JP4050725B2 - Electronic devices - Google Patents

Description

  The present invention relates to an electronic device, and more particularly, an electronic device obtained by simultaneously firing a low dielectric constant material and a high dielectric constant material using Ag or Cu, or an alloy containing Ag or Cu as a main component as an internal conductor. About.

  In recent years, chip components such as a chip capacitor, a chip inductor, and a chip filter have been manufactured using a thick film forming method such as a printing method or a sheet method. In addition, electronic devices formed by simultaneously firing multiple types of porcelain compositions with different material properties include LC filters composed of combinations of magnetic and dielectric materials, and combinations of high and low dielectric constant materials. And a circuit board (element) having a built-in capacitor.

  For example, a capacitor formed by simultaneously firing the above-described high dielectric constant material and low dielectric constant material can reduce the distributed capacity compared to a capacitor made of only the high dielectric constant material. Further, the capacity can be increased as compared with a capacitor made of only a low dielectric constant material.

  In the above electronic device, in order to improve loss characteristics, it is desirable to use Ag or Cu having a low resistance as a conductor electrode, or an alloy mainly composed of Ag or Cu. However, since these conductor metals have a low melting point, the porcelain composition used in the electronic device is required to be baked (having low-temperature sintering properties) at a temperature lower than the melting point of the conductor metal.

Also, in order to fire multiple types of porcelain compositions at the same time, the linear expansion coefficients of the porcelain compositions must match to some extent. If the difference in the linear expansion coefficients is large, cracks will occur in the fired product. It will occur. For example, a general porcelain composition having a perovskite structure such as titanium oxide, barium titanate or calcium titanate, a tungsten bronze structure such as barium-rare earth-titanium oxide, or a spinel structure such as NiCuZn ferrite has a linear expansion coefficient. Is about 80 to 130 × 10 ⁻⁷ / ° C. Even if it is a porcelain composition to which the above-mentioned low-temperature sintering property is imparted by adding glass or the like to these, the linear expansion coefficient is almost the same (about 80 to 130 × 10 ⁻⁷ / ° C.). . However, many of the conventional low dielectric constant ceramic compositions mainly composed of glass have a linear expansion coefficient of about 40 to 80 × 10 ⁻⁷ / ° C., and impart low temperature sintering properties by adding the above glass. The coefficient of linear expansion is lower than that of the dielectric material and the magnetic material, and when these are fired at the same time, there is a problem that a crack occurs in the product.

  The present invention has been made in view of such circumstances, and can be sintered with an internal conductor alone with low-temperature sinterability, and has a high linear expansion coefficient and other porcelain compositions. An object of the present invention is to provide an electronic device using a low dielectric constant porcelain composition that can be fired simultaneously.

In order to solve such an object, the present invention has a low dielectric constant material which is a low dielectric constant ceramic composition mainly composed of Ba-based glass and α-quartz, and barium-rare earth-titanium oxide as a main component. Obtained by co-firing with a high dielectric constant material, comprising Ag or Cu, or an alloy containing Ag or Cu as a main component as an internal conductor, wherein the low dielectric constant ceramic composition contains the content of the Ba glass There 61.1 to 66.5 wt%, the α content of silica is in the range of 21.0 to 26.0 wt%, range Al ₂ O ₃ less 9.0 to 12.9 wt% in containing the components of the Ba-based glass, in terms of oxide, BaO and 21 to 25 mol%, a SiO ₂ 64 to 70 mol%, and contained within a range of the Al ₂ O ₃ 7~11 mol%, further, BaO, the sum of SiO ₂ and Al ₂ O ₃ 100 mol equivalents Ri contains B ₂ O ₃ in the range of 4 to 6 mol, and α quartz, four crystal phases _{[BaAl 2 SiO 8 + BaSi 2} O 5], [BaAl 2 SiO 8 + BaSi 2 O 5 + Al 2 O 3] , [BaAl ₂ SiO ₈ + Al ₂ O ₃ ], [BaSi ₂ O ₅ + Al ₂ O ₃ ], and a linear expansion coefficient of 80 × 10 ⁻⁷ / ° C. to 150 × 10 ⁻⁷ / ° C. And having a relative dielectric constant of 7.0 or less .

  In a preferred embodiment of the present invention, the firing temperature is in the range of 850 to 960 ° C.

