JP2007142092A - Manufacturing method of high density wiring substrate, high density wiring substrate manufactured by using the method, electronic device and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high density wiring substrate, an electronic device using the substrate, and an electronic apparatus. <P>SOLUTION: An imprint method by a printing plate wherein a micron, submicron or nanometer size pattern is formed in a quartz substrate, a sapphire substrate, a metal substrate or the like for the formation of a resist pattern for the chemical etching of metallic foil such as copper foil or conductive additive plating such as copper is employed in a manufacturing method of a high density wiring substrate such as a rigid wiring substrate, an FPC, a wiring tape for TAB or the like. The manufacturing method of the high density wiring substrate comprises an imprint process for resist pattern formation in all processes of resist film formation on a metallic foil, chemical etching or additive plating and resist pattern peeling processes, or in a part of the processes as an in-line. A wiring substrate manufactured by using the method, an electronic device using the substrate, and an electronic apparatus are also provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to the field of high-density wiring boards used in small portable devices, high-performance electronic devices, and the like. In addition to digital cameras and mobile phones, small and highly functional electronic devices and electronic devices used in biotechnology and medicine are included.

  Currently, high density wiring board manufacturing methods include a subtractive method of photochemical etching using a metal foil such as copper foil, and an additive method of manufacturing by conductive metal plating such as copper plating. In the subtractive method, a resist pattern for chemical etching is first formed using a photo process. Thereafter, the wiring is formed by etching with an aqueous etching solution such as ferric chloride, and the resist pattern is finally peeled off to complete. This manufacturing process is shown in FIG. FIG. 1 shows a manufacturing process of FPC (Flexible Printed Circuit) and TAB (Tape Automated Bonding) by the subtractive method. Since FPC and TAB usually use a material obtained by laminating a thin copper foil on a resin film such as polyimide, a manufacturing method using a continuous winding method is used.

FIG. 1A shows a resist coating process in which a photosensitive resin (hereinafter referred to as photoresist 11) is applied to a material (hereinafter referred to as MCL; Metal Clad Laminate) in which a metal foil 10 is bonded to an electrically insulating resin tape 9. Indicates. The manufacturing method of MCL1 includes a method in which a metal foil such as a copper foil is bonded to a film made of an electrically insulating resin tape 9 such as polyimide using an adhesive. Further, it is also manufactured by a method in which a base conductive layer is first formed directly on a polyimide film or the like by a vapor deposition method such as vapor deposition or sputtering, and then the conductive layer is thickened by electroplating such as copper. The thickness of the metal foil such as copper foil is usually 10 to 20 μm, and the thickness of the electrically insulating resin tape such as polyimide is 20 to 50 μm. Since this MCL material is thin and easy to wind continuously, it is suitable for a so-called reel-to-reel manufacturing process. The MCL material has a width of 200 mm to 500 mm and a length of 100 to 200 m for FPC, and a width of 35 to 125 mm and a length of 50 to 150 m for TAB. The MCL material is coated with a liquid photoresist using a photoresist coater 4. A roller coater is usually used for the coating method of the photoresist, but a method in which the photoresist is dry-filled and bonded using a heating roll is also used. In a liquid photoresist containing a solvent, a baking process for drying the organic solvent after coating is required.
These photoresists are characterized by being cured or decomposed by ultraviolet rays having wavelengths of, for example, 365 nm and 254 nm. For this reason, the photoresist coating process needs to be performed in a room where natural light including ultraviolet rays or light such as an illumination lamp is blocked.

  FIG. 2B shows a process of exposing the MCL coated with the photoresist using the photomask exposure machine 5. Since this process uses a photomask on which a fine pattern is drawn, it is performed in a dust-free room. This process also needs to be performed in a room where natural light including ultraviolet rays or light such as an illumination lamp is blocked. The exposure machine used in this process is not only very expensive, but also has a problem that the lamp life of the ultra high pressure mercury lamp is short and the running cost is high. As shown in FIG. 1, the photoresist coating (a) and the exposure (b) are not continuous but separate steps. The purpose of this is to protect the exposure machine, which is a precision optical instrument, from a corrosive environment because the coating process includes wet processes such as degreasing and pickling.

