JP2020172410A - Glass - Google Patents

Abstract

To provide glass having high ion conductivity and high fluidity when softened.SOLUTION: The glass contains, in cation%, Li+ of 50% or more and less than 90%, and B3+ of more than 10% to 50% or less, and contains, in anion%, O2- of 30% or more and less than 100%, SO42- of more than 0% to 60% or less, and Cl- of more than 0% to 30% or less.SELECTED DRAWING: None

Description

The present invention relates to glass, a solid electrolyte containing the glass, and a binder to be attached.

The glass material can be sintered at a lower temperature than the ceramic material composed of crystals. Taking advantage of this property, glass powder has been used as a binder for attaching powder materials such as ceramic powder for low-temperature co-fired ceramic multilayer substrate and electrode powder. By using a glass powder that can be sintered at a low temperature as a binder for binding, even a powder material that is easily denatured by heat can be bound while suppressing the degeneration.

In order to lower the softening point of the glass so that it can be sintered at a lower temperature, it is effective to add an alkali metal to the glass, and in particular, it is effective to add lithium.
Lithium-containing glass is expected to be used as a material for forming a dielectric layer (insulator layer) in a high-density circuit board by mixing with, for example, functional ceramic powder. It is also expected to be used as a material for forming a conductive layer by mixing with a conductive powder such as metal.

Further, since glass containing lithium has high ionic conductivity, it is expected as a material for a solid electrolyte. For example, Patent Documents 1 and 2 disclose that glass containing a predetermined amount of Li ₂ O is used as an electrolyte.

JP-A-2015-63447 Special Fair 3-61286 Gazette

The glass electrolytes disclosed in Patent Documents 1 and 2 cannot be said to have sufficiently high ionic conductivity, and improvement has been desired.

Further, depending on the composition of the glass containing LiO ₂ as disclosed in Patent Documents 1 and 2, when it is heated and softened, crystals having a high melting point are precipitated. Since such crystals exist in the softened glass without melting, the fluidity of the softened glass is reduced. When the fluidity of the softened glass is lowered, the softened glass cannot sufficiently fill the voids between the powder materials, so that a dense sintered body cannot be obtained, which adversely affects the performance of the resulting multilayer substrate and solid electrolyte.
Therefore, a glass having high fluidity at the time of softening has been desired.

The present invention has been made in view of the above, and an object of the present invention is to provide a glass having high ionic conductivity and high fluidity at the time of softening.

The glass of the present invention that solves the above problems contains Li ^{+ in an amount} of 50% or more and less than 90% and B ³⁺ in an amount of more than 10% and 50% or less in cation% notation, and O ^{2- in} anion% notation. less than 30% or more 100%, _SO ^{4 2-} 0 percent to 60% or less, and, Cl ^- and containing 0% or less than 30%.
In one aspect of the glass of the present invention, the difference between the crystallization start temperature Tc1-on and the glass transition point Tg ((Tc1-on) -Tg) may be 30 ° C. or higher.
In one aspect of the glass of the present invention, the glass transition point Tg may be 200 ° C. or higher and 450 ° C. or lower.
In one aspect of the glass of the present invention, the ionic conductivity may be 7.0 × ^10-7 S / cm or more.
In one aspect of the glass of the present invention, the softening fluidity measured by the following method may be 10% or more.
(Measuring method of softening fluidity)
Grinding using the glass mortar, a glass powder is obtained through a 300 mesh sieve. 100 mg of the obtained glass powder is filled in a DTA cell having an inner diameter of 5 mm and a depth of 5 mm. At this time, the diameter of the filled glass powder group is R1. Subsequently, the glass powder group is heated, and the diameter when the diameter of the glass powder group is minimized is defined as R2. Using these, the softening fluidity is calculated by the following formula.
Softening fluidity (%) = {(R1-R2) / R1} x 100
Further, the solid electrolyte of the present invention includes the glass of the present invention.
In addition, the binding binder of the present invention includes the glass of the present invention.

The glass of the present invention has high ionic conductivity and high fluidity when melted.

1A and 1B are views for explaining a method for measuring softening fluidity, FIG. 1A is a top view of a DTA cell before heating, and FIG. 1B is a top view of a DTA cell being heated. It is a figure. FIG. 2 is a diagram schematically showing an example in which the glass of the present invention is used for a laminated ceramic capacitor. FIG. 3 is a diagram schematically showing an example in which the glass of the present invention is used for a low-temperature co-fired ceramic multilayer substrate. FIG. 4 is a diagram schematically showing an example in which the glass of the present invention is used in a lithium ion secondary battery.

Hereinafter, embodiments of the present invention will be described. The present invention is not limited to the embodiments described below.

In the present specification, "cation%" is divided into a cation component and an anion component of the glass, and the molar content of each cation component is expressed as a percentage with respect to the total molar content of all cation components contained in the glass. It is a unit that has been used. In the present specification, when the content of the cation component is expressed in%, it means cation% unless otherwise specified.
The content of each cation component contained in the glass is determined from the result of inductively coupled plasma emission spectroscopy (ICP-AES: Inductively Coupled Plasma-Atomic Emission Spectroscopy) of the obtained glass.

In the present specification, "anion%" is a component of glass divided into a cationic component and an anion component, and the molar content of each anion component is expressed as a percentage with respect to the total molar content of all anion components contained in the glass. It is a unit that has been used. In the present specification, when the content of the anion component is expressed in% notation, it means anion% unless otherwise specified.
The content of each anion component contained in the glass can be obtained from the result of the quartz tube combustion ion chromatograph method.

