JPH0797536B2 - Ceramic and circuit substrate and electronic circuit substrate using the same - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a ceramic that can be used as an electronic material such as a dielectric ceramic substrate, a circuit substrate using this ceramic, and an electronic circuit substrate.

[Prior Art] Conventionally, an electronic circuit substrate is configured to include only a conductor circuit, a conductor circuit and a resistor, or a conductor circuit and a resistor and a limited range of capacitors, and other functional parts are separated as elements. Attached to the base.

That is, for example, in the conventional porcelain substrate, the substrate having the conductor and the resistor built therein is the center, and the capacitor is mounted by soldering as a chip component or the like. Therefore, there is a limit to downsizing the electronic circuit. FIG. 11 shows an example thereof. 111 is a porcelain substrate, 112 is a conductor circuit, 113 is a resistor, 114
Is a chip capacitor.

In recent years, attempts have been made to incorporate a plurality of capacitors in a substrate by changing the dielectric constant within the same porcelain substrate. That is, as shown in FIG. 12, it is an attempt to form a plurality of capacitors in the same substrate by separating the portions 121 and 123 having a high dielectric constant ε ₁ and the portion 122 having a low dielectric constant ε ₂ . However, conventionally, it is very difficult to form different dielectric parts in the same substrate, and it is obvious that, for example, considering the complexity of manufacturing a monolithic ceramic capacitor, a substrate containing a plurality of capacitors Is currently not realized or put into practical use. Also, the high dielectric constant portion 121,123
It has also been an important technical problem to make the devices sufficiently separated from each other as device functional parts so that they do not affect each other in operation in a limited structure space.

Further, the problem of the separation and incorporation of the functional portion related to the electronic component or the circuit substrate is not limited to the dielectric porcelain, and when two or more functional portions of the same type or different types are to be formed in the ceramic, It was usually manifested.

[Object and Summary of the Invention] A first object of the present invention is to provide a ceramic capable of defining and incorporating a plurality of functional parts in a sufficiently separated state.

A second object of the present invention is that, as described above, a plurality of functional parts are formed of ceramics that can be defined and incorporated in a sufficiently separated state, so that they are sufficiently separated from each other as device functional parts. An object of the present invention is to provide a circuit board and an electronic circuit board that can incorporate a plurality of electronic component constituent units in a state.

The first object is to provide a first region made of a first dielectric ceramic having an insulating layer at a crystal grain boundary of a semiconductor porcelain containing a semiconducting agent, and the amount of the semiconducting agent in the first region. Since the first dielectric porcelain is provided with a second region composed of a second dielectric porcelain having a different permittivity due to a different type, the first dielectric porcelain has two or more functional parts separated from each other. This is achieved by the ceramic of the present invention, which is characterized in that

The second object is to have an electrode inside or around the ceramic of the present invention and, if necessary, at least one functional portion of a conductor, a resistor, an insulator and the like. A circuit substrate of the present invention, and an electrode inside or around the ceramic of the present invention, and if necessary, at least one functional portion of a conductor, a resistor, an insulator, etc. is present. And an electronic circuit component of the present invention is characterized in that the electronic circuit component is mounted on the ceramic.

[Detailed Description and Examples of the Invention] When the ceramic of the present invention is used as, for example, an electronic material ceramic, the functional portion that can be formed in the ceramic of the present invention is, for example, a dielectric or a conductor forming a capacitor, Examples thereof include electronic component constitutional units such as semiconductors, resistors, insulators, diodes, and transistors. In the present invention, these functional portions can be formed in the first region or the second region, and a combination of these regions, a combination of these regions and a region other than these regions, or these regions can be formed. It can also be formed in other regions.

Further, for example, two or more of the first regions are arranged separately with the second region interposed, or vice versa, two or more of the second regions are interposed with the first region interposed. By arranging these areas separately, it is possible to form two or more functional portions constituted by the first area or the second area in a sufficiently separated state. Further, both the first area and the second area can be used as a functional portion.

