JP3514453B1 - High frequency components - Google Patents

Abstract

An object of the present invention is to provide a high-frequency component capable of improving circuit performance by setting the ground of the high-frequency component to an absolute ground potential, thereby improving the communication quality. A required electrode among a plurality of electrodes formed inside a laminate is used as a ground electrode, and a mounting auxiliary pad mechanically bonded to a circuit board is provided at the center of a mounting surface. In the high frequency component 1 provided, the ground electrode g was electrically connected to the mounting auxiliary pad 6 via the through hole 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency component mounted on a circuit board such as an LC filter, a duplexer, a balun transformer, an antenna switch module used in various wireless communication devices such as a mobile phone. .

[0002]

2. Description of the Related Art As a high-frequency component mounted on a circuit board, a common antenna is used to switch between a transmission circuit and a reception circuit of a first transmission / reception system, and a transmission circuit and a reception circuit of a second transmission / reception system. There has been proposed a multi-band high frequency switch module or the like that can switch between. The high-frequency switch module for multiband is composed of a high-frequency circuit including a branching circuit, a switch circuit, a low-pass filter circuit and the like. The branching circuit and the switch circuit are composed of a capacitor, an inductor, etc., and are formed as an inductor electrode and a capacitor electrode in a laminated body formed by laminating a plurality of dielectric layers. It becomes a multi-band high frequency switch module having a function. (See Patent Document 1)

[0003]

[Patent Document 1] Japanese Patent Laid-Open No. 11-225088

[0004]

By the way, in such a conventional structure, there is a case where each high-frequency circuit is provided with each circuit which is appropriately grounded. Specifically, there is a π-type low pass filter circuit that constitutes a high frequency circuit. The π-type low-pass filter circuit is composed of one inductor and two capacitors whose one side is grounded. For example, the capacitor is formed inside the laminated body by a plurality of capacitor electrodes and a ground electrode. Here, the ground electrode is grounded via a line formed inside the laminated body or a connection terminal for connecting to an external circuit formed on the side surface of the laminated body.

However, the ground electrode formed in the laminated body causes an inductance component due to being grounded via the line or the side electrode, and an absolute ground potential can be obtained. I couldn't. For this reason, the capacitance value of the capacitor using the ground electrode among the elements configuring the low-pass filter circuit may be different from the desired capacitance value, and the performance of the low-pass filter or the like may be degraded, so that there is a limit to improving the communication quality. It was happening. Therefore, it is an object of the present invention to provide a high-frequency component capable of improving the performance of a high-frequency circuit by obtaining an absolute ground potential by a ground electrode forming the high-frequency circuit, thereby improving the communication quality.

[0006]

The present invention is a high frequency component in which a ground electrode is formed in a laminated body formed by laminating a plurality of dielectric layers, which is formed on the periphery of the mounting surface of the laminated body, A terminal pad to be joined to a circuit board pad connected to a required conductive path of the circuit board, and a mounting auxiliary pad to be joined to the circuit board pad formed at the center of the mounting surface and connected to the ground of the circuit board. , The ground electrode and the auxiliary pad for mounting are electrically connected, and the ground electrode
Is connected to the ground terminal of the terminal pads.
A high frequency component characterized by comprising (claim 1).

In this structure, the terminal pad and the mounting auxiliary pad are formed by screen printing, and the high frequency component is mounted on the circuit board by reflow soldering via the terminal pad and the mounting auxiliary pad. It
Here, the terminal pad is electrically connected to a required conductive path of the circuit board. On the other hand, the mounting auxiliary pad is connected to the ground of the circuit board. As a result, the mounting auxiliary pad has a ground potential, and also plays a role of mechanically joining the high-frequency component to the circuit board and suppressing peeling from the circuit board.

The present inventor has found that the circuit performance of the high frequency component is improved by electrically connecting the ground electrode and the mounting auxiliary pad. It is considered that this is because it is possible to obtain an absolute ground potential by electrically connecting the ground electrode and the mounting auxiliary pad. Therefore, the mounting auxiliary pad plays a role of suppressing peeling of the high-frequency component from the circuit board, and also plays a role of improving, for example, the attenuation characteristic of the low-pass filter forming the high-frequency circuit of the high-frequency component. .

Further, a structure is proposed in which the ground electrode which is electrically connected to the mounting auxiliary pad is the ground electrode located in the lowermost layer among the ground electrodes formed in the laminated body. 2).

