JP4679298B2 - Coating equipment - Google Patents

Description

The present invention, the liquid relates equipment you applying to a substrate such as a glass substrate or a silicon wafer, in particular, to that equipment be coated with a die coating method.

  Conventionally, in order to apply a thin film with a high degree of film thickness accuracy (for example, within ± 2%) to a round substrate such as a silicon wafer used for semiconductor products, a spin coating method is generally used. However, in the spin coating method, most of the coating liquid dropped on the base material is blown off by centrifugal force, so that there is a drawback that the liquid-saving property is poor. In addition, there are also disadvantages that the coating liquid adhering to the base material tends to wrap around the back surface and that it is difficult to form a thick film.

  In view of this, a method and an apparatus have been proposed for coating a round base material by a die coating method using a die head (also referred to as a slit nozzle) that discharges a coating liquid in a film form (for example, Japanese Patent Application Laid-Open No. 2002-2002). 204996 and JP-A-2004-209340). FIG. 5 is a schematic perspective view showing an example of a conventional apparatus for coating a round base material by a die coating method, and FIGS. 6A and 6B are schematic side views showing the apparatus shown in FIG. 5 in different operating states. In order to make it easy to understand, the base material, the base material support base, the coating film, etc. are shown in cross section and with exaggerated thickness. 5 and 6, the coating apparatus 1 includes a base 2, a base material support 3 provided on the upper surface of the base 2, guide means 4 provided on the upper surface of the base 2, and the guide means 4. A moving table 5 held so as to reciprocate, a drive device (not shown) for moving the moving table 5 back and forth, a head holding member 6 provided so as to move up and down on the moving table 5, and its head A driving device (not shown) for raising and lowering the holding member 6, a die head 7 that is held by the head holding member 6 and has a slit that discharges the coating liquid into a film shape, and a coating liquid is supplied to the die head 7 A liquid supply system (not shown) is provided. The base material support 3 used here has a round base material 8 such as a silicon wafer to be coated on the upper surface, and the upper surface 8a of the base material 8 is the upper surface 3a of the base material support table 3. Are provided with recesses 9 that support the surfaces substantially in the same plane. The inner diameter of the recess 9 is set to be slightly larger (for example, about 1 to 2 mm larger) than the outer diameter of the substrate 8 so that the substrate 8 can be easily taken in and out. There is a small gap between the 9 side surfaces.

  The coating operation by the coating apparatus 1 having this configuration is performed as follows. That is, as shown in FIG. 6A, the upper surface of the base material support 3 from which the die head 7 is removed from the base material 8 in a state where the base material 8 is fitted and supported in the recess 9 of the base material support table 3. Positioned above 3a, the die head 7 is lowered to a position suitable for coating on the upper surface 3a of the base material support 3 and the upper surface 8a of the base material 8 at that position, and the coating liquid is applied from the die head 7 to the film. The die head 7 is moved along the base material support table 3 while being discharged in the form of a plate, so that the upper surface 3a of the base material support table 3 and the upper surface 8a of the base material 8 are moved as shown in FIG. After forming the coating film 10, passing through the upper surface 8 a of the base material 8, and forming the coating film 10 on the subsequent upper surface 3 a of the base material support 3, the coating liquid from the die head 7 is stopped. By the above, the coating film 10 of fixed thickness can be formed in the whole area | region of the upper surface 8a of the base material 8 with a die coat system.

However, when the coating film 10 is formed on the entire upper surface 8a of the base material 8 and the upper surface 3a of the base material support stand 3 adjacent thereto as shown in FIG. Until the coating film 10 is dried, as shown in FIG. 7B, the coating liquid 10a flows from the coating film 10 into the gap between the side surface of the substrate 8 and the side surface of the recess 3b. May wrap around the back surface of the substrate 8. For this reason, it is necessary to remove the coating liquid 10a that has come around by washing the back surface of the base material 8 in the next step, and there is a problem that the number of steps increases.
JP 2002-204996 A JP 2004-209340 A

The present invention has been made in view of such a problem, and a base material such as a round base material is fitted into and supported by a recess provided on the upper surface of the base material support base, and a coating liquid is applied to the upper surface by a die coating method. the when applied, the coating solution and to provide the possibility and the coating KoSo location to prevent the sneaking into substrate back surface through a gap between the substrate and the recess.

In order to solve the above-mentioned problems in the coating apparatus in which the base material is supported by the concave portion of the base material support base and applied using a die head, the invention according to claim 1 of the present invention provides a base material to be coated. As a base material support table to be supported, a concave portion for supporting the base material on an upper surface, wherein the base material is placed in a state where the upper surface of the base material is substantially flush with the upper surface of the base material support table. A recess for supporting a state in which a gap is formed between the side surface of the material and the side surface of the recess, and when the substrate is supported by the recess, the side surface of the substrate and the side surface of the recess Using a base material support base provided with an air passage for supplying air to the bottom region of the gap formed between the two, and further comprising air supply means for supplying air to the air passage of the base material support base; In addition, a slope extending outward is provided at the upper end of the side surface of the recess of the substrate support base. It is obtained by the configuration of that.

The invention according to claim 2 is the invention according to claim 1 , wherein the air passage includes a groove formed along the entire circumference of the side surface of the recess on the bottom surface of the recess.

The invention according to claim 3 is the invention according to claim 2 , wherein the groove is a gap formed between the side surface of the substrate and the side surface of the recess when the recess is supported by the substrate. It is arranged so as to be positioned on the extension, and the width of the groove is determined to be equal to the width of the gap.

According to the coating KoSo location of the present invention described above, the gap between the time of performing coating with a die head is supported in the recess is provided with the substrate on the substrate support table top, a base side and a recess side surface In this state, the applied coating liquid does not flow into the gap, so that the coating liquid wraps around the back surface of the substrate. Thus, it is possible to eliminate the substrate back surface cleaning step. Furthermore, by forming a slope that spreads outward at the upper end of the side surface of the recess, the air flowing in the gap is directed outward (in the direction away from the base material), so that the coating liquid does not flow too much on the base material side. Thus, the flow of the coating liquid into the gap can be prevented more satisfactorily.

  FIG. 1 is a schematic perspective view of a coating apparatus according to a preferred embodiment of the present invention, and FIGS. 2A and 2B are a schematic plan view and a schematic cross section of a substrate support base used in the coating apparatus. FIG. 3 is a schematic cross-sectional view showing a state in which a coating film is formed on a substrate support base and a substrate surface with a die head in the coating apparatus shown in FIG. 1, and FIG. It is a schematic sectional drawing shown in the state in the process of coating, and the thickness and width | variety of some components are exaggerated and shown in these drawings. 1 and 2, a coating apparatus generally indicated by reference numeral 1 </ b> A includes a base 2, a base material support 13 provided on the upper surface of the base 2, and guide means 4 provided on the upper surface of the base 2. A movable table 5 held so as to reciprocate by the guide means 4, a driving device (not shown) for moving the movable table 5 back and forth, and a head holder provided so as to move up and down on the movable table 5. A member 6, a drive device (not shown) that moves the head holding member 6 up and down, a die head 7 that is held by the head holding member 6 and includes a slit that discharges the coating liquid into a film, and the die head 7 A liquid supply system (not shown) for supplying the coating liquid is provided. Here, the guide means 4, the moving table 5, and the driving device thereof are for moving the die head 7 so that the die head 7 moves along the upper surface of the substrate support table 13, and the die head is the substrate. A moving mechanism is configured to move at least one of the die head and the base material support table so as to move relatively along the upper surface of the support table. In addition, as a moving mechanism, it is good not only as a structure which moves the movable stand 5 holding the die head 7, but it is good also as a structure which moves the base material support stand 13 horizontally.

