JP6589132B2 - Electronic components - Google Patents

Description

  The present invention relates to an electronic component used in various electronic devices.

  In recent years, electronic control of automobile drive systems and control systems has been increasingly advanced, and a large number of electronic control devices have been installed in a single automobile, and further downsizing and higher reliability of electronic control devices are desired. It is rare.

  In addition, electronic components used in these electronic control devices are also required to have high reliability that can be surface-mounted for miniaturization and are required for in-vehicle components.

  Next, an example in which a coil element is used as a circuit element for such a conventional electronic component will be described with reference to the drawings.

  FIG. 10 is a plan view of a conventional electronic component, FIG. 11 is a cross-sectional view taken along line AA of FIG. 10, and FIG. 11 shows a state where the electronic component is mounted on a mounting board.

  As shown in FIGS. 10 and 11, a conventional electronic component is formed by winding a copper wire with an insulating film to form a coil element 1, and the coil element 1 is made of a binder composed of a metal magnetic powder and a thermosetting resin. The body 2 is formed by embedding in the mixed powder and pressure forming, and the lead wires 3 at both ends of the coil element 1 protruding from the side surface of the body 2 are crushed into a flat plate shape and from the side surface of the body 2 The surface mounting type terminals 4 were formed by bending toward the bottom surface, and thus the electronic component was configured.

  And this electronic component was mounted with the solder 7 on the land 6 of the mounting board | substrate 5 using the reflow solder tank.

  As prior art document information related to the invention of this application, for example, Patent Document 1 is known.

JP 2009-123927 A

  In recent years, the mounting positions of electronic control devices for automobiles are increasing from outside the engine room to the inside of the engine room, and it is desired to further improve the vibration resistance.

  However, since the conventional surface mount type electronic component described above is configured such that the terminal 4 is bent from the side surface of the body 2 toward the bottom surface, a slight gap is formed between the terminal 4 and the body 2 by the spring back of the bent portion. 8 sometimes occurred.

  When the gap 8 is generated, when the vibration of the vehicle is transmitted to the body 2 through the mounting substrate 5, the terminal 4 is bent by the size of the gap 8, and this is alternately repeated by the reciprocating motion. Causes vibration.

  As a result of repetition of this vibration, the stress is concentrated with the bent portion 9 of the terminal 4 or the boundary portion 10 between the terminal 4 and the fillet of the solder 7 as a fulcrum, and eventually the metal fatigues and breaks. There has been a problem that parts may be disconnected.

  An object of the present invention is to provide a highly reliable electronic component as a vehicle-mounted component by preventing breakage of a terminal due to vibration.

  In order to solve the above-described problems, the present invention includes a substantially quadrangular prism-shaped body having a circuit element therein and a pair of plate-like terminals connected to the circuit element. In an electronic component in which the terminal is bent from the side surface of the body along the bottom surface, a side-side solder attachable film made of a film having solder wettability is provided at the lower end portion of the body side surface facing the terminal. is there.

  With the above configuration, a side-side solder attachable film made of a film having solder wettability is provided at the lower end of the side surface of the body facing the terminal, so that when the electronic component is reflow-soldered to the mounting board, the molten solder Wraps around the side of the body, which is the back side of the terminal, and comes into contact with the side solder attachable layer, adheres to the side solder attachable layer and spreads wet, and solder between the terminal and the side solder attachable layer. Can be stopped.

  As a result, since the solder can be in a gap between the terminal and the side surface of the body formed by the springback after the terminal is bent, the body generated by the gap between the body side surface and the terminal No longer vibrates like a pendulum, and the terminal can be prevented from breaking.

  As described above, according to the present invention, it is possible to obtain the effect of preventing the breakage of the terminal due to vibration and improving the reliability of the electronic component.

The bottom side perspective view of the electronic component in one embodiment of this invention Sectional drawing of the BB line in FIG. Sectional drawing which shows the state which mounted the electronic component in one embodiment of this invention in the mounting board | substrate The figure explaining the manufacturing process of the electronic component in one embodiment of this invention The figure explaining the manufacturing process of the electronic component in one embodiment of this invention The figure explaining the manufacturing process of the electronic component in one embodiment of this invention The figure explaining the manufacturing process of the electronic component in one embodiment of this invention The figure explaining the manufacturing process of the electronic component in one embodiment of this invention The figure explaining the manufacturing process of the electronic component in one embodiment of this invention Plan view of conventional electronic components Sectional view of the AA line of FIG.

