JP2008098428A - Manufacturing method of semiconductor device - Google Patents

Abstract

The present invention provides a method for manufacturing a semiconductor device in which a dicing tape and a push-up pin that have been conventionally used can be eliminated in a series of semiconductor device manufacturing processes.
A first manufacturing method of a semiconductor device according to the present invention includes a step of attaching a surface protection sheet to a circuit surface of a semiconductor wafer having a circuit formed on the surface, a step of grinding the back surface of the wafer, and surface protection A process of full-cut dicing for each circuit from the grinding surface side while being supported by a sheet to separate the wafer, and a suction table that has a plurality of independently controllable suction parts and can suck and fix the wafer as a whole , A process of adhering and fixing the grinding surface of the wafer to face, a process of peeling and removing the surface protection sheet from the singulated wafer, and partially releasing or weakening the adsorption force by controlling each adsorption part of the adsorption table The method includes a step of picking up an individual wafer for each chip and a step of bonding the chip to a semiconductor substrate.
[Selection] Figure 3

Description

  The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device that can eliminate dicing tapes and push-up pins that have been conventionally used in a series of semiconductor device manufacturing steps.

  In general, in a semiconductor device manufacturing process, a semiconductor wafer on which an element is formed is separated along dicing lines or chip dividing lines and separated into individual pieces to form a plurality of semiconductor chips. At the time of dicing, the semiconductor wafer is separated on a device-by-element basis using a dicing blade or the like of a dicing device while being fixed on an adhesive sheet called a dicing tape. After dicing, the chip is picked up by protruding (raising) the chip from the back side of the dicing tape with a push-up pin.

  However, in such a pickup method, the chip may be damaged by the impact at the time of pushing up, and the yield may be reduced. In particular, in recent years, the spread of IC cards has progressed, and further reduction in thickness has been desired. However, the ultrathin chip has a low bending strength, and thus is easily damaged during pickup.

In Patent Document 1, an individual semiconductor wafer having an adhesive tape affixed to a circuit forming surface is sucked and fixed to a suction table that has a plurality of independently controllable suction portions and can suck and fix the wafer as a whole. Then, after the adhesive tape is peeled off from the circuit formation surface, a technique for picking up a chip by controlling each suction portion of the suction table to partially cancel or weaken the suction force is disclosed.
JP 2003-179126 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a semiconductor device in which a dicing tape and a push-up pin that have been conventionally used can be eliminated in a series of semiconductor device manufacturing processes.

A first manufacturing method of a semiconductor device according to the present invention includes:
A step of attaching a surface protection sheet to a circuit surface of a semiconductor wafer having a circuit formed on the surface;
Grinding the backside of the wafer;
A step of separating the wafer into individual pieces by full-cut dicing for each circuit from the grinding surface side while being supported by the surface protection sheet;
A suction table that has a plurality of suction units that can be controlled independently and can hold and fix the wafer as a whole;
A step of peeling and removing the surface protection sheet from the separated wafer,
Controlling each suction part of the suction table to partially release or weaken the suction force, picking up individual wafers for each chip, and bonding the chip to a semiconductor substrate Yes.

A second method for manufacturing a semiconductor device according to the present invention is as follows.
A step of attaching a surface protection sheet to a circuit surface of a semiconductor wafer having a circuit formed on the surface;
Grinding the backside of the wafer;
Applying an adhesive sheet to the ground surface of the wafer;
A step of separating the wafer into individual pieces by full-cut dicing for each circuit in a form including the adhesive sheet from the adhesive sheet side while being supported by the surface protective sheet;
A process of adsorbing and fixing an adhesive sheet surface of the wafer to an adsorbing table having a plurality of independently controllable adsorbing parts and capable of adsorbing and fixing the wafer as a whole;
A step of peeling and removing the surface protection sheet from the separated wafer,
The process of picking up individual wafers together with the adhesive sheet for each chip by controlling each suction part of the suction table to partially cancel or weaken the suction force, and the semiconductor substrate through the adhesive sheet It is characterized by comprising a bonding step.

  According to the present invention as described above, dicing tapes and push-up pins that have been conventionally used can be eliminated in a series of semiconductor device manufacturing processes. In addition, when the chip is bonded to the semiconductor substrate, the amount of adhesive applied can be made uniform, and variations in quality between products can be reduced.

Hereinafter, the present invention will be described more specifically with reference to the drawings.
In the present invention, as shown in FIG. 1, a surface protection sheet 2 is first attached to the circuit surface of a semiconductor wafer 1 having a circuit formed on the surface to protect the circuit.

  Since the surface protective sheet 2 needs to be peeled off from the circuit surface in a later step, a peelable adhesive sheet is used. As such a pressure-sensitive adhesive sheet, a weak pressure-sensitive adhesive sheet or an energy ray-curable pressure-sensitive adhesive sheet capable of reducing or eliminating the adhesive force by irradiation with energy rays is preferably used.

  Next, the back surface of the semiconductor wafer 1 is ground using the grinding wheel 3 of the wafer back surface grinding apparatus (see FIG. 1). This step is performed in order to remove the oxide film generated during circuit formation and to make the wafer have a predetermined thickness.

  Thereafter, with the circuit surface supported by the surface protection sheet 2, the wafer 1 is fully cut and diced for each circuit from the grinding surface side (back surface side) with a dicing blade 4 of a dicing apparatus. To obtain the chip 5 (see FIG. 2). Since the circuit surface of the wafer is on the lower side, a dicing apparatus that can be observed from the lower surface side of the wafer or a dicing apparatus having a camera that can be seen through silicon is used to read the dicing line.

Next, in the present invention, the chip 5 is picked up as follows.
First, the grinding surface side of the wafer (the chip 5 assembly in an aligned state) is suction fixed on a predetermined suction table 10.

  The suction table 10 has a plurality of suction units 11 that can be controlled independently. In FIG. 3, the example which has six adsorption | suction parts was shown. A detailed description of such a suction table 10 is described in, for example, Japanese Patent Application Laid-Open No. 2003-179126. As shown schematically, the suction table 10 has a plurality of suction portions 11, and a valve 12 is connected to each suction portion so that the suction force can be controlled independently. The valve 12 is connected to a vacuum source such as a vacuum pump or an ejector. Therefore, the suction force of each suction part can be controlled independently by controlling the opening and closing of the valve. Moreover, you may make it connect two or more vacuum sources to one adsorption | suction part.

  Each chip 5 is fixed to the suction part by placing the grinding surface side of the chip 5 on the suction table 10 and connecting the suction part 11 to a vacuum source. Thereafter, the surface protection sheet 2 is peeled off. The surface protective sheet 2 can be peeled off easily by sticking an adhesive tape or a heat seal type adhesive tape (peeling tape) on the base material surface of the surface protective sheet 2 and starting from this peeling tape. . As a result, the chip 5 is sucked to the suction table 10 while maintaining the aligned state.

  Next, the chip 5 is picked up from the suction table 10 using a suction collet. At this time, since the suction state is eliminated by opening the valve connected to the suction portion where the chip to be picked up is sucked, the chip can be picked up more smoothly.

  Next, an adhesive paste or the like is applied to the back surface (grind surface) of the picked-up chip 5 or the semiconductor substrate to be bonded to form an adhesive layer, and bonding is performed to a predetermined semiconductor substrate via this adhesive layer. Thus, a semiconductor device can be obtained.

By the way, as described above, when an adhesive layer is formed using a paste-like adhesive, the amount of paste applied becomes uneven, and quality may vary between products.
The second manufacturing method according to the present invention is for solving such a problem, and eliminates unevenness in the amount of adhesive between chips and ensures equivalent quality between products. It is an object. That is, the second manufacturing method further improves the first manufacturing method and provides a process for easily manufacturing a chip having a certain amount of adhesive layer.

A second method for manufacturing a semiconductor device according to the present invention is as follows.
Similar to the first manufacturing method, the surface protection sheet 2 is attached to the circuit surface of the semiconductor wafer 1 on which the circuit is formed, and the back surface of the wafer 1 is ground.

Next, an adhesive sheet 6 is attached to the ground surface of the wafer 1 (see FIG. 4).
The adhesive sheet 6 is made of a sheet-shaped adhesive, and a resin sheet in which a resin used for a normal adhesive is formed into a sheet shape is used without particular limitation. Such a resin may be thermosetting or thermoplastic. As the thermosetting resin, for example, an epoxy resin, an acrylic resin, a polyimide resin, a phenol resin, a urea resin, a melamine resin, a resorcinol resin, or the like is used, and preferably an epoxy resin or an acrylic resin is used. The thermosetting adhesive sheet 6 may be variously blended with the thermosetting resin as described above in order to maintain the sheet shape at room temperature or high temperature and to improve the adhesiveness. For example, the compounding of the thermoplastic resin mentioned later for an adhesive improvement, and the mixing | blending of energy-beam curable resins, such as an ultraviolet-ray, for the purpose of maintenance of a sheet | seat shape are mentioned.

