JP5574161B2 - Multi-communication module - Google Patents

Description

  The present invention relates to a multi-communication module, and more particularly to a structure of a ground electrode applied to a module having a plurality of communication functions such as Cellular, WLAN, Bluetooth, FM communication, and GPS.

  In electronic devices having communication functions such as mobile phones, smartphones, mobile PCs, etc., with the advancement of high functionality and multi-function, for example, multiple types such as Cellular (cell phone), WLAN (wireless LAN), Bluetooth, FM communication, GPS, etc. It is becoming common to provide a communication function.

  In order to mount a plurality of types of communication functions in such an electronic device, a plurality of communication modules having a single communication function are separately incorporated in the device, or a communication module configured as a composite module having a plurality of communication functions. Is incorporated into the equipment. In addition, when multiple types of communication functions are provided in this way, each communication function unit may be mounted as it is without taking any special measures, but in order to prevent mutual interference, isolation between each communication function unit is required. Circuit elements to be secured may be provided.

  Further, there is the following patent document that discloses a technique related to a module including a plurality of functional units.

JP 2004-119598 A Japanese Patent Laid-Open No. 2007-150566

  By the way, when an electronic device is provided with a plurality of types of communication functions, the mounting area is inevitably increased according to a method of simply incorporating individual communication modules provided as separate components as in the past. It is difficult to meet the demand for downsizing. Further, when two or more communication functions are used at the same time, there is a problem that the mutual communication characteristics deteriorate due to mutual interference.

  On the other hand, in order to prevent such characteristic deterioration, a matching circuit may be provided between the communication function units. However, providing such a circuit separately causes an increase in the number of parts and the number of manufacturing processes, which causes an increase in manufacturing cost. In addition, there is a difficulty in increasing the size of the electronic device.

  On the other hand, the technique described in the above-mentioned patent document, in particular, Patent Document 1 (Japanese Patent Laid-Open No. 2004-119598) devise a multilayer substrate mounting structure for the purpose of stabilizing the potential of a plurality of functional groups and preventing mutual interference of noise. It is. However, the technique described in this document is not intended for interference among a plurality of types of communication functions, and there is room for further improvement in terms of more effectively preventing mutual interference.

  Therefore, an object of the present invention is to suppress interference between a plurality of types of communication functions mounted on a module without separately providing circuits and components, and to improve the communication characteristics of the module.

  In order to solve the above-described problems and achieve the object, a multi-communication module according to the present invention is mounted on a multilayer substrate having one or more internal wiring layers and the surface of the multilayer substrate to realize a specific type of communication function. At least one of a multi-function IC having two or more communication function units mounted thereon, a front surface wiring layer that is the surface of the multilayer substrate, the one or more internal wiring layers, and a back surface wiring layer that is the back surface of the multilayer substrate A multi-communication module including a ground electrode disposed on each of one or more wiring layers including an internal wiring layer including at least one layer, wherein the multi-function IC is mounted on a surface of the multilayer substrate; When one of the two or more communication function units of the multi-function IC is arranged in each of two or more regions when the device is viewed from the plane, two or more are provided in the multi-communication module. One or more on the side closer to the surface of the multilayer substrate in the stacking direction, including the ground electrode located in the uppermost layer, when the communication functional component placement region is formed and the top surface side of the multilayer substrate is the upper layer and the back surface side is the lower layer The ground electrodes were divided grounds corresponding to the communication functional component placement regions when viewed from the plane.

  In the multi-communication module according to the present invention, a multi-function IC is mounted on the surface of a multilayer substrate to provide a plurality of types of communication functions in a single module. This multi-function IC, for example, realizes two or more types of communication functions using specific frequency bands such as Cellular communication (mobile phone or PHS), WLAN (wireless LAN), Bluetooth, FM communication, GPS, etc. Two or more communication function units including a circuit for realizing each communication function are provided. Note that the types and combinations of the communication functions mounted on the multi-function IC are not particularly limited, and the multi-function can be selected by appropriately selecting two or three or more of the above-exemplified or various types of communication functions. It is possible to configure the module of the present invention in an IC. In the following description, the multi-communication module may be simply referred to as “module”, and the multi-function IC may be simply referred to as “IC”.

