JPS61168564A - Ceramic insulation substrate - 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] [Field of Application of the Invention] The present invention relates to a ceramic insulating substrate, in which rounded bins for inputting and outputting electric signals are attached, and semiconductor components are mounted on the ceramic insulating substrate to form a functional module. The present invention relates to a ceramic substrate suitable for configuring a cell.

[Background of the invention]

In recent years, as integrated circuits such as L and 9I have become faster and more dense, a method of mounting chips directly on the circuit board has been used to improve heat dissipation and increase the density of elements. There is. However, this mounting method has the problem that as the size of integrated circuits such as LSIs increases, the stress caused by temperature changes during mounting increases between the integrated circuit materials such as LSIs and the circuit board materials. was there.

That is, A, which is currently the mainstream of ceramic multilayer wiring boards.
40g means that the thermal expansion coefficient of AtzOs itself is 30x10, which is the thermal expansion coefficient of silicon, which is a material for integrated circuits such as LSI
-'/C (room temperature to 500C), about twice as much kH2
The coefficient of thermal expansion of O3 is large. For this reason, miniaturization of the connecting portion of a silicon semiconductor chip such as an LSI to an AtmOs multilayer circuit board by direct soldering or the like tends to worsen the mounting life. To solve this problem, it is necessary to develop a substrate material with a low dielectric constant in order to bring the thermal expansion coefficient of the multilayer circuit board closer to that of silicon and to increase the propagation speed of electrical signals within the multilayer circuit board. There is. For this purpose, a multilayer wiring board using a sintered body of mullite (3A!40s/23i01) may be considered. This is because mullite has a coefficient of thermal expansion of 40 to 55×10 −′/C, which is close to that of silicon, and a relative dielectric constant of about 6.7 (IMHz), which is low.

However, the composition of mullite, ALx's and S102
If you try to make a multilayer wiring board using a mixed system,
Firing temperature 16 applied to LL2os multilayer wiring board
At around 00C, there are disadvantages such as k4 Q3, S l oz, etc. remaining in an unreacted state, being porous, and having a large coefficient of thermal expansion. In order to produce a dense mullite material, it must be sintered at a high temperature of about 1800 C or more, which is inefficient for mass production.

Therefore, it was necessary to develop a mullite-based material that can be sintered at a temperature around 1600 tZ'. For this purpose, materials consisting of mullite and glass are conceivable.

An example of this is a mullite sintered body and its manufacturing method (Japanese Patent Laid-Open No. 115895/1989). An example of this would be a crow such as Kojie? (2MgO・2AlzOs・
58i0z) The composition is different.

However, this material consists of mullite crystals bonded to glass or crystals derived from glass. The strength of the material therefore depends on the glass bonding the mullite crystals or the crystals formed therefrom; in fact the strength of this material is at most 16 to 9/-. For this reason, when signal input/output pins of a multilayer wiring board are brazed, cracks occur in the wiring board due to the difference in thermal expansion between the brazing material and the multilayer wiring board. In order to obtain useful multilayer wiring boards using mullite-based materials, it is necessary to develop materials with even higher strength. An object of the present invention is to provide a mullite-based ceramic insulating substrate.

[Summary of the invention]

To summarize the present invention, the present invention relates to a ceramic insulating substrate, and is characterized in that the mullite-based ceramic insulating substrate is sintered in the atmosphere by adding metal Si as a sintering aid to mullite. It is something.

Conventionally, it was thought that it would be difficult to sinter mullite unless it was made of glass, but by adding metal Si to mullite and firing it in the atmosphere, a silicon oxidation reaction was achieved. The metal s1 is mullite (3A40s/23
siow is the -component of (to), and its 510
2 performed a diffusion reaction with mullite in the solid phase, and it was confirmed that sufficient sintering was possible. Furthermore, mullite-based materials have small pores, making it possible to develop materials with high strength. Further, in contrast to the conventional mixed powder of raw material powders, the present invention is very simple because the raw material powders are mullite and metal S1. In addition, in the conventional Murai) K glass addition (Japanese Patent Application Laid-open No. 115895/1989), MgO is added, but MgO is very unstable and has good water absorption, so it is not suitable for magnesium hydroxide. There are problems with storage.

