JP4619139B2 - Slit nozzle - Google Patents

Description

  The present invention relates to a slit nozzle that applies a coating liquid to a substrate surface with a certain width.

  As a method of applying a coating solution such as a photoresist on the surface of a glass substrate or the like, there is a method of dropping the coating solution from a normal nozzle onto the substrate surface and then rotating to make a uniform thickness. More than 90% of the coating solution is scattered and a large amount is wasted. Therefore, after applying the coating liquid to the substrate with a constant width using a slit nozzle, the coating liquid is applied to the substrate with a constant width by using a method of rotating the coating film to a certain degree by rotating to some extent, or using a slit nozzle, In recent years, the coating process has been completed.

  In order to reduce the waste of the coating solution as described above, it is necessary to make the thickness of the coating film uniform without rotating the substrate as much as possible. For this reason, it is necessary for the slit nozzle that the amount of the coating liquid discharged from the discharge port is uniform along the slit-shaped discharge port. Conventionally, various proposals have been made to ensure this uniformity.

In Patent Document 1, two coating liquid reservoirs are provided on one half of the slit nozzle so as to be spaced apart from each other in the vertical direction, and the slit nozzle in the width direction of the portion communicating with the two coating liquid reservoirs is disclosed in Patent Document 1. Proposals have been made to ensure the uniformity of the coating amount by providing a blocking portion at a location corresponding to the central portion.
In Patent Document 2, the slot (slit-shaped flow path) is divided into two stages of slot elements in the flow direction of the coating liquid, and the gap of each slot element is made different to control the pressure loss of the coating liquid. There have been proposals to ensure the uniformity of the coating amount.
In Patent Literature 3, a coating liquid reservoir is provided on one half of the slit nozzle, and a pressure regulator is continuously formed below the reservoir, and discharged through the pressure regulator. There has been a proposal that the coating liquid is uniformly discharged along the discharge port by supplying the coating liquid to the outlet.
Patent Document 4 proposes that a coating liquid reservoir is provided in one half of the slit nozzle, and a nozzle flow path forming member is disposed in the reservoir to provide a uniform coating amount. Has been made.

JP-A-7-326564 JP 2000-051777 A Japanese Patent Laid-Open No. 2002-086045 JP 2002-370057 A

As in the slit nozzles disclosed in Patent Document 2 and Patent Document 3, by providing a reservoir and a pressure regulating section on the lower side thereof, a certain degree of uniform application is possible, but this is not sufficient.
Further, as in the slit nozzles disclosed in Patent Document 1 and Patent Document 4, the storage portion is mountain-shaped, and a blocking portion is provided below the storage portion, or a member for forming a flow path in the nozzle is disposed in the storage portion. As shown in FIG. 6, the flow rate of the coating solution at the central portion in the width direction is reduced, the flow rate of the coating solution is increased on both sides outside the central portion, and both ends are coated with the coating solution. There is a tendency for the flow rate to decrease.

In order to solve the above problems, a slit nozzle according to the present invention is a slit nozzle in which a slit-like discharge port that opens downward is formed in a state in which two nozzle halves are combined. A first reservoir of the coating liquid is formed in one of the two, and a second reservoir that is shallower than the first reservoir is formed on the lower side continuous with the first reservoir with reference to the thickness direction of the nozzle half. And a flat surface that forms an orifice having a lower end serving as a slit-like discharge port between the other nozzle half and the lower side continuous to the second reservoir, and the first reservoir is formed of the nozzle half The portion communicating with the coating liquid supply hole formed in the central portion in the width direction is the highest and is formed in a mountain shape so that both ends are low, and the lower side of the second reservoir is the central portion in the width direction of the nozzle half Lowest and higher as you go to both ends And configured to form a V-shaped inclined surface.
Preferably, the starting point of both ends of the V-shaped inclined surface is a point where the amount of flow of the coating liquid is the largest when the lower side of the second reservoir is linear.

  By setting it as said structure, the quantity of the coating liquid which flows down from a slit-shaped discharge port becomes uniform along the width direction of a discharge port. Therefore, since the thickness of the coating liquid applied on the substrate becomes uniform, the product yield can be improved.

As described above, according to the slit nozzle according to the present invention, the flow rate of the coating liquid from the slit-like discharge port extending in the width direction of the nozzle becomes equal at any location, so that the coating formed on the substrate is formed. The film thickness is uniform.
In particular, since the thickness of the resist film can be accurately controlled within a range of 10 to 20 μm, for example, by applying an integrated circuit forming technique to an accurate height bump (projection electrode) on the IC pattern surface. It can be easily formed. It can also be used to provide a metal column instead of wire bonding on the chip.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 is an overall perspective view of the slit nozzle according to the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, FIG. 3 is a direction view along arrow BB in FIG. FIG. 5 is an enlarged cross-sectional view of the lower end portion of the nozzle.

