JPS62179198A - Transcription material for printed circuit board and printed circuit board using the transcription material and manufacture of the same - Google Patents

Abstract

(57) [Summary] 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 provides a method for forming a printed circuit board at the same time as forming the printed wiring board.
+5. The present invention relates to a transfer material for a printed wiring board on which a circuit is formed by transfer on the surface of the printed wiring board, a printed wiring board using the transfer 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), and methods to form circuits on the base material by screen printing using conductive ink. However, these methods In order to attach it to a product, it was necessary to perform post-processing such as drilling holes, adding ribs, and punching out the outer shape of the printed wiring board.

A method to solve this problem is to use heat-resistant thermoplastic resin and mold the base material for printed wiring boards by injection molding, and provide rough holes and ribs on the base plate, eliminating the need for post-processing. There is a method in which a circuit is formed on the surface of the substrate by an additive screen printing method.

However, the additive method and the screen mark 111 method are techniques that are mainly used for flat surfaces and cannot be used for 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 conventional transfer materials have low melting temperatures, such as acrylic and vinyl chloride resins.

Therefore, the above method had the following drawbacks.

+a+ When a transfer material on which a circuit pattern layer and an adhesive layer are formed using general plastic resin as a binder is created and placed in an injection mold for simultaneous molding transfer, the molten resin injected during injection molding At the same time, the circuit pattern layer and adhesive layer melt and flow.

fb1 circuit circuit - turf layer Using a thermosetting resin as a binder to prevent melting, a transfer material is created in which the circuit pattern layer is hardened in 1 minute, and when molding and simultaneous transfer is performed in the same way, in this case, the circuit pattern layer melts. Although this does not occur, the adhesive strength between the molding resin and the printed wiring board is so weak that it cannot be used even after transfer.

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

Means for Solving the Problems> In order to achieve the object, the present invention has the following configuration. That is, in the transfer material for printed wiring according to the present invention, in a transfer material in which a circuit pattern layer is provided on a base sheet and an adhesive layer is further provided thereon, the main component of the adhesive layer is thermally deformed at 120 to 300°C. This is a transfer material for a printed wiring board, characterized in that it is made of a thermoplastic resin that initiates.

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 base material, and the main component of the adhesive layer is 120 to 3
This is a printed wiring board characterized in that it is made of a thermoplastic resin that starts thermal deformation at 00°C.

In addition, in the method for manufacturing a printed wiring board according to the present invention, the main component of the adhesive layer of the transfer material, in which a circuit pattern layer is provided on a base sheet and an adhesive layer is further provided thereon, is thermally deformed at 120 to 300°C. Place a printed wiring board transfer material made of a thermoplastic resin in an injection mold,
Close the mold, inject the molten resin, open the mold after the molten resin has solidified, and sort the substrates! , 11. This is a method for manufacturing a printed wiring board, characterized in that a circuit pattern layer is formed on the surface of a printed wiring board substrate by separating the printed wiring board by 11 times.

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 is composed of conductive pattern layers 2, 4.6 and an insulating 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 layer 8 formed to cover the circuit pattern layer 9 is 12
It is made of a thermoplastic resin that starts thermal deformation at 0 to 300°C, preferably 150 to 250°C. This is because when the molten injection molding resin comes into contact with the adhesive N8 of the transfer material, the adhesive layer 8 softens slightly without melting, thereby making the adhesive stronger. Examples of such koplastic resins include polysulfone, polyether sulfone, polyetherimide, polyimide amide, polyallylsulfone, polyarylate, polyphenylene oxide, polyphenylene sulfone, polycarbonate,
There are polyamides, etc.

The base sheet l may be made of heat-resistant polyester film, polyimide film, polyether sulfone film, polyether ether ketone film, polyphenylene sulfide film, polymethylpentene film, polyethylene film, polypropylene film, etc. alone or laminated. 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.

A conductive ink is prepared by selecting an appropriate solvent and uniformly mixing these solvents. Further, some surfactants, chicken-like additives, etc. may be added to the ink to improve its performance as a printing ink.

Insulating layers 3 and 5 are '4t! ! Formed on the entire surface or in a pattern by printing or coating with edge ink. As the binder for the insulating ink, thermoplastics such as polyethersulfone or polysulfone, polyetherimide, polyamideimide, polyallylsulfone, polyarylate, polyphenylene oxide, polyphenylene sulfone, polycarbonate, polyamide, etc. can be used as the binder for the conductive pattern layer. resin or epochino, phenol,
Use a hardening resin such as 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, helium 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, 6 and the insulating layers 3, 5 has a thermal deformation start temperature of 1.
When formed using a tetraelectric ink and/or an insulating ink using a thermoplastic resin or curable resin that is heat resistant to 20° C. or more as a binder, a printed wiring board with excellent IT heat resistance can be obtained.

