JP3260511B2 - Sealant drawing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for applying a sealant, and in particular, dispenses a sealant (adhesive) for sealingly joining upper and lower substrates of a liquid crystal display element to a predetermined portion in a required amount. The present invention relates to a sealant drawing method.

[0002]

2. Description of the Related Art For example, in various electronic devices in which a flat substrate such as a liquid crystal display element is adhered to a predetermined portion of a peripheral portion thereof with a specific pattern with a sealant interposed therebetween, the seal is applied by screen printing. Was common.

In particular, in a liquid crystal display element having various functional films including an alignment film on its inner surface, in order to avoid contact between the applied sealant and the functional film, the sealant is discharged from a nozzle and continuously applied. A so-called dispense coating method has been used.

FIG. 11 is a schematic diagram for explaining a schematic configuration of a liquid crystal display element, wherein 1 is a glass substrate (1a is an upper substrate, 1
b is a lower substrate, 4 is a sealant (epoxy resin adhesive or the like), and 4a is a liquid crystal injection opening.

[0005] The upper substrate 1a and the lower substrate 1b are formed by applying a sealant 4 to the peripheral portions thereof and bonding them together, and injecting liquid crystal from a liquid crystal injection opening 4a between the bonded gaps and sealing them.

[0006] Figure 12 is an enlarged view of a corner portion of the sealing material after bonding, the coating after the corner portion 4 b of the sealant 4 electroconductive paste (silver - epoxy resin) is applied,
When the sealant 4 is cured and the upper and lower substrates are bonded,
The conductive paste applied to the corners 4b is also hardened to electrically connect the conductive layers formed on the upper and lower substrates 1a and 1b.

FIG. 13 is an enlarged view of an essential part for explaining an example of a sealing agent application pattern in a corner portion by a conventional screen printing and a sealing agent pattern when the upper and lower substrates are bonded to each other. In order to secure a space for applying the conductive paste to the corners when enlarging the sealant and applying the sealant, shapes such as a and b are given as shown in FIG. When the upper and lower substrates are bonded together, this sealant pattern is spread out between the substrates, and as a result, the width of the corner portion is equal to the width of the straight portion as shown in FIGS. It becomes possible to secure a coating space.

However, in such screen printing ,
Because there was a problem, it began to dispense the coating is adopted.

FIG. 14 is a schematic view for explaining a schematic configuration of a conventional dispensing apparatus, wherein 10 is an XYZ table movable in X, Y, and Z directions, 11 is a glass substrate of a liquid crystal display element, and 12 is A nozzle arm, 13 is a nozzle, 14 is an air source, 15 is a sensor arm, and 16 is a gap sensor.

In FIG. 1, a glass substrate 11 of a liquid crystal display element is fixedly held on an XYZ table 10 and a nozzle arm 12 holding a nozzle 13 for dispensing a sealant thereabove, a glass substrate 11 and a nozzle 13.
A sensor arm 15 holding a gap sensor 16 for keeping a gap between the sensor arm 15 and the gap constant is arranged.

A predetermined sealant is stored in the nozzle 13 in advance, and an air source 14 for applying a predetermined pressure to the sealant is connected.

This dispensing applicator moves the XYZ table 10 in the X and Y directions while moving the nozzle 13
The sealant is dispensed on the periphery of the glass substrate 11. During the dispensing, a sensor 16 that moves the position preceding the nozzle 13 together with the nozzle on the glass substrate 11 measures a gap between the surface of the glass substrate 11 and the nozzle 13 so that the gap is always constant. The position of the XYZ table 10 is adjusted in the Z direction.

In some cases, the nozzle arm 12 and the sensor arm 15 are moved in the XYZ directions instead of the XYZ table.

In this type of dispenser, the sealant is dispensed by applying pressure to the sealant with a constant pressure applied from the air source 14. Therefore, the dispensing of the sealant becomes a so-called one-stroke drawing pattern. The discharge amount of the sealant during drawing is constant, and the amount of the sealant dispensed on the glass substrate 11 is controlled to be constant by keeping the gap constant.

The prior art relating to this type of dispensing apparatus is disclosed in Japanese Patent Laid-Open No. 2-19.
8417, JP-A-1-200228, JP-A-63-177113, JP-A-63-19201
9 and JP-A-63-236008.

[0016]

In the dispensing device according to the prior art described above, the discharge amount of the sealant when the discharge of the sealant is started and when the discharge of the sealant is stopped largely fluctuates. for that reason,
The spread of the sealant when the upper and lower substrates are bonded differs between the start and the stop of the discharge, and the increase in the application amount at the corner deteriorates the characteristics of the conductive paste separately applied to the corner. There was a problem that would.

