JPH0547974A - Semiconductor chip module - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a semiconductor chip module that does not hinder high-speed performance by realizing good heat dissipation. A semiconductor chip module according to the present invention is mounted on a semiconductor substrate 6 on which a wiring portion is formed and a circuit surface facing upward, and one or a plurality of semiconductors arranged on the wiring portion. Chip 4, heat sink 3 whose one end is in contact with the circuit side of these semiconductor chips 4, and hole 2 for exposing the other end of these heat sinks 3 to the outside
a is provided, and a cap 2 that encloses all the semiconductor chips 4 is provided. Since the bonding wire 8 that connects the semiconductor substrate 6 and the face-up type semiconductor chip 4 mounted on the semiconductor substrate 6 is covered with an insulating material, the electrical characteristics even if the heat sink 3 and the bonding wire 8 come into contact with each other. Does not get worse. Therefore, the size of the heat sink 3 can be increased, and heat can be efficiently radiated. In addition, the yield can be improved in manufacturing, and the conductor can be easily used as the material of the heat sink 3, so that the material cost can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor chip module having a semiconductor chip such as a multi-chip module or a single chip module, which is applicable to a field requiring high speed signal processing such as computer and communication. ..

[0002]

2. Description of the Related Art With the demand for large-scale and high-speed functions of electronic devices, the delay time per logic LSI gate has been increased to several hundreds ps. On the other hand, in the conventional mounting mode in which a large number of DIPs and plug-in packages are mounted on the printed circuit board, it has become difficult to sufficiently exert the performance of the accelerated LSI. For this purpose, a high-speed multi-chip module in which many chips are mounted at high density on one ceramic substrate has been developed and put into practical use (LSI Handbook, First Edition, pp.
415-416, IEICE, 1984).

As shown in FIG. 4, when the semiconductor chips are mounted face up in such a multi-chip module system, the heat generated in the semiconductor chips 4 is transferred in the X direction as shown in FIG. It was missed to the substrate 1 side. The semiconductor chip module has prevented the performance deterioration due to thermal resistance due to this heat radiation operation.

[0004]

However, it is not always possible to sufficiently dissipate heat only by the method of releasing the generated heat to the substrate side, the performance of the semiconductor chip module gradually deteriorates, and the failure rate increases. However, there was a drawback that it could not be used for a long time. Therefore, an object of the present invention is to provide a semiconductor chip module capable of a good heat dissipation design without deterioration of performance.

[0005]

A semiconductor chip module according to the present invention is mounted in a so-called face-up manner on a semiconductor substrate on which a wiring portion is formed, that is, a circuit surface faces upward, and the semiconductor chip module is mounted on the wiring portion. Placed in
One or more semiconductor chips, a heat sink whose one end is in contact with the center of the upper surface of the semiconductor chip, and a hole for exposing the other end of this heat sink to the outside are provided.
The semiconductor device is characterized in that it has a cap that encloses all semiconductor chips, and that the bonding wires connecting the semiconductor substrate and the semiconductor chips mounted on this semiconductor substrate are covered with an insulating material.

[0006]

According to the semiconductor chip module of the present invention, the heat generated from the face-up type semiconductor chip is conducted from one end of the heat sink contacting the upper surface of the semiconductor chip to the other end. By this heat conduction, heat is guided to the outside of the cap and radiated outside the cap.

Further, since the bonding wire connecting the semiconductor substrate and the semiconductor chip mounted on the semiconductor substrate is covered with the insulating material, even if the heat sink is a conductive material, the heat sink and the bonding wire are not separated. The electrical characteristics are not deteriorated by the contact, and the heat sink can be increased in size.

[0008]

1 is a perspective view showing the appearance of a semiconductor chip module according to an embodiment of the present invention, and FIG. 2 is a sectional view of the semiconductor chip module shown in FIG. 1 taken along line II II '. is there. The lower substrate 1 is made of, for example, an alumina material, and a plurality of lead pins 5 connected to the electrical wiring formed on the upper substrate 6 extend from the side surface of the lower substrate 1.
The upper substrate 6 is formed of a low dielectric constant insulating material, and for example, a 3-inch square polyimide multilayer wiring structure having a thermal resistance of 3 ° C./W and a summer bayer can be used (“copper polyimide multilayer wiring substrate”, HYBRIDS). , VOL.
7, No. 7, pp. 10-12).

The lower substrate 1 is composed of a flat plate larger than the upper substrate 6, and the upper substrate 6 is fixed on the upper surface of the lower substrate 1 in a stacked state. An edge portion of the cap 2 is covered on the upper surface of the lower substrate 1 where the upper substrate 6 does not overlap. Therefore, the upper substrate 6 is enclosed by the cap 2 and the lower substrate 1. The electrodes are exposed on the surface of the upper substrate 6, and the face-up type semiconductor chip 4 and the face-down type semiconductor chip 4a are mounted as shown in the figure so as to be connected to these electrodes. Face-up type semiconductor chip 4
Literally has a circuit surface facing upward and is electrically connected to the wiring of the upper substrate 6 by a bonding wire method. Also, a face-down type semiconductor chip 4a
Are electrically connected to the wiring of the upper substrate 6 by a die bonding method or the like so that the circuit surface faces downward.

The cap 2 has a thickness of 1 mm, for example.
Is formed in the shape of a lid by Kovar, and a hole 7a having a diameter of, for example, 30 to 50 μm is formed at a position corresponding to the mounting position of the face-down type semiconductor chip 4a.
Further, a hole 7 having a diameter larger than that of the hole 7a is formed at a position corresponding to the mounting position of the face-up type semiconductor chip 4. One ends of the heat sinks 3 and 3a are inserted into these holes 7 and 7a, respectively. These heat sinks 3 and 3a are made of a material having high thermal conductivity such as Al or CuW.
It is composed of an insertion part and a heat dissipation part. The insertion portion has a rod shape, for example, which can be easily inserted into the perforations 7, 7a. Further, the heat radiating portion has a structure having a large surface area so as to be easily automatically cooled, and is, for example, a disk. The cooling speed increases as the number of stages of the heat radiation unit increases. Since the heat sinks 3 and 3a have such a configuration, they can be easily inserted into the inside of the cap 2, and the heat generated in the face-up type semiconductor chip 4 and the face-down type semiconductor chip 4a can be transferred to the outside of the cap 2. Can be released efficiently. In order to efficiently transfer heat from the face-up type semiconductor chip 4 and the face-down type semiconductor chip 4a to the heat sinks 3 and 3a, it is desirable that the heat sink 3 and the semiconductor chip surface are brought into surface contact. Therefore, when the upper surfaces of the face-up type semiconductor chip 4 and the face-down type semiconductor chip 4a are flat, it is desirable that the tips of the insertion portions of the heat sinks 3 and 3a are flat. Even if the heat sink 3 comes into contact with the circuit surface, the circuit surface is not covered with SiN or S.
Since it is protected by the passivation film made of iON, no performance problem occurs.

In general, a conductive heat sink has better thermal conductivity and better heat dissipation efficiency than an insulating heat sink. Therefore, considering only this point, it is preferable to use a conductive heat sink. Further, the heat dissipation can be further improved by enlarging the heat sink.
However, when a large conductive heat sink is used, there is concern that the electrical characteristics may deteriorate due to contact with the bonding wire. Therefore, in the present embodiment, the bonding wire 8 is set to 0.5 so that the conductive heat sink can be increased in size.
It is covered with an insulating material such as urethane having a thickness of ˜0.7 μm. For this reason, even a conductive heat sink may come into contact with the bonding wire 8, the size of the heat sink can be increased, and heat dissipation can be improved.

