JP4450176B2 - Dielectric paste for level difference elimination constituting laminated electronic parts and margins - Google Patents

Description

  The present invention relates to a dielectric paste for level difference elimination that constitutes a laminated electronic component and a blank portion.

  In general, a multilayer ceramic electronic component such as a multilayer ceramic capacitor is manufactured by the following process. First, a green sheet is produced by applying a dielectric paste made of ceramic or the like on the upper surface of a PET (polyethylene terephthalate) film. Subsequently, a plurality of internal electrodes made of a conductive paste are printed on the upper surface of the dielectric paste by a screen printing method. Then, a plurality of green sheets are laminated so that the internal electrodes and the dielectric paste are alternately overlapped.

  Next, after the laminated body thus formed is pressed, it is cut into a size corresponding to the electronic component unit to obtain a laminated chip body. Subsequently, after firing under predetermined conditions, external electrodes are formed on both end portions of the multilayer chip body to obtain a multilayer ceramic electronic component (see Patent Document 1).

  However, when the laminated structure exceeds 100 layers, a step due to the thickness of the internal electrode cannot be ignored. In other words, in the finished product, a step due to the presence / absence of the internal electrode occurs between the stacked region of the blank area where the internal electrode is not printed and the stacked region including the internal electrode. Such a level difference induces cracks and delamination during firing, causing deterioration of product characteristics and a decrease in yield.

  In addition, one surface of the laminated structure is deformed into a curved shape, which causes a problem that an adsorption error occurs in the mounter during mounting on the substrate, and a tombstone phenomenon occurs during soldering.

Furthermore, it is known that the above step is eliminated by a method of printing a dielectric paste around the internal electrodes (margin printing method). In this case as well, a laminated region consisting only of a dielectric including a margin printing portion and Further, since the firing shrinkage ratio differs between the laminated region including the internal electrodes, there is still a possibility that cracks or delamination may occur.
Japanese Unexamined Patent Publication No. 7-37750

  An object of the present invention is to provide a highly reliable multilayer ceramic electronic component capable of preventing the occurrence of cracks, delamination, and the like in a firing process, and a step-dissolving dielectric paste constituting a blank portion.

  In order to solve the above-described problems, the present invention provides a laminated electronic component configured by alternately laminating a plurality of insulating layers and a plurality of electrode layers, each of the electrode layers including an internal electrode portion and A blank portion disposed on a side, and the blank portion includes blank conductive particles of the same material as the electrode conductive particles included in the internal electrode portion.

  According to this, since the conductive material for the blank of the same material as the conductive particle for an electrode contained in the internal electrode portion is also included in the blank portion, cracks and delamination are prevented from occurring during firing. be able to.

  The conductive particles for blank have an average particle size less than twice the average particle size of the conductive particles for electrode, and 0.1 to 100 parts by weight of the inorganic material constituting the blank portion. 2.0 parts by weight is added, or the average particle diameter is equal to or less than the average particle diameter of the electrode conductive particles, and 0 parts by weight with respect to 100 parts by weight of the inorganic material constituting the blank part. .1 to 3.0 parts by weight may be added. The average particle size is obtained by measuring 20 particle sizes randomly from the SEM image of the crystal particles and averaging them.

  According to this, while adding conductive particles to the blank space to prevent cracks and delamination, by selecting the appropriate particle size and amount of conductive particles, unintentional short-circuiting can occur. Can also be prevented.

  Ni particles can be used as the conductive particles for electrodes and the conductive particles for blanks.

  Another aspect of the present invention for solving the problem is a step eliminating dielectric paste that forms a blank portion on the side of the internal electrode portion of the multilayer electronic component, and the step eliminating dielectric paste includes the internal electrode. The conductive particles for blanks of the same material as the conductive particles for electrodes contained in the part are included.

  According to this, it is possible to prevent the occurrence of cracks and delamination during firing by forming the blank portion using the dielectric paste for level difference elimination.

  The conductive particles for blank have an average particle size less than twice the average particle size of the conductive particles for electrode, and 0.1 to 100 parts by weight of the inorganic material constituting the blank portion. 2.0 parts by weight is added, or the average particle diameter is equal to or less than the average particle diameter of the electrode conductive particles, and 0 parts by weight with respect to 100 parts by weight of the inorganic material constituting the blank part. 0.1 to 3.0 parts by weight should be added.

  According to this, while adding conductive particles to the blank space to prevent cracks and delamination, by selecting the particle size and amount of the conductive particles appropriately, unintentional short-circuiting occurs. Can also be prevented.

  Other features of the present invention and the operational effects thereof will be described in more detail by way of examples with reference to the accompanying drawings.

  Hereinafter, a multilayer electronic component according to the present invention will be described with reference to the accompanying drawings as an embodiment in which the multilayer electronic component is applied to a multilayer ceramic capacitor. In the drawings, the same reference numerals indicate the same or corresponding parts.

  FIG. 1 is a cross-sectional view showing an example of a multilayer ceramic capacitor according to Embodiment 1 of the present invention. The illustrated multilayer ceramic capacitor 1 has a plurality of internal electrode portions 5 and 7 embedded in a dielectric substrate 3 in layers. Two adjacent internal electrode portions 5 and 7 face each other through a layer made of a dielectric. In the present embodiment, the internal electrode portions 5 and 7 are mainly composed of Ni or the like. The number of layers of the internal electrode portions 5 and 7 varies depending on the required capacitance, and is several tens to several hundreds.

  The internal electrode portion 5 is electrically connected to the external electrode portion 9 among the pair of external electrode portions 9 and 11 provided on the opposite side surfaces of the dielectric substrate 3, and the internal electrode portion 7 is electrically connected to the external electrode portion 11. It is allowed.

  FIG. 2 shows a laminated structure in which portions including three layers of internal electrode portions 5 and 7 are schematically extracted from the dielectric substrate 3 of FIG. In the dielectric substrate 3, a plurality of dielectric layers as insulating layers and a plurality of electrode layers are alternately stacked.

  Specifically, as shown in FIG. 2, an electrode layer 23 is formed on the upper surface of one dielectric layer 21 by printing. Another dielectric layer 25 is laminated on the upper surface of the electrode layer 23. Another electrode layer 27 is formed on the upper surface of the dielectric layer 25 by printing. On the upper surface of the electrode layer 27, another dielectric layer 29 is laminated. On the upper surface of the dielectric layer 29, another electrode layer 31 is formed by printing.

  The dielectric layers 21, 25, and 29 are each formed by firing a dielectric paste. In the present embodiment, the compounding ratio of the components constituting the dielectric paste is 100 parts by weight for the dielectric material (inorganic material), 28 parts by weight for terpineol, 14 parts by weight for toluene, and 0.2% by weight for the dispersant. Part and lacquer are 36.5 parts by weight.

  The electrode layers 23, 27, 31 have internal electrode portions 5, 7 and blank portions 33, 35 arranged on the sides thereof. Each of the internal electrode portions 5 and 7 is formed by printing and baking a conductor paste. In the present embodiment, the compounding ratio of the components constituting the conductor paste is 44.6% by weight of Ni, 52% by weight of terpineol, 3% by weight of ethyl cellulose, and 0.4% by weight of benzotriazole. . In addition, Ni contained in the conductive paste as the conductive particles for electrodes has an average particle size of 0.3 μm.

  On the other hand, each of the blank portions 33 and 35 is formed by printing on the blank portion with a dielectric paste for level difference elimination and baking. The level difference eliminating dielectric paste includes Ni, which is the same material as the electrode conductive particles contained in the conductor paste, as blank conductive particles. In this embodiment, the compounding ratio of the components constituting the level difference eliminating dielectric paste is 100 parts by weight for the dielectric material (inorganic material), 111 parts by weight for terpineol, 0.2 part by weight for the dispersant, and ethyl cellulose. 9 parts by weight and further 0.1 to 2.0 parts by weight of Ni. That is, the step eliminating dielectric paste is obtained by adding conductive particles of the same material as the electrode conductive particles contained in the conductor paste to the dielectric paste. Moreover, Ni contained in the dielectric paste for level | step difference elimination has an average particle diameter of less than twice (namely, less than 0.6 micrometer) of Ni contained in a conductor paste.

Next, a manufacturing process of the multilayer ceramic capacitor 1 having the above configuration will be described with reference to FIG. First, a dielectric paste 43 using barium titanate (BaTiO ₃ ) as a main component of an inorganic material is applied to the upper surface of a flexible PET film (support) 41. As a result, a so-called green sheet 45 in which the dielectric paste 43 is provided on the upper surface of the PET film 41 is obtained. The conductor paste 43 was applied using a doctor blade or an extrusion head so that a layer thickness of 2.5 μm was obtained by drying after application.

  Subsequently, after the green sheet 45 is dried, the conductor paste 47 is disposed on the upper surface of the sheet. The conductive paste 47 is formed by screen printing or gravure printing so that the layer thickness after drying is 1.2 μm.

  When the conductive paste 47 is disposed, a stepped portion 49 due to the thickness of the conductive paste 47 itself is generated on the sides thereof. Accordingly, margin printing is performed to fill the stepped portions 49 with the step-dissolving dielectric paste 51. The level difference eliminating dielectric paste 51 is printed by a screen printing method, and a screen plate making 53 having a printing pattern surface excluding the area corresponding to the printing pattern of the conductive paste 47 is used. The level difference eliminating dielectric paste 51 is printed by a thickness corresponding to 50 to 150% of the conductive paste 47. Further, the step eliminating dielectric paste 51 is fired to finally form the margin portions 33 and 35 in the electrode layers 23, 27 and 31.

  In this way, 200 sheets of the sheet in which the conductor paste 47 and the step eliminating dielectric paste 51 are arranged on the dielectric paste 43 are laminated in this embodiment, and the uppermost and lowermost parts are laminated as necessary. A dielectric sheet serving as a protective layer is applied to obtain a laminated structure.

  Next, after pressing the laminated structure, the laminated structure is cut to a size of a component unit (length of 1.6 mm, width, and height of 0.8 mm after firing) to obtain a laminated chip body.

Further, a binder removal step of burning out an organic binder or the like from the multilayer chip body is performed. As the conditions, the binder removal treatment was performed in a mixed gas atmosphere of N ₂ gas and H ₂ gas at a holding temperature of 600 ° C. and a holding time of 2 hours.

Next, a baking process and a heat treatment process at 1000 to 1400 ° C. are performed. The conditions were a holding temperature of 1300 ° C. and a holding time of 2 hours, and firing was performed in a mixed gas atmosphere of N ₂ gas and H ₂ gas. Moreover, as conditions in the heat treatment step, a holding temperature: 1100 ° C., a holding time: 3 hours, and N ₂ gas atmosphere were performed.

  Finally, the external electrode portions 9 and 11 made of Cu or the like are baked on the opposing side surfaces of the multilayer chip body to obtain the multilayer ceramic capacitor 1. Ni electroplating or Sn electroplating may be formed on the Cu baking electrode.

  In the multilayer ceramic capacitor 1 according to the present embodiment described above, the marginal parts 33 and 35 arranged on the sides of the internal electrode parts 5 and 7 are used for the electrodes included in the internal electrode parts 5 and 7. Since the blank conductive particles Ni, which is the same material as the conductive particles Ni, are included, cracks and delamination can be prevented from occurring during firing. Further, while the conductive particles Ni are added to the blank portions 33 and 35, it is possible to prevent an unintended short circuit from occurring by appropriately selecting the particle size and the amount of the particles Ni. .

  Next, a multilayer ceramic capacitor according to the second embodiment of the present invention will be described. In the second embodiment, the structure and manufacturing mode of the multilayer ceramic capacitor are the same as those of the first embodiment. In the second embodiment, the blending ratio of the components of the step eliminating dielectric paste constituting the blank portions 33 and 35 is different from that of the first embodiment. That is, the blending ratio is 100 parts by weight for dielectric material (inorganic material), 111 parts by weight for terpineol, 0.2 part by weight for dispersant, 9 parts by weight for ethyl cellulose, and 0.1 to 3.0 for Ni. It is part by weight. Moreover, Ni contained in the dielectric paste for level difference elimination has an average particle size equal to or less than that of Ni contained in the conductor paste (that is, 0.3 μm or less).

  Also in this embodiment, by adding margin conductive particles Ni, which is the same material as the conductive particles Ni of the internal electrode portions 5 and 7, to the margin portions 33 and 35, as in the first embodiment. It is possible to prevent cracks and delamination from occurring during firing. Moreover, it is possible to prevent an unintended short circuit from occurring by appropriately selecting the particle size and the addition amount of the conductive particles Ni in the blank portions 33 and 35.

  Next, the relationship between the particle size and added amount of the conductive particles for blank and the occurrence of defects such as cracks and shorts will be described based on the results of experiments conducted by the present applicant. The average particle diameter of the electrode conductive particles Ni was 0.3 μm, and the average particle diameter of the blank conductive particles Ni was 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, and 0.6 μm. Moreover, the addition amount of the conductive particles for blanks was selected in the range of 0.1 to 4.0 parts by weight with respect to 100 parts by weight of the inorganic material of the step eliminating dielectric paste 51.

About 1000 multilayer ceramic capacitors were prepared by laminating sheets with a combination of the size and amount of conductive particles for blanks, and 100 were randomly extracted from the rods to investigate the occurrence of cracks and shorts. . The appearance of the crack was observed with a magnifier of about 10 times, and the short was confirmed with an insulation resistance meter (DC 50 V). as a result,
Results as shown in Table 1 were obtained. Note that the process conditions of the binder removal process, the firing process, and the heat treatment process in the production of the multilayer ceramic capacitor are the same as the conditions described in the description of the first embodiment.

表１の結果から分かるように、余白用導電性粒子Ｎｉの粒径が内部電極部に含まれている電極用導電性粒子Ｎｉの平均粒径の２倍（０．６μｍ）未満の場合には、余白用導電性粒子Ｎｉを、余白部（段差解消用誘電体ペースト）を構成する無機材料１００重量部に対して０．１〜２．０重量部添加しても、クラック不良及びショート不良の何れも発生しなかった。

As can be seen from the results in Table 1, when the particle size of the conductive particles Ni for blanks is less than twice the average particle size (0.6 μm) of the conductive particles Ni for electrodes contained in the internal electrode part, Even if 0.1 to 2.0 parts by weight of the conductive particles Ni for margin are added to 100 parts by weight of the inorganic material constituting the margin (dielectric paste for level difference elimination), crack failure and short circuit failure None occurred.

  Further, when the average particle size of the conductive particles Ni for blanks is equal to or less than the average particle size (0.3 μm) of the conductive particles Ni for electrodes included in the internal electrode portion, the conductive particles Ni for blanks When 0.1 to 3.0 parts by weight was added to 100 parts by weight of the inorganic material constituting the blank part (dielectric paste for level difference elimination), neither crack failure nor short-circuit failure occurred.

  Although the contents of the present invention have been specifically described with reference to the preferred embodiments, various modifications can be made by those skilled in the art based on the basic technical idea and teachings of the present invention. It is self-explanatory. For example, the material of the conductive particles for blanks is not limited to Ni, and when Cu is used for the conductive particles for electrodes, the same Cu can be used as the conductive particles for blanks. Further, the present invention is not limited to the multilayer ceramic capacitor, but can be applied to other multilayer electronic components.

It is sectional drawing which shows an example of the multilayer ceramic capacitor which concerns on embodiment of this invention. It is a figure which shows the laminated structure which took out typically the part containing the internal electrode part of three layers in the multilayer ceramic capacitor of FIG. It is a figure which shows the process of forming a blank part by the screen printing method in the multilayer ceramic capacitor of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Multilayer ceramic capacitor 5, 7 Internal electrode part 9, 11 External electrode part 21, 25, 29 Dielectric layer (insulating layer)
23, 27, 31 Electrode layer 33, 35 Margin

Claims (5)

A laminated electronic component configured by alternately laminating a plurality of insulating layers and a plurality of electrode layers,
Each of the electrode layers has an internal electrode portion and a margin portion arranged on the side thereof,
The blank portion includes conductive particles for blanks of the same material as the conductive particles for electrodes contained in the internal electrode portion ,
The conductive particles for blank have an average particle size less than twice the average particle size of the conductive particles for electrode, and 0.1 to 100 parts by weight of the inorganic material constituting the blank portion. 2.0 parts by weight are added,
Laminated electronic components. A laminated electronic component configured by alternately laminating a plurality of insulating layers and a plurality of electrode layers,
Each of the electrode layers has an internal electrode portion and a margin portion arranged on the side thereof,
The blank portion includes conductive particles for blanks of the same material as the conductive particles for electrodes contained in the internal electrode portion,
The conductive particles for blank have an average particle size equal to or less than the average particle size of the conductive particles for electrode, and 0.1 to 3 parts by weight with respect to 100 parts by weight of the inorganic material constituting the blank portion. 0.0 part by weight is added,
Laminated electronic components. The laminated electronic component according to claim 1 or 2,
The electrode conductive particles and blank conductive particles are Ni particles.
Laminated electronic components. A dielectric paste for level difference elimination that forms a margin part on the side of the internal electrode part of the laminated electronic component,
It contains conductive particles for blanks of the same material as the conductive particles for electrodes contained in the internal electrode part,
The conductive particles for blank have an average particle size less than twice the average particle size of the conductive particles for electrode, and 0.1 to 100 parts by weight of the inorganic material constituting the blank portion. 2.0 parts by weight are added,
Dielectric paste for level difference elimination. A dielectric paste for level difference elimination that forms a margin part on the side of the internal electrode part of the laminated electronic component,
It contains conductive particles for blanks of the same material as the conductive particles for electrodes contained in the internal electrode part,
The conductive particles for blank have an average particle size equal to or less than the average particle size of the conductive particles for electrode, and 0.1 to 3 parts by weight with respect to 100 parts by weight of the inorganic material constituting the blank portion. 0.0 part by weight is added,
Dielectric paste for level difference elimination.

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