KR102260412B1 - Fpcb manufacturing method of double access method - Google Patents

Abstract

The present invention relates to a method for manufacturing an FPCB of a double access method, comprising the steps of: preparing a base; Laminating the upper coverlay processed on the upper surface of the base by roll-to-roll processing; processing the base based on the processed upper coverlay; laminating a lower coverlay to the lower surface of the base; and processing the lower coverlay with a UV laser.

Description

FPCB manufacturing method of double access method {FPCB MANUFACTURING METHOD OF DOUBLE ACCESS METHOD}

The present invention relates to a method for manufacturing an FPCB of a double access method, and more particularly, in a method for manufacturing an FPCB in which an upper surface coverlay and a lower surface coverlay are laminated on both sides of a copper base to form a hole, the base cover It is characterized in that the FPCB manufacturing cost is reduced and the working time is shortened by omitting the process of temporarily welding the lay and forming a hole in the lamination and the coverlay in the base through the roll-to-roll process and UV laser processing.

With the recent development of electronic component technology, a flexible flat cable (hereinafter, referred to as 'FFC') has been used in various fields to reduce the weight and volume of a product and free wiring.

FFC is manufactured through a process of arranging conductors at regular intervals between the upper and lower parts of an insulating film and laminating them with instantaneous heat and pressure. However, the width and thickness of the applicable conductors are limited, and there are limitations in that only straight-line wiring is possible. Due to such a low degree of freedom in circuit design, it was difficult to expand to various application fields.

In order to overcome the limitations of the conventional FFC, a flexible printed circuit board (hereinafter referred to as 'FPCB') has recently been developed. Because it retains the flexible characteristics of FFC and forms a circuit pattern through an etching process, it has a higher degree of freedom in circuit design than FFC and has the advantage of being able to respond to the line width of a narrow microcircuit, which is expanding to various application fields.

This FPCB is divided into three types according to the number of coverlays. A single-sided type that combines one coverlay on the upper or lower portion of the base, a double-type that combines a coverlay on the upper and lower portions of the base, and a multi-layer (multilayer) in which the combination of the coverlay and the base is laminated in plurality Multi) type.

Figure 1 is a representation of the lamination step of the conventional double-sided type FPCB. Hereinafter, a conventional double-sided type FPCB lamination step will be described with reference to FIG. 1 .

The base of the double-sided type FPCB is constructed by sequentially stacking copper, insulating film, and copper. At this time, the coverlay is laminated on the upper and lower surfaces of the base, respectively. The coverlay is sequentially laminated with a coverlay film and a coverlay adhesive. At this time, the coverlay adhesive is melted by pressing and heating through a hot press device not shown on the coverlay, whereby the coverlay and the base are laminated. After laminating the coverlay and the base, a hole is formed in the coverlay through a punching operation to complete the FPCB.

This hot-press type lamination method requires a large number of hot-press devices for mass production, so the installation cost is excessive, and there is a problem in that the cost is increased. In addition, in order to proceed with the hot press process, it is necessary to lay-up auxiliary materials on the upper or lower surface of the coverlay to assist the heating and pressurization of the hot press device. should be glued Subsidiary materials are made of Kraft paper, Sus plate, PVC, etc. In this case, there is a problem of quality deterioration in the temporary welding process, and a large amount of work time is required due to the nature of manual work. In addition, there is a problem in that the cost burden for the provision of a large amount of laminated auxiliary materials is increased.

Republic of Korea Patent Publication No. 10-2006-0114647

The present invention relates to a method for manufacturing an FPCB of a double access method, and more particularly, in a method for manufacturing an FPCB in which an upper surface coverlay and a lower surface coverlay are laminated on both sides of a copper base to form a hole, the base cover It is characterized in that the FPCB manufacturing cost is reduced and the working time is shortened by omitting the process of temporarily welding the lay and forming a hole in the lamination and the coverlay in the base through the roll-to-roll process and UV laser processing.

In order to achieve the above object, the method for manufacturing a double access method FPCB according to the present invention comprises the steps of preparing a base; Laminating the upper coverlay processed on the upper surface of the base by roll-to-roll processing; processing the base based on the processed upper coverlay; laminating a lower coverlay to the lower surface of the base; and processing the lower coverlay with a UV laser.

In addition, the step of laminating the processed upper coverlay on the upper surface of the base of the double access method FPCB manufacturing method according to the present invention by roll-to-roll processing includes: manufacturing the processed upper coverlay in a roll form; manufacturing the base in the form of a roll; and laminating the processed upper coverlay and the base by penetrating the end of the roll-shaped processed upper coverlay and the end of the roll-shaped base to be in contact with each other between a pair of rollers.

In addition, the step of processing the base based on the processed upper coverlay of the FPCB manufacturing method of the double access method according to the present invention includes exposure, development, corrosion, and peeling steps based on the processed upper coverlay. A pattern is formed on the base.

In addition, the step of processing the lower coverlay with a laser of the double access method FPCB manufacturing method according to the present invention opens the terminal portion of the lower coverlay with the UV laser.

