JPH02107374A - Preparation of printed wiring board - Google Patents

Abstract

PURPOSE:To prevent the deterioration of post treatment quality, in a method for coating a printed wiring board with a liquid coating agent by a spin coater, by forming the board into a flat plate-shape and providing a taper part reduced in its wall thickness outwardly to the peripheral part of said board. CONSTITUTION:For example, the printed wiring board of a liquid crystal display device is processed by dripping a photoresist solution on a flat glass substrate and rotating the same at low and high speeds. At this time, the excessive photoresist solution is turned to the rear of the substrate from the side surface thereof at the time of low speed rotation and the removal thereof becomes difficult. Thereupon, the glass substrate 10 is prepared so that the wall thickness of the wiring region part to which pattern processing is applied to said substrate is made uniform and a taper part reduced in its wall thickness outwardly is formed to the peripheral edge part thereof. That is, an inclined surface 12a is formed to the surface 10a of the substrate 10 and a curved part 12b is formed to the end part thereof. By this constitution, the excessive photoresist solution is easily scattered outwardly through the inclined and curved parts 12a, 12b at the time of low speed rotation to avoid such a state that the photoresist solution creeps to the rear of the substrate 10 from the side surface thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a wiring board suitably used for glass substrates used in, for example, liquid crystal display elements, and more specifically relates to a method for manufacturing a wiring board that is suitably used for glass substrates used in liquid crystal display devices, etc. The present invention relates to the shape of a wiring board that is suitably used when patterning a transparent conductive film or the like by coating a square glass substrate with photoresist or the like.

Conventional Technology In the manufacturing process of a so-called active 7-trix type liquid crystal display device equipped with a thin film transistor (TPT), for example, as shown in FIG. It is necessary to process fine patterns of transparent conductive films, various metal films, semiconductor films, insulating films, etc., and a photoetching method is used for this fine pattern processing. This photoetching method uses a spin coater, in which a photoresist solution is dropped onto the glass substrate 1, the glass substrate 1 is rotated, and the dropped photoresist solution is spread over the surface of the glass substrate 1 by the centrifugal force generated at this time, thereby coating the surface of the glass substrate 1. A coating device called .

FIG. 6 is a cross-sectional view for explaining the application operation of photoresist liquid. -Finally, when applying the photoresist liquid 2, first rotate the glass substrate 1 at low speed to spread the dropped photoresist liquid 2 over the entire surface 1a, and then shake it off at high speed. Determine the film thickness. As described above, the rotation speed of the glass substrate 1 changes in two stages from low speed rotation to high speed rotation, but during the low speed rotation, the centrifugal force is small, so that the excess photoresist liquid 2 does not scatter to the outside. , a phenomenon occurs in which the light wraps around from the side surface 1b of the glass substrate 1 to the back surface 1c.

In order to remove the photoresist liquid 2 adhering to the back surface 1c, a back-rinsing method has conventionally been used in which a cleaning liquid is sprayed toward the back surface 1c of the glass substrate l to dissolve and remove the photoresist liquid 2.

Although this pack-rinsing method can remove excess photoresist solution 2 attached to the back surface 1c of the glass substrate 1, does it remove excess photoresist solution 2 attached to the side surface 1b? It is difficult to remove 1!2. The excess photoresist solution 2 adhering to the side surface 1b and back surface 1c of the glass substrate 1 contaminates the baking furnace and its atmosphere in the next resist baking step, and furthermore, the dried extra photoresist is peeled off in the next exposure step. This causes dust to float in the air and cause poor exposure.

An object of the present invention is to provide a method for manufacturing a wiring board that can improve the processing quality of a processing step after applying a liquid coating material such as a photoresist solution.

Means for Solving the Problems The present invention provides a substrate having a flat plate shape and having a tapered portion in which the thickness decreases toward the outside at the periphery, and rotating the substrate in a direction extending in the thickness direction. This is a method of manufacturing a wiring board, characterized in that the liquid coating agent is applied to the surface of the substrate by centrifugal force by rotating the substrate around an axis.

According to the present invention, a tapered portion is formed at the peripheral edge of the substrate, the thickness of which decreases toward the outside, so that the substrate is rotated to apply a liquid coating agent such as a photoresist solution. In the coating process where centrifugal force is applied to the substrate surface, for example, even when the centrifugal force is small at low speed rotation,
The excess photoresist scatters outward along the tapered portion without going around to the back surface of the substrate, thereby preventing excess liquid coating agent from adhering to parts other than the front surface of the substrate. Therefore, it is possible to prevent deterioration of the processing quality of the processing step after the coating process due to the adhesion of excess liquid coating agent.

Embodiment FIG. 1 shows a glass substrate 1 used in an embodiment of the present invention.
FIG. This glass substrate 10 is used, for example, in a so-called active matrix type liquid crystal display device equipped with a thin film transistor (TPT), and various wirings such as a transparent conductive film are formed on its surface by photoetching.

