JP2013168566A - Chip mounting method and chip mounting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mounting device and a mounting method in which highly precise mounting operation in a manufacturing process of a chip laminated body can be achieved at low cost.SOLUTION: After a chip 1 is picked up by a collet 3 in a pickup position, a chip rear surface image is acquired by a chip recognition camera 6 which has recognized the chip 1 in the pickup position through a reflective inverse mechanism 21, in an eccentricity quantity detection position which is shifted from the pickup position. Then, the collet 3 which sucks the chip 1 is rotated for a predetermined angle in the eccentricity quantity detection position. In this status, the chip rear surface image is acquired again by the chip recognition camera 6 through the reflective inverse mechanism 21. Afterward, a rotation eccentricity quantity of the chip 1 is calculated using chip rear surface image data acquired before the rotation and chip rear surface image data acquired after the rotation.

Description

  The present invention relates to a chip mounting method and a chip mounting apparatus.

  In the manufacture of semiconductor devices, a chip bonding technique in which a wafer on which a large number of elements are fabricated is diced and separated into individual semiconductor chips, which are bonded one by one to a predetermined position such as a lead frame. Is adopted.

  Generally, as shown in FIG. 3, a die bonder having a horizontal movement operation A1, D1, G1, a lowering operation B1, E1, an ascending operation C1, F1, and a collet 51 that performs a rotating operation as necessary is used. ing.

  A die bonding method using the die bonder shown in FIG. 3 will be described. First, the collet 51 moves horizontally (A1), descends at the pickup position (B1), and picks up the semiconductor chip 52. In this case, a pickup stage 55 is disposed immediately below the adhesive sheet 53 at the position to be picked up, and a push-up pin 56 for separating the semiconductor chip 52 from the adhesive sheet 53 is accommodated in the pickup stage 55 so as to be movable up and down. It is arranged. Then, the push-up pin 56 is raised, and the back surface of the semiconductor chip 52 is peeled off from the adhesive sheet 53 to facilitate picking up by the collet 51.

  Thereafter, the collet 51 rises (C1), moves horizontally (D1), descends at the bonding position (E1), bonds the semiconductor chip 52 to the island portion of the lead frame 57, and rises (F1). Move (G1). By repeating this process, the semiconductor chip 52 is picked up at the pickup position and bonded to the lead frame 57 at the bonding position.

  Incidentally, in recent years, a semiconductor device in which a plurality of chips are stacked has been developed for the purpose of high integration of the semiconductor device (Patent Document 1). In this case, there is a case where the upper and lower chips are stacked with the directions of the upper and lower chips being different, for example, in order to make the drawing direction of the wire from the chip different.

  For this reason, conventionally, when forming a stacked semiconductor device, the chip 52 is stacked in the following steps. First, one chip 52 is picked up from the wafer at the pick-up position. And this chip | tip 52 is mounted in the mounting position of a board | substrate. In this case, the positional relationship between the collet 51 and the chip 52 is assumed to be a relationship (referred to as a positive direction in this case) as shown in FIGS.

  Next, after the chip 52 is picked up from the wafer at the pick-up position, the collet 51 is rotated by a predetermined angle (for example, 90 degrees or 180 degrees) around its axis to change the direction of the chip as shown in FIG. To do. The positional relationship between the collet 51 and the chip 52 is as shown in FIGS. 4A and 4B (in this case, called the reverse direction). Then, the chip 52 in this state is mounted on the chip 52 mounted at the mounting position.

  In the manufacturing process of the semiconductor device having this stacked structure, in order to mount the chip 52 with high accuracy, the displacement amount of the chip 52 is detected in the mounting operation of the chip 52 in the forward direction and the mounting operation of the chip 52 in the reverse direction. Then, the amount of deviation is corrected for mounting.

JP 2003-86758 A

  The detection (calculation) of the shift amount in the manufacturing process of the semiconductor device having the stacked structure is usually a shift amount in the X direction and the Y direction. In such a case, the correction value for the eccentric amount in the rotation direction could not be calculated until after mounting. That is, since the observation is from above, it is difficult to align the center of the collet and the center of the chip, and it has been necessary to check the amount of displacement by mounting it once on a substrate or the like.

  Therefore, in view of such a situation, the present invention intends to provide a mounting device and a mounting method capable of realizing a high-precision mounting operation in a manufacturing process of a chip stack at a low cost.

  In the mounting method of the present invention, a plurality of chips are stacked by picking up a chip with a collet at a pickup position, transporting the collet to the mounting position, and mounting the chip adsorbed by the collet at the mounting position. A chip recognition method for recognizing a chip at a pickup position via a reflection inversion mechanism at an eccentricity detection position shifted from the pickup position after the chip is picked up by a collet at the pickup position In this state, the collet holding the chip is rotated by a predetermined angle at this eccentricity detection position, and in this state, through the reflection reversal mechanism by the chip recognition camera. The chip back image is acquired again, and then the data of the chip back image before rotation and And it calculates the rotational eccentricity of the chip in the data of the chip rear surface image after rotation.

  According to the mounting method of the present invention, the amount of rotational eccentricity of the chip can be calculated using a chip recognition camera (existing camera that performs observation from above) and a reflection inversion mechanism. And you can mount the chip.

  The predetermined angle may be 90 ° or 180 °. Even at such an angle, the rotational eccentricity of the chip can be calculated. The reflection inversion mechanism may be set manually.

  After the chip is picked up by the collet at the pick-up position, the collet is shifted from the pick-up position to the eccentricity detection position, and then a reflection inversion mechanism is set that enables the chip recognition camera to acquire the chip back surface image. There may be. As described above, if the reflection inversion mechanism is set at the eccentricity detection position, it is not necessary to move the chip recognition camera, and an existing one can be used as the chip recognition camera.

  The mounting device of the present invention stacks a plurality of chips by picking up a chip with a collet at the pickup position, transporting the collet to the mounting position, and mounting the chip adsorbed by the collet at the mounting position. A chip recognition device for recognizing a chip at a pickup position, a rotation drive mechanism for rotating a collet around its axis, and a reflection that enables acquisition of a chip back surface image by the chip recognition camera A reversing mechanism and a calculation means for calculating the rotational eccentricity of the chip based on the chip back surface image obtained by the chip recognition camera before and after the collet is rotated are provided.

  The mounting device of the present invention can acquire a chip back surface image via a reflection inversion mechanism with a chip recognition camera that recognizes a chip at a pickup position. Further, the calculation means can calculate the rotational eccentricity of the chip based on the chip back image obtained by the chip recognition camera before and after the collet is rotated.

  Further, it is preferable to include a control means for performing rotation control of the collet based on the rotational eccentricity calculated by the calculation means.

  The collet may be provided with a setting mechanism that automatically sets the reflection inversion mechanism at an eccentricity detection position where the collet is displaced from the pickup position.

  In the present invention, the rotational eccentricity of the chip can be calculated, and the chip can be mounted based on the rotational eccentricity. For this reason, it is possible to mount the chips with high accuracy, and it is possible to configure a high-quality chip stack. In addition, a highly accurate mounting operation can be performed regardless of the mechanical eccentricity accuracy. In particular, there is little calculation error of the calculated rotational eccentricity without being affected by the recognition error on the mount side (substrate side).

  While the chip is being transferred from the pickup position to the mount position, rotation correction data for the mount position can be obtained, and workability can be improved. In particular, since it is not necessary to perform back surface recognition in the forward direction, it is not necessary to perform back surface recognition every time, and the apparatus tact can be speeded up. In addition, this type of mounting device can be used as it is as a chip recognition camera, no additional back surface recognition camera is required, no additional mechanism other than the reflection inversion mechanism is required, and the device is prevented from becoming complicated. This can reduce the cost.

  By manually setting the reflection reversal mechanism, an automatic attachment device is not required, and the device can be made compact and low in cost. In addition, with a setting mechanism that automatically sets the reflection / reversal mechanism, workability can be improved and work time can be shortened.

  Moreover, even if the predetermined angle (rotation angle) is 90 ° or 180 °, the rotational eccentricity of the chip can be calculated, and the versatility is excellent.

It is a simplified process diagram of a chip mounting method according to an embodiment of the present invention. It is a simplified perspective view which shows the chip mount apparatus of this invention. It is a simplified diagram showing the operation of the collet of the chip mounting device. The positional relationship between the collet and the tip in the positive direction position is shown, (a) is a perspective view, and (b) is a bottom view. The positional relationship of the collet and chip | tip in a reverse direction position is shown, (a) is a perspective view, (b) is a bottom view.

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

  FIG. 2 shows a chip mount apparatus according to the present invention. This chip mount apparatus observes the supply part 2 in which the semiconductor chip 1 to be picked up is arranged, the bonding arm 10 having the collet 3 that adsorbs the semiconductor chip 1 of the supply part 2, and the semiconductor chip 1 of the supply part 2. And a recognition camera 12 for observing the chip mount position 5 of the substrate 4 at the bonding position.

  The supply unit 2 includes a semiconductor wafer 8 mounted and supported on the wafer support device 7. The semiconductor wafer 8 is divided into a large number of semiconductor chips 1. The collet 3 is connected to a collet holder 9, and the collet 3 and the collet holder 9 constitute a bonding arm 10. The bonding arm 10 can be moved between the pickup position and the bonding position via the conveying means 11. The transport unit 11 can drive the bonding arm 10 in the X, Y, θ, and Z directions. That is, the chip 1 is transported from the chip pickup position to the chip mount position as shown by the arrow A in FIG.

  Further, the collet 3 is vacuum-sucked through the suction holes opened in the lower end surface thereof, and the chip 1 is adsorbed on the lower end surface of the collet 3. If this vacuum suction (evacuation) is released, the chip 1 is detached from the collet 3.

  By the way, this chip mounting apparatus is to stack a plurality of chips 1. For this reason, the rotation of the chip 1 based on the reflection inversion mechanism 21 that enables the chip recognition camera 6 shown in FIG. 1 to acquire the chip back surface image and the chip back surface image by the chip recognition camera 6 before and after the rotation of the collet 3. Calculation means 22 for calculating the amount of eccentricity and control means 23 for determining the mount position 5 of the collet 3 based on the rotational eccentricity calculated by the calculation means 22 are provided.

  In addition, this apparatus includes a rotation drive mechanism 24 that rotates the collet 3 about its axis. The rotation drive mechanism 24 can be configured by the transport unit 11. The calculation means 22 and the control means 23 are, for example, a microcomputer in which a ROM (Read Only Memory), a RAM (Random Access Memory), and the like are connected to each other via a bus with a CPU (Central Processing Unit) as a center. The ROM stores programs executed by the CPU and data. This control means 23 controls the operation of the collet 3 and the operation of the transport means 11. In addition, a storage device (not shown) is provided as a storage means, and this storage device includes an HDD (Hard Disc Drive), a DVD (Digital Versatile Disk) drive, a CD-R (Compact Disc-Recordable) drive, an EEPROM (Electronically Erasable). and Programmable Read Only Memory).

  The reflection inversion mechanism 21 has a pair of mirrors 25 and 26 as shown in FIG. That is, the image on the back surface of the chip 1 is reflected by the first mirror 25 and is incident on the second mirror 26, and is reflected by the second mirror 26 and incident on the chip recognition camera 6.

  Further, the reflection inversion mechanism 21 is set at the eccentricity detection position. Here, the eccentricity detection position is a position shifted from the chip pickup position and is a position on the transport path of the collet 51. In this case, the reflection inversion mechanism 21 can be manually set to be detachable at the set position. It should be noted that a bolt / nut coupling, a concave-convex fitting structure, or the like can be used for fixing the reflection inversion mechanism 21 to the set.

  As shown in FIG. 1, a setting mechanism 30 that automatically sets the reflection / reversal mechanism 21 may be provided. For example, the set mechanism 30 can be configured by a cylinder mechanism or the like provided at a position deviated from the conveyance path of the collet 51. That is, if the reflection reversal mechanism 21 having the first mirror 25 and the second mirror 26 is attached to the piston rod of the cylinder mechanism, the reflection reversal mechanism 21 is moved to the eccentricity detection position by extending the piston rod. When the piston rod is contracted, the reflection reversal mechanism 21 can be moved to a position retracted from the eccentricity detection position.

  Next, a chip mounting method using the chip mounting apparatus configured as described above will be described. In this case, a plurality of chips 1 are stacked and rotated 180 degrees for each stage. In addition, it is possible to rotate 180 degrees in the same direction for each stage, or to reverse 180 degrees for each stage.

  For this operation, first, the chip 1 in the positive direction shown in FIG. 4 is mounted. That is, the collet 3 is positioned above the pickup position, and then the collet 3 is lowered to pick up the chip 1. In this case, the chip recognition camera 6 recognizes the position of the chip 1 and picks up. Then, after raising the collet 3, the collet 3 is conveyed to a position above the chip mount position, and then the collet 3 is lowered to mount the chip 1 in the forward direction at the chip mount position.

  Next, when mounting the chip 1 in the reverse direction shown in FIG. 5 (chip 1 rotated counterclockwise by 180 degrees), the chip 1 in the positive direction is first picked up by the collet 3 at the pickup position, and this pickup After raising the collet 3 at the position, the collet 3 is moved to the eccentricity detection position and stopped. In this state, the reflection inversion mechanism 21 is set at this eccentricity detection position. That is, if it is set manually, it is set manually, and if it is set automatically, it is set automatically.

  In this state, the position data of the back surface image of the chip 1 is acquired by the chip recognition camera 6 via the reflection inversion mechanism 21. Thereafter, as shown in FIG. 1B, the collet 3 is rotated 180 degrees counterclockwise around its axis from the state shown in FIG. Get image position data. That is, the position data of the back image before rotation and the position data of the back image after rotation are acquired.

  And these data are input into the calculating means 22, and the calculating means 22 calculates the rotational eccentricity amount of the chip 1 based on these data. The rotational eccentricity is input to the control means 23, and the position on the collet 3 side with respect to the chip mount position on the substrate side is determined based on the rotational eccentricity. That is, this rotational eccentricity is reflected in the rotation correction data of the chip 1 and the chip 1 is rotationally corrected while the mount position is confirmed by the confirmation camera 12 on the chip mount position side to mount the chip 1. In this case, on the chip 1 mounted in the forward direction, as shown in FIG. 1 (c), the chip 1 in the reverse direction rotated 180 degrees counterclockwise (rotated corrected chip 1). Is moved in the directions of arrows X and Y for mounting.

  Further, the chip 1 in the reverse direction may be rotated 180 degrees clockwise. In this case, the collet 3 is rotated 180 degrees clockwise around the axis. Even in this case, the position data of the back surface image of the chip 1 is acquired by the chip recognition camera 6 through the reflection inversion mechanism 21 before and after the rotation.

  And these data are input into the calculating means 22, and the calculating means 22 calculates the rotational eccentricity amount of the chip 1 based on these data. The rotational eccentricity is input to the control means 23, and the chip 1 is mounted at the chip mounting position based on the rotational eccentricity. That is, the chip 1 in the reverse direction rotated 180 degrees clockwise is mounted on the chip 1 mounted in the forward direction.

  Similarly, the forward direction chip 1 and the reverse direction chip 1 can be sequentially stacked, whereby a semiconductor device in which a plurality of chips 1 are stacked can be formed. In the above-described embodiment, the rotation angle is 180 degrees. However, the rotation angle may be 90 degrees. Even when the rotation angle is 90 degrees, the rotation angle may be counterclockwise. You may rotate clockwise.

  In this mounting method, the rotational eccentricity of the chip can be calculated using the chip recognition camera 6 (existing camera that performs observation from above) and the reflection inversion mechanism 21, and based on the rotational eccentricity. Chip 1 can be mounted. For this reason, the chip 1 can be mounted with high accuracy, and a high-quality chip stack can be configured. In addition, a highly accurate mounting operation can be performed regardless of the mechanical eccentricity accuracy. In particular, there is little calculation error of the calculated rotational eccentricity without being affected by the recognition error on the mount side (substrate side).

  While the chip 1 is being conveyed from the pickup position to the mount position, rotation correction data for the mount position can be obtained, and workability can be improved. In particular, since it is not necessary to perform back surface recognition in the forward direction, it is not necessary to perform back surface recognition every time, and the apparatus tact can be speeded up. Further, as the chip recognition camera 6, this type of mounting device can be used as it is, no additional back surface recognition camera or the like is required, no additional mechanism other than the reflection inversion mechanism 21 is required, and the device is complicated. Can be prevented and the cost can be reduced.

  When the reflection reversal mechanism 21 is manually set, an automatic attachment device is not required, and the device can be made compact and low in cost. In addition, the apparatus equipped with the setting mechanism 30 for automatically setting the reflection / reversal mechanism 21 can improve the workability and shorten the work time. Moreover, even if the predetermined angle (rotation angle) is 90 ° or 180 °, the rotational eccentricity of the chip can be calculated, and the versatility is excellent.

  As described above, the embodiment of the present invention has been described, but various modifications are possible without being limited to the above-described embodiment. For example, the number of chips to be stacked can be arbitrarily set. Instead, a prism or the like may be used. In the above embodiment, the collet 3 is shifted from the pickup position to the eccentricity detection position, and then a reflection reversal mechanism that enables acquisition of a chip back surface image by the chip recognition camera is set. The reflection inversion mechanism 21 may be fixed in advance at the eccentricity detection position, and the collet 3 and the chip recognition camera 6 may be conveyed to the eccentricity detection position. In this case, the chip recognition camera 6 reciprocates between the chip pickup position and the eccentricity detection position.

  As the set mechanism 30, other reciprocating mechanisms such as a bolt / nut mechanism and a linear guide mechanism can be used without using a cylinder mechanism.

DESCRIPTION OF SYMBOLS 1 Semiconductor chip 3 Collet 5 Chip mount position 6 Chip recognition camera 21 Reflection inversion mechanism 22 Calculation means 23 Control means 24 Rotation drive mechanism 30 Set mechanism

Claims (9)

A chip mounting method for stacking a plurality of chips by picking up a chip with a collet at a pickup position, transporting the collet to a mounting position, and mounting the chip adsorbed by the collet at the mounting position. ,
After the chip is picked up by the collet at the pick-up position, the chip back surface image is acquired by the chip recognition camera that recognizes the chip at the pick-up position at the eccentricity detection position shifted from the pick-up position. Next, at this eccentricity detection position, the collet that is adsorbing the chip is rotated by a predetermined angle, and in this state, the chip back image via the reflection reversing mechanism by the chip recognition camera is obtained again, Thereafter, the chip eccentricity is calculated from the data of the chip back surface image before rotation and the data of the chip back surface image after rotation.   2. The chip mounting method according to claim 1, wherein after calculating the rotational eccentricity of the chip, the chip is mounted based on the rotational eccentricity.   The chip mounting method according to claim 1, wherein the predetermined angle is 90 °.   3. The chip mounting method according to claim 1, wherein the predetermined angle is 180 degrees.   After picking up the chip with the collet at the pick-up position, the collet is shifted from the pick-up position to the eccentricity detection position, and then a reflection inversion mechanism is set that enables the chip recognition camera to acquire the chip back surface image. The chip mounting method according to any one of claims 1 to 4, wherein the chip mounting method is characterized.   The chip mounting method according to claim 1, wherein the setting of the reflection inversion mechanism is performed manually. A chip mounting apparatus that stacks a plurality of chips by picking up a chip with a collet at a pickup position, transporting the collet to a mounting position, and mounting the chip adsorbed by the collet at the mounting position. ,
A chip recognition camera that recognizes the chip at the pickup position;
A rotary drive mechanism that rotates the collet around its axis;
A reflection inversion mechanism that enables acquisition of a chip back image by a chip recognition camera;
A chip mounting apparatus comprising: an arithmetic means for calculating a rotational eccentricity amount of a chip based on a chip back surface image obtained by a chip recognition camera before and after rotation of the collet.   8. The chip mount device according to claim 7, further comprising control means for performing rotation control of the collet based on the rotation eccentricity calculated by the calculation means.   9. The chip mount device according to claim 7, further comprising a setting mechanism that automatically sets the reflection and reversal mechanism at an eccentricity detection position where the collet is displaced from the pickup position.

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