JPH08279533A - Semiconductor device and semiconductor chip mounting film - Google Patents

Abstract

PURPOSE: To enable the title semiconductor device to maintain the lightweight and compactness as well as the heat generated in a semiconductor chip to be rapidly radiated by a method wherein a wettability improved layer more than the other surface of insulating resin layer to molten low melting point metal is formed on a part of the insulating resin layer in contact with the low melting point metallic layer. CONSTITUTION: The electrically connecting part of connecting the substrate side connecting part of a film substrate 10 to a chip side connecting part of a semiconductor chip 12 is covered with an insulating resin layer 14 and then the semiconductor chip 12 and the insulating resin layer 14 are covered with a low melting point metallic layer 34 made of low melting point metal melting down at the temperature less than the heat resistant temperature of the semiconductor chip 12. Next, a metallic particle layer 36 as a wettability improved layer to the molten low melting point metal is formed on the surface of the insulating resin layer 14 in contact with the low melting point metallic layer 34. Through these procedures, the title semiconductor device can maintain the lightweight and compactness as well as the heat generated by the semiconductor chip 12 can be rapidly radiated.

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 a semiconductor element mounting film used in the semiconductor device.

[0002]

2. Description of the Related Art In order to make a semiconductor device compact,
Japanese Unexamined Patent Publication No. 5-283460 proposes a semiconductor device shown in FIG. In such a semiconductor device, the semiconductor element 102 is mounted on one surface side of the film substrate 100, and the substrate-side connection portion formed on the mounting surface of the film substrate 100 and the one surface side of the semiconductor element 102 facing the mounting surface. Is electrically connected to the connected element side connection portion, and the semiconductor element 102 and the film substrate 1 are connected.
The mounting surface of 00 is sealed by the insulating resin layer 104. In the semiconductor device of FIG. 11, the electrical connection between the board-side connecting portion and the element-side connecting portion is performed by using the inner lead of the conductor pattern 108 (the board) formed on one surface side of the flexible film 106 forming the film substrate 100. Side connection part) 1
10 is formed by connecting a solder bump (element-side connection portion) 112 formed on one surface side of the semiconductor element 102.
The conductor pattern 108 is insulated by being covered with a resin film 114 formed of an insulating resin such as a polyimide resin except for the inner leads 110.

Conventionally, a semiconductor device of the type shown in FIG. 12 has also been used. This type of semiconductor device is
The semiconductor element 102 mounted on an AB (Tape Automated Bonding) tape 116 is sealed with an insulating resin layer 118. Such TAB tape 116
The conductive pattern 1 is formed on one side of the flexible film 120.
22 are formed, and inner leads 124 and outer leads 126 that are sealed by the insulating resin layer 118 are formed on the conductor pattern 122. The connection between the TAB tape 116 and the semiconductor element 102 is made by the connection between the inner lead 124 and the gold bump 128 formed on the one surface side of the semiconductor element 102 facing the other surface side of the flexible film 120. The insulating resin layer 118 shown in FIG. 12 is molded and formed into a predetermined shape, and the insulating resin layer 118 shown in FIG. 13 is formed by potting a potting agent.

[0004]

According to the semiconductor device shown in FIGS. 11 to 13, it is possible to make the semiconductor device and the like compact and lightweight. However, FIGS.
In the semiconductor device of No. 3, the semiconductor element 1 facing the mounting surface of the film substrate 100 on which the semiconductor element 102 is mounted or the connection portion formed on the mounting surface of the TAB tape 116.
The connection method of connecting the solder bumps 112 and the gold bumps 128 formed on one surface of the No. 02 is adopted. The heat generated in the semiconductor element 102 is dissipated from the other surface side (back surface side) of the semiconductor element 102, but since the thermal conductivity of the insulating resin is inferior to that of metal, heat is easily generated. When a semiconductor element is mounted, heat dissipation from the package is insufficient and heat is easily stored in the package. The heat stored in this package causes a malfunction of the mounted semiconductor element and thus reduces the reliability of the semiconductor device and the like.
Therefore, an object of the present invention is to provide a semiconductor device and a semiconductor device capable of substantially maintaining weight reduction and compactness and quickly dissipating heat generated in a semiconductor element, and a semiconductor used therein. It is to provide a film for mounting an element.

[0005]

In order to achieve the above-mentioned object, the inventors of the present invention firstly connect a substrate-side connecting portion formed on a mounting surface of a semiconductor element of a film substrate and an element-side connecting portion of the semiconductor element. After sealing the electrically connected connection portion with an insulating resin, a low melting point metal layer made of a low melting point metal such as a solder alloy was formed to cover the semiconductor element and the insulating resin layer. However, although it was possible to improve the heat dissipation of the package by forming the low melting point metal layer that covers the semiconductor element and the insulating resin layer, it was found that the insulating resin layer and the low melting point metal layer are easily separated. Therefore, as a result of further studies by the present inventors to prevent the semiconductor element and the insulating resin layer from peeling off, as a result, the surface of the insulating resin layer can be improved in wettability with respect to the melted low melting point metal. The present invention has been found out that a semiconductor element and an insulating resin layer can be adhered to each other by forming a metal powder layer to which a metal powder such as copper powder is fixed as a wettability improving layer.

That is, according to the present invention, the board-side connection portion formed on the mounting surface of the film substrate on which the semiconductor element is mounted and the element-side connection formed on one surface side of the semiconductor element facing the mounting surface. In a semiconductor device electrically connected to the semiconductor device, an insulating resin layer covering a connection portion that electrically connects the substrate-side connection portion of the film substrate and the element-side connection portion of the semiconductor element, and the semiconductor element and At least one surface of an insulating resin layer covering the insulating resin layer, the low melting point metal layer made of a low melting point metal that melts at a temperature equal to or lower than the heat resistant temperature of the semiconductor element, and contacting the low melting point metal layer. In the semiconductor device, a wettability improving layer having improved wettability with respect to the melted low melting point metal compared to the other surface of the insulating resin layer is formed in the portion. The "heat-resistant temperature of the semiconductor element" here means the temperature at which the circuit of the semiconductor element is destroyed by heat.

