JP4952767B2 - Radial lead electronic components - Google Patents

Description

  The present invention relates to a radial lead electronic component having a lead wire.

  A capacitor is known in which lead wires are connected to both surfaces of an element body, and the element body to which the lead wires are connected is covered with an exterior resin (Patent Document 1). In Patent Document 1, at the portion where the lead wire is connected to the element body, the lead wires intersect with each other as viewed from the surface of the element body to sandwich the element body.

  In recent years, with the thinning of electronic devices such as liquid crystal displays, it is necessary to reduce the wiring board space on which capacitors and the like are mounted (low profile). In connection with this, after mounting the capacitor on the wiring board, the leg portion of the lead wire is bent by pressing the capacitor or the like, and measures have been made to cope with the low profile.

  However, in the conventional capacitor shape, when the lead wire is bent after the capacitor is mounted on the substrate, stress is generated in the exterior resin, and the exterior resin may be cracked or peeled off. If the outer resin fragments are scattered on the wiring board, it may adversely affect the soldering of the wiring board, resulting in variations in product quality.

JP 05-347323 A

  The present invention has been made in view of such a situation, and an object of the present invention is to reduce the height of the electronic device without cracking or peeling the exterior resin even if the leg portion of the lead wire is bent after mounting the wiring board of the capacitor. It is an object to provide a radial lead electronic component capable of satisfying the requirements.

In order to achieve the above object, a radial lead electronic component according to the present invention includes:
A flat substrate constituting the element body of the electronic component;
Electrode films respectively formed on the front and back surfaces of the substrate;
Two lead wires each having a connecting portion electrically connected to the electrode film and a lead leg extending outward from the connecting portion;
An exterior resin covering the periphery of the substrate to which the connecting portion of the lead wire is connected;
The connecting portions of the lead wires intersect at an angle of 100 to 130 degrees when viewed from the surface of the substrate.

  In radial lead electronic components, in order to ensure insulation between lead wires, a part of the lead leg portion is covered with an exterior resin in addition to the lead wire connecting portion. When the connecting portions of the lead wires are smaller than 100 degrees when viewed from the surface of the substrate, the longitudinal covering length of the lead leg portions covered with the exterior resin becomes long in order to ensure insulation between the lead wires. End up. If the covering length of the lead legs covered with the exterior resin is long, a large stress is generated in the exterior resin when the lead legs are bent after the electronic component is mounted on the wiring board.

  In the present invention, the longitudinal covering length of the lead leg portion covered with the exterior resin can be shortened by intersecting the connecting portions of the lead wires at an angle of 100 degrees or more. Therefore, when the lead leg portion is bent after the electronic component is mounted on the wiring board, the stress generated in the exterior resin can be suppressed low, and the lead leg portion is easily bent.

  Further, even if the lead leg portion is bent, the exterior resin is not cracked or peeled off, so that the quality of the wiring board can be kept constant without the pieces of the exterior resin being scattered on the wiring board.

  In addition, by crossing the lead wire connection portions at an angle of 130 degrees or less, it is possible to prevent the substrate from rotating when clipping the substrate at the connection portion of the two lead wires during manufacturing. it can.

  Preferably, the lead leg portion has a leg main body that is bent at a predetermined angle from the connection portion and is parallel to each other, and is between the lead wires in the leg main body as viewed from the surface of the substrate. The width is larger than the outer diameter of the substrate.

  Since the width between the lead wires in the leg main body is larger than the outer diameter of the substrate, it is easy to reduce the stress generated in the exterior resin when the lead leg is bent. Therefore, the lead leg portion is easily bent, and even if the lead leg portion is bent after mounting the wiring board, the exterior resin is not cracked or peeled off.

  Preferably, the lead leg portion includes a first connecting portion that is bent at a predetermined angle from the connecting portion and connects the connecting portion and the leg main body.

  By having the first connecting part that bends at a predetermined angle from the connecting part, the stress generated in the exterior resin when the lead leg part is bent can be relieved by the first connecting part.

  Preferably, the lead leg part further includes a board insertion part for inserting the lead wire into the wiring board, and the leg main body and the board insertion part are connected by a second connection part.

  Preferably, each of the second connecting portions has the lead wire from the leg main body so that each of the substrate insertion portions is positioned on a center line in the thickness direction of the substrate as viewed from a side surface of the substrate. It is bent in the direction of the center line toward the board insertion portion, and the leg main body and the board insertion portion are parallel to each other.

