Semiconductor device manufacturing: process – Semiconductor substrate dicing – With attachment to temporary support or carrier
Reexamination Certificate
1999-07-15
2001-05-01
Bowers, Charles (Department: 2813)
Semiconductor device manufacturing: process
Semiconductor substrate dicing
With attachment to temporary support or carrier
C438S460000, C438S462000, C438S463000, C438S464000, C428S343000, C428S345000, C428S354000, C428S3550RA, C428S3550RA
Reexamination Certificate
active
06225194
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a process for producing a small item such as an electronic component and an optical component (hereinafter referred to as “chip”) and a pressure sensitive adhesive sheet suitable for use in the above process.
BACKGROUND OF THE INVENTION
A semiconductor wafer of, for example, silicon or gallium arsenide is produced in a large diameter, cut and separated (diced) into elemental chips and subjected to the subsequent mounting step. In this process, the semiconductor wafer undergoes dicing, cleaning and drying steps in the state of being attached to a pressure sensitive adhesive sheet and is transferred to the subsequent pickup and mounting steps. It is desired that the above pressure sensitive adhesive sheet employed in the steps from the semiconductor wafer dicing to the pickup have an adhesive strength which is so large as to securely hold the wafer (chips) in the dicing to drying steps but which is on such a level that no adhesive remains to the wafer (chips) in the pickup step. This type of pressure sensitive adhesive sheet was proposed in, for example, Japanese Patent Laid-open Publication Nos. 60(1985)-196956 and 60(1985)-223139. In the proposed pressure sensitive adhesive sheets, however, it was practically infeasible to completely nullify the adhesive strength (vertical peeling strength) at the pickup step and, irrespective of the efforts for reduction, the vertical peeling strength at the pickup step encountered a limit of about 100 to 300 g/10 mm sq. Therefore, in actually carrying out the above process, not only are the chips pushed upward from the back of the pressure sensitive adhesive sheet by means of a thrust needle to thereby separate the chips from the pressure sensitive adhesive sheet but also pickup of the chips is performed with the use of a suction collet.
Recently, various electronic components (chips) for preventing stealth and forgery are assembled into cards, for example, ID, memory, credit and cash cards. It is required that the electronic components to be assembled in these cards have very small thickness and have large surface area relative to the thickness so as to have large capacity.
The problem has surfaced such that the use of the above thrust needle in the pickup of chips of small thickness and large surface area would break the chips to thereby gravely lower the chip yield.
The present invention has been made with a view toward resolving the above problem of the prior art. An object of the present invention is to provide a process for producing a chip in which chips of small thickness and large surface area can easily be picked up, and another object of the present invention is to provide a pressure sensitive adhesive sheet suitable for use in the above process. That is, objects of the present invention are to provide a process for producing a chip in which chips can be picked up without the need to use any thrust needle and to provide a pressure sensitive adhesive sheet suitably employed in the above process.
SUMMARY OF THE INVENTION
The process for producing a chip according to the present invention comprises the steps of:
attaching an object to be diced on a pressure sensitive adhesive sheet comprising at least one layer of shrinkable film and a pressure sensitive adhesive layer;
dicing the object into chips, and
shrinking the shrinkable film to thereby reduce an area in which the chips are in contact with the pressure sensitive adhesive.
In the present invention, it is preferred that the pressure sensitive adhesive layer be composed of an ultraviolet curable pressure sensitive adhesive. In this process, it is further preferred that a step of irradiating the pressure sensitive adhesive layer with ultraviolet rays be included prior to or subsequent to a shrinkage of the shrinkable film.
The pressure sensitive adhesive sheet according to the present invention is used in the above process for producing chip, and comprises at least one layer of shrinkable film and a pressure sensitive adhesive layer. In particular, it is preferred that the pressure sensitive adhesive sheet comprises an ordered array or stack made up of a nonshrinkable support film, a shrinkable film and a pressure sensitive adhesive layer piled or stacked in the aforesaid order.
REFERENCES:
patent: 4756968 (1988-07-01), Ebe et al.
patent: 4761335 (1988-08-01), Aurichio et al.
patent: 4965127 (1990-10-01), Ebe et al.
patent: 4999242 (1991-03-01), Ishiwata et al.
patent: 5187007 (1993-02-01), Ebe et al.
patent: 5304418 (1994-04-01), Akada et al.
patent: 5447767 (1995-09-01), Tanabe et al.
patent: 5637395 (1997-06-01), Uemura et al.
patent: 5714029 (1998-02-01), Uemura et al.
patent: 5942578 (1999-08-01), Noguchi et al.
patent: 0157508 (1985-09-01), None
patent: 0252739 (1993-10-01), None
patent: 0622833 (1994-02-01), None
patent: 622833 A1 (1994-11-01), None
Japanese Patent Laid Open No. 10-226776, Abstract, Aug. 25, 1998, PP., Japanese language.
Japanese Patent Laid Open No. 08-027239, Abstract, Jan. 30, 1996, 1 p., Japanese language.
Japanese Patent Laid Open No. 63-296222, Abstract, Dec. 2, 1988, 1 p., Japanese language.
Japanese Patent Laid-Open No. 6-16524, Abstract, Mar. 2, 1994, 1 p., Japanese language.
Japanese Patent Laid-Open No. 60-223139, Abstract, Nov. 7, 1985, 1 p., English language.
Japanese Patent Laid-Open No. 9165558, Abstract, Jun. 24, 1997, 1 p., English language.
Japanese Patent Laid-Open No. 8258038, Abstract, Oct. 8, 1996, 1 p., English language.
Japanese Patent Laid-Open No. 8225776, Abstract, Sep. 3, 1996, 1 p., English language.
Japanese Patent Laid-Open No. 5-32946, Abstract, Feb. 9, 1993, 1 p., English language.
Japanese Patent Laid-Open No. 60-196956, Abstract, Oct. 5, 1985, 1 p., English language.
Ebe Kazuyoshi
Mineura Yoshihisa
Noguchi Hayato
Numazawa Hideki
Bowers Charles
Lintec Corporation
Sarkar Asok K.
Webb Ziesenheim & Logsdon Orkin & Hanson, P.C.
LandOfFree
Process for producing chip and pressure sensitive adhesive... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for producing chip and pressure sensitive adhesive..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for producing chip and pressure sensitive adhesive... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2435010