With this configuration, it is possible to suppress the inductance component generated due to being grounded via the line or the side electrode, and to stabilize the electrical performance of the high frequency component. Become.

Further, a structure is proposed in which the ground electrode and the mounting auxiliary pad are electrically connected via a through hole (claim 3).

With this structure, the ground electrode formed in the laminated body and the mounting auxiliary pad formed on the mounting surface can be electrically connected.

Further, a structure is proposed in which a capacitor electrode is formed in the laminated body, and a ground electrode electrically connected to the mounting auxiliary pad faces the capacitor electrode (claim 4).

With such a structure, the electrical performance of the low-pass filter circuit forming the high-frequency circuit included in the high-frequency component is improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows an antenna switch module that is a high-frequency component 1. A multilayer glass ceramic substrate, which is a laminated body 2 formed by laminating glass ceramic layers as a dielectric layer, and a chip capacitor mounted on the upper surface thereof. A chip component 9 such as a diode or a diode (which cannot be seen because it is hidden here), and the chip component 9 is covered,
The metal cap 3 is mounted on the laminated body 2. In addition, the laminated body 2 has a built-in LC circuit including an inductor and a capacitor. As the high frequency component 1,
The appearance is rectangular, and the example dimensions are 1.8 mm thick and 4.
A configuration of 0 mm, horizontal 5.4 mm, etc. is exemplified.

Further, as shown in FIG. 2, a plurality of terminal pads 4 are provided on the periphery of the mounting surface of the high frequency component 1 which faces the surface of the circuit board when it is mounted on the circuit board (not shown). Are formed by screen printing. The terminal pad 4 is a transmission terminal, a reception terminal, a ground terminal, an antenna terminal, a ground terminal, a power supply control terminal, or the like, and is connected to electrodes of a plurality of capacitors or inductors forming the high frequency circuit formed inside the laminated body 2. Has been done. The terminal pad 4 is made of a conductive material made of Ag alloy.

Further, an auxiliary mounting pad 6 is formed at the center of the mounting surface. The mounting auxiliary pad 6 is also formed by screen printing. Further, in this embodiment, the mounting auxiliary pad 6 is divided into left and right partial mounting auxiliary pads 7a and 7b. The auxiliary pads 7a and 7b for partial mounting are each 1.
6 mm, width 1.1 mm, auxiliary pad 7 for partial mounting
A distance of 0.4 mm is generated between a and 7b. The above-mentioned design dimensions are merely design examples. Further, the mounting auxiliary pad 6 formed of a single pad may be used, or, of course, a plurality of three or more partial mounting auxiliary pads may be used.

Then, the high frequency component 1 is mounted on the circuit board such that the terminal pad 4 and the mounting auxiliary pad 6 are bonded to the circuit board pad via solder.
Here, the terminal pad 4 is electrically connected to a circuit board pad connected to a required conductive path of the circuit board. here,
The required conductive path includes, for example, a transmission circuit and a reception circuit. On the other hand, the mounting auxiliary pad 6 is electrically connected to the circuit board pad connected to the ground of the circuit board. That is, the mounting auxiliary pad 6 is electrically set to the ground potential. Here, the mounting auxiliary pad 6 also serves to mechanically bond the high-frequency component 1 and the circuit board to each other and prevent the high-frequency component 1 from peeling off from the circuit board.

By the way, the high frequency component 1 according to the present embodiment has a structure including an antenna switch circuit (high frequency circuit) corresponding to a dual band (high frequency transmission / reception signal DCS and low frequency transmission / reception signal GSM). As shown in FIG. 3, the antenna switch circuit (high frequency circuit) is
Connected to common antenna ANT, capacitors C1D, C
2D, C4DA, C4DB, C5D and inductor L1
A demultiplexing circuit 10 including an LC circuit composed of D, L2D, and L5, and a diode D connected to the demultiplexing circuit 10.
1, D2, transmission lines L1 and L2, a capacitor C5 and a resistor R1, a first switch circuit 11, diodes D3 and D4, transmission lines L3 and L4 and a capacitor C.
1c, C10, a resistor R2, an inductor L1c, a second switch circuit 12 and a first switch circuit 1
1 and a transmission side terminal Tx1 of GSM, and a second lowpass filter circuit 13 connected between the second switch circuit 12 and the transmission circuit terminal Tx2 of DCS. Therefore, the branching circuit 10, the switch circuits 11 and 12, and the low-pass filter circuits 13 and 14 each include a capacitor whose one side is grounded.

