JP3348937B2 - Semiconductor integrated circuit device and method of assembling the same - 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 integrated circuit device and, more particularly, to a technique effective when applied to a flip-chip type semiconductor integrated circuit device in which a semiconductor chip is mounted on a wiring board via bumps.

[0002]

2. Description of the Related Art Today, in logic LSIs such as gate arrays and microcomputers, the number of chip electrodes for connecting to external circuits has been rapidly increasing with the increase in the functions and speed of integrated circuits. A wire bonding method of connecting a wire to a bonding pad provided around a semiconductor chip to connect to an external circuit has reached a limit.

Further, the wire bonding method has a drawback that the wiring in the internal region extends to the bonding pads in the peripheral portion, so that the wiring length becomes long and the signal transmission speed is delayed. Also unsuitable for.

For these reasons, attention has been paid to a so-called flip-chip bonding technique in which a bump is formed on the uppermost layer wiring of a semiconductor chip, and the semiconductor chip is mounted on the substrate via the bump.

The flip chip method has an advantage that the number of pins of the semiconductor chip can be increased because chip electrodes can be provided not only in the peripheral area of the semiconductor chip but also in the internal area. Further, as compared with the above-described wire bonding method, there is an advantage that the wiring length on the semiconductor chip can be reduced as much as it is not necessary to extend the wiring in the internal region to the peripheral portion, and the speed of the logic LSI can be increased. .

The bumps are formed through the electrode bases of the chip electrodes. The bumps are aligned in correspondence with the electrode pads provided on the wiring board, and are passed through a heat treatment furnace to reflow the bumps for bonding. It is carried out.

[0007]

Although such a flip-chip method has the above-mentioned advantages, thermal distortion occurs in the bumps due to the mismatch in the coefficient of thermal expansion between the semiconductor chip and the wiring board, resulting in a temperature cycle. In addition, there is a problem that the connection portion is broken by thermal fatigue. In particular, the bumps located farthest from the center of the semiconductor chip will experience the largest distortion, and this tendency is even more remarkable. Therefore, in order to prevent thermal fatigue destruction of the connection portion, the thermal expansion coefficient of the wiring board is reduced by the thermal expansion coefficient of the semiconductor chip (3 × 10 ^−6).
[K ^-1 ]).

As such a wiring board, mullite or aluminum nitride is optimal (coefficient of thermal expansion: 3).
４4 × 10 ⁻⁶ [K ⁻¹ ])) The demand is low and the price is high. In recent years, the number of pins has been increased due to the high integration of semiconductor integrated circuit devices. Are difficult to adopt. On the other hand, alumina ceramic is relatively inexpensive, but has a large coefficient of thermal expansion (7 × 10 ⁻⁶ [K ⁻¹ ]), which limits the size of the semiconductor chip. Furthermore, in the case of glass epoxy resin which is a general wiring board, the thermal expansion coefficient is 15 ×.
Since it is extremely large at 10 ^-6 [K ^-1 ], mounting itself by the flip chip method is difficult.

In order to enable mounting on an inexpensive wiring board by a flip-chip method, a technique of extending the connection life by filling the space between the semiconductor chip and the board with a resin adhesive has been proposed (1992 42nd Electronic Technology). Conponents & Techno
logy Conference pp.22), it is difficult to replace semiconductor chips once they are filled with resin.

SUMMARY OF THE INVENTION An object of the present invention is to provide a technique relating to a semiconductor integrated circuit device which can be mounted by a flip chip method regardless of the matching of thermal expansion coefficients between a semiconductor chip and a wiring board.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0012]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, typical ones will be outlined as follows.

In other words, the semiconductor integrated circuit device of the present invention has a wiring board on which electrode pads are arranged in accordance with the electrode arrangement of a semiconductor chip to be mounted, and is mounted on the wiring board in a flip-chip manner via bumps. One or more semiconductor chips having the same height are brought into contact with the entire back surface of the semiconductor chip, the semiconductor chip is sandwiched between the wiring substrate and the semiconductor chip, and the semiconductor chip is pressed with a predetermined pressure. and a plate-like pressing member, wherein the wire
Form the surface shape of the electrode pad on the substrate into a concave curved surface
And, wherein that semiconductor chip is pressed against the wiring board by the pressing member, the bump while said electrode pad formed on the wiring board and the electrode of the semiconductor chip to allow the lateral position deviation It is electrically connected via the

Further, according to the method of assembling a semiconductor integrated circuit device of the present invention, one or a plurality of semiconductor chips having the same height are formed into a concave curved surface on a wiring board in a flip chip manner via bumps. Mount on the formed electrode pad,
By bringing a plate-shaped pressing member into contact with the entire back surface of the semiconductor chip, sandwiching the semiconductor chip with the wiring substrate, and pressing the semiconductor chip against the wiring substrate with a predetermined pressure by the pressing member. The semiconductor chip is electrically connected to the electrode pads on the wiring board via the bumps while allowing the semiconductor chips to be displaced in the lateral direction.

[0015]

According to the semiconductor integrated circuit device having the above-described structure, a flip chip type mounting structure in which the chip electrodes are electrically connected to the electrode pads of the wiring board by the pressing of the semiconductor chip by the pressing member. Therefore, even if the thermal expansion coefficients of the semiconductor chip and the wiring board do not match, the electrical connection state between the bumps and the electrode pads is reliably maintained even though the positional relationship between the bumps and the electrode pads is slightly shifted. .

Therefore, unlike the case where the bumps are bonded to the electrode pads by reflow by heat treatment, no thermal strain is generated in the bumps, and there is no possibility that the connection portions may be damaged by thermal fatigue. That is, according to the semiconductor integrated circuit device of the present invention, the semiconductor chip can be mounted on the wiring board by the flip chip method regardless of the matching of the thermal expansion coefficient between the semiconductor chip and the wiring board on which the semiconductor chip is mounted. Become.

Further, according to the method of assembling the semiconductor integrated circuit device having the above-described configuration, the positional relationship between the bumps of the semiconductor chip and the electrode pads of the wiring board set in the alignment does not shift, so that the pressing is performed. When the semiconductor chip is pressed and fixed to the wiring board by the member, the electrical connection between the bump and the electrode pad can be reliably achieved.

[0018]

Embodiments of the present invention will be described below in more detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a front view showing a semiconductor integrated circuit device according to an embodiment of the present invention, FIG. 2 is a sectional view of a principal part of the semiconductor integrated circuit device, and FIG. It is sectional drawing which shows the connection state of the semiconductor chip of an apparatus and a wiring board.

The semiconductor integrated circuit device 1 according to the present embodiment, via an Au bump (bump) 3 formed on the chip electrode 2,
This is a flip-chip type semiconductor integrated circuit device in which a semiconductor chip 4 is mounted on an MCM (Multi-Chip Module) wiring board (wiring board) 5.

As shown in FIG. 3, an insulating film 6 is formed on the surface of the semiconductor chip 4 to protect a built-in circuit element (not shown). -An electrode substrate 7 with a multilayer metal thin film made of Cu-Au;
Is formed. Then, through the electrode base 7,
The Au bump 3 is formed by, for example, a ball bonding method.

On the other hand, the MC connected to the Au bump 3
The M wiring board 5 has, for example, a coefficient of thermal expansion of 7 × 10 ⁻⁶ [K
^The electrode pad 8 formed here has a flat surface shape made of, for example, Au, and is connected to the wiring layer 10 through the connection hole 9 as shown in FIG. It is electrically connected.

As shown in FIG. 1, the semiconductor chip 4 is pressed against the MCM wiring board 5 by a pressing member 11, whereby the chip electrodes 2 and the electrode pads 8 are electrically connected. That is, the MCM wiring board 5 and the pressing member 11 are screwed together with the bolts 12 and the nuts 13, and the semiconductor chip 4 is provided so as to be sandwiched between them. The contact state is ensured. A coil spring 14 is mounted between the head of the bolt 12 and the outer surface of the pressing member 11, and an excessive pressing force of the pressing member 11 is adjusted by the elastic force of the coil spring 14 so that the semiconductor chip 4 is prevented from being destroyed.

As described above, in the semiconductor integrated circuit device of this embodiment, the semiconductor chip 4 is pressed by the pressing member 11 so that the chip electrode 2 formed on the semiconductor chip 4 is formed.
Have a flip-chip mounting structure electrically connected to the electrode pads 8 of the MCM wiring board 5.

Therefore, unlike the case where the Au bumps 3 are reflowed and bonded by heat treatment, the semiconductor chip 4 has a thermal expansion coefficient of 3 × 10 ^-6 [K ^-1 ] and the MCM wiring board 5 has a thermal expansion coefficient of Even when the consistency between 7 × 10 ^-6 [K ^-1 ] and both is not ensured, the semiconductor chip 4 during operation is not required.
When the heat is generated, the positional relationship between the Au bump 3 and the electrode pad 8 is slightly shifted, and the electrical connection between the two is reliably maintained.

Therefore, no thermal strain is generated in the Au bump 3, there is no possibility that the connection portion is damaged by thermal fatigue, and there is no problem in matching the thermal expansion coefficient between the semiconductor chip 4 and the MCM wiring board 5. The semiconductor chip 4 can be mounted by the flip chip method.

Further, the Au bumps 3 and M of the semiconductor chip 4
Since both of the electrode pads 8 of the CM wiring board 5 are made of Au, a good contact state with low electric resistance can be obtained.

(Embodiment 2) FIG. 4 is a front view showing a semiconductor integrated circuit device according to another embodiment of the present invention, FIG. 5 is a sectional view of a principal part of the semiconductor integrated circuit device, and FIG. FIG. 3 is a cross-sectional view illustrating a connection state between a semiconductor chip of a circuit device and a wiring board.

In the semiconductor integrated circuit device 21 of the present embodiment, as shown in FIG. 4, a radiation fin 35 is provided on the outer surface of a pressing member 31 for pressing the semiconductor chip 4 toward the MCM wiring board (wiring board) 25 side. The heat radiation fins 35 dissipate the heat of the semiconductor chip 4.

Further, as shown in FIG.
A resin film 36 is adhered to the inner surface of the electrode pad 1, and as shown in FIG. 6, the formed electrode pad 28 has a concave curved surface. Further, the MCM wiring board 25 is made of, for example, a glass epoxy resin having a thermal expansion coefficient of 15 × 10 ⁻⁶ [K ⁻¹ ].

In this embodiment and the following, the same reference numerals are given to the same components as those in the above embodiment.

In the semiconductor integrated circuit device of the present embodiment, since the radiation fins 35 are provided on the outer surface of the pressing member 31 while maintaining the features of the semiconductor integrated circuit device of the first embodiment, the semiconductor chip The heat from 4 is not limited to the path from the Au bump 3 to the MCM wiring board 25,
The heat is also radiated from the heat radiation fins 35. Therefore, the heat dissipation efficiency is improved, and the displacement between the Au bump 3 and the electrode pad 28 during operation can be minimized.

Further, since the resin film 36 is adhered to the inner surface of the pressing member 31, the displacement of the Au bump (bump) 3 of the semiconductor chip 4 with respect to the electrode pad 28 of the MCM wiring board 25 is controlled by the elastic deformation of the resin film 36. Can be prevented.

Further, since the electrode pad 28 has a concavely curved surface shape, even if a glass epoxy resin having a large thermal expansion coefficient is used for the MCM wiring board 25, the position difference between the Au bump 3 and the electrode pad 28 is caused. It is possible to reliably eliminate the possibility of conduction failure and improve reliability.

(Embodiment 3) FIG. 7 is a sectional view of a principal part showing a semiconductor integrated circuit device according to still another embodiment of the present invention.
FIG. 2 is a sectional view showing a connection state between a semiconductor chip and a wiring board of the semiconductor integrated circuit device.

In the semiconductor integrated circuit device 41 of this embodiment, the Au pumps (bumps) 3 of the semiconductor chip 4 are eutectic solder (brazing material) 57 and the electrode pads of the MCM wiring board (wiring board) 25 at the time of assembly. 28, and then the semiconductor chip 4 is pressed against the MCM wiring board 25 by a pressing member 51 and fixed.

The semiconductor integrated circuit device 41 of the present embodiment
5, a concave fixing groove 58 is formed on the inner surface of the pressing member 51, and the semiconductor chip 4 is mounted on the MCM wiring board 25 in a state fitted in the fixing groove 58.

In the semiconductor integrated circuit device of the present embodiment, in addition to the features of the semiconductor integrated circuit device of the first embodiment, the Au bump 3 is temporarily bonded to the electrode pad 28 by the eutectic solder 57 and then fixed. , A in alignment
The positional relationship between the u bump 3 and the electrode pad 28 is reliably maintained.

Further, since the concave fixing groove 58 is formed on the inner surface of the pressing member 51, the displacement of the Au bump 3 with respect to the electrode pad 28 can be reliably prevented as in the case of the second embodiment. it can.

(Embodiment 4) FIG. 9 is a sectional view showing a main part of a semiconductor integrated circuit device according to still another embodiment of the present invention.

In the semiconductor integrated circuit device 61 of this embodiment,
The through electrode 63 formed on the polyimide film 62 has A
The polyimide film 62 is provided between the semiconductor chip 4 and the MCM wiring board (wiring board) 5 and is pressed by the pressing member 11 so that the chip electrode and the electrode pad are electrically connected via the through electrode 63. Are connected together.

As described above, the semiconductor chip 4 is connected to the pressing member 1.
According to 1, according to the semiconductor integrated circuit device 61 to be mounted on the MCM wiring substrate 5, it is not necessary to reflow and bond the bumps, so that it is possible to use the polyimide film 62 on which the through electrodes 63 are formed.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various changes can be made without departing from the gist of the invention. Needless to say.

For example, the pressing members 11, 31, and 51 for mounting the semiconductor chip 4 on the MCM wiring boards 5 and 25 in the above embodiment are given a pressing force by the bolts 12 and the nuts 13 and the coil springs 14. However, besides, a structure in which the outer peripheral portions of the pressing members 11, 31, 51 and the MCM wiring boards 5, 25 are sandwiched may be adopted. That is, in the present invention, the semiconductor chip 4 is connected to the pressing members 11, 31, 5 regardless of the pressing means.
1 only needs to be pressed against the MCM wiring boards 5 and 25.

In the above embodiment, both the bumps 3 and the electrode pads 8 and 28 are made of Au. However, the bumps 3 and the electrode pads 8 and 28 may be made of Pb-Sn or the like as usual. One of them can be made of Au.

Further, the MCM wiring board 5,
Reference numeral 25 denotes an alumina ceramic and a glass epoxy resin. However, the present invention is not limited to this, and various other types can be used. Those having a coefficient of thermal expansion that is compatible with the semiconductor chip 4 may be used. .

[0047]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1) According to the semiconductor integrated circuit device of the present invention, when the semiconductor chip is pressed by the pressing member, the chip electrodes formed on the semiconductor chip are electrically connected to the electrode pads of the wiring board. This is a mounting structure by a connected flip chip method. Therefore, unlike the case where the bumps are reflowed by heat treatment and bonded, even when the thermal expansion coefficients of the semiconductor chip and the wiring board are not consistent, when the semiconductor chip generates heat during operation, the bumps and the electrode pads are not connected. Only slightly deviates from each other, and the electrical connection between the two is reliably maintained. Therefore, no thermal distortion occurs in the bumps, and there is no possibility of thermal fatigue destruction of the connection portion. Therefore, the semiconductor chip is manufactured by the flip chip method without making the thermal expansion coefficient match between the semiconductor chip and the wiring board. Can be mounted.

(2) Since the semiconductor chip can be easily replaced by removing the pressing member, replacement of a defective semiconductor chip can be easily performed.

(3) According to the semiconductor integrated circuit device in which the bumps and the electrode pads are made of Au, a good contact state with small electric resistance can be obtained, and the operation can be speeded up and stabilized.

(4) According to the semiconductor integrated circuit device in which the electrode pads of the wiring board have a concave curved surface, even if glass epoxy resin or the like having a large coefficient of thermal expansion is used for the wiring board, the bumps and the electrode pads are not formed. In this case, it is possible to reliably eliminate the possibility of conduction failure due to misalignment, and to improve reliability.

(5) According to the semiconductor integrated circuit device in which the radiation fins are provided on the outer surface of the pressing member, the heat from the semiconductor chip is also radiated from the radiation fins, so that the heat radiation efficiency is improved. In addition, the displacement between the bumps and the electrode pads during operation can be minimized.

