TW201505108A - Thin-film formation method and thin-film formation apparatus - Google Patents

Abstract

There is provided a thin-film formation method. In said thin-film formation method, even if the surface of the substrate is lyophobic, thin-film material can be used to cover the entire region of the area to be coated. T While moving the droplet-ejection location along one side of the lyophobic surface, a droplet-ejection treatment of light-curing thin-film material and a curing treatment of irradiating light to the thin-film material on the surface after the droplet-ejection are repeated performed to thus form a first thin-film on the area to be coated with the thin-film material. By coating the liquid-like thin-film material on the first film, a second film is formed. After the formation of the second film, the second film is cured by light irradiation.

Description

Film forming method and film forming device

The present invention relates to a film forming method and a film forming apparatus for forming a film by applying a liquid film material to a substrate and then curing the film.

By mounting a plurality of semiconductor wafers on one package substrate, it is possible to reduce the size and performance of the semiconductor device. Patent Document 1 discloses a technique of mounting an electronic component on a package substrate. Hereinafter, a method of mounting an electronic component disclosed in Patent Document 1 will be described.

The adhesive is applied using a droplet discharge head in a region where the electronic component is mounted on the package substrate. The adhesive is semi-hardened by irradiating ultraviolet rays to the liquid adhesive applied to the package substrate. The adhesive is hardened by mounting an electronic component on a semi-hardened adhesive and heating it. Thereby, the electronic component is bonded to the package substrate by a bonding agent.

(previous technical literature) (Patent Literature)

Patent Document 1: Japanese Patent Laid-Open Publication No. 2008-117997

When the surface of the package substrate is lyophobic, if a liquid binder is applied to the surface, the binder is collected in a part of the region. Therefore, it is difficult to cover the entire area of the region where the binder should be applied with the binder. If there is a region that is not covered by the adhesive in the region where the electronic component is mounted, the bonding strength of the electronic component is lowered. If a cavity for locking air is formed between the package substrate and the electronic component, the electronic component may be detached from the package substrate due to thermal expansion of the air.

An object of the present invention is to provide a film forming method and a film forming apparatus which can cover the entire area of a region to be coated with a film material even if the surface of the substrate is liquid repellency.

According to one aspect of the present invention, there is provided a film forming method comprising: repeating a process of buffing a photocurable film material while moving a bounced surface on a lyophobic surface, and bounces the surface to the surface The upper film material is irradiated with light to be cured, whereby a process of forming a first film on a surface of the surface on which the film material is to be applied is formed, and a liquid film is formed on the first film to form a liquid. a process of forming the second film; and a process of curing the second film by irradiating light after forming the second film.

According to another aspect of the present invention, a film forming apparatus including: a stage holding a substrate; and a nozzle head having a plurality of liquid film materials that emit light curable property toward a substrate held by the stage a nozzle hole; a moving mechanism for moving one of the substrate and the nozzle head relative to the other; and a light source for irradiating the liquid film material adhered to the substrate held by the stage to the curing light; and the control device Controlling the nozzle head, the light source, and the moving mechanism; wherein the control device discharges a liquid film material from the nozzle head while moving one of the nozzle head and the substrate to the liquid state The film material is adhered to a part of the substrate, and the liquid film material adhering to the substrate is irradiated with light for curing from the light source, thereby curing the film material, thereby forming a first film. After the first film, one of the nozzle head and the substrate is moved from the front side while moving relative to the other The film material is discharged from the liquid, and the liquid film material is adhered to the first film to form a liquid second film. After the second film is formed, the second film is irradiated with the curing light. Thereby, the second film is hardened.

The lyophobic surface is moved while the position of the bounce is moved, and the process of buffing the photocurable film material and the process of hardening the film material on the surface after the bounce and hardening are performed, thereby being elasticized. The film material can then be hardened in a short time. Therefore, even if the surface is lyophobic, the film material can be hardened before the film material is brought together in a portion of the region. The surface of the first film composed of the cured film material exhibits lyophilic properties or lyophobicity which is weaker than the lyophobic surface. Therefore, when the film material is further applied to the first film, the entire region of the surface of the first film can be easily covered with the film material.

