JP2000040782A - Lead cutting method and mold used for the method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent a decrease in yield due to adhesion of cut pieces caused by lead cutting. SOLUTION: A lead for cutting a lead projecting from the sealing body of a lead frame partially having a sealing body by a cutting operation of a die and a punch of a cutting station of a plurality of processing stations provided in a mold. In a cutting method, a scattering prevention member is arranged so that a cut piece obtained by cutting the lead does not scatter to an adjacent processing station area or to the outside, and a fall direction is applied to the lead portion to be a cut piece by external force applying means. An external force is applied simultaneously with, before, or after cutting the lead, and the cut piece is dropped downward so as not to be scattered over the scattering prevention body. A splash prevention body is disposed inside the scattering prevention body to prevent the cut piece after the lead cutting by the die and the punch from jumping upward. External force applying means by a gas blowing mechanism is incorporated in the bounce-preventing body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting leads in the manufacture of semiconductor devices and a mold used in the method, and more particularly to a technique effective when applied to a technique for cutting leads in the manufacture of a resin-sealed semiconductor device. .

[0002]

2. Description of the Related Art In a semiconductor device such as an IC (integrated circuit device), a structure is known in which a semiconductor chip, a wire, and the like are sealed with a sealing member (package) made of resin.

[0003] A lead frame is used in the production of a resin-sealed semiconductor device. The lead frame after fixing the semiconductor chip and wire bonding is
Molding is performed by a transfer molding apparatus. As a result, the semiconductor chips, wires, and the like are covered with a sealing body made of resin (resin).

[0004] Thereafter, resin burrs and unnecessary resin portions protruding from the package are removed, tie bars (dams) connecting the leads are cut off, and tab suspension leads for supporting tabs to which the semiconductor chips are fixed are provided. Cutting, lead cutting, lead molding, and the like are performed, and a desired semiconductor device is manufactured.

[0005] "VLSI packaging technology (lower)" published by Nikkei BP, published on May 15, 1993, P41 to P50, describes technologies such as deburring, dam cutting, lead cutting, and lead molding.

In the manufacture of a resin-encapsulated semiconductor device, a resin reservoir such as an overrunner, a dummy cavity, or a flow cavity is provided in a mold to prevent air bubbles (voids) from being generated in the encapsulant. Is guided to the overrunner, the dummy cavity, the flow cavity and the like. The resin bodies cured in these cavities are also cut and removed as unnecessary resin portions.

[0007] As a device for cutting and molding leads after transfer molding, for example, a cutting molding device [model CH555] of "Apic Yamada" is known. In this cutting and forming apparatus, a first press and a second press are arranged along a transfer direction of a lead frame. In the first press, flow cavity resin cutting, dam cutting, and air vent resin cutting are performed by a single operation of a press cylinder. In the second press, lead cutting, lead forming, lead size regulation cutting, and tab suspension lead cutting are performed in a single operation of the press cylinder, and a semiconductor device is manufactured.

Further, Japanese Patent Application No. 8-153626 discloses that cracks occur in a package or a semiconductor chip in a package due to the detachment and reattachment of a resin portion (resin burr) generated between leads during transfer molding. Or
It is described that lead deformation is caused.

[0009]

The most problematic defect occurring in the cutting process is the adhesion of cut pieces (cut chips) scattered on the processed surface. As a quality problem, when a piece is attached, there are various lead structures of a semiconductor device. Among them, a gull wing shape is known as a lead shape suitable for surface mounting. In the manufacture of this gull-wing type semiconductor device, after transfer molding, cutting and removing unnecessary resin cured portions and cutting of dams are performed, the leads are cut from the frame portion of the lead frame, and then the leads are formed into gull-wing shapes. In order to define the dimensions of the lead, a method of cutting (cutting) the tip of the lead again has been adopted.

In this lead size-specified cut, the cut pieces are scattered around and fall by their own weight, and are collected by a dust collector provided below by vacuum suction by a dust collector.

However, a cut piece generated by cutting the lead by the die and the punch is short because it is a re-cut after the lead is cut, and a part of the piece scattered to the side is obliquely upward depending on the direction of the force applied at the time of cutting. Some of them are scattered and adhere to the lead frame portion of the adjacent processing station or to the package.

