JPH06252282A - Shield structure of package - Google Patents

Abstract

PURPOSE:To evade remarkable increase of cost, and enable using the heat sink, as it is, which has been used. CONSTITUTION:A grounded lead 3 of a shield fence 1 is inserted into a ground through hole 5a of a printed board 5 which is close to an LSI 7 and fixed by soldering or the like. A finger strip contact part 2 of the shield fence 1 is in multipoint contact with the side surface of a heat sink 8 and in a pressed state. By installing the shield fence 1 so as to surround the LSI 7, the periphery of the heat sink is also surrounded by the shield fence 1, so that electromagnetic waves radiated from the LSI 17 are interrupted by the shield fence 1 and the heat sink 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield structure for a package, and more particularly to a shield structure for blocking an electromagnetic wave emitted from an LSI mounted on the package.

[0002]

2. Description of the Related Art Conventionally, an LSI or heat sink is electrically connected to a ground in order to block electromagnetic waves emitted from the LSI or a heat sink for cooling mounted on the LSI.

For example, in the technique disclosed in Japanese Patent Laid-Open No. 64-39100, as shown in FIGS. 5A to 5C, the outer periphery of an integrated circuit package 24 called a Dual-In-Line. The whole is covered with a rollable conductor 22 such as aluminum or copper.

By connecting the conductor 22 to the ground electrode 26 with the lead wire 25, the electromagnetic wave radiated from the integrated circuit package 24 is blocked. still,
The conductor 22 is covered with a protective film 23, and the lead terminals 21 of the integrated circuit package 24 are exposed to the outside through the protective film 23.

Further, in the technique disclosed in Japanese Utility Model Laid-Open No. 3-32498, as shown in FIGS. 6 (a) and 6 (b), an IC 34 mounted on a circuit board 36 via a ground lead 35 or the like is used. The electromagnetic wave radiated from the IC 34 is shielded by covering the shield cover 31 made of a metal plate. The shield cover 31 is bonded to the IC by an adhesive 33.
34 and the circuit board 36.

The shield cover 31 is formed by bending a metal plate to cover the IC 34 into a box body whose one surface is open, and a part of the edge of the box body is extended and protruded to the inside. Is bent into. This bent portion is the connection piece 32, and the shield piece 31 is electrically connected to the ground by pressing the connection piece 32 against the ground lead 35 of the IC 34.

Further, in the technique disclosed in Japanese Patent Laid-Open No. 2-17659, as shown in FIGS. 7 (a) and 7 (b),
The outer periphery of the heat sink 41 having a plurality of heat radiation fins 50 is covered with a coating 52 made of an electrically insulating material.
2 is covered with a coating 53 made of a conductive material.

The coating 53 is fixed to the base 45 with bolts or screws 54 and nuts 55, and is electrically connected to the conductive layer 48 arranged in the center of the base 45, so that the support pad 59 is provided on the upper surface of the wiring board 47. The electromagnetic wave radiated from the chip 46 mounted via is blocked.

Here, the chip 46 is engaged with the heat sink 41 by the cushion 58 having heat conductivity, and the heat generated in the chip 46 is conducted to the heat sink 41 through the cushion 58 and radiated from the heat radiation fin 50 of the heat sink 41. To be done.

A frame-shaped conductive metal piece 44 is mounted on the upper surface of the wiring board 47 of the base 45, and a conductive piece 42 is mounted on the frame-shaped conductive metal piece 44. The flange 51 of the heat sink 41 is mounted on the conductive piece 42,
A bolt or screw 54 is passed through a hole 43 penetrating the conductive piece 42, the frame-shaped conductive metal piece 44, and the base 45, and the bolt or screw 54 is fastened with a nut 55 to be fixed to the base 45. Blocks 49 are arranged at the four corners of the base 45.

A conductive path 56 electrically connected to the conductive layer 48 is formed in the hole 43, and a conductive region 57 is formed by these and the nut 55. Therefore, the coating 53 on the outer periphery of the heat sink 41, the conductive piece 42, and the frame-shaped conductive metal piece 44 are connected to the conductive area 57 via the bolts or screws 54, and therefore the heat sink 4
The coating 53 on the outer periphery of 1 is electrically connected to the ground, and electromagnetic waves emitted from the chip 46 are blocked.

[0012]

In the above-mentioned conventional shield structure, the heat sink that has been used up to that point cannot be used as it is in order to cool and shield the integrated circuit mounted in the package. Each of these parts must be newly processed.

Therefore, it is necessary to newly manufacture the molds for these parts or to change the conventional molds, and it is necessary to remake the molds or the like each time the shape is different, which is a factor of a significant cost increase. Has become.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems, to avoid a large increase in cost, and to provide a package shield structure in which a heat sink which has been used until then can be used as it is. It is in.

[0015]

A shield structure for a package according to the present invention includes a printed circuit board having a ground through hole, an integrated circuit mounted on the printed circuit board, and a conductive circuit mounted on the integrated circuit. A package shield structure comprising a heat sink having a contact portion that is urged in a direction parallel to the surface of the printed circuit board to contact the heat sink, and the ground through hole near the integrated circuit. A shield plate having a conductive portion that is inserted and fixed, and shields the integrated circuit.

A shield structure of another package according to the present invention is a printed circuit board having a ground through hole,
A shield structure of a package including an integrated circuit mounted on the printed circuit board and a conductive heat sink mounted on the integrated circuit, which is biased in a direction perpendicular to the surface of the printed circuit board. A shield plate having a contact portion that contacts the heat sink and a conductive portion that is inserted into and fixed to the ground through hole near the integrated circuit and that shields the integrated circuit.

Another package shield structure according to the present invention is a printed circuit board having ground through holes,
A shield structure of a package including an integrated circuit mounted on the printed circuit board and a conductive heat sink mounted on the integrated circuit, the first contact portion being capable of contacting a side surface of the heat sink. A second contact portion that can contact the bottom surface of the heat sink; a first biasing portion that biases the first contact portion in a direction parallel to the surface of the printed circuit board; A second urging portion for urging the second contact portion in a direction perpendicular to the printed circuit board surface;
A shield plate having a conductive portion that is inserted into and fixed to the ground through hole near the integrated circuit and shields the integrated circuit.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a shield fence according to an embodiment of the present invention. 1A is a sectional view of a shield fence according to an embodiment of the present invention, and FIG. 1B is a front view of the shield fence according to an embodiment of the present invention.

In these figures, the shield fence 1
Is made of a conductor plate of aluminum, copper or the like, and has an upper end 1a bent into a finger strip shape so as to have elasticity in the horizontal direction, and has a plurality of slits 4 in the vertical direction. As a result, a plurality of finger strip contact portions 2 are formed, enabling multipoint contact.

Further, the lower end portion 1b of the shield fence 1 has a plurality of ground leads 3 formed by extending and projecting a part of the edge portion. The diameter of the ground lead 3 is such that it can be inserted into a through hole (not shown) connected to the ground provided on a printed circuit board (not shown).

FIG. 2 shows an example of how the shield fence 1 of FIG. 1 is attached. In the figure, an LSI 7 is mounted on a printed circuit board 5 via a socket 6, and a heat sink 8 is attached to the upper surface of the LSI 7.

When the electromagnetic wave radiated from the LSI 7 is to be blocked, the ground lead 3 of the shield fence 1 is inserted into the ground through hole 5a near the LSI 7 on the printed circuit board 5, and the finger strip contact portion 2 of the shield fence 1 is a heat sink. The ground lead 3 is fixed by soldering or the like while being in contact with and pressed against the eight side surfaces at multiple points.

By installing the shield fence 1 so as to surround the periphery of the LSI 7, the periphery of the heat sink 8 is also surrounded by the shield fence 1. In this case, by using a conductive heat sink 8,
The SI 7 is surrounded by the shield fence 1 and the heat sink 8 which are connected to the ground. As a result, the electromagnetic waves emitted from the LSI 7 are blocked by the shield fence 1 and the heat sink 8.

FIG. 3 is a view showing a shield fence according to another embodiment of the present invention. FIG. 3A is a sectional view of a shield fence according to another embodiment of the present invention.
(B) is a front view of a shield fence according to another embodiment of the present invention.

In these figures, the shield fence 1
Reference numeral 0 is a conductor plate made of aluminum, copper, or the like. The upper end portion 10a is bent into a finger strip shape so as to have elasticity in the horizontal direction, and a plurality of slits 13 are formed in the vertical direction. As a result, a plurality of finger strip contact portions 11 are formed, enabling multipoint contact.

The shield fence 10 has a central portion 10b bent in a spring shape so as to have elasticity in the vertical direction. As a result, the plurality of finger strip contact portions 11 can make multi-point contact with the bottom surface of the heat sink (not shown).

Further, the lower end portion 1 of the shield fence 10
0c makes a part of the edge part extend and protrude, and a plurality of ground leads 1
Forming 2. The diameter of the ground lead 12 is such that it can be inserted into a through hole (not shown) connected to the ground provided on a printed circuit board (not shown).

FIG. 4 is a diagram showing an example of how the shield fence 10 of FIG. 3 is attached. In the figure, an LSI 16 is mounted on a printed circuit board 14 via a socket 15,
A heat sink 17 is attached to the upper surface of 16.

When the electromagnetic wave emitted from the LSI 16 is to be blocked, the shield fence 10 is provided in the ground through hole 14a near the LSI 16 on the printed board 14.
The ground lead 12 is inserted, and the ground lead 12 is fixed by soldering or the like in a state where the finger strip contact portion 11 of the shield fence 10 is pressed against the bottom surface of the heat sink 17 by making multiple contact.

By installing the shield fence 10 so as to surround the periphery of the LSI 16, the heat sink 17
The area around is also surrounded by the shield fence 10. in this case,
By using a conductive heat sink 17, the periphery of the LSI 16 is surrounded by the shield fence 10 and the heat sink 17, which are connected to the ground. As a result, the electromagnetic waves emitted from the LSI 16 are blocked by the shield fence 10 and the heat sink 17.

Thus, the structure of the shield fences 1 and 10 is made elastic in the horizontal direction or the vertical direction, and the finger strip contact portions 2 and 11 of the shield fences 1 and 10 are located on the side surface of the heat sink 8 or the heat sink 17. By fixing the grounding leads 3 and 12 by soldering or the like in a state where they are in contact with and pressed against the bottom surface of the LSI, electromagnetic wave noise radiated from the LSIs 7 and 16 can be shielded, and other parts can be provided. The LSIs 7 and 16 can be protected from electromagnetic noise emitted from the LSIs.

Further, by constructing the shield fences 1 and 10 as described above, the conventional heat sinks 8 and 17 mounted on the LSIs 7 and 16 can be used as they are, so that the cost is greatly increased. This can be avoided, and the cost of parts can be reduced by sharing the shield fences 1 and 10.

Further, since the finger strip contact portions 2 and 11 of the shield fences 1 and 10 can contact the side surface of the heat sink 8 or the bottom surface of the heat sink 17 at multiple points, stable grounding is possible.

In addition, in one embodiment and another embodiment of the present invention, the slits 4 and 13 are provided so that the finger strip contact portions 2 and 11 can come into contact with the side surface of the heat sink 8 or the bottom surface of the heat sink 17 at multiple points. The upper ends 1a, 1 of the shield fences 1, 10 without slits
It is also possible to simply bend 0a, and it is not limited to this.
In that case, it is necessary to allow the upper ends 1a and 10a to uniformly contact the side surface of the heat sink 8 or the bottom surface of the heat sink 17.

[0036]

As described above, according to the present invention, a shield plate that shields an integrated circuit mounted on a printed circuit board is biased in a direction parallel to or perpendicular to the surface of the printed circuit board. By providing a contact portion that contacts the heat sink and a conductive portion that is fixed by being inserted into the ground through hole near the integrated circuit, it is possible to avoid a significant increase in cost and it has been used until then. There is an effect that the heat sink can be used as it is.

[Brief description of drawings]

1A is a sectional view of a shield fence according to an embodiment of the present invention, and FIG. 1B is a front view of a shield fence according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of attachment of the shield fence of FIG.

3A is a cross-sectional view of a shield fence according to another embodiment of the present invention, and FIG. 3B is a front view of a shield fence according to another embodiment of the present invention.

FIG. 4 is a diagram showing an example of attachment of the shield fence of FIG.

5A is a perspective view of a conventional example, FIG. 5B is a side view of the conventional example, and FIG. 5C is a sectional view of the conventional example.

6A is a perspective view of a conventional example, and FIG. 6B is a sectional view of the conventional example.

7A is a developed view of a conventional example, and FIG. 7B is a sectional view of the conventional example.

[Explanation of symbols]

 1,10 Shield fence 2,11 Finger strip contact part 3,12 Ground lead 4,13 Slit 5a, 14a Ground through hole 8,17 Heat sink

Claims (3)

[Claims] 1. A printed circuit board having a ground through hole, and an integrated circuit mounted on the printed circuit board,
A shield structure for a package, which is mounted on the integrated circuit and comprises a heat sink having conductivity, wherein the contact portion is biased in a direction parallel to the surface of the printed circuit board and is in contact with the heat sink. A shield structure having a conductive portion that is inserted into and fixed to the ground through hole near the integrated circuit and that shields the integrated circuit. 2. A printed circuit board having a ground through hole, and an integrated circuit mounted on the printed circuit board.
A shield structure for a package, which is mounted on the integrated circuit and comprises a heat sink having conductivity, wherein the contact portion is urged in a direction perpendicular to the surface of the printed circuit board to abut against the heat sink. A shield structure having a conductive portion that is inserted into and fixed to the ground through hole near the integrated circuit and that shields the integrated circuit. 3. A printed circuit board having a ground through hole, and an integrated circuit mounted on the printed circuit board,
A shield structure for a package, which is mounted on the integrated circuit and comprises a conductive heat sink, comprising: a first contact portion capable of contacting a side surface of the heat sink and a second contact portion capable of contacting a bottom surface of the heat sink. A contact portion, a first biasing portion that biases the first contact portion in a direction parallel to the printed circuit board surface, and a second contact portion with respect to the printed circuit board surface. A biasing portion that biases the integrated circuit vertically in a vertical direction, and a conductive portion that is inserted into and fixed to the ground through hole near the integrated circuit, and includes a shield plate that shields the integrated circuit. Shield structure characterized by.