JPH0816021B2 - Multi-layer glass ceramic substrate and manufacturing method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layer glass ceramic substrate for mounting LSI elements at high density, and more particularly to a multi-layer glass ceramic substrate which can be sintered at a low temperature and a manufacturing method thereof.

[0002]

2. Description of the Related Art With the development of semiconductor technology, there is an increasing demand for miniaturization and higher speed of electronic devices and systems. A semiconductor element is highly integrated with VLSI and ULSI with high density, and a mounting technique for assembling these elements requires extremely high density and miniaturization. In particular, a mounting board for mounting a semiconductor element is required to have a fine wiring due to an increase in wiring density, a wiring material having a low dielectric constant and a high density wiring corresponding to a reduction in wiring resistance and a high speed. . Alumina multilayer substrates have been conventionally used as mounting substrates. As a method of manufacturing this substrate, there are a thick film printing multilayer method and a green sheet laminating method, but the green sheet laminating method is advantageous for the demand of high density. The green sheet stacking method is capable of arbitrarily increasing the number of wiring layers because it is obtained by printing wiring on each layer of thin ceramic green sheets and stacking them together, resulting in higher wiring density than the thick film printing multilayer method. Can be higher. However, the sintering temperature of alumina ceramic is 150
High as 0 ° C or higher, and the wiring conductor has a relatively high electrical resistance M
o, W metal had to be used, and miniaturization of wiring was difficult.

On the other hand, recently, low resistance conductors such as Au and Ag-P have been used.
Low-temperature sintering type ceramic materials have been developed to use d, Ag, Cu and the like. First, in the case of a composite material of alumina and lead borosilicate glass, it is possible to sinter at a low temperature of 1000 ° C. or less, and a multilayer substrate using Au, Ag—Pd, or Ag as a wiring conductor has been developed. Since this material contains lead, it is difficult to use Cu, which is a base metal, for the wiring, and the dielectric constant can be reduced to 7.5 or more. Glass-ceramic materials using borosilicate glass aiming at low dielectric constant and firing in a reducing atmosphere at 1000 ° C. or less have also been developed. It has a dielectric constant of 5.5.
Although it is suppressed to a low level, and multilayering by Cu wiring is realized by the simultaneous sintering method of the glass ceramic and the conductor, there is a drawback that the crystallization does not occur during sintering and the mechanical strength is remarkably lowered. It was In addition, as a conventional technique for coating such a raw material powder for a substrate, Japanese Patent Application Laid-Open No.
Although a means for preventing the formation of quartz crystals as described in Japanese Patent Publication No. 3-151645 has been known, a method for producing a high-strength composite material by depositing a new crystal phase by raw material powder coating is reported. Was not done.

[0004]

Since the conventional alumina multi-layer substrate can be sintered only at a high temperature, only Mo and W having high electric resistance can be used for the conductor, which results in high wiring resistance and fine wiring. There were drawbacks such as being impossible. Further, the permittivity of alumina is as high as about 10, which is disadvantageous for increasing the signal speed. Although a composite material of alumina and lead borosilicate glass can be sintered at low temperature and a low resistance conductor can be used for wiring, it has been difficult to perform firing in a reducing atmosphere or to realize base metal conductor wiring. Further, in the glass ceramic substrate using borosilicate glass, Cu multilayer wiring and a low dielectric constant are possible, but the mechanical strength is remarkably low. The mechanical strength of the substrate is a very important property. In particular, in a multi-chip mounting board in which many semiconductor elements are mounted on the board, the board size becomes large and many input / output terminals or pins are connected, so the board is damaged not only in the assembly process but also in the state of the product. And problems such as poor bonding with metal occur. The object of the present invention is to solve the problems of the conventional mounting board as described above, so that it can be fired at a low temperature of 1000 ° C. or less and in a neutral or reducing atmosphere as well as in an oxidizing property, and has a low mechanical strength. To provide an excellent multilayer glass ceramic substrate. Therefore, it is possible to apply a metal having low resistance such as Au, Ag, Cu, and Ag-Pd to the wiring conductor, and it is possible to provide a mounting board which has high-density fine wiring and can be expected to have a high speed.

