JPH0851283A - Multilayer wiring board and package for semiconductor device storage - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a multilayer wiring board and a package for accommodating a semiconductor element, which has a coefficient of thermal expansion similar to that of the semiconductor element and includes a capacitor section, on which a large-sized semiconductor element can be mounted. [Structure] Mullite, W, Mo, Re, and W are formed on or in the surface of an insulating layer 2 made of ceramics containing mullite as a main component or inside or on the surface of a ceramic insulating substrate on which a metallized wiring layer 7 is provided between insulating layers 2. A multilayer wiring board and a semiconductor element accommodating device in which a capacitor portion 6 formed by sandwiching a high dielectric layer 3 containing at least one high dielectric constant imparting agent selected from ZrO ₂ by a pair of electrodes 4 and 5 is stacked. Get the package.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layer wiring board having a capacitor portion composed of a high dielectric layer and a pair of electrodes and a package for accommodating semiconductor elements. More specifically, it has stable electrical characteristics and excellent characteristics. The present invention relates to a multilayer wiring board and a package having excellent sealing performance and mechanical strength.

[0002]

2. Description of the Related Art In a package for accommodating semiconductor elements, a semiconductor element (integrated circuit) is apt to malfunction due to external noise or unnecessary radiation. Therefore, a capacitor section having a capacity of about 30 to 100 .mu.F is provided on the power supply side and the ground side. By interposing between and, noise is absorbed and malfunction is prevented. This capacitor part is generally composed of a ceramic dielectric sandwiched between a pair of electrodes. Conventionally, this capacitor was connected externally to the package, so that the mounting density could not be improved. .

As a method for solving such a drawback, a capacitor section in which a dielectric layer such as alumina is sandwiched between a pair of electrode layers made of W or Mo between insulating layers containing alumina as a main component is interposed. A package for accommodating mounted semiconductor elements is known (see Japanese Patent Application Laid-Open No. 62-169461).

Further, as the multilayer alumina wiring board,
For example, as disclosed in Japanese Patent Laid-Open No. 3-87091, a pair of electrode layers formed by applying or printing a paste containing a high melting point metal such as W or Mo as a main component is formed on both sides, and alumina is formed. There is known a multi-layered alumina wiring substrate in which a capacitor part having a high dielectric layer containing a high dielectric constant imparting agent made of W or Mo sandwiched between electrodes is interposed between insulating layers containing alumina as a main component.

[0005]

However, the high-dielectric layer provided in the conventional wiring board or package for housing a semiconductor element is still unstable in electrical characteristics, and the electrodes holding the high-dielectric layer are sandwiched. There is a risk that the insulation resistance between the electrodes will decrease, and if it is significant, a short circuit will occur between the electrodes. Also,
The hermeticity (airtightness) of the multi-layered structure is also insufficient, and the surface resistance of the electrode layer changes due to moisture permeation, or sufficient bonding between the electrode layer and the high dielectric layer or insulating layer. There were drawbacks such as lack of strength.

Furthermore, the components in the high dielectric layer, especially W and M
A component such as o easily diffuses into the adjacent electrode layer or insulating layer, and conversely, a refractory metal such as W or Mo forming the electrode layer diffuses into the high dielectric layer, and the composition of the high dielectric layer is increased. There is a problem in that the electric characteristics of the dielectric layer change as a result, and stable electric characteristics such as relative permittivity cannot be obtained.

Further, in the well-known wiring board containing a high dielectric layer and the package for accommodating semiconductor elements as described above, 25 to 4
The thermal expansion coefficient of the insulating layer at 00 ° C. is about 7 × 10 ⁻⁶ / ° C., which is much higher than the thermal expansion coefficient of the semiconductor element made of silicon of about 3.5 × 10 ⁻⁶ / ° C. There is a possibility that the semiconductor element attached on the insulating layer may fall off. This tendency is particularly remarkable when a large-sized semiconductor element is attached, so that there is a problem that a large-sized semiconductor element cannot be mounted.

Therefore, an object of the present invention is to have a coefficient of thermal expansion similar to that of a semiconductor device, to have stable electrical characteristics and excellent airtightness and mechanical strength while having a high dielectric layer inside. An object of the present invention is to provide a multilayer wiring board on which a large-sized semiconductor element can be mounted and a package for housing the semiconductor element.

Another object of the present invention is to obtain excellent adhesion, airtightness and interlayer adhesion strength between the electrode layer and the high dielectric layer or insulating layer, and also to use the high dielectric layer of the electrode layer constituting material. It is an object of the present invention to provide a wiring board and a package for housing a semiconductor element, which are provided with a capacitor portion that can suppress the diffusion and transfer to the insulating layer and further suppress the diffusion of components such as W and Mo into the insulating layer.

[0010]

A multi-layer wiring board of the present invention is a multi-layer wiring board having a capacitor part in which a high dielectric layer is sandwiched by a pair of electrode layers, and the high dielectric layer is mullite. And at least one high dielectric constant-imparting agent selected from W, Mo, Re and ZrO ₂ .
Further, the insulating layer of the multilayer wiring board is made of ceramics containing mullite as a main component.

Further, the package for accommodating a semiconductor element of the present invention is a package for accommodating a semiconductor element, which comprises a capacitor part in which a high dielectric layer is sandwiched by a pair of electrode layers, and which has an accommodating part for a semiconductor element. The high dielectric layer is composed of mullite and at least one high dielectric constant-imparting agent selected from W, Mo, Re and ZrO ₂ .
Further, the insulating layer of the multilayer wiring board is made of ceramics containing mullite as a main component.

