JPH0613506A - Semiconductor integrated circuit device - Google Patents

Abstract

(57) [Summary] (Modified) [Object] To provide a semiconductor integrated circuit device having improved heat dissipation characteristics, which can easily improve heat dissipation efficiency without requiring special heat dissipation parts. The purpose is to A semiconductor chip, a package that houses the semiconductor chip, a plurality of metal pins that enter the package from the outside, and a metal lead that connects the plurality of metal pins and the semiconductor chip, The metal leads are for electrical connection as well as for electrical connection (H
Including C). The semiconductor chip has a metal layer 5 on the wiring layer.

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 device, and more particularly to a semiconductor integrated circuit device having improved heat dissipation characteristics.

The integration of semiconductor integrated circuit devices has advanced more and more, and the number of elements per unit area tends to increase. In a semiconductor integrated circuit device having a high degree of integration, it is required to improve heat dissipation characteristics as well as electrical properties.

[0003]

2. Description of the Related Art In a conventional semiconductor integrated circuit device,
There are semiconductor chips that are housed in a package and do not take any heat dissipation measures, but there are some measures that take heat dissipation measures.

FIG. 6 shows an example of the structure of a semiconductor integrated circuit device in which a heat radiation measure is taken by a conventional technique. 6A and 6AB have a structure in which a plurality of disk-shaped fins 52 are stacked on the surface of a resin-molded package 50 that houses a semiconductor chip. The heat transferred from the package 50 to the fins 52 is dissipated into the air from the surfaces of the fins 52.

FIGS. 6A and 6BB show a structure having parallel fins 53 standing perpendicular to the surface of a resin-molded package 50. When the fins are arranged vertically, the air warmed by the fins has a low specific gravity and rises, which facilitates natural convection.

FIGS. 6 (CA) and 6 (CB) show a structure in which a plurality of columnar heat dissipation columns are vertically formed on a ceramic package 50. In the case of forced air cooling or the like, an air flow path can be formed regardless of the direction of the air flow with such a configuration.

Although the structure in which the heat radiation fins are provided on the surface of the package 50 has been described above, there is a simpler configuration in which no heat radiation fins are provided and a heat radiation plate is provided on the surface of the package 50.

FIGS. 6 (DA) and 6 (DB) show an example of such a configuration. A heat dissipation plate 55 made of metal is arranged on the surface of the package 50 that accommodates the semiconductor chips.
The metal plate 55 has a higher thermal conductivity than the package 50 made of plastic or the like, and dissipates the heat transmitted from the semiconductor chip into the air more efficiently.

The heat radiating means as described above is formed on the package surface of the semiconductor integrated circuit device or is thermally coupled to the semiconductor chip mounting stage. When the stage on which the semiconductor chip is mounted is thermally coupled to the radiation fin, the heat generated in the semiconductor chip is efficiently transferred to the radiation fin through the stage.

[0010]

The heat dissipation means according to the prior art as described above requires special parts for heat dissipation. In addition, this complicates the assembly process.

In the semiconductor integrated circuit device, the semiconductor element is formed on the surface of the semiconductor chip. Therefore, heat generated during the operation of the semiconductor integrated circuit device is intensively generated near the surface of the semiconductor chip.

Even when the heat dissipation means is formed on the back surface side of the semiconductor chip, the heat generated on the front surface of the semiconductor chip reaches the heat dissipation means after being transferred through the semiconductor chip. The semiconductor surface side is covered with an insulating layer and generally does not have high thermal conductivity.

An object of the present invention is to provide a semiconductor integrated circuit device which can easily improve heat dissipation efficiency without requiring a special heat dissipation component. Another object of the present invention is to provide a semiconductor integrated circuit device capable of radiating heat generated near the surface of a semiconductor chip more directly.

[0014]

A semiconductor integrated circuit device according to the present invention includes a semiconductor chip, a package that accommodates the semiconductor chip, a plurality of metal pins that enter the package from the outside, and a plurality of metal pins. A metal lead for connecting to the semiconductor chip, and the metal lead includes one for thermal connection (HC) in addition to one for electrical connection (EC).

More preferably, the semiconductor chip further includes at least one metal layer on the wiring layer, and the metal layer and the metal lead for thermal connection are thermally connected.

[0016]

The semiconductor integrated circuit device is provided with metal pins for external connection. By using this metal pin as a heat radiating means, it is possible to improve the heat radiating characteristic of the semiconductor integrated circuit device without requiring a special heat radiating component.

By further forming at least one metal layer on the wiring layer of the semiconductor chip and thermally connecting the metal layer and the metal pin with a metal lead, heat generated near the surface of the semiconductor chip is removed. It can be efficiently transmitted to the outside.

