JPH10275979A - Ceramic board and divided circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ceramic board and a divided circuit board in which the continuity of an end-face electrode can be ensured even when a part of the end-face electrode is disconnected. SOLUTION: A ceramic board is provided with an insulating base body 13 in which a plurality of insulating layers 10 composed of a ceramic are laminated, with internal interconnections 11 which are formed between the insulating layers 10, with dividing grooves 7 formed on both surfaces of the insulating base body 13 and with a conductive member 21 which is formed in the thickness direction of the insulating base body 13 and which forms end-face electrodes 2. When the insulating base body 13 is divided by the dividing grooves 7, every divided circuit board 1 which comprises a plurality of end-face electrodes 2 is obtained. In this case, the dividing grooves 7 are formed so as to divide both surfaces of the conductive member 21 into two parts, a plurality of interlayer conductors 23 which are formed respectively between the insulating layers 10 are connected to the conductive member 21, and the interlayer conductors 23 are connected to each other by via-hole conductors 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic substrate and a divided circuit board which become a divided circuit board having a plurality of end electrodes when divided into unit blocks.

[0002]

2. Description of the Related Art In recent years, electronic devices have become smaller, lighter and more portable, and the circuit blocks used therein have been reduced in size, weight, and thickness, surface-mounted, and composited in accordance with the trend. .

[0003] In such a trend, ceramic circuit boards have been widely used because of their excellent heat dissipation properties and low dielectric loss, and have been widely applied mainly to hybrid ICs for surface mounting. .

Conventionally, hybrid ICs for surface mounting are used by being soldered to a ceramic circuit board. The ceramic circuit board has an end face electrode from the viewpoints of joining confirmation and maintaining reliability. From the viewpoint of the manufacturing method, the structure of the end face electrode can be roughly classified into 3
There are different types of manufacturing methods.

First, in a structure called a through-hole thick film structure, a technique such as suction is used in combination with an unfired or baked ceramic substrate in which a through hole for an end face electrode has already been formed, and a conductive film is formed by a thick film printing technique or the like. This structure is achieved by a method in which paste is coated on the inner wall surface of a through hole and baked. The advantage of this method is that a plurality of substrates can be processed, that is, when divided into unit blocks, each becomes a divided circuit substrate having a plurality of end face electrodes, which is advantageous in reducing the number of steps.

The second structure is a structure called a single formation structure, in which end electrodes are patterned and baked on a divided circuit board divided for each unit block, basically using a thick film printing technique or the like for each end face. The structure achieved in the method. The advantage of this method is that there is no dead space due to a through hole when viewed in a mounting projection area, and the method is suitable for miniaturization.

The third structure is an application of the first structure, in which a through hole is formed for each unfired green sheet layer, and an inner wall surface of the through hole is coated with a conductive paste. This is a structure achieved by laminating and integrating a hole thick film structure. This advantage is in that the connection between the internal wiring and the end face electrode can be easily made.

[0008]

However, the above 3)
Each of the structures according to the various manufacturing methods has the following disadvantages. That is, in the first through-hole thick film structure, when the ceramic substrate has the internal wiring, the connection reliability between the internal wiring and the end face electrode is lacking. If the target is an unsintered ceramic substrate, it is necessary to form a through hole by punching or the like, but the internal wiring collapses during formation, making it difficult to make contact with the end face electrode.

Further, if a fired ceramic circuit board is the target, a flux component or the like for adjusting shrinkage contained in the internal wiring floats on the inner wall surface of the through hole which is a free surface, and it is difficult to join the end surface electrode. Occurs.
In order to solve this problem, an etching process or the like may be performed, but this process may corrode the ceramics and leads to an increase in cost. Further, when a wide (large area) end face electrode is required, it is difficult to completely coat the required width because a flux component and the like float on the inner wall surface of the through hole which is a free surface.

Further, for the above reason or when the substrate is divided, the end face electrode formed in the thickness direction of the substrate may be disconnected (cut) in the middle, and the connection reliability of the end face electrode is lacking. Even when they need to be electrically connected to each other, they may not be able to conduct, or when they are joined to another mounting board by soldering, etc., they may not be able to transmit signals from the board to the mounting board. And there is a problem that desired characteristics cannot be obtained.

In the second single formation structure, since the end face is exposed, a large number of pieces cannot be formed. Therefore, when components are mounted on the surface of the ceramic circuit board, the mounting efficiency is greatly reduced.

As in the first structure, the third structure becomes inappropriate when the width of the end face electrode is increased. That is, in this structure,
It is difficult to coat only the inner wall surface of the through hole, but when the conductive paste is filled in the through hole formed in the green sheet, it is necessary to remove the conductive paste to leave the conductive paste only on the inner wall surface of the through hole. There is a problem that an operation is required, and if the conductor paste is left as it is, an extra conductor paste is required. Furthermore, since the through holes are formed for each layer by punching or the like, there is a problem that the inner wall surface of the through holes becomes uneven, and the surface of the end face electrode is also likely to be uneven when viewed as a whole substrate.

For these reasons, similarly to the first structure, the end face electrode formed in the thickness direction of the substrate may be cut in the middle, and there is a problem that the connection reliability of the end face electrode is lacking. Was.

In each of the first and third structures, it is necessary to form a through hole in advance, and it is necessary to form a conductive paste on the inner wall surface of the through hole by a thick film printing technique or the like. You have to use technology,
Extra capital investment had to be made.

Further, in the first and third structures, since the dividing groove formed on the surface of the insulating substrate passes through the conductive member serving as the end face electrode when dividing, the dividing groove is divided into two. When divided by, the conductive member will be cut directly, and the force at the time of dividing into the conductive member acts, and as described above, a part of the conductive member may be peeled or disconnected, but in this case, For example, even when it is necessary to electrically connect the internal wiring, a situation occurs where conduction cannot be performed,
There is a problem that the circuit becomes inadequate and desired characteristics cannot be obtained.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a ceramic substrate and a divided circuit board that can maintain conduction of the end electrodes even when a part of the end electrodes is disconnected.

[0017]

According to the present invention, there is provided a ceramic substrate comprising: an insulating base formed by laminating a plurality of insulating layers made of ceramic; and a conductive member forming a pair of end face electrodes formed in a thickness direction of the insulating base. And a dividing groove formed on the surface of the insulating base and formed so as to divide the surface of the conductive member into two parts, each of which has a plurality of end face electrodes when the insulating base is divided by the dividing groove. In a ceramic substrate to be a divided circuit board, an interlayer conductor is formed between the insulating layers, one end of each of these interlayer conductors is connected to the conductive member, and the interlayer conductors are connected to each other by a via-hole conductor. It is. Here, it is desirable that an internal wiring is connected to the interlayer conductor.