  Hereinafter, an example in which a coil element is used as a circuit element of an electronic component according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a bottom perspective view of an electronic component according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line BB in FIG.

  As shown in FIG. 1 and FIG. 2, the electronic component of the present invention includes a substantially square columnar body 22 having a coil element 21 therein as a circuit element, and a plate-like terminal 23 connected to the coil element 21. ing.

  The terminals 23 are fixed to the opposite side surfaces of the body 22 and are bent from the side surface toward the bottom surface. The other end of the terminal 23 is a surface mount type terminal 23 arranged on the bottom surface of the body 22. .

  Of these, the body 22 is made of a magnetic material obtained by mixing a metal magnetic powder mainly composed of iron with a binder made of a thermosetting resin such as an insulating epoxy resin, and granulating the binder. One end of the coil element 21 and the terminal 23 is embedded in this magnetic material, and pressure molding is performed using a mold. The thermoformed resin is cured by heat-treating the pressure molded body, and one end of the terminal 23 is cured. It is fixed to the side surface of the body 22.

  The coil element 21 embedded in the body 22 is formed by spirally winding an insulating coated copper wire with a fusion layer to form an air-core coil. In this embodiment, the thickness of the copper wire is A 0.28 mm copper wire was used, the shaft core diameter was 3.8 mm, the wire was wound for 48 turns, the lead wires 24 at both ends were drawn in opposite directions, and then the fusion layer was subjected to a curing reaction to maintain the shape. Is.

  In FIG. 2, the upper surface side of the electronic component is shown on the drawing, and the bottom surface side of the electronic component is shown below the drawing.

  The terminal 23 is made of a flat metal plate. In the present embodiment, the terminal 23 is electrically connected to the lead wire 24 of the coil element 21 using a phosphor bronze plate having a thickness of 0.2 mm. The wide end portion 23a is formed into a wide portion 23a, and the tip portion is formed in a U-shaped shape of Katakana, and the U-shaped protruding portion 25 is embedded and fixed in the body 22.

  The other end side of the terminal 23 is a mounting portion with a mounting board having a width narrower than that of the wide portion 23 a, the side mounting portion 23 b positioned on the side surface of the body 22, and the bottom surface mounting portion positioned on the bottom surface of the body 22. The wide portion 23a, the side surface mounting portion 23b, and the bottom surface mounting portion 23c are extended in this order, and are bent along the bottom surface from the side surface of the body 22, so that the wide portion 23a and the side surface mounting portion 23b are formed on the body. The bottom surface mounting portion 23 c is disposed on the bottom surface of the body 22.

  As for the connection between the terminal 23 and the lead wire 24, a stepped portion 26 is formed between the projecting portions 25 of the wide portion 23a, which is 0.2 mm below the flat portion of the terminal 23, and the lead wire 24 is stored in the stepped portion 26. Are electrically connected using electric welding such as resistance welding.

  The protruding portion on the opposite side of the stepped portion 26 is accommodated in a groove-like accommodation groove 27 formed on the side surface of the body 22.

  When the lead wire 24 protrudes from the stepped portion 26, it is preferable to press the lead wire 24 in advance and flatten it flatly, since the external dimensions of the electronic component do not increase.

  A part of the mounting portion 23 c on the bottom surface is housed in a housing recess 28 formed on the bottom surface of the body 22 such that the mounting surface protrudes below the bottom surface of the body 22.

  Further, separately from the present embodiment, a connecting portion may be provided in the projecting portion 25 and the lead wire 24 may be connected to arrange the connecting portion inside the body 22.

  In this way, the projecting portion 25 which is one end of the coil element 21 and the terminal 23 is embedded in the magnetic material, and the outer dimension of the other end of the terminal 23 bent from the side surface of the body 22 along the bottom surface is 10.0 ×. A surface-mount type electronic component of 10.5 × 5.5 mm is formed.

