JPH06163305A - Chip component - Google Patents

Abstract

PURPOSE:To provide a chip component including electrodes each having a side feature consisting of a thin upper part and a lower part protruding sideward, which are divided in the middle by a horizontal plane so as to prevent excess molten solder from adhering to the electrodes. CONSTITUTION:A chip component A is composed of a main body 1 in the shape of a parallelepiped, and electrodes 2 attached to opposite sides of the body. The electrodes 2 each have a side feature 3 consisting of a thin upper part 3a and a lower part 3b protruding sideward, which are divided in the middle by a horizontal plane 4. According to this structure, molten solder adheres only to the lower parts of the electrodes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip component soldered on a substrate.

[0002]

2. Description of the Related Art As a method for soldering chip parts, there is a method using a reflow furnace, and this soldering process is shown in FIG. In FIG. 5, a land portion 6 is provided on the substrate 5 (FIG. 5A), and creamy solder 7 is printed on the land portion 6 (FIG. 5B). The chip part A is placed on the land portion 6 on which the solder 7 is printed (FIG. 5C), and put in the reflow furnace in this state. When heated in the reflow furnace, the solder 7 is melted and the solder 7 is welded to the electrode portion 2 of the chip component A and the land portion 6 of the substrate 5 (FIG. 5D).

[0003]

However, the surface tension of the electrode part 2 of the chip part A is larger than the surface tension of the land part (copper board) 6, and the leakability of the solder 7 is due to the land part 6.
Since the electrode part 2 of the chip component A is better, the solder 7 sticks to the electrode part 2 side while being offset, as shown in FIG.
A so-called tempura occurs. In particular, the side surface 3 of the electrode portion 2
This tendency is remarkable in the large chip component A having a large area.

Therefore, it is an object of the present invention to provide a chip component in which soldering failure due to excessive adhesion of solder to electrode portions does not occur.

[0005]

In order to achieve the above object, a chip component according to the present invention is provided with electrode portions at both ends of a component body, and solder is welded to each electrode portion and a land portion of a substrate. In the chip component to be mounted on the substrate, a shape-changing surface that rapidly changes shape is provided substantially at the center of the side surface of each electrode portion, and the side surface is defined by the shape-changing surface as an upper surface and a lower surface. is there.

[0006]

The molten solder tends to adhere to the side surface of the electrode portion by comparing the surface tension and the leakability of the solder, but since the shape change surface exists at the boundary between the lower surface and the upper surface of the side surface, the solder extends to the upper surface. It adheres only to the lower surface without any damage.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B show a first embodiment of the present invention. FIG. 1A shows a perspective view of the chip part A. In FIG. 1A, a chip component A is composed of a rectangular parallelepiped component body 1 and electrode portions 2 fixed to both sides of the component body 1. A shape-changing surface 4 that rapidly changes in shape is provided substantially at the center of the side surface 3 of each electrode portion 2. The side surface 3 of the electrode portion 2 is defined by the shape-changing surface 4 into an upper surface 3a and a lower surface 3b. Has been done. In this example,
The shape-changing surface 4 has a lower surface 3b protruding outward with respect to the upper surface 3a, and is configured as a horizontal surface formed between the upper surface 3a and the lower surface 3b.

When the chip component A having the above structure is soldered by a method using a reflow furnace, the land portion 6 melted
The solder 7 adheres to the side surface of the electrode portion 2 due to surface tension or the like, but the shape change surface 4 causes the solder 7 due to surface tension or the like.
Of the solder 7, the solder 7 adheres only to the lower surface 3b, as shown in FIG. 1 (b). Therefore, solder 7
Is evenly welded to the land portion 6 of the substrate 5 and the electrode portion 2 of the chip component A.

Further, due to the difference in the amount of soldering of the left and right electrode portions 2 and the residual stress of soldering, stress in the direction of the arrow in FIG. 1B is generated. However, since the solder 7 adheres only to the lower surface 3b of the side surface 3, the stress generated is smaller than that in the conventional example shown in FIG. 6, and the amount of the solder 7 adhered is uniform on the left and right, so that cracks occur. Can be prevented as much as possible.

2 (a) and 2 (b) show a second embodiment of the present invention.
3 (a) and 3 (b) show a third embodiment of the present invention, and FIGS. 4 (a) and 4 (b) show a fourth embodiment of the present invention. 2 (a), 3 (a) and 4
FIG. 2A is a perspective view of the chip part A of each embodiment.
3 (b), 3 (b) and 4 (b) are cross-sectional views of the soldered state of each example.

Chip parts A of the second to fourth embodiments
Is different from that of the first embodiment only in the configuration of the shape-changing surface 4, and the other configurations are the same as those of the first embodiment. Omit it. That is, the shape change surface 4 of the second embodiment is configured as an arc surface formed between the lower surface 3b and the upper surface 3a, with the upper surface 3a protruding outward with respect to the lower surface 3b. . The shape-changing surface 4 of the third embodiment is configured as a concave surface at the boundary between the upper surface 3a and the lower surface 3b on the same plane. The shape-changing surface 4 of the fourth embodiment is formed as a convex surface on the boundary between the upper surface 3a and the lower surface 3b on the same plane.

The second to fourth embodiments have substantially the same actions and effects as those of the first embodiment. The shape of the shape-changing surface 4 is not limited to the first to fourth embodiments, and may be any shape as long as it changes the substantial center of the side surface 3 rapidly.

[0013]

As described above, the first to fifth aspects of the invention are described.
According to the invention, since the shape changing surface that defines the upper surface and the lower surface is provided on the side surface of the electrode portion, the molten solder adheres only to the lower surface. This is effective in preventing soldering defects such as tempura. In particular, it is effective for a large chip component having a large electrode area. In addition, since the solder adheres only to the lower surface of the electrode portion, the residual stress of soldering is small and the occurrence of cracks can be prevented as much as possible.

[Brief description of drawings]

1A is a perspective view of a chip component, and FIG. 1B is a cross-sectional view of a soldered state of the chip component (first embodiment).

2A is a perspective view of a chip component, and FIG. 2B is a cross-sectional view of a soldered state of the chip component (second embodiment).

3A is a perspective view of a chip component, and FIG. 3B is a cross-sectional view of a soldered state of the chip component (third embodiment).

4A is a perspective view of a chip component, and FIG. 4B is a cross-sectional view of a soldered state of the chip component (fourth embodiment).

5 (a), (b), (c) and (d) are diagrams showing respective steps of soldering using a reflow furnace.

FIG. 6 is a cross-sectional view of a soldered state of a chip component (conventional example).

[Explanation of symbols]

 A ... Chip component 1 ... Component body 2 ... Electrode part 3 ... Side surface 3a ... Upper surface 3b ... Lower surface 4 ... Shape change surface 5 ... Board 6 ... Land part 7 ... Solder

Claims (5)

[Claims] 1. A chip component in which electrode parts are provided at both ends of a component body, and solder is welded to each electrode part and a land part of the substrate to be mounted on the substrate. 1. A chip component, characterized in that each of the shape changing surfaces is provided with a shape changing surface, and the side surfaces are defined by the shape changing surface as an upper surface and a lower surface. 2. The chip component according to claim 1, wherein the shape changing surface is a horizontal plane formed between the upper surface and the lower surface. 3. The chip component according to claim 1, wherein the shape changing portion is an arc surface formed between the upper surface and the lower surface. 4. The chip component according to claim 1, wherein the shape changing surface is a concave surface. 5. The chip component according to claim 1, wherein the shape change surface is a convex surface.