JPH06271791A - Paste composition for marking - Google Patents

Abstract

PURPOSE:To obtain a paste composition with which easily discernible heat- resistant marking can be realized. CONSTITUTION:80-97wt.% dielectric powder and 20-3wt.% heat-resistant inorganic pigment powder are incorporated into the solid matter of this paste composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paste composition to which a heat resistant mark can be applied.

[0002]

2. Description of the Related Art A monolithic ceramic capacitor has a structure in which dielectrics and electrodes are alternately laminated. Generally, an electrode paste is applied on a dielectric green sheet, laminated and fired, and then cut into a predetermined chip size. After forming the external electrodes, a predetermined marking is applied to obtain a product.

By the way, if the chip size of the capacitor is sufficiently large, it is possible to mark each chip, and in that case, there is no inconvenience by using ordinary ink. However, if the chip size is small, it is difficult to mark each capacitor chip and it is not economically advantageous. Therefore, in the above manufacturing process, it was considered to perform marking in the state of a block in which dielectric green sheets coated with an electrode paste are laminated. However, in this case, since the marking ink is also exposed to the firing temperature of the derivative, heat resistance becomes important.

From these requirements, marking paste compositions using the same material as the capacitor material have been tried. However, according to this marking material, it does not react with the capacitor material and there is no problem in heat resistance, but the mark obtained by this is almost the same color as the capacitor and it is somewhat convex, so it is not readable, but the mark size When becomes smaller, it becomes extremely difficult to instantly read.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a marking paste composition capable of providing a heat-resistant mark that can be easily identified.

[0006]

In order to achieve the above object, the paste composition of the present invention comprises a dielectric powder 80 in a solid content.
It is characterized by containing ˜97 wt% and heat resistant inorganic pigment powder 20 ˜3 wt%.

[0007]

In the present invention, BaTiO 3 is used as the dielectric powder.
₃ , SrTiO ₃ , CaTiO ₃ , PbTiO ₃ , Pb
₅ Ge ₃ O ₁₁ , CaZrO ₃ , Pb (ZrTi) O ₃ ,
Pb (ZrNb) O ₃ , Pb (FeNb) O ₃ , Pb
(MgNb) O ₃ , Pb (NiW) O ₃ , Pb (Mg
W) O ₃ , Ba (TiSn) O ₃ , Bi ₄ Ti ₃ O ₁₂ ,
(BaSrCa) TiO ₃ , (BaCa) (ZrTi) O
₃ , (BaSrCa) (ZnTi) O ₃ , Pb (LiFe
W) Any one can be selected from O _{3 and the} like.

As the heat-resistant inorganic pigment powder, Cu is used.
O, Cu ₂ O, Cr ₂ O ₃ , Fe ₂ O ₃ , Cu (CrF
e) It may be appropriately selected from ₂ O _{4 and the} like. The proportion of this pigment must be 20 to 3% by weight. If it is contained in an amount of more than 20% by weight, the difference in the expansion coefficient with the capacitor becomes too large and the adhesive force is lowered, while if it is less than 3% by weight, the color development becomes too light and it becomes difficult to read.

When the dielectric powder and the inorganic pigment powder are kneaded with an organic vehicle to form a paste-like composition, application by a screen printing method becomes possible. As a vehicle, for example, a terpineol solution of ethyl cellulose is suitable, and it is advisable to mix the solid content of 60 parts by weight with the vehicle at 40 parts by weight.

[0010]

Example: 30 dielectric green sheets each having a thickness of 35 μm and containing BaTiO ₃ as a main component were cut into 25 mm square pieces, and 30 sheets were prepared. Of these, 11 pieces × 7 pieces of Pd paste for internal electrodes were prepared. Screen-printed with the capacitor electrode pattern of No. 3, dried at 80 ° C., and laminated. The remaining 10 green sheets were stacked on each of the upper and lower parts of this laminated body and put in a mold kept at 80 ° C.
A pressure of kg / cm ² was applied to obtain a laminated block having a thickness of about 1.1 mm. Six laminated blocks were prepared in the same manner.

On the other hand, BaTiO ₃ powder and Cu (CrFe)
_As shown in Table 1, ₂ O ₄ black pigment powder was blended in various proportions, and kneaded with a vehicle consisting of 60 parts by weight of the blended product and 40 parts by weight of a terpineol solution containing 15% by weight of ethyl cellulose. A marking paste composition was prepared.

The marking paste was used to mark 11 × 7 spots on the surface of the laminated block, and after drying, the green sheet was cut into a matrix of 11 × 7, and each capacitor element was heated at 1300 ° C. for 2 hours. Firing was performed to obtain a capacitor element chip. Chip size is 3.2 mm x
The thickness was 2.0 mm and the thickness was about 650 μm.

The marks of all the samples were visually observed to check the clarity and the presence or absence of peeling of the marks. If even partial peeling of the mark was recognized, the lot was marked as unacceptable (x). The results are summarized in Table 1.

[0014]

[Table 1]

It can be seen from Table 1 that when the pigment content in the solid content is less than 3% by weight, the mark lacks in clarity, and when it exceeds 20% by weight, there is a problem in adhesion.

[0016]

The marking paste of the present invention enables clear marking while maintaining heat resistance. Needless to say, the paste of the present invention is not limited to capacitors.

Claims (1)

[Claims] 1. 80 to 97% by weight of dielectric powder in solid content
A marking paste composition containing 20 to 3% by weight of a heat-resistant inorganic pigment powder.