JP2002057248A - Package and mounting structure thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that conventionally when a package is mounted on an external electric circuit board such as a printed board, the package cannot be electrically connected stably with the external electric circuit board, due to large thermal stress caused by the difference between the thermal expansion coefficients of the both. SOLUTION: A package (A) has respectively a ceramic insulation board 1, connection pads 3a formed on the rear surface or side surface of the insulation board 1, and each metallized wiring layer 3 for connecting an element 5 mounted on the top surface of the insulation board 1 with each connection pad 3a, is provided on the surface of the insulation board 1 or in its inside. Also, the package A is mounted on an external electric circuit board (B), by welding with a brazing material the connection pads 3a to the board B. In the package A, the insulation board 1 is made of a ceramic sintered body, having a thermal expansion coefficient of 80-180×10-7/ deg.C in a temperature range of 40-400 deg.C, and the element 5 is bonded to the insulation board 1 with a flexible bonding material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package and a structure for mounting the package on an external electric circuit board.

[0002]

2. Description of the Related Art Conventionally, a semiconductor element housing package for housing a semiconductor element, particularly a semiconductor integrated circuit element such as an LSI (Large Scale Integrated Circuit), is generally made of an electrically insulating material such as alumina ceramics, and has a top center. An insulating substrate having a recess for accommodating a semiconductor element in a portion thereof, a plurality of metallized wiring layers made of a refractory metal powder such as tungsten or molybdenum derived from the periphery of the recess of the insulating substrate; A plurality of connection pads formed on the lower surface or side surfaces of the metallized wiring layer and electrically connected to the metallized wiring layer, connection terminals brazed and attached to the connection pads as desired, and a lid, A semiconductor element is bonded and fixed to the bottom of the recess of the insulating substrate via an adhesive, and each electrode of the semiconductor element and the metallized wiring layer are connected via a bonding wire. By connecting the lid to the upper surface of the insulating substrate via a sealing material such as glass or resin, and hermetically sealing the semiconductor element inside the container consisting of the insulating substrate and the lid. As a semiconductor device storage package.

In order to connect the semiconductor element housing package to a wiring conductor of an external electric circuit board, a connection terminal provided on the insulating substrate of the semiconductor element housing package and a wiring conductor of the external electric circuit board are connected. Can be electrically connected by a brazing material such as solder.

In general, 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. Therefore, as more miniaturization is required, it is necessary to increase the density of terminals in the package.

[0005] As a structure for increasing the terminal density in a conventional package, a pin grid array (PGA) in which metal pins such as Kovar are connected as connection terminals to the lower surface of the package is the most common, but recently, it has been recently used. A quad flat package (QFP) in which gull-wing (L-shaped) metal pins are connected to metallized wiring layers led out on four sides of the package, and electrode pads are provided on four side faces of the package without lead pins There is a leadless chip carrier (LCC), and a ball grid array (BGA) in which connection terminals are formed by spherical terminals made of solder. Among these, BGA
It is said that the highest density is possible.

In this ball grid array (BGA), connection terminals are formed by connecting spherical or columnar terminals made of a brazing material such as solder to connection pads, and the connection terminals are formed on wiring conductors of an external electric circuit board. The terminals are placed in contact with each other, and then the terminals are heated and melted at a temperature of about 250 to 400 ° C., and the spherical terminals are 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 the external electric circuit board via the metallized wiring layer and the connection terminal.

Further, as an insulating substrate in a package for housing a semiconductor element, an insulating material made of a sintered body such as alumina, mullite, glass-ceramic or the like is mainly used depending on its use.

On the other hand, as an external electric circuit board, the surface of an insulator mainly composed of a glass-epoxy composite material has C
A wiring conductor formed of u, Ag, Au, or the like is used.

[0009]

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 its usefulness is high, its thermal expansion coefficient is about 40 to 70 × 10 ⁻⁷ / ° C., whereas glass-epoxy, which is most frequently used as an external electric circuit board on which a package is mounted, is used. The thermal expansion coefficient of a printed circuit board made of such a material is as large as 120 to 180 × 10 ⁻⁷ / ° C.