10‧‧‧ platform

11‧‧‧Mobile agencies

12‧‧‧stage

13‧‧‧Nozzle unit

14‧‧‧Camera

20‧‧‧Control device

30‧‧‧Support board

31‧‧‧Nozzle head

32‧‧‧ Hardening light source

33‧‧‧Nozzle hole

50‧‧‧Substrate (package substrate)

51‧‧‧Binder layer

52‧‧‧1st semiconductor wafer

53‧‧‧Binder layer

54‧‧‧2nd semiconductor wafer

55‧‧‧ silk thread

58‧‧‧ coated area

60‧‧‧ moving into the station

61‧‧‧ Temporary positioning station

62‧‧‧ coating station

63‧‧‧ hardening station

64‧‧‧Transporting device

65‧‧‧1st conveying roller

66‧‧‧2nd conveying roller

67‧‧‧blocks

68‧‧‧ Hardening light source

70‧‧‧ Guides

71, 72‧‧‧ Lifter

80‧‧‧Film material

81‧‧‧1st film

82‧‧‧2nd film

Fig. 1 is a schematic view showing a coating station of a film forming apparatus of an embodiment.

Fig. 2A is a perspective view of the nozzle unit, and Fig. 2B is a bottom view of the nozzle unit.

Fig. 3A is a plan view of a semiconductor element produced by using the thin film forming apparatus of the embodiment, and Fig. 3B is a cross-sectional view of the single-dot chain line 3B-3B of Fig. 3A.

Fig. 4 is a plan view showing a stage and a nozzle unit of the thin film forming apparatus of the embodiment.

Fig. 5 is a schematic view showing the entire film forming apparatus of the embodiment.

Fig. 6A and Fig. 6B are schematic side views showing a nozzle unit and a substrate in the middle of forming a film by the film forming method of the embodiment.

Figure 6C is a film formed by the film forming method of the embodiment. A schematic side view of the nozzle unit and the substrate in the middle stage, and FIG. 6D is a cross-sectional view of the substrate on which the first film is formed.

Fig. 6E is a schematic side view of a nozzle unit and a substrate in the middle of forming a film by the thin film forming method of the embodiment, and Fig. 6F is a cross-sectional view of the substrate on which the first film and the liquid second film are formed. Fig. 6G is a side view of the light source for curing and the substrate when the second film is cured.

Fig. 7A is a cross-sectional view of the substrate immediately after the film material is springed by the method of the comparative example, and Fig. 7B is a cross-sectional view of the substrate after the surface of the film material is flattened.

Fig. 1 is a schematic view showing a coating station of a thin film forming apparatus of an embodiment. The stage 12 is supported on the platform 10 via the moving mechanism 11. The stage 12 holds the substrate 50 as a target for forming a film. The xyz rectangular coordinate system in which the surface parallel to the surface of the substrate 50 is defined as the xy plane and the normal direction of the surface of the substrate 50 is defined as the z direction is defined. The nozzle unit 13 and the camera 14 are supported above the stage 12. The moving mechanism 11 moves one of the substrate 50 and the nozzle unit 13 in the x direction and the y direction with respect to the other. In the first drawing, the nozzle unit 13 is stationary with respect to the stage 10, and the substrate 50 is moved. However, the configuration in which the substrate 50 is stationary and the nozzle unit 13 is moved can be reversed.

The nozzle unit 13 has a nozzle head opposed to the substrate 50. The photocurable liquid film material is dropletized and discharged from the plurality of nozzle holes formed in the nozzle head toward the substrate 50. Borrowing the film material from the nozzle hole It is controlled by the control device 20. When a binder layer is formed on the surface of the substrate 50, for example, a liquid binder is used as the liquid film material. The camera 14 captures an alignment mark formed on the substrate 50 and transmits the image data to the control device 20.

A perspective view of the nozzle unit 13 is shown in Fig. 2A, and a bottom view of the nozzle unit 13 is shown in Fig. 2B. Two nozzle heads 31 and three curing light sources 32 are attached to the support plate 30. The two nozzle heads 31 are arranged side by side in the y direction. A curing light source 32 is disposed between the two nozzle heads 31 and outside the nozzle head 31. When focusing on one nozzle head 31, the curing light source 32 is disposed on the positive side and the negative side of the nozzle head 31 in the y direction.

A plurality of nozzle holes 33 arranged at equal intervals in the x direction are formed in the respective nozzle heads 31. In FIGS. 2A and 2B, an example in which a plurality of nozzle holes 33 of the respective nozzle heads 31 are arranged in two rows is shown. The two nozzle heads 31 are offset from each other in the x direction. The four rows of nozzle holes 33 formed in the two nozzle heads 31 are arranged at equal intervals in the x direction.

The curing light source 32 irradiates the liquid thin film material coated on the substrate 50 (Fig. 1) with light for curing. For example, when the film material is discharged from the nozzle head 31 while moving the substrate 50 (first drawing) in the y direction, the film material applied to the substrate 50 is cured by the light from the curing light source 32, and the curing light source is cured. It is disposed on the downstream side of the nozzle head 31 from which the film material is discharged.

In FIG. 2A and FIG. 2B, the number of the nozzle heads 31 is two, but the number of the nozzle heads 31 may be one. It is more than three. The curing light source 32 may be disposed on both sides of each nozzle head 31. When the number of the nozzle heads 31 is increased, the arrangement pitch of the nozzle holes 33 in the x direction is reduced. Thereby, the resolution of the pattern of the film to be formed can be improved.

Fig. 3 is a plan view showing a semiconductor element produced by using the thin film forming apparatus of the embodiment. A cross-sectional view of the single-dot chain line 3B-3B of Fig. 3A is shown in Fig. 3B. The first semiconductor wafer 52 is bonded to the package substrate 50 by the adhesive layer 51. The second semiconductor wafer 54 is bonded to the first semiconductor wafer 52 by the adhesive layer 53. The spacers formed on the first semiconductor wafer 52 and the second semiconductor wafer 54 are connected to the spacer formed on the package substrate 50 by the wires 55. The binder layer 51 and the binder layer 53 were formed by the film forming apparatus of the example.

In FIGS. 3A and 3B, the configuration in which the first semiconductor wafer 52 and the second semiconductor wafer 54 are stacked is shown. However, only one semiconductor wafer may be mounted on one package substrate 50. Further, a semiconductor wafer may be mounted on each of the plurality of surfaces of the package substrate 50.

Fig. 4 is a plan view showing the stage 12 and the nozzle unit 13 of the thin film forming apparatus of the embodiment. A substrate 50 is held on the stage 12. A plurality of coating regions 58 to which a binder is applied are defined on the surface of the substrate 50. The coating region 58 corresponds to the region where the binder layer 51 is to be formed as shown in Fig. 3B.

A nozzle unit 13 is disposed above the substrate 50. The nozzle unit 13 includes a nozzle head 31 and a hardening light source 32. The substrate 50 is ejected from the nozzle head 31 while moving the substrate 50 in the y direction by the moving mechanism 11. Thereby, the film material can be coated on the substrate 50. The control device 20 controls the timing of the movement of the substrate 50 by the moving mechanism 11 and the discharge of the film material from the nozzle head 31. Thereby, a film material composed of a binder can be applied to the application region 58. The pattern information of the coating area 58 is stored in advance in the control device 20.

By repeating the same process by moving the substrate 50 in the x direction, the film material can be applied to any region of the surface of the substrate 50.

Fig. 5 is a schematic view showing the entire film forming apparatus of the embodiment. The film forming apparatus of the embodiment includes a loading station 60, a temporary positioning station 61, a coating station 62, a hardening station 63, and a conveying device 64. The xyz rectangular coordinate system is defined. The xyz rectangular coordinate system sets the horizontal plane to the xy plane and the vertical upper direction to the positive direction of the z-axis. The loading station 60, the temporary positioning station 61, the coating station 62, and the hardening station 63 are arranged in this order in the positive direction of the x-axis. The control device 20 controls the loading station 60, the temporary positioning station 61, the coating station 62, and the respective devices in the curing station 63 and the conveying device 64.

The first transport roller 65 transports the substrate 50 to be processed from the loading station 60 to the temporary positioning station 61 in the positive direction of the x-axis. The front end of the substrate 50 conveyed by the first conveyance roller 65 is in contact with the stopper 67, whereby coarse positioning of the substrate 50 in the conveyance direction is performed.

The transport device 64 transports the substrate 50 from the temporary positioning station 61 to the coating station 62 and from the coating station 62 to the curing station 63. The conveying device 64 includes a guide 70 and two lifters 71, 72. The lifters 71, 72 are guided by the guide 70 to move in the x direction. The lifters 71, 72 have, for example, an L-shaped support arm that contacts the bottom surface of the substrate 50 to support the substrate 50. One of the lifters 71 transports the substrate 50 from the temporary positioning station 61 to the coating station 62, and the other lifter 72 transports the substrate 50 from the coating station 62 to the hardening station 63.

As shown in FIG. 1, the coating station 62 includes a stage 10, a moving mechanism 11, and a stage 12. The nozzle unit 13 (Fig. 1) is not shown in Fig. 5.

The second transfer roller 66 is disposed at the hardening station 63. The substrate 50 processed at the coating station 62 is transported to the curing station 63 by the transfer device 64, and is mounted on the second transfer roller 66. The second transfer roller 66 transports the substrate 50 in the positive direction of the x-axis. A curing light source 68 is disposed above the transport path of the substrate 50. The curing light source 68 irradiates the substrate 50 conveyed by the second transfer roller 66 with light including a wavelength component that hardens the film material.

A method of forming a film using the film forming apparatus of the embodiment will be described with reference to Figs. 6A to 6F.

Fig. 6A shows a schematic side view of the nozzle unit 13 and the substrate 50. The liquid film material 80 is dropletized while moving the substrate 50 in the positive direction of the y-axis, and is directed from the nozzle head 31 on the upstream side (negative side of the y-axis) toward the application region 58 of the substrate 50 (Fig. 4). Spit out. A first film 81 made of a liquid film material is formed in the coating region 58.

As shown in FIG. 6B, when the liquid first film 81 passes under the curing light source 32, it is cured by the curing light. Here, "hardening" means hardening with a sufficient degree of adhesion but not moving on the surface of the substrate 50. The time from the time when the film material 80 is bounced on the substrate 50 to the curing time is determined by the distance from the nozzle hole of the nozzle head 31 to the curing light source 32 on the downstream side and the moving speed of the substrate 50.

When the coating region 58 (fourth image) passes below the nozzle head 31 on the downstream side (the positive side of the y-axis), the liquid film material 80 is discharged from the nozzle head 31 on the downstream side toward the coating region 58.

When the first film 81 formed of the film material 80 discharged from the nozzle head 31 on the upstream side covers the entire area of the application region 58, the film material 80 discharged from the nozzle head 31 on the downstream side is bounced on the cured first film 81. on. Thereby, the first film 81 having a two-layer structure of a cured film material and a liquid film material is obtained.

The first film 81 formed of the film material 80 discharged from the nozzle head 31 on the upstream side does not cover the entire region of the application region 58. When the portion of the surface of the substrate 50 is discretely distributed in the application region 58, the downstream side is The film material 80 discharged from the nozzle head 31 is projected on the exposed portion of the substrate 50. Thereby, the first film 81 covers the entire area of the coating region 58 with the cured film material and the liquid film material. At this time, the first film 81 has a structure in which the hardened portion and the liquid portion are distributed in the plane.

As shown in Fig. 6C, when the application region 58 (Fig. 4) passes under the curing light source 32 on the most downstream side, the liquid portion of the first film 81 is hardened.

As shown in Fig. 6D, the entire region of the coating region 58 passing through the curing light source 32 (Fig. 6C) on the most downstream side is covered with the cured first film 81.

As shown in FIG. 6E, while the substrate 50 is moved in the negative direction of the y-axis, the film material 80 is discharged from the nozzle head 31, and a liquid film material is applied onto the first film 81. Thereby, the first film 81 is formed on the first film 81. The second film 82 is composed of a liquid film material. When the second film 82 is formed, the curing light source 32 is in a light-off state.

As shown in FIG. 6F, the entire surface of the first film 81 is covered with a liquid second film 82.

As shown in Fig. 6G, after the second film 82 is formed, the substrate 50 is transferred to the curing station 63 (Fig. 5). In the hardening station 63, the substrate 50 is conveyed by the second transfer roller 66 and passes under the curing light source 68. At this time, the liquid second film 82 is irradiated with light from the curing light source 68 and hardened. The cured first film 81 and second film 82 correspond to the adhesive layer 51 shown in FIG. The adhesive layer 53 on the first semiconductor wafer 52 can be formed in the same manner.

In the method according to the embodiment, when the liquid film material 80 is applied onto the first film 81 (Fig. 6E), the curing light source 32 is in a light-off state. The liquid second film 82 is conveyed from the coating station 62 to the curing station 63 by the conveying device 64 shown in Fig. 5, and is then cured. Therefore, the elapsed time until the liquid second film 82 is cured is long. Before the second film 82 is cured, the liquid film material spreads in the in-plane direction to planarize the surface of the second film 82.

On the other hand, the first film 81 repeats the process of causing the film material to be bounced on the surface of the substrate 50 while moving the surface of the substrate, and the film material on the surface of the substrate 50 after the bounce is irradiated with light to harden it. The process is formed. Therefore, it is impossible to ensure a sufficient time for the liquid film material to spread in the in-plane direction to flatten the surface. Since the surface of the liquid first film 81 is hardened before being flattened, the first film 81 is The surface remains with respect to the unevenness of the surface corresponding to the position of the impact point of the film material.

