JPH06181354A - Laser optical device - Google Patents

Abstract

PURPOSE:To enable a single laser source to share laser beams in a time-division manner. CONSTITUTION:Switching mirrors 3A to 3C are of chopper type and controlled in turning angle, whereby a laser beam emitted from a single laser source is surely emitted from one out of the three total reflection parts of the mirrors 3A to 3C. By this setup, laser beams are emitted from the three switching mirrors 3A to 3C in a time-division way. Furthermore, a bending mirror 5 is provided at a rearmost position, whereby an additional laser beam can be emitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser optical device for simultaneously performing a plurality of laser operations in parallel.

[0002]

2. Description of the Related Art When processing an object with a laser beam, one laser source and one object to be processed are combined. Therefore, it is necessary to prepare one laser source for each line in order to process the objects to be processed in each line simultaneously in parallel under a plurality of production lines. For example,
When the object to be processed is a semiconductor device dam bar, in order to remove each semiconductor device dam bar under four production lines, a total of four laser sources for each line are prepared, and four laser sources are simultaneously prepared. The method of removing the dam bar of the semiconductor device is adopted.

[0003]

Although it is true that a plurality of laser sources are required to process the objects on a plurality of production lines at the same time, it is necessary to perform the simultaneous simultaneous processing depending on the production lines and the objects to be processed. There are many cases where it is not necessary to do so. For example,
The object to be processed has a complicated shape and it is necessary to recognize the shape before starting the processing, or in order to align the laser irradiation position with the shape, move the object to the laser irradiation position. There are many cases that require alignment work. There is no laser emission during the recognition work and the alignment work, and it is in a so-called idle state. From the viewpoint of the work processing system, the laser source is unnecessary during this time. In particular, each laser source is expensive at several million yen, and it is not preferable to prepare for the production line or leave it idle.

For example, in an example of removing a dam bar of a semiconductor device by using a laser beam, the lead frame has 4
There is a QFP type semiconductor device that projects to the side. QF
The P type has a narrow pitch between lead frames and has a very large number of pins (the number of lead frames) of 300 to 500, but the demand thereof is increasing. It is desired to mass-produce semiconductor devices of the same type with several hundreds to several millions per month. In order to remove the dam bar of the QFP type semiconductor device on the production line, high speed, high repetition and high precision processing are required. However, in order to remove the dam bars, it is necessary to position each dam bar so as to match the irradiation position of the laser beam. This needs to be done on all four sides. Further, it is necessary to mount the semiconductor device on the processing table for removing the dam bar, and also to transfer the semiconductor device from the processing table after the removal is completed.

It is an object of the present invention to provide an optical system which allows multiple operations with a single laser source to be performed concurrently, but not completely simultaneously.

[0006]

DISCLOSURE OF THE INVENTION The present invention comprises a plurality of rotatable, linearly arranged so that their optical axes coincide with each other and having a reflective surface and a transmissive surface, which are circumferentially divided. A switching mirror, a laser source that emits a laser beam to the switching mirror in the optical axis direction, and a control unit that controls the rotation of the switching mirror so that the laser beam is emitted from one of the reflecting surfaces of the plurality of switching mirrors. And (claim 1).

The present invention further provides a plurality of rotatable switching mirrors having a reflecting surface and a transmitting surface, which are arranged in a straight line so that their optical axes coincide with each other, and are divided in the circumferential direction. A laser source that emits laser light to the switching mirror from the optical axis direction, and a plurality of laser irradiation target parts corresponding to each switching mirror that are mounted on separate work lines and are replaced by new ones after being discharged by the laser. , The rotation of the switching mirror is controlled so that the laser light is irradiated from one of the reflecting surfaces of the plurality of switching mirrors to the corresponding laser irradiation target portion, and the laser light is sequentially distributed to the plurality of laser irradiation target portions. And a control means for controlling (claim 2).

