JPH07312511A - Multilayer composite substrate for microwave and method of manufacturing the same - Google Patents

Abstract

(57) [Abstract] [Purpose] By improving the bondability between the dielectric layer and the insulating layer, delamination and substrate warpage due to firing are prevented, which results in stable and reliable quality. To realize a multi-layer composite substrate for microwave. [Structure] The first and second dielectric layers 4 and 6 made of a microwave dielectric material and the first and second dielectric layers 1 and 9 made of a glass ceramic material are provided between the first and second dielectric layers. Two
Intermediate layers 2 and 8 are interposed. The composition of the first and second intermediate layers 2 and 8 is a mixture of a microwave dielectric material and a glass ceramic material, or a mixture of a microwave dielectric material and glass powder. As the microwave dielectric material, a dielectric ceramic material containing Bi ₂ O ₃ , CaO, or Nb ₂ O ₅ as a main component, or at least BaO,
Examples thereof include dielectric ceramic materials obtained by adding glass powder to a material containing Nd ₂ O ₃ and TiO ₂ as main components.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave multi-layer composite substrate having a resonator and a filter built in the substrate and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, with the development of low temperature sintered microwave dielectric ceramics, it is possible to use Ag, Cu, etc., which have low resistance, as a conductive metal that can be used, and it is possible to form a laminated device even in the microwave region. became.

A multilayer composite substrate for microwaves was manufactured as follows. That is, after the electrode pattern is screen-printed on the microwave dielectric green sheet using the conductive metal paste, the same type of microwave dielectric green sheet is laminated on the printed surface. By repeating this process, the dielectric layer that constitutes the resonator or the filter is manufactured.

Next, after laminating an insulating layer on one or both sides of the dielectric layer, firing is carried out in the air or in a low oxygen atmosphere to obtain a multilayer composite substrate for microwaves.

[0005]

However, according to the above-mentioned conventional multilayer composite substrate for microwaves, the difference in shrinkage initiation temperature and final shrinkage ratio between the two during the firing process,
Or, the difference in the coefficient of thermal expansion between the two during the cooling process may cause warpage or delamination of the substrate at the joint between the dielectric layer and the insulating layer, thus deteriorating the stability and reliability of quality. was there.

In view of the above, the present invention prevents the delamination and the warp of the substrate due to firing by improving the bondability between the dielectric layer and the insulating layer, thereby improving the quality stability and An object of the present invention is to provide a multilayer composite substrate for microwaves having improved reliability and a method for manufacturing the same.

[0007]

In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that between a dielectric layer and an insulating layer,
An intermediate layer is provided which is bonded to at least one of these layers and relaxes the difference in shrinkage initiation temperature, final shrinkage ratio and thermal expansion coefficient between these layers. Specifically, it is a microwave multilayer. A dielectric layer made of a dielectric material for microwaves having a relative dielectric constant of 15 or more and an unloaded Q value at 1 GHz of 500 or more and an absolute value of a temperature change rate of a resonance frequency of 50 ppm / ° C. or less; An insulating layer made of an insulating material having a relative dielectric constant of 15 or less, which is provided on both sides or one side of the dielectric layer, and is interposed between the dielectric layer and the insulating layer. And a middle layer made of a middle layer material containing at least one of the constituent components of the insulating material.

The invention of claim ₂ adds to the structure of claim 1 that the dielectric material is a dielectric ceramic material containing Bi ₂ O ₃ , CaO and Nb ₂ O ₅ as main components. It is a thing.

According to a third aspect of the present invention, in the structure of the first aspect, the microwave dielectric material is BaO, Nd ₂ O ₃ or T.
In addition, a dielectric ceramic material containing iO ₂ and glass as main components is added.

According to a fourth aspect of the present invention, in the configuration of the first aspect, the intermediate layer material is a mixture of the dielectric ceramic material according to the second or third aspect and the insulating material, The composition in which the mixing weight ratio of the dielectric ceramic material described in 3 and the insulating material is within the range of 90:10 to 10:90 is added.

According to a fifth aspect of the present invention, the intermediate layer material is the dielectric ceramic material according to the second or third aspect, and B ₂
It is a mixture with a glass material containing any one of O ₃ , SiO _{2 and} BaO, and the mixing weight ratio of the dielectric ceramic material according to claim 2 or 3 and the glass material is 98: 2 to 10:90. The configuration of being within the range of is added.