In the present specification, "mol%" is a unit in which the molar content of each component is expressed as a percentage with respect to the total molar content of all the components of the glass.

<Glass>
The glass of the present embodiment contains Li ⁺ of 50% or more and less than 90% and B ³⁺ of more than 10% and 50% or less in cation% notation, and O ^2- in 30% or more in anion% notation. less than 100%, _SO ^{4 2-} 0 percent to 60% or less, and, Cl ^- and containing 0% or less than 30%.
Hereinafter, the glass of the present embodiment will be described in detail.

(Cation component)
Li ⁺ is an element that lowers the Tg of glass and further improves the ionic conductivity.
If the content of Li ⁺ in the cation component of the glass of the present embodiment is too small, Tg cannot be sufficiently lowered and sufficient ionic conductivity cannot be obtained. Therefore, the content of Li ⁺ in the cation component of the glass of the present embodiment is 50% or more, preferably 53% or more, and more preferably 55% or more.
On the other hand, if the content of Li ⁺ in the cation component of the glass of the present embodiment is too large, the content of B ³⁺ , which is a glass-forming element, is relatively small, so that the stability of the glass is lowered. Therefore, the content of Li ⁺ in the cationic component of the glass of the present embodiment is less than 90%, preferably 85% or less, and more preferably 80% or less.

B ³⁺ is a glass-forming element and is an element that contributes to improving the stability of glass.
If the content of B ³⁺ in the cationic component of the glass of the present embodiment is too small, the stability of the glass is lowered. Therefore, the content of B ³⁺ in the cation component of the glass of the present embodiment is more than 10%, preferably 20% or more, more preferably 30% or more.
On the other hand, if the content of B ³⁺ in the cation component of the glass of the present embodiment is too large, the content of Li ⁺ that contributes to the improvement of the ionic conductivity is relatively small, so that the ionic conductivity is lowered. Therefore, the content of B ³⁺ in the cation component of the glass of the present embodiment is 50% or less, preferably 45% or less, and more preferably 43% or less.

Further, the glass of the present embodiment may contain Si ⁴⁺ as a cation component. Si ⁴⁺ is a glass-forming element like B ³⁺ . Compared with B ³⁺ , Si ⁴⁺ has a large effect of stabilizing the glass against heat treatment if the content is small. However, it is not preferable to increase the content because the ionic conductivity is likely to be lowered. In addition, when the content is high, lithium silicate-based crystals are precipitated by heat treatment, so it is not preferable to increase the content.
The content of Si ⁴⁺ in the cationic component of the glass of the present embodiment may be 0%, but from the viewpoint of the stability of the glass, it is preferably 0.3% or more, more preferably 0.5% or more, still more preferably. Is 0.8% or more.
On the other hand, if the content of Si ⁴⁺ in the cationic component of the glass of the present embodiment is too large, the content of Li ⁺ that contributes to the improvement of ionic conductivity becomes relatively small, and oxygen (O) that constrains Li ions. In addition, since the potential for precipitating lithium silicate-based crystals composed of Li, Si, and O increases, the ionic conductivity decreases and the stability in heat treatment is impaired. Therefore, the content of Si ⁴⁺ in the cation component of the glass of the present embodiment is 7% or less, preferably 6% or less, and more preferably 5% or less.

The glass of the present embodiment may contain a cation component other than the above as long as the content is within the range in which the effect of the present invention is exhibited. For example, the glass of this embodiment has Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ , Si ⁴⁺ , Zr ⁴⁺ , Ge ⁴⁺ , P ⁵⁺ , Ta ⁵⁺ , W ⁶⁺ , Fe ²⁺ , Fe ³⁺ , Sc ³⁺ , Y as cation components. ^{3+, La 3+, Ce 3+,} Ce 4+, Gd 3+, Ti 4+, Cr 3+, Mn 2+, Mn 3+, Mn 4+, Co 2+, Co 3+, Ni 2+, Ni 3+, Cu 2+, Zn 2+, Al 3+, It may contain Ga ³⁺ , In ³⁺ , Sn ²⁺ , Sn ⁴⁺ , Sb ³⁺ , Sb ⁵⁺ , Bi ^{3+ and the} like. It should be noted that these are merely examples, and the cation components that the glass of this embodiment can contain other than Li ⁺ , B ³⁺ , and Si ⁴⁺ are not limited to these.

(Anion component)
Glass mainly composed of oxides (hereinafter, also referred to as “oxide-based glass”) has high chemical stability. However, since O ^2-, which is an anionic component of oxide-based glass, strongly constrains Li ⁺ , oxide-based glass has low ionic conductivity. The O ^2- of oxide glass, by Li ⁺ of binding to exchange a weak anion component, high chemical stability, high glass also ion conductivity can be obtained.

By exchanging O ⁻ in the glass with Cl ^−, which has a weak binding force of Li ⁺ , the ionic conductivity of the glass can be improved. However, when O ⁻ in the glass is replaced only with Cl ⁻ , crystals of LiCl having a high melting point precipitate when heated and softened, and the fluidity deteriorates. The present inventors have, O in the glass ^- a Cl ^- by exchanging with the SO ₄ ^2-city, found that compatible and improve ion conductivity, the suppression of the decrease in fluidity during softening. In such glass, when heated and softened, a eutectic compound of LiCl and Li ₂ SO ₄ is precipitated, and the precipitation of LiCl is suppressed. Such a eutectic compound has a low melting point and is a component that melts in softened glass during glass sintering to improve fluidity.

