JP2012165329A - Communication module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna integrated communication module which easily reduces the size and the thickness and is manufactured at low cost.SOLUTION: A communication module 1 having a substantially rectangular parallelepiped shape includes: a surface mounted circuit board 2; a resin sealing material 4 sealing electronic components 3 mounted on the circuit board 2; a radiation conductor (radiation element) 5 and a shield conductor 8 which are formed by a conductive layer 12 adhered to an outer surface of the resin sealing material 4; and a power feeding line 7. The radiation conductor 5 and a horizontal part 7a of the power feeding line 7 are printed on a top plate 4a of the resin sealing material 4. A vertical part 7b of the power feeding line 7 is formed by providing a cut-off part 13 on the conductive layer 12 located on side surfaces of the resin sealing material 4 and the circuit board 2 by trimming processing. The vertical part 7b extends to a position that covers a power feeding electrode 6 exposed on the side surface of the circuit board 2 and connects with the electrode 6.

Description

  The present invention relates to an antenna-integrated communication module suitable for use in, for example, a wireless LAN.

  An antenna-integrated communication module used in a wireless LAN or the like includes a circuit board on which electronic components such as an RF circuit are mounted, and a sheet metal shield cover that covers the component mounting surface of the circuit board. In the related art, an opening provided in the portion is configured to operate as a radiating element of a slot antenna.

  In recent years, in this type of communication module, there is a tendency to reduce the thickness, and it is desired to make the shield cover as thin as possible. However, if the shield cover is formed using a thin metal plate (for example, about 0.1 mm thick), the shield cover having the opening is likely to be warped or distorted, so the shield cover is held. The holder member to be used is required and the cost is inevitably increased, or the shape of the opening (slot shape) is restricted, and the antenna performance must be sacrificed.

  Therefore, conventionally, an antenna-integrated communication module has been proposed in which a sheet conductor shield cover is omitted by performing a metallization process such as plating to form a shield conductor corresponding to the shield cover (see, for example, Patent Document 1). ). In such a conventional example, electroless plating and electrolytic plating are performed on the outer surface of a multilayer substrate (base body) provided with a cavity for housing electronic components and the outer surface of a resin sealing material that seals the cavity. The shield conductor is formed. Also, the top surface of the multilayer board is provided with an area of a predetermined shape without a shield conductor, and power is fed from a strip line provided in the multilayer board so that this area operates as a radiating element of the slot antenna. It has become. In addition to the stripline, various wiring patterns and ground conductor patterns are provided in the multilayer substrate.

  The antenna-integrated communication module in which the shield conductor is formed by metallization processing such as plating as in the conventional example, the shield conductor is much thinner than the shield cover made of sheet metal. It is advantageous. In addition, the shield conductor is not likely to be deformed like a shield cover made of sheet metal, and a radiating element can be provided with high positional accuracy. Therefore, a communication module having stable antenna performance is easily mass-produced.

JP 2004-15160 A

  However, in the conventional antenna-integrated communication module in which the shield conductor is provided by metallization processing, the planar size and thickness dimension of this multilayer substrate are provided because the feeder line such as a strip line is provided in the multilayer substrate. Is not easy to set small. Therefore, when trying to promote downsizing and thinning of the entire module, it becomes impossible to manufacture easily, resulting in an increase in manufacturing cost.

  The present invention has been made in view of the actual situation of the prior art, and an object thereof is to provide an antenna-integrated communication module that can be easily reduced in size and thickness and can be manufactured at low cost.

  To achieve the above object, the present invention provides a circuit board to be surface-mounted, an electronic component mounted on the circuit board, and a resin sealing material that covers the circuit board including the electronic component. And a communication layer provided at least on the outer surface of the resin sealing material, and a communication element having a substantially rectangular parallelepiped shape in which an antenna radiation element is formed using the conductive layer existing on the top surface of the resin sealing material. In the module, the conductive layer existing on a predetermined side surface of the resin sealing material extends to a position where it covers the power supply electrode exposed on the side surface of the circuit board that is flush with the side surface. By providing the cut portions of the conductive layer on both side surfaces, a feed line that is electrically connected to the radiation element and the feed electrode is formed.

  In this way, the conductive layer provided on the outer surface of the resin sealing material is partially cut to form a power supply line, and when this power supply line is connected to the power supply electrode on the side surface of the circuit board, Since there is no need to install a power supply line, the space factor is improved, and the communication module can be easily reduced in size and thickness. In addition, since the conductive layer provided on the outer surface can be easily cut into a desired shape by laser trimming or the like, a power supply line with high dimensional accuracy can be efficiently formed.

