JP2001240470A - Porcelain composition for high-frequency use, porcelain for high-frequency use and method for producing porcelain for high-frequency use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a porcelain composition for insulating layer of circuit board for high-frequency use capable of lowering dielectric loss in high-frequency region and to provide a method for producing the same capable of firing at 800 to 1050 deg.C. SOLUTION: This porcelain composition comprises 30 to 99 wt.% of crystallized glass containing at least SiO2, Al2O3 and MO (M: an alkaline earth metal element), where content of Pb converted as PbO is 10 wt.% or less, and 1 to 70 wt.% of at least one filler having average diameter of primary particles of 3 μm or larger and selected from the group consisting of Al2O3, SiO2, MgTiO3, (Mg, Zn)TiO3, TiO2, SrTiO3, MgAl2O4, ZnAl2O4, cordierite, mullite, enstatite, willemite, CaAl2Si2O8, SrAl2Si2O8, (Sr, Ca)Al2Si2O8 and forsterite. The porcelain having dielectric loss at 60 to 77 GHz of 50×10-4 or less is obtained by forming the above mixture into an article followed by firing at the temperature of 800 to 1050 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency porcelain suitably used as an insulating substrate for a wiring board such as a package for storing semiconductor elements or a multilayer wiring board.
In particular, the present invention relates to a high frequency porcelain composition and a high frequency porcelain which can be co-fired with copper and silver, and a method for producing the high frequency porcelain.

[0002]

2. Description of the Related Art Conventionally, as a ceramic multilayer wiring board,
An insulating substrate made of an alumina-based sintered body having a wiring layer made of a refractory metal such as tungsten or molybdenum formed on the surface or inside thereof is most widely used.

Further, recently, with the era of advanced information, the frequency band to be used is shifting to higher and higher frequencies. In such a high-frequency wiring board that requires transmission of a high-frequency signal, in order to transmit a high-frequency signal without loss, the resistance of the conductor forming the wiring layer is small, and the dielectric of the insulating substrate in the high-frequency region is low. Low loss is required.

However, conventional tungsten (W),
Refractory metals such as molybdenum (Mo) have high conductor resistance, have low signal propagation speeds, and have difficulty in signal propagation in the high-frequency region of 1 GHz or higher. It is necessary to use low resistance metals such as silver and gold.

A wiring layer made of such a low-resistance metal is
Since the melting point is low and it is impossible to co-fire with alumina, recently, a wiring board using glass or a composite material of glass and ceramic, that is, a so-called glass ceramic as an insulating substrate is being developed.

For example, JP-A-2-212363 discloses that the average secondary particle diameter (central particle diameter) is 3.1 to 8.9 μm.
Average secondary particle diameter (center particle diameter) of 1.5 to
A porcelain which is formed by adding 16 μm borosilicate glass powder, molding and firing is described.By controlling the average secondary particle diameter of the AlN powder and the average secondary particle diameter of the glass powder to a predetermined range, It is described that the density of a molded body can be improved and the thermal conductivity of porcelain can be improved.

Also, Japanese Patent Application Laid-Open No. 4-349166 discloses
Is Al having an average secondary particle diameter of 1 to 7 μm. _TwoO_ThreeFor powder
And SiO_Two10-20% by weight of powder and PbO powder
After adding and mixing at a ratio of 20 to 30% by weight, and molding,
Baking at 960 ° C. for 15 minutes is described,_TwoO_Three
By setting the average secondary particle size of the powder to 2.5 to 6 μm
Thus, it has been described that a ceramic having high thermal conductivity and high strength can be obtained.
ing.

[0008]

However, in the porcelain obtained by mixing and firing AlN powder and glass powder as a filler disclosed in Japanese Patent Application Laid-Open No. 2-212363, the AlN powder reacts with the glass powder to form fine particles in the porcelain. The dielectric loss of AlN has a frequency dependence, and the dielectric loss increases depending on the band used. As a result, the dielectric loss of the porcelain itself increases and the transmission of high-frequency signals increases. There is a problem that loss is large and transmission characteristics may be deteriorated.

Further, a large amount of Pb is added to Al ₂ O ₃ powder having an average secondary particle diameter of 1 to 7 μm disclosed in JP-A-4-349166.
In the porcelain to which O powder is added, the thermal conductivity and the mechanical strength can be improved. However, since the Pb content is large, the dielectric loss in a high frequency band is high, and for example, in a high frequency band such as a GHz band. It cannot be applied to the use of the used wiring board as an insulating board.

Accordingly, the present invention provides a porcelain that can be fired at 800 to 1050 ° C., which can be multilayered using gold, silver, and copper as wiring conductors, has low dielectric loss even in a high frequency region, and a method of manufacturing the same. It is an object of the present invention to provide a high-frequency ceramic composition that can be manufactured.

[0011]

Means for Solving the Problems As a result of diligent studies of the above-mentioned problems, the present inventors have found that at least SiO ₂ , Al ₂ O ₃ and M
O (M: alkaline earth metal element) and a low content of Pb in the crystallized glass, the average primary particle diameter as a filler is as large as 5 μm or more, and particularly the average secondary particle diameter of the filler is large. By adding a predetermined amount of a specific ceramic filler having a particle size exceeding 5 μm or the same as the average primary particle diameter of the filler, molding and firing at 800 to 1050 ° C. for 30 minutes or more, at least SiO ₂ and Al ₂
O ₃ and MO (M: alkaline earth metal element)
The ceramic particles having a large average crystal diameter of 2.5 μm or more are dispersed in a crystal matrix precipitated from a glass having a low content of b, and the content of the amorphous glass phase is reduced to 10% by weight or less. Porcelain can be manufactured, and the dielectric loss in a high frequency band is, for example, 60 to 77 GHz.
The inventors have found that z can be reduced to 50 × 10 ⁻⁴ or less, and have reached the present invention.

