JP3323069B2 - Low temperature firing porcelain composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-resistance copper (C
u), silver (Ag), or gold (Au), etc., which relates to a low-temperature fired porcelain composition that can be simultaneously fired. The present invention relates to a low-temperature fired porcelain composition suitable for a material for a high-frequency multilayer wiring board capable of reducing signal propagation delay time and transmission loss.

[0002]

2. Description of the Related Art Conventionally, materials for various antennas include:
Teflon with a relative dielectric constant as small as 2-3 and excellent in processability,
Although the relative permittivity is 9 to 10, or 12 to 13, which is larger than that of the Teflon, an antenna having a circuit (RF / IF circuit) for converting a high-frequency signal into an intermediate-frequency signal and transmitting / receiving the same is particularly a wiring board. And alumina (Al), which have the same relative dielectric constant as
₂ and O _3), gallium arsenide (GaAs) or the like, the Teflon and as Al ₂ O ₃ and the dielectric constant having properties intermediate GaAs quartz or the like indicating a 4-5 is used.

There are various kinds of loss such as dielectric loss, conductor loss, radiation loss, etc. that affect the characteristics of the antenna material. In particular, in order to reduce the conductor loss, the conductor resistance is reduced, and In order to reduce dielectric loss, it is desirable that the relative permittivity and the dielectric loss tangent are small.

Accordingly, Cu is used as a material having a low conductor resistance.
Teflon, Al ₂ O ₃ , G
It is conceivable to form a wiring pattern on an insulating substrate such as aAs. In order to form a predetermined wiring pattern on the insulating substrate with the low-resistance conductor, a copper foil bonding method, a sputtering method, a photolithographic method, or the like is generally used. Must be employed.

[0005] However, as for the antenna material, the copper foil sticking method has a large thickness per layer, the sputtering method can only be applied to a single plate, and the photolithographic method requires a large number of materials within a predetermined thickness range. Although lamination is possible, the number of laminations is limited or the lamination itself is difficult even if a wiring pattern is formed with the low-resistance conductor, since many steps are required and the manufacturing cost is increased. There was a problem that is.

On the other hand, as a material for a high-frequency multilayer wiring board, alumina ceramics, which have been frequently used for wiring boards, have a firing temperature as high as 1500 to 1600 ° C., so that a wiring conductor that can be simultaneously fired is a conductor resistance. Therefore, a high melting point metal such as tungsten (W) or molybdenum (Mo) must be used, which causes a problem that a high conductor resistance increases a signal transmission loss in a high frequency range.

In addition, in the recent advanced information age, the speed of information transmission has been increased and the frequency has been increased, and the mounted semiconductor elements have been increased in speed and integration, and the packaging density has been increased. Since the relative dielectric constant of conventional alumina ceramics is considerably large at about 9 to 9.5 in the frequency range of 3 GHz, alumina ceramics itself is used as a wiring board material for recent high frequency. Is said to be inappropriate.

[0008] Therefore, the low-resistance Cu and Ag, the wiring conductor made of Au or the like can be formed by a simple screen-printing method, as easily and fireable low temperature sintering ceramic composition laminated, for example, SiO _2, Al Glass ceramics comprising a mixture of a glass composition containing ₂ O ₃ , MgO or the like as a main component and a ceramic have been proposed. However, demands for further improvement in mechanical strength and speeding up of arithmetic processing have been further increased. Development of glass ceramics having a lower strength and a lower dielectric constant is desired.

As a result, borosilicate glass and corrugated glass are used as wiring board materials that can be fired at a low temperature of 1000 ° C. or less, have sufficient mechanical strength, and have a lower relative dielectric constant enough to cope with high-speed arithmetic processing. Glass ceramics composed of light and alumina have been proposed (see Japanese Patent Application Laid-Open No. Hei 4-238838).

