JP2007081228A - Surface mounted electronic component array - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface mounted electronic component array capable of preventing element assembly suction trouble when sucking and holding an element assembly by means of a suction nozzle for mounting on another component. <P>SOLUTION: A surface mounted electronic component array 1 comprises an element assembly 2 having a parallelepiped shape. The element assembly 2 includes a lower surface 2a, side surfaces 2b-2e adjacent to the lower surface 2a, and an upper surface 2f confronted to the lower surface 2a and adjacent to the side surfaces 2b-2e, the lower surface 2a, the side surfaces 2b-2e and the upper surface 2f constituting a mounting surface to a printed circuit board. A plurality of external electrodes 3, 4 are formed on the surface of the element assembly 2. The external electrodes 3, 4 comprise electrode parts 3a, 4a formed on the lower surface 2a of the element assembly 2, and electrode parts 3b, 4b formed on the side surfaces 2b, 2d of the element assembly 2 so as to be linked with the electrode parts 3a, 4a, and extended from corner parts between the side surfaces 2b, 2d and the upper surface 2f in the element assembly 2, respectively. The external electrodes 3, 4 are not formed on the upper surface 2f of the element assembly 2 substantially. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a surface mount electronic component array including a plurality of electronic components such as inductors and capacitors.

As a conventional surface mount type electronic component array, for example, as described in Patent Document 1, four external electrodes serving as input / output terminals are provided on both side surfaces of a main body laminated portion (element body) formed in a rectangular parallelepiped shape. What is formed one by one is known.
JP 2003-51729 A

  When mounting a surface mount electronic component array as described above on a printed circuit board or the like, the upper surface of the element body (the surface opposite to the mounting surface) is sucked and held by a suction nozzle of a component mounter (mounter), for example. Then, mounting processing of the electronic component array is performed.

  However, in the surface-mount type electronic component array of the prior art, each external electrode is formed on three surfaces, that is, the lower surface (mounting surface), the side surface, and the upper surface of the element body. In other words, since the external electrode is also present on the upper surface of the element body, when the upper surface of the element body is adsorbed and held by the adsorption nozzle, the adsorption nozzle and the external electrode come into contact with each other, and the adsorption nozzle does not adhere to the element body. It becomes a state. For this reason, air leakage occurs between the suction nozzle and the element body, and the suction force of the electronic component array by the suction nozzle is reduced. Also, when the suction force of the suction nozzle is increased to eliminate this, the plating applied to the surface of the external electrode adheres to the tip of the suction nozzle and accumulates. The problem of power loss occurs. When such an electronic component array suction failure occurs, the mounting operation of the electronic component array may be hindered.

  An object of the present invention is to provide a surface-mount type electronic component array capable of preventing a problem of sucking an element body when the element body is sucked and held by a suction nozzle and mounted on another component.

  The present invention is a surface-mount type electronic component array including an element body having a rectangular parallelepiped shape and at least four external electrodes formed on the surface of the element body, and mounted on another component, A first surface constituting a mounting surface for another component; four second surfaces adjacent to the first surface; a third surface facing the first surface and adjacent to each second surface; The electrode includes a first electrode portion formed on the first surface, a second electrode portion formed on the second surface so as to be connected to the first electrode portion, and extending to a corner portion between the second surface and the third surface. The external electrode is not substantially formed on the third surface. Here, “the external electrode is not substantially formed on the third surface” includes the case where the external electrode is slightly formed (for example, about 100 μm at the maximum) on the edge of the third surface. Suppose that

  When mounting such a surface-mounted electronic component array on another component (printed circuit board or the like), the third surface of the element body is sucked and held by the suction nozzle of the component mounting machine. Here, since the external electrode is not substantially formed on the third surface of the element body, when the third surface of the element body is adsorbed by the adsorption nozzle, the adsorption nozzle and the third surface of the element body There is almost no gap between them. For this reason, since the suction nozzle comes into close contact with the element body, air leakage does not occur between the suction nozzle and the element body, and a decrease in the suction force of the electronic component array by the suction nozzle is suppressed. In addition, since there is no contact between the suction nozzle and the external electrode, the plating applied to the surface of the external electrode is prevented from adhering and depositing on the tip of the suction nozzle. Reduction of the adsorption power of the array can be suppressed. Accordingly, it is possible to prevent the suction failure of the electronic component array.

