KR0161537B1 - Magnetic matter of condenser for bypass - Google Patents

Abstract

The invention consists of the present invention relates to a magnetic by-pass capacitor (Bypass) (capacitor) compositions, more specifically to the _{Pb (Mg 1/3 Nb 2/3) O} 3 and PbZrO ₃ jidoe Pb (Mg _1/3 Nb _2/3 ) It is manufactured to have a composition ratio of 67 to 75 mole% of O ₃ and 25 to 33 mole% of PbZrO ₃ , and has a curie temperature of 50 to 70 ° C. and a thin dielectric layer of less than 20 μm when manufacturing a multilayer capacitor. The capacitor relates to a capacitor magnetic composition for bypass having a low change in permittivity and loss with respect to an electric field strength.

According to the present invention, when manufacturing a multilayer magnetic capacitor of 200 nF or more, a dielectric constant of 8000 or more at 25 ° C., 1 ㎑, 0 V Dc bias, and 1 Vrms is less than 3, loss is less than 3%. Curie temperature of the dielectric composition is present in the range of 50 ~ 70 ℃ when measuring, it was possible to manufacture a multilayer magnetic capacitor having a dielectric constant of 12000 or more and a loss at 1 MHz or less 1.0%.

Description

Capacitor Magnetic Composition for Bypass

The present invention relates to a capacitor magnetic composition for a computer module IC bypass, and more specifically, to Pb (Mg _1/3 Nb _2/3 ) O ₃ and PbZrO ₃ . Pb (Mg _1/3 Nb _2/3 ) O ₃ has a composition ratio of 67 ~ 75mole% and PbZrO ₃ has 25 ~ 33mole%. Curie temperature is 50 ~ 70 ℃ and 20 when manufacturing multilayer capacitor The present invention relates to a capacitor magnetic composition for bypass having a small change in permittivity and loss with respect to an electric field strength in a thin dielectric layer of less than μm.

Conventionally, the dielectric constant change rate is -82% to + 22% based on the dielectric constant at 25 ° C from Y5V (-30 ° C to + 85 ° C) of the EIA (Electronic Industry Association) standard or Z5U (25 ° C to -25 ° C to + 85 ° C) the dielectric constant change was prepared the rare earth metal oxide and titanium oxide are added as the main component BaTiO ₃ as a dielectric ceramic composition satisfying the 056% to + 22%), the temperature characteristics based on the dielectric constant at.

Dielectric magnets of this composition preferably contain Curie temperatures from 50 to 70 ° C., but thin films of less than about 20 μm, with a capacitance of 200 nF or more. Since the dielectric constant and loss change with respect to the frequency change are large at the temperature of the capacitor 50 ~ 70 ℃, there was a problem in manufacturing a capacitor having a stable bypass characteristics, that is, noise (noise) removal characteristics.

Accordingly, an object of the present invention is a bypass capacitor having a Curie temperature of 50 to 70 ° C. and having low dielectric constant and loss variation for electric field strength in a thin active layer of less than 20 μm when manufacturing a multilayer capacitor. It is to provide a magnetic composition.

In order to achieve the above object, it is composed of Pb (Mg _1/3 Nb _2/3 ) O ₃ and PbZrO ₃ , but Pb (Mg _1/3 Nb _2/3 ) O ₃ is 67 ~ 75 mol% and PbZrO ₃ is 25 The above problems have been solved by preparing a dielectric ceramic composition having a composition ratio of ˜33 mol% and using it in a bypass capacitor for a computer module IC.

The present invention is described in more detail as follows.

First, Pb0 100 mol%, MgCO ₃ 33.33 mol%, Nb ₂ O ₅ 33.33 mol% having a purity of 99% or more is mixed in a basis weight to be Pb (Mg _1/3 Nb _2/3 ) O ₃ , and preferably 850 to 950 ° C. After calcining at 900 ° C. for 2 hours, 67-75 mol% of the Pb (Mg _1/3 Nb _2/3 ) O ₃ powder and 25-33 mol% of commercialized powder PbZrO ₃ are well weighed.

An appropriate amount of the organic binder was added to the basis weight powder, mixed with an Al ₂ O ₃ ball mill for 9 to 11 hours, and molded into a tape having a thickness of about 20 μm by a doctor blade method. After that, a plurality of green tapes were laminated to have a capacity of about 200 nF, pressurized at 60 ° C., and then the chips were placed on a substrate and baked at a temperature range of 1050 ° C. to 1200 ° C. for 2 hours. do. At this time, when Pb (Mg _1/3 Nb _2/3 ) O ₃ is 75 mol% or less, the Curie temperature is less than 50 ° C., the dielectric constant at the Curie temperature is low, and Pb (Mg _1/3 Nb _2/3) When the O ₃ is 67 mol% or less, the Curie temperature is located at 70 ° C. or higher, and a problem in that the dielectric constant decreases sharply occurs. Since PbZrO ₃ is a composition other than Pb (Mg _1/3 Nb _2/3 ) O ₃ , the effect is opposite to the result of Pb (Mg _1/3 Nb _2/3 ) O ₃ . The problem is located above ℃, and less than 25 mol% occurs a problem that the Curie temperature is located below 50 ℃. The following Examples and Comparative Examples more specifically describe the efficacy and effect of the bypass capacitor magnetic composition of the present invention, but do not limit the scope of the present invention.

Example 1

PbO 100 mol%, MgCO ₃ 33.33 mol%, Nb ₂ O ₅ 33.33 mol% powder having a purity of 99% or more was weighed and mixed to make 68 mol% of Pb (Mg _1/3 Nb _2/3 ) O ₃ at 900 ° C. After calcining for 2 hours, the Pb (Mg _1/3 Nb _2/3 ) O ₃ powder and 32 mol% of PbZrO ₃ are well weighed.

50 g of the acrylic binder is added to the basis weight powder with respect to 100 g of the calcined powder, mixed with Al ₂ O ₃ ball mill for 10 hours, and has a thickness of about 16 μm by the doctor blade method. After the tape was molded, a plurality of green tapes were laminated to have a capacity of about 200 nF, pressurized at 60 ° C. with a uniaxial press for 3 minutes, and then manufactured as a MLCC chip. It was placed on a substrate and baked for 2 hours at a temperature range of 1100 ° C., and then silver-baked by applying an Ag electrode.

The dielectric constant and dielectric loss factor (tan δ) were measured at 1㎑ and 1V oscillation 0V Dc bias using HP 4274A LCR meter, and the temperature characteristics were Sandus TCC (Temperature). coefficient capacitance) measured in a chamber (chamber) and the results are shown in Table 2 below.

EXAMPLES 2-10

Silver moiety MLCC was carried out by the same method as described in Example 1, except that the mole% of Pb (Mg _1/3 Nb _2/3 ) O ₃ and PbZrO ₃ and the firing temperature were set forth in Table 1 below. After the preparation, the characteristic value thereof was measured in the same manner as in Example 1, and the results are shown in Table 2 below.

[Comparative Examples 1 and 2]

Silver moiety MLCC was carried out by the same method as described in Example 1, except that the mole% of Pb (Mg _1/3 Nb _2/3 ) O ₃ and PbZrO ₃ and the firing temperature were set forth in Table 1 below. After the preparation, the characteristic value thereof was measured in the same manner as in Example 1, and the results are shown in Table 2 below.

According to the present invention, when manufacturing a multilayer magnetic capacitor of 200 nF or more, a dielectric constant of 8000 or more at 25 ° C., 1 ㎑, 0 V Dc bias, and 1 Vrms is less than 3, loss is less than 3%. Curie temperature of the dielectric composition is present in the range of 50 ~ 70 ℃ when measuring, it was possible to manufacture a multilayer magnetic capacitor having a dielectric constant of 12000 or more and a loss at 1 MHz or less 1.0%.

In addition, since the change rate of the dielectric constant with respect to the dielectric constant of 25 ℃ in the range from 0 ℃ to +85 ℃ was in the range of -30% to + 70% it was possible to use as a composition of the dielectric multilayer magnetic capacitor.

Claims (1)

Capacitor composition for bypass, characterized in that consisting of Pb (Mg _1/3 Nb _2/3 ) O ₃ 67 ~ 75 mol% and PbZrO ₃ 25 ~ 33 mol%.