Method for separating bonded substrates, in particular disassembling a liquid crystal display device

• US 5,269,868 A
• Filed: 11/12/1992
• Issued: 12/14/1993
• Est. Priority Date: 10/12/1989
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Takasago, Hayato, Gofuku, Eishi
• Primary Examiner(s): Simmons, David A.
• Assistant Examiner(s): Osele, Mark A.
• Application Number:
  US07/975,136
• Time in Patent Office: 397 Days
• Field of Search: 156/272.2, 156/272.8, 156/273.5, 156/275.5, 156/344, 156/584, 156/643, 156/668, 359/80
• US Class Current: 156/718
• CPC Class Codes: B23K 2103/42 Plastics B23K2103/16 takes precedence
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/57 the laser beam entering a face of the workpiece from which it is transmitted through the workpiece material to work on a different workpiece face, e.g. for effecting removal, fusion splicing, modifying or reforming
• CPC Class Codes: B29C 63/0013 Removing old coatings
• CPC Class Codes: B29K 2709/08 Glass
• CPC Class Codes: G02F 1/1333 Constructional arrangements; Manufacturing methodsG02F1/135, G02F1/136 take precedence
• CPC Class Codes: Y10S 156/924 Delaminating display screen, e.g. cathode-ray, LCD screen
• CPC Class Codes: Y10T 156/1189 with shearing during delaminating
• CPC Class Codes: Y10T 156/1972 Shearing delaminating means

Abstract

A method for separating bonded substrates which are prepared by facing a plurality of substrates and bonding the substrates by an adhesive features irradiating an energy beam on the bonding portions of the bonded substrates from above one of the bonded substrates to separate the one substrate and the other substrate. The energy beam has the property of being transmitted through the one substrate and of being absorbed into the adhesive.

Claims

1. A method for separating bonded substrates which are prepared by facing a plurality of substrates and bonding the substrates by an adhesive, comprising the steps of:

generating a laser beam by an excimer laser, said laser beam having a wavelength in an ultraviolet region;

irradiating said laser beam onto portions of the bonding adhesive of the bonded substrates from above one of the bonding adhesive and separate the plurality of substrates, the laser beam having the property of being transmitted through the one substrate and of being absorbed into the adhesive, wherein the adhesive is made of a polymer material.

2. A method according to claim 1, wherein the bonded substrates are used to form a liquid crystal display device.

3. A method according to claim 1, further comprising the steps of:

holding the bonded substrates by suction; and

generating a shearing force to the bonded substrates after completion of the irradiation by the laser beam to separate the bonded substrates.

4. A method according to claim 1, further comprising the steps of:

holding the bonded substrates by suction; and

generating a shearing force to the bonded substrates during the irradiation by the laser beam to separate the bonded substrates.

5. A method according to claim 1, further comprising the steps of:

heating at least one of the bonded substrates after completion of the irradiation by the laser beam to generate thermal stress in it, thereby separating the bonded substrates.

6. A method according to claim 1, further comprising the steps of:

heating at least one of the bonded substrates during the irradiation by the laser beam to generate thermal stress in it, thereby separating the bonded substrates.