JP3323074B2 - Wiring board, package for housing semiconductor element 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 having a metallized wiring layer, a semiconductor device package having the wiring board, and a mounting structure thereof.

[0002]

2. Description of the Related Art Conventionally, a wiring board has a structure in which a metallized wiring layer is disposed on the surface or inside of an insulating substrate.
As a typical example using this wiring board, a semiconductor element housing package for housing a semiconductor element, particularly a semiconductor element such as an LSI, has a metallized wiring layer such as W or Mo on its surface and inside. Further, an insulating substrate made of alumina ceramic or the like having connection terminals disposed on the bottom surface thereof, and a cavity for accommodating a semiconductor element formed at the center of the upper surface of the insulating substrate are formed, and the cavity is hermetically sealed by a lid. You.

Generally, as the degree of integration of a semiconductor device increases, the number of electrodes formed on the semiconductor device also increases. As a result, the number of terminals in a semiconductor housing package for housing the same increases. However, as the number of electrodes increases, there is a limit in increasing the size of the package itself, and further reduction in size is required, and it is necessary to increase the formation density of connection terminals in the package.

As a structure for increasing the terminal density in a conventional package, a pin grid array (P) in which metal pins such as Kovar are connected to the lower surface of the package is known.
GA) is the most common, but recently, a quad flat package (QFP) of a type in which gull-wing (L-shaped) metal pins are connected to metallized wiring layers led to four sides of the package, A leadless chip carrier (LCC) with electrode pads on the four sides without lead pins, a chip size package (CSP) with flip-chip mounting of a Si chip, and a number of spherical terminals made of solder are arranged on the lower surface of the insulating substrate. There is a ball grid array (BGA) and the like, and among these, BGA is said to be the most capable of high density.

In this ball grid array (BGA), a spherical pad made of a brazing material such as solder is soldered to a connection pad, and the spherical terminal is placed on and abutted on a wiring conductor of an external electric circuit board. Thereafter, the terminal is heated and melted at a temperature of about 250 to 400 ° C., and the spherical terminal is bonded to a wiring conductor to be mounted on an external electric circuit board. With such a mounting structure, each electrode of the semiconductor element housed in the semiconductor element housing package is electrically connected to an external electric circuit via the metallized wiring layer and the connection terminal.

[0006]

The ceramics such as alumina and mullite used as an insulating substrate in these packages have a high strength of 200 MPa or more, and have a high reliability as a multi-layered technology with metallized wiring layers. Although the thermal expansion coefficient is about 4-7 ppm / ° C., the glass-epoxy insulating layer, which is most frequently used as an external electric circuit board on which the package is mounted, has a high thermal expansion coefficient. The thermal expansion coefficient of the printed circuit board on which the wiring layer is formed is as very large as 11 to 18 ppm / ° C.

Therefore, when a semiconductor element is accommodated in a wiring board or a package for accommodating a semiconductor element and then mounted on a printed circuit board or the like, heat generated during operation of the semiconductor element is repeatedly applied to both the insulating substrate and the printed circuit board. Then, a large thermal stress is generated due to a difference in thermal expansion between the insulating substrate and the printed board. This thermal stress has no effect when the number of terminals in the package is 300 or less, but the thermal stress increases as the number of terminals exceeds 300 or as the size of the package increases.

[0008] Therefore, thermal stress acts on the outer peripheral portion of the connection pad on the lower surface of the insulating substrate and the bonding interface between the wiring conductor and the terminal of the external electric circuit board due to repetition of the operation and stop of the semiconductor element, and the connection pad is insulated. There has been a defect that the wiring board or package cannot be stably and electrically connected to the printed board for a long period of time because the wiring board or the package is peeled off from the substrate or the terminal is peeled off from the wiring conductor.

Therefore, it is conceivable to match the coefficient of thermal expansion of the insulating substrate with the coefficient of thermal expansion of the printed circuit board. However, in the case of conventional alumina and mullite, since the coefficient of thermal expansion is largely different from the beginning, even if the composition or the like is changed. It is very difficult to match the coefficient of thermal expansion of the printed circuit board.