In the present embodiment, the laminated body 2 has an LC circuit which constitutes the demultiplexing circuit 10, and a first switch circuit 11
The transmission lines L1 to L4 of the second switch circuit 12, and the first low-pass filter circuit 13 and the second low-pass filter circuit 14 are inner layers. As a specific configuration, as shown in FIG. 4, among the plurality of electrodes laminated inside the laminated body 2, a required electrode is a ground electrode g and a required electric path is connected to the ground electrode g and a through electrode. I try to connect through the hall. In the present embodiment, the upper and lower electrodes are used to form the ground electrode g, of which the upper electrode forms the first ground electrode g1 and the lower electrode forms the second ground electrode g1. g
Make up 2.

Further, the electrode 21 constitutes the inductors 1L1 and 1L1 of the low pass filter circuits 13 and 14, and the electrode 25 constitutes the capacitors 1C12, 2C12, 1C34 and 2C34 of the low pass filter circuits 13 and 14. Here, the capacitors of the low-pass filter circuits 13 and 14 included in the high-frequency circuit are arranged inside the laminated body 2 so as to face the ground electrode g2.

The electrode 22 constitutes the inductors L1D, L2D, L5 of the demultiplexing circuit 10, and the electrode 23 constitutes the capacitors C1D, C2D, C4DA of the demultiplexing circuit 10.
It constitutes C4DB and C5D. The electrodes 24 form the transmission lines L1 to L4 of the switch circuits 11 and 12.

Further, in the present embodiment, the mounting auxiliary pad 6 formed on the mounting surface and the second ground electrode g2 are electrically connected through the through hole 20. In addition, the second ground electrode g2 is also electrically connected to the ground terminal formed on the side surface of the laminated body 2 among the terminal pads 4 formed on the mounting surface. Furthermore, the first ground electrode g1
Are connected to the second ground electrode g2 via the through holes 20.

With this structure, in addition to the ground electrode g, the mounting auxiliary pad 6 can substantially function as a ground electrode terminal.

Therefore, the mounting auxiliary pad 6 formed on the mounting surface serves to mechanically hold the high frequency component 1 to the circuit board and to prevent the high frequency component 1 from peeling off and the like. It also plays the role of making the ground electrode g, which is the inner layer of 1, an absolute ground potential.

Next, the essential part of the present invention will be described. The ground electrode g formed in the stacked body 2 by electrically connecting the mounting auxiliary pad 6 and the ground electrode g described above.
Have found that an absolute ground potential can be obtained. This is considered to be due to the fact that a portion connected to the ground is formed in the substantially central portion of the ground electrode g.

Below, the performance of the high-frequency component 1 according to the present invention in which the ground electrode g and the mounting auxiliary pad 6 are conducted, and the performance of the conventional product in which the ground electrode g and the mounting auxiliary pad 6 are not conducted. A comparative experiment example will be described. Here, an experimental result regarding an attenuation characteristic as an electrical characteristic of the low-pass filter circuits 13 and 14 (see FIG. 3) is illustrated.

FIG. 5 shows a waveform (curve A) showing the attenuation characteristic of the second low-pass filter circuit 14 constituting the high-frequency component 1 of the present invention and a waveform (curve B) showing the attenuation characteristic of the conventional low-pass filter circuit. And indicate. Note that the vertical axis of the waveform diagram is the attenuation amount (dB) and the horizontal axis is the frequency (GHz).

In the conventional product (curve B), 2
Although an attenuation pole is seen in the 3.6 GHz band corresponding to the overtone, no attenuation pole is seen in the 5.4 GHz band corresponding to the overtone. On the other hand, the product of the present invention (curve A)
Then, in addition to the 3.6 GHz band, the attenuation characteristic is seen also in the 5.4 GHz band. Furthermore, 3.6GH
In the z band, the amount of attenuation was larger than that of the conventional product, and the improvement of the attenuation characteristic was also seen.

Specifically, as shown in FIG.
Regarding the 6 GHz band (3420-3820 MHz),
The conventional product has an attenuation of 31.1 dB, while the product of the present invention has an attenuation of 32.9 dB.
It improved by about 5.8%. In addition, the 5.4 GHz band (513
0-5730MHz), the conventional product is 20.9d
The attenuation amount of B is 40.4 dB in contrast to the product of the present invention.
It is possible to obtain the attenuation amount of, which is an improvement of about 93.3%.

