JP3441950B2 - Wiring board and its mounting structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring board applied to a package for housing a semiconductor element, a multilayer wiring board, etc., and in particular, it can be co-fired with copper or silver, and a printed board. The present invention relates to a wiring board that can be mounted with high reliability on an external electric circuit board made of an organic resin such as, and its mounting structure.

[0002]

2. Description of the Related Art Conventionally, as a ceramic multilayer wiring board, one in which a wiring layer made of a refractory metal such as tungsten or molybdenum is formed on the surface or inside of an insulating substrate made of an alumina sintered body is most popular. There is.

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

However, conventional tungsten (W),
Refractory metals such as molybdenum (Mo) have a large conductor resistance, have a low signal propagation speed, and are difficult to propagate signals in a high frequency region of 30 GHz or more. Therefore, instead of metals such as W and Mo, copper, It is necessary to use low resistance metals such as silver and gold.

The wiring layer made of such a low resistance metal is
Since it is impossible to co-fire with alumina, a wiring board using glass or a so-called glass ceramics, which is a composite material of glass and ceramics, as an insulating substrate is being developed recently. For example, as in Japanese Examined Patent Publication No. 4-12639, a multilayer wiring in which a SiO ₂ -based filler is added to glass and a wiring layer made of a low resistance metal such as copper, silver and gold is co-fired at a temperature of 900 to 1000 ° C. Substrates, such as those disclosed in JP-A-60-240135, have been proposed in which zinc borosilicate glass to which a filler such as Al ₂ O ₃ or mullite is added is co-fired with a low resistance metal. . In addition, Japanese Patent Laid-Open No. 5-2
Japanese Patent Publication No. 98919 also proposes a glass ceramic material in which mullite or cordierite is precipitated as a crystal phase.

In mounting a wiring board such as a multi-layer wiring board or a package for housing a semiconductor element on a printed board whose insulating substrate such as a masser board contains an organic resin, it is mounted by a stress generated due to a difference in thermal expansion from the printed board. It is desirable that the thermal expansion coefficient of the insulating substrate be close to the thermal expansion coefficient of the printed circuit board in order to prevent the peeling of the portion and the generation of cracks.

[0007]

However, even if the above-mentioned conventional glass ceramics can be co-fired with a low resistance metal such as copper, silver or gold, the conventional glass ceramics sintered body is made of alumina. The coefficient of thermal expansion was lower than that of the quality sintered body, which was about 3 to 6 ppm / ° C., and when mounted on a printed board, the mounting reliability was low and not satisfactory in practice. Further, it has not been specifically studied as an insulating substrate for a wiring substrate using a high frequency signal such as a microwave or a millimeter wave, and most of them have high dielectric loss and do not have sufficiently high frequency characteristics.

Therefore, according to the present invention, it is possible to fire at 800 to 1000 ° C. so that gold, silver and copper as wiring conductors can be multilayered, and a high thermal expansion coefficient close to that of the printed circuit board can be obtained. An object of the present invention is to provide a wiring board having a low dielectric constant and a low dielectric loss even in a high frequency region. It is another object of the present invention to provide a mounting structure of a wiring board that can be mounted on an external electric circuit board such as a printed board with high reliability.

[0009]

Means for Solving the Problems As a result of diligent studies on the above problems, the present inventor has found that in a wiring board in which a wiring layer is provided on the surface or inside of the insulating board, the insulating board is
i, Al, Zn, Mg, comprises Zr, and Ca, constituted by a composite oxide sintered body containing as a constituent element at least one selected from among Sr, and Ba, in its sintered body, SiO ₂ By precipitating a crystalline phase, a spinel type crystalline phase containing at least Zn and Al, and a ZrO ₂ crystalline phase as constituent phases, it is possible to achieve high thermal expansion, low dielectric constant, and low dielectric loss in a high frequency region. The present invention has been accomplished by finding that the above can be realized.

