JP4883882B2 - Electronic equipment - Google Patents

Description

  The present invention relates to a communication device such as a mobile phone and a personal computer, and an electronic device incorporated in the electronic device.

  Conventionally, an electronic device provided with a high-frequency circuit is used in communication equipment such as a mobile phone.

As such a conventional electronic device, for example, as shown in FIG. 5 , a wiring such as a high-frequency circuit and a ground wiring is embedded in a multilayer wiring board 11 formed by laminating a plurality of insulating layers, and the multilayer wiring board 11 A structure in which an electronic component element 13 such as a chip inductor, a chip capacitor, a diode, or a chip resistor is mounted on an upper surface and is covered with a metal shield cover 12 is known (see, for example, Patent Document 1). ).

  The shield cover 12 is held at a ground potential (reference potential) when an electronic device is used, thereby shielding electromagnetic waves from the outside and stabilizing circuit characteristics, as well as the electronic component element 13. As such a shield cover 12, for example, a casing-shaped one having an open surface is used.

Further, when attaching the above-described casing-shaped shield cover 12 to the upper surface of the multilayer wiring board 11, the opening is placed on the upper surface of the multilayer wiring board 11 with the opening facing down, This is performed by electrically and mechanically connecting the lower end of the provided side wall 12a to a terminal electrode of a ground electrode provided on the upper surface of the multilayer wiring board 11 via a conductive adhesive 16 such as solder. .
Japanese Patent Laid-Open No. 2001-196781

  However, in the above-described conventional electronic device, when the shield cover 12 is attached to the upper surface of the multilayer wiring board 11, the shield cover 12 is placed on the multilayer wiring board 11 via the conductive adhesive 16 such as cream solder. When the conductive adhesive 16 such as solder is heated or melted, the fluid conductive adhesive 16 spreads along the gap between the upper surface of the multilayer wiring board 11 and the side wall 12a of the shield cover 12. In that case, a short circuit often occurs between the wirings provided on the multilayer wiring board 11 by the flowing conductive adhesive 16 or between the shield cover 12 and other wirings. It had a drawback that caused a decrease in productivity.

Further, in the conventional electronic apparatus described above, a gap that can be between the upper surface of the side wall 12a and the multilayer wiring board 11 of the shield cover 12 is extremely narrow, and the gap that is extremely thin thickness of the solder to be filled It has become. Therefore, the bonding strength between the shield cover 12 and the multilayer wiring board 11 tends to be insufficient, and thermal stress is applied between the shield cover 12 and the multilayer wiring board 11 or an external impact is applied to the electronic device. In other words, the shield cover 12 has a drawback that it can be removed from the multilayer wiring board 11 relatively easily.

  The present invention has been devised in view of the above drawbacks, and an object of the present invention is to provide an electronic device that is capable of firmly bonding a shield cover to a multilayer wiring board and is excellent in productivity. It is in.

The electronic device according to the present invention includes an electronic component element mounted on a rectangular parallelepiped multilayer wiring board in which a plurality of insulating layers are stacked and a ground wiring is interposed between the insulating layers, and the electronic component element is mounted on the multilayer wiring board. In an electronic device in which a rectangular shield cover made of metal is disposed so as to cover a component element, the ground wiring is opened on a side surface and an upper surface of the multilayer wiring board provided on a side surface of the multilayer wiring board. An exposed portion exposed on the surface of the cutout, and the shield cover is housed in the cutout that is erected on at least one of the four sides constituting the outer periphery of the shield cover. and bonding the leg portions, erected on two parallel sides, and a pressure-contact leg projecting portion is formed to an arc shape, below the junction leg which is housed inside the notch Write and side interval with respect to the exposed portion of the ground wiring
Opposed spaced, the pressure-contacting legs, by sandwiching the multilayer wiring board in pressure contact with the side surface of the multilayer wiring substrate such that the projection is in contact, the exposure of the ground wiring and the junction legs and parts, and the said shield cover is attached to the multilayer wiring board by electrically connecting by bonding the lower and the side of the joint leg by interposing a conductive adhesive to said distance It is characterized by this.

Furthermore, in the electronic device of the present invention, it is preferable that a lower end portion of the joint leg portion is bent inward within the notch formation region.

