KR20160085041A - Fine circuit board and its manufacturing method - Google Patents

Abstract

The present invention relates to a circuit board having a microcircuit and a manufacturing method thereof. The present invention manufactures and uses a master mold on which the microcircuit is formed via a concave part and a convex part from an electroforming mold having the microcircuit formed via the concave part and the convex part. The master mold of the present invention is manufactured by a fluoroplastic material. According to the present invention, the concave part of the master mold is filled with silver paste, and the silver paste is hardened through a heating apparatus. Then, an epoxy resin is applied to the surface part of the convex part of the master mold and the exposed surface part of the hardened silver paste. A polyimide film is bonded to an upper part of the epoxy resin. After hardening the epoxy resin, the circuit board having a microcircuit is manufactured by separating the master mold. Thereby, the circuit board having a microcircuit can be manufactured by a simple method with excellent productivity.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a micro-

The present invention relates to a method of forming a circuit on a substrate and a circuit board therefor.

The substrate includes both flexible and non-flexible forms.

Generally, a flexible one is called an FPCB. A circuit board that is not bent is called a PCB.

The circuit board of the present invention is constituted by a circuit portion by curing a silver paste. There are various techniques for constituting a cured silver paste by a circuit. It is important how the cured silver paste is bonded to the substrate in some way.

It is also important how the silver paste is constructed in a circuit. According to this method, the quality and productivity of the product are significantly changed. The present invention selects a cured silver paste circuit first in a mold and then joins the cured silver paste circuit to the substrate.

Even if the same process is used, not only the quality of the product is determined according to which mold is used, but even if the same process is performed, the product may not be manufactured depending on the nature of the mold. The present invention provides a method for fabricating a circuit board that is most productive and precise.

Generally, in order to make a circuit, a thin copper film is formed on a substrate. A photoresist is coated on the copper thin film, and a fine circuit is formed through exposure, development, and etching.

Techniques for making a fine circuit by filling a silver paste include a technique of forming a depressed portion on a substrate and filling the depressed portion with a silver paste to form a circuit.

The present invention has become an invention on the basis of this conventional technique.

The present invention proposes a method of forming a circuit portion in a mold, joining the circuit portion to another substrate in the mold, and releasing the circuit portion bonded to the substrate from the mold.

For this work, the mold is made of Teflon resin with excellent releasability, and the circuit part is formed by filling the engraved part of Teflon resin mold with silver paste.

In the present invention, a polyimide film having high chemical stability is used as a substrate, and the circuit portion is bonded to the silver paste through an epoxy resin.

After the circuit part is firmly bonded to the substrate through the epoxy resin, the mold is separated.

In the present invention, a fine circuit board is not produced by a conventional etching method, and an ultra-precision micro circuit board having excellent productivity can be produced.

When the circuit board is flexible, it is often referred to as FPCB.

It goes without saying that the present invention is applicable not only to the FPCB but also to the manufacture of a rigid substrate without bending the substrate. When an FPCB is manufactured by an etching process, various processes are necessarily required for each product.

The photoresist is uniformly applied to the substrate on which the copper thin film is formed. Thereafter, an exposure unit is formed in the shape of the pattern through an exposure operation. Then, a necessary circuit board is manufactured through a developing operation and an etching process.

The present invention allows a microcircuit substrate to be manufactured by a method of adhering a silver paste made of a circuit part to a substrate without going through such an exposure development etching process. An important point of the present invention is that the circuit portion of the silver paste can be formed precisely, cleanly, and uniformly.

Generally, when a circuit is formed using a silver paste, a circuit is formed by a printing method. However, the present invention is characterized in that the recess is filled with a silver paste to form a circuit part in the form of a mold.

It is a core technology of the present invention that only silver paste is filled in the concave portion of the mold and no silver paste is applied to other portions. For this purpose, a master mold made of Teflon resin is used in the present invention.

One of the characteristics of the Teflon resin mold is its excellent releasability. In the Teflon resin mold, it is also necessary to make the surface except for the concave portion a mirror surface. Based on the excellent releasability of the Teflon resin, even if silver paste is applied to the surface of the mirror-finished mold, the silver paste is cleanly removed once it is squeezed.