The content of SO ₄ ^2-in anionic component of the glass of the present embodiment may be a greater than 0%, but from the viewpoint of further improving the fluidity during the softening of the ion conductivity and the glass is 0.5% The above is preferable, and 1.0% or more is more preferable.
On the other hand, it the content of SO ₄ ^2-in anionic component of the glass of the present embodiment is too much likely to precipitate crystals, also the stability of the glass content of O ^2- becomes relatively less deterioration There is a risk of Further, the Cl- content is relatively low, and the ionic conductivity is lowered. Accordingly, the content of _SO ^{4 2-in} anionic component of the glass of the present embodiment is 60% or less, preferably 55% or less, more preferably 30% or less.

The content of Cl ⁻ in the anion component of the glass of the present embodiment may be more than 0%, but from the viewpoint of further improving the ionic conductivity and the fluidity during softening of the glass, it is preferably 5% or more. More preferably, it is 10% or more.
On the other hand, if the content of Cl ⁻ in the anion component of the glass of the present embodiment is too large, the crystals of LiCl are likely to be precipitated by the heat treatment, and the contents of SO ₄ ^2- and O ^2- are relatively small. .. Therefore, the content of Cl ⁻ in the anion component of the glass of the present embodiment is 30% or less, preferably 25% or less, and more preferably 20% or less.

The content of O ^2- in the anionic component of the glass of the present embodiment is less than 100%. From the viewpoint of further improving the ion conductivity, the content of O ^2- in the anionic component of the glass of the present embodiment is preferably 90 or less, more preferably 85 or less.
On the other hand, when the content of O ^2- in the anionic component of the glass of the present embodiment too little stability of the glass deteriorates. Accordingly, the content of O ^2- in the anionic component of the glass of the present embodiment is 30% or more, preferably 70% or more, more preferably 75% or more.

The glass of the present embodiment may contain an anion component other than the above as long as the content is within the range in which the effect of the present invention is exhibited. For example, the glass of the present embodiment may contain Br ⁻ , I ⁻ , S ^{2- and the} like as an anion component. It should be noted that these are merely examples, the glasses of the present embodiment is O _^2-, SO 4 ^2-, and Cl ^- anion component may contain in addition is not limited thereto.

(Characteristics of glass)
When the glass of the present embodiment is used as a binder for binding, a powder or the like to be bonded to the glass of the present embodiment is mixed, and if necessary, a resin material is mixed to form a paste, which is then heated. Sinter. The heating temperature at this time is usually set to a glass transition point Tg or more in order to sufficiently proceed with sintering to obtain a dense sintered body, and a crystallization start temperature Tc1-on or less in order to suppress crystal precipitation. And.
Here, if the heating temperature at the time of sintering is too high, there is a risk that the powder to be bound (for example, electrode material powder) reacts with the glass. From the viewpoint of suppressing this reaction, it is preferable that the glass can be sintered at a low temperature, that is, it is preferable that the Tg is low. Therefore, the Tg of the glass of the present embodiment is preferably 450 ° C. or lower, more preferably 430 ° C. or lower, and even more preferably 400 ° C. or lower.
On the other hand, if the heating temperature at the time of sintering is too low, the resin material used for pasting will not be sufficiently thermally decomposed, and the resin material will remain inside the obtained sintered body to obtain a dense sintered body. It may be difficult to get rid of. Therefore, in order to obtain a dense sintered body, it is preferable to perform sintering at a temperature at which the thermal decomposition of the resin material proceeds sufficiently. When the Tg of the glass of the present embodiment is 200 ° C. or higher, the temperature at the time of sintering is a temperature at which the resin material is sufficiently thermally decomposed, and a dense sintered body can be obtained, which is preferable.

Further, in order to prevent the heating temperature at the time of sintering from being insufficient to obtain a dense sintered body or the heating temperature to be too high to cause crystals to precipitate, Tg and Tc1 of the glass of the present embodiment are used. It is preferable that the difference between −on is large.
Therefore, the difference between Tg and Tc1-on ((Tc1-on) -Tg) of the glass of the present embodiment is preferably 30 ° C. or higher, more preferably 50 ° C. or higher.

Tg and Tc1-on can be determined by differential thermal analysis (DTA) of glass using inflection points, peaks, etc. of the DTA curve indicating the amount of heat generation-heat absorption. Both Tg and Tc1-on are temperatures inherent in the composition of the glass.

The glass of this embodiment has high ionic conductivity. The ionic conductivity of the glass of the present embodiment is preferably 7.0 × 10 ^-7 S / cm or more, more preferably 8.0 × 10 ^-7 S / cm or more, and 1.0 × 10 ^-6 S / cm. The above is more preferable.

In the present specification, the ionic conductivity means the ionic conductivity obtained by measuring the AC impedance at room temperature (20 ° C. to 25 ° C.). The ionic conductivity is measured by the AC impedance method using a sample having electrodes formed on both sides. Specifically, the applied voltage is 50 mV, the measurement frequency range is 1 Hz to 1 MHz, and the calculation is made from the arc diameter of the Niquist plot obtained by the AC impedance measurement.