  FIG. 1C shows the developing process. Development is performed by the developing device 6. There are negative photoresists that are cured by ultraviolet rays and positive photoresists that are decomposed by ultraviolet rays. The purpose of the development step is to dissolve and remove the photoresist that has not been photocured in the negative type and the photoresist that has been decomposed by photocuring in the positive type. This development process is a wet process in which a developer, a surfactant, an alkali, a dissolution aid, and the like are included. Therefore, development is also performed in a room separated from the exposure process. A photoresist pattern 12 is formed by development.

FIG. 1 (d) shows a chemical etching process. In this step, the metal foil such as copper foil is dissolved and removed by the chemical etching apparatus 7 using an oxidizing aqueous solution such as ferric chloride. Since the chemical etching apparatus uses a strong oxidizing acid, it is performed in a room completely separated from the exposure process.
FIG. 1E shows a photoresist stripping process. For peeling, a film removing apparatus 8 using a high-concentration alkaline aqueous solution is used. For this reason, the peeling process is also an independent line separated from the exposure process.

In recent years, from the viewpoint of protecting the global environment, reduction of CO2 that causes global warming has been greatly screamed. For this purpose, it is strongly desired to shorten the manufacturing process and to construct a new manufacturing process that can be manufactured without using an expensive apparatus. However, in high-density wiring boards for small electronic devices such as mobile phones and digital cameras, functions of electronic components to be mounted are further improved, and higher-density wiring boards are required.
There are the following non-patent literatures as documents in which technical problems of the high-density wiring board are arranged. In this document, the ITRS roadmap of the wiring width and wiring interval of the high-density wiring board up to 2014 and the development trend are shown.
Search for problems in printed circuit board technology and what it should be, mounting technology 21 (6) pp. 32-39

  As shown in this document, the wiring board is required not only to improve the wiring density but also to provide a precision wiring that can cope with an increase in signal processing speed. Specifically, the uniformity of the width of the wiring as a transmission line and the uniformity of the wiring interval are important. For this reason, exposure machines and chemical etching apparatuses have been developed to improve exposure resolution and to develop high-performance machines that suppress variations in etching. As described above, the conventional photochemical etching process has the disadvantage that the process is separated and the yield is poor, which is not suitable for the manufacturing method of the high-density wiring board. For this reason, there is currently a limit to mass production of high-density wiring boards by the photochemical etching process. The current wiring pitch limit is about 60 μm in the process of a cut single-wafer substrate, and 30 μm in a TAB manufactured while winding a long material.

  FIG. 1 shows a manufacturing process of a high-density wiring board by a subtractive method using chemical etching, but the problem is the same even in an additive method in which wiring is formed by copper plating or the like. In the additive method, instead of chemical etching, electrolytic copper plating is performed after development, and other steps are similar to the subtractive method. However, in the semi-additive method, unlike the subtractive method, the MCL to be used is usually made of a material in which a base copper conductive layer having a thickness of about 1.0 μm is formed on the surface of a polyimide film or the like by vapor deposition or chemical plating. Use. The underlying conductive layer is chemically dissolved and removed after the formation of the wiring pattern by electrolytic copper plating and the stripping of the photoresist.

  The method for manufacturing a high-density wiring board using an electrically insulating resin tape such as FPC or TAB has been described above. However, there are other methods for manufacturing a high-density wiring board including a rigid wiring board. In the rigid wiring substrate, a hard substrate such as glass epoxy is used as the electrically insulating resin. For this reason, the manufacturing process is not a reel-to-reel method, but a method of transporting a cut substrate, but the manufacturing method of a rigid wiring board is the same as the manufacturing process of FPC and TAB described above except for the substrate transport method. Basically the same.

