JP2007088038A - Re-sticking device and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a replacing device and a re-sticking method capable of preventing crack of a semiconductor chip and lowering of processing capability in a dicing process and pick-up process of a semiconductor wafer as a plate-shaped member. <P>SOLUTION: A wafer 20 integrated with a flame 50 is held by a dicing sheet 30 via a heat sensitive adhesive sheet 212, and the dicing sheet 30 is exfoliated from the wafer 20. A pick-up sheet 40 is stuck on a portion of the wafer from which the dicing sheet 30 is exfoliated, and is again integrated with the frame 50. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sheet rewriting device and a renewal method used when a plate-like member such as a semiconductor wafer is singulated and picked up.

  Conventionally, a semiconductor wafer as a plate-like member (hereinafter simply referred to as “wafer”) is divided into individual pieces by dicing, and the separated wafer (hereinafter simply referred to as “chip”) is picked up and mounted on a lead frame. It is done.

  For example, as such a technique, there is one as shown in Patent Document 1. Specifically, as shown in FIG. 6A, the wafer 20 is bonded to a base sheet 31 and an adhesive 32 via a heat-sensitive adhesive sheet (hereinafter simply referred to as “heat-sensitive adhesive sheet”) 212. Is integrated with the ring frame 50 by the dicing sheet 30 formed by laminating the layers, and then diced together with the heat-sensitive adhesive sheet 212 by the cutting blade 60 to be separated into chips (hereinafter referred to as “chips”). "Chip body").

  The chip body 21 manufactured in this way is conveyed to the next pick-up process while being held on the frame 50 by the dicing sheet 30 and, as shown in FIG. 6B, push-up pins 80 from the dicing sheet 30 side. Is pushed up and delivered to the suction collet 70 awaiting above. The chip body 21 is bonded to the lead frame by the adhesive force of the heat-sensitive adhesive sheet 212.

  However, even if the sheet used during dicing is excellent in dicing suitability, it is not necessarily excellent in pick-up suitability, and a sheet excellent in pick-up suitability is not necessarily excellent in dicing suitability.

  That is, the dicing sheet 30 is relatively thick so as not to be cut together with the wafer 20 by the cutting blade 60 during dicing, and the wafer 20 and the chip body 21 are moved by the vibration of the cutting blade 60, and each chip 211 is moved. High rigidity is suitable to prevent cracking. On the other hand, the pickup sheet 40 is thin and has low rigidity so that the chip body 21 can be pushed up by the push-up pin 80 at the time of pickup so that it can be appropriately delivered to the suction collet 70. Therefore, if a sheet with good dicing suitability is used, pick-up suitability is sacrificed, and if a sheet with good pick-up suitability is used, dicing suitability must be sacrificed. There is a problem that the processing capacity is lowered due to a pickup failure.

JP 2003-257898 A

  The present invention has been made in view of such circumstances. The purpose of the present invention is to break a semiconductor chip by replacing the semiconductor wafer as a plate-like member with a sheet suitable for each process at the time of dicing and picking up. Another object of the present invention is to provide a replacement device and a replacement method capable of preventing a reduction in processing capacity in each step.

In order to achieve the above object, the rewriting device according to the present invention is:
It is a pasting device intended for what is formed by adhering the separated plate-like member and the first sheet stuck to the ring frame,
Holding means for holding the ring frame and the separated plate-like member;
Peeling means for peeling the first sheet;
It has a sticking means which sticks the 2nd sheet to the part from which the 1st sheet was exfoliated.

  Moreover, the plate-shaped member separated into pieces can take the structure adhere | attached on the said 1st sheet | seat via the adhesive agent.

  Further, the second sheet can be configured such that the rigidity is smaller or the thickness is smaller than that of the first sheet.

  Further, the first sheet and the second sheet can be configured to be energy ray curable adhesive sheets.

  The plate member may be a semiconductor wafer.

In order to achieve the above-mentioned object,
It is a renewal method intended for the one in which the separated plate-like member and the first sheet affixed to the ring frame are bonded,
Holding the ring frame and the separated plate-like member;
Peeling off the first sheet;
The second sheet is pasted on the part where the first sheet is peeled off.

In addition, the second sheet can be configured to have a smaller rigidity or a smaller thickness than the first sheet.

  The plate member may be a semiconductor wafer.

  As described above, in the present invention, the wafer as an individual plate member and the first sheet affixed to the ring frame are bonded, and the first sheet is peeled off, Since the second sheet is attached to the peeled portion, a sheet having good aptitude can be used in each of the dicing process and the pick-up process. As a result, the suitability of either one is not sacrificed, and the generation of defective chips in these processes and the reduction in processing capacity in each process can be prevented.

  Furthermore, in the present invention, if the second sheet is less rigid or thinner than the first sheet, a sheet having good suitability can be used in each of the dicing process and the pickup process. Therefore, it is possible to prevent chip cracking at the time of dicing resulting from aptitude failures and a reduction in processing capacity due to defective pickup.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a semiconductor wafer is used as the plate-like member, and the wafer is singulated in a state in which the wafer is integrated with the ring frame by a dicing sheet as a first sheet through a heat-sensitive adhesive sheet (hereinafter referred to as “the wafer”). This state is referred to as a “wafer with a ring frame”), and then the dicing sheet is peeled off and a pickup sheet as a second sheet is attached to the peeled portion as an example.

  FIG. 1 is a top view showing a schematic configuration of a re-spreading apparatus according to the present embodiment, and FIG. 2 is a schematic cross-sectional view of a wafer with a ring frame. In FIG. 2, portions corresponding to those in FIG. 6 are denoted by the same reference numerals.

  First, the configuration of the rewriting device will be described with reference to FIG. The pasting device 1 includes a storage unit 11, a transport unit 12, a suction table 13 (holding unit), a peeling unit 14 (peeling unit), and a pasting unit 15 (paste unit).

  The storage unit 11 includes a storage elevator 111 that can move up and down, and a storage cassette 112 mounted on the storage elevator 111, and a plurality of wafers with ring frames 2 are spaced apart from each other in the storage cassette 112. Are stacked and stored.

  As shown in FIG. 2, the wafers 20 stored in the storage cassette 112 are separated into individual pieces through a dicing process to form an aggregate of chips 211, and on the back side of each chip 211 (on the opposite side of the circuit formation surface). The chip body 21 is formed in a state where a heat-sensitive adhesive sheet 212 having approximately the same area as each chip 211 is laminated.

  In the present invention, the chip bodies 21, 21,... Are bonded to the dicing sheet 30 in which the adhesive 32 is laminated on the circular base sheet 31, and the heat-sensitive adhesive sheet 212 side is bonded to the adhesive 32. It is held by the ring frame 50 via the dicing sheet 30. For example, if the dicing sheet 30 is of an energy ray curable type having such a property that the adhesive 32 is cured by irradiating ultraviolet rays or the like and the adhesive strength is reduced, the dicing sheet 30 is easily peeled in a peeling step described later. Is preferred.

  The transport unit 12 includes an arm 121 and a single axis robot 122. The arm 121 is supported by the slider 123 of the single-axis robot 122 and includes gripping means (not shown). The arm 121 grips the ring frame portion of the wafer 2 with the ring frame in the storage cassette 112 and is stored by the single-axis robot 122. It is configured to be movable between the section 11 and the suction table 13. The transfer means is not limited to this, and may be, for example, a well-known transfer robot equipped with a telescopic articulated arm, and various known transfer means can be applied.

  The suction table 13 is made of a porous member, and suction means such as a vacuum pump (not shown) is connected via a hose and the like, and is configured to suck and hold the wafer 2 with a ring frame transported by the transport arm 121. (See FIG. 3). Further, the suction table 13 is configured to be movable between the peeling portion 14 and the pasting portion 15 along a pair of rails R when a motor (not shown) rotates the screw shaft N.

  The peeling unit 14 includes a peeling arm 141 and a single-axis robot 143 that connects the peeling arm and can move the peeling arm 141 in the directions of arrows A and B in FIG. As shown in FIG. 4, a peeling head 142 capable of gripping the peripheral edge of the dicing sheet 30 via an adhesive tape T is connected to the tip of the peeling arm 141. The single-axis robot 143 is configured such that the dicing sheet 30 is peeled from the wafer 2 with a ring frame by moving the peeling arm 141 in the direction of arrow A. Detailed explanation is omitted because it is substantially the same as Japanese Patent Application Laid-Open No. 11-16862 already filed by the same applicant. In addition, below this peeling part 14, it has the waste BOX which is not shown in figure, and is comprised so that the peeled dicing sheet 30 can be discarded.

  As shown in FIG. 5, the pasting unit 15 includes a known feeding unit 151 that feeds the pickup sheet 40, and a press roller 152 that sticks the pickup sheet 40 to the surface of the chip body 21 from which the dicing sheet 30 has been peeled off. ing. The press roller 152 is configured to be able to attach the pickup sheet 40 while pressing the tip body 21 and the ring frame 50 over the pickup sheet 40 as the suction table 13 moves in the direction of arrow C.

  The pickup sheet 40 is configured by laminating an adhesive 42 on a circular base sheet 41 having a smaller diameter than the outer diameter of the ring frame 50, and a plurality of sheets are temporarily attached to a long release sheet 43 and rolled. It is equipped in the feeding means 151 in a state wound in a shape. In addition, it is preferable to use a pickup sheet 40 having a smaller rigidity or a thinner thickness than the dicing sheet 30. In other words, the dicing sheet 30 is relatively thick so as not to be cut together with the wafer 20 at the time of dicing, and has a high rigidity so that the chip 211 does not move or break due to vibration at the time of dicing. The pickup sheet 40 is suitably thin and low in rigidity so that the tip body 21 can be pushed up by the push-up pin 80 at the time of pickup and can be appropriately transferred to the suction collet 70. For example, the rigidity of the dicing sheet 30 and the pickup sheet 40 can be measured with reference to tensile strength, elastic modulus, and the like. If the tensile strength is high or the elastic modulus (Young's modulus) is high, the rigidity increases.

  As the configuration of the feeding means 151, for example, the peeling sheet 43 temporarily attached with the pickup sheet 40 is fed using a drive motor, a driving roller, a pinch roller, and the like, while the fed peeling sheet 43 is peeled off by a peel plate 151A (FIG. 5), the pickup sheet 40 can be peeled off from the release sheet 43 and fed out by being turned up at an acute angle and taken up by a take-up roller. The detailed description is omitted because it is substantially the same as Japanese Patent Application Laid-Open No. 2005-116289 filed by the same applicant. In this embodiment, the pickup sheet 40 is formed in a circular shape in advance. However, the pickup sheet 40 may be formed in a long shape like the release sheet 43. In this case, the pickup sheet 40 is pasted. Thereafter, it may be cut into a circular shape by a cutter or the like. Note that the pickup sheet 40 may be an adhesive sheet having an adhesive force capable of adhering and holding the chip body 21 to the ring frame 50 until the pickup process. It is preferable that the adhesive 42 is cured by irradiating the adhesive and the like, and is composed of an energy ray curable adhesive sheet having a property of reducing the adhesive strength.

  Next, the operation of the re-placing apparatus and the re-placing method will be described with reference to FIGS. 3 to 5, and FIGS. 3 is a sectional view for explaining the operation of the suction table, FIG. 4 is a sectional view for explaining the operation of the peeling portion, and FIG. 5 is a sectional view for explaining the operation of the sticking portion.

  First, the wafer 2 with the ring frame is taken out from the storage cassette 112 by the arm 121 and placed on the suction table 13 that is waiting at a predetermined position so that the dicing sheet 30 faces upward (hereinafter, this position is referred to as “standby”). Referred to as position S1).

  Next, the suction table 13 sucks and holds the wafer 2 with the ring frame that has been transported, and then the suction table 13 is rotated along the rail R by a motor (not shown) to rotate the screw shaft N. It is conveyed to a predetermined position.

  In the peeling part 14, when the peeling head 142 is positioned at the peripheral edge of the dicing sheet 30, the peeling head 142 holds the dicing sheet 30 via the adhesive tape T as shown in FIG. When the suction table 13 is moved in the direction of arrow B while being moved in the direction, the dicing sheet 30 is peeled off, and the peeled dicing sheet 30 is discarded in a waste BOX (not shown). In the case of using an energy ray curable adhesive sheet, if the dicing sheet 30 is irradiated with energy rays such as ultraviolet rays before the peeling step, peeling is facilitated.

  Next, when the suction table 13 is moved to a predetermined position of the affixing portion 15, as shown in FIG. 5, in order to affix the pickup sheet 40 to the site where the dicing sheet 30 of the ring frame-equipped wafer 2 is peeled off. The feeding means 151 feeds the pickup sheet 40. When the suction table 13 moves in the direction of arrow C in synchronization with the feeding operation, the press roller 152 presses the chip body 21 and the ring frame 50, and the chip body 21 is moved to the heat-sensitive adhesive sheet 212 side and the ring frame 50. A pickup sheet 40 is pasted.

  After that, the wafer 2 with a ring frame attached to the pickup sheet 40 from the dicing sheet 30 is transported again to the standby position S1 while being placed on the suction table 13, and then the suction is released. Stored inside. After the wafer 2 with a ring frame thus attached to the pickup sheet 40 is transferred to the pickup process, the chip body 21 is picked up from the pickup sheet 40 by the method shown in FIG. It will be implemented in the frame.

  In the present embodiment, the plate-like member is the wafer 20, but for example, the plate-like member can be applied to a thin plate-like member such as a glass plate or a resin plate. In the present embodiment, the heat-sensitive adhesive sheet 212 is attached to the back side of the wafer 20 or the adhesive is applied. However, the adhesive sheet and the adhesive are not used. Applicable. Furthermore, although the dicing sheet 30 and the pickup sheet 40 in the present embodiment are configured such that the adhesive is laminated on the entire surface of the base material sheets 31 and 41, the adhesive needs to be laminated on the entire surface in this way. For example, when the heat-sensitive adhesive sheet 212 is affixed to the wafer 20, the adhesive may be laminated only on the affixed portion with the ring frame 50. The adhesive is not limited to a heat-sensitive adhesive, and a pressure-sensitive adhesive may be used.

  As described above, in the present embodiment, the dicing sheet 30 is peeled off in the wafer 2 with a ring frame in which the chip bodies 21, 21... And the dicing sheet 30 attached to the ring frame 50 are bonded. The pick-up sheet 40 is attached to the part where the dicing sheet 30 is peeled off. That is, the dicing sheet 30 is suitable for dicing, and the dicing sheet 30 suitable for dicing can be replaced with a pickup sheet 40 suitable for the pickup process before the pickup process. As a result, for example, the dicing sheet 30 having good dicing suitability can be replaced with a suitable pick-up sheet in the pick-up process, thereby eliminating pick-up failure due to chip cracking during dicing and push-up failure during pick-up. And the yield of non-defective semiconductor chips can be improved.

  In addition, when the dicing sheet 30 has a suitable rigidity and thickness that does not move due to chip cracking or vibration during dicing, the pickup sheet 40 is less rigid or thinner than the dicing sheet 30. Then, even during pick-up, pick-up failure due to push-up failure during pick-up can be eliminated, and good yield of semiconductor chips can be improved.

1 is a schematic top view showing a schematic configuration of a pasting apparatus according to the present invention. The schematic sectional drawing of a wafer with a ring frame. Operation | movement explanatory drawing sectional drawing of a suction table. Operation | movement explanatory sectional drawing of a peeling part. Operation | movement explanatory sectional drawing of a sticking part. (A) is operation | movement explanatory sectional drawing which shows the wafer individualization method, (b) is operation | movement explanatory sectional drawing of the pick-up process of a semiconductor chip.

Explanation of symbols

1 Pasting device 13 Suction table (holding means)
14 Peeling part (peeling means)
15 Sticking part (sticking means)
2 Wafer with ring frame 20 Wafer (plate member)
21 Chip body 212 Heat-sensitive adhesive sheet (adhesive)
30 Dicing sheet (first sheet)
40 Pickup sheet (second sheet)
50 ring frame

Claims (8)

It is a pasting device intended for what is formed by adhering the separated plate-like member and the first sheet stuck to the ring frame,
Holding means for holding the ring frame and the separated plate-like member;
Peeling means for peeling the first sheet;
A pasting device having pasting means for pasting the second sheet on the part where the first sheet is peeled off. 2. The rewriting device according to claim 1, wherein the separated plate-like member is bonded to the first sheet via an adhesive. 3. The rewriting device according to claim 1, wherein the second sheet has a smaller rigidity or a smaller thickness than the first sheet. The first sheet and the second sheet are:
It is an energy beam curing type adhesive sheet, The rewriting apparatus of any one of Claim 1 thru | or 3 characterized by the above-mentioned. The plate-like member is
It is a semiconductor wafer, The pasting apparatus of any one of Claim 1 thru | or 4 characterized by the above-mentioned. It is a renewal method intended for the one in which the separated plate-like member and the first sheet affixed to the ring frame are bonded,
Holding the ring frame and the separated plate-like member;
Peeling off the first sheet;
A pasting method, wherein the second sheet is pasted on a portion where the first sheet is peeled off. The replacement method according to claim 6, wherein the second sheet is less rigid or thinner than the first sheet. The plate-like member is
The replacement method according to claim 6, wherein the replacement method is a semiconductor wafer.

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