[0017] Figure 15 is an explanatory view of a coated state of the sealant according to the conventional dispensing coating apparatus, (a) shows the air pressure applied to <br/> nozzle, (b) the seal is applied to the glass substrate Shows the shape of the agent.

[0018] As shown in the drawing, be applied to the nozzle air pressure of a predetermined level A in the coating start point, actually when the sealant is discharged from the nozzle onto the glass substrate is delayed by d ₁ , also remove the air pressure in the coating stop time, from a nozzle by residual pressure made the ejection of the sealant to a position delayed by d _2, becomes large discharge amount of the sealing agent in the coating stop position, and stop It is applied to a position beyond the position.

Therefore , it is difficult to draw a particularly short straight line, and since the amount of the sealant discharged at the corner is the same as that of the straight part, the amount of the sealant applied to the corner becomes large. Spreading of the sealant is increased by bonding the substrates. Therefore, there is a problem that the conductive paste applied to the corner portion is mixed with the sealant, thereby deteriorating the conductive connection characteristics of the upper and lower substrates.

An object of the present invention is to provide a sealant drawing method which solves the above-mentioned problems of the prior art, controls a discharge amount of a dispensed sealant, and speeds up application.

[0021]

Means for Solving the Problems In order to achieve the above object, the invention of claim 1 provides a nozzle containing a sealant,
A sealant drawing method for drawing a sealant in a required pattern on the substrate to be coated by applying a predetermined air pressure from an externally provided air source and discharging the sealant onto the substrate to be coated. By inputting a high-pressure air pulse higher than the predetermined pressure from the air source to the nozzle at the start of application of the sealant and applying a vacuum pulse at a stop point of application of the sealant, the sealing is performed. The discharge amount of the sealant at the time when the application of the sealant is started and the point at which the application of the sealant is stopped are made substantially equal, and the application position is controlled to a predetermined position.

The invention according to claim 2 is characterized in that a predetermined air pressure from an externally provided air source is applied to a nozzle storing the sealant to discharge the sealant onto the substrate to be coated. In a sealant drawing method for drawing a sealant in a required pattern on the substrate to be coated, the pattern to be drawn is constituted by a combination of two sealant coating elements of a straight line and a point, and each of the sealant coating elements is provided.
Coating of the nozzle from the air source to the nozzle
High pressure higher than the predetermined pressure at the start of applying the sealant
Input air pulse and apply vacuum at the stop point of application of the sealant.
It is characterized in that it is performed by applying a pulse .

Further, according to the present invention, a predetermined air pressure from an externally provided air source is applied to the nozzle storing the sealant to discharge the sealant onto the substrate to be coated. In the sealant drawing method of drawing a sealant on the substrate to be applied in a required pattern, the pattern to be drawn is constituted by a combination of two sealant application elements of a straight line and a point, and each of the sealant application elements is the control of the discharge amount of the sealing agent for coating, with respect to the air source or al the nozzle, and enter the predetermined higher pressure air pulse at the application start time of the sealant,
The method is characterized in that a vacuum pulse is applied at a point where the application of the sealant is stopped , and the change is performed by changing a gap between the nozzle and the substrate to be applied.

According to a fourth aspect of the present invention, a predetermined air pressure from an externally provided air source is applied to a nozzle storing the sealant to discharge the sealant onto the substrate to be coated. In the sealant drawing method for drawing the sealant in a required pattern on the substrate to be coated, the control of the discharge amount of the sealant is performed by controlling the diameter of the nozzle and the airflow.
A) the seal varies with the pressure and the viscosity of the sealant
Particular discharge amount of agent discharge amount and narrowing the gap is reduced at less range does not change much the discharge amount of the sealing agent at least a certain minimum value gap between the substrate to be coated and the nozzle wherein said nozzle based and performs the control of the gap between the substrate to be coated.

[0025] The present invention is the discharge amount control by the variation of the gap between the discharge amount control and the nozzle and the substrate to be coated by the high-pressure air pulse and vacuum pulses as described above, and a change in the relative speed between the nozzle and the substrate to be coated By appropriately combining, various complicated patterns can be drawn.

[0026]

According to the structure of the first aspect of the present invention, the corner portion is provided.
By controlling the amount of sealant required for bonding
The spread of the sealant at the corners is prevented,
Area for conductive paste to be separately applied to the corner
can do

Further, according to the configuration of the second aspect of the present invention,
Eliminates delay in applying sealant at the start of sealant application
Of the sealant at the point where the application of the sealant stops.
The increase can be prevented, and the application of the sealant stops from the application start point.
A substantially uniform coating can be applied to a predetermined position up to the stop point.
You.

