JP3265996B2 - Low temperature fired glass-ceramic multilayer wiring board and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-temperature fired glass-ceramic multilayer wiring board and a method of manufacturing the same, and more particularly, to a silicon chip manufactured by a flip chip method.
The present invention relates to a low-temperature fired glass-ceramic multilayer wiring board suitable for mounting electronic components such as LSIs and the like, which enables highly reliable external connection, and a method of manufacturing the same.

[0002]

2. Description of the Related Art As a method of manufacturing a ceramic multilayer wiring board in which insulating layers and wiring layers are alternately laminated, there are a thick film multilayer printing method and a green sheet multilayer laminating method. The multilayer laminating method has become mainstream.

In the green sheet multi-layer laminating method, a ceramic green sheet produced by a doctor blade method or the like is formed with a via hole (also called a through hole), filled with a conductive paste, and printed with an internal wiring or a surface electrode using the conductive paste. Thereafter, a predetermined number of sheets are laminated and pressed, and the laminate is fired at a time to manufacture a ceramic multilayer wiring board. In a ceramic multilayer wiring board, both sides of the laminate are composed of insulating layers without inner wiring, and the inner wiring formed in the inner intermediate insulating layer is connected to the outside via the surface electrode through via holes formed in this insulating layer. Is done.

A conventional ceramic multilayer wiring board made of alumina has the advantage that the flexural strength is high and the external connection reliability is excellent, but the relative dielectric constant is as high as about 9 to 10, so that the signal delay is large. Furthermore, since the firing temperature is high, a high melting point metal (W, Mo, etc.) having a high specific resistance is sometimes used as a wiring material, and thus there is a disadvantage that signal transmission loss increases. At present, when the operating frequency of the LSI is significantly increased, this drawback is fatal to the improvement of the performance of the computer, and the development of a ceramic material instead of alumina has been advanced.

[0005] As a ceramic material capable of solving such a problem, the relative dielectric constant is remarkably lower than that of alumina, and the firing temperature is low, so that a low melting point and low resistance metal (Ag, Cu, Au) is used.
), Which can be used as a wiring material, has attracted attention.

A low-temperature fired glass-ceramic multilayer wiring board differs from a conventional ceramic multilayer wiring board in that a mixture of glass and an inorganic substance (generally a ceramic material) called an aggregate is used instead of alumina. By selecting the material and mixing ratio of glass and aggregate, low-resistance metal such as Ag can be used as wiring material at 1050 ° C or less,
Preferably, sintering can be performed by firing at a low temperature of about 900 ° C. and the relative dielectric constant can be reduced to 4 to 6, so that the signal transmission loss is greatly improved.

However, in the glass ceramic multilayer wiring board, the bending strength tends to decrease as the relative dielectric constant decreases. Therefore, when an electronic component such as a silicon chip is externally connected and mounted on the substrate, for example, when a large external force is applied to the chip, the substrate, not the connection portion, tends to be broken, and the reliability of the external connection cannot be secured. A new problem arises.

As a means for solving this problem, Japanese Utility Model Application
No.-134081 requires that the insulating layer on the surface be made of a high-strength material on both sides.
It has been proposed that the intermediate insulating layer formed of (eg, crystallized glass) and in contact with the inner wiring be formed of a glass ceramic material having a low dielectric constant. In other words, the internal intermediate insulating layer in contact with the internal wiring for signal propagation is formed of a glass ceramic material having a low relative dielectric constant, whereas the surface insulating layer for external connection is formed of another material having higher strength. Since the surface insulating layer does not significantly affect the transmission speed of the substrate, the signal transmission loss does not increase so much even if the relative dielectric constant of the surface insulating layer is high.

Recently, as a method of mounting a silicon chip of an LSI, a flip chip method capable of maximizing a mounting density has been spreading for the purpose of miniaturization and high density. The flip chip method is a method in which a chip is directly connected to a substrate and mounted. Specifically, micro pads (called bumps) made of a solder alloy or the like are formed on the surface of one or both of the connection terminals of the chip and the surface electrodes of the substrate, and the connection parts are aligned on the substrate. After placing the chip, it is heated in a reflow furnace or the like to melt the solder alloy in the pad portion, and the substrate is connected to the chip. In this case, on the opposite surface of the substrate, a number of input / output terminals are provided with PGA (pin grid array) or BGA (ball grid array).
This terminal is connected to, for example, a printed wiring board.

