Solid battery package

Abstract

This invention relates to a solid-state battery package comprising a baseboard, a solid-state battery provided on the baseboard, and a cover provided so as to cover the solid-state battery, the cover being provided with a shape-retention layer.

Description

[Technical Field]

[0001] This invention relates to a solid-state battery package. More specifically, this invention relates to a solid-state battery packaged to facilitate mounting. [Background technology]

[0002] Rechargeable batteries, which can be repeatedly charged and discharged, have long been used in a variety of applications. For example, rechargeable batteries are used 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 transfer that contributes to charging and discharging. In other words, so-called electrolyte solutions are used in secondary batteries. However, in such secondary batteries, safety is generally required in terms of preventing electrolyte leakage. Furthermore, since organic solvents used in the electrolyte are flammable substances, safety is required in that respect as well.

[0004] Therefore, research is underway on 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 [Overview of the project] [Problems that the invention aims to solve]

[0006] Solid-state batteries are often mounted on printed circuit boards or other electronic components, requiring a structure suitable for mounting. For example, a solid-state battery package, formed by arranging solid-state batteries on a substrate, facilitates mounting by having the substrate handle the electrical connections to the outside. In addition, a covering portion may be provided to enclose the solid-state batteries in a solid-state battery package.

[0007] The inventors have discovered that when a solid-state battery package is exposed to temperature changes or the like, it can deform due to differences in thermal expansion and contraction between the components that make up the solid-state battery package (hereinafter also referred to as "package components").

[0008] This invention has been made in view of the above problems. That is, the main object of this invention is to provide a solid battery package that can cope with deformation caused by differences in thermal expansion and contraction between package components. [Means for solving the problem]

[0009] The present invention comprises a substrate, a solid battery provided on the substrate, and a covering portion provided to cover the solid battery. A solid battery package is provided, in which a shape-retaining layer is provided on the coating portion. [Effects of the Invention]

[0010] According to the present invention, a solid-state battery package can be provided that addresses deformation caused by differences in thermal expansion and contraction between package components. More specifically, in the solid-state battery package of the present invention, deformation caused by differences in thermal expansion and contraction between package components is reduced. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a schematic cross-sectional view showing one embodiment of the present invention. [Figure 2] Figure 2 is a schematic cross-sectional view showing one embodiment of the present invention. [Figure 3]FIG. 3 is a cross-sectional view schematically showing an embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view schematically showing an embodiment of the present invention. [Figure 5] FIGS. 5(A) to (D) are process cross-sectional views schematically showing a process for obtaining a solid-state battery package according to an embodiment of the present invention. [Figure 6] FIGS. 6(A) to (E) are process cross-sectional views schematically showing a process for obtaining a solid-state battery package according to an embodiment of the present invention. [Figure 7] FIG. 7 is a cross-sectional view schematically showing a conventional solid-state battery package.

[0012] Hereinafter, the solid-state battery of the present invention will be described in detail. Although the description will be made with reference to the drawings as necessary, the illustrated contents are merely schematic and exemplary for the understanding of the present invention, and the appearance and dimensional ratios may be different from the actual ones.

[0013] As used herein, the "solid-state battery package" generally refers to a solid-state battery device (or solid-state battery product) configured to protect the solid-state battery from the external environment, and specifically refers to a solid-state battery product provided with a substrate for mounting and protecting the solid-state battery from the external environment.

[0014] As used herein, the "cross-sectional view" is based on a form captured from a direction substantially perpendicular to the stacking direction in the stacked structure of the solid-state battery (specifically, the form when cut along a plane parallel to the layer thickness direction). Further, the "planar view" or "planar view shape" used herein is based on a schematic view when the object is viewed from above or below along the thickness direction of such a layer (i.e., the above-mentioned stacking direction).

[0015] In this specification, “up and down” and “left and right” as used directly or indirectly correspond to the up and down and left and right directions in the figures, respectively. Unless otherwise specified, the same reference numeral or symbol indicates the same member, part, or has the same meaning. In a preferred embodiment, the vertical downward direction (i.e., the direction in which gravity acts) can be considered as “downward” / “bottom side,” and the opposite direction as “upward” / “top side.”

[0016] In this invention, the term "solid-state battery" broadly refers to a battery whose constituent elements are solid, and narrowly refers to an all-solid-state battery whose constituent elements (particularly preferably all constituent elements) are solid. In one preferred embodiment, the solid-state battery in this invention is a stacked solid-state battery configured such that each layer constituting the battery constituent unit is stacked on top of each other, and preferably each such layer is made of a fired body. The term "solid-state battery" includes not only so-called "secondary batteries" that can be repeatedly charged and discharged, but also "primary batteries" that can only be discharged. According to one preferred embodiment of this invention, the "solid-state battery" is a secondary battery. The term "secondary battery" is not overly restrictive and may also include, for example, energy storage devices. In this invention, the solid-state battery contained in the package may also be called a "solid-state battery element."

[0017] The following describes the basic configuration of the solid-state battery of the present invention. The configuration of the solid-state battery described here is merely an example for understanding the invention and does not limit the invention.

[0018] [Basic Configuration of Solid-State Batteries] A solid-state battery comprises at least positive and negative electrode layers and a solid electrolyte. Specifically, as shown in Figure 1, the solid-state battery 100 comprises a solid-state battery laminate including a battery component unit consisting of a positive electrode layer 110, a negative electrode layer 120, and a solid electrolyte 130 interposed between them.

[0019] Furthermore, each layer constituting the solid-state battery may be formed by firing, and the positive electrode layer, negative electrode layer, and solid electrolyte may form a fired layer. Preferably, the positive electrode layer, negative electrode layer, and solid electrolyte are each fired integrally with each other, and therefore the solid-state battery laminate is a single fired body.

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

[0021] The positive electrode active material and the negative electrode active material are materials that are involved in electron transfer in a solid-state battery. ions move (conduction) between the positive electrode layer and the negative electrode layer via a solid electrolyte, and this electron transfer occurs, resulting in charging and discharging. It is preferable that each electrode layer of the positive and negative electrode layers is capable of intercalating and deintercalating lithium ions or sodium ions. In other words, it is preferable that the solid-state battery is an all-solid-state secondary battery in which charging and discharging occur through the movement of lithium ions or sodium ions between the positive and negative electrode layers via a solid electrolyte.

[0022] (Cathode active material) The positive electrode active material included in the positive electrode layer 110 can be, for example, at least one selected from the group consisting of lithium-containing phosphate compounds having a NASICON-type structure, lithium-containing phosphate compounds having an olivine-type structure, lithium-containing layered oxides, and lithium-containing oxides having a spinel-type structure. An example of a lithium-containing phosphate compound having a NASICON-type structure is Li3V2(PO4)3. An example of a lithium-containing phosphate compound having an olivine-type 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 include O2. Examples of lithium-containing oxides having a spinel-type structure include LiMn2O4 and / or LiNi 0.5 Mn 1.5 Examples include O4.

[0023] Furthermore, as a positive electrode active material capable of intercalating and deintercalating sodium ions, at least one selected from the group consisting of sodium-containing phosphate compounds having a nasicone-type structure, sodium-containing phosphate compounds having an olivine-type structure, sodium-containing layered oxides, and sodium-containing oxides having a spinel-type structure, etc.

[0024] (Negative electrode active material) The negative electrode active material contained in the negative electrode layer 120 includes, for example, at least one selected from the group consisting of oxides containing at least one element selected from the group consisting of Ti, Si, Sn, Cr, Fe, Nb, and Mo, carbon materials such as graphite, graphite-lithium compounds, lithium alloys, lithium-containing phosphate compounds having a NASCICON-type structure, lithium-containing phosphate compounds having an olivine-type structure, and lithium-containing oxides having a spinel-type structure. An example of a lithium alloy is Li-Al. An example of a lithium-containing phosphate compound having a NASCICON-type structure is Li3V2(PO4)3 and / or LiTi2(PO4)3. An example of a lithium-containing phosphate compound having an olivine-type structure is Li3Fe2(PO4)3 and / or LiCuPO4. An example of a lithium-containing oxide having a spinel-type structure is Li4Ti5O 12 These are some examples.

[0025] Furthermore, examples of negative electrode active materials capable of intercalating and deintercalating sodium ions include at least one selected from the group consisting of sodium-containing phosphate compounds having a nasicone-type structure, sodium-containing phosphate compounds having an olivine-type structure, and sodium-containing oxides having a spinel-type structure.

[0026] In addition, in a solid-state battery, the positive electrode layer and the negative electrode layer may be made of the same material.

[0027] The positive electrode layer and / or negative electrode layer may contain a conductive material. Examples of conductive materials included in the positive electrode layer and negative electrode layer include at least one of metallic materials such as silver, palladium, gold, platinum, aluminum, copper, and nickel, as well as carbon.

[0028] Furthermore, the positive electrode layer and / or negative electrode layer may contain a sintering aid. Examples of sintering aids include at least one selected from the group consisting of lithium oxide, sodium oxide, potassium oxide, boron oxide, silicon oxide, bismuth oxide, and phosphorus oxide.

[0029] The thicknesses of the positive electrode layer and the negative electrode layer are not particularly limited, but for example, they may be 2 μm or more and 50 μm or less, and especially 5 μm or more and 30 μm or less, respectively.

