JP2001127211A - Semiconductor integrated circuit provided with electromagnetic wave noise shielding part and packaging structure for the semiconductor integrated circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit and a packaging structure for the semiconductor integrated circuit. SOLUTION: In order to prevent electromagnetic wave noise, which is radiated from a semiconductor integrated circuit mounted on a printed board 3, from affecting other electronic circuits or an electronic equipment, the integrated circuit has a shielding part 1, which is provided in a form of covering the surface, which is positioned on the side opposite to the board 3, of the integrated circuit and shields the noise, and a connection part 1a for connecting the shielding part 1 with a ground 3a on the board 3. A remarkable space saving of the upper part of the board 3 and the space saving in the interior of the electronic equipment and a significant lighting of the board 3 and the equipment can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit, and more particularly, to a semiconductor integrated circuit having a shielding portion for preventing electromagnetic noise radiated from the semiconductor integrated circuit from affecting other electronic circuits or electronic devices. And a mounting structure of the semiconductor integrated circuit.

[0002]

2. Description of the Related Art In the field of electronic devices, especially wireless devices, electromagnetic noise radiated from a semiconductor integrated circuit affects other electronic circuits or electronic devices. It was one of the big problems. FIG. 9 shows one of the conventional examples for solving this problem.

FIG. 9 is a perspective view of a conventional semiconductor integrated circuit in which a semiconductor integrated circuit 10 is covered with a substantially box-shaped sheet metal shield 9 having an open bottom. As shown in FIG. 9, conventionally, a semiconductor integrated circuit 1 mounted on a printed circuit board 11 is provided.
0 is covered with a sheet metal shield 9.

FIG. 10 shows a semiconductor integrated circuit 1 shown in FIG.
0 is a cross-sectional view showing a state of cutting along a line DD ′ together with a sheet metal shield 9. As shown in FIG. 10, the sheet metal shield 9 is larger than the semiconductor integrated circuit 10 and occupies a larger mounting space. Sheet metal shield 9
Is so large that the weight is considerable. For this reason, even if the thickness of the sheet metal shield 9 is reduced, the weight when a plurality of semiconductor integrated circuits provided with the sheet metal shield 9 are mounted on a printed circuit board becomes considerable.

[0005]

In the conventional method shown in FIGS. 9 and 10, the sheet metal shield 9 has a substantially box shape larger than the outer shape of the semiconductor integrated circuit 10. Therefore, a mounting space is required in which the thickness of the sheet metal shield 9 and the space between them are added to the length of each terminal extending from the semiconductor integrated circuit 10, which is unsuitable for high-density mounting. Had become.

In addition, in terms of weight reduction, the presence of the box-shaped sheet metal shield 9 that completely covers the semiconductor integrated circuit 10 is one of the major factors that hinder the promotion of miniaturization and weight reduction of the semiconductor integrated circuit. Not only that, it can be a factor that hinders progress toward multifunctionalization. In particular, in the field of portable wireless devices that are required to be lighter and thinner year by year, it has become a significant problem that cannot be ignored.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has been developed in consideration of the above problem. It is an object to provide a semiconductor integrated circuit provided and a mounting structure of the semiconductor integrated circuit.

[0008]

According to the present invention, there is provided, in accordance with the present invention, a shielding portion provided to cover a surface of a semiconductor integrated circuit on a side opposite to a printed circuit board for shielding electromagnetic noise, It has a connection part for connecting the shielding part and the ground on the printed circuit board.

In this case, it is assumed that the shielding portion is a metal plate.

In the above, the shielding portion may be made of a resin forming a package of a semiconductor integrated circuit in which conductive particles are mixed. Alternatively, a coating formed by printing, painting, or heat transfer using a conductive paint may be used.

Further, the semiconductor integrated circuit according to the present invention is a QFP.
Wherein the connection part is a part of a plurality of terminals connected to the ground and the shield part on the printed circuit board.

In the above, the semiconductor integrated circuit may be a BGA or a PGA, and the connection may be the shield itself.

A semiconductor integrated circuit according to the present invention has a mounting structure in which the mounting surface of the semiconductor integrated circuit is grounded.