[0005]

According to the present invention, the glass-ceramic layer comprises alumina, mullite, quartz glass, α-
An inorganic composition comprising at least one selected from quartz and cordierite (hereinafter referred to as component X), a borosilicate glass, and anorthite crystals, the composition comprising alumina 12 to 59. .6% by weight,
10 to 30% by weight of at least one selected from mullite, quartz glass, α-quartz and cordierite,
Borosilicate glass is composed of 18 to 69.6% by weight and anorthite crystals is composed of 1 to 40% by weight so that the total amount is 100%, and a plurality of conductor layers are laminated through the glass ceramic layer. It is a characteristic multilayer glass ceramic substrate. Here, for the X component, there is a method of selecting 4 when it is 1 component, 6 when it is 2 components, 4 when it is 3 components, and 1 when it is 4 components, so it is 1 in total.
There are five choices.

Further, the manufacturing method is a mixed powder in which 10 to 30% by weight of X component powder and 70 to 90% by weight of organoaluminate-coated borosilicate glass powder are mixed with the raw material powder so that the total amount is 100%. Is used, and a method of forming alumina and anorthite crystals in the sintering step can be adopted. Here, the glass composition of the borosilicate glass powder, in terms of oxide title, SiO _2: 40 to 75 wt%, B ₂ O _3: 5~40 wt%, PbO: 0 to 30 wt%, CaO: 5 30 wt%, BaO: 0.1 to 20 wt%, Al ₂ O _3: 0~30
% By weight, M ¹ O: 0 to 5% by weight, M ² ₂ O: 0.1 to 5% by weight, M ³ O ₂ : 0.1 to 5% by weight (where M ¹ is Mg
And at least one selected from Zn, M ² is L
at least one selected from i, Na and K, M ³
Represents at least one selected from Ti and Zr. ) Is preferable. As a manufacturing method, these raw material powders are mixed and made into a slurry state, then made into a green sheet, then a via hole is formed, conductor printing and hole filling are carried out, then laminating, thermocompression bonding, and a temperature of 1000 ° C. or lower. A firing method is adopted.

When the present invention is carried out, since it becomes possible to sinter at a temperature of 1000 ° C. or lower, it is possible to easily form a multilayer by a desired green sheet laminating method, and the conductors of Au and A are used.
Including not only elements such as g, Pd, Pt, etc., but also elements of base metals such as Cu and Ni that are fired in a neutral or reducing atmosphere,
Alloys containing one kind or two or more kinds respectively can be used without anxiety, and it becomes possible to put into practical use a multi-layer glass ceramic substrate having high packaging density and excellent mechanical strength. Here, the mechanical strength is at least a bending strength of 200.
It is said that 0 kg / cm ² or more is required, and the present invention has sufficient strength also from this point.

[0008]

The composition of the multilayer glass ceramic substrate of the present invention is
The reason why sintering is possible at a temperature of 1000 ° C. or lower is as follows. Borosilicate glass starts softening at about 700 ° C. or higher during firing. The liquidified glass fills the voids between the particles of the X component, and the densification progresses. In this way, a sufficiently dense glass ceramic body is formed in the temperature range of 800 to 1000 ° C., and the sintering is completed. At this time, at the same time, the Al component on the glass surface reacts with the glass at a certain portion and precipitates as anorthite, and the remaining portion is oxidized to become alumina. Next, the reason why the composition can be sintered in a reducing atmosphere is that the present composition uses an element that can suppress the change from an oxide state to a metal element under this condition. For example, in the case of a composition containing lead oxide, it changes into metallic lead in a reducing atmosphere, and the insulating property of the glass ceramic body deteriorates remarkably. Mechanical strength is one of the important properties in a multilayer glass ceramic substrate, and the present invention is particularly effective for this property. Strength of 2000 kg /
The reason why it is possible to achieve cm ² or more is due to the structure of the glass ceramic body after sintering. That is, alumina and anorthite crystals can be generated on the surface of the liquid-phased glass accompanied by a chemical reaction simultaneously with sintering. Thus, alumina particles, X component particles, vitreous portions, and anorthite crystals are three-dimensionally and densely formed in the sintered glass-ceramic body, so that the ceramic and glass are firmly bonded to each other. As a substrate, sufficient characteristics of bending strength can be obtained. In the present invention, by coating the borosilicate glass with an organic aluminate and then forming a composite with alumina, the amount of anorthite crystals generated during firing can be arbitrarily controlled with respect to the alumina. Further, the coating amount at that time can be easily controlled by adjusting the concentration of the organic aluminate in the coating liquid or adjusting the number of coatings.