  The slit nozzle is configured by joining and integrating the left and right nozzle halves 1 and 2 with a butting bolt 3, and a first reservoir of coating liquid is provided on the surface of one nozzle half 1 facing the nozzle half 2. A part 4 and a second storage part 5 are formed.

  The first reservoir 4 is drilled to a depth of about half of the thickness direction of the nozzle half 1 (left-right direction in FIG. 2), and its cross-sectional shape is inclined so as to increase as the depth increases with the same width. Yes. The shape of the portion of the first reservoir 4 that is open on the surface of the nozzle half 1 facing the nozzle half 2 is such that the central portion in the width direction (left-right direction in FIG. 3) is as shown in FIG. It is formed in a mountain shape so as to be the highest and lower at both ends, and communicates with the coating liquid supply hole 6 at the highest central portion. Further, the air vent hole 7 communicates with the highest central portion.

  The second reservoir 5 is formed continuously below the first reservoir 4, and the depth thereof is smaller than that of the first reservoir 4 with respect to the thickness direction of the nozzle half 1. The lower side of the second reservoir 5 is designed to be a V-shaped inclined surface 8 that is lowest at the center in the width direction of the nozzle half 1 and increases toward both ends. It is formed 0.5 to 3 mm lower than 8a and 8a.

  Both ends of the V-shaped inclined surface 8 may extend to both ends of the nozzle, but in this embodiment, both ends 8a and 8a of the inclined surface 8 are located on the inner side from both ends of the nozzle. Specifically, the both ends 8a and 8a have the largest amount of coating liquid when the lower side of the second reservoir 5 is horizontal because the flow rate increases as shown in FIG. It has been selected as a point where the flow rate increases. By doing in this way, more uniform application | coating becomes possible.

  A flat surface 9 that forms an orifice with the other nozzle half 2 is continuously formed below the second reservoir 5, and the lower end of the orifice is a slit-like discharge port 10.

  In addition, end plates 11 and 12 are attached to both ends of the nozzle to prevent leakage of the coating liquid from the first reservoir 4, the second reservoir 5 and the orifice, and the lower portions of the nozzle halves 1 and 2. The angles of the inclined surfaces 1a and 2a are set so that the angle formed with the horizontal plane is about 30 to 60 °.

In the above, the coating liquid that has flowed into the first reservoir 4 from the coating liquid supply hole 6 is conventionally concentrated in the central portion. Are evenly distributed and further flow into the second reservoir 5.
And when the lower side of this 2nd storage part 5 is horizontal, there exists a tendency for the amount of flowing down on both sides to increase more than other places, but having made the lower side of the 2nd storage part 5 into the V-shaped inclined surface. Thus, the flow rate becomes uniform.

Whole perspective view of slit nozzle according to the present invention Sectional drawing along the AA line of FIG. BB arrow direction view of FIG. Enlarged cross-sectional view of the nozzle half forming the reservoir Enlarged sectional view of the lower end of the nozzle The figure explaining the trouble by the conventional slit nozzle

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 2 ... Nozzle half, 1a, 2a ... Lower inclined surface of nozzle half, 3 ... Bolt, 4 ... 1st storage part, 5 ... 2nd storage part, 6 ... Coating liquid supply hole, 7 ... Air vent hole 8 ... V-shaped inclined surface, 8a ... End of inclined surface, 9 ... Flat surface, 10 ... Slit-shaped discharge port, 11, 12 ... End plate.

Claims (1)

In a slit nozzle in which a slit-like discharge port that opens downward is formed in a state where the two nozzle halves are combined, a first reservoir for coating liquid is formed in one of the two nozzle halves. A second reservoir shallower than the first reservoir is formed on the lower side continuous with the first reservoir with reference to the thickness direction of the nozzle half, and the other is formed on the lower side continuous with the second reservoir. A flat surface that forms an orifice whose lower end is a slit-like discharge port is provided between the nozzle half body and the first reservoir is in communication with a coating liquid supply hole formed in the center in the width direction of the nozzle half body A V-shaped inclined surface that is formed in a mountain shape so that the position to be the highest is lower and the both ends are lower, and the lower side of the second reservoir is the lowest in the center in the width direction of the nozzle half and goes higher toward both ends It Na and further both ends of the V-shaped inclined surfaces Point, slit nozzle, characterized in that the in the case where the lower side of the second reservoir in a straight line, and the point where a stream of most coating solution is increased.