JPH06177546A - Conductor paste and ceramic multilayer interconnection board - Google Patents

Abstract

PURPOSE:To obtain conductor paste whose shrinkage is set equal to that of alumina by a method wherein nickel or the like is added to lessen tungsten and the like in sintering starting temperature, and the sintering behavior of tungsten or the like is set to conform to that of alumina. CONSTITUTION:Conductor paste 11 is composed of 99.9 to 86% by weight of tungsten powder, molybdenum powder, or mixed powder (tungsten powder and the like) of tungsten powder and molybdenum powder, 0.1 to 6% by weight of nickel powder, and below 8% by weight of ceramic powder. The conductive paste 11 is printed on an alumina tape 12, and the deformation of the conductive paste 11 is measured in a burning process. The measurement of deformation is carried out through such a manner that the warpage 16 of a sintered body 15 composed of a burned conductor wiring 13 and an alumina sintered body 14 is directly measured. When this conductor paste is used, a board and a conductor paste are nearly equal to each other in sintering behavior and shrinkage in a burning process, so that a ceramic multilayer interconnection board can be prevented from being warped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductor paste and a ceramic multilayer wiring board, and more particularly to an IC ceramic package for mounting a semiconductor chip without warping or deformation, or a semiconductor chip or an IC package. Ceramic multilayer wiring board (hereinafter,
The present invention relates to a conductor paste as a raw material of conductor wiring for forming a ceramic multilayer wiring board including an IC ceramic package) and a ceramic multilayer wiring board formed using the conductor paste.

[0002]

2. Description of the Related Art As a ceramic material for a ceramic multilayer wiring board, alumina, which has excellent insulating properties, thermal conductivity, stability and mechanical strength and is low in cost, is widely used. As the wiring material of the ceramic multilayer wiring board, tungsten, molybdenum or a mixture thereof which can be co-fired with alumina at about 1600 ° C. is used. Hereinafter, the tungsten powder, the molybdenum powder, or the mixed powder of the tungsten powder and the molybdenum powder is generically referred to as the tungsten powder or the like in the text.

In recent years, the number of pins has been increased and the electrical characteristics have been improved due to the high integration of ICs, and in particular, the multilayered ceramic wiring board and the high-density wiring have been advanced in order to reduce noise.

[0004]

As the ceramic multilayer wiring board becomes multilayered and densified, the ceramic multilayer wiring board after firing becomes different due to the difference in sintering behavior between alumina and tungsten powder when co-fired. There is a problem that deformation such as warpage occurs.

In particular, the LS is used for the ceramic multilayer wiring board.
Since the cavity is formed for mounting I, the wiring density is different between the upper part and the lower part of the ceramic multilayer wiring board, and therefore warpage is likely to occur. When the ceramic multilayer wiring board is warped, it is fixed in the cavity of the LSI, and the ceramic multilayer wiring board and the LS are fixed.
It becomes difficult to connect with I by direct wiring, to form a multilayer laminated film having fine wiring using polyimide on the upper part of the ceramic multilayer wiring board, to form vertical pins, to fix a seal cap, and the like.

The cause of the warpage of the ceramic multilayer wiring board is, for example, the difference in the sintering behavior between the alumina used for the board and the tungsten material of the wiring material during the simultaneous firing. An example of a typical profile for co-firing is a peak temperature of 1550 ° C. and a peak temperature hold time of 2 hours. Here, the time for which the peak temperature is maintained is set to 2 hours. Normally, alumina contains several wt% of a sintering aid, and the sintering aid forms a liquid layer at the time of firing. This is because it is necessary to uniformly flow between particles and stabilize the mechanical strength of alumina.

