JP5345179B2 - Circuit board - Google Patents

Abstract

A shielding board which covers an IC chip comprises an upper board part which covers an upper surface of the IC chip and a side wall part which surrounds the periphery of the IC chip. The side wall part comprises an oblique wall part. The oblique wall part is obliquely formed relative to a first side and a second side of the IC chip, and is located at a diagonal line of the IC chip which passes through the corner of the first side and the second side. The oblique wall part sags from the edge of the upper board part towards a substrate body of the circuit substrate, and has a lower edge which is installed towards the substrate body. Based on the structure, even in the circumstance of bending of the circuit substrate, corners of the IC chip can be restrained from deviating from the substrate body of the circuit substrate.

Description

  The present invention relates to the shape of a plate that covers an IC chip mounted on a circuit board and shields electromagnetic waves.

  In an electronic device as disclosed in Patent Document 1 below, a metal plate that covers an IC chip may be used to shield electromagnetic waves emitted from the IC chip.

US Patent Application Publication No. 2007/0202956

  When the housing of the electronic device is pushed from the outside, a force for bending the base material (substrate body) of the circuit board on which the IC chip is mounted may act. When the substrate body is slightly bent, a force for separating the edge of the IC chip from the substrate body acts. Such forces are particularly likely to act on the corners of the IC chip.

  An object of the present invention is to prevent the corners of an IC chip from being detached from a substrate body.

  A circuit board according to the present invention includes a board body, an IC chip mounted on the board body, a shield plate including an upper plate portion covering the upper surface of the IC chip and a side wall portion surrounding the outer periphery of the IC chip. Prepare. The side wall portion includes at least one inclined wall portion. The at least one inclined wall portion is formed obliquely with respect to both the first side of the IC chip and the second side of the IC chip, and an angle between the first side and the second side. It is located on the diagonal of the IC chip passing through. Further, the at least one inclined wall portion has a lower edge attached to the substrate main body, which is lowered from the edge of the upper plate portion toward the substrate main body. According to the present invention, the substrate body is less likely to bend near the corner of the IC chip, so that the corner of the IC chip can be prevented from being detached from the substrate body.

It is a top view of the circuit board concerning the embodiment of the present invention. It is a side view which faces the said circuit board to the arrow II shown in FIG. It is a perspective view which faces the inner side of the shield plate which covers the IC chip mounted in the said circuit board from diagonally.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a circuit board 1 according to an embodiment of the present invention. FIG. 2 is an enlarged side view of the circuit board 1 facing in the direction of arrow II shown in FIG. FIG. 3 is a perspective view of the shield plate 20 that covers the IC chip 2 mounted on the circuit board 1.

  The circuit board 1 includes a plate-like board body 10. The substrate body 10 is a rigid substrate such as a glass epoxy substrate or a paper phenol substrate. A plurality of electronic components are mounted on the substrate body 10 and a circuit pattern is formed. In FIG. 1, the IC chip 2 mounted on the substrate body 10 is shown. The IC chip 2 is mounted on the surface of the substrate body 10. For example, ball-shaped or planar electrodes arranged in a grid are formed on the bottom surface of the IC chip 2, and the electrodes are soldered to the surface of the substrate body 10. The mounting method of the IC chip 2 is not limited to this. For example, terminals formed on the edge of the IC chip 2 may be soldered to the surface of the substrate body 10. The IC chip 2 is, for example, a microprocessor that controls the entire electronic device on which the circuit board 1 is mounted, performs image processing, and performs wireless communication signal processing. The function of the IC chip 2 is not limited to these.

  The circuit board 1 includes a shield plate 20 for shielding electromagnetic waves emitted from the IC chip 2. As shown in FIGS. 1 and 3, the shield plate 20 has an upper plate portion 21 that covers the upper surface of the IC chip 2. The upper plate portion 21 has a size larger than the upper surface of the IC chip 2. In this example, the IC chip 2 is disposed substantially below the center portion of the upper plate portion 21.