Therefore, when the semiconductor integrated circuit element is accommodated in the package for accommodating the semiconductor element and then mounted on an external electric circuit board such as a printed circuit board, heat generated during operation of the semiconductor integrated circuit element is transferred to the insulating substrate. When repeatedly applied to both of the external electric circuit boards, a large thermal stress is generated between the insulating substrate and the external electric circuit board due to a difference in thermal expansion coefficient between the two. This thermal stress has no significant effect when the number of terminals in the package is relatively small, that is, 300 or less, but the influence tends to increase as the number of terminals exceeds 300 and the package itself becomes larger.

That is, when a thermal stress is repeatedly applied by repeating the operation and the stop of the package, the thermal stress is applied to 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. As a result, the connection pads are peeled off from the insulating substrate, the terminals are peeled off from the wiring conductors, and the connection terminals of the semiconductor element storage package are stably electrically connected to the wiring conductors of the external electric circuit board for a long time. It had the disadvantage that it could not be connected.

Accordingly, the present invention solves the above-mentioned drawbacks by firmly mounting a package mounting an element such as a semiconductor element on an external electric circuit board made of a high thermal expansion insulator such as a glass-epoxy resin. It is an object of the present invention to provide a highly reliable package capable of maintaining a stable connection state for a long time, and a mounting structure thereof.

[0013]

The package of the present invention comprises:
A ceramic insulating substrate, a connection pad formed on the lower surface or side surface of the insulating substrate, and a metallization disposed on or in the insulating substrate for connecting an element mounted on the upper surface of the insulating substrate and the connection pad. A wiring layer, wherein the insulating substrate has a thermal expansion coefficient of 80 to 180 × 10 in a temperature range of 40 to 400 ° C. ^-7 / ° C., wherein the element is bonded to the insulating substrate with a flexible material.

Further, the package mounting structure of the present invention is as follows.
The coefficient of thermal expansion at 40 to 400 ° C is 12 to 16 ppm
The connection pad of the above package is mounted on an external electric circuit board having a wiring conductor adhered and formed on the surface of an insulator at / ° C by bonding the connection pad to the wiring conductor via a brazing material. It is a feature.

In the above package and its mounting structure, a connection terminal made of a brazing material is attached to a connection pad of the package, or a connection terminal made of a spherical or columnar terminal made of a high melting point material is attached to the connection pad. Is desirably brazed with a low melting point brazing material.

Further, as the ceramic sintered body, S
a sintered body mainly composed of iO ₂ and Al ₂ O ₃ , wherein at least cristobalite crystal and / or mullite crystal phase is precipitated in the sintered body, or a glass phase, and 40 to 400 ° C. It is preferable that the sintered body contains a crystal phase composed of a metal oxide having a coefficient of thermal expansion of 60 × 10 ⁻⁷ / ° C. or more in the temperature range described above.

[0017]

According to the present invention, the thermal expansion coefficient in a temperature range of 40 to 400 ° C. is 80 to 180 × 10 ⁻ as an insulating substrate in a package mounted on an external electric circuit board such as a glass-epoxy board or the like. ⁷ / ℃
By using the ceramic sintered body of, the difference in thermal expansion coefficient between the insulating substrate and the external electric circuit board is reduced,
As a result, a connection failure between the package and the external electric circuit board does not occur due to a thermal stress caused by a difference in thermal expansion coefficient between the insulating substrate and the external electric circuit board. It is possible to accurately and firmly electrically connect the circuit board to the circuit board for a long period of time.

Further, as the insulating substrate, SiO ₂ and A
A ceramic sintered body consisting mainly of l ₂ O _3, sintered bodies at least cristobalite crystals and / or mullite crystalline phase in the sintered body is formed by deposition, or a glass phase, a temperature of 40 to 400 ° C. 6 coefficient of thermal expansion in the range
By using a ceramic sintered body containing a crystal phase composed of a metal oxide having a temperature of 0 × 10 ⁻⁷ / ° C. or more, the thermal expansion coefficient can be controlled to 80 to 50% by controlling the glass phase composition and the amount of the crystal phase precipitated. It can be easily controlled in the range of 180 × 10 ⁻⁷ / ° C.