  In the above configuration, the conductive layer existing on the top surface of the resin sealing material is formed by printing the conductive paste, and the conductive layer is formed on the side surface by the conductive paste deposited on the side surface of the resin sealing material. In a manufacturing process in which a large-sized substrate provided with a resin sealing material is divided (breaked) into lattice-shaped dividing grooves to obtain a large number of communication modules, a conductive paste applied to the top surface of the resin sealing material is applied. By entering the dividing groove, the conductive layer can be formed collectively on the top and side surfaces of the resin sealing material. Therefore, the communication module can be easily manufactured and the manufacturing cost can be reduced. In this case, if the conductive layer existing on the top surface of the resin sealing material is trimmed, a radiation element having a desired shape can be easily formed.

  In the above configuration, when the conductive layer on the side surface of the resin sealing material is connected to the ground conductor pattern provided on the circuit board at a location different from the power supply line, this conductive layer is used as a shield conductor. This is preferable because it can function. In this case, if the power supply electrode and the ground conductor pattern are provided in the inner layer of the circuit board, the component mounting surface of the circuit board is likely to be reduced in area, and thus the communication module can be further reduced in size.

  In the communication module having the above configuration, the type of antenna can be selected as appropriate. For example, at least a part of the conductive layer existing on the top surface of the resin sealing material can be used as a radiation conductor (radiating element) of the patch antenna. In that case, it is possible to reduce the size of the multi-resonance antenna or the broadband antenna by providing a plurality of radiation conductors. That is, as the radiation conductor of the patch antenna, the first radiation conductor provided on the top surface of the resin sealing material and the second radiation conductor provided on the insulating resin layer covering the first radiation conductor are provided. If the first radiating conductor has a larger diameter than the second radiating conductor, a small communication module including a patch antenna that can resonate in two high and low frequency bands can be obtained.

  The antenna-integrated communication module according to the present invention forms a power supply line by partially cutting away the conductive layer provided on the outer surface of the resin sealing material by printing or the like, and this power supply line is used for power supply on the side surface of the circuit board. Since it is connected to the electrode, it is not necessary to provide a power supply line in the circuit board, and miniaturization and thinning are easily promoted. In addition, this communication module is suitable for mass production because it is easy to cut a conductive layer provided on the outer surface into a desired shape by laser trimming or the like, and a power supply line with high dimensional accuracy can be efficiently formed. This makes it easy to reduce manufacturing costs.

1 is an external view of a communication module according to a first exemplary embodiment of the present invention. It is sectional drawing of the communication module shown in FIG. It is process drawing for demonstrating the manufacturing method of the communication module shown in FIG. It is an external view of the communication module which concerns on the 2nd Example of this invention. It is a side view which shows a communication module concerning a 3rd example of an embodiment of the present invention, and shows a section. It is process drawing for demonstrating the manufacturing method of the communication module shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. First, the communication module 1 and the manufacturing method thereof according to the first embodiment of the present invention will be described with reference to FIGS.

  A communication module 1 shown in FIGS. 1 and 2 is an antenna-integrated communication module that has an approximately rectangular parallelepiped shape and is used for a wireless LAN or the like. The communication module 1 includes a circuit board 2 surface-mounted on a mother board (not shown), a plurality of electronic components 3 mounted on the circuit board 2, and a resin seal provided on the circuit board 2 by a transfer molding method. A material 4, a radiation conductor 5 provided on the top surface 4a of the resin sealing material 4, a power supply line 7 extending from a power supply portion of the radiation conductor 5 and connected to the power supply electrode 6 of the circuit board 2, and a resin It is mainly composed of the sealing material 4 and the shield conductor 8 provided on the side surface of the circuit board 2. However, the radiation conductor 5, the feed line 7, and the shield conductor 8 are formed as different regions of the conductive layer 12 provided on the outer surface of the resin sealing material 4.

  The circuit board 2 is a multilayer board made of FR4 or the like, and the power supply electrode 6 and the ground conductor pattern 9 provided in the inner layer are exposed on the side surface of the circuit board 2 (see FIG. 2). As shown in FIG. 3E, the circuit board 2 is a piece obtained by dividing the large substrate 10 with the dividing grooves 11. By forming the dividing grooves 11 on the large substrate 10, The feeding electrode 6 and the ground conductor pattern 9 are exposed on the inner wall surface (side surface of the circuit board 2).

