JP2016012580A - Film forming apparatus and film forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film forming apparatus which prevents a substrate held on a stage from being floated and is capable of preventing a nozzle head from being damaged.SOLUTION: The stage holds the substrate thereon. The nozzle head is disposed at an upper side of the stage and discharges droplets towards the substrate held on the stage. A movement mechanism moves one of the substrate held on the stage and the nozzle head toward the other in a direction parallel to a top face of the substrate. A lift mechanism lifts the stage relatively to the nozzle head. When the substrate is moved up, a top frame disposed at the upper side of the stage is brought into contact with an outer peripheral part of the top face of the substrate and presses the outer peripheral part of the substrate onto the stage.

Description

  The present invention relates to a film forming apparatus and a film forming method for forming a film by forming a film material into droplets from a nozzle head and discharging them toward a substrate held on a stage.

  A technique for forming a film having a predetermined pattern on the surface of a substrate by discharging a film material from a nozzle head and discharging it is known (for example, Patent Document 1). The object on which the film is to be formed is, for example, a printed board, and the film material is a solder resist.

  When the film material is discharged as droplets, the substrate is fixed on the stage by a vacuum chuck or the like. In order to increase the resolution of the film to be formed, it is preferable to reduce the distance between the substrate and the nozzle head.

JP 2004-104104 A

  Since the printed circuit board has a structure in which a resin and a metal thin film are laminated, warpage occurs due to the difference in the thermal expansion coefficient. Even when the printed circuit board is sucked by the vacuum chuck, the edge of the circuit board may be lifted off the stage due to the warping of the circuit board. If the height of the part floating from the stage exceeds the set value of the interval between the printed board and the nozzle head, the nozzle head comes into contact with the printed board when the printed board is moved directly below the nozzle head.

  By mounting a clamp mechanism for holding the edge of the substrate on the stage, it is possible to eliminate the floating of the substrate. For example, the raised portion of the substrate can be pressed by raising the clamp, placing the substrate underneath, and then lowering the clamp. In this structure, when the clamp moves up directly below the nozzle head in a state where the clamp is raised, there is a risk that the clamp contacts the nozzle head and the nozzle head is damaged.

  An object of the present invention is to provide a film forming apparatus and a film forming method capable of preventing a substrate held on a stage from being lifted and avoiding damage to a nozzle head.

According to one aspect of the invention,
A stage for holding a substrate;
A nozzle head that is disposed above the stage and discharges droplets toward the substrate held on the stage;
A moving mechanism for moving one of the substrate held on the stage and the nozzle head in a direction parallel to the upper surface of the substrate with respect to the other;
An elevating mechanism for elevating the stage relative to the nozzle head;
There is provided a film forming apparatus that includes a top frame that is disposed above the stage and has a top frame that contacts the outer peripheral portion of the upper surface of the substrate and presses the outer peripheral portion of the substrate against the stage when the substrate is raised. .

According to another aspect of the invention,
Place the substrate on the stage and raise it, and press the outer peripheral part of the substrate downward by bringing the outer peripheral part of the upper surface of the substrate into contact with the top frame that is arranged above the stage and has a fixed height. Removing the warpage of the substrate;
There is provided a film forming method including a step of discharging droplets from a nozzle head onto the upper surface of the substrate in a state in which the warpage of the substrate is eliminated, and applying the droplets to the substrate.

  When the top frame presses the outer peripheral portion of the substrate against the stage, it is possible to eliminate the floating of the substrate. Since the stage is raised and lowered instead of raising and lowering the top frame, damage to the nozzle head due to contact between the top frame and the nozzle head can be avoided.

FIG. 1 is a schematic diagram of a film forming apparatus according to an embodiment. 2A is a plan view of the top frame, and FIGS. 2B and 2C are cross-sectional views taken along one-dot chain line 2-2 in FIG. 2A. FIG. 3 is a flowchart of the film forming method according to the embodiment. 4A is a cross-sectional view of the vicinity of the edge of the substrate held on the stage of the film forming apparatus according to the comparative example, and FIGS. 4B and 4C are views of the vicinity of the edge of the substrate held on the stage of the film forming apparatus according to the embodiment. It is sectional drawing. FIG. 5 is a plan view of a top frame of a film forming apparatus according to another embodiment, and a stage and a substrate disposed below the top frame. 6A is a perspective view of an end portion of a movable portion used in the film forming apparatus according to the embodiment shown in FIG. 5, and FIG. 6B is a perspective view of a link portion between the movable portion and the fixed portion. FIG. 7 is a plan view of a top frame of a film forming apparatus according to still another embodiment, and a stage and a substrate disposed below the top frame. 8A and 8B are cross-sectional views taken along one-dot chain line 8-8 in FIG. FIG. 9 is a connection portion between the first movable portion and the second movable portion used in the film forming apparatus according to the embodiment shown in FIG. 7 and a connection portion between the first member and the second member. FIG.