That is, the high frequency porcelain composition of the present invention has a small
At least SiO_TwoAnd Al_TwoO_ThreeAnd MO (M: alkaline earth
Metal element) and the Pb content is in terms of PbO
30 to 99% by weight of crystallized glass of 10% by weight or less,
Al with a uniform primary particle size of 3 μm or more_TwoO_Three, SiO_Two, MgT
iO_Three, (Mg, Zn) TiO_Three, TiO_Two, SrTi
O _Three, MgAl_TwoO_Four, ZnAl_TwoO_Four, Cordierite,
Mullite, enstatite, diopside, willema
Light, CaAl_TwoSi_TwoO₈, SrAl_TwoSi_TwoO₈, (S
r, Ca) Al_TwoSi_TwoO₈From the group of forsterites
1 to 70% by weight of at least one selected filler
Is contained at a ratio of

[0013] Here, the glass is fired to form a diopside crystal phase, MgAl ₂ O ₄ , ZnAl ₂ O ₄ , cordierite, mullite, enstatite, willemite, CaAl ₂ Si ₂ O ₈ , SrAl ₂ Si ₂ O ₈ , (Sr,
_{Ca) Al 2 Si 2 O 8} , it is desirable to be deposited at least one selected from the group consisting of forsterite, the softening point of the glass is desirably 700-850 ° C..

The average secondary particle diameter of the filler is 5%.
It is desirable that the average particle diameter exceeds μm, or that the average secondary particle diameter of the filler is the same as the average primary particle diameter of the filler.

The high frequency porcelain of the present invention contains at least SiO ₂ , Al ₂ O ₃ and MO (M: alkaline earth metal element), and has a Pb content of 10% by weight in terms of PbO.
In the following crystal matrix, Al ₂ O ₃ , SiO ₂ , MgTiO ₃ , (Mg, Zn) having an average crystal diameter of 2.5 μm or more
TiO ₃ , TiO ₂ , SrTiO ₃ , MgAl ₂ O ₄ , Zn
Al ₂ O ₄ , cordierite, mullite, enstatite, willemite, CaAl ₂ Si ₂ O ₈ , SrAl ₂ Si
_At least one type of ceramic particles selected from the group consisting of ₂ O ₈ , (Sr, Ca) Al ₂ Si ₂ O ₈ and forsterite is dispersed, and the dielectric loss at 60 to 77 GHz is 50 × 10 ^-4 or less. It is characterized by being.

Here, the crystal phase precipitated from the glass is MgAl ₂ O ₄ , ZnAl ₂ O ₄ , cordierite, mullite, enstatite, willemite, CaAl ₂ S
i ₂ O ₈ , SrAl ₂ Si ₂ O ₈ , (Sr, Ca) Al ₂ Si
_At least one selected from the group consisting of ₂ O ₈ and forsterite
Desirably a seed.

The content of the amorphous glass phase is 10
% Or less, and the amorphous glass phase preferably contains at least 70% by weight or more of Si in terms of oxide (SiO ₂ ), and has a coefficient of thermal expansion of 5 ppm / ° C. or more from room temperature to 400 ° C. It is desirable that the strength be 200 MPa or more and the thermal conductivity be 2 W / m · K or more.

The method for manufacturing a high-frequency porcelain according to the present invention is characterized in that at least SiO ₂ , Al ₂ O ₃ and MO (M: alkaline earth metal element) are contained and the Pb content is PbO
30 to 99% by weight of crystallized glass of 10% by weight or less in conversion
And Al ₂ O ₃ , SiO ₂ having an average primary particle diameter of 3 μm or more,
MgTiO ₃ , (Mg, Zn) TiO ₃ , TiO ₂ , Sr
TiO ₃ , MgAl ₂ O ₄ , ZnAl ₂ O ₄ , cordierite, mullite, enstatite, diopside, willemite, CaAl ₂ Si ₂ O ₈ , SrAl ₂ Si ₂ O ₈ ,
(Sr, Ca) Al ₂ Si ₂ O ₈ , a mixture of 1 to 70% by weight of at least one filler selected from the group of forsterite is formed, and then formed at 800 to 1050 ° C.
It is characterized by firing for 0 minutes or more.

Further, the wiring board of the present invention is characterized in that the above-mentioned high frequency ceramic is used as an insulating substrate, and a metallized wiring layer is provided on the surface and / or inside of the insulating substrate. .

Further, in the above wiring substrate, the metallized wiring layer is particularly effective when the main component is Cu or Ag.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The high frequency porcelain composition of the present invention comprises:
A crystallized glass containing at least SiO ₂ , Al ₂ O ₃ and MO (M: alkaline earth metal element) and having a Pb content of 10% by weight or less in terms of PbO, and 30 to 99% by weight;
Al ₂ O ₃ , SiO ₂ , Mg having an average primary particle diameter of 3 μm or more
TiO ₃ , (Mg, Zn) TiO ₃ , TiO ₂ , SrTi
O ₃ , MgAl ₂ O ₄ , ZnAl ₂ O ₄ , cordierite,
Mullite, enstatite, willemite, CaAl ₂
Si ₂ O ₈ , SrAl ₂ Si ₂ O ₈ , (Sr, Ca) Al ₂ S
It contains at least one filler selected from the group consisting of i ₂ O ₈ and forsterite in a proportion of 1 to 70% by weight.

The reason for limiting each component composition to the above range is as follows.
If the amount of the glass is less than 30% by weight, it is difficult to densify the porcelain by firing at a temperature of 1050 ° C. or less, and if it is more than 99% by weight, the crystallinity in the porcelain decreases, and This is because the loss increases.

The particularly desirable range of the glass is 45
-95% by weight, especially 45-80% by weight, furthermore 50-60%
5% by weight.

