JPH0547967A - Semiconductor chip module - Google Patents

Abstract

PURPOSE:To improve the heat dissipation property of a semiconductor chip module by a method wherein each one end of heat sinks is brought into contact to the central parts of the upper surfaces of semiconductor chips mounted in such a way that circuit surfaces are faced upward and an insulative thermal compound material is filled in the chips all over the surfaces of the chips in such a way as to come into contact to both of the chips and the heat sinks. CONSTITUTION:Holes 2a are bored at positions, which correspond to the mounting positions of face up type semiconductor chips 4 and face down type semiconductor chips 4a, on a chip 2. Each one end part of heat sinks 3 is inserted in the holes 2a and is brought into contact to the surfaces of the chips 4 and 4a. Moreover, an insulative thermal compound material 1 is filled in the chips 4 almost all over the surfaces of the chips 4 in such a way as to come into contact to both of the chips 4 and the sinks 3. Accordingly, heat which is generated in the center parts of the chips and I/O circuits on the peripheral parts of the chips 4 is transferred to the sinks 3 via the material 1. Thereby, a good heat dissipation design becomes possible and the heat resistance of a semiconductor chip module 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 that reason,
A high-speed multi-chip module has been developed and put into practical use by mounting many chips on one ceramic substrate at high density (LSI Handbook, 1st edition, pp. 41).
5-416, The Institute of Electronics and Communication Engineers, 1984).

As shown in FIG. 5, when a semiconductor chip is mounted face-up in such a multi-chip module system, heat generated in the semiconductor chip 4 is directed in the X direction as shown in FIG. It was missed to the side of the substrate 10. The semiconductor chip module has prevented the performance deterioration due to thermal resistance due to this heat radiation operation.

[0004]

However, sufficient heat dissipation cannot always be achieved only by the method of releasing the generated heat to the package 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
A plurality of or a plurality of semiconductor chips, a heat sink whose one end faces the center of the upper surface of the semiconductor chip, and a hole for exposing the other end of the heat sink to the outside are formed.
It is characterized in that a cap enclosing all the semiconductor chips and an insulative thermal compound material are filled almost all over the semiconductor chip so as to contact both the semiconductor chip and the heat sink.

[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.

Particularly, since the insulating thermal compound material is filled almost all over the semiconductor chip,
The heat generated in the peripheral portion of the semiconductor chip where the I / O circuit, which generates a relatively large amount of heat, is arranged can be conducted to the heat sink via the thermal compound material.

[0008]

1 is a perspective view showing an appearance of a semiconductor chip module in which a thermal compound material according to an embodiment of the present invention is omitted, and FIG. 2 is a view showing the semiconductor chip module shown in FIG. It is sectional drawing at the time of cutting. Further, FIG. 3 is a diagram for explaining the method of the present invention, and shows the contact state of the tip of the heat sink 3, the semiconductor chip 4, and the thermal compound material 1. The lower substrate 10 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 10. 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 10 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 10 in a stacked state. A cap 2 is provided on the upper surface of the lower substrate 10 where the upper substrate 6 does not overlap.
The edges of are covered. Therefore, the cap 2
The upper substrate 6 is contained by the lower substrate 10. The electrodes are exposed on the surface of the upper substrate 6,
A face-up type semiconductor chip 4 and a face-down type semiconductor chip 4a are mounted as shown so as to be connected to these electrodes. The 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. In addition, the face-down type semiconductor chip 4
“A” is electrically connected to the wiring of the upper substrate 6 by a die bonding method or the like so that the circuit surface is on the lower side.

The cap 2 has a thickness of 1 mm, for example.
Formed in a lid shape by Kovar, and is a face-up type semiconductor chip 4 and a face-down type semiconductor chip 4
At a position corresponding to the mounting position of a, for example, a diameter of 30 to 50
A hole 2a of about μm is formed. These perforations 2
One end of the heat sink 3 is inserted in a. These heat sinks 3 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 perforation 2a. 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 sink 3 has such a structure, it can be easily inserted into the inside of the cap 2,
The heat generated in the face-up type semiconductor chip can be efficiently dissipated to the outside of the. In order to efficiently transfer heat from the face-up type semiconductor chip 4 to the heat sink 3, the contact method between the heat sink 3 and the semiconductor chip 4 surface is
Surface contact is desirable. Therefore, when the upper surface of the semiconductor chip 4 is flat, the tip of the insertion portion of the heat sink 3 is preferably flat.