[0030] (Positive electrode current collecting layer / Negative electrode current collecting layer) Although not essential elements of the electrode layer, the positive electrode layer 110 and the negative electrode layer 120 may each comprise 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 foil. However, if greater emphasis is placed on aspects such as improved electronic conductivity through integral firing, reduction of manufacturing costs for solid-state batteries, and / or reduction of internal resistance of solid-state batteries, the positive electrode current collector layer and the negative electrode current collector layer may each be in the form of a fired body. It is preferable to use materials with high conductivity as the positive electrode current collector that constitutes the positive electrode current collector layer and the negative electrode current collector that constitutes the negative electrode current collector, for example, silver, palladium, gold, platinum, aluminum, copper, and / or nickel may be used. The positive electrode current collector and the negative electrode current collector may each have an electrical connection part for electrical connection to the outside and may be configured to be electrically connectable to an end electrode. When the positive electrode current collector layer and the negative electrode current collector layer are in the form of a fired body, they may be composed of a fired body containing a conductive material and a sintering aid. The conductive material included in the positive electrode current collector layer and the negative electrode current collector layer may be selected from materials similar to those that may be included in the positive electrode layer and the negative electrode layer. The sintering aid included in the positive electrode current collector layer and the negative electrode current collector layer may be selected from materials similar to those that may be included in the positive electrode layer and the negative electrode layer. As described above, the positive electrode current collector layer and the negative electrode current collector layer are not essential in a solid-state battery, and solid-state batteries without such positive electrode current collector layers and negative electrode current collector layers are also conceivable. In other words, the solid-state battery included in the package of the present invention may be a solid-state battery without current collector layers.

[0031] (solid electrolyte) The solid electrolyte is a material capable of conducting lithium ions or sodium ions. In particular, the solid electrolyte 130 that forms a battery constituent unit in a solid battery may form a layer capable of conducting lithium ions between the positive electrode layer 110 and the negative electrode layer 120. Specific solid electrolytes may be, for example, oxide-based. Examples include lithium-containing phosphate compounds having a NASICON structure, oxides having a perovskite structure, oxides having a garnet type or garnet type similar structure, oxide glass ceramics-based lithium ion conductors, and the like. 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 Ti, Ge, Al, Ga, and Zr). An example of the lithium-containing phosphate compound having a NASICON structure is, for example, Li 1.2 Al 0.2 Ti 1.8 (PO4)3 and the like. An example of the oxide having a perovskite structure is La 0.55 Li 0.35 TiO3 and the like. An example of the oxide having a garnet type or garnet type similar structure is Li7La3Zr2O 12 and the like. As the oxide glass ceramics-based lithium ion conductor, for example, a phosphate compound (LATP) containing lithium, aluminum, and titanium as constituent elements, and a phosphate compound (LAGP) containing lithium, aluminum, and germanium as constituent elements can be used.

[0032] In addition, examples of the solid electrolyte capable of conducting sodium ions include sodium-containing phosphate compounds having a NASICON structure, oxides having a perovskite structure, oxides having a garnet type or garnet type similar structure, and the like. Examples of the sodium-containing phosphate compound 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).

[0033] The solid electrolyte may contain a sintering aid. The sintering aid included in the solid electrolyte may be selected from materials similar to those that may be included in the positive electrode layer and the negative electrode layer.

[0034] 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, and more particularly 1 μm to 5 μm.

[0035] (end face electrode) Solid-state batteries are generally provided with end electrodes. In particular, end electrodes are provided on the sides of the solid-state battery. More specifically, there is a positive-side end electrode connected to the positive electrode layer and a negative-side end electrode connected to the negative electrode layer 120. Such end electrodes are preferably made of a material with high conductivity. The specific material of the end electrodes is not particularly limited, but at least one can be selected from the group consisting of silver, gold, platinum, aluminum, copper, tin, and nickel.

[0036] [Features of the Solid-State Battery Package of the Present Invention] Figure 1 shows a solid-state battery package according to one embodiment of the present invention. Specifically, as shown in Figure 1, the solid-state battery package 200 of the present invention comprises a substrate 10, a solid-state battery 100 provided on the substrate 10, and a covering portion 60 provided to cover the solid-state battery 100, with a shape-retaining layer 40 provided on the covering portion 60. In such a battery package 200, the substrate 10 and the covering portion 60 are provided around the solid-state battery 100 so that the solid-state battery 100 is completely surrounded (all surfaces of the solid-state battery 100 are not exposed to the outside).

[0037] In this invention, the "shape-retaining layer" refers to a layer that contributes to maintaining the shape of a solid battery package; in other words, it is a layer that suppresses or reduces deformation of the solid battery package. For example, the shape-retaining layer is a layer that suppresses or reduces warping, distortion, etc., of the solid battery package as a whole due to heat.

[0038] The solid battery package 200 of the present invention can achieve the effects described below by adopting the above-described embodiment.

[0039] Figure 7 shows a conventional solid-state battery package 200'. Each component constituting the solid-state battery package 200' (substrate 10', covering portion 60', or solid-state battery 100', etc.) has its own coefficient of thermal expansion. Therefore, each component constituting the solid-state battery package 200' can expand or contract due to thermal changes. Such temperature changes can include those that occur during the manufacturing of the solid-state battery package, surface mounting of the solid-state battery package, or use of the solid-state battery package, as will be described later.

[0040] During temperature changes, among the components constituting the conventional solid-state battery package 200', for example, the substrate 10' exhibits relatively small thermal expansion and contraction, while the coating portion 60' exhibits relatively large thermal expansion and contraction. Therefore, a relatively large difference in thermal expansion and contraction occurs between the substrate 10' and the coating portion 60'. The conventional solid-state battery package 200' can deform due to this difference in thermal expansion and contraction. For example, the entire solid-state battery package 200' may deform in a way that causes it to warp.

[0041] As shown in Figure 1, the solid battery package 200 of the present invention is provided with a shape-retaining layer 40 on the covering portion 60 that covers the solid battery 100. The shape-retaining layer 40 has a desired coefficient of thermal expansion. Therefore, the presence of the shape-retaining layer 40 suppresses or reduces warping, distortion, etc., of the solid battery package 200 as a whole due to heat. In other words, the shape-retaining layer 40 included in the solid battery package 200 of the present invention suppresses or reduces deformation of the solid battery package 200 caused by differences in thermal expansion and contraction.

[0042] Examples of deformations include deformation during the manufacturing of the solid battery package 200, deformation during surface mounting of the solid battery package 200, or deformation during use of the solid battery package 200. Examples of deformation during the manufacturing of the solid battery package 200 include deformation caused by differences in thermal expansion and contraction between package components due to heat treatment for resin curing. Examples of deformation during surface mounting of the solid battery package 200 include deformation caused by thermal expansion and contraction between package components due to thermal changes during reflow processing. Examples of deformation during use of the solid battery package 200 include deformation caused by heat generation during charging of the solid battery 100, or deformation caused by differences in thermal expansion and contraction between package components due to use in high-temperature or low-temperature environments. The shape-retaining layer 40 according to one embodiment of the present invention can act as a layer that suppresses or reduces at least one of such deformations.

[0043] In a broad sense, deformation of a solid-state battery package means that it has a shape that deviates from the desired package shape. In a narrow sense, for example, it means that the solid-state battery package has at least a curved portion of its overall contour when viewed in cross-section. Examples include the solid-state battery package warping, tilting, or distortion as a whole. Warping of the solid-state battery package as a whole means that the entire solid-state battery package 200 takes on a curved shape. For example, deformation such as the main surface of the solid-state battery package 200 becoming concave as a whole, or deformation such as the main surface of the solid-state battery package 200 becoming convex as a whole, can also be considered as deformation of the solid-state battery package. The shape-retaining layer 40 according to one embodiment of the present invention can suppress or reduce such deformation, at least if the deformation is caused by the difference in thermal expansion and contraction between the package components. Note that deformation of the solid-state battery package 200 may occur over the entire surface of the solid-state battery package 200, or it may occur only in a part of the surface of the solid-state battery package 200.

[0044] Thermal expansion and contraction refers to the expansion of an object or contraction of its components due to a change in its temperature. For example, each component of the solid battery package 200 may expand when the temperature rises and may contract when the temperature falls.

[0045] As described above, the shape-retaining layer 40 is a layer that contributes to maintaining the shape of the solid battery package 200. Compared to a conventional solid battery package 200', a solid battery package 200 equipped with the shape-retaining layer 40 can preferably suppress deformation due to external and / or internal forces, in addition to deformation caused by thermal expansion and contraction. For example, it can suppress surface cracking of the solid battery package 200' due to expansion of the solid battery caused by charging and discharging of the solid battery 100. Also, for example, it can suppress deformation of the solid battery package 200' when it is pressed.

[0046] The solid-state battery package 200 of the present invention is packaged with a substrate 10 and a covering portion 60, resulting in a battery with superior water vapor permeability prevention. Specifically, the substrate 10 is positioned proximal to one of the main surfaces of the solid-state battery 100, and is provided to shield that main surface of the solid-state battery 100 from the external environment. Furthermore, the top surface 100A and side surface 100B of the solid-state battery 100 on the substrate 10 are covered by the covering portion 60, thereby shielding the solid-state battery 100 from the external environment. As a result, deterioration of battery characteristics due to water vapor (more specifically, the phenomenon in which the characteristics of the solid-state battery deteriorate due to the ingress of water vapor from the external environment) can be further suppressed. In this specification, "water vapor" is not limited to water in a gaseous state, but also includes water in a liquid state, etc. In other words, the term "water vapor" is used to broadly encompass matters related to water, regardless of the physical state. Therefore, "water vapor" can also be called moisture, and in particular, water in a liquid state may include condensed water that has formed from the condensation of water in a gaseous state.

[0047] The possible embodiments of the solid-state battery package of the present invention will be described in detail below.

[0048] The covering portion of a solid-state battery package is typically more easily deformed than the substrate. Specifically, when the solid-state battery package experiences temperature changes, the covering portion can expand and contract relatively more significantly, while the substrate can expand and contract relatively less. The solid-state battery package may deform due to the difference between the thermal expansion and contraction of the covering portion and the substrate. In particular, the covering portion located above the solid-state battery package (for example, above the solid-state battery) is positioned opposite the substrate and is therefore prone to warping due to temperature changes, similar to a bimetallic strip. In other words, the covering portion located above the solid-state battery package is more susceptible to deformation due to thermal expansion and contraction caused by temperature changes than the covering portion that makes up the other surfaces of the solid-state battery package.

