JP2723710B2 - Multilayer glass ceramic substrate and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a function to <br/> the multilayer glass ceramic substrate and a manufacturing method thereof for mounting an LSI device, a multilayer glass ceramic substrate and in particular low-temperature sintering
The present invention relates to the manufacturing method .

[0002]

2. Description of the Related Art With the development of semiconductor technology, there is an increasing demand for smaller and faster electronic devices and systems. Semiconductor devices are becoming higher in density and higher in integration with VLSIs and ULSIs, and mounting technologies for assembling them are required to be extremely dense and fine. In particular, a mounting substrate for mounting a semiconductor element is required to have fine wiring due to an increase in wiring density, a reduction in wiring resistance, a low dielectric constant of a substrate material corresponding to high speed, and a high density wiring. . Alumina multilayer substrates are conventionally used as substrate materials. As a method of manufacturing this substrate,
There are thick film printing multilayer method and green sheet lamination method,
The green sheet lamination method is advantageous for the demand for high density. The green sheet lamination method is obtained by printing and forming wiring on each thin ceramic green sheet layer and laminating them together, so that the number of wiring layers can be increased arbitrarily.
As a result, the wiring density can be higher than that of the thick-film printing multilayer. However, alumina ceramic has a sintering temperature of 1
Mo, W metal having a relatively high electric resistance must be used for the wiring conductor, which is as high as 500 ° C. or more, and it has been difficult to miniaturize the wiring.

On the other hand, recently, low-resistance conductors such as Au and Ag-P
A low-temperature sintering type ceramic material using d, Ag, Cu or the like has been developed. For example, in the case of a composite material of alumina and lead borosilicate glass, sintering can be performed at a low temperature of 1000 ° C. or less, and a multilayer substrate using Au, Ag—Pd, and Ag as a wiring conductor has been developed. However, since this material contains lead, it is difficult to use Cu as a base metal for wiring, and the dielectric constant can be reduced to only 7.5 or more. In addition, low dielectric constant and 10
A glass ceramic material using borosilicate glass aimed at firing in a reducing atmosphere at a temperature of 00 ° C. or lower has also been developed.
This has a dielectric constant as low as about 5.5, and multilayering by Cu wiring has been realized by a simultaneous sintering method of glass ceramic and a conductor. There was a drawback that the target strength was significantly reduced.

[0004]

The conventional alumina multilayer substrate can be sintered only at a high temperature, and therefore has a high electric resistance.
Since only o and W can be used for the conductor, the wiring resistance is increased and fine wiring is impossible. Also, the dielectric constant of alumina is as high as about 10, which is disadvantageous for increasing the signal speed.
A composite material of alumina and lead borosilicate glass can be sintered at a low temperature and a low-resistance conductor can be used for wiring, but it has been difficult to realize firing in a reducing atmosphere or base metal conductor wiring. Further, in a glass ceramic substrate using borosilicate glass, C
Although u multilayer wiring and low dielectric constant are possible, the mechanical strength is significantly reduced. The mechanical strength of a board is a very important characteristic, especially in a multi-chip mounting board in which a large number of semiconductor elements are mounted on the board, the board size becomes large and many input / output terminals or pins are connected. Therefore, not only the assembly process, but also problems such as substrate damage and poor bonding with metal occur in a product state. An object of the present invention is to solve the problems of the conventional mounting board by firing at a low temperature of 1000 ° C. or lower, and in a neutral and reducing atmosphere as well as an oxidizing environment, and having a low dielectric constant, An object of the present invention is to provide a multilayer glass ceramic substrate having excellent strength.

According to the present invention, the glass ceramic layer is made of alumina.
An anorthite crystal formed at the interface between the crystal and the vitreous , and according to oxide notation, 30 to 60% by weight of aluminum oxide, 20 to 50% by weight of silicon dioxide, and calcium oxide 4 0.5 to 15% by weight, boron oxide 3
-15% by weight, Group I element oxide 0-5% by weight, Group II element (excluding calcium) oxide 0-5% by weight, IV
Group element (excluding carbon, silicon and lead) oxides
A composition selected from the group consisting of a group I element oxide, a group II element oxide, and at least one of a group IV element oxide in a composition range of 5% by weight, and a total amount of 100%; A multilayer glass-ceramic substrate comprising a plurality of conductor layers laminated via the glass-ceramic layer.

