JP4120102B2 - Semiconductor chip cooling structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooling structure for effectively cooling a semiconductor chip constituting a semiconductor component such as an LSI.
[0002]
[Prior art]
A semiconductor component such as an LSI incorporated in various electronic devices is constituted by a semiconductor chip formed by forming a circuit of a plurality of semiconductor elements on a semiconductor substrate.
[0003]
This semiconductor chip is a heat-generating component that generates heat when the circuit is driven. Here, if the temperature rises too much, the circuit will be adversely affected, so the semiconductor chip is cooled to prevent the temperature from rising. is required.
[0004]
Generally, the cooling of the semiconductor chip is designed to suppress the temperature rise by dissipating the heat generated in the circuit section from the surface of the semiconductor substrate to the air.
[0005]
[Problems to be solved by the invention]
However, in recent years, the amount of heat generated in a semiconductor chip has increased with the increase in circuit density. For this reason, it has become impossible to perform sufficient cooling with a conventional general semiconductor chip structure.
[0006]
The present invention has been made in view of such points, and it is an object of the present invention to provide a more effective cooling structure for a semiconductor chip and to enable sufficient cooling even for a semiconductor chip having a large calorific value.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is formed by forming fine irregularities on the surface of a semiconductor substrate.
In this structure, since the unevenness on the surface of the semiconductor substrate acts as a heat sink, the heat of the semiconductor chip can be radiated efficiently, so that sufficient cooling is possible.
[0008]
Further, according to the present invention, fine irregularities are formed on the surface of the semiconductor substrate, and a flow means for flowing a fluid along the irregularity forming surface is provided.
In this structure, the unevenness on the surface of the semiconductor substrate acts as a heat sink, and the heat of the semiconductor chip can be dissipated more efficiently by the fluid flow, so that more effective cooling is possible.
The flow means is composed of a thin film disposed along the uneven surface of the semiconductor substrate and a plurality of piezoelectric elements arranged in parallel on the thin film along the longitudinal direction of the thin film to vibrate the thin film. The
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0010]
FIG. 1 shows a desktop personal computer 1 as an example of an electronic device, in which 2 is a personal computer body, 3 is a display device using a CRT, and 4 is a keyboard device.
[0011]
As shown in FIG. 2, the personal computer main body 2 includes a CPU 6, a hard disk device 7, a memory (RAM) 8, a CRT controller 9, a keyboard controller 10, and the like incorporated therein. In addition, the personal computer body 2 incorporates a floppy disk drive device, a CD-ROM drive device, and a controller modem device thereof.
[0012]
A large number of semiconductor components 12 such as LSI are mounted on a substrate 11 inside the personal computer main body 2 to constitute an internal circuit.
[0013]
The semiconductor component 12 such as an LSI is constituted by a semiconductor chip 13 as shown in FIG.
The semiconductor chip 13 is formed by forming a circuit 15 including a plurality of semiconductor elements on a semiconductor substrate 14, and the circuit 15 is connected to an external circuit through a lead wire 16.
[0014]
The semiconductor chip 13 generates heat as the circuit is driven. In this case, if the temperature rises too much, the circuit drive is adversely affected. Therefore, the semiconductor chip 13 has a structure that effectively cools the circuit. Fine irregularities are formed on the surface of the semiconductor substrate 14 (the surface opposite to the surface on which the circuit 15 is formed).
[0015]
That is, in this example, as shown in FIG. 3 to FIG. 5, an infinite number of thin columnar protrusions 17 are formed on the surface of the semiconductor substrate 14 to give an uneven shape.
Here, the height h of the projections 17 is 1 nm to 10 μm, and the pitch p between the projections 17 is also about 1 nm to 10 μm.
[0016]
Such a concavo-convex shape can be easily formed by a crystal growth technique, a photo-etching technique, or the like.
[0017]
