JPH0521660A - Semiconductor chip module and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a semiconductor chip module which is small in number of parts and excellent in heat dissipating properties. CONSTITUTION:A board 2 where a wiring section is provided, a semiconductor chip 6 so mounted that its circuit surface faces the wiring section, a heat sink 3 whose one edge comes into contact with the surface of the semiconductor chip 6 opposite to its circuit surface, and a cap 4 which is provided with a hole through which the other edge of the heat sink 3 is exposed outside and envelops the semiconductor chip 6 are provided. At least, a metal film is formed both on the inner wall of the hole concerned and on the surface of the heat sink 3 inserted into the cap 4, and bonding agent is filled into the spaces between these metal films and also between the end part of the heat sink 43 and the semiconductor chip 6.

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 (multi-chip module, single-chip module) applicable to fields requiring high-speed signal processing, such as computers and communications, and a manufacturing method thereof.

[0002]

2. Description of the Related Art With the demand for large-scale and high-speed functions of electronic devices, the delay time per gate of a logic LSI has been increased to several hundred 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 bring out the performance of the accelerated LSI. For this reason, a multi-chip module system, in which many chips are mounted on one ceramic substrate and which has high-speed performance and high-density packaging, has been developed and put into practical use (LSI Handbook, 1st edition, pp.4).
15-416, IEICE, 1984).

As a conventional technique, there is known a structure in which a piston is brought into contact with a semiconductor chip by a spring to radiate heat to a cooling plate (“Materials / Processing Approaches to P”).
haseStabilization of Thermally Conductive Pastes
”Pp.713-717, IEEE TRANSACTIONS OF COMPONENTS, H
YBRIDS. AND MANUCFACTURING TECHNOLOGY, VOL.13, NO.4,
DECEMBER1990).

[0004]

However, the semiconductor chip module using the piston has a drawback that the number of parts is large and the cost is extremely high.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a semiconductor chip module and a method of manufacturing the same, which enables a good heat radiation design with a small number of parts.

[0006]

In order to achieve the above object, a semiconductor chip module according to the present invention includes a substrate on which a wiring portion is formed, a semiconductor chip mounted on the wiring portion with its circuit surface facing, and a semiconductor. The chip includes a heat sink whose one end is in contact with the side opposite to the circuit surface, and a cap which has a hole for exposing the other end of the heat sink to the outside and which contains a semiconductor chip. At least the inner wall of the hole and the cap. A metal film is formed on the surface of the heat sink to be inserted into the inside of the heat sink, and the adhesive is embedded between the metal films, and the adhesive is embedded between the tip of the heat sink and the semiconductor chip. And

The above-described method for manufacturing a semiconductor chip module includes the steps of preparing a substrate on which a semiconductor chip is mounted, a cap having a metal film formed on the inner wall of a hole in advance, and a heat sink having a metal film formed on one end thereof in advance. , The step of fixing the cap to the substrate, the step of inserting one end of the heat sink into the hole of the cap to bring one end of the heat sink into contact with the semiconductor chip, and the metal film with the one end of the heat sink in contact with the semiconductor chip. A step of filling the adhesive between the tip of the heat sink and the semiconductor chip by injecting the adhesive, fixing the heat sink to the cap and hermetically sealing the cap.

Further, in the semiconductor chip module according to the present invention, the substrate on which the wiring portion is formed, the semiconductor chip mounted with the circuit surface facing the wiring portion, and one end portion of the semiconductor chip opposite to the circuit surface of the semiconductor chip are in contact with each other. And a cap that contains a semiconductor chip and has a hole that exposes the other end of the heat sink to the outside, and a metal film is formed on at least the inner wall of the hole and the surface of the heat sink that faces the inner wall. A resin material having high thermal conductivity such as a thermal compound is embedded between the tip of the heat sink and the semiconductor chip.

The above-described method for manufacturing a semiconductor chip module is a heat sink in which a semiconductor chip is mounted on a substrate, a cap having a metal film formed on the inner wall of a hole in advance, and a metal film formed on the surface of a heat sink facing the inner wall in advance. And a step of fixing the cap to the substrate,
The process of injecting a resin material with a high thermal conductivity such as a thermal compound from the hole of the cap and applying the resin material on the semiconductor chip, and inserting one end of the heat sink into the hole of the cap By contacting the chip and embedding an adhesive between the metal films with one end of the heat sink in contact with the semiconductor chip,
Fixing the heat sink to the cap and hermetically sealing the cap.

[0010]

According to the semiconductor chip module of the present invention, the heat sink is firmly fixed to the inner wall of the cap hole, and the heat generated from the semiconductor chip that generates a relatively large amount of heat is efficiently transferred to the heat sink through the adhesive or the thermal compound. Heat is conducted to one end and conducted from one end to the other end (low temperature portion). By this heat conduction, heat is guided to the outside of the cap and radiated outside the cap.

Further, in the method of manufacturing a semiconductor chip module according to the present invention, when one end of the heat sink is inserted into the hole of the cap, the one end of the heat sink is pressed against the semiconductor chip by the weight of the heat sink. Since the tip of the heat sink and the semiconductor chip are embedded with an adhesive or a resin material having high thermal conductivity, the area through which heat is transmitted is wide. In this state, the adhesive is inserted into the hole of the cap to fix the heat sink. The adhesive for fixing the heat sink is embedded between the heat sink and the inner wall of the hole of the cap without a gap, and blocks the air flow path from the inside and the outside.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In the description, the same elements will be denoted by the same reference symbols, without redundant description. FIG. 1 is a perspective view showing the appearance of a multi-chip module as an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view of the multi-chip module according to the embodiment taken along a heat sink.

The multi-chip module according to this embodiment comprises a lower substrate 1, an upper substrate 2, a heat sink 3 and a cap 4. The lower substrate 1 is made of an alumina material, and a plurality of lead pins 7 connected to the electric circuit constituted by the upper substrate 2 extend from the side surface of the lower substrate 1. The upper substrate 2 is made of a low dielectric constant insulating material,
For example, 3 with thermal resistance of 3 ° C / W and a thermal via
Inch-square polyimide multi-layer wiring structure can be used (“Copper-polyimide multi-layer wiring board”, HYBRIDS, Vol.
7, No.1, pp.10-12).

The lower substrate 1 is composed of a flat plate larger than the upper substrate 1, and the upper substrate 2 is fixed on the upper surface of the lower substrate 1 in a stacked state. Lower substrate 1 where upper substrate 2 does not overlap
The edge of the cap 4 is covered on the upper surface of the. Therefore, with the cap 4 and the lower substrate 1, the upper substrate 2
Is in a contained state.

Electrodes are exposed on the surface of the upper substrate 2, and semiconductor chips 5 and 6 connected to these electrodes are mounted. The semiconductor chips 5 and 6 are, for example, 10 mm square IC chips, and are connected to the electrodes formed on the surface of the upper substrate 2 by a wire bonding method or a face-down mounting method (flip chip mounting method). 1 and 2, the semiconductor chip 5 is an IC chip mounted by the wire bonding method, and the semiconductor chip 6 is an IC chip mounted by the face-down mounting method. Therefore, the circuit surface of the semiconductor chip 5 is the cap 4
, The circuit surface of the semiconductor chip 6 faces the upper substrate 2.

The cap 4 is formed, for example, in the shape of a lid with a thickness of 1 mm of kovar, and at a position corresponding to the mounting position of the semiconductor chip 6 which generates a relatively large amount of heat,
For example, a hole 4a having an inner diameter of 6 to 8 mm is formed.
One end of the heat sink 3 is inserted into this hole 4a. Normally, the hole 4a has the same diameter at the inlet and the outlet, but the diameters of the outlet and the inlet may be changed.

The heat sink 3 is made of a material (A
1, CuW, AlN, CBN, diamond, etc.) and is composed of an insertion part and a heat dissipation part. The insertion portion has a shape that facilitates insertion into the hole 4a described above, and has, for example, a rod shape. Further, since the heat radiating portion is exposed to the outside of the cap 4, the heat radiating portion has a large surface area so as to be easily cooled naturally, and has a disk shape, for example.
Therefore, the insertion into the inside of the cap 4 is easy, it is easy to make contact with the upper surface of the semiconductor chip 6, and the heat from the semiconductor chip 6 can be efficiently dissipated to the outside of the cap 4. Heat sink 3 cap 4
A metal film is coated on the surface at one end inserted into the substrate, and solder is attached to the surface and between the semiconductor chip 6 and the tip of the heat sink 3 (see FIG. 2).

Next, referring to FIGS. 3 and 4, an example of a heat sink mounting structure will be described. FIG. 3 shows a structure in which the inner wall of the hole is metal-coated, and the surface of one end of the heat sink to be inserted into the hole is metal-coated. The metal m coated on the heat sink 3 and the cap 4 has a wettable property with respect to the solder s to be used. Therefore, voids (air bubbles)
It becomes possible to perform soldering without any problem, and the cap 4 can be hermetically sealed sufficiently. For example, when Sb / Pb based solder is used, a metal such as AgSn or AgPd can be used. The solder s is embedded between the semiconductor chip 6 and the tip of the heat sink 3 as follows.
Liquid solder s from between the heat sink 3 and the inner wall of the hole 4a
Can be achieved by pouring. As the material of the solder s, low temperature solder to which Bi, Cd and In are added can be used. In this case, the heat sink 3 may be heated to facilitate the flow of the solder s.