In both the multilayer wiring board and the package for housing a semiconductor element, the high dielectric constant imparting agent particles are made of at least one of W and Mo, and the electrode layer is the same as the high dielectric constant imparting agent particles. It is desirable that the material is the main component. Further, the high dielectric constant imparting agent particles have W and the electrode layer has Mo as a main component, or the high dielectric constant imparting agent particles have Mo and the electrode layer has W as a main component. The thickness is preferably 30 μm or more.

[0013]

According to the present invention, in a multilayer wiring board and a package for accommodating semiconductor elements, an insulating layer is made of ceramics containing mullite as a main component, and a high dielectric material of a capacitor portion laminated on or between insulating layers. The layer is composed of mullite and a high-dielectric layer containing at least one high-permittivity-imparting agent selected from W, Mo, Re and ZrO ₂ , whereby the coefficient of thermal expansion of the insulating layer at 25 to 400 ° C. 4 to 6.8 × 10 ⁻⁶ / ° C., which is closer to the thermal expansion coefficient (about 3.5 × 10 ⁻⁶ / ° C.) of a semiconductor element made of silicon than alumina (7 × 10 ⁻⁶ / ° C.). It is possible to prevent the element from falling off the insulating layer.

Further, by adding W, Mo, Re and ZrO ₂ to mullite in the high dielectric layer,
As a result of being able to increase the dielectric constant, a high capacitance can be obtained as a capacitor. For example, when ZrO ₂ (YSZ) containing Y ₂ O ₃ is added to mullite, as shown in FIG. 10, and by adding W, Mo, and Re, as shown in FIGS. 9 and 11. The dielectric constant can be improved.

Further, in the high dielectric layer, in the laminated state of the electrode and the insulating layer, the high dielectric constant imparting agent in the high dielectric layer gradually diffuses, the amount of the high dielectric constant imparting agent decreases, and the dielectric characteristics gradually increase. May change to. In the case of ZrO ₂ , Y ₂
In some cases, a stabilizer such as O ₃ diffuses and ZrO ₂ is destabilized to change the characteristics.

Therefore, according to the present invention, when the high permittivity-imparting agent is composed of W and Mo, the diffusion of W and Mo from the dielectric layer can be prevented by using the same material for the electrode layers. Further, when the material of the high dielectric constant-imparting agent and the material of the electrode layer are different, the characteristic change due to diffusion can be prevented by increasing the thickness of the electrode layer to 30 μm or more.

Further, when the high permittivity imparting agent comprises ZrO _2, by the addition of Y ₂ O ₃ of ZrO ₂ and a stabilizer in the ceramic insulating layer, a ZrO ₂ diffusion and Y ₂
It is possible to prevent destabilization of ZrO ₂ due to diffusion of O ₃ .

According to the present invention, when a glass phase is present in both the high dielectric layer and the insulating layer, the high dielectric layer,
It is possible to improve the adhesion strength between the insulating layer, the electrode layer, and the wiring layer, and to improve the airtightness of the package.

Furthermore, the multilayer wiring board and the package of the present invention prevent a change in the thickness of the dielectric layer of the capacitor portion during firing, and prevent a change in the dielectric characteristics and a warpage after firing, which are stable manufacturing. can do.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings. (Structure of Multilayer Wiring Board) FIG. 1 is a diagram showing an example of the multilayer wiring board according to the present invention. According to FIG. 1, in the insulating layer 2 in the wiring board 1, the capacitor portion 6 including the high dielectric layer 3 and the pair of electrode layers 4 and 5 is internally laminated. A wiring layer 7 is provided on the surface or inside of the insulating layer 2. Further, in the configuration of FIG. 1, the electrode layer 4
And 5 are led out to the substrate surface through through holes 8 and 9.

Further, in the multilayer wiring board of the present invention, in addition to the capacitor section 6 being sandwiched between the insulating layers 2 as in the embodiment of FIG. 1, for example, as shown in FIG. The electrode layer 5, the high dielectric layer 3 and the electrode layer 4 can be laminated on the outermost surface of the formed insulating layer 2. in this case,
The capacitor portion 6 may have a protective film formed of resin or the like on its surface so as not to come into contact with the outside air.

(Structure of Package for Housing Semiconductor Element) FIG. 2 is a diagram showing an example of a package for housing a semiconductor element according to the present invention. According to FIG. 2, a plurality of insulating layers 11 are laminated on the substrate of the semiconductor element housing package 10, and a wiring layer 12 is provided inside or on the surface of the insulating layer 11. Further, inside the insulating substrate, a capacitor section 16 is formed by the high dielectric layer 13 and a pair of electrode layers 14 and 15 sandwiching the high dielectric layer 13. Further, a concave portion (accommodation portion) 18 for accommodating the semiconductor element 17 is formed on the upper surface of the insulating substrate, and the accommodating portion 18 is sealed by a lid 19. In addition, the electrode layer 15 of the capacitor section 16 is
It is connected to the wiring layer through the through hole 20.
Further, in the configuration of FIG. 2, the electrode layer 1 of the capacitor section 16 is
4 is exposed to the storage portion 18 to form a bottom surface of the storage portion, and the semiconductor element 17 is mounted on the bottom surface. The wiring layer 12 is electrically connected to the external terminal 21 through a through hole or the like.

