JP2001156086A - Additional reinforcing structure of ic package and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability for reinforcing IC package and enable to perform maintenance of the IC package after resin sealing. SOLUTION: An additional reinforcing structure 1 of an IC package is mounted on a mother board 2 and sealed at a portion thereof by a resin for reinforcing the package. A box-type reinforcing member 4 with a lid covers the IC package 3 and comprises a side 4a and a lid 4b into which the package reinforcing resin 5 can be injected is mounted on the mother board 2a. The additional reinforcing member 4 has a through hole 12 passing through the lid 4b and a notch 10 passing through the side 4a, and has an opening in its periphery of two resin inlets 10, 12 free from overlapping each other in a linear direction on the same plane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an IC package reinforcement structure and a method suitable for use in mounting a ball grid array (BGA) type IC package on a motherboard, for example.

[0002]

2. Description of the Related Art In recent years, office automation (O
A) With the progress of miniaturization and multifunctionalization of devices and the like, the importance of high-density mounting technology for electronic components is increasing. Such high-density mounting of electronic components is realized, for example, by mounting a BGA type IC package on a motherboard.

Conventionally, as a mounting structure of this type of IC package, one shown in FIGS. 7A and 7B has been adopted. The mounting structure of the IC package will be described with reference to FIGS. 7A and 7B. In FIG. 7, the mounting structure of the IC package indicated by reference numeral 71 includes a motherboard 72 and an IC package 73. The motherboard 72 is made of a printed wiring board, and is housed in an electronic device housing (not shown).

[0004] The IC package 73 has an interposer substrate 74 and an electronic component 75. The interposer board 74 has through holes (not shown) and is mounted on the motherboard 72 by solder balls 76.

The electronic component 75 is entirely made of a molding resin 77.
And is mounted on the interposer substrate 74 by bonding wires (not shown) or the like. Thus, the electronic component 75 is electrically connected to the motherboard 72.

The solder balls 76 are composed of a large number of solder balls arranged in a matrix on the back surface of the interposer substrate 74 except for the chip mounting area. The solder balls 76 are welded on the surface of the motherboard 72 using a reflow soldering technique. I have.

In this type of IC package mounting structure, since the mounting of the IC package 73 on the motherboard 72 is performed only by the solder balls 76, for example, a QFP (Quad Flat) is used.
The IC package 73 is easily detached from the motherboard 72 as compared with the case where a package type IC package is mounted on the motherboard.

This is because external forces such as shock and vibration applied to the motherboard or the IC package are hardly absorbed by the solder balls 76 in the BGA type IC package, and become external forces for detaching the IC package 73 as they are. On the other hand, in the QFP type IC package, a part is absorbed by the U-shaped portion of the lead, so that an impact applied to the IC package or the mother board is reduced.

Therefore, in a BGA type IC package, when an external force such as an impact or vibration is applied to the motherboard or the IC package, the IGA on the motherboard 72 is reduced.
A connection failure occurred in the C package 73, and the reliability in package mounting was reduced. In particular, when a BGA type IC package is mounted in an electronic device such as a mobile phone, if an impact is applied to the electronic device due to a drop or the like, the IC package may be detached from the motherboard and the device cannot be used. is there.

Therefore, as means for preventing such detachment of the IC package, the entire IC package mounted on the motherboard is sealed with resin.
A device for reinforcing an IC package has been proposed.

[0011]

However, in this kind of IC package reinforcing structure, since the IC package is simply sealed with resin, it is necessary to perform sufficient resin sealing by flowing resin around the package. Could not. As a result, a required reinforcing strength cannot be obtained, that is, a sufficient connecting strength of the IC package to the motherboard cannot be obtained, and there is a problem that reliability in reinforcing the package is reduced.

For this reason, in order to obtain the required reinforcing strength, it is conceivable to seal the IC package with a large amount of resin. However, in this case, not only does the entire structure become large, but also the large amount of resin around the package. Due to the flow, other IC packages and the like cannot be mounted on the motherboard, which hinders high-density mounting of electronic components.

In a conventional reinforcing structure of an IC package, the entire IC package is sealed with resin.
There is also a problem that the C package 73 is buried in the resin, so that maintenance or the like of the IC package after resin sealing cannot be performed.

Japanese Patent Application Laid-Open No. 8-153824 discloses a method of forming a lead in contact with the motherboard from the viewpoint of preventing the package from being tilted due to the melting of the solder ball when the BGA type IC package is mounted. "Grid array package" has been proposed. However, in the package described in this publication, it was possible to perform high-precision positioning by preventing the package from tilting. However, the above-described conventional problem of detachment of the solder ball and dropping of the package based on the separation is notable. Was not mentioned.