The problem to be solved by the present invention is to solve the problems of the prior art described in the background art. The problems to be solved by the invention are shown below.
1) To provide a new manufacturing process of a high-density wiring board that can simplify the series of high-density wiring board manufacturing processes of resist coating, resist pattern formation, chemical etching, and film peeling, and connect each process.
2) To reduce manufacturing equipment costs and manufacturing equipment costs by simplifying the manufacturing process.
3) Reduce production costs by improving product yield.
4) Achieve CO2 reduction by simplifying the manufacturing process.
5) To increase the wiring density of the high-density wiring board and to reduce the size and weight of the wiring board.
6) To increase the functionality, size and weight of electronic devices by increasing the density, size and weight of high-density wiring boards.

The effects of the present invention are as follows.
1) By simplifying a series of manufacturing processes including resist coating, resist pattern formation, chemical etching, and film removal, it is possible to connect the respective steps. This makes it possible to construct a consistent manufacturing process in parallel with a reduction in the installation area of the apparatus and equipment.
2) By simplifying the manufacturing process, it is possible to reduce manufacturing equipment costs and manufacturing equipment costs.
3) By simplifying the manufacturing process, the product yield of the high-density wiring board can be improved, and the manufacturing cost can be reduced.
4) By simplifying the manufacturing process, CO2 emitted from the manufacturing process can be reduced, thereby contributing to the protection of the global environment.
5) By further increasing the wiring density of the high-density wiring board, the wiring board can be reduced in size and weight. In conventional photochemical etching, a wiring width of 15 μm and a wiring pitch of 30 μm are the limits. However, according to the present invention, a wiring having a wiring width of 2 to 10 μm and a wiring pitch of 5 to 20 μm can be formed.
6) By increasing the density, reducing the size and weight of the wiring board, it is possible to increase the functionality and reduce the size and weight of the electronic device.

  The best mode for manufacturing a high-density wiring board by the imprint method of the present invention will be described with reference to FIG. FIG. 2A shows an apparatus configuration of a resist precoat system in which everything from the resist coat to the exfoliation is in-line. First, an imprint resist 17 is precoated on the entire surface of the metal foil 10 on the electrically insulating resin tape 9 by the imprint resist coater 14, and then a pattern is directly formed by the imprint mold 15. As shown in the drawing, an uneven pattern is formed on the imprint mold, and the imprint pattern 18 is formed by pressing and pressing this pattern against the surface of the imprint resist. As the imprint resist, a thermoplastic resist, a rubber resist, a photosensitive resist, or the like is used. As the thermoplastic resin, an acrylic resin type, a styrene resin type, and an acetate resin type can be used, and as a rubber type, a polybutadiene type or a polyisoprene type can be used. In the photosensitive resin, both a negative type and a positive type for ordinary photochemical etching can be used. In the case of a negative photocurable resin, a quartz substrate, a sapphire substrate, or the like that can transmit ultraviolet rays is used as an imprint mold. An imprint mold made using these substrates is pressed against a photocurable resin applied on a metal foil, and the resin is cured by irradiating ultraviolet rays from the upper part of the mold. Further, since the positive photosensitive resin is a photodegradable resin, it may be a mold that does not transmit ultraviolet rays. In the positive type, when ultraviolet rays are irradiated before the imprint resist is removed by the film removing apparatus 8, the film is decomposed and the film is easily removed. In either case of a thermoplastic resin or a photosensitive resin, the wiring substrate is completed through the chemical etching device 7 and the film removal device 8.

  In the imprint method using the resist precoat shown in FIG. 2A, a reverse pattern of the imprint mold is formed on the resist on the metal foil. A thin resin film usually remains in the concave portion of the reverse pattern. This is a residual film of the resist that cannot be completely removed by imprinting. Since this remaining film thickness is 1/10 or less of the convex portion, it can be removed in the previous step of chemical etching. The chemical etching apparatus 7 includes this residual film removal process, which is omitted in FIG. For removing the residual film, an alkaline aqueous solution of about PH10 or an organic solvent is used. In this residual film removal process, the resist thickness of the convex portion is also reduced, but the imprint resist can sufficiently withstand chemical etching because it is not thickly dissolved and removed as compared with the concave portion.

