KR101079650B1

KR101079650B1 - Method for removing synthetic resin film from semiconductor reject die

Info

Publication number: KR101079650B1
Application number: KR1020090044506A
Authority: KR
Inventors: 김말숙
Original assignee: 주식회사 엠에스하이텍
Priority date: 2009-05-21
Filing date: 2009-05-21
Publication date: 2011-11-03
Also published as: KR20100125680A

Abstract

The present invention relates to a method for recycling a semiconductor reject die, and more particularly to a method for removing a resin film, such as a polyvinyl chloride film, from a silicon semiconductor die that has become defective during semiconductor processing.

Method for removing the synthetic resin film in the semiconductor reject die according to the present invention is the step of injecting a semiconductor die bonded to the synthetic resin film in a reservoir filled with a 10 ~ 50% sodium hydroxide solution, sodium hydroxide at a concentration of 10 to 50% Injecting a semiconductor die to which a synthetic resin film is adhered into an agitator filled with an aqueous solution, and injecting the synthetic resin film and the semiconductor chip separated in the stirring step into a rotating body together with sodium hydroxide, and a discharge hole in the rotating body. Separating the semiconductor chip and the synthetic resin film according to the size of the.

Semiconductor chip, semiconductor die, recycling

Description

METHODS FOR REMOVING SYNTHETIC RESIN FILM FROM SEMICONDUCTOR REJECT DIE

The present invention relates to a method for recycling a semiconductor reject die, and more particularly, to a method for removing a resin film, such as a polyvinyl chloride film, from a silicon semiconductor reject die that has become defective during a semiconductor process.

Semiconductor devices generally include single crystal growth, wafer cutting, surface polishing, circuit design, mask fabrication, oxidation, photoresist coating, exposure, development, etching, ion implantation, deposition, metallization, wafer automatic sorting, wafer cutting, chip bonding, metal It consists of connecting, forming and final inspection steps.

Inevitably, in each step of manufacturing such a semiconductor device, material loss or defects occur in the manufacturing process. For example, silicon powder or the like is discharged in the wafer cutting process, and a die that is defective is determined in the wafer automatic sorting step. The die determined to be good in the wafer automatic sorting step is provided to the chip bonding step for bonding the chip through the wafer cutting step, but the defective die is usually discarded.

In the wafer automatic sorting step, the defective die is marked with defects on it, and the wafer is cut into chips by fixing the wafer with an adhesive to a synthetic film, especially a polyvinyl chloride (PVC) film. Good chips from the cut wafers are recovered and provided for subsequent processing, but the defective dies are discarded as adhered to the resin film.

On the other hand, since the semiconductor wafer for memory has a purity of about 11N and the photovoltaic wafer has a purity of about 6N, a research for recycling a recently defective memory semiconductor wafer as a raw material for producing a photovoltaic wafer is necessary. It's going on.

Accordingly, an object of the present invention is to provide a raw material for manufacturing a photovoltaic wafer by separating a semiconductor die disposed in a state of being bonded to a synthetic resin film in an economical and convenient manner.

The method for removing the synthetic resin film from the semiconductor reject die to achieve the above object is a step of injecting a semiconductor die bonded to the synthetic resin film in a reservoir filled with a 10 ~ 50% sodium hydroxide solution, the concentration of 10 to 50% Injecting a semiconductor die bonded with a synthetic resin film to a stirrer filled with an aqueous solution of sodium hydroxide, stirring, injecting the synthetic resin film and the semiconductor chip separated in the stirring step with a sodium hydroxide to the rotating body, and the rotating body And rotating the semiconductor chip and the synthetic resin film according to the size of the discharge hole by rotating.

In addition, the temperature of the sodium hydroxide aqueous solution in the input step and the stirring step in the present invention is 30 ~ 150 ℃.

In addition, in the present invention, it is preferable to weaken the adhesive strength of the adhesive by heating the aqueous sodium hydroxide solution in the input step for 2-3 hours.

The present invention removes the resin film from the semiconductor reject die by using a reservoir and agitator filled with 10% to 50% sodium hydroxide, and the removed resin film and the semiconductor chip are separated from each other by the size of the discharge hole of the rotating body. Therefore, the semiconductor die bonded to the resin film can be separated in a simple and economical process.

Hereinafter, a method of removing the synthetic resin film from the semiconductor reject die according to the present invention will be described in detail with reference to the accompanying drawings.

1 shows a semiconductor die attached to a plastic film. Since the defective semiconductor die is strongly adhered to the resin film with an adhesive, the method of manually separating the semiconductor die from the resin film requires a lot of processing time and is not economical. In the present invention, a semiconductor die and a semiconductor chip are distinguished from each other, and as shown in FIG. 1, a state in which the semiconductor chips are assembled is referred to as a semiconductor die.