Further, the fact that the glass essentially contains Al ₂ O ₃ , SiO ₂ and MO (M: alkaline earth element) can reduce the dielectric loss of the glass and reduce the dielectric loss of the porcelain. Because it can increase the strength,
Desirable range of each component, Al ₂ O ₃ is 2.5 to 40 wt%, SiO ₂ is 35 to 60 wt%, MO: from the ratio of (M alkaline earth element) is a 5 to 55 wt% in total It is desirable to become. In addition, as the alkaline earth element,
It refers to at least one selected from the group consisting of Mg, Ca, Sr and Ba.

When the content of Pb in the glass exceeds 10% by weight, particularly 5% by weight, and more preferably 1% by weight in terms of PbO, the softening point of the glass is lowered and the densification at a low temperature can be promoted. According to the present invention, it is important that the content of Pb in the above-mentioned glass is 10% by weight or less in terms of PbO, because the dielectric loss in the high frequency band of the porcelain increases.

Further, ZnO, TiO ₂ , B ₂
The other components of the O ₃ or the like may be contained in a proportion of 20 wt% or less in total, but the content of B ₂ O ₃ in terms of reducing the dielectric loss, B ₂ O ₃ in terms of amount of 7 wt% The content is preferably 3% by weight or less, and in addition to PbO and B ₂ O ₃ , alkali metal elements such as Li, Na, and K, which increase dielectric loss in a high frequency band, ZrO ₂ , and Mn ₂ O. ₃ , Cr ₂ O ₃ , N
The iO component is 3 to the glass in total in terms of oxide.
% Is desirable.

The crystal phase which can be precipitated from the above glass and
For example, SiO_TwoCrystal phase, MgAl_TwoO_FourSpinel type etc.
Crystal phase, Ca (Mg, Al) (Si, Al)_TwoO₆Etc.
Iopside type crystal phase, CaMgSi_TwoO₇(Akerm
anite), CaMgSiO_Four(Monticell
item), Ca_ThreeMgSi_TwoO₈(Merwinit
e), MgSiO_Three, 3Al_TwoO_Three・ 2SiO_Two, Mg_TwoA
l_FourSi_FiveO₁₈, SrAl_TwoSi _TwoO₈, (Sr, Ca) A
l_TwoSi_TwoO₈(Slausonite), CaAl_TwoSi_TwoO
₈(Anorthite), BaAl_TwoSi_TwoO₈(Sergia
), (Ca, Sr) SiO_Three, SrSiO_ThreeEtc. are suitable
Can be used, but especially in terms of low dielectric loss and high strength
Is a diopside crystal phase, MgAl_TwoO_Four, ZnAl
_TwoO_Four, Cordierite, mullite, enstatite, c
Ilemite, CaAl_TwoSi_TwoO₈, SrAl_TwoSi_TwoO₈,
(Sr, Ca) Al_TwoSi_TwoO₈, Forsterite, special
Should preferably contain a diopside type crystal phase.
No.

Also, garnite, TiO ₂ , (Zn, M
g) TiO ₃ , (Zn, Mg) ₂ TiO ₄ , nZnO · B ₂
A crystal phase such as O ₃ may be precipitated as a sub-crystal phase.

Further, the composition of the glass capable of precipitating the diopside type crystal phase is such that the total amount of CaO and MgO in the glass is not sufficient in order to increase the rate of precipitation of the diopside type crystal phase from the glass. it is desirable 35-50 wt%, more SiO ₂ 30 to 55 wt%, Al ₂ O ₃ 4.5 to 15 wt%, MgO16～35 wt%, it is the percentage of CaO24~40 wt% desirable.

It is desirable that the glass capable of precipitating the diopside type crystal phase contains SrO in order to promote low-temperature firing of the porcelain. In this case, the glass composition is SiO ₂ 30 ~ 55% by weight, Al ₂ O ₃ 4
-15% by weight, MgO 14-30% by weight, CaO 5-2
Desirably, the ratio is 0% by weight and SrO is 10 to 25% by weight.

The diopside oxide crystal phase has a high thermal expansion characteristic of about 8 to 9 ppm / ° C. and a glass having a high Young's modulus of about 150 GPa and high strength. By precipitating a diopside oxide crystal phase from the above glass, the thermal expansion coefficient of the porcelain can be increased to, for example, 5 × 10 ⁻⁶ / ° C. or more, and the porcelain strength can be increased to, for example, 250 MPa or more.

In order to increase the thermal expansion coefficient of the porcelain, it is desirable to deposit a SiO ₂ crystal phase, MgAl ₂ O ₄ , ZnAl ₂ O ₄ , a diopside type crystal phase, enstatite, forsterite, or the like.

Further, if a large amount of an amorphous glass phase having a large dielectric loss remains in the porcelain, the dielectric loss of the porcelain increases. Therefore, the glass has a degree of crystallinity in the porcelain after firing of 90% or more, especially It is desirable to be as high as 95% or more.
The crystallinity of the glass can be determined by calculating the ratio of the amorphous glass phase by the Rietveld method using the X-ray diffraction peak of the glass after the heat treatment.

When the softening point of the glass is lowered, the densification at low temperatures is promoted, but the binder removal property is deteriorated, and a large amount of pores and residual carbon remain in the porcelain, causing discoloration, insulation properties, and dielectric loss. Causes a decrease in porcelain strength. In particular,
When co-firing with Cu metallization, the softening point of the above glass is as follows: in order to suppress the oxidation of Cu, it is necessary to fire in a non-oxidizing atmosphere, so that the binder removal property is further reduced. 700-85 higher than Pb glass)
The temperature is desirably 0 ° C, particularly 800 to 830 ° C.

