JP6848758B2 - Film deposition equipment - Google Patents

Description

The present invention relates to a film forming apparatus for forming a film of a liquid material by ejecting a high-viscosity liquid material from a nozzle and applying the film to a flat plate-shaped film forming object.

Conventionally, there is a device that extrudes a highly viscous liquid material from a nozzle and applies it to an object. For example, when a high-viscosity liquid material is applied flatly onto a flat plate-shaped film-forming object to form a film, a nozzle having a slit-shaped opening has been often used in the past. For example, there has been a technique of spreading a liquid material supplied from a pipe in a nozzle using a nozzle having a cross-sectional area larger than that of the pipe and reducing the flow velocity of the liquid material to form a uniform film. For example, Patent Document 1 discloses an apparatus for applying a high-viscosity liquid material to a film-forming object.

Japanese Unexamined Patent Publication No. 2016-182535

However, when a high-viscosity liquid material is applied onto a flat plate-shaped film-forming object, air is trapped between the liquid material and the film-forming object when the liquid material discharged from the nozzle comes into contact with the film-forming object. There was a case. Then, the entrained air may become foamy air particles and remain between the film formation target and the film of the liquid material. For example, when the liquid material is a heat conductive material such as thermal paste and heat conduction with the film forming target is performed through the film, if many air particles remain between the film forming target and the film, There is a problem that unevenness occurs in the heat transfer state, and further, the contact area between the film formation target and the film is reduced and the heat transfer efficiency is lowered.

The present invention has been made to solve the problems of the above-mentioned conventional techniques. That is, the problem is a film forming apparatus for forming a film by applying a high-viscosity liquid material to a flat plate-shaped film forming object, and the air entering between the film of the liquid material and the film forming object. The purpose is to provide a technique for controlling the amount.

The film forming apparatus according to one aspect of the present invention, which is made for the purpose of solving this problem, is a film forming apparatus including a nozzle in which a discharge port is formed, and the discharge port is a first lip portion and a second lip portion. And, a rectangular slit-shaped portion surrounded by the two spacer portions sandwiched between the first lip portion and the second lip portion, and continuous uneven portions on the first lip portion forming one side in the longitudinal direction. A high-viscosity liquid material having a shape having a viscosity μ of 120 (Pa · s) or more at a shear rate of 2.51 (1 / s) is discharged from the discharge port toward a film forming target. The width of the gap between the first lip portion and the second lip portion is 2 mm, and the width A (mm) of one recess of the uneven portion in the longitudinal direction of the discharge port is A ≦ 100 / μ. The distance B (mm) between the concave portions adjacent to the concave-convex portion in the longitudinal direction of the discharge port is B ≦ 100 / μ, and the concave portion of the uneven portion in the direction orthogonal to the longitudinal direction of the discharge port. The length C (mm) of the liquid is C ≧ 200 / μ, the uneven portion is arranged on the front side with respect to the progress direction of the film formation, and the liquid is moved relatively between the nozzle and the film formation target. The material is discharged toward the film forming target.

According to the film forming apparatus in the above aspect, the discharge port has a slit shape having uneven portions on one side in the longitudinal direction, and the width A, the interval B, and the length C of the recesses are appropriately selected. The liquid material that has passed through the uneven portion has a higher shear rate than the liquid material that has passed through the other portion. High-viscosity liquid materials tend to have lower viscosities when the shear rate is high. That is, the viscosity of the liquid material in the portion that has passed through the uneven portion is low. Since the uneven portion is arranged on the front side in the progress direction of the film formation, the liquid material of the portion that has passed through the uneven portion is arranged on the side closer to the film formation target. Therefore, since the liquid material adhering to the film-forming object is a liquid material having a low viscosity, it easily spreads along the film-forming object. As a result, the amount of air entering between the film of the liquid material and the object to be formed is suppressed.

According to the present invention, it is a film forming apparatus that forms a film by applying a high-viscosity liquid material to a flat plate-shaped film forming object, and determines the amount of air that enters between the film of the liquid material and the film forming object. Suppression technology is realized.