In the above, the semiconductor integrated circuit according to the present invention is designed such that the inner surface of the portion of the printed circuit board on which the semiconductor integrated circuit is mounted is grounded and a part of the ground appears at a location connected to the shield. The mounting structure may be formed.

In the present invention configured as described above, a conductive shielding portion connects the surface of the anti-printed substrate of the semiconductor integrated circuit to the ground provided on the mounting surface of the semiconductor integrated circuit via the connection portion. Therefore, the film is kept at the same potential as the ground, and the shielding effect by the shielding portion is achieved.

[0016] Also, in the case of a semiconductor integrated circuit of a type in which the shielding portion cannot be directly joined to a plurality of terminals, the shielding portion is connected to a part of the ground provided on the inner surface of the portion where the semiconductor integrated circuit is mounted, and The same shielding effect as in the case is achieved.

As a result, as compared with the conventional metal-made substantially box-shaped sheet metal shield, not only high-density mounting, thinning, and miniaturization of the semiconductor integrated circuit can be realized, but also significant weight reduction can be achieved. . In addition, since a cheap and simple material is used for the shielding part, the process of forming the shielding part is simplified,
It is also possible to reduce the price.

Furthermore, if the resin constituting the package of the semiconductor integrated circuit is mixed with fine particles having conductivity, the package itself exhibits a shielding effect. Therefore, it is necessary to provide the above-mentioned shielding portion. As a result, the manufacturing process of the semiconductor integrated circuit can be simplified and the size can be further reduced.

[0019]

Embodiments of the present invention will now be described with reference to the drawings.

First, a first embodiment of the present invention will be described.

In this embodiment, a conductive coating is applied to the surface of the semiconductor integrated circuit on the printed circuit board side as a member for shielding electromagnetic noise.

FIG. 1 is a perspective view of a semiconductor integrated circuit 2 on which a coating 1 is applied. FIG. 2 is a cross-sectional view showing a state where the semiconductor integrated circuit 2 shown in FIG. 1 is cut along the line AA ′ together with the coating 1.

In this embodiment, a general QFP (Quad Flat
A description will be given by taking a semiconductor integrated circuit called “wing leaded package” as an example. QFP is a type of semiconductor integrated circuit in which terminals extend toward the outside of the package.

As shown in FIG. 2, a ground 3a is provided on a mounting surface of a semiconductor integrated circuit on a printed circuit board 3 on which a wiring pattern (not shown) of a copper foil is formed.
A semiconductor element (not shown) is included therein, and a semiconductor integrated circuit 2 having a rectangular shape packaged with a thermosetting resin is mounted. The semiconductor integrated circuit 2 is arranged in such a manner that the terminals 2 a are drawn out on all sides of the component mounting surface of the semiconductor integrated circuit 2. At this time, the terminal 2a is electrically connected to the wiring pattern formed on the printed circuit board 3.

On the surface of the semiconductor integrated circuit 2 on the side opposite to the printed circuit board, a conductive film 1 serving as a shielding portion is applied. The ground 3a on the printed circuit board 3 is joined to a part 1a of a plurality of grounding terminals for grounding of the semiconductor integrated circuit, which is a connecting portion, so that conduction between the coating 1 and the ground 3a is improved. Have been.

In the above description, the film 1 is in a form in which a conductive material is contained in ink, paint, transfer foil, etc., and is brought into close contact with the semiconductor integrated circuit 2 and the terminals 2a by a method such as printing, painting, heat transfer or the like. Formed. This configuration is different from a shield structure in which a substantially box-shaped metal sheet shield 9 made of metal surrounds the entire outer shape of the semiconductor integrated circuit 10 as in the conventional example shown in FIGS. The same electromagnetic noise shielding effect can be created with an extremely compact structure.

Further, the thickness of the coating 1 is extremely small, and is formed in close contact with the surface of the semiconductor integrated circuit 2 on the side opposite to the printed circuit board. Further, the film thickness of the film 1 can be changed as appropriate in accordance with the required level of electromagnetic wave noise shielding effect, so that the film 1 also has flexibility with respect to required specifications.