  FIG. 1 shows a schematic diagram of a film forming apparatus according to an embodiment. A stage 13 is supported on the base 10 by a moving mechanism 11 and an elevating mechanism 12. A substrate 15 is held on the upper surface of the stage 13. The substrate 15 is attracted to the upper surface of the stage 13 by, for example, a vacuum chuck. An xyz orthogonal coordinate system in which the horizontal plane is the xy plane and the vertical direction is the z direction is defined. The moving mechanism 11 can move the stage 13 in the x direction and the y direction. The elevating mechanism 12 elevates the stage 13 with respect to the base 10 in the z direction.

  A top frame 18 is disposed above the stage 13. When the elevating mechanism 12 is operated to move the stage 13 up and down, the relative position of the top frame 18 with respect to the base 10 does not change and its height is constant.

A nozzle head 20 is supported above the stage 13. The nozzle head 20 can be moved up and down with respect to the base 10 by a head lifting mechanism 21. The nozzle head 20 discharges the film material into droplets from a plurality of nozzle holes toward the substrate 15 held on the stage 13. A film is formed by curing the liquid film material applied to the substrate 15. For example, an ultraviolet curable resin is used as the film material, and the film material can be cured by irradiating the film material applied to the substrate 15 with ultraviolet light.

  By operating the moving mechanism 11, the substrate 15 held on the stage 13 can be moved in the x and y directions parallel to the upper surface of the substrate 15. Instead of moving the stage 13, the nozzle head 20 may be moved in the x direction and the y direction. Alternatively, the stage 13 may be moved in the y direction and the nozzle head 20 may be moved in the x direction. As described above, a mechanism that moves one of the substrate 15 held on the stage 13 and the nozzle head 20 in the direction parallel to the upper surface of the substrate 15 as the other may be employed as the moving mechanism 11.

  The control device 23 controls the moving mechanism 11, the lifting mechanism 12, the nozzle head 20, and the head lifting mechanism 21. The control device 23 stores image data that defines the planar shape of the film to be formed. The control device 23 can form a film having a desired planar shape by controlling the movement mechanism 11 and the nozzle head 20 based on the image data.

  FIG. 2A shows a plan view of the top frame 18. The stage 13 and the substrate 15 disposed below the top frame 18 are indicated by broken lines. The top frame 18 has a rectangular opening 19. The inner peripheral edge of the top frame 18 (the edge of the opening 19) is located slightly inside the edge of the rectangular substrate 15, for example, about 5 mm inside. For this reason, the inner peripheral edge of the top frame 18 can be brought into contact with the outer peripheral portion of the upper surface of the substrate 15.

  2B and 2C are cross-sectional views taken along one-dot chain line 2-2 in FIG. 2A. FIG. 2B shows a cross-sectional view of the stage 13 lowered. A substrate 15 is held on the upper surface of the stage 13. Due to the warpage of the substrate 15, the edge of the substrate 15 is lifted from the upper surface of the stage 13. The edge of the substrate 15 is located slightly outside the edge of the opening 19.

  FIG. 2C shows a cross-sectional view of the stage 13 in the raised state. When the elevating mechanism 12 is operated to raise the stage 13, the outer peripheral portion of the upper surface of the substrate 15 contacts the top frame 18. Since the height of the top frame 18 is fixed, the outer periphery of the substrate 15 is pressed against the stage 13. Thereby, the rising of the edge of the substrate 15 is eliminated.

  Next, with reference to FIG. 3, the film forming method according to the embodiment will be described. In addition, FIG. 1 is referred as needed.

  FIG. 3 shows a flowchart of the film forming method according to the embodiment. First, in step S1, the elevating mechanism 12 (FIG. 1) is operated to lower the stage 13 (FIG. 1). In this state, a sufficient space for inserting the substrate 15 is secured between the stage 13 and the top frame 18 (FIG. 2B). In step S2, the substrate 15 (FIG. 2B) is held on the stage 13. For example, a robot arm is used to carry in the substrate 15.