The respective sintering behaviors of alumina, tung ten, etc. of the ceramic multilayer wiring board at this time are as follows.
First, in the process of raising the temperature to a peak temperature of 1550 ° C, the sintering shrinkage of alumina begins to progress from 1100 to 1200 ° C, but the sintering of ordinary Tungten powder (particles with a particle size of submicron to 10 μm) Little shrinkage occurs. However, at the stage of maintaining the peak temperature, alumina shrinks little because the sintering is almost completed, while on the other hand, the sintering shrinkage of tungsten progresses. This sintering behavior is
Since this is a basic phenomenon that always occurs in the particle size range of normal alumina and tungsten (from submicron to 10 μm), it is difficult to avoid warping and other deformations even if the co-firing profile is slightly changed.

The present invention has been made in view of the above problems, and suppresses the occurrence of warpage due to the difference in the sintering behavior between the alumina used for the substrate and the wiring material such as tungsten when firing the ceramic multilayer wiring substrate. An object of the present invention is to provide a conductor paste that can be manufactured and a ceramic multilayer wiring board that is formed using the conductor paste and has no warp.

[0009]

In order to achieve the above object, the conductor paste according to the present invention comprises a tungsten powder, a molybdenum powder or a mixed powder of a tungsten powder and a molybdenum powder (tungsten powder or the like) 99.9 to 86 wt%, nickel. It is characterized by containing a conductor component consisting of 0.1 to 6 wt% of powder and 8 wt% or less of ceramic powder.

Another conductor paste according to the present invention is tungsten powder, molybdenum powder, or a mixed powder of tungsten powder and molybdenum powder (tungsten powder, etc.).
It is characterized by containing a conductor component composed of 99.9 to 99.0 wt% and nickel powder of 0.1 to 1.0 wt%.

Further, in the ceramic multilayer wiring board according to the present invention, the composition of the conductor wiring is tungsten component, molybdenum component or mixed component of tungsten component and molybdenum component 99.9 to 86 wt%, nickel component 0.1 to 6 wt% and ceramic component. It is characterized by containing less than 8 wt%.

Further, in the ceramic multilayer wiring board according to the present invention, the composition of the conductor wiring is tungsten component, molybdenum component or mixed component of tungsten component and molybdenum component 99.9 to 99.0 wt% and nickel component 0.1 to 1.0 wt%.
It is characterized by consisting of.

In the present invention, two kinds of pastes are used, that is, a conductor paste containing nickel powder and ceramics powder such as tungsten powder as a conductor component and a conductor paste containing tungsten powder and nickel powder as a conductor component.

First, a conductor paste containing nickel powder such as tungsten powder and ceramic powder as a conductor component will be described. The conductor paste is prepared by mixing tungsten powder and the like with nickel powder and ceramic powder and dispersing them in an organic vehicle. The content of the above-mentioned tungsten powder and the like in all the conductor components is preferably 99.9 to 86 wt%. If the content of tungsten powder etc. exceeds 99.9 wt%, the sintering start temperature of the tungsten powder etc. does not decrease, while if the content of tungsten powder etc. is less than 86 wt%, the nickel powder is excessive or ceramic Since the powder becomes excessive, the following adverse effects occur, which is not preferable. The particle size of the tungsten powder or the like is preferably 0.3 to 10 μm. The particle size of the powder is 0.3 μm
The following is not preferable because it has a large specific surface area and is bulky, so a large amount of organic vehicle is required for forming a paste, and the amount of solid matter in the paste decreases, while the particle size of the powder is 10 μm.
The above is not preferable because the printability is deteriorated.

It is necessary to add a sintering accelerator to the conductor paste of the present invention, and the powder has a melting point of 1000-2000.
The metal powder in the range of ℃ is mentioned, but it has excellent oxidation resistance,
In addition, nickel powder having excellent reactivity with tungsten powder and the like is preferable. The amount of nickel powder added is preferably 0.1 to 6 wt% with respect to the entire conductor components. When the amount of nickel powder added is less than 0.1 wt%, there is almost no effect of promoting the sintering of tungsten powder and the like, while the amount of nickel powder added is 6%.
If it exceeds wt%, the sintering of the tungsten powder or the like is excessively promoted and the shrinkage amount becomes too large, which is not preferable.
Also, the preferable particle size of nickel powder is 0.01 μm to 2 μm.
m. If the particle size of the nickel powder is less than 0.01 μm, it becomes clay like when it is made into a paste, and the printability deteriorates.
If the particle diameter of the nickel powder exceeds 2 μm, it is melted during firing and the wiring shape is destroyed, and further, since nickel particles are not finely dispersed in the powder, sintering is not uniformly promoted, which is not preferable.

