JP2009186538A - Method of manufacturing substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of letting a large-size substrate adhere closely to a large-size dustproof glass substrate while adhesive permeates between these substrates sufficiently even if the large-size substrate is warped. <P>SOLUTION: In the method, transparent adhesive 41 is applied on substantially the center of the large-size dustproof glass substrate 300 and a gel-like gap material 42 is applied at points per predetermined interval at the outer periphery of the large-size dustproof glass substrate 300 when sticking the large-size substrate 110 onto substantially the whole surface of the large-size dustproof glass substrate 300 set on a stage through the transparent adhesive 41. By sticking the large-size substrate 110 to the large-size dustproof glass substrate 300 through the transparent adhesive 41 while applying pressure on them, the large-size substrate 110 is extended in the horizontal direction while it is supported by the gap material 42 to correct its warping. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a substrate in which a first large substrate is bonded to almost the entire surface of a second large substrate via a first adhesive.

  Conventionally, in a projection type display device that is representative of an electro-optical device, if dust or the like adheres to the vicinity of the surface of the display panel, it is enlarged by a projection lens or the like and projected onto a screen, thereby significantly reducing display quality. It will be. As a technique for preventing this, a technique of attaching a transparent glass substrate (first large substrate) having a dustproof function to the outer surface of the display panel is widely adopted.

  By protecting the outer surface of the display panel with a dust-proof glass substrate, it is possible to prevent adhesion of dust and the like to the display panel surface. Furthermore, even if dust adheres to the outer surface of the dust-proof glass substrate, the distance between the dust and the electro-optical material such as a liquid crystal is increased by the thickness of the glass substrate, and the image of the dust is defocused. And is not noticeable because it is displayed on the screen in a largely blurred manner.

  In general, an element substrate typified by a TFT (Thin Film Transistor) substrate is manufactured collectively on a large substrate (second large substrate) that can be obtained in large numbers. For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-11353) discloses a technique in which a large dust-proof glass substrate is bonded to the entire large substrate on which a large number of element substrates are formed.

That is, first, after setting a large dustproof glass substrate on a table, an adhesive is applied to the center of the surface of the large dustproof glass substrate. Next, a large substrate on which a large number of element substrates are formed is brought into contact with the large dust-proof glass substrate from above, and then pressurized to a predetermined degree so that the adhesive applied between the substrates penetrates the periphery. The large substrate is brought into close contact with the large dust-proof glass substrate.
JP 2006-11353 A

  By the way, on a large substrate on which a large number of element substrates are formed, insulating films and metal films are alternately laminated only on the surface opposite to the dust-proof glass substrate. This insulating film is annealed at a temperature of about 900 ° C. to flatten it, but the large substrate, the insulating film, and the metal film have different expansion coefficients. The balance is lost, and the large substrate is warped.

  In addition, when a large number of chip-like counter substrates are bonded to the large substrate, the balance of stress is lost between the counter substrate and the large substrate, and the large substrate is warped.

  If the large substrate is bonded to the dust-proof glass substrate while the large substrate remains warped, the large substrate and the large dust-proof glass substrate will be in close contact before the adhesive penetrates sufficiently, resulting in poor adhesion. Will occur.

  In the present invention, in view of the above circumstances, even if warpage occurs in the second large substrate, the second large substrate and the first large substrate are sufficiently infiltrated with the adhesive therebetween. It is an object of the present invention to provide a method for manufacturing a substrate that can be brought into close contact with each other and can effectively avoid adhesion failure.

  In order to achieve the above object, according to the first substrate manufacturing method of the present invention, a second large substrate is disposed on substantially the entire surface of the first large substrate with respect to the first large substrate set on the stage. In the method for manufacturing a substrate to be bonded through a first adhesive, the first adhesive is applied to the approximate center of the first large substrate, and a gel-like gap is formed on the outer periphery of the first large substrate. An application step of applying a material, and bonding of the second large substrate to the first large substrate while applying pressure while pressing the outer periphery of the second large substrate supported by the gap material And a combining step.