Further, the present invention comprises a film side connecting portion formed on one surface side of the flexible film, which is electrically connected to an element side connecting portion formed on one surface side of the mounted semiconductor element. A semiconductor element mounting film used in the semiconductor device or the semiconductor device, which has a low melting point formed at a peripheral portion of an element mounting portion of the semiconductor element mounting film and so as to cover the mounted semiconductor element. The semiconductor element mounting film is also characterized in that a metal layer is formed on the contact surface with the metal layer as an adhesion layer with the low melting point metal layer.

In the present invention having such a structure, the low melting point metal layer and the film are formed by forming a metal layer as an adhesion layer with the low melting point metal layer on the film substrate surface around the mounting portion on which the semiconductor element is mounted. It is possible to achieve close contact with the substrate surface. As the film substrate, a TAB tape having a conductor pattern formed on one side of the flexible film is used, and a semiconductor element is mounted on an inner lead forming the conductor pattern, or one side of the flexible film is formed. By using the TAB tape in which the semiconductor element mounting pads are formed on the conductor pattern formed in (1), the semiconductor element can be easily mounted. Further, by covering the other surface side of the semiconductor element exposed from the insulating resin layer with the low melting point metal layer, the low melting point metal layer and the other surface side of the semiconductor element can be directly contacted with each other. The heat dissipation of heat can be further improved. By electrically connecting the low melting point metal layer to the ground wiring provided on the film substrate, the number of signal nozzles can be reduced, and the electrical characteristics of the semiconductor device can be improved.

The thermal conductivity of the low melting point metal layer can be improved by mixing the low melting point metal layer with a metal powder having a melting point higher than that of the low melting point metal. As the high melting point metal powder to be mixed with the low melting point metal layer, tungsten (W), molybdenum (Mo), silver (Ag), copper (C
One or more metal powders selected from u) can be used. Further, by mixing the low melting point metal layer with an inorganic powder having a melting point higher than that of the low melting point metal, the difference in coefficient of thermal expansion between the low melting point metal layer and the semiconductor element can be reduced as much as possible. As the high melting point inorganic powder to be mixed with the low melting point metal layer, silicon dioxide (SiO ₂ ), silicon carbide (S
iC), aluminum nitride (AlN), boron nitride (B
One or more inorganic powders selected from N) and carbon (C) can be used.

In the present invention, the wettability improving layer formed on the surface of the insulating resin layer is a metal powder layer made of metal powder or a metal foil layer made of metal foil, which is fixed to the surface of the insulating resin layer. By doing so, the wettability improving layer can be easily formed. By forming this metal powder or metal foil with a metal having a melting point higher than that of the low melting point metal, the wettability of the insulating resin layer with the melted low melting point metal can be further improved. Furthermore, by using an external connection terminal composed of a bump such as a solder ball on the surface of the flexible film opposite to the mounting surface on which the semiconductor element is mounted, the semiconductor device can be easily mounted. . On the other hand, as the film substrate, a TAB tape having a conductor pattern formed on one side of the flexible film is used.
When a semiconductor element is mounted on the inner lead forming the conductor pattern, the outer lead forming the conductor pattern can be used as an external connection terminal. Moreover, by mixing an insulating inorganic material with the insulating resin layer, the thermal conductivity of the insulating resin layer can be improved.
As the low melting point metal used in the present invention, a low melting point alloy such as solder that is melted at a temperature of 450 ° C. or lower can be preferably used.

As described above, the outer surface of the low melting point metal layer that covers the insulating resin layer that seals the substrate-side connecting portion and the element-side connecting portion in the electrically connected state and the other surface side of the semiconductor element is provided. By mounting a heat dissipation member such as a heat dissipation fin, the heat dissipation of the semiconductor device or the like can be further improved. The element-side connecting portion formed on the one surface side of the semiconductor element and the board-side connecting portion formed on the mounting surface of the board can be directly connected by connecting terminals such as solder bumps. An alloy such as a solder alloy is preferably used as the low melting point metal forming the low melting point metal layer.

[0012]

In the present invention, since the semiconductor element and the insulating resin layer are covered with the low melting point metal layer, compared to the conventional semiconductor device etc. in which the semiconductor element is covered only with the insulating resin layer, the package The heat dissipation property of can be improved. Moreover, at least a part of the surface of the insulating resin layer,
A wettability improving layer, such as a metal powder layer made of metal powder, having wettability with respect to the melted low melting point metal improved more than the other surface of the insulating resin layer is formed. Therefore, when the molten low melting point metal comes into contact with the surface of the insulating resin layer,
A low melting point metal can be attached to a portion of the insulating resin layer having improved wettability. As a result, it is possible to improve the adhesion between the insulating resin layer and the low melting point metal layer, prevent the insulating resin layer from separating from the low melting point metal layer, and improve the durability of the semiconductor device and the like. Furthermore, when a metal powder having a melting point higher than that of the low-melting point metal is mixed in the low-melting point metal layer, the thermal conductivity of the low-melting point metal layer can be improved, so that the heat dissipation of the semiconductor device can be further improved. Alternatively, when an inorganic powder having a melting point higher than that of the low-melting point metal is mixed, the difference in the coefficient of thermal expansion between the semiconductor element and the low-melting point metal layer can be minimized, so that the durability of the semiconductor device or the like is improved. It can be further improved.