As an example of the ceramic of the present invention, FIGS. 1 to 3 show shape examples of the first region and the second region of a plate-shaped dielectric ceramic substrate. It is assumed here that the functional portion is constituted by the first area. In the example of FIGS. 1 to 3, 1 is a plate-shaped dielectric ceramic base, A is a first
Area, and B is the second area.

In FIG. 1, a second region B having a rectangular cross section that reaches both main surfaces of the plate-shaped dielectric ceramic base 1 is provided.
Two first regions A, A separated from each other are provided with the first region A, A sandwiched therebetween.

In the example of FIG. 2, second surface areas B and B each having a rectangular cross section are provided in respective surface layer portions of both main surfaces of the porcelain 1, and the two area portions B and B are separated from each other. One area A, A is provided.

In the example of FIG. 3, a second region B having a rectangular cross section is provided in the surface layer portion of one main surface of the porcelain 1, and the region B is sandwiched between the two regions.
Two first areas A, A separated from each other are provided.

In addition, in the example of FIG. 1 to FIG. 3, one or two second regions B are provided, but the present invention is not limited to this, and depending on the number of desired functional portions (first regions). You can decide
It goes without saying that three or more regions may be provided.

Further, as the second region, a group of two or more regions of different types having a different dielectric constant from the first dielectric ceramic is formed due to the difference in the amount or type of the semiconducting agent from the first region. You may.

When the first region is used as a region of a dielectric material for forming a capacitor, the first dielectric ceramic needs to have a high dielectric constant. It is desired that the characteristics such as the temperature change rate when the dielectric itself and the capacitor are constructed are practically preferable.

In this case, the dielectric constant of the first dielectric ceramic is 35,000.
The above is preferable. As a result, the capacitance of the capacitor is 0 even if the shape of the ceramic is included.
It is possible to form up to about 047 μF, and when it is applied to, for example, a video circuit or the like, about half the types of capacitors that are generally used can be formed in a ceramic.

Further, when the first region is used as the high dielectric region in this way, it is preferable that the dielectric constant of the first dielectric ceramic is 5 times or more that of the second dielectric ceramic. This is the performance required to eliminate the mutual influence of the functional parts, and it is very advantageous in terms of circuit miniaturization if a difference in dielectric constant of 5 times or more is provided.

When the first region is the high-dielectric region, the first dielectric ceramic preferably contains SrO and TiO ₂ as main components. In addition, the dielectric constant tends to decrease, but BaO and T
For example, a material containing iO ₂ as a main component can be applied.

SrO and Ti in dielectric ceramics containing SrO and TiO ₂ as main components
The amount ratio of O ₂ is TiO ₂ 5 per 100 mol% of the total amount of SrO and TiO _2.
0.20 to 53.50 mol% and SrO49.80 to 46.50% are optimum.

When the amount of TiO ₂ increases, that is, when the amount of SrO decreases,
The dielectric constant of the desired dielectric ceramic decreases, the dielectric loss and the change in dielectric constant with temperature increase, and the insulation resistance of the ceramic decreases. When the amount of TiO ₂ decreases, that is, when the amount of SrO increases, the permittivity of the desired dielectric ceramic decreases and the change in permittivity with temperature increases. The amount ratio of TiO ₂ and SrO in the dielectric ceramics containing SrO and TiO ₂ as the main components is such that the desired properties such as the dielectric constant, the dielectric loss, the temperature change of the dielectric constant, the insulation resistance of the porcelain, and the semiconductor conversion ability are balanced. Determined for optimal speech.

In the dielectric ceramics containing SrO and TiO ₂ as main components, Sr
Alternatively, and / or Ti may be replaced with other elements to achieve more desired properties.

Substitution elements include Ba, Ca, Pb, and Ti for Sr.
Zr, Sn and the like are preferable.

Ca has the effect of reducing the temperature coefficient of the dielectric constant, improving the sinterability of porcelain, and stabilizing each characteristic. Ca
The preferred substitution amount of is a ratio of CaO 0 to 0.30 mol in 1 mol of SrO.