Further, in the package, by bonding the element and the insulating substrate with a flexible material, even if there is a large difference in thermal expansion between the element and the insulating substrate, the element can be separated. Can be prevented.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings showing an embodiment. 1 and 3 show one embodiment of a mounting structure of a BGA type semiconductor device housing package according to the present invention, wherein A is a semiconductor device housing package, and B is an external electric circuit board.

The package A for housing a semiconductor element comprises an insulating substrate 1, a lid 2, a metallized wiring layer 3, and connection terminals 4.
And the semiconductor element 5 housed inside the package. The insulating substrate 1 and the lid 2 constitute a container 6 for airtightly housing the semiconductor element 5 inside. That is,
The insulating substrate 1 has a recess 1a in the center of the upper surface in which the semiconductor element 5 is placed and accommodated. The semiconductor element 5 is bonded and fixed to the bottom of the recess 1a via a flexible adhesive.

Further, a plurality of metallized wiring layers 3 are formed on the insulating substrate 1 from the periphery to the lower surface of the concave portion 1a in which the semiconductor element 5 is mounted and accommodated. As shown in FIG. 2, a large number of concave portions 1b are provided, and connection pads 3a electrically connected to the metallized wiring layer 3 are formed on the bottom surfaces of the concave portions 1b. Solder (tin-lead alloy) is provided on the surface of the connection pad 3a.
A protruding terminal 4 made of a brazing material is attached as a connection terminal 4 to an external electric circuit board. As a method of attaching the protruding terminal 4, there are a method of arranging a spherical or columnar brazing material on the connection pad 3a, and a method of printing the brazing material on the connection pad 3a by a screen printing method.

The connection terminal 4 attached to the connection pad 3a has a protrusion 4a on the lower surface of the insulating substrate 1,
Connection pad 3a to which each electrode of semiconductor element 5 is connected
Is connected to the wiring conductor 8 of the external electric circuit board B, and the semiconductor element housing package A is connected to the external electric circuit board B.
It works on top.

The metallized wiring layer 3 electrically connected to the connection pad 3a is electrically connected to each electrode of the semiconductor element 5 via a bonding wire 7, so that the electrode of the semiconductor element 5 is It is electrically connected to the connection pad 3a. The external electric circuit board B is
The wiring conductor 8 is formed on the surface of the insulator 9.

On the other hand, the external electric circuit board B comprises an insulator 9 and a wiring conductor 8, and the insulator 9 is formed of a printed board made of a material containing at least an organic resin.
Specifically, the coefficient of thermal expansion at 40 to 400 ° C. such as a glass-epoxy composite material is 120 to 160 ×
It is made of an insulating material of 10 ^-7 / ° C. Also, this circuit board B
The wiring conductor 8 formed on the surface of the substrate is usually made of Cu, A in view of the consistency of the linear thermal expansion coefficient with the insulator 9 and the good electrical conductivity.
u, Al, Ni, Pd-Sn and other metal conductors.
The thermal expansion coefficients in the present invention all mean linear thermal expansion coefficients.

To mount the semiconductor element housing package A on the external electric circuit board B, the insulating substrate 1 of the package A
The protruding terminal 4 made of solder attached to the connection pad 3a 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. As a result, the protruding terminal 4 itself made of a brazing material such as solder is melted, and the terminal 4 is bonded 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 be adhered to the surface of the wiring conductor 8 in order to easily connect to the protruding terminals 4 using the brazing material.

As another example, as shown in FIG. 3, as the connection terminal 4, one obtained by brazing a spherical terminal 10 made of a high melting point material to a connection pad 3a with a low melting point brazing material 11 can be applied. . The high melting point material needs to have a higher melting point than the low melting point brazing material 11 used for brazing, and the brazing brazing material is, for example, 40% by weight of Pb.
When the solder is made of solder having a low melting point of 60% by weight of Sn, the spherical terminal 10 may be made of a solder having a high melting point of 90% by weight of Pb and 10% by weight of Sn, or Cu, Ag, Ni, Al, Au, Pt, Fe.
And the like.