[0013]

FIG. 1 shows an embodiment of the semiconductor device of the present invention. The semiconductor device shown in FIG. 1 has a film substrate 10
The semiconductor element 12 is mounted from one surface side (mounting surface) of the film substrate 10 into the device hole formed in the substrate hole, and the substrate side connection portion (inner lead 20) formed in the device hole of the film substrate 10; An element-side connecting portion (gold bump 22) formed on one surface side of the semiconductor element 12 facing the mounting surface is electrically connected, and the substrate-side connecting portion and the element-side connecting portion are connected by the insulating resin layer 14. It is sealed. In this semiconductor device, the other surface side of the semiconductor element 12 is exposed from the insulating resin layer 14. In the semiconductor device shown in FIG. 1, the flexible film 16 forming the film substrate 10 is connected to the substrate-side connecting portion and the element-side connecting portion.
The inner lead 2 which forms a part of the conductor pattern 18 formed on one surface side and protrudes inward of the device hole.
0 to the gold bumps 2 formed on one surface of the semiconductor element 12.
2 are connected. On the other surface side of the flexible film 16, solder balls 26 (solder bumps) as external connection terminals connected to an external circuit are connected to the conductor pattern 18 by vias 28 penetrating the flexible film 16. ing.

In the semiconductor device of FIG. 1, the conductor pattern 18
Is covered with a resin film 24 formed of an insulating resin such as a silicone resin except the inner leads 20 to be insulated, and the surface of the resin film 24 around the device hole where the semiconductor element 12 is mounted is made of copper or the like. A metal layer 30 formed by metal foil or plating is formed. For the film substrate 10 used in this semiconductor device, a TAB tape in which a semiconductor element is mounted on one end of a conductor pattern 18 formed on one side of a flexible film can be used. FIG.
As the insulating resin forming the insulating resin layer 14 of the semiconductor device shown in FIG. 2, an insulating resin such as an epoxy resin which has been conventionally used for sealing a semiconductor element or the like can be used. In particular, by mixing an insulating inorganic material such as a filler of silicon dioxide (SiO ₂ ), the insulating resin layer 1
4 is preferable because it can improve the thermal conductivity.

The insulating resin layer 14 and the semiconductor element 12
The other surface side is covered with the low melting point metal layer 34.
As the low melting point metal forming the low melting point metal layer 34, a low melting point metal that melts at a temperature equal to or lower than the heat resistant temperature of the semiconductor element can be used. As such a low melting point metal, 4
A low melting point alloy that melts at a temperature of 50 ° C. or lower can be preferably used. If a low melting point alloy that melts at a temperature higher than 450 ° C. is used, the heat resistance of the semiconductor element 12 tends to have a problem. From this point of view, 250
It is preferable to use a low melting point alloy that melts at a temperature of ℃ or less. As such a low melting point alloy, a solder alloy can be preferably used. As such a solder alloy, Sn
-Pb-based solder alloy, Sn-Pb-Sb-based solder alloy,
Sn-Pb-Ag solder alloy, Pb-In solder alloy, Pb-Ag solder alloy, Sn-Zn solder alloy, Sn-Sb solder alloy, Sn-Ag solder alloy, Bi-Sn-In solder A solder alloy etc. can be mentioned. The "heat-resistant temperature of the semiconductor element" here means
As described above, it refers to the temperature at which the circuit of the semiconductor element is destroyed by heat.

The low melting point metal layer 34 made of such a low melting point metal layer and the other surface side of the semiconductor element 12 are usually adhered to each other by a metal layer such as nickel / gold deposited on the semiconductor element 12 to form a resin. The film 24 and the low melting point metal layer 34 are adhered to the surface of the resin film 26 by a metal foil 30 made of copper or the like, or a metal layer 30 formed by plating or the like. On the other hand, the low melting point metal layer 34 and the insulating resin layer 14 are the same as the insulating resin layer 14
Are adhered to each other via a wettability improving layer formed on the surface of which has improved wettability with respect to the molten low melting point metal.
As the wettability improving layer, as shown in FIG. 2, a metal powder layer 36 made of metal powder fixed to the surface of the insulating resin layer 14 is suitable. The metal powder layer 36 can be formed by sprinkling metal powder on the surface of the insulating resin layer 14 and then curing the insulating resin layer 14 in a heating atmosphere. The metal powder that can be used here is a metal powder having a higher melting point than the melting point of the low melting point metal forming the low melting point metal layer 34, such as tungsten (W), molybdenum (Mo), silver (Ag), and copper. The metal powder of (Cu) can be preferably used, and these metal powders may be used alone or in combination of two or more kinds.

In the present invention, instead of the metal powder layer 36 shown in FIG. 2, as shown in FIG. 3, the metal layer 38 formed on a part of the surface of the insulating resin layer 14 is also used as the wettability improving layer. Good. The metal layer 38 is formed by flattening a part of the surface of the insulating resin layer 14 by metal foil such as copper having a melting point higher than that of the low melting point metal, metal plating, or the like. . When the metal layer 38 is formed by metal plating, it is not necessary to form a flat portion on the insulating resin layer 14. Thus, even if a wettability improving layer having improved wettability with respect to the melted low-melting-point metal as compared with the other surface of the insulating resin layer 14 is formed on a part of the surface of the insulating resin layer 14, The adhesiveness between the insulating resin layer 14 and the low melting point metal layer 34 can be improved. The flexible film 16 is provided on the film substrate 10 of the semiconductor device shown in FIGS.
Conductor pattern 1 on one surface side (mounting surface of semiconductor element 12)
However, the conductor film 18 may be formed on the other surface of the flexible film 16 (the surface opposite to the mounting surface of the semiconductor element 12). In this case, the external connection terminals such as solder balls are mounted by forming a via hole in which the conductor pattern 18 is exposed on the bottom surface in a resin film such as a silicone resin covering the conductor pattern 18 formed on the other surface side of the flexible film 16. This can be done by forming and inserting an external connection terminal such as a solder ball into this via hole.

