JPH04264760A - Mounting structure for heat sink of integrated circuit package - Google Patents

Abstract

PURPOSE:To easily attach or detach a heat sink in an integrated circuit package by securing the sink to an upper surface of a flat package with pawls provided at two opposite sides of the upper surface of the package, and drawing knobs provided at the pawls to an outside to disengage an engagement with the sink. CONSTITUTION:When a heat sink 6 is pressed to a flat package 1 according to a direction B, a spring 4 is pressed to the edge of the sink 6 to be opened in a direction C. It is returned by the elasticity of the spring, a pawl 8 is engaged with the sink 6, and the sink 6 is secured to the package 1 through a thermal conductive rubber 7. When a knob 5 is pulled from this state in the direction C, the pawl 8 of the spring 4 is removed from the sink 6, and the sink 6 can be removed from the package. Accordingly, even if a mounting pitch is narrow, a signal pattern, etc., can easily be corrected.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink mounting structure for an integrated circuit package used in air-cooled electronic equipment and the like.

0002

[Background Art] In recent years, with the aim of improving performance and downsizing of electronic devices such as computers, devices have become highly integrated and densely packaged, integrated circuits have become highly integrated, and packages have become flat-packed. , efforts are being made to minimize the mounting pitch of integrated circuit packages on printed circuit boards. FIG. 3 shows a heat sink mounting structure for an integrated circuit package used in conventional air-cooled electronic equipment. In FIG. 3, 1 is a flat package containing an integrated circuit, and 2 is its lead. 1
1 is a heat sink, which is bonded to the flat package with a thermally conductive adhesive 10. A circuit of an electronic device is constructed by mounting a plurality of this integrated circuit package on a printed circuit board (not shown) at a very narrow pitch.

0003

[Problems to be Solved by the Invention] Normally, at the beginning of the development of electronic equipment, it is necessary to change the signal pattern on the printed circuit board in order to change functions, specifications, correct design errors, etc. Such a modification would disconnect the signal traces connected to the flat package leads, and the new signal traces would
This is done by connecting thin wires to the leads of the flat package. However, in the conventional integrated circuit heat sink mounting structure described above, the integrated circuit package is mounted on the printed circuit board at a very small pitch. The disadvantage is that it is difficult to perform or cannot be performed at all.

The present invention solves the above problems and makes it possible to easily attach and detach a heat sink in an integrated circuit package in order to easily carry out the above correction work.

[0005]

[Means for Solving the Problems] The integrated circuit package mounting structure of the present invention includes a plate spring having claws facing inward of the package provided on two opposite sides of the upper surface of the package in which the integrated circuit is sealed; a knob provided at the tip of the claw and protruding outward through an opening provided in the plate spring; a heat sink whose bottom edge engages with the claw and is fixed to the top surface of the package; a thermally conductive rubber sandwiched between the bottom surface of the heat sink and the package;
When the blockage is pulled outward, the heat sink is disengaged from the pawl and can be removed from the package.

[0006]

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing a heat sink mounting structure of an integrated circuit package according to an embodiment of the present invention.

In FIG. 1, 1 is a flat package containing an integrated circuit, and 2 is a plurality of leads thereof. Reference numeral 4 denotes a spring made of an elastic bent plate, one end of which is fixed almost perpendicularly to the top surface of the flat package 1, and the end of this vertical part is bent back diagonally to form a claw 8, with the tip of the claw 8 further inside. A knob 5 consisting of a protrusion provided in the center of the inwardly bent tip passes through an opening 9 provided in the vertical portion and projects outward. A pair of springs 4 are provided on two opposing sides of the flat package 1 and have spring properties in the direction of arrow C. 6 is a heat sink, and a thermally conductive rubber 7 is fixed to the bottom surface of the heat sink. When this heat sink 6 is pressed against the flat package 1 in the direction of arrow B, the spring 4 is pushed by the edge of the heat sink 6 and opens in the direction of arrow C, and then returns due to its spring property, and the claw 8 engages with the heat sink 6, causing the heat sink to 6 is fixed to the flat package 1.

AA with the heat sink 6 fixed
A cross-sectional view is shown in FIG. 2(a). In this state, the claw 8 of the spring 4
As a result, the heat sink 6 is pressed against the flat package 1 via the thermally conductive rubber 7. When the knob 5 is pulled in the direction of arrow C from the state shown in FIG. 2(a), the claw 8 of the spring 4 is detached from the heat sink 6 as shown in FIG. 2(b), allowing the heat sink 6 to be removed from the flat package 1.

Further, the flat package 1 is provided with a stopper 3. This stopper 3 is connected to the heat sink 6 that is pressed against the flat package 1 during transportation, etc. as shown in FIG.
This prevents it from shifting in the direction of arrow D shown in .

When the heat sink 6 is removed from the flat package 1, even if the mounting pitch of the integrated circuit package is narrow, the space for signal pattern correction becomes larger.

Although the thermally conductive rubber 7 is fixed to the heat sink 6 in this embodiment, it may also be fixed to the flat package 1 side. In addition, in this embodiment, an example of a plate-shaped heat sink 6 and a flat package 1 was shown, but a pin grid array (Pin
The present invention is also applicable to packages such as Grid Array.

[0013]

[Effects of the Invention] As explained above, the present invention allows the heat sink to be easily attached to and detached from the integrated circuit package.
Even when the mounting pitch is narrow, signal patterns etc. can be easily modified.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the present invention.

[Fig. 2] In the AA cross-sectional view of Fig. 1, (a) shows the heat sink 6.
(b) shows the state in which it is fixed to the flat package 1, and (b) shows it in the state in which it is removed.

FIG. 3 is a side view showing a heat sink mounting structure of a conventional integrated circuit package.

[Explanation of symbols]

1 Flat package 2 Lead 3 Stopper 4 Spring 5 Knob 6,11 Heat sink 7 Thermal conductive rubber 8 Claw 9 Opening 10 Thermal conductive adhesive

Claims (2)

[Claims] 1. A plate spring having claws facing inward of the package provided on two opposite sides of the upper surface of a package in which an integrated circuit is sealed, and an opening provided in the plate spring provided at the tip of the claw. a heat sink whose bottom edge engages with the claw and is fixed to the top surface of the package; and a heat conductor sandwiched between the bottom surface of the heat sink and the package. A mounting structure for a heat sink for an integrated circuit package, characterized in that when the knob is pulled outward, the heat sink is disengaged from the claw and can be removed from the package. 2. Stoppers are provided on two opposite sides of the top surface of the package other than the two sides on which the plate springs are provided, and a heat sink whose bottom side engages with the claws is attached to the two opposite sides of the top surface of the package. A mounting structure for a heat sink of an integrated circuit package that prevents the heat sink from traversing and coming off the package.