In addition, the base of the double access method FPCB manufacturing method according to the present invention is sequentially laminated with an upper copper layer, an insulating film layer, and a lower copper layer.

In addition, in the processed upper coverlay of the double access method FPCB manufacturing method according to the present invention, an upper coverlay film and an upper coverlay adhesive are sequentially laminated.

In addition, in the processed lower coverlay of the double access method FPCB manufacturing method according to the present invention, a lower coverlay adhesive and a lower coverlay film are sequentially laminated.

In addition, the roller of the double access method FPCB manufacturing method according to the present invention melts the upper coverlay adhesive by pressing and heating the processed upper coverlay and the base, and the processed upper coverlay and the base combine

In addition, the upper coverlay film and the lower coverlay film of the double access method FPCB manufacturing method according to the present invention is a PI film.

In addition, the rollers of the double access method FPCB manufacturing method according to the present invention rotate in opposite directions.

In addition, the roller of the double access method FPCB manufacturing method according to the present invention rotates at the same speed.

According to the present invention, the installation cost can be minimized compared to the prior art because the hot press process is unnecessary when the upper coverlay is laminated with the base by the roll-to-roll process of the upper coverlay having a hole pre-processed.

In addition, since the terminal part is formed through a UV laser when the lower coverlay is laminated, the lower coverlay and the base can be laminated without a temporary bonding process of the lower coverlay. Therefore, in forming the hole and the terminal portion in the upper coverlay and the lower coverlay, respectively, there is an advantage that, unlike in the related art, the second welding process can be omitted. Therefore, it is possible to reduce the cost by not requiring auxiliary materials required for the conventional coverlay lamination, and it is possible to improve the quality and shorten the work time by omitting manual work due to the temporary welding.

Figure 1 is a representation of the lamination step of the conventional double-sided type FPCB.
2 illustrates a state in which the base and the processed upper coverlay are laminated through the step of laminating the processed upper coverlay on the upper surface of the base by roll-to-roll processing.
3 is a schematic view of a roll-to-roll processing process in the double access method FPCB manufacturing method according to the present invention.
4 is a view showing a state in which the base and the processed upper coverlay of the double access method FPCB manufacturing method according to the present invention are laminated.
5 to 6 are diagrams for explaining a method of manufacturing a double access method FPCB according to another embodiment of the present invention.
7 shows a cross-section of a coverlay roller among a pair of rollers according to the present invention.
8(a) to (d) are schematic views of the entire processing steps of the double access method FPCB manufacturing method according to the present invention.
9 shows a manufacturing process of a double access method FPCB according to the present invention.
10 is a result of measuring the storage modulus of the coverlay adhesive layer according to an embodiment of the present invention.
11 is a photograph showing the result of not filling the coverlay adhesive layer on the etched copper copper foil during lamination of the coverlay during manufacturing of the FPCB according to an embodiment of the present invention.
12 is a photograph showing the result of filling the coverlay adhesive layer in the etched copper copper foil during lamination of the coverlay during manufacturing of the FPCB according to an embodiment of the present invention.
13 is a reflow temperature condition table according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

9 shows a manufacturing process of a double access method FPCB according to the present invention. Hereinafter, a double access method FPCB manufacturing process according to the present invention will be described with reference to FIG. 9 .

The manufacturing process of the double access type FPCB according to the present invention includes the steps of preparing a base (S100), laminating the upper coverlay processed on the upper surface of the base by roll-to-roll processing (S200), and forming the processed upper coverlay. It includes a step of processing the base as a reference (S300), laminating the lower coverlay on the lower surface of the base (S400) and processing the lower coverlay with a UV laser (S500).

2 to 7 to explain the step of preparing the base (S100) and laminating the upper coverlay processed on the upper surface of the base by roll-to-roll processing (S200). 2 shows a state in which the base and the processed upper coverlay are laminated through a step (S200) of laminating the processed upper coverlay on the upper surface of the base by roll-to-roll processing.

At this time, in the base 100 according to the present invention, it is desired that the upper copper layer 120, the insulating film layer 101, and the lower copper layer 120 are sequentially stacked, and the upper copper layer 120 and the lower copper layer ( 120) is just a different name to express the location, but has the same configuration. The insulating film layer 101 is, for example, preferably a polyimide film (PI film).

In addition, the 'processed upper coverlay 200' refers to a coverlay in which the upper coverlay hole 210 opened in the coverlay laminated to the upper surface of the base 100 is formed.

In the step (S200) of laminating the upper coverlay processed on the upper surface of the base by roll-to-roll processing, 'Roll To Roll processing' according to the present invention will be described. 3 is a schematic view of a roll-to-roll processing process in the double access method FPCB manufacturing method according to the present invention. Hereinafter, roll-to-roll processing will be described with reference to FIG. 3 .

Hereinafter, the roll-to-roll processing may be referred to as 'roll lamination processing'.

First, before roll-to-roll processing, a step of manufacturing the base 100 in a roll form is performed. At this time, it is preferable that the base 100 is wound on the base winding roller 2200, and when the base winding roller 2200 rotates, the base 100 wound on the base winding roller 2200 is unwound as shown in FIG. It is desirable to be able to move in the longitudinal direction.