The ceramic powder used in the present invention is
A ceramic powder, which is used as a sintering shrinkage suppressor for tungsten powder or the like, is chemically stable during firing and does not chemically react with the tungsten powder or the like. Examples of the ceramic powder that satisfies the above conditions include oxides such as alumina, magnesia, zirconia, and silica, and nitride-based ceramic powders such as aluminum nitride, silicon nitride, and titanium nitride. From the above point, alumina powder is preferable. In addition to the above-mentioned powder, it is also possible to use the alumina-containing powder contained in the alumina tape. In addition to alumina, the powder usually contains about 1 to 8 wt% of calcium carbonate, silica, calcined talc, kaolin or the like as a sintering aid for alumina, based on the whole alumina-containing powder. The addition amount of the ceramic powder is preferably 8 wt% or less with respect to the entire conductor component. If the amount of ceramic powder added exceeds 8 wt%,
Sintering shrinkage of the tungsten powder and the like becomes too small, and the conduction resistance of the conductor wiring becomes high, which is not preferable.

The conductor paste is prepared by mixing a predetermined amount of the conductor component powder, adding 10 to 15 parts by weight of an organic vehicle to 100 parts by weight of the conductor component, and dispersing the conductor component powder in the organic vehicle. It can be made into a paste. Here, the organic vehicle is an organic liquid medium for making the above-mentioned powder printable, and is a resin dissolved in a solvent, a plasticizer, or the like.

As the resin, for example, a cellulose resin such as ethyl cellulose, a methacrylic resin or an acrylic resin can be used. Further, as the solvent, for example, terpineol or the like can be used, and as the plasticizer, for example, dibutyl phthalate or the like can be used. It is preferable to use three rolls for kneading for forming a paste.

Next, a conductor paste containing tungsten powder and nickel powder as a conductor component will be described. The conductor paste is prepared by mixing nickel powder with tungsten powder or the like and dispersing it in an organic vehicle. The content of the conductive material such as the tungsten powder is preferably 99.9 to 99.0 wt%. in this case,
Since the amount of sintering shrinkage of tungsten powder or the like is small, it is not necessary to add ceramic powder such as tungsten powder as a sintering shrinkage suppressor. The preferable particle size of the tungsten powder or the like may be the same as that when the nickel powder and the ceramic powder such as the tungsten powder are used as the conductor component (hereinafter referred to as the ceramic powder-containing conductor component).

The amount of nickel powder used in this case is preferably 0.1 to 1.0 wt% with respect to the entire conductor components.
When the amount of nickel powder added is less than 0.1 wt%, there is almost no effect of promoting the sintering of tungsten powder, and when the amount of nickel powder added exceeds 1.0 wt%, the sintering of tungsten powder is excessively promoted. Then, the shrinkage amount becomes too large, which is not preferable. The preferable particle size of nickel powder is the same as that of the conductor component containing ceramic powder.

Further, the composition and the preparation method of the conductor paste using the conductor component are the same as those for the ceramic-containing conductor component.

A known method can be used as a method for producing an alumina green sheet using the above-mentioned two kinds of conductor pastes. Various known sintering aids are added to alumina powder to obtain a known method. Resin, solvent, plasticizer is added and mixed to form a slurry, and a green sheet having a uniform thickness is formed by a known method such as a doctor blade method,
Dry until ready for handling. This green sheet is processed into a desired shape with a cutter or a punching die, and if necessary, a through hole is formed at a desired position with a punching die or the like. Next, a conductor paste containing the conductor component as a main component is screen-printed on the processed green sheet to form a wiring pattern.
Then, a predetermined number of green sheets having the wiring pattern are laminated, pressed into a laminated body, and fired to obtain a ceramic multilayer wiring board.

