JP3363299B2 - Low temperature firing porcelain composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-temperature fired porcelain composition for a multi-layer circuit board, and more particularly to a low-temperature porcelain composition for mounting a semiconductor element and various electronic components. The present invention relates to a high-frequency low-temperature fired porcelain composition which can be used for copper wiring and is applied to a composite circuit board or the like comprising the same. 2. Description of the Related Art In recent years, with the era of advanced information, the speed of information transmission has been further increased and the frequency has been increased, and the mounted semiconductor elements have been further increased in speed and integration, and the packaging density has been further increased. Various types of alumina circuit boards, which have been widely used, have a relative dielectric constant of 9 to 9 at 3 GHz.
It is said to be unsuitable for recent high-frequency circuit boards and the like because of its considerably high dielectric constant of 9.5. In other words, in order to propagate a signal at a high speed, a lower dielectric constant is required for a substrate material.
Higher mechanical strength in order to prevent the board itself from being broken or chipped by stress applied to the board in the process of connecting various electronic components and input / output terminals to the multilayer circuit board. Is also required. [0004] In order to satisfy the above-mentioned requirements, for example, a glass sintered body composed of a glass composition containing SiO ₂ , Al ₂ O ₃ , and MgO as main components has been proposed. Although the body has the property of having a low dielectric constant, the problem of low mechanical strength remains, and it does not completely satisfy the above requirements, and various research and development have been promoted in order to solve the problems related thereto. I have. As a result, as a composition having a low dielectric constant and high strength, for example, a glass composition which precipitates mullite and cordierite as main crystal phases by heat treatment has been proposed (Japanese Patent Laid-Open No. 05-298919). Gazette). [0006] However, the multilayer circuit board made of the glass composition proposed above has a problem that the dielectric constant and the dielectric loss tangent required as a circuit board for high frequency are particularly high.
And not all properties such as mechanical strength are necessarily satisfied. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a multilayer circuit board having a sufficient mechanical strength and a low relative dielectric constant in a high frequency region. , Low dielectric loss tangent and stability, and firing at a low temperature of 800 to 1000 ° C., which enables multilayering using gold (Au), silver (Ag), and copper (Cu) as wiring conductors, can be realized. An object of the present invention is to provide a low-temperature fired porcelain composition for high frequency. The present inventor has made intensive studies on the above problems, and as a result, made use of the softening flow of glass.
By firing at 0 to 1000 ° C., multilayering and fine wiring can be performed using Au, Ag and Cu as wiring conductors, and by combining forsterite and a specific glass, a code phase as a crystal phase is obtained. Lowering the relative permittivity by precipitating the elite crystal phase,
The dielectric loss tangent can be reduced, and the dielectric loss tangent becomes smaller by precipitating the forsterite crystal phase and enstatite crystal phase. The present inventor has found that the present invention can be used, and has led to the present invention. That is, the low-temperature fired porcelain composition of the present invention contains 40 to 50% by weight of silica (SiO ₂ ) and alumina (Al ₂
O ₃ ) at 25 to 30% by weight, and magnesia (MgO) at 8
12%, 6-9 wt% of zinc oxide (ZnO), and boron oxide (B ₂ O ₃₎ and 55 to 99.9 wt% of glass consisting of a rate of 8 to 11% by weight, forsterite ( (Mg ₂ SiO ₄ ) at a ratio of 0.1 to 45% by weight was formed from a mixed powder containing nitrogen (N ₂ ) and argon (A
a sintered body obtained by firing at a temperature of 800 to 1000 ° C. in a non-oxidizing atmosphere such as r)
And a cordierite crystal phase, a forsterite crystal phase, and an enstatite crystal phase. According to the low-temperature fired porcelain composition of the present invention, since a forsterite is contained as a filler component, the cordierite crystal phase exhibiting a low dielectric constant and a low dielectric loss tangent due to the reaction with the glass phase and the enstar. The strength of the sintered body can be increased by precipitating a tight crystal phase and precipitating a spinel-type garnet crystal phase from a glass phase. That is, according to the porcelain composition of the present invention, 8
By reducing the glass component in the composition by firing at a low temperature of 00 to 1000 ° C., and by precipitating various crystal phases in combination with the filler component, a low dielectric constant and high strength are achieved by a combined action. In addition, excellent characteristics can be exhibited without problems even in resistance values, dielectric loss tangents, etc. other than the above characteristics. Further, the low-temperature fired porcelain composition of the present invention comprises 8
Since it can be fired simultaneously with the internal wiring layer of Au, Ag or Cu at a low temperature of 00 to 1000 ° C., fine wiring of a multilayer circuit board or a semiconductor device housing package having these wiring conductors can be easily achieved. it can. The low-temperature fired porcelain composition of the present invention will be described in detail below. According to the low-temperature fired porcelain composition of the present invention, at least SiO ₂ , Al ₂ O ₃ , MgO, ZnO and B
