JPS6344794A - Transcripting material for printed wiring board and printed wiring board employing the transcripting material and manufacture of the printed wiring board - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a transfer material for a printed wiring board, which forms a circuit by transfer onto the surface of the printed wiring board at the same time as forming the printed wiring board, and the transfer material. The present invention relates to a printed wiring board using the material and a method for manufacturing the same.

<Conventional technology> Conventionally, methods for manufacturing printed wiring boards include a method of attaching copper foil to a base material such as glass epoxy or phenol, and forming a circuit by etching the copper foil (subtract method); There were methods to form circuits on the base material using electrolytic plating or electrolytic plating (additive method), methods to form circuits on the base material by screen printing using conductive ink, etc. However, these methods did not work. In order to attach it to a product, it was necessary to perform post-processing such as drilling holes in the printed wiring board, attaching bosses, and punching out the outer shape.

To solve this problem, heat-resistant thermoplastic resin is used to mold the base material for printed wiring boards by injection molding, and rough holes and bosses are provided in the base material to eliminate the need for post-processing. After that, there was a method of forming circuits on the surface of the substrate using additive screen printing.

However, since additive methods and screen printing methods are mainly applied to flat surfaces, they cannot be applied to three-dimensional objects. Furthermore, the subtract method and the additive method involve many manufacturing steps such as providing and removing a resist layer, which are complicated.

Therefore, the present applicant previously developed a transfer material with a circuit pattern layer formed thereon as a method to make it possible to form a circuit on a three-dimensional object and to rationally shorten the manufacturing process by forming the circuit at the same time as forming the base material. A method of obtaining a printed wiring board by placing the resin in an injection mold and then injecting a molten heat-resistant thermoplastic resin into the mold (Japanese Patent Laid-Open No. 60-121
(see Publication No. 791).

<Problems to be solved by the invention> However, resins that satisfy the mechanical strength, heat resistance, and electrical properties required as base materials for printed wiring boards are limited to thermoplastic resins with a high melting temperature. As a condition for injection molding, it is necessary to set the mold temperature and resin temperature higher than when injection molding ordinary resins. Furthermore, the resins used in ordinary transfer materials have low melting temperatures, such as thermoplastic acrylic resins and vinyl chloride.

Therefore, the above method had the following drawbacks.

(al) If a transfer material with a circuit pattern layer and an adhesive layer formed using general plastic resin as a binder is created and placed in an injection mold for simultaneous molding transfer, the molten material injected during injection molding will The circuit pattern layer and adhesive layer melt and flow together with the resin.

(b1 If a thermosetting resin is used as a binder to sufficiently harden the circuit pattern layer to prevent the circuit pattern layer from melting, and the same molding and simultaneous transfer is performed, in this case, the circuit pattern layer will not melt. However, the adhesive strength between the molding resin and the printed wiring board is very weak, making it unusable even after transfer.Also, if you create a transfer material with the circuit pattern layer in a semi-cured state, the pattern will deteriorate depending on the progress of curing. Although the layer does not melt and excellent adhesion between the molded resin and the printed wiring board can be obtained, it is difficult to control the layer to a suitable semi-cured state.

The present invention provides a transfer material for printed wiring boards that eliminates the above-mentioned drawbacks, enables the formation of circuits on three-dimensional objects, and shortens the manufacturing process by forming the circuits at the same time as forming the substrate, and provides a transfer material using the transfer material. The purpose of this invention is to provide a printed wiring board and its manufacturing method.

<Means for Solving the Problems> In order to achieve the object, the present invention has the following configuration. That is, the transfer material for printed wiring according to the present invention is a transfer material in which a circuit pattern layer is provided on a base sheet and an adhesive layer (M) is provided on top of the circuit pattern layer, in which the main component of the adhesive layer is thermosetting and ultraviolet curing. This transfer material for printed wiring boards is characterized by being made of a resin having both properties.

Further, the printed wiring board according to the present invention is a printed wiring board in which an adhesive layer is formed on a printed wiring board base material and a circuit pattern layer is further formed on the printed wiring board, in which the main component of the adhesive layer is thermosetting and ultraviolet curing. This printed wiring board is characterized in that it is made of a resin that has both of the following properties.

In addition, in the method for manufacturing a printed wiring board according to the present invention, a circuit pattern layer is provided on a base sheet, and an adhesive layer is further provided on top of the circuit pattern layer.The main component of the adhesive layer of the transfer material is both thermosetting and ultraviolet curing. Place the marking W11 wiring board transfer material made of resin with the properties in an injection mold,
The mold is closed, the molten resin is injected, the molten resin is assimilated, the mold is opened, and the base sheet is peeled off to form a circuit pattern layer on the surface of the printed wiring board substrate, which is then cured by the heat during injection molding. This is a method for manufacturing a printed wiring board, which is characterized by performing post-heating if necessary.

First, the transfer material for printed wiring boards according to the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a transfer material according to the present invention. 1 is a base sheet, 9 is a circuit pattern layer,
This circuit pattern layer consists of a conductive pattern layer 2.4.6 and a one-color border layer 3.5. 8 is an adhesive layer.

What is important about the transfer material according to the present invention is that the main component of the adhesive N8 formed to cover the circuit pattern layer 9 is composed of a resin that has both thermosetting and ultraviolet curing properties. .

By using this resin, it is easy to control the semi-hardened state by ultraviolet drying during printing, and when the molten injection molding resin comes into contact with the adhesive layer 8 of the transfer material, the adhesive layer 8 melts. Thermal curing progresses without causing any damage, resulting in strong adhesion.

Examples of such thermoplastic resins for injection molding include polysulfone, polyethersulfone, polyetherimide, polyamideimide, polyallylsulfone, polyarylate, polyphenylene oxide, polyphenylene sulfide sun, polycarbonate, and polyamide.

The base sheet 1 may be made of heat-resistant polyester film, polyimide film, polyethersulfone film, polyetheretherketone film, polyphenylene sulfide film, polymethylpentene film, polyethylene film, polypropylene film, etc. alone or in a laminate. use. Also,
If necessary, perform mold release treatment such as silicon treatment.

The conductive pattern layers 2, 4, and 6 are formed by printing conductive ink. As the binder for the conductive ink, thermoplastic resins such as heat-resistant polyethersulfone or polysulfone, polyetherimide, polyamideimide, polyallylsulfone, polyarylate, polyphenylene oxide, polyphenylene sulfone, polycarbonate, polyamide, etc. Use hardening resins such as epoxy, phenol, polyester, and acrylic.

As the conductive powder of the conductive ink, a metal or an inorganic conductive powder such as silver, aluminum, copper, nickel, gold, carbon, graphite, or one coated with a metal on the surface of glass beads is used.

Solvents are selected appropriately, and the solvents are mixed uniformly to create a conductive ink. Further, some surfactants, chicken-like additives, etc. may be added to the ink to improve its performance as a printing ink.

The insulating layers 3 and 5 are formed on the entire surface or in a pattern by printing or coating with insulating ink. As the binder for the insulating ink, thermoplastic resins such as polyethersulfone or polysulfone, polyetherimide, polyamideimide, polyallylsulfone, polyarylate, polyphenylene oxide, polyphenylene sulfone, polycarbonate, and polyamide are used as binders for the insulating ink. Alternatively, use a hardening resin such as epoxy, phenol, urethane, polyester, or acrylic.

Further, if necessary, an insulating powder is used for the insulating ink, an appropriate solvent is selected, and the insulating ink is prepared by uniformly mixing these powders. As the insulating powder, inorganic powders such as dichromium oxide, alumina, silicon dioxide, zirconium oxide, magnesium oxide, beryllium oxide, boron nitride, mica, magnesium silicate, and steatite can be used. Further, some surfactants, chicken-like additives, etc. may be added to the ink to improve its performance as a printing ink.

Note that the circuit pattern layer 9 consisting of the conductive pattern layers 2, 4, and 6 and the insulating layers 3 and 5 is made of a conductive ink and/or a heavy-duty ink whose binder is a resin having both thermosetting and ultraviolet curing properties. It can also be formed using color edge ink.

Next, the printed wiring board and the manufacturing method thereof according to the present invention will be explained in detail.

First, the transfer material is fixed at a predetermined position within an injection mold. At this time, the surface of the transfer material on which the adhesive layer is provided is fixed in a direction in which it contacts the molten resin, which will be described later.

Next, after closing the injection mold, molten resin is injected. Injection conditions vary depending on the type of resin and the shape of the mold, and are approximately mold temperature 80-180℃, resin temperature 250-40℃.
It is in the range of 00°C.

Resins that can be used in the present invention are resins with sufficient heat resistance and electrical properties, such as polyethersulfone, polyetherimide, polyetheretherketone, polysulfone, polyarylate, polybutylene terephthalate, Thermoplastic resins such as polyethylene terephthalate can be used. In addition, additives such as glass fiber, mica, talc, titanium oxide, etc. may be added to these resins as appropriate to adjust the properties of the materials.

After injecting the molten resin, it is cooled, the mold is opened, and the molded product is taken out. At that time, by peeling off the base sheet, a printed wiring board can be obtained (see FIG. 2).

In addition, excellent adhesive strength can be obtained by further performing heat treatment if necessary.

<Example> Examples of the present invention are shown below.

