JP2002111228A - Multilayer interconnection board and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multilayer interconnection board that can be laminated without sacrificing the characteristics of at least two different insulating layers even if a conductor wiring layer containing a low-resistance metal is formed while achieving fine wiring by inhibiting shrinkage in the direction of the inside of the lamination surface of the insulating layer. SOLUTION: A first insulating layer 2 made of a first glass ceramic composition, and a second insulating layer 3 made of a second inorganic composition that differs from the first insulating layer 2, are laminated, a conductor wiring layer is formed on or in the laminate, ZnO is contained in the first glass ceramic composition and/or the second inorganic composition, and a package (multilayer interconnection board) 1 for accommodating semiconductor devices that is larger than the content of ZnO at the interface between the first and second insulating layers 2 and 3 and larger than the content of ZnO in the first glass ceramic composition and/or the second inorganic composition is created.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer wiring board having a conductor wiring layer made of a low-resistance metal, and more particularly to a multilayer wiring board in which shrinkage in an in-plane direction due to firing is suppressed and a method for manufacturing the same. Things.

[0002]

2. Description of the Related Art Hitherto, a multilayer wiring board has been proposed in which green sheets having different compositions are stacked and fired to form insulating layers having different characteristics. For example, in Japanese Patent Application Laid-Open No. 7-325511, one intermediate layer having a thickness of 0.1 to 0.3 mm and containing both components is interposed between a high dielectric constant layer and a low dielectric constant layer. It describes that warping and delamination of a substrate at an interface between a high dielectric layer and a low dielectric layer can be prevented.

In Japanese Patent Application Laid-Open No. Hei 6-283380, when laminating an insulating layer and a dielectric layer, one of the layers having a higher sintering temperature is sintered and then the other is added to the sintered body. Describes a multilayer wiring board in which green sheets for forming the above-mentioned layers are laminated and fired.

On the other hand, in the multilayer wiring board as described above, the green sheet is fired by firing (green sheet laminated surface).
However, in recent years, it has been required to increase the density of the conductor wiring layer, and with this, the multilayer wiring board has been required to have a contraction in the inward direction of the insulating layer (insulating layer laminated surface). It is intended to suppress shrinkage due to firing.

For example, Japanese Patent Application Laid-Open No. 6-97656 discloses that a first green sheet made of a mixture of lead borosilicate glass and alumina and a second green sheet made of an inorganic oxide such as cordierite have silver on the surface. By applying and laminating a conductor paste such as copper or copper, and performing the first baking at 900 ° C. and then performing the second baking at 1000 ° C., the in-plane shrinkage rate accompanying the baking of the green sheet is suppressed. It states that it can.

[0006]

However, in the multilayer wiring board using an inorganic composition such as cordierite as the second green sheet of the above-mentioned Japanese Patent Application Laid-Open No. 6-97656, the first green sheet has the first firing temperature at the first firing temperature. The glass component present in the green sheet does not sufficiently diffuse and move to the second green sheet side, and the first green sheet and the second green sheet are partially adhered to each other, resulting in sintering. There is a possibility that an unbonded portion may be formed on the lamination surface of the first insulating layer and the second insulating layer to lower the moisture resistance, and that cracks or peeling may occur due to an impact or temperature cycle during use.

Accordingly, an object of the present invention is to reduce the in-plane shrinkage of the insulating layer to achieve fine wiring, and to form a conductor wiring layer containing a low-resistance metal. It is an object of the present invention to provide a multilayer wiring board which can be laminated without deteriorating the characteristics of the insulating layer and a method for manufacturing the same.

[0008]

Means for Solving the Problems As a result of studying the above problems, the present inventor has found that ZnO is contained in the first glass ceramic composition and / or the second inorganic composition, and the firing temperature and the firing temperature are changed. By performing the two-stage firing with controlled time, ZnO is specifically diffused and moved by the two-stage firing, so that the first insulating layer and the second insulating layer are located between the first insulating layer and the second insulating layer. A region where the content of ZnO is larger than the content of ZnO in the glass ceramic composition and / or the second inorganic composition is present, and while maintaining the characteristics of each insulating layer, a partial area between the insulating layers is maintained. It has been found that it is possible to manufacture a multilayer wiring board in which a laminate of different materials is baked while suppressing shrinkage in the lamination plane direction without causing separation or the like.

That is, the multilayer wiring board of the present invention has a first
A first insulating layer made of a glass-ceramic composition and a second insulating layer made of a second inorganic composition different from the first insulating layer, and the surface and / or inside of the stacked body are laminated. A multilayer wiring board formed by forming a conductive wiring layer on the first glass ceramic composition and / or the second inorganic composition, wherein ZnO is contained in the first glass ceramic composition and / or the second inorganic composition.
The content of ZnO at the interface between the first insulating layer and the second insulating layer is larger than the content of ZnO in the first glass ceramic composition and / or the second inorganic composition. It is characterized by the following.