(6) According to the semiconductor integrated circuit device in which the resin film is adhered to the inner surface of the pressing member, the displacement of the bump of the semiconductor chip with respect to the electrode pad of the wiring board can be prevented by the elastic deformation of the resin film. It is possible to stabilize the mounting of the semiconductor chip.

(7) According to the semiconductor integrated circuit device in which the concave fixing groove is formed on the inner surface of the pressing member, the semiconductor chip is fitted into the fixing groove and mounted on the wiring board. The displacement of the bump with respect to the pad can be prevented.

(8) According to the method of assembling a semiconductor integrated circuit device, in which the semiconductor chip pump is temporarily joined to the electrode pads of the wiring board with a brazing material, and then the semiconductor chip is pressed against the wiring board with a pressing member and fixed. In addition, the positional relationship between the bumps and the electrode pads in the alignment is reliably maintained, and the reliability of the device can be improved.

[Brief description of the drawings]

FIG. 1 is a front view showing a semiconductor integrated circuit device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part of the semiconductor integrated circuit device.

FIG. 3 is a sectional view showing a connection state between a semiconductor chip and a wiring board of the semiconductor integrated circuit device.

FIG. 4 is a front view showing a semiconductor integrated circuit device according to a second embodiment of the present invention.

FIG. 5 is a sectional view of a principal part of the semiconductor integrated circuit device.

FIG. 6 is a sectional view showing a connection state between a semiconductor chip and a wiring board of the semiconductor integrated circuit device.

FIG. 7 is a fragmentary cross-sectional view showing a semiconductor integrated circuit device according to Embodiment 3 of the present invention.

FIG. 8 is a sectional view showing a connection state between a semiconductor chip and a wiring board of the semiconductor integrated circuit device.

FIG. 9 is a fragmentary cross-sectional view showing a semiconductor integrated circuit device according to Embodiment 4 of the present invention.

[Explanation of symbols]

 Reference Signs List 1 semiconductor integrated circuit device 2 chip electrode 3 Au bump (bump) 4 semiconductor chip 5 MCM wiring board (wiring board) 6 insulating film 7 electrode base 8 electrode pad 9 connection hole 10 wiring layer 11 pressing member 12 bolt 13 nut 14 coil spring Reference Signs List 21 semiconductor integrated circuit device 25 MCM wiring substrate (wiring substrate) 28 electrode pad 31 pressing member 35 radiation fin 36 resin film 41 semiconductor integrated circuit device 51 pressing member 57 eutectic solder (brazing material) 58 fixing groove 61 semiconductor integrated circuit device 62 Polyimide film 63 Through electrode

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-255176 (JP, A) JP-A-59-184553 (JP, A) JP-A-3-27552 (JP, A) Jpn. 163945 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 25/40 H01L 21/60 H01L 23/32 H01R 33/76

Claims (3)

(57) [Claims] 1. A wiring board on which electrode pads are arranged in accordance with the electrode arrangement of a semiconductor chip to be mounted, and one or the heights mounted on the wiring board in a flip-chip manner via bumps. A plurality of semiconductor chips, a plate-shaped pressing member that contacts the entire back surface of the semiconductor chip, sandwiches the semiconductor chip between the wiring substrate, and presses the semiconductor chip at a predetermined pressure; The surface shape of the electrode pad on the wiring substrate is a concave curved surface
The semiconductor chip is pressed against the wiring board by the pressing member, so that the electrodes of the semiconductor chip and the electrode pads formed on the wiring board can be displaced in the lateral direction while the semiconductor chip is pressed. A semiconductor integrated circuit device electrically connected through bumps. 2. The semiconductor integrated circuit device according to claim 1, wherein at least one of said bump and said electrode pad is made of Au. 3. One or a plurality of semiconductor chips having the same height are mounted on an electrode pad having a concave curved surface on a wiring board in a flip-chip manner via bumps, and a plate-shaped pressing is performed. The member is brought into contact with the entire back surface of the semiconductor chip, the semiconductor chip is sandwiched between the semiconductor chip and the wiring substrate, and the semiconductor chip is pressed against the wiring substrate with a predetermined pressure by the pressing member. Electrically connecting the electrode pads to the electrode pads on the wiring board via the bumps while allowing the electrodes to be displaced in the lateral direction.