In such a configuration, the spherical terminal 10 attached to the connection pad 3a 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. 10 can be mounted on the external electric circuit board B by bonding it to the wiring conductor 8 with a brazing material 12 such as solder. Au is used as a low melting point brazing material.
The connection terminal may be connected to the external electric circuit board using a -Sn alloy, 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 transmission 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 shown in FIG. 4, the metallized wiring layers 3 individually connected to the electrodes of the semiconductor element are led out to the side surfaces of the insulating substrate 1, and the metallized wiring layers 3 led out to the side surfaces are connection terminals that also serve as connection pads. 4. Further, according to the package C, in order to prevent electromagnetic interference, the concave portion 1a for accommodating the semiconductor element 5 is filled with an epoxy resin or the like, and the concave portion is sealed by the lid 13 made of a conductive resin. Further, a conductive layer 14 for grounding is formed on the bottom surface of the package C.

In order to mount the package C on the external electric circuit board B, 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 to form a brazing material or the like. For electrical connection. 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.

According to the present invention, as a package for housing a semiconductor element mounted on the surface of such an external electric circuit board B, the insulating substrate 1 is made of a ceramic sintered body and has a temperature of 40 to 400 ° C. Coefficient of thermal expansion in the range of 80 to 180 × 10 ⁻⁷ / ° C., especially 90 to 140 × 10
It is important that it is ^-7 / ° C. This alleviates the occurrence of thermal stress due to the difference in thermal expansion coefficient between the external electric circuit board B and the external electric circuit board B, and maintains a good electrical connection between the external electric circuit board B and the packages A and C for a long period of time. When the coefficient of thermal expansion is smaller than 80 × 10 ⁻⁷ / ° C. or larger than 180 × 10 ⁻⁷ / ° C.,
In any case, the thermal stress caused by the difference in thermal expansion becomes large, and it cannot be prevented that the electrical connection between the external electric circuit board B and the packages A and C deteriorates.

The thermal expansion coefficient of the insulating substrate 1 is 80 to 1
As the temperature increases to 80 × 10 ⁻⁷ / ° C., the difference in thermal expansion from the semiconductor element 5 using Si as a substrate may increase on the contrary. Therefore, according to the present invention, the semiconductor element 5
A flexible material capable of buffering a difference in thermal expansion as an adhesive to the insulating substrate 1 such as an organic adhesive such as an epoxy-based or polyimide-based adhesive, or an adhesive obtained by mixing a metal such as Ag with the adhesive in some cases. By using the material, the semiconductor element 5
Can be prevented from being separated due to a difference in thermal expansion.

A ceramic sintered body having a high coefficient of thermal expansion;
For example, for example, Al_TwoO_Three-SiO _TwoA sintered body,
Α-cristobalite crystal phase and / or
Those containing a mullite crystal phase are exemplified. α-Christo
Barite itself is 125-580 × 10^-7/ ° C high thermal expansion
Α-Cristobalite
By adding an appropriate amount, the thermal expansion
The number can be increased. In addition, the mullite crystal phase is thermally expanded.
The tension coefficient is 4.5 × 10^-7/ ℃, but with other components
By containing high melting point silica glass
High thermal expansion can be achieved as a whole body.

As a method for producing a sintered body containing the α-cristobalite crystal phase and / or mullite crystal phase in the above-mentioned sintered body, as described in Japanese Patent Application No. 6-327301, Al ₂ O ₃ powder, SiO ₂
0.5% by weight or more of a powder and a compound of at least one metal of Groups 2a and 3a of the periodic table, and 0.5% by weight or more of mullite powder; Weight ratio of amount of Si / oxide equivalent amount is 0.72
Or less than 1 or SiO ₂
Powder or SiO ₂ powder, Al ₂ O ₃ powder, at least 0.5% by weight of a compound of at least one metal of Group 2a and Group 3a of the periodic table, and 10% by weight or more of mullite powder; Cristobalite crystals are precipitated by baking at a temperature of 1600 ° C. or less using a composition in which the weight ratio of the oxide equivalent amount of Al / the oxide equivalent amount of Si in the entire composition is 0.6 or more and less than 1. be able to.

