JPS6246954A - Insulative ceramic composition - 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 [Industrial Field of Application] The present invention relates to an insulating ceramic composition used as a material for multilayer wiring boards and the like.

[Conventional technology]

Conventionally, alumina-based ceramic compositions with excellent insulation properties have been mainly used as materials for multilayer circuit boards. This porcelain composition contains approximately 96% Al2O3 powder and S i02 , M
It is obtained by firing a porcelain raw material consisting of powders such as gO and CaO in a reducing atmosphere at a temperature of 1500 to 1600°C.

Further, a conductive paste mainly composed of MO or W is used to print conductors inside the substrate.

[Problem that the invention seeks to solve]

The above conventional alumina porcelain composition has a thermal expansion coefficient of 7.5.
Because it has a large linear expansion coefficient of more than there were.

Therefore, when soldering electronic components to a multilayer wiring board, a so-called preheating process is required in which the board is heated slowly over time to a temperature close to the melting temperature of the solder.

This invention was made to solve the above-mentioned problems with conventional alumina-based insulating porcelain compositions.Its thermal expansion coefficient is smaller than that of conventional porcelain compositions, and the heat generated by soldering of electrical parts, etc. An object of the present invention is to provide an insulating ceramic composition that is less likely to cause damage such as cranking to a multilayer wiring board due to impact.

[Means to solve the problem]

The insulating porcelain composition of the present invention contains SiO2 of 12.8 to 12.8
65.6 mol%, Al2O3 from 1 to 40 mol%, M
gO from 1 to 40.7 mol% and ZrO2 from 1 to 30.3 mol%
mol%, 0.5 to 10 mol% of Li2O, Ca
5 to 45 mol% of one or more selected from the group consisting of O, SrO, BaO, and ZnO.

It is made by firing a mixture of one or more selected from the group of Mn30a, CO304+Nip, and CuO in a ratio of 0.3 to 7 mol% in an oxidizing atmosphere.

〔Example〕 Examples of the present invention will be described below.

First, the manufacturing method and conditions for each sample listed in the table below will be explained using sample 1 as an example.
g, 5.9 g of Al 203 powder, 3.0 g of MgO powder* 7.0 g of Z r 02 powder, Li
10.3 g of 2 CO3 powder, 24.5 g of Ca CO3 powder, and 4.3 g of Mn30 powder were weighed. Note that the above Ca and Li carbonate powders were all stable in the air.

The above powders were wet mixed by placing them in a ball mill and ball milling for about 15 hours.

Next, to the mixed powder, 8% by weight of polyvinyl butyral resin, 8% by weight of dibutyl phthalate, 40% by weight of acetone, and 0.5% by weight of oleic acid were added and stirred to form a slurry. Next, this slurry was drawn by a doctor blade method to produce a long unsintered porcelain sheet with a thickness of 0.25 mm, which was cut into 10-am squares.

The following three types of test pieces were made from the cut unsintered porcelain sheets. The first test piece was obtained by punching out the above sheet into a disk shape with a diameter of 16 m. The second test piece is.

Stack 17 of the above sheets and make JIE f, Shitachino.
It was cut into a size of 36 cranes in length and 4N in width, and its thickness was about 4R. The third test piece was made by printing a wiring pattern on the above sheet using a conductive paste containing Pd as a main component, stacking 6 sheets and pressing them together, and measuring 30 pieces in length, 1 piece in width, 1 piece in width.
It was cut into 5 cranes.

The thickness is approximately 1.50.

These test pieces were fired in a profile in which the temperature was raised to 1000° C. at a rate of 100° C./hour in air, this temperature was maintained for 2 hours, and then cooled to room temperature at a rate of 200° C./hour.

Subsequently, the fired test pieces were tested in the following manner.

For the first disk-shaped test piece, an In-Ga alloy was applied to its bifacial surface, and an electrode with a diameter of 10 mm was installed.
Relative permittivity ε, quality factor Q and resistivity ρ (Ωc
I11) was measured. The relative dielectric constant ε was calculated from the capacitance measured at a frequency of IMIIz at a temperature of 25° C., and Q was measured under the same conditions as the capacitance described above. Further, the resistivity ρ was calculated by applying a DC voltage of 500 V and from the insulation resistance value 60 seconds after the start of application.

Regarding the second test piece made by laminating 17 porcelain sheets, the coefficient of linear expansion α (7°C) at a temperature of 20 to 500°C was measured.

Regarding the third test piece on which the Pd wiring pattern was printed, the molten solder was heated from room temperature to 250℃ without preheating.
After soaking for a second, pull it out.

It was allowed to cool naturally to room temperature and examined for occurrence of cranks, etc. Furthermore, using this test piece, the light-shielding properties were examined by determining whether the internal wiring pattern was visible to the naked eye.

Those that could not be seen through were considered to have good light-shielding properties, and those that could be seen through were judged to have poor light-shielding properties.

Hereinafter, for Samples 2 to 78, three types of test pieces were made from porcelain compositions having the compositions shown in each column of the table below, and each test piece was tested in the same manner and under the same conditions as Sample 1. However, the firing temperature FT was different and was carried out at the temperatures shown in each column of the attached table.

As is clear from the table below, these samples 1 to 78 are:
Firing temperature FT is 950-1250℃, linear expansion coefficient α is 3
．． It was 5 to 6.5 x 10-6/''c. Also.

No cranking or the like was observed in any test of immersion in molten solder, and the light shielding properties were good.

Please note that specific figures have been omitted from the table below.

The dielectric constant ε of these samples is 6 to 9. Q is 500-200
0, and the resistivity ρ was 1×1013 to 5×101′Ω.

The composition ratio of each component of the porcelain composition according to the present invention was determined through many experiments including the above-mentioned examples, but the reason for limiting it as above is summarized as follows. .

(1) If the content of Si02 is less than 12.8 mol% or exceeds 65.6 mol%, the resistivity ρ
is lower than that of the above examples, and is not preferred as a material for multilayer wiring boards.

(2) If the A1203 content is less than 1 mol%, air bubbles will occur in the porcelain, and if the A1203 content exceeds 40 mol%, the resistivity ρ will be lower than that of the above examples, making it preferable as a multilayer wiring board. do not have.

(31MgO content is less than 1 mol%.

Bubbles are generated in the porcelain, and if it exceeds 40.7 mol %, the resistivity ρ is lower than that of the above example, which is not preferable as a multilayer wiring board.

(The content of 41ZrO2 is less than 1 mol%.

On the other hand, if it exceeds 30.3 mol %, the resistivity ρ will be lower than that of the above embodiments, which is not preferable as a multilayer wiring board.

(If the content of 51t, i2o is less than 0.5 mol%, the linear expansion coefficient α is larger than that of the above example, and
If it exceeds 10 mol %, the resistivity ρ will be lower than that of the above embodiments, and it will not be preferable as a multilayer wiring board.

(6) The content of one or more components selected from the group of CaO, SrO, BaO, and ZnO is 5 mol%.
If the resistivity ρ is lower than that of the above example,
On the other hand, if the content exceeds 45 mol%, bubbles will occur in the porcelain, making it undesirable for use as a multilayer wiring board.

(71Mn30a + CO+ 04.N i○, C
If the content of one or more components selected from the group of uO is less than 0.3 mol %, the internal wiring pattern will be visible, which is undesirable from the standpoint of protecting the security of the pattern work. Moreover, if it exceeds 45 mol %, the resistivity ρ will be lower than that of the above-mentioned examples, and this is not preferable as a multilayer wiring board.

〔Effect of the invention〕

As explained above, the insulating porcelain composition of the present invention has 3
．． A linear expansion coefficient α as low as 5 to 6.5×10−6/° C. can be obtained. Therefore, multilayer circuit boards made from this porcelain composition are typically subjected to soldering of electronic components during the process.
Crank does not occur due to thermal shock caused by a temperature difference of about 0°C. Thereby, when soldering electronic components to a multilayer wiring board, it is possible to omit a preheating step that is conventionally required.

Inventor Ken Hoshi Same as above pitched - Same as Hisashi Kamiyoshimi

Claims (1)

[Claims] 12.8 to 65.6 mol% of SiO_2 and Al_2O
_3 from 1 to 40 mol% and MgO from 1 to 40.7 mol%
, ZrO_2 1 to 30.3 mol%, Li_2O 0.5 to 10 mol%, CaO, SrO, BaO, Zn
A mixture of 5 to 45 mol% of one or more selected from the group O and 0.3 to 7 mol% of one or more selected from the group Mn_3O_4, Co_3O_4, NiO, and CuO is oxidized. An insulating porcelain composition fired in an atmosphere.