The glass-ceramic substrate of the present invention has a thickness of 100
Since sintering can be performed at a temperature of 0 ° C. or less, multilayering can be easily performed by a desired green sheet laminating method, and not only elements such as Au, Ag, Pd, and Pt as conductors but also in a neutral or reducing atmosphere. One kind and an alloy containing two or more of these elements, including elements of base metals such as Cu and Ni to be fired, can be used with confidence, and a multilayer glass ceramic substrate having a high mounting density and excellent mechanical strength can be practically used. It becomes possible to be offered to. Here, the mechanical strength of the substrate according to the present invention is 2000 kg / cm ² or more in terms of bending strength, and has a sufficient strength. According to the invention
The manufacturing method of the glass ceramic substrate is glass ceramic
The layer contains anorthite crystals and conforms to oxide notation.
30-60% by weight of aluminum oxide,
20 to 50% by weight of silicon, 4.5 to 15 of calcium oxide
Wt%, boron oxide 3 to 15 wt%, Group I element oxide 0
~ 5% by weight, Group II element (excluding calcium)
Oxide 0 to 5% by weight, group IV element (however, carbon, silicon
Excluding element and lead. ) Total amount in the composition range of 0 to 5% by weight of oxide
Multilayer gas composed of a composition selected to be 100%
A method for manufacturing a glass ceramic substrate, comprising:
Heat and melt the raw material powder except for
Melted and vitrified, quenched and pulverized glass
Gas obtained by mixing fine powder and aluminum oxide
A glass ceramic layer is formed using raw ceramic powder.
It is characterized by forming.

Next, the reasons for limiting the components of the present invention will be described. When aluminum is less than 30% by weight in terms of oxide,
When the flexural strength is less than 2000 kg / cm ² , which is insufficient, and when it exceeds 60% by weight, sintering becomes insufficient at a temperature of 1000 ° C. or less. As a result, the insulation resistance is lowered and the flexural strength is also 2000 kg / cm 2. It becomes less than ² . In addition, the dielectric constant is higher than 7, which is disadvantageous for high speed operation.
Therefore, a practical multilayer glass ceramic substrate cannot be obtained. If silicon is less than 20% by weight in terms of dioxide, the glass ceramic is difficult to sinter, and if it exceeds 50% by weight, the transverse rupture strength is less than 2000 kg / cm ² , which is not preferable. When calcium is less than 4.5% by weight in terms of oxide, formation of anorthite crystals does not occur, and the transverse rupture strength is remarkably reduced, to less than 2000 kg / cm ² . If it exceeds 15% by weight, the dielectric constant becomes higher than 7, and sintering becomes difficult. If boron is less than the weight percentage in terms of oxide, voids and voids in the glass ceramic increase, and if it exceeds 15 weight%, the insulation resistance is deteriorated, which is not preferable. When the group I element exceeds 5% by weight in terms of oxide, water resistance is deteriorated and insulation resistance is lowered, which is not preferable. If the group II element exceeds 5% by weight in terms of oxide, cracks occur during sintering, and the reliability of the substrate is undesirably reduced. When the group IV element exceeds 5% by weight in terms of oxide, the dielectric constant exceeds 7 and becomes high, and the adhesion between the conductive metal and the glass ceramic deteriorates, so that a practical multilayer glass ceramic substrate cannot be obtained. Group I element oxide, Group II element oxide, Group IV element oxidation
Other than alumina if at least none of the
When vitrifying the components, non-uniformity such as glass phase separation occurs.
Easy to grow and obtain a uniform composition as glass
Must contain at least one oxide
Is necessary.

[0008]

The composition of the multilayer glass ceramic substrate of the present invention is as follows:
Sintering can be performed at a temperature of 1000 ° C. or less, for the following reasons. In the present composition, upon firing, the vitreous portion starts softening at a temperature of about 700 ° C. or higher. At this point, the vitreous portion acts as a liquid phase to fill the gaps between the ceramic powders, and the densification proceeds. As densification proceeds, the vitreous and ceramic interfaces become active and microcrystals form. Thus, a sufficiently dense glass ceramic body is formed in a temperature range of 800 to 1000 ° C.,
Complete sintering. All of the above sintering reactions occur at a temperature of 1000 ° C. or lower because of the present composition constituting the substrate. Next, the reason why the composition can be sintered in a reducing atmosphere is that the present composition uses an element which is reduced from an oxide state under these conditions and is suppressed from changing to a metal element. For example, in the case of a composition containing lead oxide, the composition changes to metallic lead under a reducing atmosphere, and the insulating property of the glass ceramic body is significantly deteriorated. Mechanical strength is one of the important characteristics in a multilayer glass ceramic substrate, and the present invention is particularly effective for this characteristic. 2000kg / c strength
reason why can be realized in m ² or more, due to the generation of fine crystals during sintering. The present invention has the greatest feature in that the anorthite is designed to be generated as the crystallite. In other words, a structure in which vitreous material only exists between ceramic particles can provide an insufficient strength of less than 2000 kg / cm ^{2 as in} a conventional glass-ceramic body. Microcrystals of anorthite are generated at the interface of, and the action of firmly bonding the ceramic and the glass works. As a result, sufficient characteristics of the transverse rupture strength can be obtained as a substrate.

[0009]

Embodiments of the present invention will be described below in detail. Example 1 A composition for forming a glass ceramic layer is converted into an oxide and is prepared as a powder having a composition as shown in Tables 1 to 3. The method for producing the powder is described below. Al ₂ O
Other compositions except for ₃ are prepared as glass. That is, the raw materials of each component are weighed so as to have a target composition of glass, and then heated and melted at a high temperature of 1400 ° C. or more for 2 to 4 hours to vitrify. The molten glass is cooled with water or poured on a thick iron plate to form flakes, and the obtained glass pieces are finely pulverized by an alumina ball mill or the like to obtain glass powder having an average particle size of 0.5 to 3 μm. Next, the Al ₂ O ₃ powder controlled to have an average particle size of 0.5 to 3 μm and the crushed glass powder are weighed so as to have a target composition, and uniformly mixed by an alumina ball mill or the like. Prepare as a powder of the indicated composition.

The mixed inorganic powder obtained as described above is formed into a sheet by, for example, a green sheet laminating method. That is, the powder is dispersed in a solvent together with an organic binder such as polyvinyl butyral, polyvinyl alcohol or polyacrylic resin to form a slurry. The slurry is formed into a green sheet having a thickness suitable for forming an insulating layer by a slip casting method such as a doctor blade method or a roll method. Green sheet thickness is 10μm ~
It is possible to control uniformly and freely in the range of 400 μm. Next, a via hole for connecting the upper and lower conductors is formed in a green sheet by a punching device. Embedding of a conductor paste for making an electrical connection to the via hole and printing of a wiring pattern are performed. The conductors used here are Au, Ag, Ag-Pd, Cu, N
a conductor paste mainly composed of i, Ag-At, etc.
It is printed at a predetermined position by a screen printing method. A green sheet on which a conductor pattern is printed and filled with vias is laminated so as to have a predetermined number of layers, and thermocompression-bonded. The organic binder and the solvent added at the time of molding are 400 to 700.
After removal by a binder removal process at a temperature of
It was fired in a temperature range of 1000 ° C. to obtain a multilayer glass ceramic substrate. Firing conditions when a multilayer glass ceramic substrate was produced using the inorganic powders having the compositions shown in Tables 1 to 3,
Tables 4 to 9 show the wiring specifications and characteristics. Note that the sample numbers of the inorganic powders correspond to the sample numbers of the substrates shown in Tables 1 to 3, respectively.

[0011]

[Table 1]

[0012]

[Table 2]

[0013]

[Table 3]

[0014]

[Table 4]

[0015]

[Table 5]

[0016]

[Table 6]

[0017]

[Table 7]

[0018]

[Table 8]

[0019]

[Table 9]

As is clear from Tables 4 to 9, the use of the composition of the present invention not only facilitates formation of high-density and fine wiring, but also provides excellent characteristics and practical use. It is possible to obtain a multilayer glass-ceramic substrate that sufficiently satisfies the mechanical strength required for being provided. In addition,
Although the composition of the glass-ceramic layer is expressed in terms of oxide, this does not restrict the use of oxide as a starting material.

[0021]

As described above, the multilayer glass ceramic substrate of the present invention can be fired at a low temperature of 1000 ° C. or lower regardless of the oxidizing or reducing atmosphere, has a sufficiently low dielectric constant, and has a low mechanical strength. It is excellent. Therefore, Au, Ag, Cu, Ag-Pd having low resistance as a wiring conductor
And the like can be used, and a mounting substrate with high-density fine wiring and high speed can be provided.

Claims (2)

(57) [Claims] 1. A glass ceramic layer comprising alumina crystals and glass.
Containing anorthite crystals formed at the interface with the substrate and according to the oxide conversion notation, aluminum oxide 30
-60% by weight, silicon dioxide 20-50% by weight, calcium oxide 4.5-15% by weight, boron oxide 3-15% by weight, Group I element oxide 0-5% by weight, Group II element (however, calcium is 0-5% by weight of oxides, Group IV element oxides (excluding carbon, silicon and lead), and 0 to 5% by weight of oxides. Contains at least one of Group IV element oxides, total amount is 1
A multilayer glass-ceramic substrate comprising a composition selected so as to have a composition of 00% and a plurality of conductor layers laminated via the glass-ceramic layer. 2. The glass-ceramic layer contains anorthite crystals, and according to oxide notation, 30 to 60% by weight of aluminum oxide, 20 to 50% by weight of silicon dioxide, 4.5 to 15% by weight of calcium oxide. , Boron oxide 3
-15% by weight, Group I element oxide 0-5% by weight, Group II element (excluding calcium) oxide 0-5% by weight, IV
Group element (excluding carbon, silicon and lead) oxides
A method for producing a multilayer glass-ceramic substrate comprising a composition selected to have a total amount of 100% in a composition range of 5% by weight, wherein the raw material powder excluding aluminum oxide is 140%.
Forming a glass-ceramic layer using glass-ceramic raw material powder obtained by heating and melting at a temperature of 0 ° C. or more to vitrify, rapidly cooling and pulverizing the vitrified glass, and mixing with aluminum oxide. A method for producing a multi-layer glass ceramic substrate, characterized in that: