JPH0888299A - Semiconductor device - Google Patents

Abstract

PURPOSE: To improve the heat dissipation efficiency and the maintainability in a semiconductor device adapted to be used for a so-called multi-chip module in which a semiconductor chip is placed on the upper part of a circuit board. CONSTITUTION: The semiconductor device comprises a circuit board 4 placed with a semiconductor chip 3 on the upper surface and formed with external connection pins 23 on the lower surface, a cap 5 formed integrally with a heat radiating fin part 12 and made of high heat conductive material for sealing the chip 3 by arranging on the upper surface of the board 4, a base member 6 engaged with the lower surface of the board 4, and a clamping mechanism 8 for fixing the cap 5 to the member 6. The cap 5 is brought into direct contact with the chip 3, and the cap 5 and the member 6 sandwich the board 4 thereby to seal the chip 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to a semiconductor device suitable for use in a so-called multichip module in which a semiconductor chip is mounted on a wiring board.

In recent years, in the field of information and communication such as computers, there has been a demand for high speed signal processing. In order to deal with this, instead of the conventional structure in which semiconductor chips are mounted on a wiring board (printed circuit board) one by one, a plurality of semiconductor chips related to each other in constructing a system are arranged on one thin film multilayer wiring board. A method in which a module (multi-chip module) mounted in advance is created and mounted on a printed circuit board as a mother board is adopted.

On the other hand, since individual semiconductor chips are highly integrated, the power consumption of each semiconductor chip increases, and the amount of heat generated by each semiconductor chip tends to increase accordingly.

Therefore, a semiconductor device having a structure capable of efficiently radiating heat is required.

[0005]

2. Description of the Related Art Generally, a semiconductor device called a multi-chip module structure has a plurality of semiconductor chips mounted on a common substrate to achieve high performance. Conventionally,
In such a semiconductor device, the wiring board and the semiconductor chip are not housed in a hermetically sealed package, and the heat generated from the semiconductor chip is dissipated to the surroundings by radiation, or the cap and the substrate that are adhesively fixed so as to cover the semiconductor chip. It was configured to dissipate heat from the gap between and.

Further, in recent years, in order to improve the heat dissipation efficiency, a heat dissipation fin is adhered to the upper surface of the cap, and the heat transferred to the cap through the gap is radiated by the heat dissipation fin. Equipment is also provided. Heretofore, a method of fixing this radiating fin to the upper surface of the cap using an adhesive or the like has been adopted.

[0007]

However, the heat radiation structure that radiates the heat generated from the semiconductor chip to the surroundings by radiation radiates the problem that sufficient heat radiation efficiency cannot be obtained.

In addition, in a semiconductor device having a structure in which a radiation fin is adhered to the upper surface of a cap, heat treatment is often performed to cure the adhesive when the radiation fin is adhered. By this heat treatment, the wiring board and the semiconductor chip are separated. There is a problem that thermal stress is generated at the joining position of, and this thermal stress may remain and a crack or the like may occur in the wiring board or the semiconductor chip.

Further, even in the structure using the heat radiation fins, there is a problem that a sufficient heat radiation efficiency cannot be obtained because the gap formed between the cap and the substrate serves as a heat transfer path.

Further, in the conventional semiconductor device, the cap is fixed to the wiring board by using an adhesive (there is also a structure in which the cap is adhered to the base member disposed under the wiring board). However, there is a problem in that the cap cannot be removed after the bonding process is once performed, and thus the maintainability such as replacement when the semiconductor chip fails is poor.

The present invention has been made in view of the above points, and an object of the present invention is to provide a semiconductor device capable of improving heat dissipation efficiency and maintainability.

[0012]

[Means for Solving the Problems] The above-mentioned problems can be solved by taking the following means.