  The resin sealing material 4 is made of an epoxy resin or the like and seals the electronic component 3 on the circuit board 2. The outer shape of the resin sealing material 4 is a rectangular parallelepiped shape, and the size of the resin sealing material 4 is equivalent to that of the circuit board 2 in plan view. That is, the resin sealing material 4 covers the component mounting surface of the circuit board 2 including the electronic component 3.

  The radiation conductor 5 is formed as a radiation element of a patch antenna. Although this radiating conductor 5 is patterned in a substantially circular shape, as shown by a two-dot chain line T in FIG. 1, a part of the radiating conductor 5 (for example, a part on the outer peripheral side of the two-dot chain line T in order to adjust the resonance frequency). ) May be laser trimmed.

  The power supply line 7 is formed in an L shape extending from the top surface 4 a of the resin sealing material 4 to one side surface. The radiation conductor 5 present on the top surface 4a of the resin sealing material 4 and the horizontal portion 7a of the feed line 7 are screen-printed as a print pattern. In contrast, the resin sealant 4 and the vertical portion 7b of the power supply line 7 on one side surface of the circuit board 2 are formed by laser trimming the conductive layer 12 on the side surface instead of the printed pattern. That is, in this embodiment, as will be described later, the conductive paste is applied to the side surfaces of the resin sealing material 4 and the circuit board 2 by squeezing when the radiation conductor 5 and the horizontal portion 7a are screen-printed. In order to make the portion of the conductive layer 12 provided on the side surface continuous with the horizontal portion 7a of the feed line 7 as the vertical portion 7b, a cut portion 13 as shown in FIG. 1 is formed by laser trimming. Further, the remaining conductive layer 12 existing on the side surface of the resin sealing material 4 and the circuit board 2 becomes a shield conductor 8, and this shield conductor 8 is separated from the vertical portion 7 b through the cut portion 13.

  As shown in FIG. 2, the vertical portion 7b of the power supply line 7 formed in this way extends to a position where it covers the power supply electrode 6 exposed on one side surface of the circuit board 2. The vertical portion 7 b is in close contact with the power supply electrode 6 and connected to the electrode 6. Therefore, a power supply signal can be supplied to the power supply portion of the radiation conductor 5 through the power supply line 7. Further, since the shield conductor 8 is connected to the ground conductor pattern 9 exposed on the other side surface of the circuit board 2, the electronic component 3 can be electromagnetically shielded by the shield conductor 8.

  Next, a method for manufacturing the communication module 1 configured as described above will be described. First, as shown in FIG. 3A, a large substrate 10 that is a base material of the circuit substrate 2 is prepared. A wiring pattern including a power supply electrode 6, a ground conductor pattern 9, and the like are provided on the large substrate 10 in advance.

  As the next step, as shown in FIG. 3B, each electronic component 3 is mounted on the component mounting surface of the large substrate 10. Then, as shown in FIG. 3C, a resin sealing material 4 having a required thickness is laminated and fixed on the component mounting surface of the large substrate 10 by a transfer molding method. 3 is sealed.

  As the next step, as shown in FIG. 3D, lattice-shaped dividing grooves 11 are formed on the large substrate 10 provided with the resin sealing material 4. The depth of the dividing groove 11 is set slightly smaller than the dimension obtained by adding the thickness of the large format substrate 10 to the thickness of the resin sealing material 4. Specifically, the dividing groove 11 is deeper than the thickness of the resin sealing material 4 and penetrates to a depth slightly more than half the thickness of the large-sized substrate 10. As a result, the power feeding electrode 6 and the ground conductor pattern 9 are exposed in the inner part of the dividing groove 11.

  Thereafter, a conductive paste is screen-printed on the top surface 4 a of the resin sealing material 4 to print and form the conductive layer 12 used as the radiation conductor 5 and the horizontal portion 7 a of the feed line 7. At that time, by causing the conductive paste to enter the dividing groove 11 by squeezing, as shown in FIG. 3E, the inner wall surface of the dividing groove 11 (the side surface of the resin sealing material 4 and the circuit board 2) is also provided. The conductive layer 12 is formed. Most of the conductive layer 12 thus formed on the inner wall surface of the dividing groove 11 is used as the shield conductor 8, but a part thereof is used as the vertical portion 7 b of the feeder line 7 by trimming processing described later. In addition, the conductive layer 12 formed on the inner wall surface of the dividing groove 11 is tightly bonded to the exposed portions of the power supply electrode 6 and the ground conductor pattern 9.