Also, the thermal compound material 1 is filled over substantially the entire surface of each face-up type semiconductor chip 4. This is to improve heat radiation. Since it is desired to avoid contact between the bonding wire 8 and the heat sink 3, the heat sink 3 can contact only the central portion of the semiconductor chip 4. Therefore, the heat escaping to the outside of the cap 2 is mainly the heat generated in the central portion where the heat sink 3 contacts,
The heat generated in the peripheral I / O circuit is not sufficiently absorbed by the heat sink 3 and escapes to the substrate side. Generally, I /
Since the O circuit has a large amount of heat generation, it is extremely important to effectively dissipate the heat in this portion. Therefore, if the insulating thermal compound material 1 is filled almost all over the face-up type semiconductor chip 4 as in this embodiment,
Heat generated not only in the central portion of the semiconductor chip 4 but also in the peripheral portion I / O circuit can be conducted to the heat sink 3 through the insulating thermal compound material 1. Since the thermal compound material 1 is insulative, the semiconductor chip 4
No problem in performance occurs even if it is filled on the entire surface of the substrate and comes into contact with the bonding wire 8. The insulating thermal compound material 1 is made of, for example, fine powder diamond or an epoxy resin containing a large amount of cubic phase boron nitride (CBN).

The material for forming the heat sink 3 is A
In the case of a conductor such as 1 or CuW, the tip area of the heat sink 3 must be made relatively small so that a short circuit between bonding wires and between TAB pads does not occur, but AlN or cubic phase boron nitride is used. (CB
In the case of an insulator such as N), since some contact with the bonding wire 8 is acceptable, the margin is increased and the design flexibility is increased.

FIG. 4 is a top view of a face-up type semiconductor chip 4 in which the thermal compound material 1 mounted in the semiconductor chip module of this embodiment is omitted. Pads 7 are mounted on the periphery of the semiconductor chip 4 on the broken line in the figure, a heat sink 3 is placed in the center, and an insulating thermal compound material 1 is filled almost all over the face-up type semiconductor chip 4. Has been done. In this case, for example, 25μ on the bonding wire
Since the pad size t ₁ can be set to about 80 μm by using the mΦ gold wire, the pads should be arranged only on the edge of the semiconductor chip.
When the distance t ₂ between the pad end and the chip end is 50 μm, the heat sink 3 can be contacted except for a narrow place of 130 μm on one side, that is, 260 μm on both sides. With this configuration, the thermal resistance can be reduced from 10 ° C./W to about 3 ° C./W. In this face-up type semiconductor, since the parts other than the pad 7 are protected by the passivation film made of SiN or SiON, the performance problem does not occur even if the heat sink 3 contacts the circuit surface. In the multi-chip module according to the present embodiment, for example, the step of encapsulating the upper surface of the upper substrate 6 fixed to the lower substrate 10 with the cap 2 on which the semiconductor chip 4 is mounted, and one end of the heat sink 3 in the hole 2 a of the cap 2. The thermal compound material 1 is inserted by inserting the tip into contact with the upper surface of the semiconductor chip 4.
In a state where the heat sink 3 and the semiconductor chip 4 are in contact with each other, the heat sink 3 is fixed to the cap 2 by, for example, embedding solder in a gap between the perforation 2a of the cap and the heat sink 3, and then packaged. It

Further, in this embodiment, the heat sink 3 and the insulating thermal compound material 1 are mounted on all face-up type semiconductor chips 4, but it may be selectively mounted on the semiconductor chips which generate a large amount of heat. it can.
As described above, one heat sink 3 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]

As described in detail above, according to the structure of the present invention, a semiconductor chip mounted face-up is provided with an insulative thermal compound material so that the semiconductor chip is almost in contact with both the heat sink and the semiconductor chip. The entire surface is filled. Therefore, heat generated not only in the central portion of the semiconductor chip but also in the peripheral portion can be efficiently dissipated to the outside of the cap. Therefore, good heat dissipation design is possible, there is no hindrance to high-speed design, and thermal resistance can be reduced. 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, The thermal resistance can be reduced.

[0016]

[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 method of the present invention.

FIG. 4 is a top view of the semiconductor chip of this embodiment.

FIG. 5 is a diagram for explaining a conventional method.

[Explanation of symbols]

 1 ... Insulating thermal compound material 2 ... Cap 2a ... Perforation of cap 3 ... Heat sink 4 ... Face-up type semiconductor chip 4a ... Face-down type semiconductor chip 5 ... Lead pin 6 ... Upper substrate 7 ... Pad 8 ... Bonding wire 10 ... Bottom substrate

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. Portions facing each other, a hole that exposes the other end of the heat sink to the outside, and a cap that encloses all the semiconductor chips, and one end of the heat sink and the surface of the semiconductor chip are in contact with each other. In addition, a semiconductor chip module including an insulating thermal compound material that is filled over substantially the entire surface of the semiconductor chip.