The reason why the coating 1 is bonded to the grounding terminal 2a is to form an electromagnetic wave shield that allows electromagnetic noise generated from the semiconductor integrated circuit to escape to the ground 3a through the grounding terminal 2a. Of course, the coating 1 may be bonded to some terminals, for example, not only one terminal but also a plurality of terminals, but a sufficient electromagnetic wave noise shielding effect can be obtained with only some terminals.

By further developing this embodiment, as shown in FIG. 3, the coating 1 'may be applied to the surface of the semiconductor integrated circuit 2 on the printed circuit board side, or may be applied to the side surface (not shown). Is also good. As the grounding terminal 2a, a vacant spare terminal to which no input / output function is assigned may be selected.

As described above, according to the present embodiment, the printed circuit board 3 and the inside of the electronic device are compared with the conventional metal substantially box-shaped sheet metal shield structure 9 shown in FIGS. 9 and 10. Not only realizes a remarkable space saving in the mounting area, but also enables a significant weight reduction.

The coating 1 is applied in close contact with the entire surface of the semiconductor integrated circuit 2 on the side opposite to the printed circuit board, and faces the ground 3a disposed on the printed circuit board 3 at a short distance. Thereby, a higher electromagnetic wave noise shielding effect can be obtained.

Further, by applying the coatings 1 and 1 'to the semiconductor integrated circuit, it is possible to prevent electromagnetic wave noise generated from the applied semiconductor integrated circuit itself from being radiated to the outside. , And is not affected by external disturbance factors such as an external electric field, magnetic field, or noise.

Next, a second embodiment of the present invention will be described.

In this embodiment, a semiconductor integrated circuit other than the above-described QFP is a BGA in which a conductive film cannot be directly bonded to a terminal.
A metal thin plate is used as an electromagnetic wave shielding member, which is a shielding portion, so as to be applicable to a semiconductor integrated circuit such as a (Ball Grid Array) or a PGA (Pin Grid Array).

In this embodiment, a semiconductor integrated circuit called a BGA will be described as an example. The BGA is a semiconductor integrated circuit of a type in which a plurality of input / output pads are arranged on the back surface.

As shown in FIG. 5, a ground 6a is buried in the printed circuit board 6 on the mounting surface of the semiconductor integrated circuit, and a part 6a 'of the ground 6a appears on the printed circuit board 6. And
Semiconductor element (not shown) on printed circuit board 6
And a semiconductor integrated circuit 5 in the shape of a rectangle packaged with a thermosetting resin is mounted, and the ball-shaped terminals 5 a are electrically connected to a wiring pattern of copper foil formed on the printed circuit board 6. Have been.

FIG. 4 is a perspective view of a semiconductor integrated circuit 5 provided with a metal thin plate 4. FIG. 5 is a cross-sectional view showing a state where the semiconductor integrated circuit 5 shown in FIG. 4 is cut along the line BB ′ together with the metal thin plate 4.

As shown in FIG. 5, in this embodiment, in place of the coating 1 described in the first embodiment, a rectangular metal thin plate 4 matching the outer shape of the semiconductor integrated circuit 5 to be coated is used. Used. The ground 6a is embedded in the inner surface of the printed circuit board 6 so that a portion 6a 'thereof appears on the printed circuit board 6 connected to the thin plate 4, and a portion 4a of the thin plate serving as a connection portion is bent into an L-shape. , Part of the ground 6
a '. This thin plate 4 is a semiconductor integrated circuit 5
Is formed at the same time as the thermosetting resin which is a material constituting the package of the semiconductor integrated circuit. This molding method is generally called insert molding because the thin plate 4 and the thermosetting resin are integrally molded.

As in the first embodiment described above, this embodiment is further developed to form a thin metal plate 4 'as shown in FIG.
May be provided on the surface of the semiconductor integrated circuit on the printed circuit board side where the terminal 5a is attached, or may be provided on the side surface (not shown).