Next, the amount of metal 3i added to mullite is preferably 10 to 30 wt1 in terms of 8102 amount. The reason for this is that if the 5 lot amount is less than 10 wt*, the sintering temperature will be low, which is not preferable. When the amount of Sigh is more than 30wt, the dielectric constant tends to be low, but the strength is small.

Therefore, the metal 5 added to mullite as a sintering aid
The appropriate amount of iJi is 10 to 30 wt% in terms of 5iCh amount. In this case, it is dense and has a low dielectric constant.
It becomes possible to manufacture high-strength multilayer wiring circuit board materials and wiring boards. Next, as a method for manufacturing a mullite ceramic insulating substrate, there is a method of first manufacturing a green sheet (green molded body). Examples of these methods include the green sheet method, slip casting method, press molding method, and injection molding method.

The green sheet method is a method in which a solvent and a resin such as a thermoplastic resin are added to raw material powder, stirred, and the slurry is vacuum degassed, and then a green sheet making machine is produced. The slip casting method is a method of manufacturing by adding water, a dispersant, and a thermoplastic resin to raw material powder, and pouring the stirred slurry into, for example, a plaster interior.

In the mold forming method using a press, a solvent and a thermoplastic resin are added to the raw material powder, and the raw material powder is mixed and stirred in a sieve machine.
This is a manufacturing method in which the pellets are granulated through a sieve, etc., and then placed in a mold and subjected to a load. In the injection molding method, a thermoplastic resin, wax, etc. is added to the raw material powder, and the raw material powder is heated to adhere the resin, etc. to the raw material powder, and then placed in the hopper of an injection machine and heated. This is a method in which the raw material powder is fed into the mold by applying pressure to the injection nozzle part while melting the resin attached around the raw material powder. The green sheets produced by the above method are laminated or subjected to a degreasing process and then fired to produce a mullite ceramic insulating substrate.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The invention is not limited to these examples.

In addition, parts in the text indicate parts by weight, and letters in the text indicate weight %. The method for manufacturing a multilayer wiring board is to first add metal St (average particle size: 3 μm) to mullite powder (average particle size: 5 μm).
4.66.7.0, 9.33゜1L66.14.0%
was added. The above metal Si amount is 10.0, 15.0, 20.0°25.0, 30.01 in terms of 5iOz.
It is. Next, 5.9 parts of polyvinyl butyral with a degree of polymerization of 1000, 124 parts of trichlorethylene,
32 parts of tetrachlorethylene, 4 parts of n-butyl alcohol
Add 4 parts and make a 24-hour mixed slurry in a ball mill. Remove air bubbles from the slurry by vacuum degassing. Next, the slurry is applied onto a polyester film support to a thickness of 0.2 ws using a doctor blade, and dried in an oven to produce a green sheet for a mullite-based ceramic multilayer wiring board.

Next, the green sheet was cut into 50 square pieces, 30 layers were laminated, and then hot-pressed. For crimping, temperature 1
2 (Ic, pressure is 40Kg/cm". After crimping, degreasing for 1200tll" x 1 hour to remove resin, and then sintering. The sintering temperature was 1600-1650C and the holding time was 1 hour. The atmosphere was air. After cutting the sintered substrate into specimens for measuring dielectric constant and bending strength, rough polishing and final polishing were performed using a diamond lapping machine.

Table 1 shows the properties of each ceramic. In addition, for comparison, a mullite-based ceramic (Japanese Unexamined Patent Publication No. 57-1
15895) and Al40a are also shown. The figure shows the amount of metal 5i (converted to SiOs amount) (wt%) in mullite.
) and bending strength Ky/was'').