Further, according to the configuration of the third aspect of the present invention, it is possible to accurately perform a pattern of a drawing portion other than a straight line.

According to the configuration of the fourth aspect of the present invention, the amount of the sealant applied can be accurately controlled.

[0030]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1A and 1B are explanatory views of a first embodiment of a method of applying a sealant according to the present invention, wherein FIG. 1A shows air pressure applied to a nozzle, and FIG. Show the shape.

In FIG. 3A, reference symbol A denotes a predetermined air pressure level for dispensing a sealant from a nozzle;
The predetermined air pressure level A high pressure air pressure than, L is the predetermined low vacuum air pressure than the air pressure level A, O is the reference level of the air pressure 0 the sealant is not dispensed from the nozzle, A _P is pressure air pulse, the V _P is a vacuum pulse.

The substrate to be coated was shown (e.g., a liquid crystal glass substrate of the device) high pressure air pulse A high pressure have level H than a predetermined air pressure level A in the coating start point P ₁ is a position for starting the application of the sealant _{Apply P} to the nozzle. Thus, the sealant 4 is dispensed to the target coated on the substrate without delay is coated at the starting point P _1.

Thereafter, the dispensing is continued at the predetermined air pressure level A, and the vacuum air pressure level L is obtained at the application stop point P _2.
Applying a vacuum pulse V _P of. Thereby, the sealant 4
Has dispensing without coating is made over the coating stopping point P ₂ is stopped.

As described above, according to the present embodiment, the sealing agent 4 is applied to the substrate to be coated within the range from the application start point P ₁ to the application stop point P ₂ as shown in FIG. The coating is performed in a substantially uniform amount, and a non-uniform application of the sealant, which deviates from a predetermined application range as described with reference to FIG. 15, is avoided.

FIG. 2 is an explanatory view of a second embodiment of the method for applying a sealant according to the present invention, wherein 1b is a substrate to be applied (for example, a lower glass substrate of a liquid crystal element), and 4-1 is an applied sealant. The linear element, 4-2, is the applied sealant point element.

The sealant linear element 4-1 and the sealant point element 4-2 are formed by discharging and applying the sealant in the same manner as in the first embodiment. The application is interrupted at the corners, and details are applied by a plurality of sealant point elements 4-2.

FIG. 3 is an explanatory view of the state of the sealant when another substrate (for example, an upper glass substrate of a liquid crystal element) 1a is bonded to the substrate 1b having the sealant applied in FIG. In addition, the sealant linear element 4-1 pushes and spreads at a corner portion and a continuous frame-shaped seal 4-1 ′.
Becomes Similarly, the sealing agent point element 4-2 is pushed and spread to form a continuous linear pattern 4-2 '.

As described above, according to the present embodiment, it is possible to form a sealant pattern in a desired shape.

FIG. 4 is an explanatory view of a method of controlling an air pressure applied to a nozzle for discharging a sealant to each pattern of a sealant linear element and a sealant point element in the second embodiment of the present invention. (A) is an application timing diagram of the air pressure, and (b) is a pattern diagram of the discharged sealant.

Referring to FIG.
-1 applies a high pressure air pulse A _P in its application start point,
It continued dispensing at a predetermined air pressure level A, to apply a vacuum pulse V _P to the nozzle by application stop point. The sealing agent point element 4-2 applies a high-pressure air pulse A _P at the application start point, and then applies a vacuum pulse V _P to the nozzle.

As described above, by controlling the air pressure applied to the nozzles, it is possible to obtain a sealant application pattern as shown in FIG.

FIGS. 5 and 6 are explanatory views of a modification of the method of applying the sealant at the corners of the seal pattern.

FIG. 5A shows that the discharge amount is reduced by making the gap between the nozzle and the substrate to be coated (the lower glass substrate) slightly smaller at the end of the sealant linear element 4-1, that is, at the corner. Sealant point element 4- to secure an area for separately applied conductive paste
2 is applied.

When the other substrate to be coated (upper glass substrate) is bonded to the substrate to be coated (lower glass substrate) on which the sealant has been applied in this manner, a linear pattern 4- as shown in FIG. A seal pattern in which 1 'and 4-2' are continuous is obtained.