  According to the present invention, it is possible to calcinate below the melting point of Ag or Cu, or an alloy containing Ag or Cu as a main component, a high dielectric constant with a high coefficient of linear expansion and a low dielectric constant, and a low dielectric constant. Since it is an electronic device obtained by firing simultaneously with a high dielectric constant material using a low dielectric constant ceramic composition that can be fired simultaneously with different kinds of ceramic compositions such as a dielectric material and a magnetic material, Ag or Cu, Alternatively, an electronic device such as a small filter, a resonator, or a circuit board that includes an alloy mainly composed of Ag or Cu as an internal conductor and does not generate cracks is possible.

  Next, an embodiment of the present invention will be described.

The low dielectric constant porcelain composition used for the electronic device of the present invention is mainly composed of Ba glass and α-quartz. In such a low dielectric constant ceramic composition, the content of the Ba glass is 55.0 to 69.4% by weight, preferably 57.3 to 66.5% by weight, and more preferably 61.1 to 66.5%. The content of α-quartz is in the range of 12.1 to 40.2% by weight, preferably 20.7 to 30.3% by weight, more preferably 21.0 to 26.0% by weight, Al ₂ O ₃ may be contained in an amount of 24.5% by weight or less, preferably 6.4 to 18.6% by weight, more preferably 9.0 to 12.9% by weight.

  When the content of the Ba-based glass is less than 55.0% by weight, the low-temperature sinterability of the low dielectric constant ceramic composition is reduced, and a dense sintered body (with a relative density of 92% after firing at 900 ° C. Above) is not obtained. Further, when the content exceeds 69.4% by weight, a dense sintered body cannot be obtained. On the other hand, when the content of the Ba-based glass is in the most preferable range of 61.1 to 66.5% by weight, the low dielectric constant ceramic composition has a low-temperature sinterability and a dense sintered body. In addition to being obtained, a continuous space or pore is generated at the joint surface of the boundary when integrally fired with a high dielectric constant material of barium-rare earth-titanium oxide that can be sintered at a low temperature of 900 ° C. or lower. Boundary reactivity is better without.

  Further, if the content of α-quartz is less than 12.1% by weight, the low-temperature sinterability of the low dielectric constant ceramic composition is lowered, and a dense sintered body cannot be obtained and exceeds 40.2% by weight. Even in this case, a dense sintered body cannot be obtained. On the other hand, when the content of α quartz is in the most preferable range of 21.0 to 26.0% by weight, the low dielectric constant ceramic composition has a low temperature sintering property and is densely sintered. In addition to obtaining a body, it is possible to form a boundary without generating continuous spaces or pores at the interface of the boundary when fired integrally with a high dielectric constant material of barium-rare earth-titanium oxide that can be sintered at low temperature. The reactivity becomes better.

Al ₂ O ₃ added to the main component consisting of Ba-based glass and α-quartz has the effect of improving the shape retention of the low dielectric constant ceramic composition, but if the added amount exceeds 24.5% by weight, the low temperature Sinterability deteriorates and a dense sintered body cannot be obtained. On the other hand, when the addition amount of Al ₂ O ₃ is in the most preferable range of 9.0 to 12.9% by weight, the low dielectric constant ceramic composition has a low temperature sinterability and is a dense sintered body. In addition to obtaining a low-temperature-sinterable barium-rare earth-titanium oxide and other high-dielectric constant materials, it is possible to create a boundary without generating continuous spaces or pores at the boundary joint surface when fired integrally. The reactivity becomes better.

The Ba glass in the low dielectric constant porcelain composition constituting the electronic device of the present invention has components in the following ranges in terms of oxides.
BaO: 19 to 29 mol%, preferably 21 to 25 mol%
· SiO _2: 62~72mol%, preferably 64~70mol%
Al ₂ O ₃ : 6 to 11 mol%, preferably 7 to 11 mol%
BaO, SiO ₂ and Al ₂ O ₃ : ₃ to 7 mol, preferably 4 to 6 mol of B ₂ O ₃ per 100 mol in total

  In the Ba glass, if the BaO component is less than 19 mol%, vitrification is difficult, and if it exceeds 29 mol%, a dense sintered body cannot be obtained.