Further, it is characterized in that the silver paste is hardened by heating, and then separated from the Teflon resin mold.

In order to produce products by mass production, there is a characteristic that it can be repeatedly performed. The line width of the silver paste can be as much as 1 micrometer. Even if the precision of the master mold is precise, the accuracy of the product can be matched to the precision of the master mold.

Further, if the concave portion of the master die is deepened, the thickness of the circuit composed of the silver paste can be increased. Therefore, the microcircuit substrate made of the present invention can excellently increase the conductivity.

The present invention uses a die formed of a material having a releasing layer or a releasing property. The mold is provided with a recess.

Only the concave portion of the mold is filled with a silver paste, and after filling and heating, the silver paste is cured. The releasable mold having the cured silver paste is bonded to the substrate through an adhesive resin. When the adhesive resin is completely cured, it is demolded.

Silver paste is firmly bonded to the substrate by an adhesive.

The circuit of the silver paste formed on the substrate and the space between the circuits can be formed by a very rigid circuit. To this end, a concave portion formed of a silver paste and a silver paste formed on a substrate is filled with a resin and cured.

Through such a process, the circuit is buried. The buried circuit is firmly coupled to the substrate and is not separated from the substrate.

The present invention can economically produce a precise circuit board.

In the fabrication of an ultra-precise circuit board, a process of exposure and development etching is essential in the existing method.

However, in the present invention, a circuit part is formed by a simple method in a master mold made of a fluororesin.

Of course, the substrate material can be made of various materials. Of course, polyimide films that are most commonly used in FPCB can be used.

The polyimide film is chemically stable and durable.

The FPCB product using the polyimide film produced by the present invention as a substrate is advantageous in that flatness can be maintained.

When a liquid polyimide resin is applied to a master mold and the polyimide resin is cured to be used as a substrate, there is a phenomenon that the polyimide substrate is warped by heating.

In order to prevent such warping (curling phenomenon), the present invention adopts a method in which a film already made of a polyimide film is bonded to an epoxy resin.

In this case, the curling phenomenon is prevented.

1 is an explanatory diagram of a mold die.
Figs. 2 and 3 are explanatory views of a master die.
Fig. 4 is an explanatory diagram for explaining filling a master mold with a silver paste. Fig.
Fig. 5 is an explanatory diagram for explaining bonding of a substrate and a cured silver paste through an adhesive. Fig.
Fig. 6 illustrates a circuit board demolded from a master mold.
7 is an explanatory view for explaining the production of a buried circuit board.
8 is an explanatory view for explaining a polishing process of a buried circuit board.
9 is an explanatory diagram of a fully buried circuit board.
Figs. 10 and 11 are explanatory diagrams of a fully buried type circuit board on which openings are formed. Fig.
12 is an explanatory diagram of a taper structure for facilitating demoulding.

1 is an explanatory diagram of a mold die.

In the present invention, a model mold is defined as a mold for manufacturing a master mold.

In the present invention, a model die is processed by electroforming or laser processing.

In the case of manufacturing through electroforming, a photoresist is coated on a substrate to be energized, and exposure is performed on the photoresist through a pattern. After the exposure process, a development process is performed, and after the development process, plating is performed thickly.

The mold is manufactured by demolding the thick plated body from the substrate and is obtained through electroforming.

The surface of the model die is formed with the concave portion 2 and the convex portion 1.

In order to construct an ultra-fine microcircuit, the configuration of the concave portion and the convex portion having a line width of several micrometers is essential.

The concave portion and the convex portion constitute a fine circuit.

According to the present invention, the sizes of the concave portion and the convex portion are adjusted, thereby making it possible to construct a highly precise circuit portion. The line width of the circuit portion is from 1 micrometer to several tens of micrometers, and the depth of the circuit portion is several micrometers to tens of micrometers.

In order to form such fine concave portions and convex portions, a photoresist is uniformly applied to a conductive flat plate such as a stainless flat plate, exposure and development are performed on the photoresist using a photomask, Make the workpiece.

