JP3915613B2 - Pickup device and pick-up method of chip on wafer sheet - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a chip pickup device and a pickup method on a wafer sheet.
[0002]
[Prior art]
In the conventional ejector device, the pepper pot is lifted to bring the upper surface thereof into contact with the lower surface of the wafer sheet, and the nozzle of the transfer head is lowered to vacuum-suck the chip with the wafer sheet to the lower end thereof. While raising one or a plurality of needles built in the pepper pot and pushing up the tip from below, the nozzle was raised to pick up the tip. Next, the transfer head was moved above a mounting object such as a circuit board, and a chip was mounted at a predetermined position (for example, JP-A-60-102754).
[0003]
[Problems to be solved by the invention]
In recent years, the chip tends to be thinned, and an extremely thin chip having a thickness of 100 μm or less has been proposed. If the thinned chip is picked up while being pushed up with a needle, the chip is easily damaged.
[0004]
Accordingly, an object of the present invention is to provide a pickup device and a pickup method for chips on a wafer sheet that can prevent chip breakage. More specifically, an object of the present invention is to provide a chip pick-up device and a pick-up method for a chip on a needle-less wafer sheet that can eliminate the need for a needle for pushing up the chip.
[0005]
[Means for Solving the Problems]
For this purpose, the chip pick-up device on the wafer sheet according to the present invention is a chip pick-up device for picking up a chip attached to the wafer sheet by an adhesive layer by vacuum suction to the lower end of the nozzle, And an inner case disposed inside the outer case, and an opening for vacuum-sucking a wafer sheet on a side of a chip to be picked up on the inner case on the upper surface of the outer case. A first vacuum suction means for opening and opening a hole for vacuum-sucking the wafer sheet on the lower surface of the chip on the upper surface of the inner case, and sucking the inside of the outer case; and the inner case And a second vacuum suction means for sucking the inside , and a vibration means for vibrating the inner case .
[0008]
A chip pickup method on a wafer sheet according to the present invention is a chip pickup method using the chip pickup device on a wafer sheet according to claim 1, wherein the upper surface of the outer case is brought into contact with the lower surface of the wafer sheet. A step of vacuum-sucking the wafer sheet on the side of the chip on the inner case to the opening by driving the first vacuum suction means; and a chip on the inner case at the lower end of a chip pickup nozzle Vacuum-adsorbing, and driving the vibration means to vibrate the inner case to generate cavitation in a bond for adhering the chip to a wafer sheet, and to generate bubbles in the bond by the cavitation. Reducing the sticking force of the wafer sheet, raising the nozzle, and By its suction force by driving the suction means to the lower surface of the wafer sheet of the tip into the hole portion by vacuum suction and a step of peeling off the wafer sheet from the lower surface of the chip.
[0009]
In the above configuration, when a chip on a wafer sheet is picked up by vacuum suction using a nozzle, the wafer sheet on the side of the chip is firmly vacuum-sucked to the opening of the case. Then, the nozzle is raised to pick up the chip. At this time, the wafer sheet immediately below the chip is firmly vacuum-sucked into the hole of the pepper pot. Therefore, the chip can be picked up by forcibly peeling the wafer sheet on the lower surface of the chip from the chip by the adsorption force.
[0010]
In addition, by vibrating the inner case by vibration means, cavitation is generated in the bond that attaches the chip to the wafer sheet, and this cavitation creates bubbles in the bond, reducing the adhesive force between the chip and the wafer sheet. Can be easily peeled off from the wafer sheet and picked up.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
1 is a cross-sectional view showing the overall structure of a chip pickup device on a wafer sheet according to Embodiment 1 of the present invention, and FIG. 2 shows an outer case of the chip pickup device on a wafer sheet according to Embodiment 1 of the present invention. FIGS. 3A, 3B, and 3C are partial cross-sectional views showing the chip pickup operation of the chip pickup device on the wafer sheet in the first embodiment of the present invention, and FIG. FIG. 5 is a partial cross-sectional view of the chip pickup device on the wafer sheet at the time of applying vibration in Embodiment 1 of the present invention, and FIG. 5 shows the chip at the time of vibration application of the chip pickup device on the wafer sheet in Embodiment 1 of the present invention FIG. 6 is a plan view of the chip peeling force of the chip pickup device on the wafer sheet in Embodiment 1 of the present invention (chip peeling from the wafer sheet). Elevating distance of the resistor) and nozzle (a relationship diagram of the release time).
[0012]
First, the overall structure of a chip pickup device on a wafer sheet will be described with reference to FIG. The covered cylindrical outer case 3 and the covered cylindrical inner case 4 are mounted on a U-shaped support portion 11. The support portion 11 is supported by the tip end portion of the rod 13 of the cylinder 12 as the first vertical movement means, and when the rod 13 protrudes, the outer case 3 and the inner case 4 on the support portion 11 move up and down. Move. The upper surfaces of the outer case 3 and the inner case 4 are preferably flush with each other, but there may be a step within a range that does not hinder the vacuum suction of the wafer sheet 1 by the first pump 24 and the second pump 26 described later. . Note that the outer case and the inner case do not necessarily need to be physically separated from each other, and may be formed integrally. In short, it is only necessary that the gas flows in the outer case and the inner case are separated.
[0013]
The elevator 6 on which the needle 5 is erected is supported by the base 14. The support portion 11 is provided with a cylinder 15 as second vertically moving means, and the base portion 14 is supported by the tip end portion of the rod 16. Therefore, when the rod 16 protrudes and retracts, the elevator 6 and the needle 5 move up and down, and the upper end portion of the needle 5 protrudes and retracts from the hole portion 7 opened at the center of the upper surface of the inner case 4. A plurality of needles 5 may be provided. Reference numeral 27 denotes a seal member that maintains the airtightness between the inner case 4 and the lift 6.
[0014]
A slider 17 is provided on the side of the support portion 11, and the slider 17 is slidably fitted to a vertical linear guide 18. Reference numeral 19 denotes a support for the linear guide 18. Therefore, when the rod 13 of the cylinder 12 protrudes and retracts, the support portion 11 moves vertically up and down along the linear guide 18. At the time of standby, as shown in FIG. 1, the outer case 3 and the inner case 4 are in the lowered position, and their upper surfaces are separated from the wafer sheet 1 above, but when the rod 13 protrudes, they rise, The upper surfaces of the outer case 3 and the inner case 4 are in contact with the lower surface of the wafer sheet 1. The various elements such as the cylinder 12 and the support 19 are installed on the movable table 20. The movable table 20 is moved horizontally in the X direction and the Y direction by means (not shown), and the inner case 4 is positioned directly below the predetermined chip 2.
[0015]
An ultrasonic (US) vibrator 21 is attached to the inner case 4 as a vibration means, and when driven, the inner case 4 vibrates ultrasonically. In addition, a vibration means may be provided in the outer case 3, and the vibration may be transmitted to the inner case 4 through the outer case 3, and the installation position can be freely determined. The vibrating means is not always necessary. An opening 22 for vacuum-sucking the wafer sheet 1 is opened on the upper surface of the outer case 3 (see also FIG. 2). The opening 22 is located on the side of the chip 2 on the hole 7 of the inner case 4 to be picked up (push-up).
[0016]
In FIG. 1, the inside of the outer case 3 is vacuumed through a pipe 23 to a first pump 24 that is a first vacuum suction means. The inside of the inner case 4 is vacuum-sucked through a pipe 25 to a second pump 26 that is a second vacuum suction means. In FIG. 4, reference numeral 8 denotes a bond as an adhesive layer for attaching the chip 2 to the wafer sheet 1.
[0017]
In the first embodiment, the needle 5 and the vertical movement means (the elevator 6 and the cylinder 15) for moving the needle 5 up and down are provided. As will be apparent from the second embodiment to be described later, In the invention, the needle 5 and its vertical movement means are not necessary in principle.
[0018]
The chip pick-up device on the wafer sheet has the above-described configuration. Next, the chip pick-up operation will be described. 3A to 3C show the chip pickup operation in the order of operation. First, the rod 13 of the cylinder 12 is projected to raise the outer case 3 and the inner case 4, and the upper surfaces thereof are brought into contact with the lower surface of the wafer sheet 1 (see FIG. 3A). Next, the nozzle 9 of the transfer head is lowered (arrow A), the lower end thereof is landed on the upper surface of the chip 2 on the inner case 4, and the chip 2 is vacuum-sucked (indicated by a chain line in FIG. 3A). See nozzle 9). Note that the lower surface of the wafer sheet 1 may be brought into contact with the upper surface of the outer case 3 or the inner case 4 by lowering the wafer sheet 1 without raising the outer case 3 or the inner case 4, and the vertical movement thereof. Is relative.
[0019]
At this time, the first pump 24 is driven to strongly vacuum-suck the wafer sheet 1 near the side of the chip 2 into the opening 22 (the suction pressure is P1). Desirably, the US vibrator 21 is driven to vibrate the inner case 4 by ultrasonic waves (US). Then, many fine bubbles 10 are generated in the bond 8 on the lower surface of the chip 2 by the cavitation 2 (see FIGS. 4 and 5), and the adhesion force between the chip 2 and the wafer sheet 1 is reduced. Therefore, the peeling resistance of the chip 2 from the wafer sheet 1 is also reduced.
[0020]
Next, the nozzle 9 that vacuum-sucks the chip 2 also starts to rise (arrow C). At the same time, the second pump 26 is driven at this time, and the inside of the inner case 4 is vacuum-sucked, whereby the wafer sheet 1 is strongly vacuum-sucked into the hole 7 (suction pressure is P2). The operation timing of each element such as the suction timing of the chip 2 by the nozzle 9 and the rising timing of the nozzle 9 is optimally set according to the type of the chip 2 and the like.
[0021]
Now, as shown in FIG. 3C, the nozzle 9 continues to rise (arrows B and C), and the wafer sheet 1 adhered to the lower surface of the chip 2 is suctioned as the nozzle 9 rises. Due to the pressure P2, it is gradually peeled off from the lower surface of the chip 2 forcibly. 3B and 3C, the wafer sheet 1 indicated by the solid line and the chain line immediately below the chip 2 shows a state of gradually peeling from the lower surface of the chip 2. FIG. In this case, since the fine bubbles 10 are generated in the bond 8 on the lower surface of the chip 2 by cavitation as described above, the adhering force for adhering the chip 2 to the wafer sheet 1 is reduced. By P2, the wafer sheet 1 is easily peeled from the lower surface of the chip 2 without applying an excessive load to the chip 2. 3C, when the wafer sheet 1 is completely peeled from the lower surface of the chip 2, the nozzle 9 picks up the chip 2 as it is, and the mounting object (not shown) By moving upward, the chip 2 is mounted at a predetermined position on the mounting target. By repeating the above operation, the chips 2 on the wafer sheet 1 are successively picked up by the nozzles 9 and mounted on the mounting object. 3A to 3C, the needle 5 remains stopped at the lower retracted position, and the needle 5 does not push up the tip 2 when the nozzle 9 picks up the tip 2.
[0022]
FIG. 6 shows the relationship between the peeling force (chip peeling resistance) when picking up the chip 2 on the wafer sheet 1 as described above and the rising distance of the nozzle 9 (time until complete peeling). FIG. 6 means that the chip 2 is gradually and softly peeled off from the wafer sheet 1 with a relatively small peeling resistance. Therefore, the load applied to the chip 2 at the time of pick-up is small, and therefore the chip is damaged. Hateful.
[0023]
FIGS. 7A, 7B, and 7C are partial cross-sectional views showing other aspects of the chip pickup operation of the chip pickup device on the wafer sheet in the first embodiment of the present invention. The tip 2 shown in FIG. 3 is very thin, and is easily damaged when pushed up from below with the needle 5. Therefore, in Embodiment 1, the tip 2 is picked up without pushing up the tip 2 with the needle 5 (that is, without using the needle 5).
[0024]
The tip 2 'in the form shown in FIG. Therefore, in such a case, as shown in FIGS. 7A, 7B and 7C, while the needle 5 is raised and the tip 2 ′ is pushed up from below (arrow B), Pick up chip 2 '. Operations other than the operation of pushing the tip 2 ′ with the needle 5 are the same as the operations described with reference to FIG. That is, in this aspect, the push-up operation of the tip 2 ′ by the needle 5 is added to the operation described in FIG. This is because if the tip is thick and the tip 2 'is less likely to be damaged even if it is pushed up by the needle 5, the tip 2' is pushed more reliably by the nozzle 9 if the tip 2 'is pushed up by the needle 5. This is because it can be picked up.
(Embodiment 2)
FIG. 8 is a cross-sectional view showing the overall structure of a chip pickup device on a wafer sheet according to the second embodiment of the present invention, and FIG. 9 shows the vibration applied to the chip pickup device on the wafer sheet according to the second embodiment of the present invention. FIG. The second embodiment is different from the first embodiment in that a needle and its vertical movement means are not present. The pickup operation of the chip 2 is the same as the operation described with reference to FIGS. 3 (a), (b), and (c).
[0025]
Since the first embodiment includes a needle and its vertical movement means, the use or non-use of the needle is selected according to the thickness or the vulnerability of the tip. On the other hand, the second embodiment is used exclusively for picking up thin or weak chips. However, it is not prohibited to use it for picking up a chip that is thick and hardly damaged.
[0026]
【The invention's effect】
As described above, according to the present invention, since the chip is picked up while being peeled from the wafer sheet by the suction force of the hole, it is possible to pick up the chip without using a needle that is likely to cause chip damage. Therefore, it is extremely useful for pushing up a thinned chip.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an overall structure of a chip pickup device on a wafer sheet in Embodiment 1 of the present invention. FIG. 2 is an outer case of a chip pickup device on a wafer sheet in Embodiment 1 of the present invention. FIG. 3A is a partial cross-sectional view showing the chip pick-up operation of the chip pick-up device on the wafer sheet according to the first embodiment of the present invention. FIG. 3B is the first embodiment of the present invention. FIG. 4 is a partial cross-sectional view showing the chip pickup operation of the chip pickup device on the wafer sheet. FIG. 4C is a partial cross-sectional view showing the chip pickup operation of the chip pickup device on the wafer sheet in the first embodiment of the present invention. FIG. 5 is a partial sectional view of a chip pickup device for a chip on a wafer sheet when vibration is applied according to the first embodiment of the present invention. FIG. 6 is a plan view of a chip when vibration is applied to a chip pickup device on a wafer sheet according to Embodiment 1 of the present invention. FIG. 7A is a diagram illustrating another relationship between the chip pickup operation of the chip pickup device on the wafer sheet according to the first embodiment of the present invention. (B) Partial sectional view showing an aspect (b) Partial sectional view showing another aspect of chip pickup operation of the chip pickup device on the wafer sheet in the first embodiment of the present invention (c) In the first embodiment of the present invention FIG. 8 is a partial cross-sectional view showing another aspect of the chip pick-up operation of the chip pick-up device on the wafer sheet. [EXPLANATION OF SYMBOLS] partial cross-sectional view at the time of vibration application of the chip pickup device on a wafer sheet in the second embodiment of the cross section 9 the invention showing a whole structure of a chip pickup device on the wafer sheet in the 2
1 Wafer Sheet 2 Chip 3 Outer Case 4 Inner Case 7 Hole 8 Bond 9 Nozzle 21 Ultrasonic Vibrator 22 Opening 24 First Pump 26 Second Pump

Claims (2)

A chip pick-up device for picking up a chip adhered by an adhesive layer on a wafer sheet by vacuum suction to the lower end of a nozzle, and comprising an outer case and an inner case disposed inside the outer case An opening for vacuum-sucking a wafer sheet on a side of a chip to be picked up on the inner case on the upper surface of the outer case, and a wafer on the lower surface of the chip on the upper surface of the inner case A first vacuum suction unit that opens a hole for vacuum-sucking the sheet and sucks the inside of the outer case; and a second vacuum suction unit that sucks the inside of the inner case; and chip pickup apparatus in the feature and to roux Ehashito further comprising a vibrating means for vibrating the inner case. 2. A chip pickup method using the chip pickup device on a wafer sheet according to claim 1 , wherein an upper surface of the outer case is brought into contact with a lower surface of the wafer sheet, and the first vacuum suction means is driven to A step of vacuum-sucking the wafer sheet on the side of the chip on the inner case to the opening, a step of vacuum-sucking the chip on the inner case to the lower end of a nozzle for chip pickup, and driving the vibration means Causing the inner case to vibrate and generating cavitation in the bond for adhering the chip to the wafer sheet, generating bubbles in the bond by this cavitation to reduce the adhering force between the chip and the wafer sheet; The nozzle is raised, and the second vacuum suction means is driven so that the lower surface of the chip is placed in the hole. Chip pickup method on a wafer sheet which comprises a step of separating the wafer sheet from the lower surface of the chip by the suction force by vacuum suction Hashito.

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