[0018]

1 schematically shows the structure of a semiconductor integrated circuit device according to a basic embodiment of the present invention. The semiconductor chip 1 is
A large number of semiconductor element structures are formed on the surface portion, and are housed in a package 2 made of plastic, ceramic, or the like. A plurality of metal pins 3 are hermetically inserted into the package 2 from the outside.

A plurality of bonding pads 7 are formed on the surface of the semiconductor chip 1, and the bonding pads 7 and the metal pins 3 are connected by metal leads 4. The bonding pads 7 are not all connected to the semiconductor integrated circuit formed in the semiconductor chip 1, and some of them are in contact with the semiconductor chip 1 but are not electrically connected. Absent.

The metal pins 3 (HC) connected to such electrically isolated bonding pads 7 are for forming a thermal connection for radiating heat from the semiconductor chip 1.

In the illustrated structure, a metal layer 5 is formed on the uppermost layer of the semiconductor chip 1, and the metal layer 5 forms thermal coupling portions 6 with the surface of the semiconductor chip 1 at a plurality of locations.

Therefore, the heat generated in the surface portion of the semiconductor chip 1 is transferred to the metal layer 5 mainly through the thermal coupling portion 6, and the bonding pad 7 thermally coupled to the metal layer 5 leads to the metal lead. It is transmitted to the metal pin 3 (HC) via In this way, the heat dissipation characteristics from the semiconductor chip 1 can be improved without providing the package 2 with a special heat dissipation structure.

FIG. 2 is a plan view for explaining a semiconductor integrated circuit device according to a more specific embodiment of the present invention. FIG. 2A shows a planar configuration of the semiconductor chip 1. A large number of semiconductor elements are formed on the surface portion of the semiconductor chip 1, and an insulating layer covers the semiconductor elements. Semiconductor chip 1
A plurality of bonding pads 7 are formed on the peripheral portion on the surface of the. These bonding pads 7 are electrically connected to the semiconductor elements formed on the surface of the semiconductor chip 1.

Further, on the periphery of the semiconductor chip 1, a heat radiation bonding pad 7a having the same structure as the bonding pad 7 is formed. A metal layer 5 made of, for example, aluminum is formed over a large area on the surface of the central portion of the semiconductor chip.

The metal layer 5 is connected to the heat radiation bonding pad 7a. Further, in a predetermined region in the metal layer 5, a thermal coupling portion 6 for contacting the surface of the semiconductor chip 1 and the metal layer 5 is formed.

FIG. 2B shows an arrangement example of the circuit pattern and the thermal coupling portion on the surface of the semiconductor chip. A plurality of semiconductor elements Q1 to Q4 are formed on the surface of the semiconductor chip. Further, metal electrodes E are connected to the electrode portions of these semiconductor elements Q1 to Q4, respectively.

Although the semiconductor elements Q1 to Q4 are configured to achieve a predetermined circuit function, they do not occupy the entire surface of the semiconductor chip 1. A surface of the semiconductor chip 1 which is not occupied by the semiconductor element Q is selected, and the thermal coupling portion 6 is formed on that surface. The thermal coupling portion 6 has the same structure as the contact of the semiconductor element structurally, but no semiconductor element is formed under the contact portion and has no electrical function.

FIG. 3 is a sectional view showing a structural example of the thermal coupling portion. In FIG. 3A, the insulating layer 12 is formed on the surface of the semiconductor substrate 11, and an opening is provided in a part thereof. The metal layer 5 formed further above the insulating layer is
Semiconductor substrate 11 via connection metal 13 filling the opening
Connected to the surface. The heat of the surface of the semiconductor substrate 11 is transferred to the metal layer 5 via the connection portion 13.

FIG. 3B shows a structural example of the thermal coupling portion when the semiconductor integrated circuit device has a multilayer wiring structure. On the semiconductor substrate 11, the insulating layer 12a, the metal layer 13a, the insulating layer 12b, the metal layer 13b, the insulating layer 12c, the metal layer 13c,
It is assumed that the insulating layer 12d is sequentially formed.

In the region of the semiconductor substrate 11 where the semiconductor element is not formed, the region where the thermal coupling portion 6 is to be formed is selected, and the opening portions are formed in that portion in alignment with the insulating layers 12a to 12c. . The metal layers 13a to 13c are deposited in these openings at the same time when the wiring layers are formed to form a continuous metal stack from the surface of the semiconductor substrate 11.

After forming the uppermost insulating layer 12d, an opening is formed in the thermal coupling portion and a metal layer 5 for forming a heat dissipation structure is formed. This metal layer 5 is continuous with the metal stack by the connecting portion 13d. The heat of the surface portion of the semiconductor substrate 11 is efficiently transferred to the metal layer 5 on the surface through the metal stack.

Although metal generally has a higher thermal conductivity than an insulator and is preferable as a heat dissipation structure, the heat dissipation means does not necessarily have to be entirely formed of metal. Figure 3
(C) shows an example of a heat dissipation structure with an insulating layer interposed. It is assumed that an opening is formed in the insulating layer 12 formed on the surface of the semiconductor substrate 11 and the electrode 14 is formed in contact with the semiconductor substrate 11.

When the surface of the semiconductor substrate 11 is heated, the heat is easily transferred to the electrode 14. The surface of the electrode 14 is covered with an insulating layer 12, and a connecting metal portion 13 continuous with the uppermost metal layer 5 is formed on the electrode 14 via an electrically insulating layer 15 having a predetermined thickness.

The heat transmitted through the electrode 14 is transmitted to the connecting metal portion 13 through the insulating layer 15 and is transmitted to the metal layer 5. If the insulating layer 15 has a small thickness, the heat of the electrode 14 is easily transferred to the metal layer 5.

As described above, it is preferable that the heat radiation wiring is formed in contact with the semiconductor substrate or is arranged close to the wiring on the semiconductor substrate via the insulating film. Except for the step of forming the heat-dissipating metal layer 5, it can be formed only by adding a pattern in a manufacturing process similar to the conventional one.

Further, although the case where the metal layer 5 arranged in the uppermost layer has a continuous planar shape is shown, this layer is not necessarily required to have a planar shape, and may have an arbitrary lattice shape, for example. . With such a shape, it is possible to reduce the influence of stress exerted on the semiconductor chip by the metal layer.

FIG. 4 is a cross-sectional view of the heat dissipation bonding pad 7a. In FIG. 4A, the semiconductor substrate 1
On top of the 1, there are three aluminum layers 17a, 17b, 17
c and three PSG (phosphosilicate glass) layers 12
a, 12b, and 12c are alternately laminated.

The heat dissipation bonding pad 7a is formed by laminating three aluminum layers 17a, 17b and 17c. An opening is formed in the peripheral portion of the third PSG layer 12c, and the heat dissipation aluminum layer 5 covers the opening.
Are formed.

That is, the heat dissipation aluminum layer 5 is connected to the third aluminum layer 17c of the bonding pad 7a through the opening of the PSG layer 12c of the third layer, and Au, Al, Cu are added to the third aluminum layer 17c. Bonding wires 21, etc. are connected. The other end of the bonding wire 21 is connected to the lead frame 19.

The heat generated in the central region of the semiconductor substrate 11 is transferred to the heat dissipation aluminum layer 5 through the aluminum stack of the thermal coupling portion, and the heat dissipation aluminum layer 5 is formed.
Is transmitted to the aluminum layer 17c of the third wiring heat dissipation bonding pad 7a and is transmitted to the lead frame 19 via the bonding wire 21.

FIG. 4B shows another mode of heat conduction from the heat dissipation aluminum layer to the lead frame. On the semiconductor substrate 11, three aluminum wiring layers 17a, 17b,
17c and the insulating PSG layers 12a, 12b, 12c are alternately laminated as in FIG. 4A.

The heat dissipation aluminum layer 5 formed on the third PSG layer 12c extends up to the bonding pad in the peripheral portion of the chip, and is formed in direct contact with the third aluminum layer 17c at the bonding pad portion. Has been done. The bonding wire 21 is connected to the surface of the heat dissipation aluminum layer, and the other end is the lead frame 1
9 is connected.

The heat generated on the surface of the central portion of the semiconductor substrate 11 is once transferred to the heat dissipation aluminum layer 5, transferred to the heat dissipation aluminum layer 5 to the bonding pad 7 a, and then transferred to the lead frame 19 via the bonding wire 21. Be transmitted to.

As described above, the heat generated on the surface portion of the semiconductor substrate 11 is transferred to the lead frame 1 via the heat radiating aluminum layer 5 and the bonding wire 21 arranged on the uppermost layer.
9 and is radiated to the outside from the lead frame 19.

It is obvious to those skilled in the art that the same function can be achieved even if the PSG layer is replaced with another insulating layer or insulating laminated layer, or the aluminum layer is replaced with another metallic layer or metallic laminated layer. Let's do it.

FIG. 5 is a schematic view for explaining the heat radiation from the semiconductor chip to the outside in more detail. Figure 5 (A)
Shows a schematic sectional view of an IC package. The case of a ceramic package will be described as an example.

The ceramic package comprises a main body 25 and a lid body 26, and a concave portion for accommodating the semiconductor chip 1 is formed in the main body 25. A shelf portion 28 exposing the leads 19 is formed around the concave portion. Has been formed. The recess of the main body 25 becomes an airtight space by connecting the lid 26 to the main body 25.

