JP5040941B2 - Manufacturing method of electronic parts - Google Patents

Description

  The present invention relates to an electronic component manufacturing method.

  As a conventional method of manufacturing an electronic component, the first layer is formed by immersing the end face of an element (element body) formed by alternately laminating and firing green sheets and internal electrode materials in an electrode material paint (conductive paste). Is formed, and then is dipped again into an electrode material paint to form a second layer, and fired to form an external electrode (see, for example, Patent Document 1).

JP-A-5-144660

  In the above-described method for manufacturing an electronic component, after forming an element body, the external electrode is formed by immersing the end portion in a conductive paste and baking it. However, in this manufacturing method, when the element body is pulled away after immersion, the conductive paste is pulled near the center position of the end face, thereby increasing the thickness near the center position of the paste film, while the end face and side surfaces of the element body are increased. The thickness near the corners between them was thin. As a result, the thickness of the external electrode is reduced in the vicinity of the curved corner portion, and in the plating step after the firing step, there is a possibility that moisture such as a plating solution may enter the element body from the thinned portion. Therefore, in the electronic component manufactured by the conventional manufacturing method, the characteristics of the electronic component may be deteriorated due to the influence of moisture that has entered the element body during the plating process.

  An object of the present invention is to provide a method for manufacturing an electronic component that can prevent moisture such as a plating solution from entering the element body from the vicinity of a corner portion and improve the reliability of the electronic component.

An electronic component manufacturing method according to the present invention includes a pair of end faces and a substantially rectangular parallelepiped element having four side surfaces connecting the end faces, and an external electrode formed on the end face of the element body. An element body preparing step of preparing an element body having a curved corner portion between the end face and the side surface, and immersing the end face and the corner portion in a conductive paste, thereby conducting the end face, the corner portion, and the side surface. A first paste layer forming step for forming a first paste layer by attaching a functional paste, a drying step for drying the first paste layer, and screen printing by covering the dried first paste layer with a screen mesh And a second paste layer forming step of forming a second paste layer.

  In the method of manufacturing an electronic component according to the present invention, a first paste layer is formed by dipping so as to cover the end face and the corner portion of the element body having a curved corner portion between the end face and the side face. Is covered with a screen mesh and screen-printed to form a second paste layer forming step. Since the first paste layer is formed by immersion, the corner portion is rounded. When screen printing is performed on the first paste layer having rounded corner portions using a screen mesh, the screen mesh has flexibility, and the screen mesh is squared by being pressed against the squeegee. Wrap around the part. In this way, when screen printing is performed with a screen mesh on a curved corner portion, the surface area of the attached portion of the conductive paste in the corner portion can be increased compared to that which is not curved, The adhesion amount of the conductive paste can be increased. Further, since the curved surface at the corner when the squeegee is not pressed and the screen mesh are separated from each other, the margin between the curved surface at the corner and the upper surface of the screen mesh is larger than the thickness of the screen mesh. Accordingly, the conductive paste tends to accumulate at the corners of the first paste layer.

  Further, in screen printing, when the screen mesh is pulled away, the conductive paste attached to the screen mesh side is pulled near the corner portion of the second paste layer formed in the first paste layer and separated at the position. Of the conductive paste adhering to the screen mesh side, the conductive paste that is pulled to the second paste layer and cut and remains on the second paste layer side hangs down to the curved corner portion side, and the first paste near the corner portion. Part of the two paste layer. In particular, as described above, since the margin between the corner portion and the screen mesh is large, the conductive paste tends to accumulate in the corner portion. By such an action, the conductive paste forming the second paste layer adheres in the vicinity of the corner portion. Therefore, the conductive paste in the vicinity of the center position on the upper surface of the first paste layer is pulled to the corner due to the influence of the surface tension. As a result, the amount of the conductive paste is reduced near the center position on the upper surface of the first paste layer, and the amount of the conductive paste near the corner portion is further increased.

