JP2014203952A - Rf module and multilayer wiring board incorporating rf module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress malfunction of an electronic component by suppressing noise superposing the electronic component without compromising the design flexibility of an RF module, in the RF module incorporating an electronic component, and to further suppress malfunction of the RF module.SOLUTION: An RF module comprises: a first conductor layer and a second conductor layer disposed to face each other via a first insulating member; and an electronic component mounted on the first conductor layer and embedded in the first insulating member. The RF module is configured so that the second conductor layer is superposed on at least a part of the electronic component, and is set to a first fixed potential.

Description

  The present invention relates to an RF module and an RF module built-in multilayer wiring board.

  In recent years, electronic devices are required to have higher density and higher functionality in the trend toward higher performance and smaller size of electronic devices. From this point of view, a component built-in type multilayer wiring board in which various electronic components conventionally mounted on the surface of the multilayer wiring board are built in the multilayer wiring board has been developed and put to practical use. Such a component-embedded multilayer wiring board has a structure in which electronic components are introduced into the multilayer wiring board, and can therefore meet the demand for a smaller space and a higher density of the surface mounting portion. .

  In addition, since the component built-in type multilayer wiring board uses the inner layer portion of the multilayer wiring substrate, for example, a three-dimensional arrangement such as a structure in which a passive component is arranged immediately below the semiconductor component becomes possible. It is possible to reduce the lead inductance at the time of high-speed transmission, and there is an advantage that it is effective in optimizing the signal wiring for accommodating the operation.

  However, with the demand for higher functionality and higher speed of electronic components and higher density mounting on multi-layer wiring boards with built-in components, in particular, it receives information from external sources and sends the information to RFID Mobile devices. In an RF module applied to a transfer application, electronic components such as an inductor and a capacitor are required to be arranged closer to each other. However, the closer these electronic components are arranged, the more inductive and capacitive coupling occurs between the electronic components, causing the problem that the characteristics of these electronic components cannot be obtained stably.

  In view of such a problem, in Patent Document 1, an inductor is constituted by a plurality of vias provided so as to penetrate an insulating layer in which an electronic component is accommodated, and at least a part of each of these vias, preferably All are arranged in such a way that they are blind spots by the electronic components, and the vias are separated by the size of the electronic components, so that inductive coupling does not occur between the vias, that is, between the inductors. Technology is disclosed.

  However, in the technique described in Patent Document 1, since the inductor is configured by the via, the design freedom of the inductor is remarkably restricted, and there is a problem that an RF module having desired characteristics cannot be obtained. Also, if there is a peripheral pattern in the vicinity of the inductor, a return current is generated through the peripheral pattern, and this return current is superimposed on the electronic component as a noise component, causing a malfunction of the electronic component. There is.

JP 2009-49241 A

  The present invention suppresses noise superimposed on an electronic component and suppresses malfunction of the electronic component and further the RF module without impairing the design freedom of the RF module in an RF module incorporating the electronic component. With the goal.

  Another object of the present invention is to provide a multilayer wiring board incorporating the RF module.

In order to achieve the above object, the present invention provides:
A first conductor layer and a second conductor layer disposed opposite to each other via a first insulating member;
An electronic component mounted on the first conductor layer and embedded in the first insulating member;
The second conductor layer is related to the RF module, wherein the second conductor layer overlaps at least a part of the electronic component and is set to a first fixed potential.

The present invention also provides:
A multilayer wiring board having a plurality of wiring layers disposed so as to face each other through an insulating layer, and an interlayer connection body that electrically connects the plurality of wiring layers to each other;
The RF module mounted in the multilayer wiring board;
It is related with the multilayer wiring board with a built-in RF module characterized by comprising.

  According to the present invention, at least a portion of the second conductor layer disposed opposite to the first conductor layer on which the built-in electronic component is mounted overlaps the electronic component, and The potential is set to a fixed potential. In this case, since the second conductor layer acts as a noise absorbing layer for the electronic component, a peripheral pattern exists in the vicinity of the electronic component, a return current is generated through the peripheral pattern, and this return current is a noise component. As a result, the noise component is smoothed by the second conductor layer. Therefore, it is possible to avoid the problem of causing malfunction of the electronic component, and it is also possible to avoid malfunction of the RF module incorporating the electronic component.

  In an example of the present invention, a third conductor layer is disposed above the second conductor layer so as to cover the second conductor layer and the electronic component via the second insulating member. be able to. In this case, since the third conductor layer functions as a cover layer, that is, a shield layer, the second conductor layer and the electronic component are shielded from noise such as electromagnetic noise flowing from the outside of the RF module. Can do.

  Therefore, the above-described operational effects of the second conductor layer are not disturbed by external electromagnetic noise or the like, and the influence on the electronic component such as external electromagnetic noise can be suppressed. As a result, it is possible to avoid the problem of causing malfunction of the electronic component, and it is also possible to avoid malfunction of the RF module containing the electronic component.

  In one example of the present invention, the first terminal portion electrically connected to the first conductor layer and the second terminal set to the second fixed potential below the first conductor layer. A fourth conductor layer having a portion can be provided. In this case, a terminal of a measuring device that evaluates the characteristics of the electronic component is brought into contact with the first terminal portion and the second terminal portion, and the characteristics of the electronic component, that is, the characteristics of the RF module are measured by the measuring device. It is possible to measure and determine whether or not the characteristic is within the design range.

  Therefore, the quality of the RF module can be known before the RF module is built in the multilayer wiring board. For this reason, when the characteristics of the RF module are out of the design range, the ratio of manufacturing the RF module built-in multilayer wiring board outside the design range is reduced by preventing the RF module from being built in the multilayer wiring board. The manufacturing yield can be improved and the manufacturing cost can be reduced.

  In the present invention, the “RF module” means a module that receives information from an external transmission source and transfers the information to an RFID Mobile device, etc., and handles a high-frequency signal with a frequency of 100 MHz to 20 GHz. To do.

  Furthermore, in an example of the present invention, at least one of the first fixed potential and the second fixed potential can be a ground potential. This is because the ground potential can be easily set and can be clearly distinguished from the potential associated with a signal (signal current) flowing through another wiring layer.

  In the RF module built-in multilayer wiring board, the plurality of wiring layers include a first wiring layer for mounting the RF module, and a second conductor layer of the RF module with respect to the first wiring layer. The distance from the upper surface of the first conductor layer of the RF module to the lower surface of the second conductor layer of the RF module is t1, and the second wiring layer located on the opposite side is from the upper surface of the second wiring layer When the distance to the upper surface of the first conductor layer is t2, it is preferable to satisfy the relationship t1 <t2.

  When a signal current flows through the first wiring layer with respect to an electronic component built in the RF module, a return current associated therewith flows in a shield conductor adjacent to the first electronic component. Therefore, when the relationship of t1> t2 is satisfied, the return current flows through the second wiring layer through the first wiring layer of the RF module built-in wiring board, so that the potential becomes unstable, The effect of smoothing noise superimposed on the electronic component may be reduced. However, when the relationship t1 <t2 is satisfied, the return current flows through the second conductor layer of the RF module. Therefore, since the loop of the return current is small, the potential of the second conductor layer of the RF module is stabilized, and the above-described noise smoothing effect for the electronic component can be sufficiently exhibited.

  As described above, according to the present invention, in an RF module incorporating an electronic component, the noise superimposed on the electronic component is suppressed without impairing the design freedom of the RF module, and the electronic component, and further the malfunction of the RF module. Can be suppressed. In addition, a multilayer wiring board incorporating the RF module can be provided.

It is sectional drawing which shows schematic structure of RF module of 1st Embodiment. It is sectional drawing which shows schematic structure of the multilayer wiring board with a built-in RF module of 1st Embodiment. It is sectional drawing which shows schematic structure of RF module of 2nd Embodiment. It is sectional drawing which shows schematic structure of RF module of 2nd Embodiment.

  Hereinafter, other features and advantages of the present invention will be described based on embodiments for carrying out the invention.

(First embodiment)
FIG. 1 is a cross-sectional view showing a schematic configuration of the RF module of the present embodiment, and FIG. 2 is a cross-sectional view showing a schematic configuration of a multilayer wiring board with a built-in RF module including the RF module shown in FIG. In FIG. 1, the description of a resist layer or the like that functions as a protective layer is omitted to clarify the features of this embodiment.

  As shown in FIG. 1, the RF module 10 of the present embodiment includes a first conductor layer 11 and a second conductor layer 12 disposed so as to face each other with a first insulating member 21 interposed therebetween. In addition, the first electronic component 31 and the second electronic component 32 are provided on the first conductor layer 11 and embedded in the first insulating member 21. The second conductor layer 12 is disposed so as to cover the entire first electronic component 31 and the second electronic component 32, and is fixed to the first fixed potential.

  In the present embodiment, the second conductor layer 12 is formed so as to cover the entirety of the first electronic component 31 and the second electronic component 32. As long as the effects of the embodiment are exhibited, it is sufficient that at least a part of the second conductor layer 12 overlaps the first electronic component 31 and the second electronic component 32.

  In the present embodiment, the RF module 10 is a module that receives information from an external transmission source and is used for applications such as transferring the information to an RFID Mobile device, and handles a high-frequency signal having a frequency of 100 MHz to 20 GHz. It is.

  In the present embodiment, the number of electronic components incorporated in the RF module 10 is 2, but may be 1 or 3 or more as necessary.

  The RF module built-in multilayer wiring board 50 shown in FIG. 2 includes a first wiring layer 51, a second wiring layer 52, a third wiring layer 53, a fourth wiring layer 54, and a fifth wiring layer 55 in order from the bottom. And a sixth wiring layer 56. Each wiring layer is separated by an insulating layer 61, and is electrically connected by an interlayer connector 71 that penetrates the insulating layer 61. The first wiring layer 51 to the sixth wiring layer 56, the insulating layer 61, and the interlayer connector 71 constitute a multilayer wiring board 50A.

  In the present embodiment, the number of wiring layers is six, but can be any number as necessary.

  The RF module 10 shown in FIG. 1 is mounted on the second wiring layer 52 (the first wiring layer in the claims), so that the RF module 10 is built in the multilayer wiring board 50A. Has been implemented.

  As shown in FIG. 1, in the RF module 10 of this embodiment, the first fixing is performed so as to cover the first electronic component 31 and the second electronic component 32 mounted on the first conductor layer 11. A potential second conductor layer 12 is disposed. In this case, the second conductor layer 12 acts as a noise absorbing layer for the first electronic component 31 and the second electronic component 32.

  Therefore, there is a peripheral pattern in the vicinity of the first electronic component 31 and the second electronic component 32. Specifically, in the RF module built-in multilayer wiring substrate 50 shown in FIG. Even if the pattern 51A exists and a return current is generated via the peripheral pattern 51A, and this return current is superimposed on the first electronic component 31 and the second electronic component 32 as a noise component, the second conductor The noise component is smoothed by the layer 12.

  As a result, it is possible to avoid the problem that the first electronic component 31 and the second electronic component 32 malfunction, and the RF module 10 incorporating the first electronic component 31 and the second electronic component 32. In addition, it is possible to avoid malfunction of the RF module built-in multilayer wiring board 50 incorporating the RF module.

  The first electronic component 31 and the second electronic component 32 can be passive components such as capacitors (capacitors), inductors, thermistors, resistors, and the like.

  The second conductor layer 12 needs to be set to the first fixed potential. The first fixed potential can be set to any potential as long as the potential is fixed and stable. For example, a power supply potential or a ground potential can be used. However, when the second conductor layer 12 is fixed at the power supply potential, it is close to the potential accompanying the signal (signal current) supplied to the RF module built-in multilayer wiring board 50 including the RF module 10 including the second conductor layer 12. In some cases, the RF module built-in multilayer wiring board 50 may malfunction. Accordingly, the potential of the second conductor layer 12 is preferably set to a ground potential that is unlikely to cause the above-described malfunction.

  However, as long as the malfunction of the RF module 10 and the RF module built-in multilayer wiring substrate 50 does not occur, setting the potential of the second conductor layer 12 to the power supply potential is not excluded.

  In the RF module built-in multilayer wiring substrate 50 of the present embodiment, the first wiring layer is opposite to the second conductor layer 12 of the RF module 10 with respect to the second wiring layer 52 on which the RF module 10 is mounted. 51 (second wiring layer in claims) is disposed, and the distance from the upper surface of the first conductor layer 11 of the RF module 10 to the lower surface of the second conductor layer 12 of the RF module 10 is t1. Assuming that the distance from the upper surface of the second wiring layer 52 to the upper surface of the first conductor layer 11 is t2, the relationship t1 <t2 is satisfied.