On the other hand, an insulating substrate made of glass ceramic has been attracting attention as an excellent substrate material replacing alumina because it has a low dielectric constant and can form a metallized wiring layer made of a low resistance material such as Cu or Ag. I have. This glass ceramic is disclosed in JP-A-63-1179.
The 29 discloses using ZnO-Al ₂ O ₃ -SiO ₂ -based glass, by controlling the heat treatment conditions, that by generating a crystal pebbles leaflet zinc silicate and cordierite or zinc to control the thermal expansion coefficient proposed Have been. However, in such a glass ceramic, even if the composition is the same, the precipitated crystal phase is likely to change due to a slight difference in heat treatment conditions, and it is difficult to stably control the thermal expansion coefficient, and thus lacks mass productivity.

Japanese Patent Application Laid-Open No. 62-226855 proposes a low-temperature fired porcelain composition for a multilayer substrate using BaO-Al ₂ O ₃ -SiO ₂ glass. However, since the composition used in this publication is composed only of glass, the transverse rupture strength is low, and the thermal expansion coefficient is 7 ×.
Since it is as low as 10 ⁻⁶ / ° C. or less, it cannot withstand the stress generated at the time of mounting on a printed circuit board, resulting in defective mounting.

Accordingly, the present invention provides a wiring board having a metallized wiring layer on the surface or inside of an insulating substrate having high thermal expansion characteristics, and a semiconductor element housing package having high thermal expansion characteristics and housing semiconductor elements. It is an object of the present invention to provide a highly reliable semiconductor element housing package capable of maintaining a stable and stable connection state for a long time with respect to an external electric circuit using glass-epoxy resin as an insulator, and a mounting structure thereof. Is what you do.

[0013]

Means for Solving the Problems The present inventors have repeatedly studied the above problems, and as a result, have found that BaO is used as an insulating substrate.
When the glass containing 10% by weight or more crystallizes during the sintering process, the glass has a high coefficient of thermal expansion. Therefore, a metal oxide having a high coefficient of thermal expansion is further added to the glass as a filler component to reduce the sintering temperature to copper. The present inventors have found that a wiring board made of a high thermal expansion insulating substrate having a copper metallized wiring layer can be manufactured by matching the firing temperature with the metallized wiring layer.

That is, the present invention provides an insulating substrate,
Connect to the wiring layer and the external electric circuit board with brazing material
Wiring board with connection pads for
Connected to the external wiring board with the brazing material
An insulating substrate on which connection pads for
And a cavity for accommodating a semiconductor element.
In the semiconductor device package for housing, the insulating substrate, and 10 wt% or more of _{BaO, B 2 O 3, SiO} 2
Glass powder containing at least one of
% By volume and a coefficient of thermal expansion at 40 to 400 ° C. of 6 pp
40 to 40 obtained by firing a molded body containing a filler containing a metal oxide having a m / C of not less than 80% by volume at a rate of 80 to 20% by volume.
It is composed of a sintered body having a thermal expansion coefficient at 0 ° C. of 8 to 18 ppm / ° C.

Further, according to the present invention, the wiring board and the semiconductor element housing package are provided on an external electric circuit board having a wiring conductor attached to at least the surface of an insulator containing an organic resin.
The connection pad of the package is connected to the wiring conductor with a brazing material.
It is implemented as

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings showing an embodiment. FIG. 1 and FIG. 2 are views showing an embodiment of a package for housing a BGA type semiconductor device and a mounting structure thereof according to the present invention. This package has a metallized wiring layer provided on the surface or inside an insulating substrate. In addition, a so-called wiring board has a basic structure, A indicates a package for housing a semiconductor element, and B indicates an external electric circuit board.

The package A for housing a semiconductor element is composed of an insulating substrate 1, a lid 2, a metallized wiring layer 3, and a connection terminal 4. The insulating substrate 1 and the lid 2 are for hermetically housing the semiconductor element 5 therein. Is formed. Then, the semiconductor element 5 is bonded and fixed to the insulating substrate 1 via an adhesive such as glass or resin in the cavity 6.