Here, the width of the region containing a large amount of ZnO is desirably 80 μm or less, and the average thermal expansion of the first insulating layer and the second insulating layer from room temperature to 400 ° C. The difference in coefficient is 1 × 10 ⁻⁶ / ° C. or less, the difference in permittivity between the first insulating layer and the second insulating layer is 2 or less, and the difference between the first insulating layer and the Second
Dielectric loss at 10 GHz with the insulating layer of
Desirably, it is 0 × 10 ⁻⁴ or less.

[0011] Further, it is desirable that a concave portion is formed over a plurality of insulating layers from the surface of the laminate of the first insulating layer and the second insulating layer, and that the conductive wiring layer is made of metal foil. .

Further, the second insulating layer is made of Zn, Ti
And B, wherein the first insulating layer comprises Si,
It is desirable to contain glass containing Al and MO (M is an alkaline earth metal).

[0013] The method for manufacturing a multilayer wiring board according to the present invention comprises the steps of: forming a first green sheet made of the first glass-ceramic composition; and firing at a higher temperature than the first glass-ceramic composition. Forming a second green sheet made of a second inorganic composition to be bonded; forming a conductive wiring layer on the surface of the first green sheet and / or the second green sheet; 1
Laminating the green sheet and the second green sheet, and sintering the laminate at a first firing temperature at which the first green sheet is sintered and the second green sheet is not sintered. A step of firing at a second firing temperature at which the second green sheet sinters for at least 2 hours after firing for at least 2 hours, and wherein the first glass ceramic composition and / or the second inorganic material are sintered. Zn in the composition
It is characterized by containing O.

Here, it is desirable that the difference between the first firing temperature and the second firing temperature is 50 to 150 ° C.

It is desirable that the first glass ceramic composition has a softening point of 500 to 900 ° C. and a shrinkage in the in-plane direction due to firing of the laminate is 5% or less.

Further, it is desirable that a recess is formed from the surface of the laminate of the first green sheet and the second green sheet to a plurality of insulating layers.

It is preferable that the method of forming the conductive wiring layer is a method of applying a conductive wiring layer made of a metal foil on the surface of the first green sheet and / or the second green sheet.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a method for manufacturing a multilayer wiring board according to the present invention will be described. (First Green Sheet) First, to prepare a first green sheet, a glass raw material and a ceramic raw material are mixed.

The above glass material has an average particle size of 0.5
Powders such as borosilicate glass, alkali silicate glass, and silica glass having a thickness of 10 to 10 μm, particularly 1 to 3 μm are preferable.
It is desirable that glass containing O ₂ , Al ₂ O ₃ , and MO (M is an alkaline earth metal) be contained as a main component. In addition, as the alkaline earth metal (M), Mg, Ca, S
At least one selected from the group consisting of r and Ba can be used. In particular, in terms of adjusting the softening point of glass, the alkaline earth metal (M) is selected from at least one selected from the group consisting of Mg, Ca and Sr. It is desirable to become.

Further, ZnO and B ₂ O ₃ are contained in the glass in terms of adjustment of the softening point of the glass, reduction of the dielectric loss of the insulating layer, and adjustment of the dielectric constant and the coefficient of thermal expansion. Each may be contained in a proportion of 0 to 20% by weight, particularly 1 to 10% by weight in terms of oxide. Also, besides that,
The total amount of impurities of CuO, TiO ₂ , Fe ₂ O ₃ , Co ₃ O ₄ , and P ₂ O ₅ in terms of oxide relative to the total amount of glass is 0.1%.
1% by weight or less, and further, PbO,
The contents of Bi ₂ O ₃ and alkali metals (Li, Na, K) are 0.1% by weight or less in total as oxides, particularly 0.0% by weight.
It is desirable that the content be 5% by weight or less.

Also, the point of controlling the diffusion of ZnO, the point of suppressing the shrinkage ratio of the insulating layer in the laminating plane direction, the point of improving the binder removal characteristics in an oxidizing atmosphere or a non-oxidizing atmosphere, and the diffusion of components. In order to control the softening point, the softening point of the glass raw material is desirably 500 to 950 ° C, preferably 700 to 950 ° C, and more preferably 800 to 920 ° C.

Further, the above-mentioned viewpoint and thermal expansion coefficient,
From the viewpoints of dielectric constant, dielectric loss, bending strength, etc., as a glass raw material, 40 to 46% by weight of SiO ₂ and 26% of Al ₂ O ₃
~ 32 wt%, ZnO 5-10 wt%, MgO 7 ~
14 wt%, the B ₂ O ₃ or glass containing a ratio of 4 to 15 wt%, a SiO ₂ 46-54 wt%, the Al ₂ O ₃ 2 to 9 wt%, the CaO 21 to 30 wt% , MgO 1
A crystallized glass containing 4 to 25% by weight and capable of precipitating a crystal phase as described later is optimal.

