JP2003001475A - Surface plate for laser beam machining, and film carrier manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam apparatus capable of performing the stable machining with excellent accuracy when cutting a fine pattern by irradiating the laser beam in manufacturing a printed circuit board. SOLUTION: A surface plate 20 for laser beam machining is for patterning a film with laser beam irradiation and is provided with, in the laser beam irradiation part thereof, an aperture 21 having an exhaust function. In addition, in a manufacturing method for a film carrier 10, the film with an adhesive layer laminated on an organic film in this order is fixed on the surface plate for laser beam machining with the aperture 21 formed in the laser beam irradiation part at a film placement part, the film is patterned by irradiating the laser beam irradiation part with the laser beam while exhausting the aperture 21, a metal foil for circuit wiring is laminated on the adhesive layer, the metal foil is patterned, and a conductive electrode is provided in the aperture 21 as necessary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a wiring board, and more particularly to a laser processing platen for cutting fine patterns in a film for a film carrier and a method for manufacturing the film carrier.

[0002]

2. Description of the Related Art A conventional method of manufacturing a film carrier having a conductor circuit and a conductive electrode provided on a base film uses a material in which a metal foil is laminated on a resin base material, and is electrically connected to a chip or an external wiring. Openings such as vias and lands for forming conductive electrodes for taking are formed by photolithography of the resin base material layer.

As a recent technical trend of the film carrier, the diameter of the via portion is reduced to several tens of μm and the pitch is narrowed. In response to this, in the conventional film carrier manufacturing method, the diameter and pitch of the vias that can be formed in the film carrier are approaching their limits, and it is extremely difficult to form circuit wiring with higher density.

In addition, there is also known a method in which all the patterns are collectively processed on a base film using a mold and then laminated on a metal foil. However, since it is difficult for these methods to deal with complicated shapes and fine patterns, there is a problem in that the method has a limit in forming the openings.

Further, a base film with an uncured adhesive is used, and the opening is cut by a laser beam,
A method of laminating a metal foil after perforating is also known. However, in this method, there is a problem that the laser beam that cuts the base film cuts the processing surface plate of the laser device. In addition, after cutting, the cut pieces are reattached to the base film, and when laminating the metal foil, it is sandwiched as a foreign substance between the metal foil and the adhesive, resulting in poor adhesion.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a laser device capable of stably and accurately processing a fine pattern by irradiating a laser beam in the manufacture of a wiring board.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides means for solving the following problems.

That is, in the invention according to claim 1,
A laser processing surface plate for patterning a film by laser irradiation, wherein an opening is provided in a laser irradiation portion, the laser processing surface plate having an exhaust function in the opening. is there.

That is, in the invention according to claim 2,
The laser processing platen according to claim 1, further comprising a film position fixing means.

That is, in the invention according to claim 3,
The laser processing apparatus according to claim 1 or 2, further comprising a film static eliminator.

That is, in the invention according to claim 4,
The film is a structure in which an adhesive layer is laminated on an organic film, a metal foil for circuit wiring is laminated after laser irradiation, the metal foil is patterned, and a conductive electrode is formed in the opening if necessary to form a film carrier. The present invention provides a laser processing apparatus according to any one of claims 1, 2 and 3.

That is, in the invention according to claim 5,
Sequentially, the film consisting of the adhesive layer laminated on the organic film is fixed on the laser processing surface plate having the opening in the laser irradiation part of the film mounting part, and the laser irradiation part is exhausted while the opening is exhausted. A film carrier characterized by patterning the film by irradiating the film with a laser, laminating a metal foil for circuit wiring on the adhesive layer, patterning the metal foil, and forming a conductive electrode in the opening if necessary. Is provided.

According to the first aspect of the present invention, in a processing device for cutting a base film by using a laser beam, in order to prevent the laser beam that has penetrated through the surface plate from being cut by the laser during cutting by a laser, the surface plate is cut. Although an opening is provided, it is possible to prevent reattachment of cut pieces falling in the opening to the base material by providing an exhaust gas recovery function from the opening or the platen side. is there.

According to the second aspect of the invention, the film can be securely fixed, and it is an object of the present invention to improve the processing position accuracy during laser processing.