A thermosetting silver paste (epoxy binder) is screen printed on a 38 μm thick polyethylene terephthalate film base sheet that has been subjected to a solicon mold release treatment, and then cured. A transfer material for a printed wiring board was prepared by screen-printing the material and curing it to a B-stage state by irradiating ultraviolet rays (see FIG. 3).

This transfer material was aligned and placed on an injection mold, the mold was closed, and polyether sulfone resin was injected under the following conditions. After the resin hardens, open the mold and take out the molded product.
Base sheet:? When subjected to IIIM, there was no melting of the circuit pattern layer, and by heat treatment at 150'C for 30 minutes, a printed wiring board was obtained in which a circuit pattern layer with strong adhesion was formed.

In addition, when soldering was carried out using the solder dip method under the conditions of 260'C and 3 seconds, the solder was evenly applied to the areas where the grudge paste was printed, and no swelling or loss of adhesive strength occurred in other areas due to heat. There wasn't.

Injection conditions (using JC150SA made by Japan Steel Works) Mold temperature: 100-120℃ Norinda temperature: 350-380℃ Injection pressure
99% holding force
70-73% injection speed 9
9% screw rotation speed 5Orpm〈
Effects of the Invention> The present invention has the following excellent effects.

(4) The adhesive layer of the transfer material for printed wiring boards is composed of a resin that has both thermosetting and ultraviolet curing properties, and the transfer material is semi-cured only by ultraviolet irradiation, so printed wiring When a transfer material is installed in an injection mold and simultaneous transfer is performed during molding, it is easy to prevent the adhesive layer from flowing together with the resin injected during injection molding.

(b) In the case of molding simultaneous transfer, since the injection molding resin is in a molten state, it functions as an adhesive, and when the adhesive layer of the transfer material and the molten resin for injection molding come into contact, the adhesive layer does not flow during injection molding. By proceeding with curing with heat, strong adhesiveness can be obtained, and even better adhesive strength can be obtained by applying heat treatment as necessary.

If not only the adhesive layer of the transfer material for FCL printed wiring boards but also the circuit pattern layer is made of a resin that has both heat-curing and ultraviolet curing properties, overprinting can be performed only by ultraviolet irradiation, and the curing time can be shortened. It can be very shortened.

Since the present invention has the above-mentioned excellent effects, the present invention provides a transfer material for a printed wiring board that enables circuit formation on a three-dimensional object and shortens the manufacturing process by forming the circuit at the same time as forming the substrate, and the transfer material for the printed wiring board. A printed wiring board using the material and a method for manufacturing the same are obtained.

[Brief explanation of the drawing]

The drawings differ from the actual dimensional relationships in order to clarify the components. FIG. 1 is a sectional view showing an embodiment of a transfer material for printed wiring boards according to the present invention. FIG. 2 is a sectional view showing an embodiment of the printed wiring board according to the present invention. FIG. 3 is a sectional view showing a transfer material for a printed wiring board according to an embodiment of the present invention. 1...Base sheet 2.4.6...Conductive pattern layer 3, 5...1 color edge layer 8...Adhesive layer 9...Circuit pattern layer 10...Printed wiring board base material No. 1 Figure 2 Figure 3

Claims (6)

[Claims] (1) In a transfer material in which a circuit pattern layer is provided on a base sheet and an adhesive layer is further provided on top of the circuit pattern layer, the main component of the adhesive layer is composed of a resin that has both thermosetting and ultraviolet curing properties. A transfer material for printed wiring boards characterized by: (2) Claim 1, characterized in that the circuit pattern layer is composed of a conductive ink and/or an insulating ink whose binder is a resin having both thermosetting and ultraviolet curing properties. Transfer material for printed wiring boards as described in . (3) In a printed wiring board in which an adhesive layer is formed on a printed wiring board base material and a circuit pattern layer is further formed on the adhesive layer, the main component of the adhesive layer is a resin that has both thermosetting and ultraviolet curing properties. A printed wiring board characterized by comprising: (4) Claim 3, characterized in that the circuit pattern layer is composed of conductive ink and/or insulating ink whose binder is a resin that has both thermosetting and ultraviolet curing properties. Printed wiring board as described in Section. (5) The main component of the adhesive layer of a transfer material in which a circuit pattern layer is provided on a base sheet and an adhesive layer is further provided on top of the circuit pattern layer is composed of a resin that has both thermosetting and ultraviolet curing properties. The printed wiring board is produced by placing the printed wiring board transfer material in an injection mold, closing the mold, injecting the molten resin, opening the mold after the molten resin has solidified, and peeling off the base sheet. A method for manufacturing a printed wiring board, characterized by forming a circuit pattern layer on the surface of a base material. (6) The circuit pattern layer is composed of a conductive ink and an insulating ink using a resin having both thermosetting and ultraviolet curing properties as a binder. Manufacturing method for printed wiring boards.