JP2010093310A - Electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic apparatus capable of improving joint reliability of a joint part with a surface-mounted electronic component jointed to a circuit board thereat. <P>SOLUTION: Since the circuit board 10 is arranged at a position facing arrangement positions of solder balls 301 arranged at least at four corners of an outermost circumference out of solder balls 301 arranged in a lattice form on bottom faces of packages 12-14, rigidity of the circuit board 10 at the positions with the solder balls 301 jointed to the circuit board 10 can be improved; when external force is applied in a direction vertical to a first mounting surface 10a of the circuit board 10, deformation of the circuit board 10 in boundaries between positions facing the mounting parts of the packages 12-14 and a reinforcing member 11 never occurs, whereby damage of the solder balls 301 caused by the deformation of the circuit board 10 at the positions with the solder balls 301 jointed thereto can be prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic device.

  In recent years, electronic components such as semiconductor chips mounted on circuit boards have been diversified in packages, and surface-mounted electronic components (hereinafter referred to as surface mount type) that do not use leads or pins for electrical connection with the board. Mounting type electronic components) have been widely put into practical use.

  In such a surface mount type electronic component, a plurality of electrodes (pads) for connecting to an external circuit are formed on the bottom surface of the surface mount type electronic component, and bumps such as solder balls are formed in a lattice shape on the pad. There is a BGA (Ball Grid Array) package that is arranged as a connection terminal. The BGA package is mounted on the circuit board by so-called reflow soldering in which solder balls are heated and soldered in a state where the solder balls are in contact with pads of the circuit board to be connected.

  By the way, since the portable electronic device in which the circuit board is accommodated is portable, a large impact may be applied by dropping or the like. As a result, the circuit board accommodated in the electronic device may be greatly deformed, which applies a large stress to the connection part (solder part) between the surface-mounted electronic component and the circuit board, and damages the solder part. Sometimes. In particular, when an electronic device falls in a direction perpendicular to the board surface of the circuit board, the circuit board is greatly deformed, and among them, when the surface mount type electronic component is dropped, a large stress is applied to the solder portion. As a result, the solder part is easily damaged.

  Therefore, a technique for mounting a reinforcing plate on the back side of a surface-mounted electronic component with a circuit board interposed therebetween is disclosed (see Patent Document 1). The circuit board described in Patent Document 1 has a reinforcement larger than the outer dimension of the bottom surface of the surface-mounted electronic component on the back surface of the surface of the circuit board body on which the surface-mounted electronic component is mounted. The board is mounted so as to surround the mounting part of the surface-mounted electronic component.

JP 2006-210852 A

  However, the circuit board described in Patent Document 1 is mounted so that the reinforcing plate is shifted from the position facing the mounting portion of the surface-mounted electronic component. When an external force is applied in the vertical direction, the part between the position facing the mounting part of the surface-mount electronic component and the reinforcing plate is deformed, so that a large stress is applied to the solder part and the solder There is a problem that the part is damaged.

  The present invention has been made in view of the above, and an object of the present invention is to provide an electronic device that can improve the bonding reliability of a bonding portion where a surface-mount type electronic component and a circuit board are bonded. .

  In order to solve the above-described problems and achieve the object, the present invention has a housing, one surface accommodated in the housing, and the other surface positioned on the opposite side of the one surface. A circuit board, a first electronic component provided on the one surface and having two opposing first sides, and a second electronic component provided on the one surface and having two opposing second sides At least a portion is located between the electronic component, the first electronic component and the second electronic component, the third electronic component mounted on the one surface, and provided on the other surface, Two first reinforcing portions opposed to the two first side portions, two second reinforcing portions respectively opposed to the two second side portions, the two first reinforcing portions, and the two A third reinforcing portion that reinforces a region where the third electronic component is provided across the second reinforcing portion; the first reinforcing portion; and 3 located between the reinforcing portion characterized by comprising a reinforcing member including a first connecting portion that connects the two first reinforcing portion. According to another aspect of the invention, there is provided a housing, a circuit board that is accommodated in the housing and includes a first mounting area and a second mounting area, a first electronic component provided in the first mounting area, A second electronic component provided in two mounting areas, two reinforcing portions extending opposite to each other over the first mounting area and the second mounting area, the first mounting area, and the second mounting area. And a reinforcing member having a connecting portion that is located between the mounting region and connects the two reinforcing portions. According to another aspect of the invention, there is provided a housing, a circuit board that is accommodated in the housing and includes a first mounting area and a second mounting area, a first electronic component provided in the first mounting area, Located between the first mounting area and the second mounting area, the second electronic component provided in the two mounting areas, the first portion extending between the first mounting area and the second mounting area, And a reinforcing member having a second portion extending in a direction intersecting the direction in which the first portion extends.