  On the other hand, the multilayer substrate on which the multi-function IC is mounted has one or more internal wiring layers in addition to the substrate surface (surface wiring layer) and the substrate back surface (back surface wiring layer). When one of two or more communication function units included in the multi-function IC is arranged in each of two or more areas when viewed from above, two or more communication function component arrangement areas are formed in the module. To do. The communication functional component placement region is not necessarily limited to the front surface of the multilayer substrate, but is a concept including the inside (internal wiring layer) and the back surface (back wiring layer) of the multilayer substrate. The communication function part, which is a part of the IC, is arranged on the surface of the substrate, but if necessary, circuit elements and terminal electrodes may be provided. It is also possible to do.

  In the communication function component placement area (front wiring layer, internal wiring layer, or back wiring layer), in addition to the communication function unit that is a part of the IC, various components and circuit components for realizing each communication function For example, chip components, connection pads, conductor lines, circuit elements, and the like may be arranged as necessary (these can also be arranged in the internal wiring layer as described above). The entire component / element / circuit element group for realizing the communication function including the communication function unit included in the IC and these components, elements, and circuit elements is referred to as a “communication function block”. In the present application, the front surface wiring layer (the surface of the multilayer substrate), the internal wiring layer, and the back surface wiring layer are collectively referred to as a “wiring layer”.

  The multilayer substrate is provided with a ground electrode in one or more wiring layers including at least one internal wiring layer among the wiring layers (front wiring layer, internal wiring layer and back wiring layer). Then, one or more ground electrodes on the side close to the surface of the multilayer substrate in the stacking direction, including the ground electrode located in the uppermost layer, are divided corresponding to the communication functional component placement region when viewed from the plane. To form. Note that the ground electrode divided in accordance with the communication functional component arrangement region in this way is referred to as “divided ground”. In other words, the divided ground can be said to be a ground electrode formed so as not to extend over two or more communication function component arrangement regions when viewed from the plane.

  In the present invention, the ground electrode is divided in this way in order to prevent interference between communication functions when two or more communication functions are operated simultaneously. That is, if the ground electrodes are divided in accordance with the communication functional component arrangement areas in this way (if the ground electrodes are formed so as not to extend across a plurality of communication functional component arrangement areas), two or more communications Even if the functions are operated simultaneously, the leakage current or the return current to the ground penetrates from one communication function block to another communication function block (to the adjacent communication function block) through the ground electrode. Can be prevented from occurring. In order to prevent such interference, it is particularly effective to divide one or more ground electrodes located on the upper layer closer to the IC mounted on the substrate surface and including the active element as in the present invention.

  A specific example is as follows. The multilayer substrate has, for example, six wiring layers including the front and back surfaces, and the front surface (surface wiring layer) of the multilayer substrate is defined as a first layer. Hereinafter, the second layer, the third layer, It is assumed that ground electrodes are provided in the first to sixth layers as the fourth layer, the fifth layer (the second to fifth layers are internal wiring layers), and the sixth layer (back wiring layer). In this case, for example, if the ground electrodes of the first layer and the second layer, the ground electrodes from the first layer to the third layer, or the ground electrodes from the first layer to the fourth layer or the fifth layer are divided grounds. good. In addition, all the ground electrodes (in this example, the first to sixth layer ground electrodes) provided in the multilayer substrate can be divided grounds.

  On the other hand, in the module of the present invention, not the divided ground as described above, but a ground electrode that extends over two or more of the communication functional component placement regions, such as a ground electrode that extends over substantially the entire surface of the wiring layer (hereinafter referred to as a ground electrode). Of course, such a ground electrode may be referred to as a “solid ground”. In this case, ground electrodes are provided in two or more wiring layers of the multilayer substrate, of which the upper layer side is a divided ground and the lower layer side is a solid ground.

  For example, in one embodiment of the present invention, each of two or more wiring layers including at least one internal wiring layer of the front surface wiring layer, the internal wiring layer, and the back surface wiring layer includes a ground electrode, and is positioned in the uppermost layer. One or more ground electrodes on the side close to the surface of the multilayer substrate with respect to the stacking direction, including the ground electrode to be split, are divided and grounded on the side close to the back surface of the multilayer substrate with respect to the stacking direction. One or more ground electrodes are defined as a solid ground.