Further, the divided circuit board according to the present invention is a divided circuit board comprising: an insulating base formed by laminating a plurality of insulating layers made of ceramic; and an end face electrode formed on an outer peripheral surface of the insulating base. A plurality of interlayer conductors are formed between the layers, these interlayer conductors are connected to the end face electrodes, and the interlayer conductors are interconnected by via-hole conductors.

[0019]

In the ceramic substrate of the present invention, when dividing,
Even when a force acts on a conductive member serving as an end surface electrode, and a part of the end surface electrode is peeled or disconnected, as a divided circuit board, a plurality of interlayer conductors are electrically connected to each other by via hole conductors. Since they are connected, the interlayer conductors connected to the end face electrodes are electrically connected to each other, and the entire end face electrodes are conductive, so that the connection reliability of the end face electrodes can be improved. That is, for example, even when the internal wirings are connected to each other via an end face electrode, or when the electrical signals are transmitted by bonding to the mounting board on which the divided circuit board of the present invention is mounted by soldering. In other words, the electric signal is reliably transmitted via the correlation conductor and the via-hole conductor, and the reliability of the divided circuit board can be improved.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION A ceramic substrate according to the present invention comprises: an insulating substrate formed by laminating a plurality of insulating layers made of ceramic; an internal wiring formed between the insulating layers; a dividing groove formed on the surface of the insulating substrate; A conductive member that forms an end face electrode formed in the thickness direction of the insulating base. When the insulating base is divided by the dividing grooves, each of the divided circuit boards has a plurality of end face electrodes. .

The term “insulating layer made of ceramics” means including an insulating layer made of glass ceramic. The insulating base is formed by laminating a plurality of the insulating layers, and an internal wiring is formed between these insulating layers.

A dividing groove is formed on the surface of the ceramic substrate, and the dividing groove is formed so as to divide the surface of the conductive member forming the pair of end face electrodes into two. Also,
Interlayer conductors connected to the conductive members are formed as needed between the insulating layers, and these interlayer conductors are electrically connected to each other by via-hole conductors. Internal wiring is connected to the interlayer conductor. The interlayer conductor does not need to be formed between all the insulating layers, and may be formed, for example, only in the portion where the internal wiring is formed.

By dividing the ceramic substrate along the dividing groove, an insulating substrate formed by laminating a plurality of insulating layers made of ceramics, internal wiring formed between the insulating layers, and an outer peripheral surface of the insulating substrate are formed. The divided circuit board having the end face electrodes thus obtained is obtained. Between the insulating layers of the divided circuit board, interlayer conductors connected to the end face electrodes are formed as necessary, and these interlayer conductors are electrically connected to each other by via-hole conductors.

In the method of manufacturing a ceramic substrate according to the present invention, the insulating layer molded body is exposed and developed to form a straight through groove for an end face electrode at a position to be an end face electrode, and the groove is filled with a conductive paste. Then, the above process is repeated to manufacture a ceramic substrate on which a plurality of divided circuit boards each having an end face electrode are formed when divided.

Since the divided circuit boards are finally mounted by soldering, the end electrodes of the divided circuit boards must be able to be joined by soldering. Therefore, considering simultaneous firing with ceramics including glass ceramics, ceramics is a material that can be fired at about 800 to 1000 ° C., and the constituent metals of the end face electrodes are silver, palladium, platinum, copper, and silver and palladium. Of these alloys as main components, and among them, a silver alloy or copper is preferable. Since silver is eroded by solder, it is preferable to apply tin plating or the like on a nickel base. Further, since tungsten or molybdenum or the like cannot be directly connected by soldering, it is preferable to apply plating or the like to the surface of tungsten or molybdenum in this case as well.

The ceramic substrate of the present invention comprises, for example, an insulating substrate having a plurality of insulating layers made of ceramic laminated thereon.
This is a method of manufacturing a ceramic substrate which becomes a divided circuit board each having a plurality of end face electrodes when divided by a division groove, and is produced by a method including the following steps (a) to (h).

(A) an insulating layer material made of ceramics,
Step (b) of forming a slip material containing a photocurable monomer and an organic binder; (b) thinning and drying the slip material to form an insulating layer molded product; and (c) subjecting the insulating layer molded product to exposure treatment. And curing the insulating layer molded body except for the formation position of the end face electrode and the formation position of the via-hole conductor. (D) Developing the exposed insulation molded body to form an end face electrode. Forming a through hole for an end face electrode at a position and forming a through hole for a via hole at a position where a via hole conductor is to be formed; and (e) filling a conductive paste into the through groove for the end face electrode and the through hole for a via hole. f) A conductive paste is printed on the surface of the insulating layer molded body to be connected to the conductive paste in the through-hole for the end face electrode and the through-hole for the via hole. Forming Step (g) The insulating layer molded body obtained in the steps (f) and (b), (c), (d), (e) and (f) are sequentially repeated to form the insulating layer. (H) Step of firing the laminated molded body In the above-described method for manufacturing a ceramic substrate, a conductive member functioning as an end face electrode is exposed and developed, and Since it can be manufactured by filling the paste, it is not necessary to form a through hole with a punch or the like, and the manufacturing process can be simplified.

Further, since the through-hole for the end face electrode is formed by exposure and development, it is possible to form an end face electrode having a sufficient length, which has been difficult by a conventional manufacturing method using a punch or the like. Further, the number of manufacturing steps is small, and a ceramic substrate that can be obtained in large numbers can be realized. Furthermore, since a large number of devices can be formed, there is an advantage that mounting efficiency is improved when components are mounted on the surface of the ceramic substrate.

The idea of forming a through groove for an end face electrode in the thickness direction of an insulating layer for each insulating layer is basically the same as the third method described in the background art. However, unlike the case where the through hole is formed as in the third method, the method is characterized in that the conductive paste is embedded in the through groove for the end face electrode. In the conventional through-hole method, it was impossible to produce the embedded conductor due to the problem that the embedded conductor was peeled off.
It is possible to form a wide end surface electrode such as forming an end surface electrode having a width of mm.

The method for manufacturing a ceramic substrate will be described in detail. First, the slip material serving as the insulating layer is a solvent-based slip material obtained by homogeneously kneading a ceramic material, a photocurable monomer, an organic binder, and an organic solvent. In the insulating layer made of the ceramic of the present invention,
Ceramic is meant to include glass ceramic.

