JP2005277522A - Electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic component with an excellent electric characteristic while attaining a low profile. <P>SOLUTION: The electronic component is configured to include: first and second filters 11, 12 having band center frequencies different from each other; a board 15 on the mount face 15a of which the filters 11, 12 are mounted; first and second frame layers 16a, 16b laminated and arranged on the board 15 in a form of surrounding the filters 11, 12; a first ground line 23a provided between the board 15 and the first frame layer 16a and electrically connected to ground terminals of the filters 11, 12; a second ground line 23b provided to the side of the second frame layer 16b opposite to the side of the first frame layer 16a; a second ground line 23b electrically connected to the first ground line 23a; and a phase line located between the first and second frame layers 16a, 16b at a position sandwiched between the first and second ground lines 23a and 23b and electrically connected to the first filter 11. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electronic component, and more particularly to an electronic component using a resonator.

  Today, mobile communication devices typified by mobile phones, which are remarkably spreading, are rapidly being miniaturized. Along with this, miniaturization and high performance are required for components used in mobile communication devices.

  In order to branch and generate a transmission signal and a reception signal in such a mobile communication device, a duplexer (electronic component) is used. Some demultiplexers are configured by bandpass filters, bandstop filters, or combinations thereof. In order to achieve further miniaturization and higher performance, two demultiplexers having different band center frequencies can be used. Some are composed of filters.

  As a duplexer using a thin film bulk acoustic wave device, for example, as described in JP-A-2001-24476, a transmission filter in which a plurality of thin film bulk acoustic wave devices are electrically configured as a ladder type In addition, the reception filter and the phase matching circuit can be combined.

  FIG. 8 shows a functional configuration of a duplexer using two such filters. In the duplexer (electronic component) 10 shown in FIG. 8, the transmission filter 11 is connected to one line branched from the antenna terminal C. The reception filter 12 is connected to the other line via the phase matching circuit 13. By mounting the phase matching circuit 13 on the reception filter 12 in this way, the impedance characteristics of the transmission filter 11 and the reception filter 12 are matched by a change in phase (ideally, the two filters 11 and 12 are Matching is made so that the impedance on the other side becomes infinite in each pass band), and the two filters 11 and 12 are prevented from interfering with each other to deteriorate the demultiplexing characteristics. The filters 11 and 12 are connected to input / output terminals S1 and S2 of the demultiplexed signal, respectively.

  As shown in FIG. 9, the phase matching circuit 14 can be loaded on the transmission filter 11 or can be loaded only on the transmission filter 11.

  As a branching filter using a thin film bulk acoustic wave device currently on the market, a packaged two filter mounted on a printed circuit board is known. In this branching filter, a phase matching circuit is used. For example, a multilayer chip capacitor and a multilayer chip inductor are used. Therefore, since the size is relatively large, there has been a strong demand for a smaller duplexer.

  In response to such a request, as an example in which a duplexer is manufactured by integrally packaging a thin film bulk acoustic wave device and a phase matching circuit, there is a description in, for example, Japanese Patent Application Laid-Open No. 2003-179518. Here, the transmission filter and the reception filter are integrally formed using a ceramic substrate, and the phase matching circuit is formed inside the ceramic substrate using a conductor pattern. In the technique described in Japanese Patent Laid-Open No. 2003-179518, the filter is formed integrally with the ceramic substrate. It is also conceivable to form a transmission filter and a reception filter configured using a plurality of thin film bulk acoustic wave devices on separate chips. Even in these cases, if a phase matching circuit is configured using inductors and capacitors which are discrete elements and mounted on a substrate in the same manner as a filter, the package must be large.

  For this reason, it is advantageous from the viewpoint of miniaturization to form a transmission line, an inductance, a capacitor and the like inside the substrate using the internal conductor pattern.

  Here, as the phase line used in the phase matching circuit, a microstrip line, a coplanar line, and the like can be considered. However, in order to reduce the size of the apparatus, the phase line is formed by a ground layer provided above and below via a dielectric. A sandwiching structure (strip line) is preferable. In this case, if the strip line is provided below the filter mounting surface, the thickness of the entire structure increases.