In this embodiment, the ground 6a is buried in the inner surface of the printed circuit board 6 because the semiconductor integrated circuit mounted on the printed circuit board 6 is intended for a BGA or PGA. Thus, part of the ground 6a
The ground 6a is buried in the inner surface of the printed circuit board 6 so as to appear on the printed circuit board 6, and a part 6a 'of the ground is
The thin plate 4 can be grounded by connecting the thin plate 4 and the part 4a of the thin plate.

As described above, according to this embodiment, by embedding the ground in the printed circuit board so that a part of the ground appears on the printed circuit board, a BGA or PGA or the like, to which a conductive film cannot be directly bonded to the terminal, Can be applied to various semiconductor integrated circuits.

Further, since the thin metal plate 4 is used, it is difficult to achieve a significant reduction in weight as in the first embodiment described above, but nevertheless, the conventional structure shown in FIGS. Compared with the substantially box-shaped metal shield structure 9, the shield structure can be reduced in mounting space and weight. Also in this configuration, a high shielding effect can be obtained by using a configuration in which the thin plate 4 and the ground 6a on the printed board 6 are opposed to each other at a short distance.

Next, a third embodiment of the present invention will be described.

The present embodiment is not an electromagnetic wave shield formed by the conductive film or the metal thin plate 4 used in the above embodiment, but a thermosetting resin constituting a semiconductor integrated circuit as an electromagnetic wave shield member serving as a shield. The conductive fine particles are mixed and dispersed throughout the thermosetting resin.

FIG. 7 is a perspective view of the semiconductor integrated circuit 7 in which conductive fine particles 7b are mixed and dispersed over the entire thermosetting resin. FIG. 8 is a cross-sectional view showing a state where the semiconductor integrated circuit 7 shown in FIG. 7 is cut along the line CC ′.

As shown in FIG. 8, on a printed board 8 on which a wiring pattern is formed, a plurality of terminals 7a, fine particles 7b are mixed, and a dispersed packaging member is mounted. The plurality of terminals 7 a are insulated from the packaging member, and some of them are electrically connected to a wiring pattern formed on the printed circuit board 8.

Here, it is assumed that the size of the fine particles that can be mixed with the thermosetting resin is sufficiently fine with respect to the wiring pitch.

In this embodiment, in the manufacturing process of the semiconductor integrated circuit, the fine particles 7b are packaged together with the thermosetting resin.
By jigging, the resin can be dispersed at a predetermined density over the entire thermosetting resin.

As described above, according to this embodiment, the secondary processing such as printing in the above-described embodiment and the need for a thin metal plate are not required, and the package itself is sealed in the ordinary semiconductor integrated circuit manufacturing process. In this way, a semiconductor integrated circuit can be formed. In addition, in reducing mounting space and weight,
It has a remarkable advantage over the conventional shield structure.

The size and distribution density of the fine particles mixed in the thermosetting resin are within a range sufficiently smaller than the wiring pitch, depending on the type of the semiconductor integrated circuit or the required shielding level of electromagnetic noise. It can be set arbitrarily.

The embodiments of the present invention have been described above.
The present invention is not limited to the above embodiments, and the embodiments may be arbitrarily combined or appropriately changed within the scope of the technical idea of the present invention.

[0052]

As described above, according to the present invention,
The following remarkable effects are obtained.

(1) Since the semiconductor integrated circuit itself is directly provided with a coating or a metal plate, or the thermosetting resin constituting the semiconductor integrated circuit is mixed with conductive fine particles to form a package, thereby shielding the package itself. Therefore, not only the space saving on the mounting area on the printed circuit board or inside the electronic device is realized, but also the weight can be significantly reduced.

(2) For the same reason as described above, a stronger and more stable electromagnetic wave noise shielding effect can be exhibited.

(3) In a normal semiconductor integrated circuit manufacturing process, fine particles having conductivity are mixed in a package,
As a result, the effect of shielding electromagnetic wave noise is exerted, so that there is no need to provide a coating or a metal plate as a shielding portion on the semiconductor integrated circuit, and the process of mounting the semiconductor integrated circuit can be simplified.

[Brief description of the drawings]

FIG. 1 is a perspective view of a semiconductor integrated circuit 2 on which a coating 1 is applied.

FIG. 2 is a cross-sectional view showing a state where the semiconductor integrated circuit 2 shown in FIG. 1 is cut along a line AA ′ together with a coating 1;

FIG. 3 is a diagram in which a coating 1 ′ is applied to a surface of a semiconductor integrated circuit 2 on a printed circuit board side.

FIG. 4 is a perspective view of a semiconductor integrated circuit 5 provided with a metal thin plate 4;

5 is a cross-sectional view showing a state where the semiconductor integrated circuit 5 shown in FIG. 4 is cut along a line BB ′ together with a thin metal plate 4. FIG.

FIG. 6 is a diagram in which a thin metal plate 4 ′ is provided on a surface of a semiconductor integrated circuit 5 on a printed circuit board side, which is a mounting portion of a terminal 5a.

FIG. 7 is a perspective view of a semiconductor integrated circuit 7 in which fine particles 7b having conductivity are mixed and dispersed throughout the thermosetting resin.

8 is a cross-sectional view showing a state where the semiconductor integrated circuit 7 shown in FIG. 7 is cut along a line CC ′.

FIG. 9 is a perspective view of a conventional semiconductor integrated circuit in which the semiconductor integrated circuit 10 is covered with a substantially box-shaped sheet metal shield 9 having an open bottom.

FIG. 10 is a cross-sectional view showing a state where the conventional semiconductor integrated circuit 10 shown in FIG. 9 is cut along a line DD ′ together with a sheet metal shield 9;

[Explanation of symbols]

 1,1 'coating 1a Part of terminal 2,5,7,10 Semiconductor integrated circuit 2a, 5a, 7a Terminal 3,6,8,11 Printed circuit board 3a, 6a Ground 4,4' Thin plate 4a Part of thin plate 6a '' Part of the ground 7b Fine particles 9 Sheet metal shield

Claims (8)

[Claims] 1. A semiconductor integrated circuit mounted on a printed circuit board on which a wiring pattern is formed and connected to the wiring pattern via a plurality of terminals, wherein a surface of the semiconductor integrated circuit on a side opposite to the printed circuit board is provided. A semiconductor integrated device comprising: a shielding part provided in a covering form for shielding electromagnetic noise; and a connecting part for connecting the shielding part and a ground on the printed circuit board. circuit. 2. The semiconductor integrated circuit according to claim 1, wherein the shield is a metal plate. 2. The semiconductor integrated circuit according to claim 1, wherein the shield is a metal plate. 3. The semiconductor integrated circuit according to claim 1, wherein the shielding portion is a resin constituting a package of the semiconductor integrated circuit in which conductive particles are mixed. A semiconductor integrated circuit having a characteristic electromagnetic noise shielding portion. 4. The semiconductor integrated circuit according to claim 1, wherein the shielding portion is a film formed by printing, painting, or thermal transfer using a conductive paint. A semiconductor integrated circuit comprising an electromagnetic wave noise shield. 5. The semiconductor integrated circuit according to claim 1, wherein the semiconductor integrated circuit is a QFP, and the connection unit is a ground on the printed circuit board. And a part of a plurality of terminals connected to each of the shielding parts, wherein the semiconductor integrated circuit comprises an electromagnetic noise shielding part. 6. The semiconductor integrated circuit according to claim 1, wherein the semiconductor integrated circuit is a BGA or a PGA, and the connection unit is the shield unit itself. A semiconductor integrated circuit having an electromagnetic wave noise shielding portion, 7. A mounting structure of a semiconductor integrated circuit comprising the electromagnetic wave noise shielding portion according to claim 5, wherein a mounting surface of the semiconductor integrated circuit on a printed circuit board is grounded. Mounting structure of a semiconductor integrated circuit having a unit. 8. A mounting structure of a semiconductor integrated circuit comprising the electromagnetic wave noise shielding portion according to claim 5, wherein an inner surface of a portion of the printed circuit board on which the semiconductor integrated device is mounted is grounded. A mounting structure of a semiconductor integrated circuit having an electromagnetic noise shielding part, wherein the ground is formed so as to appear at a part where the ground is connected to the shielding part.