Further, if the SiO ₂ component is less than 62 mol%, a dense sintered body cannot be obtained, and if it exceeds 72 mol%, vitrification is difficult, which is not preferable.

Furthermore, if the Al ₂ O ₃ component is less than 6 mol% or exceeds 11 mol%, a dense sintered body cannot be obtained in any case.

Further, if the B ₂ O ₃ component is less than ₃ mol with respect to 100 mol in total of BaO, SiO ₂ and Al ₂ O ₃ , vitrification is difficult, and if it exceeds 7 mol, a dense sintered body cannot be obtained.

The low dielectric constant porcelain composition used in the electronic device of the present invention has low-temperature sintering properties and a linear expansion coefficient of 80 × 10 ⁻⁷ / ° C. by appropriately setting each component within the above range. It can be in the range of ˜150 × 10 ⁻⁷ / ° C. Therefore, the linear expansion coefficient of different porcelain compositions such as conventional high dielectric constant materials and magnetic materials that can be fired at a temperature lower than the melting point of Ag or Cu having a low resistance, or an alloy mainly composed of Ag or Cu. It is easy to adapt to. For this reason, even if co-firing with different materials is performed, cracks do not occur in the obtained fired product. Note that it is difficult to obtain a low dielectric constant ceramic composition used for the electronic device of the present invention having a linear expansion coefficient exceeding 150 × 10 ⁻⁷ / ° C.

Furthermore, the low dielectric constant porcelain composition used for the electronic device of the present invention has a linear expansion coefficient of 80 × 10 ⁻⁷ / ° C. depending on the firing temperature and firing time in addition to the control of the linear expansion coefficient by the composition as described above. It can be controlled within a range of 150 × 10 ⁻⁷ / ° C. In firing Ba-based glass and α-quartz, or in those in which Al ₂ O ₃ is added, crystallization of the glass occurs, and new crystal phases [BaAl ₂ SiO ₈ ] and [BaSi ₂ O ₅ ] are formed. Generate. Since each of these crystal phases has a specific linear expansion coefficient, the linear expansion coefficient can be controlled by changing the type and amount of the crystal phase according to the firing conditions.

Such a low dielectric constant porcelain composition used in the electronic device of the present invention includes α-quartz, four crystal phases [BaAl ₂ SiO ₈ + BaSi ₂ O ₅ ], [BaAl ₂ SiO ₈ + BaSi ₂ O ₅ + Al ₂ O. ₃ ], [BaAl ₂ SiO ₈ + Al ₂ O ₃ ], [BaSi ₂ O ₅ + Al ₂ O ₃ ], and has a high coefficient of linear expansion despite its low dielectric constant, and It has low-temperature sinterability.

Next, the manufacturing method of the low dielectric constant ceramic composition used for the electronic device of the present invention will be described.
First, BaO, SiO ₂ , Al ₂ O ₃ , and B ₂ O ₃ which are Ba-based glass components are prepared, and a predetermined amount is weighed and mixed, melted in a crucible, rapidly melted, and crushed. To make glass powder. The glass raw material does not need to be an oxide. For example, even if a material that becomes an oxide by heat treatment such as carbonate, hydroxide, sulfate, etc. is used, Equivalent glass powder can be obtained.

The glass raw materials can be mixed by, for example, dry mixing, and melting can be performed at 1500 to 1600 ° C. for about 0.5 to 5 hours. The pulverization of the melt is preferably wet pulverization using a ball mill or the like.
Next, α-quartz powder as the main component, the Ba-based glass powder, and, if necessary, Al ₂ O ₃ powder are prepared, and a predetermined amount thereof is weighed and mixed. A slurry is prepared by mixing the obtained powder with an organic binder such as polyvinyl alcohol, acrylic or ethyl cellulose and, if necessary, a solvent, a plasticizer or the like.

  Next, the slurry is molded into a desired shape, and the molded product is fired. The molding may be a wet molding such as a sheet method or a printing method, or a dry molding such as a press molding, and a molding method can be appropriately selected according to a desired shape. The firing temperature can be set in the range of 850 to 960 ° C., and the firing time is preferably about 0.1 to 24 hours. Therefore, it becomes possible to perform low-temperature firing below the melting point of Ag or Cu, or an alloy containing Ag or Cu as a main component. For this reason, it becomes possible to constitute an electronic component using a low resistance metal such as Ag or Cu having a low resistance as an inner conductor. In addition, it is desirable to select a firing atmosphere according to the inner conductor to be co-fired. For example, in the case of co-firing with Ag, an oxygen atmosphere such as in the air is used. In the case of co-firing with Cu, a reducing atmosphere is used. To do.