According to a sixth aspect of the present invention, the microwave dielectric material is a dielectric ceramic material containing Bi ₂ O ₃ , CaO and Nb ₂ O ₅ as main components, and the intermediate layer material is the dielectric ceramic material. 0.5 wt% to 10 wt% for material
% ZnO is added to the composition.

The invention of claim 7 is a method for manufacturing a multilayer composite substrate for microwaves according to the invention of claim 1, wherein the first green sheet is made of a dielectric material for microwaves and has a relative dielectric constant of 15 or less. A second green sheet made of the above insulating material, and a third green sheet made of a material containing at least one of the constituent components of the microwave dielectric material and the constituent component of the insulator material. And a step of producing a dielectric layer containing electrodes by using the first green sheet and a paste made of a conductive material, and the third layer on one side or both sides of the dielectric layer.
Stacking the green sheets, step of stacking the second green sheet on the third green layer, and composite stack of the dielectric layer, the third green sheet and the second green sheet. And a process of thermocompression-bonding and firing the body.

[0014]

According to the structure of claim 1, between the dielectric layer and the insulating layer, the constituent component of the microwave dielectric material forming the dielectric layer and the constituent component of the insulating material forming the insulating layer. Since the intermediate layer including at least one of the above is interposed, the same component as the component included in the dielectric layer or the insulating layer among the components included in the intermediate layer reacts at the bonding interface.

Further, the difference in the contraction start temperature, the final contraction rate and the coefficient of thermal expansion between the dielectric layer and the insulating layer is alleviated by the interposition of the intermediate layer.

According to the structure of claim 2, since the microwave dielectric material is a dielectric ceramic material containing Bi ₂ O ₃ , CaO and Nb ₂ O ₅ as main components, the sintering temperature is 1.
It is possible to reliably obtain a microwave dielectric material having a relative dielectric constant of 050 ° C. or lower, a relative dielectric constant of 15 or higher, an unloaded Q value at 1 GHz of 500 or higher, and an absolute value of the temperature change rate of the resonance frequency of 50 ppm / ° C. or lower. .

According to the structure of claim 3, since the microwave dielectric material is a dielectric ceramic material containing BaO, Nd ₂ O ₃ , TiO ₂ and glass as main components, the sintering temperature is 1050 ° C. or less, A dielectric material for microwaves having a dielectric constant of 15 or more and an unloaded Q value at 1 GHz of 500 or more and an absolute value of the temperature change rate of the resonance frequency of 50 ppm / ° C. or less can be reliably obtained.

According to the structure of claim 4, the intermediate layer material is a mixture of the dielectric ceramic material according to claim 2 or 3 and the insulating material, and the mixing weight ratio of the former and the latter is 90:10. Since it is within the range of 10:90, the bondability between the dielectric layer and the intermediate layer and the bondability between the insulating layer and the intermediate layer are improved, and the contraction between the dielectric layer and the insulating layer starts. Differences such as temperature, final shrinkage and thermal expansion are reliably mitigated by the intermediate layer.

According to the structure of claim 5, the intermediate layer material is the dielectric ceramic material according to claim 2 or 3, and B ₂ O.
₃ , which is a mixture with a glass material containing any one of SiO _{2, and} BaO, and the mixing weight ratio of the former and the latter is 9
Since it is in the range of 8: 2 to 10:90, the bondability between the dielectric layer and the intermediate layer and the bondability between the insulating layer and the intermediate layer are improved, respectively, and the dielectric layer and the insulating layer are bonded together. Differences in shrinkage initiation temperature, final shrinkage ratio, thermal expansion coefficient, etc. are reliably alleviated by the intermediate layer.

According to the structure of claim 6, the microwave dielectric material is a dielectric ceramic material containing Bi ₂ O ₃ , CaO and Nb ₂ O ₅ as main components, and the intermediate layer material is the dielectric ceramic material. Since it is a material to which 0.5 wt% to 10 wt% ZnO is added, Bi ₂ O ₃ and Zn are added.
O forms a low-melting point compound and promotes liquid phase sintering, so that particularly the bondability between the dielectric layer and the intermediate layer is improved, and the shrinkage initiation temperature between the dielectric layer and the insulating layer, Differences such as final shrinkage and thermal expansion are reliably mitigated by the intermediate layer.