Further, the glass of the present embodiment has high fluidity at the time of softening. The fluidity of the glass during softening can be evaluated by various methods. For example, the degree of shrinkage when the glass of the present embodiment is powdered and sintered can be evaluated. Specifically, it can be evaluated using the softened fluidity measured by the following method. The softening fluidity described below is preferably 5% or more, more preferably 10% or more, still more preferably 15% or more.
(Measuring method of softening fluidity)
First, glass is crushed using a mortar, and the crushed glass flakes are passed through a 300 mesh sieve to obtain glass powder. Next, 100 mg of the obtained glass powder is weighed and filled in a DTA cell 1 having an inner diameter of 5 mm and a depth of 5 mm as shown in FIG. 1 (A). The diameter of the filled glass powder group 2 at this time is defined as the initial diameter R1. Subsequently, when the glass powder group 2 is heated and sintering proceeds, the glass powder group 2 shrinks and its diameter becomes smaller. As shown in FIG. 1 (B), the diameter when the diameter of the glass powder group 2 is minimized is defined as R2. Using the obtained R1 and R2, the softening fluidity can be determined by the following formula.
Softening fluidity (%) = {(R1-R2) / R1} x 100

(Glass manufacturing method)
The method for producing the glass of the present embodiment is not particularly limited, and examples thereof include the methods shown below.

First, the raw materials are mixed to prepare a raw material mixture. The raw material is not particularly limited as long as it is a raw material used for producing ordinary oxide-based glass, and oxides, carbonates, and the like can be used. The types and proportions of the raw materials are appropriately adjusted so that the composition of the obtained glass is within the above range to prepare a raw material mixture.

Next, the raw material mixture is heated by a known method to obtain a melt. The heating temperature (melting temperature) is preferably 800 to 1400 ° C, more preferably 900 to 1300 ° C. The heating time is preferably 10 to 50 minutes, more preferably 20 to 40 minutes.

Then, the glass of the present embodiment can be obtained by cooling and solidifying the melt. The cooling method is not particularly limited. For example, it can be cooled by using a roll-out machine, a press machine, or the like, and can be rapidly cooled by dropping it on a cooling liquid or the like. The resulting glass is completely amorphous, i.e., crystallinity is 0%.

The glass of the present invention thus obtained may be in any form. For example, it may be block-shaped, plate-shaped, thin plate-shaped (flake-shaped), powder-shaped, or the like.

<Complex>
Crystals may be added to the glass of the present embodiment and used as a composite.
By adding a crystal to the glass of the present embodiment, it is possible to adjust various properties such as strength, coefficient of thermal expansion, chemical durability, optical function, ionic conductivity, electron conductivity, and electrode function. ..

The crystal body to be added may be a crystal body precipitated from the glass of the present embodiment, a crystal body to be added other than this, or both of them. The composite containing the glass of the present embodiment and the crystals precipitated from the glass of the present embodiment is, for example, a glass of the present invention having a Tc1-on or higher, which adds a sufficient heat history in the production of the glass of the present invention. It can be manufactured by a method such as heat treatment. Examples of the crystals precipitated from the glass of the present invention include ceramics and ionic conductive crystals.

The content of the crystals in the complex may be more than 0% by volume in total with respect to the total amount of the complex, but is preferably 1% by volume or more.
From the viewpoint of sinterability, the total content of the crystals in the composite is preferably 70% by volume or less, more preferably 50% by volume or less, based on the total amount of the composite.
From the viewpoint of sinterability, the content of the glass of the present embodiment in the composite is preferably 30% by volume or more, preferably 50% by volume or more, based on the total amount of the composite.
The glass content of the present embodiment in the composite may be less than 100% by volume with respect to the total amount of the composite, but is preferably 99% by volume or less.

<Yui wearing binder>
Since the glass of the present embodiment can be sintered at a low temperature, it is useful as a binder for attaching powder materials. The glass-containing binder of the present embodiment (hereinafter, also referred to as “the binder of the present embodiment”) will be described below.
The binder of the present embodiment may consist only of the glass of the present embodiment, but may contain other components. For example, the binder of the present embodiment may contain crystals. That is, the binding binder of the present embodiment may be the above-mentioned composite. Further, the binding binder of the present embodiment may contain a plurality of types of the glass of the present embodiment, and may contain a glass other than the glass of the present embodiment in addition to the glass of the present embodiment.

<Multilayer ceramic capacitor>
The glass of this embodiment is useful as a binder for binding when manufacturing a multilayer ceramic capacitor. When the glass of the present embodiment that can be sintered at a low temperature is used, a stable and dense laminated ceramic capacitor can be obtained even if a functional ceramic or an electrode material that easily deteriorates at a high temperature is used.
The multilayer ceramic capacitor manufactured by using the glass of the present embodiment will be described below.

A laminated ceramic capacitor is composed of a laminated body (hereinafter, also referred to as a “laminated unit”) in which a dielectric layer is arranged between electrode layers. The laminated ceramic capacitor may have a configuration having one such laminated unit, or may have a configuration in which two or more laminated units are laminated. By thinning the dielectric layer to reduce the distance between the electrode layers and increasing the number of laminated units, it is possible to obtain a laminated ceramic capacitor having a large electric capacity while being compact.

FIG. 2 schematically shows an example of the configuration of a multilayer ceramic capacitor. The laminated ceramic capacitor 10 is a pair of external layers sandwiching a laminate in which a dielectric layer 11 and an internal electrode layer 12 are sequentially laminated (however, the bottom layer and the top layer are dielectric layers 11) and the laminate. The electrodes 13 are provided, and the internal electrode layers 12 are alternately connected to one of the external electrodes 13. In such a laminated ceramic capacitor 10, the glass of the present embodiment is used, for example, for forming the dielectric layer 11. When the glass of the present embodiment having high fluidity at the time of softening is used, a dense and thin dielectric layer can be easily obtained, so that a compact laminated ceramic capacitor having a large electric capacity can be easily obtained. As a method for forming the multilayer ceramic capacitor 10, there are a printing method and a green sheet method, and the green sheet method will be briefly described below.

