JPH0290805A - High frequency circuit device - Google Patents

Abstract

PURPOSE:To attain flat mounting by fixing a surface acaostic wave element, keeping a dielectric layer surface generating an input matching circuit and an output matching circuit, and that generating an input electrode and an output electrode apart. CONSTITUTION:The package 10 of a TO can type, in which the elastic surface wave element 1 is accommodated, is mounted on a dielectric substrate 20. Input/ output pins 5 and 6 are inserted into through holes 21 and 22 provided on the dielectric substrate 20, and they are electrically connected with the input electrode 23 and the output electrode 24 provided on the back of the small-sized dielectric substrate 20. The input matching circuit 25 and the output matching circuit 26 are simultaneously generated on the surface of the small-sized dielectric substrate 20, and the matching circuits 25 and 26 are electrically connected with the input electrode 23 and the output electrode 24 by the through holes 27 and 28. Thus, mounting is attained on a single plane.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the structure of a high frequency circuit device equipped with a surface acoustic wave element.

[Prior art] Stem portion 40 in T○can type package 401
The surface acoustic wave element 1 fixed on the surface acoustic wave element 2 is hermetically sealed with a metal cap 405. And input pin 403
The output pins 404 were inserted through through holes provided in the dielectric substrate 4, respectively, and were electrically connected to an external circuit by solder 406. Therefore, the surface acoustic wave element 1 is connected to the other active elements 410 . The dielectric element 412 and the capacitive element 411 are mounted on the surface opposite to the surface on which they are mounted. The implementation method was used.

[Problems to be Solved by the Invention] The above-mentioned conventional technology does not take into account the planar mounting of a high-frequency circuit element equipped with a surface acoustic wave element.
When realizing a circuit that includes surface acoustic wave elements, it is not possible to plane-mount (mount from all sides) all the circuit elements on the printed circuit (motherboard), and as with conventional technology, it is not possible to mount all the circuit elements on the printed circuit (motherboard). Sufficient grounding cannot be ensured unless a special mounting method is used. The higher the frequency, the more difficult it is to ensure grounding, and in the frequency band of 800 MHz or higher used in car phone systems, there is a problem that if sufficient grounding is not provided, the isolation between input and output will deteriorate. Ta.

Furthermore, surface acoustic wave devices require an external matching circuit to be provided in order to cancel the capacitance that the transducer inherently has for surface acoustic wave excitation, but in conventional technology, the above-mentioned The matching circuit had to be formed on the printed circuit.

An object of the present invention is to provide a high frequency circuit device that can be mounted on a single plane.

Yet another object of the present invention is to provide a high frequency circuit device in which impedance matching can be performed using capacitance without the need to form a matching circuit on a printed circuit.

[Means for solving the problem] The above purpose is to fix a surface acoustic wave element on a second dielectric substrate provided on the dielectric substrate separately from the dielectric substrate on which other active elements etc. are mounted. This is achieved by

This is achieved by forming an input matching circuit and an output matching circuit, and forming an input electrode, an output electrode, and a common ground electrode as means for electrical connection with an external circuit on a substrate surface different from the above substrate surface. .

In this case, the surface acoustic wave element has electrode surfaces protected by a To-can type package, resin molding, or the like.

[Function] Since the second dielectric substrate has a grounding electrode formed on one side thereof, it is possible to completely ensure the grounding properties of the surface acoustic wave element. At the same time, by fixing the other surface to the substrate, planar mounting with other elements etc. is possible.

Furthermore, since the matching circuit is provided on the second dielectric substrate, there is no need to set a matching circuit on the printed circuit according to the surface acoustic wave element, and the design of the high frequency circuit device is facilitated. You will be able to do this.

[Example] Hereinafter, an example of the present invention in which a To-can type package is used as an electrode protection method is shown in Figs. 1 and 2.
This will be explained using figures.

Figure 1(a) is a cross-sectional view of a surface acoustic wave element sealed in a To can package, Figure 1(b) is a cross-sectional view of a small dielectric substrate, and Figure 1(c) is a cross-sectional view of a small dielectric substrate.
) are a pair of cross-sectional views of a high-frequency circuit board (motherboard).

FIG. 2(a) is a top view of a surface acoustic wave device sealed in a T○ can type package fixed to a small dielectric substrate, and FIG. 2(b) is a top view of a small dielectric substrate. ) is a bottom view. The surface acoustic wave element 1 is fixed onto the stem portion 2 with an adhesive 3, and at the same time is electrically connected to an input pin 5 and an output pin 6 by wire bonding 4. The upper surface of the stem portion 2 and the surface acoustic wave element 1 are covered with a metal cap 7 and hermetically sealed.

T that accommodates the surface acoustic wave element 1 as described above.

