JP3203679B2 - Method for producing thick film ferrite paste - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thick film ferrite composition formed by printing, baking or printing, and heat curing.

[0002]

2. Description of the Related Art Conventional ferrite products are manufactured by a green sheet method, a dry or wet press molding method, or the like. Ferrite beads or the like processed by such a method are passed through lead wires of electronic components and used for noise removal.

[0003]

However, in recent years, electronic parts have been made into chips or printed circuits (hybrid I
C, etc.), noise suppression components using ferrite have also been made into chips, but these chip products have a high component unit price and the number of components largely depends on the cost. Also, when you want to magnetically shield a part of the circuit,
Conventionally, a special material is used only for the circuit, so to speak, for example, so that there is a problem in manufacturing or cost.

In view of the above problems, an object of the present invention is to provide a thick film ferrite composition which can be formed by the same steps as those for forming a printed circuit and has high magnetic properties.

[0005]

SUMMARY OF THE INVENTION Thick film ferrite of the present invention
The method for producing the paste is NiO: ZnO: CuO: Fe
₂ O ₃ in a molar ratio of 0.28: 0.55: 0.17: 1
Weigh, mix, bake and then crush to ferrite
Form the ferrite powder and the glass powder.
And the content of ferrite powder is 60 to 80 wt%.
And adding an organic vehicle and mixing.
You. As a result, a pair of ferrite material and glass material
A paste-like composition is obtained.
Thick film ferrule with high magnetic properties by printing and firing
A light-emitting layer can be formed. This thick ferrite layer
The magnetic properties such as the saturation magnetic flux density
It can be adjusted by the ratio. In addition, the thick film ferrule of the present invention
The production method of the iron paste is NiO: ZnO: CuO:
Fe ₂ O ₃ is a mole of 0.28: 0.55: 0.17: 1
Weighed, mixed, baked, then crushed and fermented.
A light powder is formed, and the ferrite powder and a resin material are mixed.
Mix and adjust ferrite powder content to 60-80 wt%
It is characterized by the following. With this, ferrite material and
A paste-like composition consisting of a glass material is obtained.
Printed on an alumina substrate and heated for high magnetic properties
A thick ferrite layer having properties can be formed.
As a result, circuit elements are formed using thick ferrite layers
After checking the characteristics of the circuit elements,
Circuit elements by forming additional ferrite layers
Characteristics can be adjusted. Also, the composition ratio with the resin
Thereby, the magnetic characteristics can be adjusted.

[0006]

The thick-film ferrite material composition of the present invention is a paste-like composition composed of a ferrite material and a glass material, or a ferrite material and a resin material. The ferrite layer can be additionally formed by forming the ferrite layer by the same process, or by laminating the ferrite layer in more layers while observing the characteristics after forming the circuit.

[0007]

An embodiment of the present invention will be described.

[0008]

Example 1 Ni _0.28 Zn _0.55 Cu _0.17 F
e ₂ O ₄ ferrite composition, NiO: Zn
O: CuO: Fe ₂ O ₃ is 0.28: 0.55: 0.1
Weigh in a molar ratio of 7: 1 and mix well with a ball mill or mixer. Next, this mixed powder is placed in a magnetic crucible and subjected to a solid-phase reaction at 1400 ° C. for 4 hours. Thereafter, the fired ferrite was pulverized with a pulverizer or a ball mill and passed through a 325 mesh sieve to obtain a powder.

Next, the calcined ferrite powder and the lead borosilicate glass powder are each 75 wt%: 25 w
It is weighed so that it may become t%, and it mixes sufficiently by a mixer or a ball mill. Here, butyl carbitol containing 7% by weight of ethylcellulose as an organic vehicle is added so as to be 30% by weight of the mixture, and the mixture is sufficiently mixed with a three-roll or the like to form a thick film ferrite paste. Using the obtained thick film ferrite paste, printing was performed on, for example, an alumina substrate (not shown), and firing was performed at 950 ° C. to obtain thick film ferrite. The area of this thick film ferrite is 8.3 × 1
1.3 mm, and the film thickness was 87 μm.

The magnetic properties of the thick-film ferrite obtained in this example were measured at room temperature using a vibrating sample magnetometer (VSM). As a result, as shown in the magnetization curve of FIG. Stable characteristics with a residual magnetic flux density of 527 Gauss and a coercive force of 73.6 Oersteds were obtained.

Further, in the system of the ferrite material and the glass material obtained in this embodiment, after printing a thick film ferrite paste on a substrate, the ferrite material is sintered at a constant temperature of 950.degree. FIG. 2 shows the relationship between the material content and the saturation magnetic flux density. According to FIG. 2, when the ferrite material content is at least in the range of 60 to 80 wt%, the saturation magnetic flux density is gradually increased from about 1800 gauss to about 3800 gauss in proportion to the increase in the ferrite material content.

Here, the firing temperature of the thick-film ferrite paste is maintained at 950 ° C. because a printed circuit is formed on a substrate and fired at a temperature higher than 950 ° C., so that an Ag—Pd-based material for an electrode or a conductor is used. This is because Ag in the conductive paste melts, which is impractical, and the thick film ferrite paste itself causes a chemical reaction with alumina of the substrate.

On the other hand, when the thick film ferrite paste is heated at about 800 ° C. or less, the sintering phenomenon hardly occurs, so that a disadvantage that the glass material content must be added more occurs. It is.

[0014]

Example 2 The same calcined ferrite powder as in Example 1 and an epoxy resin as a thermosetting resin were weighed at a weight ratio of 75 wt%: 25 wt%, respectively, and thoroughly mixed by a mixer or a ball mill. To form a thick film ferrite resin paste. Here, the thermosetting resin is not limited to an epoxy resin, and may be, for example, a silicone resin.

Next, the obtained thick-film ferrite resin paste is applied to a ceramic substrate (not shown) (for example, an alumina substrate).
Printed thereon, heated at 125 ° C. for 1 hour and cured to obtain thick film ferrite.

[0016]

According to the thick film ferrite composition of the present invention, a ferrite material and a glass material or a resin material are mixed and fired or heat-cured, so that a thick film ferrite which can be formed by a printing method can be obtained. While you can
A thick film ferrite having magnetic properties such as a high saturation magnetic flux density can also be obtained. Further, for example, the adjustment of the saturation magnetic flux density in the magnetic properties of the obtained thick film ferrite depends not only on the chemical composition of the ferrite material but also on the content of the ferrite material (or the corresponding glass material or resin material). By doing so, it can be adjusted widely.

[Brief description of the drawings]

FIG. 1 is a magnetization curve of a thick-film ferrite obtained by using the thick-film ferrite composition of Example 1 of the present invention.

FIG. 2 is a diagram showing the content of a ferrite material of the thick film ferrite and the saturation magnetic flux density characteristics of the same.

Claims (2)

(57) [Claims] 1. A _{NiO: ZnO: CuO: Fe 2} O 3 and
Weighed at a molar ratio of 0.28: 0.55: 0.17: 1,
After mixing, firing and then crushing ferrite powder
Is formed, and the ferrite powder and glass powder are mixed.
The content of ferrite powder is 60 to 80 wt%,
Thick film cartridge characterized by adding and mixing an organic vehicle.
Manufacturing method of ferrite paste. Wherein _{NiO: ZnO: CuO: Fe 2} O 3 and
Weighed at a molar ratio of 0.28: 0.55: 0.17: 1,
After mixing, firing and then crushing ferrite powder
The ferrite powder is mixed with a resin material to form a ferrite.
The content of light powder should be 60-80 wt%.
Characteristic method for producing thick film ferrite paste.