There are various types of semiconductor device housing packages as shown in FIGS. FIG.
In the package, the high dielectric layer 13 and the electrode layers 14 and 15 are alternately laminated in multiple layers below the semiconductor element 17, and these electrode layers 14 and 15 are connected to the semiconductor element 17 through the through holes 20. It is a thing.

The package of FIG. 5 has a structure in which the capacitor portion 6 in which the electrode layers 14 and 15 are formed above and below the high dielectric layer 13 is sandwiched by the insulating layers 11, and the electrode layers 14 and 1 are formed.
Reference numeral 5 is connected to the semiconductor element 17 through a through hole 20.

In the package of FIG. 6, electrode layers 14 and 15 are formed below the semiconductor element 17 and above and below the high dielectric layer 13, and these electrode layers 14 and 15 are formed by the through holes 20 in the semiconductor element. 17 and the pins 21 are fixed to the lower surface, and these pins 21 are connected to the electrode layer 1
It is connected to the semiconductor element 17 through a through hole 22 formed by passing through Nos. 4 and 15 and the high dielectric layer 13.

In the package shown in FIG. 7, the high dielectric layer 13 and the electrode layers 14 and 15 are alternately laminated to form the capacitor section 6, and the electrode layers 14 and 15 are connected to the semiconductor element 17 through the through holes 20. Further, the semiconductor element 17 is fixed to the heat sink 23.

The package shown in FIG. 8 is a flat package in which the high dielectric layer 13 and the electrode layers 14 and 15 are alternately laminated in multiple layers, and these electrode layers 13 and 14 are connected to the semiconductor element 17 by the through holes 20. It is connected.

(High Dielectric Layer) In the wiring board and the semiconductor element accommodating package of the present invention, the high dielectric layer (No. 3 in FIG. 1, No. 13 in FIG. 2) forming the capacitor portion is mullite. W, Mo, Re and ZrO ₂
At least one high dielectric constant-imparting agent selected from Of these, W, Mo, Re and ZrO ₂ have the function of increasing the dielectric constant, and have a relative dielectric constant of 10.8 or more, particularly 13 to
A dielectric constant of 40 is applied.

The high dielectric layer has an average crystal grain size of 3 to 2
It mainly contains mullite particles of 0 μm and also contains particles of a high dielectric constant-imparting agent, but it is desirable that a further small amount of glass phase be present in these grain boundaries. A high dielectric constant-imparting agent has a relative dielectric constant of 7.5 or more, especially 1
It gives a relative permittivity of 0-20.

The glass phase present at the grain boundaries of the high dielectric layer is
For example, a reaction between an oxide of at least one element selected from Al, Si, an alkaline earth metal component and a rare earth element component mixed as a sintering aid with an alumina component or a silica component from the mullite particles is performed. It was formed. When the high-dielectric constant-imparting agent is ZrO ₂ , a small amount of ZrO ₂ is dissolved in the glass phase at the grain boundary to improve chemical resistance. The amount of the sintering aid (vitrification component) of the dielectric layer is preferably in the range of 1% by weight or more. This is because if it is less than the above range, the adhesion, airtightness and bonding strength between the high dielectric layer, the insulating layer and the electrode layer tend to be lowered.

It is desirable that ZrO ₂ as a high dielectric constant-imparting agent contains a stabilizer in order to stabilize the effect of imparting a high dielectric constant.
rO ₂ is mainly composed of tetragonal crystals and / or cubic crystals, and in some cases, a slight amount of monoclinic crystals may be mixed. This stabilizer is preferably dissolved in an amount necessary for ZrO _{2 to} have the above-mentioned crystal form, and the stabilizer is preferably added in a proportion of 5 to 15 mol%. This is because when the amount of the stabilizer is less than 5 mol%, a phase transformation from tetragonal to monoclinic occurs, which causes problems such as cracking. When the amount of the stabilizer is more than 15 mol%, ZrO ₂ itself is not formed. This is because the dielectric constant decreases and the effect of increasing the dielectric constant of the dielectric layer decreases. As the stabilizer, there are rare earth oxides and alkaline earth oxides, and as the rare earth, those represented by RE ₂ O ₃ (RE is a rare earth element) are preferable.
₂ O ₃ , Nd ₂ O ₃ , La ₂ O ₃ , Sm ₂ O ₃ , Yb ₂
There are O ₃ etc. MgO, C as alkaline earth oxides
Examples thereof include aO, SrO, BaO and the like. In addition, ZrO ₂
It is desirable that the crystal grain size of is 1.5 to 10 μm.

Further, when the high dielectric constant imparting agent is ZrO ₂ , another high dielectric constant imparting agent such as W, Mo or Re is used.
It may be used in combination with one of the above, in which case Mo is 5 to 30% by weight, the W is 5 to 50% by weight, and the Re is 10 to 60% by weight. It is desirable to contain it in a ratio.

Among the high dielectric constant-imparting agents in the high dielectric layer, ZrO ₂ is a ZrO ₂ powder in which a stabilizer is solid-solved, or a mixed powder of Y ₂ O ₃ and ZrO ₂ , or W,
Mo and Re may be added in any form, even if added as a metal powder, as an oxide powder, or as another compound, since they exist as a metal after firing.