According to the first aspect of the present invention, the wiring board having the semiconductor chip mounted on the upper surface and the external connection terminals formed on the lower surface and the radiation fin are integrally formed, and are arranged on the upper surface of the wiring board. A cap made of a high thermal conductive material that seals the semiconductor chip when installed, a base member that engages with the lower surface of the wiring board, and a fixing mechanism that fixes the cap and the base member. In the semiconductor device, the cap is configured to directly contact the semiconductor chip or indirectly via a high thermal conductive material, and the cap and the base member sandwich the wiring substrate to seal the semiconductor chip. And a screwing mechanism is used as the fixing mechanism.

The invention according to claim 2 is characterized in that an opening is formed in the base member, and the external connection terminal is externally connected through the opening.

Further, the invention of claim 3 is characterized in that the external connection terminal is constituted by a protrusion or a pin made of a conductive metal.

Further, the invention of claim 4 is characterized in that the screwing mechanism comprises a screw and a nut.

The invention of claim 5 is characterized in that a notch is formed in a corner portion of the wiring board, and the screwing mechanism is arranged in a corner portion of the cap and the base member. is there.

Further, in the invention of claim 6, a packing material is provided at a position where the cap and the wiring board face each other so as to surround the semiconductor chip and to be sandwiched between the cap and the wiring board. In addition, the packing material functions as a cushioning material between the cap and the semiconductor chip.

Further, in the invention of claim 7, a guide protruding from this surface is formed on at least one of the cap and the base at the peripheral edge of the surface facing the wiring board, and the wiring board is formed as a guide. It is characterized by being placed inside.

[0020]

The above-mentioned means operate as follows.

According to the first aspect of the present invention, since the cap integrally formed with the heat radiation fin is in direct contact with the semiconductor chip, the heat generated in the semiconductor chip is directly conducted to the cap. The heat is dissipated in the heat dissipating fins. Therefore, the semiconductor chip can be cooled efficiently.

Further, the cap and the base member sandwich the wiring board to form a package for sealing the semiconductor chip, and the screwing mechanism is used as the fixing mechanism. It is possible to release the fixation, and since the wiring board is simply sandwiched between the cap and the base member, the package constituted by the cap and the base member can be released by releasing the fixation of the screwing mechanism. It can be easily removed from the wiring board, and maintenance can be easily performed. In addition, the cap indirectly contacts the semiconductor chip via the high thermal conductive material, so that the heat dissipation of the semiconductor chip can be efficiently performed.

According to the invention of claim 2, the external connection terminal can be externally connected through the opening formed in the base member, so that the semiconductor device is mounted (surface mounting).
Can be done easily.

According to the invention of claim 3, since the external connection terminal is composed of a pin made of a conductive metal,
Even if the base member exists below the wiring board, the semiconductor device can be reliably mounted. Further, by forming the external connection terminal by the protrusion made of a conductive metal, it is possible to cope with the increase in the number of pins.

Further, according to the invention of claim 4, since the screwing mechanism is constituted by the screw and the nut which are generally used, the screwing mechanism can be constructed at a low cost, and the cap by the screwing mechanism is formed. It is possible to easily fix and release the base member.

According to the invention of claim 5, the wiring board becomes a dead space by forming the notch at the corner of the wiring board and disposing the screwing mechanism at the corners of the cap and the base member. The corner portions of the cap and the base member can be effectively used, which can contribute to the miniaturization of the semiconductor device.

Further, according to the invention of claim 6, since the packing material functions as a cushioning material between the cap and the semiconductor chip, even if the cap is directly brought into contact with the semiconductor chip, the cap and the semiconductor chip are separated from each other. It is possible to prevent various stresses from remaining in the meantime.

Further, according to the invention of claim 7, a guide projecting from this surface is formed on at least one of the cap and the base at the peripheral portion of the surface facing the wiring board. By arranging the wiring board inside, the wiring board is positioned in the space surrounded by the cap, the base and the guide, so that the wiring board can be held securely and the work of attaching the cap to the base and the wiring board Can be easily incorporated.

[0029]

Embodiments of the present invention will now be described with reference to the drawings.

1 and 2 show a semiconductor device 1 which is a first embodiment of the present invention. 1 is a cross-sectional view of the semiconductor device 1, and FIG. 2 is an exploded perspective view showing a state in which the semiconductor device 1 is mounted on a mounting board 2.