  As a next process, the laminate of the large substrate 10 and the resin sealing material 4 is divided (breaked) into strips by one of the vertical and horizontal dividing grooves 11, and then a cut portion 13 (see FIG. 1) is formed by laser trimming on the divided surface. Is provided to form a vertical portion 7 b continuous with the horizontal portion 7 a of the power supply line 7. As described above, the vertical portion 7b is connected to the power supply electrode 6 and is separated from the shield conductor 8 through the cutout portion 13, and the vertical portion 7b having high dimensional accuracy is relatively separated by laser trimming. It can be formed easily. Therefore, after that, by dividing the strip-shaped laminated body by the other divided grooves 11 in the vertical and horizontal directions, a large number of communication modules 1 shown in FIGS. 1 and 2 can be obtained.

  As described above, in the communication module 1 according to this embodiment, when the radiation conductor 5 and the horizontal portion 7a of the feed line 7 are printed on the top surface 4a of the resin sealing material 4, the resin sealing material 4 is formed. The conductive layer 12 is formed by depositing a conductive paste on the side surface of the circuit board 2, and the conductive layer 12 is used as the shield conductor 8, and the conductive layer 12 is provided with a cut portion 13 by laser trimming. A vertical portion 7b of the line 7 is formed. Therefore, the communication module 1 does not require a power supply line in the circuit board 2 and has an improved space factor, and is easily promoted to be reduced in size and thickness. In addition, by using the dividing groove 11, the radiation conductor 5, the horizontal portion 7a of the feed line 7 and the shield conductor 8 can be formed at a time in a normal printing process, and the vertical portion 7b of the feed line 7 can be efficiently formed by laser trimming. Since it is easy to form, the communication module 1 can be manufactured at a relatively low cost.

  Further, in the communication module 1 according to the present embodiment example, the power supply electrode 6 connected to the power supply line 7 and the ground conductor pattern 9 connected to the shield conductor 8 are provided in the inner layer of the circuit board 2. The component mounting surface of the circuit board 2 can be easily reduced in area. Therefore, also from this point, the communication module 1 can be easily reduced in size.

  Note that the vertical portion 7b of the power supply line 7 may be formed by trimming using a router or the like. The radiation conductor 5 needs to be provided at least on the top surface 4 a of the resin sealing material 4, but the radiation conductor (radiation element) may extend from the top surface 4 a of the resin sealing material 4 to the side surface.

  FIG. 4 is an external view of a communication module 21 according to the second embodiment of the present invention, and portions corresponding to those in FIG.

  In the communication module 21 shown in FIG. 4, the shield conductor 8 is provided in a region of the top surface of the resin sealing material 4 that surrounds the radiation conductor 5 and the horizontal portion 7 a of the feed line 7 via the cutout portion 22. This is greatly different from the first embodiment described above. The cut portion 22 is formed by laser trimming, and the cut portion 13 around the vertical portion 7 b of the power supply line 7 communicates with the cut portion 22. That is, when the communication module 21 is manufactured, a conductive paste is printed on the entire top surface of the resin sealing material 4 to form the conductive layer 12, and then a cut portion 22 is provided in the conductive layer 12 by laser trimming. Thus, the radiation conductor 5 and the horizontal portion 7a of the feed line 7 are formed. At the time of printing, a conductive paste is inserted into the dividing groove to form a conductive layer 12 on the side surface of the resin sealing material 4 and the like, and a cut portion 13 is provided by laser trimming later, whereby a vertical portion 7b of the feeder line 7 is formed. However, since this point is the same as that of the first embodiment, detailed description thereof is omitted. In the communication module 21 having such a configuration, the conductive layer 12 functioning as the shield conductor 8 can be provided in a wide area of the top surface of the resin sealing material 4.

  FIG. 5 is a side view showing a part of a communication module 31 according to a third embodiment of the present invention, and FIG. 6 is a process diagram for explaining a method of manufacturing the communication module 31. Corresponding parts are denoted by the same reference numerals.