The specific composition of the high dielectric layer is appropriately adjusted according to the kind of the high dielectric constant imparting agent used, and (a) 67-8.
7 wt% mullite powder, 5 to 30 wt% W or Mo, and 1 to 10 wt% Al, Si, an oxide of at least one element selected from alkaline earth metals and rare earth elements,
Hydroxides, carbonates, salts such as nitrates, nitrides, fluorides,
A mixture obtained by firing a mixture of a compound such as a bromide or a halide, (b) 40 to 95% by weight of mullite powder, 5 to 60% by weight of Re and 1 to 10% by weight.
Al, Si, oxides, hydroxides, carbonates, nitrates, and other salts of at least one element selected from the group consisting of Al, Si, alkaline earth metals, and rare earth elements, nitrides, hookers, halides such as bromides, borides, etc. Firing a mixture of the compounds of (c), (c) 10 to 90% by weight of mullite powder, and 90 to
10 wt% ZrO ₂ powder and 1-10 wt% Al,
From compounds such as oxides, hydroxides, carbonates, nitrates and other salts of at least one of Si, alkaline earth metals and rare earth elements, halides such as nitrides, fluffs, bromides and borides It is preferable that the mixture is one obtained by firing.

This is because when Al is less than 3% by weight, the difference in thermal expansion between the insulating layer and the high-dielectric layer becomes large when an alumina-based sintered body is used for the insulating layer, and a good laminate is obtained. Is less likely to be formed, and if it is more than 90% by weight, the effect of improving the dielectric constant becomes small. When Zr is less than 8% by weight, the effect of improving the dielectric constant is small,
This is because there is no clear difference from normal alumina porcelain that does not contain Zr. When the amount is more than 95% by weight, the thermal expansion of the insulating layer and the high dielectric layer when the alumina-based sintered body is used as the insulating layer. This is because the difference becomes large and it becomes difficult to form a good laminate. When the alumina-based sintered body containing Al ₂ O ₃ as the main component is used as the insulating layer, the Zr amount in the high dielectric layer is preferably 30 to 70% by weight in terms of oxide.

Further, when the content of at least one element selected from the alkaline earth metals, the rare earth elements and Si is less than 2% by weight in terms of its oxide, the generation of a stable grain boundary glass phase is reduced and the electrode is The joint strength between the electrode layer and the dielectric layer when co-firing with the layer is reduced.

The average crystal grain size of the mullite particles in the high dielectric layer in the present invention is preferably 3 to 20 μm. Further, it is desirable that W, Mo and Re be present in an average grain size of 5 μm or less and ZrO _{2 be 3} to 20 μm.

The thickness of the high-dielectric layer is appropriately determined according to the required capacitance and the dielectric constant of the high-dielectric layer. Usually, the thickness of the single-layer or multi-layer structure is 10 to 100.
μm, and for example, in a package or substrate having a size of 1 to 2 inches, a capacitance of several nF to several hundreds nF can be obtained.

(Electrode Layer) On the other hand, the pair of electrode layers for sandwiching the above-mentioned dielectric layer to form the capacitor portion can be constituted by a known metallization layer, and for example, at least one of W, Mo and Re is a main component. Is preferable. Such an electrode layer is formed with a thickness of approximately 3 to 15 μm. In the package for storing a semiconductor, one pair of the electrode layers may be used as a decoupling capacitor by electrically connecting one side to a semiconductor element by using one side as a power supply layer and the other side as a ground layer.

In addition to the above metal components, the components contained in the high dielectric layer or the insulating layer are added to the electrode layer in an amount of 10% by weight or less to ensure close contact with the high dielectric layer or the insulating layer. You can improve your sex.

When a metal having a lower thermal expansion than that of the high dielectric layer, such as W or Mo, is used for the electrode layer, surface compressive stress is generated on the electrode layer side, so that the strength of the entire substrate can be increased. . Such surface compressive stress is W,
Similar strength improving effect can be obtained by using Al ₂ O ₃ instead of Mo and disposing it in the outermost layer of the high dielectric layer.

Further, when the high dielectric constant imparting agent of the high dielectric layer is W or Mo, it is desirable that the electrode layers sandwiching the high dielectric constant agent contain the same material as the high dielectric constant imparting agent as a main component. In addition, when the high dielectric constant imparting agent of the high dielectric layer is W and the electrode layer contains Mo as a main component, or when the high dielectric constant imparting agent is Mo and the electrode layer contains W as a main component, the dielectric Layer thickness 30
It is desirable that the thickness is at least μm. That is, when the high dielectric constant-imparting agent and the electrode layer are made of the same material, there is no total solid solution of W or Mo, and the refractory metal W or Mo of the electrode layer is prevented from diffusing into the high dielectric, It is possible to prevent a decrease in insulation resistance of the high dielectric layer between the electrodes and prevent a leak current between the electrodes. When the high dielectric constant-imparting agent and the electrode layer are different materials, W and Mo of the electrode layer forming material are diffused into the high dielectric layer. However, by making the thickness of the high dielectric layer 30 μm or more, the electrode layer W and Mo do not diffuse throughout the high-dielectric layer, so that the insulation resistance between the electrodes can be prevented from lowering and the leakage current between the electrodes can be prevented.

(Insulating Layer) The composition and formation process of the glass phase are the same as described above. That is, in the present invention which intervenes in the grain boundary of the insulating layer, by forming the glass phase in both the high dielectric layer and the insulating layer on both sides of the electrode layer,
While improving the adhesion between the electrode layer and these layers,
The airtightness and interlayer adhesive strength of the package can be increased.