As can be seen from Table 1, ktzos, which is currently the mainstream for multi-layer wiring boards, has a dielectric constant of 9.5 (IMHz), which causes the propagation speed of electrical signals on the road board to slow down. Mullite-based ceramic (Japanese Unexamined Patent Publication No. 57-115895), in which 30% cordierite is added to mullite, has a low dielectric constant of 6-0 (IMHz), which is good, but the bending strength is 16. OK9/■2, which is only about 1/2 of the strength of ALzOs, can be obtained. Compared to that, 8iC of gold tAsi was added to mullite, which is the ceramic material of the present invention.
The material to which 10 to 30 chicordierite is added in terms of
5895) relative permittivity of 6.0 (IMHz)K,
Although it has a slightly high dielectric constant of 0.2 to 0.7, it does not have a large effect. Regarding the bending strength, the bending strength of the sintered body to which 4.66 inches of metal S1 (10 inches in terms of St (h)) was added was 20.1 Kg/■2, and the bending strength of metal S1 was 9.
The bending strength of the sintered body added with 33 inches (20 inches in terms of ston) was 2 ZOKg/ym", and the metal Si was 141 (8 inches).
Bending strength of the added sintered body 2
The bending strength of the material with 301 cordierite added to mullite is 16. About 1.3 for Q14/■2
The bending strength was improved by ~1.4 times, and it was confirmed that it is an excellent material with a low dielectric constant and high bending strength.

Next, the X-ray diffraction results of each sintered body will be explained.
115895'), spinel (At481t
) I5 Safari 7 (Mlls,s At481t
, 502oi), cordierite (MgsA48 import 0), and sillimanite (to A48j). This is probably because the glass components (cordierite, etc.) contained for firing mullite are in phase and are produced by reaction at the interface with mullite. 1 in exchange
The sintered body to which 0 to 30 Ti9 is added has Sigh in mullite.
Sillimanite (AI) produced by solid-phase diffusion in the pond
It was confirmed that there was only 4SiOs) phase 5. Therefore, it can be seen that the crystal phases produced in the sintered bodies are clearly different between those using glass (cordierite, etc.) as a sintering aid and those using metal St.

Next, when observing the fractured surface of a mullite-based ceramic using a scanning electron microscope (SEM), it was found that the fractured surface of a sintered body made by adding 30% cordierite to conventional mullite had larger voids and coarser crystal grains. It shows a similar appearance. However, the fracture surface of a sintered body in which 10 to 30 g of metal S1 is added to mullite, which is the composition of the present invention, in terms of 8'i0* amount, has a good appearance with small and dispersed voids and fine grains. It shows.

The figure is a graph showing the relationship between the amount of metal 5iit (by weight) or the amount of 5i02 (% by weight) and the bending strength of the sintered body. As can be seen from this graph, when the metal S1 is added to the mullite of the present invention in an amount of 10 to 30 t in terms of S r Ot, the bending strength of the conventional sintered body to which 30 t glass is added is 16 K4. /+w" also shows a large bending strength. Also, in any of the compositions of the present invention, the bending strength cleared 20 Kg/ws" or more, indicating stable bending strength. Therefore, as a sintering aid, metal Si is added to mullite from 4.66 to 1
By adding 4 tB (10 to 30% in terms of 8r Oz) and firing in the atmosphere, metal S1 is reduced by oxidation reaction.
sio.

Since the tonashi and the sho react with mullite in the solid phase and sinter, a dense, high-strength mullite-based ceramic multilayer substrate material with a low dielectric constant can be obtained.

〔Effect of the invention〕

According to the present invention, a metal 3i'1rSiOxK equivalent of 10
By adding ~30 weight of rice cake and sintering in the atmosphere, the metal 3i undergoes an oxidation reaction and sintering progresses through solid phase diffusion of 1) SiOx and mullite and its 5ICh, resulting in the formation of mullite particles. The growth is small and fine. Therefore, an excellent mullite-based IfIA* substrate having high strength and a dielectric constant of 6.7 (IMH2) or less can be obtained.

[Brief explanation of drawings]

The figure shows metal Si of an embodiment of the ceramic insulating substrate of the present invention.
It is an explanatory diagram of the relationship between the amount or the amount converted into 5fCh and the bending strength of the sintered body. 5LO24J-('lIZ)

Claims (1)

[Claims] 1. A mullite-based ceramic insulating substrate characterized in that silicon metal is added to mullite as a sintering aid, the remainder is mullite, and the substrate is fired in the atmosphere.