On the other hand, as the filler, Al ₂ O ₃ ,
SiO ₂ , MgTiO ₃ , (Mg, Zn) TiO ₃ , Ti
O ₂ , SrTiO ₃ , MgAl ₂ O ₄ , ZnAl ₂ O ₄ , cordierite, mullite, enstatite, willemite, CaAl ₂ Si ₂ O ₈ , SrAl ₂ Si ₂ O ₈ , (Sr,
Ca) It is preferable to include at least one filler selected from the group consisting of Al ₂ Si ₂ O ₈ and forsterite at a ratio of 1 to 70% by weight, and among them, low dielectric loss,
Al ₂ O ₃ , MgAl ₂ O ₄ , ZnAl ₂
O ₄ , enstatite, CaAl ₂ Si ₂ O ₈ , SrAl ₂
It is desirable to contain Si ₂ O ₈ , (Sr, Ca) Al ₂ Si ₂ O ₈ , and further, Al ₂ O _{3 in} terms of thermal conductivity.

If the content of the filler is less than 1% by weight, the crystallinity of the glass in the porcelain decreases, and the dielectric loss of the porcelain increases, and the strength of the porcelain decreases. If it exceeds 70% by weight, sintering becomes difficult and 105
It cannot be densified at a firing temperature of 0 ° C. or less. At least a desirable range of the filler is 5% by weight or more, especially 15% by weight or more, further 25% by weight or more, even 40% by weight or more.
% By weight or more, and 65% by weight or less, particularly 60% by weight or less, further 55% by weight or less, further 50% by weight
It is as follows.

According to the present invention, specifically, the average primary particle size of the filler, that is, the average crystal particle size of the raw material powder,
That is, the filler has an average crystal grain size of 3 μm or more, desirably 5 μm or more, particularly 5.5 μm or more, especially 7.5 μm or more, and 8.5 or more, which can be measured from a SEM photograph of the filler by a known image analysis method such as an intercept method.
It is a great feature that it is as large as at least 10 μm, and further, it is possible to reduce the dielectric loss of the porcelain, and to lower the firing temperature for densifying the porcelain, that is, at a temperature of 1050 ° C. or less. Increasing the amount of porcelain filler that can be fired can also promote higher strength and higher thermal conductivity.

The filler may be spherical, needle-like, plate-like,
Although present in the form of powder such as amorphous, the average primary particle diameter in the present invention means the average diameter of single crystal particles of the powder. Generally, the average secondary particle diameter of the ceramic powder refers to a so-called average particle diameter measured by a sedimentation method or the like, but usually, the ceramic powder is agglomerated as shown in the schematic diagram of FIG. , That is, the average primary particle size is smaller than the average particle size of the secondary particles.

According to the present invention, the average primary particle size is 3 μm.
It is important that the average primary particle diameter is close to the average secondary particle diameter in order to promote the densification of the porcelain. It is desirable that the secondary particle diameter exceeds 5 μm.

Further, in order to densify the porcelain at a low temperature, to enhance the dispersibility of the filler in the porcelain, and to improve properties such as the strength and thermal conductivity of the porcelain, the average primary particle diameter is set to the average secondary particle diameter. The same, that is, it is desirable that the secondary particles are made of single crystal particles like the ceramic powder shown in FIG. The average secondary particle diameter of the glass powder is 0.5 to
It is desirable that the thickness be 4 μm, particularly 1 to 2.5 μm.

Further, in order to promote the densification of the porcelain and improve the porcelain strength together with the above-mentioned filler having a large particle diameter, the average primary particle diameter is 1 / l of the average particle diameter of the filler having a large particle diameter. 5 or less fine particles may be added. In this case, the primary particle size distribution of the filler is as shown in FIG.
It is desirable to have two peaks as shown in FIG.
Also in this case, it is important that the average primary particle size of the entire filler is 3 μm or more from the viewpoint of reducing the dielectric loss.

The porcelain composition of the above embodiment has a composition of 800 to 10
By baking in a temperature range of 50 ° C., the relative density can be reduced to 95% or more, particularly 97% or more, and further to 99% or more.

As shown in the schematic diagram of FIG. 2, the structure of the porcelain obtained by the above sintering is at least SiO ₂ and Al ₂ O.
₃ and MO (M: alkaline earth metal element)
Has a secondary particle diameter of 2.5 μm in a crystal matrix precipitated from a glass having a content of 10% by weight or less in terms of PbO.
m or more of Al ₂ O ₃ , SiO ₂ , MgTiO ₃ , (Mg, Z
_{n) TiO 3, TiO 2,} SrTiO 3, MgAl 2 O 4,
ZnAl ₂ O ₄ , cordierite, mullite, enstatite, willemite, CaAl ₂ Si ₂ O ₈ , SrAl ₂ S
A porcelain in which at least one type of ceramic particles selected from the group consisting of i ₂ O ₈ , (Sr, Ca) Al ₂ Si ₂ O ₈ and forsterite is dispersed.

The amorphous glass phase has an amorphous glass phase content of 10% by weight or less from the viewpoint of low dielectric loss. It is desirable to contain at least 40% by weight or more of Si in terms of oxide (SiO ₂ ).

Further, at least SiO ₂ and Al ₂ O ₃
The average primary particle diameter of the crystals precipitated from glass containing and MO (M: alkaline earth metal element) is 3 to 20 μm, particularly 4 to reduce the dielectric loss of porcelain and improve the thermal conductivity.
It is desirable that the thickness be 12 μm.

Furthermore, the average primary particle size of the ceramic particles tends to be smaller than the average primary particle size of the filler in the manufacturing process, according to the present invention.
The average crystal diameter of the ceramic particles precipitated from the filler in the porcelain is 2.5 μm or more, preferably 3.0 μm.
Above, especially 4.5 μm or more, further 6 μm or more, and 8
μm or more, and more preferably 10 μm or more.

