JP3161192B2 - Electronic component mounting structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for chip-type electronic components used in a microwave band.

[0002]

2. Description of the Related Art As shown in FIG. 7, a conventional electronic component mounting structure includes a chip type electronic component 82 having external electrodes 81 formed on side surfaces, and a transmission line 84 formed by an electrode pattern on an insulating substrate 83. The external electrode 81 of the electronic component 82 and the transmission line 84 are joined by solder 86 and surface-mounted on the circuit board 85. in this case,
The solder 86 is used to mechanically join the electronic component 82 and the circuit board 85, and to connect the external electrode 81 of the electronic component 82 to the circuit board 85.
The electrical connection of the transmission line 84 is performed.

[0003]

However, in the above-described conventional electronic component mounting structure, since the external electrodes 81 of the electronic component 82 and the transmission line 84 of the circuit board 85 are connected by solder 86, high frequency In the band, the inductance component of the solder 86 occurred in the transmission line, and the electrical characteristics of the electronic component 82 changed, so that the original performance could not be exhibited. In particular, in the microwave band of 5 GHz or more, the change in the electrical characteristics of the electronic component 82 was remarkable.

The present invention has been made in order to solve such a problem, and an electronic device in which an external electrode of an electronic component is connected to a transmission line of a circuit board by electromagnetic coupling to remove an inductance component of a connecting member. It is an object of the present invention to provide a component mounting structure.

[0005]

In order to achieve the above object, according to the present invention, a transmission line is formed inside an insulating substrate, and a transmission line is formed on a surface of the insulating substrate at a position facing the transmission line. A circuit board is formed by forming a ground electrode having a window, and on the surface of the circuit board, an electronic component having an input / output electrode serving as an external electrode and a ground electrode formed on a side surface is mounted. A minute gap is formed between the ground electrode of the electronic component and the ground electrode of the circuit board through the gap, and the ground electrode of the electronic component is electromagnetically coupled to the ground electrode of the electronic component. The transmission line of the substrate and the input / output electrode of the electronic component are electromagnetically coupled.

According to the above configuration, a minute gap or a resin layer or an insulating substrate layer is interposed between the transmission line and the ground electrode of the circuit board and the external electrode of the electronic component, and the gap is formed between the transmission line and the electronic component. A high-pass filter by LC is configured. Then, the transmission line of the circuit board and the input / output electrodes of the electronic component are electromagnetically coupled via C, and the signal is transmitted at a cut-off frequency or higher.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a mounting structure for an electronic component according to the present invention will be described below with reference to FIGS. First, FIG. 1 shows a first chip-type electronic component used in the present invention. In FIG. 1, reference numeral 1 denotes a rectangular chip-type electronic component having external electrodes formed on side surfaces, and an input electrode 2 and an output electrode 3 are provided on the short side of the electronic component 1 as external electrodes.
Are formed facing each other, and the ground electrode 4
5 are formed facing each other. On the other hand, a plurality of holding electrodes 6 are formed on the bottom surface.

Next, the mounting structure of the electronic component 1 will be described.
In FIG. 2, reference numeral 21 denotes a multilayer insulating substrate made of ceramic or resin. Two linear transmission lines 22 and 23 are formed inside the insulating substrate 21 so as to face each other in a straight line. First ground electrode 24a on the surface
Is formed. On the other hand, a second ground electrode 24b is formed on the entire back surface of the insulating substrate 21 to form a circuit board 25.
Is composed. The ground electrode 24a is provided with coupling windows 24c, 24c where no electrodes exist at positions facing the ends of the transmission lines 22, 23.

The input / output electrodes 2 and 3 of the electronic component 1
The electronic component 1 is placed on the circuit board 25 such that the electronic component 1 is located above the coupling windows 24c, 24c, and the holding electrode 6 of the electronic component 1 and the ground electrode 24a between the coupling windows 24c, 24c are soldered. The electronic components 1 are connected to each other and mounted on the circuit board 25. According to such a configuration, between the input / output electrodes 2 and 3 of the electronic component 1 and the transmission lines 22 and 23 of the circuit board 25,
A small gap 27 is formed by solder 26 between the ground electrodes 4 and 5 of the electronic component 1 and the ground electrode 24a of the circuit board 25 while a part of the insulating substrate 21 is interposed.