  According to the present invention, there is an effect that it is possible to improve the bonding reliability of the bonded portion where the surface mount electronic component and the circuit board are bonded.

FIG. 1 is a perspective view of the portable computer according to the first embodiment. FIG. 2 is a perspective view showing the inside of the casing of the portable computer according to the first embodiment. FIG. 3 is a diagram illustrating an arrangement example of bumps arranged in a lattice pattern on the bottom surface of the package. FIG. 4 is an explanatory diagram showing the arrangement position of the solder balls projected onto the second mounting surface. 5 is a cross-sectional view taken along line F1-F1 of the housing shown in FIG. 6 is a cross-sectional view of the housing shown in FIG. 2 taken along line F2-F2. FIG. 7 is a perspective view of a reinforcing member according to a modified example. FIG. 8 is a perspective view of a reinforcing member according to a modification. FIG. 9 is a perspective view showing the inside of the casing of the portable computer according to the second embodiment.

  Exemplary embodiments of a portable electronic device according to the present invention will be explained below in detail with reference to the accompanying drawings. An example in which the portable electronic device of the present invention is applied to a portable computer such as a notebook personal computer will be described. However, the present invention is not limited to a portable computer, and the present invention can be applied to various electronic devices such as a digital camera, a video camera, and a personal digital assistant provided with a printed circuit board on which surface-mounted electronic components are mounted.

(First embodiment)
First, the configuration of the portable computer according to the present embodiment will be described with reference to FIGS. FIG. 1 is a perspective view of a portable computer according to the present embodiment. FIG. 2 is a perspective view showing the inside of the casing of the portable computer according to the present embodiment.

  A portable computer 1 according to the present embodiment includes a main body 2 and a display unit 3.

  The main body 2 includes a main body base 4 and a main body cover 5. The main body cover 5 is combined with the main body base 4 from above. When the main body base 4 and the main body cover 5 cooperate with each other, the main body 2 includes a housing 6 formed in a box shape.

  The housing 6 has an upper wall 6a, a peripheral wall 6b, and a lower wall 6c. The upper wall 6 a supports the keyboard 7. The peripheral wall 6b has a front peripheral wall 6ba, a rear peripheral wall 6bb, a left peripheral wall 6bc, and a right peripheral wall 6bd.

  The display unit 3 includes a display housing 8 and a liquid crystal display panel 9 accommodated in the display housing 8. The liquid crystal display panel 9 has a display screen 9a. The display screen 9 a is exposed to the outside of the display housing 8 through the opening 8 a on the front surface of the display housing 8.

  The display unit 3 is supported by a rear end portion of the housing 6 via a hinge device. Thereby, the display unit 3 is rotatable between a closed position where the display unit 3 is tilted so as to cover the upper wall 6a from above and an open position where the display unit 3 stands so as to expose the upper wall 6a.

  The housing 6 accommodates the circuit board 10, the reinforcing member 11, and the packages 12-14.

  The packages 12 to 14 are surface mount electronic components that do not use leads or pins for electrical connection with the substrate. In the present embodiment, the packages 12 to 14 have a base on which electrodes (pads) are formed on the bottom surface and the top surface, and a semiconductor chip which is an electronic component mounted on the top surface of the base is a flip chip mounting method or It is bonded to the pad by wire bonding and encapsulated by a resin member. Further, the pads formed on the upper surface of the base bonded to the semiconductor chip are electrically connected to the pads arranged in a lattice pattern on the bottom surface of the base.

