JP2004247577A - Layered electronic parts and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the generation of gaps at the end electrodes, to prevent moisture from remaining in the end electrodes in an electric plating process or the like, and to prevent the short-circuit accident with the other neighboring electronic parts due to scattering solder in a reflow process. <P>SOLUTION: In nearly rectangular parallelepiped laminate electronic parts, coil conductors 2 and a magnetic body or a non-magnetic body are laminated, and a coil is formed inside a laminate 1. The both ends of the laminate 1 are provided with end electrodes 3. The coil conductors 2 are exposed on the peripheral side faces of the laminate. The exposing positions of coil conductor leading parts 21 are arranged in maximum regional parts 30 of electrode thickness wherein the end electrodes 3 creep to the peripheral side faces of the laminate 1. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a multilayer electronic component such as a chip coil and a method for manufacturing the same, and more particularly to a multilayer electronic component for surface mounting in which a spiral coil conductor is disposed inside a multilayer body formed of a magnetic or non-magnetic material. The present invention relates to an electronic component and a method for manufacturing the same.
[0002]
[Prior art]
In a conventional laminated electronic component of this type, as shown in FIG. 2A, a spiral coil is formed inside a laminated body 1 by laminating a coil conductor 2 and a magnetic substance or a non-magnetic substance. It is known that after firing of the laminate 1, a gap 3A exists between the coil conductor lead-out portion 21 exposed to the peripheral side surface of the laminate and the laminate 1, as shown in FIG.
[0003]
When the end electrodes 3 are formed at both ends of the laminate 1 in the laminating direction by baking after the application of the end electrodes to the laminate 1, the corner portions 31 of the laminate 1 and the end portions around the end electrodes. 32, the coating thickness of the end electrode 3 is extremely reduced. Therefore, when the coil conductor lead-out portion 21 is formed near the corner portion 31 of the laminate or near the end electrode wraparound end portion 32, FIG. As shown in FIG. 2 (B), voids 3B are likely to be generated in the end electrodes 3 as well, and in the subsequent steps such as electroplating of the end electrodes, moisture tends to stay in the voids 3A and 3B. As shown in C), the laminate is shielded only by the electroplating film (metal plating film) 4 while keeping the moisture, thereby completing a multilayer electronic component.
[0004]
When the laminated electronic component shielded only by electroplating while retaining the moisture is mounted on a circuit board, FIG. 3A (the same parts as those in FIG. 2 are denoted by the same reference numerals). In most cases, as shown in ()), the solder is printed on the solder 6 printed on the land 5 of the circuit board (printed board) 7 with a metal mask or the like, and then reflowed and fixed with solder. When the reflow is performed at a temperature of 183 ° C. or higher, as shown in FIG. 3B, the moisture retained in the electronic components (the gaps 3A and 3B) is thermally expanded and vaporized, and the electroplating film 4 is formed. If the molten solder 61 is scattered at the same time as the breakage, and the scattered solder 6A reaches the terminals of other nearby electronic components and is rapidly cooled, short-circuiting due to the solder may occur, which may cause a circuit operation to be disabled.
[0005]
In the case of lead-free solder, which has been widely used in recent years, this phenomenon is more likely to appear more remarkably because the melting temperature of the solder is higher and the reflow temperature must be set higher. Is coming.
[0006]
As a well-known example, as described in the present invention, it is not intended to eliminate voids generated in the end electrodes of the multilayer electronic component, and thus to eliminate solder scattering at the time of component reflow. And Patent Document 1 and Patent Document 2 below.
[0007]
In addition, in the laminate made of a magnetic material or a non-magnetic material, as shown in FIG. 2B, a gap 3A exists between the coil conductor lead-out portion 21 exposed to the peripheral side surface of the laminate and the laminate 1 after firing. Regarding this, Patent Document 3 and Patent Document 4 below are cited.
[0008]
[Patent Document 1] Japanese Patent Application Laid-Open No. 10-284324 [Patent Document 2] Japanese Patent Application Laid-Open No. 11-265822 [Patent Document 3] Japanese Patent No. 2983049 [Patent Document 4] Japanese Patent No. 2987176
FIG. 4 is a cross-sectional view of a multilayer electronic component disclosed in Patent Literature 2, wherein 1 is a laminate, 2 is a coil conductor, 21 is a coil conductor lead-out portion, and 3 is an end electrode. In this case, a coil conductor lead-out portion is connected to a terminal end portion of the end electrode that goes around the peripheral side surface of the laminate. Therefore, it does not solve the problem of solder scattering at the time of reflow due to voids.
[0010]
[Problems to be solved by the invention]
In view of the above problems, the present invention prevents the generation of voids in the end electrodes, and thus eliminates the retention of moisture in the end electrodes in the subsequent steps such as electroplating, so that in the subsequent reflow step It is another object of the present invention to provide a multilayer electronic component capable of preventing a short circuit accident with other nearby electronic components due to scattering of solder and a method of manufacturing the same.
[0011]
Other objects and novel features of the present invention will be clarified in embodiments described later.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a laminated electronic component according to the invention of claim 1 of the present application has a substantially rectangular parallelepiped shape in which a coil conductor and a magnetic or non-magnetic material are laminated to form a coil inside the laminated body. In the configuration,
An end electrode is provided at both ends of the laminate, the coil conductor is exposed on the peripheral side surface of the laminate, and the exposed position of the coil conductor lead-out portion is such that the end electrode goes around the peripheral side surface of the laminate. It is characterized in that it is the maximum region of the electrode thickness in the portion.
[0013]
As described above, when the coil conductor is exposed on the peripheral side surface of the laminated body, the end electrode electrically connected to the coil conductor is a corner portion of the laminated body where the coating thickness is extremely reduced or an end electrode wraparound terminal end. By arranging the lead portion of the coil conductor in the maximum region of the electrode thickness, the gap generated in the lead portion of the coil conductor can be completely shielded (closed) by the end electrode.
[0014]
A multilayer electronic component according to a second aspect of the present invention is the multilayer electronic component according to the first aspect, in which a position where the coil conductor lead-out portion is exposed to the peripheral side surface of the laminate and a portion where the end electrode wraps around the peripheral side surface of the laminate. It is characterized in that the displacement of the electrode thickness from the maximum position is within four times the exposed electrode thickness of the coil conductor lead-out portion.
[0015]
The maximum thickness of the electrode in the region where the end electrode goes around the peripheral side surface of the laminate has a slight gradual change in thickness, so the position deviation between the maximum electrode thickness position (maximum point) and the exposed position of the coil conductor lead-out portion. However, if the displacement amount is within about four times the thickness of the exposed electrode of the coil conductor lead portion, the gap generated in the coil conductor lead portion can be completely shielded.
[0016]
According to a third aspect of the present invention, there is provided a method for manufacturing a laminated electronic component, comprising: laminating a coil conductor and a magnetic or non-magnetic material to form a coil inside the laminated body; In the case of manufacturing a laminated electronic component having a substantially rectangular parallelepiped shape provided with electrodes,
The wraparound dimension of the end electrode is set such that the exposed position of the coil conductor lead-out portion on the peripheral side surface of the laminate is the maximum region of the electrode thickness in the portion of the end electrode wrapping around the peripheral side surface of the laminate. It is characterized by adjustment.
[0017]
In this way, mass production can be achieved by setting the application condition of the end electrode to be applied such that the end electrode thickness is the maximum region portion with respect to the position where the coil conductor lead-out portion is exposed to the peripheral side surface of the laminate. An easy laminated electronic component can be obtained.
[0018]
According to a fourth aspect of the present invention, there is provided a method for manufacturing a laminated electronic component, comprising: laminating a coil conductor and a magnetic or non-magnetic material to form a coil inside the laminated body; In the case of manufacturing a laminated electronic component having a substantially rectangular parallelepiped shape provided with electrodes,
The lamination of the coil conductor lead-out portion is such that the exposed position of the coil conductor lead-out portion on the peripheral side surface of the laminate is the maximum region of the electrode thickness in a portion of the end electrode that goes around the laminate peripheral side surface. It is characterized by adjusting the exposure position on the side surface of the body.
[0019]
As described above, by adjusting the position of exposure to the peripheral side surface of the laminate such that the coil conductor lead-out portion is exposed at the position of the maximum area portion of the thickness of the end electrode wrapped around the peripheral side surface of the laminate. A multilayer electronic component that can be easily mass-produced is obtained.
[0020]
In the method for manufacturing a multilayer electronic component according to a fifth aspect of the present invention, in the third or fourth aspect, the position where the coil conductor lead-out portion is exposed to the peripheral side surface of the multilayer body and the end electrode is located at the periphery of the multilayer body. The electrode thickness is adjusted so that the position deviation from the maximum position of the electrode thickness in the part that goes around the side surface is within four times the electrode thickness exposed in the coil conductor lead-out part.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a multilayer electronic component and a method of manufacturing the same according to the present invention will be described with reference to the drawings.
[0022]
FIG. 1 is a sectional view showing a longitudinal direction of a chip-shaped inductor having a substantially rectangular parallelepiped shape as an embodiment of a laminated electronic component according to the present invention. The magnetic material and the spiral coil conductor 2 are alternately laminated by a printing lamination method. The winding start part and the end part of the coil conductor 2 are exposed to the peripheral side surface of the multilayer body 1 at the coil conductor lead-out part 21. Here, the printing is performed by the printing lamination method. However, the sheet lamination method in which the green sheet is provided with a through hole for printing the coil conductor 2 and spirally winding the coil conductor 2 may be used. .
[0023]
In addition, a chip-type inductor as a multilayer electronic component is formed by printing and laminating a multi-piece coil conductor pattern, cutting it into a single chip (that is, a rectangular parallelepiped laminate 1), firing at a high temperature, An electrode paste to be the terminal electrode 3 is applied to both ends in the stacking direction of the laminate 1 and baked, and an electroplating film 4 is formed on the end electrode 3 by electroplating to complete the electronic component. In the position of the coil conductor lead-out portion 21 exposed to the peripheral side surface of the multilayer body 1, a portion 30 of the maximum electrode thickness in a portion that goes around the peripheral side surface of the multilayer body is formed.
[0024]
In this manner, the position where the coil conductor lead-out portion 21 is exposed to the peripheral side surface of the laminated body is the maximum region 30 of the electrode thickness in the portion of the end electrode 3 that goes around the peripheral side surface of the laminated body. This is achieved by adjusting the wraparound dimension of the external electrode 3 (the dimension of electrode paste applied to the peripheral side surface of the laminate) and the viscosity of the electrode paste, and by adjusting the position where the coil conductor lead-out portion 21 is exposed to the peripheral side surface of the laminate. it can.
[0025]
Since the maximum region 30 of the electrode thickness in the portion where the end electrode 3 goes around the peripheral side surface of the multilayer body 1 is slightly gentle, the coil conductor lead-out portion 21 is positioned at the maximum position (maximum point) of the electrode thickness. If the displacement is within about four times the exposed electrode thickness, the gap generated in the coil conductor lead-out portion 21 can be completely shielded (closed without spreading the gap). When the product dimensions are 1608 type (length 1.6 mm, width 0.8 mm, thickness 0.8 mm), the exposed electrode thickness of the coil conductor lead-out portion 21 is about 20 μm, and the 2012 type (length 2.0 mm, width 1.2 mm) , 1.2 mm) and about 14 μm for the 1005 type (1.0 mm long, 0.5 mm wide, 0.5 mm thick).
[0026]
The electroplating is completed by sequentially plating copper and nickel and tin, nickel and tin, nickel and gold, nickel and palladium and gold, nickel and palladium and silver, or nickel and silver, etc. Nickel is the lower layer plating, tin, gold and silver are the upper layer plating).
[0027]
According to this embodiment, the following effects can be obtained.
[0028]
(1) After firing the laminate 1 in which the coil conductor 2 and the magnetic or non-magnetic material are laminated to form a spiral coil inside the laminate 1, the coil conductor lead-out portion 21 exposed to the peripheral side surface of the laminate is formed. Although a gap is formed between the laminates 1, the exposed position of the coil conductor lead-out portion 21 is such that the gap does not spread to the end electrodes, and a portion where the electrode thickness is the largest in a portion of the end electrode 3 that extends around the peripheral side surface of the laminate. By setting it to be 30, it is possible to eliminate the stagnation of water on the end electrodes in the subsequent steps such as electroplating. As a result, in the multilayer electronic component shown in the present embodiment, in the reflow process, it is possible to prevent a disadvantage that a short circuit occurs with other nearby electronic components due to scattering of solder, thereby manufacturing a highly reliable product. It becomes possible.
[0029]
(2) The position where the coil conductor lead-out portion 21 is exposed to the peripheral side surface of the laminated body is the maximum region 30 of the electrode thickness in the portion of the end electrode 3 that goes around the peripheral side surface of the laminated body. 3 is easily realized by adjusting the wraparound dimension (the dimension of electrode paste applied to the peripheral side surface of the laminate) and the viscosity of the electrode paste, and adjusting the position where the coil conductor lead-out portion 21 is exposed to the peripheral side surface of the laminate. it can.
[0030]
(3) Since the maximum region 30 of the electrode thickness in the portion where the end electrode 3 goes around the peripheral side surface of the multilayer body 1 is slightly gentle, the coil conductor lead-out portion 21 is located at the maximum position (maximum point) of the electrode thickness. If the displacement is within about four times the exposed electrode thickness, the gap generated in the coil conductor lead-out portion 21 can be completely shielded, and the gap in the end electrode 3 itself can be prevented.
[0031]
【Example】
As an example of the present invention, a paste containing Ni—Cu—Zn-based ferrite as a main component as a magnetic substance is used for the laminate 1, the interlayer thickness is set to about 50 μm, and the coil conductor 2 is a paste containing silver as a main component. The pattern width was about 150 μm, the electrode thickness of the pattern was about 20 μm, the pattern inner diameter was about 350 μm, and the pattern was a substantially semicircular pattern. The coil conductor pattern and the magnetic paste were alternately printed and laminated to obtain a large number of pieces. The substrate was completed. Thereafter, the chip is cut into single chips by a dicer or the like, and barrel polishing is performed for the purpose of removing an edge portion of the chip. Then, firing is performed at about 880 ° C. in a firing atmosphere in the air to complete the multilayer body 1. did. Further, the end electrode 3 is coated with an electrode paste containing silver as a main component, baked at about 700 ° C., and electroplating is performed in the order of copper, nickel, and tin to obtain a substantially rectangular chip-shaped inductor. Completed. The completed dimensions at that time were 1.6 mm in length, 0.8 mm in width and thickness. The exposed position of the coil conductor lead-out portion 21 on the peripheral side surface of the laminate was adjusted so as to be the maximum region 30 of the electrode thickness in the portion of the end electrode 3 that goes around the peripheral side surface of the laminate.
[0032]
In order to confirm the effect of the present invention, a reflow experiment was performed on the chip-type inductor of the above-described example with a profile having a peak temperature of 250 ° C., and as a result of confirming the scattering of solder at the terminal electrode portion, the conventional product was 20,000. Spattering of solder was observed in 21 of the pieces, but in the product of the present invention (Example), it was 0 even at 40,000. From these results, it can be determined that the method of forming the end electrode of the multilayer electronic component of the present invention is surely effective.
[0033]
Although the embodiments and examples of the present invention have been described above, it is obvious to those skilled in the art that the present invention is not limited to these and various modifications and changes can be made within the scope of the claims. There will be.
[0034]
【The invention's effect】
As described above, according to the present invention, in a laminated electronic component having a substantially rectangular parallelepiped shape in which a coil conductor and a magnetic or non-magnetic material are laminated to form a coil inside the laminated body, Even if there is a gap between the coil conductor lead-out portion and the laminate exposed to the outside, the exposed position of the coil conductor lead-out portion and the maximum area portion of the electrode thickness at the portion of the end electrode that goes around the peripheral surface of the laminate As a result, the gap does not spread to the end electrode, and the stagnation of water on the end electrode can be eliminated in the subsequent steps such as electroplating. As a result, in the multilayer electronic component of the present invention, in the reflow process, it is possible to prevent the disadvantage that a short circuit occurs with other nearby electronic components due to the scattering of solder, and it is possible to manufacture a highly reliable product. Become.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an embodiment of a multilayer electronic component and a method for manufacturing the same according to the present invention.
FIGS. 2A and 2B are cross-sectional views of a conventional laminated electronic component after end electrode baking, and FIG. 2B is a diagram showing a gap between a coil conductor lead-out portion and a laminated body of FIG. FIG. 4 is an enlarged cross-sectional view showing a gap of an electrode, and FIG. 4C is an enlarged cross-sectional view showing a state in which electroplating is performed on FIG.
3A and 3B are enlarged cross-sectional views showing a state in which an end electrode is electroplated in a conventional multilayer electronic component, in which FIG. 3A is mounted on a printed circuit board for mounting, and FIG. (A) is an enlarged sectional view showing the state of scattering of solder generated at the time of reflow.
FIG. 4 is a cross-sectional view of a laminated electronic component disclosed in a conventional Japanese Patent Application Laid-Open No. H11-265822.
REFERENCE SIGNS LIST 1 laminated body 2 coil conductor 3 end electrode 3A gap between coil conductor lead-out portion and laminate 3B end electrode gap 4 electroplating film 5 land 6 printed solder 6A scattered solder 7 circuit board 21 coil conductor lead-out portion Reference Signs List 30 maximum electrode thickness region 31 corner corner portion of end electrode laminate 32 wraparound end portion 61 of end electrode 61 molten solder

Claims (5)

In a laminated electronic component having a substantially rectangular parallelepiped shape in which a coil conductor and a magnetic material or a non-magnetic material are laminated to form a coil inside the laminated body,
An end electrode is provided at both ends of the laminate, the coil conductor is exposed on the peripheral side surface of the laminate, and the exposed position of the coil conductor lead-out portion is such that the end electrode goes around the peripheral side surface of the laminate. A multilayer electronic component, wherein the multilayer electronic component is a maximum region of the electrode thickness in the portion. The positional deviation between the exposed position of the coil conductor lead-out portion on the peripheral side surface of the laminate and the maximum position of the electrode thickness in the portion where the end electrode goes around the peripheral surface of the laminate exposes the coil conductor lead-out portion. 2. The multilayer electronic component according to claim 1, wherein the thickness is within four times the electrode thickness. A method of manufacturing a laminated electronic component having a substantially rectangular parallelepiped shape in which a coil conductor and a magnetic or non-magnetic material are laminated to form a coil inside the laminate, and end electrodes are provided at both ends of the laminate. ,
The wraparound dimension of the end electrode is set such that the exposed position of the coil conductor lead-out portion on the peripheral side surface of the laminate is the maximum region of the electrode thickness in the portion of the end electrode wrapping around the peripheral side surface of the laminate. A method for manufacturing a laminated electronic component, comprising adjusting. A method of manufacturing a laminated electronic component having a substantially rectangular parallelepiped shape in which a coil conductor and a magnetic or non-magnetic material are laminated to form a coil inside the laminate, and end electrodes are provided at both ends of the laminate. ,
The lamination of the coil conductor lead-out portion is such that the exposed position of the coil conductor lead-out portion on the peripheral side surface of the laminate is the maximum region of the electrode thickness in a portion of the end electrode that goes around the laminate peripheral side surface. A method for manufacturing a laminated electronic component, comprising adjusting an exposure position on a body peripheral side surface. The positional deviation between the exposed position of the coil conductor lead-out portion on the peripheral side surface of the laminate and the maximum position of the electrode thickness in the portion where the end electrode goes around the peripheral surface of the laminate exposes the coil conductor lead-out portion. The method for manufacturing a multilayer electronic component according to claim 3, wherein the adjustment is performed so as to be within four times the electrode thickness.

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