FIG. 12 is a schematic diagram of a part of a conventional cutting and forming apparatus. From right to left, lead forming (gull wing type) A, lead size prescribed cut (lead fixed size cut).
B shows a portion of a tab suspension lead cut (tab suspension cut) C.

In FIG. 1, a lower lead forming die 38 is provided.
A spacer 80 is interposed between the lead size defining die 39 and the lead size defining die 39 and the tab hanging lead cutting die 40. The spacer 80 is arranged for adjusting the dimensional interval of each processing station. The height of the spacer 80 is low as shown in the figure, and a relatively large gap is generated between the spacer 80 and the lead frame 30.

The lead frame 30 is clamped between the lower die by the lowering of the upper die plate 52,
Thereafter, the lead forming punch 58, the lead size defining cut punch 59, and the tab suspension lead cutting punch 60 due to the lowering of the punch holder 51 (upper die plate) are lowered.
Lead molding (gull wing type), lead size regulation cut, and tab suspension lead cutting are performed.

At this time, the cut piece 71 generated by the lead size prescribed cut enters the adjacent processing station area from the gap above the spacer 80 as shown in FIG. Etc. lead frame 3
It may adhere to zero.

The adhesion of the cut pieces causes package cracks, semiconductor chip cracks and lead bending as described above. That is, the station before the lead size defining cut station is a lead forming station, and the subsequent station is a tab hanging lead cutting station. In particular, in the case of lead molding, if a cut piece adheres to a package, the package is held by a mold, which causes a package crack or a semiconductor chip crack. Further, if the cut piece adheres to the lead, the lead piece is formed together with the cut piece at the time of forming the lead, so that the lead bend and the lead pitch defect are likely to occur.

[0017] The occurrence of cracks causes fatal damage to the product, which means that the product cannot be remedied and is discarded, resulting in a decrease in yield and an increase in the cost of the semiconductor device. Also,
If the lead is bent or the lead pitch is defective, it takes time to repair it, which leads to an increase in cost. If the lead cannot be repaired, the yield decreases.

An object of the present invention is to provide a lead cutting method capable of preventing a decrease in yield due to adhesion of cut pieces caused by lead cutting, and a die used for the method.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0020]

The following is a brief description of an outline of typical inventions disclosed in the present application.

(1) Lead cutting in which a lead projecting from the sealing body of a lead frame having a sealing body is partially cut by a die and a punch of a cutting station among a plurality of processing stations provided in a mold. The method
The scatter prevention member is arranged so that the cut piece due to the cutting of the lead does not scatter to the adjacent processing station area, and the external force in the drop direction is applied to the lead portion serving as the cut piece by external force applying means at the same time as the lead cutting or during the cutting. Acting before or after cutting, the cut pieces are dropped downward so as not to be scattered over the scatter prevention body. A splash prevention body is disposed inside the scattering prevention body to prevent the cut piece after the lead cutting by the die and the punch from jumping upward. The external force applying means is incorporated in the bounce-preventing body to prevent the cut piece from jumping and drop the cut piece downward simultaneously with the cutting of the lead.

In such a lead cutting method, the following mold is used.

A die for cutting a lead projecting from the sealing body of a lead frame partially having a sealing body by a die and a punch of a cutting station among a plurality of processing stations provided in the die. An anti-scattering body disposed between an adjacent processing station area so that a cut piece resulting from the cutting of the lead does not scatter to an adjacent processing station area, and upward of the cut piece after the lead is cut by the die and the punch. And a jump-preventing body disposed inside the scattering-preventing body for preventing the jump-up. External force applying means for applying an external force in a drop direction to the lead portion serving as the cut piece from the time of cutting the lead. The external force applying means is constituted by a gas blowing mechanism having a nozzle for blowing gas to a lead portion serving as the cut piece. A nozzle is incorporated in the bounce-preventing body to constitute the gas blowing mechanism.

(2) In the configuration of the means (1), the external force applying means includes an external force applying body fixed to the upper die plate on which the punch is fixed and which moves up and down.
An external force is applied to the lead from the time of cutting the lead due to the relative drop of the upper die plate.

(3) In the configuration of the means (1), the external force applying means has the external force applying body fixed to the upper die plate, and the external force applying body is fixed to a punch guide for guiding the punch. It is configured to be attached in a penetrating state to the jump-up preventing body.

According to the means (1), (a) since the scattering prevention member is provided between the adjacent processing station areas, the cut pieces generated by cutting are scattered around. This also prevents the scatter prevention body from entering the adjacent processing station area, and prevents the package, semiconductor chip, and lead from being damaged and deformed due to the adhesion of the cut pieces in the processing at the adjacent processing station.

(B) Since the splash preventing body is provided inside the splash preventing body, even if the cut piece generated by the lead cutting jumps upward, the cut-off preventing body prevents the cut piece from scattering upward. As a result, the cut piece does not enter the adjacent processing station area over the scattering prevention body, and breakage deformation of the package, the semiconductor chip, and the lead caused by the adhesion of the cut piece in the processing at the adjacent processing station. No longer occurs.

(C) A gas blowing mechanism is incorporated in the splash preventing body. Therefore, by blowing gas from the nozzle of the gas blowing mechanism to the lead portion serving as the cut piece, the cut piece falls down and does not enter the adjacent processing station area. The gas may be blown at all times, or may be synchronized with the cutting.

According to the means (2), the cut piece can be dropped by the external force applying member fixed to the upper die plate to which the punch is fixed, and the means (1)
As in the case of the configuration described above, it is possible to prevent the cut pieces from scattering to the adjacent processing station area.

According to the above-mentioned means (3), the cut piece can be dropped by the external force applying member that penetrates the splash prevention member fixed to the upper die plate and fixed to the punch guide. As in the case of the configuration of the means (1), it is possible to prevent the cut pieces from scattering to the adjacent processing station area.

[0031]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments of the present invention, components having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

(Embodiment 1) In Embodiment 1, an example in which the present invention is applied to a lead size regulation cut after transfer molding in the manufacture of a resin-sealed semiconductor device will be described.

The semiconductor device manufactured by the lead cutting (lead size defining cut) and the subsequent processing according to the first embodiment has an external shape as shown in FIG.

In the resin-sealed semiconductor device 1, a plurality of leads 3 are projected from both sides of a flat rectangular sealing body (package) 2, respectively. These leads 3 project at a constant pitch and are formed in a gull wing shape.

In such a semiconductor device 1, after a semiconductor chip is fixed to a tab (support portion) of a lead frame,
Each electrode of the semiconductor chip is connected to the inner end of the lead with a conductive wire, and then the inner end of the semiconductor chip, the wire, and the lead are covered with an insulating resin by transfer molding to form a package (sealed body). Then, it is manufactured by processing such as solder plating on the surface of the lead, removal of unnecessary lead frame portions and the like by a cutting and forming apparatus, and molding of the lead.

FIG. 2 is a schematic front view showing the cutting and forming apparatus 10 incorporating the mold of the first embodiment. In the cutting and forming apparatus 10, a first press 13 supported on a machine base 11 via a support portion 12 and a second press 14 located on the left side thereof are supported.

The first press 13 and the second press 14
Have the same configuration, and a cylinder 15 is fixed on the support portion 12. The rod of the cylinder 15 extends downward through the support portion 12, and the tip of the rod is fixed to an upper mold 17 constituting a mold 16. The rod portion is covered with a bellows 18,
Foreign matter is prevented from adhering.

On the machine base 11 below the first press 13 and the second press 14, a table 20 for mounting a lower mold 19 constituting the mold 16 is arranged. Below the table 20, there is provided a waste storage box 21 for storing waste such as cut pieces generated in the lower mold 19. Pipes 23 connected to a dust collector 22 disposed in the machine base 11 are connected to the dust storage box 21, and the dust such as cut pieces generated in the lower mold 19 by the driving of the dust collector 22 is forced downward. And housed in the lower dust storage box 21.

On the other hand, on two lower dies 19 arranged in series,
A guide rail 24 for guiding the lead frame is arranged. A lead frame transporter 25 is disposed above the right end of the machine base 11. The lead frame transporter 25 uses the lead frame pickup 26 of the lead frame transporter 25 to separate the lead frames accommodated in the lower magazine 27 one by one into the guide rails 2.
4 and intermittently transport the lead frame.

On the other hand, an unloader 28 is disposed above the left end of the machine base 11 to collect lead frames that are no longer needed by the second press 14.

In such a cutting and forming apparatus 10,
The lead frame is pitch-fed from right to left on the guide rail 24. In the first press 13, the cylinder 1
5, a flow cavity resin cut, a dam cut, and an air vent resin cut are performed in one operation.
In a single operation of the cylinder 15, lead cutting, lead molding, lead size regulation cutting, and tab suspension lead cutting are performed, and a semiconductor device is manufactured.

The lead frame 30 shown in FIG. 8 is one in which processing by the first press 13 has been completed. Cutting of the resin cured in the flow cavity portion, cutting of the dam, and cutting of the resin cured in the air vent portion are performed. It is a plan view performed. Although the lead frame 30 has a strip shape, this drawing shows a unit lead frame portion.

The lead frame 30 comprises a pair of parallel outer frames 31 and an inner frame 32 connecting the outer frames 31 to form a rectangular frame.
1 has a shape in which the lead 3 is projected in parallel. In the figure, the package 2 is located at the center of the frame. In addition, a thin tab suspension lead 33 extends from the overhang portion of the outer frame 31.
Are projected two. Although not shown, the tab suspension leads 33 extend into the package 2 and are connected to tabs that support the semiconductor chip to support the tabs. The holes 34 provided in the outer frame 31 are guide holes used for transporting and positioning the lead frame 30.

FIG. 3 is a cross-sectional view of the mold 16 (the upper mold 17 and the lower mold 19) of the second press 14. 4 is a plan view of the lower mold 19, FIG. 5 is a bottom view of the upper mold 17, and FIG.

The lower mold 19 has a rectangular die bed 35, and a die frame 36 is mounted and fixed along the center of the die bed 35. The die frame 36 is a combined structure, and a lead cutting die 37, a lead forming die 38, a lead size defining cut die 39, and a tab hanging lead cutting die 40 are arranged and fixed from right to left. These lead cutting die 37 and lead forming die 3
8, a feed plate 41 is located on the lead size defining cut die 39 and the tab hanging lead cutting die 40. Both edges of the feed plate 41 are connected to the guide rails 24.
Slidably supported by In addition, columns 42 are fixed to the four corners of the die bed 35 in a standing state.

The upper mold 17 is a die bed 3 of the lower mold 19.
5 has a punch holder 45 having substantially the same dimensions as the punch holder 45. The punch holder 45 has a sliding hole 46 into which the column 42 fixed to the die bed 35 is slidably fitted.
At the time of setting 7, the column 42 is inserted into the sliding hole 46. On the punch holder 45, a shank holder 4
7 is fixed. In this shank holder 47,
Rod (shank) 48 projecting from the cylinder 15
Is fixed.

Under the punch holder 45, a punch holder 51 (upper plate) is fixed via a backing plate 50. A strip plate 52 is located below the punch holder 51. This strip plate 52 is suspended by columns 53.

The strip plate 52 has a combined structure like the die frame 36, and includes a lead cutting punch 57, a lead forming punch 58, a lead size defining cut punch 59, and a tab suspension lead cutting punch 60 from right to left. The arrangement is fixed. Strip plate 5
2 is lowered by the lowering of the upper die 17, elastically sandwiches the lead frame 30 with the lower die 19, and the further lowering of the rod 48 lowers the punch portion fixed to the punch holder 51, Each processing is performed with the lower die.

In such a die 16, lead cutting, lead forming (gull wing type), lead size prescribed cut (lead fixed size cut), tab suspension lead cutting (lead cutting) by pitch feed of the lead frame 30 and press operation. The tab hanging lead cutting station is sequentially performed, and in the tab hanging lead cutting station, the semiconductor device 1 that has fallen away from the lead frame 30 by cutting the tab hanging lead from the lead frame 30 is guided by the chute and moves to the side indicated by the arrow. In a predetermined magazine.

FIG. 7 is a plan view showing the lead frame 30 at each processing station in the second press 14.
State A with gull wing shaped leads from right to left
FIG. 1 is a schematic cross-sectional view showing a state B in which cuts for defining lead dimensions are performed and a state C in which tab suspension leads are cut.