[0010]

The above-mentioned glass ceramic multi-layer wiring board in which the surface insulating layer is made of a high-strength glass-ceramic material and the intermediate insulating layer is made of a glass-ceramic material having a low relative dielectric constant is described. It has been found that when electronic components are connected by the flip-chip method, the reliability of external connection is not always sufficient on both the printed wiring board side and the chip side.

According to the present invention, when a glass-ceramic multilayer wiring board having different materials for a surface insulating layer and an intermediate insulating layer is connected to an electronic component by a flip chip method, highly reliable external connection can be reliably performed. It is an object to provide a glass ceramic multilayer wiring board and a method for manufacturing the same.

[0012]

Means for Solving the Problems The present inventors have found that the above problem can be solved by making the thickness of the surface insulating layer having no inner wiring different from each other. In addition, when the surface insulating layer has different thicknesses on both sides in this manner, there is a possibility that the warpage of the substrate at the time of baking may increase, but in that case, the surface on the side warped in a concave shape faces the setter on the setter. It has also been found that baking can minimize warpage.

Here, the present invention relates to a low-temperature fired glass-ceramic in which both surfaces are formed of insulating layers, and wiring layers are alternately laminated therein with an intermediate insulating layer. In a multilayer wiring board, the surface insulating layer is formed of a glass-ceramic material having a higher bending strength than the intermediate insulating layer, and the electronic components are free.
The thickness of the surface insulating layer on the side connected by the
Wherein the thinner than the thickness of the other surface insulating layer, off
This is a low-temperature fired glass-ceramic multilayer wiring board suitable for mounting electronic components by the lip-chip method .

In the present invention, the term “surface insulating layer” means an insulating layer on the front side, both sides of which are not in contact with the inner wiring layer, and the term “intermediate insulating layer” means that at least one side is in contact with the inner wiring layer. Means an insulating layer. For example, if the outermost inner wiring layer is formed between the third and fourth insulating layers from the surface, the third insulating layer is in contact with the inner wiring layer on one side, so that the intermediate The first and second insulating layers, which become insulating layers and both surfaces do not contact the inner wiring layer, become surface insulating layers.

As is apparent from the manufacturing method described later, the surface insulating layer can be formed from one or more green sheets. "Thickness" is the overall thickness. Therefore, “the thicknesses of the surface insulating layers on both surfaces are different from each other” can be achieved by actually changing the number of stacked green sheets on both surfaces when the surface insulating layer is formed.

The glass-ceramic multilayer wiring board of the present invention is particularly suitable for connecting an electronic component to the surface of the thinner side of the surface insulating layer by a flip-chip method.

According to the present invention, a glass-ceramic green sheet for an intermediate insulating layer and a glass-ceramic green sheet for a surface insulating layer having a different composition from the glass-ceramic green sheet are formed into predetermined via holes and filled and / or filled. After performing inner layer wiring printing, one or more green sheets for a surface insulating layer are disposed on both sides, and a plurality of green sheets for an intermediate insulating layer are disposed inside, and the layers are pressed by lamination.
A method for manufacturing a low-temperature fired glass-ceramic multilayer wiring board which is fired at a temperature of 50 ° C. or less, wherein a green sheet for a surface insulating layer forms an insulating layer having a higher bending strength than a green sheet for an intermediate insulating layer, Also provided is a method for manufacturing a low-temperature fired glass-ceramic multilayer wiring board, characterized in that the number of laminated green sheets for the surface insulating layer is different from each other on both sides.

When one side of a glass ceramic multilayer wiring board is connected to an electronic component such as a silicon chip by a flip chip method (hereinafter sometimes abbreviated as FC method) and the other side is connected to a printed wiring board by, for example, a BGA. The pad diameter of the connection part is 100-200 μm for the FC connection part, and the pad diameter for the BGA connection part.
1.0 to 2.0 mm, and the latter pad diameter is about 10 times larger.

