JPH0763792B2 - Forming device for external lead of semiconductor device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forming device that bends external leads of a semiconductor device into a predetermined shape.

(Prior Art) Conventionally, a strip-shaped lead frame in which a plurality of unit lead frames are connected and a semiconductor chip mounted on each unit lead frame is resin-sealed, and extends outward from each resin-sealed portion. To mold the leads into a predetermined shape with a press machine, there is a processing method in which the semiconductor device is separated from the frame portion of the lead frame into individual pieces after the resin sealing, and the external leads are bent in a separate process. .

In this case, it is necessary to align the semiconductor devices separated from the frame part and individually convey them to the forming device, or to store them in a box or the like and then perform bending. For this reason, first, a device or the like for supplying the semiconductor device to the forming device is complicated, and since each device is handled individually, the process is bulky and inefficient. Further, even within the forming device, it is necessary to individually send the semiconductor devices, which complicates the device, and since the individual devices are handled, the feeding speed cannot be increased, which is inefficient.

For this reason, there is a semiconductor device processing apparatus that applies a progressive press device that feeds the strip-shaped lead frame in a predetermined direction and performs predetermined processing such as cutting and bending of external leads on the feed path in multiple stages. . In this processing device, an integrated mold unit that integrates multiple molds is operated by a single press machine, and the lead frame is sequentially fed to perform multi-step press processing, and the external leads are formed into a predetermined shape. It was molded. In other words, in this processing device, since a strip-shaped lead frame can be sent by applying the method of sending a tape-shaped work piece with a progressive press device, the feed rate of the lead frame is higher than when feeding individual pieces. It is possible to increase the machining speed and the machining speed.

(Problems to be Solved by the Invention) However, in the case of the above-mentioned integrated mold unit, it is difficult to individually adjust the press conditions such as the press pressure of each mold constituting the unit. In addition, it is difficult to accurately convey the strip-shaped lead frame because it is difficult to finely adjust the conveyance conditions such as the feed pitch between the molds. For this reason, there is no problem with respect to a work piece that has low dimensional accuracy requirements and is less likely to be damaged. However, a semiconductor device that requires precise processing and is easily damaged (such as a microcrack in a resin sealing portion) can be accurately and suitably used. There is a problem that it is difficult to process.

Further, since a plurality of molds are integrated in this integrated mold unit, in order to apply a suitable pressing pressure to all the molds,
It is necessary to increase the rigidity of the integrated mold unit itself. Therefore, the integrated mold unit becomes large in size, and the press machine for operating the unit also needs rigidity, and becomes large in size. And one die in the integrated die unit is heavily worn,
Even if a partial failure occurs, it is necessary to remove the entire integrated mold unit for inspection and repair, which is inefficient.

In addition, as a press line used when performing deep drawing,
There is a transfer press line in which one die is built in one press machine and a plurality of the press machines are lined up. In this press line, the press conditions and transfer conditions can be set and adjusted for each mold, but since individual non-processed objects are transferred by the transfer mechanism and one press machine performs one pressing step, a large number of A press machine is required, the apparatus becomes complicated, the line becomes long, and the workpieces are individually handled, which makes the process bulky and inefficient.

Therefore, an object of the present invention is to set, adjust, and set a press condition, a transfer condition, and a metal mold so that an external lead of a semiconductor device can be molded into a predetermined shape with high accuracy without damaging the semiconductor device. It is an object of the present invention to provide a forming device capable of easily maintaining a mold.

(Means for Solving the Problems) The present invention is intended to eliminate the above problems and has the following configuration.

That is, according to the present invention, a plurality of unit lead frames are connected, and a strip-shaped lead frame in which semiconductor chips mounted on each unit lead frame are resin-sealed are sequentially fed by a transport mechanism, A forming device for an external lead of a semiconductor device, wherein external leads extending outward are pressed into a predetermined shape by pressing in multiple stages with a plurality of molds, except for a hanging pin of a resin sealing portion of the lead frame, A first cutting die for separating the lead from the frame portion, and a molding die for bending at least the base portion and a molding die for shaping the tip portion of at least the outer lead of the lead frame fed from the first cutting die. , A plurality of molding dies for bending the external lead into a predetermined shape in multiple stages, and cutting each hanging pin of the lead frame fed from the plurality of molding dies A plurality of molds including at least the first cutting mold, the plurality of molding molds, and the second cutting mold. According to the order, the mold units are grouped into a plurality of mold units including one or a plurality of molds, and at least one of the plurality of mold units is a mold unit including a plurality of molds. Is attached to an independent press machine having an independent press drive cylinder, respectively, so that the plurality of strip-shaped lead frames are continuously fed linearly, It is characterized by being arranged.