[0009]

EXAMPLES Examples of the present invention will be described in detail below. The compositions forming the glass ceramic layer are shown in Table 1 to Table 3.
Shown in A method for producing the composition is shown below. X
X powder: calcium borosilicate glass = 10% by weight: 90% by weight to 30% by weight: 7
The mixture is sufficiently mixed at a ratio of 0% by weight and formed into a sheet by the green sheet laminating method. At this time, in the borosilicate glass powder, calcium oxide is 10 in terms of oxide conversion.
It is included by weight percent. As a method for forming a green sheet, a mixed powder is dispersed in a solvent together with an organic binder such as polyvinyl butyral, polyvinyl alcohol, and a polyacrylic resin to make a sludge, and then a slip casting method is used. Green sheet thickness is 10
It is possible to control uniformly and freely in the range of up to 400 μm.

Next, a via hole for connecting the upper and lower conductors is formed on the green sheet by a punching device. Embedding a conductor paste for electrically connecting to the via hole and printing a wiring pattern. The conductors used here are Au, Ag, Ag-Pd, Cu, Ni,
It is a conductor paste containing Ag-Pt as a main component, and is printed at a predetermined position by a screen printing method. The via-filled green sheets on which the conductor patterns are printed are laminated in a predetermined number of layers and thermocompression bonded. The organic binder and the solvent added at the time of molding are 400 ° C to 70 ° C.
After removing by a binder removal process at a temperature of 0 ° C., 80
A multilayer glass ceramic substrate was obtained by firing in a temperature range of 0 to 1000 ° C. During the main calcination, the glass softens and the voids between the X particles are occupied by the glass, and the densification progresses.
Furthermore, crystallization of the aluminum component and a chemical reaction between the aluminum component and glass will generate anorthite.

Tables 4 to 9 show firing conditions, wiring specifications and characteristics when the multilayer glass ceramic substrate was produced. The sample numbers in Tables 1 to 3 and the sample numbers in Tables 4 to 9 showing the composition of the glass ceramic layer in the substrate after sintering correspond to each other.

[0012]

[Table 1]

[0013]

[Table 2]

[0014]

[Table 3]

[0015]

[Table 4] Firing conditions and wiring specifications for sample numbers 1 to 17 ──────────────────────────────────── Annealing Wiring Dimensions Sample Temperature Conductor Annealing Number of laminated layers ───────────── Number (℃) Atmosphere (layer) Wiring width Wiring pitch Via diameter (μm) (μm) (μm) ) ─────────────────────────────────── 1 900 Ag Air 30 120 300 150 2 900 Ag Air 30 120 300 150 3 910 Ag-Pd Air 30 120 300 150 4 880 Cu N ₂ 30 120 250 120 5 850 Cu N ₂ 30 120 250 120 6 850 Cu N ₂ 30 120 250 120 7 900 Cu N ₂ + H ₂ O 40 150 300 150 8 910 Cu N ₂ + H ₂ O 40 150 300 150 9 900 Ag Air 40 150 300 150 10 900 Ag Air 40 150 300 150 11 890 Ag Air 40 150 300 200 12 880 Ag Air 40 150 300 200 13 900 Ag -Pd Air 40 150 300 200 14 880 Ag-Pd Air 30 150 300 200 15 880 Ag-Pd Air 30 100 200 100 16 900 Ag-Pd Air 30 100 200 100 17 870 Ag Air 30 100 250 120 ───────────────────────────────────

[0016]

[Table 5] Characteristics of Sample Nos. 1 to 17 ────────────────────────────── Sample Relative Dielectric Constant Thermal Expansion Coefficient Strength Insulation resistance number (× 10 ^-7 deg ^-1 ) (kg / cm ² ) (Ωcm) ──────────────────────────── ──── 1 5.2 40 2200> 10 ¹³ 2 5.1 41 2300> 10 ¹³ 3 5.0 43 2300> 10 ¹³ 4 5.3 40 2200> 10 ¹³ 5 5.3 43 2300> 10 ¹³ 6 4.9 46 2600> 10 ¹³ 7 5.6 40 2300 > 10 ¹³ 8 5.4 44 2300> 10 ¹³ 9 5.1 48 2400> 10 ¹³ 10 4.8 49 2600> 10 ¹³ 11 5.6 43 2700> 10 ¹³ 12 5.4 47 2500> 10 ¹³ 13 5.3 49 2400> 10 ¹³ 14 5.0 52 2600> 10 ¹³ 15 6.3 41 2600> 10 ¹³ 16 6.0 45 2400> 10 ¹³ 17 6.0 46 2500> 10 ¹³ ──────────────────────────── ───

[0017]