FIG. 4 shows a structure in which the space between the semiconductor chip and the tip of the heat sink is filled with a thermal compound. In this case, a metal m is formed on the inner wall of the hole 4a of the cap and the surface of the heat sink 3 facing the inner wall, and a thermal compound t containing BN particles or Ag paste is formed on the tip of the heat sink 3 as a semiconductor. It is interposed between the chip 6. Therefore, the contact area between the semiconductor chip 6 and the heat sink 3 is effectively increased, and the thermal resistance is reduced.

The heat sink 3 is fixed to the cap 4 by the solidified solder s, with its one end in contact with the semiconductor chip 6. The above-mentioned materials as the solder s,
Since the heating method can be used, the description is omitted.

As described above, according to the multi-chip module of the embodiment, since the heat sink is mounted only on the semiconductor chip that requires heat dissipation (the amount of heat generation is large),
Selectively and efficiently, it is possible to dissipate heat from the multi-chip module.

In this case, one heat sink is attached to one semiconductor chip, and one end of the heat sink has a structure in which the length can be adjusted in the insertion direction, so that the height from the substrate surface is different. Even when a plurality of semiconductor chips are mounted on the substrate, the heat sink is surely attached to each semiconductor chip.

Further, since the heat sink is individually attached to each semiconductor chip, it is applied to a multi-chip module in which semiconductor chips mounted by the face-down method and semiconductor chips mounted by the wire bonding method are mixed. It is possible and highly practical.

Next, a method of manufacturing the multichip module according to this embodiment will be described. The multi-chip module having the mounting structure shown in FIG. 3 includes a substrate 2 on which the semiconductor chips 5 and 6 are mounted, a cap 4 in which the inner wall of the hole 4a is coated with metal m in advance, and a metal m in advance at one end.
After preparing the heat sink 3 coated with, for example, a step of encapsulating the upper surface of the upper substrate 2 fixed to the lower substrate 1 with the cap 4, inserting one end of the heat sink 3 into the hole 4 of the cap, and the tip of the semiconductor Chip 6
The step of bringing the semiconductor chip 6 into contact with the upper surface of the semiconductor chip 6 in a state where the heat sink 3 and the semiconductor chip 6 are in contact with each other by pouring a large amount of liquid solder s into the gap between the inner wall of the hole 4a of the cap and the heat sink 3. Solder s is attached to one end of the heat sink 3, the heat sink 3 is fixed to the cap 4, and the cap 4 is hermetically sealed to be packaged.

In this case, when pouring liquid solder s,
Since one end of the heat sink 3 is automatically in contact with the semiconductor chip 6 due to its own weight, the heat sink 3 can be easily fixed to the cap 4.

Further, since the liquid solder s is embedded in the heat sink 3 and the inner wall of the hole 4a of the cap without any gap,
The cap 4 can be hermetically sealed. In particular, when a thin film multi-layer substrate such as polyimide / Cu is used as the upper substrate 2, since the polyimide itself has a hygroscopic property, hermetic sealing becomes important.

Furthermore, since the tip of the heat sink 3 is also metal-coated, the solder s is embedded in the gap between the tip of the heat sink 3 and the semiconductor chip 6 due to the weight of the solder s, so that the gap between the semiconductor chip 6 and the heat sink 3 is reduced. The contact area can be increased and the thermal resistance can be reduced.

In the multi-chip module having the mounting structure shown in FIG. 4, the substrate 2 on which the semiconductor chips 5 and 6 are mounted, the cap 4 in which the inner wall of the hole 4a is coated with the metal m in advance, and the metal m in advance in one end are provided. After the coated heat sink 3 is prepared, for example, the step of encapsulating the upper surface of the upper substrate 2 fixed to the lower substrate 1 with the cap 4, the thermal compound material t is dropped from the hole 4a of the cap, and the upper surface of the semiconductor chip 6 is The step of applying one end of the heat sink 3 into the hole 4 of the cap and bringing the tip thereof into contact with the upper surface of the semiconductor chip 6, the inner wall of the hole 4a of the cap with the heat sink 3 and the semiconductor chip 6 in contact with each other. Liquid solder s is embedded in the gap between the heat sink 3 and the heat sink 3 to fix the heat sink 3 to the cap 4 and the cap. 4 is packaged through a process of hermetically sealing.