[0010]

However, the glass ceramics proposed above can have a relative dielectric constant of about 4 to 5, but have a transverse rupture strength of 100 to 150 MPa.
There is a problem that it does not always satisfy all characteristics such as relative dielectric constant and mechanical strength required as various materials for antennas and high frequencies, such as a.

[0011]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to have a relative dielectric constant in a high frequency region of 5 or less and a transverse rupture strength of 200 MPa or more,
It can be fired at a temperature of 900 to 1000 ° C., and is suitable for a high frequency antenna substrate material or various wiring substrate materials that can be multilayered by using low resistance materials such as Cu, Ag, and Au as wiring conductors at the same time. To provide a low-temperature fired porcelain composition.

[0012]

Means for Solving the Problems As a result of diligent studies of the above-mentioned problems, the present inventors have found that B ₂ O having a softening point of about 560 ° C.
Using ₃ and _{-ZnO-SiO 2 -Na 2 O-} Al 2 O 3 based glass, a filler having a specific dielectric constant of an oxide of from about 3.7 SiO _2, and Li, and the composition ratio thereof fillers with respect to the glass By increasing the firing temperature to 10
The present inventors have found that it is possible to reduce the relative dielectric constant and the dielectric loss tangent to a value as low as 00 ° C. or lower, and also to secure a sufficient strength, and have reached the present invention.

That is, the low-temperature fired porcelain composition of the present invention comprises 9
B is a sintered body that is densified at a firing temperature of 00 to 1000 ° C. and has a composition of 5 to 20% by weight and a softening point of about 560 ° C.
₂ O ₃ —ZnO—SiO ₂ —Na ₂ O—Al ₂ O ₃ -based glass, 1 to 10% by weight of Li in terms of oxide, and 79 to
The sintered body obtained is composed of 90% by weight of SiO ₂ , and has a relative dielectric constant of 5 or less and a bending strength of 200 MPa or more.

The B ₂ O ₃ —ZnO—SiO ₂ —
Na ₂ O-Al ₂ O ₃ based glass and 8-16 wt%, L
i is 4 to 8% by weight in terms of oxide, and SiO ₂ is 80 to 8%.
More preferably, it comprises 7% by weight.

[0015]

According to the low-temperature fired porcelain composition of the present invention, B ₂ O
By using _{3 -ZnO-SiO 2 -Na 2 O} -Al 2 O 3 based glass, the glass dispersed in the filler particles consisting of Li and SiO ₂ may wet the filler to flow at low temperature, with a small amount The voids between the fillers can be filled.

Li used as a filler component is
Act to further lower the softening point of the glass, like SiO ₂ is low itself, relative dielectric constant of 3 to 4, the glass of the glass ceramics comprising the glass and SiO ₂ from the not crystallized, The relative dielectric constant is about 4 to 5.

On the other hand, SiO ₂ has a dielectric loss tangent of about 0.0
Since it is as small as 008, by increasing the composition ratio in the glass ceramic, its dielectric loss tangent can be reduced, and a low relative dielectric constant and dielectric loss tangent optimal for high frequencies can be obtained.

Further, although a dense sintered body cannot be obtained by using only the glass and SiO _2, it is considered that the inclusion of Li lowers the softening point of the glass, so that the glass can be densified. As a result, the strength of the obtained sintered body increases.

Further, the low-temperature fired porcelain composition of the present invention comprises 9
Since it can be fired simultaneously with the wiring conductors of Cu, Ag, and Au at a low temperature of 00 to 1000 ° C., fine wiring of a multilayer wiring board or the like provided with these wiring conductors can be easily achieved.

[0020]

If _{B 2 O 3 -ZnO-SiO 2} -Na 2 O-Al 2 O 3 based glass low-temperature fired ceramic composition of the embodiment of the present invention is less than 5 wt%, the amount of other fillers Is within the predetermined range, the voids between the filler particles are not filled, resulting in poor sintering, and a dense sintered body cannot be obtained.
If it exceeds 0% by weight, oversintering occurs, voids are generated, and a dense sintered body cannot be obtained.