  According to the electronic device of the present invention, of the four sides constituting the outer periphery of the shield cover, at least one side is provided with two parallel connecting leg portions facing the exposed portion of the ground wiring with a predetermined interval. Since the press contact leg portion that press-contacts the side surface of the multilayer wiring board and sandwiches the multilayer wiring substrate is erected on the side, joining and positioning are performed at different locations. The thickness of the conductive adhesive intervening between the two is sufficient, and the bonding area to the multilayer wiring board can be secured sufficiently large, thereby firmly joining the shield cover to the multilayer wiring board. It becomes possible to do. Therefore, even when a thermal stress is applied between the shield cover and the multilayer wiring board or an external impact is applied to the electronic device, the shield cover can be satisfactorily attached to the multilayer wiring board. This can dramatically improve the reliability of the electronic device. In addition, if the ground electrode is disposed at the portion where the joint leg is pressed, the electrical connection between the ground electrode and the shield cover can be made more reliable.

  Then, the pressure contact leg portion of the shield cover is pressed against the side surface of the multilayer wiring substrate in the notch formation region provided on the side surface of the multilayer wiring substrate, and the multilayer wiring substrate is sandwiched between the plurality of joint legs. With this configuration, when the electronic device is assembled, even if an external force such as vibration is applied to the electronic device being assembled, the shield cover on the multilayer wiring board can be effectively prevented from being displaced.

  Further, according to the electronic device of the present invention, the joint leg and / or the pressure contact leg are accommodated in the notch provided on the side surface of the multilayer wiring board, so that the shield cover can be made of cream solder or the like when the electronic device is assembled. Even if it is placed on a multilayer wiring board via a conductive adhesive, or solder is heated or melted, the conductive adhesive with fluidity is placed inside the notch provided on the multilayer wiring board. It is well accommodated and does not spread along the gap between the upper surface of the multilayer wiring board and the shield cover side wall. Accordingly, it is possible to effectively prevent the wiring provided on the multilayer wiring board or the shield cover and other wirings from being undesirably short-circuited by the conductive adhesive, thereby improving the productivity of the electronic device. It becomes possible to improve.

  In addition, when assembling the electronic device, the shield cover is placed on the multilayer wiring board so that the joint legs are accommodated in the corresponding notch formation regions, so that the shield cover is placed on the multilayer wiring board. Can be accurately and easily aligned, which also improves the productivity of the electronic device.

  Furthermore, according to the electronic device of the present invention, the lower end of the notch is positioned above the lower surface of the multilayer wiring board, so that the area of the lower surface of the multilayer wiring board can be secured widely, Since many terminal electrodes for connection can be provided, it is possible to increase the bonding strength when the electronic device is mounted on a mother board or the like.

  Furthermore, in the electronic device according to the present invention, the lower end portion of the joint leg portion is bent inward within the notch formation region so that the edge of the bent portion is brought close to the side surface of the multilayer wiring board. Therefore, when the shield cover is placed on the multilayer wiring board when assembling the electronic device, even if the attachment position of the shield cover is about to deviate greatly in the direction connecting the two joint legs to the multilayer wiring board, The edge of the bent portion is brought into contact with the side surface of the multilayer wiring board, so that the positional deviation of the shield cover is effectively suppressed, and the workability related to the assembly of the electronic device can be improved.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

  1 is an exploded perspective view of an electronic device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the electronic device of FIG. 1, and the electronic device shown in FIG. It consists of a shield cover 2.

The multilayer wiring board 1 is constituted by a substantially rectangular laminate formed by laminating an insulating layer of multiple the thickness direction, a large number of wires to these insulating layers including the ground wire 5 (not shown) These wirings are interposed, and are electrically connected to each other via via hole conductors (not shown) embedded in the insulating layer.

  A predetermined notch 4 is provided on the upper surface of the multilayer wiring board 1 described above. In the present embodiment, two notches 4 are provided at both ends of the multilayer wiring board 1, and each notch 4 is opened at the end face of the multilayer wiring board 1.

  These cutouts 4 are for accommodating a later-described conductive adhesive 6 therein, and the conductive adhesive 6 is supported from below and from the sides by the surface of the multilayer wiring board 1 facing the cutout 4. It is supposed to be.

  The notches 4 described above are provided by forming a plurality of notches 4 in at least the uppermost layer of the insulating layer constituting the multilayer wiring board 1, and the notch 4 is formed in the region where the notches 4 are formed. A part of the ground wiring 5 is exposed on the inner surface of the facing multilayer wiring board 1.

  As a material of the insulating layer constituting such a multilayer wiring board 1, for example, a ceramic material such as glass ceramics is used, and the thickness of each insulating layer is set to, for example, 50 μm to 300 μm.

  When the insulating layer is made of a ceramic material, the multilayer wiring board 1 is obtained by laminating a plurality of ceramic green sheets obtained by adding and mixing an appropriate organic solvent, organic solvent, etc. to the ceramic raw material powder. The laminate is manufactured by press molding and then firing the laminate at a high temperature and processing the outer shape. The cutout 4 is formed by punching a predetermined portion of a ceramic green sheet used for forming an insulating layer located on the exposed portion of the ground electrode 5 into a substantially rectangular shape. At this time, if the inner surface corner of the insulating layer facing the notch 4 is processed into a concave curved surface having a curvature radius of 0.2 mm to 0.4 mm, for example, the multilayer wiring substrate 1 is fired when the multilayer wiring substrate 1 is fired. It is possible to effectively prevent cracks and the like starting from the notches 4. Therefore, when the notch 4 is formed in a substantially rectangular shape, it is preferable to process the inner corners of the insulating layer facing the notch 4 into a concave curved surface having a curvature radius of 0.2 mm to 0.4 mm.

  Moreover, as a material of the wiring provided in the inside of the multilayer wiring board 1, the surface, etc., and a via-hole conductor, the conductive material which has silver as a main component is used suitably, for example, and the thickness of each wiring is 5 micrometers-20 micrometers, for example Is set.

  For such wiring, when the multilayer wiring board 1 is manufactured by the above-described manufacturing method, before the ceramic green sheets are laminated, a conductive paste containing silver powder is predetermined on the surface of each ceramic green sheet by conventionally known screen printing or the like. It is formed by printing / coating on a pattern and simultaneously firing the ceramic green sheet at the time of firing. The via-hole conductor is formed by applying and filling a conductive paste in a through-hole previously provided in the ceramic green sheet by screen printing or the like, and simultaneously firing the ceramic green sheet at the time of firing. The

  Further, electronic component elements 3 such as a chip inductor, a chip capacitor, a chip resistor, and a diode are mounted on the upper surface of the multilayer wiring board 1 described above.

  These electronic component elements 3 are electrically connected to the corresponding wiring of the multilayer wiring board 1 described above via a conductive adhesive such as solder or a bonding material such as a fine metal wire. The component element 3 and the wiring of the multilayer wiring board 1 constitute a predetermined electric circuit.

  On the other hand, the shield cover 2 is formed to have a rectangular shape slightly smaller than the outer shape of the multilayer wiring board 1 using, for example, a metal material such as iron, white or phosphor bronze. An annular side wall 2a thicker than the thickness of 3 is erected, and a joining leg portion 2b and a pressure contact leg portion 2c are formed on the side wall 2a.

  The shield cover 2 described above is placed on the multilayer wiring board 1 so as to cover the electronic component element 3 with the lower end of the side wall 2a being in contact with the upper surface of the multilayer wiring board 1, and is provided on the side wall 2a. By electrically connecting the leg 2b to the ground wiring 5 exposed in the cutout 4 of the multilayer wiring board 1, the electromagnetic wave from the outside can be well shielded when the electronic device is used. The circuit characteristics are stabilized and the electronic component element 3 is operated normally.

  Note that a plurality of the joint legs 2b and the press contact legs 2c of the shield cover 2 described above are provided so as to correspond one-to-one with the notches 4 of the multilayer wiring board 1, and the width and length thereof are provided. Both are slightly smaller than the width and depth of the notch 4, and are kept in contact with the joint leg 2b and in contact with the press leg 2c with respect to the side surface of the multilayer wiring board 1 facing the notch 4, respectively. ing.

