JP4971869B2 - Adhesive film breaker - Google Patents

Description

  The present invention relates to an adhesive film breaking device for breaking and dividing a die bonding adhesive film mounted 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. Each of the divided semiconductor chips is mounted with a die bonding adhesive film called a die attach film having a thickness of 20 to 40 μm formed of epoxy resin or the like on the back surface, and the semiconductor chip is interposed through the adhesive film. Bonding is performed by heating to a die bonding frame that supports the substrate.

  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 an adhesive film is attached, the adhesive film is formed of a very flexible paste-like substance. Therefore, when the protective tape to which the adhesive film side is attached is expanded, the adhesive film also stretches. This makes it difficult to reliably break the adhesive film itself. Therefore, a rupture method is also attempted in which a cooling means for cooling the adhesive film is provided and the adhesive film is ruptured without being stretched by rupturing while cooling (see, for example, Patent Document 2).

Japanese Patent No. 3408805 JP 2007-27250 A

  However, the wafer is attached to the back side by sticking the back side to the adhesive film attached to the surface of the protective tape attached to the annular frame. When the attaching operation is performed by an automatic attaching machine, the outer diameter of the adhesive film is formed slightly larger (about several mm) than the outer diameter of the wafer in consideration of misalignment and the like. Thereby, in the sticking state of the adhesive film, a protruding portion in which a part of the adhesive film protrudes outside the wafer is generated. For this reason, when trying to break the adhesive film by expanding the protective tape while cooling the adhesive film, the protruding part of the adhesive film that protrudes outside the wafer is cooled and hardened, so that the protective tape is expanded simultaneously. The protruding part of the adhesive film is broken and peeled off, and it may get on the wafer or scatter around the wafer, causing a defective product on the semiconductor chip.

  The present invention has been made in view of the above, and in the case of an adhesive film having a protruding portion that protrudes outside the wafer, the breakage along the street is ensured by preventing scattering or the like due to the breaking at the protruding portion. An object of the present invention is to provide an adhesive film breaking device that can be used.

  In order to solve the above-described problems and achieve the object, the adhesive film breaking device according to the present invention has a plurality of streets formed in a lattice shape on the surface and a device in a plurality of regions partitioned by the plurality of streets. Attached to the back surface of the wafer formed with an adhesive film having a protruding portion with an outer diameter larger than the outer diameter of the wafer along the street in a state of being adhered to the surface of the protective tape attached to the annular frame An apparatus for breaking an adhesive film for breaking, comprising: a frame holding means having a holding surface for holding the frame; and a wafer to which a wafer in the protective tape attached to the frame held by the frame holding means is attached Wafer pressing means having a pressing surface acting on the sticking area, and the wafer pressing means below the holding surface Advancement / retraction means for moving from the retracted position to a pressing position above the holding surface, a casing surrounding the frame holding means, wafer pressing means, and advancement / retraction means, cooling means for cooling the inside of the casing, and the bonding And an annular gas jetting means disposed so as to cover the protruding portion of the film that protrudes outside the wafer.

  The adhesive film breaking device according to the present invention is basically capable of breaking along the street by cooling the inside of the housing with a cooling means and hardening the adhesive film in a cooled state to break it. At this time, the protruding portion that protrudes outside the wafer of the adhesive film is protected by allowing gas to be blown out by an annular gas blowing means and preventing the protruding portion from being cooled and hardened and maintained in a paste-like state. At the time of tape expansion, there is an effect that scattering due to breakage of the protruding portion can be prevented.

  Hereinafter, an embodiment of an adhesive film breaking device which is the best mode for carrying out the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing a configuration example of the adhesive film breaking device of the present embodiment, FIG. 2 is an exploded perspective view thereof, and FIG. 3 is a perspective view showing the gas blowing means upside down. 4 to 6 are longitudinal side views showing the adhesive film breaking step in the order of steps.