The composition of the entire porcelain, for example, in the case of a porcelain obtained by adding Al ₂ O ₃ to a glass capable of precipitating a diopside crystal phase, is calculated as oxides of metal elements of Si, Al, Mg and Ca. When the combined amount is 100% by weight,
The SiO ₂ from 15 to 47.6 wt%, the Al ₂ O ₃ 32.4
~ 65 wt%, MgO 8 ~ 35 wt%, CaO12 ~
40% by weight, or the total amount of each metal element of Si, Al, Mg, Ca and Sr in terms of oxide is 100
% By weight, SiO ₂ is 15 to 49.6% by weight,
l ₂ O ₃ of 32.4 to 65 wt%, the MgO 8 to 35 wt%, CaO2.5～20 wt%, it is desirable that consists proportion of SrO7.5~25 wt%.

The above-mentioned porcelain is preferably a porcelain suitable for forming an insulating layer of a high-frequency wiring board of 1 GHz or more, particularly 20 GHz or more, more preferably 50 GHz or more, or even 70 GHz or more.

Here, the coefficient of thermal expansion of the porcelain from room temperature to 400 ° C. is 5 × 10 ⁻⁶ / ° C. or more, especially 6 × 10 ⁻⁶ / ° C.
° C or higher, more than 8 × 10 ⁻⁶ / ° C, further 10 × 1
It is desirable that the temperature be 0 ⁻⁶ / ° C. or higher, but it is desirable to appropriately adjust the thermal expansion coefficient so as to approximate the thermal expansion coefficient of a chip component to be mounted or a printed circuit board. This is because if the coefficient of thermal expansion of the porcelain is different from that of the mounted chip component or printed circuit board, the temperature of the chip component, printed circuit board and package may be increased by repeated temperature cycles during solder mounting or by stopping the operation of the semiconductor element. This is because stress due to the difference in thermal expansion is generated in the mounting portion, and cracks and the like are generated in the mounting portion, which impairs the reliability of the mounting structure.

More specifically, the difference in the coefficient of thermal expansion between the GaAs-based chip component and the GaAs-based chip component is 2 ppm / ° C. or less in order to achieve matching with the GaAs-based chip component. In this case, it is desirable that the difference in the coefficient of thermal expansion from the printed circuit board is 2 ppm / ° C. or less.

Further, since the strength of the porcelain is as high as 200 MPa or more, particularly 250 MPa or more, and more particularly 300 MPa or more, breakage due to stress applied to the porcelain at the time of mounting electronic parts such as semiconductor elements or at the time of connecting leads to input / output terminals. Can be prevented.

Further, the thermal conductivity of the porcelain is as high as 2 W / m · K or more, particularly 3 W / m · K or more, and further 4 W / m · K or more, and the electronic conductivity of the wiring board or the semiconductor element mounted on the wiring board is high. It is possible to efficiently radiate the heat generated from the component and prevent malfunction due to a rise in the temperature of the electronic component.

Next, a method for producing a porcelain using the high frequency porcelain composition of the present invention will be described.

First, as a starting material, at least SiO 2
_TwoAnd Al_TwoO_ThreeAnd MO (M: alkaline earth metal element)
Contained, and the Pb content is 10% by weight or less in terms of PbO
30 to 99% by weight of crystallized glass of
Al with a uniform primary particle size of 3 μm or more_TwoO_Three, SiO_Two, MgT
iO_Three, (Mg, Zn) TiO_Three, TiO_Two, SrTi
O _Three, MgAl_TwoO_Four, ZnAl_TwoO_Four, Cordierite,
Mullite, enstatite, willemite, CaAl_Two
Si_TwoO₈, SrAl_TwoSi_TwoO₈, (Sr, Ca) Al _TwoS
i_TwoO₈, At least selected from the group of Forsterite
One kind of filler is weighed and mixed at a ratio of 1 to 70% by weight.
You.

Here, as described above, in order to produce a raw material powder in which the primary particle diameter and the secondary particle diameter of the filler material are the same, that is, the secondary particles are single crystal particles, the spray pyrolysis method is used. A hydrothermal synthesis method or the like may be used.

At the time of mixing, a solvent is added to the powder, and if necessary, an organic binder, a plasticizer, and a dispersant are added to maintain the particle size of the raw material crystal of the filler. It is desirable to perform so-called wet mixing.

Then, a molded article having a predetermined shape is produced from the mixed powder by a known molding method such as a doctor blade method, a calender roll method, a rolling method, or a press molding method. By firing in an oxidizing atmosphere or an inert atmosphere for 30 minutes or more, a high frequency porcelain can be manufactured.

Here, the reason why the firing temperature is limited to the above range is that if the firing temperature is lower than 800 ° C., the porcelain cannot be densified, the crystallinity is low, and the ratio of the glass phase in the porcelain is 5% by volume or less. The reason for this is that the dielectric loss in the high frequency region increases, and conversely, if the temperature exceeds 1050 ° C., simultaneous sintering with a low-resistance metal mainly composed of Cu, Ag, or the like cannot be performed.

In order to densify the porcelain by firing at 1050 ° C. or less and to reduce the content of glass in the porcelain to 30% by weight or less, the temperature drop rate during firing is preferably set at 7%.
It is desirable that the temperature is not less than 1000 ° C./hour at 50 ° C. or more.

In order to manufacture a wiring board having a wiring layer, a slurry is prepared by mixing the mixed powder with an appropriate organic solvent and a solvent, and the slurry is prepared by using a well-known doctor blade method or calender roll. It is formed into a sheet by a rolling method or a press forming method. Then, after a through-hole is formed in the sheet-like molded body as desired, the through-hole is filled with a metal paste containing at least one of copper, gold, and silver as a main component. And
On the surface of the sheet-shaped molded body, the thickness of the wiring layer is 5 to 30 μm in a high-frequency line pattern or the like that can transmit a high-frequency signal by a screen printing method, a gravure printing method, a transfer method, or the like using the metal paste or the metal foil. So that
Print and apply.