Furthermore, the insulating layer in the wiring substrate or the insulating substrate of the package for accommodating semiconductor elements is mainly composed of mullite particles and the glass phase existing at the grain boundaries, and the glass phase is, for example, a sintering aid. Blended as
It is formed by a reaction of an oxide of at least one element selected from 1, 1, Si, an alkaline earth metal component and a rare earth element component, and an alumina component and a silica component from mullite particles.

The specific composition of this insulating layer is 90 to 99% by weight of mullite, and an oxide of at least one element selected from Al, Si, Zr, an alkaline earth metal component and a rare earth element component. The content is 1 to 10% by weight. Further, oxides such as B and Zn can be added together as a sintering aid.

Further, the high dielectric constant-imparting agent in the high dielectric layer is Z
In the case of rO ₂ , it is desirable to contain a Zr component in the insulating layer. This is because if the Zr component is not contained in the insulating layer, the ZrO ₂ component in the high dielectric layer is eluted into the insulating layer to change the composition of the high dielectric layer, or the high dielectric layer itself. This is because stable dielectric characteristics cannot be obtained such as when the thickness of the layer becomes thin, and when Zr is excessively included, the dielectric constant of the insulating layer becomes high.

Therefore, the Zr amount is Z at the location where the wiring layer, which is required to have a low dielectric constant as the insulating layer, is provided.
0.5 to 10% by weight in terms of rO ₂ is desirable. On the contrary, where the wiring layer is not formed at all and there is no problem even if the dielectric constant is high, there is no problem even if the amount of Zr is more than 10% by weight, and the same composition as the dielectric layer may be used. .

Further, in a structure in which a high dielectric layer having different thermal expansion characteristics and an insulating layer are in contact with each other directly or through an electrode layer in a substrate, destruction due to thermal stress caused by a difference in thermal expansion easily occurs. Therefore, between the high dielectric layer 3 and the electrodes 4 and 5 and the insulating layer 2 in the multilayer wiring board of FIG. 1, and the high dielectric layer 13 and the electrodes 14 and 15 of the semiconductor element housing package of FIG. An intermediate layer having an intermediate composition such as a mixture of the composition of the high dielectric layer and the insulating layer may be interposed between the insulating layer 11 and the insulating layer 11.

As described above, according to the present invention, by incorporating Zr in the insulating layer, ZrO in the high dielectric layer is added.
_Although it is possible to prevent the diffusion of ₂ , ZrO ₂ in the dielectric layer contains a stabilizer for stabilizing ZrO ₂ , as described above. Therefore, ZrO is contained in the insulating layer.
_In order not to destabilize ₂ , it is desirable to include a small amount of a stabilizer similar to the stabilizer contained in ZrO ₂ of the high dielectric layer. Examples of the compound serving as a stabilizer include rare earth element oxides such as MgO, CaO and Y ₂ O ₃ .

(Wiring Layer) The wiring layer provided in the insulating layer is formed by a normal metallizing method,
It can be formed of at least one metal selected from W, Mo, Re, Ni, Co, Cu and the like. This wiring layer is generally formed with a thickness of about 3 to 50 μm between the insulating layers or on the surface thereof, but when high output is required, the thickness thereof may reach several mm.

(Manufacturing Method) The multilayer wiring board and the semiconductor element housing package according to the present invention are manufactured, for example, as follows. First, as an insulating layer, 88 to 96 wt% of mullite powder, SiO ₂ , MgO, CaO,
0.5 to 12% by weight of a sintering aid such as a rare earth element such as Y ₂ O ₃ or an oxide of an alkaline earth metal, and Fe as necessary.
₂ O ₃ , Cr ₂ O ₃ , MnO ₂ , TiO ₂ , Mo or W or the like is added and mixed in an amount of 5% by weight or less, and a binder such as butyral or acrylic is added to the mixture, and a solvent such as toluene is further added. Is added and mixed, and a sheet-shaped molded body having a thickness of 0.1 to 1 mm is produced by a known molding method such as a doctor blade method or a calendar roll method.

On the other hand, as a high dielectric layer, mullite powder, a high dielectric constant imparting agent, Al ₂ O ₃ , SiO ₂ , Ca
An alkaline earth metal component such as O and MgO and a sintering aid component including a rare earth oxide such as Y ₂ O ₃ are mixed in the above-described ratio, and if necessary, Fe ₂ O ₃ and Cr _{2 are} further mixed.
5% by weight of O ₃ , MnO ₂ , TiO ₂ , Mo or W
After adding and mixing, for example, a binder such as butyral or acrylic is added, and a solvent such as toluene is further added and mixed, and then the thickness is 20 to 60 μm by a known molding method such as a doctor blade method or a calendar roll method. A sheet-shaped molded body of is produced.

Zr as a high dielectric constant-imparting agent in the high dielectric layer
When using O ₂ powder, Y _{2 of} 5 to 15 mol% is previously prepared.
ZrO containing cubic crystal stabilized by solid solution such as O ₃
It is desirable to use containing ₂ powders. The reason why the content of the stabilizer is 5 to 15 mol% is that if it is less than 5 mol%, a phase transformation from tetragonal to monoclinic is likely to occur and a problem such as cracking occurs. This is because when the content is more than mol%, the dielectric constant of ZrO ₂ itself decreases, and the effect of increasing the dielectric constant of the dielectric layer decreases.