  Preferably, the thickness of the portion connecting the first electrode portion and the second electrode portion in the external electrode is 70% or more of the maximum thickness of the first electrode portion. Thereby, since the flat part in a 1st electrode part becomes large, when mounting a surface mount type electronic component array in other components (printed circuit board etc.), the sitting of the electronic component array with respect to other components becomes good. In addition, since the thickness of the first electrode portion is ensured as a whole, when the surface-mounted electronic component array is mounted on other components with solder, it is difficult for solder erosion or the like to occur.

  According to the present invention, when the surface mount electronic component array is sucked and held by the suction nozzle so as to mount the surface mount electronic component array on another component, it is possible to prevent the suction failure of the element. it can. This makes it possible to stably mount the surface mount electronic component array on other components without hindering the mounting operation of the surface mount electronic component array.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of a surface mount electronic component array according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing an embodiment of a surface mount electronic component array according to the present invention, and FIG. 2 is a plan view of the surface mount electronic component array shown in FIG. In each figure, the surface mount electronic component array 1 of the present embodiment is a multilayer chip inductor array. The surface-mount electronic component array 1 includes an element body 2 having a rectangular parallelepiped shape, and external electrodes (terminal electrodes) 3 and 4 formed on the surface of the element body 2. A plurality (four in this case) of external electrodes 3 and 4 are provided.

  The element body 2 includes a lower surface (first surface) 2a constituting a mounting surface for a printed circuit board (not shown), side surfaces (second surfaces) 2b to 2e adjacent to the lower surface 2a, and opposed to the lower surface 2a and side surfaces 2b to 2b. 2e and an upper surface (third surface) 2f adjacent to 2e. The side surfaces 2b and 2d face each other, and the side surfaces 2c and 2e face each other. The element body 2 has dimensions of, for example, a length of 2.0 mm, a width of 1.25 mm, and a height of 0.3 mm. The element body 2 has a plurality of (here, four) coil portions 5. These coil parts 5 are arranged in parallel in the longitudinal direction of the element body 2.

  FIG. 3 is an exploded perspective view of the element body 2. In the figure, the element body 2 is configured by laminating insulators 6 to 14 having a conductor pattern forming a part of a coil portion 5 and a plurality of insulators 15 having no conductor pattern. The insulators 6 to 14 are sequentially stacked upward.

  A plurality of substantially J-shaped conductor patterns 16 are formed on the insulator 6. One end of each conductor pattern 16 is drawn out to the edge of the insulator 6 so as to be exposed at the side surface 2 b of the element body 2. A plurality of conductor patterns 17 electrically connected to each conductor pattern 16 are formed on the insulator 7. The conductor pattern 17 corresponds to approximately 3/4 turns of the coil portion 5 and is formed in a substantially U shape. A plurality of conductor patterns 18 that are electrically connected to each conductor pattern 17 are formed on the insulator 8. The conductor pattern 18 corresponds to approximately 3/4 turns of the coil portion 5 and is formed in a substantially C shape. A plurality of conductor patterns 19 electrically connected to each conductor pattern 18 are formed on the insulator 9. The conductor pattern 19 corresponds to approximately 3/4 turns of the coil portion 5 and is formed in a substantially U shape. A plurality of conductor patterns 20 electrically connected to the respective conductor patterns 19 are formed on the insulator 10. The conductor pattern 20 corresponds to approximately 3/4 turns of the coil portion 5 and is formed in a substantially C shape.