That is, the wiring board of the present invention comprises an insulating board,
The wiring board is provided on the surface and / or inside thereof, and the insulating substrate is made of Si, Al, Z.
n, Mg, and Zr, and at least one selected from Ca, Sr, and Ba as a constituent element, and as a crystal phase, a SiO ₂ crystal phase and at least Z
A sintered body containing a spinel type crystal phase containing n and Al and a ZrO ₂ crystal phase and having a thermal expansion coefficient of 7 ppm / ° C. or more from room temperature to 400 ° C. is characterized. Further, the SiO ₂ crystal phase is a quartz crystal phase, the ZrO ₂ crystal phase is composed of a monoclinic crystal and / or a tetragonal crystal, and the composite oxide sintered body is made of Si.
30 to 95% by weight of glass powder containing O ₂ , Al ₂ O ₃ , MgO, ZnO and B ₂ O ₃ , and SiO ₂ 4.9 to 4
0% by weight, 0.1 to 10% by weight of a complex oxide of ZrO ₂ and at least one selected from Ca, Sr and Ba, 0 to 30% by weight of ZnO, and 0 to 10% by weight of B ₂ O _3. % After being molded and then fired at a temperature of 800 to 1000 ° C., in which case the glass powder is Si
O ₂ 40 to 52 wt%, Al ₂ O ₃ 14 to 32 wt%,
MgO 4 to 24% by weight, ZnO 1 to 16% by weight, B ₂ O
₃ is characterized in that comprising a proportion of 5 to 15 wt%.

Further, according to the wiring board mounting structure of the present invention, there is provided a wiring board having an insulating substrate, a wiring layer provided on the surface or inside thereof, and a connection terminal for connecting to an external electric circuit. Mounted on an external electric circuit board having a wiring conductor formed on at least the surface of an insulator containing an organic resin, and the connection terminals of the wiring board being brazed to the wiring conductor of the external electric circuit board The insulating substrate of the wiring substrate contains Si, Al, Zn, Mg, and Zr, and contains at least one or more selected from Ca, Sr, and Ba as constituent elements, and has a crystal phase of SiO. _A sintered body containing ₂ crystal phases, a spinel type crystal phase containing at least Zn and Al, and a ZrO ₂ crystal phase, and having a thermal expansion coefficient of 7 ppm / ° C. or more at room temperature to 400 ° C. It is characterized by.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A wiring board of the present invention will be described with reference to FIG. 1 by way of example of a package in which a semiconductor element is housed and mounted. FIG. 1 is a schematic cross-sectional view of a package for accommodating semiconductor elements, particularly a ball grid array (BGA) type package in which connection terminals are ball-shaped terminals. Figure 1
According to the package A, the cavity 3 is formed by the insulating substrate 1 made of an insulating material and the lid 2, and the semiconductor element 4 is mounted in the cavity 3.

On the surface and inside of the insulating substrate 1,
A wiring layer 5 electrically connected to the semiconductor element 4 is formed. The wiring layer 5 is preferably made of a low resistance metal such as copper, silver or gold in order to reduce conductor loss as much as possible when transmitting a high frequency signal. Further, the wiring layer 5 has a frequency of 1 GHz or more, particularly 20 GHz or more, and further 50 GHz.
In the case of transmitting a high frequency signal of Hz or higher, or even 70 GHz or higher, it is necessary to transmit the high frequency signal without loss, and therefore known strip lines, microstrip lines, coplanar lines, dielectric waveguides are known. It is composed of at least one of the lines.

Further, in the package of FIG. 1, a connection electrode layer 6 is adhered and formed on the bottom surface of the insulating substrate 1 and electrically connected to the wiring layer 5 in the package. Then, a brazing material 7 such as solder is formed on the connecting electrode layer 6.
Thus, the ball-shaped terminal 8 is adhered and formed.

According to the present invention, the insulating substrate 1 in the package as shown in FIG.
It is composed of a composite oxide sintered body containing n, Mg and Zr and containing at least one selected from Ca, Sr and Ba as a constituent element. In addition, as shown in the schematic diagram for explaining the structure of the sintered body of FIG.
The main crystal phase is any one of a crystal phase (Si) made of iO ₂ and a spinel type crystal phase (SP) made of at least ZnO and Al ₂ O _3, and all of the crystals in the sintered body are formed by these two crystals. It accounts for 50% or more of the phases. Further, according to the present invention, a ZrO ₂ crystal phase is contained as a crystal phase other than the above _two crystal phases.