  The upper plate portion 21 in this example has a plurality of leaf spring portions 21a and 21b. The leaf spring portion 21a is located inside the outer edge of the upper plate portion 21, and is formed to extend obliquely upward. Moreover, the leaf | plate spring part 21b is formed so that it may extend outside the shield plate 20 in planar view of the circuit board 1, as shown in FIG. These leaf spring portions 21a and 21b are in contact with other components included in the electronic device on which the circuit board 1 is mounted. Thereby, the shield plate 20 is electrically grounded. In this example, the leaf spring portion 21b extends in a direction perpendicular to the second side 2b of the IC chip 2 described later, and is located between the parallel wall portion 24C and the inclined wall portion 23B. Further, the upper plate portion 21 is further formed with an opening 21c. By this opening 21c, an operator can confirm the attachment state of electronic components other than the IC chip 2 disposed inside the shield plate 20, and the heat dissipation of the IC chip 2 can be improved. In this example, the opening 21c is formed along a parallel wall portion 24D described later.

  As shown in FIG. 1, the IC chip 2 is rectangular, and has a first side 2a and a second side 2b that are orthogonal to each other. The shield plate 20 has a side wall portion 22 surrounding the outer periphery of the IC chip 2 (see FIG. 3). The side wall portion 22 includes a plurality of parallel wall portions 24A, 24B, 24C, and 24D that are arranged in parallel with the direction along the first side 2a or the second side 2b. In this example, the parallel wall portion 24A and the parallel wall portion 24B are located on opposite sides of the IC chip 2 and are formed along two opposing first sides 2a. The parallel wall portion 24C and the parallel wall portion 24D are located on opposite sides of the IC chip 2 and are formed along two opposing second sides 2b.

  As shown in FIGS. 2 and 3, the parallel wall portions 24 </ b> A to 24 </ b> D are bent at the edge of the upper plate portion 21 and are lowered toward the substrate body 10 from the edge of the upper plate portion 21. The lower edges of the parallel wall portions 24 </ b> A to 24 </ b> D are attached to the surface of the substrate body 10. Specifically, the lower edges of the parallel wall portions 24 </ b> A to 24 </ b> D are soldered to the surface of the substrate body 10. Note that the lower edges of the parallel wall portions 24 </ b> A to 24 </ b> D may be attached to a ground circuit pattern formed on the substrate body 10.

  As shown in FIGS. 1 and 3, the side wall portion 22 further includes an inclined wall portion formed obliquely with respect to both the first side 2a and the second side 2b. The side wall portion 22 in this example includes a plurality (four in this example) of inclined wall portions 23A, 23B, 23C, and 23D. The outer periphery of the IC chip 2 is surrounded by the inclined wall portions 23A, 23B, 23C, 23D and the parallel wall portions 24A, 24B, 24C, 24D.

  As shown in FIG. 1, the inclined wall portions 23 </ b> A and 23 </ b> B are located on one diagonal line L <b> 1 passing through the corners of the first side 2 a and the second side 2 b of the IC chip 2. The inclined wall portions 23C and 23D are located on the other diagonal line L2 passing through the corners of the first side 2a and the second side 2b of the IC chip 2. The inclined wall portions 23A to 23D are located outside the corners of the IC chip 2 and are arranged so as to intersect the diagonal lines L1 and L2. As shown in FIGS. 2 and 3, the inclined wall portions 23 </ b> A to 23 </ b> D are bent toward the substrate body 10 at the edge of the upper plate portion 21, and are lowered toward the substrate body 10 from the edge of the upper plate portion 21. The lower edges of the inclined wall portions 23 </ b> A to 23 </ b> D are attached to the surface of the substrate body 10. Specifically, the entire lower edges of the inclined wall portions 23 </ b> A to 23 </ b> D are attached to the substrate body 10. In other words, the attachment positions of the inclined wall portions 23A to 23D and the substrate body 10 are provided across the diagonal lines L1 and L2. According to this structure, the bending of the substrate body 10 at a portion close to the corner of the IC chip 2 is suppressed by the inclined wall portions 23A to 23D. As a result, it is possible to suppress the corners of the IC chip 2 from being separated from the substrate body 10. Such a structure of the shield plate 20 is particularly effective when the IC chip 2 is mounted by the electrodes arranged in the above-described lattice shape. Note that the lower edges of the inclined wall portions 23A to 23D are attached to the surface of the substrate body 10 by soldering, for example. The lower edges of the inclined wall portions 23 </ b> A to 23 </ b> D may be connected to a ground circuit pattern formed on the substrate body 10.