As is clear from this result, the ground electrode g and the mounting auxiliary pad 6 which are present therein are connected to the through hole 2.
By conducting through 0, an absolute ground potential can be obtained, so that a harmonic corresponding to the third harmonic can be cut. Further, since the amount of attenuation of harmonics corresponding to the second harmonic is also large, this means that the electrical performance of the second low pass filter circuit 14 is improved.

As another embodiment of the present invention, as shown in FIG. 7, the ground electrode g and the auxiliary mounting pad 6 are mounted.
And may be electrically connected via the through hole 20 and the castellation. In addition, as shown in FIG. 8, the ground electrode g is provided only through the castellation.
The mounting auxiliary pad 6 may be electrically connected to the mounting auxiliary pad 6. The same effect can be obtained with either configuration.

[0033]

The present invention is a high frequency component in which a ground electrode is formed in a laminate, and is joined to a circuit board pad formed at the center of the mounting surface of the laminate and connected to the ground of the circuit board. Since the high frequency component is provided with the mounting auxiliary pad and the ground electrode and the mounting auxiliary pad are electrically connected (claim 1), it is possible to obtain an absolute ground potential, and the electrical characteristics of the high frequency component can be obtained. Performance has been improved. Therefore, the excellent effect that the call quality is improved occurs.

When the ground electrode electrically connected to the mounting auxiliary pad is the ground electrode located in the lowermost layer among the ground electrodes formed in the laminated body (claim 2), a line or It is possible to suppress the inductance component generated due to being grounded via the side surface electrode, and an effect of stabilizing the electrical performance of the high frequency component is produced.

When the ground electrode and the mounting auxiliary pad are electrically connected via the through hole (claim 3), the ground electrode formed in the laminated body and
It is possible to preferably conduct electricity to the mounting auxiliary pad formed on the mounting surface.

Further, when the capacitor electrode is formed in the laminated body and the ground electrode electrically connected to the mounting auxiliary pad faces the capacitor electrode (claim 4), it is included in the high frequency component. There is an advantage that the electric performance of the low-pass filter circuit that constitutes the high-frequency circuit can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a high frequency component 1 according to the present invention.

FIG. 2 is a rear view of the high frequency component 1.

FIG. 3 is a circuit diagram of a high frequency component 1.

FIG. 4 is a vertical cross-sectional view of the high frequency component 1.

FIG. 5 is a waveform diagram showing waveform characteristics of low-pass filter circuits 13 and 14.

FIG. 6 is a chart showing an experimental result comparing electrical characteristics.

FIG. 7 is a vertical cross-sectional view of a high frequency component 1 using through holes 20 and castellations.

FIG. 8 is a vertical cross-sectional view of a high frequency component 1 using castellation.

[Explanation of symbols]

1 High frequency components 4 terminal pad 6 Mounting auxiliary pad 7a, 7b Auxiliary pad for partial mounting 20 through holes g (g1, g2) ground electrode

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-2002-335101 (JP, A) JP-A-2001-320170 (JP, A) JP-A-8-335836 (JP, A) JP-A-9-186049 ( (58) Fields investigated (Int.Cl. ⁷ , DB name) H05K 3/46 H01L 25/00

Claims (4)

(57) [Claims] 1. A high-frequency component in which a ground electrode is formed in a laminated body formed by laminating a plurality of dielectric layers, the high-frequency component being formed on a peripheral edge of a mounting surface of the laminated body and connected to a required conductive path of a circuit board. A terminal pad that is bonded to the circuit board pad, and a mounting auxiliary pad that is bonded to the circuit board pad that is formed in the center of the mounting surface and that is connected to the ground of the circuit board. Conducts electrical connection with an auxiliary pad, and the ground electrode is the ground of the terminal pads.
A high-frequency component characterized by being electrically connected to the terminals . 2. The high frequency component according to claim 1, wherein the ground electrode electrically connected to the mounting auxiliary pad is a ground electrode located at the lowermost layer of the ground electrodes formed in the laminated body. 3. The high frequency component according to claim 1, wherein the ground electrode and the mounting auxiliary pad are electrically connected through the through hole. 4. The capacitor electrode is formed in the laminated body, and the ground electrode electrically connected to the mounting auxiliary pad is opposed to the capacitor electrode. The high frequency component described in any one of 1.