In addition, a step of manufacturing the processed upper coverlay 200 in the form of a roll is performed. At this time, it is preferable that the processed upper coverlay 200 is also wound on the coverlay winding roller 2100 , and when the coverlay winding roller 2100 rotates, the processed upper cover wound on the coverlay winding roller 2100 . It is preferable to be able to move in the longitudinal direction as shown in FIG. 3 while the ray 200 is released. For convenience of description, the base winding roller 2200 and the coverlay winding roller 2100 are referred to as a pair of winding rollers 2000 .

At this time, it is preferable that the base winding roller 2200 and the coverlay winding roller 2100 rotate in opposite directions to each other as shown in FIG. 3 , so that the wound base 100 and the processed upper coverlay 200 are It is possible to move in the same direction among the longitudinal directions. 3, the base 100 and the processed upper coverlay 200 are simultaneously moved in the left direction.

In addition, in FIG. 3, a cross section of the processed upper coverlay 200 is shown as in FIG. 3 for convenience of explanation, but in the actual invention, an open hole 210 is formed.

The manufacturing apparatus used in the FPCB manufacturing method according to the present invention includes a pair of rollers (1000). The end of the roll-shaped base 100 and the processed upper coverlay 200 in the roll form pass through between the pair of rollers 1000 .

At this time, the end of the roll-shaped base 100 and the end of the processed upper coverlay 200 in the roll form pass through between the pair of rollers 1000 and at the same time, the pair of rollers 1000 are connected to the base 100 ) by simultaneously pressing the lower surface and the upper surface of the processed upper coverlay 200 to form a structure in which the base 100 and the processed upper coverlay 200 are in contact.

In more detail, the base roller 1200 moves the base 100 in the longitudinal direction while pressing the base 100 in the direction in which the processed upper coverlay 200 is positioned while rotating, and the coverlay roller 1100 moves the processed upper coverlay 200 in the longitudinal direction while pressing the processed upper coverlay 200 in the direction in which the base 100 is positioned while rotating.

Accordingly, the pair of rollers 1000 presses the base 100 and the processed upper coverlay 200 to abut each other and at the same time presses the laminated base 100 and the processed upper coverlay 200 in the longitudinal direction. be able to move

At this time, in the pair of rollers 1000, the base roller 1200 and the coverlay roller 1100 are preferably rotated in opposite directions. 4 , the base roller 1200 rotates in a counterclockwise direction (CCW), and the coverlay roller 1100 rotates in a clockwise direction (CW). Due to this, the laminated base 100 and the processed upper coverlay 200 can be moved in the longitudinal direction.

In addition, it is preferable that heat is generated from the pair of rollers 1000 so that the upper coverlay adhesive of the processed upper coverlay 200 is melted and the processed upper coverlay 200 and the base 100 are laminated. Due to this, it is possible to easily laminate the processed upper coverlay 200 and the base 100 without a conventional temporary welding and hot press process.

At this time, it is preferable that the pair of rollers 1000 rotate at the same speed. For this reason, the base 100 and the processed upper coverlay 200 can be laminated uniformly, so that the probability of manufacturing a defective product such as twisting of the laminated FPCB is reduced.

4 is a view showing a state in which the base and the processed upper coverlay of the double access method FPCB manufacturing method according to the present invention are laminated. As such, the base 100 passing between the pair of rollers 1000 and the processed upper coverlay 200 are laminated by the heat and pressure of the pair of rollers 1000 and can move in the longitudinal direction at the same time. .

5 to 6 are diagrams for explaining a method of manufacturing a double access method FPCB according to another embodiment of the present invention. In the double access method FPCB manufacturing method according to another embodiment of the present invention, a release film 400 is added.

In the step (S200) of laminating the upper coverlay processed on the upper surface of the base by roll-to-roll processing, another embodiment of the present invention includes the step of manufacturing the release film 400 in the form of a roll. At this time, it is preferable that the release film 400 is also wound on the release film winding roller 2300, and when the release film winding roller 2300 rotates, the release film 400 wound on the release film winding roller 2300 is pulled out. while being able to move in the longitudinal direction as shown in FIG. 5 .

Accordingly, the release film 400, the processed upper coverlay 200, and the base 100 are sequentially positioned from top to bottom.

For convenience of description, the release film winding roller 2300 , the base winding roller 2200 , and the coverlay winding roller 2100 are referred to as a pair of winding rollers 2000 .

At this time, as shown in FIG. 5 , it is preferable that the base winding roller 2200 and the coverlay winding roller 2100 rotate in opposite directions to each other, so that the wound base 100 and the processed upper coverlay 200 are It is possible to move in the same direction among the longitudinal directions. 5, the base 100 and the processed upper coverlay 200 are simultaneously moved in the left direction.

In addition, it is preferable that the release film winding roller 2300 and the coverlay winding roller 2100 rotate in the same direction, so that the wound release film 400 and the processed upper coverlay 200 are in the longitudinal direction. can move in the same direction. Referring to FIG. 5 , the release film 400 and the processed upper coverlay 200 are simultaneously moved in the left direction.