(Embodiment) Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a front view of a forming apparatus 10 for molding and processing external leads of a semiconductor device, and FIG. 2 is a plan view thereof.

This forming device 10 has five press machines on the base 8.
10A, 10B, 10C, 10D and 10E are linearly arranged.
A supply mechanism 14 for supplying the lead frame 12 is provided near the first press machine 10A, and a semiconductor device discharge mechanism 16 is provided in parallel with the fifth press machine 10E.

Lead frame 12 supplied to the first press machine 10A
Is a strip-shaped lead frame in which a plurality of unit lead frames are connected and a semiconductor chip mounted on each unit lead frame is resin-sealed. The lead frame 12 is stored in the magazine 14a in a stacked state.

14A is a magazine supply device, and stores a plurality of magazines 14a. In the magazine supply device 14A, the magazines 14a are stored in parallel on the supply line M with respect to the feed position L of the lead frame 12 and are pushed in the supply direction by the supply means (not shown). When the magazine 14a is sent to the supply position m, the lead frame 12 is pushed upward by the lift device 14c located below the magazine 14a, and the uppermost lead frame 12 is sent to the feed position L by the chuck device 18. Then, when the uppermost lead frame 12 is sent, the lead device 12 is pushed up by the thickness of one sheet by the lift device 14c. Then, when the lead frame 12 in the magazine 14a disappears,
The magazine 14a is ejected to the right in FIG. 2 (not shown).
And the empty magazine 14a is sent in the anti-feed direction by a feeding means (not shown).

The lead frame 12 at the feed position L is fed by the cylinder 20 in the longitudinal direction of the lead frame 12 (the arrangement direction of the press machines) and is supplied to the first press machine 10A.

Each of the first press machine 10A to the fourth press machine 10D is provided with a transport mechanism for supplying the lead frame 12 to each press machine. As this transport mechanism, feed arms 22 are provided on the die supply side and the die discharge side of each press machine (note that the fourth press machine 10D is provided only on the supply side). These feed arms 22 are cylinders
The lead frames 12 are provided so as to be linked to the respective 24 and hold the frame portion 12a of the lead frame synchronously so that the lead frame 12 can be conveyed.

Further, the fourth press machine 10D and the fifth press machine 10E are provided with a plurality of feed rollers 26 arranged in pairs on both sides of the mold,
The feed roller 26 is provided in the frame portion 12 of the lead frame 12.
The cradle part that is part of a is clamped and conveyed by rotating.

Subsequently, a bending process and a cutting process by each of the press machines 10A to 10E will be described. An example is shown in which the external lead 30a of the semiconductor device is J-bent. Further, FIGS. 3A to 3D are cross-sectional explanatory views of a plurality of molding dies showing a bending state in each step.

In the 1st press machine 10A, removal of resin burr, dam bar 12b
Is removed by cutting (see FIG. 4).

In the second press machine 10B, a cutting process for cutting the external lead 30a into a predetermined length by the first cutting die, and a two-step bending process by the two forming dies (first bending process, second bending process) I do. That is, a die unit consisting of a first cutting die and two forming dies is installed in the second press machine 10B, and the lead frame 12 is sequentially fed in the die unit, and the above-mentioned three Progressive press working consisting of steps is performed.

In the first bending step, as shown in FIG. 3 (a), the tip of the horizontally extending external lead 30a is left (in a free state), and the intermediate portion (which may include the base portion) is used as the die 32B. Clamp with knockout 34B. Then, the tips of the external leads 30a are bent at substantially right angles by the punch 36B so as to follow the curved surface portion of the die 32B.

In the second bending step, as shown in FIG. 3 (b), the base of the outer lead 30a is clamped by the die 33B and the knockout 35B, and the outer lead 30a is bent at 45 degrees by the bending surface 33b of the punch 37B and the die 33B. .

In the third press machine 10C, the third bending step is performed by one molding die.

