JPH0986960A - Wiring board, package for storing semiconductor device using the same, and mounting structure thereof - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] When mounted on a resin-made external electric circuit board, a poor electrical connection occurs, resulting in a lack of stability and stability. SOLUTION: In a wiring board in which a metallized wiring layer of Cu or the like is arranged on the surface or inside of the insulating board or a package A for housing a semiconductor element, the insulating board 1 is made of Li ₂ O.
5 to 30% by weight, and the yield point is 400 ° C to 800 ° C
Heat at 40 ° C to 400 ° C obtained by firing a molded body containing 20 to 80% by volume of the lithium silicate glass of No. 1 and forsterite and cristobalite as essential components so that the total amount thereof is 20 to 80% by volume. Expansion coefficient is 8 ~
It is composed of a sintered body of 18 ppm / ° C., which is mounted on an external electric circuit board B in which a wiring conductor 8 is adhered and formed on the surface of an insulator 9 containing at least an organic resin.

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.
Further, as a typical example using this wiring board, a semiconductor element housing package for housing a semiconductor element, particularly a semiconductor integrated circuit element such as an LSI (Large Scale Integrated Circuit Element) is generally made of an electrical material such as alumina ceramics. An insulating substrate made of an insulating material and having a recess for accommodating a semiconductor element in the center of its upper surface, and a plurality of refractory metal powders such as tungsten and molybdenum that are led out from the periphery of the recess of the insulating substrate to the lower surface. Individual metallized wiring layers,
The insulating substrate is composed of a plurality of connection pads formed on the lower surface or the side surface of the metallized wiring layer and electrically connected to the metallized wiring layer, connection terminals brazed to the connection pads, and a lid. In addition, the semiconductor element is adhered and fixed to the bottom surface of the recess of the insulating substrate with an adhesive made of glass, resin, or the like, and each electrode of the semiconductor element and the metallized wiring layer are electrically connected through a bonding wire and insulated. The lid is bonded to the upper surface of the substrate through a sealing material such as glass or resin, and the semiconductor element is hermetically sealed inside the container including the insulating substrate and the lid. The package for housing the semiconductor element is mounted by electrically connecting the connection terminals connected to the connection pads on the lower surface of the insulating substrate and the wiring conductors of the external electric circuit board by soldering or the like.

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, it is necessary to increase the dimensions of the package itself. At the same time, it is also required to reduce the size, so that the density of connection terminals in the package needs to be increased.

The most common structure of the terminals in the package up to now is a pin grid array (PGA) in which metal pins such as Kovar are connected to the lower surface of the package, but recently, metallization led to the side surface of the package. A quad flat package (QFP) in which an L-shaped metal member is brazed to a wiring layer, a leadless leadless carrier (LCC) having electrode pads on four sides of the package as shown in FIG. 4, Further, a ball grid array (BG) having spherical terminals made of solder on the lower surface of an insulating substrate as shown in FIG.
A) and the like, and of these, BGA is said to be the most densified.

In this ball grid array (BGA), a connection terminal is composed of a terminal in which a spherical terminal made of a brazing material such as solder is brazed to a connection pad, and the spherical terminal is placed on a wiring conductor of an external electric circuit board. The terminals are brought into 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 joined to the wiring conductors to be mounted on the external electric circuit board. With such a mounting structure, each electrode of the semiconductor element housed inside the semiconductor element housing package is electrically connected to the external electric circuit through the metallized wiring layer and the connection terminal.

Further, as an insulating substrate in a package for housing a semiconductor element, it has recently been proposed that the insulating substrate be made of a sintered body such as glass-ceramics for the purpose of low temperature firing and low dielectric constant. There is.

For example, Japanese Patent Laid-Open No. 63-117929 proposes a glass ceramic body using ZnO--Al ₂ O ₃ --SiO ₂ glass. According to such a publication, the chemical composition and heat treatment conditions are set. It is reported that the coefficient of thermal expansion can be controlled by controlling the formation of crystals of cordierite or zinc pebbles in addition to zinc silicate.

[0008]

Ceramics such as alumina and mullite which have been conventionally used as an insulating substrate in these packages have a high strength of 200 MPa or more, and as a technique for forming a multilayer with a metallized wiring layer. Although it is useful because of its high reliability, its linear thermal expansion coefficient (hereinafter simply referred to as thermal expansion coefficient) is about 4.
On the other hand, the thermal expansion coefficient of the printed circuit board having the Cu wiring layer formed on the glass-epoxy insulator, which is most frequently used as the external electric circuit board on which the package is mounted, is 11 to 18 ppm. / ° C, which is very large.