  The inclined wall portions 23A to 23D are bent at the edge of the upper plate portion 21 as described above. Due to this bent portion, the deformation of the inclined wall portions 23A to 23D itself can be suppressed, and the bending of the substrate body 10 can be further effectively suppressed.

  In the following description, the inclined wall portions denoted by reference numerals 23A, 23B, 23C, and 23D are referred to as a first inclined wall portion, a second inclined wall portion, a third inclined wall portion, and a fourth inclined wall portion, respectively. As shown in FIG. 1, the first inclined wall portion 23 </ b> A and the second inclined wall portion 23 </ b> B are located on opposite sides of the IC chip 2. Further, the third inclined wall portion 23C and the fourth inclined wall portion 23D are located on opposite sides of the IC chip 2. The inclined wall portions 23A, 23B, 23C, and 23D and the parallel wall portions 24A, 24B, 24C, and 24D are alternately arranged in the circumferential direction of the IC chip 2, and generally have an approximately octagonal shape in plan view of the circuit board 1. ing.

  The shield plate 20 is formed from a single metal plate, for example, by pressing. A slit is formed between the inclined wall portion and the parallel wall portion so that the inclined wall portions 23A to 23D and the parallel wall portions 24A to 24D can be bent with respect to the upper plate portion 21 when the shield plate 20 is formed. (See FIGS. 2 and 3).

  As shown in FIG. 1, the inclined wall portions 23A to 23D are located closer to the IC chip 2 than the parallel wall portions 24A to 24D. That is, the distance from the first inclined wall portion 23A to the corner of the IC chip 2 closest to the first inclined wall portion 23A is the distance from the parallel wall portions 24A, 24B to the first side 2a of the IC chip 2, It is smaller than the distance from the parallel wall parts 24C, 24D to the second side 2b. Similarly, the distance from the inclined wall portions 23B, 23C, 23D to the corner of the IC chip 2 closest to them is the distance from the parallel wall portions 24A, 24B to the first side 2a of the IC chip 2 or the parallel wall portion. It is smaller than the distance from 24C, 24D to the second side 2b. Therefore, the bending of the substrate main body 10 near the corner of the IC chip 2 can be more effectively suppressed.

  As shown in FIG. 1, the third inclined wall portion 23 </ b> C is substantially orthogonal to the diagonal line L <b> 2 and is symmetric with respect to the diagonal line L <b> 2. Similarly, the fourth inclined wall portion 23D is also substantially orthogonal to the diagonal line L2 and symmetrical with respect to the diagonal line L2. Therefore, the inclined wall portions 23C and 23D can suppress the bending of the substrate body 10 near the corner of the IC chip 2 evenly with respect to the diagonal line L2. The third inclined wall portion 23C and the fourth inclined wall portion 23D are parallel to each other and have substantially the same width in the plan view of the circuit board 1.

  The first inclined wall portion 23A and the second inclined wall portion 23B have different widths in plan view of the circuit board 1. In this example, as shown in FIG. 1, the width of the first inclined wall portion 23A is larger than the width of the second inclined wall portion 23B. Thereby, it can suppress more effectively that the corner | angular of the IC chip 2 near the 1st inclination wall part 23A remove | deviates from the board | substrate body 10. FIG. The position of the first inclined wall portion 23A may be determined in consideration of the shape of the substrate body 10 and the like. That is, depending on the shape of the substrate body 10, a particularly large load may be applied to one of the four corners of the IC chip 2. The first inclined wall portion 23A may be formed near such a corner.