  Then, bumps such as solder balls are arranged on the pads arranged on the bottom surface of the base, which is the bottom surface of the packages 12 to 14, thereby forming the packages 12 to 14 such as BGA and CSP (Chip Size Package) packages. . FIG. 3 is a view showing an arrangement example of solder balls arranged in a lattice pattern on the bottom surface of the package. In the present embodiment, as shown in FIG. 3, solder balls (bumps) 301 are arranged in a grid pattern on the bottom surfaces (base bottom surfaces) of the packages 12-14.

  Here, the BGA package is a package system in which solder balls 301 are arranged in a lattice pattern with a dispenser on the bottom surface of the package, and is used for surface mounting and soldering in a reflow furnace. The CSP is a kind of semiconductor chip packaging method, and is a packaging method having a size that is the same as or slightly larger than the size of the chip.

  The electronic components sealed in the packages 12 to 14 are, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), various chip sets, and the like. In addition, the electronic component enclosed with the packages 12-14 is not limited to the example mentioned above, Various electronic components shall correspond.

  On the circuit board 10, packages 12 to 14 are linearly mounted on the first mounting surface 10a, and a reinforcing member 11 described later is disposed on the second mounting surface 10b, which is the back surface of the first mounting surface 10a. . In the present embodiment, an example in which the packages 12 to 14 are mounted on the first mounting surface 10a in a substantially straight line will be described.

  Here, the first mounting surface 10 a is the lower surface of the circuit board 10. The first mounting surface 10a is opposed to the lower wall 6c, and the packages 12-14 are arranged via solder balls 301 arranged on pads arranged on the bottom surface of the base, which is the bottom surface of the packages 12-14. Be joined. Note that the bonding of the packages 12 to 14 to the first mounting surface 10a is performed by heating and soldering the solder balls 301 disposed on the bottom surfaces of the packages 12 to 14 in contact with the first mounting surface 10a. It shall be performed by so-called reflow soldering.

  The second mounting surface 10b is the upper surface of the circuit board 10 and is formed on the back side of the first mounting surface 10a. The second mounting surface 10b faces the upper wall 6a, and a reinforcing member 11 to be described later is disposed.

  Next, a specific configuration of the reinforcing member 11 and a mounting method of the reinforcing member 11 will be described with reference to FIGS. FIG. 4 is an explanatory diagram showing the arrangement position of the solder balls projected onto the second mounting surface. 5 is a cross-sectional view taken along line F1-F1 of the housing shown in FIG. 6 is a cross-sectional view of the housing shown in FIG. 2 taken along line F2-F2.

  As shown in FIG. 4, the reinforcing member 11 has the second mounting positions of solder balls 301 (indicated by hatching) arranged at least at four corners among the solder balls arranged on the bottom surfaces of the packages 12 to 14. It is assumed that it is disposed so as to pass through the projection position projected onto the surface 10b. As a result, among the solder balls 301 arranged in a lattice pattern on the bottom surfaces of the packages 12 to 14, the reinforcing member 11 is directly behind the solder balls 301 that are most likely to cause damage such as cracks or poor connection due to deformation of the circuit board 10. Can be arranged.

  In the present embodiment, as shown in FIG. 4, the reinforcing member 11 is the two outermost opposing sides of the solder balls 301 arranged in a lattice pattern on the bottom surfaces of the packages 12 to 14. Projection positions obtained by projecting the arrangement positions of the solder balls 301 (indicated by reference numerals 401 and 403) arranged on two sides extending in the mounting direction of the packages 12 to 14 mounted in a straight line onto the second mounting surface 10b. It is arranged to pass through.

  In the present embodiment, as shown in FIG. 4, the reinforcing member 11 is disposed on the outermost periphery of the solder balls 301 disposed in a lattice pattern on the bottom surfaces of the packages 12 and 14 mounted on the end portions. The solder balls 301 (indicated by reference numerals 401 to 404) are disposed so as to pass through the projection positions projected on the second mounting surface 10b.