By the way, the thermal conductivity of the low melting point metal forming the low melting point metal layer 34 of the present invention is at most 50 W / m ° K, but the melting point of the low melting point metal layer 34 is higher than that of the low melting point metal. By mixing the metal powder, the low melting point metal layer 3
The thermal conductivity of No. 4 can be improved. Examples of the metal powder that can be used here include one or more metal powders selected from tungsten (W), molybdenum (Mo), silver (Ag), and copper (Cu). Among such metal powders, for example, copper (Cu) powder or tungsten (W) powder is used as a Sn-Pb-based solder alloy (Sn: Pb =).
60:40, thermal conductivity; about 50 W / m ° K), when 50% by weight is added, the resulting low melting point metal layer 34 has a thermal conductivity of about 120 W / m ° K (copper powder added) or about 70 W. / M
The temperature could be set to K (added with tungsten powder). still,
When tungsten (W) or molybdenum (Mo) metal powder is used among the metal powders, the Young's modulus of the obtained low-melting-point metal layer 34 may become high and brittle, and therefore, it is experimentally added in advance. It is preferable to investigate the relationship between the amount and Young's modulus.

Among the metal powders, tungsten
(W) or molybdenum (Mo) metal powder mixed low
The melting point metal layer 34 is formed of only a low melting point metal.
The coefficient of thermal expansion becomes smaller than that in the case. For example, Tan
Gusten (W) powder was added to Sn-Pb solder alloy (Sn:
Pb = 63: 37, thermal expansion coefficient; about 24 × 10^-6/ ° C)
When 65 wt% was added to the low melting point metal layer 34 obtained
Thermal expansion coefficient of about 6 × 10 ^-6~ 8 × 10^-6/ ℃
I was able to. Therefore, the semiconductor element 12 and the low melting point metal layer
Possible thermal and mechanical stress due to the difference in thermal expansion from
Can be reduced. Thus, the thermal expansion of the low melting point metal layer 34
To reduce the coefficient, tungsten (W) or mo
Instead of the metal powder of ribden (Mo)
Alternatively, a high melting point inorganic powder may be mixed. Such inorganic powder
As the end, silicon dioxide (SiO₂), Silicon carbide
(SiC), aluminum nitride (AlN), boron nitride
(BN), one or more selected from carbon (C)
Inorganic powder can be used. In addition, silicon carbide (SiC), nitrogen
Aluminum nitride (AlN), boron nitride (BN), carbon
When (C) was used as the inorganic powder, the low
To maintain or improve the thermal conductivity of the melting point metal layer 34.
You can

Tungsten (W), molybdenum (Mo), silver (Ag), copper (Cu) are contained in the low melting point metal layer 34.
It is preferable to add a flux in order to improve the wettability between the low melting point metal and the metal powder when the metal powder such as the above is mixed. As the flux, an organic flux such as a rosin flux is preferable for the copper powder, and an inorganic flux such as hydrochloric acid is preferable for the tungsten powder and the molybdenum powder. Also, when compounding an inorganic powder such as silicon dioxide (SiO ₂ ), silicon carbide (SiC), aluminum nitride (AlN), boron nitride (BN), or carbon (C) into a low melting point metal, only the addition of a flux is required. Since it is difficult to improve the wettability between the inorganic powder and the low melting point metal, a metal layer having good wettability with the low melting point metal, such as copper (Cu) or gold (Au), is formed on the surface of the inorganic powder. Titanium (T
It is preferable to form a metal layer such as i) and nickel (Ni). The formation of such a metal layer can be performed by electroless plating, the use of a coupling agent, ion plating, a mixed dry mill, thermal spraying and the like. However, with boron nitride (BN) powder or carbon (C) powder, it is difficult to form a metal layer having sufficient strength, and the dense low melting point metal layer 3
Since it is difficult to form No. 4, it is not suitable when the semiconductor element 12 is hermetically sealed by the low melting point metal layer 34. Even when using an inorganic powder having a metal layer having good wettability with a low melting point metal on the surface, it is preferable to add a flux to the low melting point metal.

The low melting point metal layer 34 thus formed
By electrically connecting the wiring to the ground wiring of the conductor pattern 18 formed on the mounting surface of the film substrate 10, it is possible to reduce signal noise and improve the electrical characteristics of the semiconductor device. it can. This electrical connection is made by the conductor pattern 18 formed on the film substrate 10.
Ground wiring and the metal layer 3 formed on the surface of the resin film 24
0 can be electrically connected by a via or the like, or by electrically connecting a metal layer formed on the other surface side of the semiconductor element 12 by vapor deposition or the like and the ground wiring. In the semiconductor device shown in FIGS. 1 to 3, the insulating resin layer 14 and the metal powder layer 36 or the metal layer 38.
Since the low melting point metal layer 34 is in contact with the wettability improving layer such as the above, the adhesion between both layers can be improved, and the durability of the semiconductor device can be improved. Further, the low-melting-point metal layer 34 is in direct contact with the other surface side of the semiconductor element 12, so that the heat generated in the semiconductor element 12 can be quickly dissipated and the accumulation of heat in the semiconductor device can be prevented. .

In manufacturing the semiconductor device shown in FIGS. 1 to 3, first, each inner lead 20 as a substrate side connecting portion formed on the mounting surface of the film substrate 10 on which the semiconductor element 12 is mounted, Each of the gold bumps 22 as element-side connection portions formed on one surface side of the semiconductor element 12 facing the mounting surface of the film substrate 10 is connected. This film substrate 10 uses a TAB tape in which a semiconductor element is mounted on the inner leads 20 of the conductor pattern 18 formed on the one surface side of the flexible film 16, and is provided on the other surface side of the flexible film 16. The solder balls 26 and the conductor pattern 18 thus formed are connected by vias 28, and the conductor pattern 118 except the inner leads 20 is covered by the resin film 24. Next, in order to seal the connection between the gold bumps 22 and the inner leads 20, a gap between the mounting surface of the film substrate 10 and one surface of the semiconductor element 12 is filled with an insulating resin such as epoxy resin. As a result, the insulating resin layer 14 in which the other surface of the semiconductor element 12 is exposed is formed. At this time, silicon dioxide (Si
The thermal conductivity of the insulating resin layer 14 can be improved by blending an insulating inorganic component such as a filler of O ₂ ).

