JPH09266223A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the short circuit between the adjacent wires by preventing the deformation of wires of a semiconductor device or by controlling the number of wires to a fixed quantity. SOLUTION: When the semiconductor chip 5 of a semiconductor device and the inner lead 3 of a lead frame 1 are connected by a wire 4, the deformation of wire 4 can be prevented in the bonding process and the resin sealing process when the semiconductor device is manufactured, or the quantity of the wire 4 can be controlled and the short circuit of the wire 4 can be prevented by providing the semiconductor device having the loop height of the long wire 4 differentiated by stages and the loop height is differentiated from the center part to the circumferential part of the semiconductor chip 5.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a semiconductor device,
In particular, the present invention relates to a semiconductor device ensuring wire short-circuit prevention.

[0002]

2. Description of the Related Art As is well known, a conventional resin-encapsulated semiconductor device has a semiconductor chip on which an integrated circuit or the like is formed and is attached to a die pad of a lead frame with an adhesive or the like, and each bonding pad of the semiconductor chip and corresponding After connecting the inner lead of the lead frame with a wire and then integrally molding and sealing the semiconductor chip and the inner lead around it with a synthetic resin, lead each lead on the outside of the molded package. It is manufactured by separating it from the frame and bending each lead as needed.

5A and 5B are partially enlarged perspective views of a semiconductor device in which a semiconductor chip is mounted on a die pad of a conventional lead frame. The conventional semiconductor device is shown in FIG.
As shown in FIG. 5A, the semiconductor device is configured by connecting the semiconductor chip 5 and the inner leads 3 around the semiconductor chip with wires 4 having a constant loop height, or as shown in FIG. As described above, the semiconductor device is configured by alternately making the semiconductor chip 5 and the inner leads 3 around the semiconductor chip 5 different in loop height. In the semiconductor chip 5 connected to the many inner leads 3 with the wires 4 as described above, the inner leads 3, the die pad 2 and the wires 4 are resin-sealed with a synthetic resin, leaving a part of the inner leads 3. The semiconductor device is assembled as an external terminal by cutting the leads of the resin-sealed package portion and then bending the leads.

[0004]

A first problem is that in the conventional resin-sealed semiconductor device, the wire connecting the semiconductor chip and the inner lead is washed away when the resin is sealed, but each wire is sealed. This is to induce a short circuit between adjacent wires because the flow rate due to the stop is different. The reason is,
This is because the distance between the tip of the chip pad of the semiconductor chip and the inner lead is structurally non-uniform, so that the longer the wire, the more easily the synthetic resin will flow when the resin is sealed.

The second problem is that in the conventional resin-sealed semiconductor device, the wire loop height is constant,
As the length of the wire connecting the semiconductor chip and the inner lead becomes longer, the wire after bonding is more likely to be slackened and deformed, and the resin is easily flown by the sealing resin during resin sealing to cause a short between adjacent wires. Is to induce. The reason is that as the length of the wire connecting the semiconductor chip and the inner lead increases, the flow resistance area received by the synthetic resin during resin sealing increases, and the wire tension is low, so This is because the amount of wire flow at that time increases and the amount of wire flow becomes non-uniform due to the wire length, causing a flow amount between adjacent wires and inducing a short circuit.

In the resin-sealed semiconductor device of the present invention, when the semiconductor chip and the inner lead tip of the lead frame are bonded with a wire at the time of assembling the semiconductor device, a tension is applied to the wire to prevent the wire from sagging or deforming. In addition, by preventing the flow of the wire when injecting the synthetic resin at the time of resin sealing, or by controlling the wire flow amount to a constant amount, the short circuit between the adjacent wires after resin sealing is prevented. The purpose is to

[0007]

According to the present invention, a plurality of bonding pads of a semiconductor chip mounted on a die pad of a lead frame and a plurality of inner leads of the lead frame are connected by wires, respectively, and these are made of synthetic resin. In a semiconductor device formed by sealing the wires with each other, the loop height of each wire is directed toward the bonding pad in the peripheral portion from the bonding pad in the central portion of the semiconductor chip depending on the length of each wire. It is characterized in that it is different in a staircase.

[0008]

According to the present invention, in the wire connecting between the semiconductor chip and the inner lead of the lead frame, the wire loop height is stepwise changed according to the length of the wire to make the actual wire length uniform. The tension of the wire itself can be controlled for each wire. For this reason, it is possible to prevent the wire flow from occurring due to the flow resistance of the resin when the synthetic resin is injected during the resin sealing, or to control the wire flow to a constant amount. For example, for a wire with a long distance between the bonding pad of the semiconductor chip and the inner lead of the lead frame, the wire flow amount during resin sealing is generally long because the wire length is long and the wire tension is low. Therefore, the amount of wire flow during resin encapsulation can be controlled by configuring the semiconductor device by the above method.