[0049] In the present invention, since there is a shape-retaining layer 40 that helps prevent deformation caused by the difference between the thermal expansion and contraction of the coating portion 60 and the thermal expansion and contraction of the substrate 10, deformation of the solid battery package 200 can be suitably suppressed or reduced. As shown in Figure 1, when the solid battery package 200 is considered such that the solid battery 100 is located above the substrate 10, the shape-retaining layer 40 may be positioned above the solid battery 100. In other words, the shape-retaining layer may be positioned above the main surface of the solid battery on the side facing the substrate (for example, the top surface 100A of the solid battery). In the embodiment shown in Figure 1, the solid battery 100 is located between the substrate 10 and the shape-retaining layer 40 because the shape-retaining layer 40 is positioned above the solid battery 100.

[0050] There are no particular restrictions on where the shape-retaining layer 40 is positioned, as long as it is above the solid battery 100. For example, the shape-retaining layer 40 may be provided on the top surface (or top surface) 200A of the solid battery package 200. Alternatively, the shape-retaining layer 40 may be embedded in the covering portion 60. When the shape-retaining layer 40 is embedded in the covering portion 60, it is usually not exposed from the surface of the solid battery package 200, and the entire shape-retaining layer 40 may be covered by the covering portion 60.

[0051] Specifically, a portion of the shape-retaining layer 40 may be embedded and positioned on the top surface 200A of the solid battery package 200. Alternatively, the entire shape-retaining layer 40 may be embedded and positioned within the covering portion 60. When the entire shape-retaining layer 40 is embedded and positioned within the covering portion 60, for example, as shown in Figure 2, the shape-retaining layer 40 may be positioned relatively proximal to the top surface 200A of the solid battery package 200, or the shape-retaining layer 40 may be positioned relatively proximal to the solid battery 100. In any of the above configurations, deformation of the solid battery package 200 can be further suppressed or reduced.

[0052] "Above" refers to a space or location above an object, as defined above. For example, "the shape-retaining layer is positioned above the solid battery" means that the shape-retaining layer is positioned above the solid battery, that is, in a space or location opposite to the direction in which gravity acts.

[0053] Viewing Figure 1 from a different perspective, a covering portion 60 may be provided on top of the shape-retaining layer 40. In other words, the shape-retaining layer 40 may be provided on top of the covering portion 60, or the shape-retaining layer 40 may be surrounded by the covering portion 60. In the configuration shown in Figure 1, the length from one end of the shape-retaining layer 40 to the other end may be approximately the same as the length from one side surface of the covering portion to the other side surface. In other words, the end faces of the shape-retaining layer 40 and the side surfaces of the covering portion may be flush.

[0054] "Upper layer of the covering portion 60" refers to the covering portion 60 that is proximal to the top surface 200A of the solid battery package. For example, the upper layer of the covering portion 60 may be the covering portion provided between the top surface 200A of the solid battery package and the top surface 100A of the solid battery.

[0055] Viewing Figure 2 from a different perspective, the shape-retaining layer 40 may be provided on the covering portion 60. For example, the shape-retaining layer 40 may be provided such that its main surface and the main surface of the covering portion 60 overlap. In other words, the shape-retaining layer 40 may be provided such that its main surface and the main surface of the covering portion 60 are positioned on substantially the same plane. The overlapping of the main surface of the shape-retaining layer 40 and the main surface of the covering portion 60 may be achieved, for example, by embedding the shape-retaining layer 40 within the covering portion 60 as shown in Figure 2, or by having the shape-retaining layer 40 outside the covering portion 60 (for example, by placing the shape-retaining layer 40 on top of the covering portion 60).

[0056] As can be seen from the above explanation, the term "top surface" as used herein refers to the surface located relatively higher among the surfaces constituting the solid battery package 200. Assuming a typical solid battery package with two opposing main surfaces, the term "top surface" as used herein refers to one of these main surfaces, and in particular to the main surface that is different from the main surface that is closer to the substrate 10 (i.e., the mounting surface side in the SMD type battery described later).

[0057] Furthermore, among the deformations caused by differences in thermal expansion and contraction between package components, warping deformation is relatively likely to occur. In this regard, the shape-retaining layer 40 according to one embodiment of the present invention can suppress or reduce warping of the entire solid battery package 200 in particular. In other words, in such cases, the shape-retaining layer 40 preferably corresponds to a warp prevention layer for preventing warping of the solid battery package 200.

[0058] From the viewpoint of further reducing the deformation of the solid battery package 200, the shape-retaining layer 40 and the substrate 10 may be arranged in a parallel relationship to each other in a cross-sectional view as shown in Figure 3. "The shape-retaining layer 40 and the substrate 10 being parallel to each other" can mean, for example, that the separation distance between the shape-retaining layer 40 and the substrate 10 is substantially constant in the planar direction. By arranging the shape-retaining layer 40 and the substrate 10 in a parallel relationship to each other, the direction in which the shape-retaining layer 40 expands and contracts due to heat and the direction in which the substrate 10 expands and contracts due to heat and the heat are more likely to be parallel to each other. Therefore, the shape-retaining layer 40 and the substrate 10 tend to expand and contract similarly due to heat and the heat, making it easier to suppress or reduce the deformation of the solid battery package 200.

[0059] In one embodiment, as shown in Figure 3, the solid battery package 200 may adopt a configuration in which the shape-retaining layer is arranged such that the direction of extension of the side surface 100B of the solid battery is substantially perpendicular to the shape-retaining layer 40. In particular, when the solid battery 100 can be placed on the substrate 10 such that the direction of extension of the side surface 100B of the solid battery is substantially perpendicular to the substrate 10, the shape-retaining layer 40 can also adopt the above configuration, making it easier for the direction of thermal expansion and contraction of the substrate 10 to align with the direction of thermal expansion and contraction of the shape-retaining layer 40. Therefore, deformation of the solid battery package 200 can be more easily suppressed or reduced.

[0060] In one embodiment, in a cross-sectional view as shown in Figure 3, the distance from one end to the other end of the shape-retaining layer 40 may be longer than the distance between one side 100B and the other side 100B of the solid battery. The distance from one end to the other end of the substrate 10 is usually longer than the distance between the sides 100B of the solid battery. By using a shape-retaining layer 40 having the length described above, the distances from one end to the other end of the substrate 10 and the shape-retaining layer 40 become easier to approximate. Therefore, the difference between the magnitude of thermal expansion and contraction of the substrate 10 and the magnitude of thermal expansion and contraction of the shape-retaining layer 40 tends to become smaller, making it easier to suppress or reduce deformation of the solid battery package 200.

[0061] In one embodiment, in a plan view, the outer contours of the shape-retaining layer 40 and the substrate 10 may overlap, and the edges forming the shapes of the shape-retaining layer 40 and the substrate 10 may overlap. In terms of dimensions, in a plan view, the lengths of the shape-retaining layer 40 and the substrate 10 in one direction may be approximately the same, and the lengths of the shape-retaining layer 40 and the substrate 10 in the other direction (for example, a direction perpendicular to the aforementioned one direction) may be approximately the same. As shown in Figure 1, in a cross-sectional view, the width dimensions of the shape-retaining layer 40 and the substrate 10 may be approximately the same. By adopting such a configuration, the shape-retaining layer 40 and the substrate 10 can have the same dimensions, making it easier for the deformation amounts when the shape-retaining layer 40 and the substrate 10 undergo thermal expansion and contraction to be approximately the same. Therefore, the difference in thermal expansion and contraction between the shape-retaining layer 40 and the substrate 10 can be further reduced. Consequently, warping deformation due to the difference in thermal expansion and contraction between the components can be more easily suppressed or reduced.

[0062] The components constituting the solid-state battery package of the present invention are described in detail below.

[0063] [Shape maintaining layer] The shape-retaining layer may be a layer containing resin. For example, the shape-retaining layer may be a layer containing resin components, or the shape-retaining layer may be a resin layer. Specifically, the shape-retaining layer may be a layer containing thermosetting resin or thermoplastic resin. In other words, the shape-retaining layer may be a thermosetting resin layer or a thermoplastic resin layer.

[0064] As the thermosetting resin, at least one selected from the group consisting of epoxy resin, modified epoxy resin, silicone resin, phenolic resin, urea resin, melamine resin, unsaturated polyester resin, polyimide resin, diallyl phthalate resin, polyaminobismaleimide resin, polyurethane resin, and alkyd resin can be used. From the viewpoint of further reducing deformation of the solid battery package, the shape-retaining layer may be a layer containing epoxy resin. When the shape-retaining layer is a layer containing epoxy resin, it becomes easier to adjust the thermal expansion and contraction of the shape-retaining layer. Specifically, it becomes easier to adjust the difference in thermal expansion and contraction between the shape-retaining layer and the substrate to be small, and consequently, the deformation prevention effect of the present invention becomes more apparent.

[0065] As the thermoplastic resin, at least one selected from the group consisting of polyamide resin, polycarbonate resin, polyphenylene sulfide resin, aromatic polyether ketone resin, and thermoplastic polyimide resin can be used.

[0066] The shape-retaining layer may consist of a filler in addition to the resin described above. For example, inorganic fillers and / or organic fillers may be used. Inorganic fillers may include at least one selected from the group consisting of metal powders, carbon materials, silicon oxides, metal oxides, metal hydroxides, metal nitrides, and metal sulfates. For example, ceramic particles, alumina particles, carbon black, graphite, or silica particles may be used as inorganic fillers. Organic fillers may include ABS resin, polyamide resin, etherimide resin, polyphenylene sulfide resin, cellulose, and / or phenolic resin. The shape of the inorganic and / or organic fillers is not particularly limited and may be granular, spherical, needle-shaped, plate-shaped, fibrous, and / or amorphous.

[0067] As the inorganic and / or organic fillers used in the shape-retaining layer, reinforcing fibers may be used. Examples of reinforcing fibers include glass fibers, carbon fibers, aramid fibers, ceramic fibers, potassium titanate fibers, aluminum borate fibers, or boron fibers. The form of the reinforcing fibers may be short fiber (or wool) members or long fiber (or fiber) members. From the viewpoint of further reducing deformation of the solid battery package, glass fibers may be used as fillers for the shape-retaining layer. As the form of glass fibers, glass wool or glass fibers may be used. Glass fibers are fibers with relatively small thermal expansion and contraction. By including glass fibers in the shape-retaining layer, the shape-retaining layer becomes less susceptible to thermal expansion and contraction. When the shape-retaining layer is a layer containing glass fibers, the shape-retaining layer becomes more effective at suppressing or reducing warping of the entire solid battery package.

