Manufacturing method for multilayer electronic component and mold release film

Abstract

To provide a manufacturing method for a multilayer electronic component in which reduction in quality caused by a mold release film is prevented and provide a mold release film used for the same.SOLUTION: A manufacturing method for a multilayer electronic component 1 includes a step for coating one surface of a mold release film 100 with a ceramic slurry and forming a ceramic green sheet 10, a step for printing an internal electrode pattern 12 on the ceramic green sheet 10, a step for laminating the ceramic green sheets 10 and obtaining a laminated body 2, a step for obtaining a ceramic sintered body 4, and a step for forming an external electrode 6. The mold release film 100 includes a substrate 102 and a mold release layer 110. A counter layer 2000 is provided on the surface of the substrate 102 on which the mold release layer 110 is not provided.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a multilayer electronic component and a release film.

Background Art

[0002] As a method for manufacturing a multilayer ceramic capacitor, which is an example of a multilayer electronic component, there is a method in which a ceramic slurry is applied to a release film to form a ceramic green sheet, an internal electrode pattern is printed on the ceramic green sheet, and then a plurality of them are laminated (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The above method includes a step of peeling the ceramic green sheet from the release film. Therefore, a release layer is formed on the base material of the release film.

[0005] In the release film, foreign matter may enter between the base material and the release layer. Therefore, there is a technique of increasing the thickness of the release layer so that foreign matter does not expose on the surface of the release layer. However, when the thickness of the release layer is increased, the release film is likely to warp.

[0006] When a multilayer electronic component is manufactured using a release film in which foreign matter exposes on the surface of the release layer or a warped release film, the quality of the multilayer electronic component deteriorates.

[0007] Therefore, an object of the present invention is to provide a method for manufacturing a multilayer electronic component in which a quality degradation caused by a release film is suppressed, and a release film used in the manufacturing method.

Means for Solving the Problem

[0008] The method for manufacturing a multilayer electronic component of the present invention includes a step of forming a ceramic green sheet on the release film by applying a ceramic slurry to one side of the release film and drying it, a step of printing an internal electrode pattern on the ceramic green sheet, a step of laminating at least a plurality of ceramic green sheets on which the internal electrode pattern is printed to obtain a laminate, a step of firing the laminate to obtain a ceramic sintered body, and a step of forming an external electrode on the outer surface of the ceramic sintered body. The release film includes a base material and a release layer, and a counter layer is provided on the surface of the base material where the release layer is not provided.

[0009] The release film of the present invention is a release film including a base material and a release layer, wherein the thickness of the release layer is 2 μm or more and 20 μm or less, and a counter layer is provided on the surface of the base material where the release layer is not provided.

Advantages of the Invention

[0010] According to the present invention, it is possible to provide a method for manufacturing a multilayer electronic component in which a quality degradation caused by a release film is suppressed, and a release film used in the manufacturing method.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0012] Before explaining the release film 100 of the present embodiment, a conventional release film 101 will be explained. (Release Film) FIG. 1 is a diagram showing a cross-section of a conventional release film 101. The release film 101 includes a base material 102 and a release layer 1100. The release layer 1100 is formed on at least one surface of the base material 102.

[0013] (Base Material) An example of the material of the base material 102 is polyester. An example of a preferable material among polyesters is polyethylene terephthalate (PET). However, the material of the base material 102 is not limited to polyester.

[0014] An example of the thickness 301 of the base material 102 is 30 μm or more and 50 μm or less. However, the thickness 301 of the base material 102 is not limited.

[0015] (Release Layer) Examples of the material of the release layer 1100 are materials with low surface free energy such as silicone resin and fluororesin. In other words, examples of the material of the release layer 1100 are oil-repellent materials. However, the material of the release layer 1100 is not limited to silicone resin or the like.

[0016] (Foreign Matter) A substance that is exposed from the surface 120 of the base material 102 and is composed of a substance other than the material constituting the release layer 1100 is called a foreign matter 200. The substances constituting the foreign matter include substances derived from the environment and substances derived from the material.

[0017] Those derived from the environment include those derived from the human body and the atmosphere. Examples of substances derived from the human body are sugars, proteins, sodium chloride, etc. Examples of substances derived from the atmosphere are silica, clay, etc.

[0018] Those derived from materials include those derived from polymerization catalysts and lubricants. Examples of substances derived from polymerization catalysts are antimony oxide, etc. Examples of substances derived from lubricants are silica, calcium carbonate, titanium dioxide, etc. Substances derived from materials exist as residual coarse particles.

[0019] When the thickness 302 of the release layer 1100 is thin, some foreign matters 200 may not be covered by the release layer 1100. The uncovered foreign matters 200 are exposed from the surface 122 of the release layer 1100. Also, some or all of the foreign matters exposed from the surface 122 of the release layer 1100 may protrude from the release layer 1100. The case where the thickness 302 of the release layer 1100 is thin means, for example, the case where the thickness 302 of the release layer 1100 is 0.1 μm or more and 2 μm or less.

[0020] (Multilayer Electronic Component) Take the multilayer ceramic capacitor 1 as an example of the multilayer electronic component. The dielectric layer included in the multilayer ceramic capacitor 1 is manufactured by applying a ceramic slurry to the release film 101. When the foreign matter 200 is exposed on the surface 122 of the release layer 1100, the quality of the multilayer ceramic capacitor 1 may deteriorate. Also, when the foreign matter 200 protrudes from the release layer 1100, the deterioration of the quality becomes more prominent. There is a risk of causing problems such as damage to the ceramic green sheet starting from the foreign matter when peeling the ceramic green sheet from the PET film (release film), including a decrease in the smoothness of the dielectric layer. Note that peeling the ceramic green sheet from the PET film is performed, for example, before the lamination process.

[0021] (Thickness of Release Layer) Therefore, it is conceivable to increase the thickness of the release layer 1100. This is because when the thickness 302 of the release layer 1100 is increased, it becomes difficult for the foreign matter 200 to be exposed from the surface 122 of the release layer 1100.

[0022] (Warp of the release film) However, when the release layer 1100 is thickened, the release film 101 is likely to warp. This will be described with reference to FIGS. 2A and 2B. FIG. 2A shows a release film 101 in which the thickness 303 of the release layer 1100 is a standard thickness (for example, 0.1 μm or more and 2 μm or less). For the sake of explanation, the release film shown in FIG. 2A is referred to as release film 1001 and release film 1002. FIG. 2B shows a release film 101 in which the thickness 304 of the release layer 1200 is thick (for example, 2 μm or more and 20 μm or less). For the sake of explanation, the release film shown in FIG. 2B is referred to as release film 1003 and release film 1004.

[0023] (Immediately after coating) In FIGS. 2A and 2B, the release films 1001 and 1003 on the left side of the arrow 250 show the state immediately after the release layer 1100 or the material (release agent) of the release layer 1100 is coated on the base material 102. No warp has occurred in the release films 1001 and 1003.

[0024] (After a predetermined time has elapsed after the completion of curing) In FIGS. 2A and 2B, the release films 1002 and 1004 on the right side of the arrow 250 show the state after the release agent is coated on the base material 102, the curing of the release agent is completed, and then a further predetermined time has elapsed. No warp has occurred in the release film 1002. In contrast, warp has occurred in the release film 1004.

[0025] The thickness of the release layers 1100 of the release films 1001 and 1002 shown in Fig. 2A is such that the stress generated when the release agent cures is small and the release films 1001 and 1002 do not warp. That is, the thickness of the release layer 1100 is such that the release films 1001 and 1002 do not warp when the release layer 1100 is formed. For example, the thickness of the release layer 1100 is 0.2 μm, but it is not limited to this. When using the thin release layer 1100 as described above, the problem occurs that foreign matter is exposed on the surface of the release layer 1100 as described above.

[0026] The thickness 304 of the release layer 1200 of the release film 1004 shown in Fig. 2B is thicker than that in Fig. 2A, and the stress generated when the release layer 1200 cures is greater than that in Fig. 2A. Since the stress generated when the release layer 1200 cures is greater than that in Fig. 2A, the warp generated in the release film 1004 becomes greater. Therefore, even after a predetermined time has elapsed after the curing is completed, the stress does not disappear and the warp remains. In the release film 1004, warps in the (+) direction of Y occur at both ends in the X direction.

[0027] The release film 100 of the present embodiment will be described with reference to Fig. 3. Fig. 3 is a diagram showing a cross section of the release film 100. The thickness 2022 of the release layer 110 of the release film 100 shown in Fig. 3 is thicker than the thickness 302 of the release layer 110 shown in Fig. 1. The thickness 302 of the release layer 110 shown in Fig. 1 is, for example, 0.1 μm or more and 2 μm or less. The thickness 2022 of the release layer 110 shown in Fig. 3 is, for example, 2 μm or more and 20 μm or less. The thickness 2022 of the release layer 110 shown in Fig. 3 is preferably 2 μm or more and 5 μm or less.

[0028] Since the thickness 2022 of the release layer 110 is thicker than the thickness 302 of the release layer 110 shown in Fig. 1, most of the foreign matter 200 is covered by the release layer 110. In the release film 100, the foreign matter 200 is less likely to be exposed from the surface 122 of the release layer 110.

[0029] (Counter layer) A counter layer 2000 is provided on the surface of the base material 102 where the release layer 110 is not provided. That is, the counter layer 2000 is provided on the back surface 124 of the base material 102.

[0030] Since the counter layer 2000 is provided on the back surface 124 of the base material 102, in the release film 100, layers are formed on both surfaces of the base material 102 (the front surface 120 of the base material 102 and the back surface 124 of the base material 102). Therefore, warping is less likely to occur in the release film 100. This is because the counter layer 2000 suppresses the occurrence of warping compared to the case where only the release layer 110 is provided on the base material 102.

[0031] (Direction of stress) The suppression of warping by the counter layer 2000 is remarkable when the material constituting the counter layer 2000 is a material that shrinks during film formation. FIG. 4 is a diagram showing a cross section of the release film 100. The arrows 2011 to 2014 shown in FIG. 4 indicate the direction of stress.

[0032] In the release layer 110, a stress is generated that warps the release film 100 toward the release layer 110 side. When the counter layer 2000 is composed of a material that shrinks during film formation, a stress is generated in the counter layer 2000 that warps the release film 100 toward the counter layer 2000 side. By balancing the stress generated in the release layer 110 and the stress generated in the counter layer 2000, warping is less likely to occur in the release film 100.

[0033] This will be described with reference to FIG. 4. In the counter layer 2000, as shown by the arrows 2011 and 2012, stresses are generated in the Y(-) direction on both sides in the X direction. Also, in the release layer 110, as shown by the arrows 2013 and 2014, stresses are generated in the Y(+) direction on both sides in the X direction. When the stresses shown by the arrows 2011 and 2012 and the stresses shown by the arrows 2013 and 2014 are balanced, warping is less likely to occur in the release film 100.

[0034] (Thickness of the counter layer) The thickness 2021 of the counter layer 2000 shown in FIG. 3 is not particularly limited. The stresses 2011 and 2012 generated in the counter layer 2000 differ depending on the thickness 2021 of the counter layer 2000. Therefore, the thickness 2021 of the counter layer 2000 is preferably set such that the stresses 2011 and 2012 generated in the counter layer 2000 balance with the stresses 2013 and 2014 generated in the release layer 110. Note that the thickness 2021 of the counter layer 2000 does not have to be the same as the thickness 2022 of the release layer 110. The thickness 2021 of the counter layer 2000 may be greater than or less than the thickness 2022 of the release layer 110.

[0035] (Material of the counter layer) The material of the counter layer 2000 may be the same as or different from the material of the release layer 110. Also, the material of the counter layer 2000 may be only a material containing a cationic polymerizable compound and a cationic polymerization initiator.

[0036] As described above, in the release film 100 of the present embodiment, by applying stresses that warp the release film 100 in opposite directions to the front and back surfaces of the base material 102 and balancing them, a release film 100 with warpage finally suppressed can be obtained. The release film 100 of the present embodiment enables the production of a film without warpage even when the release layer 110 is thickly coated.

[0037] (Foreign matter on the back side of the base material) When foreign matter is exposed on the back surface 124 side of the base material 102, the quality of the multilayer ceramic capacitor 1 may deteriorate. In the release film 100 of the present embodiment, a counter layer 2000 is provided on the back surface 124 of the base material 102. Therefore, it is possible to suppress a decrease in the quality of the multilayer ceramic capacitor 1 caused by foreign matter exposed on the back surface 124 side of the base material 102. The foreign matter on the back surface 124 side will be described later with reference to FIG. 6.

[0038] (Number of foreign matters) The number of foreign substances 200 exposed from the surface 122 of the release layer 110 can be counted by observing the surface 122 of the release layer 110 with a microscope or the like. The number of foreign substances 200 exposed from the surface 122 of the release layer 110 that are visually recognized or detected when observing the surface 122 of the release layer 110 in plan view with an optical microscope is defined as the number of foreign substances. Plan view means looking at the surface 122 along the direction perpendicular to the surface 122 of the release layer 110. Using an optical microscope, observations in a range of 100 mm × 100 mm were performed for 100 fields of view, and the number of foreign substances per unit square meter (m 2 ) was calculated. The number of foreign substances / m 2 was 10,000 per m 2 when the thickness of the release layer was 0.1 μm, and 10 per m 2 when the thickness of the release layer was 2 μm.

[0039] (Method for manufacturing a release film) A method for manufacturing the release film 100 will be described. A material (release agent) for forming the release layer 110 is coated on the surface 120 of a base material 102 such as a polyester film. An example of the release agent is a silicone resin. Specifically, a material for forming the release layer 110 is applied to the base material 102 such as a polyester film by overcoating. The material for overcoating can be prepared as follows. The material of the layer constituting the surface 122 of the release layer 110 is a release agent. The materials for forming the other layers can be appropriately selected. The thickness of each layer after drying and curing can be, for example, 1 μm. The number of overcoated layers can be, for example, 4 layers.

[0040] A material for forming the counter layer 2000 is coated on the back surface 124 of the base material 102. Examples of the material are a release agent (for example, a silicone resin), or a material containing a cationic polymerizable compound and a cationic polymerization initiator. Although an example of forming the release layer by overcoating the material for forming the release layer has been shown, the present invention is not limited thereto, and the release layer may be formed from a single layer instead of by overcoating. In this case, the release layer is preferably formed from a release agent. Also, the counter layer is not limited to a single layer, and may be formed by stacking a plurality of layers.

[0041] (Method for manufacturing a multilayer ceramic capacitor) With reference to FIGS. 5 to 8, a method for manufacturing the multilayer ceramic capacitor 1 will be described. In the method for manufacturing the multilayer ceramic capacitor 1, the above-described release film 100 is used.

[0042] FIG. 5 is a view showing a state in which the ceramic green sheet 10 and the internal electrode pattern 12 are formed on one side of the release film 100 and wound around a roller. As shown in FIG. 5, a ceramic slurry is applied to one side of the release film 100 and dried to form the ceramic green sheet 10 on the release film 100. Thereafter, the internal electrode pattern 12 is printed on the ceramic green sheet 10. The release film 100 on which the ceramic green sheet 10 and the internal electrode pattern 12 are formed is wound into a roll.

[0043] FIG. 6 is an enlarged view of the frame 260 in FIG. 5. For the sake of explanation, the n-th roll of the release film 100 is shown as the release film 1011. The (n + 1)-th roll of the release film is shown as the release film 1012. The back surface 124 of the base material 102 in the (n + 1)-th roll of the release film 1012 is in contact with the internal electrode pattern 12 formed on the n-th roll of the release film 1011.

[0044] Here, if foreign matter is exposed on the back surface 124 side of the base material 102, the ceramic green sheet 10 and the internal electrode pattern 12 may be damaged. For example, the ceramic green sheet 10 may be torn by foreign matter. In the release film 100 of the present embodiment, a counter layer 2000 is provided on the back surface 124 of the base material 102. Therefore, it is difficult for foreign matter to be exposed from the back surface 124 side of the base material 102. Accordingly, the ceramic green sheet 10 and the internal electrode pattern 12 are less likely to be damaged.

[0045] FIG. 7 shows a state in which the release film 100 wound in a roll shape shown in FIG. 5 is processed into the laminate 2. The diagram indicated by the arrow 281 in FIG. 7 shows a state in which the release film 100 or the like is unwound from the roll. The ceramic green sheet 10 on the release film 100 is cut by a cutting blade into a portion to be peeled off and other portions of the ceramic green sheet 10. However, in this cutting, although the ceramic green sheet 10 is cut, the release film 100 is not completely cut. Also, the cutting position corresponds to the adjacent internal electrode patterns 12. Therefore, the ceramic green sheet 10 is cut for each internal electrode pattern 12.

[0046] The process proceeds in the order of the arrow 252 and the arrow 254. The diagram indicated by the arrow 282 shows a state in which the ceramic green sheet 10 and the internal electrode pattern 12 are laminated. Before the ceramic green sheet 10 and the internal electrode pattern 12 are laminated, the release film 100 is peeled off from the ceramic green sheet 10. The release film 100 includes a release layer 110. Therefore, at the time of peeling, the release film 100 is easily peeled off from the ceramic green sheet 10. The ceramic green sheet 10 and the internal electrode pattern 12 peeled off from the ceramic green sheet 10 are laminated according to the structure of the laminate 2 and the like. After lamination, the laminate 2 is formed through pressing by water pressure or the like. The diagram indicated by the arrow 283 shows the laminate 2.

[0047] FIG. 8 is a diagram showing an outline of the multilayer ceramic capacitor 1. The laminate 2 becomes a ceramic sintered body 4 through firing. An external electrode 6 is formed on the outer surface of the ceramic sintered body 4, and the multilayer ceramic capacitor 1 is manufactured.

[0048] As described above, an example of the multilayer electronic component has been described as the multilayer ceramic capacitor 1. The multilayer electronic component is not limited to the multilayer ceramic capacitor. Other examples of the multilayer electronic component include a ceramic piezoelectric element, a thermistor element, and an inductor element.

[0049] The embodiments of the present invention have been described above. The present invention is not limited to the above-described embodiments, and various modifications, variations, and combinations are possible.

Explanation of Signs

[0050] 1 Multilayer electronic component (multilayer ceramic capacitor) 2 Laminate 4 Ceramic sintered body 6 External electrode 10 Ceramic green sheet 12 Internal electrode pattern 100 Release film 101 Conventional release film 102 Base material 110 Release layer 120 Surface of the base material 122 Surface of the release layer 124 Back surface of the base material 200 Foreign matter 250 Arrow 260 Frame 270 Cutting line 301 Thickness of the base material 302 Thickness of the release layer 303 Thickness of the release layer 304 Thickness of the release layer 305 Thickness of the release layer 2000 Counter layer 2021 Thickness of the counter layer 2022 Thickness of the release layer

Claims

1. A step of forming a ceramic green sheet on the release film by applying a ceramic slurry to one side of the release film and drying it; A step of printing an internal electrode pattern on the ceramic green sheet; A step of obtaining a laminate by laminating at least a plurality of ceramic green sheets on which the internal electrode pattern is printed; A step of firing the laminate to obtain a ceramic sintered body; A step of forming an external electrode on the outer surface of the ceramic sintered body, comprising: The release film includes a base material and a release layer; A counter layer is provided on the surface of the base material where the release layer is not provided; A method for manufacturing a multilayer electronic component.

2. The material constituting the counter layer is a material that shrinks during film formation; The method for manufacturing a multilayer electronic component according to Claim 1.

3. The thickness of the release layer is 2 μm or more and 20 μm or less; The method for manufacturing a multilayer electronic component according to Claim 1 or 2.

4. A release film including a base material and a release layer, The thickness of the release layer is 2 μm or more and 20 μm or less; A counter layer is provided on the surface of the base material where the release layer is not provided; Release film.

5. The material constituting the counter layer is a material that shrinks during film formation; The release film according to Claim 4.

6. The number of foreign substances exposed from the surface of the release layer is 10 or less per m2 in plan view; The release film according to Claim 4 or 5.

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