A release film is a kind of film used for the purpose of product protection. It is characterized in that it can be easily peeled off when using the product. According to the present invention, the release film 400 is formed between the coverlay roller 1100 and the processed upper coverlay 200 rather than in direct contact with the coverlay roller 1100 and the processed upper coverlay 200 . will be inserted Accordingly, damage to the upper coverlay 200 processed by the coverlay roller 1100 can be minimized to improve product perfection. In addition, in the present invention, since it is a release film in the form of a roll, the release film on the surface of the upper coverlay 200 processed while the release film 400 is released in the form of a roll rather than a method of inserting the release films one by one during the lamination process. Since 400 is located, there is an advantage in that work efficiency and precision are increased.

At this time, it is preferable that the release film 400 according to the present invention is formed in a multi-layer structure.

The release film is formed in a multi-layer structure, more specifically, a first release film; cushion film; And the second release film may be laminated in the order. In manufacturing the FPCB, one surface of the first release film is in contact with the coverlay, and the cushion film is laminated on the other surface of the first release film. If only a simple release film is used in the roll lamination or quick press process, a problem of not filling the pattern may occur.

In the case of the hot press method, the press time is long, so the thickness and material of the film do not have a significant effect on the fillability. However, in the case of the roll lamination method or the quick press method, the process time is shorter than the hot press method, so that the coverlay adhesive is There is a problem that is difficult to fill. In order to prevent such a problem, it is possible to prevent the problem of not filling the pattern by using a release film having a multilayer structure, unlike the hot press method.

The first release film and the second release film may be selected from the group consisting of a polymethylpentene film, a modified polybutylene terephthalate film, and a polypropylene film. The cushion film may be selected from the group consisting of a polyvinyl chloride film, a polybutylene terephthalate/polyethylene film, and a polypropylene film. The first release film, the cushion film and the second release film are not limited to the listed exemplary films, and all can be used without limitation as long as the pattern fillability can be increased on the roll lamination method or the quick press method.

The release film of the present invention is formed in a multilayer structure in order to improve the fillability of the pattern, the first release film; The cushion film and the second release film may be formed in a thickness ratio of 0.5:1:0.5 to 2:1:1. When manufacturing within the above range, it is possible to prevent the occurrence of a pattern unfilling problem on the roll lamination method or the quick press method, and when the value is less than the above range, the thickness of the cushion film is too thin, or the first release film and the second release film If the thickness of the release film is too thin, the effect due to the formation of the multilayer structure of the release film is insignificant, which may cause a pattern unfilling problem, and damage to the coverlay may occur. In addition, when the value exceeds the above range, the pressure and temperature transmitted to the coverlay through the release film may be lowered, so that a problem of not filling the pattern may occur.

When the base 100 and the processed upper coverlay 200 are laminated by a pair of rollers 1000 , the release film 400 is then removed.

7 shows a cross-section of a coverlay roller among a pair of rollers according to the present invention. Although the configuration of the coverlay roller is disclosed in FIG. 7 , the base roller also has the same structure.

The coverlay roller 1100 is preferably formed of a cylindrical heating element 1110 extending in the longitudinal direction and a shell 1120 surrounding the heating element 1110 .

If the entire roller is a heating element, the following problems arise. First, when the heating element directly contacts the base 100, the processed upper coverlay 200, the release film 400, etc., the base 100 and the processed upper coverlay 200 are damaged and the laminated FPCB is defective. can However, according to the present invention, the heating element 1110 is wrapped by the shell 1120, and the shell 1120 comes into contact with the base 100, the processed upper coverlay 200, the release film 400, and the like. 1110 does not directly contact, but indirectly applies heat, so there is an advantage in that the probability that the laminated FPCB is a defective product is lowered.

The outer skin is preferably made of a material that can function as a cushion. For example, it is preferable that silicon is used. When silicon is used, it is possible to reduce the cost, and since the heat transfer power is high, the heat of the heating element 1110 can be effectively transferred to the base 100 and the processed upper coverlay 200 .

In addition, it is preferable that the pair of rollers 1000 rotate at the same speed. For this reason, the base 100 and the processed upper coverlay 200 can be laminated uniformly, so that the probability of manufacturing a defective product such as twisting of the laminated FPCB is reduced.

6 is a view showing a state in which the base and the processed upper coverlay of the double access method FPCB manufacturing method according to another embodiment of the present invention are laminated. As such, the base 100 passing between the pair of rollers 1000 and the processed upper coverlay 200 are laminated by the heat and pressure of the pair of rollers 1000 and can move in the longitudinal direction at the same time. . In addition, the release film 400 can be moved together in the longitudinal direction. After moving, the release film 400 is removed.

At this time, a release film removal roll (not shown) may be formed so that the release film 400 to be removed is wound again in a roll shape. The release film 400 unwound from the release film winding roller 2300 assists in laminating the base 100 and the processed upper coverlay 200, and then is wound on the release film removal roll again. Through this, since the operator does not manually remove the used release film 400, there is an advantage in that the working speed is increased, and since the large release film 400 can be used, there is an advantage that the size is not limited.

