JP2897455B2 - Stamping device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marking device, and more particularly to a stamping device used in the manufacture of semiconductor devices. The present invention relates to a stamping device for inspecting a seal.

[0002]

2. Description of the Related Art In the manufacture of a semiconductor device, there is a stamping step of making a predetermined stamp on the surface of a lead frame having a large number of semiconductor elements connected in series and inspecting the stamped state.

The marking device used in the marking step is generally fixedly disposed above a lead frame transfer mechanism for intermittently transferring the lead frame in a fixed direction and at a constant pitch, and above a semiconductor element located at a marking position. And a marking unit such as a laser marking for performing a predetermined marking on the surface of the semiconductor element, and a marking unit fixedly disposed above the semiconductor element located at the inspection position in front of the lead frame moving direction to check the marking state on the surface of the semiconductor element. It consists of an inspection camera for inspection.

[0004] The above-described marking device includes, for example, a method of performing marking and inspection on the same lead frame, and a method of performing marking and inspection on separate lead frames.

[0005] In the method of performing marking and inspection on the same lead frame, the same lead frame that is intermittently transferred at a constant pitch by the lead frame transfer mechanism is fixedly arranged above the semiconductor element located at the marking position. The unit applies a predetermined seal to the surface of the semiconductor element, and is placed at the inspection position by the lead frame transfer mechanism by the inspection camera fixed above the semiconductor element located at the inspection position ahead of the lead frame in the transfer direction. An image of the stamped semiconductor element is taken and the state of the stamp on the surface is inspected.

[0006] In the method of performing marking and inspection on separate lead frames, the preceding and succeeding lead frames that are intermittently transferred at a constant pitch by a lead frame transfer mechanism are marked on the following lead frame. A predetermined marking is applied to the surface of the semiconductor device by the marking unit arranged at the position, and the lead provided in synchronization with the lead frame to be followed is synchronized by the inspection camera arranged at the inspection position in front of the lead frame in the transfer direction. The state of the stamp on the surface of the semiconductor element on which the frame has been stamped is inspected.

On the other hand, there are various types of lead frame transfer mechanisms used in the above-described marking device, such as pin feed, vertical clamp feed, and mold feed.

[0008] First, a lead frame transfer mechanism of a pin feed system is configured such that a lead frame held by a guide rail is provided with a feed hole formed at a constant pitch along a side edge thereof and a feed pin fitted into the feed hole. The feed pin is intermittently transported at a constant pitch using the feed pin. Specifically, the feed pin located above the feed hole of the lead frame is lowered and fitted into the feed hole, and in this state, the feed pin is moved in the lead frame transfer direction. Then, the feed pin is raised to withdraw from the feed hole, and then the feed pin is retracted to return to the initial position. By repeating the square motion of the feed pin, the lead frame is intermittently transferred at a constant pitch.

Next, the lead frame transfer mechanism of the upper and lower clamp feed system intermittently transfers the lead frame held by the guide rail at a constant pitch using upper and lower clampers which sandwich the front and back surfaces of the side edges from above and below. Things
The upper and lower clampers are moved closer to each other to sandwich the side edge of the lead frame, and the upper and lower clampers are moved forward with the lead frame clamped by the frictional force between the upper and lower clampers and the front and back surfaces of the lead frame. Then, the upper and lower clampers are retracted and returned to the initial position. The lead frame is intermittently transported at a constant pitch by repeating the operation of the upper and lower clampers.

Finally, the mold feed type lead frame transfer mechanism intermittently transfers the lead frame held by the guide rails at a constant pitch by using vertical feed claws inserted from above and below behind the molded part of the semiconductor element. The upper and lower feed claws approach each other from the top and bottom of the lead frame, and are inserted behind the molded part of the semiconductor element, and the upper and lower feed claws are brought into contact with the rear end face of the mold part. Push forward and press the mold part,
Thereafter, the upper and lower feed claws are separated from each other and separated from the rear of the mold portion, and then the upper and lower feed claws are retracted to return to the initial position. The lead frame is intermittently transported at a constant pitch by repeating the operation of the vertical feed claw.

[0011]

However, the conventional stamping apparatus has the following problems in the inspection method.

