JP2011086655A - Laminated inductor and circuit module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a Q value by suppressing characteristic decline due to interaction between wirings. <P>SOLUTION: First and second coil wirings 1 and 2 are formed in a plurality of wiring layers of a multilayer wiring board, and conductor lines 10 and 11 wound at least once in the plane view are provided in the respective wiring layers. The two first and second coil wirings 1 and 2 adjacent in a lamination direction within the multilayer wiring board are interconnected by a via 12 at the end parts of each other so that the directions of currents flowing through the conductor lines 10 and 11 become opposite. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a multilayer inductor formed in a plurality of wiring layers of a multilayer wiring board, and a circuit module having the multilayer inductor as one of circuit elements of a circuit device.

  As an electromagnetic element having a planar coil portion, there are a planar inductor formed on a semiconductor integrated circuit or a printed wiring board, and a planar antenna built in an IC card or the like.

  By the way, in recent years, digital devices such as digital electronic devices have been widely used, and in particular, mobile communication devices using the [GHz] band have been remarkably spread. Along with that, inductance components (inductors) are also required to support high frequencies.

  In addition, when the application is a small and light communication device such as a mobile phone, the inductor itself is required to be small, light, and low in profile while maintaining characteristics to achieve a high Q value. Yes.

  In response to such a demand, a spiral inductor structure having a high Q value has been proposed by reducing performance degradation due to mutual influence between conductor lines (see, for example, Patent Document 1).

  In the inductor structure described in Patent Document 1, the conductor line (coil wiring) is formed so that the narrow area and the wide area are adjacent to each other. Thereby, it aims at suppression that an inductance falls by the electrical and magnetic coupling of adjacent conductor lines, or Q value falls.

JP 2008-306185 A

  In the inductor structure described in Patent Document 1, in order to increase the Q value without changing the number of windings and without increasing the occupied area, it is necessary to increase the difference in the width of the conductor line (coil wiring).

  This structure has a large influence on the magnetic lines of force between the coil wirings. Therefore, when the difference in coil wiring width is increased, there is an effect of improving the Q value to some extent. However, there is a limit to making the coil wiring thinner, and if the coil wiring is made too thin, the characteristics deteriorate, conversely, it is difficult to improve the Q value significantly.

  When trying to obtain a higher Q value with this structure, the only solution is to widen the space between the coil wires. However, if the space between the coil wirings is widened, the Q value can be improved, but the occupied area becomes large, which becomes an obstacle to downsizing.

  The present invention provides an inductor having a structure in which the Q value can be improved by suppressing characteristic deterioration due to mutual influence between wirings.

The multilayer inductor according to the present invention has a plurality of coil wirings and at least one wiring connecting part for interconnecting them.
The plurality of coil wirings are formed in a plurality of wiring layers of a multilayer wiring board, and each wiring layer has a conductor line wound one or more times in a plan view.
In the wiring connection portion, the ends of any two coil wirings formed in two wiring layers adjacent to each other in the stacking direction in the multilayer wiring board are arranged so that the directions of the currents flowing through the conductor lines are opposite to each other. Interconnect.

  According to such a configuration, a magnetic field corresponding to the current flowing in each of the two coil wiring layers adjacent in the stacking direction is generated around each coil wiring layer. At that time, since the direction of the current is opposite in the conductor lines of the two coil wiring layers, the magnetic fluxes of the generated magnetic fields are intensified in each other in the region between the conductor lines.

  The circuit module according to the present invention includes the plurality of coil wirings and a wiring connection part that interconnects the plurality of coil wirings so that the direction of the current is reversed, like the multilayer inductor. The circuit module has such an inductor as one of circuit elements of a circuit device mounted on a multilayer wiring board.

  ADVANTAGE OF THE INVENTION According to this invention, the inductor of the structure which can improve Q value by suppressing the characteristic fall by the mutual influence between wiring, and a circuit module using this can be provided.

It is a three-dimensional perspective view of the multilayer inductor according to the second embodiment. It is sectional drawing along the AA line of FIG. 1 of the multilayer inductor in connection with 2nd Embodiment. It is a three-dimensional perspective view showing the inductor structure of the first comparative example. It is a distribution map of the magnetic flux vector obtained using the electromagnetic solution simulator about the inductor structure of the 1st comparative example. It is a distribution map of the magnetic flux vector obtained about the 2nd embodiment using the electromagnetic solution simulator. It is a graph which shows the frequency dependence of Q value obtained using an electromagnetic solution simulator by contrast in the case of the 2nd embodiment and the case of the 1st comparative example. It is a three-dimensional perspective view showing the inductor structure of the second comparative example. It is a graph which shows the frequency dependence of Q value obtained using an electromagnetic solution simulator by contrast in the case of the 2nd embodiment and the case of the 2nd comparative example. It is the same graph as FIG. 8 which shows the result of having replaced the characteristic parameter of the area | region between conductor lines with the thing of silicon (Si), and simulating. It is the graph of the frequency dependence of L value obtained by finely simulating the distance between conductor lines. It is a graph of the frequency dependence of Q value obtained by simulating finely the distance between conductor lines. It is a block diagram which shows the schematic structure of the mobile communication terminal device in connection with 3rd Embodiment. In 3rd Embodiment, it is a perspective view of the mounting surface which shows the device arrangement example of a front end module. In 3rd Embodiment, it is a figure which shows the switch structure of a front end module, the example of insertion of LPF, and the band correspondence of each switch.

An embodiment of the present invention will be described in the following procedure with reference to the drawings.
1. First embodiment: A schematic description of the embodiment.
2. Second Embodiment: A specific embodiment of a single-turn two-layer type multilayer inductor is shown in comparison with the first and second comparative examples.
3. Third Embodiment: An embodiment of a circuit module is shown as a front-end module for mobile communication.

First Embodiment>
The multilayer inductor according to the embodiment of the present invention is formed on a multilayer wiring board. The multilayer wiring board has a structure in which wiring layers are stacked several times with an insulating layer (core layer) interposed between layers. More specifically, the multilayer inductor of this embodiment has a plurality of coil wirings formed in a plurality of wiring layers that are continuous with a core layer sandwiched between layers in the stacking direction in the multilayer wiring board.

  A multilayer wiring board usually has electronic components mounted on at least one of its outermost surface and rear surface. Furthermore, the multilayer wiring board may have a passive component (for example, an inductor or a capacitor) formed from a wiring layer. The multilayer inductor of this embodiment can be formed as one of such internal inductors.

Each coil wiring of the multilayer inductor according to the present embodiment includes a conductor line wound one or more times in a plan view and a pad portion having a wide end portion of the conductor line.
As a feature of this multilayer inductor, any two coil wirings formed on two wiring layers adjacent to each other in the stacking direction in the layer wiring board are opposite in the direction of the current flowing through the conductor line. Interconnected to be oriented. This interconnection is achieved by, for example, a wiring connection portion that interconnects the pad portions through vias that penetrate the core layer in the thickness direction.

This coil wiring connection structure is a structure that regulates the direction of current as follows.
It is assumed that a current flowing through a certain first coil wiring flows into a second coil wiring at a different level through the wiring connection portion. At this time, when viewed in the stacking direction of the multilayer wiring board, the direction of the current flowing through the conductor pattern of the first coil wiring is opposite to the direction of the current flowing through the conductor pattern of the second coil wiring.

As a result, the first magnetic field generated by the current flowing through the first coil wiring and the second magnetic field generated by the current flowing through the second coil wiring are in a relationship of strengthening each other. Therefore, as long as the first and second coil wirings are limited, the inductor characteristics, particularly the inductance, is not reduced by the mutual interference of the coil wirings.
This effect is effective when the distance between the first and second coil wirings (core layer thickness) is reduced.

More specifically, when the present invention in which the direction of the current is the same is not applied, the inductor characteristics are degraded by the mutual interference of the coil wirings only by reducing this distance (core layer thickness).
On the other hand, when the present invention in which the direction of the current is reversed is applied, if the distance (core layer thickness) is reduced, the inductor characteristics may be deteriorated due to other factors such as eddy current loss, but the magnetic field is reduced. Since there is no weakening, the deterioration of the inductor characteristics is suppressed at that point. In other words, in terms of preventing the deterioration of the inductor characteristics caused by the weakening of the magnetic field, the effect of the present invention is that the smaller the inter-layer distance of the coil wiring, the more the relative effect compared to the non-application case. The effect will increase.

  This greatly contributes to the realization of a high-density multilayer inductor in which the inductor is compactly formed in the lamination direction with a thin core layer.

Note that the wiring connection method in which the current directions are opposite to each other and the operation and effect thereof are the same for any two coil wirings adjacent in the stacking direction in a multilayer inductor having three or more layers.
For example, when the third coil wiring is provided in the wiring layer on the opposite side of the second coil wiring to the first coil wiring, the same connection relationship is also provided between the second coil wiring and the third coil wiring. The same effect can be obtained.

  The conductor lines included in each coil wiring are one line per se, but have a plan view (planar pattern shape) wound more than once. The planar pattern may be a circular or elliptical winding as a whole, or may be a rectangular or other polygonal winding.

  When the number of windings of the conductor lines in the same wiring layer is N (≧ 2), the inductor characteristics are not affected even if the spacing pitch between the N conductor line portions adjacent in the winding local portion is relatively small. Rather, it is known that when the spacing pitch is reduced, a composite magnetic field is generated strongly in the N conductor line portions, so that the inductor characteristics are improved. When the combined magnetic field of the N conductor line portions is strong, the combined magnetic field causes an interaction with the combined magnetic field generated in the other N conductor line portions due to the reverse current on the opposite side in the planar pattern shape. As a result, the magnetic field generated by the entire inductor is further strengthened.

In this way, the direction of current in the local part of the winding in the same wiring layer may be the same, but if the direction of current is not reversed between different windings (conductor lines) in the stacking direction, the inductor characteristics will be improved. I can't expect.
The present embodiment is characterized by reversing the direction of the current flowing between any two conductor lines adjacent in the stacking direction, paying attention to this.

When a spiral pattern is generally formed on a multilayer wiring board, coil wiring is formed on the upper and lower surfaces of the core layer as a base. However, it is not limited to the form in which the coil wiring, the core layer, and the coil wiring are formed in this order.
For example, a method of forming a multilayer inductor by a build-up layer that is laminated in multiple layers may be used. For example, a base film that changes the core layer may be prepared by forming a coil wiring, and a multilayer inductor may be formed by stacking a plurality of layers. In that case, the multilayer inductor thus formed may be further embedded in the core layer of the multilayer wiring board.

When the coil wiring is formed on the base film, the wiring connection portion may be formed in advance, and the coil wirings may be electrically connected by overlapping them.
In other embodiments, generally, the coil wiring may be connected by an optimum method generally used in a printed wiring board such as a through via or a laser via.

  The multilayer wiring board may be a printed wiring board in which a circuit unit of an electronic device is built, or may be a small board module mounted on the printed wiring board.

Second Embodiment>
In this embodiment, the outline (inductor structure) described in the first embodiment is shown as a more specific embodiment with reference to the drawings.

[Multilayer inductor structure]
FIG. 1 shows a three-dimensional perspective view of the multilayer inductor according to the second embodiment. FIG. 2 is a cross-sectional view taken along the line AA in FIG.
The multilayer inductor illustrated in FIG. 1 exemplifies a case of a two-layer coil having a single winding in a plan view and a circular shape among various forms described in the first embodiment.
Here, the coil wiring on the lower layer side is called “first coil wiring”, and the coil wiring on the upper layer side is called “second coil wiring”.

The first coil wiring 1 has a conductor line 10 and two pad portions 13 and 14 integrally formed of the same conductive material at both ends thereof.
Similarly, the 2nd coil wiring 2 has the conductor line 11, and the two pad parts 16 and 18 integrally formed with the same electrically conductive material at the both ends.

The conductor lines 10 and 11 have a circular pattern in which most of the portions overlap in plan view. However, since the pad portion 13 of the conductor line 10 is disposed in the vicinity of the center of the coil, the connecting line portion up to that point is formed. 10A.
The line widths of the conductor lines 10 and 11 may be uniform or may vary with each conductor line. The film thickness of the conductor lines 10 and 11 is usually the same.

The pad portion 14 that is continuous with one end of the conductor line 10 and the pad portion 16 that is continuous with one end of the conductor line 11 are arranged so as to overlap in a plan view and are electrically connected by vias 12 therebetween. . The via 12 is an embodiment of the “wiring connection portion” in the present invention.
On the other hand, the other end side of the conductor line 10 is also provided with a pad portion at the end portion of the connection line portion 10A, and this is drawn out to the upper wiring layer by a via (not indicated).

In such a structure, the other end portion of the first coil wiring 1 drawn to the upper wiring layer and the other end portion (pad portion 18) of the second coil wiring 2 are connected to both terminals of the multilayer inductor. Become. When a signal or voltage is applied to both terminals, a reverse current flows through the conductor lines 10 and 11.
For example, it is assumed that a potential difference in which the other end portion of the first coil wiring 1 drawn to the upper wiring layer is on the positive electrode side and the other end portion (pad portion 18) of the second coil wiring 2 is on the negative electrode side is applied. In that case, a first current flows through the conductor line 10 of the first coil wiring 1 in the direction indicated by the arrow “15”, which is folded back via the via 12, and the conductor line 11 of the second coil wiring 2. Flows through the second current in the direction indicated by the arrow “17”.
For this reason, the direction of the current is reversed regardless of the overlapping portion of the conductor line 10 and the conductor line 11.

  The first coil wiring 1 and the second coil wiring 2 are preferably formed from a low resistance conductive material such as copper. The first coil wiring 1 and the second coil wiring 2 may be formed from a plurality of materials, such as covering a part of the periphery thereof with a magnetic material.

  The via 12 and the via on the other end side can be formed from, for example, a blind via hole. As a method for forming the blind via hole, for example, after processing an interlayer film (for example, the core layer 19 in FIG. 2) with a carbon dioxide laser, the processing hole is filled with a conductive material by plating, and conduction between the pad portions 14 and 16 is performed. The method of obtaining is mentioned.

It is generally known that the coil component mainly depends on the number of turns. In addition, since the direction of current in the spiral is always the same in the same coil wiring and the inductance value is larger, the maximum inductance value can be obtained by aligning the direction of this current. However, these patterns are not formed with reduced eddy current loss.
In this embodiment, the coil winding direction is aligned so that the eddy current loss can be reduced and the inductance value can be increased in the same coil wiring, and the current is reversed between different coil wirings adjacent in the stacking direction. The connection is made as follows.

  Next, the effect of reversing the current direction in the conductor lines 10 and 11 will be described. First, the structure of a comparative example having the same current direction for comparison will be described.

[First Comparative Example]
FIG. 3 is a three-dimensional perspective view showing the inductor structure of the first comparative example.
Here, an inductor having a single-layer structure will be described, and a phenomenon in which the magnetic flux density decreases between adjacent conductor lines in the same wiring layer will be described. Since this magnetic flux density lowering phenomenon can be applied between two conductor lines stacked vertically, it can be used as a comparative example of this embodiment.

  The inductor illustrated in FIG. 3 includes a spiral conductor line 101 formed on an insulating substrate 100. The conductor lines 101 are formed with the same width along the length of the spiral shape, and at the same time, the intervals between the conductor lines are the same.

  The conductor line 101 has a pad portion 102 at one end and a pad portion 103 at the other end. Further, the pad portions 102 and 103 can be respectively connected to an output terminal (not shown) of the inductor, and when a current flows from the pad portion 102 side, the current flows in the direction indicated by the arrow 104 to the other pad portions 103. Has been derived.

[Electromagnetic field simulation]
FIG. 4 shows a distribution map of magnetic flux vectors obtained using the electromagnetic solution simulator for the inductor structure of the first comparative example. FIG. 4 may be regarded as showing the magnetic flux distribution at a location along the line BB in FIG.

It can be seen from this figure that when the conductor lines 101 and 102 are arranged close to each other and a large amount of current flows in the same direction, the magnetic flux cancels out in the region between the lines.
Thus, in the inductor structure of the comparative example, the inductors are formed with the same width, and the mutual influence of the magnetic field lines due to the cancellation of the magnetic flux between the wires and the eddy current loss greatly reduces the inductance and the Q value (Quality factor). Also lower.

  FIG. 5 is a distribution diagram of magnetic flux vectors obtained by using an electromagnetic solution simulator for the second embodiment. FIG. 5 may be regarded as showing the magnetic flux distribution at the broken line in FIG.

It can be seen from this figure that when the conductor lines 10 and 11 are arranged close to each other and a large amount of current flows in the opposite direction, the magnetic flux strengthens in the region between the lines.
When the magnetic field is strengthened between the wirings in this way, the inductor value (L value) is improved, and a decrease in Q value due to eddy current is suppressed. In the first comparative example, an increase in the L value is accompanied by a decrease in the Q value due to the eddy current, so that sufficient inductor characteristics cannot be obtained. However, the inductor structure of this embodiment solves these problems.

FIG. 6 compares the frequency dependence of the Q value obtained using the electromagnetic solution simulator between the case of the second embodiment shown in FIGS. 1 and 2 and the case of the first comparative example of FIG. It is a graph shown.
In the inductor structure shown in FIG. 3 of the first comparative example, the Q value (Max) is about 180 at 3 [GHz]. A necessary Q value is not obtained in 4 to 6 [GHz].

Here, in FIG. 2 showing the second embodiment, the frequency dependence of the Q value is simulated by changing the thickness t of the core layer 19 to two types of 400 [μm] and 200 [μm]. Looking for.
When the core layer 19 of 200 [μm] is used, the Q value (Max) is about 190 around 5 [GHz]. Further, when the core layer 19 is about twice as thick as 400 [μm], the Q value (Max) becomes 205 near 5 [GHz], which is significantly increased.

  From this graph, it can be seen that even if the current direction of adjacent conductor lines in the same wiring layer is the same as in the first comparative example, a certain Q value can be obtained at a frequency of 2 to 4 [GHz]. On the other hand, if the double winding in the horizontal direction is changed to a double winding in the vertical direction (stacking direction) with the same number of windings, and the current direction is reversed, the Q value can be greatly improved. It can be seen that it is desirable to separate the coil wirings to some extent. This is because if the coil wirings are separated, the suppression of eddy current loss greatly contributes to the improvement of characteristics. By applying the present invention, a high-performance inductor in the 4 to 6 gigahertz band can be realized.

[Second Comparative Example]
FIG. 7 is a three-dimensional perspective view showing the inductor structure of the second comparative example. 7, the same components as those in FIG. 1 are denoted by the same reference numerals.
The inductor structure of the second comparative example shown in FIG. 7 is different from the structure of FIG. More specifically, in the second embodiment of FIG. 1, the pad portion 14 provided at one end of the conductor line 10 and the pad portion 16 provided at one end of the conductor line 11 are mutually connected by the via 12. It is connected. On the other hand, in the second comparative example of FIG. 7, the pad portion 18 provided at the other end of the conductor line 10 is connected to the pad portion 14 by the via 12. For this reason, the direction of the current flowing through the conductor line 11 is indicated by reference numerals “17 (FIG. 1)” and “17A (FIG. 7)” with respect to the direction of current flowing through the conductor line 10 indicated by reference numeral “15”. The opposite is true.

  The fact that the direction of this current is the same in the upper and lower coil wiring layers means that the magnetic fluxes cancel each other with the vertical magnetic flux distribution in FIG. 7 from the simulation result of the horizontal magnetic flux distribution shown in FIG. Can be easily guessed.

  FIG. 8 compares the frequency dependence of the Q value obtained using the electromagnetic solution simulator between the case of the second embodiment shown in FIGS. 1 and 2 and the case of the second comparative example of FIG. It is a graph shown. In FIG. 8, as in the second embodiment, in the second comparative example, the frequency t of the Q value is obtained in the case where the thickness t of the core layer 19 is changed to two types of 400 [μm] and 200 [μm]. Dependency is obtained by simulation.

  From the graph of FIG. 8, the Q value (Max) is around 2 [GHz] in the second comparative example in both cases where the thickness t of the core layer 19 is changed to two types of 400 [μm] and 200 [μm]. It can be seen that it is significantly reduced to around 120. Also from this result, in the inductor structure of the second embodiment in which the current direction is the same, the Q value (Max) is increased by reducing the eddy current loss and the parasitic component between the wirings, and the resonance to the high frequency side. It is confirmed that the frequency can be extended.

  Further, comparing the first comparative example and the second comparative example, it can be seen that the effect of making the current direction the same in two conductor lines adjacent in the stacking direction is particularly great. That is, in order to obtain the same number of windings 2, it is essential to reverse the direction of the current when the conductor lines are opposed to each other on the line surface. In the case of the second embodiment and the second comparative example in which the conductor lines are vertically opposed to each other on the line surface, the facing area is larger than that in the case of the line side surface of the first comparative example. In order to obtain the desired characteristics, the direction of the current must be reversed to obtain the desired characteristics.

  From the above, in order to obtain a desired number of windings N (≧ 2), it is desirable that the number of windings of each coil wiring is 1 in each layer and a multilayer inductor is formed using N layers of coil wiring. In that case, it can be concluded that reversing the direction of the current in any two conductor lines adjacent in the stacking direction is essential for improving the Q value at a high frequency.

For reference, FIG. 9 shows the result of simulation by replacing the characteristic parameters of the core layer 19 with those of silicon (Si) in consideration of the case where the present invention is applied to a semiconductor integrated circuit. Here, a semiconductor integrated circuit is assumed, and the semiconductor substrate itself is on the order of several hundreds [μm]. Therefore, the distance between the conductor patterns in the stacking direction is set to 20 [μm] as a practical value. In that case, the Q value (Max) is as low as 25 around 5 [GHz].
For this reason, the coil wiring of the semiconductor integrated circuit needs to be separated from the front surface and the back surface of the semiconductor substrate, and it is difficult to obtain a total wiring product larger than that. However, in the embodiment in which the semiconductor substrates are stacked in layers, it is possible to achieve a wiring stack number of 3 or more.

  From the above, it can be seen that the application of the present invention is preferably a multilayer inductor in a multilayer wiring board. This conclusion does not hinder the application of the present invention to a semiconductor integrated circuit.

  Next, a simulation result obtained by examining an appropriate range of the core layer 19 from both the L value and the Q value will be described.

FIG. 10 is a graph showing the results of simulation with the L value, FIG. 11 with respect to the Q value, and further taking the thickness t of the core layer 19 finely.
From this graph, there is an appropriate value for the Q value in the vicinity of the thickness t = 300 [μm], and about 100 is a practical lower limit in the 4 to 6 gigahertz band, so the above t = 40 [μm]. Is the lower limit of the practical thinness of the core layer 19. In addition, when about 100 is a practical lower limit value in the 4 to 6 gigahertz band, a desirable value of the above t is 200 [μm] to 400 [μm].
Note that since the L value varies depending on the application, even if t = 40 [μm], there are applications of about 2 [nH], which is sufficiently practical.

As described above, the distance between the conductor lines 10 and 11 in the one-turn two-layer type multilayer inductor is preferably 40 to 400 [μm], more preferably 200 to 400 [μm].
In addition, when the frequency becomes high, the surface of the conductor line does not contribute as a conductive layer, and in applications in the gigahertz band, the roughness Rz of the conductor surface is desirably 5 [μm] or less in order to maintain the conductor characteristics.
The frequency to which the present invention is applied is not limited to the gigahertz band, and is preferably 100 [MHz] z to several [GHz].

<3. Third Embodiment>
The present embodiment relates to a circuit module in which a multilayer inductor to which the present invention is applied is incorporated as an external component of a low-pass filter (LPF). Here, the front end module of the mobile communication terminal device is shown as an example of a circuit module.

  FIG. 12 is a block diagram showing a schematic configuration of the mobile communication terminal apparatus. The mobile communication terminal apparatus 200 includes an antenna 202, a front end module 203 as a circuit module, and a transmission / reception circuit 204. The transmission / reception circuit 204 includes a reception unit 205 and a transmission unit 206.

  The front end module 203 includes an antenna switch having a SP * T (Single Pole x Throw) configuration. Here, “*” is an arbitrary plurality of natural numbers, but in the mobile communication terminal apparatus according to the present embodiment capable of transmitting and receiving signals of a plurality of frequencies, “*” is 4, 5, 6, 7,. It becomes the above number. In this case, “SP * T” means a contact (switch) that has four or more operation ends and can be separately operated (connected or disconnected) to the common antenna side end. Further, the front end module 203 preferably includes a filter component in which a plurality of low pass filters (LPF) are integrated on the operation end side of each switch.

  The receiving unit 205 is a SAW (Surface Acoustic Wave) filter as a bandpass filter having a characteristic of passing a predetermined frequency band component for each frequency of the received signal, a low noise amplifier and a local oscillator for each frequency, an IF amplifier, a PLL, and Includes a mixer that performs frequency conversion. The transmission unit 6 includes a power amplifier, a local oscillator, a mixer, and the like for each frequency of the transmission signal.

  FIG. 13 shows an example of the front end module 203 (a perspective view of the mounting surface). FIG. 14 shows a switch configuration of the front end module 203, an example of LPF insertion, and band correspondence of each switch. This switch is compatible with a quad-band front end module that supports four bands.

  As shown in FIG. 13, an LPF chip, a GaAs switch chip, and a reception signal decoder chip are mounted on the surface (mounting surface) of the multilayer wiring board. Each chip is interconnected by wire bond or the like and further connected to an external terminal.

  The switch configuration diagram shown in FIG. 14 has a total of nine switches SW and adopts an SP9T (Single Pole nine Throw) configuration. As a result, the antenna switch is compatible with GSM (Global System for Mobile Communications) in two bands with different frequency bands in two transmission and reception systems. In addition, two bands and three systems are allocated for UMTS (Universal Mobile Telecommunication System).

In FIG. 14, LPFs are inserted on the GMS, for example, on the transmitter side. This LPF is provided, for example, to remove harmonic components (spurious components) caused by the nonlinearity of the power amplifier in the transmission unit 206 shown in FIG.
The LPF is usually composed of a capacitor and an inductor formed in a chip or a multilayer substrate. Among these, the inductor requires a high L value or Q value, and is therefore arranged as an external component.
In such a case, the multilayer inductor described in the first or second embodiment of the present invention can be provided in the multilayer wiring board serving as a base in FIG. Alternatively, when the LPF is not a semiconductor chip but a multilayer substrate structure having a ceramic or resin as a core layer, a multilayer inductor to which the present invention is applied can be provided therein.

According to the above first to third embodiments, the following advantages can be obtained.
In the first and second embodiments, when forming an inductor on a multilayer wiring board such as a printed wiring board, performance deterioration due to mutual influence between wirings is reduced by reversing the direction of current flowing through the layers, A multilayer inductor having a high Q value can be formed. In addition, the conductor line becomes a core layer or a build-up layer laminated in multiple layers, and the area can be reduced and the size can be reduced.
The third embodiment has a circuit device (for example, a filter component) having a multilayer inductor having the above advantages as one of the circuit elements. Therefore, the advantages of this multilayer inductor are the miniaturization and high performance of the circuit device. Contribute to.

  The present invention is not limited to the above-described embodiments and the accompanying drawings. That is, the shape of the spiral conductor line forming the inductor, the number of layers to be stacked, and the like can be variously realized. The description of the above embodiment can be variously replaced, modified, and changed without departing from the technical idea of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... 1st coil wiring, 2 ... 2nd coil wiring, 10, 11 ... Conductor line, 12 ... Via (wiring connection part), 13, 14, 16, 18 ... Pad part, 15, 17, 17A ... Direction of electric current , 19 ... Core layer, 203 ... Front end module (circuit module)

Claims (7)

A plurality of coil wirings formed in a plurality of wiring layers of the multilayer wiring board and having a conductor line wound in a single plane in a plan view in each wiring layer;
At least one interconnecting the ends of any two coil wirings formed in two wiring layers adjacent to each other in the stacking direction in the multilayer wiring board so that the directions of the currents flowing through the conductor lines are reversed. Wiring connections;
A multilayer inductor. 2. The multilayer inductor according to claim 1, wherein the number of turns in each of the plurality of coil wirings is 1, and the number N of windings (≧ 2) of the entire multilayer inductor matches the number of laminations of the plurality of coil wirings. The multilayer inductor according to claim 2, wherein a separation distance of the conductor lines in the stacking direction is 40 [μm] or more and 400 [μm] or less. The multilayer inductor according to claim 3, wherein a separation distance of the conductor lines in the stacking direction is 200 [μm] or more and 400 [μm] or less. The multilayer inductor according to claim 2, wherein the conductor line has a surface roughness of 5 μm or less. The multilayer inductor according to claim 2, wherein the conductor line has a circular, elliptical, square, or polygonal pattern in plan view. A multilayer wiring board;
An inductor that connects coil wirings arranged between layers in a plurality of wiring layers within the multilayer wiring board; and
A circuit device having the inductor as one of circuit elements and mounted on the multilayer wiring board;
Have
The inductor is
A plurality of coil wirings formed in a plurality of wiring layers of the multilayer wiring board and having a conductor line wound in a single plane in a plan view in each wiring layer;
At least one interconnecting the ends of any two coil wirings formed in two wiring layers adjacent to each other in the stacking direction in the multilayer wiring board so that the directions of the currents flowing through the conductor lines are reversed. Wiring connections;
Including circuit module.

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