  Next, an Example is shown and this invention is demonstrated further in detail.

Example 1
First, BaCO ₃ , SiO ₂ , Al ₂ O ₃ , and B ₂ O ₃ as Ba-based glass components were weighed so as to have the compositions shown in the glass composition columns of Tables 1 to ₃ below, and dry-mixed with a shaker. The mixture was then placed in a crucible and melted at 1550 ° C. for 1 hour. Thereafter, the melt was quenched with pure water, coarsely pulverized with a rake machine, and wet pulverized with a ball mill to obtain a Ba-based glass powder.

Next, Ba-based glass powder, α-quartz powder, and Al ₂ O ₃ powder obtained as described above were weighed so as to have the ratios shown in the column of material composition in Tables 1 to ₃ below. 15 parts by weight of an acrylic resin as an organic binder, 60 parts by weight of toluene as a solvent, and 5 parts by weight of n-butylphthalyl n-butyl glycolate (BPBG) as a plasticizer with respect to 100 parts by weight of the mixed powder In addition, 57 kinds of organic slurries were prepared by dispersing with a ball mill.

  Subsequently, 57 types of green sheets (samples 2 to 10 and 12 to 59) were prepared by the doctor blade method using the organic slurry. Thereafter, the green sheet was formed in a predetermined size according to the following measurement conditions, and baked at 900 ° C. for 2 hours.

  Next, the low temperature sinterability (relative density is 92% or more after firing at 900 ° C.) is evaluated for each of the above samples, and the relative dielectric constant and the linear expansion coefficient are measured by the following measuring method and contained. The crystal phase was measured by the following method, and the results are shown in Tables 1 to 3 below.

  Samples 8, 23, and 41 were fired integrally with a high dielectric constant material of barium-rare earth-titanium oxide that can be sintered at low temperature, and the fractured interface was scanned with a scanning electron microscope (JEOL datum ( JED-2001), and a compo image (2000 times) of the interface after integrated firing was taken and shown in FIG.

Measuring method of relative dielectric constant A rod-shaped sample of about 1 mm square is prepared, and the relative dielectric constant (2 GHz) is measured by the cavity resonator perturbation method (using 83620A, 8757C manufactured by Hewlett-Packard Co., Ltd.)
did.

Method of measuring linear expansion coefficient A sample of about 4 × 4 × 28 mm was prepared, and the linear expansion coefficient (100 to 700 ° C.) was measured with a horizontal linear expansion apparatus (DL-7000Y-RH manufactured by Vacuum Riko Co., Ltd.).

Method for measuring crystal phase Sintered sintered body in mortar and measured by powder X-ray diffraction method (Mac Science Co., Ltd.)
Made using MXP ³ system. The measurement condition is that the target is Cu, 45 kV,
40 mA, 1 deg / min, and 2θ = 10-60.
In Tables 1 to 3 below, α, A, B, C, and D represent the following crystal phases, respectively.
α: α quartz A: BaAl ₂ SiO ₈ + BaSi ₂ O ₅
B: BaAl ₂ SiO ₈ + BaSi ₂ O ₅ + Al ₂ O ₃
C: BaAl ₂ SiO ₈ + Al ₂ O ₃
D: BaSi ₂ O ₅ + Al ₂ O ₃

As shown in Tables 1 to 3, samples (2 to 9, 12, 13, 17 to 21, 23, 23) having Ba-based glass and α-quartz as main components and each component within the scope of the present invention. 34, 39-47, 50-54) all have excellent low-temperature sinterability, and can be fired below the melting point of Ag or Cu, or an alloy containing Ag or Cu as a main component, and also have a dielectric constant. And the linear expansion coefficient was in the range of 80 × 10 ⁻⁷ / ° C. to 130 × 10 ⁻⁷ / ° C. (7 or less (2 GHz)).

