JP3073329B2 - Lead frame for cerdip package - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame for a cerdip package.

[0002]

2. Description of the Related Art FIG. 3 shows a state in which a slit is formed between adjacent lead frames in a manufacturing process of a lead frame for a cerdip package. The lead frame for cerdip package is formed by connecting a plurality of lead frames as shown in the figure.
After forming a lead pattern such as this, punching is performed so as to leave a connection portion between adjacent lead frames. The lead frame for cerdip package is formed by connecting the outer ends of the external leads 5 to the frame 6, so that the leads are not deformed when the lead frame is transferred or assembled. The connection part 7 connects between the frame frames 6 of the adjacent lead frames. In FIG. 3, a hatched portion is a portion to be slit by a punch. The frame 6 is formed by being connected in a rectangular frame shape except for the connecting portion 7 by the slitting process.

[0003]

The punch used for slitting is of a thin thickness corresponding to the punching width. In FIG. 3, A indicates the punch position used for slitting. As shown in the drawing, in the slit punching process, one end side of the punch is extended to a position outside the lead frame. For this reason, one end side becomes free at the time of slitting, and there arises a problem that a scrap is moved, rotated, or scraped up in the die.

FIG. 3 shows a state in which the lead frame is processed in a flat state to form a lead pattern and the like. Thereafter, the lead frame is formed by bending the leads at substantially right angles to obtain a final product. . In FIG. 3, a broken line B indicates a bending position where the lead is bent. The bending position is a boundary position in a range where the semiconductor chip is mounted on the lead frame and sealed, and corresponds to a boundary position between the external lead and the internal lead.
In the lead frame product, the outer end of the external lead 5 is connected to and supported by the frame 6 as described above. However, when the lead is formed by bending, the lead and the frame 6 are bent together to form a substantially U-shape. It is formed in a shape.

When the frame 6 is bent together with the external leads 5, the edge of the frame 6 at the bending position slightly bulges outward due to the thickness at the bending position where the frame 6 is bent. The frame 6 is finally separated from the external leads 5 and becomes unnecessary for the semiconductor device. However, when assembling the semiconductor device, the frame 6 is supported and positioning is performed. There is a problem that minute swelling at the bending position of the frame 6 lowers the accuracy of positioning and the like.

For this reason, it is useful if the problem of bulging at the bending position can be solved and the problem of the above-mentioned scum rising can be solved. Therefore, the present invention has been made to solve these problems, and an object of the present invention is to prevent scraps from rising during slit punching in manufacturing a lead frame for a cerdip package, and to reduce a frame frame. It is an object of the present invention to provide a lead frame for a cerdip package that can effectively solve the problem of swelling at a bending position during bending.

The present invention has the following arrangement to achieve the above object. That is, the outer end of the lead is
Lead frame connected to and supported by the opposite frame
Frames are placed adjacent to each other and
Frame is the other opposing frame of the frame frame
Are connected by connecting portions formed at the outer edges of the
And over de the other of the opposing frame portion, at rie de external lead and corresponding to the boundary position of the inner lead bending bent at the location shaped by Cerdip package lead frame formed in a substantially U-shape together , The connection portion is
Formed by slitting the frame material in the width direction.
Adjacent frames formed by the slitting process
Wherein the switching <br/> cutout portion in the bending position of each of the outer edge portion facing the over arm portion.

[0008]

By forming the notch at the bending position of the frame frame, it is possible to prevent the frame from expanding beyond the frame width of the frame frame at the bending position when the frame frame is bent and formed. Thus, when performing assembly or the like, allowing the <br/> this that female accurately positioning the rie de frame. In addition, it is possible to solve the problem that the product is scratched during transportation due to the swelling of the frame. Also, the frame of the adjacent lead frame
Prevents dregs when slitting frames
Can be processed.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The third package lead frame according to the present invention is characterized in that when slitting is performed in the manufacturing process, slitting is performed so that a notch is formed at a position where the frame 6 is bent and formed.
FIG. 1 is an enlarged view of a portion where a lead frame is slit. In the drawing, the passing range of the punch is indicated by C, and the portion from which the lead frame material is removed by slitting is indicated by oblique lines.

As shown in the drawing, in this embodiment, a notch is formed in the frame 6 to cut out the slit. Therefore, a punch having small projections formed on the outer surface is used. The notch 10 is formed in the outer edge. In the figure, the broken line B indicates the bending position when the frame 6 and the external lead 5 are bent as described above, and the cutout portion 10 is set so as to be located on the bending position B. The punch is provided with projections on both side surfaces thereof, and a notch 10 is simultaneously formed in the outer edge of the adjacent frame 6 to perform slit punching. Although FIG. 1 shows one punch for slitting the lead frame, slits are similarly formed on the opposite side across the connection portion 7.

According to the method of forming the notch 10 in the frame 6 and cutting the slit, the chip is guided by the notch so that the chip does not move or rotate in the die. It is possible to eliminate a problem such as dregs rising. Further, by forming the notch 10 in the frame 6, it is possible to prevent the outer edge of the frame 6 from bulging outward at the bending position even when the frame 6 and the external lead 5 are bent during bending. Can be. In the lead frame in which the notch portion 10 is formed, the bending position of the frame frame 6 is formed to have a narrow width in advance, so that the outer edge of the frame frame 6 can be prevented from bulging outward during bending.

FIG. 2 is a cross-sectional view after the lead frame for cerdip package is bent at the position of the line B. The cross section shows the position of the dashed line D in FIG. 1, and the frame 6 and the external lead 5 are both bent into a substantially U-shape as shown in FIG. The above-mentioned bulge at the bending position of the frame frame 6 occurs at the bending position B in FIG. 2. However, in the case of the lead frame with slits described above, the bulge at the outer edge of the frame lead 6 when the bending process is performed. Therefore, the lead frame can be bent with high dimensional accuracy. Also, in the case of the present method, there is not much difficulty in processing a die, a punch, and the like, and a slit punching process similar to the conventional one can be performed.

[0013]

According to the lead frame for cerdip package according to the present invention, as described above, the outer edge of the frame does not bulge outward at the bending position of the frame when the frame is bent. When assembling a semiconductor device, it is possible to accurately perform operations such as positioning a lead frame with a frame frame.
Further, by preventing swelling in the frame frame, it is possible to solve the problem that the product is scratched when the lead frames are overlapped . In addition, adjacent
Slit the lead frame
To prevent lead-in
It has a significant effect, such as being able to work .

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an enlarged part of a lead frame for a cerdip package in which a slit is formed.

FIG. 2 is an explanatory view showing a state in which a lead frame for a cerdip package is bent and formed.

FIG. 3 is an explanatory view showing a conventional slit cutting method for a lead frame for a cerdip package.

[Explanation of symbols]

 5 External lead 6 Frame 7 Connection 10 Notch

Claims (1)

(57) [Claims] An outer end of a lead is opposed to one of opposite sides of a frame.
Lead frame connected to and supported by the frame part
Are arranged adjacent to each other and the adjacent lead frame
Outside the other opposing frame of the frame
It is connected by the connection part formed in the edge part, and
A frame portion for the other opposing, in rie de external lead and bent at the boundary position corresponding bending positions of inner leads molded in Cerdip package lead frame formed in a substantially U-shaped in together, the connection Part slits the lead frame material in the width direction.
And formed by the slitting process.
Of each opposing outer edge of the adjacent frame
Cerdip package lead frame, characterized in that the notch on are formed in the bending position.