Ba has the effect of increasing the dielectric constant. The preferable substitution amount of Ba is
The ratio of BaO is 0 to 0,10 mol in 1 mol of SrO.

Pb has the effect of increasing the sinterability of porcelain more than Ca, and is advantageous in the manufacturing process.

Sn has the effect of improving the dielectric loss (tan δ) and also has the effect of increasing the sinterability of the porcelain.

Zr contributes to the improvement of the dielectric constant.

The other components of the first dielectric porcelain are, for example, Mn for the purpose of improving the properties of the porcelain and stabilizing the properties.
Components such as O ₂ , SiO ₂ , and ZnO can be contained. For example, preferable contents of MnO ₂ and SiO ₂ are as follows.

0.1 ≦ MnO ₂ ≦ 5.0 0.01 ≦ SiO ₂ ≦ 2.00 (both are mol parts relative to 100 mol parts of the main component of the first dielectric ceramic) MnO ₂ and ZnO have a role of sintering aids for forming porcelain are those, for example, rate of change of capacity of the capacitor that MnO ₂ is the amount of MnO ₂ was 0.1 to 5.0 molar parts with respect to 100 moles of the main component portion is desired to be less than 0.1 molar parts is increased. This is because if it exceeds 5.0 parts by mole, the dielectric loss increases.

SiO ₂ has a function as a grain boundary improving agent for semiconductor porcelain. The grain boundary improver is to apply the additive to the surface of the semiconductor porcelain, and then, in firing in air to diffuse the additive to the crystal grain boundaries, to make the diffusion of the additive uniform at the grain boundaries. By doing so, it is possible to stabilize and homogenize the characteristics. However, in the expectation of such an effect, when using SiO ₂ , if the amount of SiO ₂ is less than 0.001 part by mol relative to 100 parts by mol of the main component, the effect is not sufficiently expressed, and 2.0 parts by mol is used. If it exceeds, the desired dielectric constant of the capacitor is lowered, which is not preferable.

Examples of the semiconducting agent used in the present invention include Y,
Dy, La, Nb, Sb, Ta, Ce, Nd, Cd, Al, Pr ₂ O ₃ , ThO ₂ , P
One or more of m ₂ O ₃ , Sm ₂ O ₃ , Eu ₂ O ₃ , Lu ₂ O ₃ , Tb ₂ O ₃ , Tm ₂ O ₃ and Yb ₂ O ₃ can be used.

These semiconducting agents are appropriately selected and used in consideration of the characteristics of the dielectric material itself such as the dielectric constant and the characteristics such as the dielectric loss, the insulation resistance, the temperature coefficient of the dielectric constant when the capacitor is constructed.

One of the characteristics of the present invention is that the second dielectric porcelain forming the second region is made different from the first region in that the type or amount of the semiconducting agent is different from that of the first region. is there. Therefore, the second dielectric porcelain may have substantially the same type and amount of components excluding the semiconducting agent as the first dielectric porcelain, or may have some or all of the components different.

However, in order to allow the first and second dielectric porcelains to exist in the ceramic as an integral structure, it is necessary that the interfaces have reactivity at the interface and, conversely, deformation at the joint, It is desirable not to increase the reactivity so much that the strength distribution is largely changed or the stress is not included.

The present invention takes advantage of the fact that the electrical characteristics of porcelain can be changed significantly by changing the quantity of the semiconducting agent, which makes it possible to separate functional parts within the ceramic. For example, when the amount of Y ₂ O ₃ in the SrO-TiO ₂ -ZnO ₂ -Y ₂ O ₃ system porcelain is slightly changed around 1%, the dielectric constant is It was confirmed that there was a very significant change in the order of hundreds to tens of thousands. Therefore, it is possible to define regions having different permittivities and incorporate them in the same ceramic without significantly changing the composition of the porcelain.

Such effects also appear when a combination of different types of semiconducting agents is used.

A suitable amount of the semiconducting agent for increasing the dielectric constant of the first dielectric ceramic is shown below.

(Both are based on 100 parts by mole of main component) 0.06 ≤ La ₂ O ₃ ≤ 1.47 0.06 ≤ Y ≤ 1.47 0.06 ≤ Dy ≤ 1.47 0.1 ≤ La ≤ 1.5 0.02 ≤ Nb ≤ 1.99 0.02 ≤ Sb ≤ 1.99 0.02 ≤ Ta ≤ 1.99 0.03 ≤ Ce ≤ 1.1 0.1 ≤ Pr ₂ O ₃ ≤ 1.5 0.1 ≤ ThO ₃ ≤ 1.5 0.1 ≤ Pm ₂ O ₃ ≤ 1.5 0.1 ≤ Sm ₂ O ₃ ≤ 1.5 0.1 ≤ Eu ₂ O ₃ ≤ 1.5 0.1 ≤ Lu ₂ O ₃ ≤ 1.5 0.1 ≤ Tb ₂ O ₃ ≤ 1.5 0.1 ≤ Tm ₂ O ₃ ≤ 1.5 0.1 ≤ Yb ₂ O ₃ ≤ 1.5 A specific mode in which the dielectric constants of the first dielectric ceramic and the second dielectric ceramic are different It is as follows.

-Adjust the amount using the same type (including the case where two or more types are the same) of the semiconducting agent.

-Use different types of semiconducting agents having different degrees of semiconductivity (including the case where at least one is different in the case of two or more kinds). In this case, the amount can also be adjusted.

An example of the method for producing the ceramic of the present invention will be described below. Here, the porcelain-forming composition forming the semiconductor porcelain in the first region is C ₁ and the porcelain-forming composition forming the second region is C ₂ .

This manufacturing example can be performed by the steps as shown in FIG.

That is, a partition plate that can be removed to the mold 11 shown in FIG.
12 is provided, 13 and 14 are filled with C ₁ , 15 is filled with C ₂ , and the partition plate is removed. Then, pressure molding is performed. Here, the molded body is shown in FIG. 21, 22 are filled with C ₁ particles, and 23 are filled with C ₂ particle groups. This molded body is subjected to primary firing to convert the C ₁ portion into a semiconductor, and then, for example, the surface of the semiconductor porcelain thus obtained is coated with an additive serving as a diffusion component to a crystal grain boundary and secondarily fired to C _An insulating layer is formed on the crystal grain boundaries of the semiconductor porcelain constituted by ₁ to make it a dielectric porcelain.

The primary firing is performed in a reducing atmosphere such as a mixed gas of hydrogen and nitrogen, a mixed gas of hydrogen and argon, or in a neutral atmosphere such as nitrogen or argon, more preferably in a reducing atmosphere, and preferably
A semiconductor ceramic is obtained by firing at 1320 to 1450 ° C.

The second firing is preferably performed at 1100-1300 ° C. in an oxidizing atmosphere.

As the additive, any conventionally known additive for forming an insulating layer at a crystal grain boundary of a semiconductor ceramic can be used. For example, manganese, bismuth, vanadium, lead,
In addition to oxides of chromium, iron, cobalt, nickel, copper, astatine, antimony, thallium, etc., particularly preferably used in the present invention are boron oxide and sodium oxide, and good results are obtained when these are used. can get. The additive may be in the form of these oxides as a result of firing, and when supplied to the surface of the semiconductor porcelain, it may be in the form of oxide, nitride, carbonate or the like.

One example of the shape of the ceramic of the present invention is shown in Fig. 7 (a) (plan view) and Fig. 7 (b) (A-A sectional view of Fig. 7 (a)).

The ceramic shown in FIGS. 7 (a) and 7 (b) has a plurality of high dielectric constant regions 71, 71, 71, ... Inside the plate-shaped dielectric ceramic 1.
Are defined in the low permittivity region 72,7
They are separated from each other by 2,72, ....

Next, the circuit substrate of the present invention has at least electrodes inside or around the ceramic of the present invention, and if necessary, at least one functional portion of a conductor, a resistor, an insulator and the like. It is characterized by

As a structural example of the circuit board of the present invention, when the same elements are represented by the same reference numerals, the circuit board shown in FIG. 8 has the high dielectric constant of each of the ceramics shown in FIGS. 7 (a) and 7 (b). A pair of electrode groups 81, 81 ', 81, 8 composed of a thick film of conductive paste such as silver paste on both main surfaces of the region
It has 1 ', 81, 81'.

The example of the circuit board shown in FIG. 9 is formed by leaving the via hole portion 91 provided on the circuit board shown in FIG. 8 as needed by screen printing of an insulating paste such as glass. Insulating layers 92, 92 ', conductor circuit portions 92 ... And resistor portions 94 printed in the via holes 91 and on the insulating layer.

Furthermore, the electronic circuit substrate of the present invention has an electrode inside or around the ceramic of the present invention, and if necessary, a conductor,
It is characterized in that at least one kind of functional portion of a resistor, an insulator, etc. is present, and an electronic circuit component is mounted on this ceramic.

When the same elements are denoted by the same reference numerals, for example, the electronic circuit board shown in FIG. 10 is the flexible printed IC chip 101 in which the circuit board shown in FIG. 9 is connected to the conductor circuit portion 93.
And 102 are attached.

Hereinafter, the present invention will be described in more detail with reference to Reference Examples and Examples.

Reference Examples 1-27 A green compact (diameter: 16 mm, height: 0.7 mm) having the composition shown in Table 1 below was prepared, fired at 1320 ° C. for 4 hours in the air, and then 1300 ° C., 2
A semiconductor porcelain was prepared by firing in a reducing atmosphere of hydrogen 10% and nitrogen 90% for a time. Next, the porcelain was soaked in a grain boundary insulating agent having the components shown in Table 1 and fired in an oxidizing atmosphere at 1300 ° C. for 2 hours to form an insulating layer at a crystal grain boundary of the semiconductor porcelain.

Apply silver paste to the dielectric ceramic thus obtained, 900
After baking at 30 ° C. for 30 minutes to form a pair of electrodes, the dielectric constant of the dielectric ceramic was measured. The results are shown in Table 1.

As is clear from Table 1, it can be seen that the dielectric constant shows an extremely large change by changing the amount or type of the semiconducting agent.

Examples 1 to 9 According to the process explanatory diagram shown in FIG. 6, among the dielectric ceramic forming compositions of Reference Examples 1 to 27 shown in Table 1 above, a composition having a high dielectric constant (C ₁ ) and a low dielectric constant were used. Using the combinations shown in Table 2 as the composition of the ratio (C ₂ ), the partition plate 12 was set up in the mold 11 shown in FIG. 4, and the voids 13 and 14 were filled with C ₁ and the voids 15 were filled with C ₂ . After that, the semiconductor was converted into a semiconductor under the same conditions as in Reference Examples 1 to 27, and C ₁ shown in Table ₁
A grain boundary insulating layer was formed under the same firing conditions by using the same grain boundary insulating agent used in the above, and as shown in FIG. 5, two grain boundary insulating layers were separated from each other with a low dielectric constant region 23 interposed therebetween. Ceramics with high permittivity regions 21, 22 were prepared.

Electrodes were formed on both main surfaces of the high-dielectric constant regions 21 and 22 of the ceramic thus obtained in the same manner as in the reference example, and the capacitor characteristics were measured. The results are shown in Table 2.

As is clear from the above, according to the ceramic of the present invention,
It may have a plurality of capacitor functional parts, well separated.

[Effects of the Invention] According to the ceramic of the present invention, a plurality of functional parts can be built in in a sufficiently separated state.

Further, according to the circuit substrate and the electronic circuit substrate of the present invention,
As described above, by being composed of a ceramic capable of defining and incorporating a plurality of functional parts in a sufficiently separated state, a plurality of electronic component structural units are sufficiently separated from each other as element functional parts. Can be built-in.

[Brief description of drawings]

1 to 3 are schematic cross-sectional views showing examples of the shapes of the first region and the second region in the ceramic of the present invention. FIG. 4 is a schematic perspective view of a die for producing the ceramic of the present invention used in the examples, and FIG. 5 is a schematic perspective view of a ceramic produced by using a molded body of the die as a raw material. FIG. 6 is a perspective view, and FIG. 6 is a process explanatory view of manufacturing the ceramic. FIG. 7 (a) is a plan view showing a structural example of the ceramic of the present invention, and FIG. 7 (b) is a sectional view taken along line AA in FIG. 7 (a). 8 and 9 are schematic cross-sectional views each showing a structural example of the circuit substrate of the present invention, and FIG. 10 is a schematic cross-sectional view showing a structural example of the electronic circuit substrate of the present invention. is there. FIG. 11 is a schematic sectional view of a conventional porcelain substrate. FIG. 12 is a cross-sectional view of a magnetic substrate having a plurality of high-dielectric-constant portions according to a conventionally attempted method. A ... 1st area | region, B ... 2nd area | region, 71, 71, 71 ... High dielectric constant part, 72, 72, 72 ... Low dielectric constant part, 81, 81 '... Electrode, 91
… Via holes, 92… Insulators, 93… Conductor circuits, 94… Resistors, 101,102… Chip parts.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area H05K 1/16 A 7726-4E

Claims (12)

[Claims] 1. A first region composed of a first dielectric porcelain having an insulating layer at a crystal grain boundary of a semiconductor porcelain containing a semiconducting agent, and the first region are different in amount or kind of the semiconducting agent. Due to the difference, the first dielectric porcelain and the second region composed of the second dielectric porcelain having a different dielectric constant are provided, and thus the first dielectric porcelain has two or more functional parts separated from each other. Characteristic ceramic. 2. The ceramic according to claim 1, wherein the first dielectric ceramic has a dielectric constant of 35,000 or more. 3. The ceramic according to claim 1, wherein the dielectric constant of the first dielectric ceramic is at least 5 times the dielectric constant of the second dielectric ceramic. 4. The first and second dielectric porcelains are both SrO and T
The ceramic according to claim (1) containing iO ₂ as a main component. 5. A first region composed of a first dielectric porcelain having an insulating layer at a crystal grain boundary of a semiconductor porcelain containing a semiconducting agent, and the first region are different in the amount or kind of the semiconducting agent. Due to the difference from the first dielectric porcelain, the second region composed of the second dielectric porcelain having a different permittivity is provided, so that the ceramic having two or more functional parts separated from each other is provided. A circuit substrate having electrodes inside or around it and, if necessary, at least one functional portion of a conductor, a resistor, an insulator and the like. 6. The circuit board according to claim 5, wherein the first dielectric ceramic has a dielectric constant of 35,000 or more. 7. The circuit board according to claim 5, wherein the dielectric constant of the first dielectric ceramic is 5 times or more the dielectric constant of the second dielectric ceramic. 8. The first and second dielectric porcelains are both SrO and T
The circuit substrate according to claim (5), which contains iO ₂ as a main component. 9. A first region made of a first dielectric porcelain having an insulating layer at a crystal grain boundary of a semiconductor porcelain containing a semiconductor agent and the first region are different in amount or kind of the semiconductor agent. Due to the difference from the first dielectric porcelain, the second region composed of the second dielectric porcelain having a different permittivity is provided, so that the ceramic having two or more functional parts separated from each other is provided. Characterized by having an electrode inside or around, at least one functional portion of a conductor, a resistor, an insulator, etc., being present if necessary, and mounting an electronic circuit component on a ceramic An electronic circuit substrate. 10. The electronic circuit substrate according to claim 9, wherein the first dielectric ceramic has a dielectric constant of 35,000 or more. 11. The electronic circuit substrate according to claim 9, wherein the dielectric constant of the first dielectric ceramic is 5 times or more the dielectric constant of the second dielectric ceramic. 12. The electronic circuit substrate according to claim 5, wherein both the first and second dielectric porcelains contain SrO and TiO ₂ as main components.