  In such a configuration, the second large substrate is bonded while being pressed while being supported by the gap material applied to the outer periphery of the first large substrate, so that the second large substrate is warped. Even so, the second large substrate and the first large substrate can be brought into close contact with the first adhesive sufficiently spread between them. As a result, poor adhesion is effectively avoided and product yield is improved.

  The second substrate manufacturing method is characterized in that, in the first substrate manufacturing method, the gap material does not have affinity with the first adhesive. Here, having no affinity means that the gap material and the first adhesive do not mix when they contact each other on the first large substrate.

  In such a configuration, since the gap material does not have an affinity with the first adhesive, even if the first adhesive spreads and contacts the gap material, the gap material is mixed into the first adhesive. No deterioration of product quality can be prevented.

  The third substrate manufacturing method is characterized in that, in the first or second substrate manufacturing method, the gap material is composed of a gel-like second adhesive and gap material fine particles. To do.

  In such a configuration, the gap material is composed of the gel-like second adhesive and the fine particles for the gap material mixed in the second adhesive. Therefore, the first large substrate and the second large size are used. The gap of the adhesive layer between the substrate and the substrate can be defined by the gap material fine particles.

  The fourth substrate manufacturing method is characterized in that, in the third substrate manufacturing method, the fine particles for gap material do not have an affinity for the first adhesive.

  In such a configuration, since the gap material fine particles have non-affinity with the first adhesive, even if the first adhesive penetrates, the gap material fine particles do not penetrate into the first adhesive. There is no mixing, and the product quality can be prevented from deteriorating.

  The fifth substrate manufacturing method is characterized in that, in the third or fourth substrate manufacturing method, the second adhesive is an ultraviolet curable adhesive.

  In such a configuration, since the second adhesive is an ultraviolet curable adhesive, both the large substrates are temporarily fixed by bonding the ultraviolet curable adhesive after the two large substrates are bonded together. Can be manufactured easily.

  The sixth substrate manufacturing method is characterized in that, in the first to fifth substrate manufacturing methods, the gap material is plotted on the outer periphery of the first large substrate at set intervals.

  In such a configuration, since the gap material is plotted on the outer periphery of the first large substrate, the material cost can be reduced compared with the case where the gap material is applied to the entire periphery.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view of a liquid crystal display device, and FIG. 2 is a perspective view of a state in which a chip-like counter substrate is bonded to a large substrate.

  First, the overall configuration of the liquid crystal display device will be briefly described with reference to FIG. FIG. 1 shows a TFT active matrix drive type liquid crystal display device with a built-in drive circuit.

  Reference numeral 1 in FIG. 1 denotes a liquid crystal display device that is representative of an electro-optical device, which is a TFT (Thin Film Transistor) substrate 10 as a first substrate made of a quartz glass substrate and the like, and a quartz glass disposed to face the TFT substrate. A liquid crystal panel 120 is formed by bonding a counter substrate 20 as a second substrate made of a substrate or the like via a sealing material 52, and between the opposing surfaces of both substrates 10, 20 formed by the sealing material 52. A liquid crystal 50 as an electro-optical material is enclosed.

  Pixel electrodes (ITO) 9a constituting pixels are arranged in a matrix on the TFT substrate 10, and a counter electrode (ITO) 21 is provided on the entire surface of the counter substrate 20. Further, the alignment films 16 and 22 subjected to the rubbing process are formed on the entire surface of the pixel electrode 9a of the TFT substrate 10 and the counter substrate 20, respectively. The alignment films 16 and 22 are made of a transparent organic film such as a polyimide film.

  A data line driving circuit 101 and an external connection terminal 102 are formed on one side outside the region where the sealing material 52 of the TFT substrate 10 is formed. Although not shown, a scanning line driving circuit is provided along two sides adjacent to the one side, and a wiring pattern for connecting the scanning line driving circuits is formed on the remaining side.

