JPH0210606A - Conducting paste and thin film component using same - Google Patents

Abstract

PURPOSE:To prevent the structural defect of a conductor layer such as delamination or cracks and obtain the good characteristic with no open circuit failure or the like by containing Ag and at least one or more kinds of specific metallo- organics or their decomposed materials. CONSTITUTION:Conducting paste is laminated on an oxide element material and concurrently burnt. A conducting material Ag and at least one or more kinds of Mg, Ti, Sn, Ca metallo-organics or their decomposed materials are contained. The metallo-organics or their decomposed materials 0.1-7wt.% in metal conversion, preferably 0.5-3wt.%, are contained against Ag. Silver oxide may be used for part Ag serving as a conducting material, or Ag-Cu, Ag-Pd alloy may be used if it is mainly made of Ag. Ag 95wt.% or above is contained in this case. In the metallo-organics, the center metal such as Mg, Ti, Sn, Ca is connected to the ligand (coordinating atom) via the hetero metal, and O, S, N is preferable for the hetero atom.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a conductive paste and thick film parts such as a multilayer ceramic inductor and a multilayer ceramic LC part using the conductive paste as a conductor layer.

<Prior art> Conductive pastes used for conductive layers of multilayer ceramic inductors, multilayer ceramic LC parts, etc. have conventionally been made into spherical or spherical-like shapes, scale shapes, or spherical and scale shapes as conductive materials. Conductive inorganic particles having a mixture of both shapes are used.

In particular, in multilayer ceramic inductors and LC parts that use Ni-based ferrite such as Ni-Cu-Zn ferrite for low-temperature firing as a magnetic material, Ag is used as the conductive material in order to obtain a high quality factor.

<Problems to be Solved by the Invention> When the conductive paste using Ag particles described above is fired simultaneously with the printed magnetic paste to form a conductor layer, the electrode (conductor) component may be deposited inside the chip after firing. Delami,
Structural defects such as cracks were observed, which caused problems such as a decrease in the inductance of the magnetic material, an increase in the DC resistance of the conductor, and a decrease in the quality factor.

In this case, structural defects such as delamination and cracks are thought to occur frequently because the shrinkage and linear expansion coefficients during firing are significantly different between the conductive layer and the magnetic material.

The present invention provides a conductive paste that can prevent structural defects such as delamination and cracks when used as a conductor layer, and provides good characteristics without disconnection defects, as well as multilayer ceramic inductor parts and multilayer ceramic LCs using the conductive paste. The purpose is to provide thick film parts such as parts.

Means for Solving the Problems> In order to achieve the above object, the conductive paste of the present invention is laminated on an oxide element body and co-fired,
Conductive material Ag, Mg metallo-organic, T
It contains at least one of metallo-organic (I), metallo-organic (Sn), and metallo-organic (Ca) or a decomposed product thereof.

In this case, it is preferable that the metallo-organic or its decomposition product is contained in an amount of 0.1 to 7 wt% in terms of metal based on Ag.

In the thick film component of the present invention, such a conductive paste is laminated on an oxide element, preferably a magnetic oxide element, and then simultaneously fired to form a conductor layer.

The configuration of the present invention will be explained below.

The conductive paste of the present invention contains Ag as a conductor material and Mg as a conductive material.
metallo-organic, Ti metallo-organic, Sn metallo-organic and Ca metallo-organic, or a decomposition product thereof.

Metallo-organics are those in which the central metal is bonded to a ligand (C atom) through a heteroatom, whereas organometallics are those in which the central metal is bonded directly to the C atom. They are different. Therefore, the above mekrow organics have central metals of Mg, Ti, and Mg, respectively.
These are Sn and Ca.

The hetero atom is any one of 0, S, N, and P, and preferably any one of O, S, and N is particularly preferred.

For example, such metallo-organics include R-S-M, R-S-M-S-R (where M is Mg, Ti, Sn or Ca, and R
is an aromatic group or an aliphatic group. ).

Metallo-organics are sometimes referred to as metal resinates, in which the organic portion is derived from a resin or other natural product.
Metal resinates are those that contain one metal atom in the compound, whereas metallo-orgex generally consists of a mixture of resinates. The mixture of MetalloogreX or resinate is prepared in the form of a liquid or a paste.

For more information on this metallo-organic or metal resinate, please visit C, Y, Cuo, 5solidState
Technology, 17f2), 49-55(1
974) etc. can be referred to.