First, the glass powder of the present embodiment is mixed with the functional ceramic powder required to form the dielectric layer 11 to obtain a mixed powder. Functional ceramics may be appropriately selected, but in order to increase the relative permittivity, barium titanate (BaTIO ₃ ) or the like having a perovskite-type structure may be used. The content of the glass powder of the present embodiment with respect to the total amount of the mixed powder is preferably 1 to 10% by volume.

Next, the mixed powder, a vehicle in which a resin material is dissolved in a solvent, and a plasticizer or a dispersant are appropriately mixed to prepare a viscous liquid called a dielectric paste or slurry, which is sheeted on a film substrate. A green sheet is obtained by molding into a shape and drying.

As the resin material, for example, polyvinyl butyral resin, acrylic, methacrylic resin polyethylene glycol, polyvinyl alcohol, ethyl cellulose, methyl cellulose, nitro cellulose, butyl cellulose acetate, propyl cellulose acetate, poly α-methyl styrene, polypropylene carbonate, polyethylene carbonate and the like are used. can do.
Polyvinyl butyral resin is suitable for improving the stability of pastes and slurries, and it is easy to obtain the strength and flexibility of green sheets and the thermal pressure bonding property at the time of lamination, but it is poor in pyrolysis property, especially when it is fired at low temperature. Decomposition residues are likely to remain, which may impair the sinterability of the green sheet or cause the sintered body to swell due to the pyrolysis gas.
Acrylic and methacrylic resins have good thermal decomposability, and are particularly suitable for obtaining a good sintered body when fired at a low temperature. On the other hand, it is difficult to obtain the strength, flexibility, and thermocompression bonding property of the green sheet at the time of laminating, but the drawbacks can be suppressed by copolymerizing those to which various functional groups are added.

As the film base material, for example, PET (polyethylene terephthalate) or the like that has undergone a surface treatment such as a mold release treatment can be used.
The method of molding the paste or slurry into a sheet on the film substrate is not particularly limited, and examples thereof include screen printing, transfer, and a doctor blade method.
The green sheet obtained as described above is a mixed powder bonded with a resin material or the like.

Next, a conductive paste containing silver or copper as a main component is applied in order to form an internal electrode layer on a necessary portion on the green sheet. After that, a plurality of green sheets coated with the conductive paste are laminated, and heat and pressure are appropriately applied and pressure-bonded to integrate them to obtain a laminated sheet.

By adding the glass of the present embodiment to the conductive paste, the interlayer adhesiveness can be improved. The method of applying the conductive paste is not particularly limited, and examples thereof include screen printing and gravure printing.
The heating temperature during crimping is, for example, 40 to 80 ° C.

Next, the obtained laminated sheet is cut into individual pieces (chips), heated to burn the resin material components and the like, and then the glass of the present embodiment is sintered to obtain a fired laminate.
When the laminated ceramic capacitor is formed by batch firing of the laminated sheets in this way, it is possible to obtain a laminated ceramic capacitor having excellent adhesion between the layers and excellent dielectric performance and stability over time.

Heating is performed using a firing furnace in a predetermined atmosphere such as in the atmosphere, in an inert gas, or in a vacuum. The heating temperature is preferably 30 ° C. or higher than the Tg of the glass of the present embodiment and lower than Tc1-on. Specifically, the heating temperature is preferably 280 to 600 ° C., more preferably 280 to 550 ° C. in terms of promoting firing and reducing manufacturing costs. The heating time is, for example, 1 to 3 hours.

Then, if necessary, a conductive paste serving as an external electrode is applied to the fired laminate, dried, fired, and further plated with Ni or Sn, if necessary.

If necessary, a conductive paste is applied to the fired laminate, dried, and fired to form an external electrode 13, and if necessary, Ni or Sn is plated to obtain a laminated ceramic capacitor.
By adding the glass of the present embodiment to this conductive paste, the interlayer adhesiveness can be improved.

In the above, an example of using the glass of the present embodiment as a binder for binding has been described, but a composite containing the glass and crystals of the present embodiment may be used as a binder for binding, and a binder containing other materials may be used. Wearing binders may be used. Regardless of which binder is used, it is preferable to prepare the mixed powder so that the ratio of the glass of the present embodiment to the total amount of the mixed powder is 1 to 10% by volume.

<Low temperature co-fired ceramic multilayer substrate>
The glass of this embodiment is useful as a binder for binding when manufacturing a low-temperature co-fired ceramic multilayer substrate. When the glass of the present embodiment that can be sintered at a low temperature is used, a stable and dense low-temperature co-fired ceramic multilayer substrate can be obtained even if functional ceramics or electrode materials that are easily deteriorated at a high temperature are used.
The low-temperature co-fired ceramic multilayer substrate manufactured using the glass of the present embodiment will be described below.

The low-temperature co-fired ceramic multilayer substrate is composed of a laminate (hereinafter, also referred to as a “laminate unit”) that forms a three-dimensional wiring in which an electrode wiring layer is separated by an insulator layer. The low-temperature co-fired ceramic multilayer substrate may have a configuration in which one of the laminated units is provided, or may have a configuration in which two or more laminated units are laminated. By thinning the insulator layer to reduce the distance between the electrode wiring layers and laminating a large number of laminated units, it is possible to obtain a compact but complicated wiring board.

