JP3847242B2 - Semiconductor device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor device having a wireless communication function, and more particularly, to a semiconductor device with high productivity and low manufacturing cost and a manufacturing method thereof.
[0002]
[Prior art]
FIG. 4 shows a configuration of a conventional non-contact IC tag. 21 is a semiconductor chip, 21a is a first terminal of the semiconductor chip 21, and 21b is a second terminal. A first lead 23, a second lead 24, and a die pad 25 are formed on the wiring board 22.
[0003]
As shown in FIG. 4, the semiconductor chip 21 is placed on the die pad 25. The first terminal 21 a and the second terminal 21 b of the semiconductor chip 21 are connected to the internal terminal (left terminal) of the first lead 23 and the internal terminal of the second lead 24 via wires 26, respectively. ing. Further, the semiconductor chip 21 and the die pad 25 are sealed with a sealing resin 27 including the wire 26. On the other hand, the first terminal 29a and the second terminal 29b of the metal wire coil 29 are connected to the external terminal (right terminal) of the first lead 23 and the external terminal of the second lead 24 by soldering, respectively. . These components are finally molded with the exterior resin 28 to form a non-contact IC tag.
[0004]
In this non-contact IC tag, the metal wire coil 29 functions as an antenna, and can communicate with the reader / writer of the equipment body in a non-contact manner.
[0005]
Such a conventional non-contact IC tag has a problem that the manufacturing cost increases for the following reasons.
[0006]
(1) Many components such as a wiring board, a metal wire coil, a sealing resin, and an exterior resin are used.
[0007]
{Circle around (2)} The manufacturing process is complicated, including the connection between the wiring board and the metal wire coil, the molding with the exterior resin, and the like.
[0008]
{Circle around (3)} Manufacturing costs are expensive because it takes man-hours to handle (divide and package) the wiring board.
[0009]
(4) The wiring board is expensive.
[0010]
As a countermeasure against such an increase in cost, there is a means that eliminates the need for a metal wire coil by forming a coil-shaped antenna circuit on a wiring board in advance by patterning as described in Patent Document 1.
[0011]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-150068 (page 4, FIG. 1)
[0012]
[Problems to be solved by the invention]
However, according to this means, there is a problem that a space for forming the antenna circuit is required, which increases the size of the wiring board and increases its price.
[0013]
Further, when manufacturing a non-contact IC tag, it is ideal to use a plastic mold package used in a normal semiconductor package because the cost required for the package can be minimized. It is extremely difficult to use a mold package. That is, the communication distance of the antenna is generally proportional to the number of turns and the diameter of the coil, but when forming the coil with lead wires, the length of the lead wire (hereinafter referred to as the lead length) is increased when the number of turns and the diameter of the coil are increased. Is inevitably long, so that lead wires are deformed or short-circuited during transfer molding and handling of sealing resin in plastic mold packages due to insufficient strength of lead wires. Wireless communication characteristics tend to be unstable.
[0014]
For this reason, conventionally, when a plastic mold package is used, it has been difficult to manufacture a non-contact IC tag having an antenna circuit that supports long-distance communication.
[0015]
An object of the present invention is to solve such problems in the prior art and to provide a non-contact IC tag that can be manufactured at a low cost and has a long communication distance.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, a semiconductor device of the present invention includes a die pad and a semiconductor chip placed on the die pad. Here, a plurality of lead wires are arranged around the die pad. A plurality of lead wires are connected in series via wires, and a coiled circuit is formed around the die pad by the plurality of lead wires and wires. Further, the semiconductor chip, the die pad, the plurality of lead wires, and the wire are sealed with a sealing resin.
[0017]
In order to achieve the above object, in the method of manufacturing a semiconductor device of the present invention, a step of placing a semiconductor chip on a die pad of a lead frame in which a plurality of lead wires and a die pad are connected, and a plurality of lead frames The lead wires are connected in series via wires, and a coil-shaped circuit is formed by a plurality of lead wires and wires, and the semiconductor chip, die pad, the plurality of lead wires and wires are sealed with a sealing resin. And a step of separating the lead wire and the die pad from the lead frame.
[0018]
According to these configurations, each lead wire is connected to and held by the lead frame until it is separated from the lead frame. Therefore, even when the overall length of the coiled circuit becomes long, for example, the lead wire is not deformed during transfer molding or handling of the sealing resin in a plastic mold package, and the semiconductor device has high productivity and low manufacturing cost. Can be provided.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the structure of the lead frame portion of the non-contact IC tag in the present embodiment. The lead frame 2 is connected to the die pad 4 and has a plurality of lead wires arranged around the die pad 4. The plurality of lead wires form a first lead group 3 a at the top of the lead frame 2, and a second lead group 3 b at the bottom of the lead frame 2. Hereinafter, the plurality of lead wires will be referred to as the lead wire 10a, the lead wire 20a, and the lead wire 30a in order from the die pad 4 side (inner side) of the first lead group 3a, and the die pad of the second lead group 3b. The four leads are referred to as a lead wire 10b, a lead wire 20b, and a lead wire 30b, respectively.
[0020]
In this state, since each lead wire is connected to the lead frame 2 and does not form a coil shape, it does not function as an antenna. Moreover, since the total length of each lead wire is short and both ends thereof are connected to the lead frame 2, the strength of each lead wire is high and its shape is stable.
[0021]
FIG. 2 shows the structure of a non-contact IC tag. Thus, the semiconductor chip 1 is placed on the die pad 4 disposed in the center.
[0022]
