JP2591499B2 - Semiconductor device - Google Patents

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 having a silicon IC chip mounted on a printed wiring board.

[0002]

2. Description of the Related Art Conventionally, as a structure for mounting a silicon IC chip (hereinafter simply referred to as a chip) on a printed wiring board, as shown in FIG. In this structure, the bump 32 is directly connected to the circuit pattern 33a of the printed wiring board 33. However, in this structure, when the ambient temperature changes, a thermal stress is generated between the chip 31 and the printed wiring board 33 when the ambient temperature changes,
Problems such as peeling of the connection portion by the solder bump 32 or cracking of the chip 31 occur. This problem becomes more conspicuous as the difference between the coefficients of thermal expansion of the chip 31 and the printed wiring board 33 increases, and as the chip size increases.

In order to absorb such thermal stress, Japanese Patent Application Laid-Open No. 4-29337 discloses a multilayer printed wiring board 41 whose cross section matches a solder bump of a chip 42 as shown in FIG. The glass epoxy substrates are laminated as described above to form flip-chip substrate pads 43, and deep grooves 44 are formed between the substrate pads 43. Therefore, when the solder bumps of the chip 42 are connected to the substrate pads 43, the individual substrate pads 43 can have flexibility independently by the deep grooves 44, so that thermal stress can be absorbed.

As another countermeasure, Japanese Patent Laid-Open No. Hei 5-294
In Japanese Patent No. 89, a chip 52 is connected to a ceramic multilayer wiring board 51 by solder bumps 53 as shown in FIG. In this example, the upper surface of the chip 52 is soldered to the cap 54, and the cap 54 is fixed to the ceramic multilayer wiring board 51 by solder 55,
A cooling plate 56 is attached to the upper surface. In this configuration, the thermal expansion coefficient α of silicon constituting the chip 52
1 and the thermal expansion coefficient α2 of the ceramic multilayer wiring board 51 are within 10%, and the temperature rise ΔT of the chip 52
1. Assuming that the temperature rise of the ceramic multilayer wiring board 51 is ΔT2, the value of α2 / α1 is set to ΔT1 / Δ within a predetermined error range.
The thermal expansion coefficient α2 of the ceramic multilayer wiring board 51 is set so as to be equal to T2, and the stress at the connection part due to the solder bump 53 is reduced.

Further, in Japanese Unexamined Patent Publication No. Hei 2-116152, as shown in FIG. 21, a silicon circuit board 63 is attached to a board mounting mount island 62 of a lead frame 61 and interconnected by bonding wires 64. A chip 65 is mounted on the silicon circuit board 63 by solder bumps 66. The whole is packaged with a transfer mold resin 67. In this configuration, since the silicon circuit board 63 and the chip 65 are made of the same silicon, the thermal expansion coefficients of the two are equal, and the generation of thermal stress can be prevented. Further, by using the silicon circuit board 63, the wiring density is dramatically improved, the passive elements can be integrally formed on the silicon circuit board, and the mounting density can be improved.

[0006]

As described above, in the conventional structure for coping with thermal stress, in the structure in which the independent substrate pads 43 of FIG.
There is a problem that the manufacturing process of (1) becomes complicated, leading to an increase in cost. Further, the wiring density of the printed wiring board 41 is 3
Since it is 0 cm / cm ² / layer, there is a problem that it is not suitable for high density. Further, even when a plurality of chips are mounted, the interval between the chips cannot be reduced.

The ceramic multilayer wiring board 5 shown in FIG.
In the configuration using 1, the thermal stress cannot be completely prevented because the thermal expansion coefficient is close to that of the silicon chip but there is a slight difference. Further, the wiring density is 40 to 200 c.
m / cm ² / layer, and there is a limit in increasing the density.