Even if the stabilized or partially stabilized ZrO ₂ is not used as a raw material powder, the stabilizer element oxide and its compound necessary for stabilizing the ZrO ₂ by the formulation are added and stabilized at the firing stage. You may make it.

A metallizing paste containing a metal component such as W, Mo or Mo-Mn for forming a wiring layer is printed on the surface of the sheet-shaped molded product in a wiring pattern by a screen printing method or the like. , Through holes are formed, and the metallizing paste is also filled in the through holes.

On the upper and lower surfaces of the high-dielectric layer sheet-shaped molded product produced as described above, W as an electrode layer,
70 to 100% by weight of Mo or Re, if necessary A
An electrode layer forming paste containing 0 to 30% by weight of l ₂ O ₃ , SiO ₂ , ZrO ₂ , alkaline earth metal, rare earth metal and its compound is applied.

Then, the high-dielectric layer sheet-shaped compact coated with the electrode layer forming paste is interposed between the insulating-layer sheet-shaped compacts or the surface of the insulating-layer sheet-shaped compact is provided. The high dielectric layer sheet-shaped compacts are laminated and pressure-bonded under a predetermined pressure.

When a thin high dielectric layer is formed, an electrode layer forming paste is applied, a high dielectric layer forming slurry is applied, and an electrode layer forming paste is applied on the surface of the insulating layer sheet-shaped molded product. It can also be manufactured by sequentially performing. Also in this case, it is desirable that the sintering additive component added to the high dielectric layer is 2% by weight or more.

The laminated body produced as described above is placed in a reducing atmosphere such as a humidified nitrogen / hydrogen mixed gas at 17
By firing at a temperature of 00 ° C. or lower for 1 to 2 hours, a multilayer wiring board is formed in which a capacitor portion having a high dielectric layer sandwiched by a pair of electrode layers is laminated.
The firing temperature is set as a condition for firing the insulating layer, the wiring layer, and the capacitor portion at the same time. If the firing temperature is lower than 1400 ° C., it becomes difficult to simultaneously fire the wiring layer and the electrode layer made of a refractory metal. When firing at 1400 ° C. or lower, it is preferable to use metallization of Ni or Cu, or a mixture thereof with a refractory metal powder, as the wiring layer.

The capacitor section may be constructed by alternately stacking high dielectric layers and electrode layers, and a high capacitance can be obtained by such a laminated structure.

Further, in the case of manufacturing a package for storing a semiconductor, an insulating layer is formed to form a recess 18 for storing the semiconductor element in FIG. 2 based on a well-known method in addition to the above-described method of manufacturing a multilayer wiring board. After laminating and pressure bonding, the wiring board is manufactured by co-firing, and then a separately manufactured lid is used to seal the concave portion of the wiring board by Au-Sn solder, solder, low melting point glass, welding (seam weld). ) Etc., it can be obtained by adhering to the insulating substrate.

The present invention will be specifically described below with reference to the following examples. Example 1 (insulating layer mullite-high dielectric layer mullite + W, M
o) As raw material powder, a sintering aid component of 7% by weight of SiO ₂ , 0.5% by weight of CaO, 0.5% by weight of MgO, and W or M
10 to 30% by weight of the high dielectric constant-imparting agent consisting of o and the balance of mullite powder having an average particle diameter of 3 μm were prepared, and a binder consisting of an acrylic resin was added thereto.
Furthermore, toluene and isopropyl alcohol (IPA),
After adding and mixing a material such as a plasticizer, a sheet was formed by a doctor blade method to obtain a high dielectric layer molded body.

On the other hand, the insulating layer molded body was prepared by using 92% by weight of mullite powder having an average particle diameter of 3 μm and SiO ₂ as a sintering aid.
7 wt%, CaO 0.5 wt%, MgO 0.5 wt%
Then, a binder made of butyral was added, and toluene was further added and mixed, and then formed into a sheet by the doctor blade method to produce an insulating layer molded body. Then, through holes were formed in the high dielectric layer molded body and the insulating layer molded body, and W high-melting point metal paste was filled therein.

After that, W is formed on the upper and lower surfaces of the high dielectric layer molded body.
And 98% by weight of mullite and 2% by weight of mullite were screen-printed to form an electrode layer.

Then, the high dielectric layer molded body coated with the electrode layer paste is interposed between the insulating layer molded bodies, and thereafter,
In a humidified nitrogen-hydrogen mixed gas (reducing atmosphere), 1
The high dielectric layer molded body, the insulating layer molded body, and the electrode layer were simultaneously fired at 600 ° C. for 2 hours.

The type and amount of the high dielectric constant-imparting agent of the high dielectric layer molded body and the material of the electrode layer are changed, and the capacitance of the substrate obtained as described above is measured and the result is shown. Table 1
It was shown to. The dielectric constant of the high dielectric layer was also measured.

In this experiment, the electrode shape was 25 mm × 2.
The thickness of the high dielectric layer is 5 to 6 μm and the thickness of the high dielectric layer is 25 to 50 μm.
m. In addition, the capacitance is measured by the LCR meter (Y.H.P.
4284A), 100 KHz, 1.0 Vr
It was measured at 25 ° C. under the condition of m.

