JP2782607B2 - Film exposure method and film exposure apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a film exposure method and a film exposure apparatus of a projection exposure system suitably used for transfer of a circuit pattern, for example. The present invention relates to a film exposure method and a film exposure apparatus capable of easily removing a positive photoresist in a peripheral portion in a width direction by development.

[Conventional technology]

Conventionally, liquid crystal display panels, cameras, calculators, IC cards, etc. have a thickness of 25-125μ
For example, a polyester film, a polyimide film, or the like having a length of about m is used.

In particular, in the field of semiconductor chip mounting technology, mounting by a film carrier method as one of wireless bonding instead of conventional wire bonding has become popular.

In mounting a semiconductor chip by this film carrier method, a conductive thin film such as a copper foil is pasted on an insulating film substrate such as a polyester film, and the conductive thin film is patterned by photolithography to produce a film circuit board. Then, using the film circuit board as a lead, a semiconductor chip having bumps made of gold or the like is collectively bonded onto the lead. The mounting of the semiconductor chip by the film carrier method is sometimes called a TAB (Tape Automated Bonding) method.

In this photolithography technique, a film circuit board is usually manufactured through a photoresist coating step, an exposure step for transferring a circuit pattern, a development step, an etching step, and the like.

In the photoresist coating step, a photoresist is usually applied by a roll coater on a conductive thin film attached to the surface of an insulating film substrate to form a photoresist layer. This roll coater has a structure similar to that of a rotary press of a printing press and the like, in which a rod on which a photoresist is applied is pressed against a film substrate to be transferred and rotated, and the photoresist is pressed on one side of the film substrate or by a pressing force. It is applied to the entire surface on both sides.

FIG. 4 is a cross-sectional view showing a state of a photoresist layer applied to one surface of a film substrate by the roll coater. 81 is an insulating film substrate, 82 is a conductive thin film attached to the insulating film substrate 81, 83 is a photoresist layer, and 84 is a perforation formed on the insulating film substrate 81. Here, a conductive thin film 82 is stuck on an insulating film substrate 81, and further a photoresist layer is formed.
The materials provided with 83 are hereinafter collectively referred to as “film substrate materials”. In some cases, the insulating film substrate 81 is not used. In this case, a material in which the photoresist layer 83 is provided on the conductive film 82 is referred to as a film substrate material.

Thus, when a photoresist layer 83 in which a photoresist is applied on the conductive thin film 82 by a roll coater is formed, as shown in FIG. 4, not only the pattern formation portion F _C of the photoresist layer 83 but also the outside thereof. Photoresist is also applied to the peripheral portion F _{P in the} width direction, and the peripheral portion F _P
Photoresist, the thickness of even coating film more in the pattern forming portion F _C increases.

[Problems to be solved by the invention]

However, in the conventional film exposure device, the peripheral portion F _P other than the pattern forming portion F _C because they are not exposed is shielded by the aperture or the like, the photoresist on the peripheral portion F _P is not sensitive, therefore, the following in the development step, the photoresist of the peripheral portion F _P may remain without being removed. With such photoresist in the peripheral portion F _P remains in the subsequent etching step, by the remaining photoresist, a conductive thin film portion of the peripheral portion F _P is unnecessarily remains unetched, proper read It is not possible to manufacture a film circuit board that plays the role of a film circuit.

Therefore, conventionally, before reaching the etching process, the troublesome work such as scraping the photoresist remaining on the peripheral portion F _P has a problem that required.

The present inventors, as will be exposed simultaneously to the peripheral portion F _P at its external not pattern forming section F _C only, the photoresist of the peripheral portion F _P tried to remove in a development step.

However, it turned out that there was a new problem here. That is, the photoresist in the peripheral portion F _P, the pattern forming section
Since film thickness than the thicker F _C, the pattern forming unit F _C about the same illuminance, a problem is difficult to photoresist in the peripheral portion F _P be easily removed in a development step.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a film exposure method and a film exposure apparatus capable of easily removing a peripheral portion in a width direction other than a pattern forming portion of a positive photoresist by development.

[Means for solving the problem]

In order to achieve the above object, in the film exposure method of the present invention, while intermittently transporting a long film substrate material having a surface coated with a positive photoresist to an exposure area, the light from the lamp is exposed to light. In a projection exposure type film exposure method in which a mask is transmitted and made incident on an imaging lens, and this light is imaged on an exposure area to expose the surface of the positive photoresist, a pattern forming portion of the positive photoresist is exposed to light. A configuration is adopted in which an image of the pattern of the mask is formed and exposed, and a peripheral portion in the width direction outside the pattern forming portion is exposed with higher illuminance than the pattern forming portion.

In the film exposure apparatus of the present invention, the lamp, the light transmitted from the photomask irradiated with the light from the lamp, the image forming lens for connecting the light transmitted through the photomask to the exposure area, and forming an image of the photomask, and the positive surface on the surface. A transport system for intermittently transporting a long film substrate material coated with a mold photoresist to an imaging position, and light from an imaging lens directed outward in the width direction of the transported film substrate material. A configuration including a pair of peripheral reflecting mirrors for reflecting light inward in the direction to irradiate the peripheral portion in the width direction of the film substrate material with light is adopted.