[0068] When preparing the shape-retaining layer, the layer may consist of a cross member. The cross member may be a cloth-like member made of fibers. The form of the cross member may be any form, such as woven fabric, knitted fabric, or nonwoven fabric. The fibers constituting the cross member may be glass fibers, carbon fibers, aramid fibers, ceramic fibers, potassium titanate fibers, aluminum borate fibers, or boron fibers. From the viewpoint of further reducing the deformation of the solid battery package, glass fibers may be used as the fibers constituting the cross member. In other words, glass cloth may be used as the cross member. As described above, glass fibers are fibers with relatively small thermal expansion and contraction. Furthermore, since glass cloth is a cloth-like member made from glass fibers, its strength may be improved compared to using glass fibers as they are. Therefore, when the shape-retaining layer is a layer consisting of glass cloth, the shape-retaining layer can more effectively suppress or reduce the deformation of the solid battery package.

[0069] As the shape-retaining layer, a material containing FRP (fiber-reinforced plastic), which is made by impregnating reinforcing fibers with resin and forming it into a sheet, may be used. The FRP may be formed by directly impregnating the fibers with resin, or by using a prepreg. As the FRP, a reinforcing fiber cross member impregnated with resin may be used, or a sheet-like member in which reinforcing fibers are aligned in one direction (UD) and impregnated with resin may be used. There are no particular limitations on the direction of the fibers or the weaving method of the fiber cloth. From the viewpoint of further reducing deformation of the solid battery package, it is preferable to form it using a cross prepreg. Regarding the shape-retaining properties of the shape-retaining layer, isotropy is further improved, making it easier to suppress or reduce warping of the entire solid battery package. In one preferred embodiment, glass epoxy (also called epoxy glass), which is glass cloth impregnated with epoxy resin, may be used. More specifically, the shape-retaining layer may be a glass epoxy substrate. A shape-retaining layer having glass epoxy can more effectively suppress or reduce deformation of the solid battery package.

[0070] The shape-retaining layer may be a layer in which the resin is filled with a filler (preferably highly filled). From the viewpoint of further reducing deformation of the solid battery package, for example, the filler content of the shape-retaining layer may be preferably 30% to 90% by weight, more preferably 50% to 90% by weight, and even more preferably 70% to 90% by weight, relative to the total weight of the shape-retaining layer. Including filler within the above range in the shape-retaining layer makes it easier to suppress or reduce warping of the entire solid battery package.

[0071] The shape-retaining layer may be a layer containing metal. In other words, the shape-retaining layer may be a layer containing metallic components. For example, metal may occupy the entire shape-retaining layer, in which case the shape-retaining layer may be a metallic layer. A metal foil may be used as the metallic layer. The metal foil may consist of, for example, copper, silver, titanium, aluminum, or stainless steel. The stainless steel in question refers to stainless steel as defined in, for example, "JIS G 0203 Steel Terminology," and may be an alloy steel containing chromium or chromium and nickel. For example, the shape-retaining layer may partially contain metal, in which case the metal may be included in the shape-retaining layer as a filler. The filler included in the shape-retaining layer as metal may be metal particles or metal oxide particles.

[0072] The method for providing the shape-retaining layer to the coating is not particularly limited. For example, the raw materials for the shape-retaining layer (for example, if resin and filler are used, a sheet-like material made by pre-mixing and compounding the resin and filler) may be provided to the coating, and then the shape-retaining layer may be formed by heat curing or the like. Alternatively, a pre-formed shape-retaining layer may be provided to the coating.

[0073] There are two types of thermal expansion coefficients: "linear expansion coefficient" and "volumetric expansion coefficient," but in this invention, the thermal expansion coefficient refers to the "linear expansion coefficient." In this invention, the thermal expansion coefficient may be measured, for example, using a thermomechanical analyzer (TMA). The thermal expansion coefficient may be a value obtained by a method in accordance with JIS 7197:2012 "Test method for linear expansion coefficient of plastics by thermomechanical analysis," JIS Z2285:2003 "Measurement method for linear expansion coefficient of metallic materials," and JIS C 6481 "Test method for copper-clad laminates for printed wiring boards."

[0074] In this specification, "coefficient of thermal expansion" may refer to the average linear thermal expansion coefficient measured in a temperature range of 0°C to 300°C.

[0075] The thermal expansion coefficient of the shape-retaining layer is preferably 1 ppm / °C to 25 ppm / °C, more preferably 5 ppm / °C to 25 ppm / °C, even more preferably 5 ppm / °C to 15 ppm / °C, and particularly preferably 7 ppm / °C to 13 ppm / °C. When the thermal expansion coefficient of the shape-retaining layer is within the above range, it becomes easier to adjust the difference in thermal expansion and contraction between the shape-retaining layer and other components of the solid battery package (especially the substrate) to be small. Therefore, it becomes easier to suppress or reduce warping of the entire solid battery package.

[0076] The thermal expansion coefficient of the shape retention layer may be the thermal expansion coefficient of the material used as the shape retention layer. For example, the thermal expansion coefficient of the shape retention layer may be the value obtained by measuring the shape retention layer (for example, the substrate or metal foil material used to create the shape retention layer) in the state of the material alone, according to the measurement method exemplified above, before it is provided in the solid battery package. Alternatively, it may be the value obtained by measuring the shape retention layer removed from the solid battery package, according to the measurement method exemplified above.

[0077] The thermal expansion coefficient of the shape-retaining layer is preferably 0.1 to 2.5 times, more preferably 0.5 to 2.5 times, even more preferably 0.5 to 1.5 times, and particularly preferably 0.7 to 1.3 times, of the thermal expansion coefficient of the substrate. An example of the thermal expansion coefficients of the shape-retaining layer and the substrate is that, for example, if the thermal expansion coefficient of the substrate is 10 ppm / °C, the thermal expansion coefficient of the shape-retaining layer is preferably 0.1 ppm / °C to 25 ppm / °C, more preferably 0.5 ppm / °C to 25 ppm / °C, even more preferably 5 ppm / °C to 15 ppm / °C, and particularly preferably 7 ppm / °C to 13 ppm / °C. When the thermal expansion coefficient of the shape-retaining layer is within the above range, it becomes easier to suppress or reduce warping of the entire solid battery package.

[0078] The thermal expansion coefficient of the shape-retaining layer may be smaller than that of the coating. Specifically, the thermal expansion coefficient of the shape-retaining layer may be smaller than that of the coating by 10 ppm / °C to 50 ppm, preferably in the range of 20 ppm / °C to 50 ppm, and more preferably in the range of 30 ppm / °C to 50 ppm. When the thermal expansion coefficient of the shape-retaining layer is within the above range, it becomes easier to suppress or reduce warping of the entire solid battery package.

[0079] The shape-retaining layer 40 itself may be a layer that is less prone to deformation than other package components (especially the covering portion 60). By providing such a shape-retaining layer 40 on the covering portion 60, the thermal expansion and contraction of the covering portion 60 is more easily suppressed due to the presence of the shape-retaining layer 40. In other words, the covering portion 60 on which the shape-retaining layer 40 is provided tends to have relatively smaller thermal expansion and contraction as a whole. Therefore, the difference between the thermal expansion and contraction of the covering portion 60 on which the shape-retaining layer 40 is provided and the substrate 10 tends to be relatively small. In other words, even if a temperature change occurs, deformation of the solid battery package 200 caused by the difference between the thermal expansion and contraction of the substrate 10 and the thermal expansion and contraction of the covering portion 60 can be suppressed.

[0080] The Young's modulus of the shape-retaining layer is preferably 1.0 GPa or more and 450 GPa or less, more preferably 5.0 GPa or more and 450 GPa or less, even more preferably 10 GPa or more and 450 GPa or less, and particularly preferably 20 GPa or more and 450 GPa or less. As a method for measuring Young's modulus, dynamic viscoelasticity measurement, tensile test, compression test, torsion test, resonance method, ultrasonic pulse method, pendulum method, etc. may be used. For example, the value of Young's modulus is a value obtained by a method conforming to JIS standards (JIS C 6481 "Test method for copper-clad laminates for printed wiring boards", JIS K 7244 "Test method for dynamic mechanical properties of plastics", JIS K 7161 "Plastics - Method for determining tensile properties", JIS K 7171:2016 "Plastics - Method for determining bending properties", JIS K 7181 "Plastics - Method for determining compression properties", or JIS Z2241:2011 "Tensile test method for metallic materials", etc.). If the Young's modulus of the shape-retaining layer is within the above range, the strength of the solid-state battery package may be improved. Therefore, even when forces are applied from the outside and / or inside of the solid-state battery package, the package will be able to maintain its shape more easily.

[0081] The thickness of the shape-retaining layer is preferably 20 μm to 500 μm, more preferably 20 μm to 300 μm, even more preferably 50 μm to 300 μm, and particularly preferably 50 μm to 150 μm. When the thickness of the shape-retaining layer is within the above range, the overall size of the solid battery package can be reduced while further reducing the warping of the entire solid battery package. In other words, it is easier to obtain a solid battery package that strikes a better balance between the two.

[0082] [Covered part] As shown in Figure 1, the covering portion 60 is a layer provided to cover the main surface 100A and side surface 100B of the solid battery 100. As shown in Figure 1, the covering portion 60 is provided to cover at least the top surface 100A and side surface 100B of the solid battery, and the solid battery 100 on the substrate 10 is largely enclosed as a whole by the covering portion 60. The material of the covering portion 60 can be any type as long as it exhibits insulating properties. For example, the covering portion 60 may contain a resin, and that resin may be either a thermosetting resin or a thermoplastic resin. The covering portion 60 may contain an inorganic filler. This is merely one example, but the covering portion 60 may be composed of an epoxy resin containing an inorganic filler such as SiC. As shown in Figure 1, if the covering portion 60 is considered as a member that surrounds the solid battery 100, it can be said that the covering portion 60 has an insulating layer that covers the solid battery 100 and a shape-retaining layer.

