KR100609023B1 - Production method of flexible circuit board - Google Patents

Abstract

The present invention discloses a circuit forming process for inputting a raw material of a circuit board and forming a circuit pattern on the raw material; A protective insulating process of forming a protective insulating layer on the substrate on which the pattern is formed; A post-treatment process of forming a plating layer on a portion of the upper surface of the substrate on which the protective insulating layer is formed for the electrical connection, and performing a selective process such as adhesion of a reinforcing bar and mounting of a component, and then cutting only a desired area. In the circuit board manufacturing method, the detailed process of the protective insulating treatment process, the pre-treatment process for removing oxides, impurities and moisture in the copper foil laminate having a circuit pattern formed through a circuit forming process; A vacuum-thermocompression step of pressing a photosensitive coverlay film on the pretreated copper foil laminate; A first aging step of primary aging the copper foil laminated sheet to which the photosensitive coverlay film is pressed; An alignment and exposure step of exposing the master film on the photosensitive coverlay film of the copper foil laminated plate aged by the first aging step, and then exposing the master film; A second aging and developing step of secondary aging and developing the copper foil laminate after the exposure step; And a complete drying step of completely drying the photosensitive coverlay film on the copper foil laminate after removal to remove volatile substances, and completely bonding the photosensitive coverlay film. Characterized in that consisting of.

Printed Circuit Board, Manufacturing Method, Photosensitive, Coverlay, Film

Description

Printed circuit board formation method {Production method of flexible circuit board}

1 and 2 is a process block diagram illustrating a method of forming a printed circuit board according to the prior art;

3 is a process block diagram for explaining a method of forming a printed circuit board according to the present invention;

4 shows a device for forming a printed circuit board according to the present invention.

The present invention relates to a method for forming a printed circuit board. More specifically, after the photosensitive coverlay film is pressed onto the copper foil laminated plate on which the circuit pattern is formed, bubbles existing on the copper foil laminated plate and the photosensitive coverlay film are removed by vacuum-thermocompression method, and then, the exposure method is applied to the fine circuit pattern. The present invention relates to a printed circuit board forming method for forming a suitable exposed portion to produce a circuit board having a fine circuit pattern.

<Conventional method 1>

As shown in FIG. 1, after the copper foil laminate (CCL), which is a raw material of the circuit board, is introduced (B101), the photosensitive dry film is adhered to the copper foil laminate and then pressed by applying a predetermined heat and pressure. Exposure step (B104) and developing step (B105), after which the pattern film is aligned (B103), and then the light is incident upon exposure to ultraviolet rays to remove the remaining dry film while leaving the hardened part. After performing the exposure step (B104) and the developing step (B105) after performing the corrosion process (B106) and the peeling process (C106) to corrode the unnecessary copper foil region from which the dry film has been removed with a chemical and then remove the dry film of the remaining region ( B107) is performed sequentially to form a circuit. After each process is completed, the circuit forming process shown in FIG. 1 is completed.

Then, a step (B108) of preliminarily bonding the polyimide back coverlay film in which an open portion is previously formed on the copper foil laminated plate on which the circuit is formed through the above process is performed, and the temporary bonding is performed on the copper foil laminated plate. Pressure and heat are applied to the polyimide ash coverlay film to be compressed to perform compression (B109).

At this time, when performing the temporary bonding process (B108), the open portion formed on the polyimide coverlay film and the exposed portion of the copper foil laminate should be aligned to be well aligned with each other. After each process is completed, the protective insulation process shown in FIG. 1 is completed.

In addition, the circuit exposed portion of the copper-clad laminate in which the polyimide coverlay film is pressed to the upper portion through the thermocompression bonding process (B109) is subjected to the plating process 110 for connection, binding, and mounting of parts to form a plating layer. In some cases, an optional punching step (B111), such as reinforcing plate bonding or component mounting, is performed, and an external punching step (B112) of cutting only a desired area is performed. After each process is completed, the post-treatment process shown in FIG. 1 is completed.

In this case, the coverlay film provisional bonding process and the pressing process are detailed processes constituting a protective insulating process for forming a protective insulating layer.