After that, at least a part of the exposed surface of the insulating resin layer 14 is a metal powder layer 36 or a metal as a wettability improving layer capable of improving wettability with respect to a low melting point metal such as a solder alloy melted at 450 ° C. or lower. Form layer 38. The metal powder layer 36 is a metal powder having a melting point higher than that of the low melting point metal forming the low melting point metal layer 34, and includes tungsten (W), molybdenum (Mo), silver (Ag),
It can be formed by sprinkling one or more metal powders of copper (Cu) on the surface of the insulating resin layer 14 and then curing the insulating resin layer 14 in a heating atmosphere. Further, the metal layer 38 can be formed on a portion of the surface of the insulating resin layer 14 which is flattened by a metal foil such as copper having a higher melting point than the melting point of the low melting point metal or metal plating.

Further, a low melting point metal layer 34 covering the insulating resin layer 14 and the other surface side of the semiconductor element 12 is formed by melting a low melting point metal such as a solder alloy. In this low melting point metal, a metal powder having a higher melting point than the low melting point metal, such as tungsten (W), molybdenum (Mo), silver (Ag), copper (C
By mixing one or more metal powders of u), the thermal conductivity of the low melting point metal layer 34 can be improved, and the thermal expansion coefficient of the low melting point metal layer 34 can be reduced to reduce the semiconductor element 12. Matching with the coefficient of thermal expansion of Further, it is an inorganic powder having a melting point higher than that of a low melting point metal, such as silicon dioxide (SiO ₂ ), silicon carbide (Si
C), aluminum nitride (AlN), boron nitride (B
The difference in the coefficient of thermal expansion between the low melting point metal layer 34 and the semiconductor element 12 can be minimized by mixing one or more inorganic powders of N) and carbon (C). The metal powder and the inorganic powder may be used in combination.

As shown in FIG. 4, a heat radiation fin 40 as a heat radiation member for promoting heat radiation is attached to the outer surface of the low melting point metal layer 34 shown in FIGS. 1 to 3 to dissipate the heat of the semiconductor device. Can be further improved. As such a heat dissipation member, a heat spreader, a water cooling channel, or the like can be used instead of the heat dissipation fin 34. Further, by connecting the metal layer 30 in contact with the low melting point metal layer 34 and the solder ball 27 with the via 29 penetrating the flexible film 16 and the resin film 24, the solder ball 27 is formed.
Is connected to the ground wiring of the mounting substrate, the electrical characteristics of the semiconductor device can be improved. Further, as a TAB tape constituting the film substrate 10, as shown in FIG. 5, a flexible film 16 on which a conductor pattern 18 is formed.
TAB tape having a conductor pattern to which the solder bumps 22 of the semiconductor element 12 are connected on the same surface of the TAB tape,
A so-called area TAB tape can be used. As the area TAB tape, as shown in FIG. 6, a mounting surface on which the semiconductor element 12 is mounted on the other surface side of the flexible film 16 opposite to the one surface on which the conductor pattern 18 is formed. A so-called 2-metal TAB tape having a conductor pattern formed on it can be used.

In addition to the semiconductor device described above, FIG.
The present invention can be applied to the semiconductor device shown in FIG. The semiconductor device shown in FIG. 7 uses a TAB tape in which the conductor pattern 18 formed on one surface side of the flexible film 16 is composed of an inner lead 20 and an outer lead 54 protruding inward of the device hole. Is. The semiconductor element 12 is inserted from the other surface side of the flexible film 16 into the device hole of the TAB tape, and the inner lead 20 and the gold bump 22 provided on the one surface side of the semiconductor element 12 are connected. The inner lead 20 and the semiconductor element 12
The gold bumps 22 are sealed by the insulating resin layer 14 whose other surface side of the semiconductor element 12 is exposed. The semiconductor element 12 and the insulating resin layer 14 are covered with a low melting point metal layer 34 made of a low melting point metal such as solder, and the low melting point metal layer 34 and the flexible film 16 surround the periphery of the device hole. The metal layer 30 formed on the part adheres closely. The low melting point metal layer 34 and the insulating resin layer 14 are adhered to each other by the metal powder layer 36 shown in FIG. 2 or the metal layer 38 shown in FIG. The metal powder layer 3
The description of 6 or the metal layer 38 is omitted here.

In order to further improve the heat dissipation of the semiconductor device shown in FIG. 7, a heat spreader 56 may be provided on the outer surface of the low melting point metal layer 34, as shown in FIG.
A heat radiation fin 58 may be provided as shown in FIG. Further, the area TAB tape 60 shown in FIG. 10 can be used in place of the TAB tape used in the semiconductor device shown in FIGS. The area TAB tape 60 has a conductive pad 18 formed on one surface of the flexible film and a mounting pad to which the gold bump 22 of the semiconductor element 12 is connected. It should be noted that the conductor pattern 18 is insulated by the resin film 24 made of a resin such as polyimide resin except for the mounting portion of the semiconductor element 12 and the outer lead 54.

In the semiconductor device shown in FIGS. 1 to 10 described above, the flexible film 16 electrically connected to the element-side connection portion formed on one surface of the semiconductor element 12 to be mounted. A TAB tape is used as a semiconductor element mounting film having a film side connecting portion formed on one surface side. As such a TAB tape, the semiconductor element 10 mounted on the peripheral portion of the element mounting portion is mounted.
A metal layer 30 is preferably used as an adhesion layer with the low melting point metal layer 34 on the contact surface with the low melting point metal layer 14 formed so as to cover the. The metal layer 30 is formed on the surface of the flexible film 16 of the TAB tape or on the surface of the resin film 24 formed of an insulating resin such as a silicone resin that insulates a part of the conductor pattern 18, a copper foil or the like. It can be formed by fixing the metal foil of or by metal plating such as copper plating.

