JP2800176B2 - Glass ceramic composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a glass ceramic composition suitable for a multilayer circuit board and an insulating layer of a thick film circuit. (Prior Art) Conventionally, alumina is used as a material for a multilayer circuit board. On the other hand, various materials have recently been proposed for low-temperature sintered substrates. Here, the former is 1500 in H ₂ -N ₂ atmosphere
It must be manufactured under firing conditions of 16001600 ° C. for 20 to 40 hours. Furthermore, the dielectric constant of alumina is as high as 9 to 10, and it has been evaluated that it is not suitable for high-speed signal circuits. On the other hand, in the latter case, a so-called low-temperature sintering substrate material which is fired at 850 to 1100 ° C. for 2 to 10 hours is being developed, but has a drawback of low mechanical strength and low thermal conductivity. In the case of firing in a nitrogen gas atmosphere, the substrate may be blackened by residual carbon after firing and the insulation resistance may be reduced. On the other hand, when used as an insulating layer, a lower conductor is printed on an alumina substrate using a conductive paste, and an insulating paste of glass ceramics is printed on the conductor to form an insulating layer and fired. Next, a conductor paste is printed and baked on the insulating layer to form an upper conductor. However, a conventional insulating paste cannot obtain a dense insulating layer by firing, and thus has a low insulation resistance and a low breakdown voltage. In addition, even if such characteristics are sufficient,
There were problems such as poor solder wettability with the upper conductor, low adhesive strength of the upper conductor, and low heat resistance, and none of them was sufficiently satisfactory as a composition for an insulating layer. (Problems to be Solved by the Invention) The present invention solves the above-mentioned problems of the conventional glass ceramic composition, and has high mechanical strength and thermal conductivity, high insulation resistance and high dielectric breakdown voltage, It is an object of the present invention to provide a glass-ceramic composition which is excellent in solder wettability of a conductor formed thereon, does not cause blackening even when fired in a nitrogen atmosphere, and is suitable for an insulating layer and a substrate. (Means for Solving the Problems) In the present invention, the inorganic component is expressed by weight%,
95%, ceramic powder 5 to 65% and oxidizing agent consist of 1 to 10% based on the total amount of glass powder and ceramic powder,
The glass powder is substantially SiO ₂ 35 to 65% Al ₂ O ₃ 1 to 10% MgO + CaO + SrO + BaO 5 to 35% Li ₂ O + Na ₂ O + K ₂ O + Cs ₂ O 0 to 10% PbO 0 to 1.4% ZnO 0 there is provided a _{~5% ZrO 2 + TiO 2 0~5} % B 2 O 3 multi-layer circuit board and thick film circuit consisting of 1-14% insulating layer glass ceramics composition. The composition according to the present invention is suitable as an insulating layer material for forming a lower conductor on a ceramic substrate, forming an insulating layer on the lower conductor, and forming an upper conductor on the insulating layer. It is also suitable as a material for the green sheet of a multilayer substrate manufactured by printing a conductor paste on a green sheet, laminating and firing the paste. In the present invention, if the content of the glass powder is less than 35% by weight, the ceramic powder cannot be sufficiently wetted, so that a dense sintered layer cannot be formed and the strength is reduced. It is not preferable because the amount of the ceramic powder decreases and the strength decreases.
The glass powder is more preferably in the range of 40 to 90% by weight in the above range. On the other hand, if the content of the ceramic powder is less than 5% by weight, the strength is reduced, the reactivity with the conductor or the resistor is increased, and not only the original characteristics of the conductor and the resistor are impaired, but also the electrical properties of the insulating layer are reduced. It is not preferable because the insulating property is also impaired, and if it exceeds 65% by weight, a dense sintered layer cannot be formed, the strength is reduced, and the wet-life load life characteristic as an insulating layer, that is, the reliability characteristic is deteriorated. Absent. By adding the oxidizing agent, it is possible to prevent carbon in the organic binder from remaining and blackening in the firing step.
The content of the oxidizing agent is preferably 1 to 10% by weight based on the total amount of the glass powder and the ceramic powder. If the amount of the oxidizing agent exceeds 10%, the withstand voltage characteristic of the substrate is undesirably reduced. The content of the oxidizing agent is 1 to 5% in the above range.
Is more desirable. Such an oxidizing agent is not particularly limited as long as it has an oxidizing effect of removing residual carbon during a firing step in an air or nitrogen atmosphere. Among them, CeO ₂ , SnO ₂ , TiO ₂ , BaO
₂ is particularly preferred because it is easily available and easy to handle. Such oxidizing agents may be used alone or in combination of two or more. The reasons for limiting the amount of each component in the glass powder will be described.
Unless otherwise specified,% is% by weight. SiO ₂ is a glass network former. If it is less than 35%, the softening point is too low, the heat resistance is lowered, and deformation is likely to occur during re-firing, which is not preferable. On the other hand, SiO ₂ is 95%
If it is larger, the softening point becomes too high, so that the ceramic powder cannot be sufficiently wetted and the strength decreases, which is not preferable. Al ₂ O ₃ is essential from the viewpoint of improving the water resistance of glass.
%, The water resistance of the sintered body is inferior. If it exceeds 10%, the softening temperature of the glass becomes high, and the sintering temperature becomes too high. MgO + CaO + SrO + BaO is added for the purpose of improving the solubility during the production of glass powder and for adjusting the coefficient of thermal expansion.
If it is less than 5%, the above-mentioned solubility is not sufficiently improved, and devitrification tends to occur during glass production. If it exceeds 35%, the coefficient of thermal expansion becomes too large, which is not preferable. Li ₂ O + Na ₂ O + K ₂ O + Cs ₂ O is not essential, but by adding it, it is possible to improve the reactivity with ceramic powder and the solubility of glass, but it is not preferable in terms of electrical properties, especially insulation resistance properties Since it is a component, it is preferably kept to 10% or less as necessary. PbO is used as a flux component of glass. 1.4%
If it is larger, the thermal expansion coefficient of the glass becomes too large, and Ag / P
It is also not preferable because it causes a decrease in adhesiveness to a conductor such as d and Cu. Although not essential, ZnO can be introduced up to 5% for the purpose of improving compatibility with conductors such as Ag / Pd and Cu or improving solubility. ZrO ₂ + TiO ₂ is not essential, but adding it can improve the chemical resistance of the glass. The amount is 5%
Is enough. B ₂ O ₃ is used as a flux component, but if it is less than 1%, the sintering temperature becomes too high, and if it exceeds 14%, the chemical resistance (acid resistance) of the glass is undesirably reduced. More as long amount of components 97% or higher for the remainder of 3% can contain _{V 2 O 5, Cr 2 O} 3, MnO 2, SnO 2, SO 3,. Among the above ranges, more desirable glass powders are as follows. _{SiO 2 40~60% Al 2 O 3} 3~10% MgO + CaO + SrO + BaO 6~34% Li 2 O + Na 2 O + K 2 O + Cs 2 O 0~7% PbO 0~1.2% ZnO 0~3% ZrO 2 + TiO 2 0~3% B ₂ O _{3 2 to} 13% In the above glass powder, each component is expressed in terms of% by weight. If the total amount of each component is 97% or more, it can be used essentially, and the remainder is V ₂ as described above. O ₅ , Cr ₂ O ₃ , MnO ₂ , Sn
Components such as O ₂ and SO ₃ can be contained. Such glass powder has sufficient fluidity at a low temperature (for example, 1000 ° C. or less), sufficiently wets the ceramic powder,
In addition, it has the property of reacting with ceramic powder and partially crystallizing, thereby improving heat resistance and strength. If the particle size of the glass powder and the ceramic powder is too small, cracks are generated when drying the green sheet or the like, which is not preferable. On the other hand, if the particle size is too large, the glass cannot sufficiently wet the ceramic powder and the strength is reduced. Is not preferred. Preferred particle size is 0.5μ
m to 4 μm, and the ceramic powder is 0.1 to 5 μm. On the other hand, alumina, α-quartz,
Ceramic powders of zircon, cordierite, forsterite, mullite, and zirconia are used alone or in combination. The reason is that such a substance has a large strength and a high thermal conductivity, so that the substrate after sintering is used. Such characteristics can also be improved. Further, these ceramic powders have an advantage that they are relatively easily available. Although the composition of the present invention is one in which each powder is mixed in the above ratio, a multilayer circuit board using it is, for example,
It is manufactured as follows. An organic binder, a plasticizer and a solvent are added to the composition of the present invention and kneaded to form a slurry. As the organic binder, butyral resin, (meth) acrylic resin,
As the plasticizer, dibutyl phthalate, dioctyl phthalate, butylbenzyl phthalate can be used, and as the solvent, toluene, alcohol, or the like can be used. Next, the slurry is formed into a sheet and dried to form an unsintered sheet, a so-called green sheet. Next, a hole for a via hole is made in this green sheet, and in the case of firing in air on one side, Ag or Ag /
In the case of baking in a Pd paste or a nitrogen atmosphere, a thick film of a Cu paste is printed on a predetermined circuit. At this time, the via hole is A
g or Ag / Pd paste or Cu paste is filled. Next, a predetermined number of these printed green sheets are stacked and laminated by thermocompression bonding, and fired to sinter the green sheets and circuits. The circuit manufactured in this manner is a circuit in which circuits are stacked in multiple layers via an insulating substrate. These materials can be converted into a paste and used as an insulating layer for a thick film circuit. A thick film circuit using the same is manufactured, for example, as follows. An organic vehicle composed of an organic binder and a solvent is added to the composition of the present invention and kneaded to prepare a paste. Ethyl cellulose and nitrocellulose can be used as the organic binder, and α-terpineol, butyl carbitol acetate and the like can be used as the solvent. Further, a surfactant may be added as a dispersant. Then, in the case of firing in air on an alumina substrate, Ag,
Or Ag / Pd paste, Cu for firing in a nitrogen atmosphere
Print the paste on the given circuit, dry, 850-900 ° C 10
Bake in minutes. Next, the above-mentioned insulating paste is printed on an insulating portion, dried, and fired at 850 to 900 ° C. for 10 minutes in each atmosphere. Usually, printing, drying and baking of the insulating paste are repeated to form the insulating layer with a thickness of 30 to 40 μm. Further, the conductor is printed on a predetermined circuit, dried, and fired at 850 to 900 ° C. for 10 minutes. In the case of a multilayer, the printing, drying and baking are repeated to form a multilayer thick film circuit. In addition, it is also possible to form a multilayer thick-film circuit by simultaneously firing not only individual printing but also drying and drying repeatedly at the same time. The substrate and the insulating paste may each be added with 0 to 5% of a coloring pigment for coloring. [Example] (Example 1) Each raw material was prepared so as to have a target composition, and this was put in a platinum crucible and melted while heating at 1350 to 1500 ° C for 2 to 3 hours while stirring. Next, this was granulated or flaked, and further pulverized by a pulverizer so that the average particle size by weight was 0.5 to 4 μm, to produce a glass powder having the composition shown in Table 1. Then alumina, α-quartz, zircon, cordierite,
Forsterite, mullite, and zirconia ceramics were ground to an average of 0.1 to 5 μm. Next, these glass powder and ceramic powder were mixed at the ratios shown in Table 1 to obtain four types of compositions (samples Nos. 1 to 4) according to the present invention. Dibutyl phthalate as an agent and toluene as a solvent are added and kneaded to obtain a viscosity of 10,000 to 30,000.
A slurry of cps was made. The slurry is then added to about 0.2
After forming a sheet having a thickness of mm, the sheet was dried at about 70 ° C. for 2 hours. Next, this sheet was fired at 900 ° C. for 1 hour in the air or in a nitrogen atmosphere to produce a sintered substrate. The bending strength, thermal conductivity, coefficient of thermal expansion, dielectric constant, heat resistance, chemical resistance, and blackening of the substrate fired in a nitrogen atmosphere (N _{2 in the} table)
(Described as firing blackening). These results are shown in Table-2. Separately, a paste was screen-printed on a dried sheet to form an Ag / Pd or Cu conductor. Next, the sheets on which the conductors were formed were laminated and fired at 900 ° C. for 1 hour in each atmosphere to produce a multilayer circuit element. Next, an Ag / Pd or Cu conductor was formed on the uppermost surface of the device. For this, the upper conductor solder wettability and adhesive strength were measured, and the results are also shown in the same table. As is clear from Table 2, the composition according to the present invention has excellent electrical properties, coefficient of thermal expansion, and flexural strength, and has properties that can be sufficiently used as a multilayer circuit board. As comparative examples (samples Nos. 5 to 10), the same evaluations were performed for compositions other than the composition according to the present invention, and the results are also shown in Tables 1 and 2. (Example 2) An organic vehicle composed of ethyl cellulose as an organic binder and α-terpineol as a solvent was added to the ten compositions described in Example 1 (of which six were comparative examples), and the mixture was kneaded to have a viscosity of 20. A paste of × 10 ⁴ cps was created.
Next, on an alumina substrate, an Ag / Pd paste in the case of baking in air, and a Cu paste in the case of baking in a nitrogen atmosphere, were screen-printed on a predetermined circuit, dried, and fired at 850 ° C. to 900 ° C. for 10 minutes. Next, the above-mentioned insulating paste was screen-printed on an insulating portion in a 200-mesh screen, dried, and 850 to 900 in each atmosphere.
Firing was performed at 10 ° C. for 10 minutes. Printing, drying and firing of the insulating paste were repeated to form an insulating layer having a thickness of 30 to 40 μm.
Furthermore, Ag / Pd paste or Cu paste is screen printed on a predetermined circuit, dried, and 850 to 900 in each atmosphere.
Firing was performed at 10 ° C. for 10 minutes. Thus, a circuit element was created. For this circuit element, insulation resistance, insulation breakdown voltage, upper conductor solder wettability,
The adhesive strength was measured. These results are shown in Table-3. Samples Nos. 5 to 10 in the table are comparative examples. As is clear from the table, the composition according to the present invention has excellent electrical properties and has properties enough to be used as a paste for a thick circuit insulating layer. In addition, the measuring method of each characteristic is as follows. -Five bending strength green sheets were laminated and sintered at 900 ° C for 1 hour. The sample shape after sintering is 12mm wide x 35mm long x 1mm thick. The breaking strength of this sample was determined by a three-point bending test.・ Thermal conductivity The sample is baked under the same conditions as above and 10mm for measurement
It was processed into a φ, 1.5 mm thickness and measured by the laser flash method. -Dielectric constant Make a sample under the same conditions as above, 45 mm for measurement
It was processed to × 45 mm and 1.5 mm thickness. The dielectric constant at 1 MHz was measured by the bridge method.・ Heat resistance: Prepare a sample under the same conditions as above and 12mm for measurement
Width x 35mm length x 1mm thickness, put both ends on the support base, R
After efire, the amount of deflection deformation was measured. A sample having no deformation due to this processing was determined to be good, and a maximum deformation amount at the central portion was determined to be 30 μm or more. Refire temperature and time are 850 ℃, 10 minutes ×
The conditions were three times. -Insulation resistance One minute value of the insulation resistance when 100 V was applied was measured with a minute current potentiometer. -The breakdown voltage was stepped up every 100 V by a voltage application device, held at each voltage for 1 minute, and those having a leak current exceeding 0.5 mA were regarded as failures and regarded as breakdown voltages.・ Solder wettability of conductor formed on the upper conductor
The sample was dipped in a Pb-Sn eutectic solder bath at 5 ° C. for 5 seconds, and the wet area was measured. Good if 80% or more wet, 80
% Was judged as no.・ Adhesive strength Measure the tensile strength of a soldered copper wire (8mmφ) with 2mm x 2mm conductor formed on the insulating layer, 90 ° bending after horizontal soldering, pulling up vertically and peeling. [Effect of the Invention] A substrate baked using the composition according to the present invention has high bending strength, high thermal conductivity, excellent heat resistance, chemical resistance, and solder wettability of the conductor formed on the uppermost layer. I have. The insulating layer for a thick-film circuit fired by using the composition according to the present invention has good insulating properties, a high dielectric breakdown voltage, and excellent solder wettability of the conductor formed on the uppermost layer.

Claims (1)

(57) [Claims] The inorganic component is expressed in weight%, glass powder is 35 to 95%, ceramic powder is 5 to 65%, and the oxidizing agent is 1 to 10% based on the total amount of glass powder and ceramic powder, and the glass powder is expressed in weight%. in substantially _{SiO 2 35~65% Al 2 O 3} 1~10% MgO + CaO + SrO + BaO 5~35% Li 2 O + Na 2 O + K 2 O + Cs 2 O 0~10% PbO 0~1.4% ZnO 0~5% ZrO 2 + TiO 2 0~5% B ₂ O ₃ multi-layer circuit insulating layer glass ceramic composition of the substrate and thick film circuit consisting of 1-14%. 2. The composition according to claim 1, wherein the ceramic powder is at least one selected from alumina, α-quartz, zircon, cordierite, forsterite, mullite, and zirconia. 3. 3. The composition according to claim 1, wherein said ceramic powder has an average particle size of 0.1 to 5 [mu] m, and said glass powder has an average particle size of 0.5 to 4 [mu] m. 4. The oxidizing agent _{may, CeO 2, SnO 2, TiO} 2 and at least one kind of Claims first term of selected from BaO _2, paragraph 2 or composition of the third term describes.