(Gillera filler) On the other hand, as ceramic raw materials, for example, oxides having an average particle size of 0.5 to 15 μm, further 1 to 10 μm, further 1.5 to 8 μm,
Consisting of nitride or carbide powder, especially Al ₂ O ₃ , S
_{iO 2, MgTiO 3, CaTiO 3} , SrTiO 3, cordierite, enstatite, forsterite, steatite, willemite, ZnTiO _3, Zn ₂ Ti
O ₄ , diopside, ZrO ₂ , MgO, AlN, Si
It is desirable that at least one selected from the group consisting of C and Si ₃ N ₄ be the main component.

The mixing ratio of the above-mentioned glass raw material and the ceramic raw material as the filler component is such that the glass raw material 40
It is desirable that the ratio be from 80 to 80% by weight, especially 50 to 70% by weight, and from 20 to 60% by weight, especially 30 to 50% by weight of the ceramic raw material.

(Second Green Sheet) On the other hand, to produce the second green sheet, for example, an average particle size of 0.5
１５15 μm, further 1-10 μm, further 3-8 μm
And 1050 ° C or less, particularly 1000 ° C or less,
A ceramic raw material or a glass raw material and a ceramic raw material that can be densified to 90% or more at a temperature lower than 000 ° C. are prepared.

As specific ceramic raw materials,
Ilmenite crystal phase represented by (Zn, Mg) TiO ₃ containing Zn, Mg and Ti, (Zn, Mg) ₂ TiO ₄
And the (Zn, Mg) ₂ S
Raw material powder capable of precipitating at least one selected from the group of the willemite type crystal phase represented by iO ₄ , for example, Zn
O, TiO ₂ , MgO oxide powder, or ZnTi
O ₃ , Zn ₂ TiO ₄ , MgTiO ₃ , Mg ₂ TiO ₄ , Mg
SiO ₃ , Mg ₂ SiO ₄ , ZnSiO ₃ , Zn ₂ SiO ₄ ,
Composite oxides such as CaTiO ₃ , and ceramic powders such as carbonates, acetates, and nitrates that can form oxides during the firing process can be used.

Also, in particular, 1050 ° C. or less,
In order to densify the sintered body to a relative density of 95% or more at a temperature of 0 ° C. or lower, and even lower than 1000 ° C., to improve the adhesion between the first insulating layer and the second insulating layer, to prevent the voids are generated in addition to the ceramic powder, B ₂ O ₃ powder 0.05 to 20% by weight, it is desirable to add a proportion of particularly 3 to 10 wt%.

(ZnO component) Here, according to the present invention,
It is important that ZnO is contained in the first glass ceramic composition and / or the second inorganic composition, so that the ZnO component present in each layer specifically differs from the first insulating layer. As a result of diffusion and movement to the interface with the second insulating layer, which can firmly join the two, the binding force between the first insulating layer and the second insulating layer is high, and peeling or the like occurs at the interface. A superior laminate and multilayer wiring board can be manufactured. The ZnO component desirably exists as a matrix in the ceramics forming the insulating layer in view of the above-mentioned ease of diffusion and movement.

When the ZnO component is present in the first glass ceramic composition, when the first green sheet is sintered at the first firing temperature, the ZnO component is contained in the glass ceramic composition. When the glass component increases at the lamination interface with the second green sheet, the glass component has an effect of increasing the adhesion force and the binding force of the first and second green sheets. On the other hand, when the ZnO component is present in the second glass ceramic composition, the first insulating layer is fired at the first firing temperature, and then the second green sheet is fired at the second firing temperature. At the time of binding, the ZnO component in the second inorganic composition selectively diffuses and moves to a region where the glass is large so as to bond with the glass generated at the first firing temperature. Between the second insulating layer and Zn
While there are regions where the O component is high, the first and second regions
Can be prevented from being separated between the insulating layers.

In addition to the above ceramic raw materials, cordierite, forsterite, enstatite, quartz,
Diopside, Slyisonite, Anorthite, Sr
Ceramic raw materials such as TiO ₃ and titania, and softening point of 9
50 to 1050 ° C. glass, especially 60 to 90% by weight
And a mixture obtained by mixing the above ceramic raw materials at a ratio of 10 to 40% by weight.

(Preparation of Green Sheet) An organic binder, a dispersant and a solvent are added to each of the raw material powders, if desired, and mixed to form slurries. A first green sheet and a second green sheet are formed by a molding method, a rolling method, and the like. The thickness of the green sheet is desirably 150 to 250 μm.