In order to ensure the reliability of the substrate for external connection, it is necessary to increase the initial strength of the substrate so that the substrate is broken at the solder portion which is a connection portion when an external force is applied, so that the substrate is not broken. It is known that the surface insulating layer is formed of a glass ceramic material having a high bending strength for this purpose, as described above.

In this case, assuming that the substrate breakdown occurs in the intermediate insulating layer which is weak in strength, it is necessary that the stress generated by the external force does not reach the intermediate insulating layer when the solder breakdown occurs. However, when the pad diameters formed on both sides of the substrate are largely different as described above, the stress applied to the substrate below the connection part through the connection part formed from the pad differs, and the larger the pad diameter, the larger the stress. Will be added. Therefore, it is necessary to change the thickness of the surface insulating layer necessary for preventing the substrate from being broken and ensuring the reliability of the external connection on both sides. That is, the thickness of the surface insulating layer on the side where the pad diameter is small and which is connected to the electronic component by the FC method may be smaller than the opposite side where the pad diameter is large and the side is connected to the printed wiring board.

Further, it has been found that reducing the thickness of the surface insulating layer on the side to be externally connected by the FC method improves the reliability of the external connection from another aspect. That is, the pad diameter for FC connection is usually 100 to 200 μm, but the pad pitch is almost twice the pad diameter, and the via hole diameter formed in the surface insulating layer below the pad is 70 to 150 μm. Since no inner layer wiring is formed inside the surface insulating layer, when the surface insulating layer is formed from two or more green sheets,
It is necessary to provide via holes in each green sheet with the same diameter and the same pitch. It is very difficult to form a fine via hole with a diameter of 70 to 150 μm so as to penetrate a plurality of green sheets from the viewpoint of the positional accuracy of drilling and the positional accuracy when laminating the green sheets. Making the thickness of the surface insulating layer as small as possible within a range that guarantees the adhesion strength of the pad is advantageous in improving the reliability of external connection from the viewpoint of the accuracy of via holes in the surface insulating layer. Further, although the signal passing through the via hole in the surface insulating layer is smaller than the signal passing through the inner layer wiring, the signal passing therethrough is affected by the surrounding material (that is, the surface insulating layer having a relatively large relative dielectric constant). When the thickness of the surface insulating layer is reduced to the minimum necessary for securing the strength, the signal delay when passing through the via hole is also minimized. Of course, it is also advantageous in that the manufacturing cost is reduced.

However, when different glass ceramic materials are used for the surface insulating layer and the intermediate insulating layer, and the thickness of the surface insulating layers on both sides (ie, the number of laminated layers) is changed, two types of glass ceramic green used are used. If the firing shrinkage ratios of the sheets are different, a considerably large warp may be generated during the batch firing of the laminate. If the thickness of the surface insulating layer on both sides is the same, even if the firing shrinkage rates of the two types of green sheets are different, the same shrinkage behavior is exhibited on both sides, so that the shrinkage is offset each other, and a multilayer wiring board without warpage can be obtained. can get.
If the warpage of the substrate caused by the difference in the thickness of the surface insulating layer on both surfaces increases, especially the FC with a small pad diameter
In connection, some of the pads do not fuse well with the pads of the corresponding chip, and a connection failure occurs. Therefore, it is important to manufacture a glass-ceramic multilayer wiring substrate having substantially no warpage while minimizing warpage during batch firing.

The firing step in the manufacture of a glass-ceramic multilayer wiring board is often carried out by placing the laminate on a ceramic plate called a setter and heating it in a heating furnace. According to a preferred embodiment of the present invention, when the combined laminated body that is warped if directly fired as it is is fired at a time, the surface of the concavely warped side faces the setter (that is, the surface is turned downward). B) Place on the setter and bake. Thereby, warpage is remarkably suppressed,
Preferably, a glass-ceramic multilayer wiring board having substantially no warpage can be manufactured.

