JP5657234B2 - Shield member and electronic apparatus including the shield member - Google Patents

Description

  The present invention relates to a shield member and an electronic apparatus including the shield member, and particularly to a mobile phone mounted with a circuit board on which a CPU (central processing unit) that radiates high-frequency electromagnetic noise is mounted. The present invention relates to a shield member suitable for use in shielding the CPU, and an electronic apparatus including the shield member.

  In recent cellular phones, various characteristics have been made high-spec, and accordingly, the operating speed of the CPU has been improved, and the frequency of electromagnetic noise radiated from the CPU has been increased. The radiation of electromagnetic wave noise by the CPU is 860 MHz to 895 MHz corresponding to 3G (third generation mobile communication system) provided as a function via each antenna in the mobile phone in which each component is mounted at high density, There is a problem that a reception band of 470 MHz to 770 MHz corresponding to the above is squeezed and interferes with a reception signal to deteriorate the reception performance of the internal antenna. For this reason, a shield structure in which a sheet metal shield frame is put on the CPU is often used as a method for preventing the CPU from radiating electromagnetic waves around the CPU.

  However, in mobile phones, resin coating reinforcement is applied to each LSI (Large Scale Integrated circuit) such as a CPU as a measure for preventing destruction due to dropping. In this case, it is necessary to provide an opening for resin coating on the top surface of the mounting shield portion that is mounted on the automatic mounting machine at the same time as the CPU. There is a problem that radiation of electromagnetic noise cannot be suppressed, and mechanical strength and reception sensitivity are not compatible. In addition, in order to solve this problem, there is a case where a structure is used in which the shield has a double structure and the cover shield part is mounted on the mounting shield part that is opened on the top surface. Because there are manufacturing tolerances in the shield part and cover shield part, the outer dimensions of the mounting shield part and the inner dimension of the cover shield part cannot be designed with the same dimensions. As a result of the large size, there is a problem in that, after all, a complete shield structure is not achieved, and an effect on sensitivity (reduction in reception performance) occurs.

  If the inner dimension of the cover shield part is set to the same setting (zero setting) as the outer dimension of the mounting shield part, giving priority to reception performance, the cover shield part cannot be assembled in the worst condition. And problems such as deformation of the cover shield part due to excessive fitting. For this reason, when the shield is configured with a double structure, a cover shield part is required that can improve both the built-in cover shield and prevent deterioration of mobile phone communication sensitivity and one-segment viewing sensitivity due to electromagnetic noise radiation. Has been.

As this type of related technology, for example, there is a shield case described in Patent Document 1.
The shield case covers a shield target portion on the board surface of the circuit board and is fixed to the board surface with a conductive bonding material (for example, solder). Further, the shield case has a joining terminal that is inclined upward from the lower end edge in contact with the substrate surface and extended outward. The joining terminal and the substrate surface are joined by a conductive joining material interposed therebetween. As a result, the shield case is fixed to the substrate surface with good bonding strength, and is grounded to the ground portion provided on the circuit board.

  Moreover, in the shield case described in Patent Document 2, a frame standing on the periphery of the shield countermeasure portion of the circuit board and a cover that fits over the frame and covers the shield countermeasure portion are provided. The cover has a flat cover body portion that covers the shield portion and a peripheral wall portion that fits into the frame. The peripheral wall portion has an elastic wall portion that can be elastically deformed in the cover inner and outer directions with the upper side as a fulcrum. An elastic pressing portion that elastically presses the frame is provided on the distal end side of the elastic wall portion. The elastic wall portion is provided with a plurality of openings intermittently in the circumferential direction of the peripheral wall portion. The opening is formed to extend from a position above the elastic pressing portion to a position where it enters the end edge of the cover main body. The width of the elastic wall portion between adjacent openings is set to be narrower than the width of the opening in the circumferential direction of the peripheral wall. Thereby, the deformation | transformation of the cover which comprises a shield case is prevented.

