JPH09293947A - Manufacture of three-dimensional molded circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacturing method of a three-dimensional molded circuit board of beautiful appearance having almost no hole in the circuit formed body consisting of resin of easily plating property. SOLUTION: In this three-dimensional molded circuit board 1 manufacturing method in which a circuit formed body 2 is formed by injection-molding resin 2a of easily plating property into the first metal mold, the circuit formed body 2 is taken out from the above-mentioned first metal mold and housed in the second metal mold, and the temperature of the above-mentioned mold when the resin 2a of easily plating property is injection-molded is set at 80 to 100 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a three-dimensional molded circuit board, and more particularly to a method for manufacturing a three-dimensional molded circuit board formed by integrally molding an easily plating resin and a difficult plating resin. is there.

[0002]

2. Description of the Related Art Conventionally, polyether sulfone or the like has been used as an easy-plating resin that constitutes a circuit-formed body of a three-dimensional molded circuit board, but nowadays, from the viewpoints of prevention of deformation over time, prevention of heat deformation, rigidity and the like. Liquid crystal polymer (hereinafter referred to as LCP) resin is used.

FIG. 2 is a cross-sectional view of a conventional three-dimensional molded circuit board.
Shown in

As shown in FIG. 2, a three-dimensional molded circuit board 11 is provided.
Is injection-molded with an easily plateable resin (not shown) made of LCP resin in a first die (not shown) to form the circuit-formed body 12.
And the circuit forming body 12 is taken out from the inside of the first mold and accommodated inside the second mold (not shown), and the space between the second mold and the circuit forming body 12 (not shown). It is obtained by filling and molding a difficult-to-plate resin (not shown) to form the insulator 13. That is, the three-dimensional molded circuit board 11 has a structure in which a part of the circuit forming body 12 is exposed from the surface of the insulator 13. The surface of the three-dimensional molded circuit board 11 has an easily-platable resin portion 12 a and a hard-to-plate resin portion. 13a and 13a exist.

The easily plated resin portion 12a of the three-dimensional molded circuit board 11 is roughened, and a copper layer having a certain thickness is formed on the roughened easily plated resin portion 12a by electroless copper plating. Then electroless nickel on the copper layer,
And a protective plating layer of electroless gold plating is formed to obtain a plastic injection molded substrate with a plating circuit.

At this time, if there is no abnormality in the electric circuit,
There was no problem even if the holes 14 and the like were present inside the circuit-formed body 12 made of the easily-platable resin, and it was not necessary to care.

[0007]

However, since the three-dimensional molded circuit board 11 is formed by connecting a large number of chips, it is necessary to finally perform a process such as dicing to make chips into a product. There is.

At this time, if the holes 14 are present inside the circuit-forming body 12 made of the easily-platable resin, the appearance of the product is not so preferable, and therefore the easily-platable resin is injection-molded in the first mold. When doing so, it is necessary to prevent the formation of voids.

Therefore, the present invention solves the above problems and provides a method for producing a three-dimensional molded circuit board having a beautiful appearance, with almost no voids formed inside a circuit-formed body made of an easily-platable resin. Especially.

[0010]

In order to solve the above-mentioned problems, the invention of claim 1 forms a circuit-formed body by injection-molding an easily-platable resin in a first mold, and forms the circuit-formed body. Three-dimensional molding for taking out from the inside of the first mold and accommodating it in the inside of the second mold, and filling the space between the second mold and the circuit forming body with the plating-resistant resin to form an insulator. In the method for manufacturing a circuit board, the temperature of the first mold is 80 to 100 ° C. when the easily plateable resin is injection molded.

According to a second aspect of the present invention, a circuit-formed body is formed by injection-molding an easily-platable resin in the first die, and the circuit-formed body is taken out from the inside of the first die and then the second die. In the method for producing a three-dimensional molded circuit board, which is housed inside and in which a space between the second mold and the circuit forming body is filled with a difficult-to-plate resin to form an insulator, The injection speed at the time of injection molding is 60 to 90 mm / s.

According to a third aspect of the present invention, a circuit forming body is formed by injection-molding an easily-platable resin in the first die, and the circuit forming body is taken out from the inside of the first die and the second die is formed. In the method for producing a three-dimensional molded circuit board, which is housed inside and in which a space between the second mold and the circuit forming body is filled with a difficult-to-plate resin to form an insulator, The holding pressure at the time of injection molding is 350 kg / cm ² , and
The suck back amount is set to 5 mm or less.

The reasons for limiting the above numerical range will be described below.

The reason for limiting the temperature of the first mold to 80 to 100 ° C. when injection-molding the easily-platable resin is that the temperature of the first mold is lower than 80 ° C., for example, 40 to 50 ° C. , Because the curing speed of the easily-platable resin is too fast,
When the temperature of the first mold is higher than 100 ° C., for example, 12
This is because the curing rate of the easily-platable resin is too slow at 0 to 150 ° C.

The reason why the injection speed at the time of injection-molding the easily-platable resin is limited to 60 to 90 mm / s is that it is far from the filling port (gate port) of the easily-platable resin when the injection speed is slower than 60 mm / s. This is because unfilling occurs inside the first mold, and when the injection speed is higher than 90 mm / s, the flow of the easily-platable resin in the first mold is directed to the outside, and the inside of the first mold is inside. This is because the easy-plating resin cannot be filled properly.

The reason why the holding pressure at the time of injection-molding the easily-platable resin is limited to 350 kg / cm ² is that the holding pressure is 35.
If it is lower than 0 kg / cm ² , the injection speed will decrease (60 m
This is because of less than m / s).

The reason why the suck back amount is limited to 5 mm or less is that when the suck back amount is larger than 5 mm, the easily-platable resin entraps excess air, which causes a void inside the molded product. .

According to the above configuration, the temperature of the mold when injection-molding the easily-platable resin is adjusted, the injection speed is adjusted when injection-molding the easily-platable resin, or the easily-platable resin is injected. Since the holding pressure and suck back amount during molding were adjusted, almost no holes were created inside the circuit-formed body made of easily-platable resin, and a three-dimensional molded circuit board with a beautiful appearance can be obtained. .

[0019]

Embodiments of the present invention will be described below.

The method of manufacturing a three-dimensional molded circuit board according to the present invention is
In the first mold having a predetermined shape and maintained at a temperature of 80 to 100 ° C., an easily-platable resin (for example, LCP) was used.
Resin) is injection-molded to form a circuit-formed body. This circuit-formed body is taken out from the inside of the first mold and accommodated in the inside of the second mold which is the outer frame of the entire three-dimensional molded circuit board. This second
In the space between the die and the circuit-formed body, a difficult-to-plate resin (for example, polyphenylene sulfide resin; hereinafter, PPS)
(Hereinafter referred to as "resin"), and the insulating body is integrally formed with the circuit forming body.

A cross-sectional view of the three-dimensional molded circuit board is shown in FIG.

As shown in FIG. 1, the three-dimensional molded circuit board 1
Is composed of a circuit-forming body 2 made of an easily-platable resin and an insulator 3 made of a difficult-plating resin, and a part of the circuit-forming body 2 (lead portion in a three-dimensional molded circuit board) is located above the surface of the insulator 3. Exposed structure, that is, three-dimensional molded circuit board 1
On the surface of the plate, the easily-platable resin part 2a and the difficult-platable resin part 3
a and exist.

The easy-plating resin portion 2a of the three-dimensional molded circuit board 1 is roughened, and a copper layer having a certain thickness is formed on the roughened easy-plating resin portion 2a by electroless copper plating. To do. Then, electroless nickel and a protective plating layer of electroless gold plating are formed on the copper layer to obtain a plastic injection molded substrate with a plated circuit.

The LCP resin used as the easily-platable resin in the present invention is a resin that easily causes voids inside unless the injection conditions are strictly adjusted. However, the temperature of the first mold for injection molding the LCP resin is set to a predetermined value. Is adjusted within the range (60 to 90 ° C.). This makes it possible to suppress the formation of voids in the LCP resin after forming the circuit-formed body.

In the method for manufacturing a three-dimensional molded circuit board according to the present invention, LCP resin was used as the easily-platable resin and PPS resin was used as the hardly-platable resin, but the invention is not limited to this combination and may be, for example, polyether. Sulfide (PES) resin / PPS resin, LCP resin / LC
It may be a combination of P resin, epoxy resin / PPS resin, LCP resin / epoxy resin and the like.

Next, another embodiment will be described.

A circuit-formed body is formed by injection-molding an easily-platable resin in a first mold having a predetermined shape at an injection speed of 60 to 90 mm / s. This circuit-formed body is taken out from the inside of the first mold and accommodated in the inside of the second mold which is the outer frame of the entire three-dimensional molded circuit board. The space between the second mold and the circuit-formed body is filled with a difficult-to-plate resin so that the insulator is integrally formed with the circuit-formed body.