When a so-called low-temperature fired ceramic fired at 850 to 1050 ° C. is used as a composite circuit block, a ceramic material and a glass material (both are called solid components) are generally used for the insulating layer. .

Examples of the ceramic material include powders such as cristobalite, quartz, corundum (α-alumina), mullite, zirconia, and cordierite, and the average particle size thereof is preferably 1.0 to 6.0 μm, and more preferably 1 to 6.0 μm. 0.5 to 4.0 μm. These ceramic materials may be used in combination of two or more. Here, 1.0-6.
When the ceramic material having a thickness of 0 μm is used, it is difficult to form a slip when the average particle size of the ceramic material is less than 1.0 μm. If the average particle size exceeds 6.0 μm, it becomes difficult to obtain a dense insulating layer.

The glass material is a glass frit containing a plurality of metal oxides, and after firing at 850 to 1050 ° C., cordierite, mullite, anorthite, serdian, spinel, garnite, willemite, dolomite, petalite and its replacement. As long as at least one derivative crystal is deposited, an insulating layer with high strength can be obtained. In particular, when a crystallized glass frit that precipitates anorthite or Celsian is used, an insulating layer with higher strength is obtained, and when a crystallized glass frit that can precipitate cordierite or mullite is used, thermal expansion after firing is performed. Since the rate is low, it is optimal as a circuit board for arranging a silicon chip such as an IC on the circuit board.

The most preferred glass materials in consideration of the strength and the coefficient of thermal expansion of the insulating layer include B ₂ O ₃ , SiO ₂ , Al
It is a glass frit containing ₂ O ₃ , ZnO, and alkaline earth oxide. Since such a glass frit has a wide vitrification range and a yield point around 600 to 800 ° C.,
When firing at about 850 to 1050 ° C., it is suitable for the sintering behavior of copper-based, silver-based, and gold-based conductive materials serving as internal wiring and via-hole conductors used for low-temperature fired multilayer ceramic circuit boards.

As an action of each component, B ₂ O ₃ , Si
O ₂ is mainly used as a network former, and Al ₂ O ₃
Mainly acts as an intermediate, and ZnO and alkaline earth oxides mainly further act as a network modifier.

Such a glass material can be obtained by mixing the above-mentioned predetermined components in a predetermined ratio, heating and melting, quenching and then pulverizing. The average particle size of the crushed glass frit is 1.0 to 5.0 μm, preferably 1.5
３3.5 μm.

Here, the reason why the average particle size of the crushed glass frit is 1.0 to 5.0 μm is that the average particle size is 1.
If the thickness is less than 0 μm, it is difficult to form a slip,
Exposure light is irregularly reflected at the time of exposure to be described later, so that sufficient exposure cannot be performed. Conversely, if the average particle size exceeds 5.0 μm, dispersibility is impaired, and specifically, the powder is uniformly dissolved between ceramic powders as insulating materials This is because they cannot be dispersed and the strength is extremely reduced.

The composition ratio of the above-mentioned ceramic material and glass material is such that the ceramic material is 10% by weight to 50% by weight,
It is preferably 20% to 35% by weight, and the glass material is 90% to 50% by weight, preferably 80% to 6% by weight.
5% by weight.

Here, the ceramic material is 10% by weight to 5% by weight.
The reason why 0 wt% and the glass material are 90 wt% to 50 wt% is that if the ceramic material is less than 10 wt% and the glass material exceeds 90 wt%, the insulating layer becomes too vitreous and the insulating layer has too much glass. It is unsuitable from the viewpoint of strength and the like, and the ceramic material exceeds 50% by weight and the glass material is 5% by weight.
If the content is less than 0% by weight, exposure light is irregularly reflected at the time of exposure to be described later, and sufficient exposure cannot be performed, and the denseness of the insulating layer after firing is also impaired.

In addition to the above-mentioned ceramic materials, the constituent materials of the slip material include a photocurable monomer, an organic binder, and an organic solvent which are eliminated by sintering. A water-based slip material may be used instead of the solvent-based slip material.

The photocurable monomer of the solvent-based slip material must have excellent thermal decomposition properties in order to cope with a low-temperature, short-time baking step. As a photocurable monomer, a monomer having a secondary or tertiary carbon, which needs to be photopolymerized by exposure after application of a slip material and drying, capable of forming free radicals and chain growth addition polymerization. For example, alkyl acrylates such as butyl acrylate having at least one polymerizable ethylenic group and the corresponding alkyl methacrylates are effective. Further, polyethylene glycol diacrylates such as tetraethylene glycol diacrylate and methacrylates corresponding thereto are also effective. The photo-curable monomer is added in such a range that the photo-curable monomer is cured by exposure and a portion other than the exposure can be easily removed by development. For example, 5 to 15 parts by weight based on 100 parts by weight of the solid component
Not more than parts by weight.

The organic binder of the solvent-based slip material must have good thermal decomposability like the photocurable monomer. Specifically, thermal decomposition must be possible at 600 ° C. or lower. More preferably, the temperature is 500 ° C. or lower. If the thermal decomposition temperature exceeds 600 ° C., it remains in the insulating layer and is trapped as carbon, discoloring the substrate to gray, and lowering the insulation resistance and Q value of the insulating layer. In addition, it may become a void and cause delamination.

As a slip material, a sensitizer, a photo-initiating material or the like may be added as required. For example,
Examples of the photoinitiating material include benzophenones and acyloin ester compounds.

As described above, a glass-ceramic or ceramic material, a photo-curable monomer, an organic binder, and an organic solvent are mixed and kneaded to form a solvent-based slip material serving as an insulating layer. The method of mixing and kneading may be a conventionally used method, for example, a method using a ball mill. The method of thinning the slip material is, for example, a doctor blade method (knife coat method), a roll coat method, a printing method, and the like. A blade method or the like is suitable. The slip material is adjusted to a predetermined viscosity according to the method of thinning.

The conductive paste of the conductive material used as the end face electrode is obtained by homogeneously kneading a powder of at least one metal material of a silver alloy or copper, a low melting point glass component, an organic binder and an organic solvent. Is preferably used. The conductive paste of the conductor material used as the internal wiring, the interlayer conductor and the via hole conductor may be the same as that of the end face electrode, or may be the one containing silver as a main component. These are, in particular, because the firing temperature is 850 to 1050 ° C.
As the metal material, a material having a relatively low melting point and a low resistance is selected, and the low melting point glass component is also sintered with an insulating layer molded article (coated with a slip material and dried) serving as an insulating layer. Taking the behavior into consideration, a material whose yield point is around 700 ° C. is used.