  First, an adhesive film or the like to be broken will be described with reference to FIG. The adhesive film 1 of the present embodiment is mounted on the back surface of a wafer 4 in which a plurality of streets 2 are formed in a lattice shape on the surface and devices 3 are formed in a plurality of regions partitioned by the plurality of streets 2. And used for die bonding. Here, the wafer 4 that has been divided along the street 2 through the deteriorated layer forming step and the wafer dividing step by irradiation with a pulsed 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 affixed on the adhesive film 1 affixed on the surface of the 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. Since the wafer 4 is attached to the adhesive film 1 using an automatic sticking machine, the outer diameter of the adhesive film 1 is slightly larger (a few millimeters) than the outer diameter of the wafer 4. In this state, the protruding portion 1a slightly protrudes outside the wafer 4 in a state where the wafer 4 is adhered. The protective tape 6 is made of a material having a lower freezing point than the adhesive film 1.

  Such a breaking device for the adhesive film 1 adhered to the back surface of the wafer 4 includes a frame holding means 10, a wafer pressing means 20, a frame restricting means 30, an advance / retreat means 40, a housing 50, and a cooling means. 60 and gas ejection means 70 are provided.

  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 holds the annular frame 5. 14 functions. In addition, below the four corners of the holding member 11, an air piston mechanism 15 that moves the holding member 11 up and down between a standby position and a breaking position is provided.

  Further, the wafer pressing means 20 is a circular pressing surface 21 that acts on the wafer attaching region where the wafer 4 is attached to the protective tape 6 attached to the frame 5 held on the holding surface 14 of the frame holding means 10. Have 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 extension auxiliary rollers 23 are used for reducing the frictional resistance generated when the wafer pressing means 20 is moved to the pressing position and expanding the protective tape 6 so that the tensile force acts equally.

  The advancing / retreating means 40 is connected to the lower side of the wafer pressing means 20 for moving the pressing surface 21 of the wafer pressing means 20 from a retracted position below the holding surface 14 to a pressing position above the holding surface 14. For example, the servo motor is used.

  The housing 50 surrounds the frame holding means 10, the wafer pressing means 20, and the advance / retreat means 40, and has a rectangular parallelepiped housing 51 and a box in which the upper opening of the housing 51 is closed by a hinge 52 so as to be opened and closed. It is for forming the cooling chamber 54 inside. Here, a shutter mechanism 55 for taking in and out the frame 5 and the like is provided in a part of the housing 51 so as to be freely opened and closed.

  The frame restricting means 30 is disposed between the housing 51 and the lid body 52, and the frame 5 placed on the holding surface 14 is held between the holding surface 14 by raising the frame holding means 10. This is formed in a rectangular plate shape, and has a circular opening 31 having a size equivalent to that of the opening 5a and the opening 13 at the center. The frame regulating means 30 includes a cooling gas introduction port 32 and a cooling gas discharge port 33.

  On the other hand, the cooling means 60 is for cooling the inside of the cooling chamber 53 to, for example, about 0 ° C., and connects the cooling gas supply means 61 and the cooling gas supply means 61 and the cooling gas inlet 32. A cooling gas supply pipe 62 and a cooling gas discharge pipe 63 connecting the cooling gas discharge port 33 and the cooling gas supply means 61 are provided.

  Further, the gas jetting means 70 is disposed so as to cover the protruding portion 1a protruding outside the wafer 4 of the adhesive film 1, and is formed so as to jet a gas of about 15 to 30 ° C. toward the protruding portion 1a. It consists of an annular body 71 and is disposed at a position around the opening 31 of the frame restricting means 30. Here, the gas ejection means 70 has a plurality of ejection nozzles 72 formed downward at an annular position corresponding to the position directly above the protruding portion 1a, and a gas introduction path 73 communicating with these ejection nozzles 72 therein. Have. The gas introduction path 73 is connected to a gas supply pipe (not shown) for connecting to an external gas supply means (not shown).

  In such a configuration, the breaking process of the adhesive film 1 will be described in the order of steps. First, as shown in FIG. 4, while the wafer pressing means 20 is lowered to the retracted position and the frame holding means 10 is lowered to the standby position, the shutter mechanism 55 is opened, and the adhesive film is formed on the protective tape 6. The frame 5 having the divided wafer 4 attached through 1 is introduced into a predetermined position on the holding surface 14.