[Table 6] Firing conditions and wiring specifications for sample numbers 18 to 34 ──────────────────────────────────── Annealing Wiring Dimensions Sample Temperature Conductor Annealing Number of laminated layers ───────────── Number (℃) Atmosphere (layer) Wiring width Wiring pitch Via diameter (μm) (μm) (μm) ) ─────────────────────────────────── 18 850 Ag Air 30 100 250 120 19 890 Ag Air 30 100 250 120 20 900 Ag Air 35 100 300 150 21 900 Cu N ₂ + H ₂ O 40 100 200 90 22 900 Cu N ₂ + H ₂ O 40 100 200 90 23 880 Cu N ₂ + H ₂ O 40 100 200 90 24 880 Ag Air 40 100 200 90 25 850 Ag Air 40 100 200 90 26 850 Ag Air 40 100 200 90 27 860 Ag Air 40 100 200 90 28 870 Ag Air 40 100 200 90 29 900 Cu N ₂ + H ₂ O 40 100 200 90 30 900 Cu N ₂ + H ₂ O 40 100 200 90 31 900 Cu N ₂ 35 100 300 150 32 850 Cu N ₂ 35 100 300 150 33 930 Cu N ₂ 35 100 300 150 34 900 Cu N ₂ 40 150 300 150 ───────────────────────────────────

[0018]

[Table 7] Characteristics of Sample Nos. 18 to 34 ────────────────────────────── Sample Relative Dielectric Constant Thermal Expansion Coefficient Strength Insulation resistance number (× 10 ^-7 deg ^-1 ) (kg / cm ² ) (Ωcm) ──────────────────────────── ──── 18 5.8 49 2500> 10 ¹³ 19 6.0 47 2700> 10 ¹³ 20 5.9 47 2500> 10 ¹³ 21 5.6 50 2500> 10 ¹³ 22 5.7 46 2400> 10 ¹³ 23 5.7 46 2600> 10 ¹³ 24 5.6 50 2600 > 10 ¹³ 25 6.0 43 2400> 10 ¹³ 26 6.1 48 2500> 10 ¹³ 27 6.1 41 2500> 10 ¹³ 28 5.8 45 2700> 10 ¹³ 29 5.7 48 2500> 10 ¹³ 30 5.6 46 2300> 10 ¹³ 31 5.9 43 2500> 10 ¹³ 32 5.6 48 2800> 10 ¹³ 33 6.6 39 2400> 10 ¹³ 34 5.9 45 2500> 10 ¹³ ──────────────────────────── ───

[0019]

[Table 8] Firing conditions and wiring specifications for sample numbers 35 to 50 ──────────────────────────────────── Annealing Wiring Dimensions Sample Temperature Conductor Annealing Number of laminated layers ───────────── Number (℃) Atmosphere (layer) Wiring width Wiring pitch Via diameter (μm) (μm) (μm) ) ─────────────────────────────────── 35 910 Cu N ₂ + H ₂ 40 150 350 150 36 900 Au Air 40 150 350 150 37 900 Ag Air 40 150 250 150 38 880 Cu N ₂ 40 150 250 150 39 950 Cu N ₂ 40 120 300 120 40 930 Ag-Pd Air 30 120 300 120 41 900 Ag-Pd Air 30 120 300 120 42 900 Au Air 30 120 300 120 43 930 Cu N ₂ 30 120 250 100 44 910 Cu N ₂ 30 120 250 100 45 950 Ag-Pd Air 30 120 250 100 46 950 Ag-Pd Air 30 100 200 80 47 930 Ag-Pd Air 40 100 250 120 48 960 Ag-Pd Air 40 100 250 120 49 900 Ag Air 40 100 250 120 50 900 Cu N ₂ 40 80 200 80 ─────── ────────────────────────────

[0020]

[Table 9] Characteristics of sample Nos. 35 to 50 ────────────────────────────── Sample relative dielectric constant Thermal expansion coefficient Strength Insulation resistance number (× 10 ^-7 deg ^-1 ) (kg / cm ² ) (Ωcm) ──────────────────────────── ──── 35 5.7 48 2500> 10 ¹³ 36 5.6 50 2600> 10 ¹³ 37 5.6 51 2700> 10 ¹³ 38 6.0 53 2800> 10 ¹³ 39 6.5 45 2500> 10 ¹³ 40 6.4 47 2500> 10 ¹³ 41 6.2 49 2400 > 10 ¹³ 42 6.0 51 2300> 10 ¹³ 43 6.5 48 2400> 10 ¹³ 44 6.3 50 2400> 10 ¹³ 45 6.2 51 2300> 10 ¹³ 46 6.2 51 2300> 10 ¹³ 47 6.5 50 2400> 10 ¹³ 48 6.3 52 2300> 10 ¹³ 49 6.2 54 2200> 10 ¹³ 50 6.3 55 2100> 10 ¹³ ───────────────────────────────