Therefore, the amount of the glass is 5 to 20% by weight.
In particular, from the viewpoint of increasing the strength and decreasing the dielectric loss tangent, 8 to 16% by weight is more desirable.

If the content of Li is less than 1% by weight, the softening point of the glass does not decrease even if the amounts of the glass and SiO ₂ are within the respective limited ranges. When the content exceeds 10% by weight, oversintering occurs, voids occur, and sintering becomes poor.

Therefore, the amount of Li is 1 to 1 in terms of oxide.
It is 10% by weight, more preferably 4 to 8% by weight.

On the other hand, if the amount of SiO ₂ is less than 79% by weight, the amount of glass becomes too large, resulting in oversintering. If it exceeds 90% by weight, on the contrary, the amount of glass becomes too small, resulting in poor sintering. Also in this case, the dielectric loss tangent becomes large.

Therefore, the amount of SiO ₂ is specified to be 79 to 90% by weight, and from the point of dielectric loss tangent, it is 80 to 87% by weight.
Is more preferable.

Next, when the firing temperature is lower than 900 ° C., sintering failure may occur even if the compounding amounts of the raw materials are respectively predetermined, and the obtained sintered body has low strength and dielectric strength. In many cases, the tangent becomes large, and when the temperature exceeds 1000 ° C., oversintering often occurs. As in the case of poor sintering, the obtained sintered body has low strength, a large dielectric tangent, Cu and Ag. ,
Simultaneous firing using an Au conductor becomes impossible.

When a wiring board is produced using such a low-temperature fired porcelain composition, for example, a mixture of raw material powders is formed by a known tape forming method, that is, a doctor blade method, a rolling method, or the like. After molding the green sheet of the above, as a metallization for the wiring layer on the sheet surface,
A wiring pattern is formed by means of screen printing, gravure printing, offset printing or the like using a metal paste containing Cu, Ag, or Au powder, particularly Cu powder, and if necessary, a through hole is formed in the sheet to form the wiring pattern. After filling the paste into the through holes, and then laminating and pressing a plurality of sheets, the wiring layer and the insulating layer are simultaneously formed by firing at a firing temperature in a non-oxidizing atmosphere such as N ₂ or Ar gas. Can be fired.

[0028]

EXAMPLES Hereinafter, the low-temperature fired porcelain composition of the present invention will be described in detail. First, B ₂ having an average particle size of 5 μm or less
And _{O 3 -ZnO-SiO 2 -Na 2} O-Al 2 O 3 based glass, carbonate having an average particle diameter of less 10 [mu] m Li, and an average particle size of less SiO ₂ 5 [mu] m were mixed according to the composition of Table 1 .

Then, an organic binder, a plasticizer, and an organic solvent are added to the mixture to prepare a slurry, and the slurry is dried and passed through a mesh to form a molding powder. Press molding and thickness 6.5mm
, And two types of molded bodies having a thickness of 4.5 mm were obtained.

The molded body thus obtained was placed in the air for 45 minutes.
After removing the binder at a temperature of 0 ° C., it was fired under the conditions shown in Table 1 to obtain a sintered body of a low-temperature fired porcelain composition.

A glass ceramic composed of borosilicate glass and cordierite was used as a comparative example, and the average particle size was 5%.
μm or less of Al ₂ O ₃ —SiO ₂ —ZnO—B ₂ O ₃ —
A sintered body was prepared by adding 10% by weight of cordierite having an average particle size of 5 μm or less to 90% by weight of an MgO-based glass in the same manner as described above.

[0032]

[Table 1]

The sinterability, relative dielectric constant, dielectric loss tangent, and bending strength were measured and evaluated by the following methods using the above-described sintered body for evaluation.