  A plurality of conductor patterns 21 electrically connected to each conductor pattern 20 are formed on the insulator 11. The conductor pattern 21 has the same structure as the conductor pattern 17 described above. A plurality of conductor patterns 22 electrically connected to each conductor pattern 21 are formed on the insulator 12. The conductor pattern 22 has the same structure as the conductor pattern 18 described above. A plurality of conductor patterns 23 electrically connected to the respective conductor patterns 22 are formed on the insulator 13. The conductor pattern 23 has the same structure as the conductor pattern 19 described above. A plurality of substantially J-shaped conductor patterns 24 electrically connected to the respective conductor patterns 23 are formed on the insulator 14. One end of each conductor pattern 24 is drawn out to the edge of the insulator 14 so as to be exposed at the side surface 2d of the element body 2. In addition, the electrical connection between the conductor patterns of different insulators is performed through through holes formed in the insulator.

  The insulator 15 having no conductor pattern is stacked on the insulator 6. The insulator 15 protects the conductor pattern 16 formed on the insulator 6. Further, another insulator 15 is laminated under the insulator 14.

  The insulators 6 to 15 are magnetic materials such as ferrite (Ni—Cu—Zn ferrite, Ni—Cu—Zn—Mg ferrite, Cu—Zn ferrite, Ni—Cu ferrite), glass ceramics, etc. The non-magnetic material is used. The conductor patterns 16 to 24 are made of a conductive material such as Ag, Ni, or an Ag—Pd alloy.

  When manufacturing such an element body 2, first, a green sheet for forming the insulators 6 to 15 is prepared. Specifically, for example, a magnetic green sheet having electrical insulation is formed by applying a slurry of ferrite powder as a raw material onto a film by a doctor blade method. Then, for example, conductive patterns 16 to 24 are formed by screen-printing a conductive paste containing Ag as a main component on a green sheet and drying it. Subsequently, a green sheet on which any one of the conductor patterns 16 to 24 is formed and a green sheet on which no conductor pattern is formed are stacked and bonded as shown in FIG. Disconnect. And the said laminated body is baked at predetermined temperature (for example, 800-980 degreeC). Thereby, said element | base_body 2 is obtained.

  A plurality of external electrodes 3 electrically connected to each conductor pattern 16 and a plurality of external electrodes 4 electrically connected to each conductor pattern 24 are formed on the surface of the element body 2. These external electrodes 3 and 4 are L-shaped.

  Specifically, the external electrode 3 is formed on the side surface 2b of the element body 2 so as to be connected to the electrode part (first electrode part) 3a formed at one end of the lower surface 2a of the element body 2 and the electrode part 3a. The electrode body (second electrode portion) 3b extends to the corners of the side surface 2b and the upper surface 2f of the element body 2. The external electrode 4 is formed on an electrode part (first electrode part) 4a formed on the other end of the lower surface 2a of the element body 2 and on the side surface 2d of the element body 2 so as to be connected to the electrode part 4a. 2 includes an electrode portion (second electrode portion) 4b extending to the corner between the side surface 2d and the upper surface 2f.

  The external electrodes 3 and 4 are not substantially formed on the upper surface 2 f of the element body 2. Each vertex and each edge of the element body 2 are formed to be slightly curved. For this reason, when the electrode portions 3b and 4b are formed at the corners of the side surfaces 2b and 2d and the upper surface 2f in the element body 2, the electrode portions 3b and 4b come around the edge of the upper surface 2f by about 100 μm at the maximum (see FIG. 4). Therefore, in this case, it is assumed that the external electrodes 3 and 4 are not substantially formed on the upper surface 2f when the external electrodes 3 and 4 are formed on the edge of the upper surface 2f by about 100 μm.

  At this time, as shown in FIG. 4, the thickness R1 of the external electrode 3 formed at the corner between the lower surface 2a and the side surface 2b in the element body 2, that is, the thickness R1 of the portion connecting the electrode portions 3a and 3b of the external electrode 3 Is preferably 70% or more of the maximum thickness H of the electrode part 3a, more preferably 80% or more of the maximum thickness H of the electrode part 3a. The same applies to the thickness of the external electrode 4. As a result, the flat areas of the electrode portions 3a and 4a are widened. Therefore, when the surface-mounted electronic component array 1 is mounted on a printed board (not shown) by soldering, the surface-mounted electronic component array 1 with respect to the printed board is mounted. The sitting condition is improved and solder erosion is less likely to occur.