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 this time, by separating the base sheets by 11 degrees, a printed wiring board can be obtained (see FIG. 2).

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

First Example A silver paste (thermosetting phenol binder) and an insulating paste of thermosetting epoxy resin were printed on a base sheet which had been subjected to mold release treatment by coating a polyethylene terephthalate film with a thickness of 38 μm with epoxy resin. , silver paste (thermosetting phenol binder) was successively screen printed, and finally adhesive ink of Composition 1 was printed on the entire surface, followed by heat treatment to create a transfer material for printed wiring boards (see Figure 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 solidified, the mold was opened, the molded product was taken out, and the base sheet was peeled off, and the pattern did not melt.
In addition, a printed wiring board having two conductive pattern layers with strong adhesion was obtained.

Continuity between the conductive pattern layers was tested and found to be good.

Moreover, all the parts that should be insulated were insulated, and the resistance value was 1X10''Ω or more.

Composition l (wt%) Polysulfone 30 Aerosil (manufactured by Nippon Aerosil Co., Ltd.) 5 Container (cyclohexanone;)'narcellosol acetate) 65 Injection conditions (Japan Steel New JC150SΔ) Mold temperature
100~120℃ cylinder temperature
350~380℃ injection pressure
99% holding force 70
~73% injection speed 99% screw rotation speed 5 Orpm Second fruit pupil Silver paste (epoxy binder) is screen printed on a 38 μm thick polyethylene terephthalate film base sheet that has been subjected to silicone mold release treatment, and then A transfer material for a printed wiring board was prepared by screen-printing an adhesive ink of composition 2 and heat-treating it (see FIG. 4).

When a molded product was produced using this transfer material in the same manner as in Example I, a printed wiring board was obtained in which the circuit pattern layer did not melt and had a circuit pattern layer with strong adhesion.

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

Composition 2 (wt%) Polyether sulfone 30 Alumina A transfer material for a printed wiring board having a structure similar to that of Example 2 was prepared by sequentially overprinting adhesive paste and adhesive ink by screen printing, and then heat treatment and drying.

When a molded product was produced using this transfer material in the same manner as in Example 1, a printed circuit board was obtained in which a circuit pattern layer was formed with no melting of the pattern and strong adhesion. When the resistance value was measured, it was found to be less than 10Ω for a pattern with a width of 1 am and a length of 100 dragons.

Composition 3 (1% by weight) Polysulfone 101 (flake) 67) 6 agents (cyclohexanone;) tylcellosol acetate) 23 <Effects of the Invention> The present invention has the following excellent effects.

The adhesive layer of the transfer material for fal printed wiring board is 120-300℃
Since it is made of thermoplastic resin that starts deforming due to heat, even if the printed wiring transfer material is installed in the injection mold and simultaneous molding transfer is performed, the adhesive layer will be removed together with the resin injected during injection molding. It doesn't flow.

(Since the bl injection molding resin is in a /8 melting 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 only softens slightly, and the adhesive layer melts.) No, the adhesive strength is very strong.

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 the substrate is formed, 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 drawings]

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. The second leap 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 a first embodiment of the present invention. FIG. 4 is a sectional view showing a transfer material for a printed wiring board according to a second embodiment of the present invention. ■...Base sheet 2.4.6...First conductive pattern layer 3.5...First insulating layer 8...Adhesive layer 9...Circuit pattern layer 10...Printed wiring board base material

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 a thermoplastic resin that starts to thermally deform at 120 to 300°C. A transfer material for printed wiring boards characterized by: (2) The circuit pattern layer is formed of a conductive ink and/or an insulating ink whose binder is a heat-resistant thermoplastic resin or curable resin with a heat deformation onset temperature of 120° C. or higher. A transfer material for printed wiring boards according to claim 1. (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 thermoplastic resin that starts to thermally deform at 120 to 300°C. A printed wiring board characterized by comprising: (4) The circuit pattern layer is formed of a conductive ink and/or an insulating ink whose binder is a heat-resistant thermoplastic resin or curable resin with a heat deformation onset temperature of 120° C. or higher. A printed wiring board according to claim 3. (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 1.
A printed wiring board transfer material made of a thermoplastic resin that starts deforming due to heat at 20 to 300°C is placed in an injection mold, the mold is closed, and the molten resin is injected. 1. A method for manufacturing a printed wiring board, which comprises opening the mold after solidification and peeling off the base sheet to form a circuit pattern layer on the surface of the printed wiring board substrate. (6) A patent claim characterized in that the circuit pattern layer is formed of a conductive ink and an insulating ink using a heat-resistant thermoplastic resin or a curable resin as a binder with a heat deformation onset temperature of 120°C or higher. A method for manufacturing a printed wiring board according to scope 5.