When only the first film 81 is used as the adhesive layer 51 shown in FIG. 3B, irregularities are present on the surface of the adhesive layer 51. When the first semiconductor wafer 52 is bonded to the adhesive layer 51, voids containing air remain at the interface between the adhesive layer 51 and the first semiconductor wafer 52. The bonding strength of the first semiconductor wafer 52 is lowered due to the void. Further, the expansion of the air in the cavity may cause the first semiconductor wafer 52 to fall off from the substrate 50.

In the embodiment, since the surface of the second film 82 is flattened, it is difficult to form a void at the interface between the adhesive layer 51 and the first semiconductor wafer 52. Thereby, it is possible to prevent a decrease in the bonding strength of the first semiconductor wafer 52 and a fall of the first semiconductor wafer 52.

Next, an effect of forming the first film 81 (FIG. 6F) as a base of the second film 82 in order to form the second film 82 will be described.

Fig. 7A is a cross-sectional view showing the substrate 50 immediately after the liquid film material 80 is spring-applied to the application region 58 of the substrate 50. Immediately after the impact, the film material 80 is attached to each of the impact locations. When the surface of the substrate 50 is lyophobic, as shown in FIG. 7B, if the surface of the substrate 50 is bounced from the film material until the surface is flattened, the liquid film material 80 is collected in one portion. In the area. Thereby, a region in which the surface of the substrate 50 is exposed is formed in the coating region 58. When the film material 80 is cured in this state, the region where the substrate 50 is exposed remains.

In the embodiment, if the first film 81 (Fig. 6F) is formed in advance as the first In the base of the film 82, the surface of the substrate 50 is not affected by liquid repellency, and the entire area of the application region 58 can be covered by the first film 81 and the second film 82. In order to cover the entire area of the application region 58 with the first film 81, in the process of forming the first film 81 (Fig. 6A, Fig. 6B), the film material adhered to the impact point is lyophobic by the surface. It is preferred to harden the film material before moving from the impact point.

In the above embodiment, the light source 32 (Fig. 6B) for curing the first film 81 and the light source 68 for curing the second film 82 (Fig. 6F) are prepared (Fig. 5, Fig. 6G). However, the second film 82 may be cured by the light source 32. At this time, in the process shown in FIG. 6E, after the liquid second film 82 is formed, the stage 12 is waited until the surface of the second film 82 is flattened. Thereafter, the curing light source 32 is turned on, and the substrate 50 is moved. When the second film 82 passes under the light source 32 for curing, the second film 82 is cured by irradiation with light for curing.

The present invention has been described based on the above examples, but the present invention is not limited thereto. For example, it will be apparent to those skilled in the art that various modifications, improvements and combinations can be made.

12‧‧‧stage

31‧‧‧Nozzle head

32‧‧‧ Hardening light source

50‧‧‧Substrate (package substrate)

63‧‧‧ hardening station

66‧‧‧2nd conveying roller

68‧‧‧ Hardening light source

80‧‧‧Film material

81‧‧‧1st film

82‧‧‧2nd film

Claims (4)

A film forming method comprising: repeating a process of causing a photocurable film material to be elasticated while moving a surface of a liquid on a liquid-repellent surface; and irradiating the film material on the surface to be hardened after being bounced a process of forming a first film on a surface of the surface on which the film material is to be applied, and a process of forming a liquid second film by applying a liquid film material to the first film; and After the formation of the second film, the process of irradiating light to cure the second film is performed. The method for forming a film according to claim 1, wherein in the process of forming the first film, before the liquid droplets of the film material are moved from the impact point by the liquid repellency of the surface, The film material is hardened. The film forming method according to claim 1 or 2, wherein, in the process of forming the second film, the entire surface of the surface of the first film is covered with the liquid film material. A film forming apparatus comprising: a stage for holding a substrate; and a nozzle head having a plurality of nozzle holes for discharging a liquid-like film material which is light-curable to the substrate held by the stage; and a moving mechanism for the substrate and One of the aforementioned nozzle tips is relative to Another light source that irradiates the liquid film material adhering to the substrate held by the stage to the curing light; and a control device that controls the nozzle head, the light source, and the moving mechanism; and the control device Discharging a liquid film material from the nozzle head while moving one of the nozzle head and the substrate relative to the other, and attaching a liquid film material to a portion of the substrate, and from the light source The liquid film material adhering to the substrate is irradiated with light for curing, and the film material is cured to form a first film. After the first film is formed, one of the nozzle head and the substrate is opposed to each other. While moving the other, the liquid film material is discharged from the nozzle head, and the liquid film material is adhered to the first film to form a liquid second film. After the second film is formed, The second film is cured by irradiating light to the second film.