JP3143538B2 - Processing equipment for semiconductor devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device processing apparatus suitable for dam bar processing.

[0002]

2. Description of the Related Art In order to prevent resin from flowing into a lead frame during resin molding of a semiconductor device, a dam bar is formed so as to connect the lead frames. After completion of the resin mold, the dam bar is removed. A QFP-type semiconductor device in which a lead frame is led outward from each of four sides is known as a semiconductor device for increasing the density of a lead frame. QF
Laser beams are often used to remove dam bars in a P-type semiconductor device because the dam bar pitch is narrow. For example, there is JP-A-3-294077. This conventional example,
The dam bar of the QFP type semiconductor device is removed by a laser beam, and the processing is controlled by preparing a program along a processing locus and running the program to remove the dam bar.

[0003]

Problems to be Solved by the Invention
No. 7 does not describe movement control of a semiconductor device for dam bar removal. In particular, there is no description of having a plurality of production lines and simultaneously removing dam bars on each of these production lines. In order to mass-produce semiconductor devices, it is necessary to have multiple production lines, mount multiple semiconductor devices on each production line instead of one, and continue a series of dam bars for these multiple semiconductor devices. Removal is required. As a result, a large number of semiconductor devices can be produced on a small production line.

In addition, since the number of laser light sources is as high as one million yen, it is desirable that a large number of semiconductor devices can be simultaneously processed in parallel with a small number of laser light sources. On the other hand, QFP
The semiconductor device of the shape has regular four sides and the arrangement of the dam bars is also regular, and such a regularity should be utilized for dam bar processing of a plurality of semiconductor devices at the same time.

SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor device processing apparatus for emphasizing and simplifying a drive system for controlling the movement of a semiconductor device for dam bar processing.

[0006]

SUMMARY OF THE INVENTION The present invention provides a holder on which a semiconductor device is mounted, an x drive system and a y drive system for enabling the holder to move independently in two orthogonal directions x and y. A rotary drive system that enables the holder to rotate, and a series of laser processing paths along the dam bar for dam bar removal on each side to be connected is performed by driving only the x drive system. Positioning to the leading dam bar is performed by using a y drive system, a rotary drive system, or a combination of an x drive system. Furthermore, this is Q
Application to FP type (Claim 2).

Further, the present invention provides a plurality of semiconductor production lines in which a plurality of QFP type semiconductor devices are sequentially supplied with holders in which the plurality of QFP type semiconductor devices are regularly arranged and mounted on a processing table. An x drive system and a y drive system that can be driven independently in the vertical and horizontal directions, a rotation drive system that can rotate the table, and dam bar processing means that performs dam bar processing by laser for each production line. At the same time, the machining path along the dam bar for removing a series of dam bars connecting the connected sides is performed by driving only the x drive system, and the positioning of the series of dam bars connecting the sides to the top dam bar is performed by the y drive system and the rotation. The drive system is used or the x drive system is combined (claim 3).

Further, according to the present invention, in the machining path, a movable portion relating to the y drive system and the rotary drive system is restrained (claim 4).

Further, according to the present invention, the laser light source is made to be a single light source through a plurality of production lines, and each of the production lines is irradiated in a time division manner and sequentially for dam bar processing by switching a switching mirror. (Claim 5).

Further, in the present invention, the laser beam for dam bar processing has a rectangular shape having a major axis in a longitudinal direction of the lead frame.

[0011]

According to the present invention, since the machining path along the dam bar for removing a series of dam bars on each side to be connected is performed by driving only one driving system, the x driving system, the roles of the three driving systems are divided. Can be clarified (claims 1, 2, 4).
Further, dam bars can be removed from all sides only by the x drive system, and the other two drive systems may be used only for positioning (claims 1 and 2). Furthermore, only the x drive system needs to have high accuracy, and the other two drive systems do not require such high accuracy, which leads to labor saving, simplification, and high speed of the drive system. ).

Further, according to the present invention, a holder in which a plurality of QFP type semiconductor devices are regularly arranged vertically and horizontally is mounted on a table of each production line, and dam bar processing is performed by laser for each production line. 3). Further, in each production line, a machining path along a dam bar for removing a series of dam bars connecting each side is performed only by the x drive system (claim 3).

Further, according to the present invention, a single laser beam source is used for a plurality of production lines, and the laser light is sequentially radiated to each production line in a time-sharing manner by switching a switching mirror. Dam bar processing along a plurality of production lines can be realized with a single laser source (claim 5). Further, the shape of the laser beam is a rectangular shape having a major axis in the longitudinal direction of the lead frame, whereby dam bar processing can be surely achieved even if a displacement occurs in the longitudinal direction (y-axis direction) of the lead frame ( Claim 6).

[0014]

FIG. 2 is a diagram showing an embodiment in which the optical device of the present invention is applied to a processing device for a semiconductor device. The four transport production lines (work lines) 1 to 4 constitute a feeding device 17. On each of the lines 1 to 4, a semiconductor device 9 (actually, The robot 16 holds the holder 32 with a hand and is fixed on the processing table 10. The semiconductor device 9 on the holder 32 is to be processed. .

The laser source 1 has four transport production lines 1-4.
A single laser source. The laser beam switching unit 2 distributes the laser beam from the laser source 1 in a time-division manner in the form of a chopper, and simultaneously and concurrently processes the semiconductor devices on the holders of the four processing tables on the four transport lines. It is provided in. 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. Excitation of the laser beam from the laser source 1 is performed at a preset timing. The TV camera 14 is a monitor for positioning the holder and the semiconductor device and the dam bar fixed thereon via the lens 15, and the image processing device 20 captures the imaging signal, performs necessary image analysis, and performs positioning control. To serve.

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

After dam bar cutting is completed, another robot 18 removes the holder 32 on which the semiconductor device is mounted from the processing table, puts it on the carry-out line 19, and sends it out for the next process. The laser beam from the single laser source 1 is distributed and supplied by the switching unit 2, and the semiconductor devices 9 on the four holders 32 are processed in parallel. The operation of this switching unit will be described below.

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

The switching mirrors 3A, 3B, 3C are
A, 4B and 4C.
B and 4C are rotated in the circumferential direction by the driver 7 under the control of the controller 8. By performing this rotation, the laser beam 6 is successively reflected by one of the total reflection portions (1) of the switching mirrors 3A, 3B, and 3C, and is sequentially distributed as laser beams a, b, and c.
If all of the switching mirrors 3A, 3B, and 3C transmit the laser beam (that is, the transmitting portions correspond), the laser beam is reflected by the last bending mirror 5 and distributed as the laser beam d.

In order to achieve the distribution of the laser beam by the switching mirrors 3A, 3B and 3C, the rotation direction arrangement and the rotation control of the switching mirrors 3A, 3B and 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 optical axis of the laser beam 6 (this is called the first quadrant). The total reflection portion (1) of the switching mirror 3B is located at the position of the fourth quadrant, and the total reflection portion (1) of the switching mirror 3C is located at the position of the third quadrant.

(1) Under this initial position, the laser beam 6 undergoes total reflection only at the total reflection portion (1) of the switching mirror 3A, and can be emitted as a laser beam a in a right angle direction. No laser beam is emitted to the switching mirrors 3B, 3C and the reflecting mirror 5. (2) Next, to emit the laser beam b instead of the laser beam a, the driver 7 switches the switching mirror 3
A, 3B, and 3C are all rotated counterclockwise by 1/4 quadrant. Thereby, 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 changes. Move to the fourth quadrant. Thus, the switching mirror 3A transmits the laser beam 6, is totally reflected by the total reflection portion (1) of the switching mirror 3B, and the laser beam b
Can be released.

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

As described above, the switching mirrors 3A, 3B, and 3C are rotated by the driver 7 in quarter quadrants, whereby a
Laser beam distribution can be performed in a time division manner of → b → c → d. Therefore, dam bars can be removed by arranging the processing tables of the four production lines in the discharge directions of a, b, c, and d. Further, by repeating the above switching sequence, the removal of the dam bars on the four sides can be achieved.

FIGS. 4 and 5 show a QFP type semiconductor device, particularly a triple semiconductor device in which three semiconductor devices are connected.
FIG. 4 is a view showing a state after the resin mold to be processed in this embodiment.
FIG. 3 is a plan view of a continuous semiconductor device. The triple type semiconductor device is
The three semiconductor devices # 1 to # 3 are connected to the lead frame unit 20.
In a continuous state. FIG. 5 shows an overall example thereof. The lead frame section 20 includes the semiconductor sections 21A and 21A.
B, 21C and each of the lead frames 26, 30, 31. In FIG. 4, only the semiconductor portion 21A is particularly shown. The semiconductor portions 21A, 21B, and 21C are already resin-molded, and generally start dam bar cutting in the process of the present embodiment and then bend in the subsequent process.

In FIG. 4, each of the semiconductor devices # 1, # 2, # 3
Has square semiconductor portions 21A, 21B, 21C,
In addition, lead frames 26, 30, and 31 are derived from the four sides in a direction orthogonal to each other. This is called a QFP (quadrilateral flat package device). # 1 and #
2, and # 2 and # 3 are separated by holes 24 and 25. In addition to this three-unit type, a six-unit type with six units in series,
There is a parallel 6-series system in which the triple system is arranged in parallel.

In the semiconductor device # 2 shown in FIG. 4, lead frames 26A, 26B, 26C and 26D are led out from four sides of a semiconductor portion 21A resin-molded therearound in a direction orthogonal to the sides. Each lead frame 26A, 26B,
26C, 26D are the lead frames 22A, 22B, 2
2C and 22D, and dam bars 23A, 23B, 23C and 23D which are connected to the respective lead frame main bodies in the orthogonal direction. The dam bars 23A to 23D serve as members for preventing the resin from flowing into the lead frame when the resin is molded into the semiconductor portion 21A.

After the resin sealing, the dam bars 23A to 23A
D is cut to make each lead frame body electrically independent. FIG. 6 shows a state in which the dam bars 23A to 23D have been removed and unnecessary lead frame members on the peripheral sides have been 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.

Holder 32 to one processing table 10
The mounting of will be described. The processing table 10 is provided on a work line as shown in FIG.
Then, the holder 32 on the line is placed on the processing table 10 and fixed on the table. Placing the semiconductor device 9 directly on a line or directly on a table is not preferable because it damages the semiconductor device itself. Further, damage during processing on the table 10 is also conceivable. Therefore, the semiconductor device 9 is mounted on the holder 32 and fixed, and the holder 32 is mounted on a line and sent. The robot 16 grasps the holder 32 and the processing table 10.
And fix it on a table with a chuck or the like, and then remove the dam bar of the semiconductor device.

FIG. 7 shows an example of one holder 32 to which a semiconductor device is fixed. On the holder 32, three triple semiconductor devices (FIG. 5) 36A, 36B, 36C are mounted and fixed. In the drawings, dam bars and the like are omitted to avoid complication, but the dam bars naturally exist before processing. Each triple type 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 32. At each of the four corners of each base 33, fixing pins 35 are provided, and the fixing pins are used to connect the multiple semiconductor devices 36A to 36A.
C is fixed to the base 33.

Processing table 10 to which holder 32 is fixed
Is movable in the x and y directions on a horizontal coordinate system xy, and is also rotatable in this coordinate system. This is performed by the drive system of the table 10 (FIG. 1 described later). Further, it can also be moved perpendicularly to the paper surface of FIG. 7 (that is, in the Z-axis direction). These movements and rotations are necessary operations for positioning the laser beam on a target dam bar.

The holder 32 shown in FIG. 7 is fixed to one processing table 10. One processing table 10 is irradiated with one laser beam, and the irradiation of the laser beam is performed. The position is fixed. Therefore, to remove the dam bars of the nine semiconductor devices as shown in FIG. 7, it is necessary to move the holder itself, that is, to move the table on which the holder 32 is fixed. To move the laser beam to a predetermined dam bar position, the movement and rotation in the x and y directions and z
A movement in the direction (adjustment of the distance between the laser beam and the dam bar in the z direction) is required.

FIG. 1 is a diagram showing an embodiment of the processing table 10. The processing table 10 has an x drive shaft 10A, a y drive shaft 1
0B, three drive shafts 10C of the rotary drive shaft 10C (however, in the figure, a rotary table is shown for convenience for convenience, but the rotary drive shaft is originally referred to as a shaft for rotating this rotary unit). And rotation (rotation about the z-axis). In addition, there is a drive axis in the z-axis direction, but it is omitted. The holder 32 is mounted on the circular table 100 of the rotary drive shaft, chucked and fixed. Each drive shaft 1
0A, 10B, and 10C can be independently driven. The x drive shaft 10A provides a machining path for removing a series of successive dam bars on each side. This route is
This is a path along the center position of a series of dam bars. During this movement, the x drive shaft 10A moves at a constant speed. By performing the movement at a constant speed, the appearance of the pitch of the dam bar becomes an equal time interval. By irradiating the laser beam at the equal time interval, only the dam bar is reliably removed.

On the other hand, the y drive shaft 10B and the rotary drive shaft 1
0C is used as a drive shaft for positioning on the leading dam bar for processing a series of dam bars on each side. Of course, the positioning to the leading dam bar may be performed using the x drive shaft 10A, but the main function of the x drive shaft 10A is to set a machining path for dam bar cutting.

FIG. 8 shows one holder 32 shown in FIG.
FIG. 6 is a diagram for explaining a movement path for processing control when three sets of three triples are mounted on the cradle. X-axis in horizontal direction, y in vertical direction
The movement in the x-axis direction is performed by the x drive shaft 10A, and the movement in the y-axis direction is performed by the y drive shaft 10B. The rotation (90 ° rotation) of the holder 32 is performed by the rotation drive shaft 10C. In the figure,
a → b → ... → k → movement path for the route R ₁ to m are processed and edges Q1 and Q3, route R to a '→ ... → m'
₂ is a moving path for processing the edges Q2 and Q4.
Here, needless to say, the laser light is always applied to the fixed position, and the optical path of the laser light is fixed,
Moving the paths R ₁ and R ₂ is realized by moving the table 10, that is, by driving the drive shafts 10A, 10B and 10C.

In FIG. 8, for the route R ₁ , the positions a to
m is set as follows. Position _{a ... (x 1, y 1} ), position _{b ... (x 2, y 1} ) position _{c ... (x 2, y 2} ), position _{d ... (x 1, y 2} ) position e ... (x _1, y _3), the position _{f ... (x 2, y 3} ) position _{g ... (x 2, y 4} ), the position _{h ... (x 1, y 4} ) located _{i ... (x 1, y 5} ), the position j ... (x ₂ , y ₅ ) Position k (x ₂ , y ₆ ), Position m (x ₁ , y ₆ ) Among these a to m, a, c, e, g, i, k
Is the top position for dam bar processing. This a, c,
Positioning to e, g, i, k is performed only on the y drive shaft 10B.
Alternatively, it can be realized by a combination of the y drive shaft 10B and the x drive shaft 10A. Further, b, d, f, h, j, and m are stop positions after dam bar processing, and the drive shaft 10B or 10
By using B and 10A, the head positions c, e,
Positioning to g, i, and k can be performed.

On the other hand, a → b, c → d, e → f, g → h,
Each path i → j, k → m is a processing path. The x drive shaft 10A provides this machining path. During this machining path, only the x drive shaft 10A operates and the y drive shaft 1
0B and the rotary drive shaft 10C do not operate. By operating the x drive shaft 10A, a machining path is formed, and by irradiating a laser beam in synchronization with the appearance position of the dam bar,
A series of dam bars existing on the machining path are removed.

On the other hand, the moving route from a 'to m'
2. This route is used for dam bar processing of Q4. In order to machine the dam bars on the sides Q2 and Q4 according to this route, it is possible to operate the y drive shaft 10B.
For that purpose, the y drive shaft 10B needs to have the same function as the x drive shaft 10A. However, in order to achieve a machining path by R _1, x drive shaft 10A is necessary to control with high precision of the drive system, such as slide into passing the dam bars appearing position at the correct time timing, these It is necessary that the y drive shaft also has a function. But With rotary drive shaft 10C which performs 90 ° rotation of the holder 32, it is possible to provide a machining path on the route R ₂ by the x drive shaft 10A, utilizing the y drive shaft 10B to form the machining path It becomes unnecessary.

For this purpose, in FIG. 8, when the final end point m for machining Q1 and Q3 is reached, the holder 32 is rotated counterclockwise by 90 ° by the rotary drive shaft 10C. Due to this 90 ° rotation, the optical path of the laser light is eventually shifted to the position a ′. And Q from this position
2, the dam bar machining path with Q4 can be formed by moving only the x drive shaft 10A, the dam bar machining path with Q2, Q4 can be formed by moving only the x drive shaft 10A,
Dam bars of Q2, Q4 can be removed according to the route R _2.

FIG. 9 shows the path R ₁ , the counterclockwise rotation of 90 °, and the path R ₂ . FIG.
Arrangement of the holder 32 when the processing of (b) is under the path R ₁ (longitudinal direction of the processing), 9 (b) a state of rotating counterclockwise 90 °, Fig. 9 (c) is its shows the arrangement of the holder 32 when the processing (the processing in the width direction) in the original path R ₂ which are in the later 90 ° rotation.

In the machining path, only the x drive shaft 10A is operated, but at this time, the y drive shaft 10B and the rotary drive shaft 10C are not operated. In addition to this non-operation, mechanical or electrical restraint is performed so that the y drive shaft 10B and the rotary drive shaft 10C do not slightly move during the machining path. As the mechanical restraining method, the drive shaft 10B, 1
There is a method of mechanically pressing a movable table driven by 0C or each axis or preventing a movable table from being moved by a stopper. The mechanical method is simple and reliable in that a piston is embedded in a fixed portion and the movable portion is restrained by protruding the piston when necessary. Also, the motor shaft can be fixed with an electromagnetic clutch, or conversely, a clamp jig that is half-split on the motor shaft can be forcibly opened with a magnet while moving and the shaft can be rotated. There is also a structure that is automatically restrained by the spring force when it is cut. As an electrical restraining method, for example, in order to restrain the moving base of the drive shafts 10B and 10C from moving, a method of fixing the rotating shaft of the motor by short-circuiting the terminals of the motor, or holding the motor at the same position There is also a way to control the position so that

FIG. 10 is a diagram showing a time sequence of the x drive axis 10A. FIG. 9A shows the speed sequence of the x drive shaft 10A, and the section 1 is the start position of the machining path (FIG. 9).
(A, c, etc. of FIG. 1) shows a state in which the table 10 is present. In this section 1, the x drive shaft 10A is in a stopped state. From this state, the x drive shaft 10A starts driving in section 2, accelerates in section 3, decelerates through sections 4 and 5, and reaches constant speed section 6. The constant speed section is from section 6 to section 8. This constant speed moving section is a section for actually processing the dam bar.

That is, the x drive shaft 1 is defined by the sections 1 to 5.
The table driven at 0A moves from the position a in FIG. 8 to the actual dam bar existing position P ₁ (corresponding to the head dam bar position). From this position, the lead frame pitch is constant, and the dam bar appears at each position determined by the pitch. Therefore, a laser beam is radiated from the leading dam bar position at a fixed period determined by the moving speed and the pitch, and the dam bars are removed one after another. From position a to position b, there are three dam bar existing sides, P ₂ between the first side and the second side,
The between P ₃ and a second side and the third side, there is a nonexistent location of each dam bar. Therefore, a portion (position and length) P _{2 where} a dam bar connecting these sides does not exist,
By converting P ₃ into data in advance, laser irradiation during that period is not performed.

[0043] From until section 9 to 11 dam bar removal completion of the last third of the sides, showing a section P ₄ to the stop of x driving shaft 10A. In this section, the vehicle decelerates from the constant speed, and eventually reaches the speed 0 and stops. Section 12 shows the stopped state.
This stop position is, for example, a position b in FIG. Then
The movement from b to c is performed, and from position c to d, FIG.
The x drive shaft 10A moves in a speed pattern as shown in FIG.

FIG. 10B shows an acceleration pattern of the x drive shaft 10A, FIG. 10C shows a backlash pattern, and FIG. 10D shows a dam bar machining timing section. The machining timing section in FIG. 10D is the constant speed movement section. During this interval, the backlash is constant and does not adversely affect positioning.

The above is an example in which all the dam bars of one holder 32 are removed. FIG. 11 shows a processing sequence for the four lines 1 to 4 in such a case. First, for the line 1, all the dam bars of the 3 × 3 semiconductor devices on the holders 32A (the holders 32 of each line are described as 32A to 32D) are moved by using the moving path of a → m and a ′ → m ′. It is removed (F1). This is as shown in FIG. During the processing of the line 1, the line 2 is mounted on the table of the holder 32B, fixed by the chuck, and positioned. Next, in order to remove the dam bar of the line 2, the switching mirror is switched to switch the laser beam path for removing the dam bar of the line 2 (FIGS. 2 and 3). Then, all the dam bars of the 3 × 3 semiconductor devices on the holder 32B are removed by the method shown in FIG. 8 (F2). Thereafter, dam bars are removed from the semiconductor devices on lines 3 and 4 in a similar sequence (F
3, F4). When the four lines 1 to 4 are completed, the process returns to line 1 again.

Other movement and machining sequences for the four lines include removal of some of the dam bars on line 1 → removal of some of the dam bars on line 2 → removal of some of the dam bars on line 3 → removal of some of the lines on line 4. Dambar removal → removal of some dambars on line 1 → removal of some dambars on line 2 → ...
There is also a removal method. This example is shown in FIGS.
(G) '.

(A) First, the processing table 1 is set so that the first dam bar of the first side Q1 (see FIG. 7) of the semiconductor device 36A belonging to the holder 32A can be irradiated with the laser beam a.
Position 0. In conjunction 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, the table 10 on which the holder 32A is placed is moved in the x direction, and 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 for 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 for pointing the holder 32B is positioned so that the laser beam b can be irradiated on the first dam bar of the first side Q1 of the semiconductor device 36A belonging to the next holder 32B. After the completion of the positioning, the removal of all the dam bars on the first side Q1 of the holder 32A is waited, and the switching mirrors 3A to 3B are controlled by the driver 7 so that the switching mirror 3B can emit the laser beam b. After the control of the switching mirrors 3A to 3B is completed, the processing table 10 supporting 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 top dam bar is moved.
The removal of 1 is performed by irradiating the laser beam b corresponding to the dam bar.

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

By this series of operations, holders 32A-32
32D. First side Q of semiconductor device 36A belonging to each of 32D
One removal of all dam bars is performed.

(B) Next, the process moves to the movement of the holder 32A. There is a considerable free time after the removal of the dam bar of the holder 32A in (a) until the removal of the dam bar of the holder 32D. Therefore, by utilizing the vacant time, the processing table to which the holder 32A belongs is moved in the y direction, and the third side Q of the semiconductor device 36A to which the holder 32A belongs is moved.
3 is positioned so that the laser beam a can be irradiated. Similarly, each of the holders 32B, 32C, and 32D performs positioning by using the idle time determined respectively. Therefore, in the figure, it seems that the light beams move simultaneously in the y direction at 32A to 32D, but they move at 32A → 32B → 32C.
→ The movement in the y direction and the positioning are 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, as described in (a). After the cutting of all dam bars on the third side of the semiconductor device 36A belonging to the holder 32A is completed, a laser beam b is selected instead of the laser beam a, and thereafter, all the third sides Q3 of the semiconductor device 36A belonging to the holder 32D are removed. Dam bar cutting is performed in the same manner as in (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 (c) in the semiconductor device 36A is completed, the semiconductor device 36B is moved in the y direction by using an appropriate blank time, and is positioned so as to be the first side Q1 of the semiconductor device 36B. Then, it is moved in the y-direction according to (b) and positioned so as to be the third side Q3, and is processed according to (c). This is also performed for the semiconductor device 36C.

By performing the above (a) to (c) ′, 3
All 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 by 90 °. As a result, the second side Q2 of the semiconductor device 36A of the holder 32A with respect to the laser beam a is subjected to dam bar processing. Then, positioning is performed such that the head dam bar on the second side Q2 is at the irradiation position of the laser beam a. This 90 ° rotation of the holder 32A and the positioning of the leading dam bar are performed during idle time during dam bar processing in the other holders 32B, 32C and 32D. Therefore, even in this case, 3
Rotation and positioning by 90 ° in the order of 2A → 32B → 32C → 32D are performed using the respective idle times.

(E), (f), (g) This operation is performed in Q2
And Q4, which are the same operations as (a) to (c). (G) ′, (e) to (g) indicate the Q of the semiconductor device 36A.
2, Q4, and (E) to (G) are repeated for the semiconductor devices 36B and 36C.

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

In the course of the series of operations (a) to (g) ', the holders 32A → 32B → 32C → 32
Dam bars can be removed one after another in the order of D. Therefore, when the removal of the dam bar from the holder 32A is completed, the robot 18 removes the holder 32A from the table 10 using the idle time, sends the holder 32A to the feed line 19, and transports it to the next process. On the other hand, since a new holder has been sent to the receiving line 1, the new holder is gripped by the robot 16 and mounted and fixed on the processing table 10. Similarly, 32B, 32C, and 32D are sent out after the dam bar is removed and replaced with a new holder.

In this way, the holders on which the semiconductor devices carried on the four lines 1 to 4 are mounted on the processing table one after another and processed. During this time, a single laser beam is distributed in a time-division manner, and the dam bar is removed in a time-division manner. In the meantime, during the work on other holders, the other holders are moved and rotated using idle time, so that efficient operation of time-division laser distribution and simultaneous operation of multiple work lines are performed. Processing work can be done.

FIG. 13 is a diagram showing an embodiment of the control device according to this embodiment. The host computer 50 is a computer that controls each control of a 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 trajectory in the movement mode as shown in FIG. 12. According to the contents of this memory, the processing line control system 51 and the mirror control system 52 control the line, mirror, laser Is performed. Here, the processing line control system 51 refers to lines 1 to
In step 4, the robot 16 controls the holding of the holder, mounting and fixing to the table, movement and rotation of the table, and discharge of the holder by the robot 18 after dam bar removal. The mirror control system 52 includes the driver 7 of FIG. 3 and controls switching of the switching mirrors 3A to 3C. The laser control system 53 controls the laser emission timing of the laser source 1 in FIG. 2, and can be realized by an electronic circuit.

FIG. 14 shows the machining line control system 51 of FIG.
FIG. The machining line control system 51 includes a robot drive system 51A, an x drive system 51B, a y drive system 51C,
A rotary drive system 51D, and the x drive shaft 10A shown in FIG.
It comprises a y drive shaft 10B and a rotary drive shaft 10C. Drive system 5
1B, 51C, and 51D are composed of a power system such as a stepping motor, and are turned on by a command from the host computer 50.
/ OFF control to move or stop the drive shafts 10A, 10B, and 10C.

FIGS. 15 and 16 are diagrams showing an embodiment of the present invention relating to the shape of a 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 narrow down by a focusing lens, and it is preferable if the dam bar can be reliably removed by the narrowed down beam. However, if the aperture is narrowed down too much, the diameter becomes small and uncut portions may remain in a part of the dam bar. If the aperture is not narrowed down too much, a part of the frame connected to the dam bar may be removed. In particular, in a QFP semiconductor device, the lead frame pitch (dam bar pitch) is narrow, so that the diameter of the laser beam is so large that the dam bar can be reliably removed and at the same time the removal of a part of the lead frame can be absolutely avoided. It is necessary to be. Therefore, an embodiment from this viewpoint is shown in FIGS.

In FIG. 15, the laser beam 57 has a circular aperture and is converted into a rectangular shape by a cylindrical lens 56. The long axis direction of the rectangle is the lead frame 26
It is the direction along. The size of the short 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 the size. By irradiating the rectangular shaped laser beam 55 to the dam bar, the dam bar can be reliably removed, and at the same time, a part of the adjacent lead frame can be prevented from being removed. FIG. 16 shows a state before and after the dam bar is removed, and a broken line portion 57 shows a portion of the removed dam bar.

In the position control of the machining table,
By providing a reference point and monitoring the movement of the reference point, the table can be easily positioned at the target position. For this 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. If the reference holes are provided at the four corners of the holder or the four corners of the lead frame, not only movement but also rotation can be monitored.

In this embodiment, three triple units are mounted on one holder, but one triple unit 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, the movement locus (including the rotation locus) of the holder for dam bar removal can be variously changed. Needless to say, there is a movement procedure other than that shown in FIG.

The above is an example of removing a dam bar from a semiconductor device. In addition to this, the optical device of the present invention can be applied to other examples of cutting a semiconductor device, such as cutting of a lead frame and cutting of an outer lead frame. The device is applicable. Further, the present invention can be applied to work such as material processing other than the semiconductor device. Furthermore, application to other than the QFP type is also possible, and the drive system of x and y is
Although the direction of the two opposite sides of the QFP type is set, the orthogonal coordinate system x and y other than the two opposite sides may be taken.

[0067]

(1) The dam bar can be machined with high speed and high accuracy. (2) The feed operation in the dam bar row direction required for processing is limited to a drive device capable of performing a constant-speed and high-accuracy feed operation, and by using this, a highly accurate and highly reliable positioning operation can be performed. (3) The positioning accuracy is further improved by appropriately restraining and fixing the driving parts of the driving device in other directions that are not necessary for processing. (4) By limiting the number of driving devices at the time of processing, the number of lead frame detecting devices can be simplified and the required number can be reduced. (5) Due to the above effects, the processing device can be made simple and inexpensive.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a drive system according to the present invention.

FIG. 2 is a diagram showing an embodiment of a semiconductor processing apparatus having four production lines.

FIG. 3 is an embodiment of a laser beam switching device.

FIG. 4 is a plan view of a triple semiconductor device.

FIG. 5 is a schematic view of a triple semiconductor device.

FIG. 6 is a diagram showing an example of dam bar arrangement by a QFP type semiconductor device.

FIG. 7 is a plan view on a holder on which three sets of triple semiconductor devices are mounted.

FIG. 8 is a diagram illustrating an example of a movement trajectory for processing the holder of FIG. 7;

FIG. 9 is a diagram illustrating an example of holder control for obtaining the movement locus of FIG. 8;

FIG. 10 is a diagram showing a time chart of an x-axis drive system for obtaining a processing locus.

FIG. 11 is a flowchart of dam bar processing of four lines 1 to 4;

FIG. 12 is an explanatory diagram of another movement locus of four lines 1 to 4;

FIG. 13 is an embodiment diagram of the control device of the present invention.

FIG. 14 is an embodiment diagram of a processing line control system of the present invention.

FIG. 15 is a view showing an embodiment of a rectangular laser beam according to the present invention.

FIG. 16 is a diagram showing dam bar cutting by the rectangular laser beam of the present invention.

[Explanation of symbols]

 Reference Signs List 1 laser source 2 switching unit 3 (3A to 3C) switching mirror 6 laser beam (beam) 9 semiconductor device 10 table 10A x drive shaft 10B y drive shaft 10C rotation drive shaft 16, 18 robot 32 holder

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeyuki Sakurai 650 Kandamachi, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Tsuchiura Works (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01L 23/50 B23K 26/00

Claims (6)

(57) [Claims] 1. A holder on which a semiconductor device is mounted, an x drive system and a y drive system for independently moving the holder in two orthogonal directions x and y, and a rotary drive for rotating the holder. A series of laser-based machining paths along the dam bar for removing the dam bar on each side to be connected and connected along the dam bar are performed by driving only the x drive system, and the positioning of each side to the first dam bar is performed by the y drive. A processing apparatus for a semiconductor device, wherein the processing is performed using a system, a rotary drive system, or a combination of an x-axis drive system. 2. The apparatus according to claim 1, wherein the semiconductor device is a QFP type semiconductor device, and the orthogonal directions x and y are directions of two orthogonal sides of the QFP type semiconductor device. . 3. A plurality of semiconductor production lines in which a plurality of QFP semiconductor devices are sequentially supplied with holders in which the plurality of QFP type semiconductor devices are regularly arranged and mounted on a processing table, and the table extends along the length and width of the semiconductor device. An x drive system and a y drive system that can be independently driven in directions, a rotation drive system that can rotate the table, and dam bar processing means that performs dam bar processing by laser for each production line, and are connected. The machining path along the dam bar for removing a series of dam bars connecting each side is performed by driving only the x drive system, and the positioning of the series of dam bars connecting each side to the first dam bar is performed by the y drive system and the rotary drive system. An apparatus for processing a semiconductor device using or combining an x-axis drive system. 4. In the machining path, a y drive system,
4. The apparatus for processing a semiconductor device according to claim 1, wherein the movable portion related to the rotary drive system is restrained. 5. A single laser light source through a plurality of production lines, and a switching mirror is switched to irradiate each production line in a time-division manner and sequentially for dam bar processing. Semiconductor device processing equipment. 6. The semiconductor device processing apparatus according to claim 1, wherein the laser beam for dam bar processing has a rectangular shape having a major axis in a longitudinal direction of the lead frame.