Glass ceramic material, laminate, and electronic component

Abstract

The glass ceramic material contains a glass including SiO2, B2O3, and M2O (M is an alkali metal), a filler including quartz, and at least one metal oxide selected from the group consisting of MnO, NiO, CuO, and ZnO. The content of the metal oxide is from 0.05 weight part to 2 weight parts per 100 total weight parts of the glass and the filler.

Description

[Technical field]

[0001] The present invention relates to a glass-ceramic material, a laminate, and an electronic component. [Background technology]

[0002] In recent years, sintered bodies of dielectric materials that can be fired simultaneously with conductive materials at temperatures of 1000° C. or less have been used in multilayer ceramic substrates. For example, Patent Document 1 discloses a glass ceramic composite material that is characterized by comprising 50-90% borosilicate glass made of 70-85% SiO2, 10-25% B2O3, 0.5-5% K2O, and 0.01-1% Al2O3, and 10-50% of one or more SiO2 fillers selected from the group consisting of α-quartz, α-cristobalite, and β-tridymite. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-187768 A Summary of the Invention [Problem to be solved by the invention]

[0004] During firing of glass-ceramic composite materials (hereinafter also referred to as glass-ceramic materials), densification progresses due to the viscous flow of glass while the maximum temperature is maintained. When a certain amount of firing objects is put into a firing furnace, the time at which the maximum temperature is reached varies among the firing objects. Therefore, it is necessary to adjust the holding time longer so that the firing objects that reach the maximum temperature later can be sufficiently densified.

[0005] However, if the maximum temperature is held for a long time during firing, the small amount of remaining carbon components in the areas where densification has progressed quickly will gasify and generate pores. If the pores are trapped in the sintered body obtained after firing, they will not be expelled to the outside and will remain as voids, resulting in a problem of reduced density and reduced insulation. In particular, in glass ceramic materials containing a large amount of SiO2 components as in Patent Document 1, the glass viscosity at the maximum temperature during firing is relatively high. For this reason, it is necessary to hold the maximum temperature for a long time during firing, which makes the above problem more pronounced.

[0006] The present invention has been made to solve the above problems, and has an object to provide a glass ceramic material that can produce a dense sintered body even when the maximum temperature is held for a long time during sintering, a laminate formed by stacking a plurality of glass ceramic layers that are sintered bodies of the glass ceramic material, and an electronic component that includes the laminate. [Means for solving the problem]

[0007] The glass ceramic material of the present invention contains a glass containing SiO2, B2O3, and M2O (M is an alkali metal), a filler containing quartz, and at least one metal oxide selected from the group consisting of MnO, NiO, CuO, and ZnO, and is characterized in that the content of the metal oxide is 0.05 parts by weight or more and 2 parts by weight or less per 100 parts by weight of the total of the glass and the filler.

[0008] The laminate of the present invention is characterized in that it is formed by laminating a plurality of glass ceramic layers which are sintered bodies of the above-mentioned glass ceramic material.

[0009] The electronic device of the present invention is characterized by including the above laminate. Effect of the Invention

[0010] According to the present invention, it is possible to provide a glass ceramic material that can produce a dense sintered body even when the maximum temperature is held for a long time during sintering, a laminate formed by stacking a plurality of glass ceramic layers that are sintered bodies of the glass ceramic material, and an electronic component that includes the laminate. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of the laminate of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing an example of an electronic component of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The glass ceramic material, laminate, and electronic component of the present invention will be described below. Note that the present invention is not limited to the following configurations, and may be modified as appropriate without departing from the gist of the present invention. In addition, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0013] The glass-ceramic material of the present invention is a low-temperature co-fired ceramic (LTCC) material. In this specification, the term "low-temperature co-fired ceramic material" refers to a glass-ceramic material that can be sintered at a firing temperature of 1000° C. or less.

[0014] [Glass ceramic materials] The glass ceramic material of the present invention contains a glass containing SiO2, B2O3, and M2O (M is an alkali metal), a filler containing quartz, and at least one metal oxide selected from the group consisting of MnO, NiO, CuO, and ZnO, and is characterized in that the content of the metal oxide is 0.05 parts by weight or more and 2 parts by weight or less per 100 parts by weight of the total of the glass and the filler.

[0015] In the glass ceramic material of the present invention, since it contains the above-mentioned metal oxide in a specific amount, densification proceeds uniformly even when the maximum temperature is held for a long time during firing, so that a dense sintered body can be obtained.

[0016] <Glass> In the glass-ceramic material of the present invention, the glass comprises SiO2, B2O3, and M2O (M is an alkali metal).