In the first embodiment, the scattering prevention member 70 is arranged between adjacent processing stations before and after the lead size defining cut station (lead cutting station), that is, between the lead forming station and the tab hanging lead cutting station. . The scattering prevention body 70 is obtained by, for example, increasing the height of a conventionally arranged spacer. Due to the presence of the scattering prevention member 70, the cut piece 71 generated by cutting by the lead size defining cut die 39 and the lead size defining cut punch 59 is
Even if it scatters around, it collides with this scatter prevention body 70 and is reflected and falls downward. At this time, the cut pieces 71 fall downward due to the forced exhaust by the driving of the dust collector 22.

However, since the lead frame 30 moves above the scattering prevention member 70, the upper surface thereof must be low enough not to contact the lead frame 30. In the first embodiment, the cut piece 71 generated by the lead size prescribed cut is used to prevent the cut piece 71 from passing over the scattering prevention body 70 and entering the adjacent processing station area through this gap. It is provided inside the scattering prevention body 70.

The anti-scattering body 70 is incorporated and fixed in the die frame 36 of the lower mold 19. Further, the jump-up preventing body 72 is fixed to the strip plate 52.

The projecting length of the bounce-preventing body 72 is set to a value such that the strip plate 52 is lowered and the lead frame 30 is clamped between the lower die 19 and does not come into contact with the lead of the cut portion formed by the lead molding. It has a gap of about 5 mm or less. This is because, when the tip of the gull-wing-shaped lead 3 protruding from the package 2 is pushed down, the lead 3 is deformed in an arcuate shape, and the cut position of the lead dimension defining cut is displaced, so that it does not conform to the standard. What is necessary is just to be in a state in which even if the lower end of the jump-up preventing body 72 contacts the lead 3, the bow-shaped deformation does not occur. The size of the gap may be determined in consideration of variations in the thickness of the lead frame.

In the first embodiment, external force applying means is provided. The external force applying means acts at the same time as the lead cutting or before or after the cutting to drop the cut piece 71 downward so as not to fly over the scattering prevention body 70. A mechanical structure and a structure using air pressure are conceivable. In the first embodiment, a structure using air pressure is employed.

That is, the nozzle 73 having an opening at the lower end of the splash preventing body 72 is
It is provided in. A gas, for example, air is injected from the nozzle 73. The nozzle 73
A gas blowing mechanism including an air pressure feeding unit (not shown) is configured, and an external force applying unit is configured.

By the air pressure by this gas blowing mechanism,
The cut piece 71 generated by cutting by the lead size defining cut die 39 and the lead size defining cut punch 59 is:
Fall down. If the bow of the lead 3 is not caused to deform, the air may be injected before the lead is cut.

According to the first embodiment, the following effects can be obtained.

(1) According to the lead cutting method and the metal mold of the present invention, in the lead size defining cut station, a scattering prevention member is provided between adjacent processing station areas (lead forming station and tab hanging lead cutting station). Since the cut pieces 70 are provided, even if the cut pieces 71 generated by cutting are scattered to the surroundings, the cut pieces 71 are blocked by the scattering prevention member 70 and do not enter the adjacent processing station area, and the processing at the adjacent processing station is performed. In this case, breakage and deformation of the package, the semiconductor chip, and the lead due to the adhesion of the cutting piece 71 do not occur.

(2) Since the splash preventing body 72 is provided inside the scattering preventing body 70, even if the cut piece 71 generated by the lead cutting jumps upward, it is moved upward by the splash preventing body 72. Can be prevented, so that the cut pieces 71 do not enter the adjacent processing station area over the anti-scattering body 70, and the package, semiconductor, and the like caused by the adhesion of the cut pieces 71 in the processing at the adjacent processing station. Chip,
No breakage or deformation of the lead occurs.

(3) A gas blowing mechanism is incorporated in the splash prevention body 72. Therefore, by blowing air from the nozzle 73 of the gas blowing mechanism to the lead portion serving as the cut piece, the cut piece 71 falls downward and does not enter the adjacent processing station area.

(4) Due to the above (1) to (3), breakage and deformation of the package, the semiconductor chip and the lead caused by the cut piece 71 generated at the time of cutting the lead dimensions are eliminated, so that the quality is improved and the production yield is improved. Can be improved.

(Embodiment 2) FIG. 10 is a schematic view showing a part of a mold and a lead cutting method according to another embodiment (Embodiment 2) of the present invention. The second embodiment is different from the first embodiment.
In the above, the external force applying means includes an external force applying body 81 to which the lead size defining cut punch 59 is fixed and which is fixed to an upper die plate (punch holder 51) which moves up and down, and which is driven by a relative drop of the punch holder 51. An external force is applied to the lead 3 after the lead is cut.

According to the second embodiment, the cut piece 71 can be dropped by the external force applying member fixed to the vertically moving punch holder 51 to which the lead size defining cut punch 59 is fixed. As in the case of the first configuration, it is possible to prevent the cut pieces 71 from scattering to the adjacent processing station area.

(Embodiment 3) FIG. 11 is a schematic diagram showing a part of a mold and a lead cutting method according to another embodiment (Embodiment 3) of the present invention. The third embodiment is similar to the first embodiment.
In the above, the external force applying means has the external force applying body 81 fixed to the upper die plate (punch holder 51), and the external force applying body 81 is a punch guide (strip plate) for guiding the lead size defining cut punch 59. 52) The bouncing prevention member 7 fixed to
2 is attached in a penetrating state.

According to the means of the third embodiment, the falling of the cut piece 71 is determined by the upper die plate (punch holder 51).
And a punch guide (strip plate 5)
This can be performed by the external force applying body 81 penetrating the jump-up preventing body 72 fixed in 2), and the scattering of the cut pieces 71 to the adjacent processing station area can be prevented as in the case of the first embodiment. .

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention. Needless to say.

[0068]

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows.

(1) In the lead size defining cut station, since the scattering prevention member is provided between the adjacent processing station areas, the cut pieces generated by cutting are scattered around. It is blocked by the shatterproof body so that it does not enter the adjacent processing station area, and in the processing at the adjacent processing station, breakage and deformation of the package, semiconductor chip and lead due to the adhesion of the cut pieces do not occur, and the quality of the semiconductor device is reduced. , And a reduction in manufacturing cost due to an improvement in yield can be achieved.

(2) Since the splash preventing body is provided inside the splash preventing body, even if the cut piece generated by the lead cutting jumps upward, it is prevented from flying upward by the splash preventing body. As a result, the cut piece does not enter the adjacent processing station area over the scattering prevention body, and breakage deformation of the package, the semiconductor chip, and the lead caused by the adhesion of the cut piece in the processing at the adjacent processing station. No longer occurs, so that the quality of the semiconductor device can be improved and the manufacturing cost can be reduced by improving the yield.

(C) A gas blowing mechanism is incorporated in the splash preventing body. Therefore, by blowing gas from the nozzle of the gas blowing mechanism to the lead portion serving as the cut piece, the cut piece falls down and does not enter the adjacent processing station area, and the quality of the semiconductor device is reduced. Improvement and reduction in manufacturing cost due to improvement in yield can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a part of a mold and a lead cutting method according to an embodiment (Embodiment 1) of the present invention.

FIG. 2 is a schematic perspective view showing a cutting and forming apparatus for performing the lead cutting method of the first embodiment.

FIG. 3 is a schematic sectional view showing a mold according to the first embodiment.

FIG. 4 is a plan view showing a lower die in the die.

FIG. 5 is a plan view showing an upper mold in the mold.

FIG. 6 is a schematic plan view showing the lower mold.

FIG. 7 is a schematic plan view showing a lead frame on the lower mold.

FIG. 8 is a plan view showing the lead frame when dam cutting is completed.

FIG. 9 is a perspective view of a semiconductor device manufactured by the lead cutting method and the subsequent processing according to the first embodiment.

FIG. 10 is a schematic view showing a part of a mold and a lead cutting method according to another embodiment (Embodiment 2) of the present invention.

FIG. 11 is a schematic view showing a part of a mold and a lead cutting method according to another embodiment (Embodiment 3) of the present invention.

FIG. 12 is a schematic view showing a part of a conventional mold and a method of cutting leads.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor device, 2 ... Sealed body (package), 3 ... Lead, 10 ... Cutting molding apparatus, 11 ... Machine base, 12 ... Support part,
13 ... 1st press, 14 ... 2nd press, 15 ... cylinder, 16 ... mold, 17 ... upper mold, 18 ... bellows, 19 ... lower mold, 20 ... table, 21 ... waste storage box, 22 ... dust collector,
23 ... pipe, 24 ... guide rail, 25 ... lead frame transporter, 26 ... lead frame pickup, 27
... Magazine, 28 ... Unloader, 30 ... Lead frame, 31 ... Outer frame, 32 ... Inner frame, 33 ... Tab hanging lead,
34 ... hole, 35 ... die bed, 36 ... die frame, 37 ... lead cutting die, 38 ... lead forming die, 39 ... lead size regulation cut die, 40 ... tab hanging lead cutting die, 4
DESCRIPTION OF SYMBOLS 1 ... Feed plate, 42 ... Column, 45 ... Punch holder, 46 ... Sliding hole, 47 ... Shank holder, 48 ... Rod, 50 ... Backing plate, 51 ... Punch holder, 52 ... Strip plate, 53 ... Column, 57 ... Lead cutting punch, 58: Lead forming punch, 59: Lead size cut punch, 60: Tab hanging lead cutting punch, 70: Anti-scattering body, 71: Cut piece, 72: Jump-up preventing body, 73: Nozzle, 80: Spacer , 81 ... external force applying body.

Claims (11)

[Claims] 1. A lead cutting method for cutting a lead projecting from a sealing body of a lead frame having a sealing body in part by a die and a punch of a cutting station among a plurality of processing stations provided in a mold. Wherein the lead is cut by disposing an anti-scattering member between the adjacent processing station areas so that the cut pieces resulting from the cutting of the lead do not scatter to the adjacent processing station areas. Method. 2. A lead cutting method for cutting a lead projecting from a sealing body of a lead frame having a sealing body by a die and a punch of a cutting station among a plurality of processing stations provided in a mold. The lead portion which becomes a cut piece by an external force applying means, while arranging an anti-scattering body between adjacent work station areas so that cut pieces by cutting the lead do not scatter to an adjacent work station area A method of cutting a lead, wherein an external force in a drop direction is applied simultaneously with or before or after cutting of the lead to drop the cut piece downward so as not to fly over the scattering prevention body. 3. The lead according to claim 1, wherein a splash preventing body is disposed inside the scattering preventing body to prevent the cut piece after the lead cut by the die and the punch from jumping upward. Cutting method. 4. The reed according to claim 3, wherein said external force applying means is incorporated in said bounce-preventing body to prevent said cut piece from jumping and drop said cut piece downward simultaneously with cutting of said lead. Cutting method. 5. A lead frame protruding from a sealing body of a lead frame partially having a sealing body is cut by a die and punch cutting operation of a cutting station of a plurality of processing stations provided in a mold. What is claimed is: 1. A mold, comprising: a scatter prevention member disposed between an adjacent processing station area so that a cut piece obtained by cutting the lead does not scatter to an adjacent processing station area. 6. A mold for cutting a lead projecting from a sealing body of a lead frame having a sealing body in part by a die and a punch of a cutting station among a plurality of processing stations provided in the mold. A scatter prevention member arranged between the adjacent processing station areas so that the cut pieces by cutting the lead do not scatter to the adjacent processing station area, and the cut pieces after the lead is cut by the die and the punch. A mold having a splash preventing body disposed inside the scattering preventing body for preventing upward splashing. 7. A mold for cutting a lead projecting from the sealing body of a lead frame having a sealing body in part by a die and a punch of a cutting station among a plurality of processing stations provided in the mold. An anti-scattering body arranged so that a cut piece caused by cutting the lead does not scatter to an adjacent processing station area; and an external force applied to the lead portion serving as the cut piece in an external force in a drop direction from the time of cutting the lead. And a mold. 8. The external force applying means includes an external force applying body to which the punch is fixed and which is fixed to an upper die plate that moves up and down, and that the external force applying means applies the external force to the leads from a point at which the lead is cut by a relative drop of the upper die plate. The mold according to claim 7, wherein the mold is configured to apply an external force. 9. The external force applying means has the external force applying member fixed to the upper die plate, and the external force applying member penetrates through the bouncing prevention member fixed to a punch guide for guiding the punch. The mold according to claim 8, wherein the mold is mounted. 10. The mold according to claim 7, wherein the external force applying means is constituted by a gas blowing mechanism having a nozzle for blowing gas to the lead portion serving as the cut piece. 11. The mold according to claim 10, wherein a nozzle is incorporated in the bounce-preventing body to constitute the gas blowing mechanism.