Explaining in more detail with reference to FIG. 3, since the bonding wire 8 is covered with an insulating material, the distance t between the heat sink 3 and the bonding wire 8 can be minimized until they come into contact with each other. It is possible to increase the size of the heat sink 3. Further, even if the heat sink 3 and the bonding wire 8 come into contact with each other to some extent, the electrical characteristics are not affected, so that the mounting and manufacturing tolerances can be reduced and the manufacturing can be performed, and the yield can be improved. Furthermore, AlN and cubic phase boron nitride (CB
N), Al and Cu that are cheaper than insulators such as diamond
Since it is possible to use a conductor such as W, the material cost can be reduced. In addition, electrically, it does not matter if the heat sink 3 and the bonding wire 8 are slightly in contact with each other,
Great care must be taken not to reduce the mechanical reliability.

In the multi-chip module according to this embodiment, for example, a face-up type semiconductor chip 4 and a face-down type semiconductor chip 4a are mounted, and an upper surface of an upper substrate 6 fixed to a lower substrate 1 is enclosed by a cap 2. Process: Inserting one end of the heat sink 3, 3a into the perforation 7, 7a of the cap 2 and bringing its tip into contact with the upper surface of the semiconductor chip 4, heat sink 3, 3a and face-up type semiconductor chip 4 and face-down type semiconductor chip With the 4a in contact, for example, the perforation 2 of the cap
By embedding solder in the gaps between a and the heat sinks 3 and 3a, the heat sinks 3 and 3a are fixed to the cap 2 to be packaged.

Further, in this embodiment, the heat sinks 3 are mounted on all the face-up type semiconductor chips 4, but they can be selectively mounted on the semiconductor chips which generate a large amount of heat. As described above, one heat sink is attached to one semiconductor chip, so that the heat sink can be surely attached to a plurality of semiconductor chips having different heights from the substrate surface.

[0015]

According to the structure of the present invention, since the heat sinks are individually mounted on the semiconductor chips mounted face-up, good heat dissipation design is possible and high-speed design is not hindered. The thermal resistance of the semiconductor chip can be reduced.

Further, since the bonding wire connecting the semiconductor chip mounted face up and the semiconductor substrate is covered with the insulating material, the electrical characteristics are not deteriorated even if the bonding wire and the heat sink come into contact with each other. Therefore, it is possible to increase the size of the heat sink and improve heat dissipation. Also, in the manufacturing of semiconductor chip modules, the conductors are easy to use, the material cost is low, and the production cost can be reduced because the yield is improved. Moreover, since the heat sink can be selectively attached to one semiconductor chip respectively, even in a multi-chip module in which face-up mounting type semiconductor chips and face-down mounting type semiconductor chips are mixed, face-up mounting chips are also included. It is possible to reduce the thermal resistance of the.

[Brief description of drawings]

FIG. 1 is a perspective view of a semiconductor chip module of this embodiment.

FIG. 2 is a cross-sectional view of the semiconductor chip module of this embodiment.

FIG. 3 is a diagram for explaining the present invention.

FIG. 4 is a diagram for explaining a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Lower substrate 2 ... Cap 3 ... Large heat sink 3a ... Small heat sink 4 ... Face-up type semiconductor chip 4a ... Face-down type semiconductor chip 5 ... Lead pin 6 ... Upper substrate 7, 7a ... Cap hole 8 ... Insulating bonding wire 8a … Non-insulating bonding wire

Claims (1)

[Claims] 1. A semiconductor substrate on which a wiring portion is formed, one or a plurality of semiconductor chips arranged on the wiring portion so that a circuit surface faces upward, and one end at a central portion of an upper surface of the semiconductor chip. A bonding wire for connecting the semiconductor substrate and the semiconductor chip, the heat sink being in contact with the semiconductor chip, and a cap having a hole for exposing the other end of the heat sink to the outside and including all the semiconductor chips. A semiconductor chip module, wherein the semiconductor chip module is covered with an insulating material.