  As described above, the thickness of the second paste layer increases in the vicinity of the corner portion of the first paste layer (that is, the corner portion of the element body). By firing and plating in this state, it is possible to sufficiently secure the thickness of the external electrode near the corner portion of the element body. Therefore, when performing plating, it is possible to prevent moisture such as plating solution from entering the element body from near the corners of the element body, thereby improving the reliability of the electronic component.

  In particular, for example, when the first paste layer is formed by screen printing and the second paste layer is formed by dipping, the corners of the first paste layer are caused by variations in the radius of curvature of the corner portions of the element body due to manufacturing errors. When the thickness near the portion cannot be secured sufficiently, and as a result, the thickness of the external electrode near the corner portion may not be secured, and the thickness of the external electrode (H dimension) on the side surface of the element body is too large. There is. However, according to the manufacturing method according to the present invention, since the first paste layer is formed by dipping, the corners are naturally rounded. Therefore, the thickness of the external electrode in the vicinity of the corner portion of the element body can be reliably ensured regardless of variations in the radius of curvature of the corner portion of the element body. Furthermore, since it is possible to prevent the thickness (H dimension) of the external electrode on the side surface of the element body from becoming too large, it is possible to improve the solderability during mounting and reduce mounting defects.

  Further, in the first paste layer forming step, the first paste layer is formed by immersing it in a conductive paste so as to cover the end surface, thereby forming a portion of the external electrode that wraps around the four side surfaces orthogonal to the end surface. The size (dimension B) can be increased. Thereby, it is possible to prevent the chip from standing when the electronic component is mounted. Furthermore, since the second paste layer is formed using a flexible screen mesh, when holding the element body for screen printing, the height direction or the horizontal direction between the held element bodies. Even when there is variation in the thickness, the first paste layer having a substantially uniform thickness and shape can be formed between the element bodies. Thereby, the productivity of electronic components can be improved. In addition, since the conductive paste is attached to the end face of the element body through the screen mesh, it is possible to prevent foreign matters from being mixed into the external electrode due to the filtration effect of the screen mesh.

  Moreover, in the manufacturing method of the electronic component which concerns on this invention, it is preferable to further have the blotting process which presses an end surface to a plane board after a 1st paste layer formation process. As a result, the thickness of the first paste layer near the center position of the end face can be adjusted, and the dimensions of the external electrodes can be adjusted.

  In the method for manufacturing an electronic component according to the present invention, the element body is configured by alternately laminating a plurality of dielectric layers and a plurality of internal electrodes in a direction orthogonal to a direction in which a pair of end faces face each other. In the case of having a first region that is a region where dielectric layers and internal electrodes are alternately stacked, and a second region that is a region consisting of at least a pair of dielectric layers sandwiching the first region in the stacking direction, The thickness of the first paste layer at the position of the internal electrode closest to the second region among the internal electrodes of the first region is F1, the thickness of the second paste layer is F2, and the first paste at the central position of the first region When the thickness of the layer is T1 and the thickness of the second paste layer is T2, it is preferable that the relationship of (T2-T1) <(F2-F1) is satisfied. As described above, when the plating is performed while ensuring the thickness near the corner portion of the external electrode by increasing the size near the corner portion of the second paste layer and decreasing the size near the center position of the first region. Thus, it is possible to form an external electrode having a thickness matched to the product standard size while preventing moisture from entering. Here, the reason why it is particularly preferable to satisfy the relationship of (T2-T1) <(F2-F1) will be described below. That is, the present inventors can prevent the penetration of the plating solution by forming the dimension R2, which is the thickness of the corner of the second paste layer, but the outermost internal electrode in the stacking direction. It has been found that adjusting the dimension F that affects a region closer to the above is more effective for the penetration of the plating solution. It has also been found that this is because the thickness of the external electrode at the position of the outermost internal electrode in the stacking direction is the shortest distance when moisture reaches the element body in the plating step. Therefore, in the present invention, by satisfying the relationship of (T2-T1) <(F2-F1), a more advantageous effect on the invasion of the plating solution can be obtained as compared with the case where the dimension R2 is simply increased. Obtainable.

  According to the present invention, it is possible to prevent moisture such as plating solution from entering the element body from the vicinity of the corner portion and improve the reliability of the electronic component.

It is sectional drawing which shows the electronic component manufactured by the manufacturing method which concerns on embodiment of this invention. It is a flowchart which shows the manufacturing method of an electronic component. It is a figure which shows the process content from a 1st paste layer formation process to a plating process. It is a figure which shows the process content of a 2nd paste layer formation process. It is a figure which shows the process content of a 2nd paste layer formation process, Comprising: It is an expanded sectional view which shows a mode that a squeegee is pressed on the end surface of an element | base_body. It is a figure which shows the process content of a 2nd paste layer formation process, Comprising: It is an expanded sectional view which shows the mode after pressing a squeegee to the end surface of an element | base_body. It is sectional drawing which shows an example of the electronic component after finishing the 2nd paste layer formation process in the manufacturing method of the electronic component which concerns on embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  With reference to FIG. 1, the structure of the electronic component 1 manufactured by the manufacturing method of the electronic component which concerns on embodiment of this invention is demonstrated. FIG. 1 is a cross-sectional view showing an electronic component 1 manufactured by a manufacturing method according to an embodiment of the present invention.

  As shown in FIG. 1, an electronic component 1 is an electronic component such as a ceramic capacitor, for example, and is an element body 2 configured in a substantially rectangular parallelepiped shape by stacking and integrating a plurality of plate-shaped ceramic green sheets. And external electrodes 3 and 4 formed on both end faces of the element body 2. The element body 2 has a pair of end faces 2a and 2b facing the longitudinal direction of the element body 2 and parallel to each other, and four side faces 2c orthogonal to the end faces 2a and 2b and connecting the end faces 2a and 2b. The external electrode 3 is formed so as to cover one end surface 2a and a part of each edge of the four side surfaces 2c orthogonal to the end surface 2a. The size of the portion covering the four side surfaces 2c, that is, the dimension between the position where the thickness in the portion covering the end surface 2a of the external electrode 3 is maximum and the end portion in the portion covering the side surface 2c (B in FIG. Will be referred to as dimension B below. The dimension B is set to about 0.5 to 0.6 mm, for example. The external electrode 4 is formed so as to cover a part of each edge of the other end surface 2b and the four side surfaces 2c orthogonal to the end surface 2b. For example, the electronic component 1 is set to have a length of about 1.9 to 2.2 mm, a width of about 1.1 to 1.3 mm, and a thickness of about 1.1 to 1.3 mm. .

  The external electrodes 3 and 4 are formed at a predetermined temperature (for example, about 700 ° C.) after a conductive paste mainly composed of Cu, Ni, Ag, Pd or the like is attached to the outer surface of the element body 2 by a method described later. It is formed by baking and further electroplating. Ni, Sn, etc. can be used for electroplating.

  As shown in FIG. 1, the element body 2 is configured as a laminated body in which a plurality of rectangular plate-like dielectric layers 6, a plurality of internal electrodes 7, and internal electrodes 8 are stacked. The internal electrodes 7 and the internal electrodes 8 are arranged one by one in the element body 2 along the stacking direction of the dielectric layers 6 (hereinafter simply referred to as “stacking direction”). The internal electrode 7 and the internal electrode 8 are disposed so as to face each other with at least one dielectric layer 6 interposed therebetween. In the actual electronic component 1, the plurality of dielectric layers 6 are integrated to such an extent that the boundary between them cannot be visually recognized. The element body 2 includes a first region 2A that is a region in which a plurality of internal electrodes 7 and 8 and dielectric layers 6 are alternately stacked, and a pair of dielectric layers 6 that sandwich the first region 2A in the stacking direction. And a second region 2B which is a region. The second region 2B may be formed of two or more pairs of dielectric layers 6. The element body 2 is chamfered so that the corner portion 9 between the end faces 2a, 2b and the side surface 2c is curved and has a predetermined radius of curvature. Although not shown, chamfering is performed so that the corner portion of the outer edge of the side surface 2c is also curved and has a radius of curvature. The radius of curvature of the corner portion 9 of the element body 2 is, for example, about 0.05 to 0.15 mm.

  The internal electrodes 7 and 8 include, for example, a conductive material such as Ni or Cu. The thickness of the internal electrodes 7 and 8 is, for example, about 1 to 5 μm. The shape of the internal electrodes 7 and 8 is not particularly limited as long as the internal electrodes 7 and 8 have shapes that overlap with each other when viewed from the stacking direction, and have a rectangular shape, for example. The internal electrodes 7 and 8 are configured as a sintered body of a conductive paste containing the conductive material. The internal electrode 7 is electrically connected to the external electrode 3, and the internal electrode 8 is electrically connected to the external electrode 4.

  Then, the manufacturing method of the electronic component 1 which concerns on embodiment of this invention with reference to FIGS. FIG. 2 is a flowchart showing a method for manufacturing the electronic component 1.

  As shown in FIG. 2, the manufacturing process of the electronic component 1 starts from an element body preparation process S1. In this element body preparation step S1, the following processing is performed. That is, after a ceramic green sheet to be the dielectric layer 6 is formed, the pattern of the internal electrodes 7 and 8 is printed on the ceramic green sheet with a conductive paste and dried to form an electrode pattern. A plurality of ceramic green sheets on which electrode patterns are formed in this way are stacked, and the laminate of the ceramic green sheets is cut into chips each having the size of the element body 2. Subsequently, chamfering of the corner portion 9 of the chip is performed by putting water, a plurality of chips, and a polishing medium into a sealed rotating pot made of a material such as polyethylene, and rotating the sealed rotating pot. The corner portion 9 is curved to have a predetermined radius of curvature (barrel polishing). The binder is removed by subjecting the chamfered chip to heat treatment at a predetermined temperature for a predetermined time. After the binder removal, the element body 2 is obtained by further baking at a higher temperature. The element body preparation step S1 is completed by the above processing.

  After the element body preparation step S1, an element body holding step S2 is performed. This element body holding step S2 is a process of holding a plurality of element bodies 2 prepared in the element body preparing step S1 side by side. In the element holding step S2, the side face 2c is held on the other end face 2b side using a known holding jig 50 such as a carrier plate so that one end face 2a of the element body 2 faces upward (FIG. 4).

  FIG. 3 is a diagram showing process contents from the first paste layer forming process S3 to the plating process S8. After the element body holding step S2, a first paste layer forming step S3 is performed. In the first paste layer forming step S3, the end surface 2a of the element body 2 held by the holding jig 50 is immersed in a conductive paste placed on a plate-shaped application bed, whereby the first paste layer 16 is formed. It is a process of forming. By performing this first paste layer forming step S3, the conductive paste can be adhered to the four side surfaces 2c of the element body 2 by surrounding the end surface 2a. Thereby, the first paste layer 16 as shown in FIG. 3A is formed.

  After the first paste layer forming step S3 is performed, a blotting step S4 is performed. In the first paste layer forming step S3, when the end surface 2a is dipped in the conductive paste and pulled up, the attached first paste layer 16 is pulled and the thickness near the center position of the end surface 2a increases. Therefore, in the blotting step S4, the first paste layer 16 is pressed against the plate and pulled away to wipe away the thick portion of the conductive paste, and the thickness of the first paste layer 16 at the center position can be reduced. After wiping off the conductive paste, a drying step S5 is performed. In the drying step S5, the first paste layer 16 is cured by heating at 150 to 170 ° C. for 7 to 9 minutes for drying. Here, when drying in the drying step S5 is performed by natural drying, the paste in the corner portion 9 may be flattened by leveling due to surface tension, and the thickness may be further reduced. However, in the present embodiment, it is possible to prevent the paste thickness at the corner portion 9 from being thinned by positively heating the drying in the drying step S5.

  After the drying step S5, a second paste layer forming step S6 is performed. FIG. 4 is a diagram showing process contents of the second paste layer forming process S6. In the second paste layer forming step S6, the first paste layer 16 formed on the end face 2a is covered with the screen mesh 51 and screen-printed to form the second paste layer 17 so as to cover the first paste layer 16. It is a process to do. In the second paste layer forming step S6, specifically, as shown in FIG. 4, the first paste layer 16 on the end surface 2a of the element body 2 fixed to the holding jig 50 is covered with a screen mesh 51 from above, and the screen On the upper surface side of the mesh 51, the squeegee 53 is moved so as to scrape the conductive paste 52 in one direction D. As a result, when the screen mesh 51 is pressed against the first paste layer 16 on the end surface 2 a of the element body 2 with the squeegee 53, the conductive paste 52 is printed on the first paste layer 16 to form the second paste layer 17. The After the second paste layer forming step S6 on the end face 2a side, the same process contents are performed from the element body holding step S2 to the second paste layer forming step S6, whereby the first paste layer 16 is also provided on the end face 2b side. And the 2nd paste layer 17 is formed. Alternatively, the first paste layer 16 may be formed on the end surface 2a side, the first paste layer 16 may be formed on the end surface 2b side, and then the second paste layer 17 may be formed.

  When the second paste layer forming step S6 is completed, a firing step S7 is performed. In the firing step S7, the external electrodes 3 and 4 are fired as shown in FIG. 3C by performing a heat treatment at 700 to 800 ° C. After the firing step S7 is performed, a plating step S8 is performed. The plating step S8 is a step of forming a Ni plating layer or a Sn plating layer on the surface of the electronic component 1. Specifically, in this plating step S8, after the electronic component 1 is immersed in the plating solution in the barrel, the surface of the electronic component 1 is plated while rotating the barrel. With the above, the process shown in FIG. 2 is completed, and the electronic component 1 can be obtained.

  Next, the operation and effect of the method for manufacturing the electronic component 1 according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a diagram illustrating the process contents of the second paste layer forming process S <b> 6 and is an enlarged cross-sectional view illustrating a state in which the squeegee 53 is pressed against the first paste layer 16 of the element body 2. FIG. 6 is a diagram showing the process contents of the second paste layer forming process S6, and is an enlarged cross-sectional view showing a state after the squeegee 53 is pressed against the first paste layer 16 of the element body 2.

  In the conventional method for manufacturing an electronic component, after forming the element body, a process is performed in which the end is only immersed once or a plurality of times in the conductive paste (the same process as S3 of the present embodiment is performed). The external electrode was formed by firing. However, in this manufacturing method, when the element body is pulled away after immersion, the conductive paste is pulled near the center position of the end face, so that the thickness near the center position of the paste film is increased, while the area near the corner portion of the element body is increased. The thickness was thin. As a result, the thickness of the external electrode is reduced in the vicinity of the corner portion having the radius of curvature, and in the plating step after the firing step, there is a possibility that moisture such as a plating solution may enter the element body from the thinned portion. Therefore, in the electronic component manufactured by the conventional manufacturing method, the characteristics of the electronic component may be deteriorated due to the influence of moisture that has entered the element body during the plating process. In particular, in a ceramic capacitor, since the insulation resistance is small, there is a possibility that a problem of leakage current occurs. Further, when the external electrode is formed by immersing the end portion in the conductive paste a plurality of times, the thickness (T dimension) of the external electrode at the center position of the end surface becomes too thick, which is excessive with respect to the standard dimension of the product. Thickness can be formed.

  In the manufacturing method of the electronic component 1 according to the first embodiment of the present invention, the end surfaces 2a and 2b and the corner portions 9 are covered with respect to the element body 2 in which the radius of curvature is formed at the corner portions 9 of the outer edges of the end surfaces 2a and 2b. The first paste layer 16 is formed by dipping, and the second paste layer 17 is formed by covering the first paste layer 16 with the screen mesh 51 and screen-printing to form the second paste layer 17. Yes. When screen printing is performed on the first paste layer 16 having the rounded corner portions 16a using the screen mesh 51, the screen mesh 51 has flexibility. As shown, when pressed against the squeegee 53, the screen mesh 51 goes around to the corner portion 16a. When the screen mesh 51 goes around to the corner portion 16a, the conductive paste can be attached to substantially the entire curved surface of the corner portion 16a. If screen printing is performed on a corner portion where the corner portion is not rounded, the screen mesh 51 cannot go around the corner portion. Therefore, when screen printing is performed with the screen mesh 51 on the corner portion 16a of the first paste layer 16 having a large radius of curvature, the surface area of the conductive paste adhering portion in the corner portion 16a can be increased. The amount of conductive paste attached can be increased.

  Further, as shown in FIG. 5B, the margin between the first paste layer 16 and the upper surface of the screen mesh 51 is the same as the thickness of the screen mesh 51. The thickness of the attached conductive paste is substantially the same as the thickness of the screen mesh 51. On the other hand, since the curved surface of the corner portion 16 a when the squeegee 53 is not pressed and the screen mesh 51 are separated from each other, the margin between the curved surface of the corner portion 16 a and the upper surface of the screen mesh 51 is the screen mesh 51. It becomes larger than the thickness (in FIG. 5, the maximum dimension M1 of the margin is shown). Therefore, the conductive paste tends to accumulate in the corner portion 16a.

  As shown in FIG. 6, the element body 2A shows that the squeegee 53 passes through the first paste layer 16 on the end face 2a and the screen mesh 51 is separated. When the screen mesh 51 is separated, the conductive paste 52 attached to the screen mesh 51 side is pulled by the second paste layer 17 formed on the end surface 2a side in the vicinity of the corner portion 16a and separated at the position. A state after the conductive paste 52 of the screen mesh 51 is separated from the first paste layer 16 is shown in the element body 2B. Of the conductive paste 52 of the screen mesh 51, the conductive paste that is pulled by the second paste layer 17 and is cut and remains on the second paste layer 17 side hangs down to the curved corner portion 16a side, and the corner portion 16a. It becomes a part of the nearby second paste layer 17. In particular, since the margin between the corner portion 16a and the screen mesh 51 is large as described above, the conductive paste 52 is likely to accumulate in the corner portion 16a, and the thickness of the second paste layer 17 is as follows. It becomes larger in the vicinity of the corner portion 16a.

  Further, the element body 2C shows a state after the conductive paste hangs in the vicinity of the corner portion 16a. Due to the above-described action, a large amount of the conductive paste forming the second paste layer 17 adheres in the vicinity of the corner portion 16a. Therefore, the conductive paste near the center position on the upper surface of the first paste layer 16 is pulled by the corner portion 16a due to the influence of the surface tension. As a result, the amount of the conductive paste is reduced near the center position on the upper surface of the first paste layer 16, and the amount of the conductive paste near the corner portion 16a is further increased. The conductive paste stays at the corner portion 16a due to the surface tension, and therefore does not go around to the side surface side of the first paste layer 16. Therefore, the thickness (H dimension) of the external electrode on the side surface 2c of the element body 2 can be prevented from becoming too large.

  As described above, the thickness of the second paste layer 17 is increased in the vicinity of the corner portion 16a. By forming the second paste layer 17 in this state, firing and plating, it is possible to sufficiently secure the thickness of the external electrode 3 near the corner portion 9. Therefore, in the plating step S8 after the firing step S7, moisture such as a plating solution can be prevented from entering the element body 2 from the vicinity of the corner portion 9, and the reliability of the electronic component 1 can be improved.

  In particular, for example, when the first paste layer 16 is formed by screen printing and the second paste layer 17 is formed by dipping, the first radius is caused by variations in the radius of curvature of the corner portion 9 of the element body 2 due to manufacturing errors. In some cases, the thickness near the corner portion 9 of the paste layer 16 cannot be secured sufficiently. As a result, the thickness of the external electrode near the corner portion 9 cannot be secured. ) May be too large. However, according to the manufacturing method of the present embodiment, since the first paste layer 16 is formed by dipping, the corner portions 16a are naturally rounded. Therefore, the thickness of the external electrode in the vicinity of the corner portion 9 can be reliably ensured regardless of variations in the radius of curvature of the corner portion 9 of the element body 2. Furthermore, since it is possible to prevent the thickness (H dimension) of the external electrode on the side surface 2c of the element body 2 from becoming too large, it is possible to improve solderability at the time of mounting, and to reduce mounting defects.

  Further, in the first paste layer forming step S3, the end surfaces 2a and 2b are immersed in a conductive paste to form the first paste layer 16, whereby the outer electrodes 3 and 4 are orthogonal to the end surfaces 2a and 2b. The size of the portion surrounding the four side surfaces 2c, that is, the B dimension can be increased. Thereby, it is possible to prevent the chip from standing when the electronic component 1 is mounted.

  Further, when the paste layer is formed with a metal mask plate, the paste layer thickness or the like when there is a variation in the height direction or the horizontal direction between the held element bodies 2 in the element body holding step S2. The shape is different for each element body 2. However, in the present embodiment, since the second paste layer is formed using the screen mesh 51 having flexibility, in the element body holding step S2, the height direction or horizontal between the held element bodies 2 is set. Even if there is variation in the direction, the first paste layer having a substantially uniform thickness and shape can be formed between the element bodies 2. Thereby, the productivity of the electronic component 1 can be improved.

  Further, since the conductive paste is attached through the screen mesh 51 to the first paste layer 16 formed on the end surfaces 2a and 2b of the element body 2, the filtration effect of the screen mesh 51 causes the external electrodes 3 and 4 to be attached. It can suppress that a foreign material mixes.

  In addition, the method for manufacturing the electronic component 1 according to the present embodiment further includes a blotting step S4 for pressing the end surfaces 2a and 2b against the flat plate after the first paste layer forming step S3. As a result, the thickness of the first paste layer 16 in the vicinity of the center position of the end faces 2a, 2b can be adjusted, and the dimensions of the external electrodes 3, 4 can be adjusted.

  Here, FIG. 7 is a cross-sectional view showing an example of the electronic component 1 after finishing the second paste layer forming step S6 in the method for manufacturing the electronic component 1 according to the embodiment of the present invention. As shown in FIG. 7, in the electronic component 1 manufactured by the manufacturing method according to the embodiment of the present invention, the boundary portion between the first region 2A and the second region 2B of the element body 2, that is, the innermost portion in the stacking direction. The thickness of the second paste layer 17 at the position of the electrode 8 (the distance between the outer end portion of the second paste layer 17 and the end face 2a of the element body 2 at the position, indicated as F2 in FIG. 7) The difference in the thickness of the first paste layer 16 (the distance between the outer end of the first paste layer 16 and the end face 2a of the element body 2 at the position, which is indicated as F1 in FIG. 7), The thickness of the paste layer 17 corresponding to the center position of the first region 2A of the element body 2 (the distance between the outer end of the second paste layer 17 and the end surface 2a of the element body 2 at the position). Yes, indicated as T2 in FIG. The difference between the thickness of the first layer 16 (the distance between the outer end of the first paste layer 16 and the end face 2a of the element body 2 at the corresponding position, indicated as T1 in FIG. 7) Can do. That is, the relationship of (T2-T1) <(F2-F1) is established among the dimension T2, the dimension T1, the dimension F1, and the dimension F2. As described above, by increasing the size of the second paste layer 17 near the corner portion 9 and decreasing the size of the first region 2A near the center position, the thickness of the outer electrodes 3 and 4 near the corner portion 9 can be reduced. It is possible to form the external electrodes 3 and 4 having a thickness according to the product standard size while ensuring and preventing the ingress of moisture in the plating step S8. Here, the present inventors can prevent the penetration of the plating solution by forming the thickness of the external electrodes (dimensions R1 and R2) in the vicinity of the corner portion 9, but the outermost in the stacking direction. It has been found that adjusting the dimension F affecting the region closer to the internal electrode 8 has a more remarkable effect on the penetration of the plating solution. The reason is also that the thickness of the external electrodes 3 and 4 at the position of the outermost internal electrode 8 in the stacking direction is the shortest distance when moisture reaches the element body 2 in the plating step S8. It was. Therefore, in the present embodiment, by satisfying the relationship of (T2-T1) <(F2-F1), a more advantageous effect on the infiltration of the plating solution compared to the case where the dimension R is simply increased. Can be obtained.

  Next, the Example of the electronic component 1 manufactured with the above-mentioned manufacturing method is shown. In this embodiment, the conductive paste forming the first paste layer 16 has a viscosity of 10 rotations of 60 Pa · s and a viscosity of 100 rotations of 22.3 Pa · s. The viscosity of the second paste layer 17 is 30 Pa · s for 10 rotation viscosity and 23.2 Pa · s for 100 rotation viscosity. This viscosity is a value measured by a coaxial double cylindrical rotational viscometer based on the measuring method shown in “JIS Z 8803”.

  When each paste layer is formed under these conditions, dimensions T1, T2, F1, F2, R1, R2, B1, B2, H1, and H2 shown in FIG. The dimension B2 is a dimension between the position where the thickness of the second paste layer 17 is maximum and the end portion of the portion that wraps around to the side surface 2c, and the dimension B1 is that the thickness of the first paste layer 16 is maximum. And the end portion of the portion that wraps around to the side surface 2c. Note that r in Table 1 is the radius of curvature of the corner portion 9 of the element body 2. Further, the dimension H1 and the dimension H2 are substantially the same size.

  The preferred embodiments of the present invention have been described above. However, the present invention is not necessarily limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  For example, in the present embodiment, the blotting step S4 is performed after the first paste layer forming step S3, but it is not always necessary, and the drying step S5 may be performed without performing the blotting step S4.

  DESCRIPTION OF SYMBOLS 1 ... Electronic component, 2 ... Element body, 2a, 2b ... End surface, 2c ... Side surface, 2A ... 1st area | region, 2B ... 2nd area | region, 3, 4 ... External electrode, 6 ... Dielectric layer, 7, 8 ... Inside Electrode, 9 ... corner portion, 16 ... first paste layer, 17 ... second paste layer, 51 ... screen mesh, S2 ... element body preparation step, S3 ... first paste layer forming step, S4 ... blotting step, S5 ... drying Step, S6 ... Second paste layer forming step.

Claims (3)

A method of manufacturing an electronic component comprising a substantially rectangular parallelepiped element having a pair of end faces and four side faces connecting the end faces, and an external electrode formed on the end face of the element,
An element body preparation step of preparing the element body in which a corner portion between the end surface and the side surface is curved;
A first paste layer forming step of forming the first paste layer by adhering the conductive paste to the end face, the corner part, and the side surface by immersing the end face and the corner part in a conductive paste ;
A drying step of drying the first paste layer;
A second paste layer forming step of forming a second paste layer by covering the dried first paste layer with a screen mesh and screen printing;
A method for manufacturing an electronic component, comprising:   The method of manufacturing an electronic component according to claim 1, further comprising a blotting step of pressing the end face against a flat plate after the first paste layer forming step. The element body is configured by alternately laminating a plurality of dielectric layers and a plurality of internal electrodes in a direction orthogonal to a direction in which the pair of end faces face each other, and the dielectric layer and the internal electrodes In the case of having first regions that are alternately stacked regions and second regions that are regions composed of at least a pair of dielectric layers sandwiching the first regions in the stacking direction,
Of the internal electrodes of the first region, the thickness of the first paste layer at the position of the internal electrode closest to the second region is F1, and the thickness of the second paste layer is F2, The relationship of (T2-T1) <(F2-F1) is established when the thickness of the first paste layer at the center position is T1 and the thickness of the second paste layer is T2. 3. A method for producing an electronic component according to 1 or 2.

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