As described above, since such mekrow organic is in liquid or paste form, the dispersibility when producing a conductive paste is improved.

This improvement in dispersibility is due not only to the improvement in initial dispersibility, but also to the fact that the oxides that are decomposed and produced during firing, which is performed to make thick-film parts as described later, have good dispersibility. Therefore, the sintering control effect is high.

In addition, the oxide produced in this way is made into a finer powder than ever before, with an average particle size of 0.01 to 0.1 μs.
It will be about. This pulverization also provides a high sintering control effect during firing.

In the present invention, part or all of the metallo-organic may be a decomposition product thereof.

The decomposition products are usually oxides, and the above effects can be similarly achieved by the presence of metallo-organic oxides. In this case, such an effect is not achieved when oxide particles are included in the conductive paste in advance.

Such decomposed oxides can be obtained by heat-treating the paste composition or its raw material composition at, for example, 200 to 400°C.

Such metallo-organics or their decomposition products are
0.1 to 7 wt% in terms of metal relative to Ag of the conductor material
, preferably 0.1 to 3 wt%, more preferably 0.1 to 3 wt%.
It is preferable to contain 5 to 2 wt%.

By including it in this way, the effects of the present invention are enhanced.

Since the conductive paste of the present invention is used as the internal winding of the inductor of the multilayer ceramic inductor or multilayer ceramic LC component, which is the thick film component of the present invention, as described above,
Ag is applied as a conductor material. In this case, part of the Ag may be silver oxide.

In addition, if Ag is the main component, Ag-Cu, Ag
- An alloy such as Pd may be used.

At this time, Ag is contained in an amount of 95 wt% or more.

The conductive paste of the present invention is one in which Ag and metallo-organic or a decomposed product thereof are dispersed in an organic vehicle.

Specifically, when adding the organic vehicle to Ag, the metallo-organic may be added and sufficiently dispersed by, for example, roll treatment.

At this time, as described above, Ag may be dispersed in a metallo-organic manner, heat-treated at about 200 to 400°C, and then dispersed in an organic vehicle.

The organic vehicle contains a binder and a solvent.

As the binder, any known binder such as ethyl cellulose, acrylic resin, butyral resin, etc. can be used.

The bangu content is above 0~5% by weight.

As the solvent, any known solvent can be used, such as terpineol, butylcarpitol, kerosene, and the like.

The solvent content is approximately 20 to 55% by weight.

In addition, dispersants such as sorbitan fatty acid esters and glycerin fatty acid esters, plasticizers such as dioctyl phthalate, dibutyl phthalate, butyl butyl phthalyl glycolate, and dielectric materials may be used, if necessary, within a total amount of about 10% by weight or less. , various ceramic powders such as magnetic materials, insulators, etc. can also be added.

The thick film component of the present invention is produced by applying the conductive paste of the present invention onto an oxide element by a known means such as screen printing, drying as necessary, and repeating this application and drying as necessary. A conductor layer pattern is formed, which is then laminated and fired.

Alternatively, a green sheet may be laminated as a conductor layer by a known method and then fired.

The firing temperature may be a known temperature depending on the material, and is usually carried out at normal pressure.

FIG. 1 shows an example of a multilayer ceramic inductor as a thick film component of the present invention.

The multilayer ceramic inductor 10 according to the invention has an internal winding 5, a magnetic layer 6 and a pair of external electrodes 41, 45, as in the prior art.

The internal winding 5 of the multilayer ceramic inductor 10 is formed from the above-mentioned conductive paste.

Therefore, such a multilayer ceramic inductor is
The electrical resistance is low and the Q value of the inductor is improved.

Various spinel soft ferrites having a spinel structure can be used as the material for the magnetic layer 6 of the multilayer ceramic Intact 10, but it is preferable to use Ni-based ferrite due to the firing temperature.

Ni-based ferrite is a low-temperature firing material, and when such a magnetic layer is used, the multilayer ceramic inductor of the present invention does not generate a liquid phase during firing and has better electrical resistance. Become.

Examples of Ni-based ferrite include Ni ferrite, N 1-
Cu ferrite, Ni-Zn ferrite, Ni-Cu-
Examples include Zn ferrite.

In this case, the Ni content is 45 to 5 in terms of NiO.
5mo1% is preferable, and a part of this Ni is Cu and/or
Alternatively, Zn may be substituted with about 40 mo1% or less.3 In addition, Co, Mn, etc. may be contained with about 5 wt% or less of the total, and furthermore, CaSi, Bi, v, pb
The content may be about 1 wt% or less.

Such a ferrite-based magnetic layer 6 is made of a conductive paste of the present invention with a thickness of 600 to 1000'C1, particularly 800 to 10'C1.
Simultaneous firing is possible at a firing temperature of 00°C.

The laminated ceramic inductor 10 may have a conventionally known structure, and its outer shape is usually approximately rectangular parallelepiped. As shown in FIG. 1, the internal winding 5 is normally arranged in a spiral shape within the magnetic layer 6, and both ends thereof are connected to each external electrode 41, 45.

In such a case, the winding pattern of the internal winding 5, that is, the shape of the closed magnetic circuit, can be made into various patterns, and the number of turns can be selected as appropriate depending on the application. There is no limit to these, and they may be selected as appropriate depending on the purpose.

In addition, insider #i! The thickness of 5 is usually 5 to 30.111
1, and the winding pitch is usually about 30 to 100. The thickness of the external electrode 41.45 is usually 50 to 500-
shall be.

Furthermore, there are no restrictions on the material of the external electrodes 41, 45, and any of various conductor materials can be used, such as printed films, plating films, vapor-deposited or sputtered films, or laminated films of these, such as Ag-Pd, Ni, and Cu. It is.

To manufacture such a multilayer ceramic inductor 10, a conventionally known printing method may be used.

Ferrite paste is produced as follows.

First, a predetermined amount of Nip, ZnOlCuOlFew Os
A predetermined amount of ferrite raw material powder is wet-mixed using a ball mill or the like. The particle size of each powder used is approximately 0.1 to 10 microns.

The wet-mixed mixture is usually dried using a spray dryer, and then calcined.

This is usually wet-pulverized in a ball mill until the powder particle size becomes about 0.01 to 0.1μ,
Dry with a spray dryer.

The obtained mixed ferrite powder is dissolved in a binder such as ethyl cellulose and a solvent such as chil, neol, butyl calpitol, etc. to form a paste.

Note that various glasses and oxides can be contained in the paste.

Such a multilayer ceramic inductor 10 is mounted on a printed circuit board by soldering the external electrodes 41, 45, etc., and is used in various electronic devices.

Although the present invention has been described above using a laminated ceramic coil as an example, the present invention is essentially the same in the case of a laminated ceramic transformer, and there is no difference in the various materials used and the manufacturing process.

FIG. 2 shows a laminated ceramic L as a thick film component of the present invention.
An example of C part is shown.

The LC composite component 100 shown in FIG. 2 is one in which a multilayer ceramic inductor 10 and a multilayer ceramic capacitor 11 are integrated. The inductor 10 is made by laminating magnetic layers 6 with intervening internal windings 5 formed in a predetermined pattern. The capacitor 11 that is integrated into the inductor 10 is made by laminating ceramic dielectric layers through internal electrodes.

The multilayer ceramic inductor 10 of such a multilayer ceramic LC composite component 100 is similar to the multilayer ceramic inductor 10 shown in FIG. 1 described above.

In addition, it can also be used as an internal conductor for a multilayer wiring board or as a through-hole conductor in accordance with the above.

For example, as multilayer wiring board materials for low-temperature firing, there are known glass-alumina, glass-alumina-forsterite, and boric acid-tin-barium materials. It can be combined with pastes and green sheets for various ceramic materials, and can be co-fired at a temperature of 600 to 1400°C.

<Example> Hereinafter, the present invention will be explained by examples.

Example 1 Mg resinate (trade name: Metal Ra5) was added to spherical Ag powder (average particle size: 0.8, 11) as a metal resinate.
inate, manufactured by Engelhard) at 2wt% in terms of metal.
In addition, after heat treatment at 350° C., it was dispersed in an organic vehicle to prepare a conductive paste.

The organic vehicle used was 0.2 parts by weight of terpineol and 0.2 parts by weight of ethyl cellulose per 1 part by weight of Ag powder.
A mixture of 0.3 parts by weight and 0.1 parts by weight of butylcarpitol was used.

This is referred to as conductive paste N011.

Furthermore, conductive pastes No. 2, No. 3, No. 4 are obtained by adding Ca resinate, Ti resinate, and Sn resinate instead of Mg resinate to conductive paste No. 1, respectively.

Furthermore, a conductive paste to which no metal resinate was added was prepared as a comparative conductive paste and designated as conductive paste No. 10.

Also, Sn is used as a metal oxide instead of metal resinate.
A conductive paste 5 is prepared by adding it% of O□ (average particle size: 0.5 μm) to Ag.

Next, as a ferrite raw material, particle size 0.1 to 1, Opx
Nip, Cub, ZnO, and Fears powders of about 100% were wet mixed using a ball mill, and then this wet mixture was dried using a spray dryer.
It was calcined at 750'C to form granules, which were ground in a ball mill and then dried in a spray dryer to obtain a powder with an average particle size of 0.1.

Next, this powder was dissolved in terpineol along with a predetermined amount of ethyl cellulose, mixed with a Henschel mixer, and dispersed with three rolls to produce ferrite paste No. 100 of Ni-Cu-Zn ferrite.

The above conductive paste No. 1 to No. 4 (the present invention),
No. 5, No. 10 (comparison) were each printed on a polyester film in a size of 5 x 5 x 0.5 mm, and 3
Deirametry was measured at a temperature increase rate of 00°C/hr.

Similarly, ferrite paste N on polyester film
Measurements were also made on those printed with o and 100.

These results are shown in FIG.

From the results shown in FIG. 3, it can be seen that the conductive paste containing the metal resinate of the present invention has a shrinkage rate that is similar to that of the ferrite paste up to the firing temperature when making thick film parts.

Example 2 Using the conductive paste and ferrite paste of Example 1, a 4.5 mm x 3.2 mm x 1.1
A ceramic inductor shown in FIG. 1 of mm was fabricated.

The thickness of each ferrite layer is 40μ, the thickness of the internal winding is 20μ
The wire width of the door is 300P, and the length of the coil is 2.5mffI.
, and an elliptical shape with a minor axis of 1.3 mm.

The external electrode is Ag-Pd-glass paste or Ag-P
It was composed of d paste.

The firing temperature was 850°C, and the sintering time was 2 hours.
The firing atmosphere was air. The cross sections of these multilayer ceramic inductors were observed using an electron microscope.

As a result, no delamination or cracking was observed in the conductive pastes of the present invention No. 001 to No. 4, but no delamination or cracking was observed in the conductive pastes of the comparison. It was done.

Furthermore, the number of cracks generated was investigated and the following results were obtained. In addition, the number of cracks generated is
The number of defects out of 500 was measured using a microscope. The results are shown below.

Conductive paste No. Number of cracks 1 (present invention) 2 (present invention) 3 (present invention) 4 (present invention) 5 (comparison) 10 (comparison) <Effects of the invention> According to the present invention, metal resinate By adding
When used as a conductor layer for thick film parts, it is possible to make the shrinkage rate of the magnetic material similar, especially the shrinkage rate up to the firing temperature when making thick film parts, and to prevent delamination, cracks, etc. of the electrode components during firing. A good product with no structural defects can be obtained.

Explanation of symbols 10... Multilayer ceramic inductor, 100... Multilayer ceramic LC component, 5... Internal winding, 6... Magnetic material

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view showing an example of a multilayer ceramic inductor as a thick film component of the present invention. FIG. 2 is a partially cutaway perspective view showing an example of the thick film component of the present invention being a multilayer ceramic LC component. FIG. 3 is a graph showing the results of deirametry. Patent applicant: TDC Co., Ltd. (FIG, 2 FIG, 3 Itsuhiro CC)

Claims (4)

[Claims] (1) A conductive paste that is laminated and co-fired on an oxide element body, comprising conductive materials Ag, Mg metallo-organic, Ti metallo-organic, Sn metallo-organic and Ca metallo-organic. - A conductive paste containing at least one organic material or a decomposed product thereof. (2) At least one or more of Mg metallo-organic, Ti metallo-organic, Sn metallo-organic and Ca metallo-organic or their decomposition products are 0.1 to 7 wt in terms of metal relative to Ag.
% of the conductive paste according to claim 1. (3) A thick film component in which the conductive paste according to claim 1 or 2 is laminated on an oxide element body and then simultaneously fired to form a conductive layer. (4) The thick film component according to claim 3, wherein the oxide element is a magnetic oxide element.