The semiconductor device 1 is a semiconductor device having a multi-chip module structure, and roughly speaking, the semiconductor chip 3, the wiring board 4, the cap 5, the base member 6, the packing material 7,
And a screwing mechanism 8 and the like.

The semiconductor chip 3 is a chip that consumes a large amount of power due to high integration, and therefore generates a large amount of heat. The semiconductor chip 3 is mounted on the upper surface of the wiring board 4 by face down bonding.
The wiring board 4 is composed of a board portion 9 and a thin film circuit portion 10 formed on the board portion 9.

In this embodiment, flip chip bonding is employed in which solder bumps are formed on the lower surface of the semiconductor chip 3 and the solder bumps are directly connected to the thin film circuit section 10. As a method of connecting the semiconductor chip 3 to the wiring board 4, it is also possible to adopt a TAB (Tape Automated Bonding) method.

The thin film circuit section 10 has a structure in which a plurality of wiring layers and insulating layers are laminated, and the semiconductor chip 3 is connected to the uppermost layer as described above. The wiring layers are connected by via holes or the like, and the via 9a formed in the substrate portion 9 is connected to the bottom layer. In addition, the substrate unit 9
An external connection pin 23 made of a conductive metal, which serves as an external connection terminal, is disposed at the lower end portion of the via 9a formed in. The external connection pin 23 is fixed to the board portion 9 by being soldered and is electrically connected to the via 9a.

The cap 5 is made of a metal having good thermal conductivity such as aluminum, and has a structure in which the cap portion 11 and the radiation fin portion 12 are integrally formed. By forming a recess in the portion of the cap portion 11 facing the semiconductor chip 3, the cavity portion 13 is formed.
Are formed. The semiconductor chip 3 is configured to be located inside the cavity portion 13.

Further, the radiation fin portion 12 is the cap portion 11
Multiple pieces are formed so as to extend further upward,
It is configured to improve the heat dissipation effect by increasing the contact area with the air. Further, a storage groove 14 for storing the packing material 7 is formed in an annular shape at a position outside the formation position of the cavity portion 13 of the cap 5. Further, a flange portion 15 is formed at the outermost peripheral position of the cap 5, and a guide portion 5a for guiding the wiring board 4 by engaging with the outer peripheral portion of the wiring board 4 is formed inside the flange portion 15. ing.

Similar to the cap 5, the base member 6 is made of a metal having good thermal conductivity such as aluminum, and an opening 16 having a shape slightly smaller than the shape of the wiring board 4 is formed in the central portion thereof. With (detailed in Figure 2),
A guide portion 6a that engages with and guides the outer peripheral portion of the wiring board 4 is formed at the edge of the opening 16. Further, at the outermost peripheral position of the base member 6, a flange portion 18 having substantially the same shape as the flange portion 15 formed on the cap 5 is formed. The screwing mechanism 8 is arranged on the collar portions 15 and 18.

The packing material 7 is, for example, a heat-resistant rubber formed in an annular shape, and is housed in the housing groove 14 formed in the cap 5 as described above. The packing material 7 has a sealing function of hermetically sealing the cavity 13 in a state where the semiconductor device 1 is assembled as described later, and a cushioning function between the semiconductor chip 3 and the cap 5.

The screwing mechanism 8 is the screw 1 in this embodiment.
9 and a nut 20. The screwing mechanism 8 functions as a fixing mechanism that fixes the cap 5 and the base member 6. The flanges 15 and 18 formed on the cap 5 and the base member 6 described above have through-holes 21 that communicate with each other.
22 (shown in FIG. 2) are formed in the through hole 2
The cap 5 and the base member 6 are fixed by inserting the screw 19 into the screws 1 and 22 and screwing the nut 20 onto the screw 19.

