JPS62291994A - Foil and method for transcription of circuit - 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] [Field of the Invention] The present invention relates to a circuit transfer foil and a transfer method, and more particularly to a circuit transfer foil that can be connected to other electrical circuits, electrical components, electrical equipment, etc. by soldering, and the circuit transfer foil. This is related to the circuit transfer method used.

[Technical background of the invention]

Conventionally, as a method for forming an electric circuit having conductive paths made of conductive resin on a wiring board or the like, as shown in FIG. A method of forming a circuit 5 by laminating it on the transfer body 2 and transferring only the circuit portion onto the transfer body 2 using a heating plate 4 having a pattern 3 that can heat and press only the circuit pattern portion (transfer portion). Kaisho 55-141789
No.) is known.

Such an electric circuit 5 is often connected to other electric circuits, electric parts, electric equipment, etc. by soldering, but the electric circuit 5 transferred and formed with the above-mentioned conductive resin is The drawback was that it was impossible to connect electrical circuits, electrical components, electrical equipment, etc. with solder. That is, the conductive resin such as the conductive coating film that becomes the conduction path of the electric circuit 5 as described above is generally made by adding an appropriate amount of conductive particles to the resin to impart conductivity to the resin. When the amount of the conductive particles added is small, the conductivity of the conductive resin provided with such conductive particles tends to improve as the amount of the conductive particles added increases; As the amount of added particles increases,
It is known that conductivity tends to decrease as the contact resistance between particles increases.

Even in conductive resin, if a large amount of conductive metal particles is added, soldering becomes possible, but as mentioned above, if the amount of metal particles added is such that it can be soldered, the resistance of the electric circuit will increase. The disadvantage is that the value increases and the characteristic values necessary for the circuit cannot be satisfied, and as a result, at present, transfer circuits made of conductive resin that can be soldered have not been put to practical use.

[Summary of the invention]

The present invention has been made in view of the above points, and provides a circuit transfer foil capable of transferring an electric circuit using a conductive resin having good conductivity and soldering as a conductive path, and a circuit transfer foil for transferring the electric circuit. The purpose of this invention is to provide a transfer method.

Therefore, the circuit transfer foil according to the present invention contains 500 to 2000 conductive particles per 100 parts by weight of resin in the support film.
Adding parts by weight to basically form a conductive coating film for solder having easy peelability from the support film immediately after heating and pressurizing,
This conductive coating film for solder is characterized by laminating a basic conductive coating film for conductive path by adding 500 to 1000 parts by weight of conductive particles to 100 parts by weight of resin. .

Further, the circuit transfer method according to the present invention basically consists of adding 500 to 2,000 parts by weight of conductive particles to 100 parts by weight of resin to the support film, so that the conductive particles can be easily separated from the support film immediately after heating and pressing. A conductive coating film for soldering is provided, and 500 to 1000 parts by weight of conductive particles are added to 100 parts by weight of resin to the conductive coating film for soldering, and it is applied to the transfer target by heating and pressing. A circuit transfer foil with M1 layers of conductive coating film for conductive paths to be adhered is laminated so that the conductive coating film for conductive paths is in close contact with the object to be transferred, and only the desired circuit pattern portion is heated and pressurized to cover the electric circuit. It is characterized by being transferred onto a transfer body.

In the circuit transfer foil and circuit transfer method according to the present invention, a conductive coating film with a high metal content is provided on a support film,
Since a conductive path-forming conductive coating film is further formed on this conductive coating film, there is an advantage that soldering is possible and an electrical circuit with good conductivity can be formed by transfer.

[Detailed description of the invention]

As shown in FIG. 1, the circuit transfer foil according to the present invention has a conductive coating film 12 for soldering at a predetermined position on a support film 1), and a conductive coating film 12 for conductive paths. It has a structure in which conductive coating films 13 are laminated.

