JPS61222957A - Low temperature burnt ceramics - 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 low-temperature fired ceramics particularly suitable for electronic industrial parts and used for other heat-resistant industrial parts, tableware, kitchen parts, ornaments, etc.

Go to 11 11 As computers become more connected and consumer equipment becomes more high-frequency,
Conventional alumina substrates have a large dielectric constant (ε-10)
, which causes signal delay, and there is a strong demand for an alternative low dielectric constant substrate.

Furthermore, since the firing temperature of the alumina substrate is high, the conductors used are limited to MO and W, which are high-melting point metals with relatively high resistance, which causes signal delays. Therefore, Au SAa and Cu, which have a low dielectric constant and low resistance, can be fired at temperatures below 1000°C, which allows them to be used as conductors, and in consideration of increasing the size of LSI chips, we have developed a method that reduces stress due to the difference in thermal expansion between the chip and the substrate. Low-temperature fired substrates with a coefficient of thermal expansion close to that of silicon are beginning to be put into practical use as they become smaller. At the same time, we have developed board characteristics that are compatible with the movement of new electronic devices.
In addition to increasing the size and lowering costs of substrates that also serve as general plastic substrates, high-speed firing (conventionally alumina 20 to 30 hours)
) is strongly required.

In other words, in the future, electronic devices will become lighter, thinner, shorter, and smaller, and their life cycles will become shorter and shorter. Therefore, the challenge for low-temperature firing substrates will be to be able to provide a wide variety of products in small quantities in a short period of time.
For this purpose, it is important to perform high-speed firing to shorten the trial production and manufacturing period. However, in the low-temperature firing substrates that have been published in the past, particularly in compositions consisting of a mixture of glass powder and alumina, much faster firing than conventional alumina substrates has not been achieved.

This is true not only for substrates but also for other ceramics.

Problems to be Solved by the Invention It is an object of the invention to provide a mixed low-temperature firing ceramic made of glass powder and alumina powder, which is suitable for electronic circuits and other applications, and which enables high-speed firing with an average heating rate of 10°C/min or more. It is something.

For example, in order to fire a low-temperature fired substrate at high speed, a green tape made of glass powder, alumina powder, and an organic material for forming tape needs to be fired at high speed in a belt-type thick film furnace.

During the firing process in a thick film furnace, the most important step is the binder removal step. If the binder removal is insufficient, carbon will remain and the incorporated carbon will cause bubbles to form in the substrate. Also, in the case of multi-layer conductor stacks, it may cause disconnection.

Organic binders (acrylic or butyral) are
As shown in Figure 6, it should normally decompose completely by 500 to 600°C and be combusted into CO2 and Hz O.
If the temperature increase speed becomes faster, the reaction will continue to occur up to a higher temperature than the usual 500 to 600° C., resulting in unreacted carbon being incorporated into the substrate that has started shrinking.

Means for Solving the Problems In the present invention, in order to facilitate debinding,
We found that it is extremely effective for green tape to exist without starting to shrink up to 700°C, and we also focused on the fact that the temperature at which this shrinkage starts is almost proportional to the yielding point of the glass used. The gist is a low-temperature-fired ceramic characterized by being made of a mixed composition of glass powder and alumina with a yield point of 700°C or higher, and fired at 800-1000°C.

As the glass powder having a yield point of 700° C. or higher in the present invention, borosilicate glass, aluminoborosilicate glass, lithium aluminoborosilicate glass, magnesia aluminoborosilicate glass, calcia aluminoborosilicate glass, etc. are used, and in particular Si 02-AI 203 -CaO-based glass powder or powder containing 8203 is used.

In the present invention, 0 to 5% of NazO is added as an impurity.
or alkali metal oxides such as 20, other M(J
O, BaO, PbO.

Fe2O3, MnO2, Mn3O4, Cr 203, Ni O, co +! 03 and the like up to 10% by weight.

In the present invention, the above glass powder and alumina are mixed,
In addition to alumina, anorthite, celsian, etc. can also be used.

In the present invention, the reason why the binder can be easily removed is that the tape does not shrink at all until the reaction rate of decomposition of the binder and oxidation of carbon is sufficiently high (700°C or higher), so there is no closed bore, and the reaction rate of the decomposition of the binder and the oxidation of carbon are sufficiently high. CO2 generated by combustion of organic binder and residual carbon,
This is because gases such as 820 can be easily removed through the open pores, and air necessary for combustion can also easily pass through.