After forming through holes as desired in these green sheets, the through holes are filled with a conductive paste containing a low-resistance metal as a main component. The surface of the green sheet may be printed with the metal paste by a screen printing method or a gravure printing method to form a conductive wiring layer containing a low-resistance metal. From the viewpoint of forming an accurate conductor wiring layer, it is desirable to form the conductor wiring layer using a metal foil made of a low-resistance metal having a purity of 99% or more.

Here, as the low resistance metal, Cu, A
At least one selected from the group consisting of g, Pb, Sn, Al, Ni and Co is cited, but it is desirable to use Cu or Ag as a main component particularly in terms of low resistance, It is desirable to contain Cu having a small migration (diffusion) as a main component.

In order to form a conductor wiring layer on the surface of the green sheet using the metal foil, first, a metal foil is attached to a resin sheet, and is processed into a conductor wiring pattern by etching using a resist or the like. After that, a method of forming a conductor wiring layer having a predetermined pattern by transferring the conductor wiring pattern to a predetermined position on the surface of the green sheet can be suitably used. According to this method, the cross-sectional shape of the conductive wiring layer becomes an inverted trapezoidal shape by the etching treatment, so that the first green sheet and the second green sheet can be connected in a wedge shape, and the first insulating sheet is formed after firing. Separation of the layer and the second insulating layer can be prevented.

Thereafter, the plurality of green sheets on which the wiring layers have been formed are aligned and laminated, and are stacked at 40 to 50 ° C., 5 ° C.
Thermocompression bonding is performed at 0 to 100 MPa. At this time, in order to increase the adhesiveness between the first green sheet and the second green sheet and form an intermediate layer free from peeling or porosity, an epoxy is applied to the laminated surface of the first green sheet and the second green sheet. It is desirable to apply a contact liquid obtained by diluting an organic binder such as a resin, an acrylic resin, or polyvinyl butyral (PVB) with a solvent.

Then, the laminate is fired. Regarding the firing, for example, when the conductor wiring layer contains a metal that is oxidized by firing in an oxidizing atmosphere such as Cu, 600 to 750 in a non-oxidizing atmosphere or a weakly oxidizing atmosphere.
After performing the binder removal process at a temperature of, for example, 50 to 300
C., the first green sheet is sintered and the second green sheet is sintered.
At a first firing temperature at which the green sheet of Example 1 does not sinter, for example, 750 to 925C, particularly 850 to 900C.
The first green sheet is sintered for 5 hours or more, particularly for 0.5 to 2 hours, and further for 1 to 1.5 hours.

At this time, although the first green sheet tends to shrink by sintering, the surface of the sheet is adhered to the second green sheet, and the shrinkage in the in-plane direction of the lamination surface is caused by the adhesive force. It is suppressed and selectively contracts in the thickness direction of the first green sheet. Further, at the first firing temperature, the glass component in the first green sheet exudes to the surface on which the second green sheet is laminated, and the glass component diffuses toward the second green sheet due to capillary action. The diffusion of the glass component forms a layer lacking the glass component on the lamination surface side of the first green sheet.

Thereafter, for example, in order to increase the binding force between the first green sheet and the second green sheet and to prevent cracking and peeling due to a local temperature rise, the temperature is raised at a rate of 50 to 400 ° C./hour. , Especially 100 to 30
At 0 ° C./hour, a second firing temperature, desirably 1050 ° C. or less, particularly 9 ° C., which enables simultaneous firing with the low-resistance metal described above.
The second green sheet is sintered by holding at 00 to 1050 ° C., and further at 930 to 980 ° C. for 2 hours or less.

Although the second green sheet tends to shrink by sintering due to the holding at the second firing temperature, the surface of the second green sheet is in contact with the first insulating layer in which the first green sheet is sintered. The second green sheet is adhered, and the contraction in the laminating plane direction is suppressed due to the adhesive force, and the second green sheet is selectively contracted in the thickness direction. In addition, at the time of this baking, the component in the second green sheet diffuses into a portion where the glass component existing on the lamination surface side of the first insulating layer is absent, and the second green sheet is diffused on the lamination surface side of the first insulating layer. A sheet (insulating layer) having a large component is formed.

That is, by the above-mentioned baking, a region having a large ZnO component is formed between the first insulating layer and the second insulating layer. In this region, the porosity is 0.5% or less,
In particular, it is desirably 0.4% or less, and more desirably 0.2% or less. Due to the presence of the region containing a large amount of ZnO component, shrinkage in the lamination plane of the first insulating layer and the second insulating layer is suppressed, and the two layers can be firmly joined without deteriorating the characteristics of both layers.

The width of the region containing a large amount of ZnO component is as follows:
1 to 80 μm, particularly 3 to 20 μm, in order to reduce the adhesive strength between the first insulating layer and the second insulating layer and the change in characteristics between the first insulating layer and the second insulating layer. Is desirable. Further, in the region where the ZnO component is large, Z
nO may be present as glass or crystallized.