  In another aspect of the present invention focusing only on the internal wiring layer, the multilayer substrate has one or more (or two or more) internal wiring layers, and one or more (or two or more) internal wirings. One or more (or 2) on the side close to the surface of the multilayer substrate in the stacking direction, including a ground electrode in one or more (or two or more) of the layers and including the ground electrode located in the uppermost layer among the ground electrodes The ground electrode of the layer or more) is divided and grounded. In this embodiment as well, a ground electrode may be provided on the surface wiring layer. In this case, the ground electrode of the surface wiring layer is also a divided ground.

Furthermore, in the module of the present invention , each of two or more wiring layers including at least one internal wiring layer among the front wiring layer, the one or more internal wiring layers, and the back wiring layer is provided with a divided ground. placing the high-frequency transmission line between the split ground. By arranging the high-frequency transmission line between the divided grounds separated for each communication function in this way, it is possible to prevent interference between the communication functions when two or more communication functions are operated simultaneously. Needless to say, the high-frequency transmission line and the divided ground sandwiching the high-frequency transmission line have the same communication function (belong to the same communication function block).

  In the present invention, the type of the multilayer substrate is not particularly limited. For example, a resin substrate can be used, or a ceramic substrate such as an LTCC (low temperature co-fired ceramic) substrate can be used. In addition, various multilayer substrates such as a substrate made of a composite material in which an inorganic filler is mixed into a resin may be used.

  The multi-function IC can also be mounted by wire bonding, but the IC is preferably mounted by flip-chip mounting by so-called face-down in order to reduce the size and thickness of the module. In addition, the back wiring layer, which is the back surface of the multilayer substrate, can be provided with terminals (signal terminals, ground terminals, and the like) for connecting the communication module to a motherboard or the like of the electronic device.

  An electronic device according to the present invention includes any of the multi-communication modules according to the present invention. Examples of the electronic device include a mobile phone, a smartphone, a personal computer, a PDA (Personal Digital Assistant), Electronic devices having various communication functions such as game machines are included. Note that it does not matter whether the electronic device is a portable device or a stationary device.

  According to the multi-communication module of the present invention, it is possible to reduce interference between a plurality of types of communication functions mounted on the module without separately providing circuits and components, and to obtain good communication characteristics.

  Other objects, features, and advantages of the present invention will become apparent from the following description of embodiments of the present invention described with reference to the drawings. In addition, in each figure, the same code | symbol shows the same or an equivalent part.

FIG. 1A is a plan view schematically showing a multi-communication module (first layer / substrate surface of a multilayer substrate) according to an embodiment of the present invention. FIG. 1B is a plan view schematically showing the multi-communication module (second layer of the multilayer substrate) according to the embodiment. FIG. 1C is a plan view schematically showing the multi-communication module (the third layer of the multilayer substrate) according to the embodiment. FIG. 1D is a plan view schematically showing the multi-communication module (sixth layer of multilayer board / back of board) according to the embodiment. FIG. 2 is a diagram schematically showing a cross-sectional structure of the multi-communication module according to the embodiment. FIG. 3 is a diagram schematically showing another cross-sectional structure of the multi-communication module according to the embodiment. FIG. 4 is a diagram showing electrical characteristics (frequency-SN ratio) of the FM communication unit in the multi-communication module of the embodiment. FIG. 5 is a diagram showing electrical characteristics (frequency-SN ratio) of the FM communication unit in the multi-communication module of the comparative example. FIG. 6 is a diagram showing electrical characteristics (frequency-SN ratio) of the FM communication unit in the multi-communication module of the embodiment. FIG. 7 is a diagram showing electrical characteristics (frequency-SN ratio) of the FM communication unit in the multi-communication module of the comparative example.

  As shown in FIG. 1A to FIG. 1D and FIG. 2, a multi-communication module 11 according to an embodiment of the present invention has a multi-function IC 21 mounted on the surface of a substrate 12, and the multi-function IC 21 includes a plurality of types of multi-function ICs 21. A circuit for realizing a communication function is provided. Specifically, the IC 21 includes a first communication function unit (circuit for realizing the first communication function) 21a and a second communication function unit (circuit for realizing the second communication function) 21b. And a third communication function unit (circuit for realizing a third communication function) 21c. These first to third communication functions 21a to 21c are respectively a wireless LAN communication function, Bluetooth communication function and FM communication function.

