Apparatus of compressing tape

Abstract

(Problem) To provide a tape compression device that does not damage the wafer even when the tape of an annular frame with the tape attached is compressed against the back side of the wafer using a compression roller. (Solution) A tape compression device comprises an upper chamber, a lower chamber, a lifting mechanism for switching between a closed state in which the upper chamber is lowered to contact the lower chamber and an open state in which the upper chamber is separated from the lower chamber, a vacuum section for creating a vacuum in the upper chamber and the lower chamber in the closed state, and an atmospheric opening section for opening the upper chamber and the lower chamber to the atmosphere. The lower chamber accommodates a wafer table having a retaining surface that includes a circular concave portion that supports only the excess outer periphery of the wafer and keeps the device area non-contacted. The tape compression device comprises a positive pressure generating section that supplies air to the circular concave portion of the wafer table to create a positive pressure greater than the atmospheric pressure in the upper chamber and the lower chamber.

Description

Technology Field

[0001] The present invention relates to a tape compression device that compresses a tape, which is compressed on an annular frame having a central opening for receiving a wafer, onto the back surface of the wafer. Background Technology

[0002] A wafer having a device area partitioned by multiple streets where multiple devices such as ICs and LSIs intersect, and an outer surplus area surrounding the device area formed on its surface, is formed to a desired thickness by grinding the back surface, then divided into individual device chips by a dicing device and a laser processing device, and each divided device chip is used in electrical devices such as mobile phones and personal computers.

[0003] The applicant proposed a technique to facilitate the transport of a ground wafer by leaving a ring-shaped reinforcing member on the back surface corresponding to the outer surplus area, performing a predetermined processing, then supporting the wafer with an annular frame while pressing a dicing tape on the back surface of the wafer, and removing the ring-shaped reinforcing member from the wafer (see, for example, Patent Document 1).

[0004] However, in the technology disclosed in Patent Document 1, there was a problem that productivity was poor because it was difficult to compress a dicing tape onto the back side of a wafer having a ring-shaped reinforcing member formed on the outer circumference to form an integral with an annular frame, and it was also difficult to cut the ring-shaped reinforcing member and remove it from the wafer.

[0005] To solve this problem, it is possible to use a wafer table that supports the surface side of the wafer in the process of attaching a dicing tape to the back side of the wafer and integrating it with an annular frame. It is preferable that the wafer table has a circular concave portion formed therein that supports only the outer excess area and keeps the device area non-contacted so as not to damage the device area formed on the surface of the wafer. Prior art literature

[0006] Patent Document 1: Japanese Published Patent Application No. 2010-62375 The problem to be solved

[0007] However, in a configuration where only the outer surplus area on the surface side of the wafer is supported by a wafer table having a circular concave portion, and the tape of an annular frame with the tape attached is pressed against the back side of the wafer by a pressure roller, there is a problem that the wafer may be damaged.

[0008] Therefore, the objective of the present invention is to provide a tape compression device that does not damage the wafer even when the tape of an annular frame with the tape attached is compressed against the back surface of the wafer using a compression roller. means of solving the problem

[0009] According to the present invention, a tape compression device for compressing a tape compressed on an annular frame having a central opening for receiving a wafer onto the back surface of the wafer comprises: an upper chamber; a lower chamber receiving a wafer table having a retaining surface including a circular concave portion that supports only the outer surplus area of ​​the wafer and keeps the device area non-contact; a lifting mechanism for switching between a closed state in which the upper chamber is lowered to contact the lower chamber and an open state in which the upper chamber is separated from the lower chamber; a vacuum portion for creating a vacuum in the upper chamber and the lower chamber in the closed state; an atmospheric opening portion for opening the upper chamber and the lower chamber to the atmosphere; and a positive pressure generating means for supplying air to the circular concave portion of the wafer table to create a positive pressure inside the circular concave portion that is greater than the atmospheric pressure in the upper chamber and the lower chamber. In a state where the tape of the annular frame, having a tape attached to the back surface of the wafer supported on the wafer table, is positioned, the lifting mechanism is operated to create a vacuum in the upper chamber and the lower chamber while maintaining the closed state, and a pressure placed in the upper chamber A tape compression device is provided for compressing the tape of an annular frame, to which the tape is attached, onto the back surface of the wafer using a roller.

[0010] Preferably, when the compression roller compresses the wafer through the tape, the positive pressure generating means operates. A ring-shaped reinforcing member may be formed convexly on the back surface corresponding to the excess outer area of ​​the wafer. Effects of the invention

[0011] Since the tape compression device of the present invention includes a positive pressure generating means that supplies air to a circular concave portion of a wafer table to create a positive pressure greater than the air pressure of the upper chamber and the lower chamber, the wafer is not damaged even when the tape of an annular frame with the tape attached is compressed against the back surface of the wafer by a compression roller. Brief explanation of the drawing

[0012] FIG. 1 is a perspective view of a tape compression device of an embodiment of the present invention. FIG. 2 is an exploded perspective view of the tape crimping device shown in FIG. 1. FIG. 3 is a cross-sectional view of the tape compression device shown in FIG. 1. FIG. 4(a) is a perspective view of a wafer with a reinforcing member, and FIG. 4(b) is a perspective view of a wafer without a reinforcing member. FIG. 5 is a perspective view of an annular frame with tape attached. FIG. 6 is a schematic cross-sectional view illustrating the state of initiating compression of the tape. FIG. 7 is a schematic cross-sectional view illustrating the state in which the pressure of the tape has ended. Specific details for implementing the invention

[0013] Hereinafter, a tape compression device of an embodiment of the present invention will be described with reference to the drawings.

[0014] (Tape crimping device (2))

[0015] As illustrated in FIG. 1, the tape compression device (2) comprises an upper chamber (4), a lower chamber (6), a lifting mechanism (8) for switching between a closed state in which the upper chamber (4) is lowered to contact the lower chamber (6) and an open state in which the upper chamber (4) is separated from the lower chamber (6), a vacuum section (10) for creating a vacuum in the upper chamber (4) and the lower chamber (6) in the closed state, and an atmospheric opening section (12) for opening the upper chamber (4) and the lower chamber (6) to the atmosphere.

[0016] (Upper chamber (4))

[0017] The upper chamber (4) includes a circular ceiling plate (14) and a cylindrical side wall (16) that hangs down from the periphery of the ceiling plate (14), and the lower part of the side wall (16) is open. Referring to FIGS. 2 and 3, in the receiving space defined by the lower surface of the ceiling plate (14) and the inner circumference of the side wall (16), a pressure roller (18) for pressing a tape of an annular frame with a tape attached onto a wafer, a support piece (20) that rotatably supports the pressure roller (18), and an X-axis transfer mechanism (22) (see FIG. 2) that moves the support piece (20) in the X-axis direction indicated by the arrow (X) in FIG. 2 are arranged.

[0018] As shown in FIG. 2, the X-axis transfer mechanism (22) has a ball screw (24) connected to a support member (20) and extending in the X-axis direction, and a motor (26) that rotates the ball screw (24). The X-axis transfer mechanism (22) converts the rotational motion of the motor (26) into linear motion by the ball screw (24) and transmits it to the support member (20), and moves the pressure roller (18) together with the support member (20) along a pair of guide rails (28) extending in the X-axis direction.

[0019] (Lower chamber (6))

[0020] As illustrated in FIGS. 2 and 3, the lower chamber (6) has a cylindrical side wall (30). The upper part of the side wall (30) is open, and the lower part of the side wall (30) is closed. Inside the side wall (30), a wafer table (32) that holds a wafer and an annular frame is accommodated.

[0021] The wafer table (32) has a retaining surface (34) formed in a concave shape that retains only the outer surplus area of ​​the wafer and keeps the device area out of contact. The retaining surface (34) has an annular retaining part (36) that retains the outer surplus area of ​​the wafer and an annular frame, and a circular concave part (38) corresponding to the device area. A rubber ring (40) is arranged along the circumferential edge of the circular concave part (38) in the annular retaining part (36), and a plurality of suction holes (40a) are installed in the rubber ring (40) at intervals in the circumferential direction. Each suction hole (40a) is connected to a suction source (44) (see FIG. 2) through a flow path (42).

[0022] (lift mechanism (8), vacuum section (10), atmospheric opening section (12))

[0023] The lifting mechanism (8) may be composed of a suitable actuator, such as an air cylinder, mounted on the upper surface of the ceiling plate (14) of the upper chamber (4). The vacuum section (10) may be composed of a suitable vacuum pump. The vacuum section (10) is connected to the lower chamber (6) through a passage (46). Additionally, the passage (46) is equipped with an atmospheric opening (12) that includes a suitable valve capable of opening the passage (46) to the atmosphere.

[0024] (Positive pressure generating means (48))

[0025] Continuing the description with reference to FIGS. 2 and 3, the tape compression device (2) of the present embodiment includes a positive pressure generating means (48) that supplies air to a concave area (circular concave portion (38)) of a wafer table (32) to create a positive pressure greater than the air pressure of the upper chamber (4) and the lower chamber (6). The positive pressure generating means (48) has a supply hole (50) formed in the circular concave portion (38) and an air supply source (54) (see FIG. 2) connected to the supply hole (50) through a flow path (52).

[0026] (Wafer(W))

[0027] FIG. 4(a) illustrates a disc-shaped wafer (W) that is pressed onto a tape of an annular frame to which a tape is attached by a tape pressing device (2). The wafer (W) can be formed from a suitable semiconductor material such as silicon (Si) or silicon carbide (SiC). The surface (Wa) of the wafer (W) has a circular device area (Rd) and an outer surplus area (Rs) surrounding the device area (Rd). The device area (Rd) is divided into a plurality of rectangular areas by a grid-shaped street (S), and a device (D), such as an IC or LSI, is formed in each of the plurality of rectangular areas. Additionally, for convenience, the boundary (B) between the device area (Rd) and the outer surplus area (Rs) is shown as a dotted line, but in reality, there is no line indicating the boundary (B).

[0028] In the wafer (W) illustrated in FIG. 4(a), a ring-shaped reinforcing portion (R) is formed convexly on the back surface (Wb) corresponding to the outer periphery excess region (Rs). Because of this, the thickness of the outer periphery excess region (Rs) is greater than the thickness of the device region (Rd).

[0029] In addition, the wafer that is pressed onto the tape of the annular frame to which the tape is attached by the tape pressing device (2) may not have a ring-shaped reinforcing member installed on the back side (Wb'), as shown in the wafer (W') in FIG. 4(b). In addition, the following description mainly describes the case where the tape is pressed onto a wafer (W) having a reinforcing member (R).

[0030] (Annular frame with tape attached (FT))

[0031] FIG. 5 illustrates an annular frame (FT) to which a tape is attached to which the above-mentioned wafer (W) is compressed. The annular frame (FT) to which the tape is attached comprises an annular frame (F) having an opening (Fo) for receiving the wafer (W), and a circular adhesive tape (T) compressed on the annular frame (F).

[0032] Next, the operation of the tape compression device (2) as described above will be explained.

[0033] In this embodiment, first, the lifting mechanism (8) is operated to open the upper chamber (4) by separating it from the lower chamber (6). Next, as shown in FIG. 2, the wafer (W) is placed on the holding surface (34) of the wafer table (32) with the surface (Wa) on which the device (D) is formed facing downward.

[0034] When placing a wafer (W) on the holding surface (34), the outer excess region (Rs) of the wafer (W) is positioned on the rubber ring (40) of the annular holding portion (36), and the device region (Rd) of the wafer (W) is positioned on the circular concave portion (38). By doing so, even when placing the wafer (W) on the holding surface (34) of the wafer table (32) with the surface (Wa) on which the device (D) is formed facing downward, the device (D) in the device region (Rd) does not come into contact with the holding surface (34), thereby preventing damage to the device (D).

[0035] Next, the suction source (44) is operated to generate suction force in each suction hole (40a) of the rubber ring (40) to suction and maintain the excess area (Rs) on the outer edge of the wafer (W). At this time, the pressure in the suction hole (40a) can be, for example, an absolute pressure of about 100 Pa.

[0036] When a wafer (W) is held in place on a wafer table (32), an annular frame (FT) with tape attached is placed on the annular holding portion (36) of the wafer table (32) (see FIG. 2). At this time, the tape (T) of the annular frame (FT) with tape attached is positioned on the back surface (Wb) of the wafer (W) supported on the wafer table (32), and the adhesive surface of the tape (T) is positioned downward so that the adhesive surface of the tape (T) faces the back surface (Wb) of the wafer (W).

[0037] After placing the annular frame (FT) with the tape attached on the wafer table (32), the upper chamber (4) is lowered by the lifting mechanism (8) so that the lower end of the side wall (16) of the upper chamber (4) comes into contact with the upper end of the side wall (30) of the lower chamber (6) (see FIG. 3). By doing so, the upper chamber (4) and the lower chamber (6) are closed. Then, as shown in FIG. 6, the pressure roller (18) comes into contact with the annular frame (FT) with the tape attached, and the adhesive surface of the tape (T) comes into contact with the upper end of the reinforcing part (R) of the wafer (W).

[0038] Next, the vacuum unit (10) is operated with the atmosphere opening (12) closed to create a vacuum inside the upper and lower chambers (4, 6). However, the pressure inside the upper and lower chambers (4, 6) is made greater than the pressure in the suction hole (40a) (e.g., an absolute pressure of about 200 Pa). By doing this, the force for suctioning the wafer (W) is slightly weakened, but even if the inside of the upper and lower chambers (4, 6) is made a vacuum, the state of suctioning and maintaining the wafer (W) by the wafer table (32) can be maintained.

[0039] Next, as illustrated in FIGS. 6 and 7, a pressure roller (18) placed in the upper chamber (4) is rolled in the X-axis direction by an X-axis transfer mechanism (22) to press the tape (T) of the annular frame (FT) to which the tape is attached with the pressure roller (18) against the back surface (Wb) of the wafer (W). At this time, the wafer (W) is pressed downward through the tape (T) by the pressure roller (18). When this happens, only the outer excess region (Rs) of the wafer (W) is supported by the rubber ring (40) of the annular retainer (36), and since the device region (Rd) is located in the circular concave portion (38), the wafer (W) bends downward due to the pressure by the pressure roller (18), and there is a risk that the wafer (W) will be damaged.

[0040] However, the tape compression device (2) of the present embodiment is equipped with a positive pressure generating means (48) that supplies air to the circular concave portion (38) to create a positive pressure greater than the air pressure of the upper and lower chambers (4, 6), so that the wafer (W) can be prevented from being bent and damaged by the compression roller (18).

[0041] Specifically, when the wafer (W) is compressed through the tape (T) by the compression roller (18), the air supply source (54) of the positive pressure generating means (48) is activated to supply air to the circular concave portion (38) from the supply hole (50), and the circular concave portion (38) is made positive pressure from the air pressure of the upper and lower chambers (4, 6). At this time, the air pressure of the circular concave portion (38) is made slightly higher than the air pressure of the upper and lower chambers (4, 6) to the extent that the wafer (W) is prevented from bending due to the compression by the compression roller (18). For example, if the air pressure of the upper and lower chambers (4, 6) is approximately 200 Pa absolute pressure, the air pressure of the circular concave portion (38) should be approximately 300 Pa absolute pressure.

[0042] In this way, in the tape compression device (2) of the present embodiment, the circular concave portion (38) is made more positive than the upper and lower chambers (4, 6) by the positive pressure generating means (48), so when the wafer (W) is compressed through the tape (T) by the compression roller (18), the wafer (W) can be prevented from bending, and thus the wafer (W) can be prevented from being damaged.

[0043] When the tape (T) is pressed onto the wafer (W) with the pressure roller (18), if the inside of the upper and lower chambers (4, 6) is vacuumed, the suction force of the wafer (W) by the wafer table (32) is weakened as described above. However, in this embodiment, since the outer surplus area (Rs) of the wafer (W) is located on the rubber ring (40) of the annular holding part (36), when the tape (T) is pressed onto the wafer (W) with the pressure roller (18), the positional misalignment of the wafer (W) is prevented by the frictional force between the rubber ring (40) and the wafer (W).

[0044] In this embodiment, since a ring-shaped reinforcing member (R) is formed on the back side (Wb) of the wafer (W), even if the tape (T) is pressed against the back side (Wb) of the wafer (W) with a pressure roller (18), there may be a part where the tape (T) does not adhere to the bottom of the ring-shaped reinforcing member (R).

[0045] In this regard, in the present embodiment, the tape (T) is pressed onto the wafer (W) by the pressure roller (18) while the interior of the upper and lower chambers (4, 6) is under vacuum. Therefore, after moving the pressure roller (18), if the atmospheric opening (12) is opened, the tape (T) is compressed by atmospheric pressure and the tape (T) can be pressed against the wafer (W) along the bottom of the reinforcing part (R).

[0046] In addition, although the present embodiment describes the case where the tape (T) is an adhesive tape, the tape (T) may be a heat-press tape in which an adhesive layer is not attached to the sheet. The heat-press tape is a tape made of a thermoplastic synthetic resin (e.g., a polyolefin-based resin) and is a tape that softens or melts and exerts adhesive force when heated to a temperature near its melting point.

[0047] In the case where the tape (T) is a heat-pressed sheet, the tape (T) can be heat-pressed onto the back side (Wb) of the wafer (W) by the pressure roller (18) by heating at least one side of the pressure roller (18) or the wafer table (32) to a temperature at which the tape (T) softens or melts. Explanation of the symbols

[0048] 2: Tape crimping device 4: Upper chamber 6: Lower chamber 8: Elevator 10: Vacuum section 12: Atmosphere opening 18: Compression Roller 32: Wafer table 34: Yujimyeon 48: Means of generating positive pressure W: Wafer Wa: Surface of the wafer Wb: Back side of the wafer Rd: Device area Rs: Outsourcing surplus area R: Reinforcement part FT: Circular frame with tape attached F: Circular frame Fo: Opening T: Tape

Claims

Claim 1 A tape compression device for compressing a tape, which is compressed onto an annular frame having a central opening for receiving a wafer, onto the back surface of said wafer, comprising: an upper chamber; a lower chamber having a wafer table having a retaining surface that supports only the outer surplus area of ​​said wafer and keeps the device area non-contact; a lifting mechanism for switching between a closed state in which the upper chamber is lowered to contact the lower chamber and an open state in which the upper chamber is separated from the lower chamber; a vacuum section for creating a vacuum in the upper chamber and the lower chamber in the closed state; an atmospheric opening section for opening the upper chamber and the lower chamber to the atmosphere; and a positive pressure generating means for supplying air to the circular recess of said wafer table to create a positive pressure inside the circular recess that is greater than the atmospheric pressure in the upper chamber and the lower chamber; wherein, while the tape of the annular frame having the tape attached to the back surface of said wafer supported on said wafer table is positioned, the lifting mechanism is operated to create a vacuum in the upper chamber and the lower chamber while maintaining the closed state, and the compression roller disposed in said upper chamber A tape compression device configured to compress the tape of an annular frame to which the tape is attached onto the back surface of the wafer, and by operating the lifting mechanism to bring the compression roller into contact with the annular frame to which the tape is attached, and by rolling the compression roller to compress the tape of the annular frame to which the tape is attached onto the back surface of the wafer, when the compression roller compresses the wafer through the tape, the positive pressure generating means is operated. Claim 2 A tape compression device for compressing a tape, which is compressed onto an annular frame having a central opening for receiving a wafer, onto the back surface of said wafer, comprising: an upper chamber; a lower chamber having a wafer table having a retaining surface that supports only the outer surplus area of ​​said wafer and keeps the device area non-contact; a lifting mechanism for switching between a closed state in which the upper chamber is lowered to contact the lower chamber and an open state in which the upper chamber is separated from the lower chamber; a vacuum section for reducing the pressure of the upper chamber and the lower chamber in the closed state; an atmospheric opening section for opening the upper chamber and the lower chamber to the atmosphere; and a positive pressure generating means for supplying air to the circular surplus of said wafer table to make the pressure inside the circular surplus of said wafer table positive than the atmospheric pressure of said upper chamber and the lower chamber; wherein the retaining surface of said wafer table comprises a ring member arranged along the periphery edge of said circular surplus to suction and maintain the outer surplus area of ​​said wafer, and a tape of an annular frame having a tape attached to the back surface of said wafer supported on said wafer table A tape compression device that, while in a positioned state, operates the lifting mechanism to maintain the closed state and reduces the pressure in the upper chamber and the lower chamber to a level where the suction state of the wafer by the ring member is maintained, and compresses the tape of the annular frame to which the tape is attached with a compression roller disposed in the upper chamber onto the back surface of the wafer. Claim 3 A tape compression device according to paragraph 2, wherein the positive pressure generating means operates when the compression roller compresses the wafer through the tape. Claim 4 A tape compression device according to claim 1 or 2, wherein a ring-shaped reinforcing portion is formed convexly on the back surface corresponding to the outer surplus area of ​​the wafer. Claim 5 In paragraph 2, the above-mentioned ring member is made of rubber, tape compression device.

Images