  Further, the ground leg 5 exposed in the joint leg portion 2b of the shield cover 2 and the notch formation region of the multilayer wiring board 1 is formed by the conductive adhesive 6 such as solder accommodated in the notch 4. Electrically and mechanically connected.

  In the present embodiment, the press contact leg 2c is formed with a protrusion 2c 'in which a portion that contacts the side surface of the multilayer wiring board 1 forms an arc shape, and such a structure has the protrusion 2c'. Since there are no sharp corners or the like in the vicinity, even if the press contact leg 2c is pressed against the multilayer wiring board 1, the surface of the multilayer wiring board 1 is hardly damaged, which is a preferable mode.

As described above, the joint legs 2b are arranged in parallel so that the side surfaces of the exposed portions of the ground wiring 5 are opposed to each other at a predetermined interval on at least one of the four sides constituting the outer periphery of the shield cover 2. The press contact leg 2c formed with an arc-shaped protrusion 2c ' standing on two sides is pressed against the side surface of the multilayer wiring board 1 so that the protrusion 2c' is in contact with the multilayer wiring board 1 In addition, the shield cover 2 is attached to the multilayer wiring board 1 by electrically connecting the joint leg 2b and the exposed portion of the ground wiring 5 with the conductive adhesive 6 interposed in the gap. Therefore, since the bonding and positioning are performed at different locations, the thickness of the conductive adhesive 6 interposed in the gap generated between the bonding leg 2b and the multilayer wiring board 1 becomes sufficiently thick, and the multilayer wiring board Adhesive area for 1 is also wide enough Can be coercive, it is possible to firmly bonded thereto by a shield cover 2 with respect to the multilayer wiring board 1. Accordingly, or thermal stress is applied between the shield cover 2 and the multilayer wiring board 1, even or an external shock is applied to the electronic device, favorably preparative shield cover 2 with respect to the multilayer wiring board 1 The reliability of the electronic device is dramatically improved. In addition, if the exposed portion of the ground wiring 5 is arranged at the portion where the joint leg 2b is erected, the electrical connection between the ground wiring 5 and the shield cover 2 can be made more reliable. it can.

  The shield cover 2 is configured to sandwich the multilayer wiring board 1 with a plurality of legs in a state in which the pressure contact leg 2c is pressed against the side surface of the multilayer wiring board 1 located in the region where the cutout 4 is formed. Therefore, when the electronic device is assembled, even if an external force such as vibration is applied to the electronic device being assembled, it is possible to effectively prevent the shield cover 2 on the multilayer wiring board 1 from being displaced. it can.

  Furthermore, in the present embodiment, the joining leg 2b and / or the press-contacting leg 2c are accommodated in the notch 4 provided on the side surface of the multilayer wiring board 1, thereby shielding the electronic device during assembly. Even if the cover 2 is placed on the multilayer wiring board 1 via the conductive adhesive 6 such as cream solder, or the solder or the like is heated and melted, the conductive adhesive 6 having fluidity is multilayered. The cutout 4 provided in the wiring board 1 is satisfactorily accommodated in the notch 4 and does not spread along the gap between the upper surface of the multilayer wiring board 1 and the shield cover side wall 2a. Therefore, it is possible to effectively prevent the wiring provided on the multilayer wiring board 1 and the shield cover 2 and other wirings from being undesirably short-circuited by the conductive adhesive 6. Productivity can be improved.

  Further, when assembling the electronic device, the shield cover 2 is placed on the multilayer wiring board 1 so that the above-described joint leg 2b is accommodated in the corresponding formation region of the notch 4, and thereby the shield cover 2 is placed. Can be accurately and easily aligned with the multilayer wiring board 1, and this also improves the productivity of the electronic device.

  In the present embodiment, the lower end of the notch 4 is positioned above the lower surface of the multilayer wiring board 1, thereby ensuring a large area on the lower surface of the multilayer wiring board 1, and a terminal for connecting to the outside. Since a large number of electrodes can be provided, it is possible to increase the bonding strength when the electronic device is mounted on a mother board or the like.