_{If the} amount of glass containing ₂ O ₃ is less than 55% by weight, or in other words, the amount of forsterite is more than 45% by weight, the porcelain cannot be sufficiently densified at a temperature of 800 to 1000 ° C. If the amount is greater than 99.9% by weight, in other words, if the amount of forsterite is less than 0.1% by weight, the mechanical strength will be less than 200 MPa. Therefore, the content of the glass is 55 to 9
It is specified to be 9.9% by weight, more preferably in the range of 60 to 95% by weight. FIG. 1 is a schematic view showing the structure of a sintered body of the low-temperature fired porcelain composition of the present invention. As shown in FIG. 1, the low-temperature fired porcelain composition of the present invention comprises a garnitite crystal phase 1, a cordierite crystal phase 2, a forsterite crystal phase 3, an enstatite crystal phase 4, and a glass phase. 5, and the garnite crystal phase 1 exists as a main crystal in the sintered body. The glass is almost crystallized, and the glass phase 5 exists only at the triple point. As described above, according to the present invention, a low dielectric constant and a low dielectric loss tangent can be obtained by the presence of a cordierite crystal phase in a sintered body, and a forsterite crystal phase and an enstatite crystal can be obtained. The presence of the phase allows a lower dielectric loss tangent to be obtained. Further, when the sintering temperature is adjusted to precipitate a garnitite crystal phase of a spinel-type crystal phase in the sintered body, the crystal phase exists in a form that reinforces the network of each crystal phase. A sintered body having high mechanical strength can be obtained. Next, as a specific method for producing the low-temperature fired porcelain composition of the present invention, SiO ₂ is used as a starting material.
-Al ₂ O ₃ -MgO-ZnO-B ₂ O ₃ glass
5 to 99.9% by weight, particularly preferably 60 to 95% by weight
And 0.1 to 4 forsterite as a filler component
5% by weight, in particular forsterite, is mixed in a proportion of 5 to 40% by weight of the total amount. The forsterite, which is a filler component, serves as a nucleus to promote the crystallization of the glass component into a cordierite crystal phase. However, it is important to crystallize the glass and precipitate the cordierite crystal phase uniformly. From this point of view, it is desirable that the forsterite powder is a fine powder having a size of 1.5 μm or less, particularly 1.0 μm or less. Further, as a starting material, SiO ₂ --Al ₂
O ₃ to use -MgO-ZnO-B ₂ O ₃ based glass, spinel-type crystal phase is deposited by the use of glass of this system, the crystal phase present in the form of reinforcing the network of the glass, high This is because a strong sintered body can be obtained. Further, 55 to 9 of such a glass is used.
The reason for adding 9.9% by weight is that when the amount of glass is less than 55% by weight, the densification temperature of the sintered body is 100%.
This is because the temperature is higher than 0 ° C., and gold, silver and copper conductors cannot be used. If the glass content is more than 99.9% by weight, the bending strength of the porcelain itself decreases. On the other hand, as a more specific composition of the glass, SiO ₂ is 40 to 45% by weight and Al ₂ O ₃ is 25 to 45% by weight.
30% by weight, 8 to 12% by weight of MgO, 6 to 9 of ZnO
Wt%, B ₂ O ₃ is desirably 8-11% by weight. After appropriately adding a binder to the mixed powder added and mixed at the above ratio, the mixture is molded into a predetermined shape, and N 2
_2. 800 to 100 in a non-oxidizing atmosphere such as Ar
Bake at 0 ° C for 0.1-5 hours. If the firing temperature at this time is lower than 800 ° C., the porcelain will not be sufficiently densified and
If the temperature exceeds 000 ° C., gold, silver and copper conductors cannot be used. When a wiring board is produced using such a low-temperature fired porcelain composition, for example, the mixed powder prepared as described above is mixed with a known tape molding method, for example, a doctor blade method, a rolling method or the like. After forming a green sheet for forming an insulating layer, a powder of Au, Ag or Cu, particularly C
Using a metal paste containing u powder, a wiring pattern is formed on the sheet surface by means of screen printing, gravure printing, offset printing, or the like, and in some cases, a through hole is formed in the sheet to fill the hole with the paste. . Then, after laminating and pressing a plurality of sheets, the wiring layer and the insulating layer can be simultaneously fired by firing under the above-described conditions. EXAMPLES Hereinafter, the low-temperature fired porcelain composition of the present invention will be described in detail. First, SiO ₂ —Al ₂ O ₃ —Mg
As O-ZnO-B ₂ O ₃ based crystalline glass, crystalline glass A: SiO ₂ 44 wt% -Al ₂ O ₃ 29 wt% -MgO11 wt% -ZnO7 wt% -B ₂ O ₃ 9 wt% crystalline glass B: and two glass SiO ₂ 50 wt% -Al ₂ O ₃ 25 wt% -MgO9 wt% -ZnO8 wt% -B ₂ O ₃ 8% by weight, average particle size below forsterite 1μm Table 1 according to the composition. Then, an organic binder, a plasticizer, and toluene were added to the mixture, and a green sheet having a thickness of 300 μm was prepared by a doctor blade method. After that, five green sheets are laminated, and 100
Thermocompression bonding was performed by applying a pressure of kg / cm ² . After debinding the obtained laminate in a nitrogen atmosphere containing water vapor at a temperature of 700 ° C., it was fired in dry nitrogen under the conditions shown in Table 1 to obtain a sintered body of a low-temperature fired porcelain composition. . The obtained sintered body was evaluated for dielectric constant, dielectric loss tangent, and bending strength by the following methods. The dielectric constant and the dielectric loss tangent were determined by cutting a sample having a diameter of 50 mm and a thickness of 1 mm from the sintered body and measuring 3.0 GH.