A metallized wiring layer 3 is provided on the surface and inside of the insulating substrate 1 so that the semiconductor element 5 is electrically connected to connection terminals 4 formed on the lower surface of the insulating substrate 1. Has been established. According to the package of FIG. 1, the connection terminal 4 is connected to the solder (tin-tin) through the connection pad 4a.
A protruding terminal 4b made of a brazing material such as a lead alloy is attached. The protruding terminals 4b are formed by arranging spherical or columnar brazing materials on the connection pads 4a, or by printing a brazing material on the connection pads 4a by a screen printing method.

On the other hand, the external electric circuit board B is composed of an insulator 7 and a wiring conductor 8, and the insulator 7 is made of a material containing at least an organic resin. Specifically, a glass-epoxy composite material It is made of an insulating material having a thermal expansion coefficient of 12 to 16 ppm / ° C. at 40 to 400 ° C., and a printed board or the like is generally used. In addition, the wiring conductor 8 formed on the surface of the substrate B usually has a thermal expansion coefficient matching with the insulator 7 and a good electric conductivity in terms of good electrical conductivity.
It is made of a metal conductor such as Cu, Au, Al, Ni, and Pb-Sn.

To mount the semiconductor element storage package A on the external electric circuit board B, the insulating substrate 1 of the package A
The protruding terminal 4b on the lower surface is placed and abutted on the wiring conductor 8 of the external electric circuit board B, and then heated at a temperature of about 250 to 400 ° C., thereby forming a protruding terminal made of a brazing material such as solder. 4b itself is melted and joined to the wiring conductor 8 to be mounted on the external electric circuit board B. At this time,
It is desirable that a brazing material is formed on the surface of the wiring conductor 8 so as to easily connect to the protruding terminals 4b using the brazing material.

As another example, as shown in FIG. 3, as the connection terminal, a connection pad 4a in which a spherical terminal 9 made of a high melting point material is brazed with a low melting point brazing material 10 can be applied. This high melting point material needs to have a higher melting point than the low melting point brazing material used for brazing, and the brazing material is, for example, Pb 40% by weight-Sn6.
When a low melting point solder of 0% by weight is used, the spherical terminal is made of a high melting point solder of, for example, 90% by weight of Pb-10% by weight of Sn, or A
g, Cu, Ni, Al, Au, Pt, Fe and other metals.

In such a configuration, the spherical terminal 9 on the lower surface of the insulating substrate 1 of the package A is placed and abutted on the wiring conductor 8 of the external electric circuit board B, and then the spherical terminal 9 is soldered by a brazing material 11 such as solder. It can be mounted on the external electric circuit board B by bonding to the wiring conductor 8. The connection terminal may be connected to an external electric circuit board using an Au-Sn alloy as a low melting point brazing material, and a columnar terminal may be used instead of the spherical terminal.

Next, the mounting structure of the leadless chip carrier (LCC) type package C on the external electric circuit board B will be described with reference to FIG. In FIG. 4, the same members as those in FIG. 1 are denoted by the same reference numerals. In the package C in FIG. 4, the metallized wiring layers 3 individually connected to the electrodes of the semiconductor element are led out to four side surfaces of the insulating substrate 1, and the metallized wiring layers led out to the side surfaces constitute connection terminals 4. . According to this package C,
In order to prevent electromagnetic wave interference, an epoxy resin or the like is filled in a cavity 6 for housing the semiconductor element 5, and the cavity is sealed by a lid 12 made of a conductive resin. A conductive layer 13 for grounding is formed on the bottom surface of the package C.

In order to mount the package C on an external electric circuit board B such as a printed circuit board, the connection terminals 4 on the side of the insulating substrate 1 of the package C are placed and abutted on the wiring conductors 8 of the external electric circuit board B. And electrically connected by brazing material or the like. At this time, the connection terminals 4 are desirably coated with a brazing material on the surface of the wiring conductor 8 in order to facilitate connection with the brazing material.

(Material of Insulating Substrate) According to the present invention, as the package for housing a semiconductor element mounted on the surface of such an external electric circuit board B, the insulating substrate 1 has a thickness of 40 to 4 mm.
Thermal expansion coefficient in the temperature range of 00 ° C is 8 to 18 ppm
/ ° C, particularly 9 to 14 ppm / ° C. This is important to alleviate the generation of thermal stress due to the difference in thermal expansion between the external electric circuit board B and the external electric circuit board B, and to maintain a good electrical connection between the external electric circuit board B and the package A for a long time. Whose coefficient of thermal expansion is less than 8 ppm / ° C. or 18 ppm / ° C.
If the temperature is higher than ° C., the thermal stress caused by the difference in thermal expansion becomes large, and it is impossible to prevent the electrical connection between the external electric circuit board B and the package A from deteriorating.