According to the structure of claim 7, the component and the insulation of the microwave dielectric material are provided on one side or both sides of the first green sheet made of the microwave dielectric material and the dielectric layer made of the conductor material. After stacking a third green sheet made of a material containing at least one component of the body material, a second green sheet made of an insulating material having a relative dielectric constant of 15 or less is formed on the third green layer. In order to stack the green sheets of, among the constituent components of the microwave dielectric material forming the dielectric layer and the constituent components of the insulator material forming the insulating layer, between the dielectric layer and the insulating layer. An intermediate layer containing at least one component of can be interposed.

[0022]

EXAMPLE An example of the microwave multilayer composite substrate according to the present invention will be described below. FIG. 1 shows a sectional structure of a multilayer composite substrate for microwaves according to the present invention. As shown in FIG. 1, a first intermediate layer 2 and a first conductor layer are formed on a first insulating layer 1. 3, the first dielectric layer 4, the second conductor layer 5, the second dielectric layer 6, the third conductor layer 7, the second intermediate layer 8 and the second insulating layer 9 are sequentially formed, Second insulating layer 9
The surface electrode 10 formed on is connected to the second conductor layer 5. The microwave multi-layer composite substrate according to the present invention includes the first and second intermediate layers 2 and 8 on the upper and lower surfaces of the first and second dielectric layers 4 and 6 which are resonators or filter portions. This is a multilayer composite structure in which the first and second insulator layers 1 and 9 are laminated. That is, the first and second dielectric layers 4,
6 and the first and second insulator layers 1 and 9 are not directly in contact with each other and are laminated via the first and second intermediate layers 2 and 8. The connection between the second conductor layer 5 and the surface electrode 10 was realized by filling the through holes 11 formed in the green sheet by punching or the like with the conductor paste.

An embodiment of a method for manufacturing a multilayer composite substrate for microwaves according to the present invention will be described below.

Example 1 First, a microwave dielectric material for forming the first and second dielectric layers 4 and 6 will be described.

Bi ₂ O ₃ : 63.7 wt%, CaC
After adding 0.5 wt% of CuO to the powder prepared so as to have O ₃ : 12.2 wt% and Nb ₂ O ₅ : 24.1 wt%, they are mixed well. Hereinafter, the microwave dielectric material having the above composition will be referred to as a first dielectric material. First
The characteristics of the sintered body obtained by firing the dielectric material of No. 3 at 900 ° C. are as follows: relative permittivity ε _r = 58, unloaded Q = 650 (3.8
GHz), temperature characteristics of resonance frequency τ _f = + 23 ppm /
It was ℃.

After that, an organic binder, a solvent and a plasticizer are added to the mixed powder of the first dielectric material and mixed to obtain a slurry, which is then subjected to a doctor blade method.
A film is formed on the first green sheet having a thickness of 0.1 to 0.3 mm.

Next, an insulating material for forming the first and second insulating layers 1 and 9 will be described.

[0028] As the insulating material, PbO-B ₂ O ₃ -
SiO ₂ glass powder and Al ₂ O ₃ as filler
A glass ceramic having a mixing ratio of 50:50 (wt%) is used. Hereinafter, the insulating material having the above composition will be referred to as a first insulating material. The first insulator material is formed by the doctor blade method in the same manner as described above.
A second green sheet having a thickness of 0.3 mm was produced.
The characteristics of the sintered body obtained by firing the first insulator material at 900 ° C. are as follows.
Hz), temperature characteristics of resonance frequency τ _f = −40 ppm /
° C., was flexural strength 2500 (kg / cm ^2). still,
Examples of the insulating material include cordierite-based ceramics, mullite-based ceramics, forsterite-based ceramics, etc. in addition to glass ceramics. The type does not matter.