Here, the reason why the holding time at the first firing temperature is set to 0.5 hours or more is that if the holding time is shorter than 0.5 hours,
It is difficult to densify the green sheet, and the sintering proceeds at the subsequent second firing temperature, and the green sheet shrinks together with the second green sheet in the in-plane direction of the green sheet. The amount of the glass component diffused to the green sheet side of the second green sheet is insufficient, and the first green sheet and the second green sheet
This is because connection failure occurs locally on the layered surface with the green sheet. Further, in order to adjust the amount of diffusion and movement of the glass component in the first green sheet, the holding time at the first firing temperature is desirably 0.5 hours or more.

Further, the holding time at the second firing temperature is 3
The holding time at the second baking temperature is 3 hours or less.
If the time is longer than this, the first insulating layer is over-sintered, a large amount of voids are generated in the first insulating substrate, and a part of the component may be washed away from a region containing a large amount of ZnO. In order to sufficiently densify the second green sheet and improve the substrate strength, the holding time at the second firing temperature is 0.5 to 2.5 hours, particularly 1 to 2 hours. It is desirable.

The temperature difference between the first firing temperature and the second firing temperature is set to 50 to 50% in order to reduce the shrinkage in the in-plane direction of the lamination due to firing and to make each layer denser.
The temperature is desirably 150 ° C, particularly 70 to 100 ° C, and more preferably 80 to 90 ° C.

According to the present invention, electronic parts such as semiconductor elements are housed and hermetically sealed on the surface of the laminate of the first green sheet and the second green sheet. Even in the case where a concave portion (cavity) for stopping is formed, a multilayer wiring board with high dimensional accuracy in the direction of the lamination surface can be manufactured without causing cracks or the like due to partial contraction of the laminate.

In order to form a recess on the surface of the laminate of the first green sheet and the second green sheet, at least one green sheet having a cavity of a predetermined shape is alternately laminated. Good.

(Mounting) Then, electronic components such as semiconductor elements are appropriately mounted on the surface of the wiring board or in the concave portions.
Connection is made with the wiring layer so that signals can be transmitted. As a connection method, it can be mounted directly on the wiring layer and connected,
Alternatively, a resin of about 50 μm, Ag-epoxy, Ag-
Glass, a resin such as Au-Si, a metal, an adhesive such as ceramics, the semiconductor element is fixed to the surface of the insulating substrate,
The wiring layer and the semiconductor element are connected by wire bonding, ribbon bonding, TAB tape, or the like.

Further, an insulating material of the same kind as the insulating layer, another insulating material, a metal having good heat dissipation, or the like is formed on the surface of the wiring board on which electronic components such as semiconductor elements are mounted or in the opening in the concave portion. It is desirable that the lid is bonded with an adhesive such as glass, resin, brazing material or the like to hermetically seal the inside of the recess.

Further, a connection terminal electrically connected to the wiring layer of the wiring board and mounted on an external circuit board may be provided on the back surface of the wiring board. Note that the connection terminal is made of solder or the like, and may be in a layer shape or a ball shape.

(Substrate) Next, with respect to the multilayer wiring board of the present invention obtained by the above-described method, a schematic sectional view of an element storage package for storing an element such as the semiconductor element of FIG. 1 as an example is shown. I will explain based on. According to FIG. 1, a semiconductor element housing package 1 has first insulating layers 2 made of a first glass ceramic composition and second insulating layers 3 made of a second inorganic composition alternately stacked. ,
It has a configuration in which a conductor wiring layer 5 containing a low-resistance metal is formed on the surface and inside of an insulating substrate 4 which is a laminate of the first insulating layer 2 and the second insulating layer 3.

According to FIG. 1, the insulating substrate 4 is formed by alternately laminating two or more first insulating layers 2 and two or more second insulating layers 3 according to the present invention. For example, the present invention is not limited to this, and may have a configuration in which, for example, the second insulating layer 3 is laminated on both surfaces of the first insulating layer 2. The conductor wiring layers 5 and 5 formed on both surfaces of the insulating layers 2 and 3 are electrically connected by via-hole conductors 6 formed through the insulating layers 2 and 3.

According to the present invention, ZnO in the first glass ceramic composition and / or the second inorganic composition is provided between the first insulating layer 2 and the second insulating layer 3. It is a major feature that there is a region where the content of ZnO is larger than the content, and as described above, it is possible to suppress the shrinkage in the in-plane direction of the lamination due to the baking, and to reduce the crack or the like during the baking or during use. Delamination can be prevented.

Here, the porosity in the region where the content of ZnO is large is 0.5% or less, particularly 0.4% or less, more preferably 0.2% or less.
% Or less, and the width of the region containing a large amount of ZnO is preferably 80 μm or less, particularly 1 to 80 μm, and more preferably 3 to 20 μm.

The difference between the average thermal expansion coefficient of the first insulating layer 2 and that of the second insulating layer 3 at room temperature (25 ° C.) to 400 ° C. in terms of suppressing cracks and delamination during firing or use. Is 1 × 10 ⁻⁶ / ° C. or less, particularly 0.5 × 10 ⁻⁶ / ° C.
It is desirable that the temperature is not more than ° C.

The difference in the dielectric constant between the first insulating layer 2 and the second insulating layer 3 is 2 or less, particularly 1 or less, in order to prevent a change in impedance and to make the signal transmission characteristics uniform. Is desirably 0.5 or less.

Further, the insulating substrate 4 has a dielectric constant of the first
A third insulating layer 10 different from that of the second insulating layers 2 and 3 by 5 or more, especially by 10 or more may be formed.

Further, a package 1 for housing a semiconductor element.
In particular, when transmitting a high-frequency signal of 1 MHz or more, especially 1 GHz or more, in order to improve the transmission characteristics of the high-frequency signal, the dielectric loss of the first insulating layer 2 and the second insulating layer 3 is, for example, 20 at 10 GHz. × 10 ^-4 or less, especially 15
× 10 ^-4 or less, it is desirable smaller and 10 × 10 ^-4 or less.

On the other hand, according to FIG. 1, a concave portion (cavity) 8 is formed on the surface of the insulating substrate 4, and a semiconductor element such as a semiconductor element such as Si, Si-Ge, Ga-As or the like is formed in the concave portion 8. The element 9 is mounted. A lid 11 made of the above-described material is formed at the opening of the recess 8, and is joined to the opening of the recess 8 by the above-mentioned adhesive, so that the recess 8 is hermetically sealed. The semiconductor element 9 is electrically connected to the conductor wiring layer 5 via the above-described wire bonding 12 and the like.

When a high-frequency signal is applied to the semiconductor element 9 and the conductor wiring layer 5, the lid 11 is preferably made of a material capable of preventing leakage of electromagnetic waves between the semiconductor element 9 and the outside. The shape of the conductor wiring layer 5 is a strip line, in order to reduce transmission loss of a high-frequency signal.
It is desirable to be composed of at least one of a microstrip line, a coplanar line, and a dielectric waveguide line. In order to reduce the transmission loss of high-frequency signals, the conductor wiring layer 5 contains one of low-resistance metals such as copper and silver, and it is particularly desirable that these metals be the main components.

Further, connection terminals 14 for mounting the package 1 on the external circuit board 13 are formed on the back surface of the insulating substrate 4. According to the present invention, the insulating substrate 4 may be warped or the like. Package 1 through connection terminal 14
Can be mounted on the external circuit board 13.

Further, in the package 1 of FIG. 1, the semiconductor element 9 is hermetically sealed with the insulating substrate 4 and the lid 11, but the present invention is not limited to this. May not be formed, and the semiconductor element 9 may be sealed with a resin mold or the like.

[0062]

EXAMPLES (Example 1) Average particle size 2 having the composition shown in Table 1
A μm crystallized glass and a ceramic powder having an average particle size of 2 μm having the composition shown in Table 2 were prepared.

[0063]

[Table 1]

[0064]

[Table 2]

The above-mentioned glass powder and ceramic powder were mixed at the ratio shown in Table 3, and an organic binder, a plasticizer, and toluene were added and mixed to prepare two types of slurries. Then, green sheets each having a thickness of 200 μm were prepared. Then, a via hole was formed at a predetermined position of the green sheet, and the via hole was filled with a conductive paste containing Cu powder as a main component.

On the other hand, a copper foil having a thickness of 12 μm is adhered to the surface of the resin sheet using an adhesive, and a conductive wiring pattern is formed by etching using a resist. It is placed in alignment with the via hole conductor and placed at 40 ° C. for 5 minutes.
After pressurizing to 0 MPa, the conductor wiring layer was transferred to the surface of the green sheet by peeling off the resin sheet.

Then, each of the green sheets is
The sheets are laminated alternately one by one, and subjected to thermocompression bonding at a temperature of 50 ° C. while applying a pressure of 50 MPa. The obtained laminate is subjected to a binder removal treatment at 700 ° C. in a steam-containing / nitrogen atmosphere and then in dry nitrogen. It was fired under the conditions shown in Table 3 to obtain a multilayer wiring board.

With respect to the obtained multilayer wiring board, the dimension in the in-plane direction of the insulating substrate was measured, and the shrinkage due to firing was calculated. In addition, a scanning electron microscope (SEM) and an electron probe microanalysis (EPMA) observation are performed on the laminated surface portion of the insulating layer of the insulating substrate to inspect the appearance of the interface, to confirm the presence or absence of a region containing a large amount of ZnO component, and The width of the ZnO-rich region was measured. Note that FIG. The results of EPMA line analysis for No. 3 are shown.

From the result of the EPMA line analysis, Z
The width of the region with a large amount of nO component and the porosity in that region were measured by Luzex analysis. In addition, the ends of two wiring layers having a length of 20 mm and connected with a via-hole conductor interposed therebetween were connected to a tester, and the resistivity of the wiring circuit was measured. The results are shown in Table 3.

(Comparative Example 1) An example in which the components of the first green sheet and the second green sheet were mixed at a 1: 1 ratio between the first and second green sheets shown in Table 3. 100 μm in thickness produced in the same manner as the green sheet
A multilayer wiring board was prepared and evaluated in the same manner as in Example 1 except that the green sheets for forming an intermediate layer of m were laminated, and evaluated (Sample No. 18). The results are shown in Table 3.

Comparative Example 2 A glass paste containing SiO ₂ —ZnO—B ₂ O ₃ -based glass powder was applied to a thickness of 20 μm between the first and second green sheets shown in Table 3,
A multilayer wiring board was prepared and evaluated in the same manner as in Example 1 except that the first green sheet and the second green sheet were laminated (Sample No. 19). The results are shown in Table 3.

[0072]

[Table 3]

Further, the obtained insulating substrate of the multilayer wiring board is ground and the first insulating layer and the second insulating layer are taken out, and the dielectric constant and dielectric loss at 10 GHz are obtained by the dielectric columnar resonator method. A thermal expansion curve at 25 to 400 ° C. was taken to calculate an average thermal expansion coefficient. The results are shown in Table 4.

[0074]

[Table 4]

As apparent from the results in Tables 3 and 4, the first
The holding time at the sintering temperature and the holding time at the second sintering temperature are shorter than 0.5 hours. In 1,
The presence of a region with a large amount of ZnO component was not observed, and the firing shrinkage ratio was increased. Sample No. 1 in which the same glass was blended in the first insulating layer and the second insulating layer. In No. 15, there was no generation of a region with a large shrinkage ratio of the lamination surface and a large amount of ZnO component. Further, the sample N containing no ZnO in both the first glass ceramic composition and the second inorganic composition
o. In No. 17, partial peeling occurred between the first insulating layer and the second insulating layer, the porosity at the interface was high, and the resistivity was 2.5 mΩ · cm. The sample No. In No. 17, the relative density of the second insulating layer could not be increased to 90% or more, and the dielectric constant and the dielectric loss at a high frequency could not be measured.

Further, Sample No. 1 having another green sheet having an intermediate composition between the first green sheet and the second green sheet was interposed. In No. 18, the generation of a region with a large ZnO component was not observed, and the shrinkage ratio of the laminated surface was large. Sample No. 1 in which the first insulating layer and the second insulating layer were bonded with glass was used. In No. 19, peeling occurred at the interface with the shrinkage of the glass as the bonding layer due to firing shrinkage, and the glass moved to each green sheet side, so that a region with a large amount of ZnO component could not be confirmed.

On the other hand, according to the present invention, the laminated body of the first green sheet and the second green sheet is formed by sintering the first green sheet and sintering the second green sheet. After maintaining at a sintering temperature for a predetermined time, the temperature is raised at a predetermined rate and the second green sheet is sintered.
Sample No. held at the firing temperature for a predetermined time. 2-14, 1
In No. 6, the presence of a region containing a large amount of ZnO component was confirmed, and the contraction rate of the laminated surface was 1% or less and the resistivity was 1.5 mΩ · c.
m and excellent characteristics.

(Example 2) Sample N of Tables 1 to 4 of Example 1
o. 5 × 3 m inside each of the first green sheet and the second green sheet
By forming a cavity of m, laminating the same as in Example 1, and firing in the same manner as in Example 1, a multilayer wiring board having a concave portion formed on the surface as shown in FIG. 3 was produced.

With respect to the obtained multilayer wiring board, the thicknesses t ₁ and t ₂ of the insulating substrate at the center and near the periphery of the bottom of the concave portion of the insulating substrate were measured. As a result, the thickness difference between t ₁ and t ₂ was 2 μm or less. It was found that the warpage of the insulating substrate was small. Also, the multilayer wiring board was successfully mounted on an external circuit board.

Comparative Example 3 Sample N in Tables 1 to 4 of Example 1
o. A green sheet laminate in which a recess was formed on the multilayer wiring board of Example 3 using only the first green sheet in the same manner as in Example 2 and held at a firing temperature of 850 ° C. for 1 hour except that firing only temperature was produced in the same manner as in example 2, example 2 in the same manner as in the thickness t ₁ of the insulating substrate in the vicinity of the central portion and the peripheral edge of the bottom surface of the recess of the insulating substrate, t ₂ result of measuring the, t ₁ And the thickness difference between t ₂ and t ₂ was 10 μm, indicating that the warpage was larger than that of the insulating substrate of Example 2. In addition, as a result of mounting the multilayer wiring board on an external circuit board, the connection terminals were peeled off due to large warpage.

[0081]

As described in detail above, the multilayer wiring board of the present invention is capable of miniaturizing the wiring by suppressing the shrinkage of the insulating layer in the in-plane direction, and the conductive wiring layer containing a low-resistance metal. Can be manufactured without deteriorating the characteristics of two or more different types of insulating layers.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a package for housing a semiconductor element, which is an example of a multilayer wiring board of the present invention.

FIG. 2 shows a sample No. of Example 1. FIG. 3 is a diagram showing a line analysis result on the ZnO content (Zn concentration) of EPMA No. 3;

FIG. 3 is a schematic cross-sectional view illustrating a configuration of a multilayer wiring board according to Example 2 and Comparative Example 3.

DESCRIPTION OF SYMBOLS 1 Package for storing semiconductor element 2 First insulating layer 3 Second insulating layer 4 Insulating substrate 5 Conductor wiring layer 6 Via hole conductor 8 Depression (cavity) 9 Semiconductor element 10 Third insulating layer 11 Lid 12 wire bonding 13 external circuit board 14 connection terminal

Claims (15)

[Claims] 1. A first insulating layer made of a first glass-ceramic composition and a second insulating layer made of a second inorganic composition different from the first insulating layer are laminated. A multilayer wiring board having a conductor wiring layer formed on the surface and / or inside of a body, wherein the first glass ceramic composition and / or the second inorganic composition contain ZnO, The content of ZnO at the interface between the first insulating layer and the second insulating layer is larger than the content of ZnO in the first glass ceramic composition and / or the second inorganic composition. A multilayer wiring board characterized by the above-mentioned. 2. The region having a high ZnO content has a width of 80%.
2. The multilayer wiring board according to claim 1, wherein the thickness is not more than μm. 3. The method according to claim 1, wherein the difference between the average thermal expansion coefficient of the first insulating layer and that of the second insulating layer from room temperature to 400 ° C. is 1 × 1.
3. The method according to claim 1, wherein the temperature is 0 ^-6 / ° C. or less.
The multilayer wiring board as described in the above. 4. The multilayer wiring board according to claim 1, wherein a difference in dielectric constant between said first insulating layer and said second insulating layer is 2 or less. 5. The method according to claim 1, wherein the dielectric loss at 10 GHz of the first insulating layer and the second insulating layer is 20 × 10 ⁻⁴ or less. Multilayer wiring board. 6. The method according to claim 1, wherein a concave portion is formed from a surface of the laminate of the first insulating layer and the second insulating layer to a plurality of insulating layers. Multilayer wiring board. 7. The multilayer wiring board according to claim 1, wherein said conductor wiring layer is made of a metal foil. 8. The method according to claim 8, wherein said second insulating layer comprises Zn, Ti and B.
The multilayer wiring board according to any one of claims 1 to 7, further comprising: 9. The method according to claim 1, wherein the first insulating layer is made of Si, Al, MO,
9. The multilayer wiring board according to claim 1, further comprising a glass containing (M is an alkaline earth metal). 10. A step of producing a first green sheet made of a first glass ceramic composition, and a step of producing a first green sheet made of a second inorganic composition sintered at a higher temperature than the first glass ceramic composition. Forming a green wiring sheet, forming a conductive wiring layer on the surface of the first green sheet and / or the second green sheet, and forming the first green sheet and the second green sheet. And firing the laminate at a first firing temperature at which a first green sheet is sintered and the second green sheet is not sintered, for at least 0.5 hour, and then a second green sheet is fired. Baking at a second baking temperature for 2 hours or less at the time of sintering, and wherein ZnO is contained in the first glass ceramic composition and / or the second inorganic composition. Method for manufacturing a multilayer wiring board, characterized in that. 11. The method according to claim 10, wherein a difference between the first firing temperature and the second firing temperature is 50 to 150 ° C. 12. The method according to claim 10, wherein the softening point of the first glass ceramic composition is 500 to 950 ° C. 13. A laminate according to claim 10, wherein a shrinkage rate in an in-plane direction by firing the laminate is 5% or less.
3. The method for manufacturing a multilayer wiring board according to any one of 2. 14. The multilayer according to claim 10, wherein a recess is formed from a surface of the laminate of the first green sheet and the second green sheet to a plurality of insulating layers. Manufacturing method of wiring board. 15. The method of forming a conductive wiring layer according to claim 1, wherein
The method for producing a multilayer wiring board according to any one of claims 10 to 14, wherein a conductive wiring layer made of a metal foil is applied to the surface of the green sheet and / or the second green sheet. .