The thermal expansion coefficient of the insulating substrate is 8 to 18 p.
With the increase in pm / ° C., the difference in thermal expansion between the semiconductor element and the semiconductor element using Si as the substrate increases. Therefore, it is necessary to appropriately select an adhesive for the semiconductor element to the insulating substrate so that the semiconductor element does not peel off due to a difference in thermal expansion. Desirably, it is desirable to bond with a flexible material capable of buffering the difference in thermal expansion. For example, an epoxy-based or polyimide-based organic adhesive or a metal such as Ag may be blended in some cases. Are preferably used.

According to the present invention, BaO is used as a sintered body constituting an insulating substrate having such a high coefficient of thermal expansion.
0 wt% or more and, B ₂ O _3, glass containing at least one of SiO ₂ (hereinafter, sometimes referred BaO-based glass.) And 20 to 80% by volume, a filler component 8
It is constituted by a sintered body obtained by firing a molded body containing 0 to 20% by volume. In addition, as BaO-based glass,
It is preferably a crystalline glass. The crystalline glass has a property of precipitating a crystal phase by itself in the sintering process, or a property of reacting with glass and a filler to generate a crystal phase.

The reason why the amounts of the BaO-based glass and the filler component are limited to the above range is that the glass component is less than 20% by volume, in other words, if the filler component is more than 80% by volume, liquid phase sintering is performed. It is necessary to bake at a high temperature before the metallization is performed, and in that case, the metallization is melted in the simultaneous baking of the metallization. In addition, when the crystalline glass is 8
If the content is more than 0% by volume, in other words, if the filler component is less than 20% by volume, the properties of the sintered body greatly depend on the properties of the crystalline glass, and it becomes difficult to control the material properties, and the sintering start temperature is reduced. Since it becomes low, there is a problem that it cannot be fired simultaneously with the wiring conductor. Also, the cost of the raw material increases.

Further, in the BaO-based glass of the insulating substrate, BaO is contained in the glass in an amount of 10% by weight or more.
Since, when the BaO content is less than the above range, the thermal expansion coefficient is lower than 8 ppm / ° C., because the SiO ₂ is also high substitution to sintering temperature. The BaO-based glass contains at least one of B ₂ O ₃ and SiO ₂ . These promote low temperature sinterability as glass,
It is a component that reacts with BaO to promote crystallization. Other glass constituents include ZnO, Al ₂ O _3, etc.
It is contained at a ratio of 0% by weight or less. The BaO-based glass is to be crystallized during the sintering process to precipitate a crystal phase containing at least Ba and Si such as BaAl ₂ Si ₂ O ₈ or BaSi ₂ O ₅ or BaB ₂ Si ₂ O _8. Is desirable.

Further, the deformation point of the BaO-based glass is 4
The temperature is desirably from 00 to 800 ° C, particularly preferably from 400 to 650 ° C. This is because when molding a mixture of glass and filler, a molding binder such as an organic resin is added, but this binder is efficiently removed and matching of firing conditions with metallization that is fired simultaneously with the insulating substrate. Required to achieve a yield point of 40
If the temperature is lower than 0 ° C., the sintering of the crystalline glass starts at a low temperature.
This is because simultaneous firing with metallization at 0 to 800 ° C. cannot be performed, and densification of the molded body starts at a low temperature, so that the binder cannot be decomposed and volatilized, and a binder component remains to affect the properties. On the other hand, the yield point is 800
If the temperature is higher than ℃, sintering becomes difficult unless the amount of crystalline glass is increased, and the cost of the sintered body is increased because a large amount of expensive crystalline glass is required.

It is desirable that the amount of the filler component is appropriately adjusted according to the yield point of the crystalline glass. That is, when the yield point of the crystalline glass is as low as 400 ° C. to 650 ° C., the sinterability at low temperatures is increased, so that the content of the filler can be relatively large as 50 to 80% by volume. On the other hand, when the yield point of the crystalline glass is as high as 650 ° C. to 800 ° C., the sinterability is reduced, so that the content of the filler is 20 to
It is desirable to add a relatively small amount of 50% by volume.