The crystal phase (Si) made of SiO ₂ is preferably a quartz type crystal phase, and at least Z
Spinel type crystal phase (S containing mainly nO and Al ₂ O ₃
Examples of P) include garnite represented by ZnAl ₂ O ₄ . The ZrO ₂ crystal phase is monoclinic (ZrO ₂
(M))) and / or a tetragonal crystal (ZrO ₂ (T)), and it is particularly desirable to include a tetragonal crystal.

In addition to the main constituent metallic elements, other metallic elements may be solid-dissolved in each of the above-mentioned crystal phases to the extent that the crystal structure is not changed. For example, ZnAl ₂ O ₄
MgAl ₂ O ₄ forms a solid solution with (Zn, Mg) Al.
_It may consist of a spinel type crystal phase of ₂ O ₄ . Also,
In addition to SiO ₂ , Zn and B may form a solid solution in the quartz crystal phase.

Further, according to the present invention, in addition to the above three crystals, a cordierite type crystal phase represented by 2MgO.2Al ₂ O ₃ .5SiO ₂ may be present in a trace amount. Furthermore, in the sintered body structure, at the grain boundaries of the above crystal phase,
There may be a glass phase containing SiO ₂ , or SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , or an alkaline earth.

The overall composition of the complex oxide sintered body constituting the insulating substrate of the present invention is Si, Al, Z.
When the total amount of at least one metal selected from Ca, Sr, and Ba containing n, Mg, and Zr is calculated as 100 wt%, SiO ₂ is 30 to 60 wt%, Al 18 to 25% by weight of ₂ O ₃ and 5 to 3 of ZnO
It is desirable that the total amount of 5 wt%, ZrO ₂ 1-3 wt%, MgO 5-13 wt%, CaO, SrO, and BaO be 6-16 wt%.

Further, according to the present invention, as the crystal phase, the SiO ₂ crystal phase, the spinel type crystal phase and the ZrO ₂ crystal phase have high thermal expansion characteristics themselves at room temperature to 400 ° C. , Quartz type crystal is 13 ~ 20
ppm / ° C, 7-8 ppm / ° C for garnite type crystals, Z
Since the rO ₂ crystal phase has a thermal expansion coefficient of 7 to 9 ppm / ° C., the thermal expansion coefficient of the insulating substrate tends to increase by forming a sintered body from these crystal phases. In order to increase the coefficient of thermal expansion, it is desirable to use SiO ₂
The crystal phase, especially the quartz type crystal phase, is most preferable. As the SiO ₂ crystal phase, there are cristobalite and tridymite in addition to quartz.
It is not desirable because it has a bending point of the coefficient of thermal expansion near 00 ° C.

According to the present invention, the insulating substrate made of the above complex oxide sintered body has a low dielectric constant of 6 or less, particularly 5 or less, and improves the reliability of mounting on a printed circuit board. The thermal expansion coefficient of the insulating substrate from room temperature to 400 ° C is 7 ppm / ° C or higher, particularly 9 ppm / ° C or higher, and further 1
It is preferably 0 ppm / ° C or higher. This is because when the coefficient of thermal expansion is lower than 7 ppm / ° C., the thermal expansion difference between the printed circuit board and the printed circuit board causes heat to be applied to the mounting part of the printed circuit board and the package due to repeated temperature cycles due to the operation stop of the semiconductor element. Stress caused by the difference in expansion occurs,
This is because a crack or the like occurs in the mounting portion, and the reliability of the mounting structure is impaired.

Therefore, the mounting structure in the present invention is as shown in FIG.
As shown in FIG. 3, with respect to the external electric circuit board B in which the wiring conductor 10 is formed on the surface of the insulating substrate 9 made of an insulating material containing an organic resin such as a polyimide resin, an epoxy resin, or a phenol resin, a brazing material is used. It will be implemented.
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 electric circuit board B are brought into contact with each other to make a brazing material 11 such as solder such as Pb-Sn. It is mounted by brazing. Also,
The ball-shaped terminal 8 itself may be melted and connected to the wiring conductor 10.