Further, when firing at a temperature exceeding 1600 ° C., a mullite crystal phase is precipitated, and high thermal expansion S
Since a so-called SiO ₂ glass containing iO _{2 as a} main component is generated, high thermal expansion can be realized.

The other sintered body may be a so-called vitreous sintered body or a glass-ceramic sintered body. As a glass-forming component, a compound having a high thermal expansion itself is added. A crystalline phase having a high thermal expansion coefficient can be precipitated as the crystalline phase to control the thermal expansion coefficient. As the composition of these sintered bodies, SiO ₂ is an essential component, and other components are alkali metals such as Li, Na, and K; alkaline earth metals such as Ca, Ba, Sr, and Mg; Al, Zn, and Pb; A crystalline phase having at least one kind selected from the group consisting of Ti, Zr, P and B and having a high thermal expansion in such a sintered body, specifically having a thermal expansion coefficient of 60 × 10 at 40 to 400 ° C. ^-7
Cristobalite (Si)
O ₂ ), quartz (SiO ₂ ), tridymite (Si
O ₂ ), forsterite (2MgO.SiO ₂ ), spinel (MgO.Al ₂ O ₃ ), wollastonite (CaO
・ SiO ₂ ), Monticellanite (CaO ・ MgO ・
SiO 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 (Mg
O), alumina (Al ₂ O ₃ ), carneginite (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 .2Si)
O ₂ ) and a sintered body in which at least one or more selected from the group consisting of B ₂ O ₃ .2MgO.2SiO ₂ are precipitated. Particularly, a crystal phase of 80 × 10 ⁻⁷ / ° C. or more is preferable.

The metallized wiring layer 3 disposed in the insulating substrate 1 of the packages A and C may be made of one of Cu, Ag, Ni, Pd and Au in addition to a high melting point metal such as W and Mo. It can be composed of more than one kind.

As a method of manufacturing such packages A and C, a suitable organic binder, a plasticizer and a solvent are added to a raw material powder for forming the insulating substrate 1 and mixed to form a slurry, and the slurry is formed. Is manufactured as a green sheet (raw sheet) by employing a doctor blade method or a calendar roll method. And the metallized wiring layer 3
And, as the connection pad 3a, a metal paste obtained by adding an organic binder, a plasticizer, and a solvent to a suitable metal powder and mixing is printed and applied on the green sheet in a predetermined pattern by a known screen printing method. Also, in some cases,
An appropriate punching process is performed on the green sheet to form a through hole, and this hole is filled with a metallizing paste. By stacking a plurality of these green sheets and simultaneously firing the green sheets, the metallized wiring layers 3 and the connection pads 3a, a package having a multilayer structure can be obtained.

When co-firing is performed as described above,
Simultaneous firing of insulating substrate material depending on the type of rise wiring layer
It is necessary to control it. For example, meta
The rise wiring layer is made of a high melting point metal such as W and Mo.
In this case, a high temperature of 1400 to 1700 ° C.
E.g. Al_TwoO_Three-SiO_Two, A
l_TwoO_Three-MgO, Al_TwoO_Three-SiO_Two-Composition of MgO
Is good. Further, the metallized wiring layer is made of Cu, Ag, Ni, etc.
In the case of using a low temperature of 850 to 1300 ° C
Such as SiO_Two-MgO, SiO_Two
-Al_TwoO_Three-Na_TwoO, SiO_Two-MgO-CaO, Si
O_Two-Al_TwoO_Three−Li_TwoO, SiO_Two-MgO-Li_TwoO,
SiO_Two-ZnO-Li_TwoO, SiO_Two-MgO-Ba
O, SiO _Two-BaO-Al_TwoO_Three-B_TwoO_Three, SiO_Two-N
a_TwoOP_TwoO_Five-CaO, SiO_Two-Na_TwoO-Al_TwoO_Three
−P_TwoO_Five-ZnO, SiO_Two-BaO-Al_TwoO_Three-Mg
O-TiO_Two-ZrO_Two, SiO_Two-Al_TwoO_Three-BaO-
Na_TwoA composition such as O is desirable.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to more specific examples. Example 1 The weight ratio of Al ₂ O ₃ / SiO ₂ in all the raw materials was 0.
Mixed powder of 4 or more and 1 or less (average crystal grain size of Al ₂ O ₃ .
6 μm, average crystal grain size of SiO ₂ 0.8 μm), CaC
O ₃ · MgCO ₃ powder (average crystal grain size 1.5 μm), Y ₂
Mullite powder to O ₃ powder (average crystal grain size: 1.0 μm)
Are weighed and mixed such that the composition of the molded article has the ratio shown in Table 1, and 3.5 × 3.5 × 15 mm by a uniaxial press molding method.
After being formed into the shape shown in Table 1, it was fired in the atmosphere under the firing temperature conditions shown in Table 1. The CaCO ₃ and MgCO ₃ powders are
The results are shown as changed to CaO and MgO.

