JPS59111987A - Manufacture of composite sintered body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method for manufacturing composite sintered bodies. To explain in more detail, the present invention relates to a method for manufacturing a composite sintered body having a plurality of layers, for example, for a semiconductor integrated circuit device.

Generally, in order to manufacture the above-mentioned composite sintered body, as shown in FIG. Print the conductor layers 2, 2.2 of the cross-sections and form holes 3 in the desired interconnection areas of each of the substrates.

After being filled with a conductive material, the substrates 1 and 1 are stacked to form a laminate such that the conductor layers 2 and 2 have the desired interconnection connections.

It has been common practice to then complete a composite sintered body, such as a multilayer wiring board or a multilayer wiring package, by heating the stack of substrates at a temperature sufficient for sintering and for a certain period of time.

However, such a method has problems, especially in the interconnection of the respective substrates. In other words, when attempting to fill a hole 3 drilled at a desired location in a substrate 1, 1.1 containing a conductor layer with conductor material, the hole is so small that the conductor material cannot be completely filled into the hole. As a result, mutual wiring connections may not be complete and disconnections may occur, resulting in extremely unreliable connections. In order to solve this problem, there is a technique in which the conductor material is vacuum-suctioned and filled into the hole, but this increases the number of work steps and is not suitable for mass production.

Furthermore, such a method requires a number of substrates equal to the number of layers of multilayer wiring, and requires a punching step for punching each substrate into a predetermined shape, which increases the number of work steps. It also requires a step of laminating the substrates and hot pressing them, and if they are not completely laminated during hot pressing, the lamination may become unstable (
Uncertainty in adhesion) Causes that lead to defects, such as airtight leaks due to VC and unnecessary deformation of the substrate, are likely to occur. In addition, due to the difference in shrinkage rate between the raw ceramic sheet and the conductor layer during firing, the ceramic sheet may warp due to firing deformation, and the bonding strength between the metallized conductor layer and the ceramic sheet may decrease, resulting in peeling, etc. may occur.

Therefore, the process is relatively complicated, resulting in lower yields and higher costs.

The present invention has been made to solve the above-mentioned drawbacks, and its purpose is to provide a method for manufacturing a composite sintered body that facilitates multilayer wiring connections and has high reliability. Another object of the present invention is to provide a method for manufacturing a composite sintered body that saves labor in the process. Still another object of the present invention is to provide a method for manufacturing a composite sintered body in which the thickness of the composite sintered body is made extremely thin, thereby eliminating waste of raw materials. Another object of the present invention is to provide a method for producing a compact composite sintered body that has a sealed structure that eliminates airtight leaks, unnecessary deformation of the substrate, etc., and has a relatively high degree of durability. .

Still another object is to eliminate the difference in shrinkage rate during sintering between a raw ceramic sheet and a printed layer, and to provide a method for manufacturing a composite sintered body without sintering deformation.

Still another object is to produce a printing paste whose shrinkage rate matches that of a raw ceramic sheet used as a composite sintered body.

Thus, according to the present invention, the interconnections of each layer can be extremely easily interconnected, and each layer is formed by printing ceramic paste and conductive paste on a raw ceramic sheet, and the thickness can be controlled to be sufficiently thin. Therefore, the thickness of the composite sintered body of multilayer wiring can be made sufficiently thinner than in the conventional method.

Furthermore, according to the present invention, since the raw ceramic sheet and the printing paste are formed from the mixture after forming a mixture of inorganic materials, the shrinkage rate of the raw ceramic sheet and the printing paste during sintering is the same, which is different from that in the conventional method. It is possible to obtain a good composite sintered body that is free from peeling, disconnection, cracking, and warpage due to differences in shrinkage rates. That is, according to the present invention, since the Kosei Ceramic sheet and the printing paste are made of the same mixture, they have the same material and the same mixing ratio, and have the same shrinkage rate during sintering. .

FIG. 2 is a sectional view of a completed composite sintered body obtained by the present invention, in which 1 represents a ceramic sheet, 4 represents an insulating layer, and 2 represents a conductive layer.

FIG. 3 shows the manufacturing process according to the present invention.

) Alumina (A40
s) as the main component, and mineralizer powders such as silica (Si20) and magnesia (MgO) are added to it, for example, Ao:
91% by weight, Sin: 6.8% by weight, MgO: 2
．． A mixture is prepared in which 2% by weight of Putvar (trade name, Monsando) is further added as a binder to provide bonding properties between the ceramic inorganic raw materials. Note that the sintering temperature can be changed as appropriate depending on the amount of mineralizer added.

(2) An alumina powder mixture is obtained by mixing the above mixture for about 30 minutes using a ball mill.

(3) Next, add a solvent that easily forms into a sheet (a low-boiling point solvent), such as an azeotropic mixture (
trichlorethylene: 60% by weight, butyl alcohol: 23% by weight, perchlorethylene = 17% by weight),
In addition, butylphthalyl butyl glycolate is prepared as a plasticizer for raw ceramic. Next, alumina mineralizer: 1
For 0011, putbar: 6g, low boiling point solvent: 38
,9. Plasticizer: Add and mix 2.81.

(4) An alumina slip is obtained by sufficiently mixing the above viscous mixture using a ball mill over a period of 3 hours.

(5) By casting the above alumina slip onto a resin film such as Lumirror (trade name) or release paper, a sheet slip of a desired shape with a constant thickness of approximately 1.0 RB) is made, and then used as a paste. (3)' Into the alumina powder mixture produced in step (2) above, a solvent that is easy to print (high boiling point solvent), such as butyl calpitol acetate, is added as a putter solvent, and then 106 g of the above alumina powder mixture is mixed with a plasticizer of 2.8.!i' and a high boiling point solvent of 389 g.