The present invention has been made in view of such circumstances, and by mounting a headed box-shaped reinforcing member into which a resin for package reinforcement can be injected into a motherboard, the reliability in package reinforcement is improved. It is an object of the present invention to provide a reinforcing structure for an IC package capable of performing maintenance and the like of the IC package after resin sealing.

[0016]

In order to achieve the above object, an IC package reinforcing structure according to claim 1 of the present invention is mounted on a motherboard and at least partially sealed with a package reinforcing resin. A reinforcing structure for an IC package to be stopped, wherein a headed box-shaped reinforcing member including a side surface portion and a ceiling surface portion capable of covering the IC package on a motherboard and injecting resin therein is attached, and the ceiling surface portion is attached to the reinforcing member. A first resin injection port that penetrates and a second resin injection port that penetrates the side surface portion are provided, and both of these resin injection ports are formed of openings such that each opening edge avoids overlapping in a linear direction in the same plane. There is a configuration.
Therefore, the IC package is reinforced by a box-shaped reinforcing member that covers the IC package on the motherboard and a package reinforcing resin injected into the reinforcing member.

According to a second aspect of the present invention, there is provided the method according to the first aspect.
In the reinforcing structure of the C package, the first resin injection port is arranged at a corner of the ceiling surface. Therefore, the IC package is reinforced by injecting the resin for package reinforcement into the reinforcing member from the first resin injection port on the ceiling surface.

According to a third aspect of the present invention, there is provided the method according to the first aspect.
In the reinforcing structure of the C package, the first resin injection port is arranged at a position separated from the edge of the ceiling surface by a predetermined dimension. Therefore, when the first resin injection port is disposed at a position separated from the edge of the ceiling surface, the rigidity of the reinforcing member is further enhanced as compared with the case where the first resin injection port is disposed at the corner of the ceiling surface.

According to a fourth aspect of the present invention, in the reinforcing structure for an IC package according to the first, second or third aspect, the second resin inlet is formed of a cutout opening at an edge of the side surface. Therefore, while the resin for package reinforcement is injected into the reinforcing member from the second resin injection port,
The wiring of the IC package is drawn out of the reinforcing member from the second resin inlet.

According to a fifth aspect of the present invention, in the reinforcing structure for an IC package according to any one of the first to fourth aspects, a through hole for reducing the weight of the reinforcing member is provided in the ceiling surface. Therefore, the weight of the reinforcing member is reduced by the through hole, and the IC package is reinforced.

According to a sixth aspect of the present invention, there is provided an IC package comprising: mounting an IC package on a motherboard; and sealing at least a part of the IC package with a package reinforcing resin. When the IC package is sealed with a resin, a headed box-shaped reinforcing member with a resin inlet is provided on the motherboard so as to cover the entire IC package. Therefore, a reinforcing structure of the IC package reinforced by the resin for reinforcing the package and the reinforcing member is obtained.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. FIGS. 1A and 1B are a plan view and a front view illustrating a reinforcing structure of an IC package according to a first embodiment of the present invention, and FIGS. Sectional view and bottom view for explaining the reinforcing structure of the IC package according to the first embodiment,
FIG. 3 is an exploded perspective view showing the reinforcing structure of the IC package according to the first embodiment of the present invention, and FIG. 4 is an assembled perspective view showing the reinforcing structure of the IC package according to the first embodiment of the present invention. 1 (a) and 1 (b) and FIGS. 2 (a) and 2 (b), the reinforcing structure of the IC package denoted by reference numeral 1 includes a motherboard 2, an IC package 3, a reinforcing member 4, and a package reinforcing resin 5. ing.

The motherboard 2 is made of a printed wiring board, like the conventional motherboard 72 (shown in FIG. 7), and is housed in an electronic equipment housing (not shown). As shown in FIG. 3, a positioning hole 2 a for positioning a leg piece (described later) of the reinforcing member 4 is provided on the motherboard 2. The IC package 3 is composed of a BGA type IC package having an interposer substrate 6 and an electronic component 7, and is mounted on the motherboard 2 by a large number of solder balls 8 arranged in a matrix like the conventional IC package 73.

The interposer substrate 6 has through holes (not shown), and solder balls 8
Connected through. The electronic component 7 is composed entirely of an IC chip sealed with a mold resin 9 and has bonding wires (not shown) on the interposer substrate 6.
And so on. Thereby, the electronic component 7 is electrically connected to the motherboard 2 via the interposer substrate 6.