Therefore, when the semiconductor integrated circuit element is housed inside the semiconductor element housing package and then mounted on an external electric circuit board such as a printed circuit board, the heat generated during the operation of the semiconductor integrated circuit element acts as an insulating substrate. When repeatedly applied to both the external electric circuit board, a large thermal stress is generated between the insulating board and the external electric circuit board due to the difference in thermal expansion coefficient between the both. This thermal stress has no significant effect when the number of terminals in the package is relatively small, such as 300 or less, but the effect tends to increase as the number of terminals exceeds 300 and the package itself becomes larger. That is, when thermal stress is repeatedly applied by repeating the operation and stop of the package, this 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. , As a result, the connection pad is peeled off from the insulating substrate, the terminal is peeled off from the wiring conductor, and the connection terminal of the package for housing the semiconductor element cannot be stably electrically connected to the wiring conductor of the external electrode circuit for a long time. It had a drawback.

Therefore, it is conceivable that the insulating substrate and the substrate in the semiconductor housing package are made of a material having a high coefficient of thermal expansion. For example, it has been reported that a substrate having a high coefficient of thermal expansion can be obtained from an integrated circuit package substrate using a glass ceramic body disclosed in JP-A-63-117929. However, as described in the publication, there is a problem that even with the same composition, the precipitated crystal phase changes due to slight differences in heat treatment conditions, and it is difficult to stably control the thermal expansion coefficient.

Further, in order to make the glass-ceramic sintered body have high thermal expansion, it is desirable to deposit a filler component having high thermal expansion. Among them, cristobalite, quartz and forsterite have a high coefficient of thermal expansion of 10 ppm / ° C. or more, and are suitable fillers for achieving high thermal expansion. However, in terms of thermal expansion characteristics, these crystalline phases have a bending point at which the coefficient of thermal expansion abruptly changes near 230 ° C. for cristobalite and 570 ° C. for quartz, so when used near this temperature. Due to the change in the thermal expansion characteristics, a connection failure may occur between the wiring board and the printed circuit board or the metallized wiring layer. Moreover, the dielectric constant of forsterite alone tended to increase.

Therefore, the present invention provides a highly reliable wiring board and semiconductor capable of maintaining a stable and stable connection state of a wiring board or a package for housing a semiconductor element to an external electric circuit board such as a printed board. An object of the present invention is to provide an element housing package and its mounting structure.

Further, according to the present invention, it is possible to perform simultaneous firing with the Cu metallized wiring layer, to efficiently remove the binder, and to carry out sintering at a low temperature even with a relatively small amount of glass. An object of the present invention is to provide a substrate and a package for housing a semiconductor element.

[0014]

As a result of repeated studies on the above problems, the inventors of the present invention found that Li ₂ was used as an insulating substrate.
When lithium silicate glass containing 5 to 30 wt% O is mixed with forsterite and cristobalite, a lithium silicate crystal having a thermal expansion coefficient of 13 ppm / ° C. is stably precipitated during the sintering process, and MgO is solidified in cristobalite. It was found that by melting, a sintered body having a small change in thermal expansion coefficient at 400 ° C. or less can be obtained. That is, by adding a compound having a high coefficient of thermal expansion as a filler component and calcining the compound, a sintered body having a high coefficient of thermal expansion without a rapid change in the coefficient of thermal expansion in a temperature range of 400 ° C. or less can be produced, and lithium Silica glass has a relatively low yield point compared to borosilicate glass,
As a result, they have found that low-temperature firing is possible even if the amount of glass added is small, and completed the present invention.

That is, according to the present invention, in a wiring board in which a metallized wiring layer is provided on the surface or inside of the insulating substrate, the insulating substrate contains 5 to 30% by weight of Li ₂ O and the yield point is 400 ° C. The coefficient of thermal expansion at 40 ° C. to 400 ° C. obtained by firing a molded body containing 20 to 80% by volume of lithium silicate glass at ˜800 ° C. and 20 to 80% by volume of forsterite and cristobalite in a total amount. It is characterized by comprising a sintered body of 8 to 18 ppm / ° C.

Further, as an insulating substrate in a package for accommodating semiconductor elements, it contains 5 to 30% by weight of Li ₂ O,
2 lithium silicate glass with a yield point of 400 ℃ ~ 800 ℃
The thermal expansion coefficient at 40 ° C. to 400 ° C. is 8 to 18 which is obtained by firing a molded body containing 0 to 80 vol% and forsterite and cristobalite in a total amount of 20 to 80 vol%.
It is composed of a sintered body of ppm / ° C.

Further, according to the present invention, for storing a semiconductor element, the above-mentioned sintered body is provided as an insulating substrate on an external electric circuit board in which a wiring conductor is adhered and formed on the surface of an insulating body containing at least an organic resin. The package is mounted by brazing and connecting to the wiring conductor of the circuit board via the connection terminal.

[0018]

According to the present invention, as a wiring substrate or an insulating substrate for a semiconductor element housing package, 20 to 20% of lithium silicate glass containing 5 to 30% by weight of Li ₂ O and having a yield point of 400 to 800 ° C is used. 40 ° C. to 400 ° C. by firing a molded body containing 80 vol% and forsterite and cristobalite as essential components in a proportion of 20 to 80 vol%.
A sintered body having a coefficient of thermal expansion at 8 ° C of 8 to 18 ppm / ° C can be easily and reproducibly manufactured.