Further, conventionally, when the film is charged,
The cut pieces that were peeled off when cut by laser irradiation were likely to be re-adsorbed on the film, and in some cases, physical exhaustion could not completely absorb and collect. Therefore, in order to efficiently perform the exhaust mechanism, the third aspect of the present invention can prevent the reattachment of the cut piece to the working surface plate.

Further, in claim 4, the present invention shows a film in which the effect of the present invention is remarkable. By applying this film, it is possible to obtain a film having a level of several μm which is required for the processing position accuracy in the plane of the film carrier. Position accuracy can be obtained.

As the laser of the present invention, any laser can be used as long as it can be used for cutting, but generally used are CO ₂ , excimer, YAG laser and the like. If necessary, it is possible to use a method in which a CO ₂ laser and an excimer laser are used in combination.

As the laser irradiating section, it is premised that the positions of the film and the surface plate are determined, and that the desired cutting section of the film or the contour of the cutting section is predetermined. Alternatively, it means the position of the surface plate corresponding to the predetermined position of the contour portion of the cutting portion. By performing laser irradiation on such a portion, the laser irradiation portion and the portion surrounded by the laser irradiation portion are separated from other film portions and fall into the opening.

The opening means a part where the surface plate provided in the other part is open without the surface plate. The patterning of the film means that by irradiating the laser irradiation portion with laser, the laser irradiation portion and the portion surrounded by the laser irradiation portion are separated from other film portions, and thus the remaining portion not separated is separated. Forming a film.

The laser processing platen serves as a target of laser irradiation and is not a target of laser processing, but it defines the positional relationship between the laser and the film. Various means can be used as the means for fixing the position of the film. For example, there is a position fixing means for directly adsorbing the film to the surface plate so that the processing surface plate has a suction function by vacuum at the opening and a portion other than the vicinity of the opening.

In addition to this, a means having a function of holding the outer periphery of the film and the outside of the processing area may be provided to apply tension, or a means for applying a guide pin to the sprocket hole to apply tension. .

At this time, the film may have a gap with respect to the surface plate or may have no gap and is in direct contact with the surface plate. The accuracy increases.

As described above, in order to suppress the deterioration of the positional accuracy due to the warp expansion / contraction of the film during the cutting by the laser,
It is preferable to use a means for applying a tension by providing a jig having a function of holding the outer peripheral portion of the film and the outside of the processing area. The reason for this is that by applying a means for applying tension to the film, the film is less likely to bend and the positional deviation is reduced.

The film may be made of any material, but particularly commonly used films are organic films, and among them, materials that are easily charged are often used. In the conventional technique, since such a film was easily charged, it was easily re-adsorbed by the film itself. On the other hand, in the present invention, even if the material of the film is an organic film or a material that is particularly easily charged among the organic films, the cut pieces peeled off when cut by laser irradiation are not re-adsorbed. Therefore, when such a material that is easily re-adsorbed must be used, the use of the present invention makes it possible to perform cutting by laser irradiation without re-adsorption, which could not be achieved conventionally, and is highly effective.

Particularly, as the organic film of the film carrier film according to claims 4 and 5, a polyimide resin,
An organic film made of a phenol resin, an acrylic resin, a polyester resin, a fluorine resin, a polyphenyl ether resin, a polymer liquid crystal or the like can be used. The thickness is not limited, but in practice, about 10 to 60 μm is practical.

As the adhesive material, a polyimide adhesive, a polyester adhesive, an epoxy adhesive, an olefin adhesive, a silicone adhesive, etc., and an adhesive obtained by mixing two or more of these materials are used. It is possible. The thickness is not limited, but in practice, about 5 to 15 μm is practical.

As for the exhaust function, any function may be used as long as it has a suction port provided at the side of the opening and the like and can suck the cut pieces from the suction port. Further, as the static eliminator, any device can be used as long as it can remove static electricity from the film to prevent reattachment of cut pieces, and various devices such as an ionizer for static elimination and a static elimination sheet are used. It is especially effective when the physical exhaust cannot be used for suction and recovery.

Generally, the specifications of commercially available organic films include a type in which an adhesive is attached to the back surface and a user side is used to attach a metal foil such as copper foil, and a metal foil such as copper foil is laminated. Or the laminated type, but the former type is preferable as the film relating to claims 4 and 5.