The thickness of the photosensitive layer coincides with the thickness of the circuit part.

This prismatic work becomes a model mold.

At this time, in exposing the photosensitive layer, it is preferable that exposure of the photosensitive layer is tapered to easily demould the poling workpiece.

The fact that the electroformed workpiece is easily demoulded means that the following master mold can easily be demolded, which means that it is easy to demold the hardened silver paste to be described later.

The tapered exposure of the photosensitive layer is one of the key technologies. Such a tapered exposure is dependent on the function of the exposure device.

The taper will be described with reference to FIG.

And causes the conductive substrate 31 to be exposed in a tapered shape.

The space portion is configured in the shape of a reverse taper (30).

When the electric conductor 33 is electrically energized to perform plating, the electroformed plated body 32 filled in the space portion is formed into a reverse taper shape.

When electroplating is completed, the electrophotographic workpiece 34 is demolded from the electroconductive substrate 35. At this time, demoulding can be facilitated due to the presence of the taper.

In the present invention, one of the core technologies of the present invention is to form the tapered concave portion and the convex portion to facilitate the demoulding.

In the present invention, in order to perform such a tapered exposure, the touched exposure can be easily performed by using the linear light source exposing apparatus using the lenticular according to the present invention.

In manufacturing the model mold, another embodiment is laser processing. However, it is not easy to manufacture a tapered circuit part when performing laser processing.

As a processing method, a line width of a circuit part of several micrometers can be processed through laser processing.

In general, such fine precise mold 3 is a polished electroforming work or a metal substrate is processed by a laser, so that the mold is a metal mold in the present invention.

Figs. 2 and 3 are explanatory views of a master die.

It is possible to make a mold replicated from the mold die described in Fig.

The master mold 4 can be manufactured by pouring the liquid resin into the mold die 6.

Alternatively, a master mold made of a resin can be produced by heating a heat to a resin plate made in the form of a resin film or a flat plate made of a film in a mold.

As a most typical embodiment of the present invention, a sheet material formed of a Teflon resin in the form of a flat plate is placed on a model die by electroforming, and the sheet is molded by heating and pressing.

Once the molding is finished, if the mold is demolded after cooling, a Master mold is produced, which replicates the shape of the mold precisely.

As another embodiment, a Teflon resin film may be used, and a reinforcing material such as a metal plate may be formed and processed to maintain the shape of the flat plate.

The reason for making a master mold with Teflon resin among the ones made of resin is the greatest reason for ease of demoulding. The Teflon resin is excellent in releasability, and the silver paste can not be adhered to the master mold made of the Teflon resin.

It is to be noted that the epoxy resin used as an adhesive in the master mold of the Teflon resin can not exert an adhesive force in the present invention.

As another embodiment of the present invention, a master die made of metal can be used. In this case, a release layer should be formed on the master mold of the metal.

In order to form the releasing layer, a releasing agent should be coated or a releasing material should be applied.

In the present invention, a plurality of master molds can be duplicated from a model mold to produce the master mold. In this way, a plurality of molds replicated from the molds can be produced.

In the present invention, this is referred to as master mold.

The concave portion of the model mold 6 becomes the convex portion 5 of the master mold 4 and the convex portion of the model mold becomes the concave portion of the master mold.

When making a product using master mold, it is important that the product to be demolded from the mold comes off well from the master mold.

For this demolding, a release layer may be formed on the surface of the master mold or a coating for release may be used to facilitate demoulding.

The master mold can be made of metal or various types of resin.

Examples of the present invention include those using a Teflon resin.

When a master mold is made of Teflon resin, the Teflon resin mold itself is excellent in releasability. In this case, there is no need for a mold release layer or coating for mold release on the master mold. The master mold 7 shown in Fig. 3 is deformed from the model die.

Fig. 4 is an explanatory diagram for explaining filling a master mold with a silver paste. Fig.

The embodiment of the master mold made of Teflon resin will be mainly described.

The Teflon resin or the fluororesin used in the present invention will be described in detail.