FIG. 2B shows a direct imprint method. In this method, since it is not necessary to use the imprint resist coater 14, the process can be further shortened. In the direct imprint method, an imprint resist is applied to an imprint mold and then directly transferred to a metal foil. In this transfer method, both a method of applying an imprint resist to the convex portion of the mold and a method of transferring the imprint resist into the concave portion of the mold are possible. When the imprint resist is filled in the concave portion of the mold, a release material treatment for preventing the imprint resin from adhering to the convex portion is performed. In FIG. 2 (b), it becomes possible to manufacture a high-density wiring in only three in-line processes of imprinting, chemical etching, and exfoliation. The direct imprint method has a feature that a residual film removal process is unnecessary.
In addition, the best embodiment is not limited to in-line in all processes from imprint to resist stripping, but also a method for in-line from resist precoat and imprint, resist imprint and chemical etching, or resist imprint to resist stripping, etc. Inline in part is also included. Some examples of the best mode will be described below.
As described above, since the imprint method does not use a photomask mask exposure machine, which is a precision optical instrument, it is possible to inline each process of the wiring board manufacturing process.

In Example 1, a method for manufacturing a high-density wiring board by a resist precoat (FIG. 2A) method using a thermoplastic resin or a thermosetting resin as an imprint resist will be described.
As the thermoplastic resin, for example, a solvent diluted resin such as an acrylic resin-based IPA (isopropyl alcohol) solution such as PMMA (polymethyl methacrylate) can be used. As the thermosetting resin, for example, an epoxy resin can be used. In the epoxy resin, a two-component compounding agent of an epoxy resin and a curing agent is used as an imprint resist.
First, a polyimide film is prepared as the electrically insulating resin tape 9, and a CCL (Copper Clad Laminate) material in which a thin copper foil is bonded as the metal foil 10 is prepared. For example, a polyimide film having a thickness of 25, 50 μm, a width of 70, 105 mm, and a length of 100 to 200 m is used. When a 9 μm or 12 μm thick copper foil is bonded to the entire surface of the polyimide film using a thermosetting epoxy adhesive or a thermoplastic adhesive such as a modified polyimide, two layers of copper foil / polyimide film are obtained. CCL is completed. In addition, the two-layer CCL is formed by sputtering a thin film of chromium or titanium on a polyimide film, further forming a copper film thereon by a vapor phase method, and then forming a copper film by electroless copper plating or electrolytic copper plating. It can also be manufactured by a method of attaching. This is called a non-adhesive material type two-layer CCL material, but this two-layer CCL material may be used. All of these materials are generally marketed for TAB, FPC and the like. This copper foil / polyimide two-layer CCL material is used in a state of being wound around a delivery reel 2 as shown in FIG.

Next, the imprint resist is precoated on the entire surface of the copper foil excluding the positioning holes 19 by using the imprint resist coater 14 while feeding the two-layer CCL material from the reel. In the two-layer CCL material, imprint positioning holes 19 are processed on both sides in the width direction by a punching method using a punching die. This positioning hole 19 is also used in photomask exposure. The imprint mold is provided with a convex portion that matches the hole pitch shape of the positioning hole of the two-layer CCL. When this convex portion is inserted into the positioning hole and aligned, the positioning is accurately performed with respect to the positioning hole. Imprinting can be performed.
The coating thickness of the imprint resist is preferably in the range of 2 to 10 μm with the solvent dried. In a thermoplastic resin, when the solvent is dried after coating, a resin film of an imprint resist is formed on the surface of the copper foil. Although drying is omitted in FIG. 2A, a drying furnace is built in the imprint resist coater 14. The film thickness of the imprint resist to be imprinted can be controlled by the resin content of the solvent-diluted resin to be precoated and the initial precoat thickness.