  In step S3, the stage 13 is raised to eliminate the lifting of the edge of the substrate 15 as shown in FIG. 2C. In step S <b> 4, the film material is applied to the upper surface of the substrate 15 by moving the stage 13 (FIG. 1) in the y direction and discharging the film material from a plurality of nozzle holes of the nozzle head 20. A film material is applied to a region having a desired shape by controlling the discharge timing from the nozzle hole based on image data defining the planar shape of the film to be formed. By irradiating the liquid film material with ultraviolet rays, the film material is cured to form a film. For example, the ultraviolet rays are emitted toward the substrate 15 from a light source attached to the side of the nozzle head 20.

In step S5, the stage 13 (FIG. 1) is lowered. In step S6
The substrate 15 is unloaded from the stage 13 with the stage 13 lowered. If an unprocessed substrate remains, the process returns to step S2 to execute a film forming process for the next substrate. When all the substrates have been processed, the film forming process ends.

  With reference to FIG. 4A-FIG. 4C, the outstanding effect of the said Example is demonstrated. 4A to 4C are sectional views in the vicinity of the edge of the substrate 15.

  FIG. 4A shows a cross-sectional view of a state in which the substrate 15 is held on the stage 13 of the film forming apparatus according to the comparative example. In the comparative example, the top frame 18 (FIG. 1) is not disposed. Due to the warpage of the substrate 15, the edge of the substrate 15 is lifted from the upper surface of the stage 13. When the distance between the edge of the substrate 15 and the upper surface of the stage 13 is large, it is difficult to adsorb the edge of the substrate 15 to the stage 13 by a vacuum chuck. If the stage 13 is moved in the y direction while the edge of the substrate 15 is lifted, the lifted edge of the substrate 15 may come into contact with the nozzle head 20.

  FIG. 4B is a cross-sectional view of the stage 13, the substrate 15, and the top frame 18 immediately after step S2 (FIG. 3) in the film forming apparatus according to the embodiment. The edge of the substrate 15 is lifted from the upper surface of the stage 13. A top frame 18 is disposed above the raised edge of the substrate 15. The upper surface of the top frame 18 is lower than the lower end of the nozzle head 20.

  FIG. 4C shows a cross-sectional view of the stage 13, the substrate 15, and the top frame 18 immediately after step S3 (FIG. 3) in the film forming apparatus according to the embodiment. By operating the lifting mechanism 12 to raise the stage 13, the edge of the substrate 15 is pressed against the stage 13 by the top frame 18. For this reason, lifting of the edge of the substrate 15 is eliminated.

  When operating the elevating mechanism 12 to raise the stage 13, the height of the top frame 18 remains fixed. For this reason, the contact between the substrate 15 and the nozzle head 20 can be prevented. If the gap G in the height direction between the nozzle head 20 and the top frame 18 is fixed to about 0.1 mm, and the thickness H of the top frame 18 is set to about 0.3 mm, the gap between the substrate 15 and the nozzle head 20 is reduced. It can be set to about 0.4 mm.

  When a clamp or the like for pressing the substrate 15 is moved up and down with respect to the stage 13, there is a risk that the nozzle head 20 and the clamp come into contact with each other while the clamp is raised. In the embodiment, since the top frame 18 does not move up and down with respect to the nozzle head 20, even if there is an operation mistake or the like, the risk of occurrence of a contact accident between the nozzle head 20 and the top frame 18 is low.

  The top frame 18 is in contact with an outer peripheral region of the upper surface of the substrate 15 where no film is formed. For this reason, the top frame 18 does not become an obstacle to film formation on the substrate 15. The width W of the region where the substrate 15 and the top frame 18 are in contact is determined to be smaller than the width of the region where no film is formed in the outer peripheral portion of the upper surface of the substrate 15. As an example, the width W is 5 mm or less. If the width W is too small, the substrate 15 cannot be stably pressed down. In order to hold down the substrate 15 stably, the width W is preferably set to 1 mm or more.

  FIG. 5 is a plan view of the top frame 18 of the film forming apparatus according to another embodiment, and the stage 13 and the substrate 15 disposed below the top frame 18. Hereinafter, differences from the embodiment shown in FIGS. 1 to 4C will be described, and description of the same configuration will be omitted.

In the embodiment shown in FIG. 5, the top frame 18 includes a fixed portion 30 and a movable portion 31.
The fixing part 30 has the same planar shape as the top frame 18 of the embodiment shown in FIG. 2A. The movable portion 31 extends from one side of the opening 19 (a side parallel to the y axis in FIG. 5) to a side facing it. The movable portion 31 is movable in a direction parallel to the side of the opening 19 with which the movable portion 31 is linked (y direction in FIG. 5).