In particular, by using lithium silicate glass containing 5% to 30% by weight of Li ₂ O as an essential component as the above glass, a high thermal expansion lithium silicate ( For example, Li ₂ SiO ₃ )
Can be deposited, and the yield point is relatively low,
Since low temperature firing is possible even when the amount of glass added is small, it is possible to fire at the same time as the metallized wiring layer made of Cu.

Further, by using a lithium silicate glass having a deformation point of 400 ° C. to 800 ° C., it is possible to reduce the glass content, increase the filler amount, and increase the firing shrinkage start temperature. . As a result, it is possible to efficiently remove the molding binder such as the organic resin added at the time of molding and match the firing conditions with the metallization that is fired at the same time as the insulating substrate.

On the other hand, when cristobalite is added as a filler, there may be an inflection point at which the coefficient of thermal expansion sharply changes at around 200 ° C. According to the present invention, the combination of forsterite and cristobalite causes a change in forsterite. MgO partially forms a solid solution with cristobalite. This causes a peculiar phenomenon that the inflection point of the thermal expansion coefficient of cristobalite itself in the temperature range of 40 to 400 ° C. disappears, and as a result, there is no inflection point in the thermal expansion characteristics and the thermal expansion coefficient is 8 to 18 ppm / It can be controlled in the range of ° C.

When the filler component is only forsterite, a sintered body having a thermal expansion coefficient of 8 ppm / ° C. or more can be obtained, but the dielectric constant exceeds 6, and the insulating substrate material having the wiring layer is obtained. Is not suitable for.

The coefficient of thermal expansion of the lithium silicate crystal phase precipitated from the lithium silicate glass is about 13 ppm / ° C. By adding forsterite and cristobalite to such glass, quartz having a higher coefficient of thermal expansion is stably deposited. it can. Also as a filler,
By adding a metal oxide having a thermal expansion coefficient of 6 ppm / ° C. or higher at 40 ° C. to 400 ° C., the thermal expansion coefficient of the entire sintered body can be easily controlled within the range of 8 to 18 ppm / ° C.

As described above, as an insulating substrate in a package for accommodating semiconductor elements mounted on an external electric circuit formed of a printed circuit board such as a glass-epoxy substrate, 4
The coefficient of thermal expansion in the temperature range of 0 to 400 ° C. is 8 to 18
By using the ppm / ° C ceramics, the difference in the coefficient of thermal expansion between the insulating substrate and the external electric circuit board becomes small, and as a result, the difference in the coefficient of thermal expansion between the insulating board and the external electric circuit board results. The terminal does not cause a connection failure with the wiring conductor of the external electric circuit due to the thermal stress.
This also makes it possible to electrically connect the semiconductor element housed inside the container and the external electric circuit accurately and firmly for a long period of time.

Further, since the thermal expansion coefficient of Cu used as the internal wiring of the package is approximately 18 ppm / ° C., the reliability of the adhesion of the metallized wiring to the substrate can be improved. it can.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings showing an embodiment.

(Mounting Structure) FIGS. 1 and 2 are views showing an example of the present invention, which has a basic structure of a so-called wiring board in which a metallized wiring layer is provided on the surface or inside of an insulating substrate. 1 and 2 show one example of a semiconductor element housing package and its mounting structure as a typical example thereof, A is a BGA type package, and B is an external electric circuit board. .

In FIG. 1, a package A comprises an insulating substrate 1, a lid 2, a metallized wiring layer 3, terminals 4 and a semiconductor element 5 housed inside the package.
The insulating substrate 1 and the lid body 2 constitute a container 6 for hermetically housing the semiconductor element 5 therein. That is, the insulating substrate 1 is provided with the recess 1a in which the semiconductor element 5 is placed and housed in the center of the upper surface, and the semiconductor element 5 is made of glass on the bottom surface of the recess 1a.
It is adhered and fixed via an adhesive such as resin.

A plurality of metallized wiring layers 3 are adhered and formed on the insulating substrate 1 from the periphery of the concave portion 1a in which the semiconductor element 5 is mounted and accommodated to the lower surface thereof. As shown in FIG. 2, a large number of recesses 1b are provided, and connection pads 3a electrically connected to the metallized wiring layer 3 are adhered to the bottom surface of the recesses 1b. Solder (tin-lead alloy) is formed on the surface of the connection pad 3a.
A protruding terminal 4 made of a brazing material such as is attached as a connection terminal 4 to the external electric circuit board. As a method of mounting the protruding terminals 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 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 the 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 has the effect of being mounted on top.

The metallized wiring layer 3 electrically connected to the connection pads 3a is electrically connected to each electrode of the semiconductor element 5 through the bonding wires 7, so that the electrodes of the semiconductor element are connected to each other. It will be electrically connected to the pad 3a.