  The base material support 13 is made of metal, ceramic, stone, plastic or the like, and a round base material 8 such as a silicon wafer to be coated is provided on an upper surface, and an upper surface 8a of the base material 8 is provided. Is provided with a concave portion 14 that is supported on the upper surface 13a of the base material support base 13 so as to be substantially flush with each other. The diameter of the side surface 13b of the concave portion 14 is selected to be slightly larger than the diameter of the base material 8 supported by the concave portion 14, so that the base material 8 is concentric with the concave portion 14 as shown in FIGS. When supported in a shape, a small gap 15 having a constant width is formed over the entire circumference of the substrate 8 between the side surface 13 b of the recess 14 and the side surface 8 b of the substrate 8. The gap 15 is for preventing the coating liquid from flowing into the gap 15 by blowing air upward from the gap 15 during coating. The gap width effectively prevents the coating liquid from flowing. It is preferable to make it 3 mm or less from the top to prevent. On the other hand, if the width of the gap 15 is too small, it becomes difficult to put the base material 8 in and out of the concave portion 14, and therefore the width of the gap 15 is preferably 0.5 mm or more from the viewpoint of workability.

  The base material support 13 further has an air passage 17 for supplying air to the bottom region of the gap 15 formed between the side surface of the base material and the side surface of the concave portion when the base material 8 is supported by the concave portion 14. Is formed. In this embodiment, the air passage 17 is formed on the bottom surface of the recess 14 so as to communicate with the annular groove 17a formed along the entire circumference of the side surface 13b and a part of the annular groove 17a. An air supply path 17b is provided, and air supply means (not shown) for supplying air is connected to the air supply path 17b. With this configuration, by supplying air to the air passage 17 by the air supply means, an upward air flow can be generated in the gap 15 over the entire circumference of the gap 15.

  Here, the width, depth, position, and the like of the annular groove 17a for sending air into the gap 15 are arbitrary as long as an upward air flow can be generated in the gap 15, but as shown in the figure, The air flow generated upward in the annular groove 17a flows through the gap 15 as it is so that the groove 17a is positioned on the extension of the gap 15 and the width of the groove 17a is equal to the width of the gap 15. It is preferable because a stable upward flow can be generated in the gap 15. Further, the depth of the groove 17a is preferably about 5 to 10 times the width of the groove 17a so that a stable upward flow can be generated in the groove 17a. The pressure of the air supplied to the air passage 17 by the air supply means is determined so that an air flow having a flow velocity capable of preventing the coating liquid from flowing down in the gap 15 can be generated. Then, the flow velocity of the air in the gap 15 becomes too large, and the applied coating liquid is scattered more than necessary. For this reason, it is preferable that the pressure of air shall be about 0.01-0.05 MPa.

On the side surface 13b of the recess 14 formed on the base material support base 13 , as shown in an enlarged view in FIG. 4, a slope 13c extending outward is formed at the upper end of the side surface . By forming such an inclined surface 13c, the air flowing in the gap 15 is directed outward (in a direction away from the base material 8), so that the coating liquid does not flow so much on the base material 8 side.

  A vacuum suction hole (not shown) for sucking and holding the substrate 8 is provided on the bottom surface of the recess 14 provided in the substrate support 13. Moreover, the extrusion pin (not shown) for extruding the base material 8 after coating to the outer side of the recessed part 14 is also provided.

  Next, the coating operation by the coating apparatus 1A provided with the base material support 13 having the above-described configuration will be described. First, the substrate 8 to be coated is set concentrically in the recess 14 on the upper surface of the substrate support 13. Thereby, a gap 15 having a constant width is formed around the base material 8. Next, air is supplied to the air passage 17 at a pressure of about 0.01 to 0.05 MPa by the air supply means. Thereby, an upward air flow is formed on the entire circumference of the gap 15 surrounding the base material 8, and air is blown upward from the gap 15. In this state, coating with the die head 7 is performed in the same procedure as described for the conventional apparatus with reference to FIGS. 6A and 6B, and the substrate support 13 is removed as shown in FIG. The coating film 10 is formed on the upper surface 13 a and the upper surface 8 a of the substrate 8. And after forming a coating film in the application | coating area | region shown with the dashed-two dotted line 20 in Fig.2 (a), it waits for a coating film to dry to some extent, and the base material 8 is taken out from the base material support stand 13. FIG. Thus, the coating operation is completed.