2 is a schematic diagram of a system for implementing a method of removing a resin film from a semiconductor reject die in accordance with the present invention. First, the semiconductor die bonded to the synthetic resin film is introduced into a storage tank 10 in which an aqueous sodium hydroxide (NaOH) solution is stored. The injected synthetic resin film adhesive semiconductor die is caught by the rake-type rotating member 13 (see FIG. 3) attached to the rotating rod 12 and moved to the right. The storage device 10 is equipped with a heater device 11 for lowering the temperature of the aqueous sodium hydroxide solution. The heater device 11 is preferably installed below the reservoir 10, but may be installed elsewhere.

The semiconductor die which is not separated from the reservoir 10 is introduced into the stirrer 20 through the conveyor 40 in a state of being bonded to the synthetic resin film. An aqueous sodium hydroxide solution is also stored in the stirrer 20 in the same manner as the storage tank 10. The injected semiconductor die is transferred to the stirring blade 23 by rotating the motor 24 capable of forward and reverse rotation, and the stirring die 23 is separated from the synthetic resin film while the semiconductor die adhered to the synthetic film is stirred. . The lower part of the stirrer 20 is equipped with the heater apparatus 21 to heat a sodium hydroxide aqueous solution, and to raise a temperature. The heater device 21 may be provided elsewhere in the stirrer 20. The semiconductor chip separated from the synthetic resin film is introduced into the rotating device 30 through the outlet 22 together with the synthetic resin film and the sodium hydroxide aqueous solution.

The synthetic resin film, the semiconductor chip and the sodium hydroxide aqueous solution introduced through the inlet 35 of the rotating device 30 are injected into the rotating body 31, and the semiconductor chip and the sodium hydroxide through the discharge hole 32 of the rotating body 31. The aqueous solution is discharged and discharged to the left outlet 33. Since the rotor 31 has an inclined structure having a high left side and a low right side, the synthetic resin film, the semiconductor chip, and the sodium hydroxide aqueous solution move to the right in the rotor 31 by the rotational drive of the motor 34. The small semiconductor chip and the sodium hydroxide aqueous solution are discharged through the left outlet 33 and sent to the conveyor 5. The aqueous sodium hydroxide solution is collected at the bottom of the conveyor 50 to be recycled or discarded and the semiconductor chips are collected in one place by the conveyor 50. In addition, the synthetic resin film is discharged through the right outlet 37 is mounted on the conveyor 60 is collected in one place.

In FIG. 2, the sodium hydroxide aqueous solution, the semiconductor chip, and the synthetic resin film are separated and discharged while moving from the left to the right by inclining the rotor 31, but by installing a screw in the rotor 31, the aqueous sodium hydroxide solution and the semiconductor are shown. The chip and the synthetic film may be moved from left to right.

Figure 3 is an enlarged perspective view of the reservoir 10 according to the present invention, the reservoir 10 of the present invention is a rotary rod 12 and a rake for moving the semiconductor die bonded to the synthetic resin film to the right in the reservoir (10) The mold rotating member 13, and the heater device 11 for heating the sodium hydroxide aqueous solution accommodated therein by raising the temperature of the reservoir (10). The material of the rotating rod 12 and the rotating member 13 is not particularly limited, but may be made of metal or plastic that does not corrode in aqueous sodium hydroxide solution. In addition, the present invention adopts a method of installing the heater device 11 in the lower portion of the reservoir 10, but may use an induction heating method.

4 is a perspective view of the rotary device 30 according to the present invention, the aqueous sodium hydroxide solution, semiconductor chip and synthetic resin film discharged through the outlet 22 of the stirrer 20 is the inlet 35 of the rotary device 30 It is injected into the injection hole 36 of the rotating body 31 via. The size of the injection hole 36 is not particularly limited but may be larger than the diameter of the synthetic resin film. By the rotation of the inclined rotor 31, the sodium hydroxide aqueous solution and the semiconductor chip are discharged to the discharge hole 32 while moving.

Example

The semiconductor die adhered to the synthetic resin film is introduced into a reservoir 10 filled with an aqueous sodium hydroxide solution. The concentration of the aqueous sodium hydroxide solution in the reservoir 10 was set to 10 to 50 percent concentration (hereinafter abbreviated as "percent"). If the concentration of the aqueous solution of sodium hydroxide is less than 10 percent, the concentration is insufficient to separate the semiconductor die adhered to the resin film, and if the concentration exceeds 50 percent, the cost of separating the semiconductor die increases, so the concentration of the aqueous solution of sodium hydroxide is 10 to 50 percent is preferred.

The sodium hydroxide aqueous solution was heated to about 30 to 150 ° C. using a heater device 11 mounted at the bottom of the reservoir 10 to activate the aqueous sodium hydroxide solution. The heating time was set to 2 to 3 hours so that the adhesive strength of the adhesive applied to the synthetic resin film could be weakened. Since the reservoir 10 primarily aims to weaken the adhesive force of the adhesive of the injected synthetic resin film, the semiconductor die adhered to the synthetic resin film is generally not separated, but the separated semiconductor chip is settled under the reservoir 10 so that it cannot be collected. Can be.

