Hermetic packaging of microbattery devices

Abstract

The present invention relates to a hermetic package of a microbattery device. A method for manufacturing a microbattery is provided. The method includes forming a microbattery device by forming a first metal anode via and a first metal cathode via in a first substrate, forming a first metal layer on the bottom side of the first substrate, forming a first battery element on the top side of the substrate, forming an encapsulation layer around the first battery element, forming grooves through the encapsulation layer and the first substrate on different sides of the first battery element, and forming a metal sealing layer in the groove to at least cover multiple sidewall surfaces of the first battery element. The metal sealing layer is electrically connected to the battery element through the first metal layer and the first metal cathode via.

Description

Technical Field

[0001] The present disclosure relates to microbatteries, and in particular to a hermetic sealing structure (ie, packaging) of a microbattery using a metal seal. Background Art

[0002] A hermetic seal of a microbattery device may be desirable to prevent or minimize the possibility of leakage of battery material outside the battery package. In some microbattery devices, the sealing of the microbattery is achieved using a polymer material, which may not be sufficient to achieve hermeticity. In addition, some sealing structures for microbattery devices may include a metal sealing layer. However, the metal sealing layer may not hermetically seal all sides of the microbattery device, which may allow a path for leakage from one or more sides of the microbattery device. In addition, some microbattery devices include an anode and a cathode on the same side of the device, which may complicate the parallel or series connection of multiple microbattery devices. Summary of the invention

[0003] Some embodiments of the present disclosure relate to a method for manufacturing a microbattery device. In some embodiments, the method includes forming a microbattery device by forming a first metal anode via and a first metal cathode via in a first substrate, forming a first metal layer on the bottom side of the first substrate, forming a first battery element on the top side of the substrate, forming an encapsulation layer around the first battery element, forming grooves through the encapsulation layer and the first substrate on different sides of the first battery element, and forming a metal sealing layer in the groove to cover at least a plurality of sidewall surfaces of the first battery element. The metal sealing layer is electrically connected to the battery element through the first metal layer and the first metal cathode via.

[0004] Some other embodiments relate to a microbattery device, including a first microbattery device, the first microbattery device including a first substrate. The first substrate includes a first metal anode via and a first metal cathode via. The first microbattery device also includes a first battery element formed on the substrate, the first battery element including a first cathode current collector, a first anode current collector, a first cathode and a first anode. The first cathode current collector is electrically connected to the first cathode through the first metal cathode via, wherein the first anode current collector is electrically connected to the first anode through the first metal anode via. The metal sealing layer is formed at least on the sidewall surface of the first battery element, and the metal sealing layer is electrically connected to the first cathode.

[0005] Some other embodiments relate to a microbattery device including a microbattery device. The microbattery device includes a first substrate, the first substrate including a first metal anode via and a first metal cathode via. A first battery element is formed on the first substrate, the first battery element including a first cathode current collector, a first anode current collector, a first cathode and a first anode. The first cathode current collector is electrically connected to the first cathode through the first metal cathode via, and the first anode current collector is electrically connected to the first anode through the first anode via. A second substrate is formed on the first battery element and includes a second metal anode via and a second metal cathode via. A second battery element is formed on the second substrate, the second battery element including a second cathode current collector, a second anode current collector, a second cathode and a second anode. The second cathode current collector is electrically connected to the second cathode through the second cathode via, and the second anode current collector is electrically connected to the second anode through the second anode via. The microbattery device also includes a metal interconnect that electrically connects the first anode to the second anode, and a metal sealing layer formed on the sidewall surfaces of the first battery element and the second battery element. The metal sealing layer is electrically connected to the first cathode and the second cathode.

[0006] The above summary is not intended to describe each illustrated embodiment or every implementation of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The accompanying drawings included in this application are incorporated into the specification and form a part of the specification. They illustrate embodiments of the present disclosure and together with the specification explain the principles of the present disclosure. The accompanying drawings only illustrate certain embodiments and do not limit the present disclosure.

[0008] Figure 1A is a cross-sectional view depicting a microbattery device at an intermediate stage in the manufacturing process according to an embodiment.

[0009] Figure 1B According to the embodiment Figure 1A Cross-sectional view of a microbattery device after additive manufacturing operations.

[0010] Figure 1C According to the embodiment Figure 1B Cross-sectional view of a microbattery device after additive manufacturing operations.

[0011] Figure 1D According to the embodiment Figure 1C Cross-sectional view of a microbattery device after additive manufacturing operations.

[0012] Figure 1E According to the embodiment Figure 1D Cross-sectional view of a microbattery device after additive manufacturing operations.

