figure 8A shows a schematic representation of a system-on-package design for an electronic unit that incorporates the stacked battery structure. 100 contains. As in Fig. As shown in 8A, the stacked battery structure can be seen 100 on a wiring substrate 190 to be mounted on which one or more external electronic components 192A , 192B such as a processor, a memory, a sensor are mounted.

[0102] Fig. Figure 8B shows a schematic representation of a system-on-battery design for an electronic unit that incorporates the stacked battery structure. 100 contains. As in Fig. As shown in 8B, the stacked battery structure functions 100 as an interposer or substrate on which one or more electronic components are mounted. 172A , 172B are mounted. In this embodiment, the stacked battery structure has 100 the wiring layer180 on the upper surface of the stacked battery layers 110 , 140A , 140B up to the stacked battery structure 100 with one or more on the stacked battery structure 100 to connect mounted electronic components. The system-on-battery design can be advantageous for further miniaturization.

[0103] Since the power source of the electronic unit requires little space, the overall size of the electronic unit can be miniaturized.

[0104] According to one or more embodiments of the present invention, the overall thickness of the battery structure can be reduced while maintaining its capacity, or alternatively, the capacity of the battery structure can be increased while maintaining the overall thickness of the battery structure.

[0105] With reference to Fig. 9A and Fig. Section 9B describes a comparison between stacked battery structures with and without applying the novel process for removing a carrier substrate according to the exemplary embodiment of the present invention.

[0106] Fig. 9A and Fig. 9B represent stacked battery structures that have three battery layers, both with and without an intermediate substrate. The in Fig. The stacked battery structure shown in 9A has a base battery layer. 110 and two battery layers 140A , 140B on, whereby the carrier substrates 142A , 142B , which are used to manufacture the thin-film battery cell 150A , 150B during the manufacturing process, the novel process for removing a carrier substrate has completely eliminated the need for additional support. In contrast, the [document / process] in Fig. 9B shown stacked battery structure 500also a basic battery layer 510 and two battery layers 540A , 540B on, whereby the substrates 542A , 542B , on which the thin-film battery cell 550A , 550B is trained, still in the final structure 500 are available.

[0107] Although, as described above, the thickness of the substrates 542A , 542B The thickness of the substrates can be reduced to 75 to 50 µm through a standard process of grinding the back side. 542A , 542B still several times larger than the thickness of the thin-film battery cell 520 , 550A , 550B , which may be less than or equal to approximately ten micrometers (~10 µm).

[0108] As in Fig. As shown in 9B, there are alternating insulators. 562 and substrates 542 in the stacked battery structure 500Therefore, the insulator must 562 before stacking, a pre-structuring process using photolithography can be employed to create a hole in the insulator. 562 to form. In addition, an anisotropic dry etching process is required to prepare the substrate. 542 , which may involve silicon, to drill after stacking. Both the pre-structuring process and the anisotropic dry etching process are costly processes. This increases the cost of drilling the through-hole.

[0109] In contrast to the one in Fig. Battery structure shown in 9B with the intermediate substrate 542 can the stacked battery structure 100 according to one or more embodiments of the present invention, have a lower overall thickness while maintaining their capacity, since the carrier substrate 142 , on which the thin-film battery cell 150is designed in such a way that the thickness can be reduced or preferably eliminated, whereas the thin-film battery element 150 through the protective layer 144 is protected. In other words, the stacked battery structure can have a large capacity while maintaining the overall thickness of the battery structure. Since the thickness to be increased by stacking a single battery layer is small, it is possible to increase the number of battery layers stacked within a given thickness and volume. Therefore, it can be described as volume-efficient.

[0110] The embodiments described above involve stacked structures comprising multiple thin-film battery elements. However, one or more embodiments according to the present invention are not limited to stacked structures comprising multiple thin-film battery elements and further relate to a method for manufacturing a stacked structure in which a highly integrated unit structure comprising multiple units, i.e., units other than the battery, can be achieved in a novel manner.

[0111] The terminology used herein serves only to describe certain embodiments and is not intended to limit the invention. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. Furthermore, it is understood that the terms "has" and / or "having" when used in this description denote the presence of specified features, steps, layers, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, layers, elements, components, and / or groups thereof.