It is a schematic block diagram which shows the film forming apparatus of this embodiment. It is explanatory drawing which shows the shape of the discharge port of a nozzle. It is explanatory drawing which shows the film forming state by the film forming apparatus of this embodiment. It is a graph which shows the relationship between the shear rate and the viscosity of thermal paste. It is explanatory drawing which shows the film formation state by the nozzle which has a rectangular discharge port. It is a table which shows the experimental result.

Hereinafter, the embodiment of the present invention will be described in detail with reference to the accompanying drawings. In this embodiment, the present invention is applied to a film forming apparatus in which a flat plate-shaped cooler is coated with high-viscosity thermal paste to form a film.

The schematic configuration of the film forming apparatus 100 of this embodiment is shown in FIG. The film forming apparatus 100 of this embodiment is an apparatus for discharging a high-viscosity liquid material into a flat plate. The film forming apparatus 100 of this embodiment is used, for example, when applying thermal paste 102, which is a high-viscosity liquid material, to one surface of a cooler 101, which is a flat plate-shaped film forming target.

As shown in FIG. 1, the film forming apparatus 100 includes a nozzle 10 and a supply unit 20, and pushes the thermal paste 102 supplied from the supply unit 20 out of the nozzle 10 while pushing the nozzle 10 and the cooler 101 together. By moving them relatively, a film of thermal paste 102 is formed on the cooler 101. In FIG. 1, it is the moving direction of the nozzle 10 when the cooler 101 is fixed and the nozzle 10 is moved, and the traveling direction of the film formation is indicated by an arrow. The direction in which the film is formed is defined as the "front side" on the side where the film is to be formed and the "rear side" on the side where the film has been formed.

The cooler 101, which is the object of film formation, is, for example, a metal plate material, and at least the surface on the side where film formation is formed has a substantially planar shape. The thermal paste 102, which is a liquid material, is a high-viscosity liquid material containing, for example, a base oil such as silicon oil and a solid additive having high thermal conductivity such as fine metal powder. The viscosity μ of the thermal paste 102 is, for example, 120 (Pa · s) or more at a shear rate of 2.51 (1 / s).

The supply unit 20 of the film forming apparatus 100 includes a first chamber 201 containing a first liquid containing a base oil, a second chamber 202 containing a second liquid containing a solid additive, and a mixing chamber 203. To be equipped. The supply unit 20 mixes the first liquid extruded from the first chamber 201 into the mixing chamber 203 and the second liquid extruded from the second chamber 202 into the mixing chamber 203 in the mixing chamber 203, and the nozzle 10 Push towards. Since the cross-sectional area of the flow path of the mixing chamber 203 is smaller than the cross-sectional area of the flow path of the nozzle 10, the thermal paste 102 extruded from the mixing chamber 203 spreads inside the nozzle 10 and the flow velocity decreases.

The nozzle 10 of the film forming apparatus 100 is provided with a discharge port 11 on the lower surface in FIG. 1, and the thermal paste 102 supplied from the supply unit 20 is directed toward the cooler 101 arranged below in the drawing. Discharge from the discharge port 11. Further, the nozzle 10 moves in the direction of progress of the film formation while discharging the heat radiating grease 102, so that the band-shaped heat radiating grease 102 adheres to the upper surface of the cooler 101.

Next, the shape of the discharge port 11 of the nozzle 10 will be described. FIG. 2 shows the shape of the discharge port 11 as viewed from the lower side of the nozzle 10, that is, the outside of the discharge port 11. In FIG. 2, the advancing direction of the film formation, that is, the advancing direction of the nozzle 10, is indicated by an arrow. The direction indicated by the arrow in FIG. 2 is the same as the direction indicated by the arrow in FIG.