On the other hand, the external electric circuit board B is made of a material containing an organic resin such as a glass-epoxy resin composite material, and has a coefficient of thermal expansion of 12 to 40 at 400 to 400 ° C.
On the surface of the insulator 9 of 16 ppm / ° C., as a wiring conductor,
It is a general printed board on which a wiring conductor 8 made of a metal such as Cu, Au, Al, Ni, or Pb-Sn is adhered.

In order to mount the semiconductor element housing package A on the external electric circuit board B, the projecting terminals 4 made of solder attached to the connection pads 3a on the lower surface of the insulating board 1 of the package A are externally electrically connected. Wiring conductor 8 of circuit board B
By placing and abutting on top, and then heating at a temperature of about 250 to 400 ° C., the protruding terminals 4 themselves made of a brazing material such as solder are melted and the terminals 4 are joined to the wiring conductors 8. Is mounted on the external electric circuit board B.
At this time, it is desirable that a brazing material is adhered to the surface of the wiring conductor 8 in order to easily connect the terminal 4 with the brazing material.

As another example, as shown in FIG. 3, a spherical terminal 10 made of a high melting point material is brazed to the connection pad 3a by a low melting point brazing material 11 as shown in FIG. 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 brazing material is, for example, Pb 40 wt% -Sn.
In the case of being composed of a solder having a low melting point of 60% by weight, the spherical terminal may be, for example, a solder having a high melting point of 90% by weight of Pb and 10% by weight of Sn,
It is composed of a metal such as Cu, Ag, Ni, Al, Au, Pt, and Fe. In this configuration, package A
The spherical terminals 10 attached to the connection pads 3a on the lower surface of the insulating substrate 1 are placed and abutted on the wiring conductors 8 of the external electric circuit board B, and then the spherical terminals 10 are soldered with a brazing material 12 such as solder. External electric circuit board B by being adhered to the wiring conductor 8
Can be implemented on. 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, referring to FIG. 4, an external electric circuit board B of a leadless chip carrier (LCC) type package C is shown.
The mounting structure for is explained. 4, the same members as those in FIG. 1 are designated by the same numbers. In the package C in FIG. 4, the metallized wiring layer 3 is led out to the side surface of the insulating substrate 1, and the metallized layer led out to the side surface constitutes the connection terminal 4. Also, this package C
Then, for example, in order to prevent electromagnetic interference, the recess 1a for housing the semiconductor element 5 is filled with an epoxy resin or the like, and the recess is sealed by a lid 13 made of a conductive resin. Further, a conductive layer 14 for grounding is formed on the bottom surface of the package C.

To mount the package C on the external electric circuit board B, the connecting terminals 4 on the side surface of the insulating substrate 1 of the package C are placed on and abutted on the wiring conductors 8 of the external electric circuit board B, and brazing material or the like. To electrically connect. At this time, it is desirable that the surface of the connection terminal 4 or the wiring conductor 8 is coated with a brazing material in order to facilitate connection with the brazing material.

(Substrate Material) 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, its insulating substrate 1 has a temperature of 40 to 400 ° C.
Coefficient of thermal expansion in the temperature range of 8 to 18 ppm / ° C,
In particular, it is important that the sintered body be 9 to 14 ppm / ° C. This is important for alleviating the generation of thermal stress due to the difference in thermal expansion between the external electric circuit board B and the electrical connection state between the external electric circuit board B and the package A maintained for a long period of time. And the coefficient of thermal expansion is 8
If it is lower than ppm / ° C. or higher than 18 ppm / ° C., the thermal stress due to the difference in thermal expansion becomes large and the electrical connection between the external electric circuit board B and the package A is prevented from deteriorating. I can't.

The thermal expansion coefficient of the insulating substrate is 8 to 18 p.
When the semiconductor element is bonded to the insulating substrate, its glass, organic adhesive, etc. are increased because the difference in thermal expansion between the semiconductor element and the semiconductor element using Si as a substrate becomes large as the pm / ° C. increases. It is necessary to appropriately select from In order to buffer the stress due to the difference in thermal expansion, it is desirable to use a flexible material. For example, an epoxy-based or polyimide-based organic adhesive material or a material obtained by adding a metal such as Ag to this adhesive material is preferable. Used for.

According to the present invention, as a sintered body constituting such an insulating substrate having a high coefficient of thermal expansion, a molded body containing 20 to 80% by volume of crystalline glass and 80 to 20% by volume of a filler component is fired. It is configured by a sintered body obtained by. The reason why the amounts of the crystalline glass and the filler component are limited to the above range is that the amount of the crystalline glass component is 20% by volume.
If it is less, in other words, more than 80% by volume of the filler component, liquid phase sintering cannot be performed and it is necessary to fire at a high temperature. In that case, the metallization melts in the metallization simultaneous firing. Further, the crystalline glass is more than 80% by volume, in other words, the filler component is 20% by volume.
If the amount is smaller, the properties of the sintered body will largely depend on the properties of the crystalline glass, making it difficult to control the material properties and causing a problem that the sintering start temperature becomes low and it cannot be co-fired with the wiring conductor. . Also, the cost of the raw material increases.