  Since each second connecting portion is bent in a different direction, when the lead wire is inserted into the wiring board, the second connecting portion functions as a stopper, and the lead leg portion above the second connecting portion. Is not inserted into the wiring board.

  The second connecting portion may be bent in advance so that the surface of the element body is inclined in a direction approaching the wiring board.

  When the second connecting portion is bent in advance, it is not necessary to apply an external force after mounting the electronic component on the wiring board. Accordingly, since no stress acts on the exterior resin, cracking and peeling of the exterior resin can be surely reduced, and the height can be easily reduced without adding a special process.

  Preferably, the electronic component is one of a ceramic capacitor dielectric, a varistor resistor, and a resistor element resistor.

FIG. 1 is a front view of a radial lead electronic component according to an embodiment of the present invention. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is an external view showing the shape of the connecting portion of the lead wire. FIG. 4A is a schematic cross-sectional side view when the radial lead electronic component is mounted on the wiring board, and FIG. 4B is a schematic cross-sectional side view of the radial lead electronic component after the lead wire is bent. FIG. 5 is a schematic sectional side view of a radial lead electronic component according to another embodiment of the present invention.

First Embodiment As shown in FIGS. 1 and 2, a radial lead electronic component 2 according to an embodiment of the present invention includes a disk-shaped element body 4 constituting a ceramic capacitor 3 and front and back surfaces of the element body 4. The electrode film 6 to be formed, a pair of lead wires 8, and an exterior resin 12 are included. Although it does not specifically limit as the exterior resin 12, For example, it is comprised with an epoxy resin.

  The element body 4 shown in FIGS. 1 and 2 is formed of a ceramic capacitor, but may be a varistor, an inductor, or the like in addition to the capacitor. In the following description, it is assumed that the element body 4 is a ceramic capacitor.

  As shown in FIGS. 1 and 2, the size of the element body 4 is not particularly limited, but it is preferable that the thickness T is 0.3 to 2.0 mm and the diameter D is 3 to 7 mm.

  The dielectric ceramic composition constituting the element body 4 shown in FIG. 2 is not particularly limited, and is composed of a dielectric ceramic material such as barium titanate, strontium titanate, calcium titanate, or a mixture thereof.

  The electrode film 6 is formed on the front and back surfaces of the element body 4 shown in FIG. 2 by, for example, screen printing. The electrode film 6 is baked as necessary. The electrode film 6 is made of a conductive material. Examples of the conductive material used for the electrode film 6 include Cu, Cu alloy, Ag, and Ag alloy.

  As shown in FIG. 2, each lead wire 8 is formed with a connection portion 8 a connected to the electrode film 6 via the solder 10. The solder 10 is not particularly limited, but is composed of, for example, Sn—Ag—Cu solder. A lead leg portion 8f that extends substantially in the longitudinal direction of the lead parallel to the center line in the thickness direction of the element body 4 is formed integrally with the connection portion 8a. As shown in FIGS. 1 and 4A, the lead leg portion 8f includes a first connection portion 8b, a leg main body 8c, a second connection portion 8d, and a board insertion portion 8e.

  As shown in FIG. 4A, the lead leg portion 8f is bent at a predetermined angle α from the front and back surfaces of the element body 4 when viewed from the side surface of the element body 4, and connects the connection portion 8a and the leg portion body 8c. A first connecting portion 8b. The angle α is preferably in the range of 30 to 50 degrees.

  The connecting portion 8a and the first connecting portion 8b are covered with the exterior resin 12, and insulation between the lead wires 8 is ensured. The leg main body 8 c is parallel to the center line in the thickness direction of the element main body 4. Further, as shown in FIG. 4A, the lead leg portion 8f has a board insertion portion 8e for inserting the lead wire 8 into the wiring board 14, and the leg portion main body 8c and the board insertion portion 8e are the second ones. It is connected by a connecting portion 8d.

  Each substrate insertion portion 8e is located on the center line in the thickness direction of the element body 4 when viewed from the side of the element body. The substrate insertion portion 8 e is parallel to the center line in the thickness direction of the element body 4. Each of the second connecting portions 8d is bent so as to connect the leg main body 8c and the board insertion portion 8e.

  As shown in FIG. 1, the leg main bodies 8 c are parallel to each other when viewed from the surface of the element main body 4, and maintain a predetermined distance L. The interval L is preferably 7.5 mm or more. Thereby, insulation between the lead wires not covered with the exterior resin 12 can be secured. The relationship between the substrate diameter D of the element body 4 and the predetermined interval L is preferably D <L. As shown in FIG. 1, the leg main body 8 c, the second connecting portion 8 d, and the board insertion portion 8 e are arranged on the same line when viewed from the surface of the element main body 4. The second connecting portions 8d and the substrate insertion portions 8e are separated by a predetermined distance L, and insulation between them can be ensured.

