Semiconductor device

A semiconductor device according to the present invention includes a base tape (film carrier tape); a semiconductor chip mounted on the base tape; conducting leads formed on the base tape to be connected to the semiconductor chip; input terminals and output terminals connected to the conducting leads; and a protecting layer formed to cover the conducting leads completely. The base tape is provided at its side edges with roller-contact regions, where carrier rollers are to be in contact with. No holes and no unevenness area is formed on the roller-contact regions.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the priority of Application No. 2007-288026, filed Nov. 6, 2007 in Japan, the subject matter of which is incorporated herein by reference.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a semiconductor device fabricated using a tape-shaped base member. In more detail, the present invention relates to a semiconductor device (package) of a structure of COF (Chip On Film), TCP (Tape Carrier Package) or the like.

BACKGROUND OF THE INVENTION

According to TCP and COF using a tape-shaped base member, a semiconductor package is fabricated, for example, using a polyimide tape having a width of about 35 mm. A copper foil or a copper plating layer is formed on the polyimide tame to form an electric circuit thereon. According to a TCP type of semiconductor package, a polyimide tape is removed at an area for a semiconductor chip, and copper leads connected to the semiconductor chip are exposed, which is called “flying lead structure”. On the other hand, according to a COF type of semiconductor package, a polyimide tape remains at an area for a semiconductor chip, which is not a “flying leads structure”.

FIGS. 1 and 2show a conventional COF type of semiconductor package10, hereinafter called “COF package”.FIG. 1is a perspective view, whileFIG. 3shows a couple of COF package10connected to each other. InFIG. 1, a reference numeral11represents a semiconductor chip; and a reference numeral12represents bump electrodes formed on the semiconductor chip11. A reference numeral14represents a flexible base film (base tape), which may be made of an insulating material such as a polyimide resin and a glass epoxy resin; a reference numeral13represents conductive leads formed on the base film14; and a reference numeral16represents a solder resist for protecting the conductive leads. The solder resist16is formed, as shown inFIG. 1, to cover a surface of the package except an area on ends of the conductive leads13and surroundings.

Inner leads17are connected to the bump electrodes in a thermocompression bonding process. A sealing resin15is formed on upper and side surfaces of the semiconductor chip11to cover the semiconductor chip. A reference numeral18represents input terminals to be connected to an input circuit board; and a reference numeral19represents output terminals to be connected to an output circuit board. The tape (base film) is proved at its sides with perforations holes (sprocket holes)20, which are used when conveying the base film. The perforation hoes20are arranged to have a pitch of 4.75 mm, in general.

An individual COF package10has a length of 17 mm. However, since COF packages are formed on a base tape, as shown inFIG. 2, each of divided COF packages has a length of 19 mm. That is because, the pitch of the perforation holes20is 4.75 mm and four perforation holes are arranged on each COF package. Practically, base film is shaped to have a length of 40 to 80 m with a number of COF packages each having a length of 19 mm.

As described above, according to the conventional COF package, even thought an effective package size (length) is 17 mm, the perforation holes20cause a worthless space corresponding to a multiple of 4.75 mm. In other words, each of the COF package is shaped to have a length of 19 mm including a worthless length of 2 mm.

For conveying a tape carrier, in addition to the above-describe type of structure using sprocket holes, a type of device which is carried using rollers has been proposed.

In patent applications, JPH06-310570A and JP2003-229441A, a tape carrier is conveyed by a roller mechanism.

According to a structure shown in Patent Publication 1, since sprocket holes are provided at a region where a roller is to be in contact with, there were the following problems.(1) The strength of a tape is lowered by sprocket holes.(2) Unevenness over the sprocket holes makes vibration in a conveying process, and therefore, a tape is hardly conveyed smoothly.

Further, according to a structure shown in Patent Publication 2, the same or similar problems as the Patent Publication 1 arise.

OBJECTS OF THE INVENTION

It is an object of the present invention is to provide a semiconductor package structure in which flexibility of package size may be improved.

Another object of the present invention is to provide a semiconductor package structure in which reliability of conveying process is improved.

Still another object of the present invention is to provide a semiconductor package structure which may be fabricated easily with simpler process with lower manufacturing costs.

SUMMARY OF THE INVENTION

According to the present invention, a semiconductor device includes a base tape (film carrier tape); a semiconductor chip mounted on the base tape; conducting leads formed on the base tape to be connected to the semiconductor chip; input terminals and output terminals connected to the conducting leads; and a protecting layer formed to cover the conducting leads completely. The base tape is provided at its side edges with roller-contact regions, where carrier rollers are to be in contact with. No holes and no unevenness area is formed on the roller-contact regions.

According to the present invention, since no sprocket hole is formed on a base tape, an actual package size may be selected and designed flexibly. Usually, a COF has a length of 40 m. According to conventional technology, shown inFIGS. 1 and 2, each package occupies a length of 19 mm and 2105 pieces of packages can be mounted on the tape of 40 m long. On the other hand, according to the present invention, each package may have a length of 17.1 mm, and 2339 pieces of packages (COFs100) may be mounted on the tape of 40 m long. Namely, according to the present invention, as compared with the conventional technology, 11% of more packages can be formed on the same length of tape; and therefore, manufacturing costs may be reduced and fabrication effectiveness may be improved.

Further, according to the present invention, since no sprocket hole is formed on a base tape, the tape may be shaped flat at an area which is to be in contact with a roller. Therefore, a possibility of miss conveying can be reduced. In addition, according to the present invention, a process for forming sprocket holes can be omitted, and as a result, a package may be fabricated easily with simpler process with lower manufacturing costs. Still further, according to the present invention, since no sprocket hole is formed on a base tape, a base tape has a higher strength at edges.

If a base tape (base tape) is provided with an area for contact with a roller, which is covered with a protection layer, such as a solder resist, strength of the base tape may be increased.

DESCRIPTION OF REFERENCE NUMERALS

DETAILED DISCLOSURE OF THE INVENTION

FIG. 3is a plan view (perspective view) showing a COF package according to a first preferred embodiment of the present invention.FIG. 4is a plan view showing COF packages shown inFIG. 3, which are mounted on a base tape. A semiconductor package (COF package)100according to the present embodiment, includes a base tape (film carrier tape)104; a semiconductor chip101mounted on the base tape104; conducting leads103formed on the base tape104to be connected to the semiconductor chip101; input terminals108and output terminals109connected to the conducting leads103; and a protecting layer (solder resist)106formed to cover the conducting leads103to protect the conducting leads103. The protecting layer106is formed not to cover the ends of the conducting leads103and their surroundings.

The base tape104is a flexible tape and may be formed of an insulating material, such as a polyimide resin, a glass epoxy resin, and the like. The base tape104includes roller-contact regions100X, where carrier rollers are to be in contact with. The roller-contact regions100X are arranged about right and left edges of the base tape104. The roller-contact regions100X are formed to be flat in level and not provided with holes, such as perforation holes, or unevenness parts.

The roller-contact regions100X are completely covered with the protecting layer106. That is, the protecting layer106covers the conducting leads103and extends to the edges of the base tape104.

Bump electrodes102are formed on the semiconductor chip101and are connected to the inner leads107. The inner leads107are connected to the bump electrodes102by heating and applying pressure to them. Upper and side surfaces of the semiconductor chip101are covered with a sealing resin105for protection. The input terminals108are connected to an input-side circuit board while the output terminals109are connected to an output-side circuit board.

InFIG. 4, each package100has a length of about 17 mm. Next two packages200has a distance between them, and therefore, an actual package size (length) would be 17 mm+α (alpha). Here, a value α (alpha) is about 0.1 mm. On the other hand, according to a conventional structure, shown inFIGS. 1 and 2, the size of a semiconductor chip is defined by a multiple of perforation holes. According to the present invention, no perforation holes are formed on the base tape, a semiconductor package may have more flexibility in dimension.

Usually, a COF has a length of 40 m. According to conventional technology, shown inFIGS. 1 and 2, each package occupies a length of 19 mm and 2105 pieces of packages can be mounted on the tape of 40 m long. On the other hand, according to the present invention, each package may have a length of 17.1 mm, and 2339 pieces of packages (COFs100) may be mounted on the tape of 40 m long. Namely, according to the present invention, as compared with the conventional technology, 11% of more packages can be formed on the same length of tape; and therefore, manufacturing costs may be reduced and fabrication effectiveness may be improved.