If the surface warped in the concave shape is placed downward on the setter and baked, when warpage occurs, the central part of the substrate rises from the setter and both ends contact the setter, so that friction with the setter occurs. This is considered to be due to being less likely to warp. Therefore, if the difference in thickness between both surfaces (difference in the number of stacked layers) is not so large, the amount of warpage can be reduced to zero. The amount is significantly reduced.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION In the glass-ceramic multilayer wiring board of the present invention, both the surface insulating layer and the intermediate insulating layer are made of a glass-ceramic material (that is, a material obtained by firing a mixture of glass and aggregate). Are different from each other, and the surface insulating layer has higher bending strength.

The glass ceramic material is generally borosilicate glass (mainly composed of SiO ₂ and B ₂ O ₃ , alkali metal,
Glass that further contains oxides of other metals such as alkaline earth metals and aluminum), and various inorganic substances as aggregates (eg, ceramics such as alumina, quartz, fused quartz, cordierite, zirconia, aluminum nitride) ), And various types of glass-ceramic materials having different characteristics and different firing temperatures can be obtained depending on the types of glass and aggregate and their mixing ratio. In the present invention, a glass ceramic material that can be fired at 1050 ° C. or lower, preferably 1000 ° C. or lower, more preferably 950 ° C. or lower is used.

The surface insulating layer preferably has a transverse rupture strength of at least 20 kgf / mm ² , especially at least 30 kgf / mm ² . Such high-strength glass-ceramic materials include, for example, alkaline earth metal oxides (eg, MgO, CaO), alkali metal oxides (eg, Li ₂ O, Na ₂ O, K ₂ O), and alumina. It can be obtained by mixing borosilicate glass containing one or more species with an aggregate containing alumina as a main component. The mixing ratio of glass and aggregate is 80:20 to 35:
It is preferably within the range of 65. Of course, other glass-ceramic materials that can be fired at a low temperature can be used as long as the transverse rupture strength is high as described above. In general, a high-strength glass-ceramic material contains alumina as an aggregate, and therefore has a high relative dielectric constant. However, as described above, the relative dielectric constant of the surface insulating layer depends on the signal transmission loss of the obtained glass-ceramic multilayer wiring board. Does not have much effect, but it is desirable to make the surface insulating layer as thin as possible to minimize the delay of signals passing through the via holes.

The intermediate insulating layer is preferably formed from a glass ceramic material having a low relative dielectric constant. The relative dielectric constant of the intermediate insulating layer is preferably 6 or less, more preferably 5 or less.
It is as follows. Such a glass-ceramic material having a low relative dielectric constant has, for example, a low content of metal oxides other than SiO ₂ and B ₂ O ₃ (eg, a total of 10% by weight or less), and an alkaline earth metal. Borosilicate glass containing almost no oxide and quartz-based material with low dielectric constant (quartz, fused silica)
Can be obtained by blending an aggregate mainly composed of The mixing ratio of glass to aggregate is 80:
It is preferable to be in the range of 20 to 35:65. As long as the relative dielectric constant is low, other glass ceramic materials that can be fired at a low temperature can also be used.

The role of the surface insulating layer is to reduce the strength of the substrate so that when a strong external force is applied to the substrate or the electronic components mounted thereon, the substrate is broken at the external connection portion and the substrate is not broken. Is to increase. As described above, the thickness of the surface insulating layer required to prevent this substrate breakdown depends on the size of the external connection portion, and the larger the connection portion, the greater the external force applied to the substrate below the connection portion. In addition, it is necessary to increase the thickness of the high-strength surface insulating layer.

Therefore, when the connection is made by the FC (flip chip) method, the diameter of the FC connection portion is 100 to 100 as described above.
BGA for input / output terminals on the opposite side, as small as about 200 μm
Or because the diameter of the PGA connection is about 10 times larger,
Make the thickness of the surface insulating layer on the connection side (chip side) smaller than the thickness of the surface insulating layer on the side for the input / output terminals (printed wiring board side). Specifically, as will be described later, the number of laminated green sheets used for forming the surface insulating layer may be small on the surface on the FC connection portion side and large on the input / output terminal side surface. The specific thickness of the surface insulating layer (or the number of stacked green sheets) required to prevent substrate destruction on each side varies depending on conditions such as the strength of this insulating layer and the connecting portion, the diameter of the connecting portion, etc. Therefore, it may be determined by experiment.