  Moreover, in the shield member described in Patent Document 3, a frame body having a main surface and a side surface and a lid-shaped member having a main surface and a side surface covering the frame body are provided, and the frame body and the lid-shaped member The main surface has contacts at a plurality of locations. Thereby, the fitting rate of a frame and a lid-like member increases, and shield performance improves.

  Further, the shield case described in Patent Document 4 has a side wall portion that surrounds an electronic component mounted on the circuit board, and a frame body that is attached to the circuit board with the top surface open, A lid attached to cover the top of the body is provided. The frame body has an extending portion that extends from the top surface side edge portion of the side wall portion and is folded back to the outside of the side wall portion, and the lid body has an engaging portion that engages with the extending portion. Yes. As a result, the separate shield case is thinned.

WO2006 / 035542 Publication JP 2007-073609 A JP 2008-182082 A JP 2009-1111076 A

However, the related technology has the following problems.
In other words, the shield case described in Patent Document 1 is fixed to the substrate surface with good bonding strength. However, for example, the shield case is not configured to take into account the prevention of interference by a conductive bonding material (solder). The configuration is different from that of the present invention.

  In the shield case described in Patent Document 2, the cover is prevented from being deformed. However, the elastic wall portion includes a plurality of openings provided intermittently in the circumferential direction of the peripheral wall portion. Is different.

  In the shield member described in Patent Document 3, the fitting rate between the frame body and the lid-like member is increased, and the shielding performance is improved. However, the frame body and the main surface of the lid-like member have contacts at a plurality of locations. The configuration is different from that of the present invention.

  In the shield case described in Patent Document 4, the separate shield case is thinned, but the frame has an extending portion and the lid has an engaging portion that engages with the extending portion. The configuration is different from that of the present invention.

  The present invention has been made in view of the above-described circumstances, and provides a shield member capable of achieving both a shielding property and a built-in property of a shield structure that suppresses electromagnetic noise radiation by a CPU and the like, and an electronic device including the shielding member. The purpose is to do.

In order to solve the above problems, the configuration of the present invention relates to a shield member that shields electromagnetic noise radiated from an electronic component mounted on a circuit board, and is formed in a rectangular shape having an opening on the top surface side. A mounting shield portion mounted on the circuit board so as to surround the electronic component, and a cover shield portion crowned from the top surface side with respect to the mounting shield portion, the cover shield portion Is composed of a top surface and a side wall portion, and the side walls of the side wall portions of each side are bent at right angles from the end of the top surface to the mounting shield portion side in the regions near the four corners. right angle bent portion comprising Te is being formed, in the other areas, an acute bent portion the side walls is bent at an acute angle to said mounting shield portion from an end portion of said top surface,該鋭pens From the lower end of the curved part, the side wall is predetermined outside Bent and warped portion that extends is being formed, the mounting shield portion, in a state of being mounted on the circuit board by a conductive bonding material, wherein the warp portion prevents interference with the conductive bonding material On the other hand, the right-angled bent part makes it difficult to determine the crowning position with respect to the mounting shield part when observed from above when the cover shield part is crowned to the mounting shield part. It plays the role of positioning for complementing the structure and preventing deformation of the side wall in the other region.

  According to the configuration of the present invention, it is possible to realize a shield member in which both the shield property after reinforcing the strength of the electronic component that radiates electromagnetic noise and the incorporation property are compatible.

It is a disassembled perspective view which shows the structure of the principal part of an electronic device provided with the shield member which is 1st Embodiment of this invention. It is an AA line section of Drawing 1 (e) at the time of using uncovered cover shield 6 for incorporation. It is sectional drawing at the time of using the cover shield 6A for an installation in which countermeasures were taken. It is a figure explaining the problem of the cover shield 6A for incorporation in FIG. It is sectional drawing which shows the structure of the shield member which is 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the shield member which is 3rd Embodiment of this invention. It is a figure which shows the structure of the shield member which is 4th Embodiment of this invention. It is a figure explaining the problem and advantage of the shield member of FIG.