[0029]

EXAMPLES The present invention will be described in more detail by way of examples. Example 1 A TAB tape in which a conductor pattern 18 is formed on one side of a flexible film 16 made of a polyimide resin, and an inner lead 20 is projected inside a device hole formed in the flexible film 16 is used. used. On the other surface side of the flexible film 16 forming the TAB tape, there is formed a terminal connection pad portion provided with a bump (solder ball) as a terminal for connection with the mounting substrate. This TA
An insulative resin film 24 was formed by screen-printing a silicone-based elastomer paste on the entire surface of one side of the tape for B except the device hole. Then, a 70 μm-thick copper foil was placed on the formed resin film 24, and the TAB tape was cured to fix the metal layer 30 on the resin film 24. This cure is performed under a dry nitrogen atmosphere at 150 ° C. for 2 hours.
It was a condition of time. The electrodes formed on one surface side of the semiconductor element 12 of 15 mm square were connected to the inner leads 20 of the semiconductor mounting film thus obtained by the single bonding method. Incidentally, this semiconductor element 12
Has a gold vapor deposition layer formed on the other surface side (back surface side).

Then, the connecting portion between the semiconductor mounting film and the semiconductor element 12 was sealed with an insulating resin layer 14 formed of a silicone potting agent. Copper powder is sprinkled on the surface of the insulating resin layer 14 to form a metal powder layer 36, and then the insulating resin layer 14 is heated to 150 in a dry nitrogen atmosphere.
A metal powder layer 3 formed by fixing copper powder on the surface of the insulating resin layer 14 by performing curing at 1 ° C. for 1 hour.
6 was formed. The back surface side of the semiconductor element 12 is exposed from the insulating resin layer 14. In this way, to cover the back surface side of the semiconductor element 12 mounted on the semiconductor mounting film,
Sn-Pb to which 65 wt% of 80-100 mesh tungsten powder plated with electroless nickel was added
A eutectic solder paste was applied to form a solder paste layer, and an aluminum alloy radiation fin having a gold sputtered film formed on the bottom surface was placed on the solder paste layer. After that, with the flexible film 16 facing upward, flux is applied to the pad for terminal connection, and then Sn—Pb eutectic solder balls are arranged, and after drying, in a dry nitrogen atmosphere, at 250 ° C. for 1 minute. Reflow processing was performed.

The semiconductor device obtained after the reflow treatment is
In the semiconductor device shown in FIG. 4, the low-melting-point metal layer 34 that covers the semiconductor element 12 and the insulating resin layer 14 is a gold vapor deposition layer on the other surface side of the semiconductor element 12, and a metal powder layer 36 of the insulating resin layer 14. , And the metal layer 30 fixed on the resin film 24, the semiconductor element 12, the insulating resin layer 14, and the resin film 2
It is closely attached to 4. Therefore, as for the durability of the obtained semiconductor device, good results could be obtained even in a thermal cycle test and the like, and the heat dissipation of the semiconductor device was also good.

Example 2 For area TAB, a mounting pad to which a solder bump 22 of a semiconductor element 12 is connected is formed on a conductor pattern 18 formed on one surface side of a flexible film 16 made of a polyimide resin. Tape was used. This area TA
The flexible film 16 forming the B tape has a terminal connection pad portion provided with bumps (solder balls) as terminals for connection with the mounting substrate. An epoxy resin prepreg is arranged on the entire surface of the tape for area TAB except the mounting surface of the semiconductor element 12 to form an insulating resin film 24, and a copper foil having a thickness of 35 μm is arranged on the resin film 24. Then, heat and pressure adhesion was performed to fix the metal layer 30 on the resin film 24. This heat and pressure adhesion is 180 ℃, 3
The condition was 0 kg / cm ² . The semiconductor element 12 is formed by the flip-chip bonding method in which the solder bumps 22 formed on one surface side of the 11 mm square semiconductor element 12 are directly connected to the conductor pattern formed on the mounting surface of the semiconductor mounting film thus obtained. equipped. The semiconductor element 12 has nickel / nickel on the other side (back side).
The gold vapor deposition layer is formed.

Next, the connecting portion between the semiconductor mounting film and the semiconductor element 12 was sealed with an insulating resin layer 14 formed of an epoxy potting agent. This insulating resin layer 14 is sprinkled with copper powder on the surface thereof, and then cured under a dry nitrogen atmosphere at 150 ° C. for 1 hour to fix the copper powder to the surface of the insulating resin layer 14. A metal powder layer 36 formed by the above was formed. Semiconductor element 12
The back side of is exposed from the insulating resin layer 14. In this way, the semiconductor element 12 mounted on the semiconductor mounting film
So as to cover the back side of the above, 100 wt.% Of copper powder is added by 50% by weight, a Sn-Pb eutectic solder paste is applied to form a solder paste layer, and further, on this solder paste layer, An aluminum alloy radiating fin having a nickel / gold sputtered film formed on the bottom surface was placed. Thereafter, with the flexible film 16 facing upward, flux is applied to the terminal connecting pad portion, and then Sn—Pb eutectic solder ball bumps are arranged, and after drying, in a dry nitrogen atmosphere, 23
Reflow treatment was performed at 0 ° C. for 1 minute.

The semiconductor device obtained after the reflow treatment is
In the semiconductor device shown in FIG. 5, the low melting point metal layer 34 covering the semiconductor element 12 and the insulating resin layer 14 includes a nickel / gold vapor deposition layer on the other surface side of the semiconductor element 12 and the insulating resin layer 14.
The metal powder layer 36 and the metal layer 30 fixed on the resin film 24 adhere to the semiconductor element 12, the insulating resin layer 14, and the resin film 24. Therefore, as for the durability of the obtained semiconductor device, good results could be obtained even in a thermal cycle test and the like, and the heat dissipation of the semiconductor device was also good.