The reinforcing member 4 has a side surface 4a and a ceiling surface 4b, and is mounted on the motherboard 2 so as to cover the electronic components 7. The reinforcing member 4 is formed of a sheet metal or the like made of a boxed box having a flat rectangular shape as a whole. As a result, the package reinforcing resin 5 does not flow around the package, and sufficient resin sealing of the IC package 3 is performed.

The side surface portion 4a is composed of two pairs of thin plates which are opposed to each other via the electronic component 7, and are integrated into a frame by welding or the like. Each side 4a has
A wide cutout 10 is formed by punching or the like as a second resin injection port that opens at the center in the width direction of the lower edge. Thus, when the package reinforcing resin 5 is injected into the reinforcing member 4 on the motherboard 2 from the notch 10 by using the nozzle (M) as shown in FIG. 4, the gap between the front surface of the motherboard 2 and the rear surface of the interposer substrate 6 is mainly increased. Is sealed with resin, and this portion is reliably reinforced. Further, the wiring W of the IC package 3 in the reinforcing member 4 is drawn out of the reinforcing member 4 from the notch 10, so that the wiring of the IC package 3 is not pressed when the reinforcing member 4 is attached to the motherboard 2, and the wiring W Disconnection is prevented.

As shown in FIG. 3, a leg piece 11 (only two leg pieces are shown) which can be inserted into the positioning hole 2a and positioned can project from the lower edge of one side part of each side face part 4a. Have been. Thereby, the reinforcing member 4 with respect to the motherboard 2
If the leg piece 11 is inserted into the positioning hole 2a and positioned at the time of mounting, the mounting operation is performed easily and quickly. The number and formation positions of the leg pieces 11 (positioning holes) are not particularly limited, and can be changed as appropriate.

The ceiling surface portion 4b is formed of a single thin plate having the same thickness as the side surface portion 4a, and closes the upper opening (opening opposite to the motherboard 2) on the upper surface of each side surface portion 4a. So that it is welded. The ceiling surface portion 4b is provided with a through hole 12 having a substantially fan-shaped flat surface (a quarter of a perfect circle) serving as a first resin inlet opening at four corners by punching or the like. Thus, when the package reinforcing resin 5 is injected from the through hole 12 into the reinforcing member 4 on the motherboard 2 using the nozzle (N) as shown in FIG. 4, the four corners of the IC package 3 are resin-sealed. This portion is reliably reinforced.

The through hole 12 (first resin injection port) and the notch 10 (second resin injection port)
The openings 10a and 10a are formed by openings that avoid overlapping in the linear direction in the same plane. That is, the through hole 12 and the notch 10 are
2a and 10a are provided on the ceiling surface portion 4b and the side surface portion 4a, respectively, so that they do not overlap each other in a linear direction in the same plane. Thereby, the side part 4a of the reinforcing member 4
In addition, the rigidity of the reinforcing member 4 is reliably increased as compared with the case where the second resin inlet and the first resin inlet are provided on the ceiling surface portion 4b such that the opening edges overlap each other in a straight line in the same plane.

The reinforcing member 4 in the present embodiment is
Although the case where a plurality of thin plates serving as the side surface portion 4a and the ceiling surface portion 4b are formed by integrating them has been described, it may be formed by bending a single thin plate. Further, although the sheet metal is used as the material of the reinforcing member 4 in the present embodiment, any material other than the sheet metal may be used. Further, the notch 10a in the present invention
In addition, the formation position, the opening shape and the size of the through hole 12a are appropriately changed according to the shape, the size, the degree of reinforcement and the like of the IC package 3.

In addition, in this embodiment, the through hole 1
2 has been described as being disposed at the corner of the ceiling surface 2b, but the present invention is not limited to this, and as shown in FIG. You may arrange | position at the site | part separated only by the dimension. In this case, the rigidity of the reinforcing member 4 is further enhanced as compared with the case where the reinforcing member 4 is arranged at the corner of the ceiling surface 4b.

The package reinforcing resin 5 is made of a thermosetting resin for sealing at least a part of the IC package 3, and is enclosed in the reinforcing member 4. By using the nozzles (M) and (N) as shown in FIG. 4 and injecting the package reinforcing resin 5 into the reinforcing member 4 on the nozzle motherboard 2 from the notch 10 and the through hole 11, the IC package 3 And the gaps between the front surface of the motherboard 2 and the back surface of the interposer substrate 6 are sealed with resin, so that these portions are reliably reinforced.

In this embodiment, the reinforcing member 4
A case has been described in which the package reinforcing resin 5 is injected so as to leave a space therein and at least a part of the IC package 3 is sealed, but the reinforcing member 4 is filled with the package reinforcing resin 5 and the IC package 3 is filled. It is also possible to seal the whole of 3. Further, in the present embodiment, a case where a thermosetting resin is used as the package reinforcing resin 5 has been described, but the present invention is not limited to this, and for example, a resin adhesive may be used as another resin.

Next, a method of reinforcing the IC package according to the present embodiment will be described with reference to FIGS.
That is, the reinforcement of the IC package is performed sequentially through the steps of “mounting the IC package”, “attaching the reinforcing member”, and “injecting the resin for package reinforcement” (automation processing). [Mounting of IC Package] First, the IC package 3 is mounted on the motherboard 2 with the solder balls 8 in contact with the board surface. Next, the motherboard 2 mounted with the IC package 3 is accommodated in the reflow, and the IC package 3 is mounted on the surface of the motherboard 2.

[Attachment of Reinforcing Member] First, as shown in FIG. 3, each leg piece 11 is inserted into the positioning hole 2a and positioned, whereby the IC is mounted on the surface of the motherboard 2.
The reinforcing member 4 is mounted so as to cover the entire package 3. Next, the reinforcing member 4 is fixed on the surface of the motherboard 2 by soldering each leg piece 11 to the periphery of the opening of the positioning hole 2a. In this case, since the opening edges 12a, 10a of the through hole 12 and the notch 10 are formed by openings that avoid overlapping each other in a straight line in the same plane, the rigidity of the reinforcing member 4 is reliably increased. Can be

"Injection of Package Reinforcement Resin" As shown in FIG. 4, the package reinforcement resin 5 is injected into the reinforcement member 4 from each notch 10 by the nozzle (M), and the reinforcement member is injected by the nozzle (N). The package reinforcing resin 5 is injected into the through hole 11 from the through hole 11, and the gap between the front surface of the motherboard 2 and the back surface of the interposer substrate 6 and the IC
The four corners and the like of the package 3 are sealed with resin. in this case,
Since the flow of the package reinforcing resin 5 is regulated by the reinforcing member 4, the resin does not flow outside the reinforcing member 4, and sufficient resin sealing is performed.

Therefore, in the present embodiment, it is possible to reliably obtain a required reinforcing strength by the reinforcing member 4 and the package reinforcing resin 5, that is, to obtain a sufficient connection strength of the IC package 3 to the motherboard 2. In this case, since the opening edges 12a, 10a of the through hole 12 and the notch 10 are formed by openings that avoid overlapping each other in a straight line in the same plane, the rigidity of the reinforcing member 4 is reliably increased. As a result, a higher reinforcing strength of the IC package 3 can be obtained.

In the present embodiment, the reinforcing member 4
As a result, the package reinforcing resin 5 does not flow around the package, so that a large amount of the package reinforcing resin 5 is not required, and the entire structure can be reduced in size.
A larger number of electronic components can be mounted on the mother board as compared with the conventional structure. Further, in the present embodiment, since only a part of the IC package need be sealed with resin, a part of the IC package 3 is
It can be exposed outside.

Next, a third embodiment of the present invention will be described with reference to FIG.
This will be described with reference to (a) to (c). 6 (a) to 6 (c)
Are plan views, front views, and cross-sectional views for explaining a reinforcing structure of the IC package according to the third embodiment of the present invention, in which the same members as those in FIGS. And detailed description is omitted. In the figure, the IC package reinforcing structure indicated by reference numeral 61 includes a motherboard 2, an IC package 3, a reinforcing member 62, and a package reinforcing resin 5.

The reinforcing member 62 has a side surface portion 4a and a ceiling surface portion 62a, and is mounted on the motherboard 2 so as to cover the electronic components 7, similarly to the reinforcing member 4 in the first embodiment. It is formed of a sheet metal or the like formed of a headed box having a shape.

The ceiling portion 62a is formed of a single thin plate having the same thickness as the side portion 4a, and is welded to the upper surface of each side portion 4a so as to close the upper opening. The ceiling surface portion 62a is provided with a through hole 63 having a substantially fan-shaped planar shape as a first resin injection port opened at four corners by punching or the like. Thereby, the nozzle (N)
And through holes 63 in the reinforcing member 4 on the motherboard 2.
When the package reinforcing resin 5 is injected from above, the four corners of the IC package 3 are sealed with resin, and the reinforcement of this portion is reliably performed.