The third bending step is, as shown in FIG. 3 (c), a die 32C.
The semiconductor device 30 is supported by the knockout 34C.
Hold the base of the outer lead 30a with the bending punch 36 with a cam mechanism (not shown) in the bending direction of the outer lead 30a.
C is brought into contact with the surface of the outer lead 30a without slipping, and is lowered in an arc shape to bend the outer lead 30a almost vertically.

In the fourth press machine 10D, preliminary curling for bending the tip of the outer lead 30a in an arc shape and forming curling (fourth bending step) are performed by two forming dies. That is, a die unit composed of two forming dies is mounted on the fourth press machine 10D, and the lead frame is placed in the die unit.
12 are sequentially sent, and the progressive press working consisting of the above two steps is performed.

Both the pre-curling and the molding curling are putt blocks
The upper surface of the semiconductor device 30 and the bases of the external leads are pressed by 34D, and the tips of the external leads 30a are bent in an arc shape by the bent portions 32d of the die 32D. The curvature of the bent portion 32d of the die 32D is different between the preliminary curling and the molding curling. Reference numeral 38 is an eject pin that protrudes the semiconductor device 30 after curling.

In the fifth press 10E, the bent semiconductor device 30 is separated from the lead frame 12 by the second cutting die.

In the above steps, as shown in FIG. 4, the first to fourth pressing machines 10A are connected with the frame portion 12a of the lead frame 12 and the corner portion of the semiconductor device 30 connected by the hanging pins 12c.
Each cutting and bending is performed at ~ 10D.

As described above, the semiconductor device 30 separated by the second cutting die in the fifth press machine 10E is conveyed onto the tray 42 by the robot hand 40 having the suction cup 40a. On the other hand, the cradle portion of the frame portion 12a is discharged by the feed roller 26 in front of the fifth pressing machine 10E.

As shown in FIG. 1, each press machine 10A to 10E is driven by each independent press drive cylinder, whereby each mold unit is opened and closed to perform each of the above steps. .

Next, the discharge mechanism will be described.

The robot hand 40 adsorbs the semiconductor device 30 with the suction cup 40a, moves up (shown by arrow a in FIG. 1), and then moves horizontally to a predetermined position (shown by arrow b in FIG. 2) at this predetermined position. The semiconductor device 30 is placed on the tray 42 by lowering (shown by the arrow in FIG. 1c) to release the suction by the suction cup 40a. This tray 42 is a lift device (not shown) in the lower space 46 of the fifth press machine 10E.
The uppermost trays 42 stacked on top of each other are sequentially pushed out by the pushing means 48 by one row onto the supporting device 52 of the storage frame 50. Therefore, the tray 42 is pushed out in synchronization with the movement of the robot hand 40.
This is performed while the semiconductor device 30 is placed on the semiconductor device 30 and the next semiconductor device 30 is sent. Therefore, the robot hand
The semiconductor devices 30 can be sequentially housed in the tray 42 by repeating the same movement of 40. When the tray 42 is full, the tray 42 is sent onto the previous tray 42 and operates in the same manner as above. The storage frame 50 has two trays 42 that can be arranged side by side, and when the storage frames 50 are stored in one row, the storage frame 50 has rails 54.
Slide along to allow storage in the other side. Then, the frame portion 12a is discharged by the roller 26.

Next, the operation of the forming device for external leads of the semiconductor device according to the present invention will be described.

According to the present invention, since the external lead is separated from the frame portion of the strip-shaped lead frame and is supported by the hanging pins, the external lead is of a J shape or the like in a state in which the plurality of semiconductor devices are supported by the frame portion. It is molded into a predetermined shape.
That is, the plurality of semiconductor devices connected to the frame portion with the hanging pins are transported through the frame portion until the external leads are molded into a predetermined shape and finally separated. Thus, by using the frame portion of the strip-shaped lead frame, the semiconductor devices can be sequentially and efficiently supplied to the plurality of linearly arranged press machines, and the external leads can be efficiently processed. . That is, it can be said that it has the same advantage as that of the conventional sequential feeding press device that "the workpiece can be efficiently conveyed and processed".

Further, a plurality of molds used for cutting and bending are divided into a plurality of mold units including one or a plurality of molds, and at least one of the plurality of mold units is a plurality of mold units. The following effects are obtained by mounting each die unit on an independent press machine.