Further, according to the present invention, the reflecting surface of each of the switching mirrors is one total reflecting surface of the same size, and the arrangement in which the optical axes coincide with each other does not mean that any one of them is on the path of the laser beam. The arrangement is such that the total reflection surface appears (Claim 3).

Further, according to the present invention, a total reflection mirror is provided at the end of the plurality of switching mirrors, and a laser irradiation target portion is also provided in the laser light reflection direction of the total reflection mirror (claim 4).

[0010]

According to the present invention, under a single laser source, the switching mirror is switched in a time-division manner so that the laser beams can be irradiated simultaneously in parallel (claims 1, 2, 3, 4). .

[0011]

FIG. 2 is an embodiment diagram in which the optical device of the present invention is applied to a semiconductor device processing apparatus. The four transfer lines (working lines) 1 to 4 compose a feeding device 17, and on each of these lines 1 to 4, the semiconductor device 9 after the completion of work in the previous process is mounted, and the robot 16 is The semiconductor device is gripped by a hand, placed on the processing table 10 and fixed, and becomes a processing target.

The laser source 1 is a single laser source for the four carrier lines 1-4. The laser beam switching unit 2 is provided for time-divisionally distributing the laser beam from the laser source 1 in a chopper type to process the semiconductor devices of the four processing tables on the four transfer lines in parallel. . The switching unit 2 includes at least three switching mirrors 3A, 3B, and 3C, a bending mirror 5 for reflection, a condenser lens 12, a processing head 13, and a TV camera 14 for monitoring. The laser beam excitation from the laser source 1 is performed at preset timing. TV
The camera 14 is a monitor for positioning the semiconductor device and the dam bar via the lens 15, and the image processing device 20.
Captures the image pickup signal, performs necessary image analysis, and provides the position alignment control.

Since the laser beam from the switching unit 2 is given from a fixed position, the processing table 10
Is movable so that the laser beam can be accurately applied to the cutting dam bar positions on the four sides and each side of the QFP.

After the cutting of the dam bar is completed, another robot 18 removes the semiconductor device from the processing table, puts it on the carry-out line 19 and sends it out for the next process. In this way, the laser beam from the single laser source 1 is switched to the switching unit 2
Are distributed and supplied, and the four semiconductor devices 9 are processed in parallel.

FIG. 1A is a view showing a switching mirror in the processing unit 2. Chopper type switching mirror 3A,
As shown in FIG. 2B, 3B and 3C are disc-shaped bodies having a total reflection portion (1) and a transmission portion in the circumferential direction. In the figure (b), the total reflection part (1) is a quarter of the circumference.
It occupies a section (that is, a quarter quadrant), and the rest is a transmission part (0). The switching mirrors 3A, 3B, 3C are arranged linearly in the optical axis direction through which the laser beam 6 emitted from the laser source 1 passes. That is, they are arranged so as to coincide with the optical axis. A bending mirror 5 serving as a reflection mirror is installed at the tail end.

The switching mirrors 3A, 3B and 3C are provided with a supporting portion 4.
It is supported by A, 4B and 4C.
B and 4C rotate in the circumferential direction by the driver 7 under the control of the controller 8. By performing this rotation, the laser beam 6 is reflected by any one of the total reflection portions (1) of the switching mirrors 3A, 3B, 3C, and is distributed as the laser beams a, b, c. Switching mirrors 3A, 3B,
If any of 3C is transmitted with respect to the laser beam (that is, the transmitting portion corresponds), it is reflected by the rearmost bending mirror 5 and distributed as a laser beam d.

In order to achieve the distribution of the laser beam by the switching mirrors 3A, 3B, 3C, the rotational direction arrangement and the rotational control of the switching mirrors 3A, 3B, 3C are as follows. First, as an initial arrangement, as shown in FIG. 2B, the total reflection part (1) of the switching mirror 3A is present on the passing optical axis of the laser beam 6 (this is called the first quadrant), The total reflection portion (1) of the switching mirror 3B is set in the fourth quadrant, and the total reflection portion (1) of the switching mirror 3C is set in the third quadrant.

(1) At this initial position, the laser beam 6 is totally reflected only by the total reflection portion (1) of the switching mirror 3A and can be emitted as a laser beam a in the orthogonal direction. No laser beam is emitted to the switching mirrors 3B and 3C and the reflection mirror 5. (2) Next, in order to emit the laser beam b instead of the laser beam a, the driver 7 switches the switching mirror 3
Rotate all of A, 3B and 3C counterclockwise by 1/4 quadrant. As a result, the total reflection portion (1) of the switching mirror 3A moves to the second quadrant, the total reflection portion (1) of the switching mirror 3B moves to the first quadrant, and the total reflection portion (1) of the switching mirror 3C moves. Move to the 4th quadrant. Thus, the switching mirror 3A transmits the laser beam 6 and is totally reflected by the total reflection portion (1) of the switching mirror 3B, so that the laser beam b
Can be released.

(3) In order to emit the laser beam c instead of the laser beam b, in the same manner, the driver 7 rotates each of the switching mirrors 3A, 3B and 3C by a quarter quadrant, and the switching mirror 3C is rotated. Only the position where the laser beam 6 is totally reflected becomes a position where the laser beam c can be emitted. (4) Finally, each of the switching mirrors 3A and 3A for 1/4 quadrant
When B and 3C are rotated, all switching mirrors 3A, 3B and 3
C becomes a transmissive state, the laser beam 6 hits the bending mirror 5, and the laser beam d can be emitted.

In this way, by rotating the switching mirrors 3A, 3B, and 3C by the driver 7 in quadrants,
The laser beam can be distributed by time division such that → b → c → d. Therefore, by disposing the processing table in the discharge directions of a, b, c, and d, the dam bar can be removed. Further, the dam bars on the four sides can be removed by repeating the above switching sequence.

FIGS. 3 and 4 show a QPF type semiconductor device, particularly a triple semiconductor device in which three semiconductor devices are connected.
FIG. 3 shows 3 after resin molding which is a processing target of this embodiment.
It is a top view of a continuous semiconductor device. The triple semiconductor device is
The lead frame unit 20 includes three semiconductor devices # 1 to # 3.
It is a continuous device. The whole example is shown in FIG. The lead frame portion 20 includes the semiconductor portions 21A and 21A.
B and 21C and lead frames 26, 30, and 31, and in FIG. 3, only the semiconductor portion 21A is shown in particular. The semiconductor parts 21A, 21B, 21C are resin-molded, and generally, the dam bar cutting is performed in the process of this embodiment, and the bending process is performed in the subsequent process.

In FIG. 3, each semiconductor device # 1, # 2, # 3 is used.
Has square semiconductor parts 21A, 21B, 21C,
Moreover, the lead frames 26, 30, and 31 are led out in the direction orthogonal to each of the four sides. This is called a QFP (quadrilateral flat package device). # 1 and #
2 and between # 2 and # 3 are separated by holes 24 and 25. In addition to this three-series system, a six-series system with a six-series configuration in series,
There is a parallel 6-series system in which 3 serial systems are arranged in parallel.

In the semiconductor device # 2 of FIG. 3, lead frames 26A, 26B, 26C and 26D are led out from the four sides of the semiconductor portion 21A resin-molded around the sides in a direction orthogonal to the sides. Each lead frame 26A, 26B,
26C and 26D are lead frames 22A, 22B and 2
2C and 22D, and dam bars 23A, 23B, 23C and 23D that are connected to the respective lead frame bodies in the orthogonal direction. The dam bars 23A to 23D serve as members for preventing the resin from flowing out to the lead frame when the resin is molded into the semiconductor portion 21A.

After the resin sealing, the dam bars 23A-23
D is cut to make each lead frame body electrically independent. FIG. 5 shows a state in which the dam bars 23A to 23D are removed and the unnecessary lead frame members on each side of the periphery are removed. This corresponds to the portion shown by the dotted line portion 27 in FIG. The removed dam bars 23A to 23D are shown by dotted lines in FIG.

The mounting of the semiconductor device on one processing table 10 will be described. As shown in the drawing, the processing table 10 is provided on a work line, and the robot 16 mounts the semiconductor device 9 on the line on the processing table 10 and then fixes it on the table. It is not preferable to place the semiconductor device 9 directly on the line or directly on the table because it may damage the semiconductor device itself. Further, damage on the table 10 during processing is also conceivable. Therefore, the semiconductor device 9 is placed and fixed on the chair holder 32, the holder 32 is placed on the line and sent, and the robot 16 grips the holder 32, places it on the processing table 10, and then fixes it on the table with a chuck or the like. Then, the dam bar of the semiconductor device is removed.

FIG. 6 shows an example of one holder 32 to which the semiconductor device is fixed. Three triple semiconductor devices (FIG. 4) 36A, 36B, 36C are mounted and fixed on the holder 32. In the drawings, the dam bar and the like are omitted in order to avoid complication, but the dam bar is naturally present before processing. Each triple semiconductor device 36A, 36
B and 36C are respectively held by a fixed frame 34, and the fixed frame 34 is fixed to the base 33 of the holder 34. Fixing pins 35 are provided at four corners of each base 33, and the fixing pins are used to form multiple semiconductor devices 36A to 36A.
C is fixed to the base 33.

Processing table 10 with holder 32 fixed
Can be moved in the x and y directions on the horizontal coordinate system xy, and can also be rotated within this coordinate system. This is performed by the drive system (not shown) of the table 10. Further, it can move vertically (that is, in the Z-axis direction) to the paper surface of FIG. These movements and rotations are the movements required to position the laser beam at the desired dam bar.

The holder 32 shown in FIG. 6 is fixed to one processing table 10, but one processing table 10 is irradiated with one laser beam.
Moreover, the irradiation position of the laser beam is fixed. Therefore, in order to remove the dam bars of the nine semiconductor devices as shown in FIG. 6, it is necessary to move the holder itself, that is, to move the table to which the holder 32 is fixed.
In order to adjust the laser beam to a predetermined dam bar position, movement and rotation in the x and y directions and movement in the z direction (distance adjustment between the laser beam and the dam bar in the z direction) are required. .

In order to process the semiconductor device on the holder 32 shown in FIG. 6, various movement modes are possible. The distribution destination of the laser beam is determined according to the movement mode. 7 and 8
An example is shown in. FIG. 7 is a diagram when processing is performed by dividing the four processing tables 10 for each side. The holders 32 on the four processing tables 10 are indicated as 32A to 32D.

(A) First, the processing table 1 is provided so that the laser beam a can be radiated to the leading dam bar on the first side Q1 (see FIG. 6) of the semiconductor device 36A belonging to the holder 32A.
Position 0. Together with this positioning, the driver 7 controls the switching mirrors 3A to 3C so that the laser beam a can be emitted from the switching mirror 3A. Immediately after this, move the table 10 on which the holder 32A is placed in the x direction,
A series of dam bars including the leading dam bar are successively irradiated with the laser beam a to remove the dam bars. Here, the series of dam bars is the first side Q1 through # 1, # 2, and # 3 of the triple semiconductor device 36A shown in FIG. Here, the lead frame pitch (or dam bar pitch) is defined, and the space distance between Q1 between # 1 and # 2 and the space distance between Q1 between # 2 and # 3 are also known. Since the moving speed of the table in the x direction is also known, the timing of exciting the laser beam can be automatically determined. This determination process is performed by a computer (not shown).

During the above operation, the processing table 10 is positioned so as to direct the holder 32B so that the head beam of the first side Q1 of the semiconductor device 36A belonging to the next holder 32B can be irradiated with the laser beam b. After completion of this positioning, the driver 7 controls the switching mirrors 3A to 3B so that the laser beam b can be emitted from the switching mirror 3B after completion of removal of all the dam bars on the first side Q1 of the holder 32A. After the control of the switching mirrors 3A to 3B is completed, the processing table 10 that supports the holder 32B is moved in the x direction, and the first side Q of the semiconductor device 36A belonging to the series of holders 32B including the leading dam bar.
1 is removed by emitting the laser beam b corresponding to the dam bar.

Similarly, during this operation, the holder 32C
The semiconductor device 36A belonging to the holder 32B is positioned, and after switching all the dam bars of the semiconductor device 36A belonging to the holder 32B, the switching mirrors 3A to 3C are switched so that the laser beam C can be emitted. And holder 32C
The dam bar on the first side Q1 of the semiconductor device 36A belonging to 1) is removed. The same applies to the holder 32D.

By this series of operations, the holders 32A ...
First side Q of semiconductor device 36A belonging to each of 32D
All dam bars in 1 are removed.

(B) Next, the movement of the holder 32A is started. However, there is a considerable free time from the removal of the dam bar of the holder 32A to the completion of the removal of the dam bar of the holder 32D in (A). Therefore, using this free time, the machining table to which the holder 32A belongs is moved in the y direction, and the third side Q of the semiconductor device 36A belonging to this holder 32A is moved.
Positioning is performed so that the laser beam a can be irradiated to the laser beam 3. Similarly, each of the holders 32B, 32C, and 32D also performs positioning using the free time determined by each. Therefore, in the figure, it seems that 32A to 32D simultaneously move in the y direction, but 32A → 32B → 32C.
→ Y-direction movement and alignment will be performed in the order of 32D.

(C) The semiconductor device 36 of the holder 32A
The dam bar on the third side Q3 of A is processed. This processing requires movement of the table and irradiation of the laser beam a each time the cutting dam bar appears, which is as described in (a). After cutting all the dam bars on the third side of the semiconductor device 36A belonging to the holder 32A, the laser beam b is selected in place of the laser beam a, and thereafter, all of the third side Q3 of the semiconductor device 36A belonging to the holder 32D is selected. The dam bar cutting is performed in the same manner as (a).

(C) ′ The above is the cutting of the first side Q1 and the third side Q3 of the semiconductor device 36A.
(B) to (C) are repeated for 6B and 36C. That is, after the operation of (c) in the semiconductor device 36A is completed, the y-direction is moved by using an appropriate blank time, and the semiconductor device 36B is positioned so as to become the first side Q1. Processing is performed in accordance with (b), then moved in the y direction according to (b), positioned so as to become the third side Q3, and processed according to (c). This is also performed for the semiconductor device 36C.

By performing the above (a) to (c) ', 3
All the dam bars on the first side Q1 and the third side Q3 of 6A to 36C are removed.

(D) Next, the holder 32 is rotated 90 °. As a result, the second side Q2 of the semiconductor device 36A of the holder 32A becomes the dam bar processing target for the laser beam a. Then, the positioning is performed so that the leading dam bar on the second side Q2 is the irradiation position of the laser beam a. The 90 ° rotation of the holder 32A and the positioning of the leading dam bar are performed during the idle time during the dam bar processing in the other holders 32B, 32C and 32D. Therefore, even in this case, 3
90 ° rotation and positioning are performed in the order of 2A → 32B → 32C → 32D by utilizing each idle time.

(E), (f), (g) This operation is Q2
And Q4, which are similar to the operations (a) to (c). (G) ', these (e) to (g) are Q of the semiconductor device 36A.
2 is an example of Q4, and (e) to (g) are repeated for the semiconductor devices 36B and 36C.

Thus, all sides Q1, Q2, Q3 of the holders 32A to 32D having the triple semiconductor device mounted thereon,
The dam bar of Q4 is removed.

In the course of the series of operations (a) to (g) ', the holder 32A → 32B → 32C → 32
The dam bars can be removed one after another in the order of D. Then, when the dam bar removal of the holder 32A is completed, the robot 18 removes the holder 32A from the table 10 by utilizing the idle time, sends it to the feeding line 19, and carries it to the next process. On the other hand, since the new holder has been sent to the receiving line 1, the robot 16 holds the new holder and mounts and fixes it on the processing table 10. Similarly, with respect to 32B, 32C, and 32D, after the dam bar is removed, it is sent out and replaced with a new holder.

In this way, the holders having the semiconductor devices carried on the four lines 1 to 4 are successively placed on the processing table and processed. Then, during this period, a single laser beam is distributed in a time division manner to remove the dam bar in a time division manner. During this period, while other holders are working, the other holders are moved and rotated using idle time, so efficient operation of time-division laser distribution and simultaneous operation of multiple work lines are performed. It became possible to do work-like work.

FIG. 8 is a diagram showing another embodiment of the movement control.
The difference from FIG. 7 is that the four holders 32A to 32 in FIG.
A semiconductor device (for example, 36A) at the same position with respect to D #
The first side Q1 of 1 to # 3 is sequentially processed in a time-sharing manner, but in FIG. 8, one semiconductor device (for example, # 1) in the triple system is intensively processed. It is in. That is, in the figure (a), the movement in the x direction is performed, and Q1 of # 1 of 32A → Q1 of # 1 of 32B → ... → 32
Machining is performed in the order of Q1 of # 1 of D, and then, in the figure (b),
Move in the y direction, and at (C), Q3 → # 3 of # 1 of 32A
2B # 1 Q3 → ...... → 32D # 1 Q3 is processed in this order. Further, rotate 90 ° in Fig. (D) and 32 in (E).
Processing is performed in the order of A # 1 Q2 → 32B # 1 Q2 → ... → 32D # 1 Q2. Similarly, Q4 is processed by (F) and (G).

In the operation shown in FIG. 8 described above, the following # 2 is processed by the steps (a) to (g), and further # 3 is processed by the steps (a) to (g). Of course, it is the same as in FIG. 7 that the blank time is used in other tables during these processes to perform movement, rotation, and positioning.

FIG. 9 is a time chart. Figure (a)
Shows a timing signal generated by the controller 8 shown in FIG. 2 at time T ₁ . When the first timing signal is generated, processing preparation on the processing table on line 1 is performed during this time T ₁ . Here, the processing preparation refers to positioning of the table, control for distribution in the laser beam a direction by switching the switching mirrors 3A, 3B, and 3C, and the like.
In FIG. 2, although the mirror switching is performed by the driver 7, the table control system is omitted, but a timing signal is also sent to the omitted control system to perform table positioning control. Hereinafter, processing preparation on the line 2 with the time width T ₁ of the second control signal, the time width T of the third control signal
_{In step 1} , processing preparations are performed on the line 3, and processing preparations on the line 4 are performed with the time width T ₁ of the fourth control signal. The cycle T ₂ of the control signal, the one cycle cycle T ₃ after passing through the four control signals, and the time width T ₁ are values determined in advance according to the movement mode shown in FIGS. 7 and 8.

FIG. 9B shows a line 1 signal for designating a dam bar machining section on the machining line of line 1, and this line 1 signal is continuous from the head dam bar on the machining table which was previously positioned. Line 1 processing control is performed to remove a series of dam bars. Here, the processing control means control of moving the processing table and irradiating the matching dam bar with the laser beam a. If the moving speed of the table is constant, the dam bar pitch (or frame pitch) of the side Q of the semiconductor device at that time is constant, so that the excitation timing of the laser source that emits the laser beam a is also constant and the side Q is constant. You can surely remove the dam bar.

Similarly, in (c), (d), and (e), line 2 signal, line 3 signal, and line 4 signal are generated one after another to control the machining. The side Q to be processed in each of these line signals is different between FIGS. 7 and 8, and the time width thereof is also different.

FIG. 10 is an embodiment diagram of the control device of this embodiment. The host computer 50 is a computer that controls each processing line, mirror switching, and laser excitation, and corresponds to the controller 8 in FIG. The computer 50 has a memory for storing the movement locus in the movement mode as shown in FIGS. 7 and 8. According to the contents of this memory, the machining line control system 51 and the mirror control system 52 use the laser control system 53 to make Controls each mirror and laser. Here, the processing line control system 51 means the line 1
4 to 4 hold the holder 16 by the robot 16, mount the table, fix the table, move and rotate the table, and eject the holder by the robot 18 after removing the dam bar. Mirror control system 52
Is the one including the driver 7 of FIG.
The switching control of A to 3C is performed. Laser control system 5
3 is for controlling the timing of laser emission of the laser source 1 of FIG. 1, and this can be realized by an electronic circuit.

11 and 12 are views showing an embodiment of the present invention relating to the shape of the laser beam. The vertical cross section of the beam is essentially circular in shape, and it is possible to remove the dam bar by applying it to the dam bar. However, in order to increase the energy of the laser beam, it is necessary to perform focusing with a focusing lens, and it is preferable that the dam bar can be reliably removed by this focused beam. However, if the aperture is narrowed down too much, the diameter may be reduced, and an uncut portion may remain in a part of the dam bar. If the aperture is not narrowed down, a part of the frame connected to the dam bar may be removed. Particularly in the semiconductor device of QFP, the lead frame pitch (dam bar pitch) is narrow, and therefore the diameter of the laser beam is large enough to surely remove the dam bar and at the same time to avoid the removal of part of the lead frame. It needs to be Therefore, an embodiment from this point of view is shown in FIGS.

In FIG. 11, the laser beam 57 has a circular aperture and is converted into a rectangular shape by the cylindrical lens 56. The long axis direction of the rectangle is the lead frame 26.
Is along the direction. The size of the minor axis is set to a value corresponding to the size of the dam bar 23 in the width direction or a value slightly smaller than that. By irradiating the dam bar with the rectangular laser beam 55, the dam bar can be surely removed, and at the same time, it is possible to prevent a part of the adjacent lead frame from being removed. FIG. 12 shows the state before and after the dam bar is removed, and the dotted line portion 57 shows the removed dam bar portion.

FIG. 13 and FIG. 14 are views showing a processing flow from gripping of the holder by the robot to sending of the holder upon completion of a series of dam bar removals. This operation is basically the same as that described in the operation of FIGS.

In controlling the position of the machining table,
By providing a reference point and monitoring the movement of this reference point, it becomes easy to position the table at the target position. For that purpose, for example, a reference hole may be provided in a part of the holder or a part of the lead frame and the reference hole may be monitored. Further, if the reference holes are provided at the four corners of the holder and the four corners of the lead frame, not only the movement but also the rotation can be monitored.

In the present embodiment, an example in which three triple-types are mounted on one holder has been described, but one triple-type is mounted on one holder.
There may be an example in which one semiconductor device is mounted on one holder.
With such a mounting configuration, various movement paths (including a rotation path) of the holder for removing the dam bar are possible. It goes without saying that there are movement procedures other than those shown in FIGS.

FIG. 15 shows an example of a movement locus in the case where the four sides of one semiconductor device 36 are intensively processed. A locus 60 passing through the dam bar in the movement locus 61 is a machining locus.
Reference holes 62 are provided at the four corners of this lead frame,
The reference hole is used to monitor whether or not the processing table is aligned with the predetermined dam bar arrangement. The locus of such a semiconductor device, even in the example of mounting three triple type in a holder,
Both the example in which one semiconductor device is mounted and the example in which one semiconductor device is mounted are both possible. There may be examples other than QFP.

The above is an example of removing the dam bar of the semiconductor device. However, in addition to this, other examples of cutting the semiconductor device, such as cutting of the lead frame and cutting of the outer peripheral lead frame, can be achieved by the optical element of the present invention. The device is applicable. It can also be applied to work other than semiconductor devices such as material processing.

[0056]

According to the present invention, a plurality of laser beams can be emitted in a time-division manner with only a single laser source, and a plurality of laser works can be realized concurrently.

[Brief description of drawings]

FIG. 1 is an embodiment of a switching mirror of the present invention.

FIG. 2 is an embodiment diagram of a 4-line dam bar processing apparatus of the present invention.

FIG. 3 is a diagram showing a configuration example of a triple QFP semiconductor device to be processed according to the present invention.

FIG. 4 is a planar layout configuration diagram of a triple QFP semiconductor device to be processed according to the present invention.

FIG. 5 is a diagram showing a state of the semiconductor device of the QFP of the present invention after cutting the dam bar.

FIG. 6 is a diagram showing an example of mounting a semiconductor device on a holder mounted on a processing table according to the present invention.

7 is a diagram showing a sequence for processing with the holder of FIG.

8 is a diagram showing another sequence for processing with the holder of FIG.

FIG. 9 is a time sequence example diagram of the present invention.

FIG. 10 is a diagram showing an embodiment of a control system of the present invention.

FIG. 11 is an example diagram of a laser beam aperture.

FIG. 12 is a diagram showing an example of a laser beam aperture.

FIG. 13 is a processing flowchart of the present invention.

FIG. 14 is a processing flowchart of the present invention.

FIG. 15 is a diagram showing an example of sequential removal of dam bars on four sides in one semiconductor device of the present invention.

[Explanation of symbols]

 1 Laser Source 2 Laser Beam Switching Unit 3A, 3B, 3C Switching Mirror 5 Bending Mirror 6 Laser Beam 9 Semiconductor Device 16, 18 Robot 32 Holder

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location H01L 23/50 A 9272-4M K 9272-4M (72) Inventor Yoshiaki Shimomura Kachidate Town, Tsuchiura City, Ibaraki Prefecture 650 Hitachi Construction Machinery Co., Ltd. Tsuchiura Plant (72) Inventor Shigeyuki Sakurai Kazunachicho, Tsuchiura City, Ibaraki Prefecture 650 Hitachi Construction Machinery Co., Ltd. Tsuchiura Plant

Claims (4)

[Claims] 1. A plurality of rotatable switching mirrors, which are arranged linearly so that their optical axes coincide with each other, have a reflecting surface and a transmitting surface that are divided in the circumferential direction, and to the switching mirrors. A laser optical device comprising: a laser source that emits laser light from the optical axis direction; and a control unit that controls the rotation of the switching mirror so that the laser light is emitted from one of the reflecting surfaces of the plurality of switching mirrors. 2. A plurality of rotatable switching mirrors, which are linearly arranged so that their optical axes coincide with each other, have a reflective surface and a transmissive surface that are divided in the circumferential direction, and to the switching mirrors. A laser source that emits laser light from the optical axis direction, a plurality of laser irradiation target parts corresponding to each switching mirror, which are mounted on separate work lines and discharged after the work by the laser to replace a new one, A control unit that controls the rotation of the switching mirror and sequentially distributes the laser light to the plurality of laser irradiation target portions so that the corresponding laser irradiation target portion is irradiated with the laser light from one of the reflecting surfaces of the individual switching mirrors. And a laser optical device comprising. 3. The reflection surface of each of the switching mirrors is one total reflection surface of the same size, and the arrangement in which the optical axes coincide with each other is always any one total reflection surface on the passage of the laser light. The laser optical device according to claim 1 or 2, wherein the arrangement is such that 4. A total reflection mirror is provided at the end of the plurality of switching mirrors arranged, and a laser irradiation target portion is also provided in the laser light reflection direction of the total reflection mirror.
Or the laser optical device of 3.