1. Field of the Invention
The present invention relates to a technique for manufacturing liquid crystal display devices with a slim bezel by surface close attachment.
2. Description of the Background Art
In most cases, when manufacturing liquid crystal display devices, a plurality of panels are provided on a single mother glass, and then divided into individual panels. In recent years, in order to eliminate generation of small scraps to simplify the manufacturing steps, and to make efficient use of the mother glass, it has become increasingly common to manufacture liquid crystal display devices by closely attaching adjacent panels (hereinafter referred to as “surface close attachment”). Further, a bezel region constituting a non-display region around a panel tends to be made slim, and so-called bezel slimming has been promoted.
In this manner, when panels are formed by surface close attachment and bezel slimming becomes advanced, a region for forming a transfer member and a sealing member provided on a bezel region (for the sealing member, especially protrusions in which an inlet is provided) as well as a margin of distance for a cutting line for separating between panels and for adjacent panels are reduced.
In addition, such a transfer member and a sealing member are both typically formed in such a manner that a paste material that has been applied is sandwiched between substrates and then spread therebetween, and therefore positions for formation and amounts of spread vary to a relatively large extent.
Therefore, it has become difficult to form a transfer member and a sealing member in a predetermined region of formation for these members without making their paste materials spread out of the region of formation. If the paste materials spread out over the cutting line for separating between panels or over an adjacent panel region, the glass substrate may be adhered (bonded) by the paste material at a portion not desired, resulting in wrong cutting.
As described above, in the case in which panels are formed by surface close attachment and with a slimmer bezel, probability of a wrong cutting due to spreading of the paste materials increases, and consequently it is difficult to manufacture liquid crystal display devices at a high yield ratio.
Thus, regarding the spreading out of paste materials, Japanese Patent Application Laid-Open No. 2003-215622, International Publication No. WO00/45360, and Japanese Patent Application Laid-Open No. 2006-268020, for example, disclose a method of forming a transfer member a within a predetermined region by enclosing a region of formation for a transfer member and a sealing member by a sealing member or a columnar spacer in a form of a bank.
Further, Japanese Patent Application Laid-Open No. 2001-166121 discloses provision of a cutting mark as an indication of a position for cutting, near an intersection between cutting lines.
However, according to the method described in Japanese Patent Application Laid-Open No. 2003-215622, when using the sealing member to form an enclosure for enclosing the transfer member, there is still a concern that the sealing member as the bank itself may spread out, and as a result, it is not possible to provide the transfer member near a cutting line, and a contribution of this method to bezel slimming is not that much.
Further, according to the method described in International Publication No. WO00/45360, when using a columnar spacer to form a projection for enclosing both the sealing member and the transfer member, an enclosure in a form of the bank is to be additionally provided around the sealing member only to prevent spreading out. Therefore, a region for forming an enclosure in a form of a bank itself increases, and a contribution of this method to bezel slimming is limited.
Moreover, according to the method described in Japanese Patent Application Laid-Open No. 2006-268020, when forming the transfer member and an enclosure using a columnar spacer for enclosing the transfer member inwardly from the sealing member for enclosing liquid crystals, there is a possibility that the transfer member is brought into contact with the liquid crystals while it is possible to prevent an unnecessary region from increasing in the outside of the sealing member. This results in a concern of a reduced yield ratio brought by factors such as display defects due to contamination of the liquid crystals.
Furthermore, as described in Japanese Patent Application Laid-Open No. 2001-166121, it is commonly employed to provide the cutting mark near the intersection between the cutting lines, and such a cutting mark is also formed in the case of surface close attachment and bezel slimming. However, the cutting mark is primarily provided as the indication of the position for cutting, and may not particularly affect spreading out of paste materials as typically formed by a thin film of a metal, a resin or the like. This means that the cutting mark described in Japanese Patent Application Laid-Open No. 2001-166121 may not solve the above problems.
As described above, there has not been proposed an effective method which may allow manufacturing of liquid crystal display devices with a sufficiently slim bezel both by surface close attachment and at a high yield ratio.