The support film 1) on which the conductive coating film 12 for soldering is laminated is not fundamentally limited in the present invention, and has good adhesion to the conductive coating film 12 for soldering at room temperature. , it is effective to use a synthetic resin film that easily separates from the conductive coating film 12 for soldering immediately after heating and pressurizing, has heat resistance or smoothness, and is not attacked by the solvent contained in the conductive coating film. It can be used for.

Specific examples of the support film 1 include plastic films such as polyester films, polyimide films, and bopropylene films, and aluminum foil.

Such a conductive coating film 12 for solder is laminated on the support film 1) using a conductive paint having a higher content of metal particles than the conductive coating film 13 for conductive paths described below. Since this conductive coating film for soldering is a part to be soldered, unlike the conductive coating film 13 for conductive paths, conductivity is not so much of a problem, and good solder can be formed. It is required to have good adhesive strength with the conductive coating film 13 and to be easily peeled off from the support film 1 immediately after heating.

Examples of resins that satisfy these conditions include acrylic, polyamide, epoxy, polyether, and polyester resins, cyclized rubber,
One or more types of chlorinated rubber, rosin, etc., for example, MEK
, MIBK, ketone solvents such as cyclohexanone,
Aromatic hydrocarbon solvents such as toluene and xylene, IP
A, alcohol solvents such as butanol, ether solvents, ester solvents, DMF as others,
It can be a conductive coating provided by a resin solution dissolved in one or more solvents such as N-methylpyrrolidone.

In particular, in the case of ordinary soldering (conducted at about 260° C.), it is necessary to use a heat-resistant resin, a thermoplastic resin with a high softening point, or a thermosetting resin.

Such resin solutions include polyether salvone,
A resin solution can be used in which one or more heat-resistant resins such as polysalvon and polyetherimide are dissolved in one or more solvents such as DMI, N-methylpyrylidone, and D-sol.

Furthermore, it is clear that metal particles with good solderability are preferable as the metal particles added to this resin solution.

In general, metal particles having a smaller ionization tendency than hydrogen are preferred. Examples of such metal particles include gold, silver,
It can be one or more of metal particles such as platinum, copper, nickel, and tin, or composites and alloy powders whose surfaces are coated with the above metals.

Furthermore, the amount of metal particles added to the conductive coating film 12 for solder is 500 to 2000 parts by weight based on 100 parts by weight of the resin. If it is less than 500 parts by weight, the metal particle content is too small and soldering becomes difficult, while if it exceeds 2000 parts by weight, the conductive amount for the conductive path is 1! i! 13 and the support film 1 becomes poor, and
This is because it becomes brittle and cannot be put to practical use, and furthermore, it has the disadvantage of increasing cost.

Further, the particle size of the metal particles is preferably 0.3 to 1O
It would be better if it was μ seagull.

Basically, the thickness of the conductive coating film 12 for soldering is sufficient as long as it has sufficient solderability and coating properties. Therefore, the thickness of this conductive coating film 12 for soldering is preferably 1 μm.

The conductive coating film 13 for a conductive path, which is layered on the conductive coating film 12 for solder, has the conductivity required for a circuit having a conductive path filled with conductive particles of this type, that is, a surface resistance of 1Ω/
It has a conductivity of 4 or less, and also has basic performance as a transfer foil, such as adhesion to the transferred object 2 with sufficient strength without destroying the circuit pattern immediately after heating and pressing only the circuit pattern part. It is necessary to satisfy various conditions such as:

In order to satisfy these conditions, it is necessary to improve the resin (solvent and solute) that is the base material of the conductive coating film for solder and the conductive coating film for conductive paths, as well as the conductive particles added to this resin. It is important to select the type, etc., and it is also necessary to consider the amount of conductive particles added and the particle size. The resin serving as the base material of such a conductive paint is a resin component (solute) that adheres well to the conductive paint film 12 for soldering and can be transferred to the object immediately after heating and pressing, such as an acrylic resin. ,
One or more types of polyamide, epoxy, polyether, polyester resins, cyclized rubber, chlorinated rubber, rosin, etc., for example, MEK.