  In addition, the thickness R1 of the external electrode 3 formed at the corner between the lower surface 2a and the side surface 2b in the element body 2 is preferably less than 120% of the maximum thickness H of the electrode portion 3a. The same applies to the thickness of the external electrode 4. Accordingly, for example, in the measurement taping process, it is possible to prevent a problem that the part formed at the corner of the element body 2 in the external electrodes 3 and 4 is caught by the feeder and the flow of the process is deteriorated.

  The external electrodes 3 and 4 are made of, for example, a conductor paste whose main component is Ag, Ni, or Cu. The length of the electrode portions 3a and 4a formed on the lower surface 2a of the element body 2 is, for example, about 100 to 300 μm corresponding to the size of the land of the printed circuit board to be mounted.

  A method of forming such external electrodes 3 and 4 on the surface of the element body 2 will be described with reference to FIGS. First, an application bed 25 and a blade 26 as shown in FIG.

  The application bed 25 includes a base 27 and four plate-like protrusions 28 provided on the upper surface of the base 27. These plate-like projections 28 form three grooves 29 extending in parallel with each other. A concave portion 30 is formed in the central portion of each plate-like protrusion 28. The blade 26 includes a base 31 and a scraping portion 32 fixed to the base 31. A plurality of teeth 33 that enter the grooves 29 are formed in the scraping portion 32.

  Then, as shown in FIG. 5B, for example, a conductor paste 34 mainly composed of Ag is deposited so as to cover the concave portions 30 of the respective plate-like protrusions 28 of the application bed 25. As a result, the conductor paste 34 is filled in the recesses 30 of the plate-like protrusions 28.

  Subsequently, as shown in FIG. 6A, the blade 26 is positioned with respect to the application bed 25 so that each tooth 33 of the scraping portion 32 of the blade 26 enters each groove 29 of the application bed 25. Then, the blade 25 is moved along the extending direction of the groove 29 to scrape the conductor paste 34 in each groove 29. At this time, since the conductor paste 34 has fluidity, as shown in FIG. 6B, a part of the conductor paste 34 remaining in each recess 30 flows down, and as a result, the bottom surface portion of each recess 30 and each The conductive paste 34 remains on the upper surface of the plate-like protrusion 28.

  Subsequently, as shown in FIGS. 7A and 8A, the element body 2 is arranged so that the side surface 2 b of the element body 2 is in contact with the upper surface of each plate-like protrusion 28. As a result, the conductive paste 34 adheres to the side surface 2b of the element body 2, so that the base layer 35 of the electrode portion 3b of the external electrode 3 is gathered on the side surface 2b of the element body 2 as shown in FIG. One will be formed. In addition, the side surface 2d of the element body 2 is in a state of being stuck and held on an adhesive portion of a holding plate (not shown). Then, depending on the case, the element body 2 is moved away from the application bed 25, and the conductor paste 34 attached to the side surface 2b is dried at a predetermined temperature (for example, 80 to 150 ° C.).

  Subsequently, as shown in FIGS. 7B and 8B, the element body 2 is placed in each recess 30 so that the side surface 2 b of the element body 2 faces the bottom surface of the recess 30 of each plate-like protrusion 28. The element body 2 is moved relative to the application bed 25 so that the lower surface 2a of the element body 2 is in contact with one side surface 30a of each recess 30 in a state where the element body 2 is straddled. As a result, the conductive paste 34 adheres to the lower surface 2 a of the element body 2, so that the base layer 36 of the electrode portion 3 a of the external electrode 3 is gathered on the lower surface 2 a of the element body 2 as shown in FIG. One will be formed. At this time, the length (the length of the electrode portion 3a) that the conductor paste 34 wraps around the lower surface 2a of the element body 2 is determined by the depth at which the element body 2 enters the recess 30. Thereafter, in some cases, the element body 2 is moved away from the application bed 25, and the conductor paste 34 attached to the upper surface 2a is dried at a predetermined temperature (for example, 80 to 150 ° C.).