(Evaluation of Characteristics of Sintered Body) Next, the crystal phase of the sintered body obtained as described above was identified by X-ray diffraction measurement. Further, the coefficient of thermal expansion at 40 to 400 ° C. was measured and is shown in Table 1. The sintered body is 60 mm in diameter and 2 m in thickness.
m, and the relative permittivity was determined by the method of JISC2141. The measurement was performed using a Q meter (YHP4284A), the capacitance at 25 ° C. was measured under the conditions of 1 MHz and 1.0 Vrsm, and the relative dielectric constant at 25 ° C. was measured from the capacitance. The results are shown in Table 1.

(Heat cycle test at mounting) Next, using each raw material composition shown in Table 1, toluene + I was used as a solvent.
PA, acrylic resin as binder, D as plasticizer
500μm thickness by doctor blade method using BP
Green sheet was produced.

A metallized wiring layer was coated on the surface of the green sheet with a W metallized paste by screen printing. In addition, a through hole was formed at a predetermined portion of the green sheet so that the inside of the through hole was finally exposed on the lower surface of the substrate, and the inside of the through hole was filled with a W metallizing paste. Then, six green sheets to which the metallizing paste was applied were laminated and pressure-bonded while positioning the through holes.

The laminated body was subjected to 1600 at each firing temperature shown in Table 1.
The metallized wiring layer and the insulating substrate were simultaneously fired in an atmosphere at a temperature of ℃ to produce a wiring substrate for a package.

Next, a concave portion was formed on the lower surface of the wiring substrate at a position connected to the through hole, a connection pad made of tungsten was manufactured, and after Ni plating, Au plating was performed.

Then, a spherical terminal made of solder (10% tin-90% lead) was attached to the connection pad as shown in FIG. The spherical terminals were formed on the entire lower surface of the wiring substrate at a density of 25 terminals per 1 cm ² .

On the other hand, a glass-epoxy substrate 40
A printed board was prepared in which a wiring conductor made of copper foil was formed on the surface of an insulator having a thermal expansion coefficient of 130 × 10 ⁻⁷ / ° C. at −800 ° C.

Then, the above-mentioned package insulating substrate is aligned so that the wiring conductor on the printed board and the spherical terminal of the package insulating substrate are connected, and this is placed in an atmosphere of N ₂ at 260 ° C. for 3 minutes. After heat treatment, the package insulating substrate was mounted on the surface of the printed circuit board. By this heat treatment, it was confirmed that the spherical terminals of the package insulating substrate were melted and electrically connected to the wiring conductors of the printed circuit board.

Next, the test sample was mounted on the surface of the printed circuit board with the package insulating substrate mounted as described above in a thermostat controlled at −40 ° C. and 125 ° C. in an air atmosphere for 15 minutes / 15 minutes. Up to 1 with 1 cycle of holding
000 cycles were repeated.

The electrical resistance between the wiring conductor of the printed circuit board and the package insulating substrate was measured for each cycle, and the number of cycles until the electrical resistance changed was shown in Table 1.