FIG. 3 schematically shows an example of the configuration of a low-temperature co-fired ceramic multilayer substrate. In the low-temperature co-fired ceramic multilayer substrate 20 shown in FIG. 3, the substrate body is composed of a dielectric (insulator) layer 21, and a plurality of main surfaces parallel to the main surface of the substrate body are provided inside and outside the substrate body. It has a planar electrode 22. Further, it has an internal vertical electrode 23 having a main surface orthogonal to the main surface of the substrate body, which is arranged inside the substrate body so as to electrically connect the predetermined plane electrodes 22 to each other. Further, the internal mounting component 25 is arranged so as to be in contact with the (internal) flat electrode 22 inside the substrate main body, and the surface mounting component 24 is arranged so as to be in contact with the (external) flat electrode 22. The surface mount component 24 has an electrode, and the electrode and another (external) planar electrode 22 other than the above are electrically connected by a feeding wire 27. The low-temperature co-fired ceramic multilayer substrate 20 has a heat-dissipating via 26 so as to penetrate the substrate main body, and a surface mount component 24 is mounted directly above the heat-dissipating via 26.
In such a low-temperature co-fired ceramic multilayer substrate 20, the glass of the present embodiment is used, for example, for forming the dielectric layer 21. When the glass of the present embodiment having high fluidity at the time of softening is used, a dense and thin dielectric layer can be easily obtained, so that a small but complicated wiring board can be easily obtained. There are a printing method and a green sheet method as a method for forming a low-temperature co-fired ceramic multilayer substrate, and the green sheet method will be briefly described below.

First, the glass powder of the present embodiment is mixed with the functional ceramic powder required to form the dielectric layer 21 to obtain a mixed powder. Functional ceramics may be appropriately selected, but in order to increase the strength, alumina or the like may be used. The content of the glass powder of the present embodiment with respect to the total amount of the mixed powder is preferably 40 to 70% by volume.

Next, a green sheet is obtained in the same manner as in the method for manufacturing a multilayer ceramic capacitor described above.

Next, a conductive paste containing silver or copper as a main component is applied to a necessary portion on the green sheet in order to form an internal wiring or, in the case of the outermost wiring, a flat electrode layer to be an external wiring. By adding the glass of the present embodiment to the conductive paste, the interlayer adhesiveness can be improved. When forming a resistor layer, a resistor paste containing ruthenium oxide as a main component is applied. The internal vertical electrode is formed by pre-drilling a green sheet and then filling and applying a conductive paste containing silver or copper as a main component to the portion. Similarly, the heat-dissipating via is formed by pre-drilling the green sheet and then filling and applying a paste made of a material having high thermal conductivity containing silver or copper as a main component to the portion. In addition, internally mounted components may be mounted as needed.
The method of applying these pastes is not particularly limited, and examples thereof include screen printing and gravure printing.
Then, a plurality of these sheets are laminated and appropriately applied with heat or pressure to be pressure-bonded and integrated to obtain a laminated sheet. The heating temperature during crimping is, for example, 40 to 80 ° C.

Next, the obtained laminated sheet is heated to burn the resin material components and the like, and then the glass of the present embodiment is sintered to obtain a fired laminate.
By manufacturing the low-temperature co-fired ceramics multilayer substrate for batch firing of the laminated sheets in this way, it is possible to obtain a low-temperature co-fired ceramic multilayer substrate having excellent adhesion between the layers and excellent reliability over time. ..

Heating is performed using a firing furnace in a predetermined atmosphere such as in the atmosphere, in an inert gas, or in a vacuum. The heating temperature is preferably 30 ° C. or higher than the Tg of the glass of the present embodiment and lower than Tc1-on. Specifically, the heating temperature is preferably 280 to 600 ° C., more preferably 280 to 550 ° C. in terms of promoting firing and reducing manufacturing costs. The heating time is, for example, 1 to 3 hours.

Then, if necessary, the portion to be the external electrode of the fired laminate is plated with Ni or Au. Further, if necessary, the laminated sheet is half-cut before firing, and then cut into chips after firing. Alternatively, use a dicing saw or the like to make chips. Further, for example, a power feeding wire for connecting the surface mount component or the electrode of the surface mount component to the external electrode is provided on the external electrode.

In the above, an example of using the glass of the present embodiment as a binder for binding has been described, but a composite containing the glass and crystals of the present embodiment may be used as a binder for binding, and a binder containing other materials may be used. Wearing binders may be used. Regardless of which binder is used, it is preferable to prepare the mixed powder so that the ratio of the glass of the present embodiment to the total amount of the mixed powder is 40 to 70% by volume.

<Solid electrolyte>
The glass of this embodiment is useful as a material for a solid electrolyte. When the glass of the present embodiment, which can be sintered at a low temperature and has high fluidity at the time of softening, is used, a particularly dense solid electrolyte can be stably obtained even if a material that easily deteriorates at a high temperature is used. Further, since the glass of the present embodiment has high ionic conductivity, the glass of the present embodiment can be used to obtain a solid electrolyte having high ionic conductivity. Hereinafter, the glass-containing solid electrolyte of the present embodiment (hereinafter, also referred to as “solid electrolyte of the present embodiment”) will be described.

If necessary, the solid electrolyte of the present embodiment may contain components other than the glass of the present embodiment as long as the effects of the present invention are not impaired. Other components that can be contained in the solid electrolyte of the present embodiment include ionic conductive crystals and the like. The content of the glass of the present embodiment in the solid electrolyte of the present embodiment is preferably 40 to 100% by volume, more preferably 70 to 100% by volume, and further preferably 100% by volume.
As the material of the solid electrolyte of the present embodiment, a composite containing the glass and the crystal body of the present embodiment may be used. However, if the complex already contains a sufficient amount of crystal components for a solid electrolyte such as an ion conductive crystal, it is not necessary to further add such a crystal component to the solid electrolyte.

