JPS6022443B2 - insulation material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an insulating material, and particularly to an insulating material suitable as a capacitor electrode material and an air-core coil base material of LC composite parts.

In recent years, automatic component insertion machines have been used to accurately assemble components of electronic devices.

Chip components are suitable as the components used in this automatic component insertion machine, and various chip components are provided for this purpose, with resistors, capacitors, and the like in particular being provided in large numbers. Recently, various LC composite parts have been proposed that have a monolithic structure in which a coil L and a capacitor C are combined. Among them, Utility Model Publication No. 57-29131, Utility Model Publication No. 57-12813
In Publication No. 3, a coil portion is created by printing and laminating magnetic layers and coil-forming conductors alternately by applying printing techniques, and a concessionary layer and an electrode are placed on this laminate or separately. It has been proposed to form an LC composite component by alternately printing and laminating forming conductors, and then baking the coil laminate and capacitor laminate in a folded state at a high temperature to integrate them. In one example, as shown in FIG. 1, a dielectric layer 1 is formed by printing a paste of dielectric powder such as Ti02 or mother Ti03 on a suitable removable substrate (not shown) by a printing method. On top of that, a paste of metal powder such as Ag, Ag-Pd, Pd, etc. is printed on this current transfer layer 1 by a printing method to form an electrode 2, and then a dielectric layer 3 is printed on top of this (see the drawings). (The structure is shown exploded to make it easier to understand), and another electrode 4 is formed on this transfer body layer 3.

Then, on this electrode 4, an intermediate layer 5 made of a paste of glass powder or a ferrite-dielectric powder mixture is printed, and on top of that, a magnetic layer 6 made of a paste of permeable magnetic ferrite powder is printed, and then the above-mentioned A coil-forming conductor 7 is printed using a powder paste similar to metal powder, a magnetic layer 8 that masks a part of the conductor 7 is printed, and a conductor 9 to be connected to the conductor 7 is printed. Thereafter, magnetic layer 10, conductor 11, magnetic layer 12, conductor 13, magnetic layer 14, and conductor 15 are printed in the same manner, and finally, magnetic layer 16 is laminated. The thus obtained laminate is fired at a high temperature to convert it into an integrated solid body, and as shown in FIG. Complete the LC composite part.

At this time, the equivalent circuit becomes as shown in FIG.
In the above case, the existence of the intermediate layer 5 is due to the following reason. That is, the magnetic layers 1 and 3 forming the foundation of the capacitor laminate are composed of Tj02 and mother Ti03, and the magnetic layers 6, 8, 10, forming the coil laminate are composed of Tj02 and mother Ti03.
Since the layers 12, 14, 16, etc. are made of permeable magnetic ferrite, these dielectric layers and magnetic layers have different coefficients of thermal expansion. Therefore, if these dielectric layers and magnetic layers are simply laminated as they are, the shrinkage rates will be different during cooling after solidification, so cracks and warpage will likely occur, resulting in defective parts. Therefore, it is necessary to interpose an intermediate layer 5 having a coefficient of thermal expansion intermediate between these. Composite parts with this structure are mechanically strong, small, and have a simple shape, making it easy to attach directly to a printed circuit board and automate this process. Although it has the advantage of being suitable for mass production because it can be manufactured by simultaneous printing, there is a difference in thermal shrinkage between the capacitor laminate part and the coil laminate part, so even if an intermediate layer is used, thermal stress may occur. There are distortions, cracks, and characteristic fluctuations due to this, and the disadvantage is that it is not possible to obtain a suitable intermediate layer.

By the way, when a composite component having a circuit configuration as shown in FIG. 3 is used for a trap or the like at a frequency of 80 to 11.0 MH2, it is sufficient to obtain L≠1 or more.

The present inventor has discovered that a C composite component used for such purposes can be sufficiently realized without using a magnetic layer in the L portion. and all insulator layers (L part and C
Developed a laminated LC composite part made of the same non-magnetic material (both parts) and used it as a 57-1 machine 6.
The application was filed as No. 6 (Refer to Tokusekki Shobara Publication No. 145114). According to this, since the same insulating layer is used for both the L part and the C part, it is possible to improve the problem that existed due to the difference in thermal shrinkage rate between the capacitor laminate part and the coil laminate part. did it. However, in this case, since a material such as ordinary competitive ceramic was used for the insulator layer, the firing temperature was extremely high at 1200 oo to 1400 qo, so expensive Pd was used for the internal electrodes of the capacitor part and the conductor of the coil part. There was a problem that it had to be done.

Therefore, in order to improve such problems, the present invention aims to provide an insulating material for laminated capacitors and coils that can be commonly used for the inductance part and capacitor part of LC composite parts and has a low firing temperature. purpose.

In order to achieve this objective, the present inventor has conducted research and has developed a multilayer capacitor using a composition containing 1wt% or less of Ni-Cu-Zn ferrite in crystallized glass containing SiO2, ASO2Q, Ca○, etc. We discovered that all we need to do is to configure the dielectric material and the basics for the coil.

An embodiment of the present invention will be described below based on FIGS. 4 to 8.

First, Si02:Aso20 is used as a starting material for crystallized glass.
3: Ca0 was prepared in a weight ratio of approximately 3:1:2, and T
A suitable amount of i02, Zno, &03, Mnu, etc. is contained, and once vitrified, it is finely pulverized.

This powder is then added to a ferrite material (e.g. Fe203).
to 50 mol% and Ni○-COO-Zn0 at a molar ratio of about 2
A 1:2 mixture was added with a pulverized product) and wet-mixed in pure water for about 1 hour, dehydrated and dried, and an appropriate amount of binder and solvent were added to form a paste. At this time, the first surface material of each material was weighed as a sample so that the composition ratio of crystallized glass and ferrite was finally in the state shown in Table 1.

Then, the insulating layer 21 shown in FIG. 4 is formed by printing the insulating paste made of the material thus obtained on the surface of a removable sheet (not shown) by, for example, screen printing. On top of this, an electrode 22 is printed using Ag conductive paste, but at this time, one end T of the electrode 22 is exposed on the left side of the insulating layer 21.The same insulating paste is printed on top of this to form an insulating layer 23. An electrode 24 is formed and printed thereon, with the end T2 exposed on the right side of the stack. If desired, the printing process of this capacitor section can be carried out further until the required number of stacks is obtained.
Next, an insulator 26 is further printed on the laminate, and a linear conductor 27 for forming a coil is printed thereon using a conductive paste.

At this time, the terminal end T3 of the conductor 27 is exposed on the left side of the laminate. Next, an insulating layer 28 is printed on the left side of the laminate to the extent that it does not cover the right end of the conductor 27, and a linear conductor 29 is placed on top of it so that the end overlaps with the end of the linear conductor 27. Print. The illustrated dotted lines schematically indicate that they are interconnected. Thereafter, in the same manner, the insulator layer 30 and the linear conductor 3 are
1. The insulator layer 32 and the linear conductor 33 are sequentially formed by printing.
This step can also be repeated until the desired number of laminated layers is obtained. Then, an insulator layer 34 is further printed on this laminate, and a conductor is drawn out to the right end T4 of the laminate by printing a linear conductor 35. Finally, an insulator layer 36 serving as a surface layer is printed to complete the lamination process. The laminate thus obtained is placed in a bag in a firing furnace, and is heated to approximately 800 to 900 ml.
Firing is performed at 00oC for about 2 hours to make the laminate into an integrally fired body, and if necessary, additional heat treatment is performed to remove distortions and adjust the characteristics. The thus obtained laminate was individually cut to form a single LC composite component element, and electrodes were formed only on the capacitor portion and the inductance portion to obtain a test sample, and its electrical characteristics were measured. Figure 7,
The results shown in FIG. 8 were obtained.

Note that FIGS. 7 and 8 show examples of firing at 860 ○ for 2 hours. Of course, if this element body is provided with external terminals 37 and 38 as shown in FIG. 5, an L having the electric circuit shown in FIG.
C It becomes a composite part. According to Fig. 7, the capacitor part has a dielectric loss ta despite wide frequency changes.
n8 (%) is almost constant in the range of 1% to 1% ferrite, and the concession rate is also in the range of 11 to 13, and varies slightly depending on (i) to 1% in Table 1. It can be seen that although there is a difference in frequency, this is also approximately constant despite wide changes in frequency.

Further, FIG. 8 shows the characteristics of the inductance portion. This inductance part is 86
This is an example of baking for 2 hours at Pi 0, length 3.2 pigs, width 2,
A 5-rib conductor is laminated with an insulator layer having a thickness of 2.2 m and a turn of 1 um to form a coil, and its inductance value is as shown by L in Figure 8, at a frequency of 29 m/day 2.
Even if it changes from ~79MH2, the value remains approximately constant. It can also be seen that the Q value of the coil increases linearly and gently as the frequency increases, making it practically excellent. Further, in the insulating material of the present invention, the secondary Ti02-based or BaTi03-based ceramic material has a content of 1200 qo to 1
8 whereas it had to be fired at 40,000
It can be fired at a low temperature of 00 to 900°C.

Therefore, there is no need to use expensive Pd for the internal electrodes.
It becomes possible to use Ag, which is cheaper than Pd and has a lower resistance value. As a result, by configuring a composite component by providing external terminals, it is possible not only to reduce costs but also to provide a component with good characteristics. Furthermore, the addition of ferrite makes it possible to color white glass (Fe30: yellow), which also eliminates the drawback of conspicuous stains. Incidentally, the electrical characteristics of those with a ferrite content of IM% or less are almost the same as those of FIG. 7.

However, if it is less than lwt%, the color becomes quite pale and stains become noticeable. Therefore, if the conspicuousness of this stain is not a concern, there is no problem in practical use with less than IM%. If the ferrite content exceeds loWt%, the shrinkage rate of ferrite is 3% or more smaller than that of crystallized glass, resulting in more holes and weakening strength, making it unusable as a dielectric.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of manufacturing a subordinate LC composite part, Fig. 2 is a sectional view of the same part, Fig. 3 is its circuit diagram, and Fig. 4 is an LC composite part using the insulating material of the present invention. FIG. 5 is a sectional view of the component, FIG. 6 is a circuit diagram thereof, and FIGS. 7 and 8 are characteristic diagrams of the insulating material of the present invention. 1, 3... Dielectric layer, 2, 4... Electrode, 5... Intermediate layer, 6, 8, 10, 12, 14,
16... Magnetic layer, 17, 18... External terminal, 21, 23, 26, 28, 30, 32, 34, 36
...Insulator layer, 22, 24... Electrode,
27, 29, 31, 33, 35... linear conductor,
37, 38...external terminals. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] 1. 10W of Ni-Cu-Zn-based ferrite is added to crystallized glass containing SiO_2, Al_2O_3, CaO, etc.
An insulating material used as a dielectric material for capacitors and a base material for air-core coils, characterized by containing an amount of t% or less. 2 The Ni-Cu-Zn ferrite is 1 to 10 wt.
Claim 1 characterized in that it contains %
An insulating material used as a dielectric material for capacitors and a base material for air-core coils as described in 2.