JPH087631Y2 - Semiconductor pellet positioning device - Google Patents

Description

[Detailed description of the device] [Industrial applications]

The present invention relates to a semiconductor pellet positioning device.

2. Description of the Related Art Semiconductor devices such as ICs, LSIs, and transistors are manufactured by bonding a semiconductor pellet in which a predetermined circuit is formed on a silicon substrate in advance to a predetermined position on a lead frame and connecting the terminal pad on the pellet. After performing wire bonding to connect the leads on the lead frame and mounting the pellet part with resin,
A manufacturing process is performed in which the lead frame is divided into individual semiconductor devices and leads of each part are formed. Of the above manufacturing steps, the following method is generally adopted in the step of bonding the pellet onto the lead frame. First, a large number of semiconductor elements are integrally formed on a single wafer, and the wafer is divided into individual semiconductor elements by temporarily adhering the semiconductor elements to an elastic sheet and scribing. Then, the sheet is stretched by a predetermined amount to widen the interval between the pellets that were in a state of being in close contact with each other only by being divided. After that, in the bonding device, the pellets are picked up one by one by a collet that reciprocates between a predetermined bonding position on the lead frame and carried on the lead frame,
Bond. By the way, since the pellets carried on the stretchable sheet do not have uniform postures, the pellets picked up from the sheet are not carried directly to the lead frame and bonded, but once the intermediate positioning device is used. Carry the pellet to the posture, ie X.
The positions in the Y direction and the θ direction are determined, and the pellets thus positioned are picked up again by a bonding collet that moves accurately in a predetermined process, and are bonded onto the lead frame by this bonding collet. As the above-mentioned positioning device, the applicant of the present invention uses
In Japanese Patent No. 3321, even if the size of the pellet is changed, it is possible to perform positioning while relatively easily responding to the change. The semiconductor pellet positioning apparatus disclosed in the above publication transmits the swinging motion of the bell crank that abuts against the rotary cam and swings to the motion of the positioning claw that reciprocates on the positioning stage by the motion transmission mechanism. The bell crank is supported by a swing arm whose swing position can be adjusted by a micrometer head. By doing so, if the swing position of the swing arm is adjusted, the swing fulcrum of the bell crank can be changed to change the swing angle range of the bell crank. Then, the range of movement of the positioning claw can be adjusted according to the size of the semiconductor pellet to be positioned.

[Problems to be solved by the device]

However, the above-described semiconductor pellet positioning device still has the following problems to be solved. That is, since the rotating cam and the bell crank driven by the rotating cam are used as the input portion for driving the positioning claw, there is a limit to reducing the vertical height of the constituent parts of this input portion, and the positioning device is There is an unavoidable problem of increasing the size of the constituent units. A micrometer head for adjusting the swing position of the swing arm also increases the vertical height of the unit. As described above, the positioning device unit becomes bulky in the vertical direction in the arrangement of the transport path of the lead frame and the support mechanism of the stretchable sheet carrying the scribed semiconductor pellets in configuring the pellet bonding apparatus. In particular, the horizontal distance between the elastic sheet support mechanism and the lead frame transport path must be increased due to restrictions, and as a result, the movement of the collet to pick up and bond each semiconductor pellet. This causes a problem that the process is increased and the bonding speed cannot be increased beyond a certain level. Further, although it is possible to adjust the moving range of the positioning claw, it is because the operator manually operates the micrometer head, and it cannot be said that the operability and the adjustment reproducibility are necessarily excellent. There are also problems. The present invention has been devised under the circumstances described above, and it is possible to solve the above-mentioned conventional problems, significantly reduce the vertical height and planar occupied space of the unit, and perform positioning. An object of the present invention is to provide a semiconductor pellet positioning device capable of automatically controlling the movement range of the claws and corresponding to semiconductor pellets of various sizes.

[Means for Solving the Problems]

In order to solve the above conventional problems, the present invention takes the following technical means. That is, the semiconductor pellet positioning apparatus according to the present invention includes a pair of X-direction positioning claws that are supported so as to advance and retreat in the X direction toward the pellet mounting portion at the center of the positioning stage and that are constantly biased in the advancing direction. One Y-direction positioning claw that is supported so as to be able to move forward and backward in the Y direction toward the pellet placement part and is always biased in the backward direction;
The X-direction positioning claw is moved forward and backward by the rotation of the rotary cam that abuts on the cam follower attached to the positioning claw advancing direction side, and the Y-direction positioning claw is positioned with respect to the cam follower attached thereto. The rotary cam that abuts on the backward direction of the artificial pawl is moved forward and backward by rotation, and is rotated by control means corresponding to the rotary cam for the X-direction positioning pawl and the rotary cam for the Y-directional positioning pawl. A step motor to be controlled is provided, and the rotation of the step motor is transmitted to each of the rotary cams through an endless rope that is wound between a pulley provided on its output shaft and a pulley provided on the shaft of each rotary cam. In addition, the control means advances the pair of X-direction positioning claws to clamp the pellet on the pellet mounting portion. In the state of positioning in the X direction, only by advancing the one Y direction positioning claw to a predetermined position, without sandwiching the pellet between the Y direction positioning claw and another object, It is characterized in that it is configured to perform directional positioning.

[Action and effect]

In the present invention, the pellets placed on the positioning stage are first pinched by the pair of X-direction positioning claws that advance toward the center of the stage to perform positioning in the X direction. Since the X-direction positioning claw is always biased in the advancing direction, the forward output of the X-direction positioning claw retracted by the rotary cam is given by the biasing force. Therefore, the driving force of the step motor is not directly transmitted from the X-direction positioning claw to the pellet, and the pellet can be properly positioned in the X-direction without a problem that the pellet is damaged by an appropriate clamping force. Done. Next, the Y-direction positioning of the pellet is performed by advancing one Y-direction positioning claw while being sandwiched by the pair of X-direction positioning claws by the biasing force to perform the X-direction positioning. In this case, the positioning in the Y direction is performed only by advancing the Y direction positioning claw, and the pellet is not sandwiched between other external objects. In the case of the Y-direction positioning claw, since the positioning claw that is always biased in the backward direction is forcibly advanced by the rotating cam, the pellet is pressed against the clamping force of the X-direction positioning claw by a sufficient pressing force. Can be moved to the proper position in the Y direction. Then, as described above, the Y-direction positioning claw does not clamp the pellet like the X-direction positioning claw, but only moves the pellet to a predetermined position with one claw, and thus rotates as described above. Even if the rotating force of the cam acts directly, there is no fear of damaging the pellet. Since there is only one Y-direction positioning claw,
For example, as compared with a case where a pair is provided, the planar occupied space of the positioning unit including the X-direction positioning claw and the Y-direction positioning claw is reduced by that much, and the device becomes more compact. Further, since each of the rotary cams is rotated by the step motor controlled by the control means, the moving range of the positioning claw can be freely and accurately changed, and the semiconductor pellet to be positioned can be easily moved. According to the size and shape, the moving range of the positioning claw can be set accurately so that the positioning can be performed most efficiently. Furthermore, since the rotating cam is rotated via the endless cord that is wound around the pulley attached to the shaft and the pulley attached to the shaft of the step motor, there is no problem in shortening the shaft of the rotating cam as much as possible. Moreover, since the step motor can be arranged on the side of the rotary cam,
The vertical height of the positioning device as a unit can also be significantly reduced. As described above, the semiconductor pellet positioning apparatus of the present invention can conveniently set the moving range of the positioning claw that reciprocates on the positioning stage according to the size and shape of the semiconductor pellet, and the pellet bonding apparatus It is possible to greatly reduce the planar occupied space and the vertical height as a positioning device unit that constitutes a part. Then, the collet for picking up the pellets on the stretchable sheet, or the collet moving process for transporting the pellets from the positioning device to the bonding position can be shortened, which also improves the efficiency of the pellet bonding process. There is.

[Explanation of the embodiment]

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. As shown in FIG. 1, a semiconductor pellet positioning apparatus 1 of this example includes a positioning stage 3 having a vacuum hole 2 in the center, and an upper surface of the positioning stage 3 sandwiching opposite side surfaces of the semiconductor pellet in the X direction. And a pair of opposed X-direction positioning claws 4 which are slidably supported so that the distance between them expands and contracts, and the other side surface of the semiconductor pellet is pressed to slide in the Y-direction. It is provided with one Y-direction positioning claw 5 supported. The pair of X-direction positioning claws 4, 4 are plate-like L-shaped in a plan view on a block 7 slidably supported by a guide bar 6 attached to a frame (not shown) so as to extend in the X-direction. The claw bodies 8 are fixed to each other. The tip end clamping surfaces 8a of the claw bodies 8 are exactly parallel to each other. In the same manner, the Y-direction positioning claw 5 also has a plate-like claw body 11 on a block 10 slidably supported by a guide bar 9 attached to a frame body (not shown) so as to extend in the Y direction. It is fixedly configured. The tip of the claw body 11 has a narrow width so that it can be advanced between the positioning claws 4, 4 even when they are closest to each other. The positioning claws 4 and 4 are constantly urged by springs 12 and 12 in a direction of advancing toward the center of the stage 3. On the other hand, the positioning claw 5 is constantly urged by the spring 13 in the direction of retracting from the center of the stage 3. Further, roller-shaped cam followers 14, 14, 15 are attached to the lower surfaces of the blocks 7, 7, 10 of the positioning claws 4, 4. The positioning pawls 4, 4 movable in the X direction are located in the middle of the cam followers 14, 14 and are in contact with the cam followers 14, 14 at the same time, and are driven by the rotary motion of the rotary cam 16 which is rotated about the vertical axis. . The rotary cam 16 is fixed to the upper end of a vertical shaft 17 rotatably supported by a frame (not shown), and has a plate shape extending in the horizontal direction. The both ends of the rotary cam 16 are spaced from the center of the shaft 17. Cam surfaces 16a, 16b are formed that gradually change as they move in the direction of rotation. As is apparent from FIG. 1, when the rotary cam 16 rotates, the distance between the cam followers 14, 14 that are driven while being in contact with the cam surfaces 16a, 16b changes, so that the positioning claws 4, 4 are spaced apart from each other. Although it is driven so as to expand and contract, particularly in this example, as shown in FIG. 2, the moving distance of the cam followers 14, 14 proportional to the rotation angle of the rotary cam 16 is obtained on the cam surfaces 16a, 16b. As described above, the curved surface is formed as a so-called constant velocity cam. This allows the positions of the positioning claws 4, 4 to be easily defined in correspondence with the rotation angle of the rotary cam 16. On the other hand, the positioning claw 5 movable in the Y direction is also driven by the rotational movement of the rotary cam 18 rotated about the vertical axis. This rotary cam 18 is also fixed to the upper end of a vertical shaft 19 rotatably supported by a frame body (not shown), and has a plate shape extending in the horizontal direction. Similarly, a curved cam surface 18a as a so-called constant velocity cam is formed. Pulleys 20 and 21 are attached to the lower ends of the shafts 17 and 19 that support the rotary cams 16 and 18 at the upper ends, and the pulleys 20 and 21 and the shafts 17 and 19 are displaced laterally. Endless belts 26 and 27 are respectively attached to the pulleys 24 and 25 attached to the output shafts of the step motors 22 and 23 supported at the respective positions.
Is hung around. The step motors 22 and 23 are each controlled by a control means composed of a microcomputer or the like.
The output shafts of the step motors 22 and 23 are provided with rotating plates 28 and 29 with holes, and output shaft rotational position detecting means 32 and 33 including photo interrupters 30 and 31, respectively. The reference positions of the positioning claws 4, 4 and 5 can be set. In the above configuration, first, when the step motor 22 is rotated in one direction to rotate the rotary cam 16 in the direction of the arrow a in FIG. 1, the cam surfaces 16a and 16b of the rotary cam 16 move the spring 12
The spacing between the cam followers 14, 14 is widened against the urging force of the positioning claws 4, 14 to retract the positioning claws 4, 4 from the center of the positioning stage 3. On the other hand, when the step motor is rotated in the opposite direction to rotate the rotary cam 16 in the direction of arrow b in FIG. 1, the cam followers 14, 14 are driven by the spring 12 so that the cam surfaces 16a, 1
The positioning claws 4, 4 move toward the center of the positioning stage 3 while being close to each other while being regulated by 6b. At this time, if a semiconductor pellet is present on the positioning stage 3, the positioning claws 4, 4 sandwich the opposing side surface thereof by the biasing force of the spring, and the position of the semiconductor pellet in the X direction is accurately determined. Further, when the step motor 23 is rotated in one direction to rotate the rotary cam 18 in the direction of arrow c in FIG. 1, the cam surface 18a of the rotary cam resists the biasing force of the spring 13 and the cam follower 1 moves.
5 is pushed to move the positioning claw 5 toward the center of the positioning stage 3. At this time, the positioning stage 3
When the semiconductor pellet exists on the upper side, the positioning claw 5 presses the other side surface of the semiconductor pellet to determine the position in the Y direction. On the other hand, when the step motor is rotated in the reverse direction to rotate the rotary cam 18 in the direction of arrow d in FIG. 1, the cam follower 15 moves while being regulated by the cam surface 18a by the urging force of the spring 13, and the positioning claw 5 moves. Is the positioning stage 3
Retreat from the center of. As the positioning procedure, the semiconductor pellets picked up from the elastic sheet (see FIG. 4) arrive at the positioning stage 3 in a state where the positioning claws 4, 4 are retracted, and the semiconductor pellets are moved to the center of the stage. , The pair of opposed X-direction positioning claws 4, 4 are first advanced to perform positioning in the X-direction, and then the positioning claws 4,
At 4, the Y-direction positioning claws 5 are advanced with the opposite side surfaces of the semiconductor pellet being sandwiched. In this way, the position of the semiconductor pellet in the XY direction and the θ direction is determined on the positioning stage 3. After the positioning, the positioning claws 4, 4 are respectively retracted, and the positioned semiconductor pellets are transported to the bonding portion on the lead frame by the bonding collet and bonded. In this example, the stepper motors 22 and 23 are used to drive the rotary cams 16 and 18, but the rotary positions of the rotary cams 16 and 18 are not fed back, but the rotary plates 28 and 29 attached to the rotary shaft of the motor are used. The photo interrupters 30 and 31 are used to define the reference position of the rotary shaft of the motor or the rotary cams 16 and 18. Then, the position where each positioning claw 4, 4, 5 holds the semiconductor pellet carried on the stage by the pickup collet can be set according to the semiconductor pellet, and the control is performed as follows, for example. First, as shown by phantom lines in FIG. 3, each positioning claw 4,
4,5 is a reference position is the most retracted position corresponding to the largest semiconductor pellet, and the through holes formed in the rotating plates 28, 29 when the positioning claws 4, 4, 5 take this reference position. Are detected by the photo interrupters 30 and 31. Then, when the positioning claws 4, 4, 5 retreat immediately after the positioning, they are retreated to this reference position. This is the step motor 2 until the detection signal of the through holes of the rotary plates 28, 29 by the photo interrupters 30, 31 is input to the control means.
It suffices to perform control to rotate the 2, 23 in a predetermined direction. As shown in FIG. 3, the positioning of the semiconductor pellet is
Each positioning claw 4, 4,5 should be moved inward from a position about 1 mm away from the four sides of the semiconductor pellet, that is,
Depending on the degree of misalignment on the stage of the semiconductor pellets carried on the stage by the pickup collet,
In order to improve the positioning efficiency, it is preferable that the positioning claws 4, 4 waiting for the arrival of the pellets to move inward from positions close to the four sides of the pellet. To do that,
It is necessary to advance each positioning claw 4, 4, which has retreated to the reference position, to the pellet waiting position as described above, but this requires the number of pulses selected according to the size of the pellet to be the above reference. By simply rotating the step motor from the position, the positioning claws 4, 4, can be accurately positioned at the pellet waiting position. Then, when the semiconductor pellets arrive on the stage, as described above, in the X direction,
The positioning claws 4, 4 move forward in the Y direction to perform positioning. As described above, the semiconductor pellet positioning device of the present invention can reduce the vertical thickness as a positioning device unit. Therefore, the positional relationship between the lead frame transport path and the elastic sheet holding mechanism as shown in FIG. You can choose. As can be seen from this figure, when a positioning device unit with a small vertical thickness is arranged on the side of the lead frame transport path, the elastic sheet holding mechanism is arranged so that the elastic sheet held by this extends below the positioning device unit. Since it can be arranged so as to move in the horizontal direction, the process of carrying the semiconductor pellets on the elastic sheet onto the positioning stage of the positioning device unit by the pickup collet, and the semiconductor pellets after positioning from the positioning stage to the lead frame. It is possible to shorten the process of carrying onto the lead frame on the carrying path, whereby the process cycle of the positioning process or the bonding process can be significantly shortened, and the manufacturing efficiency can be improved. Of course, the scope of the present invention is not limited to the above embodiments. For example, the example has been described on the assumption that the semiconductor pellet is positioned in the middle of bonding the pellet on the stretchable sheet to the lead frame, but when the laser diode is manufactured, the laser diode chip is attached to the stem. The same positioning is performed when bonding,
It goes without saying that the present invention can be applied as a positioning device in this case.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing an embodiment of the present invention, FIG. 2 is a plan view showing the shape of a rotary cam, FIG. 3 is an explanatory view of an operation example of a positioning pawl, and FIG. It is explanatory drawing of the example of arrangement in the pellet bonding apparatus of the applied positioning apparatus. 1 ... Positioning device, 3 ... Positioning stage, 4, 5 ...
… Positioning claws, 14,15 …… Cam followers, 16,18 …… Rotating cams, 22,23 …… Stage motor, 24,25 …… Pulley, 1
6,17 …… Endless rope (endless belt).

Claims (1)

[Scope of utility model registration request] 1. A pair of X-direction positioning claws that are supported in the center of the positioning stage so as to advance and retreat in the X direction and are always urged in the advancing direction, and a pair of X direction positioning claws that face the pellet mounting part. And a Y-direction positioning claw that is supported so as to be able to advance and retreat in the Y direction and is always biased in the backward direction, and the X-direction positioning claw contacts the cam follower attached thereto on the side of the positioning claw advancing direction. The Y-direction positioning pawl is moved forward / backward by the rotation of the rotating cam in contact therewith, and the Y-direction positioning pawl is moved forward / backward by the rotation of the rotary cam abutting on the positioning pawl advancing / retracting direction side with respect to the cam follower attached thereto. Step motors, which are rotationally controlled by control means, are provided corresponding to the rotary cam for the positioning claw and the rotary cam for the Y-direction positioning claw, respectively. The rotation of the step motor is transmitted to each of the rotary cams through an endless rope that is wound around a pulley provided on the output shaft of the step motor and a pulley provided on the shaft of each of the rotary cams. The control means advances the one Y-direction positioning claw to a predetermined position in a state where the pair of X-direction positioning claws are advanced to sandwich the pellet on the pellet mounting portion and the X-direction positioning is performed. The semiconductor pellet positioning device is configured to position the pellet in the Y direction without sandwiching the pellet between the Y direction positioning claw and another object. .