JPH06234028A - Stamping die for mass production - Google Patents

Abstract

PURPOSE:To reduce an energy consumption and a noise by orthogonally inclining a specific surface against a specific direction in a stamping die for mass production on where plural numbers of recessed parts corresponding to punches are provided parallel to the specific direction 'on the specific surface of a die body being opposite to the plural numbers of the punches. CONSTITUTION:An upper surface 14 of a die body 12 of a stamping die (die) 10 is made possible to oppose to plural numbers of punches. It is inclined by an angle A so that a right side is descended on a X axis. A die insert 18 of the die part is provided parallel to a Y axial direction as a specific direction. The Y direction is a feeding direction of a lead frame. Each die insert is provided in a position corresponding. to each punch. When the punch is stamped on the die insert 18, the lead frame (work) interposed between both can be punched in a prescribed shape. Therefore, when the punch and the die part are approached, a shear angle is relatively formed between both, they are gradually sheared while waiting a time difference and the driving force is also made small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stamping die for mass production. More specifically, a plurality of die parts corresponding to punches are arranged in parallel in a particular direction on a particular surface of a die body portion facing the plurality of punches. For stamping dies for mass production.

[0002]

2. Description of the Related Art For example, a stamping die is used for press molding of a lead frame for a semiconductor device. In fields such as lead frames where a large amount of molding is required in a short time, mass production in which a plurality of die parts corresponding to the punches are arranged side by side in a particular direction on a particular surface of the die body that faces the plurality of punches. The stamping die for is used.

[0003]

However, the above conventional mass-production stamping mold has the following problems. In the conventional stamping die for mass production, since a plurality of punches are simultaneously driven to punch a work such as a lead frame at a stretch, a large driving force is required, which causes a problem of large energy consumption. There is also a problem that a large noise is generated each time stamping is performed because the work is punched out at a stretch with a large driving force. Further, since the punched work receives the punching energy at the same time, a large amount of residual stress is accumulated in the punch outer peripheral portion, and a large amount of residual stress is accumulated, resulting in a defective product such as twisting at the time of production. There is a problem called. Therefore, the present invention provides a stamping die for mass production, which can reduce energy consumption required for punching a work and noise generated when punching a work, and further can suppress twisting of a product after punching. With the goal.

[0004]

In order to solve the above problems, the present invention has the following constitution. That is, in a stamping die for mass production, in which a plurality of die portions corresponding to the punches are arranged in parallel in a specific direction on a specific surface of a die body portion facing the plurality of punches, the specific surface is perpendicular to the specific direction. It is characterized in that it is inclined in the direction.

[0005]

[Operation] The operation will be described. Since the specific surface is inclined in the direction perpendicular to the specific direction, a shear angle is relatively formed between the punch and the die when the punch and the die approach each other. Therefore, the workpiece to be stamped can be sheared with the shear angle.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. In this embodiment, a stamping die for mass production used for press molding of a lead frame for a semiconductor device will be described as an example. FIG. 1 shows a perspective view of a mass-production stamping die (die) 10 of an embodiment. In FIG. 1, reference numeral 12 denotes a die main body which is a die main body and is made of metal such as iron. The upper surface 14 of the die body 12, which is a specific surface, can face the plurality of punches 16 (see FIG. 2). The upper surface 14 of the die body 12 is inclined by an angle A (for example, 3 degrees, a preferable range is about 10 degrees or less) so that the right side is lowered in the X-axis direction. Reference numeral 18 is a die insert which is a mold part and is arranged in parallel in the Y-axis direction which is a specific direction. The Y-axis direction is the lead frame feeding direction. Each die insert 18 is arranged at a position corresponding to each punch 16. When the punch 16 is stamped into the die insert 18, the lead frame (workpiece) interposed therebetween can be punched into a predetermined shape.

FIG. 2 shows a state in which each die insert 18 is set so as to correspond to the punch 16. In FIG. 2, reference numeral 20 denotes a stripper plate, and a plurality of punches 1
6 is vertically slidable. In the set state, each punch 16 is arranged at a position corresponding to each die insert 18 of the die 10. The stripper plate 20 can be moved up and down by an up-and-down moving mechanism (not shown) (see, for example, Japanese Patent Laid-Open No. 2-25227), and can be stamped when it is moved down in the direction of arrow B.

A side view of the die 10 and punch 16 is shown in FIG. The lower end of the punch 16 is horizontally formed in the left-right direction (X-axis direction in FIG. 1). By forming the lower end of the punch 16 horizontally, the re-polishing of the punch 16 can be easily performed. Therefore, the cost of re-polishing as well as the re-use and reuse of the punch 16 can be reduced and the economical efficiency can be improved. On the other hand, the lower surface 22 of the stripper plate 20 is inclined by an angle A so as to follow the upper surface 14 of the die body 12 so that the right side is lowered in the left-right direction (X-axis direction in FIG. 1). The lower surface 22 of the stripper plate 20 is inclined by the angle A so that the upper surface 14 of the die body 12 and the lower surface 22 of the stripper plate 20 are prevented from interfering with each other during stamping and the lead frame (workpiece) is pressed as usual. This is to ensure the function of peeling off. Also, a fitting hole 24 for attaching the punch 16 to the stripper plate 20.
(See FIG. 4) may be drilled vertically.