  Subsequently, in a state where the side surface 2b side of the element body 2 is attached to and held on the adhesive portion of a holding plate (not shown), the element body 2 is held in the same manner as described above with reference to FIGS. 7 (A) and 8 (A). ). As a result, as shown in FIG. 9C, four base layers 37 of the electrode portions 4 b of the external electrode 4 are collectively formed on the side surface 2 d of the element body 2. Then, in the same manner as described above, the element body 2 is arranged as shown in FIGS. 7B and 8B, and the element body 2 is in contact with the side surface 30a of each recess 30 so that the lower surface 2a of the element body 2 abuts. 2 is moved relative to the application bed 25. As a result, as shown in FIG. 9D, four underlying layers 38 of the electrode portions 4 a of the external electrode 4 are collectively formed on the lower surface 2 a of the element body 2.

  Thereafter, the base layers 35 to 38 on the surface of the element body 2 are baked at a predetermined temperature (for example, 640 to 740 ° C.), and then electroplating is performed on the base layers 35 to 38, whereby the external electrodes 3 and 4 are formed. It is formed. For electroplating, Cu and Ni and Sn, Ni and Sn, Ni and Au, etc. are used.

  Here, as a comparative example, a conventional surface mount electronic component array is shown in FIG. In the figure, the surface-mount type electronic component array 50 has four external electrodes 51 and 52 formed on the surface of the element body 2. Each external electrode 51 is formed in a U shape across the lower surface 2a, the side surface 2b, and the upper surface 2f of the element body 2, and each outer electrode 52 extends over the lower surface 2a, the side surface 2d, and the upper surface 2f of the element body 2. It is formed in a U shape.

  When such a surface mount electronic component array 50 is mounted on a printed circuit board (not shown), as shown in FIG. 11, the upper surface 2f of the element body 2 is picked up by a suction nozzle 54 of a component mounter (mounter) 53. In a state in which the electronic component array 50 is sucked and held, the mounter is moved to place the electronic component array 50 on the land of the printed circuit board. In addition, cream solder is previously applied to the land of the printed circuit board.

  At this time, since the terminal electrodes 51 and 52 exist on the upper surface 2 f of the element body 2, the tip surface of the suction nozzle 54 comes into contact with the terminal electrodes 51 and 52, and the tip surface of the suction nozzle 54 and the element body A gap G is formed between the upper surface 2f of the two. For this reason, since the air for suction by the suction nozzle 54 leaks in the gap G, the suction force of the element body 2 by the suction nozzle 54 is reduced, and as a result, the electronic component array 50 is successfully mounted on the printed circuit board. It becomes difficult.

  As a countermeasure, it is conceivable to increase the suction force of the suction nozzle 54. However, in this case, when the upper surface 2f of the element body 2 is sucked and held by the suction nozzle 54, the contact force between the plating applied to the surfaces of the external electrodes 51 and 52 and the suction nozzle 54 becomes higher than necessary. For this reason, when the electronic component array 50 is mounted on the printed board, the electronic component array 50 is unlikely to be separated from the suction nozzle 54. As a result, the electronic component array 50 remains attached to the suction nozzle 54 and may not be mounted on the printed circuit board. In addition, the plating applied to the surfaces of the external electrodes 51 and 52 adheres and accumulates on the tip of the suction nozzle 54, so that the suction force of the element body 2 by the suction nozzle 54 may further decrease.

  Such a phenomenon appears remarkably in a small surface-mount electronic component array that is light in weight. In particular, the dimensions of the element body are 3.2 mm × 1.6 mm × 1.2 mm or less and four or more external electrodes are used. It tends to occur in the surface mount electronic component array.