  As a result, as shown in FIGS. 5 and 6, among the solder balls 301 arranged in a lattice pattern on the bottom surfaces of the packages 12 and 14 mounted on the end portions, the solder balls 301 arranged on the outermost periphery. The reinforcing member 11 can be disposed directly behind the first member. Further, as shown in FIG. 6, two solder balls 301 arranged in a lattice pattern on the bottom surface of the package 13 mounted on the portion other than the end portions are opposed to the outermost two opposite sides and are substantially linear. The reinforcing member 11 can be disposed directly behind the solder balls 301 disposed on the two sides extending in the mounting direction of the mounted packages 12 to 14.

  The reinforcing member 11 is provided with eight screw holes 11a, and the second mounting surface 10b of the circuit board 10 is formed with mounting holes (not shown) for screwing screws. In the present embodiment, first, the solder balls 301 indicated by reference numerals 401 to 404 disposed on the bottom surfaces of the packages 12 and 14 and the solder balls 301 indicated by reference numerals 401 and 403 disposed on the bottom surface of the package 13 are opposed to each other. The reinforcing member 11 is placed on the second mounting surface 10b so that the reinforcing member 11 is disposed at the position. Next, the position of the reinforcing member 11 is adjusted on the second mounting surface 10b so that the position of the mounting hole formed in the circuit board 10 and the position of the screw hole 11a provided in the reinforcing member 11 coincide. To do. Then, the reinforcing member 11 is attached to the circuit board 10 by inserting a screw through the screw hole 11 a of the reinforcing member 11 and further screwing it into the mounting hole of the circuit board 10. In the present embodiment, the reinforcing member 11 is made of a highly rigid metal or resin as a material.

  Thus, according to the present embodiment, among the solder balls 301 arranged on the bottom surfaces of the packages 12 to 14, the reinforcing member 11 is arranged directly behind the solder balls 301 arranged at least at the four corners. Therefore, the rigidity of the circuit board 10 at the position where the solder ball 301 and the circuit board 10 are joined can be improved, and an external force is applied in a direction perpendicular to the first mounting surface 10a of the circuit board 10. Since the deformation of the circuit board 10 does not occur at the boundary between the position facing the mounting portion of the packages 12 to 14 and the reinforcing member 11 when added, the deformation of the circuit board 10 at the position where the solder balls 301 are joined is performed. Damage to the solder ball 301 can be prevented.

  Conventionally, since the reinforcing member is provided for each package mounted on the circuit board, the portion between the packages (that is, the reinforcing member is disposed) with respect to the portion where the reinforcing member is provided. There is a problem that the rigidity of the circuit board in the portion not provided) is relatively weak, and the circuit board is locally curved in the portion between the packages.

  However, according to the present embodiment, the mounting locations of the plurality of packages 12 to 14 are reinforced by the integrated reinforcing member 11 and the rigidity of the circuit board 10 in the portion between the packages is also improved. Since the local curvature of the circuit board 10 in a portion between the packages can be suppressed and the deformation of the circuit board 10 can be further reduced, the damage of the solder balls 301 due to the deformation of the circuit board 10 can be more effectively performed. Can be prevented.

(Modification)
In the first embodiment, among the solder balls 301 arranged in a lattice pattern on the bottom surfaces of the packages 12 and 14 mounted on the end portions, the solder ball 301 arranged on the outermost periphery has a second arrangement position. Although the reinforcing member 11 is disposed so as to pass through the projection position projected onto the mounting surface 10b, the present invention is not limited to this.

  For example, among the solder balls 301 arranged in a lattice pattern on the bottom surface of the package mounted on the portion other than the end, a projection obtained by projecting the arrangement position of the solder balls 301 arranged on the outermost periphery onto the second mounting surface 10b The reinforcing member 11 may be disposed so as to pass through the position. Alternatively, among the solder balls 301 arranged in a lattice pattern on the bottom surface of the package mounted on at least one of the end portions and other than the end portions, the arrangement position of the solder balls 301 arranged on the outermost periphery is the second mounting position. The reinforcing member 11 may be disposed so as to pass through the projection position projected onto the surface 10b.

  FIG. 7 is a perspective view of a reinforcing member according to this modification. 7 includes solder balls 301 (reference numerals 401 to 404) arranged on the outermost periphery among the solder balls 301 arranged in a lattice pattern on the bottom surface of the package 13 mounted on the portion other than the end portion. Are arranged so as to pass through the projection position projected on the second mounting surface 10b.