FIG. 2 is a partial cross-sectional view of the first I2I as viewed from the section line ■-■. The glass substrate 10 is composed of a wiring area portion 11 on which various types of wiring patterns such as transparent electrodes are patterned on one surface thereof, and a tapered portion 12 formed around the wiring area portion 11. . The wiring region portion 11 is formed to have a uniform thickness. On the other hand, the tapered part 12 is formed so that its thickness decreases as it goes outward, and more specifically, the surface of the glass substrate 10 (the surface to which fine pattern processing is applied, the upper side in FIG. 2) An inclined surface 12a having a constant inclination is formed at 10a, and a curved portion 12b is formed at the end thereof.

FIG. 3 is a diagram showing a simplified configuration of the spin coater 15 for applying photoresist onto the glass substrate 10. As shown in FIG. The spin coater 15 includes a container 16 and a glass substrate 10.
A resist discharge nozzle 18 discharges a photoresist solution, and a back rinse liquid discharge nozzle 19 discharges a back rinse liquid.

The vacuum chuck 17 is rotationally driven by a rotation motor (not shown), and the glass substrate 10 is thereby rotationally driven.

FIG. 4 is a graph showing the application operation of the photoresist liquid. In FIG. 4, the horizontal axis represents time (seconds), and the vertical axis represents the number of revolutions per minute (rpm) of the glass substrate 10. The operation of the spin coater 15 will be described with reference to FIGS. 3 and 4.

In FIG. 4, a photoresist 1 is deposited on a glass substrate 10 using a resist discharge nozzle 18 for a period W1 from time 10.
-Drop the liquid and end at time t1.

Thereafter, the rotation of the glass substrate 10 is started from time t2, and when the rotational speed reaches a constant rotational speed R1 (20 Orpm) (time t3), backrinsing liquid is immediately applied from one backrinsing liquid discharge nozzle to the glass substrate for a period W2. The photoresist liquid is discharged onto the back surface 10b of the substrate 10, and the photoresist liquid adhering to the back surface 10b is dissolved and removed. During the period (from time t3 to time t4) 1.1 during which the rotation speed of the glass substrate 10 is maintained at a constant rotation speed R1, the glass substrate 10
The resist liquid dropped on top is spread over the entire surface.

After this, from time t4, the 5 rotation speed of the glass substrate 10 is increased to the rotation speed R2 (1000 rpm), and the glass substrate 10
The excess photoresist liquid on top is shaken off, and the film thickness of the photoresist liquid is determined. The operation of discharging the backlin and solute liquids is continued until time t5, and at time L6, the rotation of the glass substrate 10 is stopped and the coating operation of the photoresist I liquid is completed.

Here, a low speed rotation period T during which an operation is performed to spread the dropped resist solution over the entire area of the glass substrate 10 is performed.
1, although the centrifugal force during the glass period 10 is small in this period, since the tapered portion 12 is formed at the peripheral edge of the glass substrate 10 as described above, the excess on the surface 10b of the resist l-M The flow of the photoresist liquid improves, and the photoresist liquid easily scatters outward through the inclined portion 12a and the curved portion 12b of the tapered portion 12.

Therefore, due to the small centrifugal force, excess photoresist *a is avoided. In addition, the back side 1. The photoresist liquid adhering to the O b is dissolved and removed by a back rinse liquid.

Therefore, as described in the prior art section, it is possible to prevent deterioration in the quality of subsequent processing due to excess photoresist solution adhering to the side or back surface of the glass substrate.
Note that at the stage of completion of the product as a liquid crystal display element, the tapered portion 12 is removed, and the wiring area portion 11 having a uniform thickness is removed.
Only this type of material is used as a substrate for liquid crystal display devices.

Effects of the Invention As described above, according to the present invention, the tapered portion is provided at the peripheral edge of the substrate, so that during the coating operation in which the substrate is rotated and a liquid coating agent such as photoresist liquid is applied, the substrate is It is possible to prevent excess liquid coating agent from adhering to areas other than the surface, and it is possible to improve the processing quality of subsequent processing steps.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a glass substrate 1o according to an embodiment of the present invention;
Figure 2 is a sectional view taken from the section line ■-■ in Figure 1;
The figure shows a simplified configuration of the spin coater 15.
The figure is a graph showing the coating operation of photoresist liquid by the spin coater 15, FIG. 5 is a perspective view of a typical prior art glass substrate 1, and FIG. 6 is a sectional view of a portion thereof. DESCRIPTION OF SYMBOLS 10... Glass substrate, 11... Wiring area part, 12.
・Taper part, 15...Spin coater agent Patent attorney Kei Saikyo Part 1-r--Go- WI W2

Claims (1)

[Scope of Claims] A flat plate-shaped substrate having a peripheral edge formed with a tapered portion whose thickness decreases toward the outside is prepared, and the substrate is rotated about a rotation axis extending in the thickness direction. A method for manufacturing a wiring board, characterized in that a liquid coating agent is applied to the surface of the board using centrifugal force.