Example 3 A conductor pattern 18 made of a copper foil having a thickness of 25 μm is formed on one surface of a flexible film 16 made of a polyimide resin and having a thickness of 75 μm. The TAB tape is used in which the inner lead 20 is projected inside the punched square-shaped device hole, and the outer lead 54 is projected outward from the peripheral portion of the flexible film 16. At the periphery of the device hole on the other surface of the TAB tape, a square-shaped thickness of 25 μm
After adhering the copper foil of m, the metal layer 30 in which the surface of the copper foil is gold-plated is formed. Then, using a simple point bonder, a semiconductor element 1 of 11 mm square
After bonding all the bumps on one surface side of 2 and the inner lead 20 of the TAB tape, the connection between the semiconductor element 12 and the inner lead 20 of the TAB tape is formed by a solvent type bisphenol epoxy type potting agent. The resin layer 14 was sealed. This insulating resin layer 14 is sprinkled with copper powder on the surface thereof, and then cured under a dry nitrogen atmosphere at 150 ° C. for 1 hour to fix the copper powder to the surface of the insulating resin layer 14. A metal powder layer 36 formed by the above was formed. The back side of the semiconductor element 12 is
It is exposed from the insulating resin layer 14.

Thus, the Sn-Pb eutectic solder paste containing 50% by weight of 100-mesh copper powder was applied so as to cover the back surface side of the semiconductor element 12 mounted on the semiconductor mounting film. To form a solder paste layer,
Further, an aluminum alloy radiating fin having a nickel / gold sputtered film formed on the bottom surface was placed on the solder paste layer. After that, with the flexible film 16 facing upward, flux is applied to the pad portion for terminal connection, and then Sn-Pb is applied.
Eutectic solder balls were placed, dried, and then reflowed at 230 ° C. for 1 minute in a dry nitrogen atmosphere.

The semiconductor device obtained after the reflow treatment is
In the semiconductor device shown in FIG. 9, the low melting point metal layer 34 that covers the semiconductor element 12 and the insulating resin layer 14 includes a nickel / gold vapor deposition layer on the other surface side of the semiconductor element 12 and the insulating resin layer 14.
The metal powder layer 36 and the metal layer 30 fixed on the insulating film 24 are in close contact with the semiconductor element 12, the insulating resin layer 14, and the flexible film 16. Therefore, as for the durability of the obtained semiconductor device, good results could be obtained even in a thermal cycle test and the like, and the heat dissipation of the semiconductor device was also good.

Example 4 A solder bump 22 as a connection terminal formed on one surface of the semiconductor element 12 is connected to the same surface as the conductor pattern 18 formed on the flexible film 16 made of polyimide resin and having a thickness of 35 μm. The area TAB tape on which the conductor pattern to be formed is formed was used. This area TA
On the periphery of the mounting surface of the semiconductor element 12 of the tape for B (on the same side as the conductor pattern 18), a square-shaped copper foil having a thickness of 35 μm is provided with a resin film 24 made of an epoxy-based prepreg layer having a thickness of 60 μm. I arranged it. Then, this copper foil was fixed on the resin film 24 by heat and pressure adhesion to form the metal layer 30. This heat and pressure adhesion is 180 ° C, 30 kg / c
The condition was m ² . The conductor pattern formed on the mounting surface of the semiconductor mounting film thus obtained has a length of 11 m.
The semiconductor element 12 was mounted by a flip chip bonding method in which the solder bumps 22 formed on one surface side of the m-square semiconductor element 12 were directly connected. The semiconductor element 12 has a nickel / gold vapor deposition layer formed on the other surface side (back surface side).

Next, the connecting portion between the semiconductor mounting film and the semiconductor element 12 is formed of an insulating resin layer 14 formed by a solvent type bisphenol epoxy potting agent.
It was sealed with. The insulating resin layer 14 is sprinkled with copper powder on its surface, and then cured under a dry nitrogen atmosphere at 150 ° C. for 1 hour to fix the copper powder to the surface of the insulating resin layer 14. Then, the metal powder layer 36 is formed. The back surface side of the semiconductor element 12 is exposed from the insulating resin layer 14. Thus, the Sn—Pb eutectic crystal in which 60 wt% of 80-100 mesh tungsten powder plated with electroless nickel is added so as to cover the back surface side of the semiconductor element 12 mounted on the semiconductor mounting film. Apply a system solder paste to form a solder paste layer,
Further, an aluminum alloy radiating fin having a nickel / gold sputtered film formed on the bottom surface was placed on the solder paste layer. Then, the semiconductor mounting film on which the semiconductor element 12 was mounted was subjected to reflow treatment at 230 ° C. for 1 minute in a dry nitrogen atmosphere.

The semiconductor device obtained after the reflow treatment is
In the semiconductor device shown in FIG. 10, the low melting point metal layer 34 covering the semiconductor element 12 and the insulating resin layer 14 includes a nickel / gold vapor deposition layer on the other surface side of the semiconductor element 12 and the insulating resin layer 1.
4, the metal powder layer 36 of No. 4 and the metal layer 30 fixed on the resin film 24, the semiconductor element 12, the insulating resin layer 14,
And is closely attached to the resin film 24. Therefore, as for the durability of the obtained semiconductor device, good results could be obtained even in a thermal cycle test and the like, and the heat dissipation of the semiconductor device was also good.

[0041]

According to the present invention, it is possible to provide a semiconductor device which can substantially maintain the weight reduction and the size reduction and can quickly dissipate the heat generated in the semiconductor element. The reliability of the semiconductor device can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing one embodiment of a semiconductor device according to the present invention.

2 is a partial cross-sectional view illustrating a metal powder layer as a wettability improving layer formed on the surface of an insulating resin layer of the semiconductor device shown in FIG.