[0083] The solid battery package 200 of the present invention may be covered by a covering portion 60 so as to completely enclose the solid battery 100 provided on the substrate 10. In other words, the solid battery 100 on the substrate 10 is packaged so as to be enclosed by the covering portion 60. In such a configuration, all surfaces of the solid battery are not exposed to the outside, thus preventing water vapor permeation.

[0084] The solid-state battery package 200 of the present invention can be embodied in various forms. For example, the following forms may be adopted.

[0085] In one embodiment of the present invention, as shown in Figure 3, the solid-state battery 100 is provided on the substrate 10, and a covering portion 60 is provided to cover the solid-state battery 100, with the covering portion 60 including a shape-retaining layer 40. In particular, the covering portion 60 has a covering insulating layer 30 and a covering inorganic layer 50 on the covering insulating layer 30. As a result, the covering insulating layer 30 and the covering inorganic layer 50 work together to more effectively prevent water vapor permeation. In one preferred embodiment, the shape-retaining layer 40 is arranged between the covering insulating layer 30 and the covering inorganic layer 50.

[0086] Figure 3 shows one embodiment in which a solid-state battery 100 provided on a substrate 10 is covered with a covering portion 60 consisting of a covering insulating layer 30 and a covering inorganic layer 50. The covering portion 60 may consist of at least the covering insulating layer 30 and the covering inorganic layer 50 on the covering insulating layer 30.

[0087] [Insulating coating layer] The insulating coating layer 30 may be a layer provided so as to cover at least the top surface 100A and side surface 100B of the solid battery 100. As shown in Figure 3, the solid battery 100 provided on the substrate 10 may be largely enclosed as a whole by the insulating coating layer 30. In one preferred embodiment, the insulating coating layer 30 is provided over the entire battery surface area (at least the entire battery "top" region and battery "side" region) of the solid battery 100, including the top surface 100A and side surface 100B.

[0088] The insulating coating layer 30 is preferably a resin layer. In other words, it is preferable that the insulating coating layer 30 contains resin and that it forms the base material of the layer. As can be seen from the embodiment shown in Figure 3, this means that the solid battery 100 provided on the substrate 10 is sealed with the resin of the insulating coating layer 30. Such an insulating coating layer 30 made of resin, in combination with the inorganic coating layer 50, contributes to a water vapor barrier.

[0089] The material of the insulating coating layer can be any type as long as it exhibits insulating properties. For example, if the insulating coating layer contains a resin, the resin may be either a thermosetting resin or a thermoplastic resin. There are no particular limitations, but specific resins for the insulating coating layer include, for example, epoxy resins, silicone resins, and / or liquid crystal polymers. This is merely an example, but the thickness of the insulating coating layer may be 30 μm or more and 1000 μm or less, for example, 50 μm or more and 300 μm or less.

[0090] The thermal expansion coefficient of the insulating coating layer is preferably 0.1 ppm / °C to 50 ppm / °C, more preferably 0.1 ppm / °C to 25 ppm / °C, even more preferably 1 ppm / °C to 25 ppm / °C, and particularly preferably 1 ppm / °C to 15 ppm / °C. When the thermal expansion coefficient of the insulating coating layer is within the above range, the effect of preventing the entire solid battery package from warping is more easily realized.

[0091] The solid-state battery package of the present invention may take the following forms. For example, in a plan view, the outer contour of the shape-retaining layer 40 and the outer contour of the insulating coating layer 30 may overlap each other. In other words, in a plan view, the edges forming the shape-retaining layer 40 and the edges forming the insulating coating layer 30 may overlap each other. In terms of dimensions, in a plan view, the length of one side of the shape-retaining layer 40 and the length of the insulating coating layer 30 in that direction may be approximately the same, and the length of the other side of the shape-retaining layer 40 (for example, a direction perpendicular to the above-mentioned direction) and the length of the other side of the insulating coating layer 30 may be approximately the same. As shown in Figure 3, in a cross-sectional view, the width dimension of the shape-retaining layer 40 and the width dimension of the insulating coating layer 30 may be approximately the same. By adopting such a configuration, the shape-retaining layer 40 covers the entire insulating coating layer 30, and the thermal expansion and contraction of the entire insulating coating layer 30 can be further suppressed. Therefore, warping deformation due to differences in thermal expansion and contraction between components can be more easily suppressed or reduced.

[0092] From the viewpoint of further reducing deformation of the solid battery package 200, the solid battery package of the present invention may take the following further forms. For example, in a plan view, the outer contours of the shape-retaining layer 40, the insulating coating layer 30, and the substrate 10 may overlap with each other, and the edges that form the shapes of the shape-retaining layer 40, the insulating coating layer 30, and the substrate 10 may overlap with each other. In terms of dimensions, in a plan view, the lengths of the shape-retaining layer 40, the insulating coating layer 30, and the substrate 10 in one direction may be approximately the same, and the lengths of the shape-retaining layer 40, the insulating coating layer 30, and the substrate 10 in the other direction (for example, a direction perpendicular to the above one direction) may be approximately the same. As shown in Figure 3, in a cross-sectional view, the width dimensions of the shape-retaining layer 40, the insulating coating layer 30, and the substrate 10 may be approximately the same. By adopting such a configuration, the shape-retaining layer 40 covers the entire insulating coating layer 30, and the thermal expansion and contraction of the entire insulating coating layer 30 can be further suppressed. Furthermore, since the shape-retaining layer 40 can have the same dimensions as the substrate 10, the amount of deformation when the shape-retaining layer 40 and the substrate 10 undergo thermal expansion and contraction will be approximately the same. Therefore, the difference in thermal expansion and contraction between the shape-retaining layer 40 and the substrate 10 can be further reduced. Consequently, warping deformation due to the difference in thermal expansion and contraction between the components becomes easier to suppress or reduce.

[0093] From the viewpoint of further reducing deformation of the solid battery package, the covering insulating layer and the shape-retaining layer may have the following relationship.

[0094] The thermal expansion coefficient of the shape-retaining layer may be smaller than that of the insulating coating layer. Specifically, the thermal expansion coefficient of the shape-retaining layer may be smaller than that of the insulating coating layer by 10 ppm / °C to 50 ppm, preferably in the range of 20 ppm / °C to 50 ppm, and more preferably in the range of 30 ppm / °C to 50 ppm. When the thermal expansion coefficient of the shape-retaining layer is within the above range, the difference in thermal expansion and contraction between the components of the solid battery package tends to become smaller. This makes it easier to suppress or reduce warping of the entire solid battery package.

[0095] The shape-retaining layer itself may be a layer that is less prone to deformation compared to other package components. For example, the shape-retaining layer may have higher rigidity than the insulating coating layer. In one preferred embodiment, the shape-retaining layer has a higher Young's modulus than the insulating coating layer. For example, the Young's modulus of the shape-retaining layer may be higher than that of the insulating coating layer in the range of 1 GPa to 450 GPa, preferably 10 GPa to 450 GPa, more preferably 50 GPa to 450 GPa, and even more preferably 100 GPa to 450 GPa. By providing a shape-retaining layer with a Young's modulus within the above range in a solid battery package, the rigidity of the insulating coating layer can be increased by the presence of the shape-retaining layer, making it easier to suppress deformation of the solid battery package.

[0096] [Inorganic coating layer] The inorganic coating layer 50 is provided so as to cover the insulating coating layer 30. As shown in Figure 3, since the inorganic coating layer 50 is positioned on the insulating coating layer 30, together with the insulating coating layer 30, it has a configuration that largely encloses the solid battery 100 on the substrate 10 as a whole.

[0097] The coating inorganic layer 50 preferably has a thin film form. The material of the coating inorganic layer 50 is not particularly limited as long as it contributes to an inorganic layer having a thin film form, and may be metal, glass, oxide ceramics, or mixtures thereof. In one preferred embodiment, the coating inorganic layer 50 contains a metal component. That is, the coating inorganic layer 50 is preferably a thin metal film. Although this is merely an example, the thickness of such a coating 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. The coating inorganic layer 50 may be called a coating inorganic film based on its thickness.

[0098] In particular, depending on the manufacturing method, the coating inorganic layer 50 may be a dry-plated film. Such a dry-plated film is obtained by a vapor phase method such as physical vapor deposition (PVD) or chemical vapor deposition (CVD), and has a very small thickness on the nano-order or micron-order. Such a thin dry-plated film contributes to more compact packaging.

[0099] The dry plating film may consist of at least one metallic component, a metalloid component, an inorganic oxide, and / or a glass component selected from the group consisting of, for example, aluminum (Al), nickel (Ni), palladium (Pd), silver (Ag), tin (Sn), gold (Au), copper (Cu), titanium (Ti), platinum (Pt), silicon (Si), and SUS. Since dry plating films made of such components are chemically and / or thermally stable, they can provide solid-state batteries with excellent chemical resistance, weather resistance, and / or heat resistance, resulting in improved long-term reliability.

[0100] The inorganic coating layer 50 can function as a water vapor barrier film. In other words, the inorganic coating layer 50 covers the top surface 100A and side surface 100B of the solid battery 100 so as to serve as a barrier that prevents moisture from entering the solid battery 100. In this specification, "barrier" broadly means having water vapor permeability blocking properties to such an extent that water vapor from the external environment does not pass through the inorganic coating layer and cause undesirable degradation of the solid battery's properties, and narrowly means a water vapor transmission rate of 5.0 × 10⁻⁶ -3 g / (m 2 This means that it is less than 0 days. Therefore, simply put, the water vapor barrier film is preferably 0 to 5 × 10 -3 g / (m 2 It has a water vapor transmission rate of less than 1 / 4 day. In this specification, "water vapor transmission rate" refers to the transmission rate obtained using a gas transmission rate measuring device manufactured by MORESCO, model WG-15S, under measurement conditions of 85°C and 85%RH, by the MA method.