(4) Prepare an alumina slip by thoroughly mixing the above viscous mixture using a ball mill for 3 hours, and divide it into two parts.

(5) Use one of the alumina slips as a raw ceramic paste as an insulating layer.

(5) Adding and mixing a conductor powder, for example, a powder of a highly heat-resistant metal such as tungsten, molybdenum, or titanium, singly or as a composite, to the other alumina slip;
Make conductor paste. At this time, the resistance value of the conductor can be determined by controlling the amount of metal additive.

These pastes are printed, for example, by a silk screen process onto green ceramic sheets in a single layer or in alternating layers of conductive and insulating pastes. Note that the paste is dried at 80C after each printing process.

The raw ceramic sheet and paste laminate described above are placed in a reducing or neutral atmosphere, such as N2 or N,+, and the conductive paste is metallized and sintered.

In addition, when forming a raw ceramic sheet in the above specific example, a solvent (low boiling point solvent) that is easy to form into a sheet is added to the alumina mixture (this means that if it is a low boiling point solvent, it will volatilize at room temperature). It is added because it is convenient for the work to form a sheet.Therefore, it is not limited to this in any way, and a high boiling point solvent may be used.In addition, in the above-mentioned specific examples, it is added at the same time. A plasticizer was added to make the sheet easier to handle, but when adding a high boiling point solvent, it is difficult to volatilize at room temperature, so if you leave it to some extent and use it as a plasticizer, you can add a plasticizer separately. It doesn't matter if you don't do it.

Furthermore, when forming a paste, a solvent that is easy to print (high-boiling point solvent) is added to the alumina mixture. This is to eliminate clogging. Therefore, since the problem can be solved by improving the printing means, a low boiling point solvent may be used.

Next, another specific embodiment will be described based on the manufacturing process shown in FIG.

(1) Ceramic raw material The main component is alumina (A 20.), and silica (SiO).

Powder of a mineralizing agent such as magnesia (MgO), for example,
? , o: 91% by weight, Sin: 6.8% by weight, and MgO: 2.2% by weight. The sintering temperature can be changed appropriately depending on the amount of the mineralizer added.

Next, Putvar (trade name) is used as a binder to provide bonding properties between the ceramic inorganic raw materials, and a low-boiling point solvent such as "azeotropic mixture" is used as a solvent for Putvar.
trichlorethylene: 60% by weight, butyl alcohol: 23% by weight, perchlorethylene = 17% by weight),
In addition, butylphthalyl butyl glycolate was prepared as a plasticizer for raw ceramic, and alumina + mineralizer: 1ooy to putbar: 61! , low boiling point solvent: 38Fs plasticizer: 2.811 are added and mixed.

(2) An alumina slip is obtained by thoroughly mixing the above mixture using a ball mill over a period of 3 hours.

(3) Cast the above alumina slip in the form of a sheet onto a resin film such as Lumirror (trade name) or release paper to a certain thickness of about 1. Qm), a raw ceramic sheet of the desired shape is formed. The raw ceramic sheet is heated to volatilize the low boiling point solvent and dry.

(3)' If the above alumina slip is used as a paste, the low boiling point solvent will evaporate at room temperature and solidify rapidly, causing screen clogging during printing and making it difficult to clean the screen after printing. ,
Temporarily replace the low boiling point solvent with a high boiling point solvent. For example, for alumina slip 500&, butylcarpitol acetate) 12 (1°
A paste is obtained by adding 0.2 g of Toshi Silicone 5H5520) and heating in vacuum (10 -3 Torr, 80 to 90 C) to scatter the low boiling point solvent.

The paste obtained in step (3)' above can be used as is as an insulating paste.

(31 Also, in order to obtain a conductor paste, powders of highly heat-resistant metals such as tungsten, molybdenum, or titanium are added to the above paste either singly or as a composite and mixed. Depending on the amount of these metal additives, the conductor The resistance value is determined by printing the paste on a green ceramic sheet, for example by a silk screen process, either in a single layer or in alternating layers of conductive paste and insulating paste.

After each printing process, the paste is dried at 80C.

The raw ceramic sheet and paste laminate described above are heated to 1450 to 1650 C in a reducing atmosphere such as hydrogen to transform the raw ceramic sheet and the insulating paste into ceramics, and at the same time, metallize the conductive paste and sinter them.

The raw ceramic thus obtained and the insulating layer or (
and) The composite sintered body with the metal layer is formed from raw ceramic sheets and printing paste from the raw materials by the same crushing mill, so especially since their mixing degree is the same, during their firing. Since there is no fluctuation in the sintering temperature, the shrinkage rate is completely the same, there is no deformation during firing, and a product with extremely high bonding strength between the conductor and the substrate can be obtained.

In the above embodiments of the present invention, ceramic raw material inorganic components,
Although the types and amounts of components such as binders and solvents were specified and explained,
It goes without saying that in the present invention, the types and component ratios of the materials can be changed as appropriate without exceeding the scope of the claims.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing each of the thin plates disassembled and shown separately in the conventional method, Fig. 2 is a sectional view of a concrete completed product obtained by the method of the present invention, and Figs. 3 and 4 are the main parts. FIG. 3 is a manufacturing process diagram of a specific embodiment of the invention. 1... Ceramic sheet, 2... Conductor layer, 3...
Hole, 4... Insulating layer. Figure 1, 9 Figure 2

Claims (1)

[Claims] 1. A step of forming a mixture of inorganic materials, a step of making a part of the mixture into a raw ceramic sheet, a step of making the other part of the mixture into an insulation paste, applying the above insulation paste on the raw ceramic sheet. A method for manufacturing a composite sintered body, comprising a step of forming a composite sintered body.