  Further, transparent glass substrates (hereinafter referred to as “dust-proof glass substrates”) 30 and 31 having a dust-proof function are attached to both surfaces of the liquid crystal panel 120. The dust-proof glass substrates 30 and 31 prevent dust and the like from adhering to the surface of the liquid crystal panel 120 and defocus the dust and the like away from the liquid crystal display surface, thereby making the image of the dust and the like inconspicuous. Have

  In order to realize such a function, the dust-proof glass substrates 30 and 31 are formed to be relatively thick with a plate thickness of about 1 to 3 mm, and the material is the same as that of the TFT substrate 30 and the counter substrate 20. in use. Further, the dust-proof glass substrates 30 and 31 are a silicon-based adhesive or acrylic-based adhesive adjusted to the same refractive index as the TFT substrate 30 or the counter substrate 20 (and the dust-proof glass substrates 30 and 31) with respect to the surface of the liquid crystal panel 120. A thermosetting transparent adhesive 41 as a first adhesive made of an agent or the like is used to bond the TFT substrate 30 and the outer surface of the counter substrate 20 with air bubbles removed.

  The TFT substrate 10 and the counter substrate 20 are individually bonded through different processes and then bonded together. As shown in FIG. 2, at the time of bonding, a counter substrate 20 formed in a chip shape is bonded to a large substrate 110 as a second large substrate on which a large number of TFT substrates 10 are formed. Then, liquid crystal is injected between the TFT substrate 10 and the counter substrate 20 and sealed.

  In addition, although the large sized board | substrate 110 by this embodiment is formed in disk shape, a shape is not limited to this, For example, you may form in the rectangular shape. In the figure, twelve TFT substrates 10 are formed on one large substrate 110, but the number of TFT substrates 10 formed on one large substrate 110 is not limited to this. .

  The dustproof glass substrates 30 and 31 are attached to a large substrate 110 as shown in FIG. 2 in a state where a plurality of liquid crystal panels 120 are formed. FIG. 3 shows a process of mounting the dustproof glass substrates 30 and 31 on the liquid crystal panel 120. This work is performed in a clean room.

  Step (a): First, after a plurality of liquid crystal panels 120 are formed on a large substrate 110 in a predetermined manner, the liquid crystal panel 120 is cleaned and inspected for its operating state.

  Step (b): a first large large substrate 110 having a shape slightly smaller than that of the large substrate 110 on the outer surface (the lower surface in FIG. 2) that is the surface opposite to the surface on which the counter substrate 20 is bonded. A large dust-proof glass substrate 300 as a substrate is attached. The large dust-proof glass substrate 300 becomes the dust-proof glass substrate 30 by being divided into chips.

  Step (c): After that, the entire substrate is cleaned, and the outer surface (upper surface in FIG. 2), which is the surface opposite to the surface facing the large substrate 110, of each counter substrate 20 has substantially the same shape as the counter substrate 20. A small dust-proof glass substrate 31 is attached.

  Step (d): A scribe line L is formed on the surface of the large substrate 110 where the counter substrate 20 is bonded, the large substrate 110 is divided along the scribe line L, and the chip-like liquid crystal display device 1 is cut out. At this time, the large dustproof glass substrate 300 is also cut out into the chip-shaped dustproof glass substrate 30.

  By the way, since the gap member 42 described later is dotted on the periphery of the large substrate 110 and does not affect the region of the liquid crystal display device 1 to be cut out, the large substrate 110 is divided along the scribe line L. When discarded.

  In the mounting process of the dust-proof glass substrates 30 and 31, the process (b) and the process (c) are interchanged, and before the large dust-proof glass substrate 300 is attached to the large-sized substrate 110, the small dust-proof glass is applied to the counter substrate 20. You may make it affix the glass substrate 31. FIG.

  Next, the process of attaching the large dustproof glass substrate 300 shown in FIG. 3B will be described in more detail with reference to the process diagram of FIG.

  Step (a): A large dust-proof glass substrate 300 is placed on the stage 40. As shown in FIG. 6, the stage 40 is formed with a recess 40 a for attaching a large dustproof glass substrate 300, and an elevating device 43 is disposed around the recess 40 a. Since the periphery of the large substrate 110 is placed on the lifting device 43, the large substrate 110 according to the present embodiment has a larger outer shape than the large dust-proof glass substrate 300.