[0101] The covering inorganic layer 50 may be a sputtered film. In other words, a sputtered thin film is provided as a dry plating film that covers the covering insulating layer 30.

[0102] A sputtered film is a thin film obtained by sputtering. In other words, a film is used as a coated inorganic thin film in which ions are sputtered onto a target, knocking out the atoms and depositing them on a coating insulating layer 30.

[0103] Such sputtered films, while having an extremely thin form on the nano- or micro-order, become dense and / or homogeneous films, making them suitable as water vapor permeability barriers for solid-state batteries. Furthermore, because sputtered films are formed by atomic deposition, they have relatively high adhesion and can be more suitably integrated with the coating inorganic thin film. Therefore, sputtered films are more readily formed together with the coating insulating layer 30 to constitute a water vapor barrier film for solid-state batteries. In other words, a sputtered film provided together with the coating insulating layer 30 to cover at least the top surface 100A and side surface 100B of a solid-state battery can serve as a barrier to prevent water vapor from the external environment from entering the solid-state battery.

[0104] In one preferred embodiment, the sputtered film comprises at least one selected from the group consisting of, for example, Al (aluminum), Cu (copper), and Ti (titanium), and its film thickness is 1 μm to 100 μm, for example, 5 μm to 50 μm. Furthermore, although not particularly limited, it is preferable that the sputtered film has substantially the same thickness dimension whether it is located on the top surface or on the side surface of the solid-state battery. This is because it is possible to more uniformly prevent water vapor from the external environment from entering the battery as a whole package.

[0105] Furthermore, dry-plated films, such as sputtered films, can be achieved with a more suitable thickness from the viewpoint of water vapor barrier properties. For example, a thicker film can be provided by relatively increasing the number of sputtering cycles, while a thinner film can be provided by relatively decreasing the number of sputtering cycles. In addition, a coated inorganic layer with a layered structure can be provided, for example, by changing the type of target during sputtering. In other words, the coated inorganic layer can be provided as a multi-layer structure consisting of at least two layers. The multi-layer structure is not limited to dissimilar materials, but may also be between the same materials.

[0106] A wet plating film may be provided on top of a dry plating film. Wet plating films generally have a faster deposition rate than dry plating films. Therefore, when providing a thick film as a coating inorganic layer, a dry plating film may be combined with a wet plating film to achieve efficient film formation.

[0107] [substrate] In the solid battery package 200 of the present invention, the substrate 10 may be a package member provided to support the solid battery 100. That is, the substrate 10 provided closer to one main surface side of the solid battery 100 (the main surface opposite to the main surface forming the top surface) may serve as the support substrate. As shown in Figure 1, the substrate 10 has a main surface larger than, for example, the solid battery 100. The substrate 10 may be a resin substrate or a ceramic substrate. In short, the substrate 10 may belong to the category of printed circuit board, flexible circuit board, LTCC circuit board, or HTCC circuit board, etc.

[0108] When the substrate 10 is a ceramic substrate, the substrate 10 contains ceramic, which constitutes the base material component of the substrate. A substrate made of ceramic is preferable in terms of preventing water vapor permeation and heat resistance during substrate mounting. Such a ceramic substrate can be obtained through firing, for example, by firing a green sheet laminate.

[0109] The substrate 10 preferably serves as a component for the external terminals of the packaged solid battery. In other words, the substrate 10 can be said to be a terminal substrate for the external terminals of the solid battery 100. A solid battery package with such a substrate allows the solid battery to be mounted on another secondary substrate, such as a printed circuit board, with the substrate interposed. For example, the solid battery can be surface mounted via the substrate through solder reflow. For these reasons, the solid battery package of the present invention is preferably an SMD (Surface Mount Device) type battery package.

[0110] Since it is a terminal substrate, it is preferable that it has wiring and electrode layers, and in particular, the substrate may have an electrode layer that electrically connects the upper and lower main surfaces. In other words, a substrate 10 according to a certain preferred embodiment has an electrode layer that electrically connects the upper and lower main surfaces of the substrate and serves as a component for the external terminal of the solid battery package 200. In a solid battery package 200 equipped with such a substrate, the electrode layer of the substrate and the terminal portion of the solid battery are connected to each other. Specifically, the electrode layer of the substrate 10 and the end face electrode 140 of the solid battery 100 are electrically connected to each other. For example, the positive end face electrode of the solid battery is electrically connected to the positive electrode layer of the substrate, while the negative end face electrode of the solid battery is electrically connected to the negative electrode layer of the substrate. By being electrically connected in this way, the positive and negative electrode layers of the substrate are used as the positive and negative terminals of the solid battery package 200, respectively.

[0111] The thermal expansion coefficient of the substrate (especially the base material of the substrate) is preferably 0.1 ppm / °C or more and 50 ppm / °C or less, more preferably 0.1 ppm / °C or more and 25 ppm / °C or less, even more preferably 5 ppm / °C or more and 25 ppm / °C or less, and particularly preferably 5 ppm / °C or more and 15 ppm / °C or less. When the thermal expansion coefficient of the substrate is within the above range, the difference in thermal expansion and contraction between the substrate and the shape-retaining layer is more easily reduced. In other words, the effect of preventing the entire solid battery package from warping becomes more apparent.

[0112] The thickness of the substrate is preferably 20 μm to 500 μm, more preferably 20 μm to 300 μm, even more preferably 50 μm to 300 μm, and particularly preferably 50 μm to 200 μm. When the thickness of the substrate 10 is within the above range, the overall size of the solid battery package 200 can be reduced while further suppressing or reducing warping of the entire solid battery package. In other words, it is easier to obtain a solid battery package that strikes a good balance between the two.

[0113] From the viewpoint of further reducing deformation of the solid battery package, the solid battery package of the present invention may take the following forms. For example, in a plan view, the outer contour of the shape-retaining layer 40 and the outer contour of the substrate 10 may overlap each other. In other words, in a plan view, the edges forming the shape-retaining layer 40 and the edges forming the substrate 10 may overlap each other. In terms of dimensions, in a plan view, one length of the shape-retaining layer 40 and the corresponding length of the substrate 10 may be approximately the same, and the other length of the shape-retaining layer 40 (for example, a direction perpendicular to the above-mentioned one direction) and the corresponding length of the substrate 10 may be approximately the same. In a cross-sectional view, the width dimension of the shape-retaining layer 40 and the width dimension of the substrate 10 may be approximately the same. By adopting such a configuration, the shape-retaining layer 40 can have the same dimensions as the substrate 10, so the amount of deformation when the shape-retaining layer 40 and the substrate 10 undergo thermal expansion and contraction will be approximately the same. Therefore, the difference in thermal expansion and contraction between the shape-retaining layer 40 and the substrate 10 can be further reduced. Therefore, warping deformation due to differences in thermal expansion and contraction between components is more easily suppressed or reduced.

[0114] When the substrate 10 is a ceramic substrate, the effect of preventing water vapor permeation by the substrate 10 is more easily achieved. When the substrate has water vapor barrier properties, as shown in Figure 3, water vapor permeation from the top and sides of the solid battery 100 can be prevented mainly by the insulating coating layer 30 and the inorganic coating layer 50, while water vapor permeation from the bottom (bottom) of the solid battery 100 can be prevented mainly by the substrate 10. Considering that the substrate 10 is preferably a terminal substrate, it can be said that the prevention of water vapor permeation from the bottom (bottom) of the solid battery 100 is mainly achieved by the terminal substrate.

[0115] In one embodiment of the present invention, the substrate 10 may have the form of a multilayer wiring board. That is, the solid battery may be supported by a substrate having multiple layers of wiring. For example, as shown in Figure 4, the substrate 10 may consist of a multilayer wiring board having at least inner via holes 14. In the illustrated substrate 10, that is, in the substrate 10, wiring layers 15 are formed inside the substrate, and the upper and lower wiring layers 15 are connected to each other by inner via holes 14. Having multilayer wiring in this way increases the design freedom of the external terminals as a package product. That is, the external terminals can be positioned at any location on the bottom surface of the battery package product.

[0116] The present invention can be embodied in various forms.

[0117] <<Methods for suppressing deformation during manufacturing>> In this embodiment, deformation of the solid battery package and / or its constituent components that may occur during manufacturing is reduced by the shape-retaining layer. For example, during manufacturing, processes such as forming the constituent components of the solid battery package involve thermal changes, which can cause differences in thermal expansion and contraction between the package constituent components. Differences in thermal expansion and contraction that occur during such processes can be a cause of deformation of the solid battery package and / or its constituent components. Therefore, by providing a shape-retaining layer during package manufacturing, deformation caused by differences in thermal expansion and contraction during manufacturing is suppressed or reduced. Examples of embodiments during manufacturing include the following:

[0118] (Methods for suppressing deformation during resin curing) Solid-state battery packages may contain resin components, and their formation generally involves thermal changes, which can lead to differences in thermal expansion and contraction between the package components. For example, heat treatment may be performed to form the resin components by curing, which can result in differences in thermal expansion and contraction between the package components.

[0119] When the coating portion of a solid-state battery package is composed of a coating insulating layer and a coating inorganic layer, and the coating insulating layer is provided as a resin layer, the resin layer may be formed by curing its precursor. In such cases, a shape-retaining layer may be provided for the resin layer precursor, and the resin layer precursor may be cured together with the shape-retaining layer. In the formation of such a coating insulating layer, the presence of the shape-retaining layer suppresses or reduces package deformation caused by the difference in thermal expansion and contraction when the coating insulating layer is formed from the precursor.

[0120] <<Methods for suppressing deformation during surface mounting>> When surface-mounting solid-state battery packages onto an external substrate, heat treatments such as reflow soldering are performed. This means that reflow soldering generally involves thermal changes, which can lead to differences in thermal expansion and contraction between the package components. For example, reflow soldering, which involves mounting solid-state battery packages to an external substrate via solder, reaches a peak temperature of approximately 260°C. Therefore, significant temperature changes can occur in the solid-state battery package during reflow soldering.