The ceiling surface portion 62a is provided with four pairs (eight in total) of through holes 64 each having a plane perfect circular opening arranged in parallel with each side of the square at predetermined intervals. Accordingly, the weight of the reinforcing member 62 can be reduced, and thus the weight of an electronic device such as a mobile phone having the present reinforcing structure can be reduced. In this case, the through hole 64 is
Although it is provided on the side surface 2a, it is needless to say that it may be provided on the side surface portion 4a, and the number, the opening shape and the formation position are not particularly limited as long as the required rigidity as the reinforcing member 62 can be maintained. Absent.

In each of the embodiments, a case where the present invention is applied to a structure using a BGA type IC package has been described. However, the present invention is not limited to this, and may be applied to a structure using another IC package. It is applicable similarly to the embodiment.

[0044]

As described above, according to the present invention, a headed box-shaped reinforcing member which covers an IC package on a motherboard and injects a resin for package reinforcement into the inside through two resin injection ports is provided. Therefore, the IC package is reinforced by the reinforcing member and the package reinforcing resin. Therefore, the required reinforcing strength can be reliably obtained, and the reliability in reinforcing the package can be enhanced. In this case, since both resin injection ports are formed of openings such that each opening edge avoids overlapping in the linear direction in the same plane, the rigidity of the reinforcing member is reliably increased,
Higher IC package reinforcement strength can be obtained.

Further, since the package reinforcing resin does not flow around the package due to the reinforcing member, a large amount of the package reinforcing resin is not required, so that the entire structure can be reduced in size, and a large number can be obtained as compared with the conventional structure. Electronic components can be mounted on a marza board, and can be adapted to high-density mounting of electronic components. Furthermore, I
Since only part of the C package need be sealed with resin,
Part of the C package can be exposed outside the package reinforcing resin, so that maintenance of the IC package after resin sealing can be performed.

[Brief description of the drawings]

FIGS. 1A and 1B are a plan view and a front view illustrating a reinforcing structure of an IC package according to a first embodiment of the present invention.

FIGS. 2 (a) and 2 (b) are a cross-sectional view and a bottom view for explaining a reinforcing structure of the IC package according to the first embodiment of the present invention.

FIG. 3 is an exploded perspective view showing a reinforcing structure of the IC package according to the first embodiment of the present invention.

FIG. 4 is an assembled perspective view showing a reinforcing structure of the IC package according to the first embodiment of the present invention.

FIG. 5 is an assembled perspective view showing a reinforcing structure of an IC package according to a second embodiment of the present invention.

FIGS. 6A to 6C are a plan view, a front view, and a cross-sectional view illustrating a reinforcing structure of an IC package according to a second embodiment of the present invention.

FIGS. 7A and 7B are a plan view showing an IC package and a front view showing a mounting structure thereof, respectively.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 IC package reinforcement structure 2 Motherboard 3 IC package 4 Reinforcement member 4a Side surface 4b Ceiling surface 5 Package reinforcement resin 6 Interposer substrate 7 Electronic component 8 Solder ball 9 Mold resin 10 Notch 10a Opening edge 11 Leg piece 12 Through hole 12a Opening edge M, N nozzle

Claims (6)

[Claims] 1. A reinforcing structure of an IC package mounted on a motherboard and at least partially sealed with a package reinforcing resin, wherein the IC package is covered on the motherboard, and the resin is placed inside the motherboard. A headed box-shaped reinforcing member consisting of a side part and a ceiling part that can be injected is attached to the reinforcing member. A first resin inlet that penetrates the ceiling part and a second resin inlet that penetrates the side part are provided on the reinforcing member. The reinforcing structure for an IC package, characterized in that both of the resin injection ports have openings such that each opening edge avoids overlapping in a linear direction in the same plane. 2. The reinforcing structure for an IC package according to claim 1, wherein the first resin injection port is arranged at a corner of the ceiling surface. 3. The reinforcing structure for an IC package according to claim 1, wherein the first resin injection port is disposed at a position separated by a predetermined dimension from an edge of the ceiling surface portion. 4. The reinforcing structure for an IC package according to claim 1, wherein said second resin injection port is formed of a cutout opening at an edge of said side surface portion. 5. The ceiling surface portion is provided with a through hole for reducing the weight of the reinforcing member.
The reinforcement structure for an IC package according to any one of the above. 6. A method for reinforcing an IC package by mounting an IC package on a motherboard and sealing at least a part of the IC package with a resin for reinforcing the package, the method comprising: A method for reinforcing an IC package, comprising: attaching a reinforcing member having a resin-injection port having a headed box shape to cover the entirety of the IC package on the mother board when performing resin sealing.