  The cover shield part (the built-in cover shield) realizes a shield member in which a warped part bent outward at a predetermined angle is formed at the tip of each side wall part.

The mounting shield portion (mounting shield) is configured to be mounted on the circuit board by a conductive bonding material (soldering), and the warped portion of the cover shield portion is formed of the conductive bonding material (solder). It has a shape that prevents interference due to attachment. Further, the cover shield part is set to have a longer side wall length than in the case where there is no warped part. In addition, the four corners of the side wall portion of each side and the region in the vicinity of the four corners, when the cover shield portion is attached to the mounting shield portion, are applied to the four sides of the cover shield portion with uniform contact pressure. It is made into the shape made to contact the said shield part for mounting.

Embodiment 1

FIG. 1 is an exploded perspective view showing a configuration of a main part of an electronic apparatus including a shield member according to the first embodiment of the present invention.
The electronic apparatus of this form is a mobile phone 1 as shown in FIG. 1A, and an electronic component such as a CPU 3 is mounted on a mounting board 2 (circuit board) as shown in FIG. In addition, an antenna 4 is formed. Further, as shown in FIG. 2C, a mounting shield 5 formed in a rectangular shape having an opening on the top surface side is mounted on the mounting substrate 2 so as to surround the CPU 3. In this case, as shown in FIG. 4D, a resin coating clearance CL is provided on the top surface of the mounting shield 5 as a resin coating opening. Further, as shown in FIG. 5E, the built-in cover shield 6 is attached to the mounting shield 5 from the top surface side. The mounting shield 5 and the built-in cover shield 6 constitute a shield member that shields electromagnetic noise radiated from the CPU 3.

  In this cellular phone, as the processing capacity of the CPU 3 mounted on the mounting substrate 2 is increased in speed and load, high frequency electromagnetic noise is radiated from the CPU 3 and wraps around the antenna 4 for communication function, thereby improving the reception performance. In order to prevent problems that may be reduced, the CPU 3 is surrounded by a mounting shield 5 that is mounted by automatic mounting in the same manner as the CPU 3. Further, as a measure for preventing immediate destruction of the CPU 3 when the mobile phone 1 is dropped or folded, it is necessary to reinforce the CPU 3 with resin coating, and the top of the mounting shield 5 is used for resin coating. Since the surface is greatly opened, the built-in cover shield 6 is further provided with the mounting shield 5 for the purpose of closing the opening in order to suppress electromagnetic wave noise radiation from the top opening of the mounting shield 5. To be crowned. Then, by integrating the mounting shield 5 and the built-in cover shield 6, a shield member that completely closes the periphery of the CPU 3 is realized.

  Actually, since the shielding performance cannot be ensured only by attaching the built-in cover shield 6 to the mounting shield 5, the shape of the built-in cover shield 6 is devised, and a conductive material specification such as plating is used. The shield performance is ensured by completely conducting two shields made of sheet metal. At that time, the shape of the cover shield 6 for incorporation is also devised in consideration of the ease of assembly, and a structure that realizes both shield performance and strength after reinforcement of strength to parts is realized.

FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1 (e) when an unmeasured built-in cover shield 6 is used, and FIG. 3 is a cross-section when the built-in cover shield 6A is used. FIG. 4 and FIG. 4 are diagrams for explaining problems of the built-in cover shield 6A in FIG.
With reference to these drawings, the shape of the shield member of this embodiment will be described.
In this shield member, the outer dimension of the mounting shield 5 and the inner dimension of the built-in cover shield 6 are the same, and when the built-in cover shield 6 is crowned, Shielding performance is ensured by contact between the side wall and the inner side wall of the built-in cover shield 6 for electrical connection. Actually, however, manufacturing tolerances exist for each shield, and as shown in FIG. 2, the built-in cover shield 6 can be worn even under the worst condition of component tolerance. Since it is designed with a large size (that is, a certain clearance setting for absorbing tolerances), it does not end up with a shield structure that ensures complete continuity, and the reception performance deteriorates due to leakage of electromagnetic noise. It is not completely prevented.