[0121] The solid battery package of the present invention has a shape-retaining layer inside, so deformation is suppressed or reduced even with large temperature changes during reflow processing. In other words, the shape-retaining layer included in the solid battery package more effectively suppresses or reduces package deformation caused by differences in thermal expansion and contraction during reflow processing.

[0122] <<Methods for suppressing deformation during use>> Solid-state battery packages are subjected to charging and discharging during use, or are placed in high-temperature or low-temperature environments.

[0123] For example, during charging, heat may be generated due to electrochemical reactions between the electrodes of a solid-state battery, causing the solid-state battery package to undergo thermal changes. In other words, during charging, such thermal changes may cause differences in thermal expansion and contraction between the package components. The solid-state battery package of the present invention has a shape-retaining layer inside, so such deformation caused by temperature changes during charging is suppressed or reduced. In other words, the shape-retaining layer included in the solid-state battery package more effectively suppresses or reduces package deformation caused by differences in thermal expansion and contraction during charging.

[0124] Furthermore, when a solid-state battery package is placed in a higher or lower temperature environment, it undergoes thermal changes. In other words, thermal changes caused by the temperature environment during use of the solid-state battery package can result in differences in thermal expansion and contraction between the package components. In this regard, the solid-state battery package of the present invention has a shape-retaining layer inside, so that deformation caused by such temperature changes in the surrounding environment is suppressed or reduced. In other words, the shape-retaining layer included in the solid-state battery package more effectively suppresses or reduces package deformation caused by differences in thermal expansion and contraction due to temperature changes.

[0125] [Manufacturing method for solid-state battery packages] The packaged product of the present invention can be obtained by preparing a solid-state battery comprising a battery component having a positive electrode layer, a negative electrode layer, and a solid electrolyte between these electrodes, and then packaging the solid-state battery.

[0126] The manufacturing of the solid-state battery package of the present invention can be broadly divided into the manufacturing of the solid-state battery itself (hereinafter also referred to as the "pre-packaged battery"), which is a preliminary step to packaging, the preparation of the substrate, and packaging.

[0127] <<Method of manufacturing batteries before packaging>> Pre-packaged batteries can be manufactured by printing methods such as screen printing, the green sheet method using green sheets, or a combination of these methods. In other words, the pre-packaged battery itself may be manufactured in accordance with the conventional manufacturing methods for solid-state batteries (therefore, the raw materials such as the solid electrolyte, organic binder, solvent, any additives, positive electrode active material, and negative electrode active material described below may be those used in the manufacture of known solid-state batteries).

[0128] In the following, one manufacturing 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 description and other chronological matters below are merely for explanatory purposes and are not necessarily binding.

[0129] (Laminate block formation) A slurry is prepared by mixing a solid electrolyte, an organic binder, a solvent, and any additives. Then, a sheet containing the solid electrolyte is formed from the prepared slurry by calcination. A paste for the positive electrode is prepared by mixing the positive electrode active material, solid electrolyte, conductive material, organic binder, solvent, and any additives. Similarly, a paste for the negative electrode is prepared by mixing the negative electrode active material, solid electrolyte, conductive material, organic binder, solvent, and any additives. Print the positive electrode paste onto the sheet, and print the current collector layer and / or negative layer as needed. Similarly, print the negative electrode paste onto the sheet, and print the current collector layer and / or negative layer as needed. A laminate is obtained by alternately stacking sheets printed with positive electrode paste and sheets printed with negative electrode paste. The outermost layer (top and / or bottom layer) of the laminate may be an electrolyte layer, an insulating layer, or an electrode layer.

[0130] (Formation of battery-fired body) After the laminate is compressed and integrated, it is cut to a predetermined size. The resulting cut laminate is then degreased and fired. This yields a fired laminate. Alternatively, the laminate may be degreased and fired before cutting, and then cut.

[0131] (Edge electrode formation) The positive end electrode can be formed by applying a conductive paste to the exposed positive electrode side of the fired laminate. Similarly, the negative end electrode can be formed by applying a conductive paste to the exposed negative electrode side of the fired laminate. The positive and negative end electrodes may be provided so as to extend to the main surface of the fired laminate, because they can be connected to the main electrode layer of the substrate over a small area in the next step (more specifically, an end electrode provided so as to extend to the main surface of the fired laminate has a folded portion on the main surface, and such a folded portion can be electrically connected to the main electrode layer of the substrate). The components of the end electrodes can be selected from at least one selected from silver, gold, platinum, aluminum, copper, tin, and nickel.

[0132] Furthermore, the end electrodes on the positive and negative sides are not limited to being formed after the firing of the laminate; they may also be formed before firing and subjected to simultaneous firing.

[0133] By following the process described above, the desired pre-packaged battery can finally be obtained.

[0134] <Preparation of circuit boards> (Resin substrate) If the substrate is a resin substrate, its preparation may be carried out by laminating multiple layers and subjecting them to heating and pressurizing treatment. For example, at least one resin sheet, which is made by impregnating a resin raw material with a base material such as a fibrous cloth and / or paper, and at least one metal sheet (e.g., a sheet of metal foil) are prepared, and these are stacked on top of each other to form a substrate precursor. Then, the substrate precursor is subjected to heating and pressurizing in a press machine to obtain a resin substrate.

[0135] The main surface electrode layer provided on the main surface of the substrate, which is electrically connected, may be patterned as appropriate.

[0136] (Ceramic substrate) If the substrate is a ceramic substrate, its preparation may be carried out, for example, by laminating and firing multiple green sheets.

[0137] The semi-rack substrate may have vias and / or lands. In such cases, for example, holes may be formed in the green sheet by punch press or carbon dioxide laser, and conductive paste material may be filled into the holes, or precursors of conductive parts / wirings such as vias, lands, and / or wiring layers may be formed by printing or other methods. Then, a green sheet laminate is formed by stacking a predetermined number of such green sheets and heat-pressing them together, and a ceramic substrate can be obtained by firing the green sheet laminate. Lands and the like can also be formed after firing the green sheet laminate.

[0138] By going through the above process, the desired substrate can finally be obtained.

[0139] <<Packaging>> The battery and substrate obtained above are used for packaging. Figures 5(A) to (D) schematically show the process of obtaining the solid battery of the present invention through packaging.

[0140] First, as shown in Figures 5(A) and (B), the unpackaged battery 100 is placed on the substrate 10. In other words, an "unpackaged solid battery" is placed on the substrate 10 (hereinafter, the battery used for packaging will also be simply referred to as a "solid battery").

[0141] Preferably, the solid battery 100 is placed on the substrate 10 such that the conductive portion of the substrate 10 and the end face electrodes of the solid battery 100 are electrically connected to each other. In one embodiment, a conductive paste may be applied to the substrate 10 to electrically connect the conductive portion of the substrate 10 and the end face electrodes of the solid battery 100. More specifically, the positive electrode mounting land on the substrate surface may be aligned with the folded portion of the positive electrode end face electrode of the solid battery 100, and the negative electrode mounting land may be aligned with the folded portion of the negative electrode end face electrode of the solid battery, and then a conductive paste (e.g., Ag conductive paste) may be used for bonding. In addition to Ag conductive paste, any conductive paste that does not require cleaning with flux after formation can be used as such a bonding material, such as nanopaste, alloy paste, or brazing material.

[0142] Next, as shown in Figure 5(C), a covering portion 60 is provided so as to cover the solid battery 100 on the substrate 10. Specifically, the covering portion 60 is provided so as to cover the top surface 100A and the side surface 100B of the solid battery 100 placed on the substrate 10.

[0143] After providing the covering portion 60, a shape-retaining layer 40 is provided on the covering portion 60 as shown in Figure 5(D). If the shape-retaining layer 40 is a layer containing resin, a shape-retaining layer precursor may be provided instead of the shape-retaining layer 40. In one embodiment, when providing the shape-retaining layer 40 to the covering portion 60, the shape-retaining layer 40 may be provided above the solid battery 100. The location where the shape-retaining layer 40 is provided is not particularly limited as long as it is above the solid battery 100. For example, a part of the shape-retaining layer 40 may be embedded and positioned on the top surface 200A of the solid battery package 200. Alternatively, the entire shape-retaining layer 40 may be embedded and positioned within the covering portion 60. When the entire shape-retaining layer 40 is embedded and positioned within the covering portion 60, for example, the shape-retaining layer 40 may be positioned relatively close to the top surface 200A of the solid battery package 200, or the shape-retaining layer 40 may be positioned relatively close to the solid battery 100.

[0144] After applying the shape-retaining layer 40 to the coating portion 60, the coating portion 60 and the shape-retaining layer 40 are heat-cured simultaneously. In one preferred embodiment, the coating portion 60 may be molded by applying pressure in a mold.

[0145] When a covering insulating layer 30 and a covering inorganic layer 50 are used as the covering portion 60, the following embodiments can be adopted.

[0146] Figures 6(A) and 6(B) represent the same process as those described above for Figures 5(A) and 5(B). In other words, by going through the process shown in Figures 6(A) and 6(B), a solid-state battery 100 is obtained that is placed on the substrate 10.

[0147] Next, as shown in Figure 6(C), a covering insulating layer 30 is provided so as to cover the solid battery 100 on the substrate 10. Specifically, the covering insulating layer 30 is provided so as to cover the top surface 100A and the side surface 100B of the solid battery 100 placed on the substrate 10. If the covering insulating layer 30 is a layer containing resin, a covering insulating layer precursor may be provided on the substrate 10 instead of the covering insulating layer 30.