As described above, by using the screwing mechanism 8 composed of the screw 19 and the nut 20 as the fixing mechanism, the nut 20 is removed from the screw 19 after the fixing and the cap 5
Then, the fixing of the base member 6 can be released. That is,
By using the screwing mechanism 8, the cap 5 and the base member 6 can be fixed and released.

Next, a method of manufacturing the semiconductor device 1 mainly composed of the above-mentioned components will be described with reference to FIG.

To manufacture the semiconductor device 1, first, the semiconductor chip 3 is mounted on the upper surface of the wiring board 4 provided with the thin film circuit portion 10 and the external connection pins 23 (not shown in FIG. 2). Further, the packing material 7 is stored in the storage groove portion 14 of the cap 5 in which the cap portion 11, the radiation fin portion 12, the cavity portion 13, and the storage groove portion 14 are formed in advance. The packing material 7 is configured to protrude downward from the storage groove portion 14 in a state of being stored in the storage groove portion 14 (this configuration will be described later in detail).

Subsequently, the cap 5 is mounted on the wiring board 4 on which the semiconductor chip 3 is mounted, and the wiring board 4 is mounted.
The base member 6 is attached to the lower part of the. As a result, the collar portion 15 of the cap 5 and the collar portion 18 of the base member 6 face each other, and the through holes 21 and 22 formed in the collar portions 15 and 18 communicate with each other. Further, as described above, since the guide portions 5a and 6a for guiding the wiring board 4 are formed on the cap 5 and the base member 6, respectively, the wiring board 4 can be easily mounted, and at the same time, the cap 5 and the base member can be mounted. 6 can be easily positioned.

Furthermore, since the opening 16 is formed in the base member 6 as described above, the external connection pin 23 extending downward from the lower surface of the wiring board 4 has this opening 16.
And extends below the base member 6.

Subsequently, the screw 19 constituting the screwing mechanism 8 is inserted into the through holes 21 and 22, and the nut 20 is screwed to the screw 19. As a result, the cap 5 and the base member 6 are fixed to each other, and the wiring substrate 4 is accordingly capped with the cap 5
And the base member 6 are sandwiched and fixed. In this fixed state, the cap 5 and the base member 6
Cooperate with each other to form a package for sealing the semiconductor chip 3.

Further, in this fixed state, the upper surface of the semiconductor chip 3 is configured to directly contact the upper surface 13a of the cavity portion 13 formed on the cap 5. Specifically, the semiconductor chip 3 directly contacts the cap 5 in the fixed state by appropriately selecting the formation depth of the cavity portion 13.

Further, as described above, the packing material 7 is configured to project downward from the storage groove portion 14 in a state of being stored in the storage groove portion 14, so that when the cap material 5 is mounted on the wiring board 4, The lower surface of the cap 5 does not directly contact the upper surface of the wiring board 4, but the packing material 7 contacts the upper surface of the wiring board 4.

Although the cap 5 and the base member 6 are fixed by the screwing mechanism 8 as described above, as shown in an enlarged view in FIG. 1B, the cap 5 is fixed in this fixed state.
A minute gap 24 is formed between the base member 6 and the base member 6, and a minute gap 25 is also formed between the upper surface of the wiring board 4 and the cap 5 (in the figure,
The size of the gaps 24 and 25 is shown by the arrow h). That is, in the fixed state, the wiring board 4 is sandwiched between the packing material 7 arranged on the cap 5 and the step portion 17 formed on the base member 6. Furthermore, the wiring board 4
The outer peripheral portion of is configured to be guided by the guide portions 5a and 6a formed on the cap 5 and the base member 6.

The semiconductor device 1 manufactured as described above is
Since the semiconductor chip 3 is configured to be in direct contact with the cap 5, the heat generated in the semiconductor chip 3 is directly conducted to the cap 5 and is dissipated in the heat dissipating fin portion 12, so that the heat dissipating efficiency is good and the semiconductor chip 3 can be reliably cooled.

Further, as described above, the gaps 24 and 25 having a minute dimension h are formed between the cap 5 and the base member 6 and between the upper surface of the wiring board 4 and the cap 5. In the fixed state, the wiring board 4 is sandwiched between the packing material 7 and the step portion 17 formed on the base member 6. Further, as described above, the outer peripheral portion of the wiring board 4 is guided by the guide portions 5a, 6a formed on the cap 5 and the base member 6. Therefore, the packing material 7 has an original packing function of defining the inside of the cavity 13 with respect to the outside air, and absorbs the stress between the semiconductor chip 3 and the cap 5 when the stress occurs. Also works as.

That is, when fixing the cap 5 and the base member 6 by the screwing mechanism 8, it is considered that mechanical stress is generated at the contact position between the semiconductor chip 3 and the cap 5.
Further, when the semiconductor device 1 is subjected to the soldering process, thermal stress may occur at the contact position between the semiconductor chip 3 and the cap 5.

However, the wiring board 4 has the guide portions 5
It is configured such that it can be slightly displaced in the cavity portion 13 while being guided by a and 6a, and the elastic force of the packing material 7 formed of an elastic material causes the base member 6
Since it is configured to be pressed by the (step portion 17), even if the above various stresses are generated, the packing material 7 can be elastically deformed to absorb the stresses.

Therefore, it is possible to prevent various stresses from remaining between the cap 5 and the semiconductor chip 3, and therefore, the semiconductor chip 1 and the wiring board 4 are not cracked and the semiconductor device 1 is reliable. It is possible to improve the sex.

Further, since the screwing mechanism 8 is used as the fixing mechanism for fixing the cap 5 and the base member 6, the screwing mechanism 8 fixes the fixing between the cap 5 and the base member 6 and releases the fixing by the nut 20. Can be easily performed by the operation of. The wiring board 4 is simply sandwiched between the cap 5 and the base member 6.

Therefore, by rotating the nut 20 to release the fixation by the screwing mechanism 8, the cap 5 is released.
The package constituted by the base member 6 and the base member 6 can be easily removed from the wiring board 4, and thus maintainability (maintainability) can be improved.

Further, in the present embodiment, the screwing mechanism 8 is constituted by the screw 19 and the nut 20 which are generally used, so that the screwing mechanism 8 can be constructed at a low cost, and the screwing mechanism 8 can be used. The cap 5 and the base member 6 can be easily fixed and released.

In order to mount the semiconductor device 1 having the above structure on the mounting board 2, the external connection pins 23 of the mounting board 2 are beforehand prepared.
The connection hole 26 is formed at a position corresponding to the arrangement position of the external connection pin 23, the external connection pin 23 is inserted into the connection hole 26 at the time of mounting, and the external connection pin 2 protruding to the back surface of the mounting substrate 2 is formed.
Solder 3 As a result, the semiconductor device 1 can be fixed to the mounting substrate 2, and the semiconductor device 1 and the mounting substrate 2 can be electrically connected. At this time, the base member 6
Since the opening 16 is formed in the external connection pin 23 and the external connection pin 23 is configured to extend downward through the opening 16, the base member 6 interferes with the soldering work of the external connection pin 23. There is no such a case, and the mounting work can be easily performed.

FIG. 3 shows a semiconductor device 30 which is a first modification of the semiconductor device 1 according to the first embodiment described above, and FIG. 4 shows a second modification of the semiconductor device 1 according to the first embodiment. The semiconductor device 40 which is an example is shown. In the figure, the same components as those of the semiconductor device 1 according to the first embodiment described with reference to FIGS. 1 and 2 are designated by the same reference numerals and the description thereof will be omitted.

A semiconductor device 3 according to a first modification shown in FIG.
In place of the external connection pins 23 used in the semiconductor device 1 according to the first example, the external connection pads 0 are provided on the lower surface of the wiring board 31 and face the external connection pads 32 of the mounting board 2. It is characterized in that the electrode pad 33 is arranged at the position.

In the structure in which the external connection pads 32 are provided on the lower surface of the wiring board 31, the external connection pads 32 formed on the wiring board 31 and the electrode pads 33 formed on the mounting board 2 are separated from each other. Therefore, the flat-plate socket 34 is interposed between the wiring board 31 and the mounting board 2.

The socket 34 has a structure in which an electrode portion 36 made of, for example, conductive rubber is provided on a base member 35 made of a flexible deformable insulating member.
Therefore, the external connection pad 32 and the electrode pad 33 are electrically connected to each other via the electrode portion 36 by interposing the socket 34 in the separated portion formed between the external connection pad 32 and the electrode pad 33. be able to.

On the other hand, in the semiconductor device 40 of the second modification shown in FIG. 4, the external connection protrusions 42 are provided on the lower surface of the wiring board 41 in place of the external connection pins 23 used in the semiconductor device 1 according to the first embodiment. In this embodiment, the solder bumps are provided, and the electrode pads 43 are provided at positions facing the external connection protrusions 42 of the mounting substrate 2.

Also in the semiconductor device 40 according to the second modification, since the separated portion is formed between the external connection projection 42 and the external connection projection 42, the socket 34 similar to that described in the second modification is formed. External connection protrusion 42 and external connection protrusion 4
It is interposed between the two.

As described above, the wiring boards 4, 31, 41
As the structure of the external connection terminal arranged in, there are a pin shape (external connection pin 23), a pad shape (external connection pad 32)
It is possible to use terminals having various configurations such as a projection shape (external connection projection 42).

Therefore, when the external connection pin 23 is used as the external connection terminal, the wiring board 4 and the mounting board 2 can be electrically connected without using the socket 34, and the external connection pad 32 and By using the external connection protrusion 42, it is possible to cope with the increase in the number of pins.

FIG. 5 shows a semiconductor device 30 according to the first modification.
9A and 9B show a mounting structure when the semiconductor device 40 according to the second modification is mounted on the mounting substrate 2.

The semiconductor device 1 according to the first embodiment has the external connection pins 23. By inserting the external connection pins 23 into the connection holes 26 formed in the mounting board 2 and soldering them. The semiconductor device 1 and the mounting substrate 2 are collectively electrically connected and mechanically fixed.

However, the semiconductor device 3 according to the first modification.
0 and the semiconductor device 40 according to the second modified example is the wiring board 3
Since the socket 34 is interposed between the mounting boards 1 and 41 and the mounting board 2, the mounting screws 44 and the mounting nuts 45 are used to mount the semiconductor device 30 and the semiconductor device 40 on the mounting board 2. . Further, insertion holes 46 and 47 for inserting the mounting screws 44 are formed in each of the collar portions 15 and 18 of the cap 5 and the base member 6, and the mounting screws 44 are also inserted into the mounting substrate 2. An insertion hole 48 is formed.

Then, the mounting screw 44 is inserted into the insertion holes 46 to 4
The semiconductor device 30 and the semiconductor device 40 can be mounted on the mounting substrate 2 by inserting the mounting nut 45 into the mounting screw 44 protruding from the rear surface side of the mounting substrate 2 and the mounting nut 45.

In the mounting method described above, the soldering work for the plurality of external connection pins 23 as in the first embodiment is not necessary, and the semiconductor device 30 and the semiconductor device 30 can be obtained by simply engaging the mounting screws 44 and the mounting nuts 45. Since the semiconductor device 40 can be mounted on the mounting substrate 2, the mounting work can be facilitated. Further, similarly to the screwing mechanism 8 described above, the semiconductor device 30 and the semiconductor device 4 are mounted on the mounting substrate 2.
Since 0 has a removable structure, maintainability (maintainability) can be improved.

6 to 9 show a semiconductor device 50 which is a second embodiment of the present invention.