According to the present invention, in the surface mount type package which is mounted by brazing with the ball-shaped terminal 8 interposed, it is soldered and mounted on the external electric circuit board made of the insulating substrate containing the organic resin. In this case, since the difference in thermal expansion between the external electric circuit board and the insulating substrate can be made smaller than that of the conventional ceramic material, stress generation is suppressed even when a thermal cycle is applied to such a mounting structure. As a result, the long-term reliability of the mounting structure can be improved.

Next, a method of manufacturing the composite oxide sintered body which constitutes the insulating substrate of the wiring substrate in the present invention will be described. First, as starting materials, SiO ₂ , Al
Crystallized glass powder containing ₂ O ₃ , MgO, ZnO, B ₂ O ₃ , and ZnO powder, SiO ₂ powder, or willemite (Zn ₂ SiO ₄ ) powder as a filler component, B
A composite oxide of ₂ O ₃ powder and at least one oxide (MO) selected from Ca, Sr and Ba and ZrO ₂ is used in combination, and these are mixed in a desired ratio.

The desirable composition of the crystallized glass used is as follows: SiO ₂ 40 to 52 wt%, Al ₂ O ₃ 14 to 32
Wt%, MgO4～24 wt%, ZnO1～16 wt%, it is desirable that the B ₂ O ₃ 5 to 15 wt%.

Then, with respect to 30 to 95% by weight, especially 60 to 90% by weight of the above glass powder, 4.9 SiO ₂ is added.
-40% by weight, especially 9-30% by weight, MO and ZrO ₂ are added in a total amount of 0.1-10% by weight, especially 1-5% by weight, and ZnO as an optional component is 0-30% by weight. % And B ₂ O _{3 in an amount} of 0 to 10% by weight.

In the above raw material powder, the reason why each component is limited to the above range is that when the glass powder is less than 30% by weight, it is fired at a temperature of 1000 ° C. or less unless B ₂ O ₃ is blended in a large amount. Is not possible, and if it exceeds 95% by weight, the thermal expansion coefficient of 7 ppm / ° C. or more cannot be achieved.

When the amount of SiO ₂ is less than 4.9% by weight, the absolute amount of the SiO ₂ crystal phase in the sintered body decreases, so that a sintered body having a high thermal expansion cannot be obtained and 40% by weight is obtained. This is because if it exceeds 1.0, it becomes difficult to sinter and cannot be densified at a firing temperature of 1000 ° C. or less.

MO and ZrO ₂ are MZ such as CaZrO _3.
It is most desirable to add it as a rO ₃ -based composite oxide, and especially by adding MO and ZrO ₂ , the sinterability of such a system can be greatly improved. Voids can be reduced. Further, the thermal expansion coefficient of the glass phase made of Al ₂ O ₃ or SiO ₂ is generally as low as 5 to 6 ppm / ° C. But,
When SrO is allowed to react with Al ₂ O ₃ or SiO ₂ in the glass to precipitate a complex oxide such as slausonite, the slausonite has a high thermal expansion property of about 7 ppm / ° C. The thermal expansion coefficient of the whole is SrO
Can be increased by about 0.5 to 1 ppm / ° C. as compared with the case where no is added. The remaining ZrO ₂ plays a role of promoting the above crystallization. However, since the dielectric constant of ZrO ₂ itself is high, if a large amount of ZrO ₂ remains, the dielectric constant of the entire system becomes high, which is not desirable.

Therefore, if the amount of addition of MO and ZrO ₂ is less than 0.1% by weight, the effect of improving sinterability and the effect of reducing voids are small, and if it is more than 10% by weight, the dielectric constant becomes high.

B ₂ O ₃ and ZnO are optional components, and the addition of these components can improve the sinterability. However, if the amount of ZnO exceeds 30% by weight, it is difficult to fire at 1000 ° C or lower, and the coefficient of thermal expansion of the sintered body becomes low, and if the amount of B ₂ O ₃ exceeds 10% by weight, dissolution of the B component in the solvent, etc. This is because it becomes difficult to form a slurry and a tape from the above problem.

Then, a predetermined molded body is prepared by using the mixed powder which is weighed and mixed with the above composition, and the molded body is mixed with 80
It can be produced by firing in an oxidizing atmosphere or an inert atmosphere at 0 to 1000 ° C.

