JP2000183490A - Mounting structure for surface mounting-type electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a mounting structure with which a surface mounting-type electronic component can surely be fixed and electrically connected to a board. SOLUTION: In this mounting structure for a surface mounting-type electronic component, the surface mounting-type electronic component 1, such as a chip component or the like in which an electronic 11a and an electrode 11b are formed on both ends, is mounted on a board 2 on which a prescribed conductor pattern is formed. A recessed part 22, in which a connecting electrode 21a is formed at least one place on the inner wall, is formed on the board 2. The surface mounting-type electronic component 1 is housed in the recessed part 22. The connecting electrode 21a and the electrode 11a on one side of the surface mounting-type electronic component 1 are connected and fixed, by pressing the surface mounting-type electronic component 1 from the side of the electrodes 11a, 11b on both ends, while a conductive elastic body 4 is interposed therebetween.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure of a surface-mounted electronic component such as a chip component, which is mounted on a substrate on which a predetermined conductor pattern is formed.

[0002]

2. Description of the Related Art Conventionally, as a method of mounting a surface mount type electronic component such as various chip components such as a resistor and a capacitor on a substrate on which a predetermined conductor pattern is formed, a solder cream is applied to the conductor pattern of the substrate. There is a method in which printing is applied to a predetermined portion of a connection electrode, a surface-mounted electronic component is mounted on the substrate, and then heated and reflow soldered. In this mounting method, as shown in FIG. 4, a hakama-shaped embossed portion called a solder fillet 3 is formed at a joint between the electrode 11 of the surface mount electronic component 1 and the connection electrode 21 of the conductor pattern of the substrate 2. Thereby, the surface-mount type electronic component 1 is fixed to the substrate 2, and the electrical connection with the connection electrode 21 of the conductor pattern of the substrate 2 is made.

[0003]

However, in the above-described mounting method, the molten solder is attracted onto the connection electrode 21 of the conductor pattern due to the surface tension of the molten solder at the time of reflow, and the self-alignment is performed. Since self alignment is performed, the surface mount electronic component 1
Has the advantage of simplifying the process of alignment on the substrate 2, but since the fixing between the surface-mount type electronic component 1 and the substrate 2 is performed only at the joints by the solder fillets 3, the temperature cycle and the There is a problem that fatigue cracks and slip cracks are generated in the solder fillet 3 due to stress generated by an external environment such as vibration and impact, thereby impairing fixing and electrical connection of the surface mount electronic component 1.

Japanese Patent Application Laid-Open No. 7-66207 discloses that
Although a method of fixing and electrically connecting a surface-mounted electronic component and a substrate using solder bumps is disclosed, even in this method, the fixing and electrical connection of both are performed only at the joints by the solder bumps. Therefore, there was a similar problem as described above.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a surface mounting device capable of securely fixing and electrically connecting a surface mounting type electronic component on a substrate. An object of the present invention is to provide a mounting structure for a die-type electronic component.

[0006]

According to the first aspect of the present invention,
In a mounting structure of a surface-mounted electronic component in which a surface-mounted electronic component such as a chip component provided with electrodes at both ends is mounted on a substrate on which a predetermined conductor pattern is formed, connection electrodes are provided at least at one position on an inner wall. The recessed portion is formed in the substrate, and the surface-mounted electronic component is accommodated in the recessed portion, and the connection electrode and one electrode of the surface-mounted electronic component are interposed with a conductive elastic body. The surface mount electronic component is connected and fixed by pressing from both electrode sides.

According to a second aspect of the present invention, in the first aspect of the present invention, the connection electrodes are provided on both opposing side walls of the recess, and the electrodes provided at both ends of the surface mount electronic component are connected to the electrodes. The connection electrodes on both side walls are opposed to each other, and the conductive elastic body is interposed between at least one of the electrodes provided at both ends of the surface-mounted electronic component and the connection electrode. It is characterized by the following.