  In this example, the second inclined wall portion 23B, the third inclined wall portion 23C, and the fourth inclined wall portion 23D have substantially the same width, and these widths are the widths of the two parallel wall portions 24A and 24B facing each other. Smaller than. Thereby, the area | region inside the shield plate 20 can be enlarged. The first inclined wall portion 23A described above has a larger width than the three inclined wall portions 23B, 23C, and 23D. In this example, the leaf spring portion 21b is formed adjacent to the parallel wall portion 24C, and the width of the parallel wall portion 24C is smaller than the parallel wall portions 24A and 24B by the width of the leaf spring portion 21b. . The leaf spring portion 21b extends in a direction perpendicular to the side of the IC chip 2 (in this example, the second side 2b). According to such an arrangement of the leaf spring portion 21b, the leaf spring portion 21b can be easily formed without reducing the width of the inclined wall portion (in this example, the second inclined wall portion 23B).

  Further, the distance from the first inclined wall portion 23A to the corner of the IC chip 2 closest to the first inclined wall portion 23A is the 2IC chip 2 closest to the second inclined wall portion 23B from the second inclined wall portion 23B. Is less than the distance to the corner. Also with this structure, it is possible to effectively suppress the corner of the IC chip 2 close to the first inclined wall portion 23A from being detached from the substrate body 10.

  As shown in FIG. 1, the first inclined wall portion 23A and the second inclined wall portion 23B in this example are formed obliquely to each other. That is, the direction A along the first inclined wall portion 23A is inclined with respect to the direction B along the second inclined wall portion 23B. Thereby, the circuit board which has tolerance with respect to the bending around more straight lines is obtained. That is, according to this structure, the circuit board 1 can have high resistance not only to the diagonal line L1 but also to bending around a straight line inclined with respect to the diagonal line L1 (for example, the straight line L3 in FIG. 1).

  Further, in the structure in which all of the inclined wall portions 23A to 23D are orthogonal to the diagonal line L1 or the diagonal line L2, the degree of freedom in the layout of electronic components and circuit patterns arranged inside or outside the shield plate 20 is reduced. By providing the shield plate 20 with the second inclined wall portion 23B and the first inclined wall portion 23A that are inclined with respect to each other, the degree of freedom in the layout of electronic components and circuit patterns can be increased.

  As described above, the lower edges of the inclined wall portions 23 </ b> A to 23 </ b> D and the lower edges of the parallel wall portions 24 </ b> A to 24 </ b> D are attached to the surface of the substrate body 10. As shown in FIG. 3, attachment portions 23a and 24a are formed on the lower edges of these. The attachment portions 23 a formed on the inclined wall portions 23 </ b> A to 23 </ b> D are bent with respect to the inclined wall portions 23 </ b> A to 23 </ b> D so as to be parallel to the substrate main body 10, thereby forming a flange shape. Similarly, the attachment portions 24a formed on the parallel wall portions 24A to 24D are bent with respect to the parallel wall portions 24A to 24D so as to be parallel to the substrate body 10 and have a flange shape. The attachment portions 23a and 24a are attached to the substrate body 10 by, for example, solder. By forming such attachment portions 23a and 24a on the lower edge, the attachment strength of the lower edge can be increased, and the bending of the substrate body 10 can be more effectively suppressed.

  In this example, the attachment portions 23 a and 24 a are bent to the outside of the shield plate 20 in the plan view of the circuit board 1. Therefore, it is easy to secure an area for arranging electronic components other than the IC chip 2 inside the shield plate 20.

  As described above, the shield plate 20 includes the inclined wall portions 23A to 23D. The inclined walls 23A to 23D are formed obliquely with respect to both the first side 2a and the second side 2b of the IC chip 2, and are diagonal lines L1 or L2 passing through the corners of the first side 2a and the second side 2b. Located on the top. The inclined wall portions 23 </ b> A to 23 </ b> D are lowered from the edge of the upper plate portion 21 toward the substrate body 10, and the lower edge is attached to the substrate body 10. According to this structure, the substrate body 10 is less likely to bend near the corner of the IC chip 2, so that the corner of the IC chip 2 can be prevented from being detached from the substrate body 10.