3 is a partial cross-sectional view illustrating a metal layer as a wettability improving layer formed on the surface of an insulating resin layer of the semiconductor device shown in FIG.

FIG. 4 is a sectional view showing another embodiment of the semiconductor device according to the present invention.

FIG. 5 is a sectional view showing another embodiment of the semiconductor device according to the present invention.

FIG. 6 is a sectional view showing another embodiment of the semiconductor device according to the present invention.

FIG. 7 is a sectional view showing another embodiment of the semiconductor device according to the present invention.

FIG. 8 is a sectional view showing another embodiment of the semiconductor device according to the present invention.

FIG. 9 is a sectional view showing another embodiment of the semiconductor device according to the present invention.

FIG. 10 is a sectional view showing another embodiment of the semiconductor device according to the present invention.

FIG. 11 is a cross-sectional view showing an example of a conventional semiconductor device.

FIG. 12 is a cross-sectional view showing an example of a conventional semiconductor device.

FIG. 13 is a cross-sectional view showing another example of a conventional semiconductor device.

[Explanation of symbols]

 10 film substrate 12 semiconductor element 14 insulating resin layer 16 flexible film 18 conductor pattern 20 inner lead 22 solder bump 24 insulating film 26 solder ball (bumps) 30 metal layer 34 low melting point metal layer 36 metal as wettability improving layer Powder layer 38 Metal layer as wettability improving layer

Claims (19)

[Claims] 1. A substrate-side connecting portion formed on a mounting surface of a film substrate on which a semiconductor element is mounted and an element-side connecting portion formed on one surface side of a semiconductor element facing the mounting surface are electrically connected to each other. Electrically connected semiconductor device, an insulating resin layer covering a connecting portion for electrically connecting the substrate side connecting portion of the film substrate and the element side connecting portion of the semiconductor element, the semiconductor element and the insulating resin layer And a low melting point metal layer made of a low melting point metal that melts at a temperature equal to or lower than the heat resistant temperature of the semiconductor element, and melts on at least a part of the surface of the insulating resin layer in contact with the low melting point metal layer. A wettability improving layer having improved wettability with respect to the low melting point metal as compared with the other surface of the insulating resin layer is formed. 2. The semiconductor device according to claim 1, wherein a metal layer as an adhesion layer with the low melting point metal layer is formed on the film substrate surface around the mounting portion on which the semiconductor element is mounted. 3. The low melting point metal layer covers the other surface side of the semiconductor element exposed from the insulating resin layer.
Alternatively, the semiconductor device according to claim 2. 4. The wettability improving layer is a metal powder layer made of metal powder or a metal foil layer made of metal foil, which is fixed to the contact surface of the insulating resin layer or the film substrate which is in contact with the low melting point metal layer. The semiconductor device according to any one of claims 1 to 3. 5. The semiconductor device according to claim 4, wherein the metal powder or the metal foil is made of a metal having a higher melting point than that of the low melting point metal. 6. The semiconductor device according to claim 1, wherein the low melting point metal layer is mixed with a metal powder having a melting point higher than that of the low melting point metal. 7. The high melting point metal powder mixed in the low melting point metal layer is tungsten (W) or molybdenum (M).
The semiconductor device according to claim 6, which is one or more metal powders selected from o), silver (Ag), and copper (Cu). 8. The semiconductor device according to claim 1, wherein the low melting point metal layer is mixed with an inorganic powder having a melting point higher than that of the low melting point metal. 9. The high melting point inorganic powder mixed in the low melting point metal layer is silicon dioxide (SiO ₂ ), silicon carbide (SiC), aluminum nitride (AlN), boron nitride (BN), carbon (C). The semiconductor device according to claim 8, which is one kind or two or more kinds of inorganic powders selected from the following. 10. The semiconductor device according to claim 1, wherein an insulating inorganic material is mixed in the insulating resin layer. 11. The semiconductor device according to claim 1, wherein the low melting point metal layer and the ground wiring of the conductor pattern provided on the film substrate are electrically connected. 12. The semiconductor device according to claim 1, wherein a heat dissipation member such as a heat dissipation fin or a heat spreader is mounted on the outer surface of the low melting point metal layer. 13. An element-side connecting portion formed on one surface side of a semiconductor element and a substrate-side connecting portion formed on a mounting surface of a film substrate are directly connected by connecting terminals such as solder bumps. 13. The semiconductor device according to any one of 1 to 12. 14. A TAB (Tape Auto) having a conductor pattern formed on one side of a flexible film as a film substrate.
The semiconductor device according to any one of claims 1 to 13, wherein a tape for mating bonding is used, and a semiconductor element is mounted on an inner lead forming the conductor pattern. 15. A TAB (Tape Automated Bondin) in which a pad for mounting a semiconductor element is formed on a conductor pattern formed on one surface side of a flexible film as a film substrate.
The semiconductor device according to claim 1, wherein a tape for g) is used. 16. The external connection terminal is an outer lead forming a conductor pattern.
13. The semiconductor device according to claim 1. 17. The external connection terminal formed of a bump such as a solder ball is formed on the surface of the flexible film opposite to the mounting surface on which the semiconductor element is mounted. Semiconductor device. 18. The low melting point metal is a low melting point alloy such as solder which is melted at a temperature of 450 ° C. or lower.
The semiconductor device according to claim 1. 19. A film-side connecting portion formed on one surface side of a flexible film, which is electrically connected to an element-side connecting portion formed on one surface side of a mounted semiconductor element,
The semiconductor element mounting film used in the semiconductor device according to claim 1, wherein the low melting point metal is formed at a peripheral portion of an element mounting portion of the semiconductor element mounting film and so as to cover the mounted semiconductor element. A film for mounting a semiconductor element, wherein a metal layer is formed on a contact surface with the layer as an adhesion layer with the low melting point metal layer.