KR100900636B1 - Manufacturing method of non-shirinkage ceramic substrate - Google Patents

Abstract

Disclosed is a method of manufacturing a non-contraction ceramic substrate. In the method of manufacturing a non-shrinkable ceramic substrate, forming a plurality of ceramic green sheets including a via electrode portion, forming a ceramic laminate by stacking a plurality of ceramic green sheets, and providing a restraint layer having a filling portion And laminating the filling portion of the constraint layer to be bonded to the via electrode portion of the ceramic laminate, and firing at a firing temperature of the ceramic laminate. Accordingly, it is possible to prevent the settling region from occurring in the via electrode part during the firing process by the filling part of the constraint layer.

Ceramic Substrate, Non-Shrinkage, Restraint Layer, Charge Section, Via Electrode Section

Description

Manufacturing method of non-shrinkable ceramic substrate {Manufacturing method of non-shirinkage ceramic substrate}

The present invention relates to a method for manufacturing a non-shrinkable ceramic substrate, and more particularly, to a method for manufacturing a non-shrinkable ceramic substrate using a restraint layer including a filling part.

Recently, in the electronic component area, as the miniaturization trend is gradually strengthened and continued, small modules and substrates have been developed through precision, fine patterning, and thinning of electronic components. However, when a commonly used printed circuit board (PCB) is used in a miniaturized electronic component, there are disadvantages such as miniaturization in size, signal loss in a high frequency region, and reliability deterioration at high temperature and high humidity.

In order to overcome this disadvantage, a substrate using ceramics, rather than a PCB substrate, is used. The main component of the ceramic substrate is a ceramic composition containing a large amount of glass (glass) capable of low-temperature co-firing.

Low temperature co-fired ceramic (multi-layer ceramic) substrates have a variety of methods for manufacturing, depending on whether the ceramic substrate shrinks during firing can be classified into shrinkage method and non-shrinkage method. Specifically, a shrinkage method is a method of manufacturing the ceramic substrate by shrinkage during firing. However, in the shrinkage method, since the degree of shrinkage of the ceramic substrate is not generated uniformly as a whole, dimensional deformation occurs in the plane direction of the substrate. Such a surface shrinkage of the ceramic substrate causes deformation of the printed circuit pattern included in the substrate, resulting in problems such as deterioration in precision of the pattern position and disconnection of the pattern. Therefore, in order to solve the problems caused by the shrinkage method, a shrinkage method has been proposed to prevent the shrinkage of the ceramic substrate in the plane direction during firing.

The non-shrinkage method is a method of forming a restriction layer on both surfaces of a ceramic substrate and baking it. In this case, the constraint layer may be made of a material that is easy to control shrinkage without shrinking at the temperature at which the ceramic substrate is fired. By the constraint layer, the shrinkage of the ceramic substrate in the plane direction does not occur during firing, and thus the shrinkage layer can be contracted only in the thickness direction.

1A to 1C are vertical cross-sectional views illustrating a method of manufacturing a non-condensation ceramic substrate according to the prior art. Referring to FIG. 1A, a ceramic laminate 1 is formed by manufacturing and stacking a plurality of ceramic green sheets 1a, 1b, 1c, and 1d. In this case, the via electrode part 3 and the internal electrode 4 may be formed in each ceramic green sheet to implement the internal circuit pattern. Specifically, the via electrode part 3 may be formed by punching a portion of the ceramic green sheet to form the via hole 2 and then filling the conductive paste into the via hole 2. In this case, the via electrode portion 3 is used as a surface electrode. In addition, the conductive paste may be screen printed on the via electrode portion 3 of the ceramic green sheet to form the internal electrode 4.

Thereafter, as shown in FIG. 1B, the restraining layers 5a and 5b are laminated on the upper and lower surfaces of the ceramic laminate 1 to suppress the shrinkage in the x and y directions of the ceramic laminate 1. do. And the ceramic laminated body 1 is baked at about 600-1000 degreeC temperature.

As a result of the firing, as shown in Fig. 1C, the ceramic laminate 1 is sintered and shrunk. Accordingly, the ceramic laminate 1 contracts about 35 to 50% in the z direction.

When the firing process is completed, the external electrode 6 is formed by screen printing a conductor paste on the via electrode portions 3 located on the upper and lower surfaces of the ceramic laminate 1. According to such a method, the non-contraction ceramic substrate 10 can be manufactured.

On the other hand, during the firing process shown in FIG. 1C, shrinkage occurs only in the z direction of the ceramic laminate 1, so that the density of the conductor paste constituting the via electrode portion 3 is lowered to partially settle the region. do. In particular, the generation of the settling region is more prominent in the via electrode portion 3 formed in the ceramic green sheet in the uppermost layer and the lower layer region as compared with the ceramic green sheet in the intermediate region bonded to the internal electrode 4.

2A and 2B are SEM photographs of the via electrode portion 3 according to various embodiments of the prior art. Referring to FIG. 2A, a circular via hole 2 is formed in an upper surface of the ceramic laminate 1, that is, the ceramic green sheet 1d, and the via electrode part 3 is formed in the via hole 2. It is. In this case, it can be seen that due to the firing process shown in FIG.

In addition, referring to the ceramic green sheet 1d illustrated in FIG. 2B, the via electrode part 3 is formed in the rectangular via hole 2, and the settling region is formed in the via electrode part 3. As such, since the settling region is formed in the via electrode part 3 used as the surface electrode, when the external electrode is formed or surface-mounted, defects due to electrical connection cause a decrease in product reliability.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to stack vias during firing by depositing a constraint layer including a charging unit at positions corresponding to via electrode portions formed on upper and lower surfaces of the ceramic laminate. The present invention provides a method of manufacturing a non-condensation ceramic substrate for preventing generation of a settling region in an electrode portion.

According to an aspect of the present invention, there is provided a method of manufacturing a non-shrinkable ceramic substrate, the method comprising: forming a plurality of ceramic green sheets including a via electrode part, stacking the plurality of ceramic green sheets, and forming a ceramic Forming a laminate, preparing a constraint layer having a filling portion, laminating the filling portion of the constraint layer to be bonded to a via electrode of the ceramic laminate, and firing at a firing temperature of the ceramic laminate Steps.

In this case, the preparing of the constraint layer on which the filling part is formed may be performed by applying a conductive paste to a position corresponding to the via electrode part formed on the upper and lower surfaces of the ceramic laminate of one surface of the constraint layer. It includes.

On the other hand, the filling unit is preferably formed of the same conductor paste as the via electrode portion formed on the upper and lower surfaces of the ceramic laminate.

In addition, the charging unit is preferably formed of a conductor paste corresponding to 30% of the total amount of the conductor paste constituting the via electrode portion formed on the upper and lower surfaces of the ceramic laminate.

The method of manufacturing the non-shrinkable ceramic substrate may include removing the restraining layer when the ceramic laminate is completely baked, and forming external electrodes on the via electrode portions formed on the top and bottom surfaces of the ceramic laminate. It may further comprise the step.

In this case, removing the constraint layer may include polishing the via electrode portions of the upper and lower surfaces of the ceramic laminate to be planarized.

According to the present invention, the via electrode portions may be densified during firing by laminating and constraining the constraint layer having the filling portions formed at positions corresponding to the via electrode portions formed on the upper and lower surfaces of the ceramic laminate. Accordingly, it is possible to prevent the settling region from being generated in the via electrode part in the firing process, thereby forming an external electrode in the ceramic laminate or providing good electrical connection when the surface is mounted. As a result, the reliability of the non-contraction ceramic substrate can be improved.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

3A to 3D are vertical cross-sectional views illustrating a method of manufacturing a non-contraction ceramic substrate according to an embodiment of the present invention.

Referring to FIG. 3A, first, a plurality of ceramic green sheets 11a, 11b, 11c, and 11d are formed, and then laminated to manufacture a ceramic laminate 11. Specifically, an organic binder, a dispersant, and a mixed solvent are added to the glass-ceramic powder and then dispersed using a ball mill. The slurry thus obtained is filtered and degassed, and a ceramic green sheet having a predetermined thickness is formed by using a doctor blade method. In addition, in the manufacture of each ceramic green sheet, the via electrode 12 is formed by filling the conductor paste in the via hole 12 by forming the via hole 12. In addition, a conductive paste is applied on each ceramic green sheet to form the internal electrode 14. In this case, the via electrode portions 13 formed in the lowermost ceramic green sheet 11a and the uppermost ceramic green sheet 11d of the ceramic laminate 11 in FIG. 3A are used as surface electrodes. The surface electrode may be a portion for electrical connection during external electrode formation and surface mounting.

Thereafter, as shown in FIG. 3B, restraint layers 15a and 15b for suppressing the z-direction shrinkage of the ceramic laminate 11 are manufactured. The upper and lower restraint layers 15a and 15b may not be sintered at the firing temperature of the ceramic laminate 11 and at a temperature of about 600 ° C. to 1000 ° C., and may be manufactured using a ceramic material that facilitates shrinkage control. For example, a slurry is prepared by adding an organic binder, a dispersant, a mixed solvent, and the like to alumina (Al ₂ O ₃ ) powder. And after apply | coating a slurry using a doctor blade method, constraint layers 15a and 15b can be manufactured.

Then, by applying and drying the conductor paste on the upper and lower restraint layers 15a and 15b, the filling portions 16a, 16b, 16c, and 16d are formed. In this case, the charging portions 16a, 16b, 16c, and 16d may be formed at positions corresponding to the via electrode portions 13 of the upper and lower surfaces of the ceramic laminate 11 of the constraint layers 15a and 15b. . In addition, the conductive paste constituting the charging parts 16a, 16b, 16c, and 16d may be made of the same material as the via electrode part 13 of the ceramic green sheets 11a, 11b, 11c, and 11d. The conductor pastes constituting the via electrode portion 13 and the charging portions 16a, 16b, 16c, and 16d may be Ag, Ni, Pb, W, Sn, or the like.

In addition, the conductive paste constituting the charging portions 16a, 16b, 16c, and 16d may be coated with an amount corresponding to about 30% of the total amount of the conductive paste constituting the via electrode portion 3.

Thereafter, FIG. 3C stacks the constraint layers 15a and 15b manufactured in FIG. 3B on the upper and lower surfaces of the ceramic laminate 11 manufactured in FIG. 3A. In this case, the surface on which the charging portions 16a, 16b, 16c, and 16d are formed among the constraint layers 15a and 15b may be laminated so as to be bonded to the upper or lower surface of the ceramic laminate 11.

And it bakes at about 600-1000 degreeC which is the baking temperature of the ceramic laminated body 11. In this process, pressure may be applied to the upper restraint layer 15a and the lower restraint layer 15b to facilitate suppression of shrinkage in the z direction.

As shown in FIG. 3C, when the ceramic laminate 11 is fired by using the restraining layers 15a and 15b having the charging portions 16a, 16b, 16c, and 16d formed thereon, the surface electrodes of the ceramic laminate 11 are formed. That is, the via electrode portion 13 of the uppermost green sheet 11d and the via electrode portion 3 of the lowermost green sheet 11a are densified by the charging portions 16a, 16b, 16c, and 16d to settle. No area is generated.

Next, as shown in FIG. 3D, when the firing process of the ceramic laminate 11 is completed, the restraining layers 15a and 15b are removed. Restraint layers 15a and 15b can be removed using conventional techniques such as plate polishing, buff polishing and sand blasting. In addition, although not shown in detail through the drawings, after removing the restraint layer (15a, 15b), located on the upper and lower surfaces of the ceramic laminate 11 for the planarization of the surface of the ceramic laminate (11) The via electrode portion 13 can be polished. This polishing process is at the manufacturer's option and is not essential.

Thereafter, the conductor paste is screen printed on the upper and lower portions of the ceramic laminate 11 to form the external electrode 17. In this case, firing may be performed to fix the ceramic laminate 11 and the external electrode 17. According to this method, the non-contraction ceramic substrate 100 of the present invention can be manufactured. In this case, the non-shrinkable ceramic substrate 100 does not have a settling region formed in the via electrode portion of the ceramic laminate 11, so that the electrical connection with the external electrode 17 is excellent.

4A and 4B are SEM images of the via electrode unit according to various embodiments of the present disclosure. FIG. 4A is a SEM photograph of the ceramic laminate 11 from which the restraint layers 15a and 15b are removed after the firing process of FIG. 3C. A circular via hole 12 is formed in the upper portion of the ceramic laminate 11, that is, the ceramic green sheet 11d, and the via electrode part 13 is formed in the via hole 12. Compared with the via electrode portion 3 shown in FIG. 2A, the via electrode portion 13 of FIG. 4A is improved in densification by the charging portions 16a, 16b, 16c, and 16d in the firing step, and thus a settling region is generated. It doesn't work. Therefore, when the external electrode is formed or surface mounted, the electrical connection is good.

4B is a SEM photograph of the via electrode unit according to another exemplary embodiment. Compared with the via electrode portion 3 shown in FIG. 2B, the via electrode portion 13 of FIG. 4B also has an improved degree of densification by the charging portions 16a, 16b, 16c, and 16d so that no settling region is generated. Therefore, the electrical connection is good, the product reliability of the non-contraction ceramic substrate 100 can be improved.

While the above has been shown and described with respect to preferred embodiments of the invention, the invention is not limited to the specific embodiments described above, it is usually in the art to which the invention belongs without departing from the spirit of the invention claimed in the claims. Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

1A to 1C are vertical cross-sectional views illustrating a method of manufacturing a non-condensation ceramic substrate according to the prior art;

2A and 2B are SEM images of the via electrode unit according to various embodiments of the prior art,

3A to 3D are vertical cross-sectional views for explaining a method of manufacturing a non-contraction ceramic substrate according to an embodiment of the present invention, and

4A and 4B are SEM photographs of a via electrode unit according to various embodiments of the present disclosure.

<Description of the symbols for the main parts of the drawings>

100: non-contraction ceramic substrate 11: ceramic laminate

11a, 11b, 11c, 11d: Ceramic Green Sheet

12: via hole 13: via electrode portion

14: internal electrode 15a, 15b: restraint layer

16a, 16b, 16c, 16d: charging unit 17: external electrode

Claims (6)

Forming a plurality of ceramic green sheets including via electrode portions; Stacking the plurality of ceramic green sheets to form a ceramic laminate; Providing a restraining layer on which a charging unit is formed; Stacking the charging part of the constraint layer to be bonded to the via electrode part of the ceramic laminate; And, Baking at the firing temperature of the ceramic laminate; The method of claim 1, Providing the restraining layer in which the filling unit is formed, And applying and drying a conductive paste at a position corresponding to the via electrode portions formed on the top and bottom surfaces of the ceramic laminate among one surface of the constraint layer. . The method of claim 1, The charging unit, A method of manufacturing a non-shrinkable ceramic substrate, characterized in that it is formed of the same conductor paste as the via electrode portions formed on the upper and lower surfaces of the ceramic laminate. The method of claim 1, The charging unit, And a conductor paste corresponding to 30% of the total amount of the conductor paste constituting the via electrode portions formed on the upper and lower surfaces of the ceramic laminate. The method of claim 1, Removing the restraining layer when firing of the ceramic laminate is completed; And, Forming an external electrode on the via electrode portion formed on the upper surface and the lower surface of the ceramic laminate, further comprising a non-condensation ceramic substrate. The method of claim 1, Removing the constraint layer, And polishing the via electrode portions of the upper and lower surfaces of the ceramic laminate to be flattened.

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