FIG. 6A shows that the gap between the nozzle and the substrate to be coated (lower glass substrate) is made smaller than the discharge limit at the end of the sealant linear element 4-1, that is, at the corner. To stop the discharge amount, or to stop the discharge by applying the above-described vacuum pulse,
The sealant point element 4-2 for securing an area for a separately applied conductive paste is applied.

When the other substrate to be coated (upper glass substrate) is bonded to the substrate to be coated (lower glass substrate) on which the sealant has been applied in this manner, a straight line pattern 4 as shown in FIG. A seal pattern in which 1 'and 4-2' are continuous is obtained.

FIG. 7 is a schematic configuration diagram of a sealant applying apparatus for explaining the control of the discharge amount of the sealant by changing the gap between the nozzle and the substrate to be applied, wherein 1b is the substrate to be applied (lower glass substrate). 2 is a nozzle, 3 is a gap sensor,
Reference numeral 4 denotes an applied sealant, and reference numeral 7 denotes an air pressure control device.

FIGS. 8 and 9 are explanatory diagrams of the sealant discharge control shown in FIG. 7, and the same reference numerals as those in FIG. 7 correspond to the same parts.

In FIG. 7, a predetermined amount of a sealant is stored in a nozzle 2 and set up and down in the direction of the arrow by a mechanism (not shown). In the nozzle 2, the discharge amount of the sealant discharged from the nozzle 2 is set by the air pressure introduced from the air pressure control device 7.

[0051] As shown in FIG. 8, when the gap between the substrate to be coated (the lower glass substrate) 1b and the nozzle 2 is G _1, the moving speed of the sealing agent 4 is an air pressure control device 7 and the nozzle 2 The amount determined by the above substrate to be coated (lower glass substrate)
1b.

On the other hand, as shown in FIG. 9, the gap between the coating substrate (lower glass substrate) 1b and the nozzle 2 is G
When the width is reduced to ₂ , the sealant 4 is applied to the substrate (lower glass substrate) 1b in a smaller amount than the discharge amount in FIG.

As described above, the discharge amount of the sealant can be controlled by changing the gap between the nozzle and the substrate to be coated.

When the gap is reduced to a certain degree or more, the discharge of the sealant 4 from the nozzle 2 is stopped.

In the sealant applying apparatus shown in FIG. 7, the gap between the nozzle and the substrate to be coated is measured by the gap sensor 3 installed on the nozzle, and the measured gap is fed back to the nozzle raising / lowering mechanism so as to be based on the set nozzle gap value. Thus, the sealant is discharged while keeping the gap constant. When the discharge amount of the sealant is changed, the gap control is performed based on the same gap by changing the set nozzle gap value.

FIG. 10 is an explanatory diagram showing the relationship between the size of the gap and the discharge amount of the sealant. The horizontal axis represents the gap height (gap size), and the vertical axis represents the discharge amount of the sealant from the nozzle. Take and show.

The condition shown in the figure is that the nozzle diameter is 0.2 mm,
The air pressure is 294 kpa and the coating speed is 30 mm 2 / s . Although the discharge amount of the sealant is also affected by the viscosity, here, a general epoxy resin used for sealing a liquid crystal element is used.

As shown, the size of the gap is 4
At 0 μm or less, the discharge of the sealant is stopped. And
In the range of 40 to 100 μm, the discharge amount of the sealant changes depending on the size of the gap. In addition, when the value is 100 or more, the relationship between the gap and the discharge amount does not change much.

As described above, the amount of the sealant to be discharged can be controlled by controlling the gap.

[0060]

As described above, according to the present invention,
With sealant applying delay is eliminated at the application start time of the sealant, it is possible to prevent the discharge amount increase of the sealant in the coating stopping point of the sealant, stop applying the coating starting point of the sealant
Substantially uniform application can be performed at a predetermined position up to the stop point .

Further, by controlling the amount of the sealant applied for bonding the corner portion, the spread of the sealant at the corner portion is prevented, and a region for applying the conductive paste to be separately applied to the corner portion is secured. can do.

Further, the pattern of the drawing portion other than the straight line can be accurately formed, and the application amount of the sealant can be accurately controlled.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a first embodiment of a sealing agent applying method according to the present invention.

FIG. 2 is an explanatory view of a second embodiment of the sealing agent applying method according to the present invention.

FIG. 3 is an explanatory diagram of a state of a sealing agent when another substrate is bonded to a substrate to be coated having the sealing agent applied in a second embodiment of the sealing agent applying method according to the present invention.

FIG. 4 is an explanatory diagram of a control method of an air pressure applied to a nozzle for discharging a sealant to each pattern of a sealant linear element and a sealant point element in a second embodiment of the present invention.