In order to manufacture a wiring board having a wiring layer using the above-mentioned sintered body, the above-mentioned mixed powder is used,
A slurry is prepared by mixing using a suitable organic solvent and a solvent, and the slurry is formed into a sheet by a conventionally known doctor blade method, calender roll method, rolling method or press molding method. Then, after forming a through hole in the sheet-shaped molded product as desired, in the through hole,
A metal paste containing at least one of copper, gold and silver is filled. Then, a high-frequency line pattern capable of transmitting a high-frequency signal is printed and applied on the surface of the sheet-shaped molded product by using a metal paste so that the wiring layer has a thickness of 5 to 30 μm by a screen printing method, a gravure printing method, or the like. . After that, a plurality of sheet-shaped compacts are aligned, laminated and pressure-bonded, and then fired in an oxidizing atmosphere or a non-oxidizing atmosphere at 800 to 1000 ° C. to manufacture a wiring board.

A semiconductor element is 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, it is directly mounted on the wiring layer for connection, or wire bonding or TA
The wiring layer and the semiconductor element are connected by a B tape or the like.

Furthermore, on the surface of the wiring board on which the semiconductor element is mounted, a cap made of the same insulating material as the insulating board, other insulating material, or a metal having a good heat dissipation property, such as glass, resin, or brazing material, is used. By joining with an adhesive, the semiconductor element can be hermetically sealed, and thus a package for accommodating a semiconductor element can be manufactured.

[0036]

Example Two kinds of glass having the following compositions were prepared.

Glass A: 44% by weight of SiO ₂ -Al ₂ O
₃ 29% by weight-MgO 11% by weight-ZnO 7% by weight-B
₂ O ₃ 9% by weight Glass B: SiO ₂ 44% by weight-Al ₂ O ₃ 26% by weight
-MgO 19% by weight-ZnO 1% by weight-B ₂ O ₃ 10% by weight And, with respect to this crystallized glass powder, the average particle size is 1
Silica powder (quartz) and ZnO powder of Mm or less, MZ
rO ₃ powder (M is at least one selected from Ca, Sr, and Ba) and B ₂ O ₃ powder were used and mixed according to the compositions shown in Tables 1 and 2.

Then, an organic binder, a plasticizer and toluene are added to this mixture to prepare a slurry, and the slurry is used to obtain a thickness of 300 by a doctor blade method.
A μm green sheet was prepared. And 5 sheets of this green sheet are laminated and 100 kg / c at a temperature of 50 ° C.
A pressure of m ² was applied for thermocompression bonding. The obtained laminated body was debindered at 700 ° C. in a water vapor-containing / nitrogen atmosphere and then fired in dry nitrogen under the conditions shown in Tables 1 and 2 to obtain a sintered body for an insulating substrate.

The dielectric constant and the dielectric loss of the obtained sintered body were evaluated by the following methods. For the dielectric constant and the dielectric loss, a sample with a shape of 10 mm in diameter and 5 mm in thickness is cut out, and it is 15-2.
The measurement was performed by a dielectric cylinder resonator method using a network analyzer and a synthesized sweeper at 0 GHz. In the measurement, the sample dielectric substrate was sandwiched between φ50 Cu plate jigs. The dielectric constant and the dielectric loss were calculated from the resonance characteristics of the TE011 mode of the resonator. Further, the thermal expansion curve from room temperature to 400 ° C. was taken and the thermal expansion coefficient was calculated. The measurement results are shown in Tables 1 and 2.

The crystal phase in the sintered body was identified by X-ray diffraction measurement, and the constituent elements in the amorphous phase were EDX.
(TEM) and EPMA give 1000
Table 1 and Table 2 show elements of ppm or more.

Further, with respect to the above green sheet,
After forming a via hole and filling with copper paste, the copper paste is printed and applied on the surface of the sheet to form a wiring pattern, and on the bottom surface of the lowermost green sheet, an electrode layer that conducts with the internal wiring layer is formed. Then, 5 layers of these were laminated and fired under the same conditions as above to prepare a multilayer wiring board having a size of 35 mm square and a thickness of 1.2 mm.

Ball-shaped terminals made of solder of 90% by weight of Pb-10% by weight of Sn were attached to the electrode layers of this multilayer wiring board by low melting point solder (37% by weight of Pb-63% by weight of Sn). The ball-shaped terminals were formed on the entire bottom surface of the wiring board at a density of 30 per cm ² .

This wiring board is made of a glass-epoxy board and has a coefficient of thermal expansion of 13 at 40 to 800 ° C.
It was mounted on a printed board in which a wiring conductor made of copper foil was formed on the surface of an insulating board of ppm / ° C. The mounting was performed by aligning the wiring conductor on the surface of the printed board and the ball-shaped terminal of the wiring board and mounting with the low melting point solder.

The printed circuit board on which the multilayer wiring board is mounted as described above is placed at −40 ° C. and 125 ° C. in an air atmosphere.
Holding for 15 minutes / 15 minutes in a constant temperature bath controlled to each temperature of ° C was set as one cycle, and a maximum of 1000 cycles were repeated. Then, the electric resistance between the wiring conductor of the printed circuit board and the wiring board was measured for each cycle, and the number of cycles until a change in the electric resistance appears is shown in Tables 1 and 2.

Further, for some of the samples, Al ₂ O ₃ powder and cordierite powder were used in place of ZnO and SiO ₂ as filler components, and sintered bodies were similarly prepared and evaluated (Sample No. 8). , 9, 24, 25). Further, instead of the above-mentioned crystallized glasses A and B, the same evaluation was carried out using glasses C and D having the following compositions (Samples No. 26 to 29).

Glass C: SiO ₂ 10.4 wt% -Al ₂ O ₃ 2.5 wt% -B ₂ O ₃ 45.3 wt% -CaO 35.2 wt% -Na ₂ O 6.6 wt% Glass D: SiO ₂ 14 wt% -Al ₂ O ₃ 24.7 wt% -B ₂ O ₃ 22.6 wt% -BaO14.2 wt% -Li ₂ O12.8 wt% -Na ₂ O11.7 wt%

[0047]

[Table 1]

[0048]

[Table 2]

As is clear from the results of Tables 1 and 2, according to the present invention, the thermal expansion coefficient including the quartz type crystal phase and the spinel type crystal phase as the main components and including the ZrO ₂ crystal phase is 7 p.
All of the sintered bodies having a high coefficient of thermal expansion of pm / ° C. or higher have a dielectric constant of 6 or less at a measurement frequency of 15 to 20 GHz.
In addition to having excellent dielectric properties with a dielectric loss of 30 × 10 ⁻⁴ or less, in mounting on a printed circuit board, no mounting failure with the printed circuit board occurred in the thermal cycle test even after 1000 cycle tests.

On the other hand, in terms of composition, SiO ₂ −
In the sample No. 1 in which the amount of glass containing Al ₂ O ₃ —MgO—ZnO—B ₂ O ₃ was more than 95% by weight, the thermal expansion coefficient of 7 ppm / ° C. or higher was not achieved, and the sample was less than 30% by weight. In No. 15, it was difficult to sinter at low temperature unless a large amount of B ₂ O ₃ was added, and as a result, the liquid phase component was eluted and a sintered body was not formed. In addition, the amount of ZnO is 30
Sample No. 12, which exceeded the weight percentage, was difficult to fire at 1000 ° C. or lower and had a low coefficient of thermal expansion.

Further, in samples No. 1, 7, and 17 in which SiO ₂ was not added or the amount of SiO ₂ was less than 4.9% by weight, the coefficient of thermal expansion was low. Conversely, 40
In Sample No. 13 in which the content was more than 10% by weight, densification could not be performed at 1000 ° C or lower.

Sample No. in which the amount of B ₂ O ₃ exceeds 10% by weight.
In Nos. 14 and 15, the liquid phase was eluted and could not be densified.

Samples Nos. 8, 9, 24 and 25 were prepared by mixing Al ₂ O ₃ or cordierite as an additive component to glass, but cordierite or Al ₂ O was added to the sintered body.
Crystals such as ₃ were precipitated and the coefficient of thermal expansion became low.

Further, in samples No. 26 to 29 using glasses C and D containing no MgO or ZnO as the glass, the dielectric loss tended to increase.

