JP2006237504A - Semiconductor chip stripper and process for manufacturing semiconductor device employing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a semiconductor chip from cracking when it is picked up. <P>SOLUTION: When a semiconductor chip 15 stuck to a sheet 12 is picked up, only a sheet 12 where the semiconductor chip 15 being picked up is located is irradiated intensively with UV-rays. More specifically, UV-rays are irradiated from a push-up collet 16 located below the semiconductor chip 15. Consequently, only the semiconductor chip 15 being picked up can be stripped surely from the sheet 12. Furthermore, other semiconductor chips 15 not to be picked up can be sustained in a state stuck to the sheet 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor chip peeling apparatus and a semiconductor device manufacturing method using the same, and more particularly to a semiconductor chip peeling apparatus that facilitates peeling of a semiconductor chip from a sheet and a semiconductor device manufacturing method using the same. .

  In the process of manufacturing a semiconductor device, individual semiconductor chips are obtained by separating the semiconductor wafer that has undergone the semiconductor pre-process by dicing or the like. In the dicing process, the semiconductor wafer is separated into individual semiconductor chips while being attached to the sheet provided with the adhesive material. Therefore, in order to use the semiconductor chips separated in this way, the individual semiconductor chips must be peeled from the sheet.

  A general method for peeling the semiconductor chip 101 from the sheet 100 will be described with reference to FIG. 6 (see Patent Document 1 below).

  Referring to FIG. 6A, first, a semiconductor wafer 101 is bonded to the surface of a sheet 101 by dicing the semiconductor wafer. The tip of the holder 102 is in contact with the lower surface of the sheet 100 where the semiconductor chip 101 to be picked up is located. The holder 102 has a pin 102A built therein so as to be movable up and down.

  Next, referring to FIG. 6B, the back surface of the semiconductor chip 101 is peeled off from the surface of the sheet 100 by raising the pins 102 </ b> A built in the holder 102. By locally pushing up the sheet 100 with the pins 102 </ b> A, the back surface of the semiconductor chip 101 in the region excluding the place where the pins 102 </ b> A come into contact is forcibly separated from the surface of the sheet 100.

  Next, referring to FIG. 6C, the suction collet 103 is brought into contact with the surface of the semiconductor chip 101 pushed up by the pins 102A. Then, by applying a suction force to the collet 103, the semiconductor chip 101 is peeled off from the sheet 100 and transported.

The semiconductor chip 101 separated by the above-described processes is completed as a package through a bonding process, an encapsulation process, and the like.
Japanese Patent Laid-Open No. 11-312695

  However, the semiconductor chip peeling method described above has a problem that cracks are generated in the semiconductor chip.

  Specifically, along with reduction of on-resistance and downsizing of electronic devices, semiconductor chips are also required to be downsized and thinned. For example, semiconductor chips having a thickness of about 50 μm have appeared. Such a thin semiconductor chip is weak in mechanical strength of the chip itself, so that when it is pushed up by the pins 102A, it bends following the sheet 100 and cracks occur.

  Further, when a sheet (UV sheet) whose surface adhesiveness is reduced by irradiating light such as ultraviolet rays, the semiconductor chip 101 can be peeled from the sheet 100 without being pushed up by a pin. However, when a UV sheet is used, the entire sheet 100 is irradiated with ultraviolet rays. Accordingly, when the entire sheet 100 is irradiated with ultraviolet rays, all the semiconductor chips 101 are separated from the surface of the sheet 100, which makes it difficult to store the remaining semiconductor chips that are not adsorbed by the adsorption collet 103.

  The present invention has been made in view of the above problems. An object of the present invention is to provide a semiconductor chip peeling apparatus that efficiently peels a semiconductor chip from a sheet, and a method of manufacturing a semiconductor device using the semiconductor chip peeling apparatus.