Also in the method for manufacturing a three-dimensional molded circuit board according to this embodiment, the same effects as those of the method for manufacturing a three-dimensional molded circuit board of the present invention can be obtained.

Further, as another embodiment, the easy-plating resin is kept in the first mold having a predetermined shape with a holding pressure of 35.
A circuit-formed body is formed by injection molding at 0 kg / cm ² and suck back amount of 5 mm or less. This circuit-formed body is taken out from the inside of the first mold and accommodated in the inside of the second mold which is the outer frame of the entire three-dimensional molded circuit board. The space between the second mold and the circuit-formed body is filled with a difficult-to-plate resin so that the insulator is integrally formed with the circuit-formed body.

Also in the method for manufacturing a three-dimensional molded circuit board according to this embodiment, the same effects as those of the method for manufacturing a three-dimensional molded circuit board of the present invention can be obtained.

Needless to say, the combination of the respective injection conditions makes it possible to further reduce the occurrence of voids in the circuit-formed body.

[0032]

EXAMPLE Each of the three-dimensional molded circuit boards obtained by the present invention and the conventional method for manufacturing a three-dimensional molded circuit board,
Dicing was performed using a blade having a thickness of 0.2 mm, and each was made into chips. The appearance of the cut surface of each chipped three-dimensional molded circuit board was observed.

The injection conditions in the present invention are adjusted (mold temperature: 80 to 100 ° C., injection speed: 60 to 90 mm / s,
Holding pressure: 350 kg / cm ² or more and suck back amount: 5 mm or less)
Almost no holes were observed on the cut surface.

On the other hand, the mold temperature is 80 to 100 ° C.
In the three-dimensional molded circuit board obtained by adjusting to a range other than,
60% or more of the chipped three-dimensional molded circuit boards had medium-sized holes in the cut surface.

Similarly, in the three-dimensional molded circuit board obtained by adjusting the injection speed to a range other than 60 to 90 mm / s, although the size is small, 75% or more of the chipped three-dimensional molded circuit board has an empty surface. There were holes.

Similarly, in the three-dimensional molded circuit board obtained by adjusting the holding pressure to 350 kg / cm ² or less and the suck back amount to 5 mm or more, the cut surface of the chipped three-dimensional molded circuit board is 65% or more. Large holes were generated.

[0037]

In summary, according to the present invention, since the injection conditions of the easily-platable resin are adjusted, almost no holes are formed inside the circuit-formed body, and a three-dimensional molded circuit board having a beautiful appearance can be obtained. Exerts an excellent effect.

[Brief description of drawings]

FIG. 1 is a view showing a cross section of a three-dimensional molded circuit manufactured by using the method for manufacturing a three-dimensional molded circuit board of the present invention.

FIG. 2 is a diagram showing a cross section of a three-dimensional molded circuit manufactured by using a conventional method for manufacturing a three-dimensional molded circuit board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Three-dimensional molded circuit board 2 Circuit forming body 2a Easy-plating resin part 3 Insulator 3a Hard-plating resin part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiaki Ichige 5-1-1 Hidaka-cho, Hitachi City, Ibaraki Prefecture Hitachi Cable Co., Ltd. Hidaka Plant (72) Inventor Toshiyuki Oaku Hidaka-cho, Hitachi City, Ibaraki Prefecture 5-1-1 Hitachi Cable Co., Ltd. Hidaka Factory (72) Inventor Kazuya Endo 5-1-1 Hidakacho, Hitachi City, Ibaraki Hitachi Cable Co., Ltd. Hidaka Factory

Claims (3)

[Claims] 1. A circuit-formed body is formed by injection-molding an easily-platable resin in a first mold, and the circuit-formed body is taken out from the inside of the first mold and housed inside the second mold, The second
In a method of manufacturing a three-dimensional molded circuit board, wherein a space between a mold and the circuit forming body is filled with a difficult-to-plate resin to form an insulator, the first method for injection-molding the easily-platable resin is used. A method for producing a three-dimensional molded circuit board, wherein the temperature of the mold is 80 to 100 ° C. 2. A circuit-formed body is formed by injection-molding an easily-platable resin in the first mold, and the circuit-formed body is taken out from the inside of the first mold and housed inside the second mold. The second
In a method of manufacturing a three-dimensional molded circuit board in which a space between a mold and the circuit forming body is filled with a difficult-to-plate resin to form an insulator, an injection