Teflon resin is superior to general plastics and has superior heat resistance, chemical resistance, low temperature resistance, electrical insulation, and high frequency characteristics compared to general plastics. It also has non-tackiness and low friction characteristics.

Fluorine resins can be made into various types of materials by compression and extrusion molding using fluororesin raw materials.

On the surface of the Teflon resin, almost all materials do not stick together.

The melting point of fluoropolymer varies from 270 ° C to 327 ° C depending on the product type.

Teflon can be used at -260 degrees Celsius to +260 degrees Celsius, and it can stand at 300 degrees Celsius for a short time, and TEFLON FEP can be used continuously at 232 degrees Celsius.

Teflon surface does not get wet with oil or oil. Thus, the surface is not only contaminated but also easily cleaned. The coefficient of friction of Teflon is generally about 0.5 ~ 0.20 although it varies slightly depending on speed and load. Teflon is generally stable for all chemicals. Teflon has very high electrical properties even in a wide frequency range. It has a non-insulating property as well as an excellent surface resistivity. Its physical characteristics remain unchanged even at extremely low temperatures. Teflon is used at temperatures as low as -260 degrees Celsius.

The master mold made of the Teflon resin in the present invention can be easily replaced by Teflon coating the general mold. Therefore, the Teflon resin mold of the present invention can be replaced with the Teflon coated mold, which is also claimed in the present invention.

In the present invention, first, a silver paste 8 is filled in a concave portion of a master mold made of Teflon resin.

The silver paste 10 is allowed to enter only the concave portion of the master mold through the squeeze 9.

The surface of the convex part of the master mold made of Teflon resin is clean, and the more easily the mirror surface is made, the easier it is to remove the silver paste on the convex part.

The surface of the convex portion of the master mold is clean, and when it becomes a mirror surface, the silver paste on the flat surface of the convex portion is cleanly removed even if it is squeezed once by the squeeze.

This is a very important technique in the present invention.

In the master mold or the Teflon resin master mold having the release layer formed, the silver paste embedded in the convex portion of the master mold is easily removed by squeezing.

The silver paste filled in the recess is cured by heating.

The cured silver paste serves as a circuit for electricity.

After the silver paste is cured, the upper surface of the convex water of the master mold and the upper surface of the silver paste are polished.

A silver paste arranged by squeezing on the surface portion of the convex portion of the master mold of the fluorine resin may remain a little small. The silver pastes remaining as such remain in a state in which they are not tacked to the surface portion of the convex portion without any binding force after being cured.

It is polished and removed through an abrasive having an extremely fine particle size. Through this polishing, the surface of the master mold of the fluororesin becomes smoother.

In some cases, the work can proceed without grinding.

In another embodiment of the present invention, the metal layer is filled in the concave portion of the master mold by sputtering without filling the silver paste.

Of course, the metal layer is also formed in the convex portions by sputtering.

When the metal layer is almost filled in the concave portion, the metal layer deposited on the convex portion is removed.

In the case of a Teflon resin mold having high releasability, it is easy to remove the metal layer deposited on the convex portion.

Fig. 5 is an explanatory diagram for explaining bonding of a substrate and a cured silver paste through an adhesive. Fig.

The substrate may be of various types such as a rigid substrate, a transparent substrate, an opaque substrate, an epoxy substrate, a rigid resin substrate, a film, a transparent film, an opaque film, a polyimide film, a transparent polyimide film and an opaque polyimide film.

When the substrate of the bent material is used, it becomes an FPCB substrate.

Polyimide film is used as the most typical substrate material of FPCB.

A variety of bonding agents can also be used. Various adhesive resins, urethane resins, polyimide resins, epoxy resins, and the like can be used.

The adhesive is selected according to the properties required for the product.

An epoxy resin is used as the most representative embodiment of the present invention.

This is because self-curing occurs even in the absence of air.

Also, it is not broken well and has excellent adhesive strength.

If a polyimide resin is to be used, the polyimide resin must be cured if it is required to provide a structure for allowing the released gas to escape to the outside.

Epoxy resins are easy to adhere to polyimide films and have good adhesive strength.

It is also resistant to impact and can withstand bending.

The epoxy resin also has excellent adhesion to cured silver paste.

A polyimide film (11) and a master mold filled with a cured silver paste are bonded by an epoxy resin (13).

A liquid epoxy resin can be uniformly applied to the surface of the master mold.

It may be carried out by uniformly applying a liquid epoxy resin to the polyimide film.

At this time, it is preferable to form a coating film of a uniform epoxy resin.

For this purpose, the rollers 12 can be used to maintain a constant thickness.

It is a matter of course that bonding to the polyimide film layer through the epoxy resin can be carried out with respect to the embodiment in which the metal layer is piled up in the concave portion by sputtering and the metal layer stacked on the convex portion is removed.

Fig. 6 illustrates a circuit board demolded from a master mold.

After applying the epoxy resin, it is cured by heating.

The epoxy resin 16 can be cured even when no air permeability is present.

When the polyimide resin is selected as the bonding agent, curing does not occur in the absence of air permeability. Therefore, it is necessary to first cure the polyimide resin at an appropriate temperature, and then to bond it.

The epoxy resin 16 is excellent in bonding with the polyimide film 17.

The epoxy resin is also excellent in bonding with the cured silver paste 15.

Epoxy resin is one of the most widely used plastics, and its role in the fields of chemical, electrical, mechanical, and civil engineering is very important, such as adhesives, paints, laminated products, molds and molded products.

Epoxy is used with curing agents because of its high reactivity. The epoxy resin reacts with the curing agent, and the properties thereof greatly vary depending on the type and the compounding ratio of the curing agent, the curing conditions, and the like. The epoxy resin can be adhered to anything except silicon resin, fluororesin, polyethylene, polypropylene and the like. Epoxy resin adhesives are available in various forms such as liquid, paste, powder, and stick, and liquid is most widely used.

Epoxy resin is also used for adhesion of copper foil.

It is also used for encapsulation of electronic components (encapsulation).

In the case of compression molding, the molding conditions are a molding temperature of 140 to 160 ° C, a molding pressure of 100 to 200 kgf / cm 2, and a curing time of about 100 to 200 sec / mm.

Since this molding material does not produce volatile substances as a by-product at the time of curing, the dimensional change of the cured product is small and the electrical properties are good. In addition, since it is rich in fluidity and can be molded even at a relatively low pressure, it is suitable for molded articles having many complicated shapes and inserts.

Dimensional stability and electrical performance, it is mainly used for electric parts with many inserts and mechanical parts requiring dimensional accuracy.

In the case of semiconductors, most of them are encapsulated with an epoxy resin.

After the epoxy resin is cured and the cured silver paste and the polyimide film are adhered, the substrate is detached from the master mold.

The substrate that has been detached from the master mold becomes a circuit board having a circuit portion formed on the polyimide film. There is a space portion 14 between the circuit portion and the circuit portion.

Master molds made of master mold or teflon resin with mold releasing layer are excellent in releasing property, so demoulding is easy.

When a polyimide film is used and an epoxy resin is used as an adhesive, the circuit board subjected to demoulding becomes a polyimide FPCB.

In the present invention, it is possible to construct a circuit having a very high precision of several micrometers in line width of a circuit.

The polyimide circuit board manufactured by the method of the present invention is characterized in that the flatness can be maintained.

The polyimide film bends well and curling occurs depending on the environment.

The curl phenomenon describes the phenomenon of drying.

The epoxy bonded to the polyimide film and the metal layer formed by the cured silver paste or spots contribute to maintaining the flatness of the polyimide film.

Since the polyimide circuit board of the present invention has no curling phenomenon, it can be laminated to form a multilayer substrate

7 is an explanatory view for explaining the production of a buried circuit board.

Polyimide films have high thermal stability and effective mechanical properties. Polyimide (PI) film is a high-tech, high-performance industrial material that can withstand temperatures of 400 degrees Celsius or higher and a temperature of minus 269 degrees Celsius, and is thin and flexible.

It has strong chemical resistance and abrasion resistance and is widely used in areas that require stable performance in harsh environments. It is mainly used for a disk of a flexible circuit board (FPCB).

Polyimide is a heat-resistant polymer with high mechanical strength, impact resistance and dimensional stability. Electrical insulation, abrasion resistance and chemical resistance are also good. It is also flame retardant. The disadvantages are mostly thermosetting and poor moldability.

As electronic equipment has become smaller and more highly integrated, film-shaped polyimide has become a popular material for FPC applications.

The polyimide film is developed as a COF (Chip On Flexible Printed Circuit or Chip On Film), and has not only a function as a bendable electric conductor but also a dimensional stability and a mechanical property to the extent that the component can be surface-mounted.

The copper-clad laminated polyimide film is a material for a flexible circuit board (FPCB) in which a polyimide film and a copper foil are laminated using a heat-resistant flame-retardant epoxy adhesive. It has excellent heat resistance, chemical resistance, and excellent electrical and mechanical properties, making it an ideal material for products requiring high functionality, miniaturization, and light weight, such as mobile phones and digital cameras.

In the polyimide circuit substrate demolded in the present invention, the space portion 14 is formed between the circuit portion and the neighboring circuit portion.

When the space portion is filled with the nonconductive resin, the circuit portion is firmly attached to the substrate.

For this purpose, as an embodiment, the space portion is filled with an epoxy resin, and the filled epoxy resin 18 is cured.

In the present invention, the side surface of the circuit portion is buried, and the exposed surface is defined as a buried circuit board.

The non-conductive resin to be filled may be a liquid polyimide resin.

This is because the liquid polyimide resin is easily cured by heating in air.

8 is an explanatory view for explaining a polishing process of a buried circuit board.

After the epoxy resin is cured, the surface of the circuit board is cleanly cleaned through the fine grinder 19.

9 is an explanatory diagram of a fully buried circuit board.

In the polyimide circuit substrate that has been demolded, the circuit portion 21 cured to the polyimide film 23 is bonded to the epoxy resin layer 22.

At this time, a space portion is formed between the circuit portion and the neighboring circuit portion.

When covering the entire upper portion of the circuit portion including the space portion with the nonconductive resin 20, not only the circuit portion is firmly attached to the substrate but also the circuit is insulated.

As an example, an epoxy resin is used as the nonconductive resin. Of course, polyimide resins can also be used for nonconductive resins.

In the present invention, a circuit board completely buried up to the side surface of the circuit portion and the surface of the circuit portion is defined as a fully buried circuit board.

Figs. 10 and 11 are explanatory diagrams of a fully buried type circuit board on which openings are formed. Fig.

As shown in FIG. 11, a completely buried circuit board is defined as a fully buried type circuit board in which an opening is formed by cutting an upper portion of a top-buried circuit board to form an opening.

The opening is thus formed to expose a part of the circuit part so as to be electrically connected to the exposed circuit part.

First, as shown in FIG. 10, a fabrication process is required to fabricate this.

First, a lid 25 is formed on a part of the buried circuit board as shown in FIG.

The cover may be made of a material such as an adhesive tape or the like.

Also, a photosensitive material may be used to form a cover.

To this end, a photosensitive material is first applied to the top of the buried circuit board.

It is possible to precisely manufacture the cover by leaving the photosensitive material only in the necessary portion through the exposure and development process to the photosensitive material. When the lid is formed using the photosensitive material, the lid can be easily removed. That is, the cover can be easily removed by chemical treatment.

After the lid 25 is formed, a non-conductive resin 24 is applied to the top of the buried circuit board and cured.

In the lower portion of the non-conductive resin 24, an epoxy resin 27 is filled between the circuit portions 26.

The non-conductive resin may be a liquid epoxy resin.

Or a liquid polyimide resin can be used.

After the non-conductive resin is cured, the cover 25 is removed.

The circuit part 28 is exposed as shown in Fig.

The exposed circuit portion 28 can be electrically connected to another circuit.

12 is an explanatory diagram of a taper structure for facilitating demoulding.

When manufacturing a mold through a preformed workpiece, tapered exposure work is performed on the photoresist to start manufacturing.

The photoresist 29 is exposed on the conductive flat plate 31, and exposure and development are progressed with a tapered structure.

A tapered photoresist 29 and a tapered space portion 30 are formed.

When the plating is started by connecting electricity to the conductive flat plate 33, the electroforming workpiece 32 is formed.

When the electrophotographic workpiece 34 is demoulded from the conductive flat plate 35, a mold can be easily demoulded.

The present invention includes a method of manufacturing a flexible circuit board having a microcircuit and a flexible circuit board having a microcircuit made by the method.

The present invention includes a flexible circuit board having a microcircuit and a method of manufacturing the same, characterized in that a circuit portion constituted by an energizing circuit is bonded to a polyimide film substrate by an epoxy resin.

The present invention also includes a circuit board configured as a buried type or a completely buried type.

It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It is not.

1: convex part 2: concave part 3: model mold 4: master mold
5: convex part 6: model mold 7: master mold 8: silver paste
9: Squeeze 10: Silver paste 11: Polyimide film
12: roller 13: epoxy resin 14:
15: Cured silver paste 16: Epoxy resin 17: Polyimide film
18: filled epoxy resin 19: fine grinding machine 20: nonconductive resin
21: circuit part 22: epoxy resin layer 23: polyimide film
24: non-conductive resin 25: lid 26: circuit part 27: epoxy resin
28:

Claims (18)

Preparing a master mold in which a microcircuit is formed through a concave portion and a convex portion from an electroforming die in which a fine circuit is formed through a concave portion and a convex portion;
Filling a concave portion of the master mold with a silver paste, and curing the silver face through a heating device;
Applying an epoxy resin to the surface portion of the convex portion of the master mold and the exposed surface portion of the cured silver paste;
Joining the polyimide film through the epoxy resin, and curing the epoxy resin;
And removing the master mold from the master mold. The method of manufacturing a flexible circuit board according to claim 1, wherein the master mold is made of Teflon resin. The method of manufacturing a flexible circuit board according to claim 1, wherein the master mold is fabricated as a metal or a resin. The method of manufacturing a flexible circuit board having a microcircuit according to claim 3, wherein a release layer is formed on the surface of the mold. The method for manufacturing a flexible circuit board according to any one of claims 1 to 4, wherein the flexible circuit board is used as a polyimide resin or a liquid resin for a liquid epoxy resin instead of an epoxy resin. A flexible circuit board having a microcircuit, which is manufactured by any one of claims 1 to 6. Wherein a cured silver paste constituted by an energizing circuit is bonded to the polyimide film substrate by an epoxy resin. 8. The flexible circuit board according to claim 7, wherein the silver paste is embedding-type. 8. The flexible circuit board according to claim 7, wherein the silver paste is formed in a completely buried form. Preparing a master mold in which a microcircuit is formed through a concave portion and a convex portion from an electroforming die in which a fine circuit is formed through a concave portion and a convex portion;
Forming a metal layer on the concave portion of the master mold by sputtering;
Applying an epoxy resin to the surface portion of the convex portion of the master mold and the sputtering metal layer of the concave portion;
Joining the polyimide film through the epoxy resin, and curing the epoxy resin;
And removing the master mold from the master mold. The method of manufacturing a flexible circuit board according to claim 10, wherein the master mold is made of Teflon resin. The method of manufacturing a flexible circuit board according to claim 10, wherein the master die is fabricated as a metal or a resin. 13. The manufacturing method of a flexible circuit board having a microcircuit according to claim 12, wherein a release layer is formed on the surface of the mold. The method for manufacturing a flexible circuit board according to any one of claims 10 to 13, wherein the resin is used as a polyimide resin or a liquid resin for a dielectric resin instead of an epoxy resin. A flexible circuit board having a microcircuit, which is manufactured by any one of claims 10 to 14. Wherein a metal layer formed by a spark ring constituted by an energizing circuit in a concave portion of the master mold is bonded to the polyimide film substrate by an epoxy resin. 17. The flexible circuit board according to claim 16, wherein the sputtering metal layer is formed in a buried shape. 17. The flexible circuit board according to claim 16, wherein the sputtering metal layer is formed in a completely buried form.

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