  In the above coating operation, during the coating film formation by the die head 7, as shown in FIG. 4, upward air is always present in the gap 15 formed between the side surface 8b of the substrate 8 and the side surface 13b of the recess. Flowing. For this reason, the air pushes up the coating liquid applied on the gap 15, and the coating liquid does not flow down through the gap 15. There is nothing. As a result of the air flowing through the gap 15 pushing up the coating liquid, the coating liquid swells 10 b and 10 c are generated on both sides of the gap 15, but the swell 10 b generated on the base material side is Since it only occurs in an area within 5 mm and only outside the effective range used as a product in the base material 8, it is not a problem. Thus, by using this coating apparatus, a coating film having a desired film thickness can be formed with high accuracy on the effective area of the substrate 8 by the die head 7, and the coating liquid is applied to the back surface of the substrate 8. Since it does not go around and become dirty, the back surface cleaning process can be eliminated.

  In the above-described embodiment, the case where the round base material 8 is used has been described. However, the base material 8 to be coated in the present invention is not limited to the round shape, and may be any shape such as an ellipse or a rectangle. Yes, what is necessary is just to change the shape of the recessed part formed in a base-material support stand upper surface according to the shape of the base material to be used. Moreover, although the base material made into the object of application | coating by this invention can mention the silicon wafer used for a semiconductor product as a representative example, it is applicable not only to this but arbitrary materials. Furthermore, the above-described embodiment is for explaining the present invention, and does not limit the present invention. It goes without saying that the present invention can be variously modified within the scope of the claims.

Schematic perspective view of a coating apparatus according to a preferred embodiment of the present invention (A), (b) is the schematic plan view and schematic sectional drawing of the base-material support stand which are used for the coating apparatus shown in FIG. In the coating apparatus shown in FIG. 1, a schematic cross-sectional view showing a state in which a coating film is formed with a die head on the substrate support base and the substrate surface Schematic cross-sectional view showing the substrate end region in the state of coating Schematic perspective view showing an example of a conventional coating apparatus (A), (b) is a schematic side view which shows the coating apparatus shown in FIG. 5 in a different operation state. (A) is a schematic sectional drawing which shows the state immediately after forming a coating film on a base-material support stand and a base-material surface, (b) is a schematic sectional drawing which shows the state in which a coating liquid wraps around the base-material back surface

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A coating apparatus 2 Base 3 Base material support stand 4 Guide means 5 Moving stand 6 Head holding member 7 Die head 8 Base material 8a Upper surface 8b Side surface 9 Recess 10 Coating film 10a Coating liquid 10b, 10c Swell 13 Base material support stand 13a Upper surface 13b Side surface of recess 13c Slope 14 Recess 15 Clearance 17 Air passage 17a Annular groove 17b Air supply path 20 Application region

Claims (3)

A substrate support for supporting a substrate to be coated, wherein the substrate is a recess for supporting the substrate on an upper surface, and the upper surface of the substrate is the upper surface of the substrate support A concave portion for supporting the upper surface so as to form a gap between the side surface of the base material and the side surface of the concave portion in a substantially coplanar state, and when the base material is supported by the concave portion A substrate support base having an air passage for supplying air to a bottom region of a gap formed between a side surface of the base material and a side surface of the recess, and supplying air to the air passage of the substrate support base Moving air supply means, a die head for discharging the coating liquid in a film shape, and moving at least one of the die head and the substrate support so that the die head moves relatively along the upper surface of the substrate support A moving mechanism that is widened outwardly at the upper end of the side surface of the recess of the base material support. Coating apparatus characterized by slope is formed. The coating apparatus according to claim 1, wherein the air passage includes a groove formed on the bottom surface of the concave portion along the entire side surface of the concave portion . The groove is disposed so as to be positioned on an extension of a gap formed between a side surface of the substrate and a side surface of the recess when the recess is supported by the substrate, and the width of the groove The coating apparatus according to claim 2, wherein is determined to be equal to a width of the gap .

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