  On the other hand, the substrate 12 includes six wiring layers 12a to 12f including the front surface and the back surface of the substrate 12. The substrate surface 12a is a first layer, and the four internal wiring layers 12b to 12e are a second layer in order from the upper layer. When the third layer, the fourth layer, the fifth layer, and the back surface 12f of the substrate are the sixth layer, the wiring layers 12a, 12b, 12c of the first layer to the third layer are provided with the divided ground 41a (41b, 41c). The fourth to sixth wiring layers 12d, 12e, and 12f are provided with a solid ground 41d. The solid ground 41d does not necessarily mean only an electrode formed so as to spread over substantially the entire surface of the wiring layer like the ground electrode on the back surface 12f of the substrate shown in FIG. 1D (sixth layer). It means the ground electrode formed so as to straddle the above communication functional component arrangement region.

  In addition, as shown in FIG. 1A, the substrate (module) is divided into three areas when viewed from above, and a circuit for realizing the first communication function (wireless LAN communication) is arranged in the first area. A first communication function component placement region 31a for performing the second communication function component placement region 31b for placing a circuit for realizing the second communication function (Bluetooth communication). The area is a third communication functional component arrangement area 31c for arranging a circuit for realizing the third communication function (FM communication).

  Then, the first to third areas 31a to 31c, that is, the first communication functional component arrangement area 31a, the second communication functional component arrangement area 31b, and the third communication functional component arrangement area 31c, respectively, The IC 21 is mounted on the substrate surface 12a so that the one communication function unit 21a, the second communication function unit 21b, and the third communication function unit 21c are arranged. The IC 21 is mounted by face-downing the flip chip and electrically connecting the connection pads provided on the substrate surface 12a via metal bumps.

  In addition, in addition to the communication function units 21a to 21c included in the IC 21, the chip components 22a to 22c are surface-mounted on the first layer of the communication function component arrangement regions 31a to 31c on the first surface. Further, circuit elements (not shown) for realizing each communication function may be appropriately incorporated in each of the internal wiring layers 12b to 12e from the second layer to the fifth layer. Then, the first communication function (wireless LAN communication) is realized in the first communication function component arrangement region 31a by the communication function units 21a to 21c, the chip components 22a to 22c and the circuit elements with built-in circuit boards of the IC 21. One communication function block, a second communication function block for realizing the second communication function (Bluetooth communication) in the second communication function component arrangement area 31b, and a third communication function (FM in the third communication function parts arrangement area 31c). 3rd communication functional block which implement | achieves (communication) is each comprised.

  Furthermore, as described above, the ground electrodes provided on the first to third wiring layers 12a to 12c are divided grounds 41a, 41b, and 41c on the substrate 12, and the fourth to sixth wiring layers 12d. The ground electrodes provided in ˜12f are solid grounds 41d. The divided grounds 41a, 41b, 41c provided in the upper layer of the substrate are dedicated ground electrodes (hereinafter referred to as individual grounds included in the divided grounds) used in each communication function block. The electrodes are referred to as “divided ground electrodes”), and are sized and shaped so that they can be accommodated in the communication functional component placement regions 31a, 31b, 31c when viewed from above (see FIGS. 1B and 1C). The communication functional component placement areas 31a, 31b, 31c are formed so as not to reach (enter).

  More specifically, for example, the divided ground electrode 41a connected to the circuit of the first communication function block is formed in the second communication function component placement region 31b and the third communication function component placement region 31c when viewed from the plane. The size and shape will not reach the maximum. The divided ground electrode 41a typically has a size, a shape, and an arrangement that can be accommodated in the first communication functional component arrangement area 31a. However, the divided ground electrode 41a does not necessarily need to be accommodated in the communication functional part arrangement area 31a. As long as it does not enter the second communication function component placement region 31b and the third communication function component placement region 31c, it may protrude from the first communication function component placement region 31a. In short, the divided ground electrodes 41a, 41b and 41c are ground electrodes formed so as not to straddle two or more communication function component arrangement regions 31a, 31b and 31c. The same applies to the divided ground electrode 41b connected to the circuit of the second communication functional block and the divided ground electrode 41c connected to the circuit of the third communication functional block.