Furthermore, among the above samples 8, 23, and 41, the content of Ba glass is in the range of 61.1 to 66.5% by weight, and the content of α-quartz is in the range of 21.0 to 26.0% by weight. Sample 8 and Sample 23 (see FIGS. 1 and 2) containing Al ₂ O ₃ in the range of 9.0 to 12.9% by weight are barium-rare earth-titanium oxides that can be sintered at low temperature. The boundary reactivity at the time of integrated firing with a high dielectric constant material was particularly good as compared with the sample 41 (see FIG. 3).

On the other hand, the sample 1 whose BaO component is less than 19 mol% in the glass composition, the sample 11 whose B ₂ O ₃ component is less than ₃ mol per 100 mol in total of BaO, SiO ₂ and Al ₂ O ₃ , and the SiO ₂ component In sample 14 exceeding 72 mol%, vitrification was difficult, and a porcelain composition could not be obtained.
Further, none of the other samples in which the content of the constituent component deviated from the scope of the present invention was densified by firing at 900 ° C., and the relative density was less than 92%.

(Example 2)
First, an organic slurry having the same composition as Samples 39 to 43 in Example 1 was prepared in the same manner as in Example 1.

  Next, using the organic slurry, five types of green sheets (samples A to E) were prepared in the same manner as in Example 1, and then the green sheets were formed to the same predetermined size as in Example 1. Firing was performed under two conditions of 880 ° C. for 2 hours and 920 ° C. for 2 hours.

  Next, for each of the above samples, the linear expansion coefficient was measured in the same manner as in Example 1, and the results are shown in Table 4 below. Table 4 also shows the measurement results of Samples 39 to 43 (fired at 900 ° C. for 2 hours) in Example 1.

According to the measurement results shown in Table 4, the low dielectric constant ceramic composition used in the electronic device of the present invention has a linear expansion coefficient of 80 × 10 ⁻⁷ / ° C. to 130 × 10 ⁻⁷ by changing the firing conditions in the same composition. It became clear that control was possible within the range of / ° C.

  It is manufactured by simultaneous firing of a low dielectric constant material and a high dielectric constant material, and can be used for an electronic device including an internal conductor.

FIG. 1 is a scanning electron micrograph in place of a drawing, showing a broken boundary surface of Sample 8 obtained by integrally firing sample 8 with a high dielectric constant material in Example 1. FIG. 2 is a scanning electron micrograph in place of a drawing showing the fractured boundary surface of the sample 23 obtained in Example 1 by firing the sample 23 integrally with a high dielectric constant material. FIG. 3 is a scanning electron micrograph in place of a drawing showing a boundary surface of the sample 41 obtained by integrally baking the sample 41 with a high dielectric constant material in Example 1.

Claims (2)

Obtained by co-firing a low dielectric constant material, which is a low dielectric constant ceramic composition mainly composed of Ba-based glass and α-quartz, and a high dielectric constant material mainly composed of barium-rare earth-titanium oxide , Ag or Cu, or an alloy containing Ag or Cu as a main component is provided as an inner conductor, and the low dielectric constant porcelain composition has a Ba-based glass content of 61.1 to 66.5 % by weight, α the content of the silica is in the range of 21.0 to 26.0 wt%, the Al ₂ O ₃ contained in the range of 9.0 to 12.9 wt%, the component of the Ba-based glass, oxide in object terms, BaO and 21 to 25 mol%, a SiO ₂ 64 to 70 mol%, and contained within a range of the Al ₂ O ₃ 7~11 mol%, further, BaO, the sum of SiO ₂ and Al ₂ O ₃ the 100mol per B ₂ O ₃ contained in the range of 4 to 6 mol
α quartz and four crystal phases [BaAl ₂ SiO ₈ + BaSi ₂ O ₅ ], [BaAl ₂ SiO ₈ + BaSi ₂ O ₅ + Al ₂ O ₃ ], [BaAl ₂ SiO ₈ + Al ₂ O ₃ ], [BaSi ₂ O ₅ + Al ₂ O ₃ ],
The linear expansion coefficient is in the range of 80 × 10 ⁻⁷ / ° C. to 150 × 10 ⁻⁷ / ° C .;
An electronic device having a relative dielectric constant of 7.0 or less . The electronic device according to claim 1, wherein a firing temperature is in a range of 850 to 960 ° C.

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