JP2007123549A - Protective-tape sticking device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protective-tape sticking device stabilizing a contact-bonding force to a semiconductor wafer of a protective tape for a prolonged term, and controlling the contact-bonding force. <P>SOLUTION: The protective-tape sticking device has: a protective-tape holder 7 and a wafer holder 5 which are disposed in a vacuum chamber 2, face each other with holding surface, and in which at least either of the holders 5, 7 moves forward and backward in the other's direction; and a drive 9 making at least either of these protective-tape holder and wafer holder move in the direction of the other's side, and contact-bonding the protective tape 6 held to the protective-tape holder to the semiconductor wafer 4 held to the wafer holder. The protective-tape sticking device further has: a load sensor 8 detecting the contact-bonding force worked between the semiconductor wafer and the protective tape by the drive; and a controller 10 controlling the drive in response to the result of the detection of the load sensor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a protective tape attaching device for attaching a protective tape to the surface of a semiconductor wafer or the like.

  In the manufacture of semiconductor devices, there is a step of grinding the back side of the wafer to a desired thickness after forming a device pattern on the surface of the semiconductor wafer. In this grinding process, a protective tape (also called a back grind tape) is applied in advance for the purpose of protecting the device surface formed on the wafer surface. With the conventional protective tape applicator, the protective tape cut to the shape and size suitable for the wafer outer shape at the protective tape cutting part can be moved from the protective tape cutting part to the tape attaching part with a vertical movement and swing mechanism. The suction tape is held by a suction table and placed directly on the semiconductor wafer positioned and supplied to the wafer mounting table having a cushioning property such as a spring. (See, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2001-148412 (first page, FIG. 1)

  In the conventional protective tape applying apparatus or method as described above, the pressure applied when attaching the protective tape and the semiconductor wafer is governed only by the spring force provided at the bottom of the wafer mounting table. As the number of sheets attached (the number of treatments) increases, the deterioration of the cushion material such as a spring proceeds, and the elastic force of the cushion material decreases. As a result, the pressure-bonding force of the protective tape to the semiconductor wafer is reduced with time, and there are problems such as tape peeling and easy penetration of an etching solution from the interface between the semiconductor wafer surface and the protective tape.

  The present invention has been made to solve the above-described problems of the prior art, and the crimping force acting between the protective tape and the semiconductor wafer at the time of application does not change over a long period of time, and the crimping force is controlled. It is an object of the present invention to provide a protective tape applying device that can be used.

  A protective tape attaching device according to the present invention is provided in a vacuum chamber, each holding surface is opposed to each other, and at least one of them can be advanced and retracted in the direction of the other, a wafer holding device, and these protective tapes A driving device capable of moving at least one of the holding device and the wafer holding device in the direction of the other side and pressing the protective tape held by the protective tape holding device onto the semiconductor wafer held by the wafer holding device; and A load sensor for detecting a pressure force applied between the semiconductor wafer and the protective tape by the driving device and a control device for controlling the driving device in accordance with a detection result of the load sensor are provided.

  According to the present invention, when the protective tape and the semiconductor wafer are crimped by controlling the driving device in accordance with a signal corresponding to the crimping force acting between the protective tape and the semiconductor wafer detected by the load sensor. Change of the pressure-bonding force with time can be eliminated, and the pressure-bonding force can be stably controlled at a desired value.

Embodiment 1 FIG.
1 to 3 illustrate a protective tape applying device according to Embodiment 1 of the present invention. FIG. 1 is a sectional view schematically showing the protective tape applying device, and FIG. 2 is a control by the control device shown in FIG. FIG. 3 is a characteristic diagram conceptually showing a change in pressure-bonding force with respect to the number of treatments by the protective tape applying apparatus shown in FIG. 1 in comparison with the conventional apparatus. In the figure, a protective tape affixing device 1 includes a vacuum chamber 2, a vacuum pump 3 that evacuates the vacuum chamber 2, a wafer holding device 5 that holds the semiconductor wafer 4 provided in the vacuum chamber 2, and protection Protective tape holding device 7 for holding the tape 6, a load sensor 8 for detecting the crimping force, a drive motor 9a for generating the crimping force, and a linear motion that converts the rotational force of the drive motor 9a into a linear motion in the vertical direction in the figure. Detection result of the load sensor 8 and the drive device 9 having the output shaft 9c that transmits the linear motion of the conversion device 9b and the linear motion conversion device 9b to the wafer holding device 5 through the bottom of the vacuum chamber 2 while maintaining airtightness. A control device 10 is provided for controlling the drive device 9 according to the above.

  The vacuum chamber 2 is disposed on the lower side of a tape application chamber 2a fixed to a fixing unit (not shown) and movably disposed above the tape application chamber 2a. The upper chamber 2b is closely fixed to the upper end surface of 2a. The wafer holding device 5 includes a movable stage 5a that can move up and down, and a wafer suction table 5c that is provided on the movable stage 5a via a cushion material 5b such as a spring. The semiconductor wafer 4 is sucked and held on the wafer suction table 5c by the wafer transfer means after the orientation of the orientation flat of the supplied semiconductor wafer is made uniform in a wafer positioning unit (not shown) provided separately. Is done.

  On the other hand, the protective tape holding device 7 includes a protective tape suction table 7a integrated into the upper chamber 2b. When the protective tape 6 is held, the protective tape holding device 7 moves to another position (not shown) together with the upper chamber 2b. A protective tape 6 cut in advance to a size corresponding to the outer shape of the semiconductor wafer 4 in a protective tape cutting part (not shown) provided separately is sucked and held on the protective tape suction table 7a, and then the tape pasting chamber 2a. It is configured to be positioned directly above the semiconductor wafer 4. The protective tape holding device 7 is held so as not to move in the vertical direction with respect to the pushing force from below the wafer holding device 5 (detailed illustration is omitted). Further, in this example, the linear motion conversion device 9b includes a ball screw 9d that is directly connected to the drive motor 9a and rotates, a central portion screwed into the ball screw 9d, and a side end portion that is a fixed portion such as a frame (details). (Not shown) is supported by a movable element 9e that is supported by the ball screw 9d so as to move up and down, for example, by forward rotation and descend by reversal.

  Of course, other methods such as a linear motor, an electromagnetic actuator, and a hydraulic actuator may be used as the driving device 9. If the driving source of the driving device 9 is a direct-acting type, the linear-acting conversion is performed. The device 9b is not necessary. The load sensor 8 is incorporated in a push-up portion 9f for pushing up the movable stage 5a provided at the tip of the output shaft 9c, and is interposed between the push-up portion 9f and the movable stage 5a. It is provided to detect the crimping force. In this example, a strain gauge type load cell that outputs a signal corresponding to the load is used, and the output signal is input to the control device 10, and the control device 10 supplies a pulse signal corresponding to the output signal to the drive motor 9a. The drive device 9 is controlled.

  Next, the operation of the first embodiment configured as described above will be described. First, in a protective tape cutting unit (not shown), the protective tape 6 cut to a size corresponding to the outer shape of the semiconductor wafer 4 is adsorbed to the tape adsorbing table 7a integrated with the upper chamber 2b by negative pressure. It moves on the tape application chamber 2a in a state. On the other hand, the semiconductor wafer 4 in which the orientation of the orientation flat is fixed in the wafer positioning unit (not shown) is sucked and held on the wafer suction table 5c by negative pressure by a wafer transfer means (not shown). Next, after the upper chamber 2b is lowered and the tape applying chamber 2a is sealed, the vacuum pump 3 is activated and the vacuum chamber 2 is evacuated.

  When the inside of the vacuum chamber 2 reaches a set desired vacuum pressure, the drive motor 9a operates to raise the movable stage 5a through the ball screw 9d, the linear motion conversion unit 9b, and the push-up unit 9f. A wafer suction table 5c connected to the movable stage 5a via a cushion material 5b raises the sucked semiconductor wafer 4 and presses the semiconductor wafer 4 to the upper protective tape 6 facing the wafer. On the other hand, the output signal of the load sensor 8 incorporated in the push-up portion 9f is always input to the control device 10, and the movable stage 5a pushes up until the crimping force reaches the set load according to the general flow conceptually shown in FIG. When the set load is reached, the number of pulses is controlled to be constant, and the ascent of the movable stage 5a is stopped. Hereinafter, a description will be given with reference to the flowchart of FIG.

  That is, in step S1, a load corresponding to the crimping force acting between the semiconductor wafer 4 and the protective tape 6 is detected from the output signal of the load sensor 8, and in step S2, it is determined whether it is within the set load range, and the set load is reached. If not (NO), the process proceeds to step S3, a predetermined signal for controlling the number of pulses of the drive motor 9a is transmitted to the drive motor 9a, and the drive motor 9a rotates in response to the signal in step S4. By this rotation, the ball screw 9d rotates and the mover 9e rises. As the mover 9e rises, the output shaft 9c pushes up the push-up portion 9f, so that the movable stage 5a rises (step S5). In this way, by controlling the number of pulses, the drive motor 9a is operated to crimp the semiconductor wafer 4 and the protective tape 3, and the movable stage 5a is raised until the crimping force reaches the set load.

  If it is determined in step S2 that the set load has been reached (YES), the process proceeds to step S6, where the drive motor 9a is stopped and held for a predetermined time, and then the crimping operation is completed. The cushion material 5b is interposed in order to transmit the load evenly to the semiconductor wafer 4. FIG. 3 conceptually shows the effect of the first embodiment of the present invention. The relationship between the number of treatments and the crimping force is indicated by a broken line, with the horizontal axis representing the number of treatments and the vertical axis representing the crimping force. In the case of “no crimping force control”, the elastic force of the cushioning material decreases as the number of treatments progresses due to deterioration of the cushioning material such as a spring, and the crimping force decreases. The case of “with crimping force control” of 1 indicates that the desired crimping force can be controlled to be constant regardless of the decrease in the elastic force of the cushion material 5b even if the number of processes is repeated.

  As described above, according to the first embodiment, since the pressure-bonding force at the time of applying the protective tape 6 to the semiconductor wafer 4 can be controlled to be constant, a change in the pressure-bonding force due to deterioration of the cushioning material can be suppressed, and the application conditions can be stabilized. Can be achieved. This also prevents the protective tape 6 affixed on the semiconductor wafer 4 from peeling off, and prevents the penetration of the chemical solution from the interface between the semiconductor wafer 4 surface and the protective tape 6. Further, since a strain gauge type load cell is used as the load sensor 8, the detected load can be converted into an electric signal, and the drive motor 9a is controlled by pulse control. Can do.

  In the first embodiment, the wafer holding device 5 provided on the lower side is moved up and down with respect to the protective tape holding device 7 disposed above. However, the present invention is not limited to this. It is not something. For example, it may be turned upside down. In short, it is only necessary that the respective holding surfaces are opposed to each other and at least one of them is disposed in the vacuum chamber 2 so as to advance and retract in the direction of the other party. Accordingly, the driving device 9 moves at least one of the protective tape holding device 7 and the wafer holding device 5 so as to advance and retreat in the direction of the other side, and the protective tape holding device is applied to the semiconductor wafer 4 held by the wafer holding device 5. What is necessary is just to be able to press-fit the protective tape 6 held by 7.

  The load sensor 8 is provided between the push-up portion 9f and the movable stage 5a. However, the load sensor 8 is not limited to this. For example, in the example of FIG. 1, for example, the protective tape suction table on the protective tape holding device 7 side. The protective tape holding device 7 is fixed above the output shaft 9c and the protective tape holding device 7 by interposing between the fixing member (not shown) that supports and fixes the protective tape suction table 7a. It may be provided at any location where the crimping force can be detected between the members. In addition, the types of the drive device 9 and the load sensor 8 and the control method of the control device 10 are not limited to those exemplified in the first embodiment, and various modifications and changes are possible within the spirit of the present invention. It is natural to be.

Sectional drawing which shows typically protective tape sticking by Embodiment 1 of this invention. The flowchart which shows the principal part of the example of control by the control apparatus shown in FIG. The characteristic view which shows notionally the change of the crimping force with respect to the number of processes by the protective tape sticking apparatus shown in FIG. 1 compared with the case of a conventional apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Protection tape sticking device, 2 Vacuum chamber, 2a Tape sticking chamber, 2b Upper chamber, 3 Vacuum pump, 4 Semiconductor wafer, 5 Wafer holding device, 5a Movable stage, 5b Cushion material, 5c Wafer adsorption table, 6 Protective tape, 7 Protective tape holding device, 7a Protective tape adsorption table, 8 load sensor, 9 drive device, 9a drive motor, 9b linear motion conversion device, 9c output shaft, 9d ball screw, 9e mover, 9f push-up unit, 10 control device.

Claims (4)

  A protective tape holding device and a wafer holding device which are arranged in a vacuum chamber and whose holding surfaces are opposed to each other, and at least one of which can advance and retreat in the direction of the other, and at least one of these protective tape holding device and wafer holding device. A driving device that moves in the opposite direction and presses the protective tape held by the protective tape holding device onto the semiconductor wafer held by the wafer holding device, and the driving device causes the semiconductor wafer and the protective tape to A protective tape affixing device comprising: a load sensor for detecting a pressing force acting between the load sensor; and a control device for controlling the driving device according to a detection result of the load sensor.   2. The protective tape applying apparatus according to claim 1, wherein the load sensor comprises a strain gauge type load cell interposed in at least one of the output shaft of the driving device and the protective tape holding device or the wafer holding device. .   The drive device includes a drive motor controlled by a pulse provided outside the vacuum chamber, a linear motion converter connected to the drive motor, and a linear motion converted by the linear motion converter. 3. The protective tape sticking apparatus according to claim 1, further comprising an output shaft that is passed through the bottom of the chamber in an airtight manner and is transmitted to the wafer holding device or the protective tape holding device. 4. The protective tape applying device according to claim 1, wherein the protective tape supplied to the protective tape holding device is cut in advance according to the shape of the semiconductor wafer. .

Images