  A side-side solder attachable film 29 made of a film having solder wettability is formed on the lower end portion of the side surface of the body 22 facing the mounting portion 23b on the side surface of the terminal 23.

  The side-side solder attachable film 29 only needs to have solder wettability, and examples of the material having good solder wettability include a tin material, a silver material, and a copper material. Can be formed.

  By doing so, the electronic component is applied to the land 31 when the electronic component is reflow-soldered to the mounting substrate 30 as shown in the cross-sectional view of the electronic component of the present embodiment shown in FIG. 3 mounted on the mounting substrate. When the solder 32 is melted and sucked into the mounting portion 23b on the side surface of the terminal 23, wraps around the side surface of the body 22 that is the back side of the mounting portion 23b on the side surface and contacts the side-side solder attachable film 29, the solder 32 adheres to the side surface solder attachable film 29 and spreads wet, so that the solder can be retained between the mounting portion 23 b on the side surface of the terminal 23 and the side surface solder attachable film 29.

  As a result, the solder 32 is interposed in a slight gap 33 between the mounting portion 23b on the side surface of the terminal 23 and the side surface of the body 22 formed by the springback after the terminal 23 is bent. It is possible to prevent the terminal 22 from being broken by suppressing the body 22 generated by the gap 33 between them from vibrating in a pendulum manner.

  In this case, the dimension (SMH) in the height direction where the side-side solder attachable film 29 is formed is preferably larger than the maximum dimension of the gap 33 in consideration of the constriction of the intervening solder 32. In consideration of the gap 33 due to the spring back, it is preferable to form the gap more than the thickness dimension of the terminal 23, and the upper limit is preferably lower than the height dimension (FH) of the solder fillet of the mounting substrate 30.

  Further, the side-side solderable film 29 may be formed at a position facing both ends of the terminal 23 in the width direction, which is a direction orthogonal to the extending direction of the terminal 23. By doing so, the width of the terminal 23 is increased. Compared with the case where the side-side solder attachable film 29 is formed in the entire direction, the amount of the solder 32 can be reduced to prevent the connection strength of the electronic component to the mounting substrate 30 from being lost. Since the solder 32 is interposed at both ends in the width direction, the pendulum-like vibration of the body 22 can be suppressed.

  In this case, the dimension (SMW) in the width direction of the terminal 23 of the side-side solderable film 29 is preferably larger than the maximum dimension of the gap 33 in consideration of the occurrence of constriction in the intervening solder 32. In consideration of the size of the gap 33 caused by the spring back of 23, it is preferable to form the gap more than the thickness of the terminal 23. The upper limit is preferably 2 mm or less in order to reduce the amount of solder 32 used.

  Further, it is preferable to form a bottom-side solder attachable film 34 made of a film having solder wettability on the side surface side of the bottom surface of the body 22 facing the mounting portion 23c on the bottom surface of the terminal 23. The solder 32 can be interposed between the mounting portion 23c on the bottom surface of the body 23 and the bottom surface of the body 22, and the corners of the side surface and the bottom surface of the body 22 are supported by the solder 32 so that the pendulum-like vibration of the body 22 is further reduced. Can be suppressed.

  In this case, the bottom surface of the body 22 and the bottom surface of the terminal 23 are taken into consideration when the dimension (LMD) from the side surface of the body 22 to the center side of the body 22 is constricted in the intervening solder 32. It is preferable to make it larger than the maximum dimension of the gap 35 with respect to the mounting portion 23c, and the upper limit is desirably 2 mm or less in order to reduce the amount of solder 32 used.

  And this bottom face side solder adherence film 34 is good to form in the position which opposes the both ends of the width direction of terminal 23, and, in this way, the bottom face side solder adherence film is formed to the whole width direction of terminal 23. Compared with the case of forming 34, the amount of solder 32 can be reduced to prevent the connection strength of the electronic component to the mounting board 30 from being lost, and the solder 32 is applied to both ends of the terminal 23 in the width direction. Since it is interposed, the pendulum-like vibration of the body 22 can be suppressed.