  Next, as shown in FIG. 5, the frame 5 placed on the holding surface 14 is held by raising the frame holding means 10 to the breaking position by the air piston mechanism 15 with the shutter mechanism 55 closed. It is held between the surface 14 and the frame restricting means 30. In parallel with this operation, the advancing / retreating means 40 is operated to move the wafer pressing means 20 slowly upward toward the pressing position. In addition, the cooling gas is introduced into the housing 50 by the cooling means 60 to cool the inside of the cooling chamber 54 to about 0 ° C., and the gas jetting means 70 causes a gas 74 of about 15 to 30 ° C. to be discharged from the ejection nozzle 72. The adhesive film 1 is sprayed from above toward the protruding portion 1a.

  In this state, as shown in FIG. 6, the protective tape 6 is radially moved by slowly moving the position of the pressing surface 21 of the pressing means 20 to a pressing position higher than the position of the holding surface 14 by the advance / retreat means 40. To expand. That is, since the freezing point of the protective tape 6 is low, the protective tape 6 does not become hard even in an atmosphere of about 0 ° C., and expands radially by receiving a tensile force by the pressing surface 21 that is displaced upward. Thereby, a tensile force acts radially also on the adhesive film 1 stuck on the protective tape 6. At this time, most of the adhesive film 1 is in a cooling atmosphere by the cooling chamber 54, and in particular, when the portion corresponding to the street 2 of the divided wafer 4 is hardened by exposure and hardened, when receiving a tensile force It is surely broken along the street 2 without extending. On the other hand, even in the adhesive film 1, the protruding portion 1 a that protrudes from the wafer 4 is prevented from being cooled and hardened by the gas 74 of about 15 to 30 ° C. being ejected from the upper ejection nozzle 72. In order to maintain the paste-like state, even if a tensile force acts on the protruding portion 1 a via the protective tape 6, it extends in the same manner as the protective tape 6. Therefore, the protruding portion 1a portion becomes hard and breaks, and there is no problem of scattering around.

  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 present embodiment, for example, a case where a relatively thick and divided wafer 4 such as 50 μm or more is pasted on the adhesive film 1 and only the adhesive film 1 is broken is described as an example. For example, in the case of a relatively thin wafer such as 50 μm or less, the wafer is divided into wafers that have been subjected to the process of forming a deteriorated layer by irradiation with a pulsed laser beam and the like, and the wafer that has not been divided is attached to an adhesive film. The present invention can be similarly applied to the case where the adhesive film breakage and the adhesive film breakage are performed simultaneously.

It is a perspective view which shows the structural example of the adhesive film fracture | rupture apparatus of embodiment of this invention. FIG. 2 is an exploded perspective view of FIG. 1. It is a perspective view which turns over and shows a gas ejection means. It is a vertical side view which shows the initial stage process of an adhesive film fracture | rupture process. It is a vertical side view which shows the transient process of an adhesive film fracture | rupture process. It is a vertical side view which shows an adhesive film fracture | rupture process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Adhesive film 1a Overhang | projection part 2 Street 3 Device 4 Wafer 5 Frame 6 Protective tape 10 Frame holding means 14 Holding surface 20 Wafer pressing means 21 Pressing surface 40 Advancement / retraction means 50 Case 60 Cooling means 70 Gas ejection means

Claims (1)

A plurality of streets are formed in a lattice shape on the front surface, and a device is formed on a plurality of regions partitioned by the plurality of streets and attached to the back surface of the wafer, and has a protruding portion with an outer diameter larger than the outer diameter of the wafer. An adhesive film breaking device for breaking an adhesive film along the street in a state of being attached to the surface of a protective tape attached to an annular frame,
Frame holding means having a holding surface for holding the frame;
A wafer pressing means having a pressing surface acting on a wafer attaching region to which the wafer in the protective tape attached to the frame held by the frame holding means is attached;
Advancing / retreating means for moving the wafer pressing means from a retracted position below the holding surface to a pressing position above the holding surface;
A housing surrounding the frame holding means, wafer pressing means and advance / retreat means;
Cooling means for cooling the inside of the housing;
An annular gas jetting means disposed so as to cover the protruding portion of the adhesive film that protrudes outside the wafer;
An adhesive film breaking device comprising:

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