  An example of the duplexer having such a structure is shown in FIG. In FIG. 10, the duplexer 10, which is an electronic component, has a five-layer structure board portion 15 on which a transmission filter 11 and a reception filter 12 are mounted, and is placed on the board portion 15 so as to surround the filters 11 and 12. And a three-layer frame 16 attached thereto. In addition, the board | substrate part 15 and the frame 16 use what laminated | stacked and fired the dielectric green sheets, such as a ceramic, resin, etc., for example, alumina. The thickness of each layer is about 200 μm. Therefore, the thickness of the substrate portion 15 is 800 μm, the thickness of the frame 16 is 600 μm, and the thickness of the entire apparatus is about 1.4 mm.

Two ground layers 17a and 17b are formed on the substrate portion 15 so as to sandwich a strip line 13 having a predetermined length as a phase matching circuit from the stacking direction. If the dielectric constant of the ceramic composing the substrate unit 15 is about 7, when attempting to configure a duplexer that operates at a frequency of about 2 GHz, the stripline 13 is not suitable for proper operation as a phase matching circuit. A length of about 14 mm is required. Since the loss due to the electrical resistance of the strip line 13 directly leads to the insertion loss of the filter, it is necessary to reduce this as much as possible. For that purpose, it is of course effective to use a low-resistance material as the conductor material of the strip line 13, but it is also effective to increase the line width.
JP 2001-24476 A JP 2003-179518 A

  However, in order to widen the line width while keeping the characteristic impedance of the strip line constant, it is necessary to increase the thickness of the dielectric layer constituting the substrate portion.

  As a result, the thickness of the device further increases, which is against the demand for a small size and a low profile.

  Accordingly, an object of the present invention is to provide an electronic component having excellent electrical characteristics while achieving a low profile.

  In order to solve the above-described problem, an electronic component according to the present invention includes a first filter including at least one resonator having different band center frequencies and a second filter including at least one resonator, and a predetermined filter. A wiring pattern is formed, and surrounds the substrate part on which the first filter and the second filter are mounted on the mounting surface via electrical connection means, and the first filter and the second filter. A first frame-like layer and a second frame-like layer made of a dielectric, which are sequentially stacked on the substrate part in a shape, and provided between the substrate part and the first frame-like layer, A first ground line electrically connected to a ground terminal of the first filter and the second filter, and provided on the opposite side of the second frame layer from the first frame layer side; , The first ground line and the power At least a portion of the first ground line and the second ground line between the first ground line and the second frame line that are connected to each other, and between the first frame layer and the second frame layer And a phase line electrically connected to at least one of the first filter and the second filter.

  In a preferred embodiment of the present invention, the substrate portion is a single layer body or a laminated body in which a conductor pattern is formed.

  In a further preferred aspect of the present invention, the first filter and the second filter are propagated through a piezoelectric resonator that obtains a signal of a predetermined resonance frequency by a bulk wave propagating inside the piezoelectric film, or a surface of a piezoelectric body. It is a filter comprising a surface acoustic wave resonator that obtains a signal having a predetermined resonance frequency by a surface acoustic wave.

  In a further preferred aspect of the present invention, the electrical connection means is a bump.

  According to the present invention, the following effects can be obtained.

  That is, according to the present invention, the first grounding line is provided on the same plane as the mounting surface of the substrate unit, and the first frame-like layer and the second frame-like layer disposed on the substrate unit are provided. Since the provided phase line is sandwiched between the first ground line and the second ground line, it is not necessary to form the phase line in the substrate portion, and the phase line is formed by only two frame layers on the mounting surface. Can be provided.

  As a result, the thickness of the substrate portion can be significantly reduced, and an electronic component having excellent electrical characteristics can be obtained while achieving a low profile.

  Hereinafter, the best mode for carrying out the present invention will be described more specifically with reference to the drawings. Here, in the accompanying drawings, the same reference numerals are given to the same members, and duplicate descriptions are omitted. In addition, since description here is the best form by which this invention is implemented, this invention is not limited to the said form.

  FIG. 1 is a cross-sectional view showing an electronic component according to an embodiment of the present invention, FIG. 2 is a plan view showing a back surface of a substrate portion constituting the electronic component of FIG. 1, and FIG. 3 is a substrate constituting the electronic component of FIG. FIG. 4 is a plan view showing a mounting surface of a substrate part constituting the electronic component of FIG. 1, and FIG. 5 is a plan view showing a first frame layer constituting the electronic component of FIG. 6 is a plan view showing a second frame layer constituting the electronic component of FIG. 1, and FIG. 7 is a sectional view showing the electronic component in another embodiment of the present invention.

  An electronic component 10 shown in FIG. 1 includes a substrate portion 15 made of ceramic, resin, or the like, and having a predetermined wiring pattern, and two filters 11 and 12 mounted on the substrate portion 15. This filter is a first filter 11 as a transmission side filter and a second filter 12 as a reception side filter having mutually different band center frequencies, and these constitute a duplexer. The filters 11 and 12 are each composed of one or a plurality of resonators.

  The first frame 11a and the second filter 12 are formed in a shape surrounding the first filter 11 and the second filter 12 on the substrate unit 15 by laminating and firing a dielectric green sheet such as alumina. A frame-shaped layer 16b is disposed. A lid member may be attached on the second frame layer 16b to hermetically seal the filters 11 and 12.

  The filters 11 and 12 are piezoelectric filters that can obtain a signal having a predetermined band center frequency by a bulk wave propagating through the inside of the piezoelectric film by a piezoelectric effect caused by voltage application. Bumps (electrical connection means) 18 such as stud bumps and plating bumps are formed on the electrodes of the filters 11 and 12, and the bumps 18 are mounted on the mounting surface 15 a of the substrate portion 15 by face-down bonding. Has been.

  As shown in detail in FIG. 2, an antenna terminal C connected to the first filter 11 and the second filter 12, and the first filter 11 are provided on the back surface 15 b opposite to the mounting surface 15 a of the substrate unit 15. An input terminal S1 for an input signal, an output terminal S2 for a signal output from the second filter, and a ground terminal G for supplying a ground potential to the first filter 11 and the second filter 12 are provided.

  As shown in FIG. 1, the board | substrate part 15 is a laminated body in which the conductor pattern was formed. The inner layer 15c is formed with a signal line 20a connected to the input terminal S1 through the side through 19 and a signal line 20b connected to the output terminal S2 through the side through 19, as shown in FIG. Has been.

  As shown in FIG. 4, the mounting surface 15a of the substrate unit 15 on which the first filter 11 and the second filter 12 are mounted is connected to the signal line 20a of the inner layer 15c through the through hole 21a. The signal line 20c connected to one signal terminal (not shown) of the second filter 12 is connected to the signal line 20b of the inner layer 15c through the through hole 21b and one signal terminal of the first filter 11 A signal line 20d connected to (not shown), a signal line 20e connected to the antenna terminal C through the side through 19 and connected to the other signal terminal (not shown) of the first filter 11. A signal line 20 f connected to the other signal terminal (not shown) of the second filter 12, and a first ground line connected to the ground terminal G via the side through 19. 23a is formed.

  The first grounding line 23a is formed in a shape that is divided by the signal line 20e facing the end of the substrate part 15, and the outer periphery of the mounting surface 15a is formed in a substantially annular shape. It is also electrically connected to the ground terminal (not shown) of the second filter.

  As shown in FIG. 5, the first frame layer 16a has a phase line 22 connected to the signal line 20e through the through hole 21c and connected to the signal line 20f through the through hole 21d. It is formed so as to be located immediately above one grounding line 23a. As described above, since the signal line 20 f is connected to the second filter 12, the phase line 22 is electrically connected to the second filter 12. With such a phase line 22, the impedance characteristics of the first filter 11 and the second filter 12 are matched by a phase change. However, the phase line may be connected to the first filter 11, or two phase lines may be formed and connected to the two filters 11 and 12, respectively.

  As shown in FIG. 6, the second frame-like layer 16 b has a second ground line 23 b electrically connected to the first ground line 23 a and the ground terminal G through the side through 19. 1 is formed at a position corresponding to one ground line 23a.

  Therefore, the phase line 22 is provided at a position sandwiched between the first ground line 23a and the second ground line 23b between the first frame layer 16a and the second frame layer 16b. .

  Here, in the present embodiment, the first grounding line 23a is formed on the substrate portion 15 and the phase line 22 is formed on the first frame-like layer 16a. However, the first grounding line 23a is the first grounding line 23a. The phase line 22 may be formed on the second frame layer 16b in the frame layer 16a. That is, if the first grounding line 23a is located between the substrate portion 15 and the first frame-like layer 16a, the phase line 22 has the first frame-like layer 16a and the second frame-like layer 16b. It suffices if it is located between.

  The conductor patterns such as the side through 19, the signal lines 20a to 20f, the through holes 21a to 21d, the phase line 22, the first and second ground lines 23a and 23b are Ag, Al, Au, Pt, Mo, and the like, for example. It is formed with.

  As described above, according to the electronic component 10 of the present embodiment, the first ground line 23 a is provided on the same plane as the mounting surface 15 a of the substrate portion 15, and the first frame shape disposed on the substrate portion 15. The phase line 22 provided between the layer 16a and the second frame layer 16b is sandwiched between the first ground line 23a and the second ground line 23b formed on the second frame layer 16b. Therefore, it is not necessary to form the phase line 22 in the substrate part 15, and it is possible to provide the phase line 22 with only two frame layers 16a and 16b on the mounting surface 15a.

  Thereby, the thickness of the board | substrate part 15 can be reduced significantly, for example, if the thickness of each layer is 200 micrometers, in the electronic component 10 of this Embodiment which becomes 4 layer structure, the whole thickness will be 0.8 mm. . For this reason, since it is possible to reduce the height significantly (0.6 mm) compared to the thickness (1.4 mm) of the conventional electronic component shown in FIG. 10 described above, the electrical characteristics can be achieved while achieving a reduction in height. An excellent electronic component 10 can be obtained.

  In the above description, the substrate portion 15 is a two-layer laminate, but may be three or more layers. Alternatively, as shown in FIG. 7, it may be a single layer body which is not a laminated structure.

  Moreover, although the filters 11 and 12 are comprised from the piezoelectric resonator, you may be comprised from the surface acoustic wave resonator etc. which acquire the signal of a predetermined resonant frequency with the surface acoustic wave which propagates the surface of a piezoelectric material.

  Furthermore, a bonding wire may be used as an electrical connection means between the filters 11 and 12 and the substrate portion 15. However, since the distance between the device formed on the filters 11 and 12 and the phase line 22 can be increased by mounting by the face-down bonding via the bump 18, the electrical connection between the device and the phase line 22 can be increased. This is desirable because it can further suppress interference.

It is sectional drawing which shows the electronic component in one embodiment of this invention. It is a top view which shows the back surface of the board | substrate part which comprises the electronic component of FIG. It is a top view which shows the inner layer of the board | substrate part which comprises the electronic component of FIG. It is a top view which shows the mounting surface of the board | substrate part which comprises the electronic component of FIG. It is a top view which shows the 1st frame-like layer which comprises the electronic component of FIG. It is a top view which shows the 2nd frame-like layer which comprises the electronic component of FIG. It is sectional drawing which shows the electronic component in other embodiment of this invention. It is a block diagram which shows an example of a functional structure of the branching filter using two filters. It is a block diagram which shows another example of the functional structure of the splitter which uses two filters. It is sectional drawing which shows the structure of the conventional splitter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electronic component 11 1st filter 12 2nd filter 13, 14 Phase matching circuit 15 Board | substrate part 15a Mounting surface 15b Back surface 15c Inner layer 16 Frame 16a 1st frame layer 16b 2nd frame layer 17a, 17b Ground Layer 18 Bump 19 Side through 20a to 20f Signal line 21a to 21d Through hole 22 Phase line 23a First ground line 23b Second ground line C Antenna terminal G Ground terminal S1 Input terminal S2 Output terminal

Claims (4)

A first filter comprising at least one resonator having a different band center frequency and a second filter comprising at least one resonator;
A predetermined wiring pattern is formed, and a substrate portion on which the first filter and the second filter are mounted on the mounting surface via electrical connection means,
A first frame-like layer and a second frame-like layer made of a dielectric, which are sequentially stacked on the substrate portion in a shape surrounding the first filter and the second filter;
A first ground line provided between the substrate portion and the first frame layer and electrically connected to ground terminals of the first filter and the second filter;
A second grounding line provided on the opposite side of the second frame-like layer from the first frame-like layer side and electrically connected to the first grounding line;
The first filter is provided at a position at least partially sandwiched between the first ground line and the second ground line between the first frame layer and the second frame layer. And a phase line electrically connected to at least one of the second filters,
An electronic component comprising: The electronic component according to claim 1, wherein the substrate portion is a single layer body or a laminated body having a conductor pattern formed therein. The first filter and the second filter are a piezoelectric resonator that obtains a signal of a predetermined resonance frequency by a bulk wave propagating inside the piezoelectric film, or a predetermined resonance by a surface acoustic wave that propagates the surface of the piezoelectric body. 3. The electronic component according to claim 1, wherein the electronic component is a filter including a surface acoustic wave resonator that obtains a frequency signal. The electronic component according to claim 1, wherein the electrical connection means is a bump.

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