In the method of manufacturing a ceramic circuit board according to the present invention, first, a slip material is thinned on a support substrate (hereinafter, referred to as a “slip material”).
(The coating is simply referred to as coating.) Drying to form an insulating layer molded body that becomes an insulating layer.

Examples of the support substrate include a glass substrate, an organic film, and alumina ceramic. This support substrate is removed before the firing step.

As a coating method, it is formed by a doctor blade method, a roll coating method, a printing method using a screen having a coating area approximately the same as that of the supporting substrate, or the like.

Next, a straight through groove for an end face electrode serving as an end face electrode and, if necessary, a through hole serving as a via hole conductor are formed in the formed insulating layer formed on the support substrate. In practice, the lower portions of the through-groove and the through-hole are closed by a support substrate or the like, but are referred to as the through-groove and the through-hole for convenience.

The method for forming the through-grooves and through-holes is performed using exposure and development. The formation of the through hole and the subsequent filling of the conductive paste are omitted for the insulating layer molded body that does not require the formation of the via hole conductor.

In the exposure processing, for example, a photo target is brought close to or placed on the insulating layer molded body, and a region other than the through-groove and the through-hole is irradiated with exposure light of a low-pressure, high-pressure, or ultra-high-pressure mercury lamp system. . As a result, the photocurable monomer causes a photopolymerization reaction in a region other than the through groove and the through hole. Therefore, only the through-groove and the through-hole portion become the fusible portion that can be removed by the developing process.

In the developing treatment, a solvent such as chlorocene is brought into contact with the exposed and solubilized portion which is a through groove or a through hole by, for example, a spray developing method or a paddle developing method, and development is performed.
Washing and drying are performed as necessary.

Next, a conductive member serving as an end face electrode and a via-hole conductor are formed by filling a through-hole or a through-hole of the insulating layer molded body with a conductive paste and drying. The filling method is performed by, for example, a screen printing method.

Next, patterns to be used as internal wirings and interlayer conductors are printed and dried using a conductive paste. The printing method is, for example, a screen printing method. If no internal wiring or interlayer conductor is required, this step is omitted.

As described above, the formation of the insulating layer molded body by applying and drying the slip material, the formation of the through-grooves and the through-holes by exposure and development, the formation of the conductive member and the pattern to be the internal wiring and the interlayer conductor by printing the conductive paste. In formation, basically 1
The formation of the insulating layer molded body for the layers is completed, and this is repeated a desired number of times to complete the unfired laminated molded body. Thereafter, the shape is adjusted by performing pressing or the like as necessary.

After that, on the surface of the laminated molded body, a dividing groove for dividing each divided circuit board is formed so that the dividing groove passes through the center of the surface of the conductive member filled in the end surface electrode through groove.

Finally, firing is performed. The firing step includes a binder removal step and a firing step.
℃), the insulation layer molding, the pattern of internal wiring and interlayer conductor,
The organic components of the conductive member of the end face electrode and the via-hole conductor disappear. Thereafter, the insulating layer molded body serving as the insulating layer, the pattern of the internal wiring and the interlayer conductor, the conductive member serving as the end face electrode, and the via hole conductor are fired at a predetermined atmosphere and at a predetermined temperature.

When the ceramic substrate is used for high-frequency applications such as a high-frequency circuit substrate or a high-frequency ceramic multilayer electronic component, it is desirable to use the following insulating layer material.

That is, the insulating layer material comprises a ceramic material and a sintering aid, and the relative permittivity of the ceramic material is 10%.
Those having 0 or less are preferable. This is because, if an insulating layer material having a relative dielectric constant exceeding 100 is used, the stray capacitance between the internal wiring and the internal electrode cannot be ignored in the circuit, which hinders miniaturization. As such a ceramic material, BaT
_{i 4 O 9, Ba 2 Ti} 9 O 20, MgO-CaO-TiO
_{2, CaZrO 3, BaO-Ln} 2 O 3 -TiO 2 (L
n is a lanthanoid element), SrZrO _{3 and the} like. These ceramic materials are produced by a general well-known synthesis method, for example, a hydrothermal synthesis method.

The sintering aid for the ceramic material promotes the low-temperature sintering of the ceramic material, and sinters the insulating layer material at 850 to 1050 ° C. Therefore, in the firing process, it must be a sintering aid that maintains the crystal structure and the like of the ceramic material that affects the dielectric properties as much as possible. For example, lead borosilicate glass frequently used in thick film dielectrics cannot be used because the ceramic material is dissolved in the firing process. In order to maintain the Q value of the dielectric ceramic at a high level, it is preferable to cause crystallization with a high Q value after / or during the process of densification by liquid phase sintering. For example, Si
Sintering aids such as O ₂ , B ₂ O ₃ , Li ₂ O, and CuO may be used according to the ceramic material, and in particular, a boron-containing compound and an alkali metal-containing compound are desirable.

In particular, the insulating layer material is a composite oxide containing at least Mg, Ti, and Ca as metal elements, and the composition formula of the metal element oxide is (1-x) Mg
TiO ₃ -xCaTiO ₃ (where x represents a weight ratio and 0.01 ≦ x ≦ 0.15) 100 parts by weight of a dielectric ceramic powder expressed as boron-containing compound as a sintering aid Is ₃ to 30 parts by weight in terms of B ₂ O ₃ and 1 to 25 parts by weight of an alkali metal-containing compound in terms of alkali metal carbonate, the measurement frequency is 7 GH.
An electronic component that has a Q value of 1300 or more and can be co-fired with a conductive paste containing Au, Cu or Ag as a main component at a low temperature of 850 to 1050 ° C., has a high Q value, and is excellent in a high frequency region. And a substrate can be obtained. In the case of this composition, the Q value at the measurement frequency of 7 GHz can be 3000 or more, particularly 5000 or more.

The ceramic raw material powder used in the production method of the present invention is characterized in that a boron-containing compound and an alkali metal-containing compound are simultaneously added and contained as sintering aids. The reason will be described. When only the boron-containing compound is blended with the dielectric ceramic powder, if the blending amount is small, the firing temperature cannot be sufficiently lowered, and the firing temperature is lower than the melting point of Au, Ag, and Cu. Can not be tied.

When the compounding amount is large, the sintering temperature is lowered.
Since it reacts with the gTiO ₃ —CaTiO ₃ system, if the blending amount is too large, MgTiO ₃ —CaT
The remaining amount of iO ₃ decreases, and a high Q value cannot be maintained. Therefore, when only a boron-containing compound is added, a dielectric ceramic composition having excellent dielectric properties in a high frequency region at a low sintering temperature cannot be obtained.