In another film exposure apparatus of the present invention, a lamp, an image forming lens for connecting light transmitted through a photomask irradiated with light from the lamp to form an image of the photomask, and a positive type photo A transport system that intermittently transports a long film substrate material coated with a resist to an image forming position, and light from an imaging lens directed outward in the width direction of the transported film substrate material, in the width direction. A configuration including a pair of peripheral lenses so as to be refracted inward and irradiate the peripheral portion in the width direction of the film substrate material with light is adopted.

[Action]

According to the film exposure method of the present invention, when exposing the pattern forming portion of the positive photoresist, also exposing the peripheral portion in the width direction other than the pattern forming portion, and the illuminance of the peripheral portion from the pattern forming portion Therefore, even when the thickness of the peripheral portion of the positive photoresist is large, the photosensitive can be sufficiently exposed.

Therefore, in the next developing step, not only the photosensitive portion of the pattern forming portion but also the peripheral portion of the photoresist can be easily removed.

According to the film exposure apparatus of the present invention, the light from the imaging lens heading outward in the width direction of the film substrate material is reflected inward in the width direction, and a pair of light irradiating the peripheral portion in the width direction. With the simple configuration of providing the peripheral reflecting mirror, the above-described film exposure method can be reliably achieved.

According to another film exposure apparatus of the present invention, the light from the imaging lens directed outward in the width direction of the film substrate material is refracted inward in the width direction to irradiate the peripheral portion in the width direction with light. With the simple configuration of providing the peripheral lens described above, the above-described film exposure method can be reliably achieved.

〔Example〕

1 and 2 show a film exposure apparatus according to an embodiment of the present invention. FIG. 1 is a side view in the length direction of the film, and FIG. 2 is a side view in the width direction. Hereinafter, a film exposure method and a film exposure apparatus according to an embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1, a long film substrate material F for TAB, the surface of which is coated with a positive photoresist,
An image of one photomask is formed by one exposure, and the image is conveyed so that areas to be exposed (hereinafter, referred to as exposure areas) are sequentially positioned at an image forming position.

When one exposure area of the film substrate material F is located at the image forming position, light from a lamp 10 such as an ultra-high pressure mercury lamp is transmitted through the photomask M and made incident on the image forming lens 70, and the second
As shown in the figure, so bear this light, simultaneously exposing both the peripheral portion F _P of the positive photoresist pattern forming portion F _C and the transverse direction. Illuminance in the peripheral portion F _P in the width direction,
Considering the thickness of the peripheral portion F _P in the width direction of the applied photoresist layer is formed by a roll coater, usually,
It may be at least 120% of the illumination of the pattern forming portion F _C.

The light from the imaging lens 70 toward the outer side in the width direction of the film substrate material F in FIGS. 1 and 2, a pair of reflecting to face the peripheral portion F _P in the width direction of the outside of the pattern forming portion F _C Peripheral mirror 52 is provided.

The pair of peripheral reflecting mirrors 52 are arranged on the outer side in the width direction so as to sandwich the film substrate material F positioned at the image forming position, and stand upright in the optical axis direction of the image forming lens 70. The length of the reflecting surface in the length direction (perpendicular to the paper surface) is equal to or slightly longer than the length of the exposure area. part F _P is overexposed so that the illuminance distribution shown in Figure 2. In addition, peripheral reflector
The posture of 52 does not need to be perpendicular to the transport surface of the film substrate material F, and may be inclined. Further, the form of the reflecting surface of the peripheral reflecting mirror 52 is not limited to a plane, but may be a curved surface.

In FIG. 1, reference numeral 15 denotes an elliptical converging mirror, 16 denotes an integrator lens for uniforming the illuminance distribution at the image forming position, and 17 denotes a condenser lens. The bright spot of the lamp 10 is located at the first focal point of the elliptical condenser mirror 15, and the center of the integrator lens 16 is located at the second focal point of the elliptical condenser mirror 15.

Reference numeral 40 denotes a shutter, and the shutter 40 is controlled to open and close at a predetermined duty cycle so as to follow intermittent conveyance of the film substrate material F.

The conveyance system of the film base material F includes a pair of friction rollers 92, 92 serving as a driving force for conveyance, and a driving source (not shown) for rotating and stopping the friction rollers 92, 92.
And a control circuit (not shown) for controlling the operation of the drive source
And a sprocket roller 94 and a pressing roller 94 'for ensuring the transport linearity of the film substrate material F and the reproducibility of the stop position. The sprocket roller 94 is fitted into a perforation 84 of the film substrate material F.

As the imaging lens 70, a lens having a resolution with an exposure line width of about 10 μm is used in order to respond to recent miniaturization of circuit patterns.

Therefore, when the thickness of the positive photoresist is thick to be the peripheral portion F _P in the width direction, which can be sufficiently sensitive, after the positive photoresist widthwise perimeter F _P in the development step It can be easily removed.

Next, another embodiment will be described. FIG. 3 is an explanatory view of another embodiment of the present invention, and is a side view in the width direction like FIG. A configuration using a pair of peripheral lenses 53 instead of the peripheral reflector is adopted.