Next, the intermediate layer material for forming the first and second intermediate layers 2 and 8 will be described. A mixed composition of the first dielectric material and the first insulator material (hereinafter, referred to as a first intermediate layer material), a mixed composition of the first dielectric material and glass (hereinafter, the second intermediate material). And a green sheet having a composition in which ZnO is added to the first dielectric material (hereinafter, referred to as a third intermediate layer material). The mixing ratios are as shown in (Table 1) and (Table 2) for the first intermediate layer material and the second intermediate layer material, respectively, and for the second intermediate layer material, the composition of the added glass. The system is also shown. Also, the sheet number (C-1 to C-7, D-1 to D-11) is assigned to each green sheet.
Was displayed. Regarding the third intermediate layer material, ZnO is added to the first dielectric material at 0.1 wt%, 0.5 wt%,
5 wt%, 10 wt% and 20 wt% were added respectively (sheet numbers are E-1 to E-5 in order). A green sheet having a sheet thickness of 0.1 to 0.3 mm was prepared by the doctor blade method as described above.

[0030]

[Table 1]

[0031]

[Table 2]

Next, the first, second and third conductor layers 3,
The conductor metal forming 5, 7 will be described. As the conductor metal, low resistance metals such as Ag and Cu were selected.
The conductor metal of the through hole and the surface electrode is also preferably Ag or Cu, which has a low resistance in the microwave region. The above conductive metal was kneaded with a vehicle to form a paste. When the conductor metal was Cu, CuO paste was used. Using this conductor paste, predetermined conductor wiring patterns were printed on a dielectric layer formed by laminating a plurality of first green sheets and an insulator layer formed by a second green sheet. Then, in addition to the green sheet on which these conductor patterns are printed, a sheet number: C-
1 to C-7, D-1 to D-11, and E-1 to E-5, using one kind of green sheet, stacked in the order shown in FIG. Pressure 5
A pressure was applied for 2 minutes at 0 MPa to obtain a laminate.

Thereafter, the laminated body is heated to 700 ° C. in air.
The heat treatment was performed at the temperature of 1 to disperse the binder. Furthermore, when Ag paste is used, it is 90% in air.
It was fired at a temperature of 0 ° C. for 2 hours, and when CuO paste was used, it was heat treated in H ₂ to make the conductor Cu.
And then baked in N ₂ at a temperature of 900 ° C. for 2 hours to obtain multilayer composite substrates for microwave.

Table 3 shows the results of examining the substrate warpage and delamination of the microwave multilayer composite substrate produced through the above steps.

[0035]

[Table 3]

Comparative Example 1 For comparison, a laminate having the same structure as in Example 1 except that the first and second intermediate layers 2 and 8 are not provided is the same as in Example 1. It was produced using a green sheet, but this laminate was completely peeled off at the interface between the dielectric layer and the insulator layer, and joining was impossible.

As can be seen from the above results, in the microwave multilayer composite substrate according to Example 1, the warp and the delamination of the substrate were extremely effectively prevented, and there was a remarkable improvement effect. In particular, when the intermediate layer was formed of a mixed composition of the first dielectric material and glass, a substrate having extremely high bondability was obtained. The same result was obtained by using any of the conductor pastes of Ag and CuO.

Example 2 As a microwave dielectric material for providing a dielectric layer, BaO—TiO ₂ —Nd ₂ O ₃ —
Sm ₂ O ₃ -Bi ₂ O ₃ system powder: 90 wt% and, PbO
-B ₂ O ₃ -SiO ₂ based glass: mixed powder consisting of 10 wt% (. Which hereinafter referred to as the second dielectric material) with the same manner as in Example 1, from a doctor blade method, 0.
A third green sheet having a thickness of 1 to 0.3 mm was produced. The characteristics of the sintered body obtained by firing the second dielectric material at 900 ° C. are as follows: relative permittivity ε _r = 55, no load Q =
630 (3.9 GHz), temperature characteristic of resonance frequency τ _f =
It was +11 ppm / ° C.

As the insulator layer, a second green sheet made of the first insulating material was used as in Example 1.

As the intermediate layer, the second dielectric material and the first dielectric material are used.
Green having a mixed composition with an insulating material (hereinafter, referred to as a fourth intermediate layer material) and a mixed composition with a second dielectric material and glass (hereinafter, referred to as a fifth intermediate layer material). Each sheet was used. The mixing ratios are shown in (Table 4) for the fourth interlayer material and (Table 5) for the fifth interlayer material. For the fifth intermediate layer material, the composition system of the added glass is also shown. In addition, each green sheet has a sheet number (F-1 to F-7, G-1 to G
-11) was displayed. Each green sheet had a sheet thickness of 0.1% by the doctor blade method as in Example 1.
The thing of 1-0.3 mm was produced.

