JP2005089208A - Method for manufacturing composition paste for laminated electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a composition paste for a laminated electronic component in which the adhesive power between green sheets is improved without increasing the quantity of an organic material in the composition. <P>SOLUTION: The method for manufacturing the composition paste for the laminated electronic component which is for the manufacture of the composition paste used for the lamination forming in the laminated electronic component includes: a 1st mixing process for mixing and dispersing inorganic material powder and a 1st tackifier, a 2nd mixing process for adding an organic binder to the mixture obtained in the 1st mixing process and mixing and dispersing the resultant mixture, a 3rd mixing process for adding a 2nd tackifier to the mixture obtained in the 2nd mixing process and mixing and dispersing the resultant mixture. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a composition paste for a laminated electronic component used for producing a laminated chip component or the like.

  A multilayer ceramic capacitor is manufactured through the following steps. First, a ceramic paste composed of an inorganic material powder serving as a dielectric, an organic binder, a plasticizer, a tackifier, a solvent, and the like is prepared. Next, the obtained ceramic paste is applied to the support surface by a doctor blade method or the like, and the solvent is dried to form a ceramic green sheet.

  Next, an electrode paste containing a metal such as palladium serving as an internal electrode is printed on the ceramic green sheet on a predetermined electrode pattern using a screen or the like. Thereafter, the printed ceramic green sheet is peeled off from the support. A plurality of ceramic green sheets formed in this way are stacked and pressed in the thickness direction for pressure bonding.

  Subsequently, the pressure-bonded laminated body is cut into a predetermined size so as to obtain a laminated body for obtaining individual ceramic capacitors to obtain a ceramic green chip. The binder in the obtained ceramic green chip is burned out (debide treatment), the organic matter is removed, and then fired. An external electrode such as silver is formed on the obtained fired body, and a multilayer ceramic capacitor is manufactured. obtain.

  In the above manufacturing process, the ceramic paste has been conventionally produced as follows. That is, first, a ball mill is used to disperse and mix inorganic material powder, plasticizer, tackifier, solvent, and the like as a dielectric (primary mixing), and then an organic binder and solvent are dispersed and mixed (secondary mixing). Mixing), and after mixing for a predetermined time, a ceramic paste is obtained by filtration.

In order to make the tackifier act effectively, after adding an organic binder and mixing for a certain period of time, the tackifier is added and mixed again, that is, the tackifier is added last. A method has been considered (see Patent Document 1).
JP 2000-133547 A

  By the way, when the ceramic green sheets are laminated, pressed in the thickness direction, and bonded by pressure, if the adhesion between the green sheets is weak, a tendency of poor adhesion between the green sheets is observed. This adhesion failure is not preferable because it significantly affects the characteristics of the electronic component.

  Such an adhesion failure causes, for example, the occurrence of a short circuit failure in a multilayer ceramic capacitor. In particular, due to the demand for multilayering, it is necessary to reduce the thickness of the dielectric layer per layer using a fine particle dielectric powder and to increase the number of laminated layers. It is. If the adhesion between the sheets is weak, firing causes structural defects such as delamination, voids, and cracks, and defects that cannot be completely removed increase the occurrence rate of pulse breakdown voltage in the measurement process and decrease the yield.

  In order to improve such adhesion failure, it is conceivable to increase the amount of the organic binder and increase the amount of the tackifier. However, even if the organic binder and tackifier are simply increased, there is not much improvement in adhesion. On the other hand, in this case, the amount of organic substances such as an organic binder and a tackifier increases, so that they are hardly burned out, and the remaining organic substances may cause structural defects and the like due to firing.

As a method that can improve adhesion without increasing the amount of organic binder and tackifier, a method of adding a hot melt adhesive to a ceramic paste and treating it at a relatively high temperature and pressure has been proposed (Patent Document 2). reference). However, the use of high temperature and high pressure causes great damage such as a reduction in the yield rate at the time of cutting, even if the adhesiveness itself is improved.
JP-A-5-279108

  The same problem is not limited to the ceramic paste used for the production of multilayer ceramic capacitors, but also when using a ferrite paste, or in the production of other multilayer electronic components such as multilayer inductors, multilayer actuators and multilayer LC filters. .

