JP2930186B2 - Semiconductor device mounting method and semiconductor device mounted body - 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 method for mounting a semiconductor device and a mounted body thereof.

[0002]

2. Description of the Related Art Conventionally, when a semiconductor device is mounted on a circuit board, a soldering method is generally used. However, in recent years, with the miniaturization of the package of the semiconductor device and the increase in the number of connection terminals, the interval between the connection terminals has been narrowed, and it has become increasingly difficult to cope with the conventional soldering technology.

[0003] Therefore, recently, a method has been devised in which a bare semiconductor device is directly mounted on a circuit board so as to reduce the mounting area and use it efficiently.
The following is an example.

According to the method, first, when a semiconductor device is electrically connected to a circuit board, a deposition film of an adhesion metal or a diffusion preventing metal is previously formed on a terminal electrode of the semiconductor device, and a solder layer formed by plating is used. Are laminated. Then, the semiconductor device having the above-described electrode structure is face-down on a circuit board, heated to a high temperature, and the solder on the terminal electrodes of the semiconductor device is fused to the connection electrodes of the circuit board.

[0005] According to this method, the connection can be performed collectively, and the mounting structure by this method has a feature that the mechanical strength after the connection is strong. Therefore,
This method is considered to be an effective method.

Further, US Pat. No. 5,121,190 discloses a semiconductor device package in which a resin is sealed between a semiconductor device and a circuit board in order to ensure the stability of a joint portion formed by soldering. I have.

Hereinafter, a conventional method for mounting a semiconductor device and its mounting body will be described. FIG. 5 is a cross-sectional view of a main part of a semiconductor device package according to the related art. In FIG.
1 is a semiconductor device, 2 is a terminal electrode of the semiconductor device 1, 4 is a circuit board, 5 is a connection electrode, 13 is a solder joint, 14
Is a sealing resin.

In this conventional technique, first, a semiconductor device 1 having a solder bump formed on a terminal electrode 2 is mounted face-down on a predetermined position of a connection terminal 5 of a circuit board 4. Next, the solder bumps on the terminal electrodes 2 are melted by heating to a high temperature of 200 to 300 ° C. and fused to the connection terminals 5. By doing so, the semiconductor device 1 and the circuit board 4
Are connected by a joint 13 made of solder. afterwards,
Liquid sealing resin 1 is provided in the gap between semiconductor device 1 and circuit board 4.
4 and cured by heating at a temperature of about 150 ° C. Through the above steps, a mounted body in which the semiconductor device 1 is sealed with the sealing resin 14 can be obtained.

[0009]

However, in the above-mentioned conventional package of a semiconductor device, the heat generated between the semiconductor device 1 and the circuit board 4 due to a change in environmental temperature when the package of the semiconductor device is used. A thermal stress is generated due to a difference in expansion coefficient, and the thermal stress is applied to the joint 13 by solder. Further, when the package of the semiconductor device is used in a particularly high-temperature region, a new thermal stress due to thermal expansion also occurs in the sealing resin 14 filled in the gap between the semiconductor device 1 and the circuit board 4, This thermal stress is also applied to the joint 13 by the solder. Therefore, in the conventional mounting body, since all of these thermal stresses are applied to the joint portion 13 made of solder, the reliability of the electrical connection between the semiconductor device 1 and the circuit board 4 deteriorates.

In order to avoid these thermal stresses, the sealing resin 14 having a small coefficient of thermal expansion (more preferably, matching the coefficient of thermal expansion of the joint 13 by soldering) is used.
It is necessary to secure the stability of the joint 13 by soldering. As such a sealing resin 14 (having a small coefficient of thermal expansion), an inorganic filler is added to the sealing resin 14 by about 40%.
~ 75% by weight (more preferably about 50-60% by weight)
It is conceivable that they are contained.

However, when such a sealing resin 14 (having a coefficient of thermal expansion small enough to match the coefficient of thermal expansion of the joint 13 by soldering) is used, a direction perpendicular to the circuit board (hereinafter simply referred to as “vertical”) is used. Although the thermal stress of the joint portion 13 due to the solder acting in the "direction" is solved, the semiconductor device 1 and the circuit board 4 which work in a parallel direction (hereinafter, referred to as "plane direction") along the circuit board. The thermal stress caused by the difference in thermal expansion coefficient cannot be solved. In addition, the use of such a sealing resin 14 further increases the thermal stress in the planar direction.