In this case, the former type is used and the film layer and the adhesive layer are cut at the same time in order to secure continuity with the metal foil on the back surface and use it as a wiring circuit after forming the opening with a laser. Greatly effective when used by laminating with metal foil.

As the metal foil, the material is rolled copper foil,
Although an electrolytic copper foil or the like may be used, the thickness is not limited, but in practice, about 5 to 20 μm is practical. As a method for patterning this metal foil, a method of melting and forming the copper foil by a subtractive method and a method of laminating a copper foil having a film thickness thinner than the copper foil and forming a wiring by plating by a semi-additive method However, a method of dissolving and removing an unnecessary portion of the copper foil can be adopted, but in reality, the subtractive method is preferable and practical in terms of the ease of supplying and laminating the copper foil.

As the material of the conductive electrode, copper or copper alloy system and solder can be adopted, but in reality, copper or copper alloy system is preferable and practical in view of film strength and electric characteristics.

As a method of patterning the conductive electrodes, electrolytic plating, electroless plating, and a method of selectively printing an ink containing a conductive paste at required places can be used, but in practice, the plating method has a smaller diameter. It is preferable and practical in terms of easiness of control of filling into. The conductive electrode is 10 to 60 μm so that the opening is partially closed in this way.
It is used as a conductive electrode by filling up to a certain thickness.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a pattern arrangement and a partial sectional view of a film carrier using a processed film according to the present invention, and FIG. 2 shows a sectional view showing a constitution of a surface plate of the present invention. As shown in FIG. 1, the film carrier 10 has a structure in which a via forming portion 11 is provided in the central portion, a land forming portion 12 is provided around the film carrier, and a wiring circuit 13 ensures electrical continuity between the via forming portion 11 and the land forming portion 12.

The processing surface plate 20 for the laser device of the present invention is
As shown in FIG. 2, it comprises an opening 21 for avoiding damage by the laser 34 and collecting cut pieces, a vacuum hole 22 for holding the base material, and an exhaust mechanism connected to the opening 21. Here, the via forming portion 11 on the processing surface plate 20
The opening 21 is provided at a portion corresponding to the land forming portion 12.

A method of forming a film carrier using the laser processing apparatus of the present invention will be described below. Figure 3
It is a sectional view of a state where a film is placed on a processing surface plate and laser irradiation is performed. FIG. 4 is a sectional view showing a state in which a metal foil is added to it. <Figure 5> It is the cross section diagram of the film carrier which uses those films.

First, the base film 32 with the adhesive 31
While the cover film 33 is still attached, the laser 41 is irradiated using the laser device on which the processing surface plate 20 is installed to form the via forming portion 11, the land forming portion 12, the alignment mark and other patterns.

The substrate is held by a vacuum hole 22 provided in the processing surface plate 20, and is cut by the UVYAG processing machine from the base film 32 side to the adhesive 31 and the cover film 33.

It is also possible to process the base film by floating it on a surface plate, and to provide a jig having a function of holding the outer periphery of the base film and the outside of the processing area to apply tension, or to a sprocket hole. A method of applying a guide pin and applying tension is possible.

During the laser processing, the laser cutting may be stopped up to the adhesive 31, but the cut pieces remain on the base material until the cover film 33 is peeled off. Since the cut pieces may redeposit on the base material, it is desirable that the cover film 33 is cut and exhausted and collected as the cut pieces in this step.

Although the cover film 33 may be peeled off and laser-processed according to the specifications, the cover film 33 is provided to prevent the smearing of the adhesive layer 31 due to smearing and the environmental pollution. It is desirable to process in the state.

As the laser processing machine, an excimer laser or carbon dioxide laser processing machine can be used.
Exhaust gas collection of the cut pieces is done after the laser cutting process is completed.
It is performed by sucking through the opening 21.

Although air may be blown for static elimination processing and exhaust processing at all times, the processed portion of the base material is held in a floating state, and if pressure is applied more than necessary, warpage of the base material and expansion / contraction of the base material will occur. Since it causes the cause, it is desirable to start weakly at the time of laser irradiation and increase the pressure to obtain the exhaust gas recovery effect at the end of cutting.

