JP2004193147A - Semiconductor chip, method of mounting it on mounting member, and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor chip which is capable of bringing electrodes uniformly into mechanical contact with each other when a semiconductor chip is mounted in a flip chip mounting manner through a pressure contact system, such as a heated pressure contact system or the like, to provide a method of mounting the same, and a semiconductor device. <P>SOLUTION: When the semiconductor chip equipped with electrodes that are laid out on its peripheral area is connected to a mounting member, such as a printed wiring board or the like, through a pressure contact system, the electrodes located at the one side of the semiconductor chip are set equal in total contact area to ones located at the opposed side. This method is effective when the semiconductor chip is mounted in flip chip mounting. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor chip, a mounting method thereof, and a semiconductor device, and more particularly to electrode connection in flip chip mounting of a semiconductor bare chip (hereinafter, referred to as a semiconductor chip).
[0002]
[Prior art]
As a method of connecting a semiconductor chip to a mounting member such as a printed wiring board or a lead frame, an anisotropic conductive film or an insulating paste is sandwiched between an electrode of the semiconductor chip and a wiring electrode of the mounting member, and thermocompression bonding is performed. A flip chip mounting method is generally known.
[0003]
In this mounting method, when using an anisotropic conductive film, the electrodes of a mounting member such as a chip and a printed wiring board are mechanically contacted with conductive particles sandwiched between the electrodes, and an insulating paste is used. Is conducted only by a mechanical contact. A mounting mechanism in which an insulating resin designed by a thermosetting resin normally plays a role in insulating and holding the adjacent electrodes and bonding the chip to the mounting member is used. (For example, see Non-Patent Document 1)
[0004]
Here, in the case of an anisotropic conductive film, the conductive particles sandwiched between the electrodes play a role of absorbing variations in the height of the electrode to be connected. To absorb variations in electrode height.
[0005]
In addition, in the case where the space between the electrodes becomes narrower, an insulating coating is formed on the conductive particles in order to maintain the insulation between the adjacent electrodes, and only the particles sandwiched between the electrodes during thermocompression bonding. In addition, there has been proposed a device in which an insulating film is broken to conduct electricity. (For example, see Patent Document 1)
At present, this mounting method is used as a standard method in a semiconductor device for driving a liquid crystal, which requires a multi-terminal, narrow-pitch connection. (For example, see Non-Patent Document 2)
[0006]
As shown in FIG. 7, the cross-section after flip-chip mounting using the conventional anisotropic conductive film is such that the chip electrode 3 of the semiconductor chip 1 and the substrate electrode 4 of the printed wiring board 2 are anisotropic conductive resin. Electrically conductive state is formed by mechanically contacting via conductive particles 5 in 6.
[0007]
On the other hand, in the case of the insulating paste, a state is established in which electrical conduction is achieved only by mechanical contact between electrodes without intervening conductive particles.
[0008]
[Patent Document 1]
JP-A-63-237372 (Japanese Patent No. 2546262) (p. 7, FIG. 1, FIG. 5)
[Non-patent document 1]
Electronics Packaging Technology (Journal of the Technical Research Council), July 1997, pp. 46-51 [Non-Patent Document 2]
Electronics Packaging Technology (Journal of the Technical Research Council), December 2000, 55-56 pages
[Problems to be solved by the invention]
By the way, in recent years, the pitch of the electrodes of a semiconductor chip has been narrowed and miniaturized, and the electrode wiring of a mounting member such as a printed wiring board also tends to be miniaturized.
In addition, the number of electrode terminals tends to increase due to an increase in the number of I / Os associated with an improvement in the function of the semiconductor chip.
The electrodes of the semiconductor chip are generally arranged at the periphery of the semiconductor chip, that is, in a so-called peripheral (peripheral side) arrangement. However, with the miniaturization of the electrodes and the increase in the number of terminals, it is necessary to make the electrode shape uniform. It tends to be difficult. Naturally, the number of electrodes arranged on each side is not necessarily equal.
[0010]
As described above, a semiconductor chip in which the electrode shape is not uniform, the number of electrodes is also uneven on each side, and a printed wiring board in which the board wiring electrodes are set to the same wiring width and length as the same rule for all terminals, Consider a case in which thermocompression bonding flip chip mounting is performed using an anisotropic conductive film or an insulating paste.
[0011]
After the electrodes are first aligned, heating and pressurization are performed from the back surface of the semiconductor chip. At this time, the electrodes come close to each other, and at the same time, the resin thermally flows and then hardens, whereby the mounting is established.
[0012]
However, at the time of this heat flow, the crimping load is applied only to the electrode portion, and if the electrode connection area, that is, the sum of the contact areas is different on each side, the crimping is performed using a flat metal or ceramic material. Since the load is uniformly applied on each side by the tool, pressure imbalance will occur.
[0013]
That is, the electrode on the side with the smaller total contact area is largely crushed, and the electrode on the side with the larger total contact area is hardly crushed.
[0014]
After that, the surrounding resin is cured, so that the entire semiconductor chip receives a compression load.However, since the difference in electrode collapse occurs, the chip itself is also inclined, and connection failure is likely to occur. Is also expected to affect the reliability of
[0015]
The present invention has been made in view of the above-described circumstances, and in a case where a semiconductor chip is flip-chip mounted using a compression bonding method such as a thermocompression bonding method, it is possible to equalize mechanical contacts between electrodes. An object of the present invention is to provide a semiconductor chip, a mounting method thereof, and a semiconductor device.
[0016]
[Means for Solving the Problems]
Therefore, the electrode connection method of the present invention, when connecting the semiconductor chip on which the electrodes are arranged peripherally, and a mounting member such as a printed wiring board by a crimping method, when the total contact area on each side is opposite to the side, I try to be equal. This method is particularly effective when performing flip chip mounting.
[0017]
According to such a configuration, the pressure applied only to the electrodes immediately after the start of thermocompression bonding is uniformly applied on the opposing sides, so that there is no difference in the collapse of the electrodes and a uniform mechanical contact state can be obtained.
[0018]
That is, the semiconductor chip of the present invention has electrodes formed on the outer surface of the semiconductor substrate and formed to have substantially the same height from the back surface of the semiconductor substrate, and opposing sides of the semiconductor substrate. The electrodes are formed so that the total area of the electrodes on the side is equal to each other.
[0019]
According to such a configuration, even when mounted on a mounting member having connection terminals formed on a flat surface, the total area of the contact portions on the opposite sides is equal to each other. Also in this case, since the pressure applied only to the electrodes immediately after the start of thermocompression bonding is uniformly applied to the opposing sides, there is no difference in the collapse of the electrodes, and uniform connection can be achieved.
[0020]
Further, in such a semiconductor chip, it is more desirable that the electrodes are arranged in a peripheral manner.
[0021]
In addition, since the contact area of the electrode can be easily adjusted, it is desirable to include at least one dummy electrode that is not electrically connected to the internal circuit.
[0022]
The mounting method of the present invention is a mounting method in which a semiconductor chip is mounted on a mounting member by a crimping method and is electrically connected, wherein a total contact area between an electrode of the semiconductor chip and the mounting member is opposite to each side. , So as to be equal.
[0023]
Also, by including at least one dummy electrode that is not electrically connected to the internal circuit, the contact area can be easily adjusted.
[0024]
In addition, it is desirable that a semiconductor chip having electrodes arranged in a peripheral manner be flip-chip mounted on a printed circuit board by a thermocompression bonding method.
[0025]
Further, the semiconductor chip has electrodes formed on an outer surface of the semiconductor substrate so that the height from the back surface of the semiconductor substrate is substantially the same, and a side of the semiconductor chip facing the opposite side. It is preferable that the electrodes have a total area equal to each other.
[0026]
Further, the electrode includes at least one dummy electrode that is not electrically connected to an internal circuit.
[0027]
Desirably, if the printed wiring electrode width of the electrode connecting portion is adjusted so that the total contact area with the electrode of the semiconductor chip is equal on each side facing each other, the electrode can be easily applied to the electrode immediately after thermocompression bonding. If such pressure is made uniform on each of the opposing sides, there is no difference in electrode crushing, and a uniform mechanical contact state can be formed.
[0028]
Also, even if the length of the printed wiring electrode of the electrode connecting portion is adjusted so that the total contact area with the electrode of the semiconductor chip is equal on the sides facing each other, similarly, immediately after thermocompression bonding, If the pressure applied to the electrode is made uniform on each of the opposing sides, there is no difference in the collapse of the electrode, and a uniform mechanical contact state can be formed.
[0029]
In addition, by adding a dummy electrode in an electrically floating state to the printed circuit board, the total contact area with the electrode of the semiconductor chip can be easily adjusted to be equal on opposite sides, It is possible to form a uniform mechanical contact state.
[0030]
Furthermore, a semiconductor device in which a semiconductor chip having electrodes disposed on a surface thereof is mounted on a printed circuit board by a flip chip method, wherein a total contact area ratio between the electrode and a wiring electrode on the printed circuit board is relatively high. It is characterized in that they are configured to be equal on opposite sides.
[0031]
According to this configuration, the pressure applied only to the electrodes immediately after the start of thermocompression bonding is uniformly applied to the opposing sides, so that there is no difference in the collapse of the electrodes and a uniform mechanical contact state can be obtained.
[0032]
Further, the semiconductor device of the present invention is a semiconductor device in which a semiconductor chip having electrodes disposed on its surface is mounted on a printed circuit board by a flip-chip method. It is characterized by being configured to be within 5 times.
From the experimental results, it was found that when the difference in the crushing amount was within 2 μm, the connection resistance value on the opposite side was stabilized. It has been found that this can be achieved by setting the connection area ratio within 1.5. By setting to such a value, the pressure applied only to the electrode immediately after the start of the thermocompression bonding is applied substantially uniformly on the side opposite to each other, so that the difference in the collapse of the electrode is reduced, and a substantially uniform mechanical contact state can be obtained. it can.
[0033]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same members as those in the prior art shown in FIG. 2 are denoted by the same reference numerals, and detailed description is omitted.
[0034]
(First Embodiment)
FIGS. 1A to 1C are views showing a semiconductor chip according to a first embodiment of the present invention. FIG. 1A is a top view showing an electrode pad arrangement of a semiconductor chip of the present invention, and FIGS. 1B and 1C are AA sectional view and BB sectional view of FIG. 1A. It is.
[0035]
The semiconductor chip of the present embodiment is formed on the outer surface of the semiconductor substrate 1, and the electrode 3 formed so that the height from the back surface of the semiconductor substrate is substantially the same, is electrically connected to the internal circuit. It is characterized in that an unconnected dummy electrode 3d is added.
[0036]
Thereby, as is clear from the comparison between FIGS. 1B and 1C, the contact portion between the electrode 3 of the semiconductor chip and the wiring electrode 4 of the printed circuit board 2 on the opposite side of the semiconductor substrate. Even when connecting by crimping method such as thermocompression bonding, the pressure applied only to the electrode immediately after the start of thermocompression is equal on the opposing sides and applied uniformly, so there is no difference in electrode collapse , Uniform connection can be achieved.
[0037]
FIGS. 2A to 2C show semiconductor devices formed by mounting the semiconductor chip 1 thus formed on the printed circuit board 2 on which the wiring electrodes 4 are formed by flip-chip. FIG. 2A is a top view showing an electrode pad arrangement of the semiconductor chip of the present invention, and FIGS. 2B and 2C are AA sectional view and BB sectional view of FIG. 2A. It is. FIG. 2A omits the printed circuit board 2 and shows only the wiring electrodes 4 of the printed circuit board.
[0038]
As is clear from this figure, since the total contact area of the electrode 3 of the semiconductor chip 1 and the connection portion that comes into contact with the wiring electrode 4 of the printed board 2 is configured to be equal on opposite sides, As described above, the pressure applied only to the electrode immediately after the start of thermocompression opposes even when connection is performed by a crimping method such as thermocompression bonding via the adhesive containing the conductive particles 5 in the adhesive resin 6. Since the edges are uniformly applied, there is no difference in the collapse of the electrodes, and uniform connection can be achieved.
[0039]
Here, one connection portion on the lower side is denoted by 7, and one connection portion on the upper side is denoted by 8.
[0040]
Further, in such a semiconductor chip, it is more desirable that the electrodes are arranged in a peripheral manner.
[0041]
Further, a dummy electrode 3d is formed on the side of the semiconductor chip 1 where the electrode 3 is small, so that the contact area can be easily adjusted.
[0042]
In this way, as shown in FIG. 1A, in the connection portion between the electrode 3 of the semiconductor chip 1 and the substrate electrode 4, the area of one connection portion 7 on the lower side and one connection portion 8 on the upper side are reduced. Since they were equal and the number of electrodes was equal, the design was such that the total contact area on the upper side and the lower side was equal. In this case, it is necessary to equalize the upper and lower electrode areas and the left and right electrode areas including the dummy electrodes in the design stage of the semiconductor electrode. Accordingly, when the flip chip mounting is performed by the thermocompression bonding method, pressure is evenly applied to the electrode connection portions on opposing sides, so that a uniform mechanical contact is established.
[0043]
(Second embodiment)
FIG. 3 is a diagram illustrating a semiconductor chip according to a second embodiment of the present invention. FIG. 3 shows a diagram in which only the wiring electrodes 4 of the printed board are arranged (the printed board 2 is omitted). FIG. 3 shows a case where the number of electrode pads on the upper side is smaller than the number of electrode pads on the lower side electrode, and the size of the semiconductor chip electrode 3 on the upper side is increased in the y direction, so that the area of the connection portion 8 on the upper side is increased. Are designed so that the total contact area on the upper side and the lower side is equal.
[0044]
That is, in the present embodiment, the length l of the electrode pads of the semiconductor chip 1 located at the electrode connection portions 7 and 8 with the wiring electrodes 4 of the printed circuit board 2 is determined by the relative total contact area with the electrodes of the semiconductor chip 1. It is characterized in that it is increased so as to be equal on the side of the opposite side.
[0045]
According to such a configuration, on the upper side where the number of the electrodes 3 is small, the length l of the electrode pad is increased so that the contact area is substantially the same. In this way, the pressure applied to the electrode immediately after the thermocompression bonding can be easily made uniform on the opposing sides, so that there is no difference in electrode collapse and a uniform mechanical contact state can be formed. Become.
[0046]
(Third embodiment)
FIG. 4 is a diagram illustrating a semiconductor chip according to a third embodiment of the present invention. FIG. 4 shows a diagram in which only the wiring electrodes 4 of the printed board are arranged (the printed board 2 is omitted). FIG. 4 shows a case in which the number of electrode pads on the upper side is smaller than the number of electrode pads on the lower side electrode. By increasing the size of the semiconductor chip electrode 3 on the upper side in the x direction, the electrode connection portion 8 on the upper side is formed. The design is such that the area is large and the total contact area on the upper side and the lower side is equal.
[0047]
That is, FIG. 4 shows a case where the number of electrodes on the upper side is smaller than the number of electrodes on the lower side, and the width W1 of the substrate electrode 4 on the upper side is increased and the width W2 of the substrate electrode 4 on the lower side is reduced. The design is such that the area of the contact connection portion 8 on the upper side becomes larger, the area of the contact connection portion 7 on the lower side becomes smaller, and the total connection area of the upper side and the lower side becomes equal.
[0048]
(Fourth embodiment)
FIG. 5 is a diagram illustrating a semiconductor device according to a fourth embodiment of the present invention. This example is characterized in that the adjustment is made with the wiring electrodes on the printed circuit board. FIG. 5 shows a diagram in which only the wiring electrodes 4 of the printed board are arranged (the printed board 2 is omitted). FIG. 5 shows a case where the number of electrodes on the upper side of the semiconductor chip 1 is smaller than the number of electrodes on the lower side, and the contact area between each electrode 3 on the lower side of the semiconductor chip and each wiring electrode 4 of the printed circuit board 2 is small. Thus, the position of each wiring electrode 4 on the printed circuit board 2 is shifted outward.
[0049]
According to such a configuration, the position of each wiring electrode 4 on the lower side of the printed board 2 is shifted to reduce the total contact area on the lower side, and the total contact area on the upper side and the lower side is designed to be equal. I have.
[0050]
(Fifth embodiment)
FIG. 6 is a diagram illustrating a semiconductor device according to a fifth embodiment of the present invention. This example is characterized in that the adjustment is made with the wiring electrodes on the printed circuit board. FIG. 6 shows a diagram in which only the wiring electrodes 4 of the printed circuit board are arranged (the printed circuit board 2 is omitted). FIG. 6 shows a case where the number of electrodes on the upper side of the semiconductor chip 1 is also smaller than the number of electrodes on the lower side, and the printed circuit board in the lower side electrode 3 at a position corresponding to the dummy electrode 3d which is not originally involved in conduction. By not providing the two wiring electrodes 4, the total contact area on the lower side is reduced, and the total contact area on the upper side and the lower side is designed to be equal.
[0051]
That is, in this example, as shown in FIG. 6, when the number of electrodes on the upper side is smaller than the number of electrodes on the lower side, the lower electrode 3 has a relative position to the dummy electrode 3d originally not involved in conduction. By not providing the wiring electrodes 4 to be formed, the total contact area on the lower side is reduced, and the total contact area on the upper side and the lower side is designed to be equal. Thereby, when the flip chip mounting is performed by the thermocompression bonding method, pressure is evenly applied to the electrode connecting portion on the opposite side, so that a uniform mechanical contact is established.
[0052]
When the number of electrodes and the electrode connection area on the upper side and the lower side are extremely different, for example, in a liquid crystal driving semiconductor chip having a small input signal and a large output signal, the first and the second are changed due to a semiconductor design change. It is sufficient to work on the embodiment.
In the mounting stage, the connection area ratio between the upper side and the lower side is designed to be 1.5 times or less by working on the third to fifth embodiments for the substrate wiring. Thereby, when the flip chip mounting is performed by the thermocompression bonding method, the pressure is almost uniformly applied to the electrode connecting portion on the opposite side, so that a substantially uniform mechanical contact is established.
This numerical range has been obtained from the results of various experiments. The connection state was observed while changing the relationship between the connection area ratio and the difference between the crushing amounts. The result is shown in FIG. Here, the vertical axis indicates the amount of crush, and the horizontal axis indicates the connection area ratio. From this result, it was found that when the difference in the crushing amount was within 2 μm, the connection resistance value on the opposite side was stabilized. It has been found that this can be achieved by setting the connection area ratio within 1.5. With this setting, the pressure applied only to the electrode immediately after the start of the thermocompression bonding is applied almost uniformly on the opposing sides, so that the difference in electrode crushing is reduced, and a substantially uniform mechanical contact state can be obtained. it can.
[0053]
Further, in the above embodiment, the mounting of the semiconductor chip on the printed circuit board has been described, but it goes without saying that the present invention is also effective for mounting on a film carrier or a lead frame.
[0054]
Further, in the above-described embodiment, the case of mounting by a thermocompression bonding method has been described.However, the present invention is not limited to this. For example, a case of mounting using a photocurable resin, a case of mounting using a thermoplastic resin, and the like. This is also applicable in the case where a crimping step is included.
[0055]
【The invention's effect】
As described above, according to the present invention, in the flip-chip mounting of the thermocompression bonding method, the electrode connection and the mechanical contact between the semiconductor bare chip and the printed wiring board are opposed to each other, such as the upper side / lower side, the left side / right side. Since the sides are uniform, it is possible to provide a mounting state with high electrical connection reliability.
[Brief description of the drawings]
FIG. 1A is a top view of a semiconductor chip according to a first embodiment of the present invention, FIG. 1B is a cross-sectional view taken along line AA of FIG. 1A, and FIG. 1) is a sectional view taken along line BB of FIG.
FIG. 2A is a top view of a semiconductor device mounted using the semiconductor chip according to the first embodiment of the present invention, and FIG. 2B is an AA of FIG. 2A; FIG. 2C is a cross-sectional view of FIG. 1A along the line BB. In FIG. 2A, the printed circuit board is omitted.
FIG. 3 is a diagram showing a second embodiment of the present invention.
FIG. 4 is a diagram showing a third embodiment of the present invention.
FIG. 5 is a diagram showing a fourth embodiment of the present invention.
FIG. 6 is a diagram showing a fifth embodiment of the present invention.
FIG. 7 is a cross-sectional view of flip-chip mounting using a conventional anisotropic conductive film.
FIG. 8 is a diagram showing a result of measuring a connection area ratio and a crush amount in a case of flip-chip mounting using an anisotropic conductive film.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Semiconductor chip 2 Printed circuit board 3 Chip electrode 4 Wiring electrode 5 Conductive particles 6 Resin of anisotropic conductive film 7 Lower electrode connection part 8 Upper electrode connection part 3d Dummy electrode

Claims (12)

An electrode formed on the outer surface of the semiconductor substrate so that the height from the back surface of the semiconductor substrate is substantially the same, and the total area of the electrodes on opposite sides of the semiconductor substrate is equal to each other. A semiconductor chip characterized by being formed on a semiconductor chip. The semiconductor chip according to claim 1, wherein the semiconductor chip has the electrodes arranged in a peripheral configuration. The semiconductor chip according to claim 1, wherein the electrode includes at least one dummy electrode that is not electrically connected to an internal circuit. In a mounting method in which a semiconductor chip is mounted on a mounting member by a crimping method and electrically connected,
A method of mounting a semiconductor chip, wherein a total contact area between an electrode of the semiconductor chip and the mounting member is equal on opposite sides of the semiconductor chip. The method according to claim 4, wherein the mounting method includes a method of flip-chip mounting the semiconductor chip on which the electrodes are peripherally arranged on a printed circuit board using a thermocompression bonding method. . The semiconductor chip has an electrode formed on the outer surface of the semiconductor substrate and formed so that the height from the back surface of the semiconductor substrate is substantially the same, and the electrode on the opposite side of the semiconductor chip. 5. The method of mounting a semiconductor chip according to claim 4, wherein a total area of the semiconductor chips is equal to each other. 7. The semiconductor chip mounting method according to claim 4, wherein the electrodes include at least one dummy electrode that is not electrically connected to an internal circuit. 5. The printed circuit board according to claim 4, wherein the printed wiring electrode width of the electrode connection portion is adjusted so that the total contact area of the electrode with the electrode of the semiconductor chip is equal on the sides facing each other. The mounting method of the semiconductor chip described in 1. The printed circuit board, wherein the length of the printed wiring electrode of the electrode connection portion is adjusted so that the total contact area of the electrode of the semiconductor chip with the electrode of the semiconductor chip is equal on opposite sides. 5. The mounting method of the semiconductor chip according to 4. The printed circuit board is provided with a dummy electrode in an electrically floating state, so that the total contact area with the electrode of the semiconductor chip is adjusted to be equal on opposite sides. The method of mounting a semiconductor chip according to claim 4. A semiconductor device in which a semiconductor chip having electrodes disposed on its surface is mounted on a printed circuit board by a flip chip method,
A semiconductor device, wherein a total contact area ratio between the electrode and a wiring electrode on the printed board is equal on opposite sides. A semiconductor device in which a semiconductor chip having electrodes disposed on a surface thereof is mounted on a printed circuit board side by a flip chip method,
A semiconductor device characterized in that the total electrode connection area ratio is 1.5 times or less on each side.

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