The BaO-based glass used in the present invention has a shrinkage onset temperature of 700 ° C. or less when no filler is added and melts at 850 ° C. or more and cannot be co-fired with a metallized wiring layer of copper or the like. . However, by mixing the filler at a ratio of 20 to 80% by volume, it is possible to form a liquid phase at the firing temperature for crystal precipitation and liquid phase sintering of the filler component. In addition, since the shrinkage start temperature of the entire molded body can be increased, it is possible to match the simultaneous firing conditions with the metallized wiring layer such as copper used by adjusting the content of the filler. In order to reduce raw material costs, it is preferable to reduce the content of expensive crystalline glass.

For example, if the metallized wiring layer is made of Ag, Cu,
When one of Au is mainly constituted, since firing of these metallizations occurs at 600 to 1000 ° C., in order to perform simultaneous firing, the yield point of the crystalline glass is 400 ° C. or higher.
650 ° C., and the content of the filler is 50 to 80% by volume.
It is preferred that Further, by reducing the amount of the expensive crystalline glass, the cost of the sintered body can be reduced.

Further, after firing the BaO-based glass at 40 ° C.
It is necessary that the thermal expansion coefficient at 400 ° C. is 6 to 18 ppm / ° C., particularly 7 to 13 ppm / ° C. This is because if the coefficient of thermal expansion deviates from the above range, a difference in thermal expansion with the filler occurs, causing a reduction in the strength of the sintered body. If the coefficient of thermal expansion of the filler is less than 6 ppm / ° C., it is also difficult to make the coefficient of thermal expansion of the sintered body 8 to 18 ppm / ° C.

BaO-based glasses satisfying the above characteristics include BaO-Al ₂ O ₃ -SiO ₂ -based and BaO-Sr
O-Al ₂ O ₃ -SiO ₂ system, BaO-Al ₂ O ₃ -B
₂ O ₃ —SiO ₂ system, BaO—CaO—Al ₂ O ₃ —S
iO _{2 system, BaO-CaO-Al 2 O} 3 -B 2 O 3 -S
iO ₂ system, BaO-MgO-ZnO-B 2 O 3 -SiO
₂ system, BaO-CaO-ZnO-MgO -Al 2 O 3 -
Examples include SiO ₂ -based and BaO-Na ₂ O-K ₂ O-SiO ₂ -based glasses.

The mixture of the crystalline glass and the filler is formed into a sheet by a desired forming means, for example, a doctor blade, a rolling method, a die press or the like, after adding an appropriate organic resin binder. Then, it is fired.

In firing, first, a binder component blended for molding is removed. The removal of the binder is performed in an air atmosphere at about 700 ° C. When Cu is used as the wiring conductor, water containing 10% water is used.
This is performed in a nitrogen atmosphere at 0 to 700 ° C. At this time, it is desirable that the shrinkage start temperature of the molded body is about 700 to 850 ° C. If the shrinkage start temperature is lower than this, it becomes difficult to remove the binder. It is necessary to control the yield point as described above.

The calcination is performed in an oxidizing atmosphere at 850 ° C. to 1300 ° C., whereby the relative density is increased to 90% or more. If the firing temperature at this time is lower than 850 ° C., densification cannot be achieved, and if it exceeds 1300 ° C., the metallized layer is melted by simultaneous firing with the metallized wiring layer. However, when Cu is used as the wiring conductor, 85
This is performed in a non-oxidizing atmosphere such as nitrogen at 0 to 1050 ° C.

In the glass ceramic sintered body thus produced, a crystal phase generated from the crystalline glass, a crystal phase generated by the reaction between the crystalline glass and the filler,
Alternatively, there is a crystal phase or the like generated by decomposition of the filler component, and a glass phase exists at the grain boundaries of these crystal phases.
In order to increase the thermal expansion coefficient of the entire sintered body, it is desirable that the crystal phase having a thermal expansion coefficient of at least 6 ppm / ° C. at 40 to 400 ° C. be precipitated.