  Next, a thermosetting transparent adhesive 41 made of a silicon adhesive or an acrylic adhesive adjusted to the same refractive index as that of the large dustproof glass substrate 300 is applied to the center of the large dustproof glass substrate 300, and the surroundings The gap material 42 is pointed at predetermined intervals. The gap material 42 may be applied to the entire outer periphery of the large dust-proof glass substrate.

  As shown in FIG. 8A, the gap material 42 includes a gel-like ultraviolet curable adhesive 42a as a second adhesive, and gap material fine particles 42b mixed in the ultraviolet curable adhesive 42a. And have. The ultraviolet curable adhesive 42 a and the gap material fine particles 42 b have no affinity for the thermosetting transparent adhesive 41.

  The fine particles 42b for the gap material have a particle size that is the same as or smaller than the gap of the adhesive layer formed between the large dust-proof glass substrate 300 and the large substrate 110. The height is set slightly higher than the gap between the adhesive layers described above.

  Further, as shown in FIG. 5, the stippling position of the gap material 42 is discarded when the chip-shaped liquid crystal display device 1 is cut out, for example, at a position that does not affect the pixels formed on the large substrate 110. Pointed to the location. However, the dust-proof glass substrate 300 and the large-sized substrate 110 bonded to the dust-proof glass substrate 300 are not spotted on the alignment mark 300a for positioning, and are also spotted at a relatively short pitch at a position close to the alignment mark 300a.

  Next, the large substrate 110 on which the plurality of liquid crystal panels 120 are formed is opposed to the large dustproof glass substrate 300 in a state where the alignment adjustment is performed in a predetermined manner, and the large substrate 110 is placed on the lifting device 43 provided around the stage 40. It is made to support and it transfers to the decompression chamber 130 in this state. As shown in FIG. 6, when the large substrate 110 is warped due to the annealing process performed in the manufacturing process of the large substrate 110 (so-called pre-process) and the stress ballast when the counter substrate 20 is bonded. There is.

  Step (b): After the large dust-proof glass substrate 300 is carried into the decompression chamber 130, the interior is decompressed, and after reaching a set pressure (for example, 2.5 [Pa]), it is left until about 300 [sec] elapses. To do. Alternatively, the decompression chamber 130 is left until reaching a preset pressure (for example, 1.0 [Pa]).

  Step (c): After the decompression chamber 130 reaches the state set in step (b), the large substrate 110 is dropped onto the large dust-proof glass substrate 300 through the lifting device 43, for example, about 0.5 [mm / sec]. Place it gently at a speed and paste it together.

  Then, it is left for a predetermined time (for example, about 300 [sec]). Then, the large substrate 110 is brought close to the large dust-proof glass substrate 300 by its own weight, and the thermosetting transparent adhesive 41 is pushed and spread around the bottom surface of the large substrate 110. At the same time, the gap material 42 drawn on the large dust-proof glass substrate 300 is brought into contact with the periphery of the large substrate 110.

  Step (d): The pressure head 44 is brought into contact with the entire surface of the large substrate 110 while being lowered from above, and the large substrate 110 is brought into contact with the predetermined pressure (for example, about 100 [g / cm 2]) for a predetermined time. Press only (for example, about 180 [sec]). Then, as shown in FIGS. 7 and 8A, the periphery of the large substrate 110 is supported by the gap material 42, and the warp is slowly corrected while the gap material 42 is crushed. In the meantime, the thermosetting transparent adhesive 41 slowly diffuses to the surroundings while extruding air between the large substrate 110 and the large dustproof glass substrate 300 in the outer peripheral direction.

  Then, as shown in FIG. 8B, the large substrate 110 is extended in the horizontal direction to correct the warp, and the thermosetting transparent adhesive 41 is evenly distributed between the large substrate 110 and the large dust-proof glass substrate 300. The two substrates 110 and 300 are bonded together with high adhesion. As a result, even if the large substrate 110 is warped, adhesion failure due to insufficient penetration of the thermosetting transparent adhesive 41 does not occur, and the product yield can be improved.

  The ultraviolet curable adhesive 42a and the gap material fine particles 42b of the gap material 42 have non-affinity with the thermosetting transparent adhesive 41. Therefore, the ultraviolet curable adhesive 42a and the gap material 42 The fine particles 42b are not mixed in the thermosetting transparent adhesive 41.