FIG. 6 is a partially cut perspective view of the semiconductor device 50, FIG. 7 is a sectional view taken along the line AA in FIG. 6, and FIG. 8 is a view taken along the line BB in FIG. FIG. 9 is a sectional view of the semiconductor device 50, and FIG. 9 is a diagram for explaining a method of mounting the semiconductor device 50 on the mounting substrate 2. Also in this embodiment, the same components as those of the semiconductor device 1 according to the first embodiment described with reference to FIGS. 1 and 2 are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, in the semiconductor device 1 according to the first embodiment, the collar portions 15 and 18 formed on both the cap 5 and the base member 6 are not formed, and instead of this, the wiring board is formed. The notches 52 are formed at the four corners (corners) of the base member 51, and the engaging portions 54 are formed at the four corners of the base member 53 so as to engage with the notches 52 formed on the wiring board 51. It is a feature. Further, insertion holes 55 and 56 into which the screws 19 are inserted are formed at four corner positions of the cap 5 and the base member 53. Further, the inner wall portion of each engaging portion 54 functions as a guide portion 53a.

Generally, at the four corner positions (corner portions) of the wiring board 51, electronic parts and wiring patterns are not formed,
This is the part that forms the so-called dead space. In the present embodiment, the notch 52 is formed by removing the corner portion forming the dead space in a triangular shape. Further, the base member 53 has an engaging portion 54 that is shaped to engage with the cutout portion 52.
To form the wiring board 51 and the base member 53.
It is configured to be attached to.

As described above, by forming the cutout portion 52 in the corner portion which becomes the dead space of the wiring board 51, this portion can be used as the mounting position of the screwing mechanism 8. Therefore, as in the first embodiment, the collar portion 1
Since it is not necessary to form the flange portions 5 and 18, the semiconductor device 50 according to the present embodiment can be downsized by the amount that the flange portions 15 and 18 are formed.

Further, as shown in FIG. 9, in the mounting structure of the semiconductor device 50 according to the present embodiment (in FIG. 9, the structure using the external connection pads 32 as external connection terminals is shown), the dual-purpose screw 57 is used. A double nut structure in which two nuts 58 and 59 are screwed together is adopted.

That is, in the embodiment shown in FIG. 5, the screw 19 used to fix the cap 5 and the base material 6 and the semiconductor devices 30 and 40 are used to fix the circuit board 2. Although the mounting screw 44 and the mounting screw 44 are separately configured, the double nut structure is used as in the present embodiment, so that the cap 5 and the base member 53 are fixed and the semiconductor device 50 is mounted on the mounting substrate 2. 1 dual-purpose screw 5
It becomes possible to do in 7. This also makes it possible to reduce the size of the semiconductor device 50.

In each of the above embodiments, the semiconductor chip 3 and the cap 5 are in direct contact with each other, but a high thermal conductive material (for example, high thermal conductivity) is provided between the semiconductor chip 3 and the cap 5. Adhesive, etc.)
The semiconductor chip 3 may indirectly contact the cap 5. Also in this configuration, the heat generated in the semiconductor chip 3 can be efficiently dissipated, and the high thermal conductivity material also functions as a cushioning material, so that the stress applied to the semiconductor chip 3 can be reduced. .

[0079]

As described above, according to the present invention, the following various effects can be realized.

According to the first aspect of the present invention, since the cap integrally formed with the radiation fin is in direct contact with the semiconductor chip, the heat generated in the semiconductor chip is directly conducted to the cap. The heat is dissipated in the heat dissipating fins, so that the semiconductor chip can be efficiently cooled.

Further, since the screwing mechanism can be fixed and released, and the wiring board is simply sandwiched between the cap and the base member, the cap can be released by releasing the screwing mechanism. The package constituted by the base member and the base member can be easily removed from the wiring board, and maintenance can be easily performed.

According to the second aspect of the invention, the external connection terminal can be externally connected through the opening formed in the base member, so that the semiconductor device is mounted (surface mounting).
Can be done easily.

According to the invention of claim 3, since the external connection terminal is composed of a pin made of a conductive metal,
Even if the base member is present below the wiring board, the semiconductor device can be reliably mounted. Further, by forming the external connection terminal by the protrusion made of a conductive metal, it is possible to cope with the increase in the number of pins.

Further, according to the invention of claim 4, the screwing mechanism can be constructed at low cost, and the cap and the base member can be easily fixed and released by the screwing mechanism.