FIG. 5 is an explanatory view of a modified example of a method of applying a sealant at a corner portion of a seal pattern.

FIG. 6 is an explanatory diagram of another modified example of a method of applying a sealant at a corner portion of a seal pattern.

FIG. 7 is a schematic configuration diagram of a sealant application device for explaining control of a discharge amount of a sealant based on a change in a gap between a nozzle and a substrate to be applied.

FIG. 8 is an explanatory diagram of the sealant discharge control according to FIG. 7;

FIG. 9 is an explanatory diagram of the sealant discharge control according to FIG. 7;

FIG. 10 is an explanatory diagram of a relationship between a gap size and a discharge amount of a sealant.

FIG. 11 is a schematic diagram illustrating a schematic configuration of a liquid crystal display element.

FIG. 12 is an enlarged view of a corner portion of a sealing agent after bonding.

FIG. 13 is an enlarged view of a main part for explaining an example of a sealant pattern when the upper and lower substrates are bonded together with a sealant application pattern in a corner portion by conventional screen printing.

FIG. 14 is a schematic diagram illustrating a schematic configuration of a conventional dispensing device.

FIG. 15 is an explanatory view of a state where a sealant is applied by a conventional dispensing apparatus.

[Explanation of symbols]

 1a Upper glass substrate of liquid crystal display element 1b Lower glass substrate of liquid crystal display element 2 Nozzle 3 Gap sensor 4 Sealant.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Keiji Yajima 3300 Hayano, Mobara-shi, Chiba Electronic Devices Division, Hitachi, Ltd. (72) Shigeru Ishida 5-2-2 Koyodai, Ryugasaki-shi, Ibaraki Prefecture Hitachi Techno Engineering Co., Ltd. Inside the Research Laboratory (72) Inventor Shozo Igarashi 5-2-2 Koyodai, Ryugasaki-shi, Ibaraki Pref. Inside the Ryugasaki Plant of Hitachi Techno Engineering Co., Ltd. (56) References JP-A-62-240931 (JP, A) JP-A-63 -177113 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/1339 505 B05D 1/26

Claims (4)

(57) [Claims] 1. A method of applying a predetermined air pressure from an air source provided outside to a nozzle storing a sealant and discharging the sealant onto the substrate to be coated by applying the sealant to the substrate to be coated. In the sealant drawing method of drawing in a required pattern above, in a corner portion of the drawing pattern, the discharge of the sealant is stopped by applying a vacuum pulse to the nozzle immediately before the corner portion, and the application is interrupted. Immediately after the corner portion, after applying a high-pressure air pulse higher than the predetermined pressure to start discharge of the sealant and restarting its application, by applying the predetermined air pressure,
A method of drawing a sealant, comprising controlling a coating amount of the sealant required for bonding the corner portion. 2. A method of applying a predetermined air pressure from an externally provided air source to a nozzle storing a sealant and discharging the sealant onto the substrate to be coated by applying the sealant to the substrate to be coated. In the sealant drawing method for drawing a required pattern on the top, the pattern to be drawn is constituted by a combination of two sealant application elements of a straight line and a point,
The application of the cloth element is applied to the nozzle from the air source.
At the time when the application of the sealant is started,
Apply high pressure air pulse and stop applying sealant
And applying a vacuum pulse at a point . 3. A method of applying a predetermined air pressure from an externally provided air source to a nozzle storing a sealant and discharging the sealant onto the substrate to be coated, thereby applying the sealant to the substrate to be coated. In the sealant drawing method for drawing a required pattern on the above, the pattern to be drawn is constituted by a combination of two sealant application elements of a straight line and a point, and the sealant for applying each of the sealant application elements the control of the discharge amount, with respect to the air source or al the nozzle, and enter the predetermined higher pressure air pulse at the application start time of the sealant, applies a vacuum pulse in the coating stopping point of the sealant A method of drawing a sealant, the method being performed by changing a gap between the nozzle and the substrate to be coated. 4. A method for applying a predetermined air pressure from an externally provided air source to a nozzle storing a sealant and discharging the sealant onto the substrate to be coated, thereby applying the sealant to the substrate to be coated. In the sealant drawing method of drawing in a required pattern on the control of the discharge amount of the sealant, the discharge amount of the sealant changes depending on the diameter of the nozzle, the air pressure and the viscosity of the sealant. When the gap between the substrate and the substrate to be applied is greater than or equal to a certain value, the discharge amount of the sealant does not change so much. A method for drawing a sealant, which is performed by controlling the gap between the sealant and a substrate.