FIG. 3 shows a second chip type electronic component used in the present invention. In FIG. 3, reference numeral 51 denotes a rectangular chip-type electronic component having external electrodes formed on the side surfaces, and the input electrode 5 is provided on the long side of the electronic component 51 as an external electrode.
2 and the output electrode 53 are formed so as to face each other, and ground electrodes 54 and 55 are formed so as to face each other on the short side surface.
On the other hand, a plurality of holding electrodes 56 are formed on the bottom surface.

Next, the mounting structure of the electronic component 51 will be described. In FIG. 10, reference numeral 71 denotes a multilayer insulating substrate made of ceramic or resin, in which two linear transmission lines 72 and 73 are formed in parallel inside the insulating substrate 71, and a first line is formed on the surface of the insulating substrate 71. Of the ground electrode 74a. On the other hand, a second ground electrode 74b is formed on the entire back surface of the insulating substrate 71 to form a circuit board 75. The ground electrode 74a is provided at the position facing the transmission lines 72, 73 with the coupling windows 74c, 74 without electrodes.
c is provided. The input / output electrode 5 of the electronic component 51
The electronic component 51 is placed on the circuit board 75 so that the electronic components 51 and 52 are located above the coupling windows 74c and 74c, and the holding electrode 56 of the electronic component 51 and the ground electrode 74a are connected by solder 76. The component 51 is mounted on a circuit board 75.
According to such a configuration, the input / output electrodes 52 of the electronic component 51,
A part of the insulating substrate 75 is interposed between the transmission line 53 and the transmission lines 72 and 73 of the circuit board 75, and the ground electrodes 54 and 55 of the electronic component 51 and the ground electrode 74 of the circuit board 75.
a small gap 77 is formed by the solder 76. In the electronic component mounting structure shown in FIGS. 2 and 4, the electronic components 1 and 51 and the circuit boards 25 and 75 are joined together.
An adhesive other than the solders 26 and 76 can be used.
Further, as shown in FIG. 5, an electronic component 1a having input / output electrodes 2a, 3a and ground electrodes 4a, 5a in which the shape of the input / output electrode and the ground electrode extends to the front and back surfaces, as shown in FIG. it can. Further, the circuit boards 25 and 75 may be those without the ground electrodes 24b and 74b on the back surface. Here, the shapes of the input / output electrode and the ground electrode of the electronic component, and the transmission line and the ground electrode of the circuit board are not limited to those shown in FIGS. Any shape or structure in which a minute gap or a resin or insulating substrate is interposed between the electrode and the transmission line of the circuit board and between the ground electrode of the electronic component and the first ground electrode of the circuit board I just need. According to the mounting structure of the electronic component configured as described above, between the input / output electrode of the electronic component and the transmission line of the circuit board, and between the ground electrode of the electronic component and the first ground electrode of the circuit board. Since a minute gap or a dielectric such as a resin or an insulating substrate is interposed, the equivalent circuit thereof is represented by L1, L2, L3, L4, L5 and C1, C2 as shown in FIG.
2 and C3. Of these, L1, L2,
L3, L4, and L5 are parasitic inductance components on the ground side of the circuit board, and C1, C2, and C3 are between the input / output terminal and the ground terminal of the electronic component and the transmission line and the first ground electrode of the circuit board. Is the capacitance component.
Then, the input / output terminals and the ground electrode of the electronic component are electromagnetically coupled to the transmission line and the first ground electrode of the circuit board by C1, C2, and C3, and L1, L2, C1, and L3, L4, C2 are: Since a high-pass filter is configured, a signal is transmitted at a frequency higher than the cutoff frequency.
Note that L5 is formed between the ground electrode of the electronic component and the ground electrode of the circuit board. However, since its inductance value is very small, it does not affect the signal. Therefore, since an inductance component having an effect on a signal is not generated in the transmission line, the characteristics of the electronic component do not change. The mounting structure of the electronic component shown in FIGS. 2 and 4 is provided between the input / output electrode of the electronic component and the transmission line of the circuit board, and the ground electrode of the electronic component and the first ground electrode of the circuit board. A dielectric such as a resin or an insulating substrate is interposed between them. Therefore, by increasing the dielectric constant of the resin or the insulating substrate, C1, C2, C2 of the equivalent circuit shown in FIG.
3 can be increased, the cutoff frequency can be reduced, and the electromagnetic coupling can be performed at a lower frequency. Furthermore, by changing the dielectric constant and thickness of the resin and the insulating substrate, the cutoff frequency can be varied, and the lower limit value of the transmission frequency can be adjusted. Impedance matching can be achieved.