  The communication module 31 shown in FIG. 5 is greatly different from the first embodiment in that it includes a patch antenna having a structure in which a pair of upper and lower radiating conductors 32 and 33 are laminated via an insulating resin layer 34. . That is, in the communication module 31, the insulating resin layer 34 covers the first radiating conductor 32 provided on the top surface 4 a of the resin sealing material 4, and the first radiating conductor 32 is formed on the insulating resin layer 34. A second radiating conductor 33 having a smaller diameter is provided. The first radiation conductor 32 is basically the same as the radiation conductor 5 in the first embodiment, and the second radiation conductor 33 is fed by capacitive coupling with the first radiation conductor 32. It has become. Such a patch antenna having a laminated structure can resonate in two high and low frequency bands, has a good planar space factor, and can be formed without difficulty even if the top surface 4a of the resin sealing material 4 is narrow. It is suitable as a double resonance antenna or a small broadband antenna. Therefore, the communication module 31 having such a laminated patch antenna is suitable for use in various small communication devices.

  The procedure for manufacturing the patch antenna of the communication module 31 will be briefly described. First, as shown in FIG. 6A, a conductive paste is printed on the top surface 4a of the resin sealing material 4, and the first radiation conductor 32 is printed. And a horizontal portion 7a of the power supply line 7 are formed. Next, as shown in FIG. 6B, an insulating resin layer 34 is formed by printing a resin paste covering the first radiation conductor 32 on the top surface 4 a of the resin sealing material 4. Thereafter, as shown in FIG. 6C, the first and second radiating conductors 32 are formed by printing a conductive paste at a substantially central portion on the insulating resin layer 34 to form the second radiating conductors 33. , 33 having a laminated structure. However, in the third embodiment, the procedure for forming the vertical portion (not shown) of the feeder line 7 and the shield conductor 8 is the same as that in the first embodiment, and the description thereof is omitted. .

  In each of the above-described embodiments, the communication module provided with the radiating conductor of the patch antenna has been described. However, the type of antenna of the communication module is not limited to the patch antenna, and can be selected as appropriate. . For example, an opening (slot) having a predetermined shape surrounded by the conductive layer 12 may be provided on the top surface of the resin sealing material 4, and this opening may be operated as a radiating element of the slot antenna. In that case, all the conductive layers 12 existing on the top surface 4a can function as shield conductors.

1, 21 and 31 Communication module 2 Circuit board 3 Electronic component 4 Resin sealing material 4a Top surface 5 Radiation conductor 6 Feeding electrode 7 Feeding line 7a Horizontal portion 7b Vertical portion 8 Shield conductor 9 Grounding conductor pattern 10 Large format substrate 11 Divided groove DESCRIPTION OF SYMBOLS 12 Conductive layer 13 Cut part 22 Cut part 32 1st radiation conductor 33 2nd radiation conductor 34 Insulation resin layer

Claims (7)

A circuit board to be surface-mounted, an electronic component mounted on the circuit board, a resin sealing material that covers the circuit board including the electronic component, and at least an outer surface of the resin sealing material A communication module having a substantially rectangular parallelepiped shape in which an antenna radiating element is formed using the conductive layer existing on the top surface of the resin sealing material.
The conductive layer existing on a predetermined side surface of the resin sealing material extends to a position where it covers the power supply electrode exposed on the side surface of the circuit board which is flush with the side surface, and both side surfaces thereof. The communication module is characterized in that a feed line connected to the radiation element and the feed electrode is formed by providing a cut portion of the conductive layer.   The conductive layer according to claim 1, wherein the conductive layer existing on the top surface of the resin sealing material is formed by printing of a conductive paste, and the side surface of the resin sealing material is attached to the side surface by the conductive paste. A communication module, wherein a conductive layer is formed.   3. The communication module according to claim 2, wherein the conductive layer existing on the top surface of the resin sealing material is trimmed.   3. The method according to claim 1, wherein a conductive layer existing on a side surface of the resin sealing material is connected to a ground conductor pattern provided on the circuit board at a location different from the power supply line. Communication module.   5. The communication module according to claim 4, wherein the power feeding electrode and the ground conductor pattern are provided in an inner layer of the circuit board.   3. The communication module according to claim 1, wherein at least a part of the conductive layer on the top surface of the resin sealing material is a radiation antenna of the patch antenna.   7. The first radiation conductor provided on the top surface of the resin sealing material as the radiation conductor according to claim 6, and a second radiation conductor provided on an insulating resin layer covering the first radiation conductor. And the first radiating conductor is larger in diameter than the second radiating conductor.

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