  As described above, a composition for a multilayer electronic component capable of producing a multilayer electronic component having high reliability and high productivity, which can improve the adhesion between the layers in response to the demand for multilayering and thinning. There has been a demand for a method for producing a paste.

In view of the above circumstances, an object of the present invention is to provide a method for producing a laminated electronic component composition paste that enables the production of a laminated electronic component with high reliability and high productivity.
Another object of the present invention is to provide a method for producing a composition paste for a laminated electronic component that can improve the adhesion between green sheets without increasing the amount of organic matter in the composition.

In order to achieve the above object, a method for producing a laminated electronic component composition paste according to the first aspect of the present invention comprises:
A method for producing a composition paste for a laminated electronic component for producing a composition paste used for laminate formation of a laminated electronic component,
A first mixing step of mixing and dispersing the inorganic material powder and the first tackifier;
A second mixing step of adding an organic binder to the mixture obtained from the first mixing step and mixing and dispersing;
A third mixing step of adding a second tackifier to the mixture obtained from the second mixing step and mixing and dispersing;
Is provided.

According to the above method, it is not necessary to use a commonly used dispersant, and by using a normal amount of a tackifier and effectively using the dispersion effect and the adhesive effect that this has, at the time of producing the composition paste Both dispersibility of the required inorganic material powder and adhesiveness required for the laminate can be realized. For this reason, the amount of the organic substance used as the dispersant can be reduced, and the removal process (heat treatment) of the organic substance can be facilitated. In addition, the yield and reliability of the laminate can be improved.
Further, by adding the tackifier from the first mixing step, the tackifier is sufficiently adsorbed on the surface of the inorganic material powder, and thereby the interlayer adhesion in the laminate is improved. As a result, it is possible to reduce the amount of the organic substance containing the tackifier and the organic binder, and the same effect as described above can be obtained.

  In the above method, in the first mixing step, the input amount of the first tackifier relative to the total input amount of the first tackifier and the second tackifier is 60% or less by weight. It is preferable to introduce the first tackifier so that

  In the above method, the first tackifier and the second tackifier may be composed of the same material. In this case, as the first tackifier, it is preferable to select a first tackifier that not only achieves desired tackiness but also has a dispersion effect during the production of the composition paste.

  In the above method, it is preferable that at least one of the first and second tackifiers is added after being dissolved in a solvent.

  In the above method, the first tackifier is, for example, rosin, rosin ester, polymerized rosin, polymerized rosin ester, rosin derivative, terpene polymer, aromatic modified terpene polymer, terpene-based hydrogenated resin, modified terpene heavy polymer. Any one of a polymer, a terpene phenol copolymer, an α-pinene polymer, a β-pinene polymer, or a combination thereof is configured.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the composition paste for laminated electronic components which enables manufacture of a laminated electronic component with high reliability and high productivity is provided.
Moreover, according to this invention, the manufacturing method of the composition paste for laminated electronic components which can improve the adhesive force between green sheets is provided, without increasing the quantity of the organic substance in a composition.

The manufacturing method of the composition paste for laminated electronic components which concerns on embodiment of this invention is demonstrated in detail below.
In the following, a method for manufacturing a ceramic paste used for manufacturing a multilayer electronic component, for example, a multilayer ceramic capacitor will be described as an example.

  The manufacturing method of the composition paste for multilayer electronic components according to the present embodiment is used as follows in the manufacturing process of the multilayer ceramic capacitor.

  First, as described in detail below, an inorganic material powder as a dielectric, an organic binder such as acrylic or butyral, a plasticizer such as phthalate ester, and a solvent such as ketone, aromatic hydrocarbon, or alcohol From the above, a composition paste is produced by the method for producing a composition paste according to the present embodiment.

  Next, it is applied to a support such as a polyethylene terephthalate (PET) film coated with a release agent such as silicone, and the solvent is dried to form a sheet called a ceramic green sheet.

  Thereafter, a predetermined electrode pattern is formed on the ceramic green sheet by using an electrode paste containing a metal that becomes an internal electrode such as palladium. Thereafter, the printed ceramic green sheet is peeled off from the support. A plurality of ceramic green sheets formed in this way are stacked and pressed in the thickness direction for pressure bonding.

  Next, the bonded ceramic laminate is cut into parts as a predetermined laminated chip body. Then, after burning out organic substances such as the binder of the multilayer chip body and firing, conductive paste is applied and baked on both ends to form a base electrode and to form a predetermined electrolytic plating film Thus, an external electrode is provided to obtain a laminated electronic component.

  Hereinafter, the manufacturing method of the composition paste for laminated electronic components of this embodiment is demonstrated. In the following description, an example of manufacturing a ceramic paste used for manufacturing a multilayer ceramic capacitor will be described.

  In the production of the ceramic paste of the present embodiment, an inorganic material powder serving as a dielectric, an organic binder, a plasticizer, a tackifier, an organic solvent, and other necessary additives are used as composition materials. It is done.

  As the inorganic material powder serving as a dielectric, for example, a fine powder of about 0.2 to 1.5 μm is used. The inorganic material used as the dielectric may be any material that is generally used in the production of multilayer ceramic capacitors. In addition to titanium oxide, oxides such as aluminum, barium, lead, zirconium, silicon, and yttrium are used. Is possible.

  As the organic binder, an acrylic resin having a predetermined molecular weight can be used.

  As the tackifier, rosin-based materials, that is, one or more of rosin, rosin ester, polymerized rosin, polymerized rosin ester, and rosin derivative are used. Besides rosin materials, terpene materials such as terpene polymers, aromatic modified terpene polymers, terpene hydrogenated resins, modified terpene polymers, terpene phenol copolymers, or pinene materials such as An α-pinene polymer, a β-pinene polymer, or the like can be used.

  As will be described later, the tackifier functions not only as a tackifier but also as a dispersant. Therefore, as a tackifier, it is possible to impart sufficient tackiness between layers in a laminated state, and it has good adsorptivity to the surface of inorganic material powder particles that become a dielectric, and has a sufficient repulsive effect in the adsorbed state. If it expresses, it will not be restricted to said thing.

  As the plasticizer, for example, a phthalate ester is used.

  As the solvent, a ketone organic solvent is used.

Among the composition materials, in the present embodiment, first, the total amount of the inorganic material powder and the organic solvent that become the dielectric and a part of the tackifier are dispersed and mixed for a predetermined time (primary mixing).
Here, the addition amount in the primary mixing of the tackifier is desirably 60% by weight or less of the total input amount.
Moreover, since the effect as a dispersing agent cannot be exhibited when the addition amount in the primary mixing of the tackifier is 0% by weight of the total input amount, at least 10% by weight of the total input amount is added.

  Since the tackifier containing rosin or the like has good affinity with ceramic particles, it is favorably adsorbed on the surface of the inorganic material powder particles serving as a dielectric. Due to the repulsion between the tackifiers on the surface due to the adsorption to the particle surface, the dispersion effect of the inorganic material powder particles as the dielectric can be obtained. Thus, the tackifier added in the primary mixing is added as a “dispersant” and functions.

  Next, the whole amount of the organic binder is added and dispersed and mixed for a predetermined time (secondary mixing).

  Finally, the remaining amount of the tackifier (40% by weight or more of the total input amount), the total amount of the plasticizer, and the total amount of the additive are added and dispersed and mixed for a predetermined time (tertiary mixing). At this time, the tackifier is desirably dissolved in the same solvent or another solvent and added in a liquid state.

  In the tertiary mixing, the tackifier is added as a tackifier that imparts tackiness between the stacked green sheets. In addition, the tackifier already added in the primary mixing also naturally contributes to the adhesion between the green sheets. However, since this tackifier is introduced during the primary mixing, the inorganic material becomes a dielectric. A relatively large amount is adsorbed on the surface of the powder particles to achieve higher adhesion.

  The manufacturing process of the composition paste according to the present embodiment is thus completed. The composition paste obtained by dispersing and mixing in three steps as described above is applied on a PET film and dried to obtain a ceramic green sheet, which is used for manufacturing a multilayer ceramic capacitor.

  The above-described method of the present embodiment in which the tackifier is added separately before and after the addition of the organic binder has two characteristic effects that have not been found in the past, namely the dispersion effect and the tack effect that the tackifier has. It is effectively expressed and used.

  According to the above embodiment, in addition to realizing higher inter-sheet adhesion, it is not necessary to use a dispersant that is usually added during primary mixing. In other words, the amount of organic matter added can be reduced accordingly. Usually, as the dispersant, an alkaline dispersant such as ammonium polycarboxylate or an acidic dispersant such as acetic acid is used, but these do not have a tackifying ability comparable to a tackifier such as rosin. Therefore, the tackifier added at the time of primary mixing functions as a dispersant at the time of input, but when considering a laminate produced thereafter, it is a tackifier that contributes to adhesion between sheets. is there.

  Moreover, according to the said embodiment, although adhesiveness improves with the same injection amount of a tackifier, the quantity of the tackifier and organic binder to be used can be reduced by this. Furthermore, if the total amount of organic substances used is reduced, these organic substances can be easily removed (heat treatment, etc.) and the occurrence of defects in the removal process can be reduced, resulting in high product yield and reliability. can get.

Hereinafter, the present invention will be described in more detail with reference to specific examples of the present embodiment.
A ceramic green chip using a ceramic paste manufactured according to the method of the present embodiment was manufactured as follows.

  The composition shown in Table 1 was used as the total input composition when preparing the ceramic paste. That is, 100 parts by weight of a mixed powder of barium titanate and a small number of metal oxides as an inorganic material powder as a dielectric, 5.71 parts by weight of an acrylic resin as an organic binder, and a phthalate ester as a plasticizer In addition to 2.85 parts by weight, 66.71 parts by weight of several organic solvents and 0.31 parts by weight of rosin as a tackifier were used.

A ceramic paste was formed in accordance with the present embodiment using the material having the above composition.
First, as a primary mixture, among the above composition, a part of inorganic material powder, organic solvent and tackifier as dielectrics (30% by weight, 50% by weight, 60% by weight, 70% by weight) Is dispersed and mixed for 5 hours using a ball mill. Then, as a secondary mixing, an organic binder and a solvent are added and dispersed and mixed for 2 hours. Finally, as the third mixing, a solution obtained by dissolving the remaining amount of the tackifier in the solvent, the total amount of the plasticizer, and the additive are added and dispersed and mixed for 13 hours. As described above, the ceramic paste manufactured by the method according to the present embodiment is obtained. Table 2 shows Examples I to IV in which the tackifiers at the time of primary mixing were 70 wt%, 60 wt%, 50 wt%, and 30 wt% of the total input amount.

(Comparative example)
In addition, as a comparative example, first of all, inorganic material powder that becomes a dielectric, plasticizer, additive, dispersant, organic solvent, tackifier, all added at once, mixed and dispersed for 3 hours, An organic binder and an organic solvent were added and mixed and dispersed for 15 hours (Comparative Example I).

In addition, the inorganic material powder as a dielectric, the organic solvent, and the dispersing agent are dispersed and mixed for 5 hours, then the organic binder and the organic solvent are added and dispersed and mixed for 2 hours, and finally the organic solvent and the adhesive are adhered. An imparting agent, a plasticizer and an additive were added and dispersed and mixed for 13 hours (Comparative Example II).
In the comparative example, a nonionic surfactant was used as the dispersant, and the total amount combined with the tackifier was made equal to the total amount of the tackifier in the examples.

  The pastes prepared in the examples and comparative examples as described above were applied to the surface of a PET (polyethylene terephthalate) film by the doctor blade method, electrodes were screen printed, peeled from the PET film with a laminator, laminated, and heated with a press. The ceramic green chip was manufactured by pressure bonding and cutting into a predetermined shape.

  With respect to the produced green chip, the defect rate was examined for adhesion failure and pulse breakdown voltage.

  The adhesion failure is mainly due to the occurrence of non-lamination due to insufficient adhesion between sheets. The non-lamination means that an area that cannot be laminated is generated because the step of the portion without the internal electrode (in the direction parallel to the internal electrode) cannot be eliminated due to the step of the internal electrode. Adhesion failure was determined by examining 500 green chips for the occurrence of non-lamination and determining that no adhesion failure (non-lamination) was detected.

  The pulse breakdown voltage was examined by applying a square wave voltage using a general tester. About the result, 5000 ppm or less was used as a reference value.

  Table 3 shows the results of poor adhesion and pulse pressure resistance tests performed on the examples and comparative examples.

  From the results shown in Table 3, in Examples I to IV by the method according to the present embodiment, when the amount of the tackifier added at the time of the primary mixing is relatively large (70% by weight of the total input amount, Examples In I), although adhesion failure and pulse pressure resistance failure are observed, when the addition amount is relatively small (60% by weight, 50% by weight, 30% by weight of the total input amount), adhesion and pulse pressure resistance are It turns out that it is sufficiently good.

On the contrary, it can be seen that in Comparative Example 1 in which the dispersant and the tackifier are added in the total amount during the primary mixing, adhesion failure and pulse breakdown voltage failure are very large.
In Comparative Example 2 in which a tackifier is not added at the time of primary mixing, a dispersant made of another substance is added, and a tackifier is added at the time of tertiary mixing, although adhesion failure is not seen, The defect is relatively high, and is higher than in Example 1 with the highest breakdown voltage defect in this example.

  From the above results, it is possible to produce green chips with good adhesion between green sheets if the paste is produced with the addition amount of the tackifier at the time of primary mixing being at least 60% by weight or less of the total input amount. I understand.

  The present invention is not limited to the above embodiment, and various modifications and applications are possible.

In the above embodiment, the same tackifier is charged during the primary mixing and the tertiary mixing. However, at the time of each mixing, different types of tackifiers may be added so that the ratio to the total input amount becomes a predetermined ratio.
In this case, a tackifier such as rosin can be used at the time of the primary mixing, and a normal tackifier such as polyvinyl alcohol, polyvinyl acetate, ethylene vinyl acetate copolymer, polyvinyl at the time of the third mixing. Pyrrolidone, polyvinyl acetal, polyvinyl butyral, polyurethane, styrene, butadiene, celluloses, starch, saccharides, paraffin, wax, or a copolymer of these resins may be added.

  Moreover, in the said embodiment, the multilayer ceramic capacitor was demonstrated as an example. However, of course, the present invention is not limited to the above example, and the present invention can also be applied to multilayer inductors, multilayer actuators, multilayer LC filters, and the like, or composite electronic components thereof.

Claims (5)

A method for producing a composition paste for a laminated electronic component for producing a composition paste used for laminate formation of a laminated electronic component,
A first mixing step of mixing and dispersing the inorganic material powder and the first tackifier;
A second mixing step of adding an organic binder to the mixture obtained from the first mixing step and mixing and dispersing;
A third mixing step of adding a second tackifier to the mixture obtained from the second mixing step and mixing and dispersing;
A method for producing a composition paste for laminated electronic components, comprising:   In the first mixing step, the input amount of the first tackifier relative to the total input amount of the first tackifier and the second tackifier is 60% by weight or less. The method for producing a composition paste for a laminated electronic component according to claim 1, wherein the first tackifier is added.   The method for producing a composition paste for a laminated electronic component according to claim 1, wherein the first tackifier and the second tackifier are composed of the same material.   4. The composition paste for laminated electronic components according to claim 1, wherein at least one of the first and second tackifiers is added after being dissolved in a solvent. 5. Production method.   The first tackifier includes rosin, rosin ester, polymerized rosin, polymerized rosin ester, rosin derivative, terpene polymer, aromatic modified terpene polymer, terpene hydrogenated resin, modified terpene polymer, terpene phenol copolymer 5. The multilayer electronic component according to claim 1, comprising any one of a polymer, an α-pinene polymer, a β-pinene polymer, or a combination thereof. Of manufacturing composition paste.