JPH0786495A - Semiconductor device - Google Patents

Abstract

PURPOSE:To reduce the size of a metallic enclosure for housing a plurality of semiconductor chips by arranging a first semiconductor chip on an insulating substrate and a second semiconductor chip which is turned over as compared with the first semiconductor chip on the first semiconductor chip. CONSTITUTION:In a metallic package composed of an insulating substrate 1 and metallic enclosure 3, a first semiconductor chip 2a is mounted 1 in an inverted state on the substrate 1 by flip-chip bonding and a second semiconductor chip 2b is mounted on the chip 2a in a normal state so that the rear surfaces of the chips 2a and 3b can meet each other. The chip 2a is connected to wiring on the substrate 1 through bump electrodes 5 and the chip 2b is connected to the wiring on the substrate 1 through bonding wires 4. Therefore, the using area of the substrate 1 becomes the same as that obtained when only the chip 2a is mounted on the substrate 1 and the size of the metallic enclosure can be reduced.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to semiconductor devices. More specifically, the present invention relates to a novel structure of a semiconductor device formed by accommodating a plurality of semiconductor chips in one metal package.

[0002]

2. Description of the Related Art Recent advances in semiconductor technology are remarkable.
A technique for mounting an extremely large number of elements at high density has been realized. However, when using a general-purpose semiconductor chip supplied as a bare chip, or when using an element such as an optical element or a superconducting element whose manufacturing process is different from that of a normal semiconductor circuit, a plurality of chips are combined. In some cases, one semiconductor device may be configured.

FIG. 4 is a diagram showing a typical structure of a semiconductor device having a plurality of semiconductor chips.

As shown in FIG. 1, this semiconductor device includes a plurality of semiconductor chips 2 loaded on an insulating substrate 1.
It is mainly composed of a and 2b and a metal casing 3 that seals the semiconductor chips 2a and 2b. Semiconductor chip 2
Each of a and 2b is configured to be connected to a wiring on the insulating substrate 1 by a bonding wire 4 and further connected to the outside via a lead pin 1a mounted on the insulating substrate 1.

In the semiconductor device as described above, the metal casing occupies a relatively large proportion of the manufacturing cost of the entire device, and it is desirable that the size of the metal casing used is small. However, in reality, it is necessary to secure a wiring space for each semiconductor chip on the insulating substrate, and in a semiconductor device including a plurality of semiconductor chips, the metal housing has to be larger than the chip size.
Therefore, a semiconductor device including a plurality of semiconductor chips tends to be expensive.

Further, the bonding wire has a large signal deterioration due to its own parasitic inductance or the like, particularly when a high frequency signal or a weak signal is handled. Further, when a bonding wire is used, the signal line length cannot be ignored in a device that requires high-speed operation.

[0007]

As described above, in a semiconductor device configured to accommodate a plurality of semiconductor chips, the metal housing becomes large, so that an increase in cost is unavoidable, and the speed is high or weak. There is a problem that signal deterioration is likely to occur.

Therefore, the present invention solves the above-mentioned problems of the prior art, can accommodate a plurality of semiconductor chips, can use a small metal housing, and can degrade high-speed signals and weak signals. It is an object of the present invention to provide a semiconductor device having a novel structure that can be used without any need.

[0009]

According to the present invention, there is provided a semiconductor device including an insulating substrate, a semiconductor chip loaded on the insulating substrate, and a metal casing for sealing the semiconductor chip on the insulating substrate. A first semiconductor chip loaded on the insulating substrate by a flip chip bonding method,
A semiconductor device is provided, comprising: a second semiconductor chip mounted on the first semiconductor chip, the front surface and the back surface of the first semiconductor chip being reversed.

[0010]

The semiconductor device according to the present invention is characterized mainly in the method of mounting a semiconductor chip on an insulating substrate.

That is, in the conventional semiconductor device, since the semiconductor chips are arranged horizontally on the insulating substrate, when a plurality of semiconductor chips are accommodated, not only the area is simply increased but also each semiconductor chip is increased. It was necessary to secure a wiring space and the like, and as a result, the size of the device was very large. Also, because the wiring between the semiconductor chips was nothing but bonding,
Due to the bonding wire inevitably having parasitic inductance, deterioration of high frequency signals and weak signals was unavoidable.

On the other hand, the semiconductor device according to the present invention not only significantly reduces the occupied area by stacking and mounting a plurality of semiconductor chips, but is also effective in reducing the wiring length. .

That is, the semiconductor chip usually has a circuit or element formed on one surface thereof. Therefore, even if a pair of semiconductor chips are stacked so that their back surfaces face each other, their functions are not affected.

Here, in the semiconductor chip on the insulating substrate, the loaded circuit or element faces the mounting surface of the insulating substrate. According to the mounting method using bump electrodes called flip chip bonding, There is no problem in mounting with the surface of the semiconductor chip facing downward.

On the other hand, the second is mounted by stacking on the semiconductor chip mounted by the flip chip bonding.
The semiconductor chip can be connected to the substrate by wire bonding as is conventionally done, and as will be described later in detail, the semiconductor chip is connected between the first semiconductor chip and the insulating substrate through a via hole formed in the first semiconductor chip. Wiring can be formed. According to such a method, it is possible to reduce the use of a bonding wire having a large parasitic capacitance,
The signal line length can also be shortened.