A can-type package 10 includes a small dielectric substrate 2
0, and the input and output pins 5 and 6 are placed on the dielectric substrate 2.
The small dielectric substrate 20 is inserted into the through holes 21 and 22 provided in the
The input electrode 23. provided on the back surface of the input electrode 23. It is electrically connected to the output electrode 24 by soldering. At this time, input pin 5.
The length of the output pin 6 is cut to a length that does not protrude from the back surface of the board, and the flatness of the back surface of the board is maintained.

A To-can type package 10 is fixed on the surface of the small dielectric substrate 2o, and at the same time an input matching circuit 25. Output matching circuits 26 are formed, and these matching circuits 25.26 are connected to the input electrodes 23.2 by means of through holes 27.28. It is electrically connected to the output electrode 24. At the same time, the terminal end of the matching circuit is electrically connected to the common ground electrode 29 on the back side through the through hole 40.41.

Furthermore, through holes 31, 32, 33, 34°35.3
6 electrically connects the stem portion 2, the metallized layer 3o on the upper surface of the small dielectric substrate 20 where the stem portion 2 is present, and the common ground electrode 29 on the lower surface of the small dielectric substrate 20.

Also, through holes 50, 51, 52, 53°54.5
5,56,60,61,62,63゜64.65.66
The metallized layer 30 on the upper surface of the small dielectric substrate 20 and the common ground electrode 29 on the lower surface of the small dielectric substrate 20 are electrically connected by this.

The small dielectric substrate 20 is fixed at a predetermined position on a high frequency circuit board (motherboard) 70 by soldering.

FIG. 3 is a perspective view of the high frequency circuit arrangement explained in FIG. 1. The high frequency circuit device 71 in which the small dielectric substrate 2o and the surface acoustic wave element 1 are integrated can be used by being fixed at a predetermined position on the high frequency circuit board (motherboard) 70.

This fixing can be done as easily as other active elements and passive elements (for example, chip capacitors) 72.

Next, an embodiment of the present invention in which the surface acoustic wave device 1 is directly chip-mounted on the dielectric substrate 20 will be described with reference to FIG.

FIG. 4(a) is a top view of the circuit element of the present invention, before taking measures to protect the electrodes.

Figure 4(b) is a sectional view of Figure 4(a), Figure 4(c)
FIG. 2 is a bottom view of the circuit element of the present invention. The surface acoustic wave element 1 is fixed on a conductor 102 formed on a dielectric substrate 120 with an adhesive 123, and is simultaneously connected to a wire bonding 4 and an input side conductor 117. Output side conductor 118
and an input matching circuit 2 formed on the lower surface of the dielectric substrate 120 via through holes 109 and 110.
5 and the output matching circuit 26.

Further, the conductor 102 has through holes 105° and 106.
．． It is electrically connected to a common ground electrode 130 formed on the lower surface of the dielectric substrate 120 via 107 and 108 . A surface acoustic wave element is fixed to the upper surface of the dielectric substrate, and at the same time an input matching circuit 25. Output matching circuit 2
6 is formed, and through the through holes 111 and 112,
Input electrode.

It is connected to the output electrode and further has a through hole 13.1.
4, and is connected to a common ground electrode.

A protective cover plate 122 for protecting the electrode surface of the surface acoustic wave element 1 and ensuring free space on the element surface, and a spacer 121 for holding the protective cover plate 122 are coated with adhesive or the like on a dielectric substrate. It is fixed at

Before fixing the protective cover plate 122 and the spacer 121 that holds it, it is possible to connect the surface acoustic wave element 1 to an external signal generator (not shown) in order to test the element characteristics. It is possible to final package only devices with good quality.

Next, an example in which a multilayer dielectric substrate is used as the dielectric substrate will be described with reference to FIG.

FIG. 5(a) is a sectional view of this embodiment.

In this embodiment, the dielectric substrate includes the first dielectric layer 201
, second dielectric calendar 202. Third dielectric layer 2°3, fourth dielectric layer 204. and a metallization JQ, that is, a first metallization layer 20 formed between each dielectric layer or on the top and bottom surfaces.
5. 2nd metallization 1206° 3rd metallization calendar 207. Fourth metallization H! A multilayer dielectric substrate consisting of I2O3, fifth metallization N209 is used.

FIG. 5(b) is a pattern diagram of the second metallization layer.

FIG. 5(c) is a pattern diagram of the third metallization layer.

FIG. 5(d) is a side view of the high frequency circuit element of the present invention, and FIG. 5(6) is a side view of the input side or output side of the high frequency circuit element of the present invention.

The third dielectric layer 203 is provided with a rectangular cavity for accommodating the surface acoustic wave device 1.

A surface acoustic wave element is fixed onto the fourth metallization layer within the cavity using an adhesive. The second dielectric layer-202 includes
A rectangular cavity is provided to ensure free space on the electrode surface of the surface acoustic wave element. A surface acoustic wave element was patterned on the third metallization layer 7 by wire bonds 4. Input matching circuit 25. It is electrically connected to the output matching circuit 26. The input matching circuit and output matching circuit.

