Semiconductor device and manufacturing method of the same

A semiconductor device includes a semiconductor element provided over a wiring board; sealing resin configured to seal the semiconductor element; and reinforcing resin provided at least at a part of a boundary part of the sealing resin and the wiring board. In the above-mentioned semiconductor device, the reinforcing resin may be provided along a perimeter of the boundary part of the sealing resin and the wiring board. The reinforcing resin may be provided at a boundary part of the sealing resin and the wiring board in a vicinity of a corner part of the sealing resin.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to semiconductor devices and manufacturing methods of the same, and more specifically, to a semiconductor device having a PBGA (Plastic Ball Grid Array) package structure and a manufacturing method of the semiconductor device.

2. Description of the Related Art

As today's electronic apparatuses have miniaturized sizes, high functionalities or high densities, it is required that electronic parts such as semiconductor devices applied to the electronic apparatuses also have miniaturized sizes or be thin. Because of this, as a package proper for high density mounting wherein a mounting area is reduced by miniaturization, a surface mount technology type package such as a PBGA (Plastic Ball Grid Array) has been suggested.

FIG. 1is a view showing a structure of a related art semiconductor device having the PBGA (Plastic Ball Grid Array) package. More specifically,FIG. 1(b) is a cross-sectional view taken along line X-X′ ofFIG. 1(a).

Referring toFIG. 1, a related art semiconductor device10having the PBGA package has a structure where a semiconductor device2is mounted on a wiring board1via a die bonding member not shown inFIG. 1, such as a die bonding film.

The semiconductor element2is connected to the wiring board1by bonding wires3made of gold (Au) or the like.

A basic material of the wiring board1is insulation resin such as glass-epoxy resin. On an upper surface of the wiring board1, a conductive layer4A made of copper (Cu) or the like is selectively provided. The conductive layer4A other than areas where the bonding wires3are connected is selectively covered with a resist layer5A.

In addition, on a lower surface of the wiring board1, a conductive layer4B made of copper (Cu) or the like is selectively provided. The conductive layer4B is selectively covered with a resist layer5B. Plural outside connection terminals (bumps)6such as spherical shape electrode terminals whose main ingredient is solder are arranged in a grid state on the conductive layer6B defined by the resist layer5B. The conductive layer4B is connected to the conductive layer4A.

The semiconductor element2and the bonding wire3are sealed by sealing resin7such as epoxy group resin.

However, the sealing resin7is not provided in the vicinities of both end parts of the wiring board1. Therefore, the wiring board1projects to outside of the sealing resin7.

A wiring pattern9formed on an upper surface of the wiring board1shown inFIG. 1(a) is made of copper (Cu). Nickel gold (Ni—Au) plating is applied on a surface of the wiring pattern9. The wiring pattern9functions as a flow path of the molten sealing resin7when the sealing resin7is provided on the wiring board1by using a mold based on a transfer molding method. Since adhesion of the Nickel gold (Ni—Au) plating to the sealing resin7is not good, it is possible to easily remove a runner.

Equipment used for manufacturing a related art lead frame type package can be applied to manufacturing the semiconductor device10having such a PBGA package structure. This is discussed with reference toFIG. 2.

Here,FIG. 2is a plan view showing a relationship between the related art semiconductor device10having the PBGA package structure shown inFIG. 1and a related art lead frame type semiconductor device. The related art semiconductor device10having the PBGA package structure shown inFIG. 1is shown at the right side ofFIG. 2, and the related art lead frame type semiconductor device20is shown at the left side ofFIG. 2.

In the lead frame type semiconductor device20, a semiconductor element provided on a die pad is connected to inner leads by bonding wires. The inner leads, the semiconductor element provided on the die pad, and the bonding wires are sealed by sealing resin21. Outer leads22are extended from the inner leads to outside of the sealing resin21.

As shown by the dotted areas inFIG. 2, configuration or package size of the semiconductor device10having the PBGA package structure shown inFIG. 1, namely configuration or size of the sealing resin7, is substantially the same as configuration or package size of the lead frame type semiconductor device20, namely configuration or size of the sealing resin21.

Accordingly, the equipment used for manufacturing the related art lead frame type semiconductor device20can be applied to manufacturing the semiconductor device10having the PBGA package structure, so that a limitation of having a large number of pins in the lead frame type semiconductor device20can be solved.