Thereafter, a plurality of sheet-like molded bodies are aligned and laminated and pressed, and baked for 30 minutes or more in a non-oxidizing atmosphere such as a nitrogen gas or a nitrogen-oxygen mixed gas at 800 to 1050 ° C. A wiring substrate can be manufactured.

A chip component such as a semiconductor element is appropriately mounted on the surface of the wiring board, and is connected to the wiring layer so that signals can be transmitted. As a connection method, a connection is made by directly mounting on the wiring layer, or resin, Ag, or the like.
-The chip component is fixed to the surface of the insulating substrate with an adhesive such as epoxy, Ag-glass, resin such as Au-Si, metal, ceramics, etc. having a thickness of about 50 μm, and the wiring layer and the semiconductor element are bonded by wire bonding, TAB tape or the like. Or make a connection.

As a semiconductor element, a Si element or Ga
Although As-based chip components can be used, they are particularly effective for mounting GaAs-based chip components in terms of approximation of the coefficient of thermal expansion.

Further, a cap made of an insulating material of the same kind as the insulating substrate, another insulating material, or a metal having a good heat radiation property and having an electromagnetic wave shielding property is provided on the surface of the wiring board on which the semiconductor element is mounted, with glass, The semiconductor element may be hermetically sealed by bonding with an adhesive such as a resin or a brazing material.

(Structure of Wiring Board) A specific structure of a package for housing a semiconductor element, which is an example of a high-frequency wiring board in which the porcelain composition of the present invention can be suitably used, and a mounting structure thereof will be described with reference to FIG. explain. FIG. 4 is a schematic sectional view of a semiconductor storage package, particularly a ball grid array (BGA) type package in which connection terminals are formed of ball-shaped terminals. According to FIG. 4, the package A has a cavity 3 formed by an insulating substrate 1 made of an insulating material and a lid 2, and a chip component 4 such as GaAs is formed in the cavity 3 by the above-mentioned adhesive or the like. Has been implemented.

Further, on the surface and inside of the insulating substrate 1,
A wiring layer 5 electrically connected to the chip component 4 is formed. The wiring layer 5 preferably contains a low-resistance metal such as copper, silver, or gold as a main component in order to minimize conductor loss during transmission of a high-frequency signal. When transmitting a high-frequency signal of 1 GHz or more to the wiring layer 5,
Since it is necessary to transmit a high-frequency signal without loss, the wiring layer 5 is formed of at least one of a known strip line, microstrip line, coplanar line, and dielectric waveguide line.

Further, in the package A of FIG. 4, a connection electrode layer 6 is formed on the bottom surface of the insulating substrate 1 and is connected to the wiring layer 5 in the package A. A ball-shaped terminal 8 is formed on the connection electrode layer 6 with a brazing material 7 such as solder. Although the ball-shaped terminals are used in FIG. 4, they can be directly connected by solder.

In order to mount the package A on an external circuit board, as shown in FIG. 4, wiring is provided on the surface of an insulating substrate 9 made of an insulating material containing an organic resin such as a polyimide resin, an epoxy resin, or a phenol resin. The external circuit board B on which the conductor 10 is formed is mounted via a brazing material. Specifically, the ball-shaped terminal 8 attached to the bottom surface of the insulating substrate 1 in the package A and the wiring conductor 10 of the external circuit board B are brought into contact with each other and soldered with solder 11 such as Pb-Sn. Implemented. Further, the ball-shaped terminal 8 itself may be melted and connected to the wiring conductor 10.

According to the present invention, the chip component 4 such as GaAs is mounted on the external circuit board such as a printed board by soldering or mounting with an adhesive or by soldering with such ball-shaped terminals 8 interposed therebetween. In such a surface mount type package, a thermal cycle was applied to such a mounting structure by making a difference in thermal expansion between a chip component such as GaAs and an insulating substrate of an external circuit board smaller than that of a conventional ceramic material. Even in such a case, the generation of stress in the mounting portion can be suppressed, so that the long-term reliability of the mounting structure can be improved.

[0070]

EXAMPLES The following composition Glass A: SiO ₂ 50.2% by weight-Al ₂ O ₃ 5.0% by weight-MgO 16.1% by weight-CaO 15.1% by weight-
SrO13.6 wt% Glass B: SiO ₂ 50 wt% -Al ₂ O ₃ 5.5 wt%
-MgO18.5 wt% -CaO26 wt% Glass C: SiO ₂ 44 wt% -Al ₂ O ₃ 29 wt% -
MgO11 wt% -ZnO7 wt% -B ₂ O ₃ 9 wt% Glass D: SiO ₂ 12 wt% -Al ₂ O ₃ 23.5 wt% -MgO0.5 wt% -CaO13 wt% -B ₂ O ₃ 2
3 wt% -Li ₂ O12.5 wt% -Na ₂ O15.5 wt% Glass E: SiO ₂ 18 wt% -Al ₂ O ₃ 55 wt% -
A glass having an average secondary particle diameter of 2 μm and containing 27% by weight of PbO 2 was prepared.

For the above glass, the average primary particle size based on the intercept method in the SEM photographs of the powders shown in Tables 1 to 4 (described as primary diameter in the table) and the average secondary particle size based on the microtrack method Add a filler (purity: 99%) in the diameter (described as secondary diameter in the table), add an organic binder, a plasticizer, and toluene, wet-mix for 20 hours to prepare a slurry, and then use this slurry. A green sheet having a thickness of 300 μm was prepared by a doctor blade method. Then, 10 to 15 green sheets were laminated, and thermocompression-bonded at a temperature of 50 ° C. by applying a pressure of 9.8 MPa. The obtained laminate was subjected to a binder removal treatment at 700 ° C. in a nitrogen atmosphere, and then fired in dry nitrogen at the firing temperatures shown in Tables 1 to 2 for 2 hours to obtain an insulating substrate porcelain. At the time of firing, the temperature raising rate and the temperature lowering rate were set at 300 ° C./h.