  When a signal current flows through the first wiring layer 51 to the first electronic component 31 and the second electronic component 32 built in the RF module 10, the return current associated therewith is the first electronic component 31. And, it flows in the shield conductor adjacent to the second electronic component 32. Therefore, when the relationship of t1> t2 is satisfied, the return current flows through the second wiring layer 52 through the first wiring layer 51 of the RF module built-in wiring board 50, so that the potential is stabilized. In some cases, the effect of smoothing the noise superimposed on the first electronic component 31 and the second electronic component 32 may be reduced.

  However, when the relationship of t1 <t2 is satisfied, the return current flows through the second conductor layer 12 of the RF module 10. Therefore, since the loop of the return current is small, the potential of the second conductor layer 12 of the RF module 10 is stabilized, and the noise smoothing effect on the first electronic component 31 and the second electronic component 32 described above is sufficiently obtained. Can be demonstrated.

  In addition, the RF module 10 and the RF module built-in multilayer wiring board 50 in the present embodiment can be manufactured by appropriately using a general-purpose manufacturing method such as a subtractive method, an additive method, a semi-additive method, or the like.

(Second Embodiment)
FIG. 3 is a cross-sectional view illustrating a schematic configuration of the RF module according to the present embodiment. The first module is disposed above the second conductor layer 12 with respect to the RF module 10 according to the first embodiment illustrated in FIG. A difference is that the third wiring layer 13 is disposed so as to cover the conductor layer 12, the first electronic component 31, and the second electronic component 32. The overall configuration of the RF module built-in multilayer wiring board is similar to that of the RF module built-in multilayer wiring board 50 in the first embodiment shown in FIG. Therefore, hereinafter, the features of the RF module of the present embodiment will be described based on the above differences.

  The same reference numerals are used for the same or similar components as those shown in FIG.

  In the RF module 10 of the present embodiment, the second conductor layer 12, the first electronic component 31, and the second electronic component 32 are disposed above the second conductor layer 12 via the second insulating member 22. A third conductor layer 13 is disposed so as to cover it. In this case, since the third conductor layer 13 functions as a cover layer, that is, a shield layer, the second conductor layer 12, the first electronic component 31, and the second electronic component 32 are external to the RF module. Noises such as incoming electromagnetic wave noise can be shielded.

  Therefore, the above-described effects of the second conductor layer 12 are not disturbed by electromagnetic wave noise from the outside, and the first electronic component 31 and the second electronic component 32 such as electromagnetic wave noise from the outside are prevented. The influence can be suppressed. As a result, it is possible to avoid the problem of causing the first electronic component 31 and the second electronic component 32 to malfunction. The RF module 10 incorporating these electronic components, and further the multilayer wiring substrate 50 incorporating the RF module. Can be avoided.

  Since other features and advantages are the same as those of the RF module 10 in the second embodiment, the description thereof is omitted.

(Third embodiment)
FIG. 4 is a cross-sectional view showing a schematic configuration of the RF module in the present embodiment. The first module layer 11 is arranged below the first conductor layer 11 with respect to the RF module 10 in the first embodiment shown in FIG. A fourth conductor layer 14 having first terminal portions 14A and 14B electrically connected to the conductor layer 11 and a second terminal portion 14C set to a second fixed potential is disposed. It is different in point. The overall configuration of the RF module built-in multilayer wiring board is similar to that of the RF module built-in multilayer wiring board 50 in the first embodiment shown in FIG. Therefore, hereinafter, the features of the RF module of the present embodiment will be described based on the above differences.

  The same reference numerals are used for the same or similar components as those shown in FIGS.

  In the RF module 10 of this embodiment, the first electronic component 31 and the second electronic component 32 are disposed below the first conductor layer 11 on which the first electronic component 31 and the second electronic component 32 are mounted so as to penetrate the third insulating member 23. By the provided via (interlayer connection body) 41, the first terminal portion 14A and the second terminal portion 14B (first terminal portion in the claims) are connected via the first layer body layer 11, Each of the first electronic component 31 and the second electronic component 32 is electrically connected to the first electronic component 31 and the second electronic component 32, respectively, and is intermediate between the first terminal portion 14A and the second terminal portion 14B. The third terminal portion 14C (second terminal portion in the claims) set to the second fixed potential is disposed without being electrically connected to the electronic component 32.

  Therefore, for example, the terminal of the measuring device that evaluates the characteristics of the first electronic component 31 is brought into contact with the first terminal portion 14A and the third terminal portion 14C, and the measuring device causes the first electronic component 31 to It is possible to measure the characteristics and determine whether or not the characteristics are within the design range. Further, the terminal of the measuring device for evaluating the characteristics of the second electronic component 32 is brought into contact with the second terminal portion 14B and the third terminal portion 14C, and the characteristics of the second electronic component 32 are measured by the measuring device. It is possible to measure and determine whether or not the characteristic is within the design range.

  As a result, the quality of the RF module 10 can be known before the RF module 10 is built in the multilayer wiring board 50A. For this reason, when the characteristics of the RF module 10 are outside the design range, the ratio of manufacturing the RF module built-in multilayer wiring substrate 50 outside the design range is prevented by not incorporating the RF module 10 in the multilayer wiring substrate 50A. The manufacturing yield can be improved, and the manufacturing cost can be reduced.

  Note that the second fixed potential can be any potential as long as the potential is fixed and stable, for example, a power supply potential or a ground potential. However, when the third terminal portion 14C is fixed at the power supply potential, the signal (the RF module built-in wiring board 50 including the RF module 10 including the fourth terminal layer 14C, that is, the fourth conductor layer 14) ( There is a case in which the RF module built-in multilayer wiring board 50 malfunctions in the vicinity of the potential accompanying the signal current. Therefore, it is preferable to set the potential of the third terminal portion 14C to a ground potential that is unlikely to cause the above-described malfunction.

  However, as long as no malfunction occurs in the RF module 10 and the RF module built-in multilayer wiring board 50, setting the potential of the third terminal portion 14C to the power supply potential is not excluded.

  Since other features and advantages are the same as those of the RF module 10 in the second embodiment, the description thereof is omitted.

  The present invention has been described in detail based on the above specific examples. However, the present invention is not limited to the above specific examples, and various modifications and changes can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 RF module 11 1st conductor layer 12 2nd conductor layer 13 3rd conductor layer 14 4th conductor layer 14A 1st terminal part 14B 2nd terminal part 14C 3rd terminal part 21 1st insulation Member 22 Second insulating member 23 Third insulating member 31 First electronic component 32 Second electronic component 41 Via (interlayer connection body)
DESCRIPTION OF SYMBOLS 50 RF module built-in multilayer wiring board 50A Multilayer wiring board 51 1st wiring layer 52 2nd wiring layer 53 3rd wiring layer 54 4th wiring layer 55 5th wiring layer 56 6th wiring layer 61 Insulating layer 71 Interlayer connection

Claims (6)

A first conductor layer and a second conductor layer disposed opposite to each other via a first insulating member;
An electronic component mounted on the first conductor layer and embedded in the first insulating member;
The RF module, wherein the second conductor layer overlaps at least a part of the electronic component and is set to a first fixed potential.   A third conductor layer is provided above the second conductor layer so as to cover the second conductor layer and the electronic component via a second insulating member. The RF module according to claim 1.   A fourth terminal having a first terminal portion electrically connected to the first conductor layer and a second terminal portion set to a second fixed potential below the first conductor layer. The RF module according to claim 1, further comprising a conductor layer.   The RF module according to claim 1, wherein at least one of the first fixed potential and the second fixed potential is a ground potential. A multilayer wiring board having a plurality of wiring layers disposed so as to face each other through an insulating layer, and an interlayer connection body that electrically connects the plurality of wiring layers to each other;
The RF module according to any one of claims 1 to 4, which is mounted in the multilayer wiring board,
A multilayer wiring board with a built-in RF module, comprising:   The plurality of wiring layers are a first wiring layer for mounting the RF module, and a second wiring layer located on the opposite side of the first wiring layer from the second conductor layer. The distance from the upper surface of the first conductor layer of the RF module to the lower surface of the second conductor layer is t1, and the first conductor layer from the upper surface of the second wiring layer. 6. The multilayer wiring board with built-in RF module according to claim 5, wherein a relationship of t1 <t2 is satisfied, where t2 is a distance to the lower surface of the RF module.

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