  Examples of the thermoplastic resin include polyester resin, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polymethacrylate, polyacrylate, polystyrene, polyethylene, polyamide, cellulose, polyisobutylene, polyvinyl ether, polyimide resin, and various types. A hot-melt adhesive or the like is used, and preferably a polyester resin or a polyimide resin is used.

  The film thickness of such an adhesive sheet 6 is preferably about 1 to 200 μm, and particularly preferably about 10 to 70 μm. In the present invention, a peelable liner (not shown) may be adhered to one side of the adhesive sheet 6.

The adhesive sheet 6 is used in a predetermined process in the form of laminated liners, and then transferred from the liner to the wafer 1. The liner is used for reinforcement so as not to be deformed by tension when the adhesive sheet 6 is attached to the wafer, for example. In addition, the surface of the adhesive sheet 6 can be protected from contamination during the cutting and separating step.

  As the liner, various thin layer products conventionally used as substrates such as pressure-sensitive adhesive tapes are used without particular limitation. For example, paper, metal foil, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, nylon, Synthetic resin films such as urethane, polyvinylidene chloride, and polyvinyl chloride are used. Moreover, these laminated products may be sufficient.

  In the present invention, in order to peel the adhesive sheet 6 from the liner surface and facilitate transfer to the wafer, the liner surface may be subjected to a peeling treatment with a silicone resin or an alkyd resin, if necessary. The surface tension of such a liner is preferably 40 mN / m or less, more preferably in the range of 20 to 40 mN / m, and particularly preferably in the range of 30 to 35 mN / m.

If the surface tension of the liner is greater than 40 mN / m, the adhesiveness of the adhesive sheet 6 to the liner will be high and transfer to the wafer may not be possible.
The adhesive sheet 6 is stuck on the semiconductor wafer 1 by sticking with a sticking device. The pressure at the time of sticking is appropriately set by the sticking method (rubber roller type, vacuum contact type) of the sticking device, but if the pressurization condition is too weak, the adhesive sheet 6 may not stick to the wafer. If it is too strong, the wafer and chip may be damaged.

The sticking temperature depends on the properties of the adhesive sheet 6 to be used. Usually, a temperature of not less than the plasticization temperature of the resin used for the adhesive sheet and not more than 180 ° C. is preferable.
Thereafter, the wafer 1 and the adhesive sheet 6 are fully cut and diced for each circuit from the adhesive sheet 6 side with the dicing blade 4 or the like of the dicing apparatus while the circuit surface is supported by the surface protection sheet 2. To obtain a chip 5 having an adhesive sheet 6 on one side (see FIG. 5).

Next, in the present invention, the chip 5 with the adhesive sheet is picked up as follows.
First, the adhesive sheet side of the wafer (an assembly of chips 5 kept in an aligned state) is suction fixed on the suction table 10 similar to the first method, and the surface protection sheet 2 is peeled off. As a result, the chip | tip 5 with an adhesive sheet is adsorb | sucked by the adsorption | suction table 10 with the alignment state maintained.

  Next, the chip 5 is picked up from the suction table 10 using a suction collet. At this time, since the suction state is eliminated by opening the valve connected to the suction portion where the chip to be picked up is sucked, the chip can be picked up more smoothly. In addition, the adhesive sheet 6 does not have adhesiveness at room temperature and develops adhesiveness by heating, so that the pickup operation is not hindered.

  Next, the picked-up chip 5 is bonded to a predetermined semiconductor substrate via the adhesive sheet 6 to obtain a semiconductor device. As described above, the adhesive sheet 6 is a thermosetting or thermoplastic resin sheet. In the case of a thermosetting resin sheet, the chip 5 can be firmly bonded to the substrate by heating and bonding to a temperature higher than the curing temperature of the resin. In the case of a thermoplastic resin sheet, the chip 5 and the substrate are bonded together by heating and cooling to a temperature equal to or higher than the softening temperature of the resin.

According to the present invention as described above, dicing tapes and push-up pins that have been conventionally used can be eliminated in a series of semiconductor device manufacturing processes. In addition, when the chip is bonded to the semiconductor substrate, the amount of adhesive applied can be made uniform, and variations in quality between products can be reduced.
[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.

An ultraviolet curable surface protective sheet (Lintec, Adwill E-3100) is applied to the mirror surface of a 720 μm thick, 200 mm unpolished silicon wafer with a tape applicator (Lintech, RAD-3500m / 12). The wafer thickness was ground to 50 μm using a wafer back grinding device (DFG-850, manufactured by DISCO Corporation).