The obtained ceramics were evaluated for permittivity and dielectric loss by the following methods. The measurement is shape, diameter 2-7mm,
Cut out to 1.5-2.5mm thickness, 60GHz
, And a dielectric cylinder resonator method using a network analyzer and a synthesized sweeper. In the measurement, the dielectric resonator was excited by an NRD guide (non-radiative dielectric line), and the dielectric constant and the dielectric loss were calculated from the resonance characteristics of the TE ₀₂₁ and TE ₀₃₁ modes.

Further, a thermal expansion curve from room temperature to 400 ° C. was taken to calculate a thermal expansion coefficient. Further, the crystal phase in the sintered body was identified from the X-ray diffraction chart. Also,
The thermal conductivity of a sample having a thickness of 1 μm was measured by a laser flash method.

The ratio of the glass phase in the porcelain was evaluated by the Rietveld method. Specifically, after the porcelain to be evaluated was pulverized, ZnO or the like was added at a predetermined ratio as an internal standard sample, and ethanol was added thereto, followed by wet mixing. After drying, X-ray diffraction measurement was performed, and the ratio of the glass phase present in the porcelain was calculated from the addition ratio of ZnO and the ratio of ZnO obtained by the Rietveld method to the crystal phase in the porcelain. The ratio of Si in the glass phase is measured by
The ratio in iO ₂ conversion was calculated. Also, JISR160
Based on No. 1, the four-point bending strength of the porcelain was measured. The results are shown in Tables 1 to 4.

[0075]

[Table 1]

[0076]

[Table 2]

[0077]

[Table 3]

[0078]

[Table 4]

As is clear from the results of Tables 1 to 4, Pb
Glass E having an O content exceeding 10% by weight in terms of PbO
Using the sample No. In the case of No. 55, the dielectric loss increased and measurement became impossible.

Further, SiO ₂ , Al ₂ O ₃ and MgO,
Sample No. 1 containing at least one of CaO and SrO and containing less than 10% by weight of PbO and less than 30% by weight of glass A, B, and C. Samples Nos. 1, 32, and 43 are difficult to sinter at low temperatures, do not densify, and have a content of the glasses A, B, and C of more than 99% by weight and a filler amount of less than 1% by weight. No. In No. 7, the crystallization ratio of the glass was reduced, and the dielectric loss was increased. Further, Sample No. using powder having an average primary particle size of less than 3 μm as a filler. In 8, 9, 38, and 47, the dielectric loss increased.

On the other hand, according to the present invention, SiO ₂ ,
The average primary particle size is as large as 3 μm or more with respect to glasses A, B, C, and D containing Al ₂ O ₃ and one or more of MgO, CaO, and SrO and having a PbO content of less than 10% by weight. A specific amount of a specific filler is added, and SiO ₂ , A
A specific crystal phase having an average particle diameter of 2.5 μm or more was dispersed in a crystal matrix containing l ₂ O ₃ and one or more of MgO, CaO, and SrO and containing less than 10% by weight of PbO. Sample No. 2-6, 10-31, 3
In 3-37, 39-42, 44-46, 48-54,
In each case, the dielectric loss was 5 at the measurement frequency of 60 GHz.
It had excellent properties of 0 × 10 ⁻⁴ or less, a coefficient of thermal expansion of 5 ppm / ° C. or more, and a porcelain strength of 200 MPa or more.

[0082]

As described in detail above, according to the high frequency ceramic composition of the present invention, since it can be fired at a low temperature of 1050 ° C. or less, it is possible to form a wiring layer mainly composed of a low-resistance metal such as copper. In addition, since the dielectric loss at 60 to 77 GHz is as low as 50 × 10 ⁻⁴ or less in the high frequency region of 1 GHz or more, the high frequency signal can be transmitted very favorably without loss.

Further, the porcelain obtained by using this composition has a high porcelain strength of 200 MPa or more and GaAs.
Since the thermal expansion characteristics can be controlled to be similar to that of a chip or a printed board, it is excellent when a GaAs chip is mounted or when mounted on a motherboard such as a printed board having an insulating substrate containing an organic resin using a brazing material or the like. A highly reliable mounting structure having heat cycle resistance can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a particle shape of a filler in a high-frequency ceramic composition of the present invention.

FIG. 2 is a schematic view showing an example of a tissue state in the high frequency porcelain of the present invention.

FIG. 3 is an example showing the distribution of the secondary particle size of the filler in the high frequency ceramic composition of the present invention.

FIG. 4 is a schematic cross-sectional view for explaining an example of a mounting structure of a package for housing a semiconductor element, which is an example of a high-frequency wiring board using a porcelain obtained by firing the composition of the present invention.

[Explanation of symbols]

 Reference Signs List A semiconductor device storage package B external circuit board 1 insulating substrate 2 lid 3 cavity 4 chip component 5 wiring layer 6 connection electrode layer 7 brazing material 8 ball-shaped terminal 9 insulating substrate 10 wiring conductor 11 brazing material

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C04B 35/44 H05K 1/03 610D 35/46 610R H01B 3/02 C04B 35/00 J H01L 23/02 35 / 10 D 23/08 35/16 A 23/15 Z H05K 1/03 610 35/18 B Z H01L 23/14 CF term (reference) 4G030 AA02 AA03 AA07 AA08 AA09 AA16 AA32 AA36 AA37 AA40 BA12 CA01 CA04 4G031 AA03 AA05 AA26 AA29 AA30 AA32 BA12 CA01 CA04 5G303 AA05 AB07 AB12 AB15 AB17 AB20 BA12 CA03 CB01 CB03 CB06 CB17 CB25 CB30 CB32 CB35 CB38 DA05