． Press conditions for molding external leads can be set and adjusted for each mold unit. For example, the press pressure can be adjusted for each mold unit. The pressing pressure has an appropriate range in each pressing step, and can be adapted to it. Therefore, it is possible to properly process a semiconductor device that is easily damaged and requires precise processing. In other words, it can be said that the conventional transfer press line has the same advantage as "the conditions can be easily set, adjusted, and maintained and managed."

Further, since the press machine is driven by the press drive cylinder, the press pressure, stroke, press speed and the like can be easily adjusted.

． It is possible to set and adjust the transport conditions of the transport mechanism that feeds the strip-shaped lead frame after resin sealing for each mold unit. For example, the pitches of a plurality of feed arms that operate in synchronization can be finely adjusted for each feed arm corresponding to each mold unit, and the feed accuracy of a strip-shaped lead frame after resin sealing can be improved.

． Since a plurality of molds are appropriately divided into groups to form a plurality of mold units, it is easier to perform maintenance and management as compared with a forming device of a progressive press machine type which is composed of only one mold unit. That is, when a defect occurs in a certain mold, it is sufficient to inspect and repair only the mold unit including the defective mold, and the work efficiency of maintenance management can be improved.

Next, another application example will be described.

In the above-mentioned embodiment, each mold unit provided by dividing a plurality of molds into five groups is mounted on the corresponding five press machines, but the present invention is not limited to this. , Can be knitted and sectioned into various forms (including selection of the number of presses). Further, it is needless to say that the forming device according to the present invention can be effectively used even when the external leads of the semiconductor device are bent into a Z shape.

Although the present invention has been variously described with reference to the preferred embodiments, the present invention is not limited to the embodiments and many modifications can be made without departing from the spirit of the invention. Is.

(Effect of the Invention) According to the present invention, a plurality of molds are grouped into a plurality of mold units including one or a plurality of molds, and at least one of the plurality of mold units is a plurality of molds. In addition to the mold units, each mold unit is mounted on an independent press machine, and the plurality of press machines are linearly arranged. Therefore, it is possible to easily set, adjust, and maintain various conditions such as press pressure for each mold unit, and, like the progressive press machine, continuously feed multiple strip-shaped lead frames linearly and efficiently. it can. That is, the present invention has both the advantage that the conditions of the conventional transfer press line can be easily set, adjusted and maintained, and that the workpiece of the progressive press machine can be efficiently conveyed and processed. ing.

Therefore, according to the present invention, the external leads of the semiconductor device can be accurately and precisely determined without damaging the semiconductor device, while adapting to the technical field of processing a semiconductor device that requires high processing accuracy. It has an advantageous effect that it can be molded into the shape.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a forming device for bending an external lead, FIG. 2 is an explanatory plan view of the same, and FIGS. 3 (a) to 3 (d).
Is a process drawing showing an embodiment of the present invention, and FIG. 4 is a schematic explanatory view of a lead frame. 10A-10E ... Press machine, 12
...... Lead frame, 12a …… Frame part, 12c …… Suspension pin, 14 …… Supply mechanism, 16 …… Discharge mechanism, 18 …… Chuck device, 22 …… Feed arm, 26 …… Feed roller, 30 ……
Semiconductor device, 30a ... External lead, 32B, 32D ... Die.

Claims (1)

[Claims] 1. A strip-shaped lead frame, in which a plurality of unit lead frames are connected and a semiconductor chip mounted on each unit lead frame is resin-sealed, is sequentially fed by a carrying mechanism, and is outwardly fed from each resin-sealed portion. In a forming device for an external lead of a semiconductor device, which presses an external lead extending to a plurality of molds into a predetermined shape in multiple stages, except for a hanging pin of a resin sealing portion of the lead frame,
A first cutting die that separates the external lead from the frame portion, and a molding die that bends at least the base portion and a molding die that forms the tip portion of at least the outer lead of the lead frame fed from the first cutting die. Including a plurality of molding dies for bending the external lead into a predetermined shape in multiple stages, and cutting the hanging pins of the lead frame fed from the plurality of molding dies into a semiconductor device and a frame part. A plurality of second cutting dies to be separated, and a plurality of dies including at least the first cutting dies, the plurality of molding dies, and the second cutting dies, according to a process order, The mold units are grouped into a plurality of mold units, and at least one of the plurality of mold units is a mold unit, and each mold unit is an independent press drive cylinder. Each of the plurality of pressing machines is linearly arranged so that the plurality of strip-shaped lead frames are continuously fed in a linear manner. Forming device for an external lead of a semiconductor device.