First, in the method of performing marking and inspection on the same lead frame, after marking on the semiconductor element at the last position of the lead frame is completed, the untested semiconductor elements from the marking position to the inspection position are thereafter removed. The pitch must be fed only by inspection, during which time the marking unit does not operate at the marking position and the next lead frame is on standby. Therefore, a time lag occurs between the completion of the inspection of the stamped state for all the semiconductor elements of the lead frame and the simultaneous start of the stamping and the inspection for the next lead frame. In order to eliminate this time lag, if the next lead frame is to be transported in synchronization with the preceding lead frame, a feed claw for two lead frames is required, which causes a problem that the lead frame transport mechanism becomes large. there were.

In the method of performing marking and inspection on separate lead frames, the marking and inspection of the preceding lead frame and the succeeding lead frame are performed separately and simultaneously. As described above, the frame must be moved in synchronization with the frame, which also requires the feed claws for two lead frames, and thus has a problem that the lead frame transfer mechanism becomes large.

Next, the above-described marking device has the following problems in the lead frame transfer system.

First, in the lead frame transfer mechanism of the pin feed system, the feed pin is inserted into a feed hole formed for each lead frame to intermittently transfer the lead frame, so that the type of the lead frame is limited. Therefore,
If the type of the lead frame changes in width, length, number of molds, and the like, the type of the lead frame transfer mechanism must be changed accordingly, and it has been very difficult to handle multiple types (flexible).

Further, in the lead frame transfer mechanism of the upper and lower clamp system, a predetermined frictional force is obtained between the upper and lower clampers and the lead frame for the lead frame before the solder plating process, but for the lead frame after the solder plating process. However, there is a problem that it is difficult to obtain a predetermined frictional force, and it is difficult to accurately stop by slipping when the lead frame is transported at a high speed, which is likely to cause a positional shift and lacks high speed and stability.

Further, in the lead frame transfer mechanism of the mold feeding system, the lead frame is intermittently transferred by inserting a vertical feed claw behind the mold portion of the semiconductor element and pressing the rear end face of the mold portion with the vertical feed claw. Therefore, when the lead frame is transported at high speed, the lead frame overruns due to inertia, and it is difficult to accurately stop the lead frame as in the case of the above-mentioned upper and lower clamp method. There was a problem of lack of stability.

Therefore, the present invention has been proposed in view of the above problems, and an object of the present invention is to enable a stable and high-speed intermittent transfer of a lead frame by a compact lead frame transfer mechanism. An object of the present invention is to provide a stamping device capable of improving an index and supporting a variety of products.

[0019]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a marking unit on a semiconductor element surface while intermittently transporting a lead frame having a number of semiconductor elements connected thereto at a constant pitch by a lead frame transport mechanism. In the marking device that inspects the marking state of the surface of the semiconductor device with an inspection camera after the marking, the lead is moved to the inspection position in front of the lead frame transfer direction with respect to the marking unit fixed at the marking position. After the semiconductor element at the last position of the lead frame is stamped on the lead frame, the lead frame is moved in a straight line such that the semiconductor element at the last position is located at the inspection position. Before the transfer mechanism returns to the initial state and starts stamping the next lead frame, the lead frame While moving toward the transfer front, characterized by comprising a inspection camera that the seal state sequentially testing a semiconductor device uninspected by direct transfer of the lead frame.

Further, according to the present invention, while a lead frame having a large number of semiconductor elements connected in series is transferred at a constant pitch by a lead frame transfer mechanism, a predetermined marking is performed on the surface of the semiconductor element by a marking unit. In a marking device for inspecting a marking state on a front surface of a semiconductor element with an inspection camera, the lead frame transfer mechanism includes a feed claw that sandwiches the front and rear surfaces of the rear end of the lead frame from above and below and simultaneously presses the rear end surface of the lead frame from behind. It is characterized by having.

[0021]

In the marking device according to the present invention, after the semiconductor element at the last position of the lead frame is stamped, the lead frame is transferred directly so that the semiconductor element at the last position is located at the inspection position. Until the mechanism returns to the initial state and starts stamping the next lead frame, the inspection camera is moved toward the front of the lead frame transfer, and the stamped state of the untested semiconductor elements by the direct transfer of the lead frame is sequentially , The time lag is eliminated, and the index can be improved with a compact lead frame transfer mechanism.

In the lead frame transfer mechanism, the lead frame is intermittently transferred by a feed claw pressing the rear end surface of the lead frame from behind while holding the front and rear surfaces of the lead frame after transfer.
It is possible to stably transfer a variety of lead frames at high speed without slipping or overrun due to inertia.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a stamping device according to the present invention will be described with reference to FIGS.

