JP2006156806A - Method and device for picking up pellet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently pick up pellets on an expanded sheet, using means of a needleless pickup unit. <P>SOLUTION: The method and device for radially expanding an elastic sheet 3 on the stage 1 of an expansion mechanism and picking up a plurality of pellets 5 on the sheet 3, sheet by sheet, by means of the oscillation arm 22 of a needleless pickup unit 20 has a function of imaging the pellet 5 on the sheet 3 by means of a camera 25 and processing the image signal at a control circuit section 30, and a function of supporting the oscillation arm 22 rotatably by 180° at an arm rotating section 40, where the oscillation arm 22 is appropriately inverted by 180° in a way of pellet pick-up operation, based on a control signal from the control circuit section 30, and the pellet pickup operation is sustained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for picking up pellets (semiconductor pellets) one by one from an expanded elastic sheet.

  An expanding mechanism for subdividing a semiconductor wafer (hereinafter referred to as a wafer) adhered to an elastic sheet into a plurality of pellets and picking up the pellets one by one from the sheet will be described with reference to FIGS. FIG. 5 is a plan view of the wafer ring component 1, and a cross section thereof is shown in FIG. The wafer ring component 1 includes an annular metal ring 2, a stretchable sheet 3 bonded to the lower surface of the ring 2, and a wafer 4 attached to the center of the upper surface of the sheet 3. The wafer 4 is substantially circular, has a plurality of pellets 5 in a lattice shape, and, for example, dicing grooves for subdividing the wafer 4 are formed between the pellets. In addition, although the pellet 5 shown in FIG. 5 is a square, the shape is various, such as a rectangle. In addition, in the substantially circular wafer 4 of FIG. 5, a plurality of non-square shaped pellets 5 ′ are shown at the periphery, but these pellets 5 ′ are portions that are not originally made products, and are to be picked up. Not.

  As shown in FIG. 6, when the wafer ring component 1 is loaded onto the cylindrical stage 10 of the expanding mechanism, the ring 2 of the wafer ring component 1 is pressurized by the ring pressure body 11 from directly above, and the sheet 3 The peripheral part of the sheet slides on the outer periphery from the upper surface of the stage 10, and the sheet 3 on the stage 10 extends (expands) by 360 °. With this sheet extension, the wafer 4 is subdivided into pellets 5, and the plurality of divided pellets 5 are dispersed in a 360 ° radial manner to create gaps between the pellets. When a sufficient gap is formed between the pellets, the ring pressurizing body 11 fixes the ring 2 to the stage 10 as shown in FIG. 7, and the extension of the sheet 3 stops. Thereafter, pellet pick-up is performed by removing the pellets 5 from the sheet 3 one by one.

  Picking up pellets from the extended sheet as described above includes a needle-type method in which the pellet is pushed up from the lower surface of the sheet with a needle (push-up pin) and peeled off the sheet (for example, see Patent Document 1), and a needle that does not use a needle There is a less expression. The former needle type pellet pick-up method may damage the pellet with the needle. The latter needleless type pellet pick-up method includes a vacuum suction method in which the sheet is vacuum-sucked from the lower surface (see, for example, Patent Document 2), and the sheet is pressed locally from the lower surface by swinging a swing arm. A swing arm method is known in which the pellet is tilted and peeled off from the sheet. Since neither of them uses a needle, there is no risk of damage to the pellet.

  The outline of the swingless arm type needleless pellet pick-up device is shown in FIGS. The pickup unit 20 shown in the figure is disposed below the stage 10 so as to be movable relative to the stage 10 in the horizontal direction. For example, the stage 10 is placed on a horizontal XYθ table (not shown), moves in two horizontal orthogonal X and Y directions, and rotates in the horizontal θ direction.

  The pickup unit 20 includes an axial arm support 21 that can move up and down, and a swing arm 22 that is connected to the arm support 21 so as to be swingable in the radial direction. The upper end surface of the arm support 21 is a circular flat pressing surface that is slightly larger than one pellet 5, and the upper end portion 22c of the swing arm 22 is appropriately fitted in a groove 23 formed in a radial direction on the pressing surface. To do. The swing arm 22 includes a lower end portion 22a pivotally attached to the lower portion of the arm support 21 by a support pin 24, an inclined intermediate portion 22b extending upward from the lower end portion 22a, and a substantially horizontal position from the upper end of the intermediate portion 22b. It has the upper end part 22c bent in the direction.

  FIG. 7 shows the state immediately before the pickup unit 20 picks up one pellet 5 from the sheet 3. The upper surface of the sheet 3 on the fixed stage 10 is imaged by, for example, a camera 25 to confirm the position and direction of the pellet 5 to be picked up, and the pickup unit 20 is lifted from directly below the pellet 5 to provide an arm support. The pressing surface at the upper end of 21 is brought into contact with the lower surface of the sheet 3. At this time, the upper end portion 22c of the swing arm 22 is fitted flush with the groove 23 of the pressing surface.

  In the state shown in FIG. 7, the swing arm 22 of the pickup unit 20 is swung with a constant stroke in the radial direction of the stage 10 as shown in FIG. By this swinging, the arm upper end 22c slides on the lower surface of the sheet 3, the swing angle increases, and the tip of the upper end 22c pushes up while sliding on the lower surface of the sheet 3 so that the sheet 3 is locally chevron-shaped. Raise and move the raised ridgeline. This ridge line movement occurs below one pellet 5, and the pellet 5 is peeled off from the sheet 3 while being tilted. At the timing when the swing arm 22 swings and the pellet 5 is peeled from the sheet 3, the collet 26 moved above the sheet 3 descends, vacuums the pellet 5, rises as it is, and a lead frame (not shown). Bond to.

When the pick-up of one pellet 5 is completed, the swing arm 22 of the pick-up unit 20 is restored, and the next pellet 5 is picked up. For example, in FIG. 8, the stage 10 moves one pitch in the left X direction in FIG. 8, and the pellet pickup operation by the pickup unit 20 is repeatedly performed. When all the pick-ups of the plurality of pellets 5 in a line parallel to the X direction are completed, for example, the stage 10 moves one pitch in the Y direction, and the operation moves to the next pellet pick-up operation in the X direction.
Japanese Patent No. 313121 Japanese Patent No. 3209736

  The swingless arm type needleless pellet pick-up method as shown in FIG. 7 has a problem that it is difficult to improve the work efficiency depending on the type of wafer. That is, in FIG. 8, as the pickup unit 20 moves relative to the stage 10 to the right side of FIG. 8, the swing arm 22 approaches the inner wall surface of the stage 10. It becomes easy to interfere with the 10 inner wall surfaces. When the wafer 4 on the sheet 3 has a large diameter and the pellet 5 on the periphery of the sheet 3 that is radially dispersed after expansion is located at a distance of about the swing stroke of the swing arm 22 from the inner wall surface of the stage 10, the pellet 5 Therefore, the swing arm 22 interferes with the stage 10 to pick up the pellet 5 substantially.

  The relative distance relationship between each of the plurality of pellets 5 on the sheet 3 and the stage 10 is known in advance, and the pellet 5 at the position where the swing arm 22 interferes with the stage 10 at the time of pellet pick-up is also known in advance. Then, when picking up the known pellet 5, the stage 10 is rotated 180 ° along with the movement in the X direction to continue the pickup operation. For example, in FIG. 8, before picking up one pellet 5 and picking up the next one pellet 5 ′, the stage 10 is rotated 180 ° along with the movement in the X direction to obtain the next one pellet 5 ′. The pickup unit 20 is positioned directly below the swinging arm 22 so that the swing arm 22 does not interfere with the stage 10 and the pickup operation is continued. In addition, after the pickup of all the pellets 5 in one row in the X direction is completed and before the operation for picking up the pellets 5 in the next row in the X direction is started, the stage 10 is rotated again by 180 ° to Perform the operation continuously.

  In this way, all of the pellets 5 on the sheet 3 can be picked up by the pickup unit 20. However, in order to rotate the stage 10 having a diameter larger than that of the wafer, a large rotational drive mechanism is required, and it is difficult to design the rotational drive mechanism to be incorporated in the XY table. In addition, the large-diameter stage 10 is difficult to rotate at high speed, and it is necessary to rotate the stage 10 a plurality of times by 180 ° for each series of pellet pick-up operations performed on a plurality of pellet rows on the sheet 3. It is difficult to increase the work efficiency of pellet pick-up.

  An object of the present invention is to provide a pellet pick-up method that facilitates improvement in work efficiency and a pellet pick-up device that simplifies the configuration of the entire apparatus.

  The method of the present invention that achieves the above object is to push a plurality of pellets on a stretchable sheet radially expanded on an expanding stage one by one from the bottom of the sheet by a swing arm of a needleless pickup unit. A pick-up method for peeling, wherein the swing arm of the pickup unit is arranged to be rotatable in a direction parallel to the sheet with respect to the sheet on the stage, and when the pellet is peeled from the sheet by the swing arm, the swing arm is separated from the stage. The swing arm is appropriately rotated so as not to interfere.

  Here, the needleless type pick-up unit expands on the expanding stage and swings while sliding up while locally pushing up the lower surface of the sheet held on the stage, and supports the swinging arm so as to be swingable. One having an arm support that can be applied. The swing arm swings back and forth in the radial direction of the stage in a cylindrical stage, for example, and peels one pellet on the sheet. If the swinging direction of the swinging arm relative to the stage is defined and a plurality of pellets on the sheet are peeled off one by one by swinging the swinging arm, the relative distance of each pellet relative to the inner wall surface of the stage varies. , The swing arm may peel all pellets without interfering with the stage, and the swing arm may interfere with the inner wall surface of the stage when peeling some pellets on the periphery of the sheet. In this latter case, the method of the present invention avoids the interference between the swing arm and the stage by rotating the pickup unit rather than rotating the stage. The pickup unit can be rotated by rotating the entire swing arm and arm support unit or by rotating only the swing arm without rotating the arm support. To do. In general, the rotation angle of the swing arm is appropriately 180 °. Such a rotary drive mechanism that rotates the swing arm can be reduced in size and simplified as compared with a rotary drive mechanism that rotates a large-diameter stage.

  In the method of the present invention, the relative distance relationship between each of the plurality of pellets and the stage is detected from an image obtained by imaging the plurality of pellets on the stage with a camera, and the swing arm of the pickup unit removes the pellet from the sheet. The presence or absence of pellets in a relative distance relationship that interferes can be determined, and the swing arm can be appropriately rotated based on the determination result.

  As the camera here, an existing camera that images the pellet on the expanded sheet and confirms the shape and position of the pellet can be applied. If the image captured by the camera is processed by the CPU of the computer and the relative distance relationship between the inner wall surface of the stage and each pellet is calculated, the pellet that the rocking arm interferes with the stage and the pellet that does not interfere are distinguished when the pellet is picked up. Can be grouped. When picking up the pellets divided into groups that do not interfere, the swinging arm is not rotated, and when picking up the pellets divided into groups that interfere, the swinging arm is rotated so that all the pellets can be picked up. . In addition, as described above, when all of the plurality of pellets divided into non-interfering groups are continuously picked up, and then when the plurality of pellets divided into the interfering group is picked up by rotating the swing arm, the swinging is performed. The arm can be rotated with the minimum number, and the working efficiency is further improved.

Further, in the method of the present invention, a plurality of pellets are dispersed in a grid pattern on a sheet, and a plurality of pellets arranged in an arbitrary row are swung in the direction of this row, and the swing arm is swung in the opposite direction from one end of the same row. When picking up one sheet at a time toward the other end, the swing arm can be rotated approximately 180 ° when picking up pellets in the middle of a plurality of pellets arranged in a row.

  In this case, the above-described pellet discrimination by the camera is not necessarily required. Normally, the pellet in the center of the upper surface of the expanded sheet on the expanding stage is farther from the inner wall of the stage than the pellet in the periphery of the upper surface of the sheet, and the swing arm that picks up the pellet swings. There is a possibility that the swinging arm may interfere with the stage when picking up the pellets at the periphery of the sheet without interfering with the stage regardless of the moving direction. Therefore, in a plurality of pellets arranged in a row on the sheet, the pellets are picked up by swinging the swing arm in the row direction from the pellets at one end of the row and in the middle of the row or in the middle of any row near it. Before picking up the plate, the rocking arm is uniformly inverted by 180 °, and while being reversed, the rocking arm is swung in the opposite direction by 180 ° and picked up to the pellet at the other end of the row. Such a pellet pick-up can be performed uniformly regardless of the size of the stage and wafer, and can be performed without using a camera, so that the control of the pellet pick-up becomes simple and can be executed with low cost equipment investment.

  In addition, the device of the present invention that achieves the above object pushes up a plurality of pellets on a stretchable sheet radially expanded on an expanding stage one by one by a swing arm of a needleless pickup unit from below. A pickup device that peels off the sheet, an arm rotation unit that rotates the swing arm of the pickup unit approximately 180 ° in a direction parallel to the sheet on the stage, a camera that images a plurality of pellets on the stage, A control circuit unit that detects a relative distance relationship between a plurality of pellets and a stage from an image captured by a camera and discriminates a pellet in a relative distance relationship that interferes with the stage when the swing arm of the pickup unit peels the pellet from the sheet And picked up by the arm rotation unit based on the discrimination result of the control circuit unit And wherein the rotating the swing arm of the unit.

  As the arm rotation unit, a rotary table mechanism that supports the pickup unit and rotates the entire unit, or a rotation drive mechanism that rotates only the swing arm with respect to the arm support of the pickup unit can be applied. The control circuit unit is a circuit that uses a CPU of a computer, calculates an image captured by the camera, calculates a relative distance relationship between the plurality of pellets on the expanded sheet and the inner wall surface of the expanding stage, When the swing arm of the pick-up unit peels the pellet from the sheet, it determines a pellet that is in a relative distance relationship with the stage and outputs a control signal as to whether or not the swing arm is rotated. An existing camera or an existing computer connected to the camera can be applied to the CPU constituting the camera and the control circuit unit, and a pellet pick-up device can be provided with an advantage in capital investment.

  According to the present invention, the pellet pick-up can be continuously performed without causing the swinging arm and the stage to interfere with each other by rotating the swinging arm smaller than the stage without rotating the expanding stage. It is easy to increase the efficiency of the pellet pick-up operation by increasing the speed, and it is possible to achieve an excellent effect that the entire pickup device can be miniaturized.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  The pellet pick-up apparatus shown in FIGS. 1 (A) and 1 (B) is applied to the pick-up apparatus shown in FIGS. 5 to 8, and the same or corresponding parts are denoted by the same reference numerals to avoid duplication of explanation. FIG. 1A and FIG. 2A are a side sectional view and a partial plan view at the time of pellet pick-up. For example, the stretchable sheet 3 is radially expanded on the stage 1 of the expanding mechanism used in the die bonder, and a plurality of pellets 5 on the sheet 3 are picked up one by one by the swing arm 22 of the needleless pickup unit 20. . The pellet 25 on the sheet 3 is imaged by the camera 25 arranged above the sheet 3, and the captured image signal is transmitted to the control circuit unit 30. The swing arm 22 of the needleless pickup unit 20 is supported by the arm rotating unit 40 so as to be rotatable by 180 °. An arm rotating unit 40 shown in FIG. 1 is a rotary table that rotates the entire unit of the pickup unit 20.

  The control circuit unit 30 is incorporated in a CPU of a computer (not shown). The control circuit unit 30 calculates a relative distance relationship between each of the plurality of pellets 5 on the expanded sheet 3 and the inner wall surface of the stage 10 by processing the pellet image on the sheet 3 captured by the camera 25. When the swing arm 22 peels one pellet 5 from the sheet 3, it is determined whether the pellet 5 is in a relative distance relationship that interferes with the inner wall surface of the stage 10, or the pellet 5 is in a relative distance relationship that does not interfere, A control signal as to whether or not to rotate the swing arm 22 is output to the drive control system 41 of the arm rotating unit 40.

  The arm rotating unit 40 rotates the pickup unit 20 by 180 ° as appropriate with respect to the swinging direction of the swinging arm 22 to reverse the swinging direction of the swinging arm 22. When the swinging direction of the swinging arm 22 is, for example, the X direction, the pickup unit 20 is moved relative to the stage 10 from the left to the right in FIG. A plurality of pellets 5 are picked up sequentially from the leftmost one. Here, in the plurality of pellets 5 in the horizontal row, for example, the plurality of pellets 5 except for the one pellet 5 at the right end are determined as “pellets in which the swing arm and the stage do not interfere with each other” by the control circuit unit 30. If it is determined that only one sheet at the right end is determined as “pellet where the swinging arm and the stage interfere”, the pickup unit 20 continuously performs the pellet pick-up operation as follows.

  In FIG. 1 (A), the pickup unit 20 is positioned directly below the one pellet 5 at the left end, the swing arm 22 is swung to the right in FIG. 1 (A), and the pellet 5 at the left end is peeled off from the sheet 3. Remove with a collet (not shown). Next, the pickup unit 20 is positioned directly below the second pellet 5 from the left end, and the swing arm 22 is swung rightward to pick up the second pellet 5. This pickup operation is continuously performed up to the pellet immediately before the rightmost pellet 5, and at the stage of shifting to the pickup of the rightmost pellet 5, an arm rotating unit is detected by a discrimination signal of “interfering pellet” from the control circuit unit 30. 40 is operated, and the pickup unit 20 is rotated by 180 ° as shown in FIG. 1 (B) and FIG. 2 (B). With this rotation, the direction of the swing arm 22 is reversed by 180 °, and when the right end pellet 5 is swung to pick up, it swings to the left in FIG. 1 (B) away from the inner wall surface of the stage 10. Does not interfere with the stage 10.

  The 180 ° rotation of the swing arm 22 in the pickup unit 20 can also be performed as shown in FIG. 3 or FIG.

  FIG. 3 shows a plurality of, for example, six pellets 5a to 5f arranged in a horizontal row, and the case where each of the pellets 5a to 5f is picked up one by one from the left end in FIG. Among the six pellets 5a to 5f arranged in a horizontal row, the pellets at both ends and in the vicinity thereof are close to the stage 10 and are “pellets with which the swinging arm and the stage may interfere”, and the central pellet is the stage 10 Generally, the pellet is located farther away from the “pellet without the possibility of interference between the swing arm and the stage”. Therefore, assuming this custom, pellet pick-up is performed by swinging the swing arm 22 of the pickup unit 20 from the left end pellet 5a in FIG. 3 to the right in FIG. When pellet pick-up by swinging rightward in FIG. 3 of the swing arm 22 is continuously performed up to the pellet 5c set in the center of the row, the swing arm 22 is uniformly rotated 180 °, Move on to pick up pellet 5d. Then, the swing arm 22 is swung leftward in FIG. 3 from the next pellet 5d to the right end pellet 5f, and the pellets 5d, 5e, and 5f are picked up in order. When the pellets arranged in a row are picked up one by one from the end of the row, the swing arm 22 is rotated by uniformly rotating the swing arm 22 in the middle of a predetermined row. Control for making it easier. This also applies to the pellet pick-up operation of FIG.

  FIG. 4 shows six pellets 5a to 5f arranged in a horizontal row, and the two pellets 5a and 5f at both ends are close to the stage 10 and are "pellets that may interfere with the swing arm and the stage". Is based on the premise that the pellet is not likely to interfere with the arm and stage. In this case, when the pellet 5a at the left end in FIG. 4 is picked up by swinging rightward in FIG. 4 by the swing arm 22 of the pickup unit 20, the swing arm 22 is uniformly rotated by 180 °. Then, the swing arm 22 is swung leftward in FIG. 4 without changing the direction of the swing arm 22 from the next pellet 5b to the rightmost pellet 5f, and the pellets 5b to 5f are picked up in order.

  In addition, the pellet pick-up method of the present invention is not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the gist of the present invention.

(A) is a sectional side view of the principal part of the pellet pick-up apparatus which shows embodiment of this invention, (B) is a sectional side view at the time of the reversal | oscillation arm of a pick-up unit. 1A is a plan view including a part of the apparatus omitted in FIG. 1A, and FIG. 1B is a partial plan view of the apparatus in FIG. It is a pellet arrangement | positioning figure for demonstrating the specific example of the pellet pick-up method of this invention. It is a pellet layout for demonstrating the other specific example of the pellet pick-up method of this invention. It is a top view of an expanding mechanism. It is sectional drawing of the principal part of the expanding mechanism of FIG. It is a sectional side view of the principal part for demonstrating the conventional needleless type pellet pick-up apparatus. 7 is a side sectional view of the device during operation.

Explanation of symbols

2 Ring 3 Sheet 4 Wafer 5 Pellet 10 Stage 11 Ring Pressurizer 20 Needleless Pickup Unit 21 Arm Support 22 Rocker Arm 25 Camera 26 Collet 30 Control Circuit 40 Arm Rotator 41 Drive Control System

Claims (4)

A pick-up method in which a plurality of pellets on a stretchable sheet radially expanded on an expanding stage are pushed up from the bottom of the sheet by a swing arm of a needleless pickup unit and peeled off from the sheet.
The swing arm of the pickup unit is arranged to be rotatable in a direction parallel to the sheet with respect to the sheet, and the swing arm swings so as not to interfere with the stage when peeling the pellet from the sheet. A pellet pick-up method, wherein the swing arm is appropriately rotated.   The relative distance between each of the plurality of pellets and the stage is detected from an image obtained by imaging the plurality of pellets on the stage with a camera, and the swinging arm of the pickup unit interferes with the stage when peeling the pellet from the sheet. 2. The pellet pick-up method according to claim 1, wherein the presence or absence of a pellet having a distance relationship is determined, and the swing arm is appropriately rotated based on the determination result.   A plurality of pellets are dispersed in a grid pattern on the sheet, and a plurality of pellets arranged in an arbitrary row are swung in the direction of this row by swinging a swing arm so that one end is directed from the other end to the other opposite end. 2. The pellet pick-up method according to claim 1, wherein when picking up one by one, the swing arm is rotated approximately 180 degrees when picking up pellets in the middle of a plurality of pellets arranged in a row. A pick-up device that pushes up a plurality of pellets on a stretchable sheet radially expanded on an expanding stage one by one from the bottom of the sheet by a swing arm of a needleless pickup unit,
An arm rotating section for appropriately rotating the swing arm of the pickup unit approximately 180 ° in a direction parallel to the sheet;
A camera for imaging a plurality of pellets on the stage;
Control that detects the relative distance relationship between the plurality of pellets and the stage from the image captured by the camera, and discriminates the pellet in the relative distance relationship that interferes with the stage when the swing arm peels the pellet from the sheet Circuit portion,
A pellet pick-up apparatus, wherein the swing arm is rotated based on a determination result of the control circuit unit.

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