<Conventional method 2>

As shown in FIG. 2, after the copper clad laminate (CCL), which is a raw material of the circuit board, is charged (B201), the photosensitive dry film is adhered to the copper foil laminate and then pressed by applying a predetermined pressure. (B202) and after the alignment film (B203) to align the pattern film (B203), the exposure process (B204) and the developing process (B205) to remove the remaining dry film while leaving the hardened part left by the incident light by exposure to ultraviolet rays After performing the exposure step (B204) and the developing step (B205), the unnecessary copper foil region from which the dry film has been removed is corroded with a chemical, and then the corrosion process (B206) and the peeling process (B207) are removed. ) Are performed sequentially to form a circuit. After each process is completed, the circuit forming process shown in FIG. 2 is completed.

Then, after performing the photosensitive liquid printing step (B208) of applying a photosensitive liquid material containing polyimide and epoxy resin to the upper portion of the copper foil laminated plate circuit formed through the above process with a printing machine, the copper foil laminated plate coated with the photosensitive liquid Perform a preliminary drying process (B209) to maximize the effects of exposure and development by first drying at a temperature of less than 100 ℃ above room temperature. The exposure and development process of exposing only the contact portion of the copper foil laminated plate by scanning ultraviolet rays after aligning the film in which the open part is previously formed on the copper foil laminated plate through the preliminary drying step (B209) (B210). Performs (B211) (B212). Main drying step (B213) which is dried at a temperature of 120 to 155 ° C. for 30 to 80 minutes in order to improve the complete molding and adhesion of the exposed and developed photosensitive liquid layer by performing the exposure and development steps (B211) and (B212) as described above. ). After each process is completed, the protective insulation process shown in FIG. 2 is completed.

Then, the circuit exposed portion of the copper foil laminated plate completely formed through the main drying step (B213) is formed by performing a plating step (B214) for connection, binding, and mounting of parts. An optional process (B215) such as mounting is performed, and an external punching process (B216) for cutting only a desired area is performed. After each process is completed, the post-treatment process shown in FIG. 2 is completed.

At this time, the photosensitive liquid material coating process, preliminary drying process, exposed portion film alignment process, exposure process, development process, the present drying process is a detailed process constituting a protective insulation treatment process for forming a protective insulating layer.

However, the conventional method of manufacturing a printed board has a problem in that bubbles are adsorbed on the periphery of the stepped region in the circuit pattern when the polyimide coverlay film is pressed onto the copper foil laminate.

In addition, when the coverlay film is temporarily bonded as in the conventional method of manufacturing a printed board, there is a problem in that it cannot maintain the degree of alignment of the copper foil pattern and the coverlay open portion and thus cannot be used in a microcircuit.

In addition, since the method of forming the open portion of the coverlay is a method of punching and opening the open portion with a mold, there is a problem in that the microprocessing and the dimensional accuracy are limited.

In addition, the coverlay processed by applying a photosensitive liquid material and drying it after applying it as in the conventional method of manufacturing a printed board is weak in flexibility, so that fine cracks are easily generated during handling, and pins are formed on the surface during the volatilization of the solvent during drying. Since holes are formed and flatness is bad, there is a problem that it is impossible to use in the process for the microcircuit.

In addition, the process is complicated and difficult to set the operating conditions, there is a problem that is difficult to maintain reliability.

Accordingly, the present invention has been made to solve the problems of the prior art as described above, an object of the present invention is to use a photosensitive coverlay film as a surface treatment material, using the vacuum thermocompression laminator method of the photosensitive coverlay film By adopting a method of exposing and developing the copper foil laminated plate, the bubbles remaining in the state adsorbed to the periphery of the stepped region in the circuit pattern are completely removed to improve the adhesive strength of the film, To provide a printed circuit board forming method for improving the dimensional accuracy.

In addition, an object of the present invention is to provide a printed circuit board forming method for finely processing the gap between the open portion and the open portion by using a photosensitive coverlay film.

It is also an object of the present invention to provide a printed circuit board manufacturing method for maintaining the flatness to 20 ㎛ by adopting a film material that is not a liquid.

It is also an object of the present invention to provide a printed circuit board manufacturing method for preventing cracks by increasing the ductility of the printed board by adopting a film material that is not a liquid.

The present invention for achieving the above object, the circuit forming process for inputting the raw material of the circuit board, forming a pattern on the raw material; A protective insulating process of forming a protective insulating layer on the substrate on which the pattern is formed; Forming a plating layer on an area open for electrical connection on the protective insulating layer, and performing a selective process such as reinforcing rod bonding and component mounting, and then cutting only a desired area; and a printed circuit board manufacturing method comprising: In the method of manufacturing a printed circuit board, a photosensitive coverlay film is used in the protective insulation process.

In this case, the protective insulating process for forming the protective insulating layer using the photosensitive coverlay film may be repeated two or more times in the entire manufacturing process of the printed circuit board manufacturing method.

 In addition, the present invention is a circuit forming process for inputting the raw material of the circuit board, forming a circuit pattern on the raw material; A protective insulating process of forming a protective insulating layer on the substrate on which the pattern is formed; A post-treatment process of forming a plating layer on a portion of the upper surface of the substrate on which the protective insulating layer is formed for the electrical connection, and performing a selective process such as adhesion of a reinforcing bar and mounting of a component, and then cutting only a desired area. In the circuit board manufacturing method, the detailed process of the protective insulating treatment process, the pre-treatment process for removing oxides, impurities and moisture in the copper foil laminate having a circuit pattern formed through a circuit forming process; A vacuum-thermocompression step of pressing a photosensitive coverlay film on the pretreated copper foil laminate; A first aging step of primary aging the copper foil laminated sheet to which the photosensitive coverlay film is pressed; An alignment and exposure step of exposing the master film on the photosensitive coverlay film of the copper foil laminated plate aged by the first aging step, and then exposing the master film; A second aging and developing step of secondary aging and developing the copper foil laminate after the exposure step; And a complete drying step of completely drying the photosensitive coverlay film on the copper foil laminate after removal to remove volatile substances, and completely bonding the photosensitive coverlay film. A printed circuit board manufacturing method, comprising the above-mentioned problem, is solved.

In this case, the washing process, the vacuum-thermocompression process, the first aging process, the alignment and exposure process, the second aging and developing process, and the complete drying process are detailed processes constituting the protective insulating process for forming the protective insulating layer.

The pretreatment process is performed by etching to a thickness of 5 μm or less to remove oxides, impurities, and moisture on the circuit pattern.

In addition, the vacuum-thermocompression process is carried out for a time of 180 seconds or less with a vacuum pressure condition of 60mmHg or less, and a temperature of 160 ° C or less.

In addition, the aging conditions of the first aging step is a method for manufacturing a printed circuit board, characterized in that the process temperature is more than room temperature 80 ℃ or less, the process time is at least 5 minutes or more, the above-mentioned problem is solved.

Moreover, exposure energy conditions of the said exposure process are 80-600 mJ / cm <^2> in exposure energy.

In addition, as for the aging conditions of the said 2nd aging process, process temperature is 80 degreeC or more at normal temperature, and a process time is at least 15 minutes or more.

In addition, the developing conditions of the developing step is a sodium carbonate or potassium carbonate solution having a concentration of 3% or less, the nozzle pressure is 0.5 ~ 10 kg / cm ² , the temperature conditions are 20 ~ 70 ℃ The process time is adjusted to 20 to 200 seconds.

In addition, the process conditions of the complete drying process is a printed circuit board manufacturing method, characterized in that the temperature is 100 ~ 200 ℃, the process time is 20 to 100 minutes, solving the above problems.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 are process block diagrams illustrating a method of forming a printed circuit board according to the prior art, and FIG. 3 is a process block diagram illustrating a method of forming a printed circuit board according to the present invention.

<Example>

As shown in FIG. 3, after the copper clad laminate (CCL), which is a raw material of the circuit board, is charged (B301), the photosensitive dry film is adhered to the upper copper foil laminate and then pressed by applying a predetermined pressure. (B302) The first exposure step (B304) and the first development step of removing the remaining part of the dry film after the alignment film (B303) alignment after the alignment (B303) by the exposure to the ultraviolet light, leaving the hardened portion remaining After performing (B305) through the first exposure step (B304) and the first development step (B305) to the corrosion of the unnecessary copper foil area from which the dry film is removed with a chemical and then to remove the dry film of the remaining area (B306) and the peeling process (B307) are performed sequentially to form a circuit. When the circuits are formed by completing the above processes, the circuit forming process shown in FIG. 3 is completed.

After that, the protective insulation process is followed.

First of all, in order to remove oxides, impurities, and moisture from the copper foil laminate having a circuit formed through the above process, the process is etched to a thickness of 5 μm or less (B308). At this time, in some cases during the washing process may be performed by adding an antirust treatment to prevent rust on the copper foil laminate.

Next, after pressing the photosensitive coverlay film on the pre-treated copper foil laminated plate (B309), the first aging for at least 5 minutes at room temperature or more than less than 80 ℃ temperature for the first aging of the adhesive layer (B310). In this case, the photosensitive coverlay film may be formed including acrylic, urethane, and imide, or may include an epoxy component.

At this time, in the photosensitive coverlay film vacuum-thermocompression process (B309), the photosensitive coverlay film is pressed onto the surface of the copper foil laminate in which a circuit is formed by a vacuum laminator as shown in FIG. 4. That is, the vacuum laminator has a structure in which upper and lower platens 50 and 60 are engaged to form a vacuum chamber. When the copper foil panel having the photosensitive coverlay film reaches the vacuum chamber, the vacuum chamber It becomes a vacuum state. At this time, the vacuum pressure condition is 60mmHg or less, the temperature is adjusted to 160 ° C or less, and the process time is 180 seconds or less. Then, heat is applied to the upper and lower platens 50 and 60 by the process according to the vacuum-thermal compression process conditions, and between the copper foil laminate and the photosensitive coverlay film placed on the upper and lower platens 50 and 60. The adsorbed bubbles become active and easily escape from the surface and are eventually removed. As described above, when the bubbles adsorbed on the surface and the bubbles adsorbed in the stepped region between the circuit pattern and the base material are removed, the photosensitive coverlay film improves the adhesive strength, and after the exposure step (B311) and the developing step (B312). The degree of opening of the open part is improved. In the accompanying drawings, reference numeral 10, which is not described in FIG. 4, is a tension roll, 20 is a pulling gripper, 30 is a take up roll, 40 is an upper roll, 70 is a board, 80 is a loading table, 90 is a take up roll, and 100 is a lower roll.

After exposing the pattern film to the upper part of the photosensitive coverlay film of the copper foil laminated plate that has undergone the first aging process (B310) as described above, the exposed portion to adjust the exposure dose conditions so that the exposure energy is 80 ~ 600 mJ / cm ² After the film alignment and the second exposure process (B311) is carried out, and the second aging process (B312) for aging for at least 15 minutes or more at room temperature or more than 80 ℃ temperature is performed, sodium carbonate having a concentration of 3% or less The potassium carbonate solution is adjusted to a nozzle pressure of 0.5 to 10 kg / cm ² , and a developing process (B312) is performed for 20 to 200 seconds at a temperature of 20 to 70 ° C. so that only an area corresponding to an exposed part of the circuit is opened. , The contour forms a clear open portion.

If necessary, the ultraviolet irradiation step B313 may be further performed after the developing step B312. Although the ultraviolet irradiation step (B313) is not a necessary step in the protective insulating treatment step, it may be necessary to carry out in order to further strengthen the photopolymerization reaction by strengthening the exposure after the development step (B312). At this time, the intensity of the ultraviolet light is preferably between 0.5 ~ 5J.

Finally, a complete drying process (B314) for 20 to 100 minutes of drying at a temperature between 100 and 200 ° C. is performed to completely remove volatiles in the photosensitive coverlay film. When the above process is completed to form the protective insulating layer, the protective insulating process shown in FIG. 3 is completed. Subsequent post-processing is followed.

In addition, a plating process (B315) using metals such as gold (Au), nickel (Ni), and the like on a portion required for connecting and binding parts and mounting the copper foil laminated plate completely formed through the complete drying process (B314). After forming the plated layer to perform a selective process (B316), such as reinforcing rod bonding and component mounting, and then the appearance punching process (B317) to cut only the desired area is performed. When the external punching process is completed, the post-treatment process shown in Figure 3 is finished to complete the printed circuit board.

Therefore, in the present invention, the photosensitive coverlay film is pressed onto the copper foil laminate by using a vacuum laminator, thereby completely removing the bubbles remaining in the state adsorbed to the periphery of the stepped region in the circuit pattern, thereby reducing the size of the open portion. To achieve the effect to be able to improve.

In addition, the present invention achieves the effect of manufacturing a printed circuit board having a fine circuit pattern by finely processing the gap between the open portion and the open portion by using the photosensitive coverlay film.

In addition, in the present invention, unlike the method of applying the photosensitive liquid material by using the photosensitive coverlay film, the thickness of the film is the same in all areas, and thus the flatness is very high.

In addition, in the present invention, the use of the photosensitive coverlay film has the advantage that the printed circuit board itself is very soft and does not generate cracks during handling.

Claims (14)

delete A circuit forming step of inputting a raw material of a circuit board and forming a circuit pattern on the raw material; A protective insulating process of forming a protective insulating layer on the substrate on which the pattern is formed; A post-treatment process of forming a plating layer on a portion of the upper surface of the substrate on which the protective insulating layer is formed for the electrical connection, and performing a selective process such as adhesion of a reinforcing bar and mounting of parts, and then cutting only a desired area; In the method of manufacturing a printed circuit board comprising: the detailed process of the protective insulating treatment process, A pretreatment step of removing oxides, impurities, and moisture from the copper foil laminate having the circuit pattern formed through the circuit formation process; A vacuum-thermocompression step of pressing a photosensitive coverlay film on the pretreated copper foil laminate; A first aging step of primary aging the copper foil laminated sheet to which the photosensitive coverlay film is pressed; An alignment and exposure step of exposing the master film on the photosensitive coverlay film of the copper foil laminated plate aged by the first aging step, and then exposing the master film; A second aging and developing step of secondary aging and developing the copper foil laminate after the exposure step; And A complete drying step of completely drying the photosensitive coverlay film on the copper foil laminate after development to remove volatile substances, and fully bonding the photosensitive coverlay film; Printed circuit board manufacturing method characterized in that consisting of. The method of claim 2, wherein the pretreatment step, A printed circuit board manufacturing method, characterized in that the etching thickness of 5㎛ or less. The method of claim 2, wherein the pretreatment step, Printed circuit board manufacturing method characterized in that for further performing anti-rust treatment. The method of claim 2, wherein the photosensitive coverlay film, Printed circuit board manufacturing method characterized in that it is formed containing acrylic (urry), urethane (urethane), imide (epide) or epoxy (epoxy). The method of claim 2, wherein the vacuum-thermal compression conditions of the vacuum-thermocompression process, A method of manufacturing a printed circuit board, wherein the vacuum pressure is 60 mmHg or less, the temperature is 160 ° C. or less, and the processing time is 180 seconds or less. According to claim 2, Process conditions of the first aging step, A printed circuit board manufacturing method, characterized in that the process temperature is at least 80 ° C. and at least 5 minutes. The method of claim 2, wherein the exposure conditions of the exposed portion film alignment and the exposure step, Printed circuit board manufacturing method, characterized in that the exposure energy is 80 ~ 600 mJ / cm ² . The process condition of claim 2, wherein the process conditions of the second aging step are A printed circuit board manufacturing method, characterized in that the process temperature is greater than or equal to 80 ° C and less than 15 minutes. The method of claim 2, wherein the developing conditions of the developing step, A method of manufacturing a printed circuit board, wherein the concentration of the sodium carbonate or potassium carbonate solution is 3% or less, the nozzle pressure is 0.5 to 10 kg / cm ² , the temperature is 20 to 70 ° C., and the process time is 20 to 200 seconds. The method of claim 2, wherein the drying conditions of the complete drying step, Printed circuit board manufacturing method, characterized in that the temperature is 100 ~ 200 ℃, the process time is 20 minutes ~ 100 minutes. The method of claim 2, Printed circuit board manufacturing method characterized in that for further performing an ultraviolet irradiation step of irradiating ultraviolet rays between the developing process and the complete drying process. The method of claim 12, Printed circuit board manufacturing method, characterized in that the intensity of the ultraviolet irradiation in the ultraviolet irradiation step is 0.5 ~ 5J. delete

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