On the other hand, the silicon circuit board 6 shown in FIG.
3, the chip 65 and the silicon circuit board 6
Since the coefficient of thermal expansion is equal to that of No. 3, it is effective in preventing generation of thermal stress. However, in this configuration, since the package is formed by the transfer mold resin 67, the thermal stress of the mold resin 67 acts on the silicon circuit board 63 and the chip 65. Also,
Since it is difficult to increase the number of leads in the lead frame 61, the number of chips to be mounted is limited, and high-density mounting becomes difficult. Further, since it is necessary to connect the silicon circuit board 63 to the lead frame 61 with the bonding wires 64 and further connect the outer leads of the lead frame 61 to the mounting board at the time of mounting, the number of connection points becomes extremely large. In addition, there is a problem that the connecting process becomes complicated and the number of assembling steps increases.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a semiconductor device which can prevent the occurrence of thermal stress, increase the density, and reduce the number of assembly steps.

[0010]

According to a first aspect of the present invention, there is provided a semiconductor device in which a silicon IC chip is mounted on a silicon circuit board, and the silicon circuit board is mounted on a printed wiring board with a flexible adhesive resin. And said
The adhesive resin has multiple voids in the plane direction of the silicon circuit board.
It is characterized in that it is arranged at a plurality of places . In this case, the silicon circuit board and the IC chip are sealed with a sealing resin or a metal cap provided on the printed wiring board, or the silicon circuit boards each having the IC chip mounted on both sides of the printed wiring board are opposed to each other. It is preferable to mount it on Also, dispose the adhesive resin at multiple locations.
The same applies to the following second to fourth inventions.
It is.

In a semiconductor device according to a second aspect of the present invention, a silicon IC chip is mounted on a silicon circuit board, a recess is provided in a printed wiring board, and the silicon circuit board is mounted in the recess and is flexible. It is characterized by being mounted with an adhesive resin.

In a semiconductor device according to a third aspect of the present invention, a silicon IC chip is mounted on a silicon circuit board, and flexibility is provided through a stress relaxation plate having a coefficient of thermal expansion intermediate between the silicon and the printed wiring board. The silicon circuit board is mounted on a printed wiring board with an adhesive resin.

In this case, a silicon IC chip is mounted on a silicon circuit board, and the silicon circuit board is mounted on a printed wiring board with a flexible adhesive resin.
Further, a stress relaxation plate having a thermal expansion coefficient intermediate between silicon and the printed wiring board may be mounted on the opposite surface of the printed wiring board with a flexible adhesive resin so as to face the silicon circuit board.

[0014]

According to a fourth aspect of the present invention, in a semiconductor device, a silicon IC chip is mounted on a silicon circuit board, the silicon circuit board is mounted on a printed wiring board with a flexible adhesive resin, and The wiring relay board is mounted on a printed wiring board.

[0016]

According to the first aspect of the present invention, the thermal stress generated between the silicon circuit board and the printed wiring board is absorbed or reduced by the flexible adhesive resin, and the thermal stress is applied to the IC chip and the silicon circuit board. Prevent influence. In particular, the sealing performance is enhanced by sealing the silicon circuit board and the IC chip with a sealing resin or a metal cap, and the heat dissipation of the IC chip and the silicon circuit board is enhanced. Further, by mounting the silicon circuit boards on both sides of the printed wiring board so as to face each other, the thermal stress generated in each silicon circuit board is canceled on both sides, and the influence of the thermal stress is further reduced.

In the semiconductor device according to the second aspect of the present invention, a silicon circuit board is provided inside a concave portion provided in the printed wiring board with a flexible adhesive resin so that the semiconductor device can be made thinner and the printed wiring board can be mounted on the printed circuit board. Shorten electrical connections and improve high frequency characteristics.

The semiconductor device according to the third aspect of the present invention uses a stress relaxation plate having a thermal expansion coefficient intermediate between silicon and a printed wiring board, so that the thermal stress is relaxed by the stress relaxation plate, and the IC is integrated.
The effect of thermal stress on the chip and the silicon circuit board is significantly reduced. Further, by mounting the stress relaxation plate on the opposite surface of the printed wiring board, the thermal stress generated in the silicon circuit board is canceled by the stress relaxation plate.