[0148] After providing the insulating coating layer 30, a shape-retaining layer 40 is provided on the insulating coating layer 30 as shown in Figure 6(D). If the shape-retaining layer 40 is a layer containing resin, a shape-retaining layer precursor may be provided instead of the shape-retaining layer 40. In one embodiment, when providing the shape-retaining layer 40 on the insulating coating layer 30, the shape-retaining layer 40 may be provided above the solid battery 100. The location where the shape-retaining layer 40 is provided is not particularly limited as long as it is above the solid battery 100. For example, a part of the shape-retaining layer 40 may be embedded and positioned on the top surface 200A of the solid battery package 200. Alternatively, the entire shape-retaining layer 40 may be embedded and positioned within the insulating coating layer 30. When the entire shape-retaining layer 40 is embedded and positioned within the insulating coating layer 30, for example, the shape-retaining layer 40 may be positioned relatively close to the top surface 200A of the solid battery package 200, or it may be positioned relatively close to the solid battery 100. In another embodiment, the shape-retaining layer 40 may be provided such that the substrate 10 on which the solid battery 100 is mounted and the shape-retaining layer 40 are parallel to each other.

[0149] In one embodiment of the present invention, the shape-retaining layer may be provided such that, in a plan view, the outer contour of the shape-retaining layer 40 overlaps with the outer contour of the insulating coating layer 30. Alternatively, in a cross-sectional view, the shape-retaining layer 40 may be provided up to the outer surface of the insulating coating layer 30 covering the side surface 100B of the solid-state battery 100.

[0150] After applying a shape-retaining layer 40 to the insulating coating layer 30, the insulating coating layer 30 and the shape-retaining layer 40 are heat-cured simultaneously. In one preferred embodiment, the insulating coating layer 30 may be molded by applying pressure in a mold. For illustrative purposes only, the insulating coating layer 30 covering the solid battery 100 on the substrate 10 may be molded by compression molding.

[0151] If the resin is one commonly used in molds, the raw material for the insulating coating layer 30 may be in granular form, and may be a thermosetting resin or a thermoplastic resin. Such molding is not limited to die molding; it may also be carried out through polishing, laser processing, and / or chemical treatment.

[0152] In addition, the following embodiment can be adopted as an alternative to Figure 6(D). For example, a shape-retaining layer having a similar coefficient of thermal expansion to the substrate 10 may be fixed parallel to the substrate 10 on which the solid battery 100 is placed, and then a covering insulating layer 30 may be formed so as to cover the solid battery 100 on the substrate 10, and the shape-retaining layer and the covering insulating layer 30 may be heat-cured simultaneously.

[0153] Next, as shown in Figure 6(E), a coating inorganic layer 50 is formed. Specifically, the coating inorganic layer 50 is formed on the "coating precursor on which each solid battery 100 is provided with a coating insulating layer 30 and a shape-retaining layer 40 on the substrate 10". For example, dry plating may be performed to form a dry-plated film as the coating inorganic layer. More specifically, dry plating is performed to form the coating inorganic layer on exposed surfaces other than the bottom surface of the coating precursor (i.e., other than the bottom surface of the substrate). In one preferred embodiment, sputtering is performed to form a sputtered film on the exposed outer surface other than the bottom surface of the coating precursor.

[0154] By going through the above process, a solid battery package can be obtained in which a shape-retaining layer 40 is arranged between the insulating coating layer 30 and the inorganic coating layer 50. In other words, the "solid battery package" according to the present invention can be finally obtained.

[0155] In the above description, an example was given of a method in which a coating insulating layer is molded to largely enclose a solid-state battery on a substrate through a compression mold, but the present invention is not limited thereto. The coating insulating layer may be formed using a coating method such as spray atomization. When a coating method is used, the cross-sectional shape of the coating insulating layer may reflect the contours of the substrate and the solid-state battery on it to a relatively large extent. In this case, the cross-sectional shape of the coating inorganic layer 50 provided on such a coating insulating layer may also reflect the contours of the substrate and the solid-state battery on it to a relatively large extent.

[0156] The embodiments of the present invention have been described above, but these are merely typical examples. The present invention is not limited thereto, and those skilled in the art will easily understand that various embodiments are conceivable without altering the essence of the invention.

[0157] For example, solid-state battery packages can expand and contract during charging and discharging, but such undesirable events caused by expansion and contraction can be suppressed or reduced by a shape-retaining layer. Specifically, when the solid-state battery in the package expands, the expansion puts a load on the package material, which can cause cracks or other damage to the package material. However, since the solid-state battery package of the present invention includes a shape-retaining layer, cracks or other damage to the package caused by expansion and contraction during charging and discharging can be suppressed or reduced. [Examples]

[0158] A demonstration test was conducted in accordance with the present invention. The structure of the solid-state battery package adopted was the structure shown in Figure 3. The process for obtaining the solid-state battery package was the process shown in Figure 6. In the demonstration test, 209 elements were fabricated together on a substrate measuring 130 mm x 130 mm. These were then cut into individual pieces.

[0159] Specifically, solid-state battery packages were manufactured that included the substrate and shape-retaining layer described in Comparative Example 1 and Examples 1-3 shown in Table 1 below. A glass epoxy substrate (4 layers, with Cu foil) was used as the substrate, and a single-layer FR-4 substrate (without copper foil) and copper foil were used for the shape-retaining layer.

[0160] [Table 1]

[0161] The coefficient of linear expansion and Young's modulus of the FR-4 substrate used for the substrate and shape retention layer were obtained using a method compliant with JIS standard JIS C 6481 "Test Method for Copper-Clad Laminates for Printed Wiring Boards".

[0162] The thickness dimensions of the substrate and shape retention layer were measured before manufacturing the solid battery package, but the thickness may also be determined from a cross-section processed using an ion milling device (Hitachi High-Tech Corporation, model SU-8040) after the solid battery package has been created.

[0163] The occurrence of warpage in the solid-state battery packages of the comparative examples and examples was evaluated. The amount of warpage of the solid-state battery packages (element size 130 mm × 130 mm) containing multiple fabricated battery elements was measured using a laser displacement meter.

[0164] Next, to evaluate the occurrence of warping due to heat, the deformation of solid battery packages (element size 6 mm x 10 mm) after cutting them into individual pieces was measured at 25°C and 260°C using the shadow moiré method to determine the coplanarity at each temperature. The difference in the maximum displacement at each temperature was calculated and defined as the amount of thermal deformation.

[0165] According to the results above, comparing the solid battery packages of Implementations 1-3 and Comparative Example 1, the examples using the shape-retaining layer showed a reduction in package warping and thermal warping. Therefore, the presence of a shape-retaining layer on the covering portion of the solid battery suppresses or reduces warping and distortion of the solid battery package as a whole due to heat or other factors. In other words, the shape-retaining layer included in the solid battery package of the present invention suppresses or reduces deformation of the solid battery package caused by differences in thermal expansion and contraction. [Industrial applicability]

[0166] The packaged solid-state battery of the present invention can be used in a variety of fields where battery use or energy storage is anticipated. While this is merely an example, the packaged solid-state battery of the present invention can be used in the field of electronics packaging. Furthermore, the electrodes of the present invention can be used in the electrical, information, and communication fields where mobile devices are used (e.g., mobile devices such as mobile phones, smartphones, laptops, digital cameras, activity trackers, arm computers, and electronic paper), in household and small-scale industrial applications (e.g., power tools, golf carts, and household, caregiving, and industrial robots), in large-scale industrial applications (e.g., forklifts, elevators, and port cranes), in transportation systems (e.g., hybrid vehicles, electric vehicles, buses, trains, electric-assist bicycles, and electric motorcycles), in power grid applications (e.g., various power generation systems, road conditioners, smart grids, and general household energy storage systems), as well as in medical applications (e.g., medical devices such as earphones and hearing aids), pharmaceutical applications (e.g., medication management systems), IoT applications, and space and deep-sea applications (e.g., space probes and submersible research vessels). [Explanation of symbols]

[0167] 10 circuit boards 14 Inner Beer Hall 15 wiring layer 30 Insulating coating layer 40 Shape retention layer 50 Inorganic coating layer 60 Covered part 100 solid state battery Top view of a 100A solid-state battery Side view of a 100B solid-state battery 110 Positive electrode layer 120 Negative electrode layer 130 Solid electrolyte or solid electrolyte layer 140 End electrode 200 Solid-State Battery Package Top view of a 200A solid-state battery package

Claims

1. circuit board and A solid battery provided on the substrate, The solid battery is provided with a covering portion, A shape-retaining layer is provided on the upper layer of the covering portion. The shape-retaining layer is plate-shaped, in a solid battery package.

2. The solid battery package according to claim 1, wherein the shape-retaining layer is positioned above the main surface of the solid battery on the side facing the substrate.

3. The solid battery package according to claim 1 or 2, wherein the thermal expansion coefficient of the shape-retaining layer is 0.7 times or more and 1.3 times or less the thermal expansion coefficient of the substrate.

4. The solid battery package according to claim 1, wherein the shape-retaining layer and the substrate are arranged parallel to each other.

5. The solid battery package according to claim 1, wherein a covering portion is further provided on the shape-retaining layer.

6. The solid battery package according to claim 1, wherein the shape-retaining layer is embedded in the covering portion.

7. The solid battery package according to claim 1, wherein the covering portion has a covering insulating layer and a covering inorganic layer provided on the outside of the covering insulating layer.

8. The solid battery package according to claim 1, wherein the covering portion has a covering insulating layer and a shape-retaining layer.

9. The solid battery package according to claim 8 or 9, wherein the thermal expansion coefficient of the shape-retaining layer is smaller than that of the insulating coating layer.

10. The solid battery package according to claim 7, wherein the shape-retaining layer has higher rigidity than the covering insulating layer.

11. The solid battery package according to claim 1, wherein the shape-retaining layer is a layer containing resin.

12. The solid battery package according to claim 1, wherein the shape-retaining layer comprises a filler.

13. The solid battery package according to claim 1, wherein the shape-retaining layer is a layer containing fiber-reinforced plastic.

14. The solid battery package according to claim 1, wherein the shape-retaining layer is a layer containing metal.

15. The solid battery package according to claim 1, wherein the shape-retaining layer is a glass epoxy substrate.

16. The solid battery package according to claim 1, wherein the thickness of the shape-retaining layer is 20 μm or more and 500 μm or less.

17. The solid battery package according to claim 1, wherein the shape-retaining layer is a warp-preventing layer for preventing warping of the solid battery package.

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