  The substrate 15 is smaller than the opening 19. For this reason, the entire outer peripheral portion of the substrate 15 cannot be pressed by the inner peripheral edge of the fixed portion 30. The fixed part 30 of the top frame 18 contacts a part of the outer peripheral part of the upper surface of the substrate 15, and the movable part 31 contacts another part of the outer peripheral part of the upper surface of the substrate 15. Specifically, the fixed portion 30 contacts two adjacent sides of the rectangular substrate 15, and the movable portion 31 contacts the other one side. The top frame 18 does not contact the remaining one side. By pressing the three sides of the substrate 15 against the stage 13, the warpage of the substrate 15 can be eliminated and the entire area of the substrate 15 can be adsorbed to the stage 13.

  FIG. 6A shows a perspective view of one end of the movable portion 31. The other end also has a similar structure. The movable portion 31 includes a flat plate-like main portion 32 that is long in the x direction, and a linkage portion 33 provided at an end of the main portion 32. A part of the linkage portion 33 protrudes from the end portion of the main portion 32 in the x direction. The upper surface of the linkage portion 33 is disposed at the same height as the bottom surface of the main portion 32. The dimension of the linkage part 33 in the y direction is smaller than the dimension (width) of the main part 32 in the y direction. For this reason, the main part 32 protrudes in the y direction from the linkage part 33.

  FIG. 6B shows a perspective view of a link location between the movable portion 31 and the fixed portion 30. The end surface of the main portion 32 contacts the side surface on the inner peripheral side of the fixed portion 30, and the linkage portion 33 is inserted under the fixed portion 30. As a result, the upward movement of the movable portion 31 is prohibited, and a downward force can be applied to the substrate 15. Since the upper surface of the linkage portion 33 is the same height as the bottom surface of the main portion 32, the bottom surface of the main portion 32 and the bottom surface of the fixing portion 30 are located on the same plane (being flush with each other). For this reason, both the bottom surface of the fixed portion 30 and the bottom surface of the main portion 32 of the movable portion 31 are in contact with the outer peripheral portion of the top surface of the substrate 15.

  In the embodiment shown in FIGS. 5 to 6B, the movable portion 31 can be moved with respect to the fixed portion 30 to cope with the substrates 15 of various sizes.

  FIG. 7 shows a plan view of a top frame 18 of a film forming apparatus according to still another embodiment, and a stage 13 and a substrate 15 arranged below the top frame 18. Hereinafter, differences from the embodiment shown in FIGS. 5 to 6B will be described, and description of the same configuration will be omitted.

  In the embodiment shown in FIG. 7, the top frame 18 includes another movable part 34 in addition to the fixed part 30 and the movable part 31. Hereinafter, the movable part 31 is referred to as a “first movable part”, and the movable part 34 is referred to as a “second movable part”. The second movable portion 34 extends from one side of the opening 19 (upper side parallel to the x axis in FIG. 5) to the first movable portion 31 and is parallel to the first movable portion 31. It can move in the direction (x direction in FIG. 5). In the embodiment shown in FIG. 5, the second movable portion 34 contacts one side (the left side in FIG. 7) of the substrate 15 that has not been pressed by the top frame 18, and the substrate 15 is brought into contact with the stage 13. Press down.

  FIG. 8A is a cross-sectional view taken along one-dot chain line 8-8 in FIG. A substrate 15 is held on the stage 13. The fixed portion 30 presses the right edge of the substrate 15 against the stage 13, and the first movable portion 31 presses the left edge of the substrate 15 against the stage 13. The second movable part 34 reaches from the fixed part 30 to the first movable part 31. When the first movable part 31 moves in the y direction, the movable part 34 expands and contracts according to the movement of the first movable part 31.

  The second movable part 34 includes a first member 35 linked to the fixed part 30 and a second member 36 linked to the first movable part 31. A first groove 37 is formed on the bottom surface of the first member 35. The first groove 37 extends in the length direction (y direction) of the first member 35 from the end portion of the first member 35 on the first movable portion 31 side (left end in FIG. 8A). The second member 36 is inserted into the first groove 37 from the left end of the first member 35. The depth of insertion of the second member 36 into the first member 35 is variable. As shown in FIG. 8B, when the first movable portion 31 is moved in the y direction according to the size of the substrate 15, the depth of insertion of the second member 36 into the first member 35 changes, The second movable part 34 expands and contracts.

