KR20050092842A - Method for fabricating tape wiring substrate - Google Patents

Abstract

Provided is a method of manufacturing a tape wiring board that can simplify the production process and reduce the production cost. This tape wiring board manufacturing method includes preparing a base film, forming a metal layer on the base film, and processing the metal layer into a wiring pattern using a laser. In addition, the metal layer may be partially etched by such a laser, and a wiring pattern may be formed using a subsequent wet etching.

Description

Method for fabricating tape wiring substrate

The present invention relates to a method for manufacturing a tape wiring board, and more particularly, to a method for manufacturing a tape wiring board for forming a wiring pattern using a laser.

Recently, with the trend of thinning, miniaturization, high integration, high speed, and pinning of semiconductor devices, the use of tape wiring boards is increasing in the field of semiconductor chip mounting technology. The tape wiring board has a structure in which a wiring pattern layer is formed on a thin base film made of an insulating material such as polyimide resin, and includes a tab (TAB) for collectively joining the leads connected to the wiring pattern layer and the bumps formed on the semiconductor chip. Automated Bonding) technology can be applied. Due to these characteristics, the tape wiring board is also called a tab tape.

1A or 1D are cross-sectional views sequentially illustrating a method of manufacturing a tape wiring board according to the prior art.

As shown in FIG. 1A, the copper foil 120 is formed on the insulating base film 110 such as polyimide resin by laminating or electroplating.

As shown in FIG. 1B, a photo resist 130 (PR) 130 is coated on the copper foil 120. Subsequently, an exposure process is performed using a light source 132 having a wavelength of several hundred μm.

As shown in FIG. 1C, the PR 130 after the exposure process is developed to pattern the PR 130.

As shown in FIG. 1D, the copper foil 120 is etched using the patterned PR 135 as an etching mask. At this time, the etching of the copper foil 120 is mainly wet etching (Wet etching) is used. When the remaining PR 135 is removed, the wiring pattern 125 is formed.

As described above, referring to the manufacturing process of the tape wiring board according to the prior art, after manufacturing the base film 110, the copper foil 120 is formed on the base film 110, and a photo / etching process. The copper foil 120 is processed into a wiring pattern 125 by using a. The photo / etching process includes many steps such as a PR coating process, an exposure process, a PR developing process, and a copper foil etching process.

Due to the photo / etching process consisting of many steps, the production line is increased, and a lot of fixed consumption materials (for example, PR, PR developer or copper foil etchant) causes a problem of increasing production cost.

In addition, since the light source 132 having the wavelength of several hundred μm is used in the photo / etching process according to the prior art, it is difficult to form the fine wiring pattern 125 having the fine pitch on the copper foil 120. have.

The technical problem to be achieved by the present invention is to provide a method for manufacturing a tape wiring board which can reduce the production cost by simplifying the production process and can form a fine pattern having a fine pitch.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

According to another aspect of the present invention, there is provided a method of manufacturing a tape wiring board, the method including preparing a base film, forming a metal layer on the base film, and using a laser to form the metal layer. And processing the wiring pattern.

In addition, the manufacturing method of the tape wiring board according to another embodiment of the present invention for achieving the technical problem, preparing a base film, forming a metal layer on the base film, and using the laser Partially removing a region other than the wiring pattern of the metal layer, and forming a wiring pattern by etching the remaining region other than the wiring pattern.

Specific details of other embodiments are included in the detailed description and the drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

The tape wiring board used herein includes a flexible printed circuit board having a wiring pattern formed on a base film such as a tape carrier package (TCP) or a chip on film (COF). Circuit Board, hereinafter FPC) can be used. The tape wiring board used herein is a structure in which a wiring pattern and an inner lead connected thereto are formed on a thin film made of an insulating material such as polyimide resin, and the bumps and tape wiring boards previously formed on a semiconductor chip are formed. And a wiring board to which a tape automated bonding (TAB) technology for bonding leads is collectively applied. The tape wiring board mentioned above is merely illustrative.

Hereinafter, a first embodiment of the present invention will be described with reference to Figs.

 2 is a flowchart of a manufacturing process of the tape wiring board according to the first embodiment of the present invention. 3A to 3C are cross-sectional views sequentially illustrating a manufacturing process of the tape wiring board of FIG. 2. 4 is a schematic view showing the structure of the exposure apparatus used in the first embodiment of the present invention.

As shown in Figure 2, first to prepare a base film (S210). Referring to FIG. 3A, the base film 310 is made of an insulating material having a thickness of 20 to 100 μm. As the insulating base film 310, an insulating material such as polyimide resin or polyester resin may be used as the main material. The polyimide thin film in the base film 310 may be obtained by applying a polyamic acid (PAA) solution as a precursor in a predetermined container to remove the solvent from the obtained film, and then by thermosetting.

And, as shown in Figure 2, to form a metal layer on the base film (S220). Referring to FIG. 3A, the metal layer 320 formed on the base film 310 is formed to a thickness of about 5 μm to 20 μm, and a metal material such as copper foil (Cu) is generally used.

A method of forming copper foil, which is an example of the metal layer 320 on the base film 310, may include casting, laminating, electroplating, and the like.

Casting is a method of spraying the liquid base film 310 on the rolled copper foil to perform thermal curing.

Laminating is a method of placing a rolled copper foil on the base film 310 and thermocompression bonding.

Electroplating is a method of depositing a seed layer (not shown) on the base film 310 and inserting the base film 310 in an electrolyte in which copper is melted to flow electricity to form a copper foil. Here, the seed layer may be formed on the base film 310 by sputtering. The seed layer (not shown) is preferably a material made of a material selected from Cr, Ti, and Ni, or a combination thereof.

And, as shown in Figure 2, to form a wiring pattern using a laser (S230). 3A and 3B, the metal layer 320 formed on the base film 310 is selectively etched using the laser 330 to form a wiring pattern 325 constituting a predetermined circuit.

Then, as shown in Figure 2, a solder resist is applied (S240). Referring to FIG. 3C, a solder resist is used to protect the wiring pattern 325 from an external environment except for a portion of the wiring pattern 325 formed on the base film 310 to be electrically connected to an external terminal. SR) 340 is applied. The solder resist 340 may be applied by screen printing.

Preferably, in order to improve the electrical characteristics of the wiring pattern 325, the surface of the wiring pattern 325 is plated with tin, gold, nickel or solder. The plating is performed after the solder resist 340 is applied to the wiring pattern 325, which is called a post plating method. Of course, in another embodiment of the present invention, after the plating of the wiring pattern 325, the lead metal method of applying the solder resist 340 may be adopted.

Hereinafter, a method of forming a wiring pattern using a laser will be described in detail with reference to FIG. 4.

Referring to FIG. 4, the laser generating exposure apparatus 400 according to an exemplary embodiment of the present invention includes a light source 410, a fly's eye lens 420 formed of a lens array, and an aperture having a predetermined shape. 430, a condenser lens 440, and a projection lens 460.

Here, the light source 410 may use a laser having a wavelength of 550 μm or less to implement the wiring pattern 325 having a fine pitch. Accordingly, the light source 410 may use any one source gas selected from the group consisting of ArF, KrF, XeCl, F ₂ , Neodymium-Yttrium Aluminum Garnet (Nd-YAG), and CO ₂ . In addition, the light source 410 may use a laser generated from a laser diode.

As shown in FIG. 4, the fly's eye lens 420 arranged as a hexagonal or various small lenses like the fly's eye is disposed where the laser passes from the light source 410. A beam equalizer such as the fly's eye lens 420 may have a uniform intensity and distribution when irradiating the mask 450 with a laser output from the light source 410.

In addition, the aperture 430 may be disposed at a portion through which light passes in order to increase the resolution of the irradiated laser while the size of the wiring pattern is reduced. The aperture 430 may be formed in a dipole, quadrupole, annular, or the like.

Thus, the laser generated at the light source 410 is converted to parallel light by the fly's eye lens 420 and partially limited by the aperture 430.

Then, the laser beam passing through the aperture 430 passes through the condenser lens 440 and is irradiated to the mask 450. The condenser lens 440 is a lens that concentrates the laser generated from the light source 410 in a desired direction, and does not directly participate in making an image, but improves the uniformity of the laser when irradiating the mask 450. .

Then, the laser that reaches the mask 450 is diffracted, and passes through the projection lens 460 to expose the metal layer 320 formed on the base film 310. In general, the projection lens 460 penetrates the mask 450 to reduce and project the laser having the shape of the mask pattern onto the metal layer 320.

In addition, the stage 470 supports the base film 310 on which the metal layer 320 is formed.

As a method of irradiating the laser layer generated from the light source 410 to the metal layer 320 on the base film 310, a stepper for irradiating the laser during the time when the mask 450 and the stage 470 are stopped is provided. Step-and-Repeat using Step-and-Repeat, and Step-and-Scan using a scanner that exposes the mask 450 and the stage 470 while moving in opposite directions with a constant speed difference. Scan) etc. can be used.

In order to process the metal layer 320 into the wiring pattern 325, only the metal layer 320 other than the wiring pattern 325 is accurately etched with a laser, and the metal layer 320 is formed by thermal energy generated from the laser. In order to minimize damage to the base film 310 positioned below, it is preferable to use a pulse type laser.

A laser output method according to the first embodiment of the present invention will be described using an ArF excimer laser (193 nm) having a pulse energy of 200 mJ as an example. Of course, the laser output method may vary depending on the equipment and process conditions. Here, the metal layer 320 is described as copper and the base film 310 is described as polyimide, but the present invention is not limited to the following specific examples.

When the etching rate for copper of the ArF excimer laser according to the first embodiment of the present invention is about 160mJ / μm and the etching rate for polyimide is about 16mJ / μm, a metal layer having a thickness of 8 μm ( The process of etching the wiring 320 to the wiring pattern 325 will be described.

In order to etch the metal layer 320 having a thickness of 8 μm, energy of 1280 mJ (= 160 mJ / μm × 8 μm) is required. Since the pulse energy of the ArF excimer laser is 200 mJ, 6.4 pulses (= 1280 mJ / 200 mJ) are required to etch the metal layer 320 having a thickness of 8 μm. Therefore, when irradiating the ArF excimer laser of 7 pulses to the metal layer 320, all of the metal layers 320 except the portion where the wiring pattern 325 is formed are etched, and 120 mJ energy (= 200 μm × 0.6 as much as 0.6 pulses) is etched. ) Is irradiated to the base film 310. Thus, the base film 310 is additionally etched by about 7.5 μm (= 120 mJ / 16 mJ / μm).

When the thickness of the polyimide that is the base film 310 is about 40 μm, the above damage does not affect the physical properties of the film experimentally.

When the metal layer 320 is etched by the pulse type laser, the pulse energy of the laser may be changed by adjusting the frequency (usually 50 to 300 Hz) and the output energy (5 to 100 W) of the laser. Therefore, when the pulse energy is properly adjusted, the amount of etching of the base film 310 such as polyimide disposed under the metal layer 320 may be minimized. The present invention is not limited to the numerical values mentioned in the above embodiments, and the metal layer 320 is minimized by minimizing the etching amount of the base film 310 by adjusting the frequency and output energy of the laser according to the material and thickness of the metal layer 320. To etch.

In addition, the heat energy may be transferred to the metal layer 320 or the base film 310 adjacent to the metal layer 320 and the laser 330 while the wiring pattern 325 is formed while the laser pattern is formed. Since the surrounding metal layer 320 may be etched or the lower base film 310 may be deformed by the thermal energy, the metal layer 320 and the laser 330 come into contact with each other while the wiring pattern 325 is formed by the laser. It is desirable to supply a refrigerant around the portion to prevent this thermal energy from being transferred to the environment.

As such refrigerants, methyl ether, ethyl chloride, methyl formate, isobutane, dichloroethylene, methylene chloride, ethyl ether, ammonia, carbon dioxide, sulfurous acid gas, methyl chloride and CFC refrigerants (freons) and the like can be used.

Hereinafter, a second embodiment of the present invention will be described with reference to Figs. 5 to 6D.

 5 is a flowchart of a manufacturing process of the tape wiring board according to the second embodiment of the present invention. 6A through 6D are cross-sectional views sequentially illustrating a manufacturing process of the tape wiring board of FIG. 5. For convenience of description, members having the same functions as the members shown in the drawings of the first embodiment are denoted by the same reference numerals, and therefore description thereof is omitted.

5 and 6A, first, the base film 310 is prepared (S510). Then, the metal layer 320 is formed on the base film 310 (S520). Here, the metal layer 320 is the same as the first embodiment.

5, 6A, and 6B, the metal layer 320 formed on the base film 310 is selectively etched using the laser 330 to form a wiring pattern 625 constituting a predetermined circuit. (S530). The metal layer 330 is composed of a wiring pattern 625 for transmitting an electrical signal and an area 622 other than the endorse pattern to be removed to form the wiring pattern 625. As shown in FIG. 6B, the region other than the wiring pattern 622 is partially removed by the laser 330 to leave the predetermined thickness. In one embodiment of the present invention, when using a copper foil of 8㎛ thickness as the metal layer 320, the laser foil etched about 7.5㎛ thick copper foil and leaves about 0.5㎛ thick copper foil. The present invention is not limited to the numerical values mentioned in the above embodiments, and the condition of re-etching the non-wiring pattern region 622 after laser etching and the convenience of the entire process and the convenience of the overall process, The thickness can vary.

As illustrated in FIG. 6C, the non-wiring pattern region 622 is removed by wet etching (S540). By the wet etching, the base film 310 disposed under the wiring pattern region 622 is exposed from the metal layer 320. As such, wet etching may be used to remove the region 622 other than the wiring pattern as a preferred embodiment of the present invention. However, the present invention is not limited thereto, and the non-wiring pattern region 622 may be removed using dry etching using plasma.

In one embodiment of the present invention, when using the metal layer 320 of copper foil, it is possible to perform wet etching using an aqueous solution containing FeCl ₃ , FeCl and HCl as an etchant. In this case, wet etching may be performed using an aqueous solution containing CuCl ₂ , CuCl, and HCl as an etchant.

And, as shown in Figure 6d, except for a predetermined portion electrically connected to the external terminal in the wiring pattern 625 formed on the base film 310 to protect the wiring pattern 625 from the external environment The resist 340 is applied (S550).

A laser output method according to a second embodiment of the present invention will be described with an ArF excimer laser (193 nm) having a pulse energy of 200 mJ as an example. Of course, the laser output method may vary depending on the equipment and process conditions. Here, the metal layer 320 is described as copper and the base film 310 is described as polyimide, but the present invention is not limited to the following specific examples.

When the etching rate with respect to copper of the ArF excimer laser according to the second embodiment of the present invention is about 160mJ / μm and the etching rate with respect to polyimide is about 16mJ / μm, the metal layer having a thickness of 8 μm ( The process of etching 320 to process the wiring pattern 625 will be described.

In order to etch the metal layer 320 having a thickness of 8 μm, energy of 1280 mJ (= 160 mJ / μm × 8 μm) is required. Since the pulse energy of the ArF excimer laser is 200 mJ, 6.4 pulses (= 1280 mJ / 200 mJ) are required to etch the metal layer 320 having a thickness of 8 μm. Thus, when irradiating the ArF excimer laser of 6 pulses to the metal layer 320, the non-wiring pattern region 622 is etched by about 7.5 [mu] m (= 1200 mJ / 160 mJ / [mu] m) thickness and remains by about 0.5 [mu] m thickness. The remaining area of the wiring pattern 622 having a thickness of 0.5 μm can be removed by wet etching. In this case, the remaining wiring pattern region 622 may be removed by dry etching using plasma.

As described above, when the primary etching by the laser and the secondary etching by the wet etching (or dry etching) are performed in parallel, the wiring pattern 625 may be processed by the laser 330 so as not to damage the base film 310. Can be.

As described above, according to embodiments of the present invention, since the metal layer may be directly processed into a wiring pattern without using PR, compared to the prior art, the process may be reduced, and thus the production cost of the tape wiring board may be reduced. .

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

As described above, according to the manufacturing method of the tape wiring board according to the present invention, the production process can be simplified to provide a manufacturing method of the tape wiring board which can reduce the production cost and form a fine pattern having a fine pitch.

1A or 1D are cross-sectional views sequentially illustrating a method of manufacturing a tape wiring board according to the prior art.

2 is a flowchart of a manufacturing process of the tape wiring board according to the first embodiment of the present invention.

3A to 3C are cross-sectional views sequentially illustrating a manufacturing process of the tape wiring board of FIG. 2.

4 is a schematic view showing the structure of an exposure apparatus used in the first embodiment of the present invention.

5 is a flowchart of a manufacturing process of the tape wiring board according to the second embodiment of the present invention.

6A through 6D are cross-sectional views sequentially illustrating a manufacturing process of the tape wiring board of FIG. 5.

 (Explanation of symbols for the main parts of the drawing)

310: base film 320: metal layer

325: wiring pattern 330: laser

340: solder resist 400: exposure apparatus

410: light source 420: fly's eye lens

430: aperture 440: condenser lens

450: mask 460: projection lens

470: stage 622: a region outside the wiring pattern

625: wiring pattern

Claims (22)

Preparing a base film; Forming a metal layer on the base film; And The method of manufacturing a tape wiring board comprising the step of processing the metal layer into a wiring pattern using a laser. The method of claim 1, And the laser is generated from any one source gas selected from the group consisting of ArF, KrF, XeCl, F ₂ , Nd-YAG and CO ₂ . The method of claim 2, And said laser is a pulse type. The method of claim 2, And said laser is a laser beam that has passed through a beam homogenizer. The method of claim 1, And a coolant is supplied to the metal layer while the wiring pattern is processed. The method of claim 5, The refrigerant is any one selected from the group consisting of methyl ether, ethyl chloride, methyl formate, isobutane, dichloroethylene, methylene chloride, ethyl ether, ammonia, carbon dioxide, sulfurous acid gas, methyl chloride and CFC refrigerant (freon) The manufacturing method of the tape wiring board characterized by the above-mentioned. The method of claim 1, The metal layer comprises a copper wiring board manufacturing method, characterized in that. Preparing a base film; Forming a metal layer on the base film; Partially removing a region other than the wiring pattern of the metal layer using a laser; And Forming a wiring pattern by etching the remaining region other than the wiring pattern. The method of claim 8, And the laser is generated from any one source gas selected from the group consisting of ArF, KrF, XeCl, F ₂ , Nd-YAG and CO ₂ . The method of claim 9, And said laser is a pulse type. The method of claim 10, And said laser is a laser beam that has passed through a beam homogenizer. The method of claim 8, And a coolant is supplied while partially removing the region other than the wiring pattern by using the laser. The method of claim 12, The refrigerant is any one selected from the group consisting of methyl ether, ethyl chloride, methyl formate, isobutane, dichloroethylene, methylene chloride, ethyl ether, ammonia, carbon dioxide, sulfurous acid gas, methyl chloride and CFC refrigerant (freon) The manufacturing method of the tape wiring board characterized by the above-mentioned. The method of claim 8, The etching is a method of manufacturing a tape wiring board, characterized in that the wet etching. The method of claim 14, And the base film disposed under the portion other than the wiring pattern by the wet etching. The method of claim 15, The metal layer comprises a copper wiring board manufacturing method, characterized in that. The method of claim 15, The wet etching method of manufacturing a tape wiring board, characterized in that using an aqueous solution containing FeCl ₃ , FeCl and HCl as an etchant. The method of claim 15, The wet etching method of manufacturing a tape wiring board, characterized in that using an aqueous solution containing CuCl ₂ , CuCl and HCl as an etchant. The method of claim 8, Forming the metal layer is a method of manufacturing a tape wiring board, characterized in that by the lamination method. The method of claim 8, Forming the metal layer is a method of manufacturing a tape wiring board, characterized in that by electroplating. The method of claim 20, wherein before forming the metal layer, And a seed layer is formed on the base film by sputtering. The method of claim 21, The seed layer is a method of manufacturing a tape wiring board, characterized in that the material consisting of a material selected from Cr, Ti and Ni or a combination thereof.