  On the other hand, the ground electrode 41d under the substrate is a solid ground common to the first to third communication function blocks, and is connected to the circuits of the first to third communication function blocks. The divided ground electrodes 41a, 41b, 41c and the solid ground 41d of the internal wiring layer are electrically connected to the solid ground 41d on the back surface 12f of the substrate by a via 10 extending in the stacking direction of the substrate 12. Further, as shown in FIG. 1D, the back surface wiring layer 12f includes a connection terminal (signal terminal and ground terminal) 13 for electrically connecting the module 11 to a motherboard of the electronic device.

  Further, in the present embodiment, when the high-frequency transmission line belonging to each communication function block (which constitutes each communication function block) is arranged in the substrate, each communication function component arrangement region 31a, 31b, It is desirable to arrange the high-frequency transmission line 14 so as to be sandwiched between the divided ground electrodes 41a and 41a (or the divided ground electrodes 41b and 41b or the divided ground electrodes 41c and 41c) arranged vertically in the 31c. This is because the high frequency transmission line 14 is arranged between the divided ground electrodes 41a, 41b, and 41c separated for each communication function block instead of the common solid ground 41d, thereby preventing interference between the communication function blocks. Moreover, by dividing the ground not only for high-frequency transmission lines but also for audible frequency lines typified by FM, it becomes possible to prevent noise generated via ground from other communication function blocks. . In addition, the divided ground can prevent the clock signal line from leaking to other communication function blocks via the ground, and can prevent the occurrence of clock-specific high-order spurious.

  As described above, according to the multi-communication module of the present invention or the above-described embodiment, even if two or more types (three types in the embodiment) of communication functions are mounted on one substrate 12, each communication function is blocked (module). The communication function block is formed by arranging circuit components for realizing each communication function together in one place when viewed from the plane), that is, communication function component arrangement areas 31a and 31b when viewed from the plane. , 31c are arranged so that each communication function is separately provided, and the ground electrodes 41a, 41b, 41c on the upper layer portion of the board are formed so as to be divided for each communication function component arrangement region 31a, 31b, 31c. Therefore, leakage current or return current to ground is unlikely to enter other adjacent communication function blocks (see the dashed line in FIG. 2), and communication It is possible to prevent interference between functional blocks. 2 indicates the flow of current from each communication functional block to the ground electrode.

  FIGS. 4 to 7 show measurement results for confirming the effects of the present invention. FIG. 4 shows a module based on the above embodiment (the grounds of the first layer and the second layer are divided grounds, and the other layers are solid). FIG. 5 shows the electric characteristics of the FM communication unit when all the grounds from the first layer to the sixth layer are solid grounds as a comparative example. The characteristic (frequency-SN ratio) is shown. In these drawings, the thin line indicates the characteristic when only the FM communication unit is operated, and the thick line indicates the characteristic when the WLAN communication unit and the FM communication unit are operated simultaneously.

  As is clear from these figures, when the present invention is applied (FIG. 4), the WLAN communication function and the FM communication function are operated simultaneously as compared with the comparative example (FIG. 5) to which the present invention is not applied. It can be seen that the characteristic deterioration (decrease in the SN ratio) can be further reduced.

  Further, FIGS. 6 and 7 similarly illustrate the module according to the embodiment (the first layer and the second layer are divided grounds and the other layers are solid grounds), and the first to sixth layers as comparative examples. The electrical characteristics (frequency-to-SNR) of the comparative example of the comparative example in which all of the grounds are solid grounds are shown. In these figures, the thin line shows the characteristics when only the FM communication part is operated. The thick lines indicate the characteristics when the Bluetooth communication unit and the FM communication unit are operated simultaneously.

  As is clear from these figures, when the present invention is applied (FIG. 6), the WLAN communication function and the FM communication function are simultaneously operated as compared with the comparative example (FIG. 7) to which the present invention is not applied. It can be seen that the characteristic deterioration (decrease in the SN ratio) can be further reduced.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to these, It is clear to those skilled in the art that a various change can be made within the range as described in a claim. .

  For example, in the embodiment, a multilayer substrate having six wiring layers is used, but the number of wiring layers of the multilayer substrate is, for example, three layers (one each for a front surface wiring layer, an internal wiring layer, and a back surface wiring layer). ) To 5 layers (surface wiring layer, 3 or more internal wiring layers, and back wiring layer) or 7 layers or more (surface wiring layer, 5 or more internal wiring layers, and back wiring layer) It may be.

  Moreover, in the said embodiment, although each function of wireless LAN, Bluetooth, and FM communication shall be provided, it may be provided with communication functions other than these, and it has a combination of communication functions other than these. There may be. Furthermore, as long as one or more ground electrodes including the uppermost layer are used as the divided ground, the number and shape of the ground electrodes, the number of layers to be arranged, and the like are not particularly limited. Any number of wiring layers may be arranged.

10 via hole 11 multi-communication module 12 multilayer substrate 12a first layer of multilayer substrate (surface wiring layer)
12b Second layer of multilayer substrate (internal wiring layer)
12c 3rd layer of multilayer substrate (internal wiring layer)
12d Fourth layer of multilayer substrate (internal wiring layer)
12e 5th layer of multilayer substrate (internal wiring layer)
12f 6th layer of multilayer board (backside wiring layer)
13 Connection Terminal 14 High Frequency Transmission Line 21 Multifunctional IC
21a First communication function unit (wireless LAN communication function unit)
21b Second communication function part 21c Third communication function part 22a, 22b, 22c Chip part 31a First communication function part placement area 31b Second communication function part placement area 31c Third communication function part placement area 41a, 41b, 41c Ground electrode (Split ground electrode)
41d Ground electrode (solid ground)

Claims (4)

A multilayer substrate having one or more internal wiring layers;
A multi-function IC that is mounted on the surface of the multilayer substrate and has two or more communication function units for realizing a specific type of communication function;
One or more wiring layers including at least one internal wiring layer among a surface wiring layer that is the surface of the multilayer substrate, the one or more internal wiring layers, and a back wiring layer that is the back surface of the multilayer substrate A ground electrode disposed on each of the
With
While mounting the multi-function IC on the surface of the multilayer substrate,
By disposing one of the two or more communication function units of the multi-function IC in each of two or more regions when the multi-layer substrate is viewed from a plane, two or more of the multi-communication module is provided in the multi-communication module. Form communication functional component placement area,
When the front side of the multilayer substrate is the upper layer and the back side is the lower layer,
One or more ground electrodes on the side close to the surface of the multilayer substrate in the stacking direction, including the ground electrode located in the uppermost layer, and divided ground corresponding to the communication functional component placement region when viewed from a plane; A multi-communication module,
Two or more wiring layers including at least one internal wiring layer among the surface wiring layer that is the surface of the multilayer substrate, the one or more internal wiring layers, and the back wiring layer that is the back surface of the multilayer substrate Each of which includes the split ground,
Arrange the high-frequency transmission line to be sandwiched between these divided grounds ,
The multi-communication module, wherein the high-frequency transmission line and the divided ground sandwiching the high-frequency transmission line realize a communication function by the communication function unit in relation to the same communication function unit . Two or more wiring layers including at least one internal wiring layer among the surface wiring layer that is the surface of the multilayer substrate, the one or more internal wiring layers, and the back wiring layer that is the back surface of the multilayer substrate Each has a ground electrode,
One or more ground electrodes on the side close to the surface of the multilayer substrate with respect to the stacking direction, including the ground electrode positioned at the uppermost layer, are divided ground corresponding to the communication functional component placement region when viewed from a plane. on the other hand,
One or more ground electrodes on the side close to the back surface of the multilayer substrate in the stacking direction, including the ground electrode located in the lowermost layer, are solid grounds extending over two or more of the communication functional component placement region. The multi-communication module according to claim 1. 3. The multi-communication module according to claim 1, wherein one or more chip components for realizing each communication function are further mounted on the surface of the multilayer substrate and in each of the communication function component arrangement regions. An electronic apparatus comprising the multi-communication module according to any one of claims 1 to 3.

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