That is, when only the boron-containing compound is added, the sintering temperature does not become 1050 ° C. or lower when the addition amount is less than 3 parts by weight in terms of B ₂ O ₃ . When the amount is more than 30 parts by weight in terms of B ₂ O ₃ , the sintering temperature is set at 1050.
° C or lower, but the boron-containing compound is MgTiO ₃ -CaTiO ₃ as described above at a high temperature such as during firing.
This is because the Q value is reduced due to the reaction.

In the case of this composition, the effect of lowering the sintering temperature of the composition due to the addition of the boron-containing compound and the effect of improving the dielectric properties of the porcelain composition after firing are in a trade-off relationship. It is difficult to obtain a composition having both a low sintering temperature and excellent dielectric properties such as a high Q value.

On the other hand, Li, N was added to the dielectric ceramic powder.
When only an alkali metal-containing compound such as a or K is added, even if the amount of addition is increased, the sintering temperature of the composition can hardly be lowered, and the composition which can be sintered at 1050 ° C. or lower can be obtained. I can't get things.

The reason why the alkali metal-containing compound is added in an amount of 1 to 25 parts by weight in terms of the alkali metal carbonate is that the addition amount of the alkali metal-containing compound, for example, the lithium-containing compound is 1%.
If it is less than 1 part by weight, sintering does not occur even at 1100 ° C., and Au,
This is because simultaneous sintering with Ag and Cu cannot be performed. Conversely, if the amount exceeds 25 parts by weight, the crystal phase changes and the dielectric properties deteriorate. The addition amount of the alkali metal-containing compound is
For 100 parts by weight of the dielectric ceramic powder, 1 to 10 parts by weight in terms of an alkali metal carbonate, for example, in terms of Li ₂ CO ₃ , is desirable, and 3 to 7 parts by weight is particularly desirable from the viewpoint of the Q value of the dielectric ceramic.

Examples of the alkali metal include Li, Na, and K. Among them, Li is particularly desirable from the viewpoint of the Q value. Examples of the alkali metal-containing compound include the above-mentioned alkali metal carbonates and oxides.

On the other hand, when the boron-containing compound and the alkali metal-containing compound are combined and added at specific ratios, the boron-containing compound and the MgTiO ₃ —Ca
Excessive reaction with a TiO ₃ system or the like is suppressed, and the sintering temperature can be further reduced as compared with the case where only a boron-containing compound is added, and at the same time, a decrease in the Q value can be suppressed.

According to the specific combination composition described above,
Achieved simultaneously lowering the sintering temperature of the dielectric ceramic composition and improving the performance of the dielectric properties such as Q value, which have been considered difficult, and mainly contains at least one of Au, Ag and Cu. It is possible to obtain a high-performance and compact ceramic laminate while simultaneously firing with a metal conductor.

The weight ratio x of CaTiO ₃ is set to 0.01 ≦
The reason why x ≦ 0.15 is that when the weight ratio x of CaTiO ₃ is less than 0.01, the temperature coefficient τf of the resonance frequency becomes large on the negative side, and the weight x becomes 0.15.
Is exceeded, the temperature coefficient τf of the resonance frequency increases to the plus side. Therefore, the weight ratio x of CaTiO ₃ is desirably 0.01 to 0.15, and particularly, 0.05 to 0.1 from the viewpoint of the temperature coefficient τf of the resonance frequency.
0 is desirable.

Further, when the insulating layer material is a composite oxide containing at least Ca and Zr as metal elements, and when the composition formula based on these molar ratios is expressed as xCaO.ZrO ₂ , x is 0.87 With respect to 100 parts by weight of dielectric ceramic powder satisfying ≦ x ≦ 1.36, a part by weight of a boron-containing compound as a sintering aid is calculated as B ₂ O ₃ , and an alkali metal-containing compound is calculated as an alkali metal carbonate. b, and a and b are 0 ≦ a ≦ 3.
When 0, 0 ≦ b ≦ 20 and 1.5 ≦ a + b are satisfied, A is set at a relatively low temperature of about 900 to 1050 ° C.
Can be fired at the same time as conductor metals such as g-based, Cu-based, and Au-based,
The dielectric ceramics can be selected from those having a relative permittivity εr suitable for the frequency used, and has such features as a high Q value, so that high-frequency electronic components and substrates can be reduced in size and improved in performance.

The reason for adding the boron-containing compound and / or the alkali metal-containing compound is that the firing temperature can be lowered. However, when the boron-containing compound alone is contained, if it exceeds a certain amount, it reacts with a high Q value crystal phase composed of CaO-ZrO _{2 as a} main component at a high temperature during firing or the like, so that the compounding amount is too large. In this case, the residual amount of the high-Q value crystal phase composed of unreacted CaO—ZrO ₂ after firing is reduced, and the high Q value cannot be maintained.

The effect of lowering the sintering temperature of the composition due to the addition of the boron-containing compound and the effect of improving the dielectric properties of the porcelain composition after sintering are in a trade-off relationship. It is difficult to obtain a composition having both temperature and excellent dielectric properties such as a high Q value.

On the other hand, Li, Na is added to the dielectric ceramic powder.
When only an alkali metal-containing compound such as is added,
The sintering temperature of the composition cannot be sufficiently lowered while maintaining a high Q value.

It is desirable that the boron-containing compound and the alkali metal-containing compound be added in combination in a specific amount ratio, respectively, because excessive mixing between the boron-containing compound and the high Q-value crystal phase composed of CaO—ZrO ₂ . The reaction is suppressed, and the sintering temperature can be further reduced as compared with the case where only the boron-containing compound is added, and at the same time, a high Q value can be achieved. This is because simultaneous firing becomes possible.

Further, the insulating layer material is a composite oxide containing at least Ba and Ti as metal elements, and a composition formula based on a molar ratio of these is expressed as BaO · x (Ti ₁ -aZ
r _a ) When expressed as O ₂ , x and a are in the range of 3.5 ≦ x ≦
4.5, 100 parts by weight of dielectric ceramic powder satisfying 0 ≦ a ≦ 0.20, 4 to 30 parts by weight of a zinc-containing compound as ZnO conversion and B ₂ O as a sintering aid ₃ to 1 part by weight, and 1 to 10 parts by weight of an alkali metal-containing compound in terms of an alkali metal carbonate, the relative dielectric constant is 20 to 40;
The f value is 30,000 [GHz] or more, and -40 to 85
The temperature coefficient τf of the resonance frequency in the temperature range of ℃ is -40 to +
40 [ppm / ° C] and the firing temperature is 950
° C or less, and an electronic component having a conductor containing Ag as a main component can be formed by simultaneously firing a dielectric porcelain and a conductor.

That is, by partially replacing Ti with Zr, the Qf value can be significantly improved to 30,000 or more.

Further, by adding a zinc-containing compound to the main component, the Qf value can be improved to some extent.
In addition, the temperature coefficient τf of the resonance frequency can be shifted from the plus side to the minus side.

By combining and adding the boron-containing compound and the alkali metal-containing compound, the calcination temperature can be reduced to 950 ° C. or less while maintaining the above-mentioned characteristics, and the relatively low temperature of 850 to 950 ° C. Thus, it can be co-fired with a conductive metal containing Ag, and exhibits excellent characteristics in a high frequency region.

The feature is that the boron-containing compound and the alkali metal-containing compound are simultaneously added and contained. The reason will be described. When only the boron-containing compound is blended with the dielectric ceramic powder, if the blending amount is small, the sintering temperature cannot be sufficiently lowered, and sintering cannot be performed at a temperature lower than the melting point of Ag. .

When the compounding amount is large, the sintering temperature is lowered. However, the boron-containing compound is not easily treated with BaO-x
Since it reacts with the (Ti _1-a Zr _a ) O ₂ system, if the blending amount is too large, the remaining amount of the BaTi ₄ O ₉ crystal phase after firing decreases, and a high Q value cannot be maintained. . Therefore, when only the boron-containing compound is added,
This is because a dielectric ceramic composition having both low sintering temperature and excellent dielectric characteristics in a high frequency region cannot be obtained.

That is, when only the boron-containing compound is added, the sintering temperature does not become 950 ° C. or lower when the addition amount is less than 1 part by weight in terms of B ₂ O ₃ . When the amount is more than 20 parts by weight in terms of B ₂ O ₃ , the sintering temperature can be lowered to 950 ° C. or lower. However, the boron-containing compound has a high Q value BaTi ₄ O _{This is} because the Q value is reduced due to the reaction with the ₉ crystal phase.

In the case of this composition, the effect of lowering the sintering temperature of the composition due to the addition of the boron-containing compound and the effect of improving the dielectric properties of the porcelain composition after firing are in a trade-off relationship, and the composition containing only the boron-containing compound is added. It is difficult to obtain a composition having both a low sintering temperature and excellent dielectric properties such as a high Q value.

On the other hand, when only an alkali metal-containing compound such as Li or Na is added to the ceramic material, the sintering temperature of the composition can hardly be lowered even if the amount of addition is increased. A composition that can be sintered at 950 ° C. or lower cannot be obtained.

On the other hand, in the composition in which the boron-containing compound and the alkali metal-containing compound are added in combination in a specific ratio, the excessive reaction between the boron-containing compound and the BaTi ₄ O ₉ crystal phase is suppressed. In addition, the sintering temperature can be further reduced as compared with the case where only a boron-containing compound is added, and at the same time, a decrease in the Q value can be suppressed.

According to the specific combination composition described above,
The sintering temperature of the dielectric porcelain composition and the improvement of the Q value, which have conventionally been considered difficult, have been achieved at the same time, and simultaneous firing with a metal conductor containing Ag as a main component is possible.

[0088]

FIG. 1 is a perspective view of a divided circuit board obtained by dividing a ceramic substrate manufactured by the manufacturing method of the present invention along a dividing groove. In FIG. 1, reference numeral 1 denotes a divided circuit board, and terminals such as input / output terminals, power supply terminals, and ground terminals are shown as end face electrodes 2. FIG.
In the example, the end face electrodes 2 are formed at a total of ten places on the four side surfaces of the divided circuit board 1. A surface electrode (wiring) 3 is formed on the surface of the divided circuit board 1, and a chip component 4 such as a resistor or a capacitor is connected to the surface electrode 3. A cavity 5 is formed in the divided circuit board 1, and a semiconductor bare chip 6 is accommodated in the cavity 5, and is connected to the surface electrode 3 by a wire.

Such a divided circuit board 1 is obtained by dividing a ceramic substrate on which the divided circuit boards 1 are assembled as shown in FIGS.

As shown in FIG. 4, the ceramic substrate of the present invention comprises insulating layers 10a to 10e, internal wirings 11, via hole conductors 12, conductive members 21 serving as a pair of end face electrodes 2, and interlayer conductors 23. The insulating base 13 is formed by the layers 10a to 10e, and the surface electrode 3 is formed on the surface. In FIG. 2, illustration of the surface electrode 3 is omitted.

The insulating layers 10a to 10e are made of a glass ceramic material, and each has a thickness of 40 to 150 μm. Such an insulating layer 10a, an insulating layer 10b, an insulating layer 1
The internal wiring 11 is formed between the insulating layer 10b and the insulating layer 10c, and between the insulating layer 10d and the insulating layer 10e. The internal wiring 11
It is made of a gold-based, silver-based, or copper-based metal material, for example, a silver-based conductor. The internal wiring 11 may be connected by a via-hole conductor 12 penetrating through the thickness of the insulating layer 10b, or may be connected in a distributed manner by capacitive coupling or the like. The via-hole conductor 12 is also made of a gold-based, silver-based, or copper-based metal material, for example, a silver-based conductor, like the internal wiring 11.

On the surface of the insulating substrate 13, a surface electrode 3 connected to the via-hole conductor 12 of the insulating layer 10e is formed. On this surface electrode 3, a thick-film resistor film or a thick-film If a protective film is formed, plated,
Further, as shown in FIG. 1, various electronic components including an IC are joined by solder or a thin bonding wire.

In the present invention, as shown in FIGS. 3 to 5, the conductive member 21 is connected to the interlayer conductors 23 formed between the respective insulating layers. Are electrically connected to each other. The internal wiring 11 between the insulating layers 10a and 10b and the internal wiring 11 between the insulating layers 10d and 10e are connected to the interlayer conductor 23.

That is, the conductive member 21 is formed so as to penetrate the insulating base 13 in the thickness direction as shown in FIGS. 4 and 5, and the dividing groove 7 is formed in the center of the conductive member 21. I have. The conductive members 21 are connected to interlayer conductors 23, and these interlayer conductors 23 are connected to each other by the via holes 12. Therefore, the conductive member 21 and the interlayer conductor 2
3 and the via hole 12 are electrically connected to each other.

The divided circuit board of the present invention is manufactured through the intermediate structure shown in FIG. First, the insulating layers 10a to 10a
Create a slip material to be e.

Examples of the solvent-based slip material include glass materials such as SiO ₂ , Al ₂ O ₃ , ZnO, MgO, and B ₂ O.
_A glass-ceramic powder comprising 50% by weight of a crystallized glass powder containing ₃ as a main component and 50% by weight of an alumina powder as a ceramic material, a photocurable monomer such as polyoxyethylated trimethylolpropane triacrylate, It is prepared by mixing an organic binder such as alkyl methacrylate and a plasticizer with an organic solvent such as ethyl carbitol acetate, and kneading the mixture in a ball mill for about 48 hours.

In this embodiment, a solvent-based slip material is prepared. However, as described above, a photo-curable monomer having a hydrophilic functional group added thereto, for example, a polyfunctional methacrylate monomer, an organic binder such as carboxylic acid Using a modified alkyl methacrylate, an aqueous slip material kneaded with ion-exchanged water may be prepared.

The internal wiring 11 and the via-hole conductor 1
2. A conductive paste to be the conductive member 21 and the interlayer conductor 23 is prepared. The conductive paste is a low melting point and low resistance metal material such as silver powder, and a borosilicate low melting point glass such as B ₂ O ₃ —SiO ₂ —BaO glass or CaO.
-B ₂ O ₃ -SiO ₂ glass, CaO-Al ₂ O ₃ -B
₂ O ₃ —SiO ₂ glass and an organic binder, for example, ethyl cellulose, are mixed with an organic solvent, for example, 2,2,4-trimethyl-1,3-pentadiol monoisobutyrate, and kneaded uniformly with a ball mill. create.

Then, first, as shown in FIG.
The above-mentioned slip material is applied onto the prepared support substrate 14 and dried to form the lowermost insulating layer molded body 20a. Specifically, first, the above-mentioned slip material is applied on the support substrate 14 by a doctor blade method, and then dried, and the insulating layer 1 which is the lowermost layer of the insulating layers 10a to 10e is formed.
Then, the insulating layer molded body 20a which becomes 0a is formed. Here, a mylar film is used as the support substrate 14 and is removed before the firing step. Drying condition after application is 60-80 ° C
For 20 minutes, and the thickness of the thinned and dried insulating layer molded body 20a is 120 μm.

Since the conductive member 21 to be the end face electrode 2 and the via-hole conductor 12 are formed in the insulating layer molded body 20a, as shown in FIG.
7 and the through-hole 29 for the via-hole conductor 12 are formed. The through-hole 27 for the end face electrode and the through-hole 29 for the via-hole conductor 12 are formed by performing an exposure process, a development process, and a cleaning / drying process.

The exposure process is performed, for example, by placing a photo target close to or on the insulating layer molded body 20a, and applying a low-pressure, high-pressure, or ultra-high-pressure mercury lamp system to a region other than the end surface electrode through groove 27 and through hole 29. Is irradiated. As a result, the photocurable monomer causes a photopolymerization reaction in a region other than the end surface electrode through groove 27 and the through hole 29. Accordingly, only the through-holes 27 and the through-holes 29 for the end face electrodes become fusible portions that can be removed by the developing process.

Specifically, the exposure treatment is performed on the insulating layer molded body 2
A photo target is placed on Oa so that the region where the end surface electrode through groove 27 and the through hole 29 are formed is shielded from light, and exposure is performed using an ultrahigh pressure mercury lamp (10 mW / cm ² ) as a light source.

As a result, the photopolymerization reaction of the photocurable monomer does not occur in the insulating layer molded body 20a in the area where the end face electrode through groove 27 and the through hole 29 are formed. In the insulating layer molded body 20a other than the region where the hole 29 is formed, a photopolymerization reaction occurs. Here, the part where the photopolymerization reaction has occurred is called an insolubilized part, and the part where the photopolymerization reaction does not occur is called a solubilized part. still,
An insulating layer molded body having a thickness of about 120 μm is formed of an ultra-high pressure mercury lamp (10
mW / cm ² ) for about 20 to 30 seconds, the exposure can be performed.

In the developing treatment, a solvent such as chlorocene is brought into contact with the exposed and solubilized portion of the insulating layer molded body 20a by, for example, a spray developing method or a paddle developing method to perform development. afterwards,
Washing and drying are performed as necessary. The development treatment is to remove the solubilized portion of the insulating layer molded body 20a with a developer, and specifically, 1,1,1-trichloroethane is developed by a spray method.

By this developing treatment, the insulating layer molded body 20a
100 to 200 μm wide straight groove for end face electrode 2
7 and the through hole 29 can be formed. It should be noted that this length can be set only for the required length of the end face electrode, and can generally be set to about 0.5 mm to about 3.0 mm. Thereafter, unnecessary debris and the like generated by the development are completely removed by a washing and drying process.

Next, as shown in FIG. 6C, the conductive paste is filled in the through-holes 27 for the end face electrodes and the through-holes 29 and dried. Specifically, the above-described conductive paste is filled in the through-holes 27 and the through-holes 29 for the end face electrodes formed in the above-described steps, and dried. Printing is performed using a screen that can be printed only on the portions corresponding to the through-holes 27 and the through-holes 29 for the end face electrodes, and then dried at 50 ° C. for 10 minutes.

Next, after firing, the internal wiring 11, the interlayer conductor 1
Printing and drying of the pattern to be 2 are performed. Specifically, as shown in FIG. 6D, the internal wiring pattern 26 serving as the internal wiring 11 disposed between the insulating layer 10a and the insulating layer 10b, the internal wiring pattern 26, the via hole conductor 1
2. An interlayer conductive pattern 30 connected to the conductive member 21 is formed by a screen printing method and dried.

Then, the steps from the formation of the insulating layer molded body to the formation of the patterns 26 and 30 are repeated.
In this manner, the uppermost insulating-layer molded body 20e is formed, and the through-hole 29 for forming the through-hole 27 for the end face electrode and the via-hole conductor 12 is formed by exposure and development processing. The conductive paste of No. 12 is printed and filled to form a five-layer laminate.
When the internal wiring pattern 26 and the interlayer conductor pattern 30 are unnecessary, the above-described steps of forming the patterns 26 and 30 are omitted.

Subsequently, a conductor film to be the surface electrode 3 is printed and
It is formed by drying. This is because each of the insulating layer molded bodies 20a-
20e, internal wiring pattern 26, interlayer conductor pattern 3
0, when the via hole conductor 12 and the conductive member to be the end face electrode 2 are fired at the same time, the conductor film to be the surface electrode 3 is also to be fired at a time.

Next, if necessary, the shape of the laminated molded product is adjusted by pressing, the dividing groove 7 is formed, and the support substrate 14 is removed. The dividing groove 7 is formed so as to pass through the center of the conductive member 21 formed in the laminated molded body as shown in FIGS. The formation of such a dividing groove 7 is formed using a snap blade.