[0112] The corresponding structures, materials, processes, and equivalents of all means or step-plus-function elements in the following claims shall optionally include any structure, material, or process for performing the function in combination with other claimed elements than expressly claimed. The description of one or more aspects of the present invention is for illustrative and descriptive purposes only and is not intended to be exhaustive or limited to the invention as disclosed.

[0113] Many modifications and variations are apparent to those skilled in the art without altering the scope and substance of the described embodiments. The terminology used herein has been chosen to best explain the basic concepts of the embodiments, their practical application, or the technical improvements compared to technologies available on the market, or to enable other skilled persons to understand the embodiments disclosed herein. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 9634334

[0004] US 2012 / 0058380

[0005]

Claims

[1] Method for manufacturing a stacked battery structure, wherein the method comprises: Preparing a base substrate; Manufacturing a battery layer formed on a support substrate, wherein the battery layer comprises a protective layer formed on the support substrate, a thin-film battery element formed on the protective layer, and an insulator covering the thin-film battery element; Placing the battery layer on the base substrate with the underside of the support substrate facing upwards; and at least partial removal of the carrier substrate from the battery layer by etching, while the thin-film battery element is protected by the protective layer. [2] Method according to claim 1, wherein the method further comprises alternating repetition until a desired number of battery layers are stacked: a stacking of an additional battery layer formed on a further support substrate, wherein the underside of the further support substrate is facing upwards, the additional battery layer comprising a protective layer, a thin-film battery element and an insulator; and at least partial removal of the further carrier substrate from the additional battery layer by etching. [3] Method according to claim 2, wherein the thin-film battery element contains current collectors and a battery cell in each battery layer which is in contact with the current collectors, wherein the method further comprises: Forming a through-hole in the battery layers stacked on the base substrate, such that it extends through at least one layer to a layer below the at least one layer, wherein the support substrates down to the layer have been removed by etching; and Filling the through-hole with a conductive material or depositing a conductive material onto an inner surface of the through-hole to form a conductive path that is electrically connected to at least one current collector in the battery layers. [4] Method according to claim 3, wherein forming the through-hole comprises: Drilling at least one protective layer and at least one insulator in the battery layers by laser processing, while the current collector remains. [5] Method according to claim 4, wherein the through-hole has several sub-sections and the several sub-sections have at least one horizontal dimension which is enlarged from bottom to top in the battery layers and overlap each other in a horizontal plane with respect to the base substrate, wherein the conductive path has contacts with several current collectors in different battery layers, each contact being made on a surface of each of the several current collectors. [6] The method of claim 3, wherein the method further comprises: Forming a wiring layer on the top side of the battery layers, wherein the wiring layer contains a conductive pattern that connects the conductive path to an external terminal, [7] Method according to claim 1, wherein the removal of the carrier substrate comprises: Wet etching of the carrier substrate until the protective layer is reached. [8] Method according to claim 7, wherein the support substrate is made from a glass material which, when wet-etched, contains a buffered hydrofluoric acid solution, the protective layer acts as an etch stopper against the buffered hydrofluoric acid solution, and the base substrate is made from a material with resistance to the buffered hydrofluoric acid solution. [9] Method according to claim 1, wherein the base substrate is provided with a base battery layer formed thereon, the base battery layer comprising a thin-film battery element formed on the base substrate and an insulator covering the thin-film battery element formed on the base substrate, wherein the battery layer is placed on the insulator of the base battery layer when the battery layer is placed on the base substrate. [10] Stacked battery structure which features: a base substrate; and two or more battery layers on the base substrate, each battery layer comprising: a protective layer; a thin-film battery cell formed on the protective layer; and an insulator that covers the thin-film battery element; wherein the battery layers are stacked in reverse with respect to the base substrate, so that each insulator is on one side of the base substrate, each protective layer is on one side opposite the side of the base substrate, and the insulator of an upper battery layer connects with a lower battery layer. [11] Stacked battery structure according to claim 10, wherein the insulator of the upper battery layers has a surface bond to the protective layer of the lower battery layers. [12] Stacked