Japanese Patent No. 3534501 discloses a semiconductor device provided by arranging a semiconductor pellet on a top plane of a substrate with plural connecting terminals. In this semiconductor device, a group of the connecting terminals is arranged in plural annular lines at the periphery of the semiconductor pellet. A space with a low height formed between the semiconductor pellet and the substrate by the connecting terminal group is filled with resin so that a reinforcing resin layer is formed.

In addition, Japanese Patent No. 3565204 discloses an electronic apparatus having the following structure. The electronic apparatus comprises an element mounting substrate having an electrode formed on the rear side of an element mounting surface, a wiring board which is arranged so as to face the element mounting substrate across a prescribed interval and which has an electrode formed at a position facing the electrode of the element mounting substrate, a meltable member for joining the electrode of the element mounting substrate with the electrode of the wiring board, and a resin reinforcing member which is arranged outboard of the meltable member for joining the end of the element mounting substrate with the site of a wiring substrate facing this end.

However, the semiconductor device10having the PBGA package structure shown inFIG. 1has a problem shown inFIG. 3. Here,FIG. 3is an enlarged view of a part surrounded by a dotted line inFIG. 1.

As discussed above, the configuration or package size of the semiconductor device10having the PBGA package structure shown inFIG. 1, namely the configuration or size of the sealing resin7, is substantially the same as the configuration or size of the package of the lead frame type semiconductor device20, namely the configuration or size of the sealing resin21. In addition, as discussed with reference toFIG. 1, the sealing resin7is not provided in the vicinities of both end parts of the wiring board1. Only the wiring board1projects to the outside of the sealing resin7.

However, coefficients of thermal expansion of members forming the semiconductor device10shown inFIG. 1are different from each other. For example, the coefficient of thermal expansion of silicon (Si) used as the semiconductor element2is 3×10−6/° C., the coefficient of thermal expansion of the sealing resin7is 8×10−6/° C., and the coefficient of thermal expansion of the wiring board1is 16×10−6/° C.

In addition, for example, the temperature inside of a reflow hearth in a reflow process for mounting a package on the wiring board1reaches around 260° C. Heat is applied as a reliability test of the semiconductor device10. Furthermore, in normal use of the semiconductor device10, the semiconductor device10may be put under atmospheric conditions wherein the temperature in summer may be higher than 80° C.

Accordingly, under the atmospheric conditions wherein such a temperature change occurs, the members may expand or contract, due to the difference of the coefficients of thermal expansion of the members, concentration of stress may be generated at a boundary part of an end part of the sealing resin7and the wiring board1.

In addition, in a process of manufacturing the semiconductor device10, for example, bending when the external configuration is formed by using a dicing blade or the like or concentration of mechanical stress due to a fall of the semiconductor device10or the like may be generated at the boundary part of an end part of the sealing resin7and the wiring board1.

Due to such concentration of stress, as shown inFIG. 3, a crack (indicated by “X” inFIG. 3) is generated in the wiring board1so that bad conductivity, namely pattern breakage, of the conductive layer4of the wiring board1is caused. As a result of this, an electric property of the semiconductor device may be degraded.

SUMMARY OF THE INVENTION

Accordingly, embodiments of the present invention may provide a novel and useful semiconductor device and manufacturing method of the same solving one or more of the problems discussed above.

More specifically, the embodiments of the present invention may provide a semiconductor device whereby stress that may be generated at a boundary part of an end part of sealing resin and a wiring board is dispersed so that generation of a crack in the wiring board can be prevented, and a manufacturing method of the same.

One aspect of the present invention may be to provide a semiconductor device, including a semiconductor element provided over a wiring board; sealing resin configured to seal the semiconductor element; and reinforcing resin provided at least at a part of a boundary part of the sealing resin and the wiring board.

In the semiconductor device, the reinforcing resin may be provided along a perimeter of the boundary part of the sealing resin and the wiring board. The reinforcing resin may be provided at a boundary part of the sealing resin and the wiring board in a vicinity of a corner part of the sealing resin. The reinforcing resin may be provided at a boundary part of the sealing resin and the wiring board at a corner part of the sealing resin. The reinforcing resin may be made of a material the same as the material of the sealing resin.