Such an increase in the thermal stress in the plane direction is caused by a large difference between the thermal expansion coefficients of the joint portion 13 made of solder and the semiconductor device 1 and the circuit board 4. In other words, even if the coefficient of thermal expansion of the sealing resin 14 is matched with the joint 13 of the solder, the coefficient of thermal expansion cannot be matched with the coefficients of thermal expansion of the semiconductor device 1 and the circuit board 4. An increase occurs. Therefore, thermal stress generated due to the difference between the thermal expansion coefficients in the planar direction is applied to the joint 13 by solder, and the reliability of the electrical connection between the semiconductor device 1 and the circuit board 4 is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a highly reliable semiconductor device package and a semiconductor device mounting method for obtaining the same. .

[0014]

According to the present invention, there is provided a method of mounting a semiconductor device on a circuit board face down, wherein the semiconductor device is mounted on the circuit board. A step of filling a liquid resin composition containing a resin and an inorganic filler in a gap between the semiconductor device and the circuit board; and a step of filling the resin in a state where the inorganic filler is located near a member having a small coefficient of thermal expansion. Curing the composition.

By doing so, in the cured resin composition interposed between the semiconductor device and the circuit board, the distribution state of the inorganic filler, that is, the portion where the inorganic filler exists and the portion where the inorganic filler does not exist, Between them, a gradient of the coefficient of thermal expansion occurs. Therefore, depending on how the inorganic filler is distributed, generation of thermal stress due to thermal expansion of the resin composition can be effectively prevented in both the vertical direction and the planar direction.

When the coefficient of thermal expansion of the semiconductor device is larger than the coefficient of thermal expansion of the circuit board, it is preferable that the resin composition is cured while the inorganic filler is located near the circuit board. Here, since the inorganic filler has an effect of improving thermal conductivity, according to the mounting method, heat conduction to the circuit board is improved, and a difference in thermal expansion coefficient between the semiconductor device and the circuit board is reduced. . Therefore, the cured resin composition has a gradient of the thermal expansion coefficient in the vertical direction, and can prevent the occurrence of thermal stress due to the thermal expansion of the resin composition in both the vertical direction and the planar direction. The circuit board can be mounted with high reliability.

Further, when the coefficient of thermal expansion of the semiconductor device is smaller than the coefficient of thermal expansion of the circuit board, it is preferable to cure the resin composition in a state where the inorganic filler is located near the semiconductor device. By doing so, the heat conduction to the semiconductor device is improved, the difference in the coefficient of thermal expansion between the semiconductor device and the circuit board is reduced, and the generation of thermal stress due to the thermal expansion of the resin composition is reduced in both the vertical direction and the planar direction. Can be prevented.

Further, as a method of positioning the inorganic filler, a method of utilizing a specific gravity difference between the resin in the liquid resin composition and the inorganic filler, and a method of positioning the resin in the liquid resin composition, A method utilizing the property of rapidly decreasing the viscosity of the polymer at high temperatures is preferred. Furthermore, as a method of positioning the inorganic filler near the semiconductor device, a method of turning over the circuit board and utilizing a difference in specific gravity between the resin and the inorganic filler is also preferable. Also,
A method in which the positioning of the inorganic filler and the curing of the liquid resin composition are performed in the same step is also preferable.

Further, a method for mounting the semiconductor device on the circuit board using solder bumps, a method for mounting the semiconductor device on the circuit board using a conductive adhesive, and a method for mounting the semiconductor device on a bump electrode It is also preferable to use a method of mounting on the circuit board using a conductive adhesive.

The semiconductor device according to the present invention has a package wherein the semiconductor device is mounted on a circuit board, and a resin composition containing a resin and an inorganic filler is provided in a gap between the semiconductor device and the circuit board. The inorganic filler in the resin composition is located near a member having a small coefficient of thermal expansion. Further, it is preferable to provide the resin composition whose coefficient of thermal expansion changes in a direction perpendicular to the circuit board. Further, when the coefficient of thermal expansion of the semiconductor device is larger than the coefficient of thermal expansion of the circuit board, the inorganic filler in the resin composition is located in the vicinity of the circuit board; and When the coefficient of thermal expansion is smaller than the coefficient of thermal expansion of the circuit board, it is preferable that the inorganic filler in the resin composition is located near the semiconductor device.

With such a configuration, in the vertical direction, the average value of the thermal expansion coefficient of the resin composition in the vertical direction and the thermal expansion coefficient of the connection portion between the semiconductor device and the circuit board in the vertical direction are obtained. The coefficient value can be kept substantially the same, and in the plane direction, the difference in the coefficient of thermal expansion between the semiconductor device side and the circuit board side is reduced by the resin composition whose coefficient of thermal expansion changes in the vertical direction. can do. Therefore, it is possible to effectively prevent the occurrence of thermal stress due to the thermal expansion of the resin composition in both the vertical direction and the planar direction. Even when the semiconductor device and the circuit board have different thermal expansion coefficients, high reliability is obtained. A package of a semiconductor device can be obtained.

Further, the average value of the thermal expansion coefficient of the resin composition in the direction perpendicular to the circuit board and the value of the thermal expansion coefficient of the connection portion between the semiconductor device and the circuit board in the direction perpendicular to the circuit board are substantially equal to each other. It is preferable to provide the resin composition in which the ratio between the resin and the inorganic filler is adjusted so as to match. It is also preferable that a spherical inorganic filler is used as the inorganic filler in the resin composition.

The semiconductor device is mounted on the circuit board using solder bumps, the semiconductor device is mounted on the circuit board using a conductive adhesive, and the semiconductor device is mounted on the circuit board using a conductive adhesive. It is also preferable that the circuit board is mounted on the circuit board using a projecting electrode and a conductive adhesive.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a process chart of a method for mounting a semiconductor device according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a semiconductor device, 2 denotes a terminal electrode, 3 denotes a conductive adhesive, 4 denotes a circuit board, 5 denotes a connection electrode, 6 denotes a joint portion using a conductive adhesive, 7 denotes a liquid resin composition, and 8 denotes a liquid resin composition. Is a resin, 9 is an inorganic filler, and 10 is a cured resin composition. Hereinafter, a method for mounting the semiconductor device according to the first embodiment will be described with reference to the process chart of FIG.

First, as shown in FIG. 1A, a conductive adhesive 3 is formed on the terminal electrodes 2 of the semiconductor device 1 in advance. In this case, the conductive adhesive 3 may be formed directly on the terminal electrode 2 or may be formed on a bump electrode (bump) formed on the terminal electrode 2 in advance.

Next, as shown in FIG. 1B, the semiconductor device 1 is turned face down (downward) and the circuit board 4 is turned down.
The semiconductor device 1 is mounted on the circuit board 4 by positioning the connection electrode 5 on a predetermined position (for example, a glass epoxy substrate). As a result, the terminal electrodes 2 of the semiconductor device 1 and the connection electrodes 5 of the circuit board 4 are electrically connected by the joints 6 made of the conductive adhesive. In this case, the thermal expansion coefficient of the semiconductor device 1 is smaller than the thermal expansion coefficient of the circuit board 4.

Next, as shown in FIG. 1C, a gap between the semiconductor device 1 and the circuit board 4 is filled with a liquid resin composition 7. Then, as shown in FIG. 1D, the liquid resin composition 7 is cured by turning the circuit board 4 upside down and heating at a temperature of about 150 ° C. Then, in the liquid resin composition 7, the cured resin composition in a state where the inorganic filler 9 has settled to the semiconductor device 1 due to the specific gravity difference between the resin 8 (for example, epoxy resin) and the inorganic filler 9 (for example, silica) The object 10 can be obtained.

Through the above steps, a package of the semiconductor device 1 as shown in FIG. 2 can be obtained. The liquid resin composition 7 used at this time contains at least the resin 8 and the inorganic filler 9. The resin composition 7
A resin in which the ratio between the resin 8 and the inorganic filler 9 is adjusted such that the coefficient of thermal expansion of the cured resin composition 10 matches the coefficient of thermal expansion of the joint 6 of the conductive adhesive is used. Can be For this reason, even when the inorganic filler 9 is settled in the cured resin composition 10, the average thermal expansion coefficient of the cured resin composition 10 in the vertical direction is smaller than that of the joint 6 of the conductive adhesive. It matches the coefficient of thermal expansion in the vertical direction.

In the above process, since the inorganic filler 9 is cured with the inorganic filler 9 being moved toward the semiconductor device 1, the cured resin composition 10 has a small thermal expansion coefficient in the plane direction. The resin composition 10 after curing has a gradient of the thermal expansion coefficient in the vertical direction, such as being small on the device 1 side and large on the circuit board 4 side having a large thermal expansion coefficient.

Therefore, even when the semiconductor device 1 is used at a high temperature, the thermal stress in the vertical and planar directions due to the thermal expansion of the cured resin composition 10 existing in the gap between the semiconductor device 1 and the circuit board 4 is reduced. Generation can be prevented. As a result, a mounted body of the semiconductor device 1 with high electrical connection reliability can be obtained.

Further, with the above configuration, even when the liquid resin composition 7 is cured by heating and then returned to room temperature, the thermal stress in the vertical and planar directions due to the heat shrinkage of the cured resin composition 10 can be improved. Can be prevented from occurring. Therefore, the reliability of electrical connection when mounting the semiconductor device 1 on the circuit board 4 is improved.

FIG. 3 shows a semiconductor device package according to a second embodiment of the present invention. In FIG. 3, 1 is a semiconductor device, 2 is a terminal electrode, 4 is a circuit board, 5 is a connection electrode, 6 is a joint made of a conductive adhesive, 10 is a cured resin composition, and 11 is a bump electrode.

The package of the semiconductor device according to the second embodiment has a configuration in which the protruding electrode 11 is provided on the terminal electrode 2 of the semiconductor device 1. Other configurations are substantially the same as those of the first embodiment. Au or the like is used as the material of the bump electrode 11. As shown in the second embodiment, when the terminal electrode 2 is provided with the protruding electrode 11,
In addition to the effects of the first embodiment, the spread of the conductive adhesive when the semiconductor device 1 is mounted on the circuit board 4 can be restricted, and bonding at a fine pitch becomes possible.

FIG. 4 shows a semiconductor device package according to a third embodiment of the present invention. In FIG. 4, 1 is a semiconductor device, 2 is a terminal electrode, 4 is a circuit board, 5 is a connection electrode, 10 is a cured resin composition, and 12 is a joint portion formed by soldering.

The mounting body of the semiconductor device according to the third embodiment has a configuration in which the terminal electrode 2 of the semiconductor device 1 is mounted on the terminal electrode 5 of the circuit board 4 at the joint 12 made of solder. Other configurations are substantially the same as those of the first embodiment.

As shown in the third embodiment, when the semiconductor device 1 is mounted on the circuit board 4 by using the bonding portion 12 made of solder, the semiconductor device 1 has the advantages of the first embodiment. The device 1 can be more firmly mounted on the circuit board 4. Further, in the conventional mounting method using solder, the material of the circuit board is limited to a material close to the coefficient of thermal expansion of the semiconductor device (for example, a ceramic substrate) due to a problem of thermal stress. A circuit board made of a material can be used.

In the first, second and third embodiments described above, it is assumed that the circuit board 4 has a larger coefficient of thermal expansion than the semiconductor device 1. Although the configuration in which the inorganic filler 9 in the resin composition is settled on the semiconductor device 1 side has been described, the present invention is not limited to this. When the coefficient of thermal expansion of the circuit board 4 is smaller than the coefficient of thermal expansion of the semiconductor device 1 (reverse relationship to the present embodiment), the configuration is such that the inorganic filler 9 in the resin composition is settled on the circuit board 4 side. This configuration may be used when curing a liquid resin composition.
It can be easily obtained by curing the circuit board 4 without turning over.

[0038]

According to the method of mounting a semiconductor device according to the present invention, even when a step of changing from a high temperature state to a normal temperature state is performed during the production of a semiconductor device package, heat shrinkage of the resin composition occurs. The generation of thermal stress in the vertical direction and the plane direction can be prevented. Therefore, the semiconductor device can be mounted on the circuit board with high reliability.

Further, according to the semiconductor device package of the present invention, even when the semiconductor device package is used in a high temperature state, the thermal expansion in the vertical direction and the planar direction due to the thermal expansion of the resin composition. Generation of stress can be prevented.
Therefore, the mounted body of the semiconductor device has high reliability.

[Brief description of the drawings]

FIG. 1 is a process chart showing a method for mounting a semiconductor device according to a first embodiment of the present invention;

FIG. 2 is a cross-sectional view of a main part of the mounted body of the semiconductor device according to the first embodiment of the present invention;

FIG. 3 is an essential part cross-sectional view of a semiconductor device package according to a second embodiment of the present invention;

FIG. 4 is an essential part cross-sectional view of a semiconductor device package according to a third embodiment of the present invention;

FIG. 5 is a cross-sectional view of a main part of a semiconductor device package according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor device 2 Terminal electrode 3 Conductive adhesive 4 Circuit board 5 Connection electrode 6 Joining part by conductive adhesive 7 Liquid resin composition 8 Resin 9 Inorganic filler 10 Cured resin composition 11 Protrusion electrodes 12, 13 Solder Joint 14 by sealing resin

Claims (21)

(57) [Claims] 1. A method of mounting a semiconductor device on a circuit board face-down, comprising the steps of: mounting the semiconductor device on the circuit board; and forming a resin in a gap between the semiconductor device and the circuit board. A semiconductor, comprising: a step of filling a liquid resin composition containing a resin and an inorganic filler; and a step of curing the resin composition in a state where the inorganic filler is located near a member having a small coefficient of thermal expansion. How to mount the device. 2. The method according to claim 1, wherein when the coefficient of thermal expansion of the semiconductor device is larger than the coefficient of thermal expansion of the circuit board, the resin composition is cured with the inorganic filler positioned near the circuit board. Semiconductor device mounting method. 3. The method according to claim 1, wherein when the coefficient of thermal expansion of the semiconductor device is smaller than the coefficient of thermal expansion of the circuit board, the resin composition is cured in a state where the inorganic filler is located near the semiconductor device. Semiconductor device mounting method. 4. The method of mounting a semiconductor device according to claim 1, wherein the method of positioning the inorganic filler uses a specific gravity difference between the resin and the inorganic filler in the liquid resin composition. . 5. The method of mounting a semiconductor device according to claim 3, wherein the method of locating the inorganic filler near the semiconductor device utilizes a difference in specific gravity between the resin and the inorganic filler by turning over the circuit board. 6. The method according to claim 1, wherein the method of positioning the inorganic filler utilizes a property that the viscosity of the resin in the liquid resin composition drops rapidly at a high temperature. A method for mounting a semiconductor device. 7. The method according to claim 6, wherein the positioning of the inorganic filler and the curing of the liquid resin composition are performed in the same step. 8. The method according to claim 1, wherein the semiconductor device is mounted on the circuit board using solder bumps. 9. The method of mounting a semiconductor device according to claim 1, wherein the semiconductor device is mounted on the circuit board using a conductive adhesive. 10. The semiconductor device is mounted on the circuit board using a bump electrode and a conductive adhesive.
A method for mounting a semiconductor device according to any one of the preceding claims. 11. A semiconductor device is mounted on a circuit board, a resin composition containing a resin and an inorganic filler is provided in a gap between the semiconductor device and the circuit board, and the inorganic filler in the resin composition is thermally expanded. A mounted body of a semiconductor device, wherein the mounted body is located near a member having a small coefficient. 12. The semiconductor device according to claim 11, further comprising the resin composition having a coefficient of thermal expansion that changes in a direction perpendicular to the circuit board. 13. The semiconductor device according to claim 11, wherein when the coefficient of thermal expansion of the semiconductor device is larger than the coefficient of thermal expansion of the circuit board, the inorganic filler in the resin composition is located near the circuit board. 13. A mounted body of the semiconductor device according to 12. 14. The semiconductor device according to claim 11, wherein when the coefficient of thermal expansion of the semiconductor device is smaller than the coefficient of thermal expansion of the circuit board, the inorganic filler in the resin composition is located near the semiconductor device. 13. A mounted body of the semiconductor device according to 12. 15. An average value of a coefficient of thermal expansion of the resin composition in a direction perpendicular to the circuit board is substantially equal to a value of a coefficient of thermal expansion of a connection portion between the semiconductor device and the circuit board in a direction perpendicular to the circuit board. Claim 12,
15. A package of the semiconductor device according to 13 or 14. 16. An average value of a thermal expansion coefficient of the resin composition in a direction perpendicular to the circuit board, and a value of a thermal expansion coefficient of a connection portion between the semiconductor device and the circuit board in a direction perpendicular to the circuit board are substantially equal to each other. The semiconductor device package according to claim 15, further comprising: the resin composition in which a ratio of the resin and the inorganic filler is adjusted to match. 17. The method according to claim 11, wherein a spherical inorganic filler is used as the inorganic filler in the resin composition.
7. A mounted body of the semiconductor device according to claim 6. 18. The semiconductor device according to claim 11, wherein the semiconductor device is mounted on the circuit board by using solder bumps. 19. The semiconductor device package according to claim 11, wherein said semiconductor device is mounted on said circuit board using a conductive adhesive. 20. The semiconductor device according to claim 1, wherein the semiconductor device is mounted on the circuit board using a bump electrode and a conductive adhesive.
18. A mounted body of the semiconductor device according to any one of 1 to 17. 21. The semiconductor device package according to claim 11, further comprising the semiconductor device having different coefficients of thermal expansion and the circuit board.