  Further, the first inclined wall portion 23A and the second inclined wall portion 23B are located on the diagonal line L1 and located on opposite sides of the IC chip 2 therebetween. According to this structure, the bending around the diagonal line L1 can be more effectively suppressed. Further, the third inclined wall portion 23C and the fourth inclined wall portion 23D are located on the diagonal line L2, and are located on the opposite sides with respect to the IC chip 2. According to this structure, the bending around the diagonal line L2 can be more effectively suppressed.

  Further, the first inclined wall portion 23 </ b> A and the second inclined wall portion 23 </ b> B have different widths in a plan view of the circuit board 1. According to this structure, it is possible to more effectively suppress the corner of the IC chip 2 near the first inclined wall portion 23A from being separated from the substrate body 10.

  Further, the first inclined wall portion 23A and the second inclined wall portion 23B are arranged obliquely to each other. According to this structure, not only the bending around the diagonal line L1, but also the bending around a straight line inclined with respect to the diagonal line L1 (for example, L3 shown in FIG. 1) can be suppressed.

  The inclined wall portions 23 </ b> A to 23 </ b> D have a flange-shaped attachment portion 23 a that is bent in a direction parallel to the substrate body 10 at the lower edge. According to this structure, the attachment strength of the lower edge is increased, and the bending of the substrate body 10 can be more effectively suppressed.

  The present invention is not limited to the circuit board 1 described above, and various modifications can be made.

  For example, the shield plate 20 of the circuit board 1 has four inclined wall portions 23A to 23D, but the number of inclined wall portions is not limited to this. For example, only one inclined wall portion may be provided on the shield plate 20. In this case, the inclined wall portion may be formed close to the corner on which the load is most applied when the substrate body 10 is bent among the four corners of the IC chip 2.

  In the above description, the leaf spring portions 21 a and 21 b are formed on the shield plate 20. However, the leaf spring portions 21 a and 21 b may not be provided on the shield plate 20. Further, in the above description, the opening 21 c is formed in the shield plate 20. However, the opening 21c is not necessarily formed.

  Further, in the above description, the flange-shaped attachment portions 23a and 24a are formed on the inclined wall portions 23A to 23D and the parallel wall portions 24A to 24D. However, such attachment portions 23a and 24a are not necessarily formed.

  1 Circuit board, 2 IC chip, 2a First side of IC chip, 2b Second side of IC chip, 10 Substrate body, 20 Shield plate, 21 Upper plate part, 22 Side wall part, 23A, 23B, 23C, 23D Inclined wall Part, 23a attaching part, 24A, 24B, 24C, 24D parallel wall part, 24a attaching part, L1, L2 diagonal.

Claims (2)

A substrate body;
An IC chip mounted on the substrate body;
A shield plate including an upper plate portion covering the upper surface of the IC chip and a side wall portion surrounding the outer periphery of the IC chip,
The side wall portion is formed obliquely with respect to both the first side of the IC chip and the second side of the IC chip, and the IC passes through an angle between the first side and the second side. A first inclined wall portion located on a diagonal line of the chip, and a second inclined wall portion located on the diagonal line and facing the first inclined wall portion with the IC chip interposed therebetween ,
The first inclined wall portion and the second inclined wall portion have different widths in a plan view of the circuit board and are disposed obliquely to each other,
The first inclined wall portion and the second inclined wall portion are lowered from the edge of the upper plate portion toward the substrate body, and are bent at a lower edge thereof in a direction parallel to the substrate body, It has a flange-like mounting part that can be attached to the board body.
A circuit board characterized by that. The circuit board according to claim 1,
The shield plate has a leaf spring portion extending laterally from an edge of the upper plate portion,
The first inclined wall portion has a larger width than the second inclined wall portion, and includes a portion located on the opposite side of the leaf spring portion with the IC chip interposed therebetween.
A circuit board characterized by that.

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