In FIG. 3, a pair of peripheral lens 53, the light from the imaging lens 70 toward the outer side in the width direction, is refracted inside the said direction, which is the light irradiation to the peripheral portion F _P in the width direction, the light passing through these of the pair of peripheral lens 53, the peripheral portion F _P of each width direction, are overexposed as shown in Figure 3.

The pair of lens periphery 53, as viewed from the photoresist in the peripheral portion F _P, in the oblique position above the outer, consisting placed for example cylindrical lenses so as to extend along the length of the film substrate material F. Incidentally, in these peripheral lens 53, so as not to refract light towards the pattern forming portion F _C, part beams directed from the imaging lens 70 to the pattern forming portion F _C is incident is pre-cut.

Further, between the imaging lens 70 and each of the peripheral lenses 53, the shielding plate 20 is disposed. The image of the shielding plate 20 is formed on the pattern forming portion F _C of the film substrate material F by the peripheral lens 53, and the end of the image at that time is formed by the pattern forming portion F _C and the peripheral portion _FP . It is designed to match the boundaries. Therefore, it is possible to prevent light suffer this boundary vividly to the pattern forming section F _C a. Therefore, not the pattern forming section F _C is over-exposed.

According to the film exposure apparatus of this embodiment, as in the embodiment, even when the thickness of the positive photoresist of the peripheral portion F _P in the width direction is thick, can be sufficiently sensitive so, after the positive photoresist in the width direction of the peripheral portion F _P can be easily removed in the development step. Moreover, because of the use of peripheral lens 53, high light collection efficiency, thus the peripheral portion F _P in the width direction, the pattern forming section F _C eg than 1.
Exposure can be performed with an illuminance of 8 times or more.

Above have been described in the embodiments the present invention, in addition to these, using an optical fiber or the like irradiating light to the peripheral portion F _P guiding light from the light source unit than the illuminance of the illuminance when the pattern forming section F _C It is also possible to make it higher.

〔The invention's effect〕

As described above, according to the first aspect of the invention, when exposing the pattern forming portion of the positive photoresist, the peripheral portion in the width direction other than the pattern forming portion is also exposed, and the illuminance of the peripheral portion is also exposed. Illuminance is higher than that of the pattern forming part, so that even when the film thickness of the peripheral part of the positive photoresist is large, it is possible to sufficiently expose the photoresist, and in the next developing step, if only the photosensitive part of the pattern forming part is exposed, In addition, the photoresist in the peripheral portion can be easily removed, and the operation of removing the photoresist in the peripheral portion, which is conventionally required, is not required.

According to the second and third aspects of the present invention, the peripheral portion in the width direction of the positive photoresist can be sufficiently exposed.

[Brief description of the drawings]

1 and 2 are explanatory views of a film exposure apparatus according to an embodiment of the present invention, FIG. 3 is an explanatory view of a film exposure apparatus according to another embodiment of the present invention, and FIG. 4 is coated by a roll coater. It is sectional drawing which shows the state of a photoresist layer. 10 Lamp, 15 Elliptical condenser mirror 16 Integrator lens 17 Condenser lens, 20 Shielding plate 40 Shutter 52 Peripheral reflector 53 Peripheral lens 70 Image lens 81: Insulating film substrate 82: Conductive thin film, 83: Photoresist layer 84: Perforation 92: Friction roller 94: Sprocket roller 94 ': Pressing roller, F _C: Pattern forming part F _P … Peripheral part in width direction, M… Photo mask F… Film substrate material

Claims (3)

(57) [Claims] 1. A method according to claim 1, wherein a long film substrate material coated with a positive photoresist on its surface is intermittently conveyed to an exposure area, and light from a lamp is transmitted through a photomask and made incident on an imaging lens. In a projection exposure type film exposure method of exposing the surface of a positive type photoresist by forming an image of the light on an exposure area, the pattern forming portion of the positive type photoresist is formed by forming an image of a pattern of a photomask. And exposing a peripheral portion in a width direction outside the pattern forming portion with higher illuminance than the pattern forming portion. 2. A lamp, an imaging lens for connecting light transmitted through a photomask irradiated with light from the lamp to an exposure area to form an image of the photomask, and a positive photoresist on the surface thereof. A conveying system that intermittently conveys the coated long film substrate material to the image forming position; and a light from an image forming lens that goes outward in the width direction of the conveyed film substrate material, and enters the light inward in the width direction. A film exposure apparatus comprising: a pair of peripheral reflecting mirrors for reflecting light to irradiate a peripheral portion in a width direction of a film substrate material. 3. A lamp, an image forming lens for connecting light transmitted through a photomask irradiated with light from the lamp to form an image of the photomask, and a positive type photoresist applied to the surface thereof. A transport system for intermittently transporting a long film substrate material to an imaging position, and refracting light from an imaging lens directed outward in the width direction of the transported film substrate material inward in the width direction. A film exposure apparatus, comprising: a pair of peripheral lenses for irradiating a peripheral portion in a width direction of a film substrate material with light.