[0009] Generally, in a plurality of wires connecting between a semiconductor chip and inner leads of a lead frame, the more the wire goes from the center of the semiconductor chip to the periphery, the more between the bonding pad of the semiconductor chip and the inner lead of the lead frame. Since the distance is long and the wire is long, the resin flow resistance during resin encapsulation also tends to increase from the center of the semiconductor chip toward the periphery. The amount of wire flow at the time of stopping can be controlled.

[0010]

Embodiments of the present invention will now be described with reference to the drawings.

1A and 1B are a plan view and a side view of the semiconductor device according to the first embodiment of the present invention, and FIG.
(A), (b) is a partially expanded perspective view of the bonding wire of FIG. In the semiconductor device according to the first embodiment of the present invention, as shown in FIGS. 1A and 1B and FIGS. 2A and 2B, an electric signal input / output to / from the semiconductor chip 5 is It is output from the bonding pad 6 to the external terminal via the wire 4 and the inner lead 3. Here, the semiconductor chip 5 and the inner lead 3 of the lead frame 1 are connected by a wire 4, but a long wire 4 of the plurality of wires 4 is connected.
By selectively lowering the loop height, the substantial wire length can be easily made uniform, and the tension of the long wire 4 is increased, so that the deformation of the wire 4 after bonding and the subsequent process can be performed. It is possible to prevent the flow of the wires 4 due to the flow resistance at the time of injecting the synthetic resin in a certain resin sealing process or to make the flow amount of the wires 4 uniform among the plurality of wires 4, and thus, in the bonding process and the resin sealing process. The semiconductor device and the manufacturing method thereof can be stabilized.

3A and 3B are a perspective view showing a wire flow amount after resin sealing and a graph showing a relation between a wire loop height and a wire tension and a wire length and a wire flow amount. As shown in FIGS. 3A and 3B, in the semiconductor device according to the first embodiment of the present invention, the higher the loop height of the wire 4, the lower the wire tension and the larger the wire flow amount. In addition, as the wire length increases, the wire tension tends to decrease and the wire flow amount tends to increase.

4A, 4B, and 4C are a side view and a perspective view of a semiconductor device according to a second embodiment of the present invention. In the semiconductor device according to the second embodiment of the present invention, as shown in FIGS. 4A and 4B, as the wire 4 extends from the center of the chip 5 to the periphery, the wire length becomes longer, but the flow resistance of the resin is increased. According to the structure, the loop height of the wire 4 is lowered stepwise from the center of the chip 5 to the periphery, or FIG.
As shown in (a) and (c), a semiconductor having a structure in which the loop height of the wire 4 is stepwise lowered in a portion where the wire length is long due to the structure of the lead frame 1 even near the central portion of the chip 5. By providing the device, it is possible to prevent the wire 4 from being deformed in the bonding process during the semiconductor device assembly and to prevent the wire from flowing in the resin sealing process, or to control the deformation amount to a certain amount.

[0014]

The first effect is that it is possible to prevent wire deformation at the time of bonding and wire flow at the time of resin encapsulation with respect to a wire having a long structure, or to control the wire flow amount to a constant amount. is there. The reason is that for a wire that is structurally long, the loop height can be made uniform and the tension can be given to the wire by selectively lowering the loop height stepwise. This is because it is possible to control the deformation due to the slack of the wire at the time of bonding, and subsequently the wire flow at the time of resin sealing.

The second effect is that the wire extending from the center of the semiconductor chip to the periphery has a higher flow resistance to the injection of the synthetic resin at the time of resin encapsulation due to the structure, but the deformation resistance depends on the flow resistance of the resin. It is possible to provide a high wire structure. The reason is that by lowering the loop height of the wire stepwise from the center of the semiconductor chip toward the periphery, tension can be applied to the wire and the wire length can be made more uniform. This is because the wire flow can be prevented or the wire flow amount can be made uniform.

[Brief description of drawings]

1A and 1B are a plan view and a side view of a semiconductor device according to a first embodiment of the present invention.

2 (a) and 2 (b) are partially enlarged perspective views of the bonding wire of FIG.

3A and 3B are a perspective view showing a wire flow amount after resin sealing and a graph showing a relationship between a wire loop height, a wire tension, and a wire length wire flow amount.

4 (a), (b), and (c) are a side view and a perspective view of a semiconductor device according to a second embodiment of the present invention.

5A and 5B are perspective views showing an example and another example of a bonding wire of a conventional semiconductor device.

[Explanation of symbols]

 1 lead frame 2 die pad 3 inner lead 4 wire 5 semiconductor chip 6 bonding pad 7 wire flow rate

Claims (3)

[Claims] 1. A semiconductor in which a plurality of bonding pads of a semiconductor chip mounted on a die pad of a lead frame and a plurality of inner leads of the lead frame are respectively connected by wires and these are sealed with a synthetic resin or the like. The semiconductor device is characterized in that the loop height of each of the wires is different stepwise. 2. The semiconductor device according to claim 1, wherein the loop height of each wire differs stepwise according to the length of the wire. 3. The semiconductor according to claim 1, wherein the loop height of each wire is different from the central bonding pad of the semiconductor chip toward the peripheral bonding pad in a stepwise manner. Placement.