<All-solid-state lithium-ion secondary battery>
Since the solid electrolyte of the present embodiment has high ionic conductivity, it is suitable for the solid electrolyte layer of the all-solid-state lithium ion secondary battery. The all-solid-state lithium ion secondary battery including the solid electrolyte of the present embodiment will be described below.

An all-solid-state lithium-ion secondary battery (hereinafter, also simply referred to as “lithium-ion secondary battery”) has a positive electrode, a negative electrode, and a solid electrolyte layer arranged between the positive electrode and the negative electrode.
The lithium ion secondary battery may have a configuration in which one unit is a laminate (hereinafter referred to as a "lamination unit") in which a positive electrode and a negative electrode are arranged with a solid electrolyte layer interposed therebetween. The above-mentioned laminated units may be laminated (hereinafter, also referred to as “multilayer structure”). By thinning the solid electrolyte layer to reduce the distance between the electrode layers and laminating a large number of laminating units, a lithium ion secondary battery having a high energy density can be obtained.

FIG. 4 schematically shows the configuration of a lithium ion secondary battery having a multi-layer structure and a series type. In the lithium ion secondary battery 30, a plurality of laminated units 34 having a positive electrode (cathode electrode) 31, a negative electrode (anode electrode) 32, and a solid electrolyte layer 33 disposed between the positive electrode 31 and the negative electrode 32 are electronic. It has a structure that is laminated via a conductor layer 35 and connected in series. In FIG. 4, the symbols “+” and “−” enclosed in circles indicate positive electrode terminals and negative electrode terminals, respectively.

For the positive electrode 31, for example, LiCoO ₂ , LiMn ₂ O ₄ , LiFePO _4, or the like is used. For the negative electrode 32, for example, metallic lithium, graphite, Li ₄ Ti ₅ O _12, or the like is used. However, these are examples, and other electrode materials may be used for the positive electrode 31 and the negative electrode 32.

Further, in the series-type multilayer all-solid-state lithium ion secondary battery 30 as shown in FIG. 4, the lamination unit 34 may have a layer other than the above. Further, the lithium ion secondary battery 30 may have a layer other than the laminated unit 34 and the electron conductor layer 35.

Further, when the multilayer all-solid-state lithium ion secondary battery is of the parallel type, for example, in the series type lithium ion secondary battery 30 shown in FIG. 4, the electron conductor layer 35 is changed to an insulator layer, and each layer is formed. Each positive electrode 31 in the unit 34 is collectively connected to the positive electrode terminal via wiring (positive electrode wiring), and each negative electrode 32 in each laminated unit 34 is collectively connected via wiring (negative electrode wiring). It may be connected to the negative electrode terminal.

An example of a method for manufacturing the multilayer all-solid-state lithium ion secondary battery shown in FIG. 4 will be described below.

First, the positive electrode active material, the solid electrolyte material containing the glass of the present embodiment, the negative electrode active material, and the electron conductive material are each pasted or slurryed, coated, and dried to prepare a green sheet.
The method of pasting is not particularly limited, and examples thereof include a method of mixing powders of each material into a vehicle. The method for applying the paste or slurry is not particularly limited, and known methods such as die coating, screen printing, transfer, and doctor blade method can be adopted. When it is desired to form a flat pattern, a method such as punching or cutting the green sheet, screen printing or gravure printing on the paste as a base material may be used.

Next, the prepared green sheets are stacked in order, and if necessary, alignment, cutting, etc. are performed to prepare a laminated body. If necessary, alignment may be performed so that the end faces of the positive electrode and the end faces of the negative electrode do not match, and the layers may be laminated.

Next, the produced laminates are collectively crimped, and then heated in an atmospheric atmosphere and fired to obtain a lithium ion secondary battery having a multi-layer structure.
The heating temperature at the time of crimping is, for example, 40 to 80 ° C.
The heating temperature at the time of firing is preferably 30 ° C. or higher than the Tg of the glass of the present embodiment and is preferably in a temperature range lower than Tc1-on of the glass, specifically 280 to 600 ° C., and firing. The range of 280 to 550 ° C. is more preferable from the viewpoint of accelerating the temperature and reducing the manufacturing cost. The heating time at the time of firing is, for example, 1 to 3 hours.

By manufacturing a lithium-ion secondary battery having a multi-layer structure by batch firing in this way, a lithium-ion secondary battery having excellent adhesion between layers and excellent battery performance and stability over time can be obtained. Since the glass of the present embodiment has excellent low-temperature sinterability, such batch firing can be easily performed. Further, since the glass of the present embodiment has high fluidity during softening, a dense and thin solid electrolyte layer can be easily obtained by heat treatment during batch firing, and the ionic conductivity is high, the glass of the present embodiment is used. As a result, a lithium ion secondary battery having particularly high battery performance can be obtained.

In the production of the multi-layered lithium ion secondary battery 30, the laminated unit 34 composed of the positive electrode 31, the solid electrolyte layer 33, and the negative electrode 32 is collectively fired in the same manner as described above, and the obtained laminate is obtained. A method may be adopted in which the units 34 are laminated via the electron conductor layer 35 paste and fired according to the firing conditions of the electron conductor layer 35 paste.