[0051]

[Table 1]

As is clear from the results in Table 1, the cristobalite crystal phase was precipitated as the crystal phase, and the thermal expansion coefficient was 80%.
In the case of a package insulating substrate manufactured using ceramics of up to 180 × 10 ⁻⁷ / ° C. as an insulating substrate, no change in electrical resistance is observed between the wiring conductor of the printed circuit board and the package insulating substrate even after 1000 cycles of temperature rise and fall. Was.

On the other hand, the conventional thermal expansion coefficient is 80 ×
Sample No. using an Al ₂ O ₃ based sintered body of less than 10 ⁻⁷ / ° C.
In No. 13, the electrical resistance increased in 100 cycles, resulting in poor connection. The thermal expansion coefficient is 180 × 10 ⁻⁷ / ° C.
Sample no. In the cases of Nos. 1 and 2, connection failure occurred in 500 cycles or less.

Example 2 BaCO ₃ , SiO ₂ , B ₂ O ₃ , MgO, Z
Using rO ₂ , Li ₂ O, CaCO _3, etc., they were weighed and mixed so as to have the composition shown in Table 2. This mixture is 850-950
After calcining at ℃, pulverizing, adding an organic binder and mixing well, and then 3.5 × 3.5 × 15 by uniaxial pressing.
A molded body having a shape of mm was produced, and the molded body was fired at 900 to 1100 ° C. in an atmosphere of the air to produce a sintered body.

Next, the crystal phase of the sintered body obtained as described above was identified by X-ray diffraction measurement. 4 more
The coefficient of thermal expansion at 0 to 400 ° C. was measured and is shown in Table 3. The sintered body was processed to a diameter of 60 mm and a thickness of 2 mm,
The relative permittivity was determined by the method of SC2141. The measurement was performed using a Q meter (YHP4284A), and 1 MHz,
The capacitance at 25 ° C. was measured under the condition of 1.0 Vrsm, and the relative dielectric constant at 25 ° C. was measured from the capacitance. The results are shown in Table 3.

(Heat cycle test at mounting) Next, using each of the raw material compositions shown in Table 2, toluene + I
PA, acrylic resin as binder, D as plasticizer
500μm thickness by doctor blade method using BP
Green sheet was produced.

A metallized wiring layer was coated on the surface of the green sheet with a Cu metallized paste by screen printing. Further, a through hole is formed at a predetermined position of the green sheet so that the inside of the through hole is finally exposed on the lower surface of the substrate.
Filled with metallized paste. Then, six green sheets to which the metallizing paste was applied were laminated and pressure-bonded while positioning the through holes.

At a firing temperature (° C.) shown in Table 2, the metallized wiring layer and the insulating substrate were simultaneously fired in a binder removal step: N ₂ + H ₂ O, and a main firing: N ₂ atmosphere. A wiring board was manufactured.

Next, in the same manner as in Example 1, a concave portion was formed on the lower surface of the wiring board at a position connected to the through hole, and a connection pad made of Cu metallized was manufactured. Then, as shown in FIG. 1, solder (30 to 10% tin-lead 7)
(0-90%). The connection terminals were formed on the entire lower surface of the wiring substrate at a density of 30 terminals per 1 cm ² .

On the other hand, a glass-epoxy substrate 40
A printed board was prepared in which a wiring conductor made of copper foil was formed on the surface of an insulator having a thermal expansion coefficient of 130 × 10 ⁻⁷ / ° C. at −800 ° C.

Then, the above-mentioned package insulating substrate is aligned so that the wiring conductor on the printed circuit board and the connection terminal of the package insulating substrate are connected, and this is placed in an atmosphere of N ₂ at 260 ° C. for 3 minutes. After heat treatment, the package insulating substrate was mounted on the surface of the printed circuit board. By this heat treatment, it was confirmed that the solder-made connection terminals of the package insulating substrate were melted and electrically connected to the wiring conductors of the printed circuit board.

Then, the test sample was placed in a thermostat controlled at -40 ° C. and 125 ° C. in an air atmosphere at a temperature of −40 ° C. and a temperature of 125 ° C., respectively. Up to 1,000 cycles were repeated with one cycle of holding for 15 minutes. Then, the electric resistance between the wiring conductor of the printed circuit board and the insulating substrate for the package was measured for each cycle, and the number of cycles until the electric resistance changed was shown in Table 3.