As the firing conditions, it is preferable to perform firing at a temperature of 1500 to 1600 ° C. for peak retention. If the firing temperature is lower than 1500 ° C, the mechanical strength is weak because the sintering of alumina is insufficient, while if it exceeds 1600 ° C, stable operation of the firing furnace becomes difficult.

In the ceramic multilayer wiring board thus obtained, the conductor wiring in the board is dispersed or decomposed by the organic components in the conductor paste printed before firing, and each component in the conductor wiring is returned to its original state. The composition remains.

[0025]

In the present invention, in order to match the sintering behavior of tungsten or the like with the sintering behavior of alumina, the sintering start temperature of tungsten or the like is lowered by adding nickel or the like,
Further, since the conductor paste in which the shrinkage amount is matched with the shrinkage amount of alumina is used, the occurrence of warpage of the ceramic multilayer wiring board is prevented.

That is, a conductor component consisting of nickel powder and ceramic powder such as tungsten powder and nickel powder, or tungsten powder is contained in the conductor paste, and the sintering start temperature is reduced by the accelerating action of the nickel powder. Alternatively, ceramic powder is further added to the powder to adjust the shrinkage amount to match the shrinkage amount of alumina by the sintering shrinkage suppression effect of the ceramic powder, so that the sintering behavior of the substrate and the conductor component during the firing process. Are approximately the same, and the shrinkage amounts of both are approximately the same, so that the occurrence of warpage of the ceramic multilayer wiring board is prevented.

[0027]

[Examples and Comparative Examples] In order to investigate the matching of the sintering shrinkage between the conductor wiring layer and the alumina, the conductor paste 11 was printed on the alumina tape 12 as shown in FIG. Was measured. The amount of deformation is measured in Fig. 1.
The warp amount 16 of the sintered body 15 including the conductor wiring 13 and the alumina sintered body 14 which were fired as shown in (b) was determined by directly measuring the warp using a micrometer manufactured by Mitsumi.

A more specific method is as follows.

First, 100 parts by weight of the conductor component of the powder having the compounding ratios shown in Tables 1 and 2 below was added to the organic vehicle.
12 parts by weight was added to obtain a conductor paste. The composition of the organic vehicle was ethyl cellulose 5 wt% and terpineol 95 wt%. The conductor paste was prepared by kneading the conductor components shown in Tables 1 and 2 below and an organic vehicle with a three-roll mill, and was printed on a tape having a thickness of 400 μm and containing 90 wt% of alumina. Alumina tape 12
Has a size of 10 mm × 10 mm, and the conductor paste 11 was applied to the entire upper surface so as to have a thickness of 20 μm. The firing profile is such that the temperature rising rate up to 1400 ° C is 150 ° C / hour, the temperature rising rate from 1400 to 1550 ° C is 60 ° C / hour, the peak temperature is 1550 ° C, and the time for holding the peak temperature is 2 hours. The temperature lowering condition was set to a rate of −250 ° C./hour.
Then, in order to obtain the deformation state of the alumina sheet in the firing process, a firing pattern as shown in FIG. 2, that is, a condition 21 of a firing temperature of 1300 ° C. and a firing temperature of 1400 ° C.
Condition 22, firing temperature 1500 ° C condition 23, firing temperature 1550 ° C without peak temperature holding time 24, firing temperature 1550 ° C peak temperature holding time 1 hour condition 25 and firing temperature 1550
Final firing conditions with a peak temperature hold time of 2 hours at ℃
After firing under 26 firing conditions, the sample was taken out, and the amount of warpage under each condition was measured by the above method. The temperature lowering condition at this time was −250 ° C./hour similar to the temperature lowering condition in the firing profile.

The results are shown in Tables 1-2. In addition, in the measurement of the amount of warp, a value of + indicates that the alumina sintered body was bent downward, and a value of − indicates that the shape was concave.

[0031]

[Table 1]

[0032]

[Table 2]

As is clear from Tables 1 and 2, when the conductor paste according to the present invention is used, the warpage during and after firing is 500 when an alumina sheet having a width of 10 mm is fired. It can be seen that it can be suppressed to less than μm.

