JPS59215701A - Method of producing composite function element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for manufacturing a semiconductor ceramic composite element having both varistor and capacitor characteristics.

Prior Art Semiconductor ceramic composite functional elements having varistor characteristics and capacitor characteristics whose main component is 5rTiOa or the like have already been mentioned. However, it has been difficult to fabricate a laminated multi-functional device having a low varistor voltage of 10 μm or less and a large capacitance. That is, even if stacked, the Stt current increases and the voltage-current nonlinearity deteriorates.

It was difficult to increase the size and capacity of the device.

The reason why lamination is difficult is that since the semiconductor ceramic layers and the electrode layers are alternately present, it is impossible to form an insulating layer of the semiconductor ceramic layers. In other words, in the case of the one-surface insulating layer type, the surface of the semiconductor porcelain is reoxidized to form an insulating layer, so each semiconductor porcelain layer is formed on the surface of the semiconductor porcelain. Heat treatment must be performed in an oxidizing atmosphere, but this is not possible with laminated semiconductor porcelain. In addition, in the case of grain boundary insulation type, it is necessary to apply a thermal diffusion substance to the outer periphery of the semiconductor porcelain and heat it to diffuse the thermal diffusion substance into one grain boundary to form an insulating layer. The diffusion of the thermal diffusive substance was blocked by the electrode layer provided in the electrode layer, and the internal valleys and semiconductor ceramic layer did not become grain boundary insulated.

OBJECTS OF THE INVENTION Therefore, an object of the present invention is to provide a manufacturing method that allows grain boundary insulating material to be well distributed even in a laminated type semiconductor ceramic composite functional element.

Structure of the Invention To achieve the above-mentioned object, the present invention is to produce a plurality of raw porcelain sheets using a porcelain powder raw material capable of obtaining a grain-boundary insulated semiconductor multifunctional device having varistor characteristics and capacitor characteristics. and a step of forming a paste coating layer by applying a conductive paste mixed with a thermal diffusion substance capable of greening the crystal grain boundaries of the semiconductor porcelain on the main surface of the ceramic sheet. , forming a raw sheet laminate by laminating the plurality of Confucian raw sheets so that one of the raw porcelain sheets is sandwiched between the pair of the m fabric layers; M of a semiconductor ceramic composite functional device including a step of firing the body in an oxidizing atmosphere
This is related to the manufacturing method.

Effects of the Invention According to the above-mentioned invention, the conductive base (i) for forming the internal T& is preliminarily impregnated with a thermal diffusion substance.

It becomes possible to diffuse the thermal diffusive substance in the ceramic layer between the electrodes and distribute it well in the grain boundaries, making it possible to provide a laminated semiconductor ceramic composite functional element with good characteristics.

Example Next, examples of the present invention will be described.

Example J SrTjOs powder 100 mol parts Nb, Og
O,Q 5% Ru part Naz0
Prepare a porcelain raw material consisting of 3 mole parts Al2o3o, s % Le part S10* 2-5 mole parts, stir and mix this in a ball mill for 24 hours, fill an alumina porcelain pot, fill it with 95 volumes of nitrogen, 1 in a reducing atmosphere (non-oxidizing atmosphere) of 5 volumes of hydrogen
It was calcined by holding at a temperature of 350° C. for 4 hours. After being calcined in this reducing atmosphere and coarsely pulverized with an atomizer,
Wet-stir with a porcelain ball mill to obtain powder particles】() μm Di
Finely ground to the bottom. The calcined powder obtained in this way has 8
Add wt% of polyvinyl butyral (binder) to make a slurry, and make 60ttm by doctor blade method.
Ceramic green sheet CII 'r shown in Figure 3 with thickness of
I created multiple copies. The main surface of the ceramic green sheet +I+ thus obtained was coated with 65 wt% of powdered Pd and Ag.
28wt%1AkOs 5i02 glass 6.2w
A conductive paste made by kneading powdered NaFO, 8 wt%, and an appropriate amount of vehicle to obtain Nato (thermal diffusant 'ji) Y, was made into a 3 mm long and 2 mm wide conductive paste.
A paste coating layer (21 pieces) was made by printing in a rectangular shape.The paste coating layer (21) was formed in such a way that one side reached the edge and a 0.3 mm thick layer was formed on the remaining three sides.

Next, 20 raw sheets (1j) were stacked as shown in Fig. 2 so that the paste coating layer (2) was exposed alternately on the left side and right side, and heated at 100°C to f300.kg/
A green sheet laminate was formed by pressing at a pressure of cm'.

The raw sheet laminate is exposed to air (in an oxidizing atmosphere)]
Heat treatment was performed at a temperature of 200° C. for 2 hours to form a sintered laminate in which the porcelain layers (1a) and internal electrode layers (2a) were alternately arranged, as shown in the third column. Ag paste' was applied so as to be connected to the exposed surface and baked to form an external electrode (31(4)) to complete a multifunctional device.

According to the above method, since NaF for obtaining NagO'Y is mixed in the conductive paste for forming internal electrodes in advance, this NaF IJ''- At the same time as converting to Na!0, this thermally diffuses to the grain boundaries of the semiconductor crystal and forms an insulating layer.At this time, the diffusion from the paste coating layer (2) is
Therefore, this paste coating layer does not prevent diffusion. As a result, it is possible to provide an element with good performance since NaxO as a heat diffusing substance exists well in the grain boundaries of the semiconductor ceramic.

When we measured the characteristic sound of the multifunctional device configured as shown in Figure 3, we found that the capacitance was 1.5 μF under the measurement conditions of 20°C and 1 kHz, the surge resistance was 7.5 Joules, and the device had a
Varistor voltage 5V determined by measuring the voltage E1 when mA of direct current flows, the above E□ and element 1c
] The nonlinear coefficient determined by the DC current ratio of OmA is 1
It became 0. The above characteristics almost match the characteristics of a multi-functional device that is not laminated.

Example 2 Composition of porcelain raw materials.

5rTiO, 100 mole parts.

Nb*OH, Taz05. VVOs, La*Os,
CeO2, Nd2O3゜Y*Os, Sm2O3,P
r60o, and at least one of D)' x Os
and 0.01 to 3.00 mol parts of seed metal oxide.

A composite nose arsenal element was made in the same manner as in Example 1, except that the modulus was set to NatOo, o 2 to 2.50, and its characteristics were measured.

Capacitance is 6μF to 1.7μF.

Surge resistance is 4.5 joules to 9 joules.

The varistor voltage is 3■~]]V.

Non-linear coefficient is 6-22 Met.

Example 3 Composition of porcelain raw materials SrTi0m] OOmo/l/part.

Nt) 205. TaxOB, VJOn, LaxO
B, Cen7. λdtOs−YvOs, Pr60o
, SmxOB, EutOs and DYxOs (both 101 to 3.00 mole parts of one metal oxide).

Na*00-02 to 2-50 mole parts.

At least 1' of AjhO, CuO', Mn01 and 5i02! 0.01 to 3.00 mole parts of M oxide.

Except for the above, a multifunctional device was manufactured using the same method as in Example] and its characteristics were measured.

The capacitance is 7 μF ~], 6 μF.

Surge resistance is 6.1 joules to 0.8 joules.

Varistor voltage is 3v~]2v.

Non-linear coefficient is 12-40 Met.

Example 4 Composition of porcelain raw materials.

” (1x) ”aX T”Oa (X is sail 0
] ~0.5) 100 molar parts.

Nb*05. 'razo,, wo,, lazo,
, ceoz, Nd20M.

YxOs, SmzOx, Pr60u, and D)'
0.01 to 3 of one or more metal oxides of z03
．． 90 mole parts.

0.0.02 to 2.50-T-# parts of Na.

Other than that, a multifunctional device was made using the same method as in Example, and its characteristic sound was measured.

The capacitance is 0.6 μF ~], 7 μF.

Surge resistance is 8.3 joules to 12 joules.

The varistor voltage is 3V~]3V.

Nonlinear coefficient is 6 to 24 Met.

Example 5 The composition of the foundation materials and materials.

” (1x) CaX TiOs (X is 0.0
(value in the range of 1 to 0.5)] 00 mole parts.

Nhx06. 'raffio,, WOa, LR*
Os, Cent, NdtOa-Y'zOa, S
one of mxOB, Pr60sr- and DytOs
The species or species of gold-phase oxide (1.01 to 3.00 mole parts).

Na, 00.02 to 2.50 molar parts.

One of AgzO, CuO, Moot, and 5ift
0.0] to 3.00 mole parts of the oxide or species.

Except for the above, a multifunctional device was manufactured using the same method as in Example 1, and its characteristics were measured.

The capacitance is 0.6 μF to 1.6 μF.

Surge resistance is 7.6 joules to 3.1 joules.

Varistor voltage is 3V''-14V.

Non-linear coefficient is 21-34 Met.

Example 6 Composition of porcelain raw materials.

Sr(1x) Bax TLOs (X is 0<
A value satisfying x≦1) 100 mole parts.

lqb, o, Tat015, WOa, La2
o8, , Cen2. NdtOa.

YzOs, Pr60o, SmtOs, EutOs
, and a small amount of oxide in DYvos O (both 1 bath of oxide 0.
OJ~3.00 mole parts.

Nazo 0-02 to 2-50 mole parts.

Other than that, a multi-functional device was fabricated using the same method as in Example], and its characteristics were measured.

The capacitance is 0.2 μF to 2.4 μF.

Surge resistance is 4.8 joules to 8.9 joules.

Paris xptE&j, 50V S-]09V non-linear coefficient was 8~]9.

Example? Composition of porcelain raw materials.

Sr (I X ) BaxTjOs (X is 0<
x≦] 100 mole parts.

Nb*Os-Ta1o,, WO5-Law's,
CeO2, HedtOs-Y20g, Pr60u, S
The lesser of mtOn, EuzOs- and DytOi (
and 0.01 to 3.00 mole parts of oxides of species.

Na1OO, 02% 2.50 mo/l/part.

0.01 to 2.00 mole parts of an oxide of at least 5 iox and A 1 t Os.

In addition, a multi-functional device was manufactured using the same method as in Example 1, and its characteristics were measured.

Capacitance is 0.5 μF to 2.8 μF.

Surge resistance is 4.9 joules to 9.3 joules.

Varistor voltage is 53V to ]05V.

Non-linear coefficient is 9.4-32 Met.

Variant This has been confirmed through various experiments.

(al) The heating temperature (calcination temperature) in a reducing atmosphere is preferably in the range of 3300-1500°C.

The range of 1350-]450'C is more preferable. Furthermore, the treatment time is preferably 2 to 8 hours.

(bl) Firing may be performed in a neutral atmosphere instead of a reducing atmosphere.

(Cl oxidation treatment (calcination) is from 850℃ to 35u℃
It is preferable to carry out the treatment for 1 to 5 hours.

(di) The thermal diffusion substance mixed into the conductive paste is.

Instead of NaFKllll, it may be Nato or an fQa compound that becomes Na or O through oxidative heat treatment. It is also applicable to other thermal diffusion materials that create a single grain boundary insulating layer.

The Na and Q mixed into the raw materials for the fel i are not limited to these, but may be Na compounds such as NaF, which will become NaxO in a later step.Also, it is also possible to mix NatO or a Na compound after calcination. good.

(fl　What is the amount of NatO that will ultimately remain in the porcelain?

A range of 0.002 to 2.50 mol parts is preferred. Therefore.

The amount of the r11a compound to be mixed into the conductive paste is also determined in consideration of this.

(-Metal elements, instead of metal oxides, starting materials for porcelain,
It may also be used as carbonate, hydroxide, nitrate, or oxalate.

(711) A 1% property improving substance may be further added to the extent that the properties of the multifunctional device according to the present invention are not impaired.

(The conductive paste is not limited to silver paste, but may also be Ni beneto, etc.)

[Brief explanation of drawings]

Fig. 1 is a plan view showing a raw sheet coated with paste according to an embodiment of the present invention, Fig. 82 is a front view showing the laminated sheet B of Fig. 11, and Fig. 3 is a completed composite FIG. 3 is a cross-sectional view showing a functional element. +11...raw sea), (:a)...porcelain layer, (2)
... paste coating layer, (2a) ... internal electrode layer,
[3++41...external electrode.

Claims (1)

[Claims] A step of forming a plurality of raw porcelain sheets using a porcelain powder raw material capable of obtaining a grain boundary insulated semiconductor ceramic composite functional element having fi+ varistor characteristics and capacitor characteristics. forming a paste coating layer by applying a conductive paste mixed with a thermal diffusion substance capable of insulating the crystal grain boundaries of the semiconductor porcelain on the main surface of the raw porcelain sheet; stacking the plurality of porcelain green sheets so that at least one of the 4jB green sheets is sandwiched between the pair of coating layers to form a green sheet laminate; A method for manufacturing a semi-reflective ceramic composite functional element, comprising the step of firing the green sheet laminate Z in an oxidizing atmosphere. (21 The porcelain powder raw material is -5rTi03-Sr(,
-x) C'aXTill (where X is 0.01 to 0.5
(7) range value). Sr (1y) B”y TlOs (where y is o<
A magnetic material whose main component is one of the values satisfying y≦] is calcined in a non-oxidizing atmosphere and then finely pulverized. 2. The method for manufacturing a multifunctional device according to claim 1, wherein the material is a substance that can be converted into NazO by heating at .