Such crystal phases having a thermal expansion coefficient of 6 ppm / ° C. or more include cristobalite (SiO ₂ ), quartz (SiO ₂ ), tridymite (SiO ₂ ), forsterite (2MgO.SiO ₂ ), spinel (Mg
O.Al ₂ O ₃ ), wollastonite (CaO.SiO)
₂ ), Monticellanite (CaO.MgO.Si)
O ₂ ), nepheline (Na ₂ O.Al ₂ O ₃ .Si)
O ₂ ), lithium silicate (Li ₂ O.SiO ₂ ),
Jiopusaido _{(CaO · MgO · 2SiO 2)} , Merubinaito _{(3CaO · MgO · 2SiO 2)} , Akerumaito _{(2CaO · MgO · 2SiO 2)} , magnesia (M
gO), alumina (Al ₂ O ₃ ), nepheline (Na ₂
O.Al ₂ O ₃ .2SiO ₂ ), jade (Na ₂ O.A)
l ₂ O ₃ · 4SiO ₂ ), Carnegieite (Na ₂ O.
Al ₂ O ₃ .2SiO ₂ ), enstatite (MgO.
SiO ₂ ), magnesium borate (2MgO.B)
₂ O ₃ ), Celsian (BaO.Al ₂ O ₃ .2SiO)
₂ ), B ₂ O ₃ .2MgO.2SiO ₂ , garnite (ZnO.Al ₂ O ₃ ), petalite (LiAlSi ₄ )
At least one selected from the group of O ₁₀ ). Among these, a crystal phase of 8 ppm / ° C. or more is particularly preferable. Further, in the above filler, the thermal expansion coefficient of the final sintered body may exceed 18 ppm / ° C. due to its addition. In that case, it is necessary to appropriately control the coefficient of thermal expansion by mixing with a filler having a small coefficient of thermal expansion.

The above sintered body was used as an insulating substrate,
In order to manufacture a wiring board or a package provided with a metallized wiring layer made of at least one of g, Cu, Ni, Pd, and Au, the above-described crystalline glass and filler for forming an insulating substrate are used. An appropriate organic binder, a plasticizer, and a solvent are added to and mixed with the raw material powder made of to produce a slurry, and the slurry is formed into a green sheet (raw sheet) by employing a doctor blade method or a calendar roll method. Then, as the metallized wiring layer 3 and the connection pads, a metal paste obtained by adding and mixing an appropriate metal powder with an organic binder, a plasticizer and a solvent is applied to the green sheet in a predetermined pattern by a known screen printing method. In some cases, the green sheet is appropriately punched to form a through hole, and the hole is filled with a metallizing paste.
By stacking a plurality of these green sheets and simultaneously firing the green sheets and metallization, a package having a multilayer structure can be obtained.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to more specific examples. Example 1 Crystalline as glass, 15% by weight ratio BaO-25% ZnO-45% P 2
O ₅ -10% Al ₂ O ₃ -5% SiO ₂ (Coefficient of thermal expansion 10
ppm / ℃, 20% BaO- 5% by sag point 500 ° C.) weight ratio Al ₂ O ₃ -10% N
_{a 2 O-10% K 2} O-55% SiO 2 ( coefficient of thermal expansion 1
0 ppm / ° C., yield point 650 ° C.) weight ratio in _{25% BaO-10% Al 2} O 3 -5% B
₂ O ₃ -60% SiO ₂ (coefficient of thermal expansion 8 ppm / ° C., yield point 800 ° C.) 25% by weight BaO-2% Al ₂ O ₃ -1% B ₂
Three kinds of glasses having O ₃ -72% SiO ₂ (coefficient of thermal expansion: 8 ppm / ° C., yield point: 850 ° C.) were prepared, and as shown in Table 1, forsterite (2MgO.SiO) was used as a filler component. ₂ , Coefficient of thermal expansion 10
ppm / ° C) Quartz (SiO ₂ , coefficient of thermal expansion 15 ppm / ° C) Cristobalite (SiO ₂ , coefficient of thermal expansion 20 ppm /
° C) Petalite (LiAlSi ₄ O ₁₀ , coefficient of thermal expansion 8 ppm
/ ° C.) MgO (thermal expansion coefficient of 9 ppm / ° C.) nepheline _{(Na 2 O · Al 2 O} 3 · 2SiO 2, a thermal expansion coefficient of 10 ppm / ° C.) mullite _{(3Al 2 O 3 · 2SiO 2} , a thermal expansion coefficient 4p
pm / ° C.) Alumina (Al ₂ O ₃ , coefficient of thermal expansion: 7 ppm / ° C.) was weighed and mixed so as to have the composition shown in Table 1. After pulverizing this mixture, an organic binder was added and mixed well, and then 3.5 × 3.5 × by a uniaxial pressing method.
A molded body having a shape of 15 mm was prepared, and this molded body was 700
After debinding in the air at ℃ 650,
It was fired at 1200 ° C. to produce a sintered body.

