JPH0547980A - Ic lead frame for semiconductor device - Google Patents

Abstract

PURPOSE:To improve the dimensional accuracy of an IC lead frame for semiconductor device use, which is manufactured by a press punching work, by a method wherein the form of the internal leads of the IC lead frame for semiconductor use is constituted into a waveform form having bent parts, more than two pieces of which are different from one another in direction. CONSTITUTION:Parts of internal leads of an IC lead frame for QFP type semiconductor device use excepting bonding areas (coining areas at the time of a press work) on the tips of the internal leads are provided with bent parts A, B and C, which are different from one another in direction. Accordingly, a difference between plastic shrinkages, which are generated in the left and right sides of the internal leads, is reduced and differences between stresses, which are inflicted on the left and right sides of the internal leads, are brought near to equality. Thereby, the deformation and positional deviation of the internal leads in after a press punching work can be prevented from being generated and the dimensional accuracy of the IC lead frame for semiconductor device use is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an IC reader for semiconductor devices.
The present invention relates to the shape of the inner lead of the dframe.

[0002]

2. Description of the Related Art Conventionally, the shape of the inner lead of an IC lead frame for a semiconductor device has a single bent portion D as shown in FIG. It is configured to extend in a horizontal direction. Further, as shown in FIG. 3, even when it has two or more bending portions, it is configured to bend in the same direction, and a corrugated shape having bending portions with different directions has not been manufactured. ..

On the other hand, in the case of manufacturing an IC lead frame for a semiconductor device by press punching, as shown in FIGS. 4 and 5, on the convex side and the concave side of the inner lead shape,
Since there is a difference in plastic shrinkage due to press punching, a shape bent in the same direction will cause deformation and displacement of the internal lead after press punching,
There is a problem that the dimensional accuracy of the IC lead frame for semiconductor devices is deteriorated.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is possible to form a corrugated shape by providing two or more bent portions with different directions. The difference in plastic shrinkage that occurs on the left and right sides of the inner lead is made smaller so that the difference in stress applied to the left and right sides of the inner lead is evenly approached, and the inner lead after press punching Prevents deformation and displacement, and ICs for semiconductor devices
It is an object to improve the dimensional accuracy of the lead frame.

[0005]

According to the present invention, the shape of the inner lead of the IC lead frame for a semiconductor device is formed in a corrugated shape having two or more bent portions in different directions. Is an IC lead frame for a semiconductor device.

[0006]

4 and 5 are a diagram and an explanatory view showing a stress state of a bent portion of an IC lead frame for a semiconductor device during bending. That is, the angle θ of the bent portion is 180 °
Below, stress acts in the direction of flowing out from the bent portion and in the direction of flowing in at 180 ° or more. Since the stress in both directions is not uniform, it causes deformation after processing. In the present invention, by providing two or more such bent portions, it is possible to achieve a balance and prevent deformation and displacement after processing.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Semiconductor device IC according to the present invention shown in FIG.
An embodiment will be described according to the lead frame. FIG. 1 shows an example applied to a QFP type IC lead frame for a semiconductor device, in which the direction is different except for the bonding area (coining area at the time of pressing) at the tip of the internal lead. Bends A, B and C are provided.

The inventor grasped the change in the dimensional accuracy of the IC lead frame for a semiconductor device when the lead pitch was variously changed as a change in the lead deviation amount, and conducted a manufacturing experiment. The experimental results are shown in. Where
The deviation amount is a dimension of a deviation between the set value and the actually measured value, and the numerical value in Table 1 is an average value of the measured values at 30 points.
Further, the lead width was set to (lead pitch × 0.5), the draft width was set to (lead pitch × 0.5), and the angle of each bent portion was set to 22 °.

[0009]

[Table 1]

As is apparent from Table 1, according to the present invention, the lead deviation amount (average value) is 1/3 to 1/5 of the conventional method.
The dimensional accuracy of the IC lead frame for a semiconductor device could be dramatically improved.
In addition, the punching punch used at this time has a corrugated shape as well, and it is possible to reduce the deflection of the punching punch during press punching and extend the life of the punch as compared with the conventional linear punch. It was possible to improve productivity as well.

[0011]

As described above, according to the present invention, the dimensional accuracy of the IC lead frame for a semiconductor device can be dramatically improved, and at the same time, the life of the punch for press can be extended. You can

[Brief description of drawings]

FIG. 1 is an IC lead frame for a semiconductor device according to the present invention.
FIG.

FIG. 2 is a perspective view showing an example of a conventional IC lead frame for a semiconductor device.

FIG. 3 is a plan view showing an example of a conventional IC lead frame for a semiconductor device.

FIG. 4 is a diagram showing a stress state of a bent portion for explaining the operation of the present invention.

FIG. 5 is an explanatory view showing a stress state of a bent portion for explaining the operation of the present invention.

[Explanation of symbols]

 1 IC lead frame for semiconductor device A First bent portion B Second bent portion C Third bent portion D Bent portion θ Bent angle

Claims (1)

[Claims] 1. An IC lead for a semiconductor device, characterized in that the shape of the inner lead of the IC lead frame for a semiconductor device is formed in a corrugated shape having two or more bent portions in different directions. Lead frame.