JP2007281212A - Chip electronic component, and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chip electronic component which can be mounted on a circuit board in a desired condition by solving a problem with a positional displacement or the like upon chip standing or soldering in the prior art. <P>SOLUTION: In the chip electronic component having an element body 11 of a nearly rectangular parallelepiped shape, one and the other of a pair of external electrodes 15, 16 formed on a pair of end faces 14 has wraparounds 17, 18 extended along parts of a pair of main surfaces 12 adjacent to the end faces and along parts of the end faces 14 and also extended toward the external electrodes 16, 15 respectively. When one 17 of the wraparounds of the external electrode 15 has a length T1 and the other 18 of the wraparounds of the other external electrode 16 present on the same main plane as the wraparound 17 of the external electrode 15 has a length T2; a difference between the lengths T1 and T2 is set not to be larger than 0.02 mm, so that the electronic component can be mounted in a desired condition on a land of a circuit board or the like without a solder displaced to one side of the land. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a chip-type electronic component having a pair of external electrodes at its ends, such as a chip-type ceramic capacitor, a chip-type varistor, and a chip-type resistor, and a method for manufacturing the same.

  A conventional chip type electronic component manufacturing method will be described by taking a chip type ceramic capacitor as an example.

  4 is a perspective view of the chip-type ceramic capacitor 40. An element body 41 of the chip-type ceramic capacitor 40 includes a pair of main planes 42, a pair of side surfaces 43 orthogonal to the main planes 42, and a pair of main planes and the side surfaces orthogonal to the side surfaces. The end surfaces (surfaces hidden under the external electrodes 45 and 46 in FIG. 4) have a substantially rectangular parallelepiped shape, and the external electrodes 45 and 46 have a pair of both end surfaces, a pair of main planes adjacent thereto, and a pair of It is extended to a part of the side.

  The pair of external electrodes 45 and 46 have external electrode wrap-around portions 47 and 48 extending from one end surface side to the other end surface side.

For example, Patent Document 1 can be cited as prior art document information relating to the formation of such external electrodes.
Japanese Patent No. 2760189

  As electronic devices have become smaller and higher in performance in recent years, smaller and higher performance chip-type electronic components have been demanded, and problems due to the external electrodes may occur with downsizing.

  For example, when soldering a small chip-type electronic component having a length of 1.0 mm, a width of 0.5 mm, and a thickness of 0.5 mm to a pair of lands formed on a circuit board, the external electrode Depending on the state, the multilayer ceramic electronic component is pulled to one of the pair of lands, and if it cannot be mounted at the desired position or if the degree of pulling is significant, only one of the external electrodes of the chip-type electronic component is soldered In some cases, there is a problem of so-called chip standing in which electronic components stand perpendicular to the circuit board.

  Moreover, after forming the coating film by an electrode paste on a flat plate as described in patent document 1, and pressing one end surface of an element | base_body to this coating film and providing a paste, it is on the other end surface after drying. Similarly, in the method of applying the paste and separately forming the pair of external electrodes, depending on the holding state of the element body, there is a problem that the external electrodes are formed obliquely as shown in FIG. There was a problem of being easy to do.

  Furthermore, when the paste is applied to the other end surface after drying, the external electrode must already be applied and dried in one end surface, and the element body must be accurately retained. Since it is affected by the shape of one of the external electrodes, it may be difficult to accurately hold the element body, and the shape of the external electrode may become uneven. In particular, in an ultra-small chip-type electronic component having a length of 0.4 mm, a width of 0.2 mm, and a thickness of 0.2 mm, the element body must be held with high accuracy, and the yield in forming the external electrode is reduced. There was a thing.

  Accordingly, the present invention solves conventional problems such as chip standing and misalignment during soldering, and provides a chip-type electronic component that can be mounted on a circuit board in a desired state, and a method for manufacturing the chip-type electronic component. The purpose is to do.

  In order to achieve this object, the chip-type electronic component of the present invention is an electronic component having a substantially rectangular parallelepiped element, and the element includes a pair of main planes and a pair of side surfaces orthogonal to the main planes, It has a pair of end surfaces orthogonal to the main plane and side surfaces, and a pair of external electrodes formed on the pair of end surfaces, and one and the other external electrodes are a pair of main planes and a pair of side surfaces adjacent to the end surfaces. A part of which has a wraparound portion extending in the direction of the other and one external electrode, and the length of the wraparound portion of the one external electrode formed on the pair of main planes is T1, A chip-type electron having a difference between T1 and T2 of 0.02 mm or less, where T2 is the length of the wraparound portion of the other external electrode on the same main plane as the wraparound portion of one external electrode Components. With, without soldering is biased on one of the land such as a circuit board, it is possible to provide a chip-type electronic component can be mounted in a desired state.

  Further, the chip type electronic component manufacturing method of the present invention is arranged in the step of applying the electrode paste at a predetermined interval through which both ends of the chip type electronic component body pass, and further the chip type electronic component element body Is performed using a paste applying apparatus having a pair of U-shaped paste applying portions having a predetermined width in the direction in which the electrode passes, and an electrode paste film is formed on the U-shaped inner surface of the paste applying portion. The chip-type electronic component element passes through this U-shaped paste applying portion to apply an electrode paste, and a pair of external electrodes are simultaneously attached to both ends of the chip-type electronic component element with high accuracy. Can be formed.

  The chip-type electronic component according to the present invention is an electronic component having a substantially rectangular parallelepiped body, and one and the other external electrodes of a pair of external electrodes formed on a pair of end surfaces are a pair of main electrodes adjacent to the end surfaces. The flat surface and a part of the pair of side surfaces each have a wraparound portion extending toward the other and one of the external electrodes, and the length of the wraparound portion of one external electrode is T1, which is on the same main plane When the length of the wraparound portion of the other external electrode is T2, the difference between T1 and T2 is 0.02 mm or less, and soldering is biased to one side of a land such as a circuit board. The chip-type electronic component that can be mounted in a desired state can be provided.

  Hereinafter, a chip-type electronic component and a manufacturing method thereof according to the present invention will be described using a multilayer chip-type ceramic capacitor as an example with reference to one embodiment and FIGS.

  In FIG. 1 to FIG. 3, the same components are denoted by the same reference numerals and description thereof is omitted.

  1A is a perspective view of the chip-type ceramic capacitor 10, FIG. 1B is a cross-sectional view of the chip-type ceramic capacitor 10, and an element body 11 of the chip-type ceramic capacitor 10 includes a pair of main planes 12, It has a substantially rectangular parallelepiped shape having a pair of side surfaces 13 orthogonal to the main surface 12 and a pair of end surfaces 14 orthogonal to the side surface 13, and the external electrodes 15, 16 are a pair of both end surfaces 14 and a pair adjacent thereto. The main plane 12 and a part of the pair of side surfaces 13 are extended.

  The pair of external electrodes 15 and 16 have external electrode wrap-around portions 17 and 18 extending from one end surface side to the other end surface side, and are alternately connected to the internal electrodes 19 shown in FIG. Has been.

  FIG. 2 is a schematic view of a paste application apparatus 21 according to the method for manufacturing a chip-type electronic component of the present invention, and the electrode paste 23 charged in the electrode paste container 22 is supplied to the paste application unit 25 through a pipe 24. .

  FIG. 3 is an enlarged cross-sectional view of the main part of the paste application unit 25 of FIG. 2, in which both ends of the chip-type ceramic capacitor element body 11 are arranged at a predetermined interval through which the chip-type ceramic capacitor element body 11 passes. The pair of paste application portions 25 is provided with an electrode paste reservoir 32 and a number of fine holes 33 having a diameter of about 0.05 mm. The electrode paste 23 supplied from the pipe 24 oozes out through the hole 33 through the electrode paste reservoir 32, whereby a film 34 made of the electrode paste is formed with a uniform thickness on the U-shaped inner surface.

  When the chip-type ceramic capacitor body 11 passes through the paste applying portion 25, the film 34 has a uniform width on the chip-type ceramic capacitor body 11 and is not inclined with respect to the end surface. In addition, the electrode paste can be applied with high accuracy, and the wraparound portions 17 and 18 of the external electrode can be formed with high accuracy.

  At this time, the chip-type ceramic capacitor element body 11 is held by a thin jig (not shown) having chuck fingers provided so as to sandwich the pair of side surfaces 13 of the chip-type ceramic capacitor element body 11, and paste is applied. The part 25 can be passed.

  Next, the manufacturing method of the chip type ceramic capacitor according to the present invention will be described in detail.

  First, ceramic slurry is prepared by mixing ceramic powder mainly composed of barium titanate, polyvinyl butyral resin as an organic binder component, solvent, plasticizer, dispersant, etc., and then using a doctor blade method to make a green sheet Is made.

  On the other hand, an electrode paste for an internal electrode is prepared by mixing Ni alone or a metal powder containing Ni as a main component and containing an additive such as Cu and a vehicle made of a solvent, a resin, a plasticizer, and the like. Is applied on a green sheet by a screen printing method to form a conductor layer.

  Next, 80 green sheets on which the conductor layer is formed are stacked, and one or more green sheets not coated with electrode paste are stacked on the upper and lower layers to form upper and lower protective layers. A body green block was prepared.

  Next, this multilayer green block was cut into dimensions of 1.2 mm length × 0.6 mm width × 0.6 mm thickness to produce a multilayer ceramic green chip (not shown). At this time, both end surfaces of the multilayer ceramic green chip have a structure in which one end portion of the conductor layer is exposed on different end surfaces alternately facing each other with the green sheet interposed therebetween.

  Next, the multilayer ceramic green chip is put into a batch-type atmosphere firing furnace and debindered, and then fired in a range of 1200 ° C. to 1250 ° C. in a reducing atmosphere with a mixed gas of nitrogen gas and hydrogen gas. A type ceramic capacitor body 11 was obtained.

  Next, a pair of external electrodes 15 and 16 were formed on both ends of the chip-type ceramic capacitor element body 11 using the paste applying apparatus shown in FIGS.

  About the pair of wraparound portions 17 and 18 in the main plane of the external electrodes 15 and 16 of 100 samples, the length of the wraparound portion on the same main plane shown in FIG. The length of the wraparound portion 18 between T1 and the other external electrode was T2. As a result of calculating the difference between the lengths T1 and T2, both were 0.02 mm or less. In FIG. 1 (b), there are a pair of wraparound portions formed on the same upper main plane and a pair of wraparound portions formed on the lower lower main plane. T1 and T2 are on the same main plane. Therefore, for example, for 100 samples, the difference between T1 and T2 is 200 measured values.

  On the other hand, as a conventional comparative example, for example, a method described in Patent Document 1 is used to form a coating film with an electrode paste on a flat surface, and press the one end face of the element body on this coating film to give the paste Similarly, with respect to 100 comparative samples in which the external electrodes 45 and 46 are formed as shown in FIG. 4 by the same method of applying the paste to the other end face after drying, the pair of wraparound portions 47 and 48 on the main plane is similarly applied. Similarly, the lengths T1 and T2 were measured, and the difference between T1 and T2 was calculated. As a result, the difference between T1 and T2 was 0.03 mm to 0.2 mm and had a large variation. In addition, in the case where the wraparound portion is formed obliquely like the wraparound portion 47 of the external electrode 45 in FIG. 4, the longest portion is the length of the wraparound portion.

  Furthermore, Ni plating (not shown) and solder plating (not shown) were formed by electrolytic plating on the external electrodes of the sample of this embodiment and the sample of the comparative example.

  A mounting test on a circuit board was performed using 10000 samples according to an embodiment of the present invention thus manufactured and 10000 samples of comparative examples according to a conventional method.

  As conditions for the mounting test, a solder paste was applied to the mounting board with a land width of 0.5 mm, a land interval of 0.5 mm, and a mounting interval of 0.1 mm, and then the sample was mounted on the center of the land and then reflow oven. Soldering was performed.

  The results of evaluating the mounting state of 10,000 samples after soldering are shown in (Table 1). For mounting position deviation, samples in which either one of the soldering positions was shifted 0.02 mm or more from the land were counted, and in the case of chip standing, the sample soldered to only one land was counted.

  As is apparent from the results of (Table 1), in the sample in which the external electrode was formed according to the present embodiment, no chip was found, and the mounting position was within a predetermined range.

  On the other hand, in the sample of the comparative example, three of the 10,000 pieces were misaligned, and five of the 10,000 pieces stood up. Further, as a result of measuring the difference between T1 and T2 of the sample of the comparative example in which mounting position deviation and chip standing occurred, the variation was as large as 0.03 mm to 0.2 mm.

  This is because when the tensile force is generated in the element due to the surface tension between the melted solder during soldering and the surface of the external electrode portion of the element, T1 and T2 in the sample in which the mounting position deviation and the chip standing of the comparative example occur. Since the difference of 0.03 mm to 0.2 mm is large, the tensile force applied to the element is biased, resulting in mounting position deviation and chip standing.

  In the present embodiment, a study was made using a chip type ceramic capacitor called a 1005 size having a length of 1.0 mm and a width of 0.5 mm. For example, 0608 size (length 0.6 mm, width 0.3 mm) In addition, when external electrodes are formed on an extremely small chip-type ceramic capacitor body such as 0402 size (length 0.4 mm, width 0.2 mm) and mounted on a circuit board, the surface tension of the dissolved solder is The effect of the present invention is further important because the mounting position shift and chip standing due to non-uniformity of the external electrode width are likely to occur.

  Further, not only chip-type ceramic capacitors but also chip-type resistors and chip-type varistors are effective for forming external electrodes of extremely small chip-type electronic components such as 1005 size, 0608 size, and 0402 size.

  That is, in such an extremely small electronic component, the element is light and the influence of the surface tension of the melted solder becomes remarkable, so that the mounting becomes even more difficult. The difference between T1 and T2 is set to 0.02 mm or less, where T1 is T1 and the length of the wraparound portion of the other external electrode on the same main plane as the wraparound portion of this one external electrode is T2. Thus, it is possible to provide a chip-type electronic component that can be mounted on a circuit board in a desired state while suppressing a chip standing at the time of mounting and a positional shift at the time of soldering.

  In the present embodiment, the difference between the lengths T1 and T2 of the wraparound portion on the main plane is 0.02 mm or less, but the difference between the lengths of the wraparound portions on the same side is 0.02 mm or less. Thus, even when the mounting is performed with the side face down, it is possible to further prevent chip standing and mounting position shift.

  An electronic component according to the present invention is a chip-type electronic component having a substantially rectangular parallelepiped body, and one of the pair of external electrodes formed on the pair of end surfaces is one pair of main electrodes adjacent to the end surfaces. Each of the plane and the pair of side surfaces has a wraparound portion extending toward the other and one of the external electrodes. The length of the wraparound portion of one of the external electrodes is T1, and the length of the one external electrode is The difference between T1 and T2 is 0.02 mm or less, where T2 is the length of the wraparound portion of the other external electrode on the same main plane as the wraparound portion. A chip-type electronic component that can be mounted in a desired state without being unevenly soldered on one side of the land can be obtained, which is useful for chip-type ceramic capacitors, chip-type varistors, chip-type resistors, etc. It is.

(A) The perspective view of the chip-type ceramic capacitor in one embodiment of this invention, (b) The sectional drawing Schematic of the paste application apparatus in one embodiment of the present invention Enlarged sectional view of the main part Perspective view of a conventional chip-type ceramic capacitor

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Chip-type ceramic capacitor 11 Chip-type ceramic capacitor body 12 Main plane 13 Side 14 End face 15, 16 External electrode 17, 18 Rounding part 19 Internal electrode 21 Paste application apparatus 22 Electrode paste container 23 Electrode paste 24 Pipe 25 Paste application part 32 Electrode paste reservoir 33 hole 34 film

Claims (2)

A chip-type electronic component having a substantially rectangular parallelepiped element body, wherein the element body includes a pair of main planes, a pair of side surfaces orthogonal to the main planes, a pair of end surfaces orthogonal to the main planes and the side surfaces, A pair of external electrodes formed on the pair of end faces, wherein one and the other external electrodes extend toward the other and one external electrode toward a part of the main plane and side surfaces adjacent to the end faces; The length of the wraparound portion of one of the external electrodes formed on the pair of main planes is T1, and the other is on the same main plane as the wraparound portion of the one external electrode. A chip-type electronic component, wherein a difference between T1 and T2 is 0.02 mm or less, where T2 is a length of a wraparound portion of the external electrode. A step of creating a chip-type electronic component element having a substantially rectangular parallelepiped shape, a step of applying an electrode paste to a pair of ends of the chip-type electronic component element, and a step of baking the electrode paste to form an external electrode The step of applying the electrode paste is arranged at a predetermined interval through which both ends of the chip-type electronic component body pass, and the chip-type electronic component An electrode paste is applied using a paste applying device having a pair of U-shaped paste applying portions having a predetermined width in the direction in which the element passes, and the inner surface of the U-shaped paste applying portion An electrode paste is formed by forming a film of an electrode paste and passing the chip-type electronic component body through the U-shaped paste applying portion. Production method.

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