Next, firing is performed. The firing includes a binder removal step and a main firing step. The debinding step is performed in a temperature range of about 600 ° C. or less, and the insulating layer molded bodies 20 a to
20e and organic binders included in the conductive members of the patterns 26, 30, the conductive member 21, and the via-hole conductor 12,
This is a process of erasing the photo-curable monomer, and the main firing step is performed at a peak temperature of 850 to 1050 ° C., for example, 900 ° C.
This is a baking process at a peak of 30 minutes, in which the insulating layer molded bodies 20a to 20e to be the insulating layers and the conductive members to be the patterns 26 and 30, the end face electrodes 2, and the via hole conductors 12 are collectively fired.

As a result, as shown in FIG. 4, the internal wiring 11, the via-hole conductor 12, the conductive member to be the end face electrode 2, the interlayer conductor 2 are provided between predetermined portions of the five insulating layers 10a to 10e.
3 is formed, and further, the ceramic substrate of the present invention on which the surface electrode 3 is formed is manufactured.

Thereafter, as a surface treatment, printing and baking of a thick-film resistive film and a thick-film protective film, plating, and bonding of electronic components including an IC chip are performed. After that, by dividing along the dividing groove 7, the divided circuit board 1 as shown in FIG. 1 is obtained. That is, as shown in FIG. 1, the end surface electrode 2 of the divided circuit board is formed along the outer peripheral surface of the insulating base so that a part thereof functions as an electrode for electrical connection.

According to the method for manufacturing a ceramic substrate,
Since the through-holes and the through-holes for the end face electrodes are formed by exposure and development using a photo target, end face electrodes of various sizes are formed depending on the pattern of the photo target, and correspond to the mating member to be connected. It can be shaped and sized, and can be manufactured using conventional manufacturing methods, such as
It is possible to form a through hole with high relative positional accuracy that cannot be obtained by punching a C punch.

Further, in the process of forming the end face electrodes, it is not necessary to provide through holes, so that it is possible to coat a conductive paste on the end face electrode portions with a conductive paste without using a thick film printing technique such as suction. The process can be simplified and unnecessary capital investment can be reduced.

Further, since the insulating layer molded body is formed by applying the slip material serving as the insulating layer, the surface of the insulating layer molded body is irrespective of the lamination state of the wiring pattern of the internal wiring.
The planar state can always be maintained, and the precision in forming the wiring pattern on the molded insulating layer becomes extremely high.

In the ceramic substrate of the present invention, when the substrate is divided, a force is applied to the conductive member serving as the end face electrode, and even if a part of the end face electrode is peeled off or disconnected.
As a divided circuit board, a plurality of interlayer conductors are electrically connected to each other by via-hole conductors, so that the interlayer conductors connected to the end face electrodes are electrically connected to each other, and Connection reliability can be improved.

That is, in FIG. 4, the insulating layers 10a and 1a
0b and the internal wiring 11 formed between the insulating layers 10d and 10e include an interlayer conductor 23, a via-hole conductor 12
The internal wiring 11 is connected to the conductive member 21 so that the internal wirings 11 are electrically connected to each other. Even if the end face electrode 2 is disconnected by dividing the ceramic substrate, the gap between the insulating layers 10a and 10b is maintained. And insulating layers 10d and 1
0e, the conduction between the internal wires 11 formed between
The reliability is ensured by the interlayer conductor 23 and the via-hole conductor 12, and the reliability of the divided circuit board can be improved.

In the above embodiment, the internal wiring 11 is
A low-temperature firing ceramic substrate manufacturing method using Au-based, Ag-based, and Cu-based low-melting point metal materials has been described. The manufacturing method of the present invention may be applied to a ceramic substrate fired in the above.
In this case, it is necessary to set the composition of the glass material of the slip material as a predetermined component, and further set the mixing ratio with the ceramic material to a predetermined value.

[0120]

According to the present invention, it is possible to provide an end face electrode structure which has good connection reliability between the internal wiring and the end face electrode and can reduce the production cost. Further, the number of manufacturing steps is small, and a ceramic circuit board that can be manufactured in large numbers can be realized. Also, because you can take many pieces,
There is an advantage that mounting efficiency is increased when components are mounted on the surface of the ceramic circuit board.

[Brief description of the drawings]

FIG. 1 is a perspective view of a divided circuit board obtained by dividing a ceramic substrate of the present invention.

FIG. 2 is a perspective view showing a ceramic substrate of the present invention.

FIG. 3 is a plan view of the vicinity of a conductive member forming a pair of end face electrodes of FIG. 2;

FIG. 4 is a cross-sectional view of the vicinity of a conductive member of the ceramic substrate of the present invention.

FIG. 5 is a conceptual diagram for explaining the vicinity of a conductive member forming an end face electrode.

FIG. 6 is a process chart for explaining the manufacturing method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Divided circuit board 2 ... End surface electrode 4 ... Chip component 7 ... Divided groove 10a-10e ... Insulating layer 11 ... Internal wiring 12 ... Via hole conductor 13 ... Insulation Base 14 Support substrate 20a to 20e Insulating layer molded body 21 Conductive member 23 Interlayer conductor 26 Internal wiring pattern 27 Through groove for end face electrode 29 Through Hole 30: Interlayer conductor pattern

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Shinichi Enami 1-4-1 Yamashita-cho, Kokubu-shi, Kagoshima Inside the Kyocera Research Institute (72) Inventor Akira Imoto 1-4-4 Yamashita-cho, Kokubu-shi, Kagoshima Kyocera Inside Research Institute, Inc.

Claims (3)

[Claims] An insulating base formed by laminating a plurality of insulating layers made of ceramics; a conductive member forming a pair of end electrodes formed in a thickness direction of the insulating base; and a conductive member formed on a surface of the insulating base. A dividing groove formed so as to divide the surface of the member into two parts, wherein when the insulating substrate is divided by the dividing grooves, each of the ceramic substrates becomes a divided circuit board having a plurality of end surface electrodes, A ceramic substrate, wherein interlayer conductors are formed between layers, one end of each of these interlayer conductors is connected to the conductive member, and the interlayer conductors are interconnected by via-hole conductors. 2. The ceramic substrate according to claim 1, wherein an internal wiring is connected to the interlayer conductor. 3. A divided circuit board having an insulating base formed by laminating a plurality of insulating layers made of ceramics and end electrodes formed on the outer peripheral surface of the insulating base. A divided circuit board formed, wherein one end of each of these interlayer conductors is connected to the end face electrode, and the interlayer conductors are connected to each other by via-hole conductors.