JPH05326520A - Semiconductor device - Google Patents

Abstract

PURPOSE:To provide a semiconductor device of a structure wherein heat generated in the semiconductor device is efficiently dissipated. CONSTITUTION:A semiconductor element 1 containing GaAs (The heat conductivity is 0.46W/cm deg.C) as its main component is formed and bumps 4 and 5 for connection with the outside are respectively formed via pads 31 and 32. A region excluding the bumps 4 and 5 is covered with a passivation film 2 consisting of an insulative SiO2 film (the heat conductivity is 0.14W/cm deg.C) for the protection and stability of a circuit. Moreover, a heat conduction film 6 consisting of a gold film (the heat conductivity is 3.1W/cm deg.C) is formed on this film 2 without being jointed with the bump 4 for electrode terminal use and being jointed with the bump 5 for heat conduction use. As the heat conductivity of the whole semiconductor element can be made to rise, a heat dissipation effect can be increased in a semiconductor device of a structure, wherein a flip-chip mounting is performed, without requiring other heat dissipation means. Thereby, a semiconductor device having power consumption higher than that of a conventional semiconductor device can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device mounted by a flip chip method.

[0002]

2. Description of the Related Art With the increase in performance and multi-functionality of electronic equipment, the speed and density of integrated circuits used in these electronic circuits have been increasing. As a result, the degree of integration of semiconductor elements has increased, and along with this, there has been a demand for a technique that is compatible with an increase in the number of connection terminals with external circuits and high-density mounting. A flip-chip method is a mounting technology that meets this demand. However, as the density of the integrated circuit increases, the heat generation density of the semiconductor chip also increases, and in order to fully exhibit the performance of the device, it is necessary to further consider the heat dissipation of the electronic circuit. For conventional technology, see IEEE TRANSACTION
S ON COMPONENTS, HYBRIDS, A
ND MANUFACTURING TECHNOLO
GY, VOL. 12, NO. 2, JUNE 1989.

[0003]

FIG. 2 shows a conventional semiconductor device which is mounted by the flip chip method.

As shown in this figure, most of the heat generated in the semiconductor device is transferred to the heat conduction bumps 5 through the semiconductor element 1 or the passivation film 2.
Therefore, GaAs (thermal conductivity 0.46 W
/ Cm ° C.) and SiO on the passivation film 2
_If a low thermal conductivity material such as ₂ (thermal conductivity 0.14 W / cm ° C) is used, heat transfer from the heat generating part in the element to the heat conduction bumps 5 will not be performed well, and the heat conduction of the element will not occur. There was a problem that the rate would decrease.

In view of the above problems, it is an object of the present invention to provide a device which efficiently dissipates heat generated in a semiconductor device.

[0006]

In order to solve the above problems, the present invention provides a semiconductor device in which bumps for heat conduction, bumps for electrode terminals, and a passivation film are formed on a semiconductor element. It has a structure in which a heat conductive film, which is a substance having excellent heat conductivity, is adhered to a desired region above, the heat conductive film and the heat conductive bumps are bonded, and the heat conductive bumps and the electrode terminals are connected. It is characterized in that it is electrically insulated from the use bump. Further, the heat conducting film may be a thin film of gold or diamond.

[0007]

According to the present invention, since the heat conductive film, which is a substance having excellent thermal conductivity, is deposited on the heat generating element in the semiconductor device through the passivation film, the heat from the heat generating element is transferred to the heat conductive film. Good transmission. Further, since the heat conducting film is connected to the heat conducting bumps, heat is radiated through the heat conducting film, and therefore the heat conductivity of the entire semiconductor device is increased. In particular, the heat conduction on the surface of the semiconductor device from the heat generating portion of the semiconductor device to the bumps for heat conduction becomes good.

[0008]

FIG. 1 shows an embodiment of the present invention. Hereinafter, description will be given with reference to the drawings. 1A is a sectional view of a semiconductor device according to an embodiment of the present invention, and FIG. 1B is a top view of this semiconductor device.

Bumps 4 and 5 for connecting the semiconductor element 1 to the outside are formed via pads 31 and 32.
Further, the area excluding the bumps 4 and 5 is the passivation film 2.
Is covered with. Further, the heat conduction film 6 is formed on the passivation film 2 so as not to be joined to the electrode terminal bumps 4 and joined to the heat conduction bumps 5.

3 to 4 show steps of the embodiment of the present invention, which will be described with reference to the drawings.

GaAs (thermal conductivity 0.46 W / cm ° C.)
On the semiconductor element 1 containing as a main component, pads 31 and 32 to be the bases of the bumps 4 and 5, and these pads 3
The passivation film 2 is formed in the region excluding the regions 1 and 32. The pads 31 and 32 are made of Pt, and the passivation film 2 is made of insulating SiO ₂ (heat conductivity of 0.14 W / cm ° C.) for protecting and stabilizing the circuit.