[0068]

[Table 1]

From Table 1, it is understood that the addition of W or Mo to mullite gradually increases the dielectric constant. Also,
It can be seen that when the electrode material and the high dielectric constant-imparting agent are the same, even if the high dielectric layer has a thickness of 25 μm, it has a high capacitance of 2.1 nF or more. In addition, even when the electrode material is different from the high dielectric constant imparting agent, the thickness of the high dielectric layer is 30 μm.
It is understood that a high capacitance can be obtained in the above cases.

By the way, in this embodiment, the insulating layer has a thermal expansion coefficient of 4.8 × 10 ⁻⁶ / ° C., and the high dielectric layer has a thermal expansion coefficient of 4.8 to 5.
It was 0 × 10 ⁻⁶ / ° C., and a wiring board provided with a capacitor portion having a thermal expansion coefficient similar to that of silicon could be manufactured.

Example 2 (insulating layer mullite-high dielectric layer mullite + Re) As a high dielectric layer molded body, SiO ₂ 7% by weight, CaO
0.5 wt%, 0.5 wt% MgO sintering aid, Re
A mixed powder consisting of 0 to 60% by weight of metal powder and the rest of mullite powder having a particle size of 3 μm was prepared, and a binder made of butyral was added thereto, and toluene was further added and mixed, and then formed into a sheet by a doctor blade method, A high dielectric layer molded body was obtained.

Through holes were formed in this high dielectric layer molded body and the insulating layer molded body of Example 1 and filled with a high melting point metal paste such as W or Mo.

Thereafter, an electrode layer paste containing metal Re and 1 to 10% by weight of mullite was screen-printed on the upper and lower surfaces of the high dielectric layer molded body to form an electrode layer having a thickness of about 8 μm. .

Then, the high dielectric layer molded body to which the electrode layer paste was applied was interposed between the insulating layer molded bodies, and then 160 in a humidified nitrogen / hydrogen mixed gas (reducing atmosphere).
It was normally fired at 0 ° C. for 2 hours to obtain a multilayer wiring board of the present invention.

The obtained multilayer wiring board was sufficiently densified in the high dielectric layer, the insulating layer and the electrode layer, and peeling between layers was not observed at all.

The change in the dielectric constant with the change in the amount of Re in the high dielectric layer was measured. At this time, the electrode shape is 25 mm
The thickness of the high dielectric layer is 25 μm, the measurement is performed using an LCR meter (Y, H, P4284A), and the capacitance at 25 ° C. is measured under the conditions of 1 KHz and 1.0 Vrm. The dielectric constant at 25 ° C. was calculated from the electrostatic capacity and shown in FIG.

From FIG. 9, it is understood that the dielectric constant increases as the amount of Re added in mullite increases. And R
An experiment was conducted in which e was added in an amount of more than 60% by weight, but in this case, the insulation resistance was lowered and the dielectric constant could not be measured.

Example 3 (insulating layer mullite-high dielectric layer mullite + ZrO ₂ ) As a high dielectric layer molded body, CaO 0.5 wt% and MgO
15 to 90% by weight of a partially stabilized ZrO ₂ (8Y-ZrO ₂ ) powder stabilized with 0.5% by weight of a sintering aid and 8 mol% of Y ₂ O ₃ , and the balance having a particle diameter of 3 μm. After preparing a mixed powder consisting of mullite powder, adding a binder consisting of butyral to this, and further adding and mixing toluene,
Sheets were formed by the doctor blade method to obtain a high dielectric layer molded body.

On the other hand, the insulating layer molded body was prepared by mixing 92% by weight of mullite powder having an average particle diameter of 3 μm and Y ₂ O ₃ as a sintering aid.
7 wt%, CaO 0.5 wt%, MgO 0.5 wt%, 8 wt% in total, butyral binder was added, and toluene was further added and mixed, and then formed into a sheet by the doctor blade method to form an insulating layer molded body. Create. Then, through holes were formed in the high dielectric layer molded body and the insulating layer molded body, and the high melting point metal paste of W was filled therein.

Thereafter, an electrode layer paste containing the metal W and 1 to 10% by weight of mullite was screen-printed on the upper and lower surfaces of the high dielectric layer molded body to form an electrode layer having a thickness of about 8 μm. .

Then, the high dielectric layer molded body to which the electrode layer paste is applied is interposed between the insulating layer molded bodies. Then, it was normally fired in a mixed gas of nitrogen and hydrogen (reducing atmosphere) at 1500 ° C. for 2 hours to obtain a multilayer wiring board of the present invention. The obtained multilayer wiring board was sufficiently densified in the high dielectric layer, the insulating layer and the electrode layer, and peeling between layers was not observed at all.

The change in the dielectric constant when the amount of 8Y-ZrO ₂ in the high dielectric layer was changed from 5 to 15 mol% was measured. At this time, the electrode shape was 25 mm × 25 mm × 6 μm, the thickness of the high dielectric layer was 25 μm, and the measurement was performed using an LCR meter (Y, H, P4284A), and 1 KHz,
The electrostatic capacity at 25 ° C. was measured under the condition of 1.0 Vrm, and the dielectric constant at 25 ° C. was calculated from this electrostatic capacity and shown in FIG.

From this FIG. 10, 8Y-Zr in mullite
It can be seen that the dielectric constant increases as the amount of O ₂ added increases. Further, it can be seen that the smaller the solid solution amount of Y ₂ O ₃ relative to the total amount of ZrO ₂ , the higher the relative dielectric constant.