At z, the measurement was performed by a cavity resonator method using a network analyzer and a synthesized sweeper. The measurement was performed with a dielectric substrate of a sample interposed between cylindrical cavities filled with sapphire. The dielectric constant and the dielectric loss tangent were calculated from the resonance characteristics of the TE011 mode of the resonator. The bending strength is 70 m in length from the sintered body.
m, a thickness of 3 mm, and a width of 4 mm were prepared and measured according to JIS.
A three-point bending test was performed according to the provisions of -C-2141. Further, as a comparative example, a sintered body was prepared and evaluated in the same manner as described above using SiO ₂ instead of forsterite as the filler component. Further, instead of the crystalline glass, crystalline glass C: 55.2% by weight of SiO ₂ -12% by weight of Al ₂ O ₃ -4.4% by weight of B ₂ O ₃ -20% by weight of BaO-ZnO 6.7 wt% -Na ₂ O1.6 wt% -ZrO ₂ 0.1 wt% crystalline glass D: SiO ₂ 60.7 wt% -Al ₂ O ₃ 9.3 wt% -B ₂ O ₃ 5 wt% -SrO15 with .4 wt% -ZnO8.6 wt% -K ₂ O1 wt% of the two glass, the average particle diameter as a filler was evaluated in the same manner by using a 1.0μm forsterite. [Table 1] As is clear from the results in Table 1, the garnitite crystal phase, the cordierite crystal phase,
The present invention, in which a forsterite crystal phase and an enstatite crystal phase are precipitated, each has a dielectric constant of less than 6, a dielectric loss tangent of 11 × 10 ⁻⁴ or less, and a strength of 260 MPa or more. You can see that it is. On the other hand, in sample No. 1 in which the amount of glass is less than 55% by weight, densification cannot be achieved unless the firing temperature is increased to 1400 ° C., and the dielectric loss tangent is also 30 × 10 5
^-4, and the amount of filler was 0.1% as in sample numbers 8 and 9.
When the content is less than 1% by weight, the glass is not sufficiently crystallized, the strength is reduced to 150 MPa, and the dielectric loss tangent is 17 × 10 ^−4.
Above is quite high. As a comparative example, sample No. 20 using SiO ₂ as a filler had a low dielectric constant but a considerably high dielectric loss tangent of 35 × 10 ⁻⁴ . In Comparative Examples 14 to 19 using the crystallized glasses C and D, BaAl ₂ Si ₂ O ₈
And SrAl ₂ Si ₂ O ₈ is produced, because they are themselves dielectric constant as high as 7 to 8, the entire porcelain dielectric constant of 7.2
As described above, the dielectric loss tangent is extremely large at 20 × 10 ⁻⁴ or more. As described in detail above, the low-temperature fired porcelain composition of the present invention has a low dielectric constant and a small dielectric loss tangent, so that it can be optimized and miniaturized in microwave circuit elements and the like. Furthermore, since the strength of the substrate material is increased, the bonding of the leads to be applied to the input / output terminals and the reliability of the substrate during mounting can be improved, and since firing at a low temperature of 800 to 1000 ° C. is possible, Au, Ag, Cu Can be formed by simultaneous firing, and can be applied as a multilayer wiring board for various high frequencies or a board for a package for housing semiconductor elements.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of the structure of the low-temperature fired porcelain composition of the present invention. [Description of Signs] 1 Garnite crystal phase 2 Cordierite crystal phase 3 Forsterite crystal phase 4 Enstatite crystal phase 5 Glass phase

Claims (1)

(57) [Claim 1] 40 to 50% by weight of silica (SiO ₂ );
Alumina (Al ₂ O ₃ ) 25 to 30% by weight, magnesia (MgO) 8 to 12% by weight, zinc oxide (ZnO) 6
To 9% by weight, and boron oxide and (B ₂ O ₃₎ 8~11 wt%
And 55 to 99.9 wt% of glass consisting of a rate of a molded article made of mixed powder containing forsterite a (Mg ₂ SiO ₄₎ in a proportion of 0.1 to 45 wt.%, Nitrogen (N _2),
800 to 10 in a non-oxidizing atmosphere such as argon (Ar)
A sintered body obtained by sintering at a temperature of 00 ° C., comprising a garnet crystal phase as a main crystal, a cordierite crystal phase, a forsterite crystal phase, and an enstatite crystal phase. Low temperature firing porcelain composition.