  A wafer is fixed to the wafer chuck surface of a dicing machine (DFD-6360, DFD-6360) so that the grinding surface of the wafer is the upper surface and the surface protection sheet side is the suction table surface, and the chip size is 10 mm × 10 mm. Full-cut dicing was performed, and the separated chip group was supported and fixed to the surface protection sheet in a wafer shape.

As shown in FIG. 3, a suction table having a suction part that is divided into seven parts and can be controlled independently is prepared, and the chip group is suction-fixed on the suction table side and the surface protection sheet is the upper surface. Heat seal type release tape (Adwill, manufactured by Lintec) at the edge of the surface protection sheet
S20) was bonded, and the release tape was pulled in the 180 ° direction to peel off the entire surface protection sheet. At this time, all the suction portions of the suction table were connected to a vacuum source with the valves opened. Thereafter, the valve was closed in order from the suction part at the end, and chips that were not sucked were picked up from above by a vacuum collet. The chip could be picked up without problems.

  As an adhesive sheet, a thermosetting epoxy resin, a thermoplastic acrylic resin, and an energy ray-curable polyfunctional acrylate are blended on the release surface of a liner made of polyethylene terephthalate film (thickness 38μm) that has been subjected to a silicone release treatment. A resin sheet (Adwill LE-5000, manufactured by Lintec Co., Ltd.) in which the resin thus formed was formed to a thickness of 50 μm was prepared.

In the same manner as in Example 1, the back surface of the wafer is ground and thinned, and the adhesive sheet is bonded to the ground surface while heating the suction table to 70 ° C. with a tape applicator (RAD-3500m / 12DBS, manufactured by Lintec). The liner was peeled off. Subsequently, the resin layer of the adhesive sheet is irradiated with ultraviolet rays to semi-cure the resin layer, and then full-cut dicing is performed from the adhesive sheet side, and the adhesive sheet and chip are separated into individual pieces to protect the surface in the form of a wafer. The sheet was supported and fixed to the sheet.

  As in Example 1, the adhesive table shown in FIG. 3 was fixed by suction with the adhesive sheet as the suction table side and the surface protection sheet as the upper surface. In the same manner as in Example 1, the surface protective sheet was peeled off, a chip with an adhesive sheet was picked up by a vacuum collet while controlling the suction portion of the suction table, and bonding to the semiconductor substrate was performed by the adhesive sheet. There was no problem with chip pickup or bonding.

1 shows one step of a method of manufacturing a semiconductor device according to the present invention. One process of the 1st manufacturing method of the semiconductor device which concerns on this invention is shown. One process of the 1st manufacturing method of the semiconductor device which concerns on this invention is shown. One process of the 2nd manufacturing method of the semiconductor device which concerns on this invention is shown. One process of the 2nd manufacturing method of the semiconductor device which concerns on this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Semiconductor wafer 2 ... Surface protection sheet 3 ... Grinding wheel 4 ... Dicing blade 5 ... Semiconductor chip 6 ... Adhesive sheet 10 ... Suction table 11 ... Suction part 12 ... Valve

Claims (2)

A step of attaching a surface protection sheet to a circuit surface of a semiconductor wafer having a circuit formed on the surface;
Grinding the backside of the wafer;
A step of separating the wafer into individual pieces by full-cut dicing for each circuit from the grinding surface side while being supported by the surface protection sheet;
A suction table that has a plurality of suction units that can be controlled independently and can hold and fix the wafer as a whole;
A step of peeling and removing the surface protection sheet from the separated wafer,
Controlling each suction part of the suction table to partially release or weaken the suction force, picking up individual wafers for each chip, and bonding the chips to a semiconductor substrate A method for manufacturing a semiconductor device. A step of attaching a surface protection sheet to a circuit surface of a semiconductor wafer having a circuit formed on the surface;
Grinding the backside of the wafer;
Applying an adhesive sheet to the ground surface of the wafer;
A step of separating the wafer into individual pieces by full-cut dicing for each circuit in a form including the adhesive sheet from the adhesive sheet side while being supported by the surface protective sheet;
A process of adsorbing and fixing an adhesive sheet surface of the wafer to an adsorbing table having a plurality of independently controllable adsorbing parts and capable of adsorbing and fixing the wafer as a whole;
A step of peeling and removing the surface protection sheet from the separated wafer,
The process of picking up individual wafers together with the adhesive sheet for each chip by controlling each suction part of the suction table to partially cancel or weaken the suction force, and the semiconductor substrate through the adhesive sheet A method for manufacturing a semiconductor device comprising the step of bonding to a semiconductor device.

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