The cover film 33 of the film carrier substrate thus laser-processed is peeled off, and the adhesive 31
The laminated base film 32 is laminated with the metal foil 35 for the wiring circuit pattern shown in FIG. 4, and the wiring circuit 13 and the conducting electrode 35 are formed by plating or the like as shown in FIG. 5 to provide a film carrier. I can do things.

[0044]

The present invention will be described in detail below with reference to the accompanying drawings. First, the base film with the adhesive is still attached to the cover film, and the via forming portion, the land forming portion, the alignment mark and other patterns are formed by using the laser device equipped with the processing surface plate.

The base film is UPILEX (50μ
m thickness: Polyimide resin as the material, Ube Industries, Ltd., and Toray 8500 (8 μm thickness: epoxy resin as the adhesive material) bonded to the adhesive were used.

The film is held by a vacuum hole provided on a processing surface plate, and an adhesive and a cover film (50 μm thick) are applied from the base film side by a UVYAG processing machine (Sumitomo Heavy Industries Ltd .: LAVIA UV 2000). )
I went to cut it up.

Exhaust gas recovery of the cut pieces was carried out by suction through the above-mentioned opening, and static elimination processing was carried out by operating an ionizer from the upper surface of the substrate. At that time, in order to prevent warping of the base material and expansion / contraction, pressure adjustment was performed such that the laser irradiation was started weakly and the pressure at which the exhaust gas recovery effect was obtained at the end of cutting was increased.

The cover film of the substrate for the film carrier thus laser-processed is peeled off, and a metal foil electrolytic copper foil for wiring circuit pattern (SLP: 18 μm, manufactured by Nippon Denshoku Co., Ltd.) is laminated on the base film with adhesive. , Patterned by the Sumtractive method to form a wiring circuit,
If necessary, connect the conductive electrode and the copper by electroplating sequentially.
It was possible to provide a film carrier having a thickness of 0 μm, a thickness of 2 μm of nickel, and a thickness of 0.4 μm of gold, and processed according to the present invention.

[0049]

Since the present invention is configured as described above, it is possible to form bumps having a small diameter of several tens of μm by using a laser, and to provide a film carrier having fine and high density circuit wiring. It can be provided easily and at low cost. Furthermore, by using the film carrier of the present invention, the number of bumps that can be formed in a narrow area can be increased, and it becomes possible to easily support high-density mounting of semiconductor devices.

[Brief description of drawings]

FIG. 1 is a pattern diagram and a sectional view showing a basic configuration of a film carrier formed according to the present invention.

FIG. 2 is a cross-sectional view showing a state in which a film is placed on a processing surface plate of the present invention, and a cut piece is in an uncompleted exhaust state.

FIG. 3 is a cross-sectional view of a state in which a film is placed on the processing surface plate of the first embodiment of the present invention and laser irradiation is performed.

4 is a cross-sectional view of the embodiment of FIG. 3 with a metal foil added.

5 is a cross-sectional view of a film carrier using the film of the embodiment of FIG.

[Explanation of symbols]

10 film carrier 11 Via formation part 12 Land formation part 13 Wiring circuit pattern 20 Processing surface plate for laser equipment 21 opening 22 Vacuum hole 31 Adhesive 32 base film 33 cover film 34 Ionizer 35 metal foil 36 Conductive electrode 41 laser

Claims (5)

[Claims] 1. A laser processing surface plate for patterning a film by laser irradiation, wherein an opening is provided in a laser irradiation portion, wherein the opening has an exhaust function. . 2. The laser processing surface plate according to claim 1, further comprising a film position fixing means. 3. The laser processing apparatus according to claim 1, further comprising a film static eliminator. 4. The film has a constitution in which an adhesive layer is laminated on an organic film, a metal foil for circuit wiring is laminated after laser irradiation, the metal foil is patterned, and a conductive electrode is formed in the opening if necessary. The laser processing apparatus according to claim 1, wherein the film is a film carrier. 5. A film having a structure in which an adhesive layer is laminated on an organic film is fixed in order on a laser processing surface plate having an opening at a laser irradiation portion of a film mounting portion,
The film is patterned by irradiating the laser irradiation part with laser while exhausting the opening, laminating a metal foil for circuit wiring on the adhesive layer, patterning the metal foil, and if necessary, a conductive electrode in the opening. A method of manufacturing a film carrier, comprising: