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 3000 is provided between the substrate 102 and the mold release layer 110. A material for forming the counter layer 3000 is a material that expands under predetermined conditions.SELECTED DRAWING: Figure 3A

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 the 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 manufacturing a multilayer electronic component using a release film in which foreign matter is exposed 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 reduction due to a release film is suppressed, and a release film used in the manufacturing method.

Means for Solving the Problem

[0008] The manufacturing method of the 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 on 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 between the base material and the release layer. The material constituting the counter layer is a material that expands under predetermined conditions.

[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, a counter layer is provided between the base material and the release layer, and the material constituting the counter layer is a material that expands under predetermined conditions.

Advantages of the Invention

[0010] According to the present invention, it is possible to provide a manufacturing method of 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 3A

Figure 3B

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode 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 preferred 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 and 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 object 200. The substances constituting the foreign object 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 those derived from 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 the material include those derived from the polymerization catalyst and those derived from the lubricant. Examples of substances derived from the polymerization catalyst are antimony oxide, etc. Examples of substances derived from the lubricant are silica, calcium carbonate, titanium dioxide, etc. Substances derived from the material exist as residual coarse particles.

[0019] When the thickness 302 of the release layer 1100 is thin, some foreign objects 200 may not be covered by the release layer 1100. The uncovered foreign objects 200 are exposed from the surface 122 of the release layer 1100. Also, some or all of the foreign objects 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 a foreign object 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 object 200 protrudes from the release layer 1100, the deterioration of the quality becomes more significant. There is a risk of causing problems such as damage to the ceramic green sheet starting from the foreign object 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 the 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 a release film 1001 and a 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 a release film 1003 and a 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 applying the release layer 1100 or the material (release agent) of the release layer 1100 to 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 applying the release agent to 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 thin enough 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 thereto. When using the thin release layer 1100 as described above, the problem occurs in 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 larger than that in FIG. 2A. Since the stress generated when the release layer 1200 cures becomes larger than that in FIG. 2A, the warp generated in the release film 1004 becomes larger. 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 FIGS. 3A, 3B, and 4. FIGS. 3A, 3B, and 4 are diagrams showing cross-sections of the release film 100. The thickness 3012 of the release layer 110 of the release film 100 shown in FIG. 3A 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 3012 of the release layer 110 shown in FIG. 3A is, for example, 2 μm or more and 20 μm or less. The thickness 3012 of the release layer 110 shown in FIG. 3A is preferably 2 μm or more and 5 μm or less. The thickness of the release layer 110 can be the same as that of the release film 100 shown in FIG. 3A also in the release film 100 of the present embodiment shown in FIGS. 3B and 4.

[0028] The thickness 3012 of the release layer 110 is thick. Therefore, most of the foreign matter 200 is covered by the release layer 110. In the release film 100, it is difficult for the foreign matter 200 to be exposed from the surface 122 of the release layer 110.

[0029] (Counter layer)

[0030] In the release film 100, a counter layer 3000 is provided between the base material 102 and the release layer 110. Therefore, the release film 100 is less likely to warp. This is because the counter layer 3000 suppresses the occurrence of warping compared to the case where only the release layer 110 is provided on the base material 102.

[0031] (Warp relaxation) The suppression of warping by the counter layer 3000 is remarkable when the material constituting the counter layer 3000 is a material that expands under predetermined conditions. The predetermined conditions mean, for example, heating.

[0032] When the material constituting the counter layer 3000 is a material that expands under predetermined conditions, there are multiple ways to process for suppressing the warping of the release film 100. They will be described in order below.

[0033] In FIGS. 3A, 3B, and 4, the release film 100 on the left side of each of the arrows 401, 402, and 403 is the isolation film 100 before processing. For the sake of explanation, the release film 100 on the left side of the arrow 401 in FIG. 3A is defined as the release film 1021. Similarly, the release film 100 on the left side of the arrow 402 in FIG. 3B is defined as the release film 1023. Also, the release film 100 on the left side of the arrow 403 in FIG. 4 is defined as the release film 1025.

[0034] Also, in FIGS. 3A, 3B, and 4, the release film 100 on the right side of each arrow 401, arrow 402, and arrow 403 is the isolation film 100 after being processed. For the sake of explanation, let the release film 100 on the right side of arrow 401 in FIG. 3A be the release film 1022. Similarly, let the release film 100 on the right side of arrow 402 in FIG. 3B be the release film 1024. Also, let the release film 100 on the right side of arrow 403 in FIG. 4 be the release film 1026.

[0035] In FIGS. 3A, 3B, and 4, the warping state of the release film 100 is not shown in the drawings. Also, the formation order of each layer is not reflected.

[0036] (First process) Referring to FIG. 3A, the first process will be described. In the first process, first, a counter layer 3000 is provided on the substrate 102. Next, the counter layer 3000 is heated or the like to expand the counter layer 3000 mainly in the X direction. Arrows 411 and 412 of the release film 1022 indicate the expansion direction of the counter layer 3000. Due to the expansion of the counter layer 3000, the length of the counter layer 3000 in the X direction in the release film 1022 is longer than the length of the counter layer 3000 in the X direction in the release film 1021.

[0037] After expanding the counter layer 3000, a release layer 110 is formed by coating a release agent on the counter layer 3000. When forming the release layer 110, the release layer 110 shrinks. However, by offsetting the shrinkage of the release layer 110 and the expansion of the counter layer 3000 that has been expanded in advance, the warping of the release film 100 can be suppressed.

[0038] (Second process) Referring to FIG. 3B, the second process will be described. Hereinafter, the differences between the second process and the first process will be mainly described. In the first process, after expanding the counter layer 3000, the release layer 110 is formed. In contrast, in the second process, the counter layer 3000 is provided on the substrate 102, and then, after forming the release layer 110, the counter layer 3000 is expanded.

[0039] When heating the counter layer 3000 to expand the counter layer 3000, the release layer 110 contracts in the X direction.

[0040] The arrows 411 and 412 of the release film 1024 indicate the direction of expansion of the counter layer 3000. The arrows 413 and 414 of the release film 1024 indicate the direction of contraction of the release layer 110. By balancing the stress in the directions of the arrows 411 and 412 acting on the counter layer 300 and the stress in the directions of the arrows 413 and 414 acting on the release layer 110, each stress is canceled out. As a result, warping of the release film 100 can be suppressed.

[0041] As described above, in the release film 100 of the present embodiment, warping of the release film 100 is suppressed by balancing the release layer 110 and the counter layer 3000.

[0042] That is, when the release layer 110 is coated on the substrate 102, the release layer 110 contracts, so a stress that deflects the release film 100 toward the release layer 110 side acts. Therefore, a layer that expands is provided between the release layer 110 and the substrate 102. Thereby, a stress that deflects the release film 100 toward the surface opposite to the release layer 110 acts.

[0043] By balancing the "stress that deflects the release film 100 toward the release layer 110 side" and the "stress that deflects the release film 100 toward the surface opposite to the release layer 110", a release film 100 with a thick coating of the release layer 110 and suppressed warping can be manufactured.

[0044] (Counter layer) Summarizing the function of the counter layer 3000 regarding warping, it is as follows. Particularly when the material constituting the counter layer 3000 is a material that expands under predetermined conditions, the counter layer 3000 generates a stress that warps the release film 100 toward the back side (the direction in which the counter layer 3000 wraps the base material 102). Therefore, with respect to the stress that warps the release film 100 by the release layer 110 toward the release layer 110 side, the counter layer 3000 has the effect of applying a stress that warps the release film 100 to the side opposite to the release layer 110. By balancing the stress generated by the counter layer 3000 and the stress generated by the release layer 110, warping of the release film 100 can be suppressed.

[0045] (Third process) Referring to FIG. 4, the third process will be described. Hereinafter, mainly matters different from the second process will be described. In the second process, the expansion of the counter layer 3000 and the contraction of the release layer 110 occur simultaneously. In contrast, in the third process, the counter layer 3000 is provided on the base material 102, and then after forming the release layer 110, the release layer 110 is cured and the release layer 110 is contracted. That is, first, the release layer 110 is contracted in the directions of arrow 413 and arrow 414 shown by the release film 1026. The release film 100 warps in the direction of wrapping the release layer 110.

[0046] Thereafter, the counter layer 3000 is expanded. As the counter layer 3000 expands, stresses act in the directions of arrow 411 and arrow 412. By canceling out the stress 411 and the stress 412 and the stress 413 and the stress 414 of the release layer 110, warping of the release film 100 can be suppressed.

[0047] (Thickness of the counter layer) The thickness 3011 of the counter layer 3000 shown in FIG. 3A is not particularly limited. The stress generated in the counter layer 3000 (arrow 411 and arrow 412) varies depending on the thickness 3011 of the counter layer 3000. The thickness 3011 of the counter layer 3000 is preferably set such that the stress 411 and stress 412 generated in the counter layer 3000 balance the stress generated in the release layer 110 (arrow 413 and arrow 414). Note that the thickness 3011 of the counter layer 3000 does not have to be the same as the thickness 3012 of the release layer 110, and may be thicker or thinner than the thickness 3012 of the release layer 110.

[0048] (Material of the counter layer) The material of the counter layer 3000 can be, for example, polyurethane. Further, the material of the counter layer 3000 may contain a foaming agent, an expanding agent, or the like.

[0049] (Number of foreign matters) The number of foreign matters 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 matters 200 exposed from the surface 122 of the release layer 110 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 matters. 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 were made in 100 fields of view in a range of 100 mm × 100 mm, and the number of foreign matters per unit square meter (m 2 ) was calculated. The number of foreign matters / m 2 was 10,000 pieces / m when the thickness of the release layer was 0.1 μm 2 and 10 pieces / m when the thickness of the release layer was 2 μm 2 .

[0050] (Manufacturing method of the release film) A method for manufacturing the release film 100 will be described. A material for forming the counter layer 3000 is applied to the surface 120 of a base material 102 such as a polyester film. An example of the material is polyurethane. Polyurethane may contain a foaming agent.

[0051] A material (release agent) for forming the release layer 110 is applied onto the counter layer 3000. An example of the release agent is a silicone resin. Specifically, the material for forming the release layer 110 is applied in multiple layers onto the counter layer 3000. The material for multiple-layer application can be obtained as follows. The material of the layer constituting the surface 122 of the release layer 110 is the release agent. The materials for constituting other layers can be appropriately selected. The thickness of each layer after drying and curing can be, for example, 1 μm. The number of layers for multiple-layer application can be, for example, 4 layers. Although an example of forming the release layer by applying the material for forming the release layer in multiple layers has been shown, the present invention is not limited thereto, and the release layer may be formed of a single layer instead of multiple layers. In this case, the release layer is preferably formed from a release agent. Further, the counter layer is not limited to a single layer, and may be formed by stacking a plurality of layers.

[0052] When manufacturing the isolation film, any one of the above-described first to third processes is appropriately selected and performed as appropriate.

[0053] (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.

[0054] FIG. 5 is a diagram showing a state where 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 onto 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.

[0055] FIG. 6 is an enlarged view of the frame 260 in FIG. 5. For the sake of explanation, the n-th release film 100 is shown as the release film 1011. The (n + 1)-th release film is shown as the release film 1012. The back surface 124 of the base material 102 in the (n + 1)-th release film 1012 is in contact with the internal electrode pattern 12 formed on the n-th release film 1011.

[0056] FIG. 7 shows how the release film 100 wound in a roll shape shown in FIG. 5 and the like are processed into the laminate 2. The diagram shown by the arrow 281 in FIG. 7 shows a state where the release film 100 and the like are 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 of the ceramic green sheet 10 and other portions. 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.

[0057] The process proceeds in the order of the arrow 252 and the arrow 254. The diagram shown by the arrow 282 shows a state where 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 shown by the arrow 283 shows the laminate 2.

[0058] FIG. 8 is a diagram showing an overview 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.

[0059] The above examples of multilayer electronic components have been described using the multilayer ceramic capacitor 1 as an example. Multilayer electronic components are not limited to multilayer ceramic capacitors. Other examples of multilayer electronic components include ceramic piezoelectric elements, thermistor elements, and inductor elements, etc.

[0060] The embodiments of the present invention have been described above. The present invention is not limited to the foregoing embodiments, and various changes, modifications, and combinations are possible.

Description of Reference Numerals

[0061] 1 Multilayer electronic component (multilayer ceramic capacitor) 2 Multilayer body 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 1021 Release film 1022 Release film 1023 Release film 1024 Release film 1025 Release film 1026 Release film 3000 Counter layer 3011 Thickness of the counter layer Thickness of the release layer 3012

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 between the base material and the release layer; The material constituting the counter layer is a material that expands under predetermined conditions; A method for manufacturing a multilayer electronic component.

2. 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.

3. 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; A counter layer is provided between the base material and the release layer; The material constituting the counter layer is a material that expands under predetermined conditions; A release film.

4. The number of foreign substances exposed from the surface of the release layer is 10 pieces / m in plan view ２ or less The release film according to Claim 3.

Images