In the film forming apparatus 100 of the present embodiment, the discharge port 11 of the nozzle 10 is a substantially rectangular space surrounded by a rear lip 12, a front lip 13, and two spacers 14, as shown by diagonal lines in FIG. is there. As shown in FIG. 2, the rear lip 12 is a rectangular plate material, and the rear lip surface 12a forming the longitudinal edge of the discharge port 11 is flat. As shown in FIG. 2, the front lip 13 is a plate material in which a plurality of comb-shaped convex portions 13a having the same shape are continuously formed on one side. The edge of the discharge port 11 formed by the front lip 13 has a rectangular corrugated surface shape in which a plurality of uneven portions are continuously formed. The spacer 14 supports the rear lip 12 and the front lip 13 at both ends in the longitudinal direction of the discharge port 11 at regular intervals. Therefore, the spacer 14 also forms a part of the edge of the discharge port 11.

As shown by diagonal lines in FIG. 2, the discharge port 11 of the nozzle 10 has a slit portion 11a which is a slit-shaped space long in the longitudinal direction of the rear lip 12 and the front lip 13, and a plurality of continuous uneven portions. Includes the comb tooth hole portion 11b. Specifically, the slit portion 11a is a slit-shaped space having a predetermined width surrounded by the rear lip surface 12a of the rear lip 12, the spacer 14, and the convex portion 13a of the front lip 13. Each comb tooth hole portion 11b is a square-shaped space formed by recesses between convex portions 13a of the front lip 13 adjacent to each other.

The traveling direction of the nozzle 10 at the time of film formation is the direction from the rear lip 12 to the front lip 13 as shown by an arrow in FIG. That is, at the time of film formation, the nozzle 10 moves by arranging the comb tooth hole portion 11b on the front side in the traveling direction. In the longitudinal direction, which is the direction perpendicular to the traveling direction of the nozzle 10, the width W of the slit portion 11a is the opening width of the discharge port 11, and is the film forming width of the thermal paste 102 formed in a strip shape.

As shown in FIG. 2, the plurality of comb tooth hole portions 11b of the discharge port 11 are formed continuously in the longitudinal direction with the same size and the same interval. The size and spacing of each comb tooth hole portion 11b of the film forming apparatus 100 of the present embodiment are as follows, using the viscosity μ (Pa · s) at the shear rate of 2.51 (1 / s) of the thermal paste 102. It is determined to be within the range that satisfies the conditions.
The width A (mm) in the longitudinal direction of one comb tooth hole portion 11b is A ≦ 100 / μ.
The distance B (mm) between adjacent comb tooth holes 11b is B ≦ 100 / μ.
The length C (mm) of the comb tooth hole portion 11b is C ≧ 200 / μ in the direction orthogonal to the longitudinal direction.

That is, on the front lip 13, convex portions 13a having a width of the interval B and a length C are formed side by side in the longitudinal direction of the discharge port 11 with a gap of the width A from each other. The lower limit of the width A and the interval B is not limited, but if it is made too small, it becomes difficult to manufacture the nozzle 10. Further, the upper limit of the length C is not limited, but if it is made too large, it is difficult to adjust the film thickness to be formed. Therefore, the lower limit of the width A and the interval B and the upper limit of the length C are appropriately selected within a range in which no problem occurs.

In the film forming step, as shown in FIG. 3, the nozzle 10 is arranged above the cooler 101 with the discharge port 11 facing down, and moves in the direction from the rear lip 12 to the front lip 13. That is, the rear lip 12 is arranged on the rear side with respect to the relative traveling direction of the nozzle 10, and the thermal paste 102 extruded from the slit portion 11a is from the cooler 101 as shown in dark color in FIG. It adheres to a distant position (upper in FIG. 3). On the other hand, the front lip 13 is arranged on the front side with respect to the relative traveling direction of the nozzle 10, and the thermal paste 102 extruded from the comb tooth hole portion 11b is attached to the cooler 101 as shown in light color in FIG. It adheres to a close position (lower in FIG. 3).