As shown in FIG. 1, the marking device of the present invention transfers a long metal lead frame (2) having a large number of semiconductor elements (1) connected in a continuous manner at a constant pitch in a fixed direction. a mechanism (3), seal units laser marking or the like for performing predetermined marking on the surface of the semiconductor element is fixedly disposed above the semiconductor element (1) located in the stamping position P ₁ (1) and (4), inspection for inspecting the marking state on the surface of the lead frame transport direction in front of the inspection positions upward is movably arranged along the lead frame transfer direction a semiconductor element of a semiconductor element located on P ₂ (1) (1) And a camera (5). In the figure,
(6) is fixedly disposed above the lead frame (2) before the stamping position P _1, a recognition camera for discriminating the front and back surfaces of the lead frame (2).

Specifically, in the above stamping device, (7)
Is a guide rail extending along the longitudinal direction of the lead frame (2). For example, a concave groove is formed on the inner surface thereof, and both side edges of the lead frame (2) are fitted into the concave groove. Thus, the lead frame (2) is slidably held in the longitudinal direction in a horizontal state. If the width of the lead frame (2) is changed by switching the type, the interval between the guide rails (7) can be adjusted accordingly in order to enable the lead frame (2) to handle a wide variety of types. It has a structure. (8) is a feed claw for intermittently transferring the lead frame (2) at the marking position with high precision. Although not shown, a lead is made by performing a square motion between the guide rails (7) by a drive source such as a servomotor as described later. The frame (2) is intermittently transported at a constant pitch. In order to make it possible to support various types of lead frames, if the length of the lead frame (2), the number of semiconductor elements (1), the interval between the semiconductor elements (1), etc. are changed by switching the type, it will be Accordingly, the transfer pitch and the stroke of the lead frame (2) in the intermittent transfer can be accurately adjusted by changing the setting of the rotation speed of the servo motor. The feed claw (8) has an openable and closable clamp / push portion (9) as shown in FIGS. 2 and 3, and the rear end surface of the lead frame (2) is transferred by the clamp / push portion (9). At the same time, the rear surface is sandwiched from above and below, and the end surface after the transfer is pressed from behind. (1
0) is a pinch roller for transporting the lead frame (2) before and after the stamping position P _1, arranged in contact with the side edge surfaces of the lead frame (2), the lead frame (2 supplied from the loader unit ) Stamping position
To P _1, also from seal position P ₁ to the unloader section through the inspection position P _2, transported with the lead frame (2) in contact resistance with the surface. (11) is a loader section of the lead frame (2), which stores a magazine (12) in which a large number of lead frames (2) are stacked and stored in a stacked state.
A magazine supply unit (13) for vertically moving and supplying according to the magazine height, an elevator unit (14) for transferring a lead frame (2) in the magazine (12) to a buffer unit (described later), and an elevator unit Placed above (14),
A buffer section (15) for temporarily storing and holding a large number of lead frames (2) taken out of the magazine (12); and a guide rail (7) in front of the buffer section (15).
Is arranged. Although not shown, the buffer unit (1
Lead frame (2) from 5) to guide rail (7)
Is carried out by a transfer mechanism having a suction pad for sucking the surface of the lead frame (2). (16) is an unloader section of the lead frame (2), which is disposed in front of the guide rail (7), and discharges a defective stamped and inspected lead frame (2) which is defective (17). And a buffer section (18) which is disposed beside the defective discharge section (17) and temporarily stores and holds a number of lead frames (2) which have been stamped and inspected, and a buffer section (18) below the buffer section (18). And an elevator section (19) for transferring the lead frame (2) in the buffer section (18) into the magazine (12), and an elevator section (19) arranged in front of the elevator section (19) and taken out of the elevator section (19). Magazine (1
2) A magazine discharge section (20) for storing and discharging the magazine. Although not shown in the unloader section (16),
In accordance with a user's request or a necessity in a post-process, the lead frame (2) with the stamped and inspected surface of the lead frame (2) sucked and held by the suction pad in front of the guide rail (7) is removed. The upper suction pad is rotated by 180 degrees in a horizontal plane, the surface of the lead frame (2) is sucked by the upper suction pad, and the back surface is sucked and held by the lower suction pad. The lead frame (2) can be turned upside down by oscillating. Reference numeral (21) denotes a magazine transporting section provided between the loader section (11) and the unloader section (16), and the elevator section (1) of the loader section (11).
The empty magazine (12) from which the lead frame (2) has been removed in 4) is unloaded by the unloader unit (1) by the moving conveyor (22).
6), and the same lead frame (2) initially stored in the elevator section (14) is collected in the empty magazine (12).

Next, the operation of the marking device will be described.

First, in the loader section (11), the magazine (12) taken out of the magazine supply section (13) is raised by the elevator section (14), and a number of lead frames stored in the magazine (12). (2) Buffer section (15)
Transfer to once. The lead frame (2) is cut out one by one from the buffer section (15) by a suction pad and arranged at a supply position before the guide rail (7).
Lead frame (2) placed at this supply position
Is transferred to the marking position P ₁ by the pinch roller, the semiconductor element (1) located at the foremost position of the lead frame (2) is arranged in the marking position P ₁ is directly below the seal unit (4). During this time, the front and back of the lead frame (2) are determined by the recognition camera (6), and if the lead frame (2) is turned upside down, the lead frame (2) is guided by the pinch roller (10) to the guide rail. (7) The sheet is passed through as it is and sent out to the defective discharge section (17) of the unloader section (16).

[0028] The lead the frame (2) is arranged in the marking position P ₁ on the guide rail (7), feed pawl (8 disposed below between the guide rails (7) as shown in FIG. 4 ) Is raised and arranged at the rear end of the lead frame (2), and the clamp / push portion (9) of the feed claw (8) sandwiches the front and back surfaces of the lead frame (2), and simultaneously holds the feed claw (8). Then, it is brought into contact with the end face. From this state, the feed frame (2) is advanced at a constant pitch by the rotation drive of the servomotor, that is, at an interval pitch of the semiconductor element (1), so that the lead frame (2) is clamped and pushed by the feed claw (8). It is intermittently transported while being gripped in (9) and pressed from behind by the feed claw (8) itself. Here, if the lead frame (2) is deformed or the like, the transfer direction of the lead frame (2) does not coincide with the action direction of the pressing force by simply pushing the rear end face of the lead frame (2). There is a possibility that the lead frame (2) may be crushed due to clogging without being performed. However, in the case of the feed claw (8), the action direction of the pressing force with respect to the transfer direction due to deformation or the like is caused by clamping the front and back surfaces of the rear end portion of the lead frame (2) from above and below with the clamp / push portion (9). Even if there is any deviation, it can be corrected so that the direction of action of the pressing force coincides with the transfer direction, and the pressing force can be applied straight in the transfer direction, so that good transfer can be realized. Further, since the front and back surfaces of the rear end portion of the lead frame (2) are sandwiched from above and below by the clamp / push portion (9), the lead frame (2) is overloaded by inertia generated when the lead frame (2) is transferred at high speed. It can be accurately positioned in the seal position P ₁ without having to run. In marking position P _1, the predetermined marking is provided on a surface of the semiconductor element (1) by stamping unit (4), the semiconductor device the marking operation at the end position from the semiconductor element (1) in the foremost position (1) Are performed sequentially.

On the other hand, the inspection position P ₂ is set to an integer multiple position of spacing pitch of the semiconductor element (1) in the lead frame transport direction ahead of the stamping position P _1, in parallel with the stamp operation described above, is intermittently transported The surface of the semiconductor element (1) having been stamped is imaged with an inspection camera (5), and the inspection state is sequentially inspected by the inspection camera (5). Incidentally, varieties stamping unit (4) inspection camera against fixed therein disposed (5) is attached to the movable table, the spacing pitch between the inspection position P ₂ and the marking position P ₁ is the lead frame (2) Is automatically switched according to.

[0030] When the seal operation by the semiconductor element (1) is stamped units reached the stamping position P ₁ (4) at the end position of the lead frame (2) as shown in FIG. 5 is completed, shown in FIG. 6 and direct transfer at high speed by nail feeding the lead frame (2) (8) so as to place the test position P ₂ of the semiconductor element (1) in its end position. Thereafter, the feed claw (8) is lowered and then retracted to return to the initial position, and at the same time, the loader (11) cuts out from the buffer (15) and places the next lead frame ( between 2) to be transported to the marking position P ₁ by a pinch roller (10), at intervals pitch inspection camera (semiconductor device toward the 5) to the lead frame transfer direction forward (1) as shown in FIG. 7 Lead frame (2) with feed claw (8) while moving
The imprint state of the untested semiconductor element (1) remaining ahead of the semiconductor element (1) at the last position, which has been generated by the direct transfer, is sequentially inspected by the inspection camera (5). This allows eliminating the tact time loss in the test position P _2, Thus also, the feed pawl clamp push portion ON-OFF (9) on a single lead frame not per pitch feed (2) (8) The index can be improved because each stroke feed is sufficient. After the above-mentioned inspection of the untested semiconductor element (1) is completed, the inspection camera (5) is returned to the initial position, and the next lead frame (2) is put on standby.