As the crystalline glass, it is important to use lithium silicate glass containing Li ₂ O in an amount of 5 to 30% by weight, particularly 5 to 20% by weight, and such a lithium silicate glass is used. By using it, lithium silicic acid having a high coefficient of thermal expansion can be deposited. If the content in Li ₂ O is lower than 5% by weight, the amount of lithium silicic acid crystals produced during firing will be small and high thermal expansion cannot be achieved. If the content is higher than 30% by weight, the dielectric loss tangent will be 100.
Since it exceeds × 10 ^-4 , the characteristics as a substrate deteriorate.
Further, it is desirable that Pb is not substantially contained in this glass. This is because Pb is toxic and requires a special apparatus and control for preventing poisoning during the manufacturing process, so that the sintered body cannot be manufactured at low cost. Considering the case where Pb is unavoidably mixed as an impurity, the amount of Pb is preferably 0.05% by weight or less.

Further, the yield point of crystalline glass is 400 ° C.
It is also necessary that the temperature is from 800 to 800C, especially from 400 to 650C. This is because when molding a mixture of crystalline glass and a filler, a molding binder such as an organic resin is added, but this binder is efficiently removed, and at the same time, firing conditions with metallization that is fired at the same time as the insulating substrate. Necessary to achieve matching, the yield point is 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.

The coefficient of thermal expansion of the crystalline glass at 40 ° C. to 400 ° C. is 6 to 18 ppm / ° C., particularly 7-1.
It is also necessary to be 3 ppm / ° C. This is because when the coefficient of thermal expansion deviates from the above range, a difference in thermal expansion with the filler occurs, which causes a decrease in 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.

Examples of the crystalline glass satisfying the above characteristics include SiO ₂ —Li ₂ O—Al ₂ O ₃ and SiO ₂ —Li ₂ O—Al ₂ O ₃ —MgO—TiO ₂ SiO ₂ —Li ₂ O. _{-Al 2 O 3 -MgO-Na 2} O-
_{F SiO 2 -Li 2 O-Al} 2 O 3 -K 2 O-Na 2 O-
_{ZnO, SiO 2 -Li 2 O-} Al 2 O 3 -K 2 O-P 2 O 5 SiO 2 -Li 2 O-Al 2 O 3 -K 2 O-P 2 O 5 -
Examples thereof include compositions such as ZnO—Na ₂ O SiO ₂ —Li ₂ O—MgO and SiO ₂ —Li ₂ O—ZnO. Of these, SiO ₂ is used for forming lithium silicic acid according to the present invention. Lithium silicic acid is an essential component, and SiO ₂ is present in a proportion of 60 to 85 wt% in the total amount of glass, and the total amount of SiO ₂ and Li ₂ O is 65 to 95 wt% in the total amount of glass. It is desirable for precipitating crystals. In this lithium silicate glass, B ₂ O ₃ is desirably 1% by weight or less.

On the other hand, as the filler component, forsterite and cristobalite in a total amount of 20 to 80% by volume,
Particularly, it is mixed in a ratio of 40 to 70% by volume, and the weight ratio of forsterite and cristobalite is 1: 9 to 9 :.
It is desirable that it is 1. These fillers alone have a thermal expansion coefficient of forsterite of 10 ppm / ° C. and cristobalite of 13 to 30 ppm / ° C., so that the thermal expansion coefficient of the glass-ceramic sintered body can be controlled by appropriately mixing these. be able to.

Further, as the filler component, other filler components may be mixed in order to control the thermal expansion coefficient. As the filler, it is desirable to use a metal oxide having a thermal expansion coefficient of at least 6 ppm / ° C. at 40 to 400 ° C.

[0046] As the thermal expansion coefficient of more than 6 ppm / ° C. the crystalline phase, quartz (SiO _2), tridymite (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・ SiO ₂ ), lithium silicate (Li ₂ O ・ SiO ₂ ), diopside (CaO ・ Mg
O.2SiO ₂ ), melvinite (3CaO.MgO.)
2SiO ₂ ), Akermite (2CaO.MgO.2S)
iO ₂ ), magnesia (MgO), alumina (Al ₂ O)
₃ ), Carnegieite (Na ₂ O.Al ₂ O ₃ .2Si)
O ₂ ), enstatite (MgO.SiO ₂ ), magnesium borate (2MgO.B ₂ O ₃ ), celsian (B
aO.Al ₂ O ₃ .2SiO ₂ ), B ₂ O ₃ .2MgO
At least one selected from the group consisting of 2SiO ₂ , garnite (ZnO.Al ₂ O ₃ ) and petalite (LiAlSi ₄ O ₁₀ ). Of these, especially 8p
A crystal phase of pm / ° C or higher is preferable. In addition, the thermal expansion coefficient of the final sintered body is 18 pp in the above filler.
It may exceed m / ° C. In that case, it is necessary to appropriately control the thermal expansion coefficient by mixing with a filler having a small thermal expansion coefficient. Even when using the other fillers as described above, it is necessary to adjust the amount of the added filler to be in the range of 20 to 80% by volume.