  In this case, for example, the outer dimension of the mounting shield 5 is 10.0 ± 0.2 mm (MAX. Finish is 10.2 mm), and the inner dimension of the built-in cover shield 6 is 10.4 ± 0.2 mm ( MAX. Finish is set to 10.2 mm), and in normal finish, there is a clearance of 0.2 mm on one side (0.4 mm on both sides in total), and the mounting shield 5 and the built-in cover shield 6 are in contact ( Do not conduct).

  For this reason, as shown in FIG. 3, in the built-in cover shield 6A, the side wall portions of each side are formed to be bent inward at an acute angle, and these bent side wall portions of the four sides are used for mounting during assembly. By being worn while being rubbed around the four sides of the shield 5, it is completely conductive without being affected by the finished dimensions within the tolerance range of the parts, and the shielding performance is ensured.

  As described above, in the first embodiment, the mounting shield 5 and the built-in cover shield 6 are completely conducted, and the shielding performance is ensured. However, by bending the four side walls of the built-in cover shield 6 inwardly, it becomes narrower than the width of the mounting shield 5 and, as shown in FIG. Problems arise, and there is a problem in the assemblability of the cover shield 6 for incorporation.

Embodiment 2

FIG. 5 is a cross-sectional view showing a configuration of a shield member according to the second embodiment of the present invention.
In the shield member of this embodiment, as shown in FIG. 5, a cover shield 6 </ b> B having a different shape is provided instead of the cover shield 6 </ b> A for incorporation in FIG. 3. In the built-in cover shield 6B, warped portions (burr portions) 6a,..., 6a that are bent outward by a predetermined angle are formed at the tip of each side wall portion of each side.

  In the built-in cover shield 6B, since the warped portion 6a is provided, interference with the mounting shield 5 at the start of assembling is avoided, and thereafter, assembling is facilitated by pushing from above. In addition, when the mounting shield 5 is soldered and mounted on the mounting substrate 2, a solder group may be sucked up slightly on the side surface of the mounting shield 5. In this built-in cover shield 6B, Interference with the side wall tip is also avoided.

Embodiment 3

FIG. 6 is a cross-sectional view showing a configuration of a shield member according to the third embodiment of the present invention.
In the shield member of this embodiment, as shown in FIG. 6 (a), instead of the cover shield for assembly 6A in FIG. 3, a cover shield for assembly 6C having a different shape is provided. As shown in (b), instead of the cover shield 6A for incorporation in FIG. 3, a cover shield 6D for assembly having a different shape is provided. In the built-in cover shield 6C, the length of the side wall is set short to prevent interference with the solder group S generated on the side surface of the mounting shield 5 when the mounting shield 5 is soldered and mounted. ing. However, when the length of the side wall is set short, the internal bending process at the time of manufacture becomes difficult. Therefore, in the built-in cover shield 6D, the warped portions 6b,..., 6b are provided so that the interference by the solder group S generated by soldering is prevented, and there is no warped portion 6b. The side wall length is set longer than the cover shield 6C. As a result, the side wall length can be set long, the side wall can be easily bent, and the low-profile shield in the mobile phone can be easily adopted.

Embodiment 4

FIG. 7 is a view showing a configuration of a shield member according to the fourth embodiment of the present invention.
In this form of shield member, as shown in FIG. 7A, instead of the cover shield 6A for assembly in FIG. 3, a cover shield 6E having a different shape is provided. As shown in (b), instead of the built-in cover shield 6A in FIG. 3, a different-shaped built-in cover shield 6F is provided. The built-in cover shield 6E is formed in the same shape as the built-in cover shield 6D of the third embodiment, but in this shape, when the built-in cover shield 6E is viewed from above. The crowning position with respect to the mounting shield 5 cannot be determined, and there is a problem that the built-in cover shield 6E is deformed when it is crowned in a shifted state. On the other hand, the built-in cover shield 6F has right-angle bent portions 6m,..., 6m formed by bending the four corners of the side wall portion of each side and the vicinity of the four corners inward at right angles. 5 is a shape used for positioning when being attached to 5. As a result, even when the built-in cover shield 6F is attached to the mounting shield 5, the assemblability is improved and problems such as deformation are avoided.