[0017] The SiO2 in the glass contributes to a decrease in the dielectric constant when the glass-ceramic material is fired, which in turn suppresses stray capacitance that accompanies higher frequencies of electrical signals.

[0018] The B2O3 in the glass contributes to lowering the glass viscosity, which results in a dense sintered body of the glass-ceramic material.

[0019] The M2O in the glass contributes to a decrease in the glass viscosity. Therefore, the sintered body of the glass ceramic material becomes dense. There is no particular limitation on the M2O as long as it is an alkali metal oxide, but Li2O, K2O or Na2O is preferable, and K2O is more preferable. One type of M2O may be used, or multiple types may be used.

[0020] The content of SiO2 in the above glass, calculated as oxide, is preferably 65% ​​by weight or more and 90% by weight or less, and more preferably 70% by weight or more and 85% by weight or less.

[0021] The content of B2O3 in the above glass, calculated as oxide, is preferably 5% by weight or more and 30% by weight or less, and more preferably 10% by weight or more and 25% by weight or less.

[0022] The content of M2O in the above glass is preferably 1% by weight or more and 5% by weight or less, calculated as oxide, and more preferably 1.5% by weight or more and 4.5% by weight or less. When multiple types of alkali metal oxides are used as M2O, the total amount of them is taken as the content of M2O.

[0023] The glass may further contain Al2O3, which contributes to improving the chemical stability of the glass.

[0024] When the glass contains Al2O3, the content of Al2O3 in the glass, calculated as oxide, is preferably 0.1% by weight or more and 2% by weight or less, and more preferably 0.5% by weight or more and 1% by weight or less.

[0025] The above glass may further contain an alkaline earth metal oxide such as CaO. However, from the viewpoint of increasing the content of SiO2 in the glass and decreasing the dielectric constant and dielectric loss, it is preferable that the glass does not contain an alkaline earth metal oxide, and even if it contains an alkaline earth metal oxide, the content thereof in the glass is preferably less than 15 wt%, more preferably less than 5 wt%, and further preferably less than 1 wt%.

[0026] The glass may contain impurities in addition to the above components. The content of impurities in the glass is preferably less than 5% by weight, more preferably less than 1% by weight.

[0027] <Filler> In the glass-ceramic material of the present invention, the filler comprises quartz. The filler contributes to improving the mechanical strength of the glass-ceramic material when it is fired. In this specification, the term "filler" refers to an inorganic additive not contained in glass.

[0028] The quartz in the filler contributes to increasing the thermal expansion coefficient of the glass ceramic material when it is fired. The thermal expansion coefficient of glass is about 6 ppm / K, while that of quartz is about 15 ppm / K, so that the glass ceramic material containing quartz has a high thermal expansion coefficient when fired. As a result, compressive stress occurs during the cooling process after firing, increasing the mechanical strength (e.g., flexural strength). In addition, reliability is improved when mounting on a mounting substrate (e.g., a resin substrate).

[0029] The filler may contain only quartz, or may further contain SiO2 other than quartz. The filler may further contain Al2O3 and / or ZrO2.

[0030] The glass ceramic material contains Al2O3 and ZrO2 as fillers, which prevents the precipitation of cristobalite crystals when fired. Cristobalite crystals are a type of SiO2 crystal, but they undergo a phase transition at about 280°C. If cristobalite crystals precipitate during the firing process of the glass ceramic material, the volume will change significantly in a high-temperature environment, reducing reliability. In addition, Al2O3 and ZrO2 in the fillers also contribute to low dielectric loss, high thermal expansion coefficient, and high mechanical strength when the glass ceramic material is fired.

[0031] When the filler contains Al2O3 and ZrO2, the content is preferably 1% by weight or more and 5% by weight or less, respectively.

[0032] More preferably, the filler comprises only quartz.

[0033] The glass ceramic material of the present invention preferably contains 50 to 90 parts by weight of the glass and 10 to 50 parts by weight of the filler, based on 100 parts by weight of the glass and the filler in total, and more preferably contains 60 to 80 parts by weight of the glass and 20 to 40 parts by weight of the filler.

[0034] <Metal oxide> The glass ceramic material of the present invention contains at least one metal oxide selected from the group consisting of MnO, NiO, CuO and ZnO, and the metal oxide is contained in an amount of 0.05 parts by weight or more and 2 parts by weight or less per 100 parts by weight of the glass and the filler in total. When multiple metal oxides are used, the total amount of all the metal oxides used is adjusted to be 0.05 parts by weight or more and 2 parts by weight or less per 100 parts by weight of the glass and the filler in total.

[0035] By including the metal oxide in the glass ceramic material of the present invention in the above range, a dense sintered body with high relative density can be obtained even if the firing time is long. Such a sintered body has excellent dielectric constant and Q value (the reciprocal of dielectric loss). As the metal oxide, CuO is preferable.

[0036] As described above, according to the glass ceramic material of the present invention, even if the firing time is long, densification proceeds uniformly, so that a dense sintered body can be obtained. In addition, in the sintered body of the glass ceramic material, glass and filler can be distinguished by analyzing the electron diffraction pattern with a transmission electron microscope (TEM).

[0037] The composition of the glass ceramic material of the present invention may be measured using the composition of a sintered body of the glass ceramic material described later. For example, as described above, in a glass ceramic material containing a large amount of SiO2 components as in Patent Document 1, the glass viscosity at the maximum temperature during firing is relatively high. Therefore, crystal precipitation from the glass during firing is unlikely to occur. In this case, the composition of the glass ceramic material of the present invention may be considered to be substantially the same as the composition of the sintered body of the glass ceramic material.

[0038] [Laminate] The laminate of the present invention is characterized in that it is formed by laminating a plurality of glass ceramic layers, which are sintered bodies of the glass ceramic material of the present invention. The compositions of the plurality of glass ceramic layers may be the same or different from each other, but are preferably the same.

[0039] The relative density of the laminate is preferably 90% or more, more preferably 95% or more. The relative density is a value obtained by dividing the apparent density measured by Archimedes' method by the true density. The true density is the density of the powder obtained by pulverizing the laminate. The apparent density is a density including voids, and the volume ratio of the voids in the laminate can be calculated by dividing the apparent density by the true density. A relative density of 100% means that the laminate does not contain voids.

[0040] The dielectric constant of the laminate is preferably 4.5 or less, as measured under 3 GHz conditions by a perturbation method.

[0041] The Q value, which is the reciprocal of the dielectric loss of the laminate, is preferably equal to or greater than 250. The Q value is determined as the reciprocal of the measured dielectric loss at 3 GHz by a perturbation method.

[0042] The laminate of the present invention may further include a conductor layer provided between the glass ceramic layers adjacent in the stacking direction and / or on the surface of the glass ceramic layer.

[0043] The laminate of the present invention may further include a via conductor that is provided so as to penetrate through the glass ceramic layer.

[0044] The conductor layer and the via conductors can be formed by screen printing, photolithography, or the like using a conductive paste containing Ag or Cu.

[0045] Fig. 1 is a cross-sectional schematic diagram showing an example of the laminate of the present invention. As shown in Fig. 1, the laminate of the present invention may be applied to a multilayer ceramic substrate. The laminate (multilayer ceramic substrate) 1 shown in Fig. 1 is formed by laminating a plurality of glass ceramic layers 3 (five layers in Fig. 1).

[0046] The laminate 1 may be formed with conductor layers 9, 10, and 11, and via conductors 12. These may constitute, for example, passive elements such as capacitors and inductors, or connection wiring that provides electrical connection between elements.

[0047] The conductor layers 9, 10, 11 and the via conductor 12 preferably contain Ag or Cu as a main component. By using such a low-resistance metal, the occurrence of signal propagation delays due to the increase in frequency of electrical signals can be prevented. In addition, since the glass ceramic material of the present invention, i.e., the low-temperature co-fired ceramic material, is used as the constituent material of the glass ceramic layer 3, it is possible to co-fire with Ag or Cu.

[0048] The conductor layer 9 is disposed inside the laminate 1. Specifically, the conductor layer 9 is disposed between two glass ceramic layers 3 adjacent to each other in the lamination direction.

[0049] The conductor layer 10 is disposed on one of the main surfaces of the laminate 1 .

[0050] The conductor layer 11 is disposed on the other main surface of the laminate 1 .

[0051] The via conductors 12 are arranged to penetrate the glass ceramic layer 3 and serve to electrically connect the conductor layers 9 in different layers, electrically connect the conductor layers 9 and 10, and electrically connect the conductor layers 9 and 11.

[0052] A multilayer ceramic substrate, which is an example of the laminate of the present invention, is produced, for example, as follows. (A) Preparation of glass-ceramic materials The glass-ceramic material of the present invention is prepared by mixing glass, filler, and metal oxide in a predetermined composition.

[0053] (B) Preparation of green sheet The glass ceramic material of the present invention is mixed with a binder, a plasticizer, etc. to prepare a ceramic slurry. The ceramic slurry is then cast onto a substrate film (e.g., a polyethylene terephthalate (PET) film) and dried to produce a green sheet.

[0054] (C) Preparation of laminated green sheets The green sheets are laminated to produce an unfired laminated green sheet. A conductor layer and a via conductor may be formed on the laminated green sheet.

[0055] (D) Firing of the laminated green sheets The laminated green sheets are fired, resulting in a laminate (multilayer ceramic substrate) 1 as shown in FIG.

[0056] The firing temperature of the laminated green sheet is not particularly limited as long as the glass ceramic of the present invention constituting the green sheet can be sintered at the temperature, and is, for example, 1000° C. or lower.

[0057] The sintering atmosphere for the laminated green sheet is not particularly limited, but when a material that is not easily oxidized, such as Ag, is used for the conductor layer and via conductor, an air atmosphere is preferable, and when a material that is easily oxidized, such as Cu, a low-oxygen atmosphere, such as a nitrogen atmosphere, is preferable. The sintering atmosphere for the laminated green sheet may also be a reducing atmosphere.

[0058] The laminated green sheets may be fired while sandwiched between constraining green sheets. The constraining green sheets contain, as a main component, an inorganic material (e.g., Al2O3) that is not substantially sintered at the sintering temperature of the glass ceramic material of the present invention that constitutes the green sheets. Therefore, the constraining green sheets do not shrink when the laminated green sheets are fired, and act to suppress shrinkage in the main surface direction of the laminated green sheets. As a result, the dimensional accuracy of the obtained laminate 1 (particularly the conductor layers 9, 10, 11 and the via conductor 12) is improved.

[0059] When the laminate of the present invention includes a conductor layer, it is preferred that the main component of the conductor layer is Cu, and the metal oxide contained in the glass ceramic layer contains at least CuO.

[0060] In conventional laminated green sheets, if the main component of the conductor layer is Cu, Cu diffuses from the conductor layer into the laminated green sheet during firing, causing uneven sintering and slow sintering. This is thought to be because Cu diffuses a lot in areas close to the conductor layer, causing slow sintering, and Cu diffuses less in areas far from the conductor layer, causing fast sintering. In contrast, if CuO is added as a metal oxide to the glass ceramic material to create a laminated green sheet, CuO is diffused in the laminated green sheet before firing, so uneven sintering is less likely to occur.

[0061] In this specification, the conductor layer is mainly composed of Cu, which means that 90% by volume or more of the conductor layer is composed of Cu. The conductor layer is preferably composed of a mixture of Cu, glass, and aluminum oxide. The glass used to form the conductor layer may be the same as the glass contained in the glass ceramic material of the present invention. The metal oxide containing at least CuO means that the metal oxide contains only CuO, or contains CuO and one or more metal oxides other than CuO. It is more preferable that the metal oxide contains only CuO.

[0062] When the laminate of the present invention includes a via conductor, it is preferred that the main component of the via conductor is Cu, and the metal oxide contained in the glass ceramic layer contains at least CuO.

[0063] [Electronic components] The electronic device of the present invention is characterized by comprising the laminate of the present invention.

[0064] The electronic device of the present invention includes, for example, a multilayer ceramic substrate which is an example of the laminate of the present invention, and a chip component mounted on the multilayer ceramic substrate. Examples of the chip component include an LC filter, a capacitor, and an inductor.

[0065] Fig. 2 is a schematic cross-sectional view showing an example of an electronic component of the present invention. As shown in Fig. 2, chip components 13, 14 may be mounted on laminate (multilayer ceramic substrate) 1 in a state of being electrically connected to conductor layer 10. In this manner, electronic component 2 including laminate 1 is formed.

[0066] The electronic component 2 may be mounted on a mounting board (eg, a motherboard) so as to be electrically connected via the conductor layer 11.

[0067] Although the above describes an example in which the laminate of the present invention is applied to a multilayer ceramic substrate, the laminate of the present invention may also be applied to chip components mounted on a multilayer ceramic substrate. That is, the laminate of the present invention may be applied to an LC filter, a capacitor, an inductor, etc. For example, when the laminate of the present invention is applied to a capacitor, the laminate includes a conductor layer between glass ceramic layers adjacent in the stacking direction.

[0068] The laminate of the present invention may be applied to applications other than multilayer ceramic substrates and chip components. EXAMPLES

[0069] EXAMPLES Hereinafter, examples that more specifically disclose the present invention will be described, however, the present invention is not limited to these examples.