  The semiconductor chip peeling apparatus of the present invention is a semiconductor chip peeling apparatus for peeling a semiconductor chip attached to the surface of a sheet, and partially on the sheet in a region where the semiconductor chip to be picked up is located. It is characterized by comprising irradiation means for irradiating light to locally reduce the adhesive strength of the sheet and peeling means for adsorbing the upper surface of the semiconductor chip and peeling it from the sheet.

  Furthermore, the semiconductor chip peeling apparatus of the present invention is characterized in that the light is ultraviolet light.

  Furthermore, the semiconductor chip peeling apparatus of the present invention is characterized in that the irradiating means irradiates the light in contact with the back surface of the sheet.

  The method of manufacturing a semiconductor device according to the present invention is the method of manufacturing a semiconductor device including a step of peeling the semiconductor chip attached to the surface of the sheet, and the sheet in the region where the semiconductor chip to be picked up is located. In addition, the semiconductor chip is adsorbed and peeled from the sheet by locally irradiating light to locally reduce the adhesive strength of the sheet.

  Furthermore, the semiconductor device manufacturing method of the present invention is characterized in that the light is irradiated onto the sheet before the semiconductor chip is sucked.

  According to the semiconductor chip peeling apparatus of the present invention and the method of manufacturing a semiconductor device using the semiconductor chip peeling apparatus, even when a thin semiconductor chip having a thickness of about several tens of μm is peeled from a sheet, the generation of cracks in the semiconductor chip is prevented. can do. Specifically, only the region where the semiconductor chip to be picked up is located is irradiated with light to locally reduce the adhesive strength of the sheet. Accordingly, since the adhesive strength of the sheet is reliably reduced locally, the semiconductor chip can be reliably peeled from the sheet without generating a crack in the semiconductor chip.

  Further, other semiconductor chips that are not picked up remain stuck to the surface of the sheet. Accordingly, other semiconductor chips that are not picked up do not move from the surface of the sheet, and can be stored as they are.

  The present embodiment will be described with reference to FIGS.

  With reference to FIG. 1, the sheet | seat 12 with which many semiconductor chips 15 were affixed first is demonstrated. 1A is a plan view of a sheet 12 to which a wafer 10 is attached, FIG. 1B is a cross-sectional view thereof, and FIG. 1C is an enlarged cross-sectional view.

  Referring to FIGS. 1A and 1B, a semiconductor wafer 10 having a large number of electric circuits formed in a matrix on the surface in a diffusion process is attached to the surface of a sheet 12. Here, the sheet 12 is affixed to the wafer ring 13 in a state where the sheet 12 is stretched so as not to be slack.

  The wafer 10 is diced along the dicing lines 11 located at the boundaries of the respective circuits while being bonded to the sheet 12. As a result, an individual semiconductor chip is obtained. Here, the surface of the wafer 10 opposite to the surface on which the electric circuit is formed is attached to the sheet 12.

  With reference to FIG. 1C, a semiconductor chip 15 is attached to the surface of the sheet 12 via an adhesive layer 14. The sheet 12 is made of a transparent resin that transmits ultraviolet rays. Specifically, acrylic, ABS, or the like can be used. The adhesive layer 14 is made of an adhesive whose adhesive strength is reduced by absorbing ultraviolet rays.

  Next, with reference to FIG. 2 and FIG. 3, the process of picking up a semiconductor chip will be described.

  Referring to FIG. 2A, first, a push-up collet 16 is positioned below the semiconductor chip 15 to be picked up. Here, the push-up collet 16 is disposed below the semiconductor chip 15 to be picked up by moving either the push-up collet 16 or the sheet 12 in a plane. At this time, ultraviolet light may be irradiated from the push-up collet 16. As a result, the adhesive force of the adhesive layer 14 under the semiconductor chip 15 can be reduced at an early stage, so that pickup can be immediately performed in a later process.

  FIG. 2B is a perspective view showing the push-up collet 16. In this embodiment, the push-up collet 16 functions as an irradiation unit. With reference to this figure, the push-up collet 16 used in this embodiment will be described. The push-up collet 16 has a configuration in which the transmission layer 16B is covered with the coating layer 16A, and the transmission layer 16B is exposed from the upper surface. The transmissive layer 16B is made of, for example, a glass fiber and a material that transmits ultraviolet rays. The covering layer 16A is made of a light-shielding resin that does not transmit ultraviolet rays.

  The planar size of the transmissive layer 16 </ b> B exposed at the top is equivalent to that of one semiconductor chip 15. For example, when the planar size of the semiconductor chip 15 is about 10 mm × 10 mm, the size of the transmissive layer 16B is also formed to be about 10 mm × 10 mm. By making both sizes equal, it is possible to irradiate ultraviolet rays only below the semiconductor chip 15 to be picked up. Further, the size of the irradiation region may be 2-3% larger than the chip size.

  Next, referring to FIG. 3A, the upper surface of the push-up collet 16 is brought into contact with the back surface of the sheet 12. The up-and-down movement of the push-up collet 16 can be performed by driving with a motor or air pressure. You may irradiate an ultraviolet-ray from the push-up collet 16 in the state of this process. That is, before the suction collet 17 comes into contact with the semiconductor chip 15, the adhesive force of the adhesive layer 14 may be reduced by irradiating the sheet 12 with ultraviolet rays. Thus, when the suction collet 17 comes into contact with the semiconductor chip 15, since the adhesive force of the adhesive layer 14 has already been reduced, the semiconductor chip 15 can be peeled immediately.

  Referring to FIG. 3B, next, the adhesive force of the adhesive layer 14 is locally reduced by irradiating the sheet 12 with ultraviolet rays from the push-up collet 16. Here, the push-up collet 16 is located only below the semiconductor chip 15 to be picked up. Accordingly, only the adhesive layer 14 in the region corresponding to the lower part of one semiconductor chip 15 is exposed. The exposed portion of the adhesive layer 14 changes its properties and decreases its adhesive strength. As a result, the adhesion strength between the semiconductor chip 15 to be picked up and the sheet 12 is reduced, and the semiconductor chip 15 can be easily peeled off.

  The adhesive layer 14 located below the other semiconductor chips 15 that are not picked up is not exposed in this step. Therefore, the other semiconductor chip 15 is maintained in a state of being adhered to the surface of the sheet 12. In addition, even when an impact is applied to the sheet 12 by the suction collet 17 or the push-up collet 16, other semiconductor chips 15 do not move, so that no positional deviation occurs.

  Further, in this step, the suction collet 17 comes into contact with the upper surface of the semiconductor chip 15 and is sucked, whereby the semiconductor chip 15 is fixed to the suction collet. The suction collet 17 is provided with an intake hole 17A communicated with suction means such as a pump. Therefore, the suction collet 17 can be suction-held and suction-released by operating suction means such as a pump. In this embodiment, the suction collet 17 functions as a peeling means for peeling the semiconductor chip 15 from the sheet 12.

  Further, after the semiconductor chip 15 is adsorbed by the adsorbing collet 17, ultraviolet rays may be irradiated from the push-up collet 16. As a result, it is possible to prevent the position of the semiconductor chip 15 from shifting due to a decrease in the adhesive force of the adhesive layer 14.

  Next, referring to FIG. 3C, the semiconductor chip 15 is peeled from the sheet 12 by raising the suction collet 17. In the previous process, the adhesive force of the adhesive layer 14 below the semiconductor chip 15 is reduced. Therefore, the back surface of the semiconductor chip 15 is easily peeled off from the adhesive layer 14.

  In this step, the back surface of the semiconductor chip 15 is not locally pressed using a push-up pin or the like as in the prior art. Therefore, the occurrence of cracks in the semiconductor chip 15 is prevented.

  Referring to FIG. 4, after the above process is completed, semiconductor chip 15 is moved to a predetermined location. The adsorption collet 17 is movable in three dimensions. Here, the semiconductor chip 15 is placed on top of the solder 22 applied to the conductive pattern 21 located on the upper surface of the mounting substrate 20. After the semiconductor chip 15 is placed on the solder 22, the semiconductor chip 15 is released from the suction collet 17 by releasing the suction force applied to the suction collet 17.

  Next, a method for manufacturing a semiconductor device including a step of picking up a semiconductor chip will be described with reference to the flowchart of FIG.

  In the first step S1, first, a wafer is formed. Specifically, a semiconductor crystal ingot is prepared and sliced to obtain a semiconductor wafer.

  In the second step S2, a large number of electric circuits are formed on the surface of the semiconductor wafer by a known diffusion step.

  In the third step S3, the characteristics of a large number of electric circuits formed on the surface of the semiconductor wafer are checked using a wafer probe or the like. Then, a good product and a defective product are selected. If a defective product is generated in this step, the defective electric circuit is set in a selectable state. The semiconductor chip on which the defective electric circuit is formed is not picked up in a later process.

  In the fourth step S4, each semiconductor chip is obtained by dicing the semiconductor wafer adhered to the sheet. In this embodiment, dicing is performed by attaching a semiconductor wafer to a sheet whose adhesive strength is reduced by irradiating ultraviolet rays.

  In the fifth step S5, the semiconductor chip divided in the previous step is picked up. As described above, in this embodiment, the semiconductor chip is peeled from the sheet while preventing damage or the like of the semiconductor chip. Therefore, the occurrence of defects in this process is suppressed and the yield is improved.

  In the sixth step S6, the semiconductor chip picked up in the previous step is fixed to a conductive material such as a conductive pattern, and the semiconductor chip is electrically connected to the conductive pattern or the like through a fine metal wire or the like.

  In the seventh step S7, sealing is performed so that the semiconductor chip and the conductive member are covered. Generally, a semiconductor chip or the like is sealed by resin sealing such as transfer molding. Through the above steps, a semiconductor device incorporating a semiconductor chip is manufactured.

It is a figure which shows the manufacturing method of the semiconductor device of this invention, (A) is a top view, (B) is sectional drawing, (C) is an expanded sectional view. It is a figure which shows the manufacturing method of the semiconductor device of this invention, (A) is sectional drawing, (B) is a perspective view. It is a figure which shows the manufacturing method of the semiconductor device of this invention, and (A)-(C) is sectional drawing. It is sectional drawing which shows the manufacturing method of the semiconductor device of this invention. 3 is a flowchart showing a method for manufacturing a semiconductor device of the present invention. It is a figure which shows the manufacturing method of the conventional semiconductor device, (A)-(C) is sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Wafer 11 Dicing line 12 Sheet 13 Wafer ring 14 Adhesive layer 15 Semiconductor chip 16 Push-up collet 16A Covering layer 16B Transmission layer 17 Adsorption collet 20 Mounting substrate 21 Conductive pattern 22 Solder

Claims (5)

In a semiconductor chip peeling apparatus for peeling a semiconductor chip attached to the surface of a sheet,
Irradiation means for locally irradiating light to the sheet in the region where the semiconductor chip to be picked up is located, and locally reducing the adhesive strength of the sheet;
A semiconductor chip peeling apparatus comprising: peeling means for adsorbing an upper surface of the semiconductor chip and peeling it from the sheet.   2. The semiconductor chip peeling apparatus according to claim 1, wherein the light is ultraviolet light.   2. The semiconductor chip peeling apparatus according to claim 1, wherein the irradiating means irradiates the light while being in contact with the back surface of the sheet. In a manufacturing method of a semiconductor device including a step of peeling a semiconductor chip attached to the surface of a sheet,
The sheet in the region where the semiconductor chip to be picked up is located is partially irradiated with light to locally reduce the adhesive strength of the sheet, and the semiconductor chip is adsorbed and peeled from the sheet. A method for manufacturing a semiconductor device. The method of manufacturing a semiconductor device according to claim 4, wherein the light is applied to the sheet before the semiconductor chip is adsorbed.

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