  Step (e): In step (d), after a predetermined time (for example, about 180 [sec]) has elapsed, the decompression chamber 130 is gradually increased in pressure to reach atmospheric pressure, and then the two bonded together from the decompression chamber 130 are combined. The substrates 110 and 300 are taken out, and the ultraviolet curable adhesive 42a of the gap material 42 applied around the large dust-proof glass substrate 300 is cured by spot irradiation with ultraviolet rays 45 to temporarily fix the substrates 110 and 300. .

  Step (f): Both substrates 110 and 300 temporarily fixed by the ultraviolet curable adhesive 42a are transported to a high temperature chamber 131 heated to a predetermined temperature (for example, about 80 [° C.]), in which a predetermined The substrate is left to stand for a period of time (for example, about 1.5 [h]), and the thermosetting transparent adhesive 41 is cured to bond the substrates 110 and 300 together. Since the large substrate 110 and the large dust-proof glass substrate 300 are temporarily fixed by the ultraviolet curable adhesive 42a, they are bonded in a stable posture without being displaced.

  Then, after elapse of a predetermined time (for example, about 1.5 [h]), the two substrates 110 and 300 bonded to each other are taken out from the high temperature chamber 131 and cooled to a predetermined level to complete the bonding of the large dustproof glass substrate 300.

  Even if the curing time of the thermosetting transparent adhesive 41 is set to be relatively long, since the whole is bonded at once, the total curing time can be significantly reduced as compared with the case of individually curing. And productivity can be improved accordingly.

  In the present invention, the electro-optical device may be a liquid crystal device having a passive matrix type liquid crystal device or a TFD (thin diode) as a switching element in addition to the TFT active matrix driving type liquid crystal device. In addition to electroluminescence devices, organic electroluminescence devices, plasma display devices, electrophoretic display devices, devices using electron-emitting devices (Field Emission Display and Surface-Conductin Electron-Emitter Display), and DLP (Digital The present invention can also be applied to various electro-optical devices such as light processing and DMD (digital micromirror device).

Schematic sectional view of a liquid crystal display device A perspective view of a state where a chip-like counter substrate is bonded to a large substrate Process diagram showing the process of mounting a dust-proof glass substrate on the outer surface of the liquid crystal panel Process diagram showing the bonding process of a large dustproof glass substrate Top view of gap dust on a large dustproof glass substrate Enlarged view of Fig. 4 (b) Enlarged view of Fig. 4 (d) Fig. 7 is an enlarged cross-sectional view showing each state.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device, 31 ... Small dust-proof glass substrate, 40 ... Stage, 40a ... Recessed part, 41 ... Thermosetting transparent adhesive, 42 ... Gap material, 42a ... Ultraviolet curable adhesive, 42b ... Fine particle for gap materials, 43 ... Lifting device, 44 ... Pressure head, 100 ... Large substrate, 110 ... Large substrate, 300 ... Large dust-proof glass substrate

Claims (6)

In the method for manufacturing a substrate in which a second large substrate is bonded to substantially the entire surface of the first large substrate with respect to the first large substrate set on the stage via the first adhesive.
An application step of applying the first adhesive to approximately the center of the first large substrate, and applying a gel-like gap material to the outer periphery of the first large substrate;
A substrate bonding step of bonding the second large substrate to the first large substrate while pressing the outer periphery of the second large substrate while being supported by the gap material. A method for manufacturing a substrate. The method for manufacturing a substrate according to claim 1, wherein the gap material does not have an affinity for the first adhesive. 3. The method of manufacturing a substrate according to claim 1, wherein the gap material comprises a gel-like second adhesive and fine particles for gap material. 4. The method for manufacturing a substrate according to claim 3, wherein the fine particles for gap material do not have an affinity for the first adhesive.   5. The method for manufacturing a substrate according to claim 3, wherein the second adhesive is an ultraviolet curable adhesive. The substrate manufacturing method according to claim 1, wherein the gap material is plotted on the outer periphery of the first large substrate at set intervals.

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