Next, the composition of the conductor wiring in the sintered body was examined by using a commercially available ICP (plasma emission analysis), and it was confirmed that the composition of each conductor component added to the conductor paste was not changed at all. I was able to confirm.

Since these results were obtained, further, when a ceramic multilayer wiring board was manufactured using the paste described in this example, the amount of deformation was extremely smaller than that of the conventional one, and
Fixing the LSI to the cavity, connecting the ceramic multilayer wiring board to the LSI by direct wiring,
Formation of multilayer laminated film with fine wiring using polyimide on the top of ceramic multilayer wiring board, formation of vertical pins,
It was possible to obtain a ceramics multilayer wiring board having no problem in fixing the seal cap.

[0036]

As described above in detail, in the conductor paste according to the present invention, tungsten powder, molybdenum powder or a mixed powder of tungsten powder and molybdenum powder is used.
99.9 to 86 wt%, nickel powder 0.1 to 6 wt% and ceramic powder containing 8 wt% or less of conductor component, or tungsten powder, molybdenum powder or mixed powder of tungsten powder and molybdenum powder 99.9 to 99.0 wt
% And nickel powder 0.1 to 1.0 wt% are contained in the conductor component, the sintering behavior of the substrate and the conductor component in the firing process is almost the same, and the shrinkage amount of both is almost the same, and the ceramic multilayer wiring It is possible to prevent the warp of the substrate.

Further, in the ceramic multilayer wiring board obtained by using the conductor paste, the conductor wiring having the same composition as the conductor component in the conductor paste is formed, and the deformation amount is much smaller than that in the conventional case. , Fixing to the cavity of LSI, ceramic multilayer wiring board and LS
A ceramic multilayer wiring board having no problems in connection with I by direct wiring, formation of a multilayer laminated film having fine wiring using polyimide on the upper surface of the ceramic multilayer wiring board, formation of vertical pins, fixing of a seal cap, etc. Can be provided.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method for measuring the amount of warpage of an alumina sintered body according to an embodiment of the present invention, FIG. 1 (a) is a side surface of an alumina green sheet on which a conductor paste is printed, FIG. 1 (b) is a side view showing the shape of the alumina green sheet after sintering.

FIG. 2 is a graph showing a firing temperature pattern in a firing step of an alumina green sheet printed with a conductor paste according to an example.

[Explanation of sign]

 11 conductor paste 13 conductor wiring

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[Procedure amendment]

[Submission date] July 13, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yoji Tozawa 2701-1 Iwakura, Tomine Omine-cho, Mine-shi, Yamaguchi Prefecture In Sumitomo Metal Ceramics Co., Ltd. (72) Tetsuya Yamamoto 2701 Iwakura Itokura, Omine-cho, Mine-shi, Yamaguchi Prefecture 1 Sumitomo Metal Ceramics Co., Ltd.

Claims (4)

[Claims] 1. Tungsten powder, molybdenum powder or mixed powder of tungsten powder and molybdenum powder 99.9 to
A conductor paste comprising a conductor component consisting of 86 wt%, nickel powder 0.1 to 6 wt% and ceramic powder 8 wt% or less. 2. Tungsten powder, molybdenum powder or a mixed powder of tungsten powder and molybdenum powder 99.9 to
A conductor paste containing a conductor component consisting of 99.0 wt% and nickel powder of 0.1 to 1.0 wt%. 3. The composition of the conductor wiring comprises a tungsten component, a molybdenum component or a mixed component of a tungsten component and a molybdenum component of 99.9 to 86 wt%, a nickel component of 0.1 to 6 wt%, and a ceramic component of 8 wt% or less. Ceramic multilayer wiring board. 4. The composition of the conductor wiring is 99.9-99.0 wt% of a tungsten component, molybdenum component or a mixed component of a tungsten component and a molybdenum component, and a nickel component 0.1-1.0.
A ceramic multilayer wiring board characterized by comprising wt%.