  On the other hand, in the surface mount type electronic component array 1 of the present embodiment, the external electrodes 3 and 4 are not substantially formed on the upper surface 2 f of the element body 2. For this reason, as shown in FIG. 12, when the upper surface 2f of the element body 2 is adsorbed and held by the adsorption nozzle 54, the tip end surface of the adsorption nozzle 54 is almost in close contact with the upper surface 2f of the element body 2. A gap is not formed between the front end surface of the suction nozzle 54 and the upper surface 2f of the element body 2. Accordingly, the suction force of the element body 2 by the suction nozzle 54 can be sufficiently obtained without increasing the suction force of the suction nozzle 54 more than necessary. Further, since the plating applied to the surfaces of the external electrodes 3 and 4 is prevented from adhering and depositing on the tip of the suction nozzle 54, the lowering of the suction force of the element body 2 by the suction nozzle 54 is reliably suppressed. Accordingly, since the surface mount electronic component array 1 is appropriately sucked and held by the suction nozzle 54, the surface mount electronic component array 1 can be stably mounted on the printed board.

  Here, one lot (about 600,000 pieces) of the multilayer chip inductor array according to the present embodiment is manufactured, the measurement taping is performed after the appearance inspection, the pickup is picked up by the mounter, and the pick-up rate is sampled (number of samples: 20,000). ). As a result, the pickup rate (ratio of the number of samples that could be properly picked up relative to the number of samples picked up) was 99.99%. Further, regarding the multilayer chip inductor array having the structure shown in FIG. 10, the pick-up rate was similarly checked, and the pick-up rate was 99.81%.

  From the above, the effectiveness of the present embodiment was confirmed. The reference value for determining whether the pickup rate is good is generally 99.9%.

  The present invention is not limited to the above embodiment. For example, the number of external electrodes formed on the surface of the element body having a rectangular parallelepiped shape may be at least four.

  The surface mount electronic component array 1 of the above embodiment is an inductor array, but the present invention is not particularly limited to this. For example, in addition to a bead array, a capacitor array, etc., a filter array including an inductor, a capacitor, and a varistor. It is also applicable to common mode filters.

1 is a perspective view showing an embodiment of a surface mount electronic component array according to the present invention. FIG. 2 is a plan view of the surface mount electronic component array shown in FIG. 1. FIG. 2 is an exploded perspective view of the element body shown in FIG. 1. FIG. 2 is a side view of the surface mount electronic component array shown in FIG. 1. It is a perspective view which shows the process of forming an external electrode in the element body shown in FIG. It is a perspective view which shows the process of forming an external electrode in the element body shown in FIG. It is a perspective view which shows the process of forming an external electrode in the element body shown in FIG. It is a side view which shows the process of forming an external electrode in the element body shown in FIG. It is a figure which shows the procedure which forms an external electrode in an element body by the process shown in FIG.7 and FIG.8. It is a perspective view which shows the surface mount type electronic component array as a comparative example. It is a figure which shows the state in which the surface mount type electronic component array shown in FIG. It is a figure which shows the state by which the surface mounting type electronic component array shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Surface mount type electronic component array, 2 ... Element body, 2a ... Lower surface (mounting surface, 1st surface), 2b-2e ... Side surface (2nd surface), 2f ... Upper surface (3rd surface), 3 ... External electrode 3a ... Electrode part (first electrode part), 3b ... Electrode part (second electrode part), 4 ... External electrode, 4a ... Electrode part (first electrode part), 4b ... Electrode part (second electrode part).

Claims (2)

A surface-mount type electronic component array comprising an element body having a rectangular parallelepiped shape and at least four external electrodes formed on the surface of the element body, and mounted on another component,
The element body has a first surface constituting a mounting surface for the other component, four second surfaces adjacent to the first surface, and faces the first surface and is adjacent to each second surface. A third surface,
The external electrode is formed on the second surface so as to be connected to the first electrode portion formed on the first surface and the first electrode portion, and to the corner portion between the second surface and the third surface. A second electrode portion extending,
The surface-mount type electronic component array, wherein the external electrode is not substantially formed on the third surface. 2. The surface-mounting type according to claim 1, wherein a thickness of a portion connecting the first electrode portion and the second electrode portion in the external electrode is 70% or more of a maximum thickness of the first electrode portion. Electronic component array.

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