The above-mentioned crystalline glass and filler are
It is desirable to appropriately adjust the amount according to the sag point of the crystalline glass. That is, the yield point of crystalline glass is 400 ° C.
When it is as low as ˜650 ° C., the sinterability at low temperature is enhanced, so that the content of the filler can be relatively large, 50 to 80% by volume. On the other hand, the yield point of crystalline glass is 650 ° C.
When it is as high as 800 ° C., the sinterability is lowered, so that it is desirable to mix the filler in a relatively small amount of 20 to 50% by volume. It is desirable to control the sag point of the crystalline glass according to the firing conditions of the metallized wiring layer.

For example, as the metallized wiring layer, Cu,
When the metallization is made of one or more of Ag, Ni, Pd, and Au, firing of these metallizations is 600 to 1000.
Since it occurs at a temperature of 0 ° C., the yield point of the crystalline glass is preferably 400 ° C. to 650 ° C., and the content of the filler is preferably 50% to 80% by volume in order to perform the co-firing. Further, by reducing the amount of the expensive crystalline glass, the cost of the sintered body can be reduced.

The mixture of the crystalline glass and the filler is added to an organic resin binder of an appropriate shape, and then formed into a sheet by a desired forming means such as a doctor blade, a rolling method or a die press. After molding, it is fired.

In the firing, first, the binder component blended for molding is removed. The binder is removed in an air atmosphere at about 700 ° C., but when Cu is used as the wiring conductor, it contains water vapor.
This is performed in a nitrogen atmosphere at 0 to 700 ° C. At this time, it is preferable that the shrinkage start temperature of the molded body is about 700 to 850 ° C., and 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 firing is carried out in an oxidizing atmosphere at 850 ° C. to 1300 ° C., whereby the relative density is densified to 90% or more. If the baking temperature at this time is lower than 850 ° C., the metallization layer cannot be densified, and if it exceeds 1300 ° C., the metallization layer is melted by simultaneous baking with the metallization wiring layer. However, when Cu is used as the wiring conductor, 85
It is performed in a non-oxidizing atmosphere at 0 to 1050 ° C.

In the glass ceramic sintered body thus produced, lithium silicate is precipitated from the crystalline glass in addition to the filler components such as forsterite and cristobalite added as fillers.

.. In addition, there may be a crystal phase generated by the reaction between the crystalline glass and the filler. Then, a glass phase exists at the grain boundaries of these crystal phases.

Further, the thermal expansion coefficient of the final sintered body may exceed 18 ppm / ° C. due to the addition of the filler. In that case, it is necessary to appropriately control the thermal expansion coefficient by mixing with a filler having a small thermal expansion coefficient.

In addition, one of Cu, Ag, Ni, Pd, and Au is used by using the glass ceramic sintered body as an insulating substrate.
In order to manufacture a wiring board or package in which a metallized wiring layer made of at least one kind is arranged, an organic binder, a plasticizer, or a suitable organic binder for the raw material powder consisting of the above-mentioned crystallized glass and a filler for forming the insulating substrate, A solvent is added and mixed to prepare a slurry, and the slurry is prepared as 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 pad, a metal paste obtained by adding and mixing an organic binder, a plasticizer and a solvent to an appropriate metal powder is printed and 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. Then, by laminating a plurality of these green sheets and simultaneously firing the green sheets and the metallization, it is possible to obtain a wiring board or a package having a multilayer structure.

The present invention will be described below in more concrete examples. Example 1 As crystalline glass, 74% by weight of SiO ₂ −1
4% Li ₂ O-4% Al ₂ O ₃ -2% P ₂ O ₅ -2% K
₂ O-2% ZnO-2% Na ₂ O (Pb content 50 pp
m or less, yield point 480 ° C), and weight ratio of 78%
_{SiO 2 -10% Li 2 O-} 4% Al 2 O 3 -2% P 2
Two kinds of glass of O ₅ -2% K ₂ O-3% K ₂ O-1% Na ₂ O (Pb content of 50 ppm or less, yield point 480 ° C.) were prepared, and as another filler component, petalite ( LiAlSi ₄ O ₁₀ , thermal expansion coefficient 8 ppm / ° C),
Nepheline (Na ₂ O.Al ₂ O ₃ .SiO ₂ , thermal expansion coefficient 9 ppm / ° C.) was used and weighed and mixed so as to have the composition shown in Tables 1 and 2. After pulverizing this mixture, adding an organic binder and thoroughly mixing the mixture, a molded product having a shape of 3.5 × 3.5 × 15 mm is produced by a uniaxial pressing method, and the molded product is subjected to N ₂ at 700 ° C. After removing the binder in + H ₂ O, it was fired at 650 to 1300 ° C. in a nitrogen atmosphere to prepare a sintered body.