Since the fine irregularities are formed on the surface of the semiconductor substrate 14 in this way, the irregularities act as a so-called heat sink, that is, the area where the surface of the semiconductor substrate 14 is exposed to air is increased, so that the circuit 15 of the semiconductor chip 13 is increased. Therefore, the semiconductor chip 13 can be sufficiently cooled and the temperature rise can be suppressed.
[0018]
FIG. 6 shows a more effective cooling structure for the semiconductor chip.
That is, in this example, in addition to the structure in which fine irregularities are formed on the surface of the semiconductor substrate 14 by innumerable columnar protrusions 17 as described above, a flow means for causing air to flow along the irregularity forming surface is provided.
[0019]
This flow means is constituted by a piezoelectric film 18 disposed along the uneven surface of the semiconductor substrate 14.
The piezoelectric film 18 has a gap g between the semiconductor substrate 14 and a predetermined distance (approximately the same as or less than the height h of the columnar protrusions 17). The piezoelectric film 18 is vibrated in a wave shape to generate a traveling wave so that air can flow in one direction along the uneven surface.
[0020]
The piezoelectric film 18 has a structure in which a plurality of piezoelectric elements 18b are juxtaposed in the longitudinal direction on a thin film 18a as shown in FIG. 7, and a current is supplied to each of the piezoelectric elements 18b by shifting the phase. Oscillates in a wave shape to cause traveling waves.
The amplitude of the piezoelectric film 18 is set to be smaller than the gap g between the piezoelectric film 18 and the semiconductor substrate 14.
[0021]
In the cooling structure configured as described above, the unevenness on the surface of the semiconductor substrate 14 acts as a heat sink, and the air flows along the unevenness forming surface, so that the heat of the semiconductor chip 13 can be radiated more efficiently. The semiconductor chip 13 can be cooled more effectively, and the temperature rise can be reliably suppressed.
[0022]
Particularly in this cooling structure, since the piezoelectric film 18 is used as the flow means, air can be sent without requiring a large-scale device such as a cooling fan, so that it can be implemented easily and at low cost. .
[0023]
In the above example, the semiconductor chip 13 is effectively cooled by allowing air to flow as a fluid. However, the fluid is not limited to air but may be other fluorocarbons having good heat conduction efficiency. It is also possible to use liquid such as pure water (in this case, the periphery of the semiconductor chip 13 needs to be sealed so that the fluid does not flow out).
[0024]
The embodiment of the present invention has been described above. Needless to say, the present invention is not limited to this example.
[0025]
【The invention's effect】
As described above, according to the cooling structure of the present invention, it is possible to effectively dissipate the heat of the semiconductor chip and perform effective cooling.
Therefore, even a semiconductor chip with a large amount of heat generation can be sufficiently cooled.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a desktop personal computer.
FIG. 2 is an explanatory diagram of the internal configuration of the personal computer.
FIG. 3 is a side view showing an example of a semiconductor chip cooling structure according to the present invention.
FIG. 4 is an enlarged view of a main part of the same.
FIG. 5 is a perspective view of the same.
FIG. 6 is a perspective view showing another example of a cooling structure for a semiconductor chip according to the present invention.
FIG. 7 is a plan view showing the structure of the piezoelectric film.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 13 ... Semiconductor chip, 14 ... Semiconductor substrate, 15 ... Circuit, 17 ... Columnar protrusion, 18 ... Piezoelectric film (flow means)

Claims (2)

A semiconductor substrate having fine irregularities formed on the surface ;
A fluidizing means for causing fluid to flow along the uneven surface of the semiconductor substrate;
With
The flow means includes a thin film disposed along the uneven surface of the semiconductor substrate and a plurality of piezoelectric elements arranged in parallel on the thin film along the longitudinal direction of the thin film to vibrate the thin film cooling structure of a semiconductor chip composed of a. The thin film is supported above the semiconductor substrate in a state where a gap of a predetermined interval is secured between the thin film and the semiconductor substrate,
2. The semiconductor chip cooling structure according to claim 1, wherein the gap is set to be larger than the amplitude of the thin film .

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