8 (a) to (d) schematically show the entire processing steps of the double access method FPCB manufacturing method according to the present invention. Hereinafter, each step will be described.

First, in Figure 8 (a) in the double access method FPCB manufacturing method according to the present invention, the step of preparing the base (S100) and laminating the upper coverlay processed on the upper surface of the base by roll-to-roll processing ( A cross-section after S200), which corresponds to FIG. 2 . Since this has been described above, detailed descriptions will be omitted to avoid duplicate descriptions.

Next, Figure 8 (b) is a cross-section after going through the step (S300) of processing the base based on the processed upper coverlay.

Based on the processed upper coverlay 200 , the pattern 110 is formed on the base 100 through exposure, development, corrosion, and peeling steps. Since this is an exposure or peeling step used in a general FPCB step, a detailed description thereof will be omitted.

Next, Figure 8 (c) is a cross-section after going through the step (S400) of laminating the lower coverlay on the lower surface of the base.

At this time, when laminating the lower coverlay 300 on the lower surface of the base 100 , since the pattern 110 is formed on the base 100 , the roll-to-roll process that has to go through a roller is not easy. Accordingly, the lower surface of the base 100 and the lower coverlay 300 are laminated through a heating and pressurizing device not shown. At this time, in the case of forming the terminal part 310, in the case of a conventional technique, since a hole must be formed in the lower coverlay in a laminated state, unlike the processed upper coverlay 200, a temporary welding process must be performed. However, in the present invention, since the terminal part 310 is directly formed on the lower coverlay 300 laminated through the UV laser, the temporary welding process of the lower coverlay 300 may be omitted.

Next, Figure 8 (d) is a cross-section after going through the step (S500) of processing the lower coverlay with a UV laser. The terminal part 310 of the lower coverlay 300 at a desired position may be opened by irradiating the UV laser from the bottom. Unlike the processed upper coverlay 200, the lower coverlay 300 has a 'post-processing' form. In addition, the terminal part 310 corresponds to the hole 210 of the processed upper coverlay 200 .

At this time, although the pattern 110, the hole 210, and the terminal part 310 are marked at arbitrary positions in FIG. 8, these are designated for convenience of explanation, and the operator can easily change and work according to the designed position. .

In the double-access type FPCB manufacturing method according to the present invention, particularly in the double-sided type FPCB, the upper coverlay 200 with the hole 210 is laminated with the base 100 in a roll-to-roll process to the upper coverlay. Since the hot press process is unnecessary during lamination, the installation cost can be minimized compared to the prior art.

In addition, since the terminal part 310 is formed through the UV laser when the lower coverlay 300 is laminated, the lower coverlay 300 and the base 100 may be laminated without a temporary bonding process of the lower coverlay 300 . Therefore, in forming the hole 210 and the terminal part 310 in the upper coverlay 200 and the lower coverlay 300, respectively, there is an advantage that, unlike in the related art, the second welding process can be omitted. Therefore, it is possible to reduce the cost by not requiring auxiliary materials required for the conventional coverlay lamination, and it is possible to improve the quality and shorten the work time by omitting manual work due to the temporary welding.

In the upper coverlay according to the present invention, it is preferable that the upper coverlay film and the upper coverlay adhesive layer are sequentially laminated. In this case, it is preferable that the upper coverlay film is, for example, a PI film. In this case, the upper coverlay here is a concept including a processed upper coverlay, and was referred to as an 'upper coverlay' to describe the interlayer configuration.

In addition, in the lower coverlay according to the present invention, it is preferable that the lower coverlay adhesive layer and the lower coverlay film are sequentially laminated. In this case, it is preferable that the lower coverlay film is, for example, a PI film. At this time, the lower coverlay here is a concept including a lower coverlay in which the terminal part is formed, and was referred to as a 'lower coverlay' to describe the interlayer configuration.

In addition, the coverlay adhesive layer (upper coverlay adhesive layer, lower coverlay adhesive layer) is formed using an adhesive composition for a coverlay, and is formed without limitation using a known method capable of forming an adhesive layer on one surface of the coverlay film. This is possible. Any manufacturing method capable of forming an adhesive layer having a predetermined thickness or more may be used without limitation.

The adhesive composition for the coverlay may include an epoxy resin; rubber resin; thermoplastic resin; hardener; inorganic particles; and a flame retardant, with respect to 100 parts by weight of the epoxy resin, 50 to 80 parts by weight of a rubber resin; 3 to 10 parts by weight of a thermoplastic resin; 8 to 15 parts by weight of a curing agent; 30 to 60 parts by weight of inorganic particles; and 50 to 80 parts by weight of a flame retardant.

The adhesive composition may further include a fast curing agent, in which case 0.01 to 0.1 parts by weight based on 100 parts by weight of the epoxy resin.