If the range of the present invention is not satisfied, desired substrate characteristics cannot be obtained for the following reason. (1) If the alumina content is less than 12% by weight, the bending strength is 2
It becomes less than 000 kg / cm ^2, which is insufficient. Again 5
If it exceeds 9.6% by weight, the sintering becomes insufficient at a temperature of 1000 ° C. or less, and as a result, the insulation resistance decreases and the bending strength also becomes less than 2000 kg / cm ² . Furthermore, since the dielectric constant exceeds 7, it is disadvantageous in speeding up, and a practical multilayer glass ceramic substrate cannot be obtained. (2) When X is less than 10% by weight, the dielectric constant exceeds 7. Further, if it exceeds 30% by weight, the sintering becomes insufficient, the insulation resistance is lowered, and the bending strength is 2000 kg / c.
It will fall below m ² . (3) When the content of borosilicate glass is less than 18% by weight, X
Since it becomes impossible to obtain a glass phase sufficient to occupy the voids between the particles, the strength decreases and reliability cannot be obtained. If it exceeds 69.6% by weight, the inherent strength of glass becomes dominant and the bending strength becomes less than 2000 kg / cm ² . (4) When the content of anorthite crystals is less than 1% by weight, the strength reinforcing effect of the anorthite crystals is lost and the bending strength is 20.
It is not possible to obtain more than 00 kg / cm ² . Further, if the anorthite crystal exceeds 40% by weight, the shrinkage of the multilayer glass ceramic substrate becomes non-uniform and the reliability is lowered. (5) When the borosilicate glass powder used as the raw material powder is less than 70% by weight, the formation of alumina and anorthite is nonuniform and the amount becomes small, resulting in a decrease in strength. If the amount exceeds 90% by weight, the glass softening reaction proceeds during firing, so that the dimensional stability of the fired substrate deteriorates and a practical substrate cannot be obtained. (6) When the calcium composition of the borosilicate glass used as the raw material powder is less than 5% by weight of calcium oxide according to the oxide conversion notation, anorthite crystals are hardly generated during firing.

[0022]

As described above, the multilayer glass ceramic substrate of the present invention not only allows easy formation of high density and fine wiring, but also has excellent characteristics.
It is a mounting board that also satisfies the mechanical strength necessary for practical use.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H05K 1/03 B 7511-4E 1/05 B 3/46 H 6921-4E T 6921-4E C04B 35 / 18 B

Claims (3)

[Claims] 1. The glass-ceramic layer comprises alumina,
An inorganic composition comprising at least one selected from mullite, quartz glass, α-quartz and cordierite, borosilicate glass, and anorthite crystals, the composition being alumina 12 to 59.6. weight%,
10 to 30% by weight of at least one selected from mullite, quartz glass, α-quartz and cordierite,
Borosilicate glass is composed of 18 to 69.6% by weight and anorthite crystals is composed of 1 to 40% by weight so that the total amount is 100%, and a plurality of conductor layers are laminated through the glass ceramic layer. Characteristic multi-layer glass ceramic substrate. 2. The method for producing a multilayer glass ceramic substrate according to claim 1, wherein the raw material powder is at least one kind of powder selected from mullite, quartz glass, α-quartz, and cordierite. % Borosilicate Glass Powder Coated with% by Weight and Organic Aluminate
A method for producing a multi-layer glass ceramic substrate, which comprises using a mixed powder mixed so that the total amount becomes 0 to 90% by weight and 100% in total. 3. The glass composition of the borosilicate glass powder has an oxide conversion notation of SiO ₂ : 40 to 75% by weight,
B ₂ O _3: 5~40 wt%, PbO: 0 to 30 wt%, C
aO: 5 to 30% by weight, BaO: 0.1 to 20% by weight,
Al ₂ O _3: 0~30 wt%, M ¹ O: 0~5 wt%, M ²
₂ O: 0.1-5% by weight, M ³ O ₂ : 0.1-5% by weight
(However, M ¹ is at least one selected from Mg and Zn, M ² is at least one selected from Li, Na and K, and M ³ is at least one selected from Ti and Zr.) 3. The method for manufacturing a multilayer glass ceramic substrate according to claim 2.