[0041]

[Table 4]

[0042]

[Table 5]

Next, using a conductor paste of Ag or CuO, a predetermined conductor is provided in each of the dielectric layer formed by laminating a plurality of third green sheets and the insulator layer formed of the second green sheet. The wiring pattern was printed. And, in addition to the green sheet on which these conductor patterns are printed, sheet numbers F-1 to F-7, G as intermediate layers
Similar to Example 1, one type of green sheet selected from -1 to G-11 was laminated in the order shown in FIG. Then, pressure and baking were performed under the same conditions as in Example 1 to obtain a multilayer composite substrate for microwaves. Table 6 shows the results of examining the substrate warpage and delamination of these multilayer composite substrates for microwaves.

[0044]

[Table 6]

(Comparative Example 2) For comparison, a laminate having the same structure as in Example 2 except that the intermediate layer according to Example 2 was not used was produced using the same green sheet as in Example 2. However, this laminate was partially peeled at the interface between the dielectric layer and the insulating layer.

As can be seen from the above results, the microwave multilayer composite substrate according to Example 2 was extremely effective in preventing warpage and delamination of the substrate and had a significant improvement effect. In particular, when a mixed composition of the second dielectric layer forming material and glass was used as the intermediate layer, a substrate having extremely high bondability was obtained. The same result was obtained by using any of the conductor pastes of Ag and CuO.

[0047]

According to the microwave multi-layer composite substrate of the first aspect of the present invention, the components and insulation of the microwave dielectric material forming the dielectric layer between the dielectric layer and the insulating layer are provided. Since the intermediate layer containing at least one of the constituent components of the insulator material forming the body layer is interposed, the at least one component reacts at the bonding interface, and thus the intermediate layer and the dielectric layer or the insulator layer. The bondability between the dielectric layer and the insulating layer is improved, and the difference in the contraction start temperature, the final contraction rate, and the thermal expansion coefficient between the dielectric layer and the insulating layer is mitigated by the intermediate layer, so that the warp of the substrate and the delamination occur. Since it becomes difficult, a high-quality multilayer composite substrate for microwaves can be easily and reliably realized.

According to the multilayer composite substrate for microwaves of the second aspect of the present invention, the dielectric material for microwaves is Bi.
_Since it is a dielectric ceramic material containing ₂ O ₃ , CaO and Nb ₂ O ₅ as main components, it has a sintering temperature of 1050 ° C. or less, a relative dielectric constant of 15 or more, a no-load Q value of 500 or more at 1 GHz, and a resonance frequency. Absolute value of temperature change rate of 50
A microwave dielectric material having a ppm / ° C. or less can be reliably obtained.

According to the microwave multilayer composite substrate of the third aspect of the present invention, the microwave dielectric material is made of BaO or N.
Since it is a dielectric ceramic material containing d ₂ O ₃ , TiO ₂ and glass as main components, it has a sintering temperature of 1050 ° C. or less, a relative dielectric constant of 15 or more, a no-load Q value of 500 or more at 1 GHz, and a resonance frequency of Absolute value of temperature change rate is 50
A microwave dielectric material having a ppm / ° C. or less can be reliably obtained.

According to the multilayer composite substrate for microwaves of the fourth aspect of the present invention, since the intermediate layer material is the mixture of the dielectric ceramic material and the insulating material of the second or third aspect, the dielectric layer is Since the bondability with the insulating layer is improved and the warp of the substrate and the delamination are more difficult to occur,
It is possible to easily and surely realize a higher-quality microwave multi-layer composite substrate.

According to the multilayer composite substrate for microwaves of the invention of claim 5, the intermediate layer material is the dielectric ceramic material of claim 2 or 3, and B ₂ O ₃ , SiO ₂ or B.
Since it is a mixture with a glass material containing any of aO, the bondability between the dielectric layer and the insulating layer is improved, and the warp of the substrate and the delamination are further less likely to occur.
It is possible to easily and surely realize a higher-quality microwave multi-layer composite substrate.