FIG. 5is an explanatory view illustrating a general structure of a carrier device, which is applicable to the present invention. InFIG. 5, a drive roller142is rotated by a servomotor140. A TAB tape (base tape104), which is a tape carrier for semiconductor devices, is gripped and carried between the drive roller142and a support roller146, which is opposing to the drive roller142. When the TAB tape104is carried, a free roller144is rotated. The free roller144opposed to another support roller148.

The rollers142,144,146and148are in contact with the roller-contact regions100X of the base tape104. According to the present invention, since no sprocket hole is formed on the base tape104, the tape may be shaped flat at the roller-contact regions100X. Therefore, a possibility of miss conveying (carrying) of the base tape104can be reduced. In addition, according to the present invention, a process for forming sprocket holes can be omitted, and as a result, a package may be fabricated easily with simpler process with lower manufacturing costs. Still further, according to the present invention, since no sprocket hole is formed on the base tape104, the base tape104has a higher strength at edges.

Further, since the roller-contact regions100X are covered completely with the protection layer106, such as a solder resist, mechanical strength of the roller-contact regions100X can be increased.

FIG. 6is a plan view (perspective view) showing a COF package200according to a second preferred embodiment of the present invention. According to the second preferred embodiment, a solder resist206does not extend to edges of a base tape104so that the solder resist206does not reach roller-contact regions200X. In other words, carrying rollers are in contact with a surface of the base tape104directly. The carrier device, shown inFIG. 5, is also applicable to the second preferred embodiment. Other components are the same as those of the first preferred embodiment, and the same description is not repeated.

FIG. 7is a plan view (perspective view) showing a TCP300according to a third preferred embodiment of the present invention. A semiconductor package (TCP)300according to the present embodiment, includes a base tape (film carrier tape)304; a semiconductor chip301mounted on the base tape304; conducting leads303formed on the base tape304to be connected to the semiconductor chip301; input terminals308and output terminals309connected to the conducting leads303; and a protecting layer (solder resist)306formed to cover the conducting leads303to protect the conducting leads303. The base tape304is provided with a device hole in which the semiconductor chip301is mounted.

In the same manner as the first and second preferred embodiments, the base tape304is a flexible tape and may be formed of an insulating material, such as a polyimide resin, a glass epoxy resin, and the like. The base tape304includes roller-contact regions300X, where carrier rollers are to be in contact with. The roller-contact regions300X are arranged about right and left edges of the base tape304. The roller-contact regions300X are formed to be flat in level and not provided with holes, such as perforation holes, or unevenness parts.

The roller-contact regions300X are completely covered with the protecting layer306. That is, the protecting layer306covers the conducting leads303and extends to the edges of the base tape304.

Bump electrodes302are formed on the semiconductor chip301and are connected to the inner leads307. The inner leads307are connected to the bump electrodes302by heating and applying pressure to them. Upper and side surfaces of the semiconductor chip301are covered with a sealing resin305for protection. The input terminals308are connected to an input-side circuit board while the output terminals309are connected to an output-side circuit board. The carrier device, shown inFIG. 5, is also applicable to the second preferred embodiment.

According to the third preferred embodiment, the same advantages as the first preferred embodiments can be obtained. According to the third preferred embodiment, since no sprocket hole is formed on the base tape304, the tape304may be shaped flat at the roller-contact regions300X. Therefore, a possibility of miss conveying (carrying) of the base tape304can be reduced. In addition, according to the present invention, a process for forming sprocket holes can be omitted, and as a result, a package may be fabricated easily with simpler process with lower manufacturing costs. Still further, according to the present invention, since no sprocket hole is formed on the base tape304, the base tape304has a higher strength at edges.

FIG. 8is a plan view (perspective view) showing a TCP400according to a fourth preferred embodiment of the present invention. According to a semiconductor package (TCP)400, a solder resist306does not extend to side edges of the base tape304. In other words, roller-contact regions400X are not covered with the solder resist306, so that carrier rollers are in contact with the surface of the base tape304directly. The carrier device, shown inFIG. 5, is also applicable to the fourth preferred embodiment. Other components and advantages are the same as those of the above described embodiments, and the same description is not repeated.