According to a third aspect of the present invention, in the first aspect of the present invention, the connection electrode is provided at a bottom of the concave portion, and is opposed to the connection electrode with the conductive elastic body interposed therebetween. A surface-mounted electronic component is accommodated in the recess.

According to a fourth aspect of the present invention, in the first to third aspects of the present invention, the elastic body is made of a resin having a metal film formed on a surface thereof.

According to a fifth aspect of the present invention, in the first to third aspects of the present invention, the elastic electrode is replaced by forming the connection electrode in a spring shape.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a mounting structure of a surface-mount type electronic component according to a first embodiment of the present invention. In the present embodiment, a recess 22 having a shape corresponding to the surface-mounted electronic component 1 (in this embodiment, a shape assuming that the surface-mounted electronic component 1 is stored horizontally) is provided at a predetermined position on the substrate 2. The connection electrodes 21 a and 21 b connected to the conductor pattern (not shown) are formed on the opposite side walls of the recess 22. Connection electrode 21
a and 21 b are formed from the side wall of the concave portion 22 to the upper surface of the substrate 2. When the surface-mounted electronic component 1 is housed in the recess 22, the surface-mounted electronic component 1 is placed parallel to the substrate 2 (sideways) and the electrodes 11 a and 11
b is inserted so as to face the connection electrodes 21a and 21b.

Here, a conductive elastic body 4 is interposed between one electrode 11a of the surface mount type electronic component 1 and the connection electrode 21a formed on the side wall of the concave portion 22. The elastic body 4 is made of, for example, a resin having a metal film formed on the surface by plating or the like. The other electrode 11b of the surface mount electronic component 1 is directly connected to the connection electrode 21b formed on the opposite side wall of the recess 22. The surface-mounted electronic component 1 housed in the recess 22 is connected to the connection electrode 2 by the conductivity of the elastic body 4.
1a, which is connected to both ends by elasticity
It is pressed from the sides 1a and 11b and fixed in the recess 22.

In the present embodiment, the elastic body 4 is interposed only between the electrode 11a and the connection electrode 21a. However, the elastic body 4 may be interposed between the electrode 11b and the connection electrode 21b. Good, or both may be interposed.

According to this embodiment, for example, in the reliability evaluation such as a heat cycle test, the stress applied to the surface mount electronic component 1 due to the thermal expansion and contraction of the substrate 2 is absorbed by the elasticity of the elastic body 5. . Therefore, the reliability of fixing the surface-mounted electronic component 1 on the substrate 2 and the electrical connection are improved.

FIG. 2 is a sectional view schematically showing a mounting structure of a surface mount type electronic component according to a second embodiment of the present invention. In the present embodiment, the substrate 2 is formed with a concave portion 23 at a predetermined position so that the surface-mounted electronic component 1 can be vertically accommodated. A connection electrode 21c is formed at the bottom of the concave portion 23. The surface mounting is performed with the conductive elastic body 4 interposed between the connection electrode 21c and one electrode 11a of the surface mount type electronic component 1. The electronic component 1 is housed in the recess 23. The other electrode 11 b of the surface mount electronic component 1 is directly connected to the connection conductor 5. The connection conductor 5 is connected to the connection electrode 21 provided around the concave portion 23 on the upper surface of the substrate 2, and presses the surface-mounted electronic component 1 from above against the elasticity of the elastic body 4. The surface-mounted electronic component 1 is fixed.

In this embodiment, the elastic body 4 is interposed only between the electrode 11a and the connection electrode 21c. However, the elastic body 4 is interposed between the electrode 11b and the connection conductor 5. Or both may be interposed.

Also in this embodiment, the thermal expansion of the substrate 2
Since the stress applied to the surface-mounted electronic component 1 due to the contraction is absorbed by the elasticity of the elastic body 4, the same effect as that of the first embodiment can be obtained.

