JPH0670227U - Multilayer chip EMI removal filter - Google Patents

Abstract

(57) [Abstract] [Purpose] The high melting point glass layer 1 and the low melting point glass layer 2
By forming multiple layers, it is possible to prevent deterioration of characteristics due to diffusion of the glass layer into the ceramic layer, smooth the surface of the glass layer, prevent handling mistakes in automatic mounting, and improve the characteristics and the mounting yield. It is to provide a chip EMI removal filter. [Arrangement] An inductor and a capacitor are provided inside a laminated body including a dielectric ceramic and a magnetic ceramic, and external terminal electrodes such as an input terminal 4, an output terminal 6, a ground terminal 7, and a non-contact terminal 3 are provided on the side surface of the laminated body. In the formed multilayer chip EMI removal filter 11, a high melting point glass layer 1 is formed on the side surface of the laminated body on which the non-contact terminal 3 is formed so as to cover the non-contact terminal 3, and a low melting point glass layer 2 is formed thereon. Is characterized by.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a laminated chip EMI removal filter which is convenient for automatic mounting.

[0002]

[Prior art]

 For example, the most basic lumped-constant type multilayer chip EMI removal filter 11 will be described. The filter is composed of one capacitor formed in the dielectric porcelain 8 and two inductors formed in the magnetic porcelain 9. The dielectric porcelain 8 and the magnetic porcelain 9 are laminated between them with an intermediate layer of the porcelain interposed therebetween.

Green sheets on which internal electrode patterns are printed are alternately laminated on the dielectric ceramic green sheets, and the green sheets are alternately led out to the sheet end portions. Next, print a pattern with a coil conductor formed on the magnetic ferrite green sheet through an intermediate green sheet that has neither a dielectric nor a magnetic substance, and superimpose it on the dielectric ceramic green sheet laminate. To form a laminated body in which a capacitor and two coils are installed. One end of each of the two coils is led out to the opposing end faces 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, and one face of the opposing face orthogonal to this. Then, draw out the other end of the two coils, and then draw out one of the internal electrodes of the capacitor and connect them to the external terminals formed on the end face to form the NC terminal 3, and 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 used as input / output terminals, and the G terminal 7 is connected as a ground electrode to another circuit terminal by soldering, while the NC terminal 3 is used for connection inside the laminated chip EMI removal filter body. It is a terminal that is only connected to other circuit terminals. Therefore, the surface of the NC terminal 3 is generally coated with glass.

Resin coating may be sufficient if only the NC terminals 3 are prevented from getting wet with solder, but if glass is applied, the external terminal electrodes and the glass can be baked at the same time, so the process is simplified. Glass is used because it has advantages and is excellent in heat resistance.

Since the IN terminal 4, the OUT terminal 6, and the G terminal 7 of the multilayer chip EMI removal filter 11 are soldered, the surface opposite to the surface on which the G terminal is formed, that is, the NC terminal 3 is formed. The surface is held by suction by the nozzle of the automatic mounting device.

[0006]

[Problems to be solved by the device]

 However, when low melting point glass is used, there is a problem that the glass component diffuses into the porcelain and the Q of the capacitor and the inductance of the inductor decrease when co-firing with the conductive paste for external terminals. When glass is used, the glass surface becomes rough, which leads to an increase in suction errors of the nozzle for automatic mounting, and none of the characteristics and automatic mounting are satisfied. An object of the present invention is to provide a laminated chip EMI removal filter that can solve the above problems by forming a high melting point glass layer 1 and a low melting point glass layer 2 doubly.

[0007]

[Means for Solving the Problems]

 Means for solving the problems is that an inductor and a capacitor are internally provided in a laminated body including a dielectric ceramic and a magnetic ceramic, and an input terminal 4, an output terminal 6, a ground terminal 7 and a non-contact terminal are provided on a side surface of the laminated body. In the laminated chip EMI removal filter 11 in which external terminal electrodes such as the contact terminals 3 are formed, a high melting point glass layer 1 is formed on the side surface of the laminated body in which the non-contact terminals 3 are formed so as to cover the non-contact terminals 3. It is a multilayer chip EMI removal filter characterized by forming a low melting point glass layer 2.

[0008]

[Action]

 A high melting point glass layer 1 is printed on the side surface of the ceramic laminated body so as to cover the non-contact terminals 3 which are used for connection between electric elements in the laminated body and which are not used for connection to other circuits, and the low melting point glass layer 2 is printed thereon. Since it was printed and co-fired with the non-contact terminal 3, the high melting point glass layer 1 rarely diffuses into the ceramic body, and the characteristics are not changed by changing the ceramic composition. Further, since the low melting point glass layer 2 is formed on the high melting point glass layer 1, 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, which makes it easier to hold under reduced pressure by suction and eliminates mounting errors.

[0009]

Example 1 A laminated body in which a ferrite magnetic layer and a dielectric ceramic layer were laminated by interposing an intermediate layer in which a part of the composition of the ferrite magnetic layer was lacking between them was fired to integrally form a laminated body. There is. Two coil conductors are formed in the ferrite magnetic layer, one coil conductor end of each is led out to one end face of the laminated body, and the other coil conductor end is faced to different end faces orthogonal to the one end face. It is derived. A capacitor is constructed by forming electrodes facing each other through the dielectric layer in the dielectric ceramic layer, and one terminal of the capacitor is led to the one end face and the other terminal is led to the end face facing the one end face. is doing. An Ag paste was applied to each end face of this 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. The external terminal electrode formed on the one end face where 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 terminal 3 was formed so as to cover the non-contact terminal 3. That is, as shown in FIG. 1, first, by applying a first glass paste mainly composed of 6 1SiO ₂ over 26Pb ₃ O ₄ over 13B ₂ O on the end face of the non-contact terminals 3, further 57SiO thereon the _2-30P b ₃ O ₄ second glass paste mainly composed of over 13B ₂ O was baked in the coating to 640 ° C.. The multilayer chip EMI removal filter has an inductance of 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, which represents the interval between the highest peak and the deepest valley of the cross-section curve, Was 1.9 μm. As a result of automatic mounting using this laminated chip EMI removal filter, 99. A mounting yield of 998% was obtained.

This baking temperature is appropriate for the first glass composition, but is higher for the second glass composition, and the second glass layer is sufficiently softened and the surface leveler Since the first glass layer in contact with the ceramic layer was baked at an appropriate temperature, the diffusion of the composition was suppressed to a small level.

[0011]

Example 2 In Example 1, 59SiO was used instead of the first glass paste.₂-28Pb ₃ O_Four-13B₂The result was the same as in Example 1 except that the third glass paste containing O as a main component was applied and the baking temperature was changed from 640 ° C. to 620 ° C. As a result, the inductance was 0.56 μH, 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.

In this example, even if the glass composition is changed, the same effect as in Example 1 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. Showing.

[0013]

Example 3 As a result of the same procedure as in Example 1 except that the glass baking temperature was set to 620 ° C., the inductance was 0.54 μH and the Rmax was 2. It was 5 μm. As a result of automatic mounting using this multilayer chip EMI removal filter, a mounting yield of 99.996% was obtained.

This example shows that, with the configuration of Example 1, the same effect can be obtained even if the baking temperature of glass is changed.

[0015]

[Comparative Example 1] Example 1 was the same as Example 1 except that the first glass paste and the second glass paste were changed to the first glass paste, and only the third glass paste was applied one layer and baked at 620 ° C. As a result of carrying out similarly, the inductance was 0.54 μH and the Rmax was 5.5 μm. As a result of automatic mounting using this multilayer chip EMI removal filter, a mounting yield of 99.980% was obtained.

In this example, the inductance was 0.54 μH, and 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 was appropriate for the glass composition, but the surface roughness was rough and unfavorable results were obtained.

[0017]

[Comparative Example 2] Comparative Example 2 was repeated except that the first glass paste and the second glass paste were changed to the first glass paste, and only the third glass paste was applied one layer and baked at 640 ° C. As a result of carrying out similarly, the inductance was 0.50 μH and the Rmax was 2.5 μm. As a result of automatic mounting using this laminated chip EMI removal filter, a mounting yield of 99.995% was obtained.

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

[0019]

[Effect of device]

 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, and to smooth the surface of the glass layer to prevent the handling mistake of automatic mounting, improving the characteristics and the mounting yield. The effect is great.

[Brief description of 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]

 1 high melting glass layer 2 low melting 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)

[Scope of utility model registration request] 1. An inductor and a capacitor are internally provided in a laminated body 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 laminated body. In the multilayer chip EMI removal filter, a high melting point glass layer is formed on the side surface of the laminated body on which the non-contact terminal is formed so as to cover the non-contact terminal, and a low melting point glass layer is formed thereon. Removal filter.