FIG. 4 shows the relationship between the shear rate and the shear viscosity of an example of the thermal paste 102 used in the film forming step of the present embodiment. The shear rate and the shear viscosity are generally related to each other in that the shear viscosity decreases by an order of magnitude when the shear rate increases by two orders of magnitude. The thermal paste 102 extruded from the slit portion 11a has, for example, a shear rate of about 2.5 (1 / s), and the shear viscosity in that case is about 200 Pa · s, as shown in FIG. On the other hand, the thermal paste 102 extruded from the comb tooth hole portion 11b has, for example, a shear rate of about 2000 (1 / s), and the shear viscosity in that case is about 3 Pa · s as shown in FIG. That is, the viscosity of the thermal paste 102 extruded from the comb tooth hole portion 11b is about 1/100 of the viscosity of the thermal paste 102 extruded from the slit portion 11a.

As shown in FIG. 3, the thermal paste 102 of the portion directly attached to the surface of the cooler 101 is a portion extruded from the comb tooth hole portion 11b, and this portion has a low viscosity. The thermal paste 102 in this portion easily spreads along the cooler 101. Therefore, it is difficult for air to enter between the cooler 101 and the thermal paste 102. On the other hand, since the rear lip 12 does not have an uneven shape, the viscosity of the thermal paste 102 adhering to a position away from the cooler 101 is high. Therefore, not all of the extruded thermal paste 102 spreads, and the coating width and coating thickness of the thermal paste 102 are appropriately maintained.

FIG. 5 schematically shows a state in which the thermal paste 102 is formed by a nozzle having a slit shape having no uneven shape on one side, that is, a nozzle having a simple rectangular discharge port. When the thermal paste 102 is extruded from the rectangular discharge port, the shear rate of the entire thermal paste 102 is, for example, about 2.5 (1 / s), and as described above, the shear viscosity is large, about 200 Pa. s. When the shear viscosity is high, the thermal paste 102 is difficult to spread, and as shown in FIG. 5, air easily enters between the cooler 101 and the thermal paste 102.

Subsequently, the experimental results of film formation using various nozzles in which the shape of the comb tooth hole portion 11b is changed by the film forming apparatus 100 of the present embodiment will be described. In this experiment, a silicon-based heat-dissipating resin having a viscosity μ of 120 to 603 (Pa · s) at a shear rate of 2.51 (1 / s) was used to form a film on a transparent plate material for the experiment. , The presence or absence of air particles was visually confirmed from the back surface of the plate material. In this experiment, various nozzles having different widths A, intervals B, and lengths C described above were used for the convex portions 13a of the front lip 13 forming the comb tooth hole portion 11b.

The results of the experiment are shown in FIG. In FIG. 6, an example in which the width A ≦ 100 / μ, the interval B ≦ 100 / μ, and the length C ≧ 200 / μ are all satisfied as the shape of the convex portion 13a is an example, and an example in which none of them is satisfied. It was used as a comparative example. In FIG. 6, in each comparative example, items that do not satisfy the conditions are marked with “Δ”. Further, in the judgment column in FIG. 6, when air particles having a diameter of 1 mm or more were visually found, they were marked with "x", and when they could not be found, they were marked with "○".

In each nozzle used in this experiment, the size of the slit portion 11a of the discharge port 11 is 60 mm × 2 mm. That is, the coating width (distance between the spacers 14) is 60 mm, and the gap between the rear lip 12 and the front lip 13 (length in the vertical direction in FIG. 2 of the spacer 14) is 2 mm.

Examples 1 to 7 and Comparative Examples 1 to 4 are the results of forming a film using a resin having a viscosity μ of 120 (Pa · s). Therefore, 100 / μ is about 0.83 and 200 / μ is about 1.67. As shown in Examples 1 to 7 in FIG. 6, even if the coating amount and the film forming speed are changed, air particles having a diameter of 1 mm or more are satisfied as long as the conditions of width A, interval B, and length C are all satisfied. Was not confirmed. On the other hand, as shown in Comparative Examples 1 to 4 in FIG. 6, when any one of them did not satisfy the conditions, air particles having a diameter of 1 mm or more were confirmed.

