JP2010027666A - Fracturing method and fracturing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To expand a protective tape by fracturing a filmy adhesive without large damage of a device and a protective tape. <P>SOLUTION: A series of processes from fracturing of the filmy adhesive 1 to expansion of the protective tape 6 are divided into a process of fracturing the filmy adhesive 1 and a process of expanding the protective tape 6, wherein the relative moving speed of a frame holding means 10 and an expanding means 20 is different between both the processes such that although the frame holding means and expanding means are moved at a first fast speed V1 in the fracturing process to give all streets 2 a cue to fracture, they are moved at a second speed V2 slower than the first speed V1 in the expanding process after the tentative fracturing, thereby giving large damage to neither the device 3 nor the protective tape 6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a breaking method and a breaking device for breaking and dividing a film adhesive stuck on the back surface of a wafer along a street.

  In the semiconductor device manufacturing process, a plurality of regions are partitioned by dividing lines called streets arranged in a grid on the surface of a substantially disk-shaped semiconductor wafer, and ICs, LSIs, etc. are partitioned in the partitioned regions. Form the device. Each semiconductor chip (device) is manufactured by dividing the region in which the device is formed by cutting the semiconductor wafer along the division line. Individually divided semiconductor chips are bonded to a film adhesive for die bonding called a die attach film (DAF) having a thickness of 20 to 40 μm formed of epoxy resin or the like on the back surface thereof. Bonding is performed by heating to a die bonding frame that supports the semiconductor chip via an adhesive.

  On the other hand, as a method for dividing a plate-like workpiece such as a semiconductor wafer, in recent years, a condensing point is used inside a region to be divided by using a pulsed laser beam having transparency to the workpiece. A laser processing method for irradiating a pulsed laser beam in combination is tried. A dividing method using this laser processing method is, for example, as shown in Patent Document 1, an infrared having a condensing point from one side of a workpiece to the inside and having transparency to the workpiece. Irradiate a pulse laser beam in the optical region to continuously form a deteriorated layer along the planned dividing line inside the workpiece, and along the planned dividing line whose strength has been reduced by the formation of this modified layer. The workpiece is divided by applying an external force.

  Here, in the case of a semiconductor wafer to which a film-like adhesive is applied, the film-like adhesive is formed of a very soft paste-like substance. Therefore, when the protective tape to which the film-like adhesive is attached is expanded, It also becomes difficult for the film-like adhesive itself to break and the film-like adhesive itself to be reliably broken. Therefore, a rupture method is also attempted in which a cooling means for cooling the film adhesive is provided, and the film adhesive is broken without being stretched by being ruptured while being cooled (see, for example, Patent Document 2). ). By carrying out breakage while cooling in this way, the film adhesive came to break without being stretched.

Japanese Patent No. 3408805 JP 2007-27250 A

  However, the standby position in which the expansion means that acts on the wafer attachment region of the protective tape attached to the opening of the annular frame and expands the protective tape and the frame holding means that holds the annular frame on the holding surface are separated from each other. If the film adhesive is broken at a relatively high speed to break the film adhesive and the protective tape between the chips is expanded, the chip (device) and the protective tape are seriously damaged.

  The present invention has been made in view of the above, and provides a breaking method and a breaking device capable of breaking a film adhesive and expanding the protective tape without causing significant damage to the device or the protective tape. With the goal.

  In order to solve the above-described problems and achieve the object, the breaking method according to the present invention includes a film-like adhesive that is attached to the back surface of a wafer in which a plurality of devices are formed in a matrix shape, and an opening portion of an annular frame. A method of breaking along a street partitioning the device in a state of being stuck on a stretchable protective tape attached to the device, and holding the annular frame on a holding surface of a frame holding means And the film adhesive breaks from a standby position spaced apart from each other between the frame holding means and the expansion means for expanding the protective tape by acting on the wafer attaching region of the protective tape attached to the annular frame. A rupturing step of relatively moving to a rupture position at a first speed, the frame holding means and the expansion means from the rupture position. Expanded position whose serial protective tape is desired amount extended along the street, characterized in that it comprises a, and extended step of relatively moving in the slower than the first speed the second speed.

  Moreover, the breaking method according to the present invention is the above invention, wherein the first speed of the breaking step is a high speed of 200 to 500 mm / s, and the second speed of the expanding step is 50 mm / s or less. It is characterized by a low speed.

  Further, the breaking device according to the present invention has a film-like adhesive affixed to the back surface of a wafer in which a plurality of devices are formed in a matrix shape on a stretchable protective tape attached to an opening of an annular frame. A tearing device that breaks along a street that divides the device in a state of being attached, a frame holding means having a holding surface for holding the annular frame, and a stand-by that is separated from the frame holding means An expansion means which is provided so as to be relatively movable from a position to an extended position intersecting each other, and which acts on a wafer sticking area of the protective tape mounted on the annular frame, and expands the protective tape; and the frame holding means Expansion movement means for relatively moving the expansion means, the frame holding means holding the annular frame, and the expansion means The extended position in which the protective tape is relatively moved at a first speed from the standby position to a break position where the film adhesive is broken, and the protective tape is expanded along the street from the break position by a desired amount. And a control means for controlling the operation of the expansion movement means so as to move relatively at a second speed slower than the first speed.

  According to the breaking method and breaking device according to the present invention, a series of steps from breaking the film adhesive and expanding the protective tape is divided into a step of breaking the film adhesive and a step of expanding the protective tape. In both steps, the frame holding means and the expanding means are moved at different speeds, and at the time of the breaking process, the entire street is moved at a high speed to give a trigger for breaking, but once broken. By moving at a second speed, which is slower than the first speed, during the subsequent expansion process, the film-like adhesive is broken and the protective tape is expanded without damaging the device or the protective tape. There is an effect that can be.

  Hereinafter, embodiments of a breaking method and a breaking device which are the best modes for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 is an exploded perspective view showing a configuration example of a film adhesive breaking device according to the present embodiment, and FIG. 2 is a partial vertical side view thereof. c) is a longitudinal side view showing the steps of the breaking process of the film adhesive in the order of steps, and FIG. 4 is an explanatory view showing a change example of the moving speed at the breaking step and at the expanding step.

  First, with reference to FIG. 1, the film adhesive etc. used as the fracture | rupture object are demonstrated. The film adhesive 1 of the present embodiment is formed on the back surface of a wafer 4 in which a plurality of streets 2 are formed in a lattice pattern on the surface and devices 3 are formed in a plurality of regions partitioned by the plurality of streets 2. It is affixed and used for die bonding. That is, it is a die attach film (DAF) having a thickness of 20 to 40 μm formed of an epoxy resin or the like. Here, as the wafer 4 of the present embodiment, a wafer that has been divided along the street 2 through a deteriorated layer forming step and a wafer dividing step by irradiation with a pulse laser beam or the like is used. Such a deteriorated layer forming step and the like are known in, for example, Patent Document 1 and the like, and thus detailed description thereof is omitted. And such a wafer 4 is stuck on the film adhesive 1 stuck on the surface of the elastic protective tape 6 with which the outer peripheral part was mounted | worn so that the opening part 5a of the cyclic | annular frame 5 might be covered. The

  Such a breaking device for the film adhesive 1 affixed to the back surface of the wafer 4 includes a frame holding means 10, an expansion means 20, a frame restricting means 30, an expansion moving means 40, and a control means 50. .

  The frame holding means 10 includes a rectangular plate-like holding member 11 made of, for example, SUS. Here, the holding member 11 includes an opening 13 having an inner diameter substantially equal to the inner diameter of the opening 5 a of the annular frame 5 at the center, and the upper surface around the opening 13 serves as a holding surface 14 that holds the annular frame 5. Function. An air piston mechanism 15 that moves the holding member 11 up and down is provided below the four corners of the holding member 11.

  Further, the expansion means 20 has a circular pressing surface 21 that acts on the wafer sticking area to which the wafer 4 is stuck on the protective tape 6 attached to the annular frame 5 held on the holding face 14 of the frame holding means 10. . The pressing surface 21 is formed with a radius smaller than the inner diameter of the opening 13 and can move up and down in the opening 13. Here, an annular groove 22 is formed in the outer peripheral portion of the pressing surface 21, and a plurality of auxiliary expansion rollers 23 are rotatably disposed along the annular groove 22. These expansion auxiliary rollers 23 are for reducing the frictional resistance generated when the expansion means 20 is moved to the expansion position to expand the protective tape 6 and to apply the tensile force evenly.