Next, the thermal expansion coefficient of the sintered body obtained as described above was measured at 40 to 400 ° C., and the results are shown in Table 1. Further, the sintered body was processed into a diameter of 60 mm and a thickness of 2 mm, and the relative dielectric constant and the dielectric loss were determined by the method of JISC2141. The measurement was performed using an LCR meter (YHP4284A) at 25 ° C. under the conditions of 1 MHz and 1.0 Vrsm.
Was measured, and the relative dielectric constant at 25 ° C. was measured from the capacitance.

Next, using each raw material composition shown in Table 1, a green sheet having a thickness of 500 μm was formed by a doctor blade method using toluene and isopropyl alcohol as a solvent, an acrylic resin as a binder, and DBP (dibutyl phthalate) as a plasticizer. Produced.

An Ag-Pt metallized paste was applied on the surface of the green sheet by a screen printing method to form a metallized wiring layer. Further, a through hole was formed at a predetermined portion of the green sheet so that the inside of the through hole was finally exposed to the lower surface of the substrate, and the inside of the through hole was filled with an Ag-Pt metallizing paste. And
Six green sheets to which the metallized paste was applied were laminated and pressed while aligning the through holes.

After removing the binder in the air at 700 ° C., the metallized wiring layer and the insulating substrate were simultaneously fired at the respective firing temperatures in the air to produce a wiring substrate for a package. At this time, with respect to the Ag metallized layer formed by the simultaneous baking, the metallized layer was evaluated for melting and sintering defects.

Next, a concave portion was formed on the lower surface of the wiring substrate at a position connected to the through hole, and a connection pad made of Ag-Pt metallized was manufactured. Then, as shown in FIG. 1, solder (60 to 10% tin-40 to 90% lead) is applied to the connection pad.
%). The connection terminals are
It was formed on the entire lower surface of the wiring board at a density of 30 terminals per 1 cm ² .

On the other hand, a glass-epoxy substrate 40
A printed circuit board having a wiring conductor made of copper foil formed on the surface of an insulator having a thermal expansion coefficient of 13 ppm / ° C. at a temperature of up to 800 ° C. is prepared. Positioning was performed so that the connection terminals of the insulating substrate were connected, and this was heat-treated at 260 ° C. for 3 minutes in an atmosphere of N ₂ to mount the package wiring substrate on the surface of the printed circuit board. By this heat treatment, it was confirmed that the solder connection terminals of the package wiring board were melted and electrically connected to the wiring conductors of the printed circuit board.

(Thermal Cycle Test During Mounting) The package wiring board mounted on the printed circuit board surface as described above was tested in a constant temperature bath controlled at -40 ° C. and 125 ° C. in the atmosphere of air. The sample was held for 15 minutes / 15 minutes as one cycle and repeated up to 1000 cycles. The electrical resistance between the wiring conductor of the printed circuit board and the wiring substrate for the package was measured for each cycle, and the number of cycles until the electrical resistance changed was shown in Table 1.

[0050]

[Table 1]

As is clear from Table 1, in the case of sample No. 9 having a glass content of less than 20% by volume, a dense sintered body could not be obtained, and in case of sample No. 2 having a glass content exceeding 80% by volume.
In 7, 15, 18 and 26, the porcelain was densified at a low temperature, and the metallization was not sintered and could not be co-fired. In addition, even if the glass amount is appropriate, the samples Nos. 6, 16 and 19 in which the thermal expansion coefficient of the sintered body deviates from 8 to 18 ppm / ° C. due to the combination with the filler, have 200 to 300 cycles in the thermal cycle test. A change in resistance occurred.