First of all, the synthetic resin film having weakened adhesive strength is introduced into the stirrer 20 via the conveyor 40. The concentration and temperature of the aqueous sodium hydroxide solution charged to the stirrer were also 10 to 50 percent and about 30 to 150 ° C. as described above. In the stirrer 20, the synthetic resin film and the semiconductor die adhered thereto were separated from each other by the stirring blade 23. In the present invention, a two-stage configuration is adopted through the reservoir 10 and the stirrer 20 to separate the semiconductor die bonded to the synthetic resin film. It is important in the present invention to separate the adhesive sufficiently weakened in the reservoir 10 from the stirrer 20 again.

The separated semiconductor chip and the synthetic resin film were discharged through the outlet 22 together with the aqueous sodium hydroxide solution and introduced into the rotating body 31 of the rotating device 30. When the semiconductor chip and the sodium hydroxide aqueous solution first exit the discharge hole 32 by the inclination of the rotating body 31, the discharge is discharged through the discharge port 33. The semiconductor chip was moved to the right by the conveyor 50 and provided in the next process. In addition, the synthetic resin film was discharged from the right side of the rotating body 31 and discharged through the discharge port 37. The discharged synthetic resin film is moved and collected to the right by the conveyor 60 and discarded or recycled.

FIG. 5 illustrates a semiconductor chip collected by moving to the right by the conveyor 50. Since the collected semiconductor chips were buried in an aqueous sodium hydroxide solution, they were moved to a washing tank filled with water (not shown) and washed two to three times to remove sodium hydroxide. The water used in the washing tank is not particularly limited, and a constant may be usually used. The cleaned semiconductor chip was moved to a dryer (not shown) and dried at about 300 ° C. for 1 minute to remove moisture. Moisture-removed semiconductor chips are typically used as raw materials for the manufacture of photovoltaic wafers.

6 is a process chart showing a process step of removing the synthetic resin film from the semiconductor reject die according to the present invention. Summarizing the process according to the present invention step by step, the semiconductor die bonded to the synthetic resin film is first heated to about 30 to 150 ℃ for 2 to 3 hours in a storage tank 10 filled with an aqueous solution of sodium hydroxide at a concentration of 10 to 50%, and then the synthetic resin The semiconductor film adhered to the film is separated from the resin film and the semiconductor die in an agitator 10 filled with an aqueous 10-50% sodium hydroxide solution heated to about 30 to 150 ° C., and the separated semiconductor chip, the resin film and the hydroxide are separated. An aqueous sodium solution is added to the rotating body 31 to separate each. Subsequently, the separated semiconductor chips are collected, the semiconductor chips are washed 2-3 times with water, dried at about 300 ° C. for 1 minute in a dryer to remove moisture. In the semiconductor chip thus obtained, a chip without a pattern is used as a raw material for a photovoltaic wafer.

Although the present invention uses an aqueous sodium hydroxide solution to separate the synthetic resin film and the semiconductor die economically and conveniently, it will be clear that other solvents having the same or similar functions as the aqueous sodium hydroxide solution fall within the protection scope of the present invention. Accordingly, the appended claims include all modifications of the invention within the spirit of the invention.

1 shows a semiconductor reject die bonded to a synthetic resin film, in particular a polyvinyl chloride film,

2 is a schematic diagram of a system for implementing a method of removing a resin film from a semiconductor reject die according to the present invention;

3 is an enlarged perspective view of a reservoir according to the present invention;

4 is a perspective view of a rotating device according to the present invention,

5 is a view showing a semiconductor chip separated from a synthetic resin film,

6 is a process chart showing a process according to the present invention.

[Description of Reference Numerals]

10: reservoir 11, 21: heater device

12: rotating rod 13: rotating member

20: agitator 22: outlet

23: stirring blade 24, 34: motor

31: rotating body 32: discharge hole

33, 37: outlet 35: inlet

40, 50, 60: conveyor

Claims

A method of removing a resin film from a semiconductor reject die,

Injecting a semiconductor die with a synthetic resin film into a reservoir filled with an aqueous 10% to 50% sodium hydroxide solution,

Adding a semiconductor die to which a synthetic resin film is attached to a stirrer filled with an aqueous 10% to 50% sodium hydroxide solution, followed by stirring;

Injecting the synthetic resin film and the semiconductor chip separated in the stirring step into a rotating body together with sodium hydroxide, and

And separating the semiconductor chip and the synthetic resin film according to the size of the discharge hole by rotating the rotating body.

The method of claim 1,

The method of removing the synthetic resin film from the semiconductor reject die, characterized in that the temperature of the sodium hydroxide aqueous solution in the input step and the stirring step is 30 ~ 150 ℃.

The method according to claim 1 or 2,

The method of removing the synthetic resin film from the semiconductor reject die, characterized in that for heating the sodium hydroxide solution in the input step 2 to 3 hours.

The method of claim 3, wherein

And removing the synthetic resin film from the semiconductor reject die, further comprising the step of cleaning and drying the semiconductor chip separated in the separating step.