[0070] <Preparation of glass powder> Glass raw material powders G1 to G4 having the compositions shown in Table 1 were mixed and placed in a Pt crucible, and melted in an air atmosphere at 1600°C for 30 minutes or more. The resulting melt was then quenched to obtain cullet. Here, carbonate was used as the raw material for K2O, which is an alkali metal oxide in Table 1. The K2O content in Table 1 indicates the ratio of carbonate converted to oxide. The cullet was coarsely crushed, then placed in a container together with ethanol and PSZ balls (diameter: 5 mm), and mixed in a ball mill. When mixing in the ball mill, the crushing time was adjusted to obtain glass powder with a median particle size of 1 μm. Here, the "median particle size" is the median particle size D measured by a laser diffraction / scattering method. 50 means.

[0071] [Table 1]

[0072] <Preparation of Glass-Ceramic Materials> Glass powder, quartz powder as a filler, and metal oxide were mixed in ethanol in a ball mill to prepare a glass ceramic material with the composition shown in Table 2. The median particle size of both the quartz powder and the metal oxide was 1 μm.

[0073] <Preparation of green sheet> The glass ceramic material prepared above was mixed with a binder solution of polyvinyl butyral dissolved in ethanol and a dioctyl phthalate (DOP) solution as a plasticizer to prepare a ceramic slurry. The ceramic slurry was then cast onto a polyethylene terephthalate film using a doctor blade and dried at 40°C to produce green sheets S1 to S29 with a thickness of 50 μm.

[0074] [Table 2]

[0075] <Preparation and evaluation of evaluation samples> Green sheets S1 to S29 were each cut into 50 mm squares, 20 sheets were stacked, and placed in a mold and pressed with a press. The resulting laminated green sheets were sintered in an air atmosphere at 900°C for 30 to 180 minutes. The sintering time was as shown in Table 2. After sintering, the apparent density of the resulting laminate was measured by the Archimedes method, and the relative dielectric constant and Q value (the reciprocal of the dielectric loss) at 3 GHz by the perturbation method. The laminate was then pulverized to measure the true density of the powder. The apparent density measured by the Archimedes method was divided by the true density to obtain the relative density, which was calculated in percentage units according to the following formula. (Apparent density) / (True density) x 100 = Relative density (%)

[0076] The evaluation results are shown in Table 2. A material was judged to be dense if its relative density was 95% or more, to have a low dielectric constant if its relative dielectric constant was 4.5 or less, and to have a low dielectric loss if its Q value was 250 or more.

[0077] The laminates of Examples 1 to 14 had a relative density of 95% or more, a relative dielectric constant of 4.5 or less, and a Q value of 250 or more.

[0078] Among the laminates of Comparative Examples 1 to 3, which did not use metal oxides such as MnO, Comparative Example 1, which had a short firing time, had appropriate relative density, dielectric constant, and Q value, but Comparative Examples 2 and 3, which had firing times of 120 minutes or more, had a relative density of 90% or less, and Comparative Example 3 also had a low Q value.

[0079] In the laminates of Comparative Examples 4 to 7, the metal oxide content exceeded 2 parts by weight, and all of them had low Q values.

[0080] In the laminates of Comparative Examples 8 to 15, the metal oxide content was less than 0.05 parts by weight, and all of them had a low relative density, and in Comparative Examples 10 and 11, the Q value was also low. [Explanation of symbols]

[0081] 1 Laminate (multilayer ceramic substrate) 2. Electronic Components 3 Glass-ceramic layer 9, 10, 11 Conductor layers 12 Via conductor 13, 14 Chip components

Claims

1. SiO ２ , B ２ O ３ and M. ２ A glass containing O (M is an alkali metal); A filler containing quartz; At least one metal oxide selected from the group consisting of MnO, NiO, CuO, and ZnO; the content of the metal oxide is 0.05 parts by weight or more and 2 parts by weight or less with respect to 100 parts by weight in total of the glass and the filler, The glass has a content of SiO ２ Contains 70% by weight or more and 85% by weight or less, B in the glass ２ O ３ The content of is 10% by weight or more and 25% by weight or less, calculated as an oxide.

1. A glass-ceramic material comprising:

2. 2. The glass ceramic material according to claim 1, comprising 50 parts by weight or more and 90 parts by weight or less of the glass and 10 parts by weight or more and 50 parts by weight or less of the filler, relative to a total of 100 parts by weight of the glass and the filler.

3. A laminate comprising a plurality of glass ceramic layers, each of which is a sintered body of the glass ceramic material according to claim 1 or 2, laminated together.

4. The laminate according to claim 3 , further comprising a conductor layer provided between the glass ceramic layers adjacent in the stacking direction and / or on a surface of the glass ceramic layer.

5. 5. The laminate according to claim 4, wherein the main component of the conductor layer is Cu, and the metal oxide contained in the glass ceramic layer contains at least CuO.

6. An electronic component comprising the laminate according to any one of claims 3 to 5.

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