The glass-ceramic multilayer wiring board of the present invention, like the conventional glass-ceramic multilayer wiring board,
It can be manufactured by a green sheet multilayer lamination method. However, different glass ceramic materials are used for the surface insulating layer and the intermediate insulating layer, the surface insulating layer is formed from a glass ceramic material having a higher transverse rupture strength, and the intermediate insulating layer is formed from a glass ceramic material having a lower dielectric constant. Preferably, it is formed. In the green sheet laminating step, the number of green sheets for forming the surface insulating layer is set to be different from each other on both sides. The surface insulating layer on the side with the smaller number of stacked layers is suitable for connecting electronic components by a flip-chip method.

Each of the surface insulating layer and the intermediate insulating layer can be formed of two or more kinds of glass ceramic materials (in this case, the lowest transverse rupture strength of the surface insulating layer is higher than that of the intermediate insulating layer). Higher than the folding strength)
Normally, the surface insulating layer and the intermediate insulating layer may each be formed of one type of glass ceramic material.

For each glass ceramic material of the surface insulating layer and the intermediate insulating layer, a glass ceramic green sheet having an appropriate thickness is formed by a well-known doctor blade method or the like. A predetermined via hole is formed in each green sheet cut into an appropriate size, and the green sheet is filled with a conductive paste. Conductive paste is printed on the green sheet for the intermediate insulating layer so as to form the inner layer wiring, and the outermost green sheet for the surface insulating layer is also printed with the conductive paste so as to form the surface electrode. Print the paste. Then, one or more green sheets for the surface insulating layer are provided on both sides (however, the number of laminations on both sides is different from each other), and a plurality of green sheets for the intermediate insulating layer are disposed inside and laminated and pressed, and the laminate is laminated. Is fired at a temperature of 1050 ° C. or less, preferably 1000 ° C. or less, more preferably 950 ° C. or less, for example, around 900 ° C.

Since the firing temperature is low, a metal having a low melting point and a low specific resistance, such as Ag, Au, or Cu, or an alloy or a mixture of these metals (eg, Ag-Pd
System) can be used. The firing atmosphere must be a reducing or inert atmosphere if the conductor paste contains Cu, but Ag or Au can be fired in the air.

The green sheet laminate is usually placed on a setter made of a ceramic plate and fired in a heating furnace under no pressure. In that case, since the number of stacked green sheets for the upper and lower surface insulating layers is different, if the firing shrinkage behavior of the green sheets differs for the surface insulating layer and the intermediate insulating layer,
The glass-ceramic multilayer wiring board obtained by firing may be warped. In such a case, if the laminate is placed on the setter such that the surface warped in the concave shape contacts the setter (towards the setter), the warpage is suppressed, and the green sheets for the upper and lower surface insulating layers are laminated. If the number is about 1 (the thickness of the green sheet is 30 to 200 μm), a glass ceramic multilayer wiring board having substantially no warpage can be obtained.

If the difference between the thicknesses of the upper and lower surface insulating layers is large and the above method cannot completely suppress the warpage,
The firing may be performed while applying pressure in the direction (sheet thickness direction).

[0037]

The present invention will be further described with reference to the following examples. In Examples,% is% by weight unless otherwise specified.
Tables 1 and 2 show the compositions of glass and aggregate of the glass ceramic material for the intermediate insulating layer and the surface insulating layer used in the examples, and the mixing ratio thereof, respectively.

[0038]

[Table 1]

[0039]

[Table 2]

After crushing the glass and the aggregate having the above composition to an average particle diameter of 1 to 5 μm, respectively, an organic binder (eg, acrylic resin), an organic solvent (eg, xylene), a plasticizer (eg,
Dioctyl phthalate) and an appropriate amount of a dispersant were added, mixed with an alumina ball mill, formed into a sheet by a doctor blade method, and dried by heating at 100 ° C. for 10 minutes to form a 150 μm thick green sheet for a surface insulating layer. A green sheet for an intermediate insulating layer was prepared.

The substrate obtained by laminating only the green sheet for the surface insulating layer and sintering in the atmosphere at the maximum holding temperature of 900 ° C. for 30 minutes had a transverse rupture strength of 37 kgf / mm ² . On the other hand, a substrate obtained by laminating and pressing only the green sheet for the intermediate insulating layer and firing under the same conditions had a flexural strength of 13 kgf / mm ² and a relative dielectric constant of 4.2. That is, the surface insulating layer had higher strength than the intermediate insulating layer, and the intermediate insulating layer had a lower relative dielectric constant.

(Embodiment 1) In this embodiment, a flip chip connection method is assumed as a method of mounting electronic components, and a BGA connection method is assumed for connection to a printed wiring board. Destruction from solder instead of substrate
The number of laminated green sheets for the surface insulating layer (soldering) was investigated for each connection method.

A test piece of a substrate for flip chip connection was prepared as follows. A glass ceramic having the composition shown in Table 3 is used to form a spike (anchor) between the surface electrode and the surface insulating layer on one side of one surface insulating green sheet cut into a square of 50 mm square to maintain the adhesion strength. The paste was printed to a thickness of about 10 μm. In addition, Ag and Pd are used to form pad-like electrodes for flip chip connection.
Of Ag: Pd paste composed of a mixed metal having a ratio of 8: 2, an organic resin (ethylcellulose resin) and an organic solvent (terpineol) at a pitch of 180 μm and a pad diameter of 18
The pattern was printed in a pattern of 0 μm and the number of pads: 4 × 4.

[0044]

[Table 3]

A predetermined number of surface insulating layers are formed so that the green sheet on which the electrodes are printed is positioned on the uppermost layer with the electrode surface facing upward on the six intermediate insulating layer green sheets cut into the same 50 mm square. A green sheet is placed on the laminate, and the laminate is pressed. The resulting laminate is held at a maximum holding temperature of 900 ° C x 30mi.
By firing all at once, a glass-ceramic multilayer substrate was prepared. In the present embodiment, since the purpose is to evaluate the strength, the formation of the inner layer wiring is omitted. Further, in order to prevent the occurrence of warpage of the fired substrate, the number of laminated green sheets for the surface insulating layer disposed on both the upper and lower surfaces was the same.

On the upper surface of the obtained fired substrate, a pitch: 15
Surface electrode pads for flip chip connection were formed at 0 μm and pad diameter: 150 μm. On this electrode pad, a chip capacitor having connection pins of pitch: 150 μm, ball diameter: 150 μm, number of connection balls: 4 × 4, solder ball composition: Pb-3wt% Sn is aligned and placed,
Heating was performed in a reflow furnace at 350 ° C. to perform flip chip connection. A shear stress was applied to the chip capacitor after the connection until the chip capacitor was broken, the broken surface was observed, and the break mode was investigated. Table 4 shows the results.

Separately, except for the pattern of the surface layer electrode pad, the BG was prepared in the same manner as the above-described flip-chip connection test piece.
A test piece for connection A was prepared. For the formation of the surface electrode of the substrate, Ag-Pd paste is pitched: 1.52 mm, pad diameter: 1.07
mm, the number of pads: 10 × 10, printed on a 50 mm square green sheet for a surface insulating layer. On the surface of the fired substrate, surface electrode pads for BGA connection having a pattern with a pitch of 1.27 mm and a pad diameter of 0.89 mm were formed.

On this electrode pad, a ball diameter: 0.89 mm
Ball composition: Pb-63wt% Sn solder balls were melt bonded by a reflow furnace at 230 ° C. Shear stress was applied to the solder balls after joining until the solder balls were broken, and the broken surface was observed to investigate the breaking mode. The results are shown in Table 4.

[0049]

[Table 4]

As is evident from Table 4, the minimum number of required surface insulating layers to satisfy the solder strength as the initial strength standard is one for flip-chip connection, whereas
In the case of BGA connection, the number is two, and it is understood that the thickness of the surface insulating layer does not need to be the same on both surfaces of the substrate. That is,
The number of laminated green sheets for the surface insulating layer depends on the pad diameter
(Electrode diameter) can be reduced on the surface on the smaller side. If the number of laminated green sheets on the side of the flip chip connection portion is reduced to one, the problem of alignment of via holes having a small pitch and a small diameter is remarkably reduced.

Example 2 In this example, the warpage of the fired substrate due to the difference in the number of laminated green sheets for a surface insulating layer is tested.

Six green sheets for an intermediate insulating layer cut into a square of 50 mm square and a predetermined number of green sheets for a surface insulating layer cut into the same square of 50 mm square are stacked and pressed on the upper and lower surfaces thereof. Maximum holding temperature 900 ℃ x
A glass ceramic multilayer substrate was prepared by firing all at once for 30 min. Since the purpose of this example was to check the warpage, the inner wiring and the surface electrode were omitted. Table 5 shows the results of the measurement of the amount of warpage of the substrate caused by firing by the method shown in FIG.

[0053]

[Table 5]

As can be seen from Table 5, if the number of laminated green sheets for the surface insulating layer is the same on both sides, even if the glass ceramic compositions of the surface insulating layer and the intermediate insulating layer are different, the warpage of the substrate at the time of firing is different. Does not happen. However, when the number of laminated surface insulating layers is different from each other on both sides, the side warped in a concave shape, that is, in this embodiment, the side with the smaller number of laminated layers is arranged so as to be in contact with the setter and fired. In the example, if the difference in the number of laminations is one, a glass-ceramic multilayer wiring board with zero warpage can be obtained, and even if the difference in the number of laminations is two, the warpage is significantly reduced.

That is, as shown in Example 1, it is advantageous to change the number of laminated green sheets for the surface insulating layer on both sides. The problem can be solved by appropriate selection.

[0056]

As described in detail above, in the low-temperature fired glass-ceramic multilayer wiring board and the method of manufacturing the same according to the present invention, the surface insulating layer is made of a higher strength glass-ceramic material different from the intermediate insulating layer. The thickness of the surface insulating layer (the number of laminated green sheets for the surface insulating layer) is different from each other on both sides of the formed substrate. Therefore, a low-temperature fired glass-ceramic multilayer wiring board having a minimum necessary thickness of the surface insulating layer for ensuring the reliability of external connection is obtained, and the manufacturing cost can be reduced. Furthermore, if the connection method for mounting electronic components such as silicon chips is the flip-chip connection method, the number of green sheets on which via holes are formed from the flip-chip connection pads on the surface insulating layer to the internal signal layer Is reduced, the alignment becomes easy, and a highly reliable via hole can be formed. Further, since the thickness of the surface insulating layer having a relatively high relative dielectric constant can be minimized, signal delay when passing through the via hole of the surface insulating layer can be suppressed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a method for measuring the amount of warpage of a glass ceramic multilayer wiring board during firing.

Continuation of the front page (56) References JP-A-3-151690 (JP, A) JP-A-2-239648 (JP, A) JP-A-61-134081 (JP, U) (58) Fields investigated (Int) .Cl. ⁷ , DB name) H05K 3/46

Claims (2)

(57) [Claims] 1. A low-temperature fired glass-ceramic multilayer wiring board in which both sides are formed of insulating layers, and wiring layers are alternately laminated therein with intermediate insulating layers. The surface insulating layer is formed from a glass-ceramic material that has higher bending strength than the intermediate insulating layer, and the electronic components are formed by the flip-chip method.
The thickness of the surface insulating layer on the side to be connected
Flip chip method , characterized by being thinner than
Low temperature fired glass ceramic multilayer wiring board suitable for mounting electronic components . 2. A glass ceramic green sheet for the intermediate insulating layer, it and the glass ceramic green sheet for the surface insulating layer having different compositions is given via hole and its filling and / or wire printing concave after green sheets for the respective one or more surface insulating layer on both sides, stacked and pressed by disposing the green sheet for the plurality of intermediate insulating layer inside the laminated body at the time of co-firing
With the surface on the side where warping occurs toward the setter,
請characterized by co-firing on over at 1050 ° C. or less
The method for producing a low-temperature fired glass-ceramic multilayer wiring board according to claim 1 .