battery structure according to claim 11, wherein the insulator of the upper and the protective layer of the lower do not have any rigid material inserted between them. [13] Stacked battery structure according to claim 10, wherein the base substrate is equipped with a base battery layer, the base battery layer includes a thin-film battery element formed on the base substrate and an insulator covering the thin-film battery element formed on the base substrate, wherein the two or more battery layers are arranged on the insulator of the base battery layer. [14] Stacked battery structure according to claim 10, wherein the thin-film battery element of each battery layer includes current collectors and a battery cell which is in contact with the current collectors, wherein the stacked battery structure further comprises: one or more conductive paths formed through at least one layer in the battery layers, each conductive path being electrically connected to at least one current collector in the battery layers. [15] Stacked battery structure according to claim 14, wherein a conductive path includes a via having contacts with multiple current collectors in different battery layers, each contact being made on an area of ​​each of the multiple current collectors. [16] Stacked battery structure according to claim 15, wherein the via has multiple subsections and the multiple subsections have at least one horizontal dimension which is enlarged from bottom to top in the battery layers and overlap each other in a horizontal plane with respect to the base substrate. [17] Stacked battery structure according to claim 14, wherein the stacked battery structure further comprises: a wiring layer formed on the top side of the two or more battery layers, wherein the wiring layer contains a conductive pattern that connects a conductive path to an external terminal. [18] Stacked battery structure according to claim 10, wherein the protective layer is made of a material that can be used as an etch stopper against wet etching using a buffered hydrofluoric acid solution. [19] Stacked battery structure according to claim 10, wherein the protective layer is made of silicon nitride. [20] Stacked battery structure according to claim 10, wherein each battery layer is provided by: Manufacturing a layered structure formed on a support substrate, wherein the layered structure includes the protective layer, the thin-film battery element and the insulator, the protective layer being formed on the support substrate; Stacking the layered structure, with the underside of the support substrate facing upwards; and at least partial removal of the substrate from the layer structure by etching, while the thin-film battery element is protected by the protective layer. [21] Electronic unit comprising an electronic component and a stacked battery structure, wherein the stacked battery structure comprises: a base substrate; two or more battery layers on the base substrate; and a wiring layer for connecting the stacked battery structure to the electronic component; where each battery layer has: a protective layer; a thin-film battery element formed on the protective layer, wherein the thin-film battery element is used to supply power to the electronic component through the wiring layer; and an insulator that covers the thin-film battery element; wherein the battery layers are stacked in reverse with respect to the base substrate, so that each insulator is on one side of the base substrate, each protective layer is on one side opposite the side of the base substrate, and the insulator of an upper battery layer connects with a lower battery layer. [22] Electronic unit according to claim 21, wherein the stacked battery structure is mounted on a wiring substrate, the wiring layer is provided as part of the wiring substrate and the electronic component is mounted on the wiring substrate or the stacked battery structure acts as a substrate on which the electronic component is mounted. [23] Method for manufacturing a stacked battery structure comprising: Placing a battery layer formed on a support substrate onto a base substrate, wherein the underside of the support substrate is facing upwards, the battery layer comprising a protective layer formed on the support substrate, a thin-film battery element formed on the protective layer, and an insulator covering the thin-film battery element; and at least partial removal of the carrier substrate from the battery layer by etching, while the thin-film battery element is protected by the protective layer. [24] Method for manufacturing a stacked structure, wherein the method comprises: Preparing a base substrate; Producing a unit element layer formed on a support substrate, wherein the unit element layer comprises a protective layer formed on the support substrate, a unit element formed on the protective layer, and an adhesive material covering the unit element; Placing the unit element layer on the base substrate with the underside of the support substrate facing upwards; and Etching of the support substrate from the underside of the support substrate until the protective layer of the unit element layer is reached. [25] Method according to claim 24, wherein the method further comprises alternating repetition until a desired number of unit element layers are stacked: a stacking of an additional unit element layer formed on a further support substrate, wherein the underside of the further support substrate is facing upwards; and a removal of the further support substrate from the additional unit element layer by etching.