Examples 8 and 5 to 6 are the results of forming a film using a resin having a viscosity μ of 205 (Pa · s). Therefore, 100 / μ is about 0.49 and 200 / μ is about 0.98. Further, Examples 9 to 10 and Comparative Examples 7 to 9 are the results of forming a film using a resin having a viscosity μ of 603 (Pa · s). Therefore, 100 / μ is about 0.17 and 200 / μ is about 0.33.

As shown in Examples 8 to 10 in FIG. 6, even if the viscosity μ of the resin is changed, if all the conditions of width A, interval B, and length C are satisfied, air particles having a diameter of 1 mm or more can be confirmed. Was not done. On the other hand, as shown in Comparative Examples 5 to 9 in FIG. 6, when any one of them did not satisfy the conditions, air particles having a diameter of 1 mm or more were confirmed.

As described in detail above, the film forming apparatus 100 of the present embodiment includes a nozzle 10 having a discharge port 11 including a slit portion 11a and a comb tooth hole portion 11b, and the comb tooth hole portion 11b is arranged on the front side in the traveling direction. Then, while moving the nozzle 10, the thermal paste 102 is pushed out from the discharge port 11. Further, the comb tooth hole portion 11b of the film forming apparatus 100 of the present embodiment has a width A ≦ 100 / μ, using the viscosity μ (Pa · s) of the thermal paste 102 at a shear rate of 2.51 (1 / s). The interval B ≦ 100 / μ and the length C ≧ 200 / μ are satisfied. Therefore, the thermal paste 102 in the portion extruded from the comb tooth hole portion 11b of the discharge port 11 has a higher shear rate and a sufficiently lower viscosity than the other portions. Then, of the extruded thermal paste 102, the portion in contact with the surface of the cooler 101 to be coated is a portion having a small viscosity extruded from the comb tooth hole portion 11b of the discharge port 11, so that the cooler 101 is used. Easy to spread along. As a result, the amount of air entering between the cooler 101 and the coating of the thermal paste 102 is suppressed.

It should be noted that this embodiment is merely an example and does not limit the present invention in any way. Therefore, as a matter of course, the present invention can be improved and modified in various ways without departing from the gist thereof. For example, according to the present invention, if the device is a device that applies a high-viscosity liquid material to a flat surface to be filmed and forms a film of the liquid material on the film-forming object, a shape other than the coated surface to be filmed. It is applicable regardless of the type of liquid material.

Further, in the present embodiment, the nozzle 10 divided into two lips has been described, but the present invention is not limited to this. For example, it may be divided into three or more. Alternatively, it may be a single nozzle having a through hole in the shape of the discharge port 11. Further, instead of providing the spacer 14, the rear lip or the front lip may be provided with a protrusion corresponding to the shape of the spacer 14.

10 Nozzle 11 Discharge port 11a Slit part 11b Comb tooth hole part 100 Film forming device 101 Cooler 102 Thermal paste

Claims (1)

In a film forming apparatus including a nozzle in which a discharge port is formed,
The discharge port has a rectangular slit shape surrounded by a first lip portion, a second lip portion, and two spacer portions sandwiched between the first lip portion and the second lip portion, and has a longitudinal shape. It has a shape having continuous uneven parts on the first lip portion forming one side in the direction.
A high-viscosity liquid material having a viscosity μ of 120 (Pa · s) or more at a shear rate of 2.51 (1 / s) is discharged from the discharge port toward a film forming target.
The width of the gap between the first lip portion and the second lip portion is 2 mm.
The width A (mm) of one concave portion of the uneven portion in the longitudinal direction of the discharge port is A ≦ 100 / μ.
In the longitudinal direction of the discharge port, the distance B (mm) between the concave portions adjacent to the uneven portion is B ≦ 100 / μ.
The length C (mm) of the concave portion of the uneven portion in the direction orthogonal to the longitudinal direction of the discharge port is C ≧ 200 / μ.
The uneven portion is arranged on the front side in the progress direction of the film formation, and the liquid material is discharged toward the film formation target while the nozzle and the film formation target are relatively moved.
A film forming apparatus characterized by this.

Images