[0063]

[Table 2]

[0064]

[Table 3]

As is clear from the results shown in Tables 2 and 3, the insulating substrate for a package made of glass ceramics having a thermal expansion coefficient of 80 to 180 × 10 ⁻⁷ / ° C. as an insulating substrate printed even after 1000 cycles of temperature rise and fall. No change in electrical resistance was observed between the wiring conductors of the substrate and the package insulating substrate, and an extremely stable and favorable electrical connection was maintained.

[0066]

According to the present invention, even when the package of the present invention is mounted on an external electric circuit board such as a printed circuit board having a large coefficient of thermal expansion, the generation of stress due to the difference between the two coefficients of thermal expansion is suppressed, and the package and the external It is possible to make accurate and strong electrical connection with the circuit board 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.

[Brief description of the drawings]

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insulating board 1a ... Depression 2 ... Lid 3 ... Metallized wiring layer 3a ... Connection pad 4 ... Connection terminal 4a ... Protrusion 5 ... Semiconductor element 6 ... Container 8 ... Wiring conductor 9 ... Insulator A ... BGA type semiconductor element storage package B ... External electric circuit board C ... LCC type semiconductor element storage package

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Takeshi Kubota 1-1, Yamashita-cho, Kokubu-shi, Kagoshima Inside the Kyocera Corporation Kagoshima Kokubu Plant (72) Inventor Ryuni Kunimatsu 1-1, Yamashita-cho, Kokubu-shi, Kagoshima No. Within the Kyocera Corporation Kagoshima Kokubu Plant (72) Inventor Noriaki Hamada 1-4 Yamashita-cho, Kokubu City, Kagoshima Prefecture Inside the Kyocera Corporation Research Institute (72) Inventor Tsukasa Yanagita 1-4 Yamashita-cho, Kokubu City, Kagoshima Prefecture Inside the Kyocera Research Institute (72) Inventor Masaya Kokubu 1-4-4 Yamashita-cho, Kokubu-shi, Kagoshima Inside the Kyocera Research Institute (72) Inventor Hitoshi Kumadahara 1-4-4 Yamashita-cho, Kokubu-shi, Kagoshima No.In Kyocera Research Institute

Claims (7)

[Claims] 1. A ceramic insulating substrate, connection pads formed on the lower surface or side surfaces of the insulating substrate, and a surface or inside of the insulating substrate for connecting an element mounted on the upper surface of the insulating substrate and the connection pads. And a metallized wiring layer disposed thereon, wherein the package is mounted on an external electric circuit board by bonding the connection pads with a brazing material. A package comprising a ceramic sintered body of 80 to 180 × 10 ⁻⁷ / ° C., wherein the element is bonded to the insulating substrate with a flexible adhesive. 2. The package according to claim 1, wherein a connection terminal made of a brazing material is attached to said connection pad. 3. The package according to claim 1, wherein connection terminals comprising spherical or columnar terminals of a high melting point material are brazed to said connection pads with a low melting point brazing material. 4. The ceramic sintered body is a sintered body mainly composed of SiO ₂ and Al ₂ O ₃ , wherein at least cristobalite crystal and / or mullite crystal phases are precipitated in the sintered body. The package according to claim 1. 5. The method according to claim 1, wherein the ceramic sintered body comprises a glass phase,
The coefficient of thermal expansion in the temperature range of 0 to 400 ° C. is 60 × 1
The package according to any one of claims 1 to 3, further comprising a crystal phase composed of a metal oxide having a temperature of ^0-7 / C or higher. 6. The package according to claim 1, wherein the flexible adhesive is an organic adhesive or an adhesive obtained by mixing a metal with the organic adhesive. 7. A thermal expansion coefficient at 40 to 400 ° C. of 12
A connection pad of the package according to any one of claims 1 to 6, wherein a wiring conductor is attached to a surface of an insulator at a temperature of up to 16 ppm / ° C. A package mounting structure characterized by being mounted by joining together.