  The expansion movement means 40 is connected to the lower side of the expansion means 20, passes through the holding surface 14 from a standby position where the pressing surface 21 of the expansion means 20 is spaced below the holding surface 14, and is located above the holding surface 14. For moving to the extended position, for example, a servo motor is used. That is, the expansion movement means 40 moves the expansion means 20 provided so as to be movable up and down from a standby position separated from the frame holding means 10 to an expansion position that intersects with each other. The control means 50 is composed of, for example, a microcomputer, and controls the operation of the expansion moving means 40 as described later when the film adhesive 1 is broken.

  Further, the frame restricting means 30 is for holding the annular frame 5 placed on the holding surface 14 with the holding surface 14 by raising the frame holding means 10, and is formed in a rectangular plate shape. A circular opening 31 having a size equivalent to that of the opening 5a and the opening 13 is provided at the center.

  In such a configuration, the breaking process of the film adhesive 1 will be described in the order of steps. First, as shown in FIG. 2, while the expansion means 20 is lowered to the standby position and the frame holding means 10 is lowered to the standby position, a shutter mechanism (not shown) is opened to form a film on the protective tape 6. The annular frame 5 having the divided wafers 4 attached via the adhesive 1 is introduced into a predetermined position on the holding surface 14.

  Next, as shown in FIG. 3A, the annular frame 5 placed on the holding surface 14 is held by raising the frame holding means 10 to a position where it abuts against the frame regulating means 30 by the air piston mechanism 15. It is held between the surface 14 and the frame restricting means 30 (holding process).

  Further, as shown in FIG. 3 (b), the film-like adhesive 1 is moved along the street 2 by moving the expansion means 20 upward from the standby position to the breaking position slightly beyond the holding surface 14 by the expansion movement means 40. To break (breaking process). In this breaking process, the control means 50 controls the expansion moving means 40 to raise the expansion means 20 while accelerating the moving speed, as shown in FIG. At the contact position in contact with the protective tape 6, for example, the first high speed of V1 = 200 mm / s is reached, and the expansion means 20 is moved to the breaking position at the first speed V1. At this time, since the entire outer periphery of the protective tape 6 that receives the pressurization of the pressing surface 21 is attached to the annular frame 5 that is fixed, the tensile force accompanying the pressurization of the pressing surface 21 acts radially. Thereby, a tensile force acts on the film adhesive 1 stuck on the protective tape 6 radially. At this time, since the radial tensile force acts by the upward movement at the high first speed V1, the film-like adhesive 1 is equally given the trigger of breaking to the all streets 2, and the film-like adhesive. 1 leads to breaking along the street 2.

  After the film adhesive 1 is broken, as shown in FIG. 3C, the expansion means 20 is moved upward from the fracture position to the desired expansion position by the expansion movement means 40, whereby the film adhesive 1 The protective tape 6 is expanded along the street 2 by a desired amount so as to be separated from each other (expansion step). In this expansion step, the control means 50 controls the expansion movement means 40 to decelerate the movement speed from the first high speed V1 at the time of breakage as shown in FIG. The expansion means 20 is raised at a sufficiently slow speed, for example, a low second speed V2 = 30 mm / s. In the vicinity of the expansion position, the expansion operation is stopped by setting the second speed to V2 = 0 mm / s.

  Thus, according to the present embodiment, a series of steps until the film adhesive 1 is broken and the protective tape 6 is expanded is divided into a step of breaking the film adhesive 1 and a step of expanding the protective tape 6. In both processes, the relative movement speeds of the frame holding means 10 and the expansion means 20 are made different, and the expansion means 20 is used as a first high-speed to give a trigger for the break to all the streets 2 during the break process. Although it is moved at the speed V1, the device 3 and the protective tape 6 are seriously damaged by moving at the second speed V2 that is sufficiently lower than the first speed V1 during the expansion process after being broken once. Without breaking, the film adhesive 1 can be broken and the protective tape 6 can be expanded. At this time, since the expansion process of the protective tape 6 is performed at the sufficiently low second speed V2, there is no problem that only the outer peripheral portion that is easily stretched as in the case of the high speed does not occur, and the expansion assistance. The rotation of the roller 23 also follows, and the protective tape 6 between all the streets 2 can be expanded evenly by applying a tensile force evenly. As a result, the processing efficiency is also improved.

  In this embodiment, the example of V1 = 200 mm / s and V2 = 30 mm / s has been described. However, according to the experiments by the inventors, the first speed V1 for breaking the film adhesive 1 is obtained. Is preferably about 200 to 500 mm / s, more preferably about 200 to 400 mm / s, and the second speed V2 for expanding the protective tape 6 is preferably 50 mm / s or less, and more Preferably it was 30 mm / s or less.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the expansion process, as shown in FIG. 5, the moving speed of the expansion means 20 is once decreased from the first speed V1 to 0 and then increased to a desired second speed V2. You may make it move. The first speed and the second speed are not necessarily constant speeds, and may include acceleration / deceleration within a predetermined speed range. FIG. 6 shows an example in which the expansion means 20 is moved using a second speed that is lower than the first speed by decelerating at a constant ratio during the expansion process.

  In the present embodiment, the expansion moving means 40 that moves the expansion means 20 up and down relative to the frame holding means 10 is used. However, the expansion movement means that moves the frame holding means 10 side up and down relative to the expansion means 20 is used. The breakage step and the expansion step may be sequentially performed as the frame holding means 10 is lowered.

  Moreover, while using the protective tape 6 which consists of a material with a freezing point lower than the film adhesive 1, as shown by patent document 2 etc., it is equipped with the cooling means to cool the film adhesive 1, and a fracture | rupture process, cooling By performing the expansion process, the film adhesive 1 may be broken without being stretched.

  Furthermore, in the present embodiment, for example, a relatively thick and divided wafer 4 such as 50 μm or more is stuck on the film adhesive 1 and only the film adhesive 1 is broken. For example, in the case of a relatively thin wafer of 50 μm or less, the deteriorated layer forming step by irradiation with a pulse laser beam or the like is completed, and the wafer undivided wafer is pasted on the film adhesive The same can be applied to the case where the wafer division and the film adhesive breakage are simultaneously performed.

It is a disassembled perspective view which shows the structural example of the fracture | rupture apparatus of the film adhesive of embodiment of this invention. FIG. 2 is a partial vertical side view of FIG. 1. It is a vertical side view which shows the process of the fracture | rupture process of a film adhesive in order of a process. It is explanatory drawing which shows the example of a change of the moving speed at the time of a fracture | rupture process and an expansion process. It is explanatory drawing which shows the modification of the example of a change of the moving speed at the time of a fracture | rupture process and an expansion process. It is explanatory drawing which shows another modification of the example of a change of the moving speed at the time of a fracture | rupture process and an expansion process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Film adhesive 2 Street 3 Device 4 Wafer 5 Ring frame 5a Opening 6 Protection tape 10 Frame holding means 14 Holding surface 20 Expansion means 40 Expansion movement means 50 Control means

Claims (3)

The device is partitioned in a state in which a film-like adhesive attached to the back surface of a wafer in which a plurality of devices are formed in a matrix is attached onto a protective tape having elasticity that is attached to an opening of an annular frame. A breaking method that breaks along the street
Holding the annular frame on the holding surface of the frame holding means; and
The film adhesive is ruptured from a standby position where the frame holding means and the expansion means for expanding the protective tape by acting on the wafer attaching region of the protective tape attached to the annular frame are separated from each other. A breaking step of relatively moving to a breaking position at a first speed;
The frame holding means and the expansion means are relatively moved from the break position to an expansion position where the protective tape is expanded by a desired amount along the street at a second speed that is slower than the first speed. Expansion process,
The breaking method characterized by including.   The said 1st speed of the said fracture | rupture process is 200-500 mm / s high speed, The said 2nd speed of the said expansion process is a low speed of 50 mm / s or less. Breaking method. The device is partitioned in a state in which a film-like adhesive attached to the back surface of a wafer in which a plurality of devices are formed in a matrix is attached onto a protective tape having elasticity that is attached to an opening of an annular frame. A breaking device for breaking along a street
Frame holding means having a holding surface for holding the annular frame;
The frame holding means is provided so as to be relatively movable from a standby position separated from each other to an extended position intersecting with each other, and acts on a wafer sticking area of the protective tape attached to the annular frame to protect the frame. Expansion means for expanding the tape;
Expansion moving means for relatively moving the frame holding means and the expansion means;
The frame holding means holding the annular frame and the expansion means are moved relative to each other at a first speed from the standby position to a breaking position where the film adhesive is broken, and from the breaking position, Control means for controlling the operation of the expansion movement means to move relative to the expansion position where the protective tape is expanded along the street by a desired amount at a second speed slower than the first speed;
A breaking apparatus comprising:

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