Further, the first terminal 1 a and the second terminal 1 b of the semiconductor chip 1 are connected to the right terminal of the lead wire 10 a and the right terminal of the lead wire 30 b via the wire 5, respectively.
[0023]
Further, the left terminal of the lead wire 10a and the right terminal of the lead wire 20a are connected to the left terminal of the lead wire 10b and the right terminal of the lead wire 10b through the wire 5, respectively.
[0024]
Also, the left terminal of the lead wire 20a and the right terminal of the lead wire 30a are connected to the left terminal of the lead wire 20b and the right terminal of the lead wire 20b through the wire 5, respectively.
[0025]
Further, the left terminal of the lead wire 30 a is connected to the left terminal of the lead wire 30 b via the wire 5.
[0026]
The semiconductor chip 1, the die pad 4, the first lead group 3 a, the second lead group 3 b, and the wire 5 are sealed and fixed by a sealing resin 6.
[0027]
In the state of FIG. 2, each lead wire is connected in series via a plurality of wires 5 to constitute one conductor. A coiled circuit is formed by this conducting wire, and has a function of an antenna. The non-contact IC tag shown in FIG. 2 can communicate with the reader / writer of the equipment body in a non-contact manner.
[0028]
FIG. 3 shows a manufacturing process of the non-contact type IC tag shown in FIG. Hereinafter, a method for manufacturing the non-contact type IC tag will be described with reference to FIG.
[0029]
First, as shown in FIG. 3A, the semiconductor chip 1 is placed on the die pad 4 connected to the lead frame 2.
[0030]
Next, as shown in FIG. 3B, each lead wire is connected in series via the wire 5 to form one conductor, and the coil-like circuit shown in FIG. 2 is formed by this conductor.
[0031]
Next, as shown in FIG. 3C, the first terminal 13 a and the second terminal 13 b of the coiled circuit are respectively connected to the first terminal 1 a and the second terminal 1 b of the semiconductor chip 1 and the wire 5. Connect.
[0032]
Subsequently, as shown in FIG. 3D, the semiconductor chip 1, the first lead group 3 a, the second lead group 3 b, the die pad 4, and the wire 5 are sealed with a sealing resin 6.
[0033]
At this stage, since each lead wire is connected to the lead frame 2 and does not form a coil shape, there is no function of the antenna. In addition, each lead wire has a short overall length and both ends thereof are connected to the lead frame 2, so that the strength of each lead wire is high and the shape is stable. Handling and resin sealing in each manufacturing process described above It is possible to prevent the lead wire from being deformed and the accompanying short circuit.
[0034]
Thereafter, each lead wire and the die pad 4 are separated from the lead frame 2 to complete a non-contact IC tag.
[0035]
In this state, each lead wire is separated from the lead frame 2 and connected in series via a plurality of wires to form a coiled circuit, and has a function of an antenna circuit.
[0036]
In the conventional example, since the lead wire forms the coil shape from the beginning of the manufacturing process, the lead length becomes long and the strength of the lead wire is insufficient, and handling of each manufacturing process and the lead wire by resin sealing In some cases, the wireless communication characteristics may become unstable in the non-contact IC tag due to deformation and a short circuit that accompanies it. However, according to the present embodiment, the lead wire is not damaged, Since the coil shape is formed, good communication characteristics can be obtained in the obtained non-contact IC tag.
[0037]
In addition, according to the present embodiment, a non-contact IC tag can be manufactured by utilizing the technology, equipment, and materials in the conventional inexpensive plastic package as described above, so that the non-contact IC tag is produced at an extremely low cost. be able to.
[0038]
In this embodiment mode, the antenna circuit is formed using six lead wires. However, the wireless communication function of the non-contact IC tag can be enhanced by using a larger number of lead wires. Further, the shape of the lead wire is not limited to the coil shape, and can be various shapes for forming the antenna circuit.
[0039]
Further, the technical idea of the present invention in which an antenna circuit is formed using a plurality of lead wires and wires is not limited to the above-mentioned non-contact IC tag, but various wireless communication functions such as a non-contact IC card are required. It can be applied to a semiconductor device.
[0040]
【The invention's effect】
According to the present invention, a semiconductor device having high productivity, low manufacturing cost, and long communication distance can be stably produced.
[Brief description of the drawings]
FIG. 1 is a plan view showing a configuration of a lead frame portion of a non-contact IC tag according to the present invention. FIG. 2 is a plan view showing an overall configuration of a non-contact IC tag according to the present invention. FIG. 4 is a plan view showing the overall structure of a conventional non-contact IC tag. DESCRIPTION OF SYMBOLS
1, 21 Semiconductor chip 1a, 21a First terminal 1b, 21b of semiconductor chip Second terminal 2 of semiconductor chip Lead frame 3a First lead group 3b Second lead group 4, 25 Die pad 5, 26 Wire 6, 27 Sealing resin 21a First terminal 21b of semiconductor chip Second terminal 22 of semiconductor chip Wiring substrate 23 First lead 24 Second lead 28 Exterior resin 29 Metal wire coil 29a First terminal 29b of metal wire coil Second terminal 10a, 20a, 30a, 10b, 20b, 30b of metal wire coil Lead wire

Claims (2)

A semiconductor device comprising a die pad and a semiconductor chip mounted on the die pad,
A plurality of lead wires are arranged around the die pad,
The plurality of lead wires are connected in series via wires, and a coiled circuit is formed around the die pad by the plurality of lead wires and wires,
The semiconductor device, wherein the semiconductor chip, the die pad, the plurality of lead wires, and the wire are sealed with a sealing resin. Placing a semiconductor chip on the die pad of a lead frame to which a plurality of lead wires and a die pad are connected;
Connecting the plurality of lead wires in series via wires, and forming a coiled circuit with the plurality of lead wires and the wires; and
Sealing the semiconductor chip, the die pad, the plurality of lead wires, and the wire with a sealing resin;
A method of manufacturing a semiconductor device, comprising: separating the lead wire and the die pad from the lead frame.

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