  Further, the reinforcing member 700 shown in FIG. 7 is solder disposed at least on the two outermost sides of the solder balls 301 disposed in a lattice pattern on the bottom surfaces of the packages 12 and 14 mounted on the end portions. It passes the projection position which projected the arrangement position of the solder ball 301 (it shows with the code | symbol 401 and the code | symbol 403) which is the ball | bowl 301, and is arrange | positioned at two sides extended in the mounting direction of the packages 12-14. It is arranged like this.

  In this modification, the reinforcing member 700 is arranged in addition to the solder balls 301 indicated by the reference numerals 401 and 403, and the arrangement positions of the solder balls 301 indicated by the reference numeral 404 of the package 12 and the solder balls 301 indicated by the reference numeral 402 of the package 14. Is disposed so as to pass through the projection position projected onto the second mounting surface 10b.

  FIG. 8 is a perspective view of a reinforcing member according to another modification. A reinforcing member 800 shown in FIG. 8 is a solder ball 301 disposed on at least two outermost sides of the solder balls 301 disposed in a lattice pattern on the bottom surfaces of the packages 12 to 14. The solder balls (indicated by reference numerals 401 and 403) disposed on two sides extending in the mounting direction 14 are disposed so as to pass through the projection positions projected on the second mounting surface 10b.

  In this modification, the reinforcing member 800 includes a solder ball 301 and a package indicated by reference numeral 404 of the package 12 in addition to the solder balls 301 indicated by reference numerals 401 and 403 of the packages 12 and 13 mounted on the ends. 14 is disposed so as to pass through the projected position of the solder ball 301 indicated by reference numeral 402 projected onto the second mounting surface 10b.

(Second Embodiment)
In the portable computer according to the present embodiment, when the package is mounted in an L shape on the circuit board, the reinforcing member is also arranged according to the mounting position of the package, so that it is the same as the first embodiment. An effect is obtained. Since the configuration of the portable computer is almost the same as that of the first embodiment, only the parts different from the first embodiment will be described.

  FIG. 9 is a perspective view showing the inside of the casing of the portable computer according to the second embodiment. As for the circuit board 10, the packages 12-14 are mounted in the L-shape on the 1st mounting surface 10a.

  The reinforcing member 900 includes at least two adjacent outermost peripheral solder balls 301 arranged in a lattice pattern on the bottom surface of the package 13 mounted on the corners of the packages 12 to 14 mounted in an L shape. The positions of the solder balls 301 (indicated by reference numerals 401 and 402) disposed on the two L-shaped sides that are bent substantially parallel to the mounting direction of the packages 12 to 14 are the second mounting surface 10b. It is arranged so as to pass through the projection position projected onto the screen. Further, the reinforcing member 900 passes through a projection position obtained by projecting the placement position of the solder ball 301 placed on the corner portion on the diagonal line of the corner portions of the two L-shaped sides onto the second mounting surface 10b. It is arranged.

  Further, in the present embodiment, the reinforcing member 900 is the solder ball 301 disposed on the outermost periphery among the solder balls 301 disposed in a lattice pattern on the bottom surfaces of the packages 12 and 14 mounted on the end portions. It arrange | positions so that the arrangement position (it shows with the code | symbol 401-404) may pass along the projection position which projected on the 2nd mounting surface 10b.

  In the present embodiment, among the solder balls 301 arranged in a lattice pattern on the bottom surfaces of the packages 12 and 14 mounted on the end portions, the reinforcing member is directly behind the solder balls 301 arranged on the outermost periphery. 11 is provided, but it is only necessary that the reinforcing member 11 be disposed directly behind the position where the solder balls 301 disposed at the four corners of the outermost periphery are joined to the circuit board 10. Not what you want.

  For example, the reinforcing member 900 is a solder ball 301 (reference numeral 401) arranged on the outermost periphery among the solder balls 301 arranged in a grid pattern on the bottom surface of the package 13 mounted on the end portion (corner portion) other than the end portion. (Shown by -404) may be arranged so as to pass through the projection position projected on the second mounting surface 10b.

  Thus, according to the present embodiment, among the solder balls 301 arranged in a lattice pattern on the bottom surfaces of the packages 12 to 14 mounted in an L shape, they are arranged at least at the four corners of the outermost periphery. Since it is disposed at a position opposite to the position where the solder ball 301 is disposed, the same effect as in the first embodiment can be obtained.

  Further, according to the present embodiment, the mounting locations of the plurality of packages 12 to 14 are reinforced by the integrated reinforcing member 900, and the rigidity of the circuit board 10 in the portion between the packages is also improved. The same effect as in the first embodiment can be obtained.

DESCRIPTION OF SYMBOLS 1 Portable computer 2 Main body 3 Display unit 4 Main body base 5 Main body cover 6 Case 6a Upper wall 6b Peripheral wall 6c Lower wall 6ba Front peripheral wall 6bb Rear peripheral wall 6bc Left peripheral wall 6bd Right peripheral wall 7 Keyboard 8 Display housing 8a Opening 9 Liquid crystal display panel 9a Display screen 10 Circuit board 10a First mounting surface 10b Second mounting surface 11,700,800,900 Reinforcing member 11a Screw hole 301 Solder ball

Claims (10)

A housing,
A circuit board housed in the housing and having one surface and the other surface located on the opposite side of the one surface;
A first electronic component provided on the one surface and having two first sides facing each other;
A second electronic component provided on the one surface and having two opposing second sides;
A third electronic component at least partially located between the first electronic component and the second electronic component and mounted on the one surface;
Provided on the other surface, two first reinforcing portions respectively opposed to the two first side portions, two second reinforcing portions respectively opposed to the two second side portions, and A third reinforcing portion for reinforcing a region where the third electronic component is provided across the two first reinforcing portions and the two second reinforcing portions; and the first reinforcing portion and the third reinforcing portion. A reinforcing member including a first connecting portion that is located between and connects the two first reinforcing portions;
An electronic device characterized by comprising:   The said reinforcing member has a 2nd connection part which connected the said 2nd 2nd reinforcement part and was located between the said 2nd reinforcement part and the said 3rd reinforcement part, The Claim 1 characterized by the above-mentioned. Electronics.   A connecting portion between the first connecting portion and the two first reinforcing portions is provided with a first screw hole portion through which a screw is passed, and the second connecting portion and the two second reinforcing portions The electronic device according to claim 2, wherein each of the connection portions is provided with a second screw hole portion through which a screw is passed. A housing,
A circuit board housed in the housing and having a first mounting area and a second mounting area;
A first electronic component provided in the first mounting region;
A second electronic component provided in the second mounting area;
The two reinforcing portions extending opposite to each other over the first mounting region and the second mounting region, and the two reinforcing members positioned between the first mounting region and the second mounting region. A reinforcing member having a connecting part connecting the parts;
An electronic device characterized by comprising: The circuit board is provided with a third electronic component, and has a third mounting region in which at least part is located between the first mounting region and the second mounting region,
The electronic device according to claim 4, wherein the connecting portion supports the third mounting region.   The electronic device according to claim 5, wherein the connection portion includes two support portions that support an outer edge portion of the third mounting region.   The circuit board includes one surface on which the first electronic component is provided and the other surface on the opposite side of the one surface and on which the reinforcing member is provided. 6. The electronic device according to 6.   8. The screw hole portion through which a screw for fixing the circuit board and the reinforcing member is passed is provided at a connection portion between the connecting portion and the two reinforcing portions. The electronic device described.   The said reinforcing member is a frame-shaped metallic plate surrounding the said 1st mounting area | region, the said 2nd mounting area | region, and the said 3rd mounting area | region, and including the said reinforcement part. Electronic equipment. A housing,
A circuit board housed in the housing and having a first mounting area and a second mounting area;
A first electronic component provided in the first mounting region;
A second electronic component provided in the second mounting area;
The first portion extending between the first mounting region and the second mounting region, and located between the first mounting region and the second mounting region, intersecting the direction in which the first portion extends. A reinforcing member having a second portion extending in the direction;
An electronic device characterized by comprising:

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