(Characteristic Evaluation) Next, the coefficient of thermal expansion at 40 to 400 ° C. was measured for the sintered body obtained as described above and shown in Tables 1 and 2. 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. LCR meter (Y.H.P.
4284A), 1 MHz, 1.0 Vrsm
The electrostatic capacity at 25 ° C. was measured under the conditions of, and the relative dielectric constant at 25 ° C. was measured from this electrostatic capacity.

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

A Cu metallizing paste was applied on the surface of the green sheet by a screen printing method to form a wiring pattern, through holes were formed at predetermined portions of the sheet to pass through to the lower surface of the substrate, and the Cu metallizing paste was also filled therein. Then, six green sheets coated with the metallizing paste were laminated and pressure-bonded. This stack 700
After removing the binder in N ₂ + H ₂ O at 0 ° C., the metallized wiring layer and the insulating substrate were simultaneously fired in a nitrogen atmosphere at each firing temperature to produce a wiring board for a package.

Next, a concave portion was formed on the lower surface of the wiring board at a position to be connected to the through hole, and a connection pad made of Cu metallization was prepared. Then, connection terminals made of solder (30 to 10% of tin-70 to 90% of lead) were attached to the connection pads as shown in FIG. The connection terminal is 1 cm ²
It was formed on the entire lower surface of the wiring board at a density of 30 terminals per contact.

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 ˜800 ° C. was prepared.

The package wiring board is aligned so that the wiring conductors on the printed circuit board and the connection terminals of the package insulating board are connected, and this is placed in an N ₂ atmosphere at 260 ° C. for 3 minutes. After heat treatment, the package wiring board was mounted on the surface of the printed 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.

(Heat Cycle Test During Mounting) Next, the package wiring board mounted on the surface of the printed board as described above was controlled to a constant temperature of −40 ° C. and 125 ° C. in the atmosphere. Test sample in tank for 15 minutes / 15
The retention of minutes was set as one cycle, and the cycle was repeated up to 1000 cycles. The electrical resistance between the wiring conductor of the printed circuit board and the package wiring substrate was measured for each cycle, and the number of cycles until the electrical resistance changed was shown in Tables 1 and 2. In addition, for the Cu metallization layer by simultaneous firing,
The peeling, melting, and sintering failure of the metallized layer were evaluated.

[0064]

[Table 1]

[0065]

[Table 2]

As is clear from Tables 1 and 2, in Sample Nos. 1 and 19 in which the glass content was less than 20% by volume, a dense sintered body could not be obtained, and the glass content exceeded 80% by volume. In samples No. 4, 15, 22, and 33, the metallized layer was melted and could not be co-fired with Cu.

On the other hand, the product of the present invention having a filler amount of 20 to 80% by volume had a dielectric constant of 6 or less, no defect of debinding, and good co-firing of Cu metallization. In addition, in a package wiring board manufactured by using a glass ceramic having a thermal expansion coefficient of 8 to 18 ppm / ° C. as an insulating substrate, there is no change in electrical resistance between the wiring conductor of the printed circuit board and the package wiring board even after 1000 cycles of temperature increase or decrease. It was not seen, and extremely stable and good electrical connection could be maintained.

As a result of the identification of the crystal phase by X-ray diffraction measurement, in the sintered bodies of the present invention, the crystal phase due to lithium silicate, forsterite, enstatite, cristobalite and other filler components was detected as the crystal phase. Was done.

In Samples Nos. 5, 623 and 24 in which the filler in the starting composition consisted of only forsterite, the dielectric constant exceeded 6, and the sample N consisting of cristobalite only.
o. 7, 8, 25, and 26 had inflection points of thermal expansion.

Sample Nos. 12 to 1 to which petalite, nepheline and lithium silicate were added as fillers
Nos. 4, 30 to 32 could be fired at a firing temperature of less than 1000 ° C.

Example 2 As the crystalline glass, as shown in Table 3, glass having different amounts of Li ₂ O was used, and forsterite and cristobalite were used at a volume ratio of 1: 1 as the filler. The fillers were mixed in a weight ratio of 30:70, molded in the same manner as in Example 1, debindered, and fired at the temperatures shown in Table 3. Then, with respect to the sintered body obtained as described above, in the same manner as in Example 1, the thermal expansion coefficient at 40 to 400 ° C., the relative dielectric constant, the dielectric loss, and the presence or absence of residual carbon after the binder removal treatment were determined. confirmed.