Further, the method for manufacturing the multi-layered lithium ion secondary battery 30 is not limited to the method by batch firing as described above, and for example, the positive electrode 31, the negative electrode 32, the solid electrolyte layer 33, and the electron conductor layer 35 are separately separated. It is also possible to adopt a method in which these are laminated in order and integrated by heat-bonding or the like after being manufactured.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to the Examples.

[Manufacturing of glass]
Each raw material powder was weighed and mixed so as to have the preparation composition shown in Table 1. Raw materials include Li ₂ CO ₃ , SiO ₂ , B ₂ O ₃ , MgO, CaCO ₃ , SrCO ₃ , BaCO ₃ , LiPO ₃ , BPO ₄ , MgP ₂ O ₆ , CaP ₂ O ₆ , SrP ₂ O ₆ , BaP. ₂ O ₆ , Y2O3, ZrO2, ZrSiO4, LiCl, Li ₂ SO ₄ were used in combination. Next, the mixed raw materials are placed in a platinum crucible and heated at 900 ° C. for 30 minutes to melt the raw materials, and then the melted raw materials are rapidly cooled by a rollout machine to form flakes (thin sections) into the glass of each example. (Hereinafter referred to as glass flakes) was produced. When the glass flakes of each of the obtained examples were observed under a microscope, no crystals were observed in any of the glass flakes.

The obtained glass flakes are subjected to DTA measurement by the following method to determine the glass transition point Tg, the crystallization start temperature Tc1-on, and the crystallization peak temperature Tc1p, respectively, and further observe the glass at the time of measurement to soften the glass. Liquidity was evaluated. In addition, the ionic conductivity of the glass flakes was measured by the following method.

[DTA measurement]
The obtained glass flakes of each example were pulverized in a mortar and passed through a 300 mesh sieve to prepare a glass powder for DTA measurement. The glass powder was weighed so as to have a weight of 100 ± 15 mg, packed in an aluminum DTA cell having an inner diameter of 5 ± 0.5 mmφ and a depth of 5 ± 0.5 mm, and DTA measurement was performed. The DTA was measured using a differential thermal analyzer (manufactured by Rigaku, trade name: Themo plus EVO2 sample observation TG-DTA). From the obtained DTA curve, Tg, Tc1-on, and Tc1p were determined. These results are shown in Table 1.
In addition, an image of a sample (glass powder group) in the DTA cell during the temperature raising process is recorded to identify the temperature at which the sintering shrinkage is maximized (the temperature at which the sample diameter is minimized), and at that time. The diameter R2 of the sample was measured on the image, and the softening fluidity was calculated by the following formula from the difference from the diameter R1 (initial diameter) of the sample before shrinkage, which was also measured on the image.
Softening fluidity (%) = {(R1-R2) / R1} x 100

[Measurement of ionic conductivity]
Gold electrodes (diameter 6 mm) were formed on both sides of the glass flakes by a vapor deposition method. Next, a measurement voltage of 50 mV was applied between the gold electrodes on both sides, and the impedance of the glass flakes was measured by the AC impedance method. For the measurement, using the FRA Solartron SI1287 comprising (frequency response analyzer) (Solartron Inc.), measurement frequency ^was set to 10 7 Hz~0.1Hz. The ionic conductivity was obtained from the arc diameter obtained by the Nyquist plot. The measurement results are shown in Table 1.

The glass of Comparative Example 1 had high ionic conductivity but low softening fluidity.
On the other hand, the glasses of Examples 1 to 18 had high ionic conductivity and also high softening fluidity.

1 DTA cell 2 Glass powder group 10 Laminated ceramic capacitor 11 Dielectric layer 12 Internal electrode layer 13 External electrode 20 Low temperature simultaneous firing ceramics multilayer substrate 21 Dielectric layer 22 Flat electrode 23 Internal vertical electrode 24 Surface mounting component 25 Internal mounting component 26 Heat dissipation Via 27 Power supply wire 30 Lithium ion secondary battery 31 Positive electrode 32 Negative electrode 33 Solid electrolyte layer 34 Laminated unit 35 Electronic conductor layer

Claims (7)

In cation% notation
Li ⁺ is 50% or more and less than 90%, and
B ³⁺ over 10% and under 50%,
As well as containing
In anion% notation,
^O2- is 30% or more and less than 100%,
SO ₄ ^2-0 percent to 60% or less, and,
Glass containing Cl ⁻ in an amount of more than 0% and 30% or less. The glass according to claim 1, wherein the difference ((Tc1-on) -Tg) between the crystallization start temperature Tc1-on and the glass transition point Tg is 30 ° C. or higher. The glass according to claim 1 or 2, wherein the glass transition point Tg is 200 ° C. or higher and 450 ° C. or lower. The glass according to any one of claims 1 to 3, wherein the ionic conductivity is 7.0 × 10 ^-7 S / cm or more. The glass according to any one of claims 1 to 4, wherein the softening fluidity measured by the following method is 10% or more.
(Measuring method of softening fluidity)
The glass is crushed using a mortar and passed through a 300 mesh sieve to obtain glass powder. 100 mg of the obtained glass powder is filled in a DTA cell having an inner diameter of 5 mm and a depth of 5 mm. At this time, the diameter of the filled glass powder group is R1. Subsequently, the glass powder group is heated, and the diameter when the diameter of the glass powder group is minimized is defined as R2. Using these, the softening fluidity is calculated by the following formula.
Softening fluidity (%) = {(R1-R2) / R1} x 100 The solid electrolyte containing the glass according to any one of claims 1 to 5. A binder containing the glass according to any one of claims 1 to 5.

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