[0013] Figure 1F According to the embodiment Figure 1E Cross-sectional view of a microbattery device after additive manufacturing operations.

[0014] Figure 1G According to the embodiment Figure 1F Cross-sectional view of a microbattery device after additive manufacturing operations.

[0015] Figure 1H According to the embodiment Figure 1G Cross-sectional view of a microbattery device after additive manufacturing operations.

[0016] Fig. 1I According to the embodiment Figure 1H Cross-sectional view of a microbattery device after additive manufacturing operations.

[0017] Figure 1J is electrically connected in series according to an embodiment Fig. 1I Cross-sectional views of several microbattery devices in the microbattery device.

[0018] Figure 1K is electrically connected in parallel according to an embodiment Fig. 1I Cross-sectional views of several microbattery devices in the microbattery device.

[0019] Figure 2A is a cross-sectional diagram depicting a single layer of a multi-layer microbattery device at an intermediate stage in the manufacturing process according to an embodiment.

[0020] Figure 2B According to an embodiment, Figure 2A Cross-sectional view of a single-layer multilayer microbattery device after the additive manufacturing operation.

[0021] Figure 2C According to the embodiment Figure 2B Cross-sectional view of a microbattery device after additive manufacturing operations.

[0022] Figure 2D According to the embodiment Figure 2C Cross-sectional view of a multilayer microbattery device after an additive manufacturing operation.

[0023] Figure 2E According to the embodiment Figure 2D Cross-sectional view of a multilayer microbattery device after an additive manufacturing operation.

[0024] Figure 2F According to the embodiment Figure 2E Cross-sectional view of a multilayer microbattery device after an additive manufacturing operation.

[0025] Figure 2G is electrically connected in series according to an embodiment Figure 2F Cross-sectional view of several microbattery devices in a multilayer microbattery device.

[0026] Figure 3A is a cross-sectional view depicting a first single layer of a multi-layer microbattery device at an intermediate stage of the manufacturing process according to an embodiment.

[0027] Figure 3B According to the embodiment Figure 3A Cross-sectional view of the second single layer of a multilayer microbattery device.

[0028] Figure 3C According to the embodiment Figure 3A and Figure 3B Cross-sectional view of the combination of the first layer and the second layer of the microbattery device after the additive manufacturing operation.

[0029] Figure 3D According to the embodiment Figure 3C Cross-sectional view of a multilayer microbattery device after an additive manufacturing operation.

[0030] Figure 3E According to the embodiment Figure 3D Cross-sectional view of a multilayer microbattery device after an additive manufacturing operation.

[0031] Figure 3F According to the embodiment Figure 3E Cross-sectional view of a multilayer microbattery device after an additive manufacturing operation.

[0032] It should be appreciated that elements in the drawings are illustrated for simplicity and clarity. For simplicity and to aid understanding of the illustrated embodiments, well-known elements that may be useful or necessary in a commercially feasible embodiment may not be depicted. DETAILED DESCRIPTION

[0033] The present disclosure describes embodiments of a microbattery device including a metal hermetic sealing layer and a method of manufacturing the microbattery device.The drawings of the present application are provided for illustrative purposes and therefore may not be drawn to scale.

[0034] Various embodiments of the present disclosure are described herein with reference to the relevant drawings. Alternative embodiments may be designed without departing from the scope of the present disclosure. Note that various connections and positional relationships (e.g., above, below, adjacent, etc.) are described between the elements in the following description and drawings. Unless otherwise specified, these connections and / or positional relationships may be direct or indirect, and the present disclosure is not intended to be limited in this regard. Therefore, the coupling of entities may refer to direct or indirect coupling, and the positional relationship between entities may be a direct or indirect positional relationship. As an example of an indirect positional relationship, the formation of layer "A" above layer "B" mentioned in this specification includes a situation where one or more intermediate layers (e.g., layer "C") are located between layer "A" and layer "B", as long as the relevant characteristics and functions of layer "A" and layer "B" are not substantially changed by the intermediate layer.

[0035] The following definitions and abbreviations are used to interpret the claims and specification. As used herein, the terms "comprises," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, mixture, process, method, article, or apparatus that includes a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, mixture, process, method, article, or apparatus.

[0036] For the purposes of the description below, the terms "upper", "lower", "right", "left", "vertical", "horizontal", "top", "bottom" and their derivatives shall refer to the described structures and methods as oriented in the accompanying drawings. The terms "overlying", "on top of", "positioned on", or "positioned on top of" indicate that a first element (e.g., a first structure) is present on a second element (e.g., a second structure), wherein intermediate elements (e.g., an interface structure) may be present between the first element and the second element. The term "direct contact" means that a first element (e.g., a first structure) and a second element (e.g., a second structure) are connected at the interface of the two elements without any intermediate conductive layer, insulating layer, or semiconductor layer. It should be noted that the term "selective to", such as "a first element selective to a second element", means that the first element can be etched and the second element can act as an etch stop layer.

[0037] For the sake of brevity, conventional techniques related to microbattery device and / or integrated circuit (IC) fabrication may or may not be described in detail herein. In addition, the various tasks and process steps described herein may be incorporated into a more comprehensive program or process having additional steps or functionality not described in detail herein. In particular, the various steps in the fabrication of microbattery devices and / or ICs are well known, and therefore, for the sake of brevity, many conventional steps will only be briefly mentioned herein or will be omitted entirely without providing well-known process details.

[0038] Typically, the various processes used to form microbattery devices fall into four general categories, namely, film deposition, removal / etching / laser milling, patterning / lithography, and injection molding welding (IMS).

[0039] Deposition is any process that grows, coats or otherwise transfers a material onto a wafer. Available techniques include physical vapor deposition (PVD), chemical vapor deposition (CVD), electrochemical deposition (ECD), molecular beam epitaxy (MBE), and more recently atomic layer deposition (ALD) and spin coating, among others. Another deposition technique is plasma enhanced chemical vapor deposition (PECVD), which is a process that uses the energy within a plasma to initiate a reaction on the wafer surface that would otherwise require the higher temperatures associated with conventional CVD. High energy ion bombardment during PECVD deposition can also improve the electrical and mechanical properties of the film.

[0040] Removal / etching is any process that removes material from a wafer. Examples include etching processes (wet or dry), chemical mechanical planarization (CMP), laser milling, etc. An example of a removal process is ion beam etching (IBE). Generally, IBE (or milling) refers to a dry plasma etching method that utilizes a remote broad beam ion / plasma source to remove substrate material by means of physically inert gases and / or chemically reactive gases. Similar to other dry plasma etching techniques, IBE has advantages such as etching rate, anisotropy, selectivity, uniformity, aspect ratio, and minimized substrate damage. Another example of a dry removal process is reactive ion etching (RIE). Generally, RIE uses a chemically reactive plasma to remove material deposited on a wafer. With RIE, a plasma is generated at low pressure (vacuum) by an electromagnetic field. High energy ions from the RIE plasma attack the wafer surface and react with it to remove material. Laser milling or laser beam machining (LBM) is a form of machining in which a laser is directed toward a workpiece for machining. The process uses thermal energy to remove material from a metal or non-metal surface. High-frequency monochromatic light on the surface of an object causes that material to melt and evaporate, allowing that portion of the object to be selectively removed.

[0041] Photolithography is the process of forming a three-dimensional relief image or pattern on a substrate so that the pattern can be subsequently transferred to the substrate. In photolithography, the pattern is formed from a photosensitive polymer called a photoresist. The photolithography and etching pattern transfer steps are repeated many times to build the complex structures that make up an electronic device. Each pattern printed on the wafer is aligned with the previously formed pattern, and conductors, insulators, and other areas are gradually built up to form the final device.

[0042] Turning now to an overview of the technology more specifically related to aspects of the present disclosure, in certain embodiments, injection molding soldering (IMS) is utilized to form a metal hermetic seal structure for a microbattery. Generally, IMS refers to a metal deposition process in which molten solder is injected directly into a hole (or space) (e.g., as patterned in a photoresist mask film), as opposed to conventional electroplating techniques. For example, an IMS deposition head provides molten solder (e.g., SAC305, which is a lead-free alloy containing 96.5% tin, 3% silver, and 0.5% copper) on one side of a patterned wafer and is then scanned to the other side of the wafer to complete the injection of the solder into the hole (or space) therein.

[0043] Now refer to the accompanying drawings Figures 1A-1K , wherein the same reference numerals represent the same or similar elements, and reference is first made to Figure 1A , showing a cross-sectional view of a portion of a microbattery 100 at an intermediate stage of the manufacturing process. As shown in FIG. 1 , a bottom substrate or first substrate 102 is provided. The first substrate 102 can be a flexible substrate. A via 104 is formed into the first substrate 102 and then filled with a conductive metal material. An anode current collector 106 is formed on the left via in the via 104. The anode current collector 106 can be a single layer or a multilayer. In one example, the anode current collector 106 includes at least one conductive metal material, such as titanium or platinum. In one embodiment of the present application, the anode current collector 106 is composed of titanium. In other embodiments, the anode current collector 106 includes any metal, such as nickel, copper, or zinc. The anode current collector may have a thickness of 10nm to 20,000nm, or any other suitable thickness.

[0044] Reference now Figure 1B , a first metal layer 108 is formed on the back side (or bottom side) of the first substrate 102. The first metal layer 108 includes at least a portion located on the left side of the first substrate 102, wherein at least a portion thereof is located on the left side of the anode current collector 106. The first metal layer 108 also includes a portion located on the right side of the first substrate 102 and formed to be in direct contact with the right side via hole in the via hole 104.

[0045] Reference now Figure 1C , the anode 110 is also formed on the bottom side of the first substrate 102 and is electrically connected to the anode current collector 106 through the left via in the via 104. The anode 110 can be a single layer or a multilayer. In one example, the anode 110 is composed of a material stack of a titanium layer, a nickel layer on the surface of the titanium layer, and a zinc layer on the surface of the nickel layer (i.e., a Ti / Ni / Zn stack).

[0046] Reference now Figure 1D, the rest of the microbattery device 100 is manufactured. The battery element 112 is formed to cover the entire anode current collector 106 and also cover a portion of the first substrate 102. It should be understood that the battery element 112 may include any suitable number of layers or other battery components. The cathode current collector 114 is formed to cover the entire battery element 112 and also cover a portion of the first substrate 102. In particular, the cathode current collector 114 directly contacts the right-side via in the via 104, thereby creating a conductive path from the cathode current collector 114 to the right-side via in the via 108 and to the right portion of the first metal layer 108. An encapsulation layer 116 is formed to cover the cathode current collector 114 and all other exposed portions of the substrate. In some embodiments, the encapsulation layer 116 is an insulating material. Finally, a second substrate 118 is formed to cover the encapsulation layer 116. The second substrate 118 may be made of the same material as the first substrate 102 or a different material, and may include several sublayers. At this stage of the manufacturing process, the left portion of first metal layer 108 is not electrically connected to any other portion of microbattery 100 device.

[0047] Now refer to Figure 1E , an adhesive layer 120 is formed on the bottom side of the first substrate 102, and a handle substrate 122 is stacked on the adhesive layer. Both the adhesive layer 120 and the handle substrate 122 are temporary structures that facilitate further fabrication of the device and will be removed later, as described in detail below.

[0048] Reference now Figure 1F The trench 150 is formed, for example, by a laser milling process using the first metal layer 108 as a stop layer (ie, the stop layer is removed when the laser reaches the first metal layer 108).

[0049] Reference now Figure 1G , the metal seal 124 is formed to fill the groove 150 and is formed on top of the second substrate 118. Therefore, the metal seal 124 covers and hermetically seals the entire side surface and the top surface of the microbattery 100 device. In some embodiments, the metal seal 124 is formed by injection molding welding (IMS), which is a metal deposition process in which molten solder is directly injected into the groove 150. Figure 1G108, thereby creating a conductive path from cathode current collector 114 to right side via 104, to the right side of first metal layer 108, through metal seal 124, and finally to the left side of first metal layer 108. The cathode can be considered to include the right and left sides of first metal layer 108 and metal seal 124. Therefore, the top of metal seal 124 (i.e., the portion covering second substrate 118) serves as the cathode on the top side of microbattery 100, and anode 110 is on the bottom side of microbattery 100. Having the cathode and anode on opposite sides of microbattery 100 can facilitate less complex series connection of multiple microbatteries 100, as described below with respect to Figure 1J Detailed description, and also facilitates less complex parallel connection of multiple microbatteries 100, as described below with respect to Figure 1K Described in detail.

[0050] Reference now Figure 1H , remove the handle substrate 122 and the adhesive layer 120, and then form a first insulator layer 126 on the bottom side of the first substrate 102. In some embodiments, a laser ablation process or an etching process can be used to remove the adhesive layer 120 and the handle substrate 122. In some embodiments, the first insulator layer 126 can be composed of an insulating polymer material and electrically separates the anode side of the microbattery 100 from the cathode side of the microbattery 100. For example, the insulating material of the first insulator layer 126 is located between the right portion of the first metal layer 108 (i.e., it can be used as a part of the cathode) and the anode 110. Figure 1H As shown, the first insulator layer 126 is formed thick enough to cover all exposed surfaces of the first metal layer 108 while still leaving the bottom surface side of the anode 110 exposed. In some embodiments, the thickness of the anode 110 is thicker than the first insulating layer 120.

[0051] Reference now Fig. 1I , showing the microbattery 100 structure after singulation. Typically, where multiple microbatteries are manufactured on a common substrate, singulation refers to the process of separating or dividing these devices into individual microbatteries. In certain embodiments, singulation includes removing portions of the first substrate 102, encapsulation layer 116, second substrate 118, first metal layer 108, and first insulator layer 126 outside the metal seal 124 (i.e., the left and right sides of the metal seal 124) to provide the microbattery 100. In one embodiment, a laser milling process may be used to perform singulation. In another embodiment, sawing is used to separate the individual microbattery 100 devices.

[0052] Reference now Figure 1J, three different microbatteries 100-1, 100-2, and 100-3 are shown connected in series. In this example for a series battery connection, the first metal layer 108-1 of microbattery 100-1 may be connected to the anode 110-3 (not shown) of microbattery 100-3. In some embodiments, the anode 110-1 of the first microbattery 100-1 contacts the upper portion of the metal seal 124-2 of the second microbattery 100-2. Although for simplicity in FIG. Figure 1J Not shown in FIG. 1 , but the same type of series electrical connection occurs between second microbattery 100 - 2 and third microbattery 100 - 3 .

[0053] Reference now Figure 1K , three different microbatteries 100-1, 100-2, and 100-3 are shown connected in parallel. In this example for a parallel battery connection, an electrical connection (not shown) for the cathode may be made through any of the first metal layer 108-1 of microbattery 100-1, the first metal layer 108-2 of microbattery 100-2, and the first metal layer 108-3 of microbattery 100-3, as they are all electrically connected through the corresponding metal seals 124-1, 124-2, and 12403. In addition, an electrical connection (not shown) may be required to connect all three anodes 110-1, 110-2, and 110-3 in the parallel battery circuit. In some embodiments, the metal seal 124-1 of the first microbattery 100-1 contacts the left portion of the metal seal 124-2 of the second microbattery 100-2, although for simplicity in FIG. Figure 1K Not shown in FIG. 1 , but the same type of parallel electrical connection occurs between second microbattery 100 - 2 and third microbattery 100 - 3 .

[0054] Reference now Figure 2A-2G , first refer to Figure 2A , an embodiment of a two-layer integrated solid-state microbattery 250 is shown. Figure 2A The illustrated single-layer microbattery 200 is shown at an intermediate stage in the fabrication process and is similar in most respects to the Figure 1D The microbattery 100 shown is similar. Therefore, for these embodiments, the detailed description will not be repeated. Figures 1A-1D Description of the manufacturing steps. Figure 2A The micro battery stack 200 and Figure 1D One difference between micro batteries is that they do not include Figure 1D Another difference is that it includes a second substrate 118. Figure 2A A polymer insulator layer 126 is provided in the embodiment of the present invention. Figure 2A The polymer insulator layer in Figure 1HThis slightly modified structure of the single-layer microbattery stack 200 allows the connection of two different battery stacks, as described below with respect to Figure 2B as described.

[0055] Reference now Figure 2B , the first microbattery stack 200-A is joined with the second microbattery stack 200-B to form a microbattery 250 device. The first microbattery stack 200-A includes a first battery stack substrate 102-A, a first battery stack via 104-A, a first battery stack anode current collector 106-A, a first battery stack metal layer 108-A, a first battery stack anode 110-A, a first battery stack battery element 112-A, a first battery stack cathode current collector 114-A, a first battery stack encapsulation layer 116-A, and a first battery stack insulation layer 126-A. Similarly, the second microbattery stack 200-B includes a second battery stack substrate 102-B, a second battery stack via 104-B, a second battery stack anode current collector 106-B, a second battery stack metal layer 108-B, a second battery stack anode 110-B, a second battery stack battery element 112-B, a second battery stack cathode current collector 114-B, a second battery stack encapsulation layer 116-B and a second battery stack insulation layer 126-B.

[0056] like Figure 2B As shown, the first battery stack 200-A is inverted (i.e., turned upside down) relative to the second battery stack 200-B, so that the first battery stack encapsulation layer 116-A is formed in direct contact with the second battery stack encapsulation layer 116-B, however, it should be understood that other layers (e.g., adhesive layers) may be formed between the first battery stack encapsulation layer 116-A and the second battery stack encapsulation layer 116-B. In addition, in some embodiments, the first battery stack metal layer 108-A is patterned slightly differently than the second battery stack metal layer 108-B. In this regard, there is a first opening 202 in the first battery stack metal layer 108-A to allow for subsequent laser milling operations, as described below with respect to Figure 2D discussed.

[0057] Reference now Figure 2C , a handling substrate 122 is attached to the first battery stack 200-B via an adhesive layer 120. The handling substrate 122 may be Figures 1A-1K The same type or different types of substrates as discussed in the embodiments.

[0058] Reference now Figure 2D, the groove 202 is formed by, for example, a laser milling process using the second battery stack metal layer 108-B as a stop layer (i.e., the stop layer removal occurs when the laser reaches the second battery stack metal layer 108-B). It should be understood that because the opening 202 is provided in the first battery stack metal layer 108-A, the first battery stack metal layer 108-A is not an obstacle to the laser milling process. Therefore, the laser milling removes all the material of the first battery stack 200-A and the second battery stack 200-B down to the level of the second battery stack metal layer 108-B.

[0059] Reference now Figure 2E , the metal seal 204 is formed to fill the groove 202. Therefore, the metal seal 204 covers and hermetically seals the entire side surface of the first battery stack 200-A and the second battery stack 200-B. In some embodiments, the metal seal 204 is formed by injection molding welding (IMS), in which molten solder is directly injected into the groove 202. Figure 2E As shown, the metal seal 204 provides a conductive path to connect the right side of the first battery stack metal layer 108-A with the right side of the second battery stack metal layer 108-B. For this example of a parallel battery connection in which the cathodes 108A and 108B are electrically connected and the anodes 110A and 110B are connected in parallel, the same voltage but increased storage capacity is obtained when compared to a single battery. In addition, the metal seal 204 provides a conductive path to connect the perimeter / left / anode electrical connection in this example of the first battery stack metal layer 108-A with the perimeter / left / anode electrical connection of the second battery stack metal layer 108-B. As also shown Figure 2E As shown, a second opening 206 is formed into the first cell stack insulating layer 126 -A to expose the first cell stack anode 110 -A.

[0060] Reference now Figure 2F , handle substrate 122 and adhesive layer 120 are removed to expose second battery stack anode 110 -B. Additionally, singulation is performed to produce individual microbattery 250 devices.

[0061] Reference now Figure 2G, showing three different microbatteries 250-1, 250-2, and 250-3 connected. Depending on the target application, the stacked battery structure of two tall cells and the associated interconnections between the cells can be used in parallel for the same voltage, but with a larger storage capacity (e.g., both cathodes are connected to external wires, and both anodes are connected to external wires), or in series for a higher voltage with the same capacity (e.g., the external wire is connected to the cathode of the first cell, the anode of the first cell is connected to the cathode of the second cell, and the anode of the second cell is connected to the external wire). Similarly, for multiple tall cells, such as three or four or more cells, the structure for integration and interconnection can allow the structure of the microbattery to be used for multiple cells in parallel, multiple cells in series, or a combination of series and parallel configurations. In some embodiments, for example for battery stacks interconnected in parallel, battery stack anode 110-B of first microbattery 250-1 contacts battery stack anode 110-A of second microbattery 250-2, and the second cathode contact (i.e., first metal layer 108) of first microbattery 250-1 contacts battery stack cathode (i.e., first metal layer 108) of second microbattery 250-2. Figure 2G 2, but the same type of parallel electrical connection occurs between the second microbattery 250-2 and the third microbattery 250-3. Alternatively, the series interconnected stack of microbatteries can also be constructed with interconnections from cathode to anode between the first microbattery 250-1 and the second microbattery 250-2, and from cathode to anode between the second microbattery 250-2 and the third microbattery 250-3.

[0062] Reference now Figures 3A-3F , first refer to Figure 3A and 3B , showing an embodiment of a two-layer integrated solid-state microbattery. Figure 3A and 3B The microbatteries 300-A and 300-B shown in FIG. 1 , respectively, are shown at an intermediate stage in the manufacturing process and are similar in most respects to the microbatteries 300-A and 300-B shown in FIG. 1 . Figure 1C Therefore, for these embodiments, the detailed description of the microbattery 100 will not be repeated. Figures 1A-1C The microbattery stacks 300-A and 300-B are Figure 1COne difference between the microbatteries 100 of FIG. 1 and FIG. 2 is that the anodes and anode current collectors are of different sizes and relative positions. In particular, the first battery stack anode 110-A and the second battery stack anode 110-B are larger than the first battery stack anode current collector 106-A and the second battery stack anode current collector 106-B, respectively, and / or extend further to the left relative to the leftmost side of the first battery stack anode current collector 106-A and the second battery stack anode current collector 106-B, respectively. This slightly modified structure of the microbattery stacks 300-A and 300-B allows for the connection of two different battery stacks, as described below with respect to FIG. Figure 3C In addition, Figure 3B As shown, metal interconnect 302 is formed to pass through second battery stack substrate 102-B and contact second battery stack anode 110-B. In addition, the entire metal interconnect 302 is formed to the left of the leftmost of first battery stack anode current collector 106-A and second battery stack anode current collector 106-B.

[0063] Reference now Figure 3C , the first microbattery stack 300-A is joined to the second microbattery stack 300-B to form a microbattery 350. The first microbattery stack 300-A includes a first battery stack substrate 102-A, a first battery stack via 104-A, a first battery stack anode current collector 106-A, a first battery stack metal layer 108-A, a first battery stack anode 110-A, a first battery stack battery element 112-A, a first battery stack cathode current collector 114-A, a first battery stack encapsulation layer 116-A and a first battery stack insulation layer 304. Somewhat similarly, second microbattery stack 200-B includes second battery stack substrate 102-B, second battery stack via 104-B, second battery stack anode current collector 106-B, second battery stack metal layer 108-B, second battery stack anode 110-B, second battery stack battery element 112-B, second battery stack cathode current collector 114-B, and second battery stack encapsulation layer 116-B. Figure 3C As shown, the top substrate 306 is formed on the top side of the first battery stack 300-A (ie, formed on the first battery stack encapsulation layer 116-A). Figure 3B The depicted metal interconnect 302 extends all the way to the lower surface of the first battery stack anode 110-A, thereby electrically connecting the first battery stack anode 110-A to the second battery stack anode 110-B. This configuration allows for stacked microbatteries with parallel connections of microbatteries having anode to anode interconnections and cathode to cathode interconnections.

[0064] Although not shown in the figure, a shift in the position of the first metal layer 108, vias 104, anode vias (i.e., metal interconnects 302), and anodes 110 (i.e., pads) in a stack of two or more cells can allow anode-to-cathode connections in a stack of microbatteries. This type of connection can provide a series interconnected battery configuration, along with electrical interconnection that avoids contact with the peripheral interconnect (i.e., trench 308 to the first metal layer 108) by means of a dielectric layer (or by lack of cathode connection to a metal seal).

[0065] Reference now Figure 3D , the trench 308 is formed, for example, by a laser milling process using the second battery stack metal layer 108-B as a stop layer (i.e., the stop layer is removed when the laser reaches the second battery stack metal layer 108-B). Thus, the laser milling removes all material of the first battery stack 300-A and the second battery stack 300-B down to the level of the second battery stack metal layer 108-B.

[0066] Reference now Figure 3E , a metal seal 310 is formed to fill the groove 308 and to be formed on top of the top substrate 306. Thus, the metal seal 310 covers and hermetically seals the entire side surface and top surface of the multi-stack microbattery 350 device. In some embodiments, the metal seal 310 is formed by injection molding welding (IMS), in which molten solder is directly injected into the groove 308. Figure 3E As shown, the metal seal 310 contacts the right and left sides of the first battery stack metal layer 108-A and the second battery stack metal layer 108-B. Therefore, the metal seal 310 electrically connects the first battery stack cathode current collector 114-A to the second battery stack cathode current collector 114-B. It can be considered that the cathode includes the right and left sides of the first battery stack metal layer 108-A and the second battery stack metal layer 108-B and the metal seal 310. Therefore, the top of the metal seal 310 (i.e., the portion covering the top substrate 306) serves as the cathode on the top side of the multi-stack microbattery 350, and the exposed portion of the anode (i.e., the second battery stack anode 110-B) is located on the bottom side of the microbattery 350. Having the cathode and anode located on opposite sides of the microbattery 350 can facilitate less complex series connection of multiple microbatteries 350, similar to the above description of Figure 1J As described in detail.

[0067] Reference now Figure 3F, singulation is performed to produce a plurality of individual microbatteries 350, and a polymer insulating layer 126-B is disposed between the second battery stack anode 110-B and the second battery stack metal layer 108-B to electrically isolate the anode and cathode. The singulation process is similar to that described above with respect to Figures 1A-1K and Figure 2A-2G As described in the embodiments.

[0068] The metal seals of the various embodiments described above provide an airtight seal for multiple sides (i.e., sidewalls and top sides) of the microbattery device. The metal sealed package enables the battery device to have higher mechanical strength while allowing a smaller seal width (e.g., a width of less than 30 μm for the sidewalls of the metal seal). This results in a smaller form factor relative to existing microbattery devices. In addition, by providing the anode and cathode on different sides of the microbattery device (e.g., the top and bottom sides), this allows for simplified series / parallel connection of multiple batteries. In addition, the airtight metal seal can achieve a longer shelf life of the microbattery (e.g., less than 3% energy loss per year).

[0069] The description of various embodiments has been presented for the purpose of illustration and is not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, practical applications, or technical improvements over technologies found on the market, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A microbattery device, comprising: A first microbattery device comprising: a first substrate including a first metal anode via and a first metal cathode via, a first battery element formed on the first substrate, the first battery element comprising a first cathode current collector, a first anode current collector, a first cathode and a first anode, wherein the first cathode current collector is electrically connected to the first cathode through the first metal cathode via, and wherein the first anode current collector is electrically connected to the first anode through the first metal anode via, and A metal sealing layer is formed at least on a side wall surface and a top surface of the first battery element, wherein the metal sealing layer is electrically connected to the first cathode.

2. The microbattery device according to claim 1, further comprising: an encapsulation layer covering the first cathode current collector; as well as A second substrate covers the encapsulation layer. 3 . The microbattery device according to claim 2 , wherein the encapsulation layer is formed between the sidewall surface of the first battery element and the metal sealing layer, and the second substrate is formed between the top surface of the first battery element and the metal sealing layer.

4. The microbattery device according to claim 1, further comprising: A second microbattery device comprising: a second battery element formed on the first battery element, the second battery element comprising a second cathode current collector, a second anode current collector, a second cathode and a second anode, and a second substrate including a second metal anode via and a second metal cathode via, wherein the second cathode current collector is electrically connected to the second cathode through the second metal cathode via, and wherein the second anode current collector is electrically connected to the second anode through the second metal anode via, wherein the metal sealing layer is formed on the side wall surface of the first battery element and the side wall surface of the second battery element, and The metal sealing layer is electrically connected to the first cathode and the second cathode. 5 . The microbattery device of claim 4 , wherein the second battery element is inverted relative to the first battery element. 6 . The microbattery apparatus according to claim 1 , further comprising a plurality of the first microbattery devices connected in series or in parallel.

7. A microbattery device comprising: A microbattery device comprising: a first substrate including a first metal anode via and a first metal cathode via, a first battery element formed on the first substrate, the first battery element comprising a first cathode current collector, a first anode current collector, a first cathode and a first anode, wherein the first cathode current collector is electrically connected to the first cathode through the first metal cathode via, and wherein the first anode current collector is electrically connected to the first anode through the first metal anode via, a second substrate formed on the first battery element and including a second metal anode via and a second metal cathode via, and a second battery element formed on the second substrate, the second battery element comprising a second cathode current collector, a second anode current collector, a second cathode and a second anode, wherein the second cathode current collector is electrically connected to the second cathode through the second metal cathode via, and wherein the second anode current collector is electrically connected to the second anode through the second metal anode via, a metal interconnect electrically connecting the first anode to the second anode, and A metal sealing layer is formed on side wall surfaces of the first battery element and the second battery element and on a top surface of the second battery element, wherein the metal sealing layer is electrically connected to the first cathode and the second cathode.

8. The microbattery device according to claim 7, further comprising: a first encapsulation layer covering the first cathode current collector, the second substrate being formed on the encapsulation layer; a second encapsulating layer covering the second cathode current collector; as well as A third substrate is formed on the second encapsulation layer.

9. The microbattery device of claim 7, wherein the second battery element is electrically connected in series with the first battery element.

10. The microbattery apparatus according to claim 7, further comprising a plurality of the microbattery devices connected in series or in parallel.

11. A method of manufacturing a microbattery device, the method comprising: A microbattery device is formed by: forming a first metal anode via and a first metal cathode via in the first substrate, forming a first metal layer on a bottom side of the first substrate, forming a first cell element on the top side of the substrate, forming an encapsulation layer around the first battery element, forming grooves through the encapsulation layer and the first substrate on different sides of the first battery element, and A metal sealing layer is formed in the groove and on the top surface of the first battery element to cover at least a plurality of side wall surfaces and the top surface of the first battery element, wherein the metal sealing layer is electrically connected to the battery element through the first metal layer and the first metal cathode via.

12. The method of claim 11, wherein forming the first battery element comprises: forming a first cathode current collector; forming a first cell on the first cathode current collector; forming a first anode current collector on the first battery; wherein the first cathode current collector is electrically connected to the first cathode through the first metal cathode via, and wherein the first anode current collector is electrically connected to the first anode through the first metal anode via.

13. The method of claim 11, further comprising electrically connecting a plurality of the microbattery devices in series. The method of claim 13 , wherein the plurality of microbattery devices are connected in a stacked configuration.

15. The method according to claim 11, further comprising electrically connecting a plurality of said microbattery devices in parallel, Wherein the plurality of microbattery devices are connected in a stacked configuration.

16. The method of claim 11, further comprising forming a plurality of the microbattery devices in a two-dimensional array.

17. The method of claim 16, further comprising separating the microbattery devices from each other using a laser milling singulation process.

Images