  Further, the right-angle bent portion 6m absorbs variation in the amount of bending fitting of the inner bent portion of the side wall of the built-in cover shield 6, and makes the four sides contact the mounting shield 5 with uniform contact pressure. There is also. That is, when the built-in cover shield 6F is normally attached to the mounting shield 5, the state shown in FIG. 8 (a) is obtained, but when there are no right-angle bent portions 6m at the four corners, Depending on the position and the weight of the operator, the left and right side wall positions may become non-uniform as shown in FIG. For this reason, a conduction failure due to a decrease in contact pressure between the built-in cover shield 6F and the mounting shield 5 may occur, and the shield performance may deteriorate.

  On the other hand, the built-in cover shield 6F is provided with right-angled bent portions 6m at the four corners. Therefore, even if it is pushed into the opposite side wall as shown in FIG. Variations in the amount of bending fitting are absorbed.

  As described above, in the fourth embodiment, the shielding member having the above-described shape can achieve both the shielding property and the embedding property after reinforcing the strength of the electronic component such as the CPU 3 that radiates electromagnetic noise. It becomes.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the embodiment, and even if there is a design change without departing from the gist of the present invention, Included in the invention.
For example, in each of the embodiments described above, the electronic component that radiates electromagnetic noise is the CPU 3, but is not limited to the CPU. For example, an EPROM (Erasable and Programmable Read Only Memory) or a DDR-SDRAM (Double Data Rate Synchronous Dynamic Random Access). If it is an electronic component that radiates high-frequency electromagnetic noise by high-speed processing, such as Memory), substantially the same operations and effects as those of the above-described embodiment can be obtained.

  The present invention is not limited to mobile phones, and can be applied to all cases where electromagnetic noise radiated from electronic components mounted on a circuit board is shielded. This is effective for ensuring the strength of parts, reception performance and productivity for the communication equipment.

1 Mobile phone (electronic equipment)
2 Mounting board (circuit board)
3 CPU (Central Processing Unit) (electronic parts)
4 Antenna 5 Mounting shield (part of shield member, mounting shield)
6,6A, 6B, 6C, 6D, 6E, 6F Built-in cover shield (part of shield member, cover shield part)
6a, ..., 6a Warp part 6b, ..., 6b Warp part 6m, ..., 6m Right angle bent part

Claims (3)

A shield member that shields electromagnetic noise radiated from electronic components mounted on a circuit board,
A mounting shield part that is formed in a rectangular shape having an opening on the top surface side and is mounted on the circuit board so as to surround the electronic component;
The cover shield part is attached from the top surface side to the mounting shield part,
The cover shield part includes a top surface and a side wall part,
Among the side wall portions of each side, right and left bent portions are formed by bending the side walls at right angles from the end portion of the top surface to the mounting shield portion side in the regions near the four corners. , given to the other areas, an acute bent portion the side walls is bent at an acute angle to said mounting shield portion from an end portion of said top surface, from the lower end of該鋭pens curved portion, the side wall is outwardly A warped part that is bent and widened is formed,
While the mounting shield portion, in a state of being mounted on the circuit board by a conductive bonding material, wherein the warp section, responsible for preventing interference with the conductive bonding material,
The right-angled bent portion complements the structure in which it is difficult to determine the crowning position with respect to the mounting shield portion when observed from above when the cover shield portion is crowned to the mounting shield portion. The shield member plays a role of positioning and preventing deformation of the side wall in the other region. The four corners of the side wall portion of each side and the area near the four corners are as follows:
When the cover shield part is attached to the mounting shield part, the four sides of the cover shield part are configured to contact the mounting shield part with uniform contact pressure. Item 2. A shield member according to Item 1.   An electronic apparatus comprising the shield member according to claim 1.

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