The lead frame (2), which has been stamped and inspected as described above, is sent out by the pinch roller (10) on the guide rail (7) and is arranged at the discharge position. In the unloader section (16), the defective lead frame (2) is discharged to the defective discharge section (17), and the non-defective lead frame (2) is replaced with the lead frame (2) as necessary as described above. After being turned 180 degrees in the horizontal plane or the lead frame (2) is turned upside down, it is sequentially stored in the buffer section (18). And
When a predetermined number of lead frames (2) are stored in the buffer section (18), they are forwarded from the loader section (11) to the unloader section (16) by the magazine forwarding section (21) and placed in the elevator section (19). The lead frame (2) of the buffer section (18) is raised by raising the empty magazine (12).
To an empty magazine (12). Then, after lowering the elevator section (19), the magazine (12) containing the stamped and inspected lead frame (2) is transferred from the elevator section (19) to the magazine discharge section (20), and the magazine is transferred. The magazine (12) is supplied from a discharge unit (20) to a post-process.

[0032]

According to the marking device of the present invention, after the semiconductor element at the last position of the lead frame is stamped, the lead frame is moved straight so that the semiconductor element at the last position is located at the inspection position. Until the lead frame transfer mechanism returns to the initial state and starts stamping the next lead frame, the inspection camera is moved to the front of the lead frame transfer, and the untested semiconductor elements are transferred by the direct transfer of the lead frame. Since the stamped state is sequentially inspected, the time lag is eliminated, and the index can be improved with a compact lead frame transfer mechanism.

In the lead frame transfer mechanism, the lead frame is intermittently transferred by a feed claw pressing the rear end surface of the lead frame from behind while holding the front and back surfaces of the lead frame at the same time.
Inconveniences due to deformation of the lead frame can be eliminated, and lead frames of various types can be stably transferred at a high speed without slipping or overrun due to inertia.

As described above, according to the present invention, it is possible to provide a marking device which is easy to cope with various types of products and has a high practical value with a high index, which enables stable high-speed transfer of a lead frame.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an embodiment of a stamping device according to the present invention.

FIG. 2 is a perspective view showing a feed claw and a lead frame of the stamping device of FIG. 1;

FIG. 3 is a front view showing a feed claw and a lead frame of FIG. 2;

FIG. 4 is a front view showing a start state of stamping of the lead frame in an operation state of the feed claw;

FIG. 5 is a front view showing a state in which the semiconductor element at the last position of the lead frame has been stamped in the operation state of the feed claw;

FIG. 6 is a front view showing a state in which the semiconductor element at the last position of the lead frame has been directly transported to the inspection position in the operation state of the feed claw;

FIG. 7 is a front view showing an inspection state of an untested semiconductor element of the lead frame in an operation state of the feed claw;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Semiconductor element 2 Lead frame 3 Lead frame transfer mechanism 4 Marking unit 5 Inspection camera 8 Feeding nail P ₁ Marking position P ₂ Inspection position

Claims (2)

(57) [Claims] 1. A stamping unit performs a predetermined marking on a surface of a semiconductor device while intermittently transporting a lead frame having a large number of semiconductor devices at a constant pitch by a lead frame transport mechanism. In a marking device for inspecting a marking state with an inspection camera, a marking unit fixedly arranged at a marking position is movably arranged along a lead frame moving direction to an inspection position in front of a lead frame moving direction in a lead frame moving direction. After stamping the semiconductor device at the last position, the lead frame is transferred directly so that the semiconductor device at the last position is located at the inspection position, and the lead frame transfer mechanism returns to the initial state and starts stamping the next lead frame. While moving the lead frame forward before
An imprinting device comprising an inspection camera for sequentially inspecting the imprinting state of untested semiconductor elements by direct transfer of a lead frame. 2. A predetermined marking is performed on a surface of a semiconductor element by a marking unit while transferring a lead frame having a large number of semiconductor elements at a constant pitch by a lead frame transfer mechanism. In the marking device for inspecting the state of marking with a test camera, the lead frame transfer mechanism has a feed claw that sandwiches the front and back surfaces of the rear end of the lead frame from above and below and simultaneously presses the transfer end surface from behind. Characteristic marking device.