In this case, the contact area between the semiconductor chip 6 and the heat sink 3 can be increased and the thermal resistance can be reduced without applying a metal coating to the tip of the heat sink 3, and a multi-chip excellent in heat dissipation can be obtained. The module can be manufactured.

The present invention is not limited to the above embodiment. In this embodiment, the multi-chip module including the semiconductor chip mounted by the wire bonding method and the semiconductor chip mounted by the face-down method, and the heat sink mounted on the semiconductor chip mounted by the face-down method has been described as an example. The present invention can be applied to a semiconductor chip module mounting a single semiconductor chip, and may include a flip chip to which a heat sink is not mounted. Further, the shape of the hole of the cap is not limited to a circular shape, and may be a square shape or a polygonal shape as long as it is substantially the same shape as one end of the heat sink. Further, the resin material is not limited to the thermal compound, and may be a material having a higher thermal conductivity than the material forming the cap and the semiconductor chip and having a certain degree of heat resistance and fluidity.

[0031]

Since the present invention is configured as described above, it can be applied to a multi-chip module and a single-chip module, has a small number of parts, and is excellent in heat dissipation capable of good heat dissipation design. A semiconductor chip module can be provided. Further, when the present invention is applied to a multi-chip module, variations due to the height of face-down bonding can be allowed and reliability is improved.

Furthermore, since the number of parts of the semiconductor chip module is small, the number of manufacturing steps is small and the cost of the semiconductor chip module can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of a multi-chip module according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a multi-chip module according to an embodiment of the present invention cut along a heat sink.

FIG. 3 is a vertical cross-sectional view showing a mounting structure example of a heat sink that can be used in a multi-chip module according to an embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view showing another mounting structure example of the heat sink that can be used in the multi-chip module according to the embodiment of the present invention.

[Explanation of symbols]

1 ... Lower substrate, 2 ... Upper substrate, 3 ... Heat sink, 4 ...
Cap, 5, 6 ... Semiconductor chip, 7 ... Lead pin, m
… Metal, s… Solder, t… Thermal compound.

Claims (4)

[Claims] 1. A substrate on which a wiring portion is formed, a semiconductor chip mounted with the circuit surface facing the wiring portion, a heat sink whose one end is in contact on the side opposite to the circuit surface of the semiconductor chip, and the heat sink. And a cap that encloses the semiconductor chip and has a hole that exposes the other end of the semiconductor chip to the outside, and a metal film is formed on at least the inner wall of the hole and the surface of the heat sink inserted into the cap. The semiconductor chip module is characterized in that the adhesive is embedded between the metal films and the adhesive is embedded between the tip portion of the heat sink and the semiconductor chip. 2. The method of manufacturing a semiconductor chip module according to claim 1, wherein the substrate on which the semiconductor chip is mounted, the cap having a metal film formed on the inner wall of the hole in advance, and the metal film having one end formed in advance are formed. A heatsink, a step of fixing the cap to the substrate, a step of inserting one end of the heatsink into a hole of the cap to bring the one end of the heatsink into contact with the semiconductor chip, By injecting an adhesive between the metal films in a state where one end of the heat sink is in contact with the semiconductor chip, the adhesive is embedded between the tip of the heat sink and the semiconductor chip, and the heat sink is fixed to the cap. And a step of hermetically sealing the cap. 3. A substrate on which a wiring portion is formed, a semiconductor chip mounted with the circuit surface facing the wiring portion, a heat sink whose one end is in contact with the side opposite to the circuit surface of the semiconductor chip, and the heat sink. A cap formed by forming a hole that exposes the other end of the semiconductor chip to the outside, and forming a metal film on at least the inner wall of the hole and the surface of the heat sink facing the inner wall, A semiconductor chip module, wherein a resin material having a high thermal conductivity is embedded between the tip of the heat sink and the semiconductor chip. 4. The method of manufacturing a semiconductor chip module according to claim 3, wherein a substrate on which the semiconductor chip is mounted, a cap having a metal film formed on the inner wall of the hole in advance, and a heat sink facing the inner wall in advance. A step of preparing a heat sink having a metal film formed on its surface; a step of fixing the cap to the substrate; a resin material having a high thermal conductivity flowing in from a hole of the cap; and the resin material on the semiconductor chip. And a step of inserting one end of the heat sink into the hole of the cap to bring one end of the heat sink into contact with the semiconductor chip, and a state in which one end of the heat sink is brought into contact with the semiconductor chip. The heat sink is fixed to the cap and the cap is airtight by embedding an adhesive between the metal films with The method of manufacturing a semiconductor chip module and a step of stopping.