  A second groove 38 is formed on the bottom surface near the left end of the second member 36. The second groove 38 extends in the x direction and reaches from one side surface of the second member 36 to the other side surface. The first movable portion 31 is inserted into the second groove 38 and penetrates the second member 36 in the x direction. With the first movable portion 31 inserted in the second groove 38, the second member 36 can be moved in the x direction with respect to the first movable portion 31.

  The structure of the right end of the first member 35 (the end linked to the fixed portion 30) is the same as the structure of the end of the first movable portion 31 shown in FIG. 6A.

  FIG. 9 is a perspective view of a link location between the first movable portion 31 and the second movable portion 34 and a connection location between the first member 35 and the second member 36. In FIG. 9, the top and bottom are shown reversed, and the bottom surfaces of the first movable portion 31 and the second movable portion 34 face upward.

  A first groove 37 is formed on the bottom surface of the first member 35, and a second member 36 is inserted into the first groove 37. The cross-sectional shape of the first groove 37 perpendicular to the y-axis matches the cross-sectional shape of the second member 36 perpendicular to the y-axis. The cross sections of the first groove 37 and the second member 36 allow the movement of the second member 36 in the y direction with respect to the first member 35, but prohibit the movement in the direction perpendicular to the y axis. Have

  A second groove 38 is formed on the bottom surface of the second member 36, and the first movable portion 31 is inserted into the second groove 38. The cross-sectional shape perpendicular to the x-axis of the second groove 38 matches the cross-sectional shape perpendicular to the x-axis of the first movable portion 31. The cross sections of the second groove 38 and the first movable portion 31 allow the second member 36 to move in the x direction with respect to the first movable portion 31, but prohibit the movement in the direction perpendicular to the x axis. Have a shape to

  The bottom surfaces of the first movable portion 31, the first member 35, and the second member 36 are located on the same plane (they are flush). When these bottom surfaces come into contact with the outer peripheral portion of the upper surface of the substrate 15 (FIGS. 8A and 8B), the edge of the substrate 15 can be pressed against the stage 13 (FIG. 1).

  In the embodiment shown in FIG. 5, the top frame 18 contacts the three sides of the upper surface of the substrate 15, but does not contact the remaining one side. In contrast, in the embodiment shown in FIGS. 7 to 9, the top frame 18 contacts the four sides of the upper surface of the substrate 15. For this reason, the board | substrate 15 can be more stably pressed to the stage 13 (FIG. 1).

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

DESCRIPTION OF SYMBOLS 10 Base 11 Moving mechanism 12 Elevating mechanism 13 Stage 15 Board | substrate 18 Top frame 19 Opening part 20 Nozzle head 21 Elevating mechanism 30 for heads Fixed part 31 Movable part (1st movable part)
32 Main part 33 Linking part 34 Movable part (second movable part)
35 First member 36 Second member 37 First groove 38 Second groove

Claims (5)

A stage for holding a substrate;
A nozzle head that is disposed above the stage and discharges droplets toward the substrate held on the stage;
A moving mechanism for moving one of the substrate held on the stage and the nozzle head in a direction parallel to the upper surface of the substrate with respect to the other;
An elevating mechanism for elevating the stage relative to the nozzle head;
A film forming apparatus comprising: a top frame that is disposed above the stage and has a top frame that contacts the outer peripheral portion of the upper surface of the substrate and presses the outer peripheral portion of the substrate against the stage when the substrate is raised.   The said moving mechanism moves one of the said board | substrate and the said nozzle head with respect to the other in the state which fixed the relative position of the said board | substrate hold | maintained at the said stage, and the said top frame. Film forming apparatus.   The film forming apparatus according to claim 1, wherein the elevating mechanism raises the stage in a state where the height of the top frame is fixed with respect to the nozzle head. The top frame is
A fixing portion that contacts a part of the outer peripheral portion of the upper surface of the substrate;
The film forming apparatus according to claim 1, further comprising: a movable portion that contacts a portion of the outer peripheral portion of the upper surface of the substrate that does not contact the fixed portion and moves according to the size of the substrate. Place the substrate on the stage and raise it, and press the outer peripheral part of the substrate downward by bringing the outer peripheral part of the upper surface of the substrate into contact with the top frame that is arranged above the stage and has a fixed height. Removing the warpage of the substrate;
A film forming method including a step of applying a film material to the substrate by discharging the film material into a droplet from a nozzle head on the upper surface of the substrate in a state in which the warpage of the substrate is eliminated.

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