  Each lead wire 8 shown in FIGS. 1 and 2 is formed by processing a conductive wire such as a metal wire, and the lead leg portion 8f has a circular cross section. The diameter of the lead wire 8 is preferably 0.4 to 0.6 mm. Further, the connecting portion 8a of the lead wire 8 shown in FIG. 2 is flattened as shown in FIG. 3 (flat surface 8g). Thereby, the connection between the electrode film 6 and the connecting portion 8a of the lead wire 8 can be improved.

  As shown in FIG. 1, each connection portion 8 a intersects at an angle θ at or near the center point P of the element body as viewed from the surface of the element body 4. The angle θ is preferably in the range of 100 to 130 degrees. If the angle θ is smaller than 100 degrees, resin cracking tends to occur when the lead leg 8f is bent after mounting the radial lead electronic component 2 on the board. When the angle θ is larger than 130 degrees, the clipping performance of the element body 4 by the connecting portion 8a of the lead wire 8 tends to be lowered.

  As shown in FIG. 2, the exterior resin 12 integrally covers the element body 4, the solder 10, the connecting portion 8 a of the lead wire 8, and the first connecting portion 8 b, and a part of the lead leg portion 8 f is part of the exterior resin. It is supposed to jump out of twelve. The end portion (substrate insertion portion 8e) of the lead leg portion 8f protruding from the exterior resin 12 is inserted and attached to the wiring substrate 14 shown in FIG. As shown in FIG. 1, the exterior resin 12 has a height from the connecting portion 8a of the lead wire 8 to at least the first connecting portion 8b of the lead leg portion 8f as shown in FIG. Covered with h1. In the length direction of the lead leg portion 8f, the height from the intersection P between the connecting portions 8a to the portion covered with the exterior resin of the lead leg portion 8f is h1, and is higher than the board insertion portion 8e of the lead leg portion 8f. And the height of the part which is not covered with exterior resin is h2.

  FIG. 4A shows a state where the board insertion portion 8 e of the lead wire 8 described above is inserted into the wiring board 14. After inserting the board insertion portion 8e into the wiring board 14, as shown in FIG. 4B, the lead leg portion 8f is bent to reduce the height. In the embodiment shown in FIG. 4B, the lead leg portion 8f is bent approximately 90 degrees so that the surface 4a of the element body 4 and the surface 14a of the wiring board 14 are substantially parallel. As long as the angle can be lowered, the angle is not necessarily 90 degrees.

  As described above, in the radial lead electronic component, in order to ensure insulation between the lead wires 8, a part of the lead leg portion 8f is covered with the exterior resin 12 in addition to the connection portion 8a of the lead wire 8. It has become. When the connecting portions 8a of the lead wires 8 are smaller than 100 degrees when viewed from the surface of the substrate, in order to ensure insulation between the lead wires 8, the longitudinal direction of the lead legs 8f covered with the exterior resin 12 The coating length becomes long.

  As a result, the height h1 shown in FIG. When the longitudinal length of the lead leg 8f covered with the exterior resin 12 is long in this way, a large stress is applied to the exterior resin 12 when the lead leg 8f is bent after the electronic component 2 is mounted on the wiring board 14. Will occur. In the present embodiment, by connecting the connecting portions 8a of the lead wires 8 at an angle of 100 degrees or more, the longitudinal covering length of the lead leg portions 8f covered with the exterior resin 12 can be shortened.

  That is, the height h1 shown in FIG. Therefore, when the lead leg portion 8f is bent after the electronic component 2 is mounted on the wiring board 14, the stress generated in the exterior resin 12 can be suppressed low, and the lead leg portion 8f is easily bent. Further, even if the lead leg portion 8f is bent, the exterior resin 12 does not break or peel off, so that the quality of the wiring substrate 14 can be kept constant without the fragments of the exterior resin 12 being scattered on the wiring substrate 14. .

  Further, by crossing the connecting portions 8a of the lead wires 8 at an angle of 130 degrees or less, the element main body 4 rotates when clipping the element main body 4 at the connecting portions 8a of the two lead wires 8 at the time of manufacture. Can be prevented.