EXAMPLES Hereinafter, the present invention will be described in detail based on Examples and Comparative Examples with reference to the drawings and tables.

Glass powders and alumina powders having various yield points shown in Table 1 are blended and mixed, 10 wt % of acrylic binder, plasticizer, and solvent are added to disperse the slurry, and the thickness is 0.9 mm using the doctor blade method. I made ~1■ green tape.

These tapes were punched into 30x45+nm samples for firing.

! -R furnace at a heating rate of up to 200°C/min.
It was fired according to the heat pattern shown in the figure. At this time, 2λ
/min of air was supplied into the furnace.

FIG. 2 shows the relationship between the temperature increase rate and the pig incidence rate for Examples 1 to 9 and Comparative Examples 1 and 2 shown in Table 1.

Figure 3 shows the temperature of Example 1.4.7 and Comparative Example 1.2 at 10℃/
It shows the shrinkage curve when the temperature is raised in minutes, and considering the shrinkage start temperature of Example 2.3.5.6.8.9 shown in Table 1, the shrinkage starts at 700°C or higher. It can be seen that when raw materials are used, the incidence of pigs is extremely low, and when raw materials that start shrinking at temperatures below 100°C are used, the incidence of pigs is extremely high.

Figure 4 shows Example 1.4 as a typical glass used.
．． 7 shows the yield point of the glass of Comparative Example 1.2. The relationship between the yielding point of these glasses and the shrinkage start temperature of the green tape is shown in FIG. This shows that the shrinkage start temperature and the yield point of the glass are almost proportional.

Therefore, if glass having a yield point of 700° C. or higher is used, it is possible to obtain a raw material for a low-temperature fired substrate suitable for rapid heating, that is, high-speed firing.

Note that in this example and comparative example, extremely large amounts of air were supplied and conditions were such that binder removal could be easily performed.However, when a large amount of samples were continuously fired using an ordinary thick film furnace 10 degrees Celsius/minute), the raw material of Example 1 did not generate any pigs when the temperature was increased by 10 degrees C/minute, but the material of Comparative Example 1 did not generate any pigs.
．． In No. 2, many puk and cracks occurred.

(Left below) Effects of the Invention According to the present invention, ceramics that are particularly suitable for electronic industrial parts, other heat-resistant industrial parts, tableware, kitchen parts, decorative items, etc. can be produced by high-speed firing, and a large variety of products can be produced in small quantities. We will be able to provide products with short delivery times.

[Brief explanation of the drawing]

Figure 1 is a graph showing firing patterns in Examples and Comparative Examples, Figures 2 to 5 are graphs showing various test results in Examples and Comparative Examples, and Figure 6 is a graph showing the state of decomposition of the binder during firing. It is a graph. Patent applicant Narumi Seito Co., Ltd. agent Patent attorney Hide Komatsu Agent Patent attorney Hiroo Asahi l Figure 2 10 25 50 +00150200 Temperature rising speed ℃/min 3 Temperature 6C 4 Temperature 0C Deflection point of glass Deflection point °C Procedural amendment (voluntary) May 17, 1985 Manabu Shiga, Commissioner of the Patent Office1, Indication of case Patent application No. 1988-0637252, Title of invention Low temperature Fired ceramics 3. Relationship with the person making the amendment Patent applicant name Narumi Seito Co., Ltd. 4. Agent 5. Date of amendment order (voluntary) 6. Detailed description of invention 1 in the specification to be amended and Drawing 7, Contents of Amendment 11) In the fourth line of page 5 of the specification, “...glass, etc. is used,” has been replaced with “...glass, etc., is used, such as amorphous or crystallized glass,” correct. (21, in lines 5 to 7 of the same page, (SiOz... is used.) is corrected as follows. rsiOz -Atz 03-Ca O, Si 0
2-Al2O2MgO, 5iOz-Al2O2-MO0
-CaO-based glass powder or these composition glasses with B
20s is used. JGl same page 10
Delete the line rMa OJ. (41 On the 12th line of the same page, after rcOzosJ, “, Ti
02 and Zr 02 J are added. (9 Correct “Polymerization ratio of glass and alumina” in the left heading column of Group 1 on page 9 to “Weight ratio % of glass and alumina”. (0 Figures 4 and 5 are shown in the attached sheet. Correct. Figure 4 Deflection point of glass Figure 5 Deflection point of glass °C

Claims (1)

[Claims] 1. A low-temperature fired ceramic comprising a mixed composition of glass powder and alumina having a yield point of 700°C or higher and fired at 800 to 1000°C.