Although referred to as a "semiconductor chip" in the above description, the present invention also applies to a chip loaded with an integrated circuit which is not necessarily an electronic circuit such as a superconducting integrated circuit or an optical integrated circuit. Needless to say, is applicable.

Hereinafter, the present invention will be described in more detail with reference to examples, but the following disclosure is merely one example of the present invention and does not limit the technical scope of the present invention.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing a concrete configuration example of a semiconductor device according to the present invention. In the figure, the same components as those in FIG. 4 are designated by the same reference numerals, and detailed description thereof is omitted.

As shown in the figure, this semiconductor device is constructed by accommodating a pair of semiconductor chips 2a and 2b in a metal package composed of an insulating substrate 1 and a metal housing 3. , Which is common to the semiconductor device shown in FIG.

However, in this semiconductor device, the first semiconductor chip 2a is inverted and mounted on the insulating substrate 1 by so-called flip chip bonding. Further, the second semiconductor chip 2b is loaded on the second semiconductor chip 2a in the normal orientation, that is, the back surfaces of the first semiconductor chip 2a and the first semiconductor chip 2a are aligned with each other.

Here, the first semiconductor chip 2a is connected to the wiring on the insulating substrate 1 via the bump electrode 5.
On the other hand, the second semiconductor chip 2b has a bonding wire 4
Is connected to the wiring on the insulating substrate 1 via.

In the semiconductor device configured as described above, the required area of the insulating substrate 1 to be used is the same as when the first semiconductor chip 2a is mounted alone. Therefore,
A small metal casing 3 can be used for sealing. Further, in particular, the first semiconductor chip 2a is
Since the flip-chip bonding method is used for mounting, the amount of bonding wires used, which easily causes signal deterioration, is also reduced.

FIG. 2 is a diagram showing another structural example of the semiconductor device according to the present invention. Also in this figure, components common to those in FIGS. 1 and 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in the figure, this semiconductor device has the same basic arrangement as that of the semiconductor device shown in FIG. 1 in terms of the basic arrangement of the insulating substrate 1, the semiconductor chips 2a and 2b, and the metal housing 3. ing.

The characteristic of this semiconductor device is the electrical connection of the second semiconductor chip 2b. That is, a plurality of via holes 6 are formed in the first semiconductor chip 2a used here, and the second semiconductor chip is connected to the circuit of the first semiconductor chip 2a via the bonding wire 4 and the via hole. It is connected.

With the above-mentioned structure, in this semiconductor device, the amount of the bonding wire, which is apt to cause the signal deterioration, is reduced, and further, the signal line length in this package is shortened.

FIG. 3 is a diagram showing still another configuration example of the semiconductor device according to the present invention. Also in this figure, constituent elements common to those in FIGS. 1, 2 and 4 are designated by the same reference numerals, and detailed description thereof is omitted.

As shown in the figure, this semiconductor device has the same basic arrangement as the insulating substrate 1, the semiconductor chips 2a, 2c, and the metal housing 3 and the wiring thereof as in the semiconductor device shown in FIG. It has the configuration of.

A characteristic of this semiconductor device is that a photodiode, which is an optical element, is used as the second semiconductor chip 2c. Therefore, the metal casing 3 is formed with a transparent window 3a for transmitting the light received by the photodiode.

In general, an electric signal output from a photodiode is extremely weak as compared with a signal handled by an ordinary electronic circuit, and the deterioration of the signal and the influence of noise are always a problem. On the other hand, in the semiconductor device configured according to the present invention, the use of the bonding wire 4, which easily causes signal deterioration, is shortened to the utmost limit, and the signal quality is easily maintained.

[0031]

As described above, the semiconductor device according to the present invention is remarkably miniaturized as a semiconductor device device having a plurality of chips. Therefore, the metal casing used for sealing can be miniaturized, so that the manufacturing cost can be reduced.

Further, not only is it physically miniaturized, but the amount of bonding wires that tend to cause signal deterioration is shortened, and when handling weak signals or high frequency signals, It can be advantageously used as a device with little signal deterioration.

The semiconductor device according to the present invention having the above characteristics uses not only a device using a plurality of semiconductor chips but also an integrated circuit other than the semiconductor such as an optical element, an optical integrated circuit, and a chip integrated circuit. It can also be suitably used in devices.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a configuration of a semiconductor device according to the present invention.

FIG. 2 is a diagram showing another configuration example of a semiconductor device according to the present invention.

FIG. 3 is a diagram showing still another configuration example of the semiconductor device according to the present invention.

FIG. 4 is a diagram showing a typical configuration of a conventional semiconductor device using a plurality of semiconductor chips.

[Explanation of reference numerals] 1 ... Insulating substrate, 2a ... First semiconductor chip, 2b ... Second semiconductor chip, 2c ... Photodiode, 3 ... Metal housing, 4 ... Bonding wire, 5 ... Bump electrodes, 6 ... Via holes

Claims (2)

[Claims] 1. A semiconductor device comprising an insulating substrate, a semiconductor chip loaded on the insulating substrate, and a metal casing encapsulating the semiconductor chip on the insulating substrate, wherein a flip chip is provided on the insulating substrate. A first semiconductor chip loaded by a bonding method, and on the first semiconductor chip,
A semiconductor device comprising: a first semiconductor chip, and a second semiconductor chip loaded with its front and back reversed. 2. The semiconductor device according to claim 1, wherein the element or circuit on the first semiconductor chip and the element or circuit on the second semiconductor chip are formed on the first semiconductor chip. A semiconductor device characterized by being connected through a via hole.