  In this case, considering that the width (LMW) of the terminal 23 in the width direction of the terminal 23 of the solder-possible film 34 is constricted in the intervening solder 32, the distance 35 between the bottom surface of the body 22 and the mounting portion 23c on the bottom surface is considered. It is preferable that the maximum dimension is larger than the maximum dimension, and the upper limit is desirably 2 mm or less in order to reduce the amount of solder 32 used.

  In addition, the side-side solder attachable film 29 and the bottom-side solder attachable film 34 may be formed separately, but the bottom-side solder-attachable film 34 is attached to the side-side solder attachable film at the side and bottom edges of the body 22. The solder 32 on the land 31 of the mounting substrate 30 may be continuously formed from the bottom surface side solder attachable film 34 to the continuous side surface solder attachable film 29. It is possible to wet and spread, and the solder 32 can be interposed between the side surface of the body 22 and the mounting portion 23b on the side surface of the terminal 23 more accurately.

  Here, in FIG. 1, the side-side solder attachable film 29 and the bottom-side solder attachable film 34 pass through the terminal 23 and are outlined by broken lines, and in FIGS. 2 and 3, The gap 33 between the body 22 and the terminal 23 is exaggerated for easy understanding.

  Next, a method for manufacturing an electronic component according to an embodiment of the present invention will be described with reference to FIGS.

  First, as shown in FIG. 4, an insulation core copper wire with a fusion layer is spirally wound to form an air-core coil element 21.

  An insulating coated copper wire with a fusion layer is wound around a predetermined winding axis, and the lead wires 24 at both ends are drawn in opposite directions, and then hot air is blown to the winding portion or a solvent is dropped to form a fusion layer. Is removed from the winding shaft while maintaining the shape of the winding portion, and the air-core coil element 21 is formed.

  Next, the terminal 23 is prepared as shown in FIG.

  The terminal 23 is formed by pressing a metal plate having a thickness of 0.2 mm such as a phosphor bronze plate.

  The terminal 23 is formed with a wide portion 23a with one end having a wide width, and a tip portion is formed in a U-shaped shape of a katakana, and a U-shaped protruding portion 25 that is embedded and fixed in the body 22 is provided. Form. A stepped portion 26 is formed between the projecting portions 25 to place the lead wire 24 of the coil element 21 that is recessed by 0.2 mm from the flat portion.

  The other end side is a mounting portion 23b on the side surface disposed on the side surface of the body 22 and a mounting portion on the bottom surface disposed on the bottom surface of the body 22 to be a mounting portion with the mounting substrate 30 narrower than the wide portion 23a. 23c is formed by extending the wide portion 23a.

The terminal 23 may be formed as an individual piece, but it is preferable to form it on a hoop material as shown in FIG. 4 because continuous production is possible and productivity can be improved.
Next, as shown in FIG. 6, the pair of plate-like terminals 23 and the coil element 21 are connected.

  After the insulation film of the lead wire 24 of the coil element 21 is peeled off, the lead wire 24 is accommodated in the stepped portion 26 of the terminal 23, and the terminal 23 and the lead wire 24 are electrically connected using electric welding such as resistance welding. Connect to.

  When the diameter of the lead wire 24 is larger than the depth of the stepped portion 26, a resistance welding electrode is pressed against, or as shown in FIG. It is preferable that the external dimensions of the electronic component are not increased so as to be equal to the height of the flat portion 23.

  Next, as shown in FIG. 7, a substantially rectangular column-shaped body 22 is formed which incorporates the coil element 21 and fixes one end of the terminal 23 to the opposite side surface.

  The body 22 is a mixture of a magnetic metal powder mainly composed of iron and a binder made of a thermosetting resin, which is granulated into a granular material, a coil element 21, and a protrusion of the terminal 23. The body 25 is formed by inserting the part 25 into a mold (not shown) and performing pressure molding, and thermosetting the resulting molded body at 180 ° C. or higher.

  At this time, the body 22 is formed with a mold, and an accommodation groove 27 for accommodating the stepped portion 26 protruding from the back surface of the terminal 23 is formed from the side surface to the bottom surface of the body 22.

  Further, a housing recess 28 for housing the mounting portion 23 c on the bottom surface of the terminal 23 is formed on the bottom surface of the body 22.

