JP2595982Y2 - Multilayer chip EMI removal filter - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer chip EMI removal filter convenient for automatic mounting.

[0002]

2. Description of the Related Art For example, the most basic lumped-constant type multilayer chip EMI removal filter 11 will be described. This filter includes one capacitor formed in a dielectric ceramic 8 and two filters formed in a magnetic ceramic 9. The dielectric porcelain 8 and the magnetic porcelain 9 are laminated between the two via an intermediate layer of the porcelain.

Green sheets on which internal electrode patterns are printed are alternately stacked on dielectric ceramic green sheets, and the green sheets are alternately led out to the sheet end. Then, through a green sheet of an intermediate layer that is not attached to the dielectric and the magnetic material, then, on a magnetic ferrite green sheet, a pattern in which a coil conductor is formed is printed and laminated on the dielectric ceramic green sheet laminate, A laminated body including a capacitor and two coils is formed. One end of each of the two coils is led out to the opposite end face of the laminated body and connected to an external terminal formed on the end face to form an IN terminal 4 and an OUT terminal 6, respectively. The other terminal of the two coils is derived, and one of the internal electrodes of the capacitor is further derived and connected to an external terminal formed on the end face, respectively, to form an NC terminal 3. On the other face of the opposite face, The other internal electrode of the capacitor is led out and connected to an external terminal formed on the end face to form a G terminal 7. The IN terminal 4 and the OUT terminal 6 are connected as input / output terminals, the G terminal 7 is connected as a ground electrode to other circuit terminals by soldering, while the NC terminal 3 is used for connection inside the multilayer chip EMI removal filter element. A terminal that is not connected to other circuit terminals. Therefore, the surface of the NC terminal 3 is generally coated with glass.

[0004] If only the NC terminals 3 should not be wet with solder, a resin coat should be sufficient. However, if glass is applied, the baking of the external terminal electrodes and the baking of the glass can be performed at the same time. Glass is used because of its excellent heat resistance.

[0005] IN of the multilayer chip EMI removal filter 11
Since the terminal 4, the OUT terminal 6, and the G terminal 7 are soldered, the surface facing the surface on which the G terminal is formed, that is, the surface on which the NC terminal 3 is formed, is suctioned by the nozzle of the automatic mounting device. Will be retained.

[0006]

However, when glass having a low melting point is used, when co-firing with the conductive paste for external terminals, the glass component diffuses into the porcelain and the Q of the capacitor and the inductance of the inductor decrease. There is a problem that, when using a glass having a high melting point, the glass surface becomes rough, which causes an increase in suction error of a nozzle for automatic mounting, and there is nothing satisfying both characteristics and automatic mounting. Was. The purpose of the present invention is to provide a high melting glass layer 1
It is an object of the present invention to provide a multilayer chip EMI removal filter which can solve the above-mentioned problem by forming a double layer of the low melting point glass layer 2 and the low melting point glass layer 2.

[0007]

The gist of the means for solving the problem is that an inductor and a capacitor are provided inside a laminated body including a dielectric porcelain and a magnetic porcelain, and an input terminal 4 and an output terminal are provided on a side surface of the laminated body. In the multilayer chip EMI removal filter 11 on which the external terminal electrodes such as the terminal 6, the ground terminal 7, and the non-contact terminal 3 are formed, a high-melting glass layer covering the non-contact terminal 3 is provided on the side of the laminate on which the non-contact terminal 3 is formed. 1 is formed, and a low-melting glass layer 2 is formed thereon.

[0008]

The high-melting glass layer 1 is printed on the side surfaces of the ceramic laminate so as to cover the non-contact terminals 3 which are used for connection between the electric elements in the laminate and are not used for connection to other circuits. Since the glass layer 2 is printed and baked simultaneously with the non-contact terminals 3, the high melting point glass layer 1 hardly diffuses into the ceramic body, and the characteristics are not changed by changing the ceramic composition. High melting point glass layer 1
Since the low melting point glass layer 2 is formed on the low melting point glass layer 2, the low melting point glass is heated at a high temperature exceeding the melting point, and the surface of the low melting point glass layer 2 becomes smooth. Therefore, the tip of the nozzle for automatic mounting comes into contact with a smooth surface, and it is easy to hold the suction under reduced pressure.

[0009]

Embodiment 1 A laminated body formed by laminating a ferrite magnetic layer and a dielectric ceramic layer via an intermediate layer between which a part of the ferrite magnetic layer lacks a composition is fired to form an integrated body. There is. Two coil conductors are formed in the ferrite magnetic layer, one of the coil conductor terminals is led out to one end face of the laminated body, and the other coil conductor terminal is led to a different opposing end face orthogonal to the one end face. doing.
A capacitor is formed by forming electrodes facing each other via a dielectric layer in a dielectric ceramic layer, and one terminal of the capacitor is led out to the one end face, and the other terminal is led out to an end face facing the one end face. doing. An Ag paste was applied to each end face of the laminate. The end faces from which the coil conductor terminals are led out are the input terminals 4 and the output terminals 6, and the end faces from which the capacitor electrodes are led out are the ground terminals 7. An external terminal electrode formed on the one end surface from which the two coil conductor terminals and one terminal of the capacitor are led out is a non-contact terminal 3. Two layers of glass paste were applied to the end face on which the non-contact terminals 3 were formed so as to cover the non-contact terminals 3. That is, as shown in FIG.
A first glass paste containing SiO ₂ -26Pb ₃ O ₄ -13B ₂ O as a main component is applied on the end surface of the non-contact terminal 3, and further, 57SiO ₂ -30Pb ₃ O ₄
A second glass paste containing -13B ₂ O as a main component was applied and baked at 640 ° C. The inductance of this multilayer chip EMI removal filter is 0.55 μH. As a result of measuring the surface roughness of the end face on which the non-contact terminal 3 is formed, Rmax representing the distance between the highest peak of the sectional curve and the deepest valley is: It was 1.9 μm. As a result of automatic mounting using this multilayer chip EMI removal filter, 9
A mounting yield of 9.998% was obtained.

This baking temperature is appropriate for the first glass composition, but higher for the second glass composition, the second glass layer is sufficiently softened and the surface leveling is reduced. As a result, the first glass layer in contact with the ceramic layer was baked at an appropriate temperature.
Diffusion of the composition was kept low.

[0011]

In Example 2 Example 1, instead of the first glass paste, 59SiO ₂ over 28Pb ₃ O ₄ over 13B ₂ O
Was performed in the same manner as in Example 1 except that a third glass paste containing as a main component was applied and the baking temperature was changed from 640 ° C. to 620 ° C., and the inductance was 0.1%.
It was 56 μH, and Rmax was 2.2 μm. As a result of automatic mounting using this multilayer chip EMI removal filter, a mounting yield of 99.997% was obtained.

This embodiment shows that even if the glass composition is changed, the same effect as that of the first embodiment can be obtained if the high melting point glass 1 is formed in the lower layer and the low melting point glass layer 2 is formed in the upper layer. ing.

[0013]

Example 3 Example 1 was repeated, except that the glass baking temperature was set to 620 ° C .. As a result, the inductance was 0.54 μH, and Rmax was
Was 2.5 μm. As a result of automatic mounting using this multilayer chip EMI removal filter, a mounting yield of 99.996% was obtained.

This embodiment shows that the same effect can be obtained by changing the baking temperature of glass in the configuration of the first embodiment.

[0015]

COMPARATIVE EXAMPLE 1 The procedure of Example 1 was repeated except that the first glass paste and the second glass paste were replaced with a single layer of the third glass paste and baked at 620 ° C. As a result of performing the same operation, the inductance was 0.54 μH and Rmax was 5.5 μm.
As a result of automatic mounting using the multilayer chip EMI removal filter, a mounting yield of 99.980% was obtained.

In this example, the inductance is 0.1.
Although it was 54 μH, a predetermined value was obtained, but Rmax was 5.5 μm, and as a result, the mounting yield was poor. That is, the baking temperature for the glass composition was appropriate, but the surface roughness was rough, and unfavorable results were obtained.

[0017]

Comparative Example 2 Example 1 was repeated except that the first glass paste and the second glass paste were replaced with a single layer of the third glass paste and baked at 640 ° C. As a result, the inductance was 0.50 μH and the Rmax was 2.5 μm.
As a result of automatic mounting using this multilayer chip EMI removal filter, a mounting yield of 99.995% was obtained.

In this example, Rmax is 2.5 μm
As a result, the mounting yield is improved, but the inductance is 0.50 μH, and a predetermined value cannot be obtained, which is not preferable. That is, the diffusion of the glass component into the ceramic layer resulted in a decrease in inductance, and an undesirable result was obtained.

[0019]

[Effects of the Invention] According to the present invention, it is possible to prevent the deterioration of the characteristics due to the diffusion of the glass layer into the ceramic layer, to smooth the surface of the glass layer, to prevent the handling error of automatic mounting, and to improve the characteristics. The effect is great in improving the mounting yield.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a multilayer chip EMI removal filter.

FIG. 2 is a perspective view of a multilayer chip EMI removal filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High melting point glass layer 2 Low melting point glass layer 3 Non-contact terminal (NC terminal) 4 Input terminal (IN terminal) 5 Porcelain 6 Output terminal (OUT terminal) 7 Ground terminal (G terminal) 8 Dielectric porcelain 9 Magnetic porcelain 10 Glass layer 11 Multilayer chip EMI removal filter

Claims (1)

(57) [Scope of request for utility model registration] An inductor and a capacitor are provided inside a laminate including a dielectric ceramic and a magnetic ceramic, and external terminal electrodes such as an input terminal, an output terminal, a ground terminal, and a non-contact terminal are formed on a side surface of the laminate. in multilayer chip EMI filters, the laminate side forming a non-contact terminal, over the non contact terminals to form a high-melting-point glass layer, to form a low-melting-point glass layer thereon, and said low melting point
The surface roughness of the glass layer is 4 μm as the maximum height (R _max ).
m . The multilayer chip EMI removal filter is characterized by being not more than m .