Stamping of a lead frame using the die 10 having the above structure will be described with reference to FIG. The lead frame 26 is mounted on the upper surface 14 of the die body 12 while being inclined. The lead frame 26 is positioned at a predetermined position on the upper surface 14 via a positioning means (not shown). In this state, the stripper plate 20 moves downward and the punch 16 comes into contact with the lead frame 26. The position of the punch 16 in that state is shown by a chain line 16a. that time,
As clearly shown in FIG. 4, a shear angle A is formed between the lower end of the punch 16 and the lead frame 26, and when the punch 16 further moves downward for stamping, the lead frame 26 has the shear angle A. To be sheared. Microscopically, this shearing is gradually sheared with a time lag, so compared with the conventional method of shearing at once together with stamping, the driving force required for stamping can be small and energy consumption is low. Noise at the time of stamping and damage to the punched lead frame 26 are also reduced as compared with the conventional case.

Next, the repolishing of the die 10 will be described with reference to FIG. The die 10 wears as it is used for stamping, requiring the upper surface 14 to be reground and regenerated. At that time, the polishing tool of the polishing apparatus generally moves horizontally. Therefore, it is necessary to keep the upper surface 14 of the inclined die 10 horizontal. The present inventor proposed that the jig 30 be provided on the bed 28 of the polishing apparatus to hold the upper surface 14 of the die 10 horizontally. On the upper portion of the jig 30, there is formed a recess 32 into which the lower portion of the die 10 can be fitted. The recess 32 is inclined at an angle A with respect to a horizontal plane parallel to the surface of the bed 28. Therefore, when the lower part of the die 10 is fitted into the recess 32, the upper surface 14 of the die 10 can be held horizontally, and the conventional polishing apparatus can sufficiently polish the surface. At this time, only the upper surface 14 of the die main body 12 needs to be polished without polishing each die insert 18.

In the above embodiment, as can be seen from FIG. 4, since the lead frame 26 is sheared at the shear angle A, the shear plane is inclined with respect to the thickness direction of the lead frame 26. If it is not desired to make this inclination the same in all shear planes, as shown in FIG.
Are arranged side by side in the Y-axis direction. At that time, the upper surface 14 of the die 10a
The inclination directions of a and the upper surface 14b of the die 10b may be opposite to each other. Although two dies 10a and 10b are provided in the example of FIG. 6, three or more dies may be provided in parallel. An intermediate block 34 may be provided between the dies 10a and 10b as shown in the figure. The method of connecting a plurality of dies 10a and 10b in this manner is suitable when processing a workpiece such as a multi-pin lead frame that requires a large number of stamping steps. The various preferred embodiments of the present invention have been described above,
The present invention is not limited to the embodiments described above, and it goes without saying that many modifications can be made without departing from the spirit of the invention.

[0012]

When the stamping die for mass production according to the present invention is used, since the specific surface is inclined in the direction perpendicular to the specific direction, when the punch and the die part approach each other, the two are placed between them. A shear angle is relatively formed. Therefore, since the work to be stamped can be sheared with the shear angle, when viewed microscopically, it is gradually sheared with a time lag, and the driving force required for stamping is compared with the conventional method of shearing at once with stamping. It is small, consumes little energy, and is economical. In addition, noise during stamping can be reduced as compared with the conventional case.
Further, it is possible to reduce distortion, twist, and the like applied to the work as compared with the conventional case. Further, when the mold is polished, only a specific surface of the mold main body needs to be polished, resulting in excellent workability and the like.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a die that is a mass-production stamping die according to the present invention.

FIG. 2 is a partial front view showing a state in which each die insert included in the die is set to correspond to a punch.

FIG. 3 is a side view of the state shown in FIG.

FIG. 4 is a partial cross-sectional view showing a state in which a lead frame is sheared by a die and a punch.

FIG. 5 is a sectional view showing a jig for polishing a die.

FIG. 6 is a perspective view showing an embodiment in which dies are arranged in series.

[Explanation of symbols]

 10, 10a, 10b Die 12 Die body 14, 14a, 14b Die upper surface 16 Punch 18 Die insert 26 Lead frame A Inclination angle (shear angle) Y Specific direction

Claims (1)

[Claims] 1. A stamping die for mass production, wherein a plurality of die parts corresponding to the punches are arranged side by side in a particular direction on a particular surface of a die body portion facing the plurality of punches, wherein the particular surface is the particular direction. A stamping die for mass production, which is inclined in a direction perpendicular to