  The shield cover 2 is attached to the multilayer wiring board 1 by first applying a conductive adhesive 6 such as cream solder to the formation region of the notch 4 where the ground wiring 5 is exposed using a dispenser or the like. Filling, and then placing the shield cover 2 on the upper surface of the multilayer wiring board 1 so that the joint leg 2b is accommodated in the formation region of the notch 4, and then the conductive adhesive 6 is applied. Curing is performed by heat or the like, and the conductive adhesive 6 is adhered to the joining leg 2b. At the same time, the ground wiring 5 and the joining leg 2b of the shield cover 2 are electrically connected.

  Thus, when the electronic device described above is used, the shield cover 2 is held at the ground potential (reference potential) via the ground wiring 5. The electronic device can be stably operated by shielding.

  The present invention is not limited to the above-described embodiment, and various changes and improvements can be made without departing from the scope of the present invention.

  For example, in the electronic device of the above-described embodiment, solder is used as the conductive adhesive 6 for joining the joining leg 2b of the shield cover 2 and the ground wiring 5 of the multilayer wiring board 1, but this is replaced. Then, they may be joined using a conductive adhesive other than solder, such as a conductive resin.

  In the embodiment described above, the multilayer wiring board 1 is formed of glass ceramics. Instead, other ceramic materials such as alumina ceramics or organic materials such as glass cloth base epoxy resin are used. Thus, the multilayer wiring board 1 may be formed.

  Further, in the above-described embodiment, the joint leg 2b is provided on two parallel sides of the four sides of the shield cover 2 formed to have a rectangular shape, and the pressure contact leg 2c is provided on the remaining two sides. However, the joint leg 2b may be erected on at least one side of the shield cover 2, and the pressure contact leg 2c may be erected on two parallel sides of the four sides of the shield cover 2. .

  Furthermore, as another embodiment, as shown in FIG. 4, if the lower end portion of the joining leg portion 2b is bent inward within the formation region of the notch 4, the bent portion 2b ' Since the edge can be disposed close to the side surface of the multilayer wiring board 1, when the shield cover 2 is placed on the multilayer wiring board 1 during the assembly of the electronic device, the mounting position of the shield cover 2 is the multilayer wiring board 1. Even if an attempt is made to make a large displacement in the direction connecting the two joint legs 2b, the edge of the bent portion 2b 'abuts against the side surface of the multilayer wiring board 1, and the displacement of the shield cover 2 can be effectively suppressed. The workability related to the assembly of the electronic device can be made good.

It is a disassembled perspective view of the electronic device which concerns on one Embodiment of this invention. FIG. 2 is a cross-sectional view of the electronic device of FIG. 1 taken along the line A-A ′. FIG. 2 is a B-B ′ cross-sectional view of the electronic device of FIG. 1. It is sectional drawing of the electronic device which concerns on other embodiment of this invention. It is sectional drawing of the conventional electronic device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Multilayer wiring board 2 ... Shield cover 2a ... Side wall 2b ... Joining leg part 2b '... Bending part 2c ... Press-contact leg part 2c' ... Projection part 3 ... electronic component element 4 ... cutout 5 ... ground wiring 6 ... conductive adhesive (solder)

Claims (2)

An electronic component element is mounted on a rectangular parallelepiped multilayer wiring board in which a plurality of insulating layers are laminated and a ground wiring is interposed between the insulating layers, and the electronic component element is covered on the multilayer wiring board. In the electronic device in which a rectangular shield cover made of metal is arranged, the ground wiring is exposed on the side surface of the multilayer wiring board provided on the side surface of the multilayer wiring board and the surface of the notch opened on the upper surface. The shield cover is parallel to a joint leg portion that is erected on at least one of the four sides constituting the outer periphery of the shield cover and is accommodated in the cutout. such erected on the two sides, and a pressure-contact leg projecting portion is formed to an arc shape, the notch inside housed a the joint leg of the lower and side it is the graph of And spaced and opposed to the exposed portion of de wire, the pressure-contacting legs, by sandwiching the multilayer wiring board in pressure contact with the side surface of the multilayer wiring substrate such that the projection is in contact, wherein the shield cover by the said exposed portion of said ground wiring and the bonding leg, said connecting lower and the lateral electrically by bonding of the bonding leg by interposing a conductive adhesive to said distance Is attached to the multilayer wiring board.   2. The electronic device according to claim 1, wherein a lower end portion of the joining leg portion is bent inward within a notch formation region.

Images