  FIG. 7 shows a state where the body 22 is transmitted, and the outline of the body 22 is indicated by a broken line.

  Next, as shown in FIG. 8, a side-side solder attachable film 29 made of a film having solder wettability is formed at the lower end of the side surface of the body 22.

  Here, in FIG. 8, the bottom surface side of the electronic component is shown as the upper side of the drawing.

  The side-side solderable film 29 is formed on the lower end portion of the side surface of the body 22 facing the pre-folded terminal 23 before the terminal 23 is bent along the bottom surface from the side surface of the body 22 after the body 22 is formed. Therefore, a material such as a tin material, a silver material, or a copper material having solder wettability is formed by a method such as a thermal spraying method or a vapor deposition method while masking.

  Further, the side-side solder attachable film 29 may be formed at positions facing both ends in the width direction of the terminal 23, which is a direction orthogonal to the extending direction of the terminal 23.

  Further, in addition to the side surface solder attachable film 29, a bottom surface side solder attachable film 34 made of a film having solder wettability is formed on the side surface side of the bottom surface of the body 22 facing the mounting portion 23c on the bottom surface of the terminal 23. Alternatively, the bottom-side solder attachable film 34 may be formed at a position facing both ends of the terminal 23 in the width direction.

  In addition, the side-side solder attachable film 29 and the bottom-side solder attachable film 34 may be formed separately. It may be formed integrally with the solderable film 29 in a continuous manner.

  Next, as shown in FIG. 9, the continuous hoop is cut into pieces.

  In FIG. 9, the bottom surface side of the electronic component is shown as the upper side of the drawing.

  Cutting into pieces is performed by press working, and the terminal 23 is cut into a predetermined shape with a predetermined length.

  After cutting into individual pieces, it is preferable to perform solder plating on the surface of the terminal 23 by immersing the terminal 23 in molten solder. When reflow soldering is performed on the mounting substrate 30, the molten solder 32 is applied to the terminal 23. It is easy to suck up, and the solder 32 adheres to the side-side solder attachable film 29 and can easily spread.

  Finally, the terminal 23 is bent from the side surface of the body 22 toward the bottom surface.

  By doing as described above, the electronic component shown in FIG. 1 can be obtained.

  In the present embodiment, the side-side solder attachable film 29 and the bottom-side solder attachable film 34 are formed before being divided into individual pieces shown in FIG. The side solder attachable film 29 and the bottom side solder attachable film 34 may be formed.

  The electronic component according to the present invention is industrially useful because it can prevent the breakage of the terminal due to vibration and can increase the reliability of the electronic component.

DESCRIPTION OF SYMBOLS 21 Coil element 22 Body 23 Terminal 23a Wide part 23b Side surface mounting part 23c Bottom surface mounting part 24 Lead line 25 Projection part 26 Step part 27 Accommodation groove 28 Accommodation recessed part 29 Side surface side solderable film 30 Mounting board 31 Land 32 Solder 33 Gap 34 Solderable film on the bottom side 35 Gap

Claims (2)

A body having a substantially quadrangular prism shape having a circuit element inside; and a pair of plate-like terminals connected to the circuit element; one end of each of the terminals is fixed to the opposite side surface of the body; In electronic parts bent from the side of the body along the bottom,
A first side-side solder attachable film and a second side-side solder attachable film made of a film having solder wettability are provided at a lower end portion of the side surface of the body facing the terminal;
A first bottom surface side solder attachable film and a second bottom surface side solder adherence film made of a film having solder wettability are provided on the side surface of the bottom surface of the body facing the terminal;
The first side surface solder adherence film and the second side surface solder adherence film are provided apart from each other at positions facing both ends in the width direction of the terminal,
The first bottom face side solder attachable film and the second bottom face side solder attachable film are provided at positions facing both ends in the width direction of the terminal, and are separated from each other. . The first side surface solder attachable film and the first bottom surface side solder adherence film are integrally provided, and the second side surface solder attachable film and the second bottom surface side solder adherence film are integrated. The electronic component according to claim 1, wherein the electronic component is provided on the electronic component.

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