FIG. 3 is a sectional view schematically showing a mounting structure of a surface mount type electronic component according to a third embodiment of the present invention. In the present embodiment, in the first embodiment, the connection electrode 21a is formed as a spring-like connection electrode 21c, so that the function of the elastic body 4 is also achieved without the elastic body 4 interposed therebetween. .

Also in this embodiment, the thermal expansion of the substrate 2
The stress applied to the surface-mounted electronic component 1 due to the contraction is absorbed by the elasticity of the spring-like connection electrode 21c.
The same effect as that of the embodiment can be obtained.

It is needless to say that a similar effect can be obtained even if the spring-like connection electrode 21c is applied to the second embodiment.

[0021]

As described above, according to the first to fourth aspects of the present invention, a predetermined conductor pattern is formed on a surface mount type electronic component such as a chip component having electrodes provided at both ends. In the mounting structure of the surface-mounted electronic component mounted on the substrate, a concave portion provided with a connection electrode in at least one position of the inner wall is formed in the substrate, and the surface-mounted electronic component is stored in the concave portion, and the connection electrode and Since one surface of the surface-mounted electronic component is connected to and fixed to one electrode of the surface-mounted electronic component by an elastic body having conductivity, the surface-mounted electronic component is connected and fixed by pressing from both electrode sides. Stress applied to the surface-mounted electronic component due to expansion and contraction is absorbed by the elasticity of the elastic body, so that the surface-mounted electronic component can be securely fixed on the substrate and electrically connected thereto. Provided with mounting structure It came.

According to the fifth aspect of the present invention, in the first to fourth aspects of the present invention, if the connection electrode is formed in a spring shape as the elastic body,
The same effect can be obtained without interposing an elastic body.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a mounting structure of a surface mount electronic component according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically illustrating a mounting structure of a surface-mounted electronic component according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view schematically illustrating a mounting structure of a surface-mounted electronic component according to a third embodiment of the present invention.

FIG. 4 is a cross-sectional view schematically showing a mounting structure of a conventional surface mount electronic component.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface-mounted electronic component 2 Substrate 3 Solder fillet 4 Elastic body 5 having conductivity 5 Conductor for connection 11, 11a, 11b Electrode 21, 21a, 21b, 21c, 21d Connection electrode 22, 23 Recess

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomohiro Inoue 1048 Kazumasa Kadoma, Osaka Prefecture Matsushita Electric Works Co., Ltd. Term (reference) 5E336 AA08 BB01 BC26 CC32 CC52 CC53 DD13 DD17 EE15 GG11

Claims (5)

[Claims] 1. A mounting structure of a surface-mounted electronic component for mounting a surface-mounted electronic component such as a chip component having electrodes on both ends on a substrate on which a predetermined conductor pattern is formed.
A concave portion provided with a connection electrode in at least one position of the inner wall is formed in the substrate, and the surface-mounted electronic component is housed in the concave portion, and the connection electrode and one electrode of the surface-mounted electronic component are electrically conductive. A mounting structure for a surface-mounted electronic component, wherein the surface-mounted electronic component is connected and fixed by pressing from both electrode sides at both ends by interposing an elastic body having a property. 2. A surface-mount type, wherein the connection electrodes are provided on both opposing side walls of the recess, and electrodes provided at both ends of the surface-mount type electronic component are opposed to connection electrodes on both side walls, respectively. The elastic body having conductivity is interposed between at least one of the electrodes provided at both ends of the electronic component and the connection electrode.
The mounting structure of the surface-mounted electronic component described. 3. The method according to claim 1, wherein the connection electrode is provided at a bottom of the recess.
2. The surface-mounted electronic component according to claim 1, wherein the surface-mounted electronic component is housed in the recess so as to face the connection electrode with the conductive elastic body interposed therebetween. Mounting structure. 4. The mounting structure for a surface-mounted electronic component according to claim 1, wherein said elastic body is made of a resin having a metal film formed on a surface thereof. 5. The mounting structure for a surface-mounted electronic component according to claim 1, wherein the connection electrode is formed in a spring shape as the elastic body.