When preparing an adhesive using the adhesive composition, an epoxy resin; rubber resin; thermoplastic resin; hardener; It can be prepared by mixing inorganic particles and a flame retardant with a solvent, and the solvent is selected from the group consisting of methyl ethyl ketone (MEK), toluene, and mixtures thereof, and preferably a mixed solvent of methyl ethyl ketone and toluene can be used. .

Preferably, the adhesive composition for the coverlay is based on 100 parts by weight of the epoxy resin, 50 to 80 parts by weight of the rubber resin; 3 to 10 parts by weight of a thermoplastic resin; 8 to 15 parts by weight of a curing agent; 30 to 60 parts by weight of inorganic particles; 50 to 80 parts by weight of a flame retardant; It may contain 0.01 to 0.1 parts by weight of a fast curing agent and 500 to 600 parts by weight of a solvent.

The epoxy resin is a bisphenol A type epoxy resin having an epoxy equivalent weight (EEW, g/eq) of 184 to 190 and an epoxy equivalent weight of 450 to 500 (EEW, g/eq) of a bisphenol A type epoxy resin 1:3 to 1:7 It can be used by mixing in a molar ratio of , preferably 1:5, but is not limited to the above example. When mixed and used within the above range, it moves between a pair of rollers, and the flowability increases under the conditions of instantaneous high temperature and high pressure to improve the filling properties of the FPCB, and also at room temperature when forming an adhesive layer on one side of the coverlay film. It is easily cured to facilitate the formation of an adhesive layer.

The phenoxy resin may be further included in the epoxy resin. The phenoxy resin is a resin that exhibits fluidity while controlling the curing rate, has a softening point and a glass transition temperature (Tg) in the range of 0 ° C to 200 ° C, and preferably has a weight average molecular weight in the range of 10,000 to 1,000,000 Do. When the phenoxy resin has a softening point and weight average molecular weight within the above range, it maintains a solid state at room temperature to reduce adhesion with the coverlay film during the process, thereby facilitating storage in the winding roller and improving flowability at high temperature. It can be given to improve the filling properties. The phenoxy resin may be included in an amount of 80 to 100 parts by weight based on 100 parts by weight of the epoxy resin, and it can exhibit fluidity while controlling the curing rate within the above range. It is possible to facilitate storage in the winding roller by reducing the adhesive force of the resin, and to improve the filling property by imparting flowability at a high temperature.

The rubber resin is nitrile-butadiene rubber, butadiene rubber, styrene-butadiene rubber, hydrogenated nitrile-butadiene rubber, carboxy-terminated liquid It may be selected from the group consisting of butadiene-acrylonitrile rubber (Carboxyl terminated butadiene acrylonitrile) and mixtures thereof, preferably xNBR, which is carboxylated NBR, but is not limited to the above example.

The xNBR has almost the unique characteristics of NBR, and additionally has characteristics of high tear resistance, abrasion resistance, tensile strength and modulus.

The thermoplastic resin is included in a small amount, but when used within the above range, it increases the flowability by instantaneous heat and pressure, and due to this flowability, it is possible to increase the fillability of the etched copper foil. Preferably, the thermoplastic resin is a polyester resin having a glass transition temperature (Tg) of 20 to 100° C., but is not limited to the above example, and when used in the adhesive composition for a coverlay of the present invention, the flowability by instantaneous heat and pressure If it can be improved, it can be used without limitation.

The curing agent may be selected from the group consisting of an amine-based curing agent, a phenol-based curing agent, an imidazole-based curing agent, and a mixture thereof. Preferably, the curing agent may be used in a mixture of 3,3'-diaminodiphenylsulfone and 2-undecylimidazole, but is not limited thereto.

The present invention is mainly characterized by using a fast curing agent rather than using only a curing agent alone.

The adhesive composition for coverlay used in the hot press method does not cause a problem due to sufficient curing even if only a curing agent is used, but in the case of the roll lamination method, some curing occurs when passing through a pair of rollers, and then hot air drying It is characterized in that it further comprises a fast curing agent to enable fast curing so that a lifting phenomenon does not occur during the process (baking process). The fast curing agent is a cycloaliphatic modified amine-based curing agent.

The fast curing agent is also included in a small amount like the thermoplastic resin, but when used within the above range, some curing occurs in the roll lamination process to increase the filling property, and then it can promote rapid curing in the hot air drying process to prevent lifting. have. If the value is less than the above range, a lifting phenomenon may occur in the hot air drying process, and if it is included in excess of the range value, curing proceeds before filling occurs sufficiently in the roll lamination process, so that the problem of unfilling may occur.

When the inorganic particles and the flame retardant are included within the above range, it is possible to increase the heat resistance of lead, thereby preventing the occurrence of a lifting phenomenon after evaluation in the reflow process.

The inorganic particles may be selected from the group consisting of titanium dioxide, talc, aluminum hydroxide trihydroxide, alumina, magnesium hydroxide, and mixtures thereof, preferably aluminum hydroxide and titanium dioxide, but are not limited to the above examples. does not

The flame retardant is selected from the group consisting of phosphorus-based flame retardants, nitrogen-based flame retardants, inorganic flame retardants and mixtures thereof, and phosphorus-based flame retardants, preferably particulate phosphorus-based flame retardants and resin-type phosphorus-based flame retardants.

As described above, the inorganic particles may include aluminum hydroxide and titanium dioxide, and the flame retardant includes a phosphorus-based flame retardant, a particulate phosphorus-based flame retardant, and a resin-type phosphorus-based flame retardant to increase lead heat resistance and float after evaluation in the reflow process phenomenon can be prevented.

[Production Example: Preparation of adhesive composition for coverlay]

An adhesive composition for a coverlay was prepared by mixing according to the composition ratio of Table 1 below. An adhesive composition was prepared by mixing an epoxy resin, a phenoxy resin, a rubber resin, a thermoplastic resin, a curing agent, a fast curing agent, an inorganic particle, and a flame retardant in a solvent.

HL1 HL2 HL3 HL4 HL5 HL6 HL7 HL8 HL9 HL10 HL11 HL12 HL13 HL14 epoxy 100 100 100 100 100 100 100 100 100 100 100 100 100 100 phenoxy - - - 90 - - - - - - - - - - rubber resin 50 60 80 60 60 60 60 60 40 90 60 60 60 60 thermoplastic resin 3 5 10 5 5 5 One 15 5 5 5 5 5 5 Hardener 8 12 15 12 12 12 12 12 12 12 12 12 12 12 fast curing agent 0.01 0.05 0.1 0.05 - 0.15 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 inorganic particles 30 45 60 45 45 45 45 45 45 45 20 70 45 45 flame retardant 50 65 80 65 65 65 65 65 65 65 65 65 40 90 solvent 500 500 500 500 500 500 500 500 500 500 500 500 500 500

(unit weight parts)

here,

The epoxy resin is a mixture of a bisphenol A type epoxy resin having an epoxy equivalent weight (EEW, g/eq) of 184 to 190 and a bisphenol A type epoxy resin having an epoxy equivalent weight of 450 to 500 (EEW, g/eq), a molar ratio of 1:5 It is an epoxy resin mixed with

The phenoxy resin has a weight average molecular weight (Mw) of 10,000 or more,

The rubber resin is xNBR,

The thermoplastic resin is a polyester resin having a glass transition temperature (Tg) of 20 to 100 °C,

The curing agent is a mixture of 3,3'-diaminodiphenylsulfone and 2-undecylimidazole, 3,3'-diaminodiphenylsulfone and 2-undecylimidazole 1 : It is mixed in a weight ratio of 0.5,

The fast curing agent is a cycloaliphatic modified amine curing agent,

The inorganic particles are a mixture of aluminum hydroxide and titanium dioxide, and a mixture of aluminum hydroxide and titanium dioxide in a weight ratio of 1:3,

The flame retardant is a particulate phosphorus-based flame retardant and a resin-type phosphorus-based flame retardant, wherein the particulate phosphorus-based flame retardant and the resin-type phosphorus-based flame retardant are mixed in a weight ratio of 1:3.

[Experimental Example 1: Preparation of Coverlay]

A polyimide film (PI) was used as a coverlay film, and an adhesive layer was formed on one surface of the polyimide film using the adhesive composition for a coverlay of Preparation Example.

The adhesive layer may be formed on one surface of the polyimide film using a known method.

[Experimental Example 2: Measurement result of storage elasticity]

The storage modulus (Pa) of the coverlay on which the adhesive layer was formed using the adhesive compositions of HL2, HL5, HL7, HL9 and HL11 was measured.

The storage modulus was measured using a Dynamic Mechanical Analyzer (DMA) Q800 from TA. Each coverlay was cut to have a width of 5 mm and a length of 50 mm in the mechanical direction (MD) and the width direction (TD), and then mounted on a dynamic mechanical analyzer so that the actual measurement length was about 20 mm. Then, after raising the temperature from 20 °C to 200 °C at a rate of 10 °C / min under the following conditions, the storage modulus (Storage Modulus) value was measured.

The result is shown in FIG. 10 .

According to FIG. 10 , it can be confirmed that HL2 is formed at the lowest temperature based on the lowest storage elasticity value and has the lowest storage elasticity value compared to HL5, HL7, HL9 and HL11.

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[Experimental Example 4: Lead heat resistance test result]

For the evaluation of the reflow process, lead-bath evaluation was performed. The solder bath temperature condition was floated at 280° C. for 30 seconds, and the occurrence of the lifting phenomenon was confirmed after evaluation.

The reflow temperature condition table is shown in FIG. 13, and the experimental results are shown in Table 3 below.

HL1 HL2 HL3 HL4 HL5 HL6 HL7 HL8 HL9 HL10 HL11 HL12 HL13 HL14 lead heat resistance O O O O O O O X X O X X X X

According to the experimental results, it was confirmed that the lifting phenomenon occurred in HL8, HL9, and HL11 to HL14. In other adhesive layers, it was confirmed that no lifting phenomenon occurred and excellent lead heat resistance.

[Experimental Example 5: Evaluation of physical properties]

Adhesion and flame retardancy of the prepared coverlay adhesive layer were evaluated. Adhesion was measured by applying the JIS K 6850 test method. The flame retardancy was measured according to the UL94 flame retardant regulations. The experimental results are shown in Table 4 below.

HL1 HL2 HL3 HL4 HL5 HL6 HL7 HL8 HL9 HL10 HL11 HL12 HL13 HL14 Adhesion (kgf/cm) 0.98 1.05 1.02 1.03 0.90 0.89 1.01 1.00 0.67 1.01 0.79 0.75 0.65 0.64 flame retardant O O O O O O O O O O O O O O

According to the experimental results, it was confirmed that the flame retardancy of all adhesive layers exhibited a flame retardancy of V0 grade. On the other hand, in the case of adhesion, it was confirmed that HL9 containing a small amount of rubber resin and HL11 to HL14 which did not contain inorganic particles and flame retardants as values within the range showed low adhesion.

[Experimental Example 6: Flowability evaluation of the adhesive layer]

In order to evaluate the flowability of the adhesive layer of the present invention, a specimen was prepared using a hot press.

Between the hot press upper plate and lower plate, an aluminum plate; TPX film; coverlay; TPX film; PVC film; Kraft paper and aluminum plate were laminated in this order, and pressed at 160° C. for 1 hour at a pressure of ^{45 kgf/cm 2 .}

The resin flowability was measured using the Visual Microscops system. The test was conducted by forming the adhesive layer of the coverlay to have a thickness of 38 µm, and the average value of five samples measured in µm was measured as the experimental result.

As a comparative example, a conventional coverlay adhesive composition for hot press was used. More specifically, in the same content range as HL2, the fast curing agent is not included, only aluminum hydroxide is included as inorganic particles, and only the particulate phosphorus-based flame retardant is mixed as the flame retardant.

Resin Flow Measurement by Hot Pressing Measure resin flow by thermosetting after roll lamination Comparative example 60 to 90 μm 0 to 20 μm HL2 90 to 150 μm 40 to 60 μm

According to the experimental results, HL2, which is an embodiment of the present invention, has high flowability in the hot press process, so it is difficult to apply to the hot press process, but when the roll lamination process is applied, there is no problem in fillability due to proper flowability, but general In the case of blending, the flowability is suitable on the hot press process, so there is no problem in fillability, but when the roll lamination process is applied, the resin hardly flows, so the problem of unfilling may occur.

In addition, it was confirmed that, after the roll lamination process, in the case of the adhesive layer of the general formulation during thermal curing, there was little flowability and thus a lifting phenomenon occurred, but in the case of HL2 of the present invention, it was confirmed that the floatation phenomenon did not occur due to the flowability.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention defined in the following claims are also present. It belongs to the scope of rights of

100: base
110: pattern
200: processed upper coverlay
210: Hall
300: lower coverlay
310: terminal part
400: release film
1000: a pair of rollers
1100: coverlay roller
1110: heating element
1120: outer shell
1200: base roller
2000: a pair of winding rollers
2100: coverlay winding roller
2200: base winding roller
2300: release film winding roller

Claims (11)

preparing a base in which an upper copper layer, an insulating film layer, and a lower copper layer are sequentially stacked;
Laminating the upper coverlay processed on the upper surface of the base by roll-to-roll processing;
processing the base based on the processed portion of the processed upper coverlay;
laminating a lower coverlay to the lower surface of the base; and
Including; processing the lower coverlay with a UV laser
Double access method for manufacturing FPCB. The method of claim 1,
Laminating the upper coverlay processed on the upper surface of the base by roll-to-roll processing,
manufacturing the processed upper coverlay in a roll form;
manufacturing the base in the form of a roll; and
Laminating the processed upper coverlay and the base by penetrating the end of the roll-shaped processed upper coverlay and the end of the roll-shaped base between a pair of rollers to abut each other;
Double access method for manufacturing FPCB. The method of claim 2,
The processing of the base based on the processed portion of the processed upper coverlay comprises:
Forming a pattern on the base through exposure, development, corrosion, and peeling steps based on the processed portion of the processed upper coverlay
Double access method for manufacturing FPCB. The method of claim 3,
The step of processing the lower coverlay with a laser,
Opening the terminal part of the lower coverlay with the UV laser
Double access method for manufacturing FPCB. delete The method of claim 4,
The processed upper coverlay,
The upper coverlay film and the upper coverlay adhesive are sequentially laminated.
Double access method for manufacturing FPCB. The method of claim 6,
The processed lower coverlay,
The lower coverlay adhesive and the lower coverlay film are sequentially laminated.
Double access method for manufacturing FPCB. The method of claim 7,
The roller is
Pressing and heating the processed upper coverlay and the base to melt the upper coverlay adhesive, and laminating the processed upper coverlay and the base
Double access method for manufacturing FPCB. The method of claim 8,
The upper coverlay film and the lower coverlay film,
PI film
Double access method for manufacturing FPCB. The method of claim 9,
The rollers rotate in opposite directions
Double access method for manufacturing FPCB. The method of claim 10,
The rollers rotate at the same speed
Double access method for manufacturing FPCB.

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