[0019]

In the semiconductor device of the fourth invention, the silicon circuit board is mounted on the printed wiring board, and the printed wiring board is mounted on the printed wiring board. The thermal stress between them is absorbed by the flexible adhesive resin to prevent the thermal stress from being generated between the silicon circuit board and the printed wiring board.

[0021]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a first embodiment of the present invention. In the silicon circuit board 1, a fine wiring pattern is formed on the silicon substrate by a selective oxidation method, impurity introduction, or the like, and a pad metal 1a formed of a metal thin film is formed as a part of the wiring pattern. Although not shown, passive elements such as resistors and capacitors are formed on the silicon circuit board 1 as necessary. A chip 2 such as a transistor or an IC formed of silicon is mounted on the upper surface of the silicon circuit board 1, and the electrodes 2 a provided on the lower surface of the chip are solder bumps 3 of the silicon circuit board 1. It is connected to pad metal 1a.

The silicon circuit board 1 is mounted on the upper surface of a printed wiring board 4 constituting a semiconductor device, and is attached using an epoxy resin having a flexible property or an adhesive resin 5 such as silicon gel. The pad metal 1a of the silicon circuit board 1 and the printed wiring board 4
Is connected by a bonding wire 6 to the circuit pattern 4a. Then, the chip 2, the silicon circuit board 1,
The entirety including the bonding wires 6 is packaged with a sealing resin 7 to perform sealing.

Here, in the silicon circuit board 1 described above, the wiring density that can be formed is 400 cm / cm ³ , and the wiring density of a normal printed wiring board is 30 cm / cm 3.
A circuit can be formed at a density 10 times or more higher than that of ² . The adhesive resin 5 such as the above-mentioned flexible epoxy resin or silicon gel can support the silicon circuit board 1 on the printed circuit board 4, while placing the silicon circuit board 1 on the printed circuit board 4. It can be supported in a state in which it can be moved in the vertical direction or the plane direction within a minute size range. Further, the sealing resin 7 has a thermal expansion coefficient as close as possible to that of silicon.

Therefore, according to this structure, when the ambient temperature is changed, since the chip 2 and the silicon circuit board 1 are formed of silicon having the same coefficient of thermal expansion, thermal stress is generated between them. No connection is caused by the solder bumps 3, and the chip 2 and the silicon circuit board 1 are not cracked. on the other hand,
Between the silicon circuit board 1 and the printed wiring board 4, the thermal expansion coefficient of silicon is 2.6 × 10 ⁻⁶ / K, whereas the thermal expansion coefficient of the glass epoxy resin constituting the printed wiring board is 1
Although there is a difference of 0 to 20 × 10 ⁻⁶ / K, since both are connected by the flexible adhesive resin 5,
The thermal stress due to the difference in the coefficient of thermal expansion between the silicon circuit board 1 and the printed wiring board 4 is absorbed by the flexibility of the adhesive resin 5, and the thermal stress is not particularly affected on the silicon circuit board 1. And the occurrence of cracks and the like can be prevented.

In this structure, the silicon circuit board 1
Is higher than the wiring density of the printed wiring board 4 by one digit or more, the wiring density for the chip 2 can be increased, and the size of the silicon circuit board can be reduced as compared with the printed wiring board mounting the same chip. It becomes possible. When mounting the silicon circuit board 1 on the printed wiring board 4, a step of attaching with a flexible adhesive resin 5, a step of performing electrical connection with bonding wires 6 thereafter, and a step of encapsulating resin 7. May be performed. Therefore, it is not necessary to connect the silicon circuit board to a lead frame or the like, and the number of manufacturing steps can be reduced, and the manufacturing can be facilitated.

Here, the results of a reliability test when a 40 mm square silicon circuit board is mounted on a printed wiring board are shown. As shown in FIG. 17, thermal histories of an adhesive resin applied to the entire surface of the silicon circuit board 1 (a), four corners (b), and a stripe applied (c) in the same area are respectively shown. A test was conducted to test the life of the adhesive strength of the silicon circuit board. As a result, it was found that the life of (b) and (c) could be improved about 1.5 times as compared with (a). Therefore, in mounting the silicon circuit board 1 on the printed wiring board 4 in the structure of FIG.
As shown in (b) and (c), it has been found that it is preferable to apply the adhesive resin 5 to the four corners or the striped portion on the back surface of the silicon circuit board 1 for attachment.

FIG. 2 is a cross-sectional view of a first modification of the first embodiment, in which parts equivalent to those in FIG. 1 are denoted by the same reference numerals (the same applies hereinafter). In this embodiment, a chip 2 is mounted on a silicon circuit board 1 by solder bumps 3, and the silicon circuit board 1 is attached to a printed wiring board 4 by a flexible adhesive resin 5, and is electrically connected by bonding wires 6. After that, the entire structure is covered with a metal cap 8 and the opening of the metal cap 8 is fixed to the printed wiring board 4 in a sealed state with an adhesive 9. The airtightness is enhanced by covering the metal cap 8, and the sealing resin 7 shown in FIG.
The sealing effect is improved by preventing the intrusion of moisture or the like through a resin as in the case of using a resin. In addition, the reliability can be improved with respect to external force. Further, it is possible to prevent the occurrence of thermal stress due to the difference in thermal expansion coefficient between the sealing resin and the chip or the silicon circuit board.

Further, as shown in FIG. 3 showing a second modification of the first embodiment, after forming the structure of FIG. 1, a metal cap 8 is put on the printed wiring board 4 from the outside of the sealing resin 7. You may comprise so that it may be fixed. In this embodiment, the sealing effect of the metal cap 8 and the sealing effect of the sealing resin 7 are synergistic, and an extremely high sealing effect can be obtained. In particular, the sealing resin 7 can prevent moisture caused by dew condensation or the like generated inside the metal cap 8 from affecting the chip 2 and the silicon circuit board 1.

FIG. 4 shows a third modification of the first embodiment in which the heat radiation effect of the chip is enhanced, and the chip 2 of the modification of FIG.
Is connected to the inner surface of the metal cap 8 by an adhesive material 10 made of a metal material such as an adhesive having high thermal conductivity, Ag paste, or solder. Further, in this case, the adhesive material 10 preferably has flexibility. Further, here, the heat sink 11 is provided on the upper surface of the metal cap 8.
Are similarly connected by an adhesive material 12 such as an adhesive having a high thermal conductivity, Ag paste, or solder. Therefore, the heat generated in the chip is directly transferred to the metal cap 8 via the adhesive material 12 and the outer surface and the heat sink 11
Since the heat is radiated from the surface of the substrate, the temperature rise of the chip 2 and the silicon circuit board 1 is suppressed, and the generation of thermal stress is more effectively prevented.

FIG. 5 shows a fourth modification of the first embodiment in which the heat radiation effect is further enhanced. A through-hole is formed in the printed wiring board 4 and an electric heat source such as a resin or metal having high heat conductivity is formed therein. The heat dissipation via 13 is formed by burying the material. A heat sink 14 is similarly connected to the lower surface of the printed wiring board 4 by a resin or metal 12 having high thermal conductivity. In this configuration, any heat generated in the chip 2 and transmitted to the silicon circuit board 1 or generated in the silicon circuit board 1 is transferred to the lower surface side of the printed wiring board 4 through the heat dissipation via 13 and the heat sink 14 Since the heat is radiated from the metal cap 8 and the heat sink 11, the heat radiating effect can be further enhanced.

FIG. 6 shows a fifth modification of the first embodiment in which the structure of the modification of FIG. 2 is provided on both sides of a printed wiring board. In this configuration, since the chip 2, the silicon circuit board 1, and the metal cap 8 are mounted symmetrically on both sides of the printed circuit board 4, the chip 2, the silicon circuit board 1 and the printed circuit board 4 are temporarily Even when thermal stress is generated, the thermal stress is generated on both sides of the printed wiring board 4 in directions symmetric to each other. As a result, both thermal stresses can be canceled out and the influence of the thermal stress can be eliminated. .

FIG. 7 shows a second embodiment of the present invention in which the thickness of the semiconductor device is reduced. A concave portion 15 is formed on the surface of the printed wiring board 4, and the silicon circuit board 1 is mounted inside the concave portion 15. And, it is attached by the flexible adhesive resin 5. Therefore, the overall height of the semiconductor device can be reduced by the depth of the concave portion 15, and the semiconductor device can be made thinner. Further, in this case, by configuring the surface of the silicon circuit board 1 to be at the same height as the surface of the printed wiring board 4, the length of the bonding wire 6 can be reduced, and the high-frequency characteristics can be improved. Also, in this embodiment, the effect of the thermal stress can be suppressed as in the first embodiment.

FIG. 8 shows a first modification of the second embodiment in which the semiconductor device is flattened. The printed wiring board 4 has a two-stage recess in which the silicon circuit board 1 and the chip 2 can be mounted. After forming the silicon circuit board 1 in the recess 16 and attaching it with the flexible adhesive resin 5, the sealing resin 7 is filled in the recess 16 to seal the chip 2. I have. A metal plate 17 is attached to the surface of the printed circuit board 4 so as to cover the recess 16. Thereby, the silicon circuit board 1 and the chip 2 can be provided inside the thick printed wiring board 4 and can be flattened.

FIG. 9 shows a second modified example of the modified example of FIG. 8 in which the heat dissipation is improved. The concave portion is covered with a heat sink 11 instead of the metal plate 17.
1 is configured so that the upper surface of the chip 2 is connected to the chip 1 with an adhesive material 10. Therefore, the heat generated in the chip 2 can be radiated through the heat sink 11 while ensuring the flatness of the semiconductor device in a portion other than the heat sink 11, and the heat radiation can be improved.

FIG. 10 shows a third modification in which the basic technical concept of the second embodiment is applied to both sides of a printed wiring board. Then, a silicon circuit board 1 and a chip 2 are respectively mounted inside, and the silicon circuit board 1 is attached with an adhesive resin 5 having flexibility. Further, each recess 15 is covered with a metal cap 8 and hermetically sealed. Therefore, by reducing the thickness of the semiconductor device and mounting the silicon circuit board 1 and the chip 2 symmetrically on both sides of the printed wiring board 4, the thermal stress on both sides can be offset to reduce the influence of the thermal stress. It is possible.

FIG. 11 shows a third embodiment of the present invention. In this embodiment, the effect of reducing thermal stress between the silicon circuit board 1 and the printed wiring board 4 is further enhanced. In each of the above embodiments, the thermal stress is reduced by mounting the silicon circuit board 1 on the printed wiring board 4 with the flexible adhesive resin 5, but when the size of the silicon circuit board 1 is increased, The mitigation effect may not be sufficient. Therefore, in this embodiment, a stress relaxation plate 18 having a thermal expansion coefficient intermediate between those of the silicon circuit board 1 and the printed wiring board 4 is used.
Is interposed. As the stress relaxation plate 18, for example, aluminum nitride having a thermal expansion coefficient of 4.5 × 10 ⁻⁶ / K is used. ^{Others, CuW (6.5 × 10 -6 /} K), Kovar (5.2 × 10 ^-6 /K),Mo(5.0×10 ^-6 /
K), Al ₂ O ₃ (6.7 × 10 ⁻⁶ / K),
SiC (3.7 × 10 ⁻⁶ / K), mullite (3.5 × 1
0 ^-6 / K) is a ceramic such as used.

The thickness and size of the stress relieving plate 18 are appropriately set, inserted between the silicon circuit board 1 and the printed wiring board 4, and adhered by the flexible adhesive resin 5, thereby obtaining the silicon circuit board 1. And printed wiring board 4
, The expansion change accompanying the temperature change between them can be reduced, and the thermal stress can be reduced.

In the first modification of the third embodiment shown in FIG. 12, the stress relaxation plate 18 is attached to the surface on the opposite side of the printed wiring board 4. The stress relieving plate 18 is attached by a flexible adhesive resin 5 similarly to the silicon circuit board 1. For this reason, a difference in expansion that occurs between the silicon circuit board 1 and the printed wiring board 4 also occurs between the stress relaxation plate 18 and the printed wiring board 4 on the back surface side of the printed wiring board 4. , The influence of thermal stress on the printed wiring board 4 and the silicon circuit board 1 can be reduced. Further, the stress relaxation plate 18 also functions as a heat radiating plate. In this embodiment, a silicon plate may be used as the stress relaxation plate 18.

FIG. 13 shows a second modification of the third embodiment in which the technique of the third embodiment is applied to the second embodiment.
6, the silicon circuit board 1 and the chip 2 are mounted. The silicon circuit board 1 is attached with a flexible adhesive resin 5, and the sealing resin 7 is filled in the recess 16. In addition, heat sinks 11 are integrally adhered to the upper surfaces of the individual chips 2 with an adhesive material 12 so as to protrude outside the sealing resin 7. On the other hand, a stress relaxation plate 18 is attached to the lower surface of the printed wiring board 4 with a flexible adhesive resin 5.
Also in this case, a silicon plate may be used instead of the stress relaxation plate.

In this embodiment, the thickness of the semiconductor device is reduced, and in particular, since the heat sinks 11 are provided independently of each other, the heat radiation of each chip 2 is improved. Can be. Further, the thermal stress between the silicon circuit board 1 and the printed wiring board 4 is reduced by the stress relaxation plate 1.
8 is the same as in the example of FIG.

FIG. 14 shows a fourth embodiment of the present invention, in which a silicon circuit board 1 on which a chip 2 is mounted by solder bumps 3 is printed by a TAB tape 19 on a printed wiring board 4.
This is an example implemented in. That is, the pad metal 1a of the silicon circuit board 1 and the circuit pattern 4a of the printed wiring board 4
Are electrically connected by TAB tape 19, and T
The silicon circuit board 1 is supported in a floating state by the TAB tape 19 due to the slight rigidity of the AB tape 19. Then, the printed circuit board 4 is fixed by covering the metal cap 8, and a heat sink 11 is attached to the upper surface of the metal cap 8 with an adhesive material 12. In this embodiment, in order to stabilize the floating state of the silicon circuit board 1, the upper surface of the chip 2 is
0 adheres to the inner surface of the metal cap 8.

In this embodiment, since the silicon circuit board 1 is held apart from the printed wiring board 4, thermal stress due to the difference in the coefficient of thermal expansion between the two is hardly generated. In addition, the effect of thermal stress can be prevented. Further, the heat generated in the chip 2 can be effectively radiated to the outside via the metal cap 8 and the heat sink 11.

FIG. 15 shows a fifth embodiment of the present invention, in which a printed wiring board 20 made of the same material as the printed wiring board 4 is formed in a multilayer wiring structure having a multilayer circuit pattern 20a. The silicon circuit board 1 is attached on the relay board 20 with a flexible adhesive resin 5. A chip 2 is mounted on a silicon circuit board 1 by solder bumps 3 as in the above-described embodiments. And
In this embodiment, on the silicon circuit board 1 and the chip 2,
A metal cap 21 also serving as a heat sink is covered and fixed to the printed wiring board 20, and the upper surface of the chip 2 is adhered to the inner surface of the metal cap 21 with a heat conductive adhesive material 10. Further, the silicon circuit board 1 and the printed wiring relay board 20 are electrically connected by bonding wires 6,
A large number of pad metals 20b are formed on the lower surface of the printed wiring relay board 20, and the printed wiring board 4 is formed by using the solder bumps 22 formed on the pad metal 20b.
Is mounted on the circuit pattern 4a.

In this configuration, the material between the chip 2 and the silicon circuit board 1 and the space between the printed wiring board 20 and the printed wiring board 4 have the same thermal expansion coefficient. No thermal stress occurs. Further, since the flexible circuit board 5 is used for bonding between the silicon circuit board 1 and the printed wiring board 20, thermal stress between the two can be suppressed.

FIG. 16 shows a second modification of the fifth embodiment. Each of the chips 2 is formed as a package 23 similar to that of the embodiment of FIG. 2 shows a configuration mounted by solder bumps 22. In this example, each package 23 has a metal cap 8 having no heat sink.
Is used. In this embodiment, a package having an occupied area as small as the chip size can be configured.

[0046]

As described above, the semiconductor device according to the first aspect of the present invention has a silicon IC on a silicon circuit board.
Since the chip is mounted and this silicon circuit board is mounted on the printed wiring board with a flexible adhesive resin, the thermal stress generated between the silicon circuit board and the printed wiring board is absorbed by the flexible adhesive resin, Alternatively, the stress is reduced to prevent the thermal stress from affecting the IC chip and the silicon circuit board. Also, connect the silicon circuit board
Resin to be applied to a plurality of places with voids in the plane direction
High reliability of bonding to heat history
The bonding strength can be extended. This effect
The result is the same in the second to fourth inventions.

Further, in the present invention, the sealing property is enhanced by sealing the silicon circuit board and the IC chip with a sealing resin or a metal cap provided on the printed wiring board, and the IC chip and the silicon circuit are sealed. The heat dissipation of the substrate can be improved. Furthermore, by mounting the silicon circuit boards on which the IC chips are mounted on both sides of the printed circuit board so as to face each other, the thermal stress generated on each silicon circuit board is offset on both sides, and the influence of the thermal stress is further reduced. Becomes possible.

In the semiconductor device according to the second aspect of the present invention, since a silicon circuit board on which an IC chip is mounted is mounted in a recess provided in a printed wiring board and mounted with a flexible adhesive resin, Can relieve stress,
It is possible to reduce the thickness of the semiconductor device, shorten the electrical connection to the printed wiring board, and improve high-frequency characteristics.

In the semiconductor device according to the third aspect of the present invention, a silicon circuit board on which an IC chip is mounted is mounted with a flexible adhesive resin via a stress relaxation plate having an intermediate thermal expansion coefficient between silicon and a printed wiring board. Therefore, the thermal stress can be reduced by the stress relaxation plate, and the influence of the thermal stress on the IC chip and the silicon circuit board can be remarkably reduced. In particular, by mounting a stress relaxation plate on the opposite surface of the printed wiring board on which the silicon circuit board is mounted so as to face the silicon circuit board, it is possible to offset the thermal stress generated in the silicon circuit board by the stress relaxation plate. is there.

[0050]

A semiconductor device according to a fourth aspect of the present invention has an IC
The silicon circuit board on which the chip is mounted is mounted on the printed wiring relay board with a flexible adhesive resin, and since this printed wiring relay board is mounted on the printed wiring board, the gap between the printed wiring relay board and the silicon circuit board Is absorbed by the flexible adhesive resin, and it is possible to prevent a thermal stress from being generated between the silicon circuit board and the printed wiring board.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention.

FIG. 2 is a sectional view of a first modification of the first embodiment of the present invention.

FIG. 3 is a sectional view of a second modification of the first embodiment of the present invention.

FIG. 4 is a sectional view of a third modification of the first embodiment of the present invention.

FIG. 5 is a sectional view of a fourth modification of the first embodiment of the present invention.

FIG. 6 is a sectional view of a fifth modification of the first embodiment of the present invention.

FIG. 7 is a sectional view of a second embodiment of the present invention.

FIG. 8 is a sectional view of a first modification of the second embodiment of the present invention.