On the other hand, the product of the present invention having an appropriate amount of glass and a coefficient of thermal expansion of the sintered body of 8 to 18 ppm / ° C.
Simultaneous firing of Pt metallization is also good, and no change in electrical resistance is observed between the wiring conductors of the printed circuit board and the package wiring board even after 1000 cycles of temperature rise and fall in the package wiring board manufactured using the same. An extremely stable and good electrical connection state could be maintained.

[0053]

As described above in detail, according to the wiring board and the package for accommodating the semiconductor element of the present invention, when mounted on an external electric circuit board such as a printed circuit board having a large thermal expansion coefficient, the thermal expansion of the both is caused. It is possible to suppress the occurrence of stress due to the difference in coefficient, and to accurately and firmly electrically connect the package and the external electric circuit for a long period of time. In addition, a highly reliable package mounting structure that can sufficiently cope with an increase in the number of pins due to an increase in the size of the semiconductor circuit element can be realized.

Further, since it is possible to co-fire with metallization of copper or the like, it is possible to provide a high-quality and inexpensive wiring board and a semiconductor element housing package.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view for explaining a mounting structure of a BGA type semiconductor element housing package of the present invention.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is an enlarged sectional view of a main part of another embodiment of the connection terminal.

FIG. 4 is a cross-sectional view for explaining a mounting structure of a leadless chip carrier type package of the present invention.

[Explanation of symbols]

 Reference Signs List A semiconductor device storage package B external electric circuit board C LCC type package 1 insulating substrate 2, 12 lid 3 metallized wiring layer 4 connection terminal 4a connection pad 4b protruding terminal 5 semiconductor element 6 cavity 7 insulator 8 wiring conductor 9 spherical Terminal 10, 11 Low melting point brazing material 13 Conductive layer

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Noriaki Hamada 1-4-4 Yamashita-cho, Kokubu-shi, Kagoshima Examiner at Kyocera Research Institute Kaoru Sakamoto (56) References JP-A-4-238837 (JP, A JP-A-63-215559 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 23/15 H01L 23/12 501

Claims (4)

(57) [Claims] An insulating substrate, a metallized wiring layer, and an external power supply;
Connection pad for connecting to the circuit board with brazing material
In the wiring substrate provided with the said insulating substrate, BaO
And 10 wt% or more, B ₂ O _3, less of SiO ₂
And 20 to 80% by volume of a glass powder containing one kind ,
The thermal expansion coefficient at 40 to 400 ° C. obtained by firing a molded body containing a filler containing a metal oxide having a thermal expansion coefficient of 6 ppm / ° C. or more at 40 to 400 ° C. at a ratio of 80 to 20% by volume is 8 to A wiring board comprising a sintered body of 18 ppm / ° C. 2. The method according to claim 1, wherein the metallized wiring layer is connected to an external electric circuit board.
Connection pads for connection with brazing material are provided
Insulating substrate, lid, and cap for housing semiconductor elements
Smell package for semiconductor device with high visibility
The insulating substrate may contain BaO of 10% by weight or more and B ₂
20 to 80% by volume of a glass powder containing at least one of O ₃ and SiO ₂ , and 80 to 20% by volume of a filler containing a metal oxide having a thermal expansion coefficient of 6 ppm / ° C. or more at 40 to 400 ° C. The coefficient of thermal expansion at 40 to 400 ° C. obtained by firing a molded body containing at a ratio of 8 to 18 p
A package for housing a semiconductor element, comprising a sintered body of pm / ° C. 3. An insulating material containing at least an organic resin.
On the external electric circuit board on which the wiring conductor is formed
Item 2. The connection pad of the wiring board according to Item 1 is used as the wiring conductor.
A mounting structure characterized by being mounted via a brazing material . 4. An insulating material containing at least an organic resin,
On the external electric circuit board on which the wiring conductor is formed
Item 3. The connection package of the semiconductor device storage package according to Item 2.
A mounting structure comprising a wiring mounted on the wiring conductor via a brazing material .