JPH0781972A - Glaze composition - Google Patents

Abstract

PURPOSE:To provide a glaze compsn. capable of glazing at low temp., having such characteristics as excellent electrical and chemical stability and more excellent especially in surface smoothness. CONSTITUTION:This glaze compsn. contains, by weight, >=90%, in total, of 15-40% B2O3, 10-30% Al2O3, 0.5-17% P2O5, <=40% SiO2 and 15.5-40% one or more kinds of alkaline earth metal oxides among CaO, SrO and BaO basing on the weights of oxides.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glaze composition for improving the surface smoothness of a ceramic substrate, for example, a chip capacitor, a chip resistor manufactured by a thin film technique or a thin film and thick film technique. The present invention relates to a glaze composition suitable for manufacturing a thin film hybrid component such as a chip inductor.

[0002]

2. Description of the Related Art Conventionally, a glaze composition has been known as a material for remarkably improving the surface smoothness of a ceramic substrate. Since this glaze composition has excellent heat storage properties and electrical insulation properties of glass, it is used in various thermal heads and the like by taking advantage of its properties.

As this glaze for thermal head,
Conventionally, a glaze composition having excellent surface smoothness containing an alkali metal / lead with good production efficiency may be used, but in recent years, for high-speed printing / printing thermal heads,
SiO ₂ with excellent heat resistance (does not contain alkali metal or lead)
A high temperature glaze composition containing as a main component has become mainstream (for example, Japanese Patent Publication No. 60-54553, Japanese Patent Laid-Open No. 60-
118648 and Japanese Patent Publication No. 61-24345).

In addition to this application, use of a glaze composition for chip parts has been studied in recent years. In other words, in order to meet the recent demands for lightness, thinness, shortness, and high precision of electronic parts, as a substrate for chip parts, a ceramic substrate with a glaze layer formed on the surface, that is, with a high-definition pattern pitch with excellent surface smoothness It is considered to utilize a glaze substrate capable of forming a thin film / thick film pattern.

[0005]

However, when the conventional glaze composition is intended to be used for chip parts, the former low-melting glass containing alkali metal / lead is used as a substrate for electronic parts. Pb in reducing atmosphere
The reliability of electrical / chemical stability cannot be satisfied, such as deterioration of electric insulation due to precipitation and damage of thin film due to migration of alkali metal ions.

Further, the latter high-temperature glaze composition containing silicate as a main component is a high-melting-point glass developed for the purpose of high heat resistance, so that the thermal expansion coefficient of the glass must be exactly matched with that of the ceramics to warp the substrate. The problem that occurs occurs. That is, since the high melting point glass has a high fixing temperature (the glass is integrated with the substrate), even if the thermal expansion coefficient is slightly different, the substrate is likely to warp. Therefore, the thickness of the ceramic substrate cannot be reduced, and it is difficult to reduce the thickness required for the chip component substrate.

Further, when the high melting point glass is used, the glass rises to a large extent, which is advantageous for partial glaze, but the entire surface or the strip-shaped glaze pattern used for the chip component substrate has sufficient smoothness. There is a problem that can not be obtained. Moreover, in these glaze substrates for thermal heads, their heat resistance is the most important characteristic, and for example, when manufacturing glaze substrates for thin film hybrids, such heat resistance is unnecessary excess quality,
It is not economical because it requires firing within a narrow high temperature range.

The required glaze thickness is, for example, in the case of a glaze substrate for a thin film hybrid, it is 50 to 50 that of a conventional glaze substrate for a facsimile thermal head.
It is desired to have an extremely thin thickness of about 5 to 30 μm as compared with 100 μm. However, in the conventional glaze composition, when the glaze thickness becomes thin, the glaze surface condition tends to deteriorate, so when a thin glaze is used. Also, a glaze composition capable of obtaining a good surface is required.

As a countermeasure against these problems, the inventors of the present application have already proposed a novel glaze composition (see Japanese Patent Application No. 4-288864) suitable for a substrate for chip parts and the like.
Furthermore, it is desired to further improve the surface smoothness. The present invention has been made in order to solve the above problems, and provides a glaze composition having properties such as low temperature glaze capable of being excellent in electrical and chemical stability, and particularly excellent surface smoothness. The purpose is to

[0010]

The invention according to claim 1 for achieving this object is B ₂ O ₃ : 15 based on the weight of oxide.
And 40 wt%, Al ₂ O _3: 10~30 wt% and, P ₂
O ₅ : 0.5 to 17% by weight, SiO ₂ : 40% by weight or less, and at least one or more alkaline earth oxides of CaO, SrO, and BaO: 15.5 to 40% by weight, in total. The gist composition is characterized by being 90% by weight or more of the total composition.

Further, in the invention of claim 2, the breakdown of the alkaline earth oxide is CaO: 1.5 to 25% by weight, Sr.
O: 20% by weight or less and BaO: 10% by weight or less are summarized as the gaze composition according to claim 1.

The reasons for limiting the content of each component of the glaze composition of the present invention as described above will be shown below. 1) B ₂ O ₃ is indispensable as a glass-forming oxide in the present invention. If it is less than 15% by weight, the crystallization tendency becomes strong and the melting point becomes high, and if it exceeds 40% by weight, heat resistance and water resistance are increased. Is not enough.

2) Al ₂ O ₃ acts as a glass-forming oxide together with B ₂ O ₃ , and if it is less than 10% by weight, the chemical durability is remarkably deteriorated. If it exceeds 30% by weight, it becomes a high melting point and crystallizes. It will be easier. 3) P ₂ O ₅ is a characteristic component of the present invention that can improve the surface smoothness by adding it.
If it is less than 5% by weight, the effect is not clear, and if it exceeds 17% by weight, the crystallization tendency becomes strong and the surface smoothness is lost.

4) SiO ₂ has the effect of improving acid resistance and water resistance when added, but if it exceeds 40% by weight, it has a high melting point and is not suitable for the purpose of the present invention. 5) Alkaline earth oxides (CaO, SrO, BaO)
Is added to help control the coefficient of thermal expansion and vitrification. If less than 15.5% by weight, vitrification is difficult,
If it exceeds 40% by weight, the tendency of crystallization becomes strong.

Of these alkaline earth oxides, CaO, which has a high effect of promoting vitrification, is the most desirable.
When the content is more than weight%, the coefficient of thermal expansion is remarkably lowered, and crystallization becomes easy. In addition, for SrO and BaO, part of CaO is replaced to adjust the coefficient of thermal expansion, and, like the mixed alkali effect, the effect of expanding the vitrification range by combining a plurality of alkaline earth oxides. There is S
If rO exceeds 20% by weight and BaO exceeds 10% by weight, the crystallization tendency becomes remarkable.

6) Other preferable components to be added include MgO, ZnO, Bi ₂ O ₃ and TiO ₂ .・ Of these, if MgO is added in a small amount, CaO,
Similar to SrO and BaO, it has a preferable effect as an alkaline earth oxide.

When ZnO is added in a small amount, it aids vitrification, but when added in a large amount, the tendency of crystallization becomes extremely strong.・ Bi ₂ O ₃ and TiO ₂ improve the chemical durability, but have a strong tendency to crystallize, so only a small amount can be added.

7) In addition, it is preferable not to include an oxide of an alkali metal, Pb or the like from the viewpoint of the reliability of the electronic component, but the chemical durability is lowered but the productivity is expected to improve. Since it can be used, it can be used when it does not hinder the subsequent steps.

[0019]

The glaze composition of the present invention is completely different from the conventional glaze composition, as described in detail below. Conventionally used glaze compositions are all made of silicate glass, although Pb / alkali metal presence / absence and heat resistance are different. If these glass compositions are converted into oxide mol%, SiO ₂ will be used without exception. Is 50 mol% or more, and usually 60 to 75 mol%. These have a skeleton (glass network forming oxide) for forming glass [S
iO ₄ ].

The reason why this silicate glass is used is supposed to be to utilize the basic characteristics of the silicate glass, such as chemical durability and heat resistance, but as already mentioned. However, this conventional silicate glass cannot sufficiently meet the recent demand for glaze substrates for thin film hybrids.

In contrast, the B ₂ O ₃ --Al ₂ O _{3 of the} present invention
The alkaline earth oxides (hereinafter abbreviated as RO) glaze composition, unlike the conventional glass skeleton, the glass ^{_{skeleton, [BO 4] - - -P}} 2 O 5, [AlO 4] -, [PO 4 ] Since it is formed of ^3- tetrahedron, it is considered that the surface smoothness is improved.

Further, alkali metal -B ₂ O ₃ system or an alkaline earth metal, known as a low-melting glass from conventional -
The B ₂ O ₃ system is not suitable for the purpose of the present invention because of its poor chemical durability and electrical insulation. The reason for this seems to be due to the instability of the skeleton structure due to [BO ₃ ] (boron of three coordinations) and the like.

Therefore, in order to obtain the effect of the present invention, B
Al ₂ O ₃ and P ₂ O ₅ are essential components together with ₂ O ₃ and RO. That is, the present invention, the glaze composition of the composition described above, it is possible to soften and glazing at a relatively low temperature, and has excellent chemical durability and high electrical insulation comparable to conventional silicate glass, Further, it was made by finding that the glaze layer has excellent characteristics such as having good flatness even when it is thinned.

[0024]

EXAMPLES The constitution and operation of the present invention described above will be further clarified.
BEST MODE FOR CARRYING OUT THE INVENTION
Reveal As a material, the melt will have the composition shown in Table 1 below.
Sea urchin₃BO₃, Al (OH) ₃, CaCO₃, SrCO
₃, BaCO₃, MgCO₃, SiO₂, H₃PO_Four, Na₂
CO₃, K₂CO₃, Pb₃O_FourWeigh each and use a crusher
Mixed. This mixture in a platinum-rhodium crucible,
Melt at 1200-1450 ° C for 3-5 hours, quench with water
Example of a glaze composition (which is within the scope of the invention)
Nos. 1 to 11 and comparative examples (outside the scope of the present invention)
Sample Nos. 12 to 16 of the laze composition and (conventional product
The sample Nos. 17 and 18 of the glaze composition of the comparative example
Prepared.

Then, the glass softening point and the coefficient of thermal expansion of the glaze compositions of Sample Nos. 1 to 18 were measured. The results are shown in Table 2 below. The glass softening point is the temperature corresponding to the second endothermic peak that appears when a differential thermal analysis is performed, and the coefficient of thermal expansion is the thermal expansion of a cylindrical glass of 3 to 5 mmφ × 20 mm. Then, the value obtained by calculation from the difference in thermal expansion from room temperature to 400 ° C. is described.

Next, each of the glaze compositions of Sample Nos. 1 to 18 was wet pulverized with an alumina pot mill to obtain fine glass powder, which was mixed with an ethylcellulose-based binder and an organic solvent to prepare a glass paste for printing. Prepared. This is 50 mm x 50 mm with Al ₂ O ₃ purity of 97%
After printing on a 0.635 mm alumina substrate surface, baking is performed at each appropriate temperature shown in Table 2 below to create a glaze substrate having a band-shaped glaze portion with a glaze width of 5 mm and a glaze thickness of 20 μm on the alumina substrate. did.

Then, the glaze state and the substrate warp state of the glaze substrate thus formed were observed. The results are also shown in Table 2 below.

[0028]

[Table 1]

[0029]

[Table 2]

As is apparent from Tables 1 and 2, the glaze compositions of Sample Nos. 1 to 11 (within the scope of the present invention) are low melting point glass having a glass softening point of about 830 ° C. or less. Therefore, the baking temperature is about 980 ° C. or lower. Moreover, no remarkable warpage occurred in the glaze substrate. Furthermore, the glaze portions of all the glaze substrates had a small area, but were smooth and smooth, and had a glossy glaze surface. Moreover, the glaze surface was extremely suitable without any small unevenness or waviness.

On the other hand, the samples Nos. 12 to 16 of the comparative examples (outside the scope of the present invention) could not undergo glazing due to crystallization and glass unmelting even if the baking conditions were changed. Nos. 13 and 14 are not preferable because they cannot form glass. In addition, the sample number of the comparative example (of the conventional product)
Since 17 is a high melting point glass containing silicate as a main component,
Compared to the examples, firing at a high temperature of 1240 ° C. or higher is required at the time of glazing, and the swelling of the edges of the glaze pattern and the warp of the glaze substrate are both large, which is not preferable.
Incidentally, the sample No. 18 of the comparative example (of the conventional product) may have a good glaze surface, but since it contains Pb and an alkali metal, it is not preferable because it has poor electrical and chemical stability.
It should be noted that the present invention is not limited to the above-mentioned embodiments and can be of course implemented in various modes within the scope of the gist of the present invention.

[0032]

As described above, the glaze composition of the present invention has a low melting point of B ₂ O ₃ -Al ₂ O ₃ -P ₂ O ₅ excellent in chemical durability, electrical insulation and surface smoothness. -RO type glaze can be provided, a glaze substrate can be manufactured at a lower glazing temperature than conventional glazes, and substrate warpage and glaze rise can be reduced. Moreover, since this glaze composition contains the above-mentioned P ₂ O ₅ in a predetermined amount, there is a remarkable effect that the smoothness of the glaze surface is further improved. Therefore, it can be suitably used as a glaze substrate for chip parts. can do.

Further, the glaze composition of the present invention can be suitably used for thermal heads such as facsimiles and thermal printers, which have been conventionally used for glazes, and especially for applications where high heat resistance is not required. Furthermore, the glaze composition of the present invention having a low softening point can be used as an overcoat glass and a sealing material for covering a ceramic multilayer substrate.

Claims (2)

[Claims] 1. B ₂ O ₃ -15 to 40, based on oxide weight.
% By weight, Al ₂ O ₃ : 10 to 30% by weight, P ₂ O ₅ :
0.5 to 17% by weight, SiO ₂ : 40% by weight or less, C
At least one or more alkaline earth oxides among aO, SrO, and BaO: the total of 15.5 to 40% by weight,
90% by weight or more of the entire composition, a glaze composition. 2. The breakdown of the alkaline earth oxide is Ca
O: 1.5 to 25% by weight, SrO: 20% by weight or less, B
The glaze composition according to claim 1, wherein aO is 10% by weight or less.