? 1rBK, ketone solvents such as cyclohexanone, aromatic hydrocarbon solvents such as toluene and xylene, rpA1
It can be a resin solution dissolved in one or more of alcohol solvents such as butanol, ether solvents, ester solvents, and other solvents such as DMF and N-methylpyrrolidone.

Further, when the above-mentioned contact portion 2 is soldered by ordinary soldering, it can be made of a heat-resistant resin, a thermoplastic resin or a thermosetting resin with a high softening point. Such a resin solution may be a resin solution in which one or more heat-resistant resins such as polyethersulfone, polysulfone, and polyetherimide are dissolved in one or more solvents such as DMF, NMP, and cyclohexane. .

The conductive particles added to the resin solution are not fundamentally limited in the present invention as long as they can be uniformly dispersed in the resin solution and impart good conductivity.

For example, gold, silver, platinum, copper, nickel, aluminum,
It can be one or more of metal particles such as tin and zinc, composites and alloy powders whose surfaces are coated with the above-mentioned metals, and carbon particles.

Such conductive particles are used in an amount of 50 parts by weight per 100 parts by weight of the resin.
Add 0 to 1000 parts by weight. If it is less than 500 parts by weight, the surface resistance required for a circuit filled with conductive particles is 1.
It becomes difficult to reduce the amount to Ω/4 or less, while if it exceeds 1,000 parts by weight, the conductivity decreases and there is a risk that sufficient adhesive strength may not be achieved.

The particle size of the conductive particles is preferably 10 μm or less.

This is because if the thickness exceeds 10 μm, problems tend to occur during painting.

The conductive paint for circuit patterns may optionally contain other additives,
For example, antioxidants, dispersants, etc. can be added.

This conductive coating film 13 for conductive path is preferably laminated on the conductive coating film 12 for solder to a thickness of 15 to 30 μm. If the thickness of the conductive coating film for the conductive path is thinner than 15 μm, a large amount of conductive particles must be filled in order to obtain the above-mentioned conductivity of 1Ω/hole or less, and the adhesive strength of the circuit may deteriorate. On the other hand, if it exceeds 30 μm, the cutting of the conductive coating film I3 for the conductive path becomes worse, and there is a possibility that the circuit pattern cannot be transferred to the transfer target 2.

The present invention also provides a transfer method using such a circuit transfer foil.

According to the circuit transfer method according to the present invention, as shown in FIG.
The surface provided with is brought into contact with the transfer target 2, and the circuit pattern 3 is
The circuit 5 is transferred to the transferred object 2 by heating and pressing only the circuit pattern 3 using a heating plate 4 on which the circuit pattern 3 is formed.

Any object may be used as the transfer object 2 as long as the conductive coating film 13 can be well adhered thereto. For example, ABS, AS, IIIPS, polyacecool,
It can be general-purpose resins and films such as thermoplastic resins such as vinyl chloride, nylon, polycarbonate, and polyethylene, or high-performance engineering plastics such as polyethersulfone and polysulfone.

The heating and pressurizing method is not limited in the present invention, and various means can be used. for example,
Transfer can be performed by heating and pressing using a heat roll, heat press, etc.

When the circuit 5 is formed by transfer in this way, the transfer is usually carried out at a temperature of 80 to 300° C. and a pressure of 5 to 10 kg/cj, although the resin used is limited.

If the transfer temperature is lower than 80°C, there is a risk that the conductive coatings 12 and 13 of the circuit transfer foil 1 will not be transferred;
If the temperature is higher than 0.degree. C., there is a possibility that warping, thermal contraction, thermal deterioration, etc. may occur in the transferred object 2.

Furthermore, if the transfer pressure is less than 5 kg/cwt, there is a risk that the conductive coating films 12 and 13 will not be transferred in accordance with the circuit pattern 3 depending on the resin used; This is because there is a risk that the circuit 5 that has been removed may collapse.