Example 4 Further, in the above-mentioned Example 3, ZrO 2 was used as the high dielectric layer.
₂ Stabilized ZrO ₂ 49.5 wt% stabilized with 8 mol% Y ₂ O ₃ , 49.5 wt% mullite,
With respect to the mixture consisting of 1% by weight of auxiliary agent, W, M
Sintering was performed using a material to which o and Re were added, and the relative dielectric constant of this material was measured, which is shown in FIG. This FIG.
As is clear from the graph, the relative dielectric constant of the material added with W, Mo and Re is further improved as compared with the case where W, Mo and Re are not added, and the added amount of W, Mo and Re is increased. It can be seen that the relative dielectric constant is improved as the value is increased. Further, the inventors of the present invention added an amount of Mo added in an amount of more than 30% by weight, added W in an amount of more than 50% by weight, and added an amount of Re in an amount of more than 60% by weight. Experiments were carried out, but when the amount of addition exceeded the above range, the insulation resistance dropped sharply and the relative permittivity could not be measured.

The present inventor also conducted an experiment in Example 2 in which two kinds of Mo and W were added at a ratio of 1: 1 and the results are shown in FIG. From this Figure 11, Mo
It can be seen that the relative dielectric constant is improved even when W and W are added. Similar effects can be obtained even if W, Mo and Re are added in the form of oxides.

[0086]

As described in detail above, in the multilayer wiring board and the package for accommodating semiconductor elements of the present invention, the insulating layer is formed mainly of mullite, and the high dielectric layer is formed of mullite containing W, Mo. , Re, and ZrO ₂ are added, the thermal expansion coefficient of the semiconductor element is closer to that of silicon than that of alumina, and the semiconductor element can be prevented from falling out of the package. Further, by adding W, Mo, Re, ZrO ₂ to mullite, a dielectric layer having a high capacitance can be formed. Therefore, a large semiconductor element can be mounted while having a high dielectric layer inside.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a multilayer wiring board of the present invention.

FIG. 2 is a vertical cross-sectional view showing an example of a semiconductor element housing package of the present invention.

FIG. 3 is a vertical sectional view showing another embodiment of the multilayer wiring board of the present invention.

FIG. 4 is a vertical cross-sectional view showing another example of the semiconductor element storage package of the present invention.

FIG. 5 is a vertical cross-sectional view showing still another embodiment of the semiconductor element housing package of the present invention.

FIG. 6 is a vertical sectional view showing still another embodiment of the package for housing a semiconductor element of the present invention.

FIG. 7 is a vertical sectional view showing still another embodiment of the semiconductor element storage package of the present invention.

FIG. 8 is a vertical cross-sectional view showing still another embodiment of the semiconductor element housing package of the present invention.

FIG. 9 is a diagram showing the relationship between the Re amount in the high dielectric layer and the dielectric constant in the present invention.

FIG. 10 is a diagram showing the relationship between the amount of ZrO _{2 and the} amount of Y ₂ O ₃ stabilizer in the high dielectric layer and the dielectric constant in the present invention.

FIG. 11 shows the amount of Mo and W in the high dielectric layer according to the present invention.
It is a figure showing the relation between the amount, Re amount, and Mo-W amount.

[Explanation of symbols]

 1 Multilayer Wiring Board 2, 11 Insulating Layer 3, 13 High Dielectric Layer 4, 5, 14, 15 Electrode Layer 6, 16 Capacitor Section 7, 12 Wiring Layer 8, 9, 20, 22 Through Hole 10 Semiconductor Device Storage Package 18 recessed part (storage part) 19 lid 21 external terminal 23 heat sink

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01L 23/14

Claims (6)

[Claims] 1. A surface of an insulating layer made of ceramics containing mullite as a main component, or a ceramic insulating substrate having a metallized wiring layer disposed between insulating layers,
And a capacitor part formed by sandwiching a mullite and a high dielectric layer containing at least one high dielectric constant imparting agent selected from W, Mo, Re and ZrO ₂ between a pair of electrodes. Multilayer wiring board. 2. The multilayer wiring according to claim 1, wherein the high dielectric constant imparting agent particles are composed of at least one of W and Mo, and the electrode layer is mainly composed of the same material as the high dielectric constant imparting agent particles. substrate. 3. The high dielectric constant imparting agent particles are W and the electrode layer is mainly composed of Mo, or the high dielectric constant imparting agent particles are Mo and the electrode layer is mainly composed of W. And the high dielectric layer has a thickness of 30 μm or more.
The multilayer wiring board described. 4. A mullite is provided inside or on the surface of an insulating layer made of ceramics containing mullite as a main component, or a metallized wiring layer is provided between the insulating layers and has a housing for housing a semiconductor element. When,
At least 1 selected from W, Mo, Re and ZrO _2.
A package for accommodating a semiconductor element, comprising: a capacitor portion formed by sandwiching a high dielectric layer containing a seed between a pair of electrodes. 5. The semiconductor device according to claim 4, wherein the high dielectric constant imparting agent particles are composed of at least one of W and Mo, and the electrode layer is mainly composed of the same material as the high dielectric constant imparting agent particles. Storage package. 6. The high dielectric constant-imparting agent particles are W and the electrode layer is mainly composed of Mo, or the high dielectric constant-imparting agent particles are Mo and the electrode layer is mainly composed of W. And the high dielectric layer has a thickness of 30 μm or more.
The package for housing a semiconductor device as described above.