As shown in FIG. 2A, when an imprint resist 17 is imprinted using an imprint mold 15, an imprint pattern 18 can be formed. A nickel electroforming mold can be used as the imprint mold. For example, in the case of a CCL material having a width of 70 mm, the nickel electroforming mold has a shape having a width of 67 mm, a length of 75 mm, and a thickness of 0.5 mm. For example, a nickel electroforming mold is formed by patterning a photoresist on a quartz substrate, a titanium or chromium film is formed on the pattern by a sputtering method, and then electroforming using an electro nickel plating technique. Thereafter, the electroformed layer can be manufactured by peeling off the quartz substrate and removing the photoresist. As the imprint mold, in addition to the electroformed mold, a mold in which a pattern is formed on a quartz substrate, a sapphire substrate, a silicon wafer, or the like can be used.
FIG. 3 shows an SEM photograph of an imprint pattern using an electroforming mold. The SEM photograph of FIG. 3 shows the appearance of the pattern having the convex portions 21 having a width of 2 and 5 μm. FIG. 3 shows a case where PMMA resin is precoated to a thickness of 4 μm, the stage 16 is heated to 75 ° C., and imprinting is performed with an imprinting additional load of 3 kgf / cm 2. Stage heating is possible with a temperature-controlled electric heater with a built-in stage. By heating the stage, the PMMA resin can be softened, and imprinting can be performed with a lower load.

After the imprint pattern is formed, a copper wiring is formed by the in-line chemical etching apparatus 7, and when the imprint resist is removed by the film removing apparatus 8, the metal foil pattern 13 is exposed and the high-density wiring board 20 is completed. . For chemical etching of copper, an aqueous ferric chloride solution or an aqueous copper ammonia solution can be used. Even in the imprinting of the PMMA-based imprint resist, a thin PMMA-based resin film remains in the recessed portion of the imprint pattern, but this remaining film can be removed by simple alkali cleaning before chemical etching.
A series of processes from the imprint resist coater to the film removing apparatus can be arranged as a continuous process between the delivery reel 2 and the take-up reel 3 and inlined. Although the total length of the apparatus depends mainly on the thickness of the copper foil related to the etching time, it can be accommodated within 15 m including incidental apparatuses such as a feeding reel and a take-up reel. In the first embodiment, as a typical example, the description has been made mainly by the imprint method using the pre-coat of the PMMA resin. However, as long as the resin can withstand chemical etching, a thermoplastic resin other than the PMMA resin or a thermosetting resin may be used. Can be used. As the thermosetting resin, for example, there are a two-part epoxy resin of a resin and a curing agent. Since the epoxy resin is solvent-free, a solvent drying step is not necessary, but a heat curing process after imprinting is necessary.

In Example 2, a method for manufacturing a high-density wiring board by the direct imprint method (FIG. 2B) will be described. Also in the direct imprint method, as in Example 1, a solvent-diluted resin such as an IPA (isopropyl alcohol) solution of a PMMA (polymethyl methacrylate) resin that is a thermoplastic resin can be used as an imprint resist. As the thermosetting resin, for example, an epoxy resin can be used. In the epoxy resin, a two-component compounding agent of an epoxy resin and a curing agent is used as an imprint resist.
As in Example 1, a polyimide film is prepared as the electrically insulating resin tape 9, and a CCL material obtained by bonding a copper foil as the metal foil 10 is prepared.
Next, direct imprinting of the solvent-diluted PMMA resin is performed on the copper foil while feeding the two-layer CCL material from the reel. Like the first embodiment, the two-layer CCL has imprinting positioning holes 19 formed on both sides in the width direction by a punching method using a punching die. As in the first embodiment, the imprint mold is provided with a convex portion that matches the hole pitch shape of the positioning hole of the two-layer CCL. When this convex portion is inserted into the positioning hole 19 and aligned, the positioning hole The imprint positioned accurately can be performed. The thickness of the PMMA resin applied to the imprint mold is preferably in the range of 2 to 10 μm. When the solvent contained in the imprint resist on the copper foil is dried after imprinting, a solventless resin film is formed on the surface of the copper foil. In FIG. 2B, this drying is omitted. The resin film thickness of the imprint resist to be formed can be controlled by the resin content of the solvent-diluted resin applied to the imprint mold and the thickness applied to the mold.

In Example 2, a nickel electroforming mold can be used as the imprint mold as in Example 1. When a nickel electroforming mold is used, it is manufactured in the same manner as in Example 1. As the direct imprint mold, in addition to an electroformed mold, a mold in which a pattern is formed on a quartz substrate, a sapphire substrate, a silicon wafer, or the like can be used. A method for applying an imprint resist to these imprint molds is shown in FIG. The resist tray 25 is filled with the imprint resist 17. On top of this, there is a resist suction stage 23, which sucks up the imprint resist from the resist tray. The resist adsorption stage is made of, for example, a porous fluorine-based resin. When the imprint mold 15 is pressed onto the resist adsorption stage, the imprint resist adheres to the convex portions of the imprint mold. When the imprint mold is pulled up, the adhesion resist 24 is formed. Next, when an imprint mold is pressed onto the CCL metal foil in this state, an imprint pattern is formed. By repeating this, imprinting can be performed continuously. In the in-line, CCL feeding is stopped during imprinting, but since the imprint time is within 5 seconds, it is possible to run the CCL intermittently. Further, when it is desired to continuously run, by providing a portion for retaining a certain length of CCL before and after the imprint process, the process before and after imprint can be continuously run.
Although the direct imprint method in which the imprint resin is attached to the convex portion of the imprint mold has been described with reference to FIG. 4, a method of attaching the resin to the concave portion of the imprint mold may be used. In this case, a release material that suppresses adhesion of the imprint resin to the convex portion of the imprint mold is processed. It is effective to use a silicone-based or fluorine-based polymer material as the release material.

After the imprint pattern is formed, a copper wiring is formed by the in-line chemical etching device 7 and the imprint resist is peeled off by the film removing device 8 to complete the high-density wiring board 20. In the direct imprint method, the thin resin residual film of PMMA does not occur in the imprint pattern recess as seen in the precoat method of Example 1. For this reason, the residual film removal process is unnecessary.
A series of processes from the direct imprinting to the film peeling apparatus can be arranged as a continuous process between the delivery reel 2 and the take-up reel 3 and inlined. Although the total length of the apparatus depends mainly on the thickness of the copper foil related to the etching time, it can be accommodated within 10 m including incidental apparatuses such as a feeding reel and a take-up reel.

  In Example 3, an example of a manufacturing method by a photoimprint method using a photosensitive resin as an imprint resist will be described. In the production method by the optical imprint method, in Example 1, a photosensitive resin is used as the imprint resist. As the photosensitive resin, a photoresist which is usually used for photochemical etching can be used. The photosensitive resin includes a negative type and a positive type. In the negative type photo-curing type, an ultraviolet transmissive quartz die or sapphire die is used as the imprint die. When the imprint mold is pressed, the resin is cured by irradiating ultraviolet rays from the upper part of the mold, and then the imprint pattern is formed on the copper foil of the CCL when the imprint mold is released. In the case of a positive resist that decomposes by light irradiation, imprinting to chemical etching is performed in a yellow room where ultraviolet rays are blocked, and the imprint resist is peeled and removed by irradiating ultraviolet rays at the final resist peeling.

Negative resists include rubber and novolak resin systems containing photopolymerization initiators, and positive resists include novolak resin systems containing photodegradation sensitizers. Even in the production of a high-density wiring board by the optical imprint method, a resin residual film is formed by the pre-coat method of the imprint resist. However, since this residual resin film is thin, it can be easily removed in the residual film removal step before chemical etching.
Also in the manufacturing method of the high-density wiring board by the pre-coating method of the optical imprint resist, the entire length of the apparatus including the feeding to the winding can be within 15 m. When the imprint mold is pressed against the CCL surface coated with the imprint resist and then the imprint mold is released from the imprint resist, the imprint resist may adhere to the imprint mold. . The same applies to the case of Example 1, but in order to prevent the imprint resist from adhering, a release material treatment to the imprint mold is effective. It is effective to use a silicone-based or fluorine-based release material.
In the manufacturing method of the wiring board by the imprint method using a photosensitive resin, an ultraviolet lamp is necessary, but a mask exposure machine which is a precision optical instrument such as photochemical etching is not required. For this reason, it is possible to perform an inline process in which the steps are connected without separating and isolating the steps of the wiring board manufacturing process.

  In Example 4, an example of manufacturing a high-density wiring board using a photosensitive imprint resist in the direct imprint method will be described. In Example 2, by using a photosensitive resin as an imprint resist, direct imprinting using a photosensitive imprint resin is possible. When using a photocurable negative photosensitive imprint resist, an ultraviolet transmissive imprint mold made of quartz or sapphire is used. Further, the photodecomposition type imprint resist may be an electroforming mold that does not transmit ultraviolet rays. In the case of the negative type, when the ultraviolet ray is irradiated from the upper part of the imprint mold during imprinting, the photosensitive resin is cured and an imprint pattern that can withstand chemical etching is formed. It is also possible to cure the resin by irradiating with ultraviolet rays after releasing the imprint mold. In the case of the positive type, the imprint resist is decomposed by irradiating the imprint resist by irradiating the imprint resist with ultraviolet rays before the imprint resist is peeled off in the yellow room where ultraviolet rays are blocked. Is easy to peel off. For these negative and positive imprint resists, the same photosensitive resin as in Example 3 can be used. Even in the production of a high-density wiring board by a direct imprint method using an optical imprint resist, the total length of the apparatus from the delivery reel to the take-up reel can be kept within 10 m.

  Example 5 describes a method of manufacturing a high-density wiring board by forming a plating resist pattern by a resist imprint method and performing additive copper plating. In Example 5, a CCL material having a thin copper layer with a copper foil thickness of about 0.3 to 1.0 μm is used. This CCL material having a thin copper layer is manufactured by vapor deposition, sputtering, or electroless copper plating, and many types of CCL are commercially available. Using this material, an imprint resist pattern is formed by the same process as in the first embodiment. Thereafter, electrolytic copper plating is performed on the opening of the resist pattern to grow the copper thick. A thin copper layer of CCL material is used for the electrode for electrolytic copper plating. The required thickness of electrolytic copper plating is determined from the current carrying capacity and reliability of the high-density wiring board. After the electrolytic copper plating, the imprint resist is peeled off, and a thin copper layer of CCL directly under the imprint resist is chemically etched to form a copper wiring pattern.

The industrial field of application of the present invention is high density wiring boards for digital and analog electronic equipment in general. It can also be applied to memory card and IC card substrates.
Further, the present invention can be applied to a COF (Chip On Film) for connecting and mounting a driver IC for a liquid crystal display or other display panel. Typical digital electronic devices include digital TVs and digital cameras. In addition to motherboards, digital TVs and digital cameras have thin high-density wiring boards for packaging semiconductor chips. These thin and high-density wiring boards are also used in SIP (System In Package) that forms a system by packaging a plurality of semiconductor chips. SIP wiring boards are currently rapidly becoming smaller and higher in density to reduce the size of electronic devices. However, the conventional photochemical etching process for manufacturing this substrate is limited by the limit of the wiring density and the decrease in yield resulting from the length of the manufacturing process.
In mobile phones, it can also be applied to RF modules that are analog circuits. The modularization of amplifiers and filters in the RF circuit can reduce the size of the wiring board of the transmission / reception unit. When the size of the RF circuit is reduced along with the reduction of the size of the baseband part by SIP, the mobile phone can be further reduced in weight, thickness, and size.
Simplifying and increasing the density of the wiring board manufacturing process not only reduces the size and weight of electronic equipment, but also contributes to the protection of the global environment by reducing CO2 and waste.