On the passivation film 2, a heat conducting film 6 is formed of gold (heat conductivity 3.1 W / cm ° C.) (FIG. 3 (a)). At this time, the heat conductive film 6 needs to be formed so as to be almost in contact with the pad 31 and be separated from the pad 31 by a distance of about the diameter of the pad 31 in order to avoid connection with the electrode terminal.

Next, a resist 7 is applied on the region excluding the pads 31 and 32, that is, on the passivation film 2 and the heat conducting film 6. Then, the plating base metal 8 of Ti / Au is formed on the entire region including the pads 31 and 32 (FIG. 3B). Area excluding above the pads 31 and 32,
That is, the thick film resist 9 is applied to the area excluding the portions where the bumps 4 and 5 are formed (FIG. 3C).

The gold plating layer 10 is entirely grown (see FIG. 4).
(D)). Then, the thick film resist 9 is lifted off (FIG. 4E). Then, the plating base metal 8 and the resist 7 in unnecessary portions are removed by performing milling and ashing, and the electrode terminal bumps 4 are provided on the pads 31.
The bumps 5 for heat conduction are formed on the pads 32 (FIG. 4 (f)).

In the above steps, gold was used for the heat conductive film 6, but a thin film obtained by vapor phase synthesis of diamond (heat conductivity of about 20 W / cm ° C.) can also be used. When a diamond thin film is used, it is not necessary to separate the electrode terminal bumps 4 from the heat conductive film 6 because diamond is an electrical insulator.

Another process different from the above is shown in FIG.

Bumps 4 and 5 are formed on the semiconductor element 1 via pads 31 and 32, and regions other than the bumps 4 and 5 are covered with the passivation film 2 (FIG. 5).
(A)). This is the same state as the conventional structure. Then, a resist 71 is applied to cover the bumps 4 (see FIG. 5).
(B)). The heat conductive film 61 is formed in all regions (FIG. 5).
(C)).

Then, the resist 71 is lifted off to remove the resist 71 covering the bumps 4 and the heat conductive film 61 to form the electrode terminal bumps 4. Also,
The bumps 5 and the heat conducting film 61 covering the bumps 5 are used as the heat conducting bumps 51 (FIG. 5D).

According to the above process, the conventional process and structure can be utilized as they are.

The present invention is not limited to the above-described embodiment, but can be variously modified.

The heat conducting film is not limited to a gold or diamond film, but may be another metal film or non-metal film as long as it has a good heat conductivity. For example, a film of Al, Cu or the like may be used. Further, the main component of the semiconductor element is not limited to GaAs, and for example,
Si may be used, and the passivation film is SiO ₂
Needless to say, for example, Si ₃ N ₄ , Al ₂ O ₃ or the like may be used.

After forming the heat conducting film, an insulating film may be further formed on the heat conducting film in order to protect and stabilize the semiconductor element. Further, when there is no hindrance to the operation of the semiconductor element, the heat conduction bump and the electrode terminal bump can be shared.

[0023]

As described above, according to the present invention, since the thermal conductivity of the entire semiconductor device can be increased, the heat dissipation effect can be obtained in the flip chip mounting semiconductor device without using other heat dissipation means. Can be large.
Therefore, a device having higher power consumption than the conventional semiconductor device can be realized.

Further, since the heat conductivity from the heat generating portion on the semiconductor device to the heat conducting bump is increased, it is particularly effective for a semiconductor device having a heat generating portion locally.

As a result, the problem of heat dissipation of the integrated circuit can be solved, and a semiconductor device in which high power semiconductor elements are integrated at high density can be realized.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention.

FIG. 2 is a schematic view of the structure of a conventional semiconductor device for flip-chip mounting.

FIG. 3 is a schematic view showing a process of an example of the present invention.

FIG. 4 is a schematic view showing a process of an example of the present invention.

FIG. 5 is a schematic view showing a process of an example of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor element, 2 ... Passivation film, 31 ... Electrode terminal bump pad, 32 ... Heat conduction bump pad, 4 ... Electrode terminal bump, 5 ... Heat conduction bump, 6 ...
Thermal conductive film, 7 ... Resist, 8 ... Plating base metal, 9 ... Thick film resist, 10 ... Gold plating layer.

Claims (2)

[Claims] 1. In a semiconductor device in which bumps for heat conduction, bumps for electrode terminals and a passivation film are formed on a semiconductor element, the heat conduction film, which is a substance having excellent heat conductivity, is formed on the passivation film. It has a structure that is adhered to a desired region, the heat conducting film and the heat conducting bump are bonded, and the heat conducting bump and the electrode terminal bump are electrically insulated. A semiconductor device characterized by. 2. The semiconductor device according to claim 1, wherein the heat conducting film is a thin film of gold or diamond.