Claims (17)

[Claims] (1) at least SiO_TwoAnd Al_TwoO_ThreeAnd MO
(M: alkaline earth metal element) and Pb.
Crystallized glass 30 having a content of 10% by weight or less in terms of PbO
-99% by weight and Al having an average primary particle diameter of 3 μm or more
_TwoO_Three, SiO_Two, MgTiO_Three, (Mg, Zn) Ti
O_Three, TiO_Two, SrTiO_Three, MgAl_TwoO_Four, ZnAl_Two
O_Four, Cordierite, mullite, enstatite, c
Ilemite, CaAl _TwoSi_TwoO₈, SrAl_TwoSi_TwoO₈,
(Sr, Ca) Al_TwoSi_TwoO₈, A group of forsterites
1 to 70 weight by weight of at least one filler selected from
% Of high frequency porcelain set
Adult. 2. The glass is fired to obtain a diopside type crystal phase, MgAl ₂ O ₄ , ZnAl ₂ O ₄ , cordierite, mullite, enstatite, willemite, CaA.
l ₂ Si ₂ O ₈ , SrAl ₂ Si ₂ O ₈ , (Sr, Ca) Al
₂ Si ₂ O _8, high-frequency ceramic composition of claim 1, wherein the can precipitate at least one selected from the group consisting of forsterite. 3. The high frequency porcelain composition according to claim 1, wherein the glass has a softening point of 700 to 850 ° C. 4. The high frequency porcelain composition according to claim 1, wherein the average secondary particle diameter of the filler exceeds 5 μm. 5. The high frequency ceramic composition according to claim 1, wherein the average secondary particle diameter of the filler is the same as the average primary particle diameter of the filler. 6. At least SiO ₂ , Al ₂ O ₃ and MO
(M: alkaline earth metal element), and in a crystal matrix having a Pb content of 10% by weight or less in terms of PbO, Al ₂ O ₃ , SiO ₂ , having an average crystal diameter of 2.5 μm or more,
MgTiO ₃ , (Mg, Zn) TiO ₃ , TiO ₂ , Sr
_{TiO 3, MgAl 2 O 4,} ZnAl 2 O 4, cordierite, mullite, enstatite, willemite, CaA
l ₂ Si ₂ O ₈ , SrAl ₂ Si ₂ O ₈ , (Sr, Ca) Al
_At least one type of ceramic particles selected from the group consisting of ₂ Si ₂ O ₈ and forsterite dispersed therein;
A high frequency porcelain characterized in that a dielectric loss at 0 to 77 GHz is 50 × 10 ⁻⁴ or less. 7. The crystal phase precipitated from the glass is MgA
l ₂ O ₄ , ZnAl ₂ O ₄ , cordierite, mullite, enstatite, willemite, CaAl ₂ Si ₂ O ₈ , S
7. The high frequency porcelain according to claim 6, wherein the porcelain is at least one selected from the group consisting of rAl ₂ Si ₂ O ₈ , (Sr, Ca) Al ₂ Si ₂ O ₈ , and forsterite. 8. The content of the amorphous glass phase is 10% by weight.
Or less, and the amorphous glass phase is at least Si
8. The high frequency porcelain according to claim 6, wherein said ceramics contains at least 40% by weight of oxide (SiO ₂ ). 9. The thermal expansion coefficient from room temperature to 400 ° C. is 5
The high frequency porcelain according to any one of claims 6 to 8, wherein the porcelain strength is not less than ppm / ° C and the porcelain strength is not less than 200 MPa. 10. The high frequency porcelain according to claim 6, wherein the heat conductivity is 2 W / m · K or more. 11. At least SiO ₂ , Al ₂ O ₃ and MO
(M: alkaline earth metal element), and the Pb content is 10% by weight or less in terms of PbO.
-99% by weight and Al having an average primary particle diameter of 3 μm or more
₂ O ₃ , SiO ₂ , MgTiO ₃ , (Mg, Zn) Ti
O ₃ , TiO ₂ , SrTiO ₃ , MgAl ₂ O ₄ , ZnAl ₂
O ₄ , cordierite, mullite, enstatite, willemite, CaAl ₂ Si ₂ O ₈ , SrAl ₂ Si ₂ O ₈ ,
_{(Sr, Ca) Al 2 Si} 2 O 8, after molding the mixture at least one filler selected from the group consisting of 1 to 70% by weight of forsterite, 3 at 800 to 1050 ° C.
A method for producing a high-frequency porcelain, which is baked for 0 minutes or more. 12. The glass according to claim 1, wherein said glass is made of MgAl.
_TwoO_Four, ZnAl_TwoO_Four, Cordierite, mullite, en
Statite, Willemite, CaAl_TwoSi_TwoO ₈, Sr
Al_TwoSi_TwoO₈, (Sr, Ca) Al_TwoSi_TwoO₈, Pho
Precipitates at least one selected from the group of stellite
The method of manufacturing a high frequency porcelain according to claim 11, wherein
Method. 13. The glass has a softening point of 700 to 850 ° C.
The method for manufacturing a high-frequency porcelain according to claim 11, wherein 14. An average secondary particle diameter of the filler is 5 μm.
The method for producing a high-frequency porcelain according to claim 11 or 13, wherein 15. The method according to claim 11, wherein the average secondary particle diameter of the filler is the same as the average primary particle diameter of the filler. 16. On the surface and / or inside of the insulating substrate,
A wiring board provided with a metallized wiring layer, wherein the insulating substrate is made of the high-frequency ceramic according to any one of claims 5 to 9. 17. The method according to claim 17, wherein the metallized wiring layer is made of Cu or A.
17. The wiring board according to claim 16, wherein g is a main component.