According to the fifth aspect of the present invention, the corner portions of the wiring board, the cap and the base member, which are dead spaces, can be effectively utilized, which contributes to downsizing of the semiconductor device.

Further, according to the invention of claim 6, since the packing material functions as a cushioning material between the cap and the semiconductor chip, even if the cap is directly brought into contact with the semiconductor chip, the cap and the semiconductor chip are separated from each other. It is possible to prevent various stresses from remaining in the meantime.

Further, according to the invention of claim 7, since the wiring board is located in the space surrounded by the cap, the base and the guide, the wiring board can be reliably held and the cap is used as the base. It is possible to easily carry out the work of attaching to and the work of assembling the wiring board.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a semiconductor device that is a first embodiment of the present invention.

FIG. 2 is an exploded perspective view for explaining the mounting structure of the semiconductor device according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view of a semiconductor device which is a first modification of the semiconductor device which is the first embodiment of the present invention.

FIG. 4 is a sectional view of a semiconductor device which is a second modification of the semiconductor device which is the first embodiment of the present invention.

FIG. 5 is an exploded perspective view for explaining mounting structures of a first modification and a second modification of the semiconductor device according to the first embodiment of the present invention.

FIG. 6 is a partially cutaway perspective view of a semiconductor device according to a second embodiment of the present invention.

7 is a sectional view taken along the line AA in FIG.

8 is a partially cutaway view taken along the line BB in FIG.

FIG. 9 is a diagram for explaining a method of mounting the semiconductor device according to the second embodiment of the present invention on a mounting board.

[Explanation of symbols]

 1, 30, 40, 50 Semiconductor device 2 Mounting board 3 Semiconductor chip 4, 31, 41, 51 Wiring board 5 Caps 5a, 6a Guide part 6,53 Base member 7 Packing material 8 Screwing mechanism 9 Board part 10 Thin film circuit part 11 Cap Part 12 Heat Dissipation Fin Part 13 Cavity Part 14 Storage Grooves 15, 18 Collar Part 16 Opening 19 Screw 20 Nut 23 External Connection Pin 24, 25 Gap 32 External Connection Pad 33, 43 Electrode Pad 34 Socket 35 Base Member 36 Electrode Part 42 External Connection Protrusion 44 Mounting Screw 45 Mounting Nut 52 Notch 54 Engagement Part 57 Dual-purpose Screw

Claims (7)

[Claims] 1. A wiring board having a semiconductor chip mounted on the upper surface and external connection terminals formed on the lower surface, and a radiation fin, which are integrally formed with each other and are arranged on the upper surface of the wiring board. In a semiconductor device configured to include a cap made of a high thermal conductive material for sealing the semiconductor chip, a base member that engages with a lower surface of the wiring board, and a fixing mechanism that fixes the cap and the base member. A package in which the cap directly contacts the semiconductor chip or indirectly through a high thermal conductive material, and the cap and the base member sandwich the wiring substrate to seal the semiconductor chip And a screwing mechanism is used as the fixing mechanism. 2. The semiconductor device according to claim 1, wherein an opening is formed in the base member, and the external connection terminal is externally connected through the opening. 3. The external connection terminal is a protrusion or a pin made of a conductive metal.
13. The semiconductor device according to claim 1. 4. The semiconductor device according to claim 1, wherein the screw attachment mechanism includes a screw and a nut. 5. The cutout portion is formed at a corner portion of the wiring board, and the screwing mechanism is provided at a corner portion of the cap and the base member. The semiconductor device according to. 6. A packing material is provided at a position facing the cap and the wiring board so as to surround the semiconductor chip and sandwiched between the cap and the wiring board. 6. The semiconductor device according to claim 1, wherein the packing material functions as a cushioning material between the cap and the semiconductor chip. 7. A guide projecting from the surface of at least one of the cap and the base is formed at a peripheral portion of a surface facing the wiring board, and the wiring board is arranged inside the guide. 7. The semiconductor device according to claim 1, wherein the semiconductor device is a semiconductor device.