First, the above-mentioned sintered body for evaluation was immersed in a penetrant solution and visually inspected for the presence or absence of permeation of the solution. Those which did not show any permeation were judged to have good sinterability.

On the other hand, relative permittivity and dielectric loss tangent were determined by cutting a sample having a diameter of 10 mm and a thickness of 5 mm from the cylindrical sintered body, and using a network analyzer and a synthesized sweeper at 10 to 30 GHz. It was measured by the method.

Specifically, measurement was performed with the sample interposed between copper plate jigs having a diameter of 50 mm, and the relative dielectric constant and dielectric loss tangent were calculated from the resonance characteristics of the TE011 mode of the resonator.

Next, the bending strength was determined by cutting out a four-point bending test piece from the flat sintered body according to the standard of JISR1601, and performing a four-point bending test at an upper span of 10 mm and a lower span of 30 mm. Calculated.

[0038]

[Table 2]

As is evident from the results in the table, the sample numbers 1, 10, 11, 17, 18, and 2, which are out of the claims of the present invention.
In the case of 4, 25, the sinterability is poor and the bending strength is 200 MPa.
Sample No. 34, which has a lower sintering temperature than 1000 ° C., has good sinterability but has a transverse rupture strength of 200M.
Sample No. 3 as low as less than Pa and different kinds of glass
Nos. 5 and 36 have poor sinterability and the dielectric properties cannot be measured.
Flexural strength is also low, less than 200 MPa,
In the sample No. 37 of the comparative example, the sinterability was good, but the bending strength was low at less than 200 MPa.

On the other hand, it can be seen that all of the present inventions have good sinterability, a flexural strength of 200 MPa or more, and satisfactory dielectric properties.

[0041]

As described above in detail, the low-temperature fired porcelain composition of the present invention has a low relative dielectric constant, and therefore, as an antenna material, has a low reflection when radiating electromagnetic waves into the air and has a good radiation efficiency. The antenna can be manufactured, the dielectric loss is small because the dielectric loss tangent is small, and the conductor loss is small because a low-resistance material such as Cu, Ag, or Au can be used as the wiring conductor. Transmission loss of the feed line can be reduced.

In addition, due to the high strength, reflow work at the time of mounting chip capacitors and chip resistors, or MMI
There is no problem with die bonding work at the time of mounting semiconductor elements such as C, it can be used alone without special reinforcement, it is also possible to form a circuit on the same substrate as the antenna, Since a dense sintered body can be obtained, an antenna having excellent chemical resistance in the manufacturing process can be obtained.

It is also suitable as a microwave substrate material for high-frequency applications, capable of high-speed signal transmission, realizing miniaturization, and further enhancing the strength to join leads at input / output terminals, As in the case of the material, the reliability of the substrate in mounting can be improved, and since it can be fired at a low temperature of 900 to 1000 ° C., wirings of Cu, Ag, Au, etc. can be formed by simultaneous firing. It is suitable as a high-frequency multilayer wiring board or a board for a package for housing semiconductor elements.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C04B 35/14

Claims (2)

(57) [Claims] 1. A borosilicate zinc (B ₂ O ₃ -ZnO-S
iO and _{2 -Na 2 O-Al 2 O} 3 system) 5 to 20 wt% glass, and 1 to 10 wt% of lithium (Li) is in terms of oxide, silica (SiO ₂₎ from 79-90 wt% A sintered body which is densified at a firing temperature of 900 to 1000 ° C., wherein the sintered body has a relative dielectric constant of 3 to 5 and a transverse rupture strength of 200 MPa or more. Porcelain composition. 2. The zinc borosilicate (B ₂ O ₃ —ZnO)
—SiO ₂ —Na ₂ O—Al ₂ O ₃ ) glass is 8 to 1
And 6 wt% of lithium (Li) oxide and 4-8 wt% in terms of silica (SiO ₂₎ is a low temperature sintered ceramic composition of claim 1, wherein the consisting of 80 to 87 wt%.