  Further, since the width L between the lead wires in the leg main body 8c is larger than the outer diameter D of the element main body 4, it is easy to reduce the stress generated in the exterior resin 12 when the lead leg 8f is bent. Therefore, the lead leg portion 8f is easily bent, and the exterior resin 12 is not broken or peeled off even if the lead leg portion 8f is bent after the electronic component 2 is mounted on the wiring board 14.

  Furthermore, the lead leg portion 8f has a first connecting portion 8b that is bent at a predetermined angle α from the front and back surfaces of the element body 4 when viewed from the side surface of the element body 4, and connects the connecting portion 8a and the leg portion body 8c. . Therefore, the stress generated in the exterior resin 12 when the lead leg portion 8f is bent can be relaxed by the first connecting portion 8b.

In addition, each second connecting portion 8d is bent so as to connect the leg main body 8c and the board insertion portion 8e, so that when the lead wire 8 is inserted into the wiring board 14, the second connecting portion 8d Functions as a stopper. Therefore, the lead leg portion 8f above the second connecting portion 8d is not inserted into the wiring board.
Second embodiment

  Since this embodiment is the same as the first embodiment shown in FIGS. 1 to 4 except for the following, a duplicate description is omitted.

  As shown in FIG. 5, in this embodiment, before the board insertion portion 8e of the lead wire 8 in the electronic component 2a of this embodiment is inserted into the wiring board 14, the second connecting portion 8d of the lead leg portion 8f is bent in advance. ing. Preferably, the second connecting portion 8d is bent in advance so that the surface 4a of the element body 4 and the surface 14a of the wiring board 14 are substantially parallel when the electronic component 2a is inserted into the wiring board 14.

  Since the second connecting portion 8d is bent in advance, only the board insertion portion 8e is inserted into the wiring board 14 in the board mounting process of the electronic component 2a shown in FIG. Therefore, since no stress acts on the exterior resin 12, cracking and peeling of the exterior resin 12 can be surely reduced, and the height can be easily reduced without adding a special process.

  In the embodiment described above, the shape of the element body 4 of the ceramic capacitor 3 has been described as being circular as viewed from the surface of the element body 4, but may be a polygon. For example, if the element body 4 is a quadrangle, the outer diameter of the element body 4 means the diameter of the circumscribed circle.

Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples.
Example

  A board mounting bending test was performed by varying the angle θ at which the connecting portions 8a shown in FIG. 1 intersect, and the cracking of the exterior resin 12 and the clipping performance of the element body 4 at the time of manufacture were evaluated. Table 1 shows the results. In this experiment, the element body 4 has a diameter D of 4.0 mm and a thickness T of 1.4 mm.

  From the experimental data shown in Table 1, it was confirmed that good results of the substrate mounting bending test and element clipping were obtained when the angle θ was in the range of 100 to 130 degrees.

DESCRIPTION OF SYMBOLS 2, 2a ... Electronic component 4 ... Element main body 6 ... Electrode film | membrane 8 ... Lead wire 8a ... Joint part 8b ... 1st connection part 8c ... Leg part main body 8d ... 2nd connection part 8e ... Board insertion part 8f ... Lead leg part 12 ... Exterior resin 14 ... Wiring board

Claims (3)

A flat substrate constituting the element body of the electronic component;
Electrode films respectively formed on the front and back surfaces of the substrate;
Two lead wires each having a connecting portion electrically connected to the electrode film and a lead leg extending outward from the connecting portion;
An exterior resin covering the periphery of the substrate to which the connecting portion of the lead wire is connected;
The connecting portions of the lead wires intersect at an angle of 100 to 130 degrees when viewed from the surface of the substrate ,
The lead leg has a leg main body that is bent at a predetermined angle from the connection part and is parallel to each other, and the width between the lead wires in the leg main body as viewed from the surface of the substrate is: Large compared to the outer diameter of the substrate,
The lead leg further includes a board insertion part for inserting the lead wire into a wiring board, and the leg main body and the board insertion part are connected by a second connection part,
Each of the second connecting portions has the lead wire inserted from the leg body into the substrate so that each of the substrate insertion portions is positioned on a center line in the thickness direction of the substrate when viewed from the side surface of the substrate. A radial lead electronic component , wherein the leg main body and the board insertion portion are parallel to each other .   2. The radial lead electronic component according to claim 1, wherein the lead leg portion includes a first connecting portion that bends at a predetermined angle from the connecting portion and connects the connecting portion and the leg main body. The electronic component is a radial lead electronic component according to claim 1 or 2, wherein the dielectric ceramic capacitor, resistor for a varistor, is either resistance element resistor.

Images