Manufacturing process of high density wiring board by conventional method Manufacturing process of high-density wiring board according to the present invention Imprint pattern according to the present invention Illustration of direct imprint method

Explanation of symbols

1 MCL
2 Sending reel 3 Take-up reel 4 Photoresist coater 5 Photomask exposure machine 6 Developing device 7 Chemical etching device 8 Stripping device 9 Electrical insulating resin tape 10 Metal foil 11 Photoresist 12 Photoresist pattern 13 Metal foil pattern 14 Imprint Resist coater 15 Imprint mold 16 Stage 17 Imprint resist 18 Imprint pattern 19 Positioning hole 20 High-density wiring board 21 Imprint convex part 22 Imprint concave part 23 Resist adsorption stage 24 Adhering resist 25 Resist tray

Claims (12)

  For the production of resist patterns for chemical etching of metal foil such as copper foil or conductive additive plating such as copper in the manufacturing method of high-density wiring boards such as rigid wiring board, FPC, TAB wiring tape, Using imprint method with printing plate with micron, submicron or nanometer size pattern formed on sapphire substrate, metal substrate, etc., resist film formation on metal foil, chemical etching or additive plating, resist pattern peeling An imprinting process for forming a resist pattern is included as an inline in all or some of these processes.   In Claim 1, the resist film formation, resist pattern formation by imprint method, chemical etching, or additive plating, and further, as a final step, all steps of resist pattern peeling are a series of continuous winding methods of long materials, or A method for producing a high-density wiring board, characterized in that it is carried out by a continuous series of conveying methods for a cut plate material.   2. The resist pattern formation according to claim 1, wherein the resist pattern formation and the resist pattern formation by the imprint method are performed by a continuous series of winding methods of a long material or a continuous series of conveyance methods of a cut plate material. The manufacturing method of a high-density wiring board.   In Claim 1, resist pattern formation by imprint method and chemical etching or additive plating such as copper are performed by a continuous series of winding methods of a long material or a continuous series of conveyance methods of a cut plate material. A method for producing a high-density wiring board, characterized in that   In Claim 1, the resist pattern formation by the imprint method, and chemical etching or additive plating such as copper, and stripping of the resist pattern are a series of continuous winding methods of a long material or continuous cutting of a plate material. A method for manufacturing a high-density wiring board, which is performed by a series of transport methods.   Form micron, submicron, or nanometer size patterns on quartz, sapphire, and metal substrates for chemical etching of metal foil such as copper foil or conductive additive plating such as copper In order to form a resist pattern, an imprint method using a printing plate is used, and further, a resist film formation on a metal foil, chemical etching, or additive plating, a resist pattern peeling process, or a part of these processes. The high-density wiring board manufactured using the method for manufacturing a high-density wiring board according to claim 1, wherein the imprinting process is included as in-line.   Resist film formation, resist pattern formation by imprint method, chemical etching, or additive plating, and as a final step, the entire resist pattern peeling process is a series of continuous winding of long material, or cut plate material The high-density wiring board manufactured using the manufacturing method of the high-density wiring board according to claim 2, wherein the high-density wiring board is manufactured by a continuous series of transport methods.   The resist film formation and the resist pattern formation by the imprint method are performed by a continuous series of winding methods of a long material or a continuous series of conveyance methods of a cut plate material. A high-density wiring board manufactured using the method for manufacturing a high-density wiring board described.   Resist pattern formation by imprint method and chemical etching or additive plating such as copper are performed by a continuous series of winding methods for long materials or a continuous series of conveying methods for cut plate materials A high-density wiring board manufactured using the method for manufacturing a high-density wiring board according to claim 4.   Resist pattern formation by imprinting method, chemical etching or additive plating such as copper, and stripping of resist pattern is a series of continuous winding of long material, or a series of continuous transporting of cut plate material A high-density wiring board manufactured by using the method for manufacturing a high-density wiring board according to claim 5.   Claims 6, 7, 8, 9, and 10 are mounted with passive elements such as resistors, capacitors, and inductors, semiconductor elements such as IC, LSI, and VLSI, and functional elements such as sensors and antennas. Electronic equipment. A small and high-performance electronic device, such as a mobile phone, a personal computer, or a digital camera, incorporating the electronic device according to claim 11.

Images