[0055]

As described above in detail, according to the wiring board of the present invention, it is possible to sinter at a low temperature of 1000 ° C. or less by forming the insulating substrate from the complex oxide sintered body in which a specific crystal phase is deposited. Therefore, a wiring layer made of a low-resistance metal such as copper can be formed, and since it has a low dielectric constant and a low dielectric loss in a high frequency region of 1 GHz or higher, a high frequency signal can be transmitted extremely excellently without loss. Moreover, since this insulating substrate has high thermal expansion characteristics, it has excellent heat cycle characteristics even when mounted on a mother board such as a printed circuit board having an insulating substrate containing an organic resin with a brazing material or the like, A highly reliable mounting structure can be provided.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view for explaining an example of a BGA type semiconductor element housing package using a wiring board of the present invention.

FIG. 2 is a schematic diagram for explaining the structure of a sintered body in the insulating substrate of the present invention.

[Explanation of symbols]

A Package for storing semiconductor element B External electric circuit board 1 Insulating substrate 2 Lid 3 Cavity 4 Semiconductor element 5 Wiring layer 6 Connection electrode layers 7, 11 Brazing material 8 Ball-shaped terminal 9 Insulating substrate 10 Wiring conductor Si SiO ₂ crystal phase SP Spinel type crystal phase Z (M) ZrO ₂ crystal phase (monoclinic) Z (T) ZrO ₂ crystal phase (tetragonal) G Amorphous phase

Continuation of front page (51) Int.Cl. ⁷ Identification code FI H05K 3/46 H01L 23/14 C

Claims (6)

(57) [Claims] 1. A wiring board comprising an insulating substrate and a wiring layer disposed on the surface and / or inside thereof.
The insulating substrate contains Si, Al, Zn, Mg, and Zr, and contains at least one selected from Ca, Sr, and Ba as a constituent element, and as a crystal phase,
A composite oxide sintered body containing a SiO ₂ crystal phase, a spinel type crystal phase containing at least Zn and Al, and a ZrO ₂ crystal phase, and having a coefficient of thermal expansion at room temperature to 400 ° C. of 7 ppm / ° C. or more. A wiring board characterized by the above. 2. The wiring board according to claim 1, wherein the SiO ₂ crystal phase is a quartz crystal phase. 3. The wiring board according to claim 1, wherein the ZrO ₂ crystal phase is composed of a monoclinic crystal and / or a tetragonal crystal. 4. The composite oxide sintered body is composed of SiO ₂ , Al.
30 to 95% by weight of glass powder containing ₂ O ₃ , MgO, ZnO and B ₂ O ₃ and 4.9 to 40% by weight of SiO ₂
And at least 1 selected from Ca, Sr and Ba
0.1 to 10% by weight of a composite oxide of a seed and ZrO _2, and Z
The wiring board according to claim 1, which is obtained by molding a mixture of 0 to 30% by weight of nO and 0 to 10% by weight of B ₂ O ₃ and then firing the mixture at a temperature of 800 to 1000 ° C. 5. The glass powder comprises SiO ₂ 40 to 52 wt%, Al ₂ O ₃ 14 to 32 wt%, MgO 4 to 24 wt%, ZnO 1 to 16 wt%, B ₂ O ₃ 5 to 15 wt%.
The wiring board according to claim 4, characterized in that 6. A wiring board comprising an insulating substrate, a wiring layer disposed on the surface and / or inside thereof, and a connection terminal for connecting to an external electric circuit, at least an insulator containing an organic resin. In a mounting structure of a wiring board, the wiring board is mounted on an external electric circuit board having a wiring conductor formed on a surface thereof, and the connection terminals of the wiring board are brazed to the wiring conductor of the external electric circuit board. The insulating substrate is S
i, Al, Zn, Mg, Zr, and at least one selected from Ca, Sr, and Ba, and the crystal phase includes a SiO ₂ crystal phase and at least Z
A wiring board comprising a complex oxide sintered body containing a spinel type crystal phase containing n and Al and a ZrO ₂ crystal phase and having a thermal expansion coefficient of 7 ppm / ° C. or more from room temperature to 400 ° C. Implementation structure of.