The lead 19 on the shelf 28 is connected to a pin 29 projecting downward from the main body 25. The state of this connection is enlarged and shown in FIG. Illustration of the package portion is omitted. The heat dissipation bonding pad 7a, the bonding wire 21, the lead 19, and the pin 29 form a continuous heat dissipation path.

Bonding pad 7 on semiconductor chip 1
a to the bonding wire 21 as shown in FIG.
Then, the semiconductor integrated circuit device is formed by connecting to the lead 19 and filling a gas such as an inert gas in the recess and sealing the lid 26 as shown in FIG. 5 (A).

Part of the bonding pad 7a is used for heat dissipation, and heat generated in the semiconductor chip 1 is transferred to the pin 29 through the bonding wire 21 and the lead 19.
Dissipate heat from.

Although the case of the gas filled ceramic package has been described, basically the same heat conduction is performed in the case of the plastic package. That is, in the plastic package, the gas filled space is replaced with the plastic filled space, and the ceramic package part is also replaced with the plastic package. However, the heat generated on the surface of the semiconductor chip 1 is bonded to the bonding wire 21 via the heat dissipation metal layer. The point of being transmitted to the leads 19 and radiating heat is the same as in the case of the ceramic package shown in FIG.

Although aluminum is used as the heat-dissipating metal layer in the above-mentioned embodiments, any metal can be used as the heat-dissipating metal layer as long as it has a high thermal conductivity.

For example, a metal such as copper, titanium or tungsten can be used. Although the case where the heat dissipation metal layer is arranged on the wiring layer has been described, the heat dissipation wiring can be arranged at the same level as the electric wiring layer.

The function of the heat dissipation metal layer is to quickly transfer the heat generated on the surface of the semiconductor substrate to the outside. However, by forming a plurality of thermal coupling portions on the heat dissipation metal layer, the semiconductor chip is formed. It also functions to disperse local heat generation on the surface. That is, the heat generated in the vicinity of one location of the thermal coupling portion is quickly transferred to the other thermal coupling portion via the heat-dissipating metal layer to prevent a rapid temperature rise of the heat generating portion.

The present invention has been described above with reference to the embodiments.
The present invention is not limited to these. For example,
It will be apparent to those skilled in the art that various changes, improvements, combinations and the like can be made.

[0056]

As described above, according to the present invention,
The heat dissipation characteristics of the semiconductor integrated circuit device can be improved. By forming the heat transfer path for heat dissipation on the front surface side of the semiconductor chip, the heat generated on the front surface portion of the semiconductor chip is quickly transferred to the outside.

Since heat conduction is achieved by the surface structure of the semiconductor chip, a package structure similar to the conventional one can be adopted.

[Brief description of drawings]

FIG. 1 is a schematic plan view for explaining a basic embodiment of the present invention.

FIG. 2 is a plan view showing a planar configuration of a chip portion of a semiconductor integrated circuit device according to an embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view for explaining a configuration of a thermal coupling portion of a metal layer formed on the front surface side of a semiconductor chip.

FIG. 4 is a schematic cross-sectional view for explaining heat conduction of a heat dissipation bonding pad portion of a semiconductor integrated circuit device according to an embodiment of the present invention.

5A and 5B are a schematic cross-sectional view and a partial conceptual view for explaining heat dissipation through a lead pin according to an embodiment of the present invention.

FIG. 6 is a diagram schematically showing a structure of a semiconductor integrated circuit device having a heat dissipation structure according to a conventional technique.

[Explanation of symbols]

 1 Semiconductor Chip 2 Package 3 Metal Pin 4 Metal Lead 5 Metal Layer 6 Thermal Bonding Part 7 Bonding Pad 7a Heat Dissipation Bonding Pad

Claims (4)

[Claims] 1. A semiconductor chip (1), a package (2) for accommodating the semiconductor chip, a plurality of metal pins (3) that enter into the package from the outside, the plurality of metal pins and the semiconductor chip. A semiconductor integrated circuit device having a metal lead (4) for connecting to and, wherein the metal lead includes one for thermal connection (HC) in addition to one for electrical connection. 2. The semiconductor chip further includes at least one metal layer (5) on a wiring layer, and the metal layer and the metal lead (HC) for thermal connection are thermally connected. The semiconductor integrated circuit device according to claim 1. 3. A semiconductor chip (1), a package (2) for accommodating the semiconductor chip, a plurality of metal pins (3) which enter the package from the outside, the plurality of metal pins and the semiconductor chip A metal lead (4) for connecting with the metal layer, a metal layer (5) formed over a wide area on the wiring layer of the semiconductor chip, and means for thermally coupling the metal layer and the outside. A semiconductor integrated circuit device having: 4. The semiconductor integrated circuit device according to claim 2, wherein the metal layer has a portion (6) that is not electrically coupled to a semiconductor element or electrode but is thermally coupled to a semiconductor surface or electrode. .