JPH02224311A - Manufacture of laminated ceramic electronic part - Google Patents

Abstract

PURPOSE:To obtain a laminated type ceramic electronic part having almost no electric inert margin part by a method wherein, when an inner electrode and an outer electrode are connected, an insulating layer is formed after a selective electric plating treatment has been provided on the inner electrode layer exposed to a side face. CONSTITUTION:When an inner electrode 2 is connected every other layer to an outer electrode 6, the inner electrode layer 2 is removed every other layer by connecting an electric plating treatment when an insulating layer 13 is formed, and also a bump electrode is formed on the inner electrode which is desired to be connected to the outside electrode. Accordingly, the insulate layer 13 can be formed precisely and accurately even when the interval of the inner electrode becomes very thin as 70 micron or less, and the inner electrode 2 and the outer electrode 14 are connected every other layer without having a short circuit or a continuity failure. As a result, a high density and microminiature laminated ceramic electronic part, having almost no electric inert margin part, can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing ceramic electronic components having a laminated structure, such as a laminated ceramic capacitor, a laminated piezoelectric actuator, a Wt layered varistor, etc. .

[Prior Art] A laminated ceramic electronic component generally has ceramic layers (21) and internal electrode layers (22) alternately laminated as shown in FIG. 8, and has an internal type 8i! 1 (22) has a structure in which every other layer is electrically connected to external electrodes (23). As you can see from Figure 8, is the multilayer ceramic electronic component internal? I! i (22) must be connected to the outer ring [i (23)] every other layer, so a margin part (24
) is provided so that the external electrode (z3) and the internal electrode (2z) are connected every other layer.

In the structure of such a laminated ceramic component, as the component shape becomes smaller, the area of the electrically inactive margin portion (24) in the component increases, and the effective area of the internal electrode (22) increases. It becomes less. Furthermore, since it is extremely difficult to make the margin smaller than a certain level due to the alignment technology during manufacturing, it is difficult to manufacture multilayer ceramic electronic components that have almost no electrically inactive margin (24). Very difficult.

[Problems to be Solved by the Invention] On the other hand, in recent years, with advances in technology for making electronic equipment lighter, thinner, and smaller, and advances in hybrid IC technology, electronic components that are smaller and more dense are required.

Therefore, an object of the present invention is to perform selective electroplating on the internal electrode layer exposed on the side surface when connecting internal electrodes and external electrodes in the process of manufacturing multilayer ceramic electronic components. The present invention provides a method for manufacturing a laminated ceramic electronic component in which layers are formed. In particular, as a manufacturing method for ultra-small laminated ceramic electronic components with an internal electrode spacing of 70 microns or less, even in a laminated sintered body with an internal tri-electrode spacing of 70 microns or less, the internal electrode layer is one layer with the external electrode layer. The effective internal electrodes are extremely large in the stacked structure with an internal electrode spacing of 70 microns or less, and the ultra-small, high-density m-layer electronic part has almost no electrically inactive margin. The purpose is to provide an effective manufacturing method that can be manufactured.

[Means for Solving the Problems] That is, the present invention provides a method for manufacturing a laminated ceramic electronic component in which every other internal electrode layer is connected to an external electrode, in which a ceramic green sheet on which internal electrode layers are printed, A predetermined number of internal electrode layers are stacked so that every other layer is exposed on opposing sides, sintered to obtain a laminated sintered body, and every other layer is exposed on opposing sides of the obtained laminated sintered body. First, one of the internal electrode layers is connected by an external electrode for electroplating, and one of the external electrodes for electroplating is used as an anode, and the other external electrode for electroplating is used as a cathode. By electroplating one side of the body, the internal electrode connected to the cathode is electroplated, and the internal electrode connected to the anode is removed to obtain a groove, and then a groove is formed for the electroplating. By replacing the anode and cathode of the external electrode and applying electrode plating to the other side of the laminated sintered body where there is no external electrode for electroplating, the internal electrode connected to the cathode is electroplated and the anode and The connected internal electrodes are removed to obtain a groove, and then an insulator layer is formed in the obtained groove, and the sintered body is laminated in a direction perpendicular to the side surface having the insulator layer to a predetermined size. Cut into
The present invention relates to a method of manufacturing a multilayer ceramic electronic component, characterized in that internal electrodes on opposing side surfaces having insulators are connected to external electrodes every IM.

The present invention also relates to a method in which an electroplatable metal material is used as the internal electrode material, and an electroplating solution containing the same metal material as the internal electrode material is used as the electroplating solution.

Furthermore, the present invention relates to a method of using silver-palladium with a silver content of 50 mol % or more as the internal electrode material and using a silver electroplating solution as the electroplating solution.

Furthermore, the invention relates to a method using nickel and copper as internal electrode materials and using a nickel electroplating solution and a silver electroplating solution as the electroplating solutions, respectively.

[Function] Hereinafter, a method for manufacturing a top layer type ceramic electronic component of the present invention will be explained with reference to the drawings.

First, internal electrodes are printed on a ceramic green sheet (about 10 to 100 microns thick) that has suitable performance as electronic ceramics. Here, internal xjJii
The layer may be printed by any conventional method, and the thickness of the internal electrode layer is typically on the order of 5 to 15 microns. Further, the material of the internal electrode layer is not particularly limited as long as it is a metal that dissolves in an anodic reaction and precipitates in a cathodic reaction in an electroplating solution during the subsequent electroplating process.

When a silver electroplating solution is used as the electroplating solution, the silver content in the silver-palladium material used for the internal electrodes must be 50 mol% or more. Internal electrodes with a silver content of less than 50 mol % are not preferred because grooves with sufficient insulation dimensions cannot be formed even if electroplating is performed using a silver electroplating solution.

Next, the ceramic green sheet (1) on which the internal electrode layer (2) has been printed is cut into a predetermined appropriate size and heat-pressed to form a single layer of the internal electrode layer (2) as shown in Figure 1. A laminate having a shape exposed on opposite sides at every other interval is produced.

The obtained laminate is degreased and fired, and the four sides of the obtained laminate sintered body are lightly polished so that the internal electrodes are exposed.

Next, as shown in FIG. 2, silver bases 1 to 1 are baked on the opposing sides of the laminated sintered body where every other internal electrode layer (2) is exposed, thereby forming external electrodes for electroplating (3). shall be.

Next, the laminated sintered body provided with the external electrode for electroplating (3) is electroplated.

The laminated sintered body (4) having the shape shown in FIG. 2 is loaded into an electroplating apparatus as shown in FIG. Soak in. Note that it is necessary to apply an insulating coating (10) with an organic value f[, etc. to the external electrode for electroplating that does not require electroplating treatment, its surroundings, and the other internal electrode side in advance (see FIG. 4).

Electroplating is performed by connecting a power source so that one of the external electrodes for electroplating has a positive voltage and the other has a negative voltage. At the internal electrode connected to a positive voltage, an anodic reaction occurs and the internal electrode melts, forming a groove. At the internal electrode connected to a negative voltage, a 112i% reaction occurs and metal precipitates, forming a protrusion. Electrodes are formed. FIG. 5 shows the laminated sintered body after electroplating on one side. Only the inner electrode N (2) connected to the outer electrode for electroplating (3) connected to a positive voltage is removed to obtain a groove (11), which is connected to the outer electrode for electroplating (3) connected to a negative voltage. Metal is deposited on the internal electrode rg(2) to form a protruding electrode (12).

Next, the electroplated side surface is coated with an insulating coating using organic paint, and then the insulation and coating on the opposite side surface is removed and electroplating is applied. First, connect the external electrode for electroplating (3) to which a positive voltage was applied to a negative voltage, connect the external electrode for electroplating (3) to which a negative voltage was applied to a positive voltage, and process in the same manner as above. Then, a protruding electrode and a groove are obtained. Note that the height of the protrusion type i (12) and the depth of the groove part (11) can be set to predetermined dimensions by selecting the electroplating conditions.

In the laminated sintered body that has been electroplated on both sides in this way, every other internal electrode layer (2) is removed to a predetermined depth to form a groove (11). Projecting electrodes are formed on internal electrodes that are not present. Next, an insulating coating is applied to the groove portion (11) so that an insulating material such as epoxy resin is impregnated therein, and the insulating material is cured to obtain an insulator 1 (13).

Next, the side surface with the insulator 11 (13) is polished and the protruding electrode (1) of the internal electrode that is to be connected to the external mold & (14) is polished.
2) Expose. Thereafter, the laminate is cut along the cutting line (A) indicated by a dotted line in FIG. 6 to obtain a laminate of a required size. The external electrode (14) of this laminate has an internal T, a polar layer (2
), the protruding electrodes (12) of every other layer are newly formed on the exposed opposing sides by paste, vapor deposition, etc., and then covered with epoxy resin, etc., to form a multilayer ceramic electronic component as shown in Figure 7. Obtainable.

In the present invention, in the process of manufacturing a multilayer ceramic electronic component, every other layer of internal electrodes (2) is connected to the external i! 1 (6
), when forming the insulator layer (13), remove every other internal electrode layer (2) by electroplating, and also form a protruding electrode on the internal electrode to be connected to the external electrode. This makes it possible to form the insulating layer (13) with high precision and accuracy even when the internal electrode spacing is extremely thin, such as 70 microns or less, and to form the insulator layer (13) with high precision and accuracy. The internal electrodes (2) and external electrodes (14) can be connected every other layer without causing short circuits or poor continuity between the internal electrodes (14).

The internal electrode layer (2) can be removed by mechanical processing, but it is also possible to reduce the size of parts, increase the number of laminated layers,
As 2) becomes thinner, it becomes impractical due to problems in processing accuracy and processing cost. On this point, the electroplating method according to the present invention uses an electroplating solution containing the same metal material as the internal electrode material, so that the electrodes to be removed can be removed selectively and simultaneously, and the protruding electrodes can be placed on the internal electrodes to be connected. Moreover, the internal electrode layer (2
) The number of steps does not depend on the number or thickness of the wafer, so it has high industrial value.

[Example] The method for manufacturing a laminated ceramic electronic component of the present invention will be further explained below with reference to Examples.

E11L First, it is suitable as a material for capacitors (Pb, Ba
) (Mg, Nb, Zr, Ti)Os-based ceramic powder is ground with a sand mill to a particle size of 1 micron or less. After adding a binder, a dispersant, an activator, and an antifoaming agent to this powder and defoaming under vacuum, a green sheet was produced using a doctor blade method.

The thickness of the obtained green sheet was 40 microns. An internal electrode layer (silver-palladium) was printed on this sheet using a screen printing method.

Next, after cutting to a size of 5 x 14 s + m, 30 sheets were stacked, heat-pressed, degreased, and fired at 1100"C to obtain a laminated sintered body. At this time, the internal electrode spacing of the laminated sintered body was 25
The thickness of the internal electrode was 5 microns. After lightly polishing the west side of this laminated sintered body to expose the internal electrode layer, a silver paste was baked on to form an external electrode for electroplating as shown in FIG. The internal electrode layer side of this laminated sintered body to be electroplated was immersed in a silver electroplating solution to perform electroplating. The electroplating process was performed by immersing it in a silver electroplating solution.

The silver electroplating solution is High Purity Chemical Silver Plating Solution S-, 7.
Electroplating was performed using 00E C for 2 minutes at a liquid temperature of 2V. As a result, the internal electrode layer with a thickness of 5 microns could be removed to a depth of 30 microns in 2 minutes, and the height of the protruding electrodes was 10 microns. After performing insulation treatment on this side surface, electroplating treatment was performed on the opposite side in the same manner.

Next, an insulating layer is formed by impregnating the groove with epoxy resin after the internal electrode layer has been removed, and is lightly polished. After cutting as shown in Figure 6, a new external electrode is formed, and the epoxy resin is applied to the groove. A multilayer ceramic capacitor with a length of 2mm x 3mm and a height of 1mm was obtained.

When the electrical characteristics of the multilayer capacitor thus manufactured were investigated, the results shown in Table 1 were obtained. Internal electrode materials with a silver content of 50 mol% or more have an insulation resistance of 10 MΩ or more, are sufficiently insulated, and function as a capacitor no different from capacitors made by conventional methods. I found out that nothing has changed. On the other hand, it has been found that those with a silver content of less than 50 mol % do not have sufficient insulation.

No. 1-1 80/20 0.25 2 100M or more 7
0/30 0.25 2 100M or more 60
/40 0.25 2 50M or more 5015
0 0.27 3 108 or more 40/60
-1--Short circuit 30/70--1 -Short introduction First, P is suitable as a material for piezoelectric actuators.
A composite helobskite compound is added as a third component to b(Z r, T i ) 03, and the strontium-modified ceramic powder is ground in a sand mill to a particle size of 1 micron or less. After adding a binder, a dispersant, an activator, and an antifoaming agent to this powder and defoaming it under vacuum, a green sheet was produced using a doctor blade method.

The thickness of the obtained green sheet was 55 microns. On this sheet, an internal battery 8i was printed using a screen printing method.
After printing iNi (silver-palladium, Ag/Pd-70/30) and cutting it into a size of 7 x 14 mm, 70
The sheets were laminated, heat-pressed, degreased, and fired at 1140°C to obtain a laminated sintered body. At this time, the interval between the internal electrodes of the N-sized sintered body was 35 microns, and the thickness of the internal electrodes was 5 microns.

After lightly polishing the four sides of this sintered body to expose the internal electrode layer, a silver paste was baked on to form external electrodes for electroplating as shown in FIG. This m-layer sintered body was placed in an electroplating device and electroplated for 5 minutes. As a result, in 5 minutes, the polar layer covered the inside of 5 microns by 2 times.
The inner electrode layer could be removed to a depth of 5 microns, and a protruding electrode was deposited at a height of 10 microns.The internal electrode layer was removed by the same operation on the opposite side to form a protruding electrode.

Next, the groove after removing the internal electrode layer is impregnated with epoxy resin to form a hardened insulator layer, lightly polished, and cut as shown in Figure 6 to form a new external electrode. A laminated piezoelectric actuator element measuring 3 mm in length, 3 mm in width, and 51 mm in height was obtained by covering with epoxy resin.

When we examined the insulation resistance of the piezoelectric actuator element produced in this way, it was found to be over 100MΩ, indicating that it was sufficiently insulated.Also, when we measured the displacement, it was found that it was displaced by 2 microns at 24V, which was sufficient displacement. .

[Effects of the Invention] As explained above, according to the present invention, even in a laminated sintered body having an internal electrode interval of 70 microns or less, every other internal electrode layer can be connected to an external electrode layer, and the internal electrode In a laminate with a spacing of 70 microns or less, the area of effective internal electrodes is extremely large, and an ultra-small, high-density laminate ceramic electronic component can be manufactured with almost no electrically inactive margin portions.

Furthermore, it is clear that the present invention can be carried out by fabricating an mM sintered body using electroplatable copper and nickel metals as internal electrode materials, and using copper and nickel electroplating solutions, respectively. .

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a laminate produced by laminating ceramic green sheets and performing vacuum heat compression bonding;
The figure shows the laminated sintered body after forming external electrodes for electroplating, FIG. 3 shows the electroplating apparatus, and FIG. 4 shows the fi! FIG. 5 is a diagram showing a cross section of the laminated sintered body after electroplating, and FIG. 6 is a cross-sectional view of the laminated sintered body after electroplating. FIG. 7 is a diagram showing a laminated sintered body after forming a new external electrode, and FIG. 8 is a diagram showing a conventional laminated ceramic electronic component. In the figure, 1... Ceramic layer, 2... Internal electrode layer, 3
...External electrode for electroplating, 4...Laminated sintered body, 5
... Power source for electroplating, 6. Ammeter, 7. Electroplating solution, 8. Electroplating tank, 9. Air agitator, 10. Insulating coating with organic paint, etc., 11. ...Groove, 12...Protruding electrode, 13...Insulator, 14...
- External electrode, 21... Ceramic layer, 22... Internal electrode layer, 23... External electrode, 24... Margin portion, A... Cutting line. Figure 2 Figure 6

Claims (5)

[Claims] 1. In a method for manufacturing a laminated ceramic electronic component in which every other internal electrode layer is connected to an external electrode, a ceramic green sheet on which internal electrode layers are printed is exposed on a side surface where every other internal electrode layer faces each other. A predetermined number of sheets are laminated and sintered to obtain a laminated sintered body, and each internal electrode layer exposed every other layer on the opposing sides of the obtained laminated sintered body is connected by an external electrode for electroplating. First, one of the external electrodes for electroplating is used as an anode and the other external electrode for electroplating is used as a cathode, and by applying electroplating to one open surface of the laminated sintered body where no external electrode for electroplating is present. electroplating the internal electrode connected to the cathode and removing the internal electrode connected to the anode to obtain a groove,
Next, the anode and cathode of the external electrode for electroplating are replaced and electrode plating is applied to the other side of the laminated sintered body where the external electrode for electroplating is absent, so that the internal electrode connected to the cathode is electrically plated. A groove is obtained by plating and removing the internal electrode connected to the anode. Next, an insulator layer is formed in the obtained groove, and the layer is laminated and fired in a direction perpendicular to the side surface having the insulator layer. 1. A method for producing a multilayer ceramic electronic component, which comprises cutting a compact into predetermined dimensions, and connecting internal electrodes on opposite sides having insulating layers to external electrodes every other layer. 2. 2. The method according to claim 1, wherein an electroplatable metal material is used as the material of the internal electrode, and an electroplating solution containing the same metal material as the internal electrode material is used as the electroplating solution. 3. 3. The method according to claim 2, wherein silver-palladium having a silver content of 50 mol % or more is used as the material for the internal electrodes, and a silver electroplating solution is used as the electroplating solution. 4. Using nickel and copper as internal electrode materials,
3. A method as claimed in claim 2, characterized in that the electroplating solutions are a nickel electroplating solution and a copper electroplating solution, respectively. 5. 5. The method according to claim 1, wherein the multilayer ceramic electronic component is a multilayer ceramic capacitor, a multilayer piezoelectric actuator element, or a multilayer varistor.