Chip-type electrolytic capacitors

Abstract

To provide a chip-type electrolytic capacitor that is less prone to misjudgment during visual inspection of the quality of soldering when mounted on a circuit board. [Solution] The chip-type electrolytic capacitor 1 comprises a capacitor body 2 having lead terminals 23 and a base plate 3 that holds the capacitor body 2. The base plate 3 has a base plate body 31 and a plurality of auxiliary terminals 40 embedded in the bottom 32 of the base plate body 31. The auxiliary terminals 40 have a main body portion 41 positioned to the side of the lead terminal storage groove 34 and a projection portion 42 that extends from the main body portion 41 toward the side surface 35(36) of the base plate body 31, with its tip protruding from the side surface 35(36). In a plan view from the bottom 32 side of the base plate body 31, when the width direction is defined as the direction perpendicular to the direction in which the lead terminal storage groove 34 extends, the widthwise center position C of the tip of the projection portion 42 on the side surface 35(36) of the base plate body 31 is further away from the widthwise center line CL1 of the lead terminal storage groove 34 than from the widthwise center line CL2 of the main body portion 41.

Description

【Technical Field】 【0001】 The present invention relates to a chip-shaped electrolytic capacitor used by being surface-mounted on a substrate. 【Background Art】 【0002】 A chip-shaped electrolytic capacitor used by being surface-mounted on a substrate is composed of a capacitor body and a seat plate. The seat plate is formed with an insertion hole through which lead terminals led out from the capacitor body are inserted, and a lead terminal storage groove for bending and storing the lead terminals drawn to the bottom side of the seat plate through the insertion hole in opposite directions (see Patent Document 1). The lead terminal storage groove extends from the insertion hole to the side surface of the seat plate, and the tip of the lead terminal protrudes from the side surface of the seat plate. When mounting the chip-shaped electrolytic capacitor on a substrate, the tip side portion of the lead terminal is electrically connected to a predetermined part of the substrate by soldering. 【0003】 In a chip-shaped electrolytic capacitor that particularly requires high vibration resistance, as in Patent Document 1, a plurality of auxiliary terminals are provided at the bottom of the seat plate, and not only the lead terminals but also the auxiliary terminals are soldered to the substrate to enhance the vibration resistance. In Patent Document 1, the seat plate is composed of a seat plate body (seat plate 10) made of resin and four auxiliary terminals embedded on both sides of a pair of lead terminal storage grooves, and the auxiliary terminals are integrated with the seat plate body by arranging the auxiliary terminals in a mold when insert molding the seat plate body. 【0004】 Patent Document 1 describes that in the manufacturing process of a chip-shaped electrolytic capacitor, two auxiliary terminals on both sides of the lead terminal storage groove are conveyed into a mold in a state of being connected via a hoop material, and the auxiliary terminals are separated from the hoop material after being mounted in the mold or after injection molding. When the positioning of the auxiliary terminals cannot be achieved in the mold in the state of being separated from the hoop material, it is necessary to separate the auxiliary terminals from the hoop material after injection molding. In this case, the tip of the auxiliary terminal will protrude slightly from the side surface of the seat plate body. 【0005】 The auxiliary terminal described in Patent Document 1 has a portion (branch piece 25b and branch plate portion 26) that is bent vertically and positioned along the side of the base plate body adjacent to the portion (branch piece 25a) that is connected to the hoop material. However, some conventional auxiliary terminals do not have such portions. An example of this is shown in Figure 9. The auxiliary terminal 90 shown in Figure 9 has a main body portion 90a and a projection portion 90b whose surfaces are exposed to the outside. The main body portion 90a is positioned along the lead terminal storage groove 92 of the base plate body 91, and the projection portion 90b extends from the main body portion 90a toward the side surface 93 of the base plate body 91. The tip of the projection portion 90b is the position where it is cut when the auxiliary terminal 90 is separated from the hoop material after injection molding. Therefore, the tip of the projection portion 90b protrudes slightly from the side surface 93 of the base plate body 91. The projection portion 90b is connected to the center of the end of the main body portion 90a on the side surface 93. Since the projection 90b and the lead terminal storage groove 92 are located close together, the auxiliary terminal 90 is soldered integrally with the lead terminal 94 in the lead terminal storage groove 92. [Prior art documents] [Patent Documents] 【0006】 [Patent Document 1] Japanese Patent Publication No. 2022-156675 [Overview of the Initiative] [Problems that the invention aims to solve] 【0007】 When mounting chip electrolytic capacitors on a circuit board, including those with auxiliary terminals, a visual inspection is sometimes performed to check the quality of the soldering between the lead terminals and the circuit board. In this visual inspection, the area around the tip of the lead terminal protruding from the side of the base plate is photographed from a direction perpendicular to the mounting surface of the circuit board, and the quality of the soldering is determined by observing the state of the solder fillet formed along the tip of the lead terminal from the captured image. 【0008】 However, in the auxiliary terminal 90 shown in Figure 9, the tip of the projection 90b protrudes slightly from the side surface 93 of the base plate body 91. Therefore, in the visual inspection described above, the tip of the projection 90b may be visible in the image taken of the area around the tip of the lead terminal 94, which may lead to misjudgment. 【0009】 The present invention aims to provide a chip-type electrolytic capacitor that is less prone to misjudgment during visual inspection of the quality of soldering when mounted on a circuit board. [Means for solving the problem] 【0010】 A chip-type electrolytic capacitor according to an embodiment of the present invention is a chip-type electrolytic capacitor comprising a capacitor body having a pair of lead terminals and a base plate that holds the capacitor body, wherein the base plate has an insulating base plate body and a plurality of auxiliary terminals embedded in the bottom of the base plate body on the side opposite to the capacitor body, the base plate body has a pair of insertion holes through which the pair of lead terminals are inserted, and the bottom of the base plate body has a pair of terminals extending from the pair of insertion holes in opposite directions, with their tips reaching the two sides of the base plate body, respectively, the pair A pair of lead terminal storage grooves are formed for storing lead terminals bent in opposite directions, and each auxiliary terminal has a main body portion positioned to the side of the lead terminal storage groove and a projection portion that extends from the main body portion toward the side surface of the base plate body and protrudes from the side surface, and in a plan view as seen from the bottom side of the base plate body, when the width direction is defined as the direction perpendicular to the direction in which the lead terminal storage groove extends, the widthwise center position of the tip of the projection portion on the side surface of the base plate body is further away from the lead terminal storage groove than the widthwise center line of the main body portion. 【0011】 With this configuration, in a plan view, the widthwise center of the tip of the auxiliary terminal's projection is further from the lead terminal storage groove than the widthwise center line of the auxiliary terminal's main body, thus ensuring a wider gap between the tip of the auxiliary terminal's projection and the tip of the lead terminal. Therefore, when a chip-type electrolytic capacitor is mounted on a circuit board by soldering the auxiliary terminal and lead terminal to the board, the tip of the projection is less likely to appear in the image taken around the tip of the lead terminal during visual inspection of the soldering quality. This reduces the occurrence of misjudgments during visual inspection of the soldering quality. 【0012】 Furthermore, in the chip-type electrolytic capacitor according to the embodiment of the present invention, the distance in the width direction between the tip of the projection and the lead terminal housing groove in the plan view may be 1 / 3 or more of the width of the tip on the side side of the base plate body of the lead terminal housing groove. 【0013】 This configuration allows for a wider gap between the tip of the auxiliary terminal's projection and the tip of the lead terminal, thereby more reliably suppressing misjudgments in visual inspection of soldering quality. 【0014】 Furthermore, in the chip-type electrolytic capacitor according to the embodiment of the present invention, the distance in the width direction between the tip of the projection and the lead terminal housing groove may be 1 / 2 or more of the width of the tip of the lead terminal on the side surface of the base plate body, in the plan view. 【0015】 This configuration allows for a wider gap between the tip of the auxiliary terminal's projection and the tip of the lead terminal, thereby more reliably suppressing misjudgments in visual inspection of soldering quality. 【0016】 Furthermore, in the chip-type electrolytic capacitor according to the embodiment of the present invention, the distance in the width direction between the tip of the projection and the lead terminal housing groove in the plan view may be 1 / 3 or more of the maximum width in the width direction of the main body. 【0017】 According to this configuration, since the distance between the tip of the protrusion of the auxiliary terminal and the tip of the lead terminal can be ensured to be wider, it is possible to more reliably suppress the occurrence of misjudgment in the visual inspection of the quality of soldering. 【Effect of the Invention】 【0018】 According to the chip-shaped electrolytic capacitor of the present invention, it is possible to make it difficult to cause misjudgment in the visual inspection of the quality of soldering during board mounting. 【Brief Description of the Drawings】 【0019】 [Figure 1] It is a schematic configuration diagram showing the appearance and internal structure of a chip-shaped electrolytic capacitor according to an embodiment of the present invention. [Figure 2] It is a bottom view of a chip-shaped electrolytic capacitor according to an embodiment of the present invention. [Figure 3] It is a perspective view of the seat plate of FIG. 2. [Figure 4] It is a perspective view of the seat plate of FIG. 2. [Figure 5] (a) is a side view of the seat plate of FIG. 2, and (b) is a cross-sectional view taken along line B-B of FIG. 2. [Figure 6] It is a partial perspective view of the seat plate. [Figure 7] It is a view of FIG. 3 excluding the auxiliary terminal. [Figure 8] It is a partial enlarged view of FIG. 2. [Figure 9] It is a partial enlarged view of the bottom view of a conventional chip-shaped electrolytic capacitor. 【Modes for Carrying Out the Invention】 【0020】 Hereinafter, a chip-shaped electrolytic capacitor 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 8. As shown in FIG. 1, the chip-shaped electrolytic capacitor 1 according to the present embodiment has a capacitor body 2 and a seat plate 3 for holding the capacitor body 2. 【0021】 The capacitor body 2 comprises a capacitor element 20, a bottomed cylindrical outer case 21 in which the capacitor element 20 is housed, a sealing body 22 that seals the open end of the outer case 21, and a pair of lead terminals 23 that are connected to the capacitor element 20 and pass through the sealing body 22. 【0022】 The capacitor element 20 is formed by winding an anode foil and a cathode foil, each having an oxide film formed on a valve-acting metal foil such as aluminum foil, with a separator in between. The anode foil and cathode foil are connected to a pair of lead terminals 23. The separator holds the electrolyte. The electrolyte may be an electrolyte solution alone, or it may be a combination of a solid electrolyte mainly composed of a conductive polymer and an electrolyte solution. 【0023】 The outer casing 21 is made of, for example, aluminum. In this embodiment, the outer casing 21 is a bottomed cylindrical shape, but it may also be a bottomed elliptical cylinder shape. The sealing body 22 is made of an elastic material such as rubber. When manufacturing the capacitor body 2, the capacitor element 20 is housed inside the outer casing 21, the sealing body 22 is placed inside the open end of the outer casing 21, and then the outer casing 21 is sealed by the sealing body 22 by crimping the area of ​​the outer casing 21 facing the sealing body 22. 【0024】 The base plate 3 is positioned opposite the sealing body 22. As shown in Figures 2 and 3, the base plate 3 has an insulating base plate body 31 and a plurality of auxiliary terminals 40 embedded in the bottom 32 of the base plate body 31. The base plate body 31 is made of a heat-resistant synthetic resin. The bottom 32 of the base plate body 31 is located on the opposite side from the sealing body 22. In other words, the bottom 32 of the base plate body 31 is located on the opposite side from the capacitor body 2. The bottom 32 has a flat bottom surface 32a. The bottom surface 32a is the surface that forms the bottom surface of the chip-type electrolytic capacitor 1. As shown in Figure 2, in a plan view of the chip-type electrolytic capacitor 1 viewed from the bottom 32 side, the base plate body 31 is approximately square, but it may be circular, elliptical, or a polygon other than approximately square. As shown in Figure 4, the base plate body 31 consists of a substantially flat bottom plate portion on which the capacitor body 2 is placed, and two side wall portions that surround the outer circumferential surface of the capacitor body 2. The number of side walls may be three or more. 【0025】 The base plate body 31 has a pair of insertion holes 33 through which a pair of lead terminals 23 are inserted. The bottom 32 of the base plate body 31 has a pair of lead terminal storage grooves 34 that extend from the pair of insertion holes 33 in opposite directions, with their tips reaching the two sides 35 and 36 of the base plate body 31, respectively. The pair of lead terminals 23 pulled out from the pair of insertion holes 33 are bent in opposite directions and stored in the pair of lead terminal storage grooves 34. The tips of the pair of lead terminals 23 protrude from the sides 35 and 36 of the base plate body 31, respectively. When mounting the chip-type electrolytic capacitor 1 onto a circuit board (not shown), the tip portions of the pair of lead terminals 23 are soldered to the circuit board. 【0026】 As shown in Figures 2 and 3, the auxiliary terminals 40 are provided in a total of four locations: two on each side of one lead terminal storage groove 34 and two on each side of the other lead terminal storage groove 34. The two auxiliary terminals 40 on each side of each lead terminal storage groove 34 are symmetrical. Furthermore, the two auxiliary terminals 40 on each side of one lead terminal storage groove 34 have the same shape as the two auxiliary terminals 40 on each side of the other lead terminal storage groove 34. 【0027】 Each auxiliary terminal 40 has a main body portion 41 and a projection portion 42, the surface of which is exposed to the outside. Each main body portion 41 is positioned to the side of the lead terminal storage groove 34. Each main body portion 41 is provided along the lead terminal storage groove 34 at a position away from the sides 35 and 36 where the tip of the lead terminal storage groove 34 is located. Each projection portion 42 extends from the main body portion 41 toward the nearby sides 35 and 36. Each projection portion 42 is connected to a portion of the end of the main body portion 41 on the side 35 and 36 side and is positioned away from the lead terminal storage groove 34. The tip of each projection portion 42 protrudes slightly from the sides 35 and 36 (see Figure 8). Both the surface of each projection portion 42 and the sides of the portion that protrudes from the sides 35 and 36 are exposed to the outside. Each auxiliary terminal 40 has a surface that lies on the same plane as the bottom surface 32a of the base plate body 31. 【0028】 As shown in Figures 5(a) and 5(b), each auxiliary terminal 40 is a plate-shaped member. Multiple auxiliary terminals 40 are integrated with the base plate body 31 by being placed inside the mold during insert molding of the base plate body 31. The two auxiliary terminals 40 on both sides of the lead terminal storage groove 34 are placed inside the mold connected to the hoop material 46 shown in Figure 6. After injection molding, the auxiliary terminals 40 are separated from the hoop material 46 at the position of the tip of the projection 42 of the auxiliary terminal 40. As shown in Figure 7, the base plate body 31 has multiple auxiliary terminal storage grooves 37 formed therein, each housing multiple auxiliary terminals 40. Note that Figure 7 is a view of Figure 3 with the auxiliary terminals 40 removed. The auxiliary terminal storage grooves 37 are connected to the lead terminal storage groove 34. 【0029】 The following describes the overall shape of the auxiliary terminal 40, including the portion embedded in the seat plate body 31. 【0030】 As shown in Figures 5(a), 5(b), and 6, the auxiliary terminal 40 is composed of a first plate portion 43, a second plate portion 44, a third plate portion 45, and a projection portion 42. The first plate portion 43, the second plate portion 44, the third plate portion 45, and the projection portion 42 are all flat plates. As shown in Figure 6, the projection portion 42 is connected to the first plate portion 43. The surface of the projection portion 42 is coplanar with the surface of the first plate portion 43. As shown in Figures 5(a) and 5(b), the second plate portion 44 extends from the end of the first plate portion 43 on the lead terminal storage groove 34 side in a direction approximately perpendicular to the first plate portion 43. The tip of the second plate portion 44 is located further back than the bottom surface of the lead terminal storage groove 34. In other words, in a direction perpendicular to the bottom surface 32a, the tip of the second plate portion 44 is further away from the bottom surface 32a than the bottom surface of the lead terminal storage groove 34. The third plate portion 45 extends diagonally to the first plate portion 43 from the end of the first plate portion 43 opposite to the second plate portion 44. In a direction perpendicular to the bottom surface 32a, the tip of the third plate portion 45 is separated from the bottom surface 32a to the same extent as the bottom surface of the lead terminal storage groove 34. 【0031】 At least the back surfaces of the first plate portion 43, the second plate portion 44, the third plate portion 45, and the projection portion 42 are in contact with the auxiliary terminal housing groove 37. The surface of the first plate portion 43 is exposed to the outside. Most of the surface of the second plate portion 44 on the side facing the first plate portion 43 is exposed to the outside within the lead terminal housing groove 34. A portion of the second plate portion 44 is embedded in the base plate body 31. In other words, both the front and back surfaces of a portion of the second plate portion 44 are in contact with the auxiliary terminal housing groove 37. A portion of the surface of the third plate portion 45 is exposed to the outside. Most of the third plate portion 45 is embedded in the base plate body 31. In other words, both the front and back surfaces of most of the third plate portion 45 are in contact with the auxiliary terminal housing groove 37. The main body portion 41 consists of the first plate portion 43, a portion of the second plate portion 44 whose surface is exposed, and a portion of the third plate portion 45 whose surface is exposed. As shown in Figures 5 and 6, the surface of the first plate portion 43 and the surface of the projection portion 42 are located on the same plane as the bottom surface 32a of the seat plate body 31. In other words, the surface of a portion of the body portion 41 and the surface of the projection portion 42 are located on the same plane as the bottom surface 32a of the seat plate body 31. Furthermore, the surface of the portion of the seat plate body 31 between the projection portion 42 and the lead terminal storage groove 34 is located on the same plane as the bottom surface 32a of the seat plate body 31. In this embodiment, the surfaces of the portions of the seat plate body 31 on both sides of the projection portion 42 are located on the same plane as the bottom surface 32a of the seat plate body 31. 【0032】 As shown in Figure 6, the projection 42 is connected to the end of the main body 41 on the side 35, 36 side, near the third plate 45. The edge of the projection 42 opposite to the lead terminal storage groove 34 is located closer to the lead terminal storage groove 34 than the connection portion between the first plate 43 and the third plate 45. However, a portion of the edge of the projection 42 opposite to the lead terminal storage groove 34 may be located further from the lead terminal storage groove 34 than the connection portion between the first plate 43 and the third plate 45. Of the two inner corners of the connection portion between the main body 41 and the projection 42, the inner corner 47 on the third plate 45 side is approximately semi-circular in shape when viewed from the bottom 32 side of the base plate body 31. The inner corner 47 is provided across the projection 42, the first plate 43, and the third plate 45. Inside the inner corner portion 47 are the flat surface 38 and the inclined surface 39 of the seat plate body 31. The flat surface 38 is located on the same plane as the surface of the projection portion 42 and the first plate portion 43. The inclined surface 39 is formed on approximately the same plane as the surface of the third plate portion 45. Because the semicircular arc of the inner corner portion 47 is formed across the projection portion 42, the first plate portion 43 and the third plate portion 45, resin can easily enter the inside of the inner corner portion 47 during injection molding of the seat plate body 31. In addition, the other of the two inner corner portions is approximately a quarter-circle arc. The two inner corner portions of the connecting portion between the main body portion 41 and the projection portion 42 may be approximately right-angle corners. 【0033】 The surface of the second plate portion 44 lies substantially flush with a portion of the side surface of the lead terminal storage groove 34 of the base plate body 31. The width of the groove formed by the lead terminal storage groove 34 of the base plate body 31 and the two second plate portions 44 is constant along its entire length, but does not have to be constant. For example, the width of the groove formed by the lead terminal storage groove 34 of the base plate body 31 and the two second plate portions 44 may gradually increase as it moves away from the insertion hole 33. The tip portion of each lead terminal 23 is positioned within the groove formed by the lead terminal storage groove 34 of the base plate body 31 and the two second plate portions 44. 【0034】 Multiple auxiliary terminals 40 are soldered to the circuit board together with a pair of lead terminals 23 when mounted on the circuit board. This increases the strength of the soldering of the chip-type electrolytic capacitor 1 to the circuit board, thereby improving the vibration resistance of the chip-type electrolytic capacitor 1. Soldering is performed by a reflow soldering process. Both the main body 41 and the projection 42 of each auxiliary terminal 40 are soldered to the circuit board. The auxiliary terminals 40 are connected to the lead terminals 23 in the lead terminal storage grooves 34 via solder. In other words, the auxiliary terminals 40 are soldered integrally with the lead terminals 23 in the lead terminal storage grooves 34. Solder is also provided on the portion of the base plate body 31 between the projection 42 and the lead terminal storage grooves 34. The portion of the circuit board to which the auxiliary terminals 40 are soldered may or may not be electrically connected to the portion of the circuit board to which the main terminals are soldered. 【0035】 Next, the position and size of the projection 42 of the auxiliary terminal 40 will be explained in more detail using Figure 8. 【0036】 Here, in a plan view of the chip-type electrolytic capacitor 1 from the bottom 32 side, the direction perpendicular to the direction in which the lead terminal storage groove 34 extends is defined as the width direction Z. Also, in a plan view, the straight line passing through the center of the width direction Z of the lead terminal storage groove 34 is defined as the width direction centerline CL1 of the lead terminal storage groove 34, and the straight line parallel to the width direction centerline CL1 of the lead terminal storage groove 34 and passing through the center of the width direction Z of the main body 41 is defined as the width direction centerline CL2 of the main body 41. 【0037】 In a plan view, the widthwise center position C of the tip of the projection 42 of each auxiliary terminal 40 is further from the widthwise center line CL1 of the lead terminal storage groove 34 than from the widthwise center line CL2 of the main body 41 to which the projection 42 is connected. This configuration allows for a wider gap between the tip of the projection 42 of the auxiliary terminal 40 and the tip of the lead terminal 23. Therefore, when the chip-type electrolytic capacitor 1 is mounted on the circuit board by soldering the auxiliary terminals 40 and the lead terminals 23 to the board, the tip of the projection 42 is less likely to appear in the image taken around the tip of the lead terminal 23 during the visual inspection of the soldering quality. This reduces the occurrence of misjudgments during the visual inspection of the soldering quality. 【0038】 In a plan view, the distance D1 in the width direction Z between the widthwise center position C of the tip of the projection 42 of each auxiliary terminal 40 and the widthwise center line CL2 of the main body 41 is greater than 1 / 4 of the width W42 of the tip of the projection 42. With this configuration, a wider gap can be secured between the tip of the projection 42 of the auxiliary terminal 40 and the tip of the lead terminal 23, thereby more reliably suppressing the occurrence of misjudgments in visual inspection of the quality of soldering. However, the distance D1 may be the same as 1 / 4 of the width W42. It is preferable that the distance D1 is 1 / 4 or more of the width W42, but it is not limited to this. Note that the width W42 of the tip of the projection 42 is the width Z of the tip of the projection 42. 【0039】 In a plan view, the distance D1 is greater than 1 / 4 of the distance D2 in the width direction Z between the tip of the projection 42 and the lead terminal storage groove 34. With this configuration, a wider gap can be secured between the tip of the projection 42 of the auxiliary terminal 40 and the tip of the lead terminal 23, thereby more reliably suppressing the occurrence of misjudgments in visual inspection of the quality of soldering. However, the distance D2 may be the same as 1 / 4 of the distance D2. It is preferable that the distance D1 is 1 / 4 or more of the distance D2, but it is not limited to this. The distance D2 may be, for example, 1.0 mm or more. 【0040】 In a plan view, the distance D2 in the width direction Z between the tip of the projection 42 of each auxiliary terminal 40 and the lead terminal storage groove 34 is greater than half the width W34 in the width direction Z of the tip of the lead terminal storage groove 34. With this configuration, a wider gap can be secured between the tip of the projection 42 of the auxiliary terminal 40 and the tip of the lead terminal 23, thereby more reliably suppressing the occurrence of misjudgments in visual inspection of the quality of soldering. However, the distance D2 may be the same as half the width W34. It is preferable, but not limited to, that the distance D2 be half or more of the width W34. Also, it is preferable, but not limited to, that the distance D2 be one-third or more of the width W34. Note that the tip of the lead terminal storage groove 34 is the end located on the side surfaces 35 and 36 of the lead terminal storage groove 34. 【0041】 In a plan view, the distance D2 is greater than half the width W23 of the tip of the lead terminal 23. This configuration allows for a wider gap between the tip of the projection 42 of the auxiliary terminal 40 and the tip of the lead terminal 23, thereby more reliably suppressing the occurrence of misjudgments in visual inspection of the quality of soldering. However, the distance D2 may be the same as half the width W23. It is preferable, but not limited to, that the distance D2 be half or more of the width W23. The width W23 of the tip of the lead terminal 23 is the width Z in the width direction of the tip of the lead terminal 23. 【0042】 In a plan view, the distance D2 is greater than 1 / 3 of the width W41 of the main body 41 in the width direction Z. With this configuration, a wider gap can be secured between the tip of the projection 42 of the auxiliary terminal 40 and the tip of the lead terminal 23, thereby more reliably suppressing the occurrence of misjudgments in visual inspection of the quality of soldering. However, the distance D2 may be the same as 1 / 3 of the width W41. It is preferable, but not limited to, that the distance D2 be 1 / 3 or more of the width W41. In this embodiment, the width W41 of the main body 41 in the width direction Z is constant. That is, the width W41 is the maximum width of the main body 41 in the width direction Z. 【0043】 In a plan view, the distance D2 is greater than the width W42 of the tip of the projection 42. This configuration allows for a wider gap between the tip of the projection 42 of the auxiliary terminal 40 and the tip of the lead terminal 23, thereby more reliably suppressing the occurrence of misjudgments in visual inspection of the quality of soldering. However, the distance D2 may be the same as the width W42. It is preferable, but not limited to, that the distance D2 be greater than or equal to the width W42. Also, it is preferable, but not limited to, that the distance D2 be 2 / 3 or more of the width W42. 【0044】 In a plan view, the distance D3 in the width direction Z between the tip of the projection 42 of each auxiliary terminal 40 and the tip portion of the lead terminal 23 housed in the lead terminal storage groove 34 is approximately the same as the width W23 of the tip of the lead terminal 23 housed in the lead terminal storage groove 34. With this configuration, a wider gap can be secured between the tip of the projection 42 of the auxiliary terminal 40 and the tip of the lead terminal 23, thereby more reliably suppressing the occurrence of misjudgments in visual inspection of the quality of soldering. However, the distance D3 may be greater than the width W23. It is preferable, but not limited to, that the distance D3 be greater than or equal to the width W23. It is preferable, but not limited to, that the distance D3 be greater than or equal to 2 / 3 of the width W23. 【0045】 In a plan view, the distance D3 is greater than 2 / 3 of the width W34 at the tip of the lead terminal storage groove 34, but may also be equal to 2 / 3 of the width W34. It is preferable, but not limited to, that the distance D3 be 2 / 3 or more of the width W34. It is also preferable that the distance D3 be 1 / 2 or more of the width W34. With this configuration, a wider gap can be secured between the tip of the projection 42 of the auxiliary terminal 40 and the tip of the lead terminal 23, thereby more reliably suppressing the occurrence of misjudgments in visual inspection of the quality of soldering. However, the distance D3 may be less than 1 / 2 of the width W34. 【0046】 In a plan view, the distance D3 is greater than half the width W41 of the main body 41 in the width direction Z, but may be the same as half the width W41. It is preferable that the distance D3 is half or more of the width W41, but is not limited to this. It is also preferable that the distance D3 is two-thirds or more of the width W41. With this configuration, a wider gap can be secured between the tip of the projection 42 of the auxiliary terminal 40 and the tip of the lead terminal 23, thereby more reliably suppressing the occurrence of misjudgments in visual inspection of the quality of soldering. However, the distance D3 may be less than two-thirds of the width W41. 【0047】 In a plan view, the distance D3 is greater than the width W42 of the tip of the projection 42, but may be the same as the width W42. Preferably, the distance D3 is greater than or equal to the width W42. With this configuration, a wider gap can be secured between the tip of the projection 42 of the auxiliary terminal 40 and the tip of the lead terminal 23, thereby more reliably suppressing the occurrence of misjudgments in visual inspection of the quality of soldering. However, the distance D3 may be less than the width W42. 【0048】 Furthermore, by setting the distance D1 in the width direction Z between the width direction center position C of the tip of the projection 42 of the auxiliary terminal 40 and the width direction center line CL2 of the main body 41 to be greater than or equal to one of the predetermined lengths described above, the occurrence of misjudgments in visual inspection of the quality of soldering can be more reliably suppressed. 【0049】 Furthermore, by setting the distance D2 in the width direction Z between the tip of the projection 42 of the auxiliary terminal 40 and the lead terminal storage groove 34 to be greater than or equal to one of the predetermined lengths described above, the occurrence of misjudgments in visual inspection of the quality of soldering can be more reliably suppressed. 【0050】 Furthermore, by setting the distance D3 in the width direction Z between the tip of the projection 42 of the auxiliary terminal 40 and the tip portion of the lead terminal 23 housed in the lead terminal storage groove 34 to be greater than or equal to one of the predetermined lengths mentioned above, the occurrence of misjudgments in visual inspection of the quality of soldering can be more reliably suppressed. 【0051】 Furthermore, of the two inner corners of the connection portion between the main body portion 41 and the projection portion 42 of the auxiliary terminal 40, the inner corner portion 47 on the third plate portion 45 side is approximately semi-circular, and the semi-circular arc is formed across the projection portion 42, the first plate portion 43, and the third plate portion 45. As a result, the position P2 of the end of the tip of the projection portion 42 of the auxiliary terminal 40 on the third plate portion 45 side (opposite the lead terminal storage groove 34) is further away from the lead terminal storage groove 34 than the position P1 closest to the lead terminal storage groove 34 within the inner corner portion 47. In other words, the projection portion 42 of the auxiliary terminal 40 is curved away from the lead terminal storage groove 34. This makes it possible to easily separate the tip of the projection portion 42 of the auxiliary terminal 40 from the lead terminal storage groove 34, thereby more reliably suppressing the occurrence of misjudgments in visual inspection of the quality of soldering. 【0052】 Although preferred embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various design modifications are possible as long as they are within the scope of the claims. 【0053】 In the above embodiment, the width in the width direction Z (the direction perpendicular to the direction in which the lead terminal storage groove 34 extends) of the main body portion 41 of the auxiliary terminal 40 is constant in a plan view from the bottom 32 side of the base plate body 31. However, in the chip-type electrolytic capacitor of the present invention, the width in the direction perpendicular to the direction in which the lead terminal storage groove extends of the main body portion is not constant in a plan view from the bottom side of the base plate body. If the width is not constant, the width direction center line of the main body portion in the present invention is a straight line that passes through the center position in the width direction of the maximum width in the direction perpendicular to the direction in which the lead terminal storage groove extends of the main body portion, and is parallel to the direction in which the lead terminal storage groove extends, in a plan view. 【0054】 In the above embodiment, the two auxiliary terminals 40 on both sides of the lead terminal storage groove 34 are symmetrical, but they do not have to be symmetrical. In the above embodiment, the two auxiliary terminals 40 on both sides of one lead terminal storage groove 34 are the same shape as the two auxiliary terminals 40 on both sides of the other lead terminal storage groove 34, but they do not have to be symmetrical. 【0055】 The chip-type electrolytic capacitor 1 in the above embodiment is an example having four auxiliary terminals in the present invention, but the number of auxiliary terminals in the present invention may be less than four. In addition to the multiple auxiliary terminals in the present invention, the chip-type electrolytic capacitor of the present invention may have auxiliary terminals other than those in the present invention at the bottom of the base plate. [Explanation of Symbols] 【0056】 1. Chip-type electrolytic capacitor 2 Capacitor body 3 Seat board 20 Capacitor elements 21 Outer case 22 Sealing body 23 Lead terminals 31 Seat board body 32 Bottom 33 Through hole 34 Lead terminal storage groove 35, 36 Side view 40 Auxiliary terminals 41 Main body 42 Protrusion C. Central position in the width direction of the tip of the protrusion CL1 Lead terminal storage groove widthwise centerline CL2 Main body widthwise centerline W23 Width of the tip of the lead terminal W34 Width of the tip of the lead terminal storage groove W41 Width of the main body (maximum width in the width direction of the main body) W42 Width of the tip of the protrusion Z width direction

Claims

[Claim 1] A chip-type electrolytic capacitor comprising a capacitor body having a pair of lead terminals and a base plate for holding the capacitor body, The seat plate has an insulating seat plate body and a plurality of auxiliary terminals embedded in the bottom of the seat plate body on the side opposite to the capacitor body. The base plate body has a pair of insertion holes through which the pair of lead terminals are inserted. The bottom of the base plate body has a pair of lead terminal storage grooves formed therein, which extend in opposite directions from the pair of insertion holes, with their tips reaching the two sides of the base plate body, and which house the pair of lead terminals by bending them in opposite directions. Each of the auxiliary terminals has a main body portion positioned to the side of the lead terminal storage groove, and a projection portion that extends from the main body portion toward the side surface of the base plate body and protrudes from said side surface. A chip-type electrolytic capacitor characterized in that, in a plan view of the base plate body as seen from the bottom side, when the width direction is defined as the direction perpendicular to the direction in which the lead terminal storage groove extends, the widthwise center position of the tip of the projection on the side side of the base plate body is further from the lead terminal storage groove than the widthwise center line of the main body. [Claim 2] The chip-type electrolytic capacitor according to claim 1, characterized in that, in the plan view, the distance in the width direction between the tip of the projection and the lead terminal housing groove is 1 / 3 or more of the width of the tip on the side surface of the base plate body of the lead terminal housing groove. [Claim 3] The chip-type electrolytic capacitor according to claim 1, characterized in that, in the plan view, the distance in the width direction between the tip of the projection and the lead terminal housing groove is 1 / 2 or more of the width of the tip of the lead terminal on the side surface of the base plate body. [Claim 4] The chip-type electrolytic capacitor according to claim 1, characterized in that, in the plan view, the distance in the width direction between the tip of the projection and the lead terminal storage groove is 1 / 3 or more of the maximum width in the width direction of the main body.

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