Further, using the compositions shown in Table 3, a wiring board having Cu as a metallized wiring layer was prepared in the same manner as in Example 1,
This was mounted on a glass-epoxy substrate, a thermal cycle test at the time of mounting was performed, and a wiring layer of Cu metallization by simultaneous firing was observed. The results are shown in Table 3.

[0073]

[Table 3]

As is clear from the results in Table 3, the sample No. 43 having a yield point lower than 400 ° C. could not be co-fired with Cu. Sample No.48 whose yield point exceeds 800 ℃
In that case, it was not possible to sinter unless the firing temperature was raised to 1200 ° C. Therefore, Cu metallization could not be performed. In addition, a sample N containing no Li ₂ O in the crystallized glass
In o.37, the coefficient of thermal expansion was lower than 6 ppm / ° C., and the occurrence of cracks which was considered to be due to the difference in thermal expansion with the filler was observed. Further, in the sample No. 46 in which the content of Li ₂ O exceeded 30% by weight, the dielectric loss was larger than 100 × 10 ^-4 .

On the other hand, the Li ₂ O content is 5 to 30.
In each of Sample Nos. 38 to 41 using glass having a yield point of 400% to 800 ° C, the binder can be removed almost completely, and a dense sintered body can be produced. I was able to. Further, co-firing with the Cu metallized layer was also possible and showed strong adhesive strength.

As a result of the identification of the crystal phase by X-ray diffraction measurement, it was found that lithium silicic acid and forsterite, cristobalite, and enstatite crystal phases were found in all the samples except for sample No. 37 in which Li ₂ O was not present. was detected.

[0077]

As described above in detail, according to the wiring board and the package for accommodating semiconductor elements of the present invention, there is no abrupt change in the coefficient of thermal expansion in the operating temperature range, such as a printed circuit board having a large coefficient of thermal expansion. When mounted on an external electric circuit board, it is possible to suppress the stress generation due to the difference in thermal expansion coefficient between the two and to electrically connect the package and the external electric circuit accurately and firmly for a long period of time. . Moreover, it is possible to realize a highly reliable package mounting structure that can sufficiently cope with the increase in the number of pins due to the increase in size of semiconductor circuit elements.

Furthermore, the combination of crystalline glass containing Li ₂ O and a specific filler reduces the raw material cost,
Moreover, since it is possible to perform co-firing with metallization and remove the binder efficiently, it is possible to provide a high-quality and inexpensive wiring board and semiconductor element housing package.

[Brief description of drawings]

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

FIG. 2 is an enlarged cross-sectional view of a main part of a connection terminal in FIG.

FIG. 3 is an enlarged cross-sectional view of a main part of a connection terminal according to another embodiment.

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

[Explanation of symbols]

 1 ... Insulating substrate 2 ... Lid body 3 ... Metallized wiring layer 4 ... Connection terminal 5 ... Semiconductor element 6 ... Container 8 ... Wiring conductor 9 ... Insulator A. ..BGA type package B ... External electric circuit board C ... LCC type package

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideto Yonekura 1-4, Yamashita-cho, Kokubun-shi, Kagoshima Prefecture Kyocera Stock Company Research Institute (72) Inventor Yasuhide Minami 1-4, Yamashita-cho, Kokubun-shi, Kagoshima (72) Inventor, Yoji Kokubo, 1-4 Yamashita-cho, Kokubun City, Kagoshima Prefecture Kyocera Corporation, Research Institute

Claims (3)

[Claims] 1. A wiring board in which a metallized wiring layer is provided on the surface or inside of an insulating substrate, wherein the insulating substrate contains 5 to 30% by weight of Li ₂ O and has a yield point of 400.
20 ~ 80% by volume of lithium silicate glass at ℃ ~ 800 ℃
And the total amount of forsterite and cristobalite is 2
The linear thermal expansion coefficient at 40 ° C. to 400 ° C. obtained by firing a molded body containing 0 to 80% by volume is 8 to 18 pp.
A wiring board comprising a sintered body of m / ° C. 2. A semiconductor element is housed in a container consisting of an insulating substrate having connection terminals attached thereto and a lid, and the connection terminals and electrodes of the semiconductor element are arranged on the surface or inside of the insulating substrate. In a package for housing a semiconductor element, which is electrically connected by the provided metallized wiring layer,
The insulating substrate contains lithium silicate glass having a Li ₂ O content of 5 to 30% by weight and a yield point of 400 ° C. to 800 ° C.
˜80% by volume, and a linear thermal expansion coefficient at 40 ° C. to 400 ° C. obtained by firing a molded body containing forsterite and cristobalite in a total amount of 20 to 80% by volume of 8 to 18 ppm / ° C. A package for housing a semiconductor element, which is composed of a united body. 3. The connection terminal of the package for accommodating a semiconductor element according to claim 2, wherein the wiring conductor is soldered to the wiring conductor on an external electric circuit board having a wiring conductor adhered to the surface of an insulator containing at least an organic resin. A mounting structure of a package for accommodating a semiconductor element, which is characterized by being attached and bonded.