Other aspect of the present invention may be to provide a manufacturing method of a semiconductor device having a structure where a semiconductor element provided over a wiring board is sealed by sealing resin, including a step of providing reinforcing resin made of a material the same as the material of the sealing resin at least a part of a boundary part of the sealing resin and the wiring board in a lump with the sealing resin when the semiconductor element is sealed.

Other aspect of the present invention may be to provide a manufacturing method of a semiconductor device having a structure where a semiconductor element provided over a wiring board is sealed by sealing resin, including a step of providing reinforcing resin made of a material different from a material of the sealing resin at at least a part of a boundary part of the sealing resin and the wiring board, after the sealing resin is provided over the wiring board and is made solid.

According to the embodiment of the present invention, it is possible to provide a semiconductor device whereby stress that may be generated at a boundary part of an end part of sealing resin and a wiring board is dispersed so that generation of a crack in the wiring board can be prevented, and a manufacturing method of the same.

Other objects, features, and advantages of the present invention will be come more apparent from the following detailed description when read in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERED EMBODIMENTS

A description is given below, with reference to theFIG. 4throughFIG. 10of embodiments of the present invention.

For the convenience of explanation, first, embodiments of a semiconductor device of the present invention are discussed and then an embodiment of a manufacturing method of the semiconductor device is discussed.

1. A Semiconductor Device of a First Example of the Present Invention

FIG. 4is a view showing a structure of a semiconductor device of a first example of the present invention. More specifically,FIG. 4(a) is a plan view andFIG. 4(b) is a view taken along a line A-A inFIG. 4(a) and seen in a direction indicated by arrows.

Referring toFIG. 4, a semiconductor device40having a PBGA (Plastic Ball Grid Array) package has a structure where sealing resin42-1is provided on a wiring board41.

Inside the sealing resin42-1, a semiconductor device (not shown inFIG. 4) is mounted on the wiring board41via a die bonding member such as a die bonding film. The semiconductor element is connected to the wiring board41by bonding wires (not shown inFIG. 4) made of gold (Au) or the like.

A basic material of the wiring board41is insulation resin such as glass-epoxy resin. On an upper surface of the wiring board41, a conductive layer43A made of copper (Cu) or the like is selectively provided. The conductive layer43A is selectively covered with a resist layer44A.

A wiring pattern45formed on an upper surface of the wiring board41shown inFIG. 4(a)is made of copper (Cu). Nickel gold (Ni—Au) plating is applied on a surface of the wiring pattern45. The wiring pattern45functions as a flow path of the molten sealing resin42-1when the sealing resin42-1is provided on the wiring board41by using a mold based on a transfer molding method. Since adhesion of the Nickel gold (Ni—Au) plating to the sealing resin42-1is not good, it is possible to easily remove a runner.

In addition, on a lower surface of the wiring board41, a conductive layer43B made of copper (Cu) or the like is selectively provided. The conductive layer43B is selectively covered with a resist layer44B. Plural outside connection terminals (bumps)46such as spherical shape electrode terminals whose main ingredient is solder are arranged in a grid state on the conductive layer43B defined by the resist layer44B. The conductive layer43B is connected to the conductive layer43A.

Meanwhile, reinforcing resin42-2is provided along a perimeter of the circumference of the sealing resin42-1.

More specifically, the reinforcing resin42-2is provided along the perimeter of a boundary part of the wiring board41and the sealing resin42-1so that the boundary part is reinforced. Furthermore, the reinforcing resin42-2has a triangle shaped cross section.

The thickness a (length in a vertical direction) of the reinforcing resin42-2and a length b in a horizontal direction of the reinforcing resin42-2can be several tens μm.

In the first example, a material of the sealing resin42-1is the same as that of the reinforcing resin42-2. Therefore, a configuration corresponding to an external configuration of the reinforcing resin42-2is formed in advance in a mold for resin molding for provided the sealing resin42-1on the wiring board41by a transfer molding method. As a result of this, the sealing resin42-1and the reinforcing resin42-2can be provided in a lump (together) in a conventional resin sealing process.

Accordingly, since a special process for providing the reinforcing resin42-2is not necessary, it is possible to easily form the structure of this example by the same process as that of the conventional art.

In addition, as the sealing resin42-1and the reinforcing resin42-2, for example, a thermosetting type epoxy resin containing a filler of approximately 70 through 90 Wt %, glass transition temperature of approximately 100 through 195° C., and a linear expansion coefficient of approximately 5×10−6through 20×10−6K−1or approximately 50×10−6through 100×10−6K−1can be used. Since such a thermosetting type epoxy resin has high filling capability, it is possible to easily form the reinforcing resin42-2on the wiring board41even if the configuration of the reinforcing resin42-2is complex.

Thus, in the semiconductor device40of the first example of the present invention, since the reinforcing resin42-2is provided along the perimeter of the external circumferential part of the sealing resin42-1, the boundary part of the wiring board41and the sealing resin42-1is reinforced in a uniform manner along the perimeter of the external circumferential part of the sealing resin42-1.

Therefore, stress that may be generated at the boundary part of the end part of sealing resin42-1and the wiring board41due to environmental temperature change or mechanical reasons is dispersed. Hence, generation of a crack in the wiring board41can be prevented and bad conductivity, namely pattern breakage, of the conductive layer43A of the wiring board11is can be prevented.

In the meantime, although the reinforcing resin42-2has a triangle shaped cross section in the first example of the present invention, the present invention is not limited to this. The reinforcing resin42-2may have, for example, a rectangular shaped cross section or a cross section having a configuration including a curved part. In any case, it is possible to reinforce the boundary part of the end part of the sealing resin42-1and the wiring board41with the reinforcing resin42-2.

In addition, although the thickness a (length in the vertical direction) of the reinforcing resin42-2and the length b in the horizontal direction of the reinforcing resin42-2are several tens μm in the first example of the present invention, the present invention is not limited to this.

A maximum thickness of the reinforcing resin42-2is equal to the thickness of the sealing resin42-1. A maximum length in the horizontal direction of the reinforcing resin42-2is the distance from the end part of the sealing resin42-1to an end part of the wiring board41. The greater the thickness a (length in the vertical direction) of the reinforcing resin42-2and the length b in the horizontal direction of the reinforcing resin42-2, the more the effect of en embodiment of the present invention is achieved.

2. A Semiconductor Device of a Second Example of the Present Invention

FIG. 5is a view showing a structure of a semiconductor device of a second example of the present invention. More specifically,FIG. 5(a) is a plan view andFIG. 5(b) is a view taken along a line B-B inFIG. 5(a) and seen in a direction indicated by arrows. InFIG. 5, parts that are the same as the parts shown inFIG. 4are given the same reference numerals, and explanation thereof is omitted.

In the above-discussed first example of the present invention shown inFIG. 4, the reinforcing resin42-2is provided along the perimeter of the external circumferential part of the sealing resin42-1. However, the present invention is not limited to this. As shown inFIG. 5, the reinforcing resin may be selectively provided at only a part where reinforcing by the reinforcing resin is especially necessary.

More specifically, in a semiconductor device50of the second example of the present invention, reinforcing resin42-3made of a material the same as that of the sealing resin42-1is provided at only boundary parts of the sealing resin42-1in the vicinities of four corners of the sealing resin42-1and the wiring board41.

Thus, a partially arranging structure where the reinforcing resin42-3is selectively provided at parts where reinforcing by the reinforcing resin is especially necessary is applied to the second example of the present invention. Therefore, while the boundary part of the end part of the sealing resin42-1and the wiring board41at a part especially weak against the stress is reinforced, the stress is eased by providing a part where the reinforcing resin42-3is not provided, that is a part where reinforcing by the reinforcing resin42-3is not made.

In the second example, as well as the first example, of the present invention, since the reinforcing resin42-3is made of the same material as that of the sealing resin42-1, a special process for providing the reinforcing resin42-3is not necessary so that it is possible to easily form the structure of this example by the same process as that of the conventional art.

Furthermore, in the second example, as well as the first example, of the present invention, although the reinforcing resin42-3has a triangle shaped cross section as shown inFIG. 5(b), the present invention is not limited to this. The reinforcing resin42-3may have, for example, a rectangular shaped cross section or a cross section having a configuration including a curved part.

Furthermore, in the second example, as well as the first example, of the present invention, the thickness (length in the vertical direction) of the reinforcing resin42-3and the length in the horizontal direction of the reinforcing resin42-3may be several tens μm. A maximum thickness of the reinforcing resin42-3is equal to the thickness of the sealing resin42-1. A maximum length in the horizontal direction of the reinforcing resin42-3is the distance from the end part of the sealing resin42-1to an end part of the wiring board41.