After the circuit 5 is transferred to the transfer target 2 as described above, the support film 1) of the circuit transfer foil 1 is peeled off, and the circuit 5 is formed on the transfer target 2. At this time, the conductive coating film for soldering is
As shown in the figure, a circuit 5 having a cross-sectional structure in which a conductive coating film 12 for solder is laminated on top of a conductive coating film 13 for a conductive path is formed. For this reason, other electrical circuits, electrical components,
It can be connected to electrical equipment by soldering. moreover,
Since the current conducts through the conductive coating film 13 having good conductivity without passing through the conductive coating film 12 for soldering which has poor conductivity, the circuit 5 can be operated without impairing conductivity. , it becomes possible to solder.

Example A conductive paint (with the following composition) was applied on the polyester film.
A conductive coating film for solder with a thickness of 5 μm was formed using a viscosity of 70 poise.

Composition 1 Acrylic resin 100 M Methyl isobutyl ketone 150,! 1 part: 800 parts by weight of copper particles Next, a conductive path coating film having a thickness of 17 μm was formed on this conductive coating film using a conductive paint (viscosity: 70 poise) having the following composition.

Composition 2: Acrylic resin: 100 parts by weight Methyl isobutyl ketone: 180 parts by weight Silver-coated copper particles: 850 parts by weight The circuit transfer foil produced in this way was brought into close contact with a transfer target made of ABS resin, and at a temperature of 190°C, 8 kg of /cn! pressure, line width 0.8 mrW, line distance 1i10.8 m
Using a heating plate having the circuit pattern of l1),
A good circuit with a line width of 0.81 and a distance between lines of 0.8 mm was transferred onto the resin. The conductivity of this circuit was 0.7Ω/portion, and the adhesive strength was also good.

Further, when electrical components were connected to the circuit by soldering, it was possible to solder them satisfactorily.

〔Effect of the invention〕

As explained above, according to the circuit transfer foil and transfer method of the present invention, a conductive coating film with a high content of metal particles is formed and then a conductive coating film for conductive paths is laminated, so that good conductivity can be obtained. , and has the advantage that circuits that can be soldered can be transferred.

Brief description of the drawings Figure 1 is a coin diagram showing the circuit transfer method using circuit transfer foil;
FIG. 2 is a cross-sectional view of an example of the circuit transfer foil according to the present invention;
FIG. 3 shows the circuit transferred by the circuit transfer foil.
FIG. 2 is a sectional view taken along line A-A in FIG. 1. FIG.

■...Circuit transfer foil, 2...Transferred object, 3...Circuit pattern, 4...Heating plate, 5...Circuit, 1)...Support film, 12...For soldering Conductive coating film, 13...
Conductive coating for conductive paths.

Applicant's agent Tadashi Ame Miya Box 1 diagram Figure 2 Figure 3 Procedural amendment (Marshal) July 29, 1986

Claims (2)

[Claims] (1) Add 500 to 2000 parts by weight of conductive particles to 100 parts by weight of resin on the support film to obtain basic
Immediately after heating and pressurizing, a conductive coating film for solder that exhibits easy peelability from the support film is provided, and this conductive coating film for solder is coated with resin 1.
A circuit transfer foil characterized in that a conductive coating film for a conductive path is laminated by adding 500 to 1000 parts by weight of conductive particles to 00 parts by weight. (2) Add 500 to 2000 parts by weight of conductive particles to 100 parts by weight of resin on the support film to obtain basic
Immediately after heating and pressurizing, a conductive coating film for solder that exhibits easy peelability from the support film is provided, and this conductive coating film for solder is coated with resin 1.
For the conductive path, a circuit transfer foil is prepared by adding 500 to 1,000 parts by weight of conductive particles to 00 parts by weight and laminating a conductive coating film for the conductive path that adheres to the transferred object by heating and pressing. A circuit transfer method characterized in that a conductive coating film is laminated so as to be in close contact with an object to be transferred, and only a desired circuit pattern portion is heated and pressurized to transfer an electric circuit to the object to be transferred.