According to the multilayer composite substrate for microwaves of the sixth aspect, the dielectric material for microwaves is Bi.
₂ O ₃ , CaO and Nb ₂ O ₅ are the main constituents of the dielectric ceramic material, and the intermediate layer material is a material obtained by adding 0.5 wt% to 10 wt% of ZnO to the dielectric ceramic material. Since the bondability between the dielectric layer and the insulating layer is improved and the warp and the delamination of the substrate are more difficult to occur, a higher quality multilayer composite substrate for microwaves can be easily and reliably realized.

According to the multilayer composite substrate for microwaves of the seventh aspect of the present invention, the constituent component of the microwave dielectric material forming the dielectric layer and the insulating layer between the dielectric layer and the insulating layer. Since an intermediate layer containing at least one of the constituent components of the insulator material forming
It is possible to reliably manufacture the multilayer composite substrate for microwaves according to the invention of claim 1.

[Brief description of drawings]

FIG. 1 is a sectional view of a multilayer composite substrate for microwaves according to an embodiment of the present invention.

[Explanation of symbols]

 1 1st insulator layer 2 1st intermediate | middle layer 3 1st conductor layer 4 1st dielectric layer 5 2nd conductor layer 6 2nd dielectric layer 7 3rd conductor layer 8 2nd middle Layer 9 Second insulator layer 10 Surface electrode 11 Through hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuya Inoue 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (7)

[Claims] 1. A dielectric layer made of a dielectric material for microwaves having a relative dielectric constant of 15 or more and an unloaded Q value at 1 GHz of 500 or more and an absolute value of a temperature change rate of a resonance frequency of 50 ppm / ° C. or less. An insulating layer made of an insulating material having a relative permittivity of 15 or less, which is provided on both sides or one side of the dielectric layer, and is interposed between the dielectric layer and the insulating layer. A multilayer composite substrate for microwaves comprising an intermediate layer made of an intermediate layer material containing at least one of the components of a wave dielectric material and the insulating material. 2. The microwave dielectric material is Bi ₂
The multilayer composite substrate for microwaves according to claim 1, which is a dielectric ceramic material containing O ₃ , CaO, and Nb ₂ O ₅ as main components. 3. The microwave dielectric material is Ba
_2. A dielectric ceramic material containing O, Nd ₂ O ₃ , TiO ₂ and glass as main components.
The multilayer composite substrate for microwaves as described in 1. 4. The intermediate layer material is a mixture of the dielectric ceramic material according to claim 2 or 3 and the insulator material, and the dielectric ceramic material according to claim 2 or 3 and the insulator. The mixing weight ratio with the material is 90:10
The multilayer composite substrate for microwaves according to claim 1, wherein the multilayer composite substrate is in the range of 10:90. 5. The intermediate layer material is a mixture of the dielectric ceramic material according to claim 2 or 3 and a glass material containing any one of B ₂ O ₃ , SiO _{2 and} BaO. The mixing weight ratio of the dielectric ceramic material described in 2 or 3 and the glass material is 98: 2 to 10 :.
It is in the range of 90, The multilayer composite substrate for microwaves of Claim 1 characterized by the above-mentioned. 6. The microwave dielectric material is Bi ₂ O.
₃ , a dielectric ceramic material containing CaO and Nb ₂ O ₅ as main components, and the intermediate layer material is a material obtained by adding 0.5 wt% to 10 wt% ZnO to the dielectric ceramic material. The multilayer composite substrate for microwaves according to claim 1. 7. A first green sheet made of a dielectric material for microwaves, a second green sheet made of an insulating material having a relative dielectric constant of 15 or less, and constituent components of the dielectric material for microwaves and the above. Each step of producing a third green sheet made of a material containing at least one of the constituents of the insulating material, and a dielectric body containing an electrode using the first green sheet and a paste of a conductive material. A step of forming a layer, a step of laminating the third green sheet on one side or both sides of the dielectric layer, and a step of laminating the second green sheet on the third green layer. And a step of thermocompression-bonding and firing a composite laminate including the dielectric layer, the third green sheet and the second green sheet. Method of manufacturing a plate.