Through the blue holes 222, 223, the second metallization layer -
Input electrode patterned on 206 - 24° output electrode -
It is electrically connected to 25.

A portion of the second metallized layer 206 other than the input electrode and the output electrode serves as a common ground electrode 226. The terminal portions of the input matching circuit-25 and the output matching circuit-26 are electrically connected to the common ground mhTA on the second metallization layer-206 through through holes 230 and 231.

Furthermore, the common ground electrode on the second metallization layer-206
Dielectric layer, -202, third dielectric! 203° was formed on the side surface of the fourth dielectric layer-204. The structure shown in FIG. 5(d) is such that contact can be made with the common ground portion of the motherboard through the metallization layer 240.

Similarly to the common ground electrode, the input electrode-23 and the output electrode-24 also include a second dielectric layer-206, a third dielectric layer-203,
The structure shown in FIG. 5(e) is such that connection with the signal electrodes of the motherboard is possible through the metallization WI-250 formed on the side surface of the fourth dielectric layer-204. .

Also in this embodiment, it is possible to connect an external signal source generator to the input electrode and output electrode before fixing the second dielectric #-201.

It should be noted that in the embodiments of the invention illustrated in FIGS. 2, 4, and 5, the metallization patterns in the figures are merely exemplary.

The circuit element of the present invention having the above configuration can be fixed on the printed circuit on the high frequency circuit board 70 by soldering like the other active elements and passive elements 72, as explained in FIG. 3, and can be electrically connected at the same time. Can be done.

Therefore, there is no need to provide through holes in the circuit board as in the prior art, and even in a circuit including one surface acoustic wave element, one circuit element can be mounted on a plane while ensuring grounding properties.

Furthermore, the high-frequency circuit element of the present invention includes an external matching circuit inside the circuit element for canceling the capacitance inherent in the transducer for surface acoustic wave excitation, which is specific to the surface acoustic wave element. To be there.

When designing a high frequency circuit, there is no need to consider an external matching circuit for the surface acoustic wave element. That is, when realizing a high frequency circuit including a surface acoustic wave element, it can be implemented as easily as other passive elements.

[Effects of the Invention] As explained above, the dielectric layer surface that fixes the surface acoustic wave element and forms the five-man power matching circuit and the output matching circuit, and the dielectric layer surface that forms the input electrode and the output electrode are separately raised. As a result, it is possible to perform planar mounting, which was impossible with conventional to-can type packages.

In addition, by forming a matching circuit within the circuit element to cancel the capacitance of the transducer for surface acoustic wave excitation, it is possible to easily design high-frequency circuits using surface acoustic wave elements. can also be made smaller.

[Brief explanation of drawings]

FIG. 1 is a diagram showing one embodiment of the present invention, FIG. 2 is a diagram showing details of the dielectric substrate 20 in FIG. 1, FIG. 3 is a perspective view of FIG. 1, and FIGS. 4 and 5. are diagrams showing other embodiments of the present invention,
FIG. 6 is a diagram for explaining the conventional technique. DESCRIPTION OF SYMBOLS 1... Surface acoustic wave element, 25... Input matching circuit, 26... Output matching circuit, 23... Input electrode, 24... Output electrode, 27... Common ground electrode, 10...・To-can package, 4...bonding wire. Prisoner 2 Non-uJri/23 27ρ

Claims (5)

[Claims] 1. The lower surface of the dielectric substrate is a common ground conductor, and the upper surface forms a signal path and at the same time forms an active element or a passive element.In a high frequency circuit device in which the active element or passive element is fixed, the surface operates at a frequency of 800 MHz or more. A high frequency circuit device characterized in that an acoustic wave element is fixed in the same plane as other active elements and passive elements. 2. A high frequency circuit board in which a common ground conductor is formed on the lower surface of a dielectric substrate and a signal path is formed on the upper surface thereof, a circuit element fixed to the upper surface side of this high frequency circuit board, and a packaged surface acoustic wave element. and a second plate inserted between the high frequency circuit board and the surface acoustic wave element for fixing the surface acoustic wave element to the upper surface of the high frequency circuit board.
A high frequency circuit device comprising: a dielectric substrate; 3. 3. The high frequency circuit device according to claim 2, wherein the second
A high frequency circuit device comprising an input matching circuit and an output matching circuit on the upper surface of the dielectric substrate on the surface acoustic wave element side, and an output electrode and an input electrode on the lower surface thereof. 4. 3. The high frequency circuit device according to claim 2, wherein a TO and can type package is used as packaging means for the surface acoustic wave device. 5. 3. The high frequency circuit device according to claim 2, wherein the second
A high frequency circuit device characterized in that a multilayer dielectric substrate in which dielectric and metallized layers are alternately formed is used as the dielectric substrate.