As described above, according to the electronic component mounting structure of the present invention, a minute gap is provided between the external electrode of the electronic component, the transmission line of the circuit board, and the first ground electrode. Alternatively, since a resin or an insulating substrate is interposed and electromagnetically coupled by the capacitance component, a connecting member for electrode connection is not required. As a result, since no inductance component is generated in the transmission line, the electrical performance of the electronic component does not change, and the original performance can be exhibited. Adjusting the lower limit of the transmission frequency by changing the dielectric constant and thickness of the resin or insulating substrate interposed between the external electrode of the electronic component and the transmission line and the first ground electrode of the circuit board. And impedance matching with the circuit side can be achieved.

[Brief description of the drawings]

FIG. 1A shows an electronic component according to an embodiment of the present invention.
Is a perspective view, and (b) is a bottom view.

FIGS. 2A and 2B are perspective views partially showing a mounting structure of an electronic component according to an embodiment of the present invention, and FIG.

3A and 3B show a second embodiment of the electronic component according to the present invention, wherein FIG. 3A is a perspective view and FIG. 3B is a bottom view.

FIGS. 4A and 4B are partial cross-sectional perspective views showing a mounting structure of an electronic component according to a second embodiment of the present invention, and FIG.

FIG. 5 is a perspective view of a third embodiment of the electronic component according to the present invention.

FIG. 6 is an equivalent circuit of a mounting structure of an electronic component according to the first and second embodiments of the present invention.

FIG. 7 is a cross-sectional view showing a conventional electronic component mounting structure.

[Explanation of symbols]

 1,51 Electronic component 2,2a, 52 Input electrode 3,3a, 53 Output electrode 4,5,4a, 5a, 54,55 Ground electrode 21,71 Insulating substrate 22,23,72,73 Transmission line 24a, 24b, 74a, 74b Ground electrode 25, 75 Circuit board 27, 77 Gap 24c, 74c Coupling window

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Koji Furuya 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto, Japan Examiner at Murata Manufacturing Co., Ltd. Takashi Nakagawa (56) References JP-A-60-242702 (JP, A) JP-A-3-129902 (JP, A) JP-A-56-85895 (JP, A) JP-A-3-230597 (JP, A) Fully open 63-121915 (JP, U) Fully open −105526 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05K 1/18 H01P 5/02

Claims (1)

(57) [Claims] A circuit board is formed by forming a transmission line inside an insulating substrate, and forming a ground electrode having a coupling window at a position facing the transmission line on a surface of the insulating substrate. An electronic component having an input / output electrode serving as an external electrode and a ground electrode formed on the side surface is mounted on the surface of the electronic component, and a minute gap is formed between the ground electrode of the circuit board and the ground electrode of the electronic component. Through the electromagnetic coupling between the ground electrode of the circuit board and the ground electrode of the electronic component, and the electromagnetic coupling between the transmission line of the circuit board and the input / output electrode of the electronic component through the coupling window. Characteristic electronic component mounting structure.