FIG. 9 is a sectional view of a second modification of the second embodiment of the present invention.

FIG. 10 is a sectional view of a third modification of the second embodiment of the present invention.

FIG. 11 is a sectional view of a third embodiment of the present invention.

FIG. 12 is a sectional view of a first modification of the third embodiment of the present invention.

FIG. 13 is a sectional view of a second modification of the third embodiment of the present invention.

FIG. 14 is a sectional view of a fourth embodiment of the present invention.

FIG. 15 is a sectional view of a fifth embodiment of the present invention.

FIG. 16 is a sectional view of a first modification of the fifth embodiment of the present invention.

FIG. 17 is a diagram showing a state in which a flexible adhesive resin according to the present invention is applied.

FIG. 18 is a cross-sectional view of an example of a conventional semiconductor device.

FIG. 19 is a perspective view of another example of a conventional semiconductor device.

FIG. 20 is a sectional view of still another example of a conventional semiconductor device.

FIG. 21 is a cross-sectional view of still another different example of the conventional semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Silicon circuit board 2 Chip (IC element chip) 3 Solder bump 4 Printed wiring board 5 Adhesive resin which has flexibility 6 Bonding wire 7 Sealing resin 8 Metal cap 11 Heat sink 15 and 16 Depression 18 Stress relaxation board 19 Heat radiation via 20 Printing Wiring relay board 22 Solder bump 23 Package

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location H01L 25/18 H01L 23/12 J H05K 1/18 N 25/04 Z (72) Inventor Kusaka Teruo 5-7-1, Shiba, Minato-ku, Tokyo NEC Corporation (56) References JP-A-56-134747 (JP, A) JP-A-62-195137 (JP, A) JP-A-6-61304 (JP, A)

Claims (7)

(57) [Claims] 1. A mounted silicon IC chip on the silicon circuit substrate, and mounted on a printed wiring board of the silicon circuit board by a flexible resistance of the adhesive resin, prior to
The adhesive resin has multiple voids in the plane direction of the silicon circuit board.
Wherein a disposed on the plurality of locations spaced. 2. The semiconductor device according to claim 1, wherein the silicon circuit board and the IC chip are sealed with a sealing resin or a metal cap provided on the printed wiring board. 3. An IC is provided on each side of a printed wiring board.
3. The semiconductor device according to claim 1, wherein the silicon circuit board on which the chip is mounted is mounted so as to face each other. 4. A silicon IC chip is mounted on a silicon circuit board, a recess is provided in a printed wiring board, and the silicon circuit board is mounted in the recess and mounted with a flexible adhesive resin . The adhesive resin is silicon
At multiple locations with multiple gaps in the plane direction of the circuit board
Wherein a being disposed. 5. A silicon IC chip is mounted on a silicon circuit board, and the silicon circuit board is printed by a flexible adhesive resin via a stress relaxation plate having a thermal expansion coefficient intermediate between the silicon and the printed wiring board. It is mounted on a board, and the adhesive resin is on the flat surface of the silicon circuit board.
A semiconductor device, wherein the semiconductor device is provided at a plurality of places having a plurality of gaps in a direction . 6. A silicon IC chip is mounted on a silicon circuit board, said silicon circuit board is mounted on a printed wiring board with a flexible adhesive resin, and has a coefficient of thermal expansion intermediate between silicon and the printed wiring board. A stress relaxation plate is mounted on the opposite surface of the printed circuit board with a flexible adhesive resin so as to face the silicon circuit board, and the adhesive resin is flat on the silicon circuit board.
A semiconductor device, which is provided at a plurality of places having a plurality of gaps in a plane direction . 7. A silicon IC chip is mounted on a silicon circuit board, the silicon circuit board is mounted on a printed wiring board with a flexible adhesive resin, and the printed wiring board is mounted on the printed wiring board. In
And the adhesive resin is plural in the plane direction of the silicon circuit board.
A semiconductor device, wherein the semiconductor device is provided at a plurality of locations with a gap .