3. A Semiconductor Device of a Third Example of the Present Invention

FIG. 6is a view showing a structure of a semiconductor device of a third example of the present invention. More specifically,FIG. 6(a) is a plan view andFIG. 6(b) is a view taken along a line C-C inFIG. 6(a) and seen in a direction indicated by arrows. InFIG. 6, parts that are the same as the parts shown inFIG. 5are given the same reference numerals, and explanation thereof is omitted.

In the third example of the present invention, as shown inFIG. 6, four corners of the sealing resin42-1are selected as parts where reinforcing by the reinforcing resin is especially necessary and reinforcing resin is provided at the four corners of the sealing resin42-1.

More specifically, in a semiconductor device60of the third example of the present invention, reinforcing resin42-4made of a material the same as that of the sealing resin42-1is provided at only four corners of the sealing resin42-1.

Thus, a corners arranging structure where the reinforcing resin42-4is selectively provided at four corners of the sealing resin42-1where reinforcing by the reinforcing resin is especially necessary because the four corners are weak against the stress, is applied to the third example of the present invention. Therefore, while the boundary part of the end part of the sealing resin42-1and the wiring board41at the four corners is reinforced, the stress is eased by providing a part where the reinforcing resin42-4is not provided, that is four sides of the sealing resin42-1where reinforcing by the reinforcing resin42-4is not made.

In the third example, as well as the first example, of the present invention, since the reinforcing resin42-4is made of the same material as that of the sealing resin42-1, a special process for providing the reinforcing resin42-4is not necessary so that it is possible to easily form the structure of this example by the same process as that of the conventional art.

Furthermore, in the third example, as well as the first example, of the present invention, although the reinforcing resin42-4has a triangle shaped cross section as shown inFIG. 6(b), the present invention is not limited to this. The reinforcing resin42-4may have, for example, a rectangular shaped cross section or cross section having a configuration including a curved part.

Furthermore, in the third example, as well as the first example, of the present invention, the thickness (length in the vertical direction) of the reinforcing resin42-4and the length in the horizontal direction of the reinforcing resin42-4may be several tens μm. A maximum thickness of the reinforcing resin42-4is equal to the thickness of the sealing resin42-1. A maximum length in the horizontal direction of the reinforcing resin42-4is the distance from the end part of the sealing resin42-1to an end part of the wiring board41.

4. A Semiconductor Device of a Fourth Example of the Present Invention

FIG. 7is a view showing a structure of a semiconductor device of a fourth example of the present invention. More specifically,FIG. 7(a) is a plan view andFIG. 7(b) is a view taken along a line D-D inFIG. 7(a) and seen in a direction indicated by arrows. InFIG. 7, parts that are the same as the parts shown inFIG. 6are given the same reference numerals, and explanation thereof is omitted.

In the third example of the present invention shown inFIG. 6, the reinforcing resin42-4made of the same material as that of the sealing resin42-1is provided at the four corners of the sealing resin42-1. More specifically, the reinforcing resin42-4has an arc shaped plan configuration in a plan view and partially covers the wiring pattern45formed on an upper surface of the wiring board41.

However, the present invention is not limited to this example.

In a semiconductor device70of the fourth example of the present invention, four corners of the sealing resin42-1are selected as parts where reinforcing by the reinforcing resin is especially necessary and reinforcing resin42-5having a plan view configuration whose substantially center part is concave is provided at the four corners of the sealing resin42-1.

Since the four corners of the sealing resin42-1are parts especially weak against stress, the reinforcing resin42-5is selectively provided at only the four corners of the sealing resin42-1.

On the other hand, since the reinforcing resin42-5has the plan view configuration where the substantially center part is concave, the amount covering the wiring pattern45in this example is smaller than that in the third example. Accordingly, it is not necessary to change the arrangement of the wiring pattern45in order to correspond to the configuration of the reinforcing resin42-5provided on the wiring board41.

In addition, the stress is eased by providing a part where the reinforcing resin42-5is not provided, that is four sides of the sealing resin42-1where reinforcing by the reinforcing resin42-5is not made.

In the fourth example, as well as the first example, of the present invention, since the reinforcing resin42-5is made of the same material as that of the sealing resin42-1, a special process for providing the reinforcing resin42-5is not necessary so that it is possible to easily form the structure of this example by the same process as that of the conventional art.

Furthermore, in the fourth example, as well as the first example, of the present invention, although the reinforcing resin42-5has a triangle shaped cross section as shown inFIG. 7(b), the present invention is not limited to this. The reinforcing resin42-5may have, for example, a cross section having a configuration including a curved part.

Furthermore, in the fourth example, as well as the third example shown inFIG. 6, of the present invention, the thickness (length in the vertical direction) of the reinforcing resin42-5and the length in the horizontal direction of the reinforcing resin42-5may be several tens μm. A maximum thickness of the reinforcing resin42-5is equal to the thickness of the sealing resin42-1. A maximum length in the horizontal direction of the reinforcing resin42-5is the distance from the end part of the sealing resin42-1to an end part of the wiring board41.

In the first through fourth examples, a material of the sealing resin42-1is the same as those of the reinforcing resins42-2through42-5. Therefore, a configuration corresponding to an external configuration of the reinforcing resins42-2through42-5is formed in advance in a mold for resin molding for providing the sealing resin42-1on the wiring board41by a transfer molding method. As a result of this, the sealing resin42-1and one of the reinforcing resins42-2through42-5can be provided in a lump in a conventional resin sealing process. Therefore, since a special process for providing the reinforcing resins42-2through42-5is not necessary, it is possible to easily form the structure of the first through fourth examples by the same process as that of the conventional art.

However, the present invention is not limited to a case where the reinforcing resins42-2through42-5are formed in a lump with the sealing resin42-1. The present invention may be applied a case where resin made of a material different from that of the sealing resin42-1is used as the reinforcing resins42-2through42-5.

In the following explanation, the case where resin made of a material different from that of the sealing resin42-1is used as the reinforcing resins42-2through42-5is discussed.

5. A Semiconductor Device of a Fifth Example of the Present Invention

FIG. 8is a view showing a structure of a semiconductor device of a fifth example of the present invention. More specifically,FIG. 8(a) is a plan view andFIG. 8(b) is a view taken along a line E-E inFIG. 8(a) and seen in a direction indicated by arrows. InFIG. 8, parts that are the same as the parts shown inFIG. 4are given the same reference numerals, and explanation thereof is omitted.

In a semiconductor device80of the fifth example, as well as the semiconductor device40shown inFIG. 4of the first example, of the present invention, the reinforcing resin81is provided along the perimeter of the external circumferential part of the sealing resin42-1. More specifically, the reinforcing resin81is provided along the perimeter of the boundary part of the wiring board41and the sealing resin42-1so that the boundary part is reinforced. In addition, a cross section of the reinforcing resin has an arc shaped part.

In the fifth example of the present invention, the reinforcing resin81is made of a material different from that of the sealing resin42-1.

In addition, as the sealing resin42-1, for example, a thermosetting type epoxy resin containing a filler of approximately 70 through 90 Wt %, glass transition temperature of approximately 100 through 195° C., and a linear expansion coefficient of approximately 5×10−6through 20×10−6K−1or approximately 50×10−6through 100×10−6K−1can be used. As the reinforcing resin81, for example, a thermosetting type liquid state epoxy resin having a viscosity of approximately 1000 through 15000 mPa·s, a filler of approximately 0 through 80 Wt %, glass transition temperature of approximately 100 through 150° C., and a linear expansion coefficient of approximately 30×10−6through 40×10−6K−1or approximately 100×10−6through 120×10−6K−1can be used.

Although details are discussed below, the structure of the fifth example of the present invention can be formed by providing the sealing resin42-1on the wiring board41and then providing the reinforcing resin81on the wiring board41with a method such as a potting method.

The thermosetting type liquid state epoxy resin having the above-mentioned properties and used as the reinforcing resin81can be formed in various configurations by controlling the velocity. Hence, in order to fit in a desirable design, after the sealing resin42-1is provided, the reinforcing resin81can be provided by controlling the configuration and amount of the reinforcing resin81.

Thus, in the semiconductor device80of the fifth example of the present invention, the reinforcing resin81made of a material different from that of the sealing resin42-1is provided along the perimeter of the external circumference part of the sealing resin42-1. Hence, the boundary part of the wiring board41and the sealing resin42-1is reinforced in a uniform manner along the perimeter of the external circumferential part of the sealing resin42-1.

Therefore, stress that may be generated at the boundary part of the end part of sealing resin42-1and the wiring board41due to environmental temperature change or mechanical reasons is dispersed. Hence, generation of a crack in the wiring board41can be prevented and bad conductivity, namely pattern breakage, of the conductive layer43A of the wiring board11can be prevented.

Especially, in the fifth example of the present invention, since the reinforcing resin81is made of a material different from that of the sealing resin42-1, in order to fit in a desirable design, after the sealing resin42-1is provided, the reinforcing resin81can be provided by controlling the configuration and amount of the reinforcing resin81.

Furthermore, in the fifth example of the present invention, although the reinforcing resin81has a arc shaped cross section, the present invention is not limited to this. The reinforcing resin81may have, for example, a rectangular shaped cross section or triangle shaped configuration like the reinforcing resin42-2shown inFIG. 4.

In addition, in the fifth example of the present invention, the thickness (length in the vertical direction) of the reinforcing resin81and the length in the horizontal direction of the reinforcing resin81may be several tens μm. A maximum thickness of the reinforcing resin81is equal to the thickness of the sealing resin42-1. A maximum length in the horizontal direction of the reinforcing resin81is the distance from the end part of the sealing resin42-1to an end part of the wiring board41.

In any case, it is possible to reinforce the boundary part of the end part of the sealing resin42-1and the wiring board41by the reinforcing resin81.

6. A Semiconductor Device of a Sixth Example of the Present Invention

FIG. 9is a view showing a structure of a semiconductor device of a sixth example of the present invention. More specifically,FIG. 9(a) is a plan view andFIG. 9(b) is a view taken along a line F-F inFIG. 9(a) and seen in a direction indicated by arrows. InFIG. 9, parts that are the same as the parts shown inFIG. 5are given the same reference numerals, and explanation thereof is omitted.

In the semiconductor device80of the fifth example of the present invention, the reinforcing resin81made of a material different from that of the sealing resin42-1is provided along the perimeter of the external circumferential part of the sealing resin42-1. However, the present invention is not limited to this.

In a semiconductor device90of the sixth example, as well as the semiconductor device50shown inFIG. 5of the second example, of the present invention, the reinforcing resin is selectively provided at only a part where reinforcing by the reinforcing resin is especially necessary.

More specifically, in a semiconductor device90of the sixth example of the present invention, reinforcing resin91made of a material different from that of the sealing resin42-1is provided at only boundary parts of the sealing resin42-1in the vicinities of four corners of the sealing resin42-1and the wiring board41.

Thus, a partially arranging structure where the reinforcing resin91is selectively provided at parts where reinforcing by the reinforcing resin91is especially necessary is applied to the sixth example of the present invention. Therefore, while the boundary part of the end part of the sealing resin42-1and the wiring board41at a part especially weak against the stress is reinforced, the stress is eased by providing a part where the reinforcing resin91is not provided, that is a part where reinforcing by the reinforcing resin91is not made.

In addition, since the reinforcing resin91is made of a material different from that of the sealing resin42-1, in order to fit in a desirable design, after the sealing resin42-1is provided, the reinforcing resin91can be provided by controlling the configuration and amount of the reinforcing resin91.

Especially, in the sixth example of the present invention, since the reinforcing resin91is made of a material different from that of the sealing resin42-1, in order to fit in a desirable design, after the sealing resin42-1is provided, the reinforcing resin91can be provided by controlling the configuration and amount of the reinforcing resin91.8

Furthermore, in the sixth example of the present invention, although the reinforcing resin91has an arc shaped cross section, the present invention is not limited to this. The reinforcing resin91may have, for example, a rectangular shaped cross section or triangle shaped configuration like the reinforcing resin42-3shown inFIG. 5.

In addition, in the sixth example of the present invention, the thickness (length in the vertical direction) of the reinforcing resin91and the length in the horizontal direction of the reinforcing resin91may be several tens μm. A maximum thickness of the reinforcing resin91is equal to the thickness of the sealing resin42-1. A maximum length in the horizontal direction of the reinforcing resin91is the distance from the end part of the sealing resin42-1to an end part of the wiring board41.

In any case, it is possible to reinforce the boundary part of the end part of the sealing resin42-1and the wiring board41by the reinforcing resin91.

Meanwhile, in the structure shown inFIG. 6orFIG. 7, a material different from the material of the sealing resin42-1can be used as a material of the reinforcing resin42-4or42-5.

[Manufacturing Method of Semiconductor Device]

Next, manufacturing methods of the above-discussed semiconductor devices are discussed with reference toFIG. 10. Here,FIG. 10is a view for explaining the manufacturing method of the semiconductor device of the present invention.FIG. 10(a) throughFIG. 10(d) shows only the end part of the above-discussed wiring board41and its vicinity.

As shown inFIG. 10(a), first, the semiconductor element35is adhered on the wiring board41via the die bonding member36such as a die bonding film. Then, the die bonding member36is cured so that the semiconductor element35is fixed to the wiring board41.

Next, as shown inFIG. 10(b), outside connection terminals of the semiconductor element35and connection terminals37of the wiring board41are connected to each other by bonding wires38.

After that, as shown inFIG. 10(c) andFIG. 10(c)′, the semiconductor element35, the bonding wires38, and others are sealed by a transfer molding method using the sealing resin42-1.

In order to form the structure having one of the reinforcing resins42-2through42-5made of the material the same as the material of the sealing resin42-1like the first through fourth example of the semiconductor device of the present invention shown inFIG. 4throughFIG. 7, a configuration corresponding an external configuration of one of the reinforcing resins42-2through42-5is formed in advance in a mold for resin molding for provided the sealing resin42-1on the wiring board41by a transfer molding method. As a result of this, the sealing resin42-1and one of the reinforcing resin42-2through42-5are provided in a lump in the resin sealing process shown inFIG. 10(c).

Accordingly, since a special process for providing one of the reinforcing resins42-2through42-5is not necessary, it is possible to easily provide one of the reinforcing resins42-2through42-5on the wiring board41by the same process as that of the conventional art.

AlthoughFIG. 10(c) shows where the reinforcing resin42-2is provided the same as shown inFIG. 4depending on the configuration formed in the mold, the reinforcing resin42-3may be provided in the vicinities of the four corners of the sealing resin42-1as shown inFIG. 5; the reinforcing resin42-4may be provided in the vicinities of the four corners of the sealing resin42-1as shown inFIG. 6; and the reinforcing resin42-5having plan configurations whose center parts are concave may be provided in the vicinities of the four corners of the sealing resin42-1as shown inFIG. 7. As discussed above, there is no limitation to the cross section of the reinforcing resins42-2through42-5.

In any case, it is possible to reinforce the boundary part of the end part of the sealing resin42-1and the wiring board41by the reinforcing resins42-2through42-5.

On the other hand, in order to form the structure having one of the reinforcing resins81and91made of a material different from the material of the sealing resin41-1like the fifth and sixth examples of the semiconductor device of the present invention shown inFIG. 4throughFIG. 7, as shown inFIG. 10(c)′, after the sealing resin42-1is provided on and fixed to the wiring board41, liquid state reinforcing resin81or91(SeeFIG. 8orFIG. 9)is caused to flow by using a potting nozzle39so that the reinforcing resin81or91is additionally provided on the wiring board41.

In this case, in order to fit in a desirable design, after the sealing resin42-1is provided, the reinforcing resin can be provided by controlling the configuration and amount of the reinforcing resin provided on the wiring board41.

As a result of this, as shown inFIG. 8, the reinforcing resin81comes in contact with a part of the external circumference of the sealing resin42-1and is provided along the perimeter of the external circumference of the sealing resin42-1. In addition, as shown inFIG. 9, the reinforcing resin91is provided in only the vicinities of the four corners of the sealing resin42-1.

In any case, it is possible to reinforce the boundary part of the end part of the sealing resin42-1and the wiring board41by the reinforcing resin81or91.

After the process shown inFIG. 10(c) orFIG. 10(c)′, as shown inFIG. 10(d), plural outside connection terminals (bumps)46such as spherical shape electrode terminals whose main ingredient is solder are arranged in a grid state on a rear surface of the wiring board41-1so that the semiconductor device is formed.

In a case where a large scale wiring board is applied as the wiring board41-1and plural semiconductor elements35are formed on the wiring board41-1, after the outside connection terminals46are provided, parts between the semiconductor elements35of the wiring board41-1are cut and separated by using a dicing blade or the like so that individual semiconductor devices are completed.

The present invention is not limited to these embodiments, but variations and modifications may be made without departing from the scope of the present invention.

This patent application is based on Japanese Priority Patent Application No. 2006-221953 filed on Aug. 16, 2006, the entire contents of which are hereby incorporated by reference.