Solid-state battery package

Abstract

Provided is a solid-state battery package comprising: a substrate; a solid-state battery that is provided on the substrate; and a covering part that is constituted by at least a covering insulating layer, which is provided so as to cover the solid-state battery, and a covering inorganic layer, which is provided outward of the covering insulating layer, wherein the covering insulating layer has a smoothed surface.

Description

[Technical Field]

[0001] The present invention relates to solid-state battery packages, and more particularly to solid-state batteries packaged in a manner conducive to substrate mounting. [Background technology]

[0002] Secondary batteries that can be repeatedly charged and discharged have been used for a variety of purposes, including as power sources for electronic devices such as smartphones and laptop computers.

[0003] In secondary batteries, a liquid electrolyte is generally used as a medium for ion migration that contributes to charging and discharging. In other words, a so-called electrolytic solution is used in secondary batteries. However, such secondary batteries generally require safety in terms of preventing leakage of the electrolytic solution. In addition, organic solvents and the like used in the electrolytic solution are flammable, so safety is also required in this respect.

[0004] Therefore, research is being conducted into solid-state batteries that use solid electrolytes instead of liquid electrolytes. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 031424 Summary of the Invention [Problem to be solved by the invention]

[0006] Solid-state batteries may be mounted on printed wiring boards or the like together with other electronic components. In this case, the solid-state battery disposed on the substrate may be covered with a covering member including a covering insulating layer to prevent water vapor transmission. The covering member may also have a covering inorganic layer as its outermost layer to further prevent water vapor transmission. However, the present inventors have found that when a covering inorganic layer is provided, if the area corresponding to the interface between the covering insulating layer and the covering inorganic layer includes irregularities, defects due to the irregularities may easily occur in the covering inorganic layer, and the overall function of preventing water vapor transmission may be reduced.

[0007] The present invention has been made in view of the above-mentioned problems, and a main object of the present invention is to provide a solid-state battery package that can further improve the water vapor permeation prevention property. [Means for solving the problem]

[0008] In order to achieve the above object, in one embodiment of the present invention, A substrate; a solid-state battery provided on the substrate; a covering portion including at least an insulating covering layer provided to cover the solid-state battery and an inorganic covering layer provided on the outer side of the insulating covering layer; The covering insulating layer is smoothed, thereby providing a solid-state battery package. [Effects of the Invention]

[0009] The solid state battery package according to one embodiment of the present invention can further improve the water vapor permeation prevention property. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view schematically showing the internal structure of a solid-state battery. [Figure 2]FIG. 2 is a cross-sectional view schematically showing the configuration of a packaged solid-state battery according to one embodiment of the present invention, and is a cross-sectional view schematically showing a partially enlarged cross-sectional view of a smoothed coating insulating layer (a coating insulating layer not including a smoothing layer). [Figure 3] FIG. 3 is a cross-sectional view schematically showing the configuration of a packaged solid-state battery according to one embodiment of the present invention, and is a cross-sectional view schematically showing a coated insulating layer whose surface is smoothed by a smoothing layer. [Figure 4] FIG. 4 is a cross-sectional view schematically showing the configuration of a packaged solid-state battery according to one embodiment of the present invention, and is a cross-sectional view schematically showing, in enlarged form, a coated insulating layer smoothed by a smoothing layer and a coated inorganic layer provided as a plating layer. [Figure 5] FIG. 5 is a cross-sectional view schematically showing the configuration of a packaged solid-state battery according to one embodiment of the present invention. [Figure 6A] FIG. 6A is a cross-sectional view showing a process for manufacturing a solid-state battery package according to one embodiment of the present invention. [Figure 6B] FIG. 6B is a cross-sectional view showing a process for manufacturing a solid-state battery package according to one embodiment of the present invention. [Figure 6C] FIG. 6C is a cross-sectional view showing a process for manufacturing a solid-state battery package according to one embodiment of the present invention. [Figure 6D] FIG. 6D is a cross-sectional view showing a process for manufacturing a solid-state battery package according to one embodiment of the present invention. [Figure 6E] FIG. 6E is a cross-sectional view illustrating a process for manufacturing a solid-state battery package according to one embodiment of the present invention. [Figure 6F] FIG. 6F is a cross-sectional view showing a process for manufacturing a solid-state battery package according to one embodiment of the present invention. [Figure 6G] FIG. 6G is a cross-sectional view showing a process for manufacturing a solid-state battery package according to one embodiment of the present invention. [Figure 7]FIG. 7 is a cross-sectional view schematically showing the configuration of a packaged solid-state battery according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The solid-state battery package of the present invention will be described in detail below. Although the description will be made with reference to the drawings as necessary, the contents shown in the drawings are merely shown as schematic examples for the purpose of understanding the present invention, and the appearance and dimensional ratios may differ from the actual product.

[0012] The term "solid-state battery package" as used herein refers, in a broad sense, to a solid-state battery device configured to protect a solid-state battery from the external environment, and, in a narrow sense, to a solid-state battery device that includes a mountable substrate and protects a solid-state battery from the external environment. Preferably, the solid-state battery package of the present invention is a surface-mount type solid-state battery package that can be surface-mounted.

[0013] The terms "cross-sectional view" or "cross-sectional diagram" used in this specification are based on the shape of the solid-state battery viewed from a direction approximately perpendicular to the stacking direction in the stacking structure (in short, the shape when cut along a plane parallel to the thickness direction of the layers).

[0014] The terms "upper and lower directions" and "left and right directions" used directly or indirectly in this specification correspond to the upper and lower directions and left and right directions in the drawings, respectively. Unless otherwise specified, the same symbols or signs indicate the same members or parts or the same meanings. In a preferred embodiment, the vertical downward direction (i.e., the direction in which gravity acts) can be considered to correspond to the "lower direction" / "bottom side," and the opposite direction can be considered to correspond to the "upper direction" / "top side."

[0015] Furthermore, in this specification, "on" a substrate, film, layer, etc., includes not only a state in which it is in contact with the upper surface of the substrate, film, or layer, but also a state in which it is not in contact with the upper surface of the substrate, film, or layer. In other words, "on" a substrate, film, or layer includes a case in which a new film or layer is formed above the substrate, film, or layer, and / or a case in which another film or layer is interposed between the substrate, film, or layer. Furthermore, "on" does not necessarily mean the upper side in the vertical direction. "On" merely indicates the relative positional relationship of the substrate, film, layer, etc.

[0016] In the present invention, the term "solid-state battery" broadly refers to a battery whose components are made of solids, and in the narrow sense refers to an all-solid-state battery whose components (particularly preferably all components) are made of solids. In a preferred embodiment, the solid-state battery of the present invention is a stacked solid-state battery in which each layer constituting a battery unit is stacked on top of another, and preferably each such layer is made of a sintered body. The term "solid-state battery" encompasses not only so-called "secondary batteries" that can be repeatedly charged and discharged, but also "primary batteries" that can only be discharged. According to a preferred embodiment of the present invention, the "solid-state battery" is a secondary battery. The term "secondary battery" is not overly limited to its name and can also include, for example, an energy storage device. In the present invention, a solid-state battery contained in a package can also be referred to as a "solid-state battery element." In this specification, the term "secondary battery" refers to a battery that can be repeatedly charged and discharged. Therefore, the term "secondary battery" is not overly limited to its name and can also include, for example, an energy storage device.

[0017] The basic structure of the solid-state battery of the present invention will be described below. The structure of the solid-state battery described here is merely an example for understanding the invention and is not intended to limit the invention.

[0018] [Basic structure of solid-state batteries] A solid-state battery has at least positive and negative electrode layers and a solid electrolyte. Specifically, as shown in Fig. 1, a solid-state battery 100 includes a solid-state battery stack including battery constituent units each consisting of a positive electrode layer 110, a negative electrode layer 120, and at least a solid electrolyte 130 interposed therebetween.

[0019] The solid-state battery is not particularly limited, but each of its constituent layers may be formed by firing, and the positive electrode layer, negative electrode layer, solid electrolyte, etc. may form fired layers. Preferably, the positive electrode layer, negative electrode layer, and solid electrolyte are each fired together, and therefore the solid-state battery stack forms a fired body.

[0020] The positive electrode layer 110 is an electrode layer containing at least a positive electrode active material. The positive electrode layer may further contain a solid electrolyte. In a preferred embodiment, the positive electrode layer is made of a sintered body containing at least positive electrode active material particles and solid electrolyte particles. On the other hand, the negative electrode layer is an electrode layer containing at least a negative electrode active material. The negative electrode layer may further contain a solid electrolyte. In a preferred embodiment, the negative electrode layer is made of a sintered body containing at least a negative electrode active material particles and solid electrolyte particles.

[0021] The positive electrode active material and the negative electrode active material are materials involved in the transfer of electrons in a solid-state battery. Charging and discharging are performed by the transfer of electrons caused by the movement (conduction) of ions between the positive electrode layer and the negative electrode layer via the solid electrolyte. Each electrode layer, the positive electrode layer and the negative electrode layer, may be a layer capable of absorbing and releasing lithium ions or sodium ions in particular. In other words, the solid-state battery may be an all-solid-state secondary battery in which charging and discharging of the battery is performed by the movement of lithium ions or sodium ions between the positive electrode layer and the negative electrode layer via the solid electrolyte.

[0022] (Cathode active material) The positive electrode active material contained in the positive electrode layer 110 may be at least one selected from the group consisting of, for example, a lithium-containing phosphate compound having a Nasicon structure, a lithium-containing phosphate compound having an olivine structure, a lithium-containing layered oxide, and a lithium-containing oxide having a spinel structure. An example of a lithium-containing phosphate compound having a Nasicon structure is Li3V2(PO4)3. An example of a lithium-containing phosphate compound having an olivine structure is Li3Fe2(PO4)3, LiFePO4, and / or LiMnPO4. An example of a lithium-containing layered oxide is LiCoO2 and / or LiCo 1 / 3 Ni 1 / 3 Mn 1 / 3 Examples of lithium-containing oxides having a spinel structure include LiMn2O4 and / or LiNi 0.5 Mn 1.5 O4, etc. The type of lithium compound is not particularly limited, and may be, for example, a lithium transition metal composite oxide and / or a lithium transition metal phosphate compound. Lithium transition metal composite oxide is a general term for oxides containing lithium and one or more transition metal elements as constituent elements, and lithium transition metal phosphate compound is a general term for phosphate compounds containing lithium and one or more transition metal elements as constituent elements. The type of transition metal element is not particularly limited, and examples include cobalt (Co), nickel (Ni), manganese (Mn), and iron (Fe).

[0023] The positive electrode active material capable of absorbing and releasing sodium ions may be at least one selected from the group consisting of sodium-containing phosphate compounds having a Nasicon structure, sodium-containing phosphate compounds having an olivine structure, sodium-containing layered oxides, and sodium-containing oxides having a spinel structure. For example, sodium-containing phosphate compounds may include Na3V2(PO4)3, NaCoFe2(PO4)3, Na2Ni2Fe(PO4)3, Na3Fe2(PO4)3, Na2FeP2O7, and / or Na4Fe3(PO4)2(PO2O7), and sodium-containing layered oxides may include NaFeO2.

[0024] In addition, the positive electrode active material may be, for example, an oxide, a disulfide, a chalcogenide, and / or a conductive polymer. The oxide may be, for example, titanium oxide, vanadium oxide, and / or manganese dioxide. The disulfide may be, for example, titanium disulfide and / or molybdenum sulfide. The chalcogenide may be, for example, niobium selenide. The conductive polymer may be, for example, a disulfide, polypyrrole, polyaniline, polythiophene, polyparastyrene, polyacetylene, and / or polyacene.

[0025] (Negative electrode active material) The negative electrode active material contained in the negative electrode layer 120 may be at least one selected from the group consisting of an oxide containing at least one element selected from the group consisting of titanium (Ti), silicon (Si), tin (Sn), chromium (Cr), iron (Fe), niobium (Nb), and molybdenum (Mo), a carbon material such as graphite, a graphite-lithium compound, a lithium alloy, a lithium-containing phosphate compound having a Nasicon structure, a lithium-containing phosphate compound having an olivine structure, and a lithium-containing oxide having a spinel structure. An example of a lithium alloy is Li-Al. An example of a lithium-containing phosphate compound having a Nasicon structure is Li3V2(PO4)3 and / or LiTi2(PO4)3. An example of a lithium-containing phosphate compound having an olivine structure is Li3Fe2(PO4)3 and / or LiCuPO4. An example of a lithium-containing oxide having a spinel structure is Li4Ti5O. 12 etc.

[0026] In addition, the negative electrode active material capable of absorbing and releasing sodium ions may be at least one selected from the group consisting of sodium-containing phosphate compounds having a Nasicon structure, sodium-containing phosphate compounds having an olivine structure, and sodium-containing oxides having a spinel structure.

[0027] In the solid-state battery, the positive electrode layer and the negative electrode layer may be made of the same material, or may be made of different materials.

[0028] The positive electrode layer and / or the negative electrode layer may contain a conductive material, which may be at least one selected from the group consisting of metal materials such as silver, palladium, gold, platinum, aluminum, copper, and nickel, as well as carbon.

[0029] Furthermore, the positive electrode layer and / or the negative electrode layer may contain a sintering aid, such as at least one selected from the group consisting of lithium oxide, sodium oxide, potassium oxide, boron oxide, silicon oxide, bismuth oxide, and phosphorus oxide.

[0030] There are no particular limitations on the thickness of the positive electrode layer and the negative electrode layer, but for example, they may each independently be 2 μm or more and 50 μm or less, particularly 5 μm or more and 30 μm or less.

[0031] (Positive electrode current collecting layer / Negative electrode current collecting layer) Although not essential elements of the electrode layer, the positive electrode layer and the negative electrode layer may each include a positive electrode current collector layer and a negative electrode current collector layer. The positive electrode current collector layer and the negative electrode current collector layer may each be in the form of a foil. However, if greater emphasis is placed on improving electronic conductivity through co-firing, reducing the manufacturing cost of the solid-state battery, and / or reducing the internal resistance of the solid-state battery, the positive electrode current collector and the negative electrode current collector may each be in the form of a sintered body. The positive electrode current collector constituting the positive electrode current collector and the negative electrode current collector constituting the negative electrode current collector are preferably made of a material with high conductivity, such as silver, palladium, gold, platinum, aluminum, copper, and / or nickel. The positive electrode current collector and the negative electrode current collector may each have an electrical connection portion for electrical connection to the outside and may be configured to be electrically connectable to an end electrode. Note that when the positive electrode current collector and the negative electrode current collector are in the form of a sintered body, they may be composed of a sintered body containing a conductive material and a sintering aid. The conductive materials contained in the positive electrode current collecting layer and the negative electrode current collecting layer may be selected from, for example, the same materials as the conductive materials that may be contained in the positive electrode layer and the negative electrode layer. The sintering aids contained in the positive electrode current collecting layer and the negative electrode current collecting layer may be selected from, for example, the same materials as the sintering aids that may be contained in the positive electrode layer and the negative electrode layer. As described above, the positive electrode current collecting layer and the negative electrode current collecting layer are not essential for a solid-state battery, and a solid-state battery that does not include such a positive electrode current collecting layer and a negative electrode current collecting layer is also conceivable. In other words, the solid-state battery included in the package of the present invention may be a solid-state battery without a current collecting layer (i.e., a solid-state battery without a current collecting layer).

[0032] (solid electrolyte) The solid electrolyte 130 is a material capable of conducting lithium ions or sodium ions. In particular, the solid electrolyte 130 constituting a battery unit in a solid-state battery may form a layer capable of conducting lithium ions between the positive electrode layer 110 and the negative electrode layer 120 (see FIG. 1). The solid electrolyte is sufficient as long as it is provided at least between the positive electrode layer and the negative electrode layer. In other words, the solid electrolyte may be present around the positive electrode layer and / or the negative electrode layer so as to protrude from between the positive electrode layer and the negative electrode layer. The specific solid electrolyte is not particularly limited. For example, the solid electrolyte may include one or more of a crystalline solid electrolyte, a glass-based solid electrolyte, a glass-ceramic solid electrolyte, and the like.

[0033] The crystalline solid electrolyte is, for example, an oxide-based crystalline material and / or a sulfide-based crystalline material. Examples of the oxide-based crystalline material include a lithium-containing phosphate compound having a Nasicon structure, an oxide having a perovskite structure, an oxide having a garnet-type or garnet-like structure, and an oxide glass ceramic-based lithium ion conductor. Examples of the lithium-containing phosphate compound having a Nasicon structure include Li x M y (PO4)3 (1≦x≦2, 1≦y≦2, M is at least one selected from the group consisting of titanium (Ti), germanium (Ge), aluminum (Al), gallium (Ga) and zirconium (Zr)). An example of a lithium-containing phosphate compound having a Nasicon structure is, for example, Li 1.2 Al 0.2 Ti 1.8 (PO4)3, etc. An example of an oxide with a perovskite structure is La 0.55 Li 0.35 Examples of oxides with garnet or garnet-like structures include Li7La3Zr2O 12 Examples of sulfide-based crystal materials include thio-LISICON, for example, Li 3.25 Ge 0.25 P 0.75S4 and / or Li 10 GeP2S 12 The crystalline solid electrolyte may include a polymer material (for example, polyethylene oxide (PEO)).

[0034] Examples of glass-based solid electrolytes include oxide-based and / or sulfide-based glass materials. Examples of oxide-based glass materials include 50Li4SiO4·50Li3BO3. Examples of sulfide-based glass materials include 30Li2S·26B2S3·44LiI, 63Li2S·36SiS2·1Li3PO4, 57Li2S·38SiS2·5Li4SiO4, 70Li2S·30P2S5, and / or 50Li2S·50GeS2.

[0035] The glass ceramic solid electrolyte is, for example, an oxide-based glass ceramic material and / or a sulfide-based glass ceramic material. As the oxide-based glass ceramic material, for example, a phosphate compound containing lithium, aluminum, and titanium as constituent elements (LATP) or a phosphate compound containing lithium, aluminum, and germanium as constituent elements (LAGP) can be used. LATP is, for example, Li 1.07 Al 0.69 Ti 1.46 (PO4)3, etc. Also, LAGP is, for example, Li 1.5 Al 0.5 Ge 1.5 (PO4), etc. Examples of sulfide-based glass ceramic materials include Li7P3S 11 and / or Li 3.25 P 0.95 Examples include S4.

[0036] In addition, examples of solid electrolytes capable of conducting sodium ions include sodium-containing phosphate compounds having a Nasicon structure, oxides having a perovskite structure, and oxides having a garnet or garnet-like structure. Examples of sodium-containing phosphate compounds having a Nasicon structure include Na x M y(PO4)3 (1≦x≦2, 1≦y≦2, M is at least one selected from the group consisting of Ti, Ge, Al, Ga and Zr).

[0037] The solid electrolyte may contain a sintering aid. The sintering aid contained in the solid electrolyte may be selected from the same materials as the sintering aids that may be contained in the positive electrode layer and the negative electrode layer, for example.

[0038] The thickness of the solid electrolyte is not particularly limited. The thickness of the solid electrolyte layer located between the positive electrode layer and the negative electrode layer may be, for example, 1 μm to 15 μm, particularly 1 μm to 5 μm.

[0039] (end face electrode) A solid-state battery typically includes end electrodes 140. In particular, the end electrodes are provided on the side surfaces of the solid-state battery. More specifically, a positive end electrode 140A connected to the positive electrode layer 110 and a negative end electrode 140B connected to the negative electrode layer 120 are provided (see FIG. 1). Such end electrodes preferably include a material with high conductivity. Specific materials for the end electrodes are not particularly limited, but may include at least one selected from the group consisting of silver, gold, platinum, aluminum, copper, tin, and nickel.

[0040] [Basic structure of solid-state battery package] The present invention is a packaged solid-state battery, that is, a solid-state battery package having a mountable substrate and a configuration in which the solid-state battery is protected from the external environment.

[0041] 2 is a cross-sectional view schematically illustrating the configuration of a packaged solid-state battery according to one embodiment of the present invention. As shown in FIG. 2, a solid-state battery package 1000 according to one embodiment of the present invention includes a substrate 200 for supporting a solid-state battery 100. Specifically, the solid-state battery package 1000 includes a mountable substrate 200 and a solid-state battery 100 provided on the substrate 200 and protected from the external environment. Such a solid-state battery package 1000 is provided with a covering section 150 including at least a covering insulating layer 160 provided so as to cover the solid-state battery 100 on the substrate 200 and a covering inorganic layer 170 provided on the outer side of the covering insulating layer (preferably, the covering inorganic layer 170 provided directly on the outer side of the covering insulating layer or in contact with it).

[0042] As shown in FIG. 2, the substrate 200 may have a main surface larger than that of the solid-state battery. The substrate 200 may be a resin substrate or a ceramic substrate. In short, the substrate 200 may be a printed wiring board, a flexible substrate, an LTCC substrate, and / or an HTCC substrate. When the substrate 200 is a resin substrate, the substrate 200 may be a substrate configured to contain a resin as a base material, for example, a substrate having a resin layer in its laminate structure. The resin material of such a resin layer may be any thermoplastic resin and / or any thermosetting resin. The resin layer may also be configured, for example, by impregnating glass fiber cloth with a resin material such as epoxy resin.

[0043] The substrate is preferably a member for the external terminals of the packaged solid-state battery. In other words, the substrate may be a terminal substrate for the external terminals of the solid-state battery. A solid-state battery package including such a substrate can mount the solid-state battery on another secondary substrate such as a printed wiring board with the substrate interposed therebetween. For example, the solid-state battery can be surface-mounted via the substrate through solder reflow or the like. For this reason, the solid-state battery package of the present invention is preferably an SMD (Surface Mount Device) type battery package.

[0044] Such a substrate can be provided to support a solid-state battery, and can also be referred to as a support substrate. Furthermore, the substrate may have wiring or an electrode layer as a terminal substrate, and in particular, may have an electrode layer that electrically connects the upper and lower surfaces or the upper and lower surface layers of the substrate. That is, a preferred embodiment of the substrate has wiring or an electrode layer that electrically connects the upper and lower surfaces of the substrate, and serves as a terminal substrate for the external terminals of a packaged solid-state battery. In this embodiment, the wiring of the substrate can be used to connect the external terminals from the solid-state battery, eliminating the need to pack the battery in a covering material before connecting it to the outside of the package, and increasing the design freedom of the external terminals.

[0045] A substrate 200 according to a preferred embodiment includes electrode layers (upper principal surface electrode layer 210 and lower principal surface electrode layer 220) that electrically connect the upper and lower principal surfaces of the substrate, and serves as a component for the external terminals of a packaged solid-state battery (see FIG. 2). In a solid-state battery package including such a substrate, the electrode layers of the substrate and the terminal portions of the solid-state battery are connected to each other. Preferably, the electrode layers of the substrate and the end electrodes of the solid-state battery are electrically connected to each other. For example, the positive end electrode 140A of the solid-state battery is electrically connected to the positive electrode layer (210A, 220A) of the substrate. Meanwhile, the negative end electrode 140B of the solid-state battery is electrically connected to the negative electrode layer (210B, 220B) of the substrate. As a result, the positive and negative electrode layers of the substrate (particularly, the electrode layers located on the lower / bottom side of the packaged product, or the lands connected thereto) serve as the positive and negative terminals of the battery package, respectively.

[0046] In order to enable electrical connection between the solid-state battery 100 and the substrate electrode layer 210 of the substrate 200, the end surface electrode 140 of the solid-state battery 100 and the substrate electrode layer 210 of the substrate 200 can be connected via a bonding member 600. The bonding member 600 may be provided on the substrate 200. This bonding member 600 is responsible for at least the electrical connection between the end surface electrode 140 of the solid-state battery 100 and the substrate 200, and may include, for example, a conductive adhesive. As an example, the bonding member 600 may be made of an epoxy-based conductive adhesive containing a metal filler such as Ag.

[0047] Furthermore, in one embodiment of the present invention, the solid-state battery package 1000 itself may be configured to be able to prevent water vapor transmission as a whole. For example, in the solid-state battery package 1000 according to one embodiment of the present invention, the solid-state battery 100 provided on the substrate 200 is covered with a covering material 150 so as to entirely surround the solid-state battery 100. Specifically, the solid-state battery 100 on the substrate 200 may be packaged so that its main surfaces (at least the upper surface 100A corresponding to the top surface, preferably both the upper surface 100A and the lower surface 100C) and its side surfaces 100B are surrounded by the covering material 150. With this configuration, the surfaces constituting the solid-state battery 100 (preferably all surfaces constituting the solid-state battery 100) are not exposed to the outside, and preferably such surfaces are not directly exposed to the outside, which can more suitably prevent water vapor transmission.

[0048] In this specification, "water vapor" is not particularly limited to gaseous water, but preferably also includes liquid water. In other words, the term "water vapor" is used to broadly encompass gaseous water, liquid water, and the like, regardless of the physical state. Therefore, "water vapor" can also be referred to as moisture, and liquid water in particular can encompass condensed water formed by condensation of gaseous water. Since the penetration of water vapor into a solid-state battery can cause deterioration of battery characteristics, the above-described packaged solid-state battery configuration contributes to extending the battery characteristics and life of the solid-state battery.

[0049] For example, as shown in Fig. 2, the covering member 150 may be composed of at least a covering insulating layer 160 and a covering inorganic layer 170. The solid-state battery 100 may have a configuration in which it is covered with the covering insulating layer 160 and the covering inorganic layer 170 as the covering member 150. The covering inorganic layer 170 is provided so as to cover the covering insulating layer 160. As shown in Fig. 2, the covering inorganic layer 170 is positioned on the covering insulating layer 160, and therefore has a configuration in which, together with the covering insulating layer 160, it largely envelops the solid-state battery 100 on the substrate 200 as a whole. The covering inorganic layer 170 may also have a configuration in which it covers the side surfaces of the substrate 200.

[0050] [Features of the solid-state battery package of the present invention] The present inventors have conducted extensive research into solutions for further improving the water vapor permeation prevention properties of the solid state battery package, and as a result have devised the present invention having the following technical concept.

[0051] Specifically, the present invention has a technical idea of ​​a "smoothed covering insulating layer" in a solid-state battery package having a solid-state battery provided on a substrate. More specifically, the present invention has a technical idea of ​​"the covering portion preferably has a covering insulating layer with a developed area ratio Sdr of 0.15 or less."

[0052] As an embodiment of the above technical idea, the present invention has the technical features described below. Fig. 2 is a partially enlarged cross-sectional view schematically illustrating the smoothing of the solid-state battery package 1000. As can be seen from this partially enlarged cross-sectional view, in the solid-state battery package 1000 of the present invention, the covering insulating layer 160 has a structure / configuration in which the covering insulating layer 160 is smoothed (e.g., a smooth surface 160').

[0053] In this specification, "smoothened" refers to the surface irregularities of the coated insulating layer being reduced, preferably the coated insulating layer having a smooth surface. For example, it refers to a state in which the surface irregularities of the outer surface or outermost layer of the coated insulating layer are reduced. For example, the coated insulating layer (or a portion thereof) that serves as a base member or main member may have a form in which the coated insulating layer has a smooth or even / flat outer surface (preferably the outermost surface or outermost surface) whether or not combined with other elements. In a preferred embodiment, "smoothened" refers to the surface of the coated part that forms the interface with the coated inorganic layer (particularly the surface related to the coated insulating layer) having a smooth surface. In a preferred embodiment, a layer located inside the coated inorganic layer, preferably the coated insulating layer located immediately inside the coated inorganic layer, has a smooth surface (particularly a smooth outer surface) or a even / flat surface (particularly a flat / flat outer surface).

[0054] Furthermore, in this specification, the term "covering insulating layer" is not limited to a single layer, but may be a layer composed of multiple layers. For example, the covering insulating layer may have a sublayer on its surface, preferably a sublayer arranged to reduce the surface irregularities (for example, the sublayer may have a smooth surface (particularly a smooth outer surface) or a flat surface (particularly a flat outer surface)). In other words, the covering insulating layer may be composed of a first covering insulating layer and a second covering insulating layer arranged on the outer surface of the covering insulating layer (preferably, a second covering insulating layer having a thickness smaller than that of the first covering insulating layer). It can also be said that the second covering insulating layer (preferably its surface) arranged on the surface irregularities of the first covering insulating layer may form or serve as the outer surface (or outermost surface or outermost surface) of the covering insulating layer.

[0055] As illustrated schematically in FIG. 2 , the solid-state battery package 1000 of the present invention may have a smooth interface between the covering insulating layer 160 and the covering inorganic layer 170. The covering insulating layer 160 preferably has an expanded area ratio Sdr of 0.15 or less. More specifically, the expanded area ratio Sdr may be 0.15 or less for the surface (particularly the outer surface) of the covering insulating layer (e.g., a covering insulating layer consisting of a single layer, or a covering insulating layer consisting of two or more layers / sublayers). An expanded area ratio Sdr of 0 means that the surface is smooth. In the present invention, the expanded area ratio Sdr of the covering insulating layer 160 is preferably 0 or more and 0.15 or less, or 0.14 or less (in some cases, the expanded area ratio Sdr may be greater than 0 and 0.15 or less, or 0.14 or less, but not including 0). When the developed area ratio Sdr of the coating insulating layer 160 is 0.15 or less, it is easy to suppress or preferably eliminate defects in the coating inorganic layer 170 caused by the surface unevenness of the coating insulating layer 160. When defects in the coating inorganic layer 170 are suppressed or eliminated, penetration of water vapor from the external environment into the solid-state battery is more effectively prevented. In a preferred embodiment, the developed area ratio Sdr of the surface (particularly the outer surface) of the coating insulating layer may be 0.01 or more and 0.15 or less, 0.02 or more and 0.15 or less, 0.03 or more and 0.15 or less, 0.03 or more and 0.14 or less, 0.04 or more and 0.15 or less, 0.05 or more and 0.15 or less, 0.06 or more and 0.15 or less, 0.07 or more and 0.15 or less, 0.08 or more and 0.15 or less, 0.09 or more and 0.15 or less, 0.1 or more and 0.15 or less, 0.11 or more and 0.15 or less, or 0.11 or more and 0.14 or less, etc.

[0056] In this specification, the "developed area ratio Sdr" refers to the Sdr value obtained by measuring the surface roughness using a laser microscope (Keyence Corporation, model number VK-X3050), and the arithmetic average value of any 20 points on the target surface may be used.

[0057] The covering insulating layer is a layer that exhibits insulating properties that contribute to covering a solid-state battery. The material of the covering insulating layer may be any type as long as it exhibits insulating properties. In this specification, "insulating" refers to the insulating properties of a general insulator, and therefore may have an electrical resistivity that is generally possessed by an insulator in the field of batteries or solid-state batteries, for example, and is merely an example, but is not limited to, at least 1.0 × 10 5 Ω·m or more, preferably 1.0×10 6 Ω·m or more, preferably 1.0×10 7 The coating insulating layer may have a resistivity of Ω·m or more (room temperature 20°C). Preferably, the coating insulating layer is a layer made of resin. When the coating insulating layer is a resin layer, the resin may be either a thermosetting resin or a thermoplastic resin. Although not particularly limited, specific resin materials for the coating insulating layer include, for example, epoxy resin, silicone resin, and / or liquid crystal polymer. By way of example only, the thickness (e.g., maximum thickness) of the coating insulating layer may be 30 μm or more and 1000 μm or less, for example, 50 μm or more and 300 μm or less.

[0058] In a preferred embodiment, the covering insulating layer contains silicon. For example, the material of the covering insulating layer may be a resin containing silicon. Silicon may be contained separately from the resin component of the covering insulating layer (for example, silicon may be contained in the resin matrix of the covering insulating layer separately from the resin matrix). In other words, it can be said that the covering insulating layer may contain silicon as a non-resin component. With respect to such silicon, the covering insulating layer may contain a silicon compound. When the covering insulating layer is a resin layer, the covering insulating resin layer may contain a silicon compound. For example, a silicon compound may be dispersed in the resin matrix of the covering insulating layer. Examples of silicon compounds include silicon oxides such as silicon dioxide. When such silicon (Si) and / or a silicon compound (e.g., silicon oxide) is contained in the covering insulating layer, the action of the Si can further increase the adhesion between the covering insulating layer and the covering inorganic layer.

[0059] The covering insulating layer 160 may contain a filler. The filler may be an inorganic filler. When the covering insulating layer 160 is made of a resin, the filler is preferably dispersed in the resin. Such a filler may preferably be mixed into the covering insulating layer and integrated with the base material (e.g., a resin material) of the covering insulating layer. The shape of the filler is not particularly limited and may be granular, spherical, needle-like, plate-like, fibrous, and / or irregular. The size of the filler is also not particularly limited and may be 10 nm to 100 μm, for example, a nanofiller of 10 nm to 100 nm, a microfiller of 100 nm to 10 μm, or a macrofiller of 10 μm to 100 μm. The filler content of the covering insulating layer may be 0% by weight or more (for example, excluding 0% by weight) and 95% by weight or less based on the entire covering insulating layer 160, for example, 0% by weight or more (for example, excluding 0% by weight) and 50% by weight or less, 0% by weight or more (for example, excluding 0% by weight) and 40% by weight or less, 0% by weight or more (for example, excluding 0% by weight) and 35% by weight or less, or 0% by weight or more (for example, excluding 0% by weight) and 30% by weight or less, or further, 5% by weight or more and 50% by weight or less, 5% by weight or more and 45% by weight or less, 5% by weight or more and 40% by weight or less, 5% by weight or more and 35% by weight or less. It may be 10% by weight or more and 50% by weight or less, 10% by weight or more and 45% by weight or less, 10% by weight or more and 40% by weight or less, 10% by weight or more and 35% by weight or less, 15% by weight or more and 50% by weight or less, 15% by weight or more and 45% by weight or less, 15% by weight or more and 40% by weight or less, 15% by weight or more and 35% by weight or less, 20% by weight or more and 50% by weight or less, 20% by weight or more and 45% by weight or less, 20% by weight or more and 40% by weight or less, 20% by weight or more and 35% by weight or less, 25% by weight or more and 50% by weight or less, 25% by weight or more and 45% by weight or less, 25% by weight or more and 40% by weight or less, 25% by weight or more and 35% by weight or less, etc. Regarding the weight percentages, when the coating insulating layer is composed of a first coating insulating layer and a second coating insulating layer thereon, as described below, the "overall standard of the coating insulating layer" may be considered to be the "overall standard of the first coating insulating layer."Furthermore, the filler content of such a coating insulating layer may be less than 10% by weight, less than 9% by weight, less than 8% by weight, less than 7% by weight, less than 6% by weight, or 5% by weight or less, as described below (for example, it may be greater than 0, but not including 0, and may be less than or equal to such a weight percentage).

[0060] The filler contained in the covering insulating layer preferably contributes to preventing water vapor transmission. That is, the filler may be contained in the covering insulating layer as a water vapor transmission preventing filler. Such a water vapor transmission preventing filler may be, for example, an inorganic filler, such as a filler containing or consisting of silicon (Si) and / or a silicon compound (e.g., silicon oxide). In a preferred embodiment, the covering insulating layer 160 contains a water vapor transmission preventing filler in its resin material. This allows the covering insulating layer 160, together with the covering inorganic layer 170, to more effectively prevent water vapor from the external environment from penetrating into the solid-state battery.

[0061] More specific examples of filler materials include, but are not limited to, metal oxides such as silica, alumina, titanium oxide and / or zirconium oxide, minerals such as mica, and / or glass.

[0062] As described above, the covering insulating layer 160 preferably contains silicon (Si) and / or a silicon compound. From this perspective, the silicon (Si) contained in the covering insulating layer 160 may be an oxide of silicon (Si), i.e., a silicon compound such as silicon oxide, for example, silica (silicon dioxide). Such silicon (Si) and / or a silicon compound (e.g., silicon oxide) may be contained as a filler (e.g., may be contained in the covering insulating layer as the above-mentioned filler). In other words, the covering insulating layer may contain a silicon or silicon oxide filler, and a filler containing silicon, such as a silicon or silicon compound-containing filler, may be dispersed within the covering insulating layer 160.

[0063] In the present invention, the smoothness or flatness / planarity of the covering insulating layer 160 can be controlled by the filler content in the covering insulating layer. For example, the smoothness or flatness / planarity of the covering insulating layer 160 can be controlled by a filler containing silicon (Si) and / or a silicon compound (e.g., silicon oxide, etc.). (In a preferred embodiment, the covering insulating layer can be made smooth even without the "smoothing layer" described below.) More specifically, the higher the filler content, the greater the tendency for the surface roughness to increase. Without being bound by any particular theory, this is thought to be due to cracking or shedding of the filler. On the other hand, when the filler content is lower, the surface roughness can be reduced accordingly, and as the filler content decreases, the covering insulating layer becomes smoother (i.e., a flatter or more planar covering insulating layer can be obtained). By keeping the filler content in the coating insulation layer low to a certain extent, it is possible to make the coating insulation layer smooth or even / flat while taking advantage of the water vapor transmission prevention properties of the filler, reduce or suppress defects in the coating inorganic layer caused by surface irregularities, and obtain the desired water vapor transmission properties. From this perspective, the filler content in the coating insulation layer may be less than 10 wt%, less than 9 wt%, less than 8 wt%, less than 7 wt%, less than 6 wt%, or 5 wt% or less based on the coating insulation layer (based on the coating insulation layer portion corresponding to the first coating insulation layer in cases where the coating insulation layer referred to in the examples is not composed of a first coating insulation layer and a second coating insulation layer) (for example, it may be more than 0 wt%, less than 0 wt%, or less than such a weight percentage). Furthermore, when the filler contained in the coating insulating layer 160 is a filler containing silicon (Si) and / or a silicon compound (e.g., silicon oxide), as the content of such filler increases, the adhesion between the coating insulating layer and the coating inorganic layer tends to become stronger due to the action and / or anchor effect of Si.

[0064] The "smoothing" or "smooth surface" (particularly a smooth outer surface) or "flat surface" (particularly a flat outer surface) in the solid-state battery package of the present invention may be achieved by a smoothing layer. The "smoothing layer" in this specification may correspond to a second covering insulating layer provided to reduce surface irregularities of the covering insulating layer, and may also be referred to as a smoothing sublayer, a smoothing sub-insulating layer, or a smoothing sub-covering insulating layer, or a smoothing surface-forming layer or a planarizing layer. Such a layer is provided on the surface of the covering insulating layer serving as the first covering insulating layer, and therefore may also be referred to as a surface insulating layer. For example, a smoothing layer may be provided as the outermost layer or outermost sublayer of the covering insulating layer 160. The smoothing layer may be the layer or sublayer with the smallest thickness among the covering insulating layers.

[0065] 3, the coating insulating layer 160 may include a smoothing layer 160B, and the coating inorganic layer 170 may be provided on the smoothing layer 160B. That is, when the coating insulating layer 160 is composed of a coating insulating layer 160A that serves as a first coating insulating layer and is in direct contact with the solid-state battery 100, and a smoothing layer 160B that serves as a second coating insulating layer on the first coating insulating layer, the smoothing layer 160B may be positioned between the first coating insulating layer 160A and the coating inorganic layer 170 (e.g., a plating layer). As shown in the figure, the smoothing layer 160B may be provided as an outer surface layer of the coating insulating layer 160, and the coating inorganic layer 170 may be provided on the outer surface of the smoothing layer 160B. In addition, this is particularly true when there are irregularities on the surface of the first covering insulating layer (especially the outer surface of the first covering insulating layer), and the smoothing layer serving as the second covering insulating layer may be provided so as to fill in the surface irregularities of the first covering insulating layer.

[0066] As shown in FIG. 3, the smoothing layer 160B is provided so as to surround the solid-state battery 100. That is, as shown in the figure, the smoothing layer 160B is at least provided so as to be positioned outside the side and / or top surface (i.e., the top surface corresponding to the main surface relatively farther from the substrate) of the solid-state battery 100 (preferably provided continuously in a cross-sectional view). More specifically, the smoothing layer 160B may be provided so as to form the surface of the covering insulating layer 160 provided on the substrate 200 so as to surround the solid-state battery 100. The developed area ratio Sdr of the smoothing layer 160B may be 0.15 or less. When the developed area ratio Sdr is 0, as described above, there is no unevenness on the surface.

[0067] In a preferred embodiment, the developed area ratio Sdr of the smoothing layer 160B is 0 to 0.15 or 0 to 0.14 (in some cases, the developed area ratio Sdr may be greater than 0 but not including 0 and less than 0.15). In particular, the developed area ratio Sdr of the outer surface of the smoothing layer 160B (i.e., the surface located relatively outside the solid-state battery package) is preferably 0 to 0.15 (in some cases, the developed area ratio Sdr is greater than 0 but not including 0 and less than 0.15, 0.14 or less, or less than 0.1). When the developed area ratio Sdr of the smoothing layer 160B is 0.15 or less, defects in the coated inorganic layer 170 due to surface irregularities of the coated insulating layer 160, including the smoothing layer 160B, can be easily suppressed, or preferably eliminated. Reducing or eliminating defects in the coated inorganic layer 170 can more effectively prevent water vapor from the external environment from penetrating into the solid-state battery. In such an embodiment, the covering insulating layer includes the smoothing layer. In other words, the covering insulating layer of the present invention can be considered to be composed of a first covering insulating layer and a smoothing layer thereon as a second covering insulating layer (provided on the surface or on the surface irregularities). In a preferred embodiment, the developed area ratio Sdr of the smoothing layer 160B with respect to the outer surface may be 0.01 or more and less than 0.1, 0.01 or more and 0.09 or less, 0.02 or more and 0.09 or less, 0.03 or more and 0.09 or less, 0.04 or more and 0.09 or less, or 0.04 or more and 0.08 or less.

[0068] Here, let us consider a case where the coating insulating layer 160, particularly the first coating insulating layer, contains a filler. As mentioned above, the filler itself contributes to preventing water vapor transmission, which is desirable in that respect. However, a high filler content can reduce the smoothness or flatness / flatness of the first coating insulating layer. Therefore, a high filler content is more likely to cause surface irregularities in the coating insulating layer (first coating insulating layer), which in turn makes the coating inorganic layer 170 more likely to have defects. In this regard, when the smoothing layer 160B is provided on the first coating insulating layer 160A, the coating insulating layer 160, which serves as the base or foundation on which the coating inorganic layer 170 is formed, has more suitable smoothness or flatness / flatness, thereby reducing, and preferably eliminating, defects in the coating inorganic layer 170 caused by surface irregularities. In other words, the smoothness or flatness / flatness of the coating insulating layer 160 can reduce or eliminate defects in the coating inorganic layer 170 caused by surface irregularities while still making the most of the water vapor transmission prevention properties of the filler, thereby making it easier to obtain the desired water vapor transmission properties. In addition, in order to make the most of the water vapor transmission prevention properties of the filler when the smoothing layer 160B is provided, the content of the filler in the coating insulating layer may be 10 wt% or more, 15 wt% or more, 20 wt% or more, 25 wt% or more, 26 wt% or more, 27 wt% or more, 28 wt% or more, 29 wt% or more, or 30 wt% or more based on the first coating insulating layer (the upper limit is not particularly limited, but may be 50 wt% or less, 45 wt% or less, 40 wt% or less, 35 wt% or less, 34 wt% or less, 33 wt% or less, 32 wt% or less, or 31 wt% or less).

[0069] In a preferred embodiment, the first covering insulating layer contains a filler, while the second covering insulating layer (i.e., the smoothing layer) does not. That is, the covering insulating layer may be composed of a first covering insulating layer provided as a filler-containing insulating layer and a second covering insulating layer provided as a filler-free insulating layer (i.e., the smoothing layer provided as a filler-free insulating layer). In such an embodiment, the water vapor transmission prevention properties of the filler can be further utilized, while the smoothness or flatness / flatness of the covering insulating layer can reduce or eliminate defects in the covering inorganic layer caused by surface irregularities, making it easier to achieve the desired water vapor transmission properties. Note that such a "smoothing layer provided as a filler-free insulating layer" can also be referred to as a filler-free smoothing layer, a filler-free smoothing layer, or a filler-free or filler-free smoothing layer.

[0070] The smoothing layer 160B may be composed of a resin. Preferably, it is a silicon-containing layer containing silicon. Examples of resins for the smoothing layer include silicon-containing resins, silicon-based resins, and / or silicone resins. When the smoothing layer 160B contains Si (silicon) as a constituent element or component of its resin material, the surface irregularities of the outermost layer of the coated insulating layer 160 are easily reduced, and defects in the coated inorganic layer 170 formed thereon are easily suppressed. Furthermore, such a smoothing layer is easily improved in adhesion to the coated inorganic layer 170 due to the action of Si, etc., and the coated inorganic layer 170 can more easily maintain its function as a water vapor barrier film. This more effectively prevents water vapor from the external environment from penetrating into the solid-state battery 100.

[0071] The silicon-containing smoothing layer may be a layer containing alkoxysilane. That is, the silicon-containing layer (particularly, the smoothing layer as a silicon-containing resin layer, preferably containing Si (silicon) as a constituent element or component of the resin material) may contain alkoxysilane. A layer containing alkoxysilane contributes to surface smoothing more favorably, while also being easily provided as a relatively dense and / or homogeneous thin layer. That is, a smoothing layer containing alkoxysilane more effectively reduces the surface irregularities of the coated insulating layer, and more effectively suppresses defects in the coated inorganic layer formed thereon. A raw material containing alkoxysilane may be applied to the coated insulating layer 160, thereby forming a smoothing layer 160B on the surface of the coated insulating layer 160 so as to reduce the surface irregularities of the coated insulating layer 160. The type of alkoxysilane is not particularly limited, and any alkoxysilane may be used as long as it contributes to the smoothing of the coated insulating layer. Furthermore, since a smoothing layer containing silicon, such as a layer containing alkoxysilane, contains silicon, it can easily improve or enhance the adhesion of the coated inorganic layer provided as a plating layer on the insulating coating layer, making it easier to maintain the function of the coated inorganic layer as a water vapor barrier (for example, it can be said that it can be easier to maintain it for a longer period of time).

[0072] The method for forming the smoothing layer 160B is not particularly limited. For example, the smoothing layer 160B may be formed by impregnation with a resin material or a solution containing a resin, or by sputtering. As just one example, the smoothing layer 160B can be formed by applying an alkoxysilane solution to the surface of the first coating insulating layer 160A.

[0073] The smoothing layer 160B may be a single layer (for example, it may be a single layer in that it is made of the same material). The thickness of the smoothing layer 160B is not particularly limited, as long as the unevenness of the coating insulating layer 160 is smoothed. The thickness (for example, the minimum thickness) of the smoothing layer 160B may be smaller than the thickness of the first coating insulating layer 160A (i.e., the inner coating insulating layer that directly contacts the solid-state battery) and / or smaller than the thickness of the coating inorganic layer 170. Specifically, it may be on the order of nanometers or micrometers. By way of example, the thickness of the smoothing layer may be 0.6 μm or more, 0.8 μm or more, 0.9 μm or more, 1 μm or more, 1.1 μm or more, or 1.2 μm or more. The upper limit of the thickness of the smoothing layer is not particularly limited, but may be, for example, 20 μm, 10 μm, 5 μm, 4 μm, 3 μm, or 2 μm. Although it is such a thin layer, the smoothing layer 160B can be a relatively dense and / or homogeneous layer. The smoothness of the covering insulating layer 160 can be controlled, for example, by the thickness of the smoothing layer. If the smoothing layer is thin, the smoothing effect may be relatively reduced. On the other hand, if the smoothing layer is thicker, the smoothing effect is enhanced and the water vapor barrier property is further improved. The thickness of the smoothing layer can also be controlled by various factors related to the raw material solution used to form the smoothing layer, such as the concentration of the alkoxysilane solution and / or the number of coatings. In this specification, the "thickness of the smoothing layer" may be considered to be the minimum thickness of the smoothing layer.

[0074] A smoothed coated insulating layer (e.g., smoothing layer 160B) can easily suppress or eliminate an event such as plating solution undesirably remaining in recesses on the surface of the outermost layer of coated insulating layer 160 when coating inorganic layer 170 is formed by plating. In other words, smoothing layer 160B makes it easier to suppress such an undesirable phenomenon, and makes it easier for coated inorganic layer 170 to more suitably serve as a water vapor barrier film. Therefore, in a solid-state battery package, water vapor from the external environment can be more suitably prevented from penetrating into solid-state battery 100.

[0075] In the present invention, the water vapor barrier property is imparted to the solid battery package due to the "smooth surface." Here, the "barrier" as used herein broadly means that the solid battery package has a water vapor barrier property (water vapor permeation reaching the solid battery) to such an extent that water vapor from the external environment does not pass through the coating portion (particularly the coating inorganic layer 170) and cause undesirable deterioration of the characteristics of the solid battery 100. In a narrow sense, the "barrier" means that the solid battery package has a water vapor barrier property of 1.0 g / (m) as measured by the method described in the "Examples" below (a method based on the amount of weight change when left for 24 hours in an environment of 85°C and 85% RH). 2 ·day), preferably less than 0.5g / (m 2 ·day), more preferably less than 0.2g / (m 2 This means that the time is less than 1000 s.

[0076] In a preferred embodiment, the coating insulating layer 160 and the coating inorganic layer 170 are integrated with each other, preferably so as to be in direct contact with each other. For example, the coating insulating layer 160 and the coating inorganic layer 170 are integrated with each other via a smoothing layer 160B of the coating insulating layer (or the coating insulating layer 160 and the coating inorganic layer 170 are integrated with each other without such a smoothing layer). Thus, the coating inorganic layer 170, together with the coating insulating layer 160, forms a water vapor barrier for the solid-state battery 100. In other words, the combination of the integrated coating insulating layer 160 and the coating inorganic layer 170 more effectively prevents water vapor from the external environment from penetrating into the solid-state battery 100.

[0077] The coated inorganic layer 170 may correspond to an inorganic layer having a thin film form, such as a metal film. The thickness of such a coated inorganic layer may be 0.1 μm or more and 100 μm or less, for example, 1 μm or more and 50 μm or less. In a preferred embodiment, the coated inorganic layer is a plating layer. That is, the coated inorganic layer may be a layer made of metal, particularly a layer containing a plated metal. The coated inorganic layer may contain at least one metal selected from the group consisting of Cu, Sn, Zn, Bi, Au, Ag, Ni, Cr, Pd, Pt, SUS, and Zn. A coated inorganic layer containing such a material contributes to better water vapor transmission prevention properties of the solid-state battery package. Note that "SUS (stainless steel)" in this specification refers to stainless steel as defined in, for example, "JIS G 0203 Iron and Steel Terminology," and may be an alloy steel containing chromium or chromium and nickel.

[0078] In a preferred embodiment, the plating layer is composed of a dry-plated layer disposed on the covering insulating layer and a wet-plated layer disposed thereon. That is, the plating layer may be composed of an inner-plated layer formed on the covering insulating layer by a dry plating process and an outer-plated layer formed on the lower-plated layer by a wet plating process. In other words, the solid-state battery package of the present invention may have a dry-plated layer disposed on the smoothed covering insulating layer and a wet-plated layer disposed on the dry-plated layer. The wet-plated layer may be provided so as to cover the dry-plated layer.

[0079] A smoothing layer 160B may be provided as the outer surface layer (outer surface sublayer) of the coating insulating layer 160, and a plating layer may be provided on the outer surface of the smoothing layer 160B as a coating inorganic layer. As shown in FIG. 4, for example, a smoothing layer 160B may be provided as the outer surface layer of the coating insulating layer 160, and a dry-plated layer 170a and a wet-plated layer 170b disposed on the outer surface of the smoothing layer 160B may be provided. Note that each of the dry-plated layer 170a and the wet-plated layer 170b may have a multi-layer structure of two or more layers. For example, the wet-plated layer 170b may be composed of at least a first wet-plated layer and a second wet-plated layer. In such a case, the first wet-plated layer may contain at least one metal selected from the group consisting of Cu, Sn, Zn, Bi, Au, and Ag. On the other hand, the second wet plating may contain at least one metal selected from the group consisting of Ni, Cr, Pd, Pt, Zn, and Cu. A coating inorganic layer containing such a material contributes to better water vapor permeation prevention properties of the solid-state battery package.

[0080] Regarding the plating layer, a dry-plated layer 170a and a wet-plated layer 170b may be laminated in this order on the covering insulating layer 160. The dry-plated layer 170a may be formed by sputtering. Because the covering insulating layer 160 is a smoothed layer, the dry-plated layer 170a can adhere more favorably to the covering insulating layer 160. Therefore, the dry-plated layer 170a, together with the covering insulating layer 160, can more favorably contribute to preventing water vapor from passing through the solid-state battery 100. Furthermore, in sputtering, the sputtered film easily penetrates into the covering insulating layer 160, and can adhere more favorably to the covering insulating layer 160. In other words, the sputtered film, which is provided so as to cover at least the main surface and side surface of the solid-state battery together with the covering insulating layer 160, can more favorably serve as a barrier to prevent water vapor from the external environment from penetrating into the solid-state battery 100. Furthermore, providing the dry-plated layer 170a inside the wet-plated layer 170b more effectively prevents the plating solution used to form the wet-plated layer 170b from penetrating into the solid-state battery. Therefore, providing the dry-plated layer 170a on the smoothed covering insulating layer 160 can easily lead to the realization of a more reliable solid-state battery package.

[0081] The dry-plated layer is a film obtained by a vapor-phase process such as physical vapor deposition (PVD) and / or chemical vapor deposition (CVD), and has an extremely small thickness on the order of nanometers or micrometers. Such a thin dry-plated film contributes to more compact packaging. The dry-plated film may be composed of at least one metal component or semimetal component selected from the group consisting of aluminum (Al), nickel (Ni), palladium (Pd), silver (Ag), tin (Sn), gold (Au), copper (Cu), titanium (Ti), platinum (Pt), silicon (Si), and stainless steel, an inorganic oxide, and / or a glass component. Preferably, the dry-plated layer contains stainless steel and / or Cu, and a coating inorganic layer containing such a material is likely to contribute to better water vapor transmission prevention properties of the solid-state battery package. For example, the thickness of the dry-plated layer 170a is preferably 1 μm to 10 μm, more preferably 2 μm to 8 μm, and even more preferably 3 μm to 6 μm. By setting the thickness of the dry-plated layer within the above range, the dry-plated layer can more effectively prevent water vapor from entering the solid-state battery 100.

[0082] As described above, the dry plating layer 170a may be, for example, a sputtered film. That is, the solid-state battery package of the present invention may be provided with a sputtered thin film as a dry plating film. A sputtered film is a thin film obtained by sputtering. That is, a film formed by sputtering ions onto a target and depositing the resulting atoms can be used as a dry plating layer. While the sputtered film has a very thin form on the nano- or micro-order, it tends to form a relatively dense and / or homogeneous layer, which contributes to preventing water vapor permeation for solid-state batteries. Furthermore, because the sputtered film is formed by atomic deposition, it can be more easily attached to the target. Therefore, the sputtered film can more effectively serve as a barrier to prevent water vapor from the external environment from penetrating into the solid-state battery. Therefore, when the coated inorganic film further includes a sputtered film as a dry plating layer, it is easier to further improve the water vapor permeation prevention property for the solid-state battery. The dry-plated layer may also be formed by other dry plating methods such as vacuum deposition and / or ion plating.

[0083] The wet-plated layer 170b has a faster layer formation rate (film formation rate) than a dry-plated film. Therefore, when a thick film is provided as a coated inorganic film, combining a dry-plated film with a wet-plated film promotes efficient formation of the coated inorganic layer. Such a wet-plated layer may be based on electroplating or electroless plating. That is, the wet-plated layer may be a layer obtained by such an electroplating process or electroless plating. In electroplating, a plating solution is used, and a plating layer is formed by applying electrical energy to two electrodes, a cathode and an anode, electrically connected via external electrodes. On the other hand, electroless plating is a plating method performed without the aid of an external power source. That is, in electroless plating, although a plating solution is used, the plating layer is formed mainly by chemical reaction energy without the aid of an external power source.

[0084] In the solid-state battery package of the present invention, the wet-plated layer 170b may correspond to the outermost layer of the inorganic coating layer. That is, the wet-plated layer 170b may form the outermost layer of the solid-state battery package so as to entirely cover the main surface and side surface of the solid-state battery package. Specifically, the outer main surface and side surface of the solid-state battery package may be covered with the wet-plated layer 170b.

[0085] Whether electroplating or electroless plating is used, the plating material is in a liquid state, and a liquid plating material containing water can be used. In plating, corrosion of the substrate by the plating solution can cause defects in the plating layer formed on the outer side. Defects in the plating layer can reduce the plating layer's function as a water vapor barrier. In the present invention, a coated inorganic layer can be formed as a plating layer on a smoothed insulating coating layer, which makes it easier to suppress, and preferably eliminate, defects in the coated inorganic layer. Therefore, the coated inorganic layer can more effectively function as a water vapor barrier. From another perspective, if the adhesion of the coated inorganic layer provided as a plating layer on the insulating coating layer in a solid-state battery package is improved or enhanced, the function of the coated inorganic layer as a water vapor barrier can be more easily maintained (e.g., it can be said that it is easier to maintain for a longer period of time).

[0086] The smoothing layer and the coated inorganic layer may extend not only to the area on the substrate but also to the side surface of the substrate. Specifically, as shown in Fig. 5, the coated inorganic layer 170 and / or the smoothing layer 160B may extend to the side surface 250 of the substrate 200. In this case, the bonding area between the coated inorganic layer and the substrate (e.g., the bonding area between the coated inorganic layer and the substrate via the smoothing layer 160B) is created or increased, thereby further suppressing peeling of the coated inorganic layer.

[0087] The thickness of each layer of the solid-state battery and the substrate may be based on an electron microscope image. For example, the thickness of each layer constituting the solid-state battery and the substrate may be based on an image acquired using an ion milling device (Hitachi High-Tech Corporation, Model No. SU-8040). In other words, the thickness in this specification may refer to a value calculated from dimensions measured from an image acquired by such a method.

[0088] Similarly, the thickness of each layer of the coating portion, such as the insulating coating layer and the inorganic coating layer, may be based on an electron microscope image, particularly a cross-sectional electron microscope image. For example, the thickness may be based on an image obtained by cutting the solid-state battery package perpendicular to the main surface and using an ion milling device (model SU-8040, manufactured by Hitachi High-Technologies Corporation). In other words, the thickness of the coating material in this specification may refer to a value calculated from dimensions measured from an image obtained by such a method.

[0089] [Solid-state battery package manufacturing method] The subject matter of the present invention can be obtained by preparing a solid-state battery including a battery building block having a positive electrode layer, a negative electrode layer, and a solid electrolyte between the electrodes, and then packaging the solid-state battery.

[0090] The production of the solid state battery of the present invention can be broadly divided into the production of the solid state battery itself (hereinafter also referred to as "battery before packaging"), which corresponds to a stage before packaging, the preparation of the substrate, and packaging.

[0091] <Manufacturing method of unpackaged batteries> The pre-packaged battery can be manufactured by a printing method such as screen printing, a green sheet method using a green sheet, or a combination of these methods. That is, the pre-packaged battery itself may be manufactured in accordance with a conventional method for manufacturing solid-state batteries (therefore, raw materials such as the solid electrolyte, organic binder, solvent, optional additives, positive electrode active material, and negative electrode active material described below may be those used in the manufacture of known solid-state batteries).

[0092] In the following, one production method will be described as an example for better understanding of the present invention, but the present invention is not limited to this method. Furthermore, the order of the following description and other chronological matters are merely for the convenience of explanation and are not necessarily binding.

[0093] (Laminated block formation) A solid electrolyte, an organic binder, a solvent, and optional additives are mixed to prepare a slurry, which is then fired to form a sheet containing the solid electrolyte. A paste for a positive electrode is prepared by mixing a positive electrode active material, a solid electrolyte, a conductive material, an organic binder, a solvent, and any additives. Similarly, a paste for a negative electrode is prepared by mixing a negative electrode active material, a solid electrolyte, a conductive material, an organic binder, a solvent, and any additives. Print the positive electrode paste onto the sheet, and if necessary, print the current collecting layer and / or negative layer. Similarly, print the negative electrode paste onto the sheet, and if necessary, print the current collecting layer and / or negative layer. A laminate is obtained by alternately stacking sheets printed with a positive electrode paste and sheets printed with a negative electrode paste. The outermost layer (top layer and / or bottom layer) of the laminate may be an electrolyte layer, an insulating layer, or an electrode layer.

[0094] (Battery firing body formation) After the laminate is pressure-bonded and integrated, it is cut to a predetermined size. The cut laminate is then degreased and fired to obtain a fired laminate. Note that the laminate may be degreased and fired before cutting, and then cut.

[0095] (Edge electrode formation) The positive electrode end electrode can be formed by applying a conductive paste to the exposed positive electrode side of the fired laminate. Similarly, the negative electrode end electrode can be formed by applying a conductive paste to the exposed negative electrode side of the fired laminate. The positive and negative electrode end electrodes may be provided so as to extend to the main surfaces of the fired laminate. The component of the end electrode can be at least one selected from silver, gold, platinum, aluminum, copper, tin, and nickel.

[0096] The end electrodes on the positive and negative electrodes do not necessarily have to be formed after firing of the laminate, but may be formed before firing and then subjected to simultaneous firing.

[0097] By going through the steps described above, a desired pre-packaged battery (corresponding to solid-state battery 100 shown in FIG. 6C) can finally be obtained.

[0098] <Preparation of substrate> In this step, the substrate is prepared.

[0099] Although not particularly limited, when a resin substrate is used as the substrate, its preparation may be carried out by laminating multiple layers and subjecting them to heating and / or pressure treatment. For example, a substrate precursor is formed using a resin sheet composed of a base fiber cloth impregnated with a resin raw material. After the substrate precursor is formed, this substrate precursor is subjected to heating and pressure in a press. On the other hand, when a ceramic substrate is used as the substrate, its preparation may be carried out, for example, by thermocompression bonding multiple green sheets to form a green sheet laminate and then firing the green sheet laminate to obtain a ceramic substrate. The preparation of the ceramic substrate may be carried out, for example, in accordance with the preparation of an LTCC substrate. The semi-lacquer substrate may have vias and / or lands. In such cases, for example, holes may be formed in the green sheets using a punch press and / or a carbon dioxide laser, and the holes may be filled with a conductive paste material, or precursors of conductive portions such as vias and lands may be formed by performing a printing method or the like. Note that lands and the like may also be formed after firing the green sheet laminate.

[0100] By going through the above steps, a desired substrate (corresponding to substrate 200 shown in FIG. 6A) can finally be obtained.

[0101] Packaging Next, the battery and substrate obtained above are packaged (see FIGS. 6A to 6G).

[0102] First, a precursor 600′ of the bonding member is formed on the substrate 200 (see FIGS. 6A and 6B), and then the pre-packaged battery 100 is placed on the substrate 200 (see FIGS. 6C and 6D). In other words, an “unpackaged solid-state battery” is placed on the substrate (hereinafter, a battery to be used for packaging will also be simply referred to as a “solid-state battery”).

[0103] Preferably, the solid-state battery is placed on the substrate so that the conductive portion of the substrate and the end electrodes of the solid-state battery are electrically connected to each other. For example, a conductive paste may be applied to the substrate to form a bonding member precursor 600', through which the conductive portion of the substrate and the end electrodes of the solid-state battery are electrically connected to each other. More specifically, the conductive portions (particularly the lower lands / bottom lands) on the positive and negative sides of the main surface of the substrate are aligned with the positive and negative end electrodes of the solid-state battery, respectively, and then bonded using a conductive paste (e.g., Ag conductive paste). In other words, a bonding member precursor for electrically connecting the solid-state battery and the substrate may be provided in advance. Such a bonding member precursor can be provided by printing a conductive paste that does not require cleaning after formation, such as Ag conductive paste, nanopaste, alloy-based paste, and / or brazing material. Next, the solid-state battery is placed on the substrate so that the end surface electrodes of the solid-state battery and the precursor of the bonding member are in contact with each other, and the solid-state battery is subjected to a heat treatment, whereby a bonding member that contributes to electrical connection between the solid-state battery and the substrate is formed from the precursor.

[0104] Next, the covering portion is formed. A smoothed covering insulating layer 160 is provided as a component of the covering portion (see FIG. 6E). Here, the smoothed covering insulating layer can be obtained by controlling the filler content, such as by lowering the filler content of the raw material or by not including any filler (i.e., it can be provided as a covering insulating layer with a low filler content or as a covering insulating layer without filler). Furthermore, when a smoothing layer is provided on the covering insulating layer, such a smoothed covering insulating layer can be obtained by forming a first covering insulating layer and then forming a smoothing layer on it as a second insulating layer.

[0105] When forming the covering portion, first, the covering insulating layer 160 is formed so as to cover the solid-state battery 100 on the substrate 200 (see FIG. 6E). For example, a covering insulating layer (first covering insulating layer) is formed that directly contacts or directly covers the solid-state battery 100. For this formation, for example, raw materials for the covering insulating layer are provided so as to completely cover the solid-state battery on the substrate. When the covering insulating layer is made of a resin material, a resin precursor is applied to the substrate and cured to form the covering insulating layer. In a preferred embodiment, the covering insulating layer may be formed by applying pressure in a mold. As a mere example, the covering insulating layer that seals the solid-state battery on the substrate may be formed using a compression mold. If the resin material is a resin material commonly used in molding, the raw materials for the covering insulating layer may be in the form of granules or may be thermoplastic. Note that such forming is not limited to mold forming, but may also be performed by polishing, laser processing, and / or chemical treatment.

[0106] When using the smoothing layer 160B to smooth the surface of the coating insulating layer 160, the smoothing layer 160B may be formed after forming a coating insulating layer corresponding to the first coating insulating layer 160A by the above-described method. Specifically, for example, an alkoxysilane solution is prepared as a raw material solution for the smoothing layer, and the solution is used to form the smoothing layer 160B as the surface layer of the coating insulating layer 160 (for example, the solution may be used for impregnation to form the smoothing layer 160B).

[0107] After the smoothing layer 160B is formed, the coated inorganic layer 170 is formed. Furthermore, when the desired smooth surface of the coated insulating layer 160 is to be obtained without the smoothing layer 160B, the coated inorganic layer 170 is formed after the formation of the coated insulating layer 160 that does not have such a smoothing layer. In other words, the coated inorganic layer 170 is formed on "a coated precursor in which each solid state battery 100 is covered with a coated insulating layer 160 having a smooth surface configuration on the substrate 200."

[0108] The coated inorganic layer may be formed by plating the coated precursor. In one embodiment, the coated inorganic layer may be provided on the coated precursor by forming a plating layer on an exposed surface other than the bottom surface of the coated precursor (i.e., other than the bottom surface of the support substrate).

[0109] When the coated inorganic layer is provided as a plating layer, multiple plating layers may be laminated by performing dry plating and wet plating in a predetermined order. For example, in one embodiment of the present invention, a single layer of dry plating may be performed on the coated precursor, and then multiple types of wet plating may be performed in order, and a dry plating layer, a first wet plating layer, and a second wet plating layer may be laminated in this order.

[0110] Wet plating can be performed by, for example, electroplating or electroless plating. When the deposition rate of plating is more important, it is more preferable to form the wet plating layer by electroplating. Therefore, in one embodiment of the present invention, the wet plating layer can be formed by electroplating, and the wet plating layer can also be referred to as an electroplated layer.

[0111] The metal source for the plating solution used in wet plating may take various forms depending on the type of dry plating layer and / or plating bath. The metal source is not particularly limited, but examples include metal salts of the metals contained in the plating composition, such as inorganic acid salts such as sulfates, hydrochlorides, pyrophosphates, and / or sulfamic acids, and / or organic acid salts such as cyanides. If necessary, the plating solution may contain various supporting electrolytes and additives (stress reducers, brighteners, conductivity aids, reducing agents, antifoaming agents, dispersants, and / or surfactants). Plating conditions include current density, temperature, and / or pH, and these conditions can be set as desired. When electroplating is used to form the plating layer, the plating method may be direct current plating or pulse plating.

[0112] By going through the above steps, a packaged product can be obtained in which the solid-state battery on the substrate is entirely covered with a "smoothed coating insulating layer" and a coating inorganic film. In other words, the "solid-state battery package" according to the present invention can be finally obtained.

[0113] While the above description deals with a configuration in which the covering portion 150 covers the solid-state battery 100, the present invention may also have a configuration in which the solid-state battery 100 is covered by the covering portion 150 to a greater extent. For example, the covering inorganic layer 170 provided on the covering insulating layer 160 that encases the solid-state battery 100 on the substrate 200 may extend to the lower main surface of the substrate 200 (see FIG. 7 ). That is, the covering inorganic layer 170 on the covering insulating layer 160 as the covering portion 150 may extend to the side surface of the substrate 200 and may extend beyond the side of the substrate 200 to the lower main surface of the substrate 200 (e.g., particularly its peripheral portion). In this configuration, a solid-state battery package that more effectively prevents moisture permeation (permeation of moisture from the outside into the solid-state battery stack) may be obtained. Furthermore, although not shown, a metal pad may be provided between the lower main surface of the substrate and the covering inorganic layer to further strengthen the bond between the covering inorganic layer and the substrate. Such a metal pad may be provided, for example, on the peripheral edge of the lower main surface of the substrate.

[0114] A solid-state battery package may be obtained by separately providing a water vapor barrier layer. For example, a separate water vapor barrier layer may be provided on the substrate to be packaged (on the main surface of the substrate, as an example). That is, a water vapor barrier may be formed on the substrate prior to packaging by combining the substrate and the solid-state battery. There are no particular limitations on the water vapor barrier layer, as long as it can form a desired barrier layer. For example, in the case of a "water vapor barrier layer having Si-O bonds and Si-N bonds," it is preferably formed by applying a liquid precursor and irradiating it with ultraviolet light. That is, the water vapor barrier layer may be formed under relatively low-temperature conditions (for example, a temperature condition of about 100°C) without using a vapor-phase deposition method such as CVD and / or PVD.

[0115] Specifically, a liquid precursor containing, for example, silazane is prepared, and the liquid precursor is applied to a substrate by spin coating or spray coating, and then dried to form a barrier precursor. The barrier precursor is then exposed to UV light in a nitrogen-containing atmosphere, resulting in a water vapor barrier layer having Si-O and Si-N bonds.

[0116] It is preferable to locally remove the water vapor barrier layer at the joining portion between the conductive portion of the substrate and the end electrode of the solid-state battery so that the water vapor barrier layer is not present at that portion. Alternatively, a mask may be used to prevent the water vapor barrier layer from being formed at the joining portion. That is, a mask may be applied to the joining portion, and the water vapor barrier layer may be formed overall, and then the mask may be removed.

[0117] Although the embodiments of the present invention have been described above, they are merely typical examples. Those skilled in the art will readily understand that the present invention is not limited to these, and that various modifications are possible within the scope of the present invention.

[0118] For example, although the wet-plated layer having a two-layer structure (a first wet-plated layer and a second wet-plated layer) has been described above as the inorganic coating layer, the present invention is not necessarily limited thereto. The wet-plated layer may be composed of more than two layers, and for example, the wet-plated layer may be provided with a third wet-plated layer in addition to the first wet-plated layer and the second wet-plated layer.

[0119] Furthermore, although a resin layer containing a resin has been mentioned as the smoothing layer, such a resin layer may contain silicon oxide. For example, a smoothing layer containing silicon (Si) as a constituent element or component of the resin material (e.g., a smoothing layer made of a resin material containing an alkoxysilane) may contain silicon oxide, or a smoothing layer not containing silicon (Si) as a constituent element or component of such a resin material may contain silicon oxide. In other words, such a smoothing layer (e.g., a smoothing layer as a silicon-containing resin layer or a smoothing layer as a silicon-free resin layer) may contain silicon oxide (e.g., a silicon oxide filler). In such cases, a raw material containing silicon oxide may be applied to the coating insulating layer to form the smoothing layer on the surface of the coating insulating layer. The type of silicon oxide contained in the smoothing layer is not particularly limited (e.g., silicon dioxide may be used as an example).

[0120] It should be clearly stated that the present invention can also be applied to the following embodiments when viewed from a different perspective. A substrate; a solid-state battery provided on the substrate; a covering portion including at least an insulating covering layer provided to cover the solid-state battery and an inorganic covering layer provided on the outer side of the insulating covering layer; a smoothing layer provided between the coating inorganic layer and the coating insulating layer, the smoothing layer comprising silicon. [Example]

[0121] A demonstration test was carried out in accordance with the present invention. The structure of the solid-state battery package shown in Figure 2 was adopted.

[0122] Specifically, solid state battery packages having the covering insulating layers and covering inorganic layers of Comparative Examples 1 and 2 and Examples 1 to 4 shown in Table 1 below were manufactured.

[0123] [Table 1]

[0124] In Comparative Examples 1 and 2 and Examples 1 to 4, an epoxy resin was used as the thermosetting resin for the insulating resin layers. SiO filler was used as the filler in Comparative Examples 1 and 2 and Examples 1 and 3 and 4 (wt% is based on the first covering insulating layer). In other words, silicon dioxide was used as the silicon / silicon oxide contained in the insulating resin layer. A layer containing alkoxysilane was used as the silicon-containing layer in Examples 3 and 4. More specifically, an alkoxysilane solution was applied to the surface of the first coating insulating layer of the coating insulating layer to form a silicon-containing layer as the second coating insulating layer (smoothing layer). The thicknesses in Examples 3 and 4 (thicknesses in Table 1) were measured by coating a smoothing layer on a glass plate under the same conditions as those used for the above-mentioned production, and measuring the thickness using a reflectance spectrophotometer (FILMETRICS, model F20-EXR). Five samples were measured for each, and the average value was used. The smoothness of the insulating coating layer was evaluated by measuring the developed surface area ratio (Sdr) of the insulating coating layer. To evaluate Sdr, the surface roughness was measured using a laser microscope (Keyence Corporation, Model No. VK-X3050) and Sdr was calculated. Measurements were made on 20 samples of each type, and the average value was used. Defects in the inorganic coating layer were examined using a microscope (Keyence Corporation, Model No. VHX-6000). Five samples were observed at a magnification of 300x. If there was a hole in the inorganic coating layer, it was judged to be "defective." The adhesion of the inorganic coating layer was evaluated in accordance with JIS K5600-5-6 "General test methods for paints - Test methods for mechanical properties of coating films - Adhesion (cross-cut method)." A cross-cut test was conducted after dry plating, and the results were graded according to the following criteria. The results of evaluation of five samples for each category are shown in Table 1. Category I: The edges of the cut are completely smooth and there is no peeling on any of the grid squares. Category B: There is minor peeling of the paint film at the intersections of the cuts, but no more than 5% of the cross-cut area is affected. Category C: The coating is partially flaking along the edges of the cut, but more than 15% but not more than 35% of the cross-cut area is affected. The water vapor transmission rate was calculated by leaving 20 of each manufactured solid-state battery package in an environment of 85°C and 85% RH for 24 hours and then dividing the weight change by the product surface area. The average value for each of the 20 packages is shown in Table 1. An ultra-microbalance (Mettler-Toledo, model XP2UV) was used to measure the weight.

[0125] As can be seen from the results shown in Table 1, the smoothness of the coated insulating layer was insufficient in Comparative Examples 1 and 2. That is, as shown in Comparative Examples 1 and 2, when the developed area ratio Sdr of the interface between the coated insulating layer and the coated inorganic layer was greater than 0.15, defects in the coated inorganic layer were observed. Therefore, the comparative examples in which defects were observed also had a higher water vapor transmission rate than the examples (more specifically, in Comparative Examples 1 and 2, the water vapor transmission rate value was 1.0 g / (m 2 ·day) or more, which was higher than in the examples. On the other hand, in Examples 1 to 4, the coating insulating layer was made as smooth as desired, more specifically, the developed area ratio Sdr of the coating insulating layer was 0.15 or less, there were no defects in the coating inorganic layer, and a more suitable solid-state battery package exhibiting a desired lower water vapor permeability was obtained (more specifically, in Examples 1 to 4, the water vapor permeability value was 1.0 g / (m 2 ·day), specifically 0.5g / (m 2 ·day), more specifically 0.2g / (m 2 Therefore, it was found that the present invention can provide a solid-state battery package capable of further improving the water vapor permeation prevention property.

[0126] In addition, the following can be seen from Table 1. The smoothness of the insulating coating layer can be controlled by the filler content in the insulating coating layer. In other words, by such control, the developed surface area ratio Sdr of the insulating coating layer can be set to 0.15 or less, and the insulating coating layer can be suitably made smooth. When an increase in the surface roughness of the coating insulation layer is expected (for example, when the filler content in the coating insulation layer increases), providing a smoothing layer can make the developed area ratio Sdr of the coating insulation layer 0.15 or less (more preferably less than 0.1), thereby more suitably smoothing the coating insulation layer. Silicon contained in the insulating layer, such as silicon oxide and / or a silicon-containing layer serving as a smoothing layer, can significantly contribute to better adhesion of the insulating layer to the inorganic layer. [Industrial Applicability]

[0127] The solid-state battery package of the present invention can be used in a variety of fields where battery use or power storage is envisioned. By way of example only, the solid-state battery package of the present invention can be used in the fields of electricity, information, and communications where mobile devices are used (e.g., the fields of electrical and electronic equipment or mobile devices including mobile phones, smartphones, laptop computers, digital cameras, activity monitors, arm computers, electronic paper, and small electronic devices such as RFID tags, card-type electronic money, and smart watches), household and small industrial applications (e.g., power tools, golf carts, and household, nursing care, and industrial robots), large industrial applications (e.g., forklifts, elevators, and harbor cranes), transportation systems (e.g., hybrid cars, electric cars, buses, trains, electrically assisted bicycles, and electric motorcycles), power system applications (e.g., various power generation systems, road conditioners, smart grids, and general household-installed power storage systems), medical applications (e.g., medical devices such as earphones and hearing aids), pharmaceutical applications (e.g., medication management systems), IoT, and space and deep-sea applications (e.g., space probes, submersible research vessels, and the like). [Explanation of symbols]

[0128] 100 solid state battery 100A Main surface of the solid-state battery (particularly the upper surface, i.e., the main surface located relatively distal to the substrate) Side view of 100B solid-state battery 100C Main surface of solid-state battery (particularly the lower surface, i.e., the main surface located relatively closer to the substrate) 110 Positive electrode layer 120 negative electrode layer 130 Solid electrolyte or solid electrolyte layer 140 End electrode 140A Positive end electrode 140B Negative electrode end surface 150 Covering part / covering material 160 Insulating coating layer 160' Smooth surface of the insulating coating 160A Covering insulation layer positioned relatively inside the second insulation layer (relative inner layer) / first covering insulation layer) 160B Smoothing layer (covering insulating layer (relative outer layer) positioned relatively outward relative to the first insulating layer / second covering insulating layer) 170 Inorganic coating layer 170a Dry plating layer 170b Wet plating layer 200 boards 210 Substrate electrode layer (upper side of substrate) 210A Positive side substrate electrode layer 210B Negative electrode layer of substrate 220 Mounting side board electrode layer (bottom side of board) 220A Positive side mounting side board electrode layer 220B Negative side mounting side substrate electrode layer 250 Side of the board 600 Joint materials 600' Precursor for joint components 1000 solid state battery packages

Claims

1. A substrate; a solid-state battery provided on the substrate; a covering portion including at least an insulating covering layer provided to cover the solid-state battery and an inorganic covering layer provided on the outer side of the insulating covering layer; Equipped with A solid-state battery package, wherein the developed area ratio Sdr of the coating insulating layer is 0.15 or less.

2. The solid-state battery package according to claim 1 , wherein the covering insulating layer includes a smoothing layer, and the covering inorganic layer is provided on the smoothing layer.

3. The solid-state battery package according to claim 2 , wherein the developed area ratio Sdr of the smoothing layer is 0.15 or less.

4. The solid-state battery package according to claim 2 , wherein the smoothing layer is provided so as to surround the solid-state battery.

5. The solid-state battery package according to claim 1 , wherein the coated inorganic layer is a plating layer.

6. The solid-state battery package according to claim 5 , wherein the plating layer comprises a dry-plated layer disposed on the covering insulating layer and a wet-plated layer on the dry-plated layer.

7. 10. The solid-state battery package of claim 1, wherein the overlying insulating layer comprises silicon.

8. 10. The solid-state battery package of claim 1, wherein the overlying insulating layer comprises silicon oxide.

9. The solid-state battery package according to claim 3 , wherein the smoothing layer is a silicon-containing layer containing silicon.

10. 10. The solid-state battery package of claim 9, wherein the silicon-containing layer comprises an alkoxysilane.

11. 2. The solid-state battery package according to claim 1, wherein the coating inorganic layer comprises at least one metal selected from the group consisting of Cu, Sn, Zn, Bi, Au, Ag, Ni, Cr, Pd, Pt, SUS, and Zn.

12. The wet-plated layer has at least a first wet-plated layer and a second wet-plated layer, 7. The solid-state battery package according to claim 6, wherein the first wet-plated layer comprises at least one metal selected from the group consisting of Cu, Sn, Zn, Bi, Au, and Ag.

13. 13. The solid-state battery package according to claim 12, wherein the second wet-plated layer comprises at least one metal selected from the group consisting of Ni, Cr, Pd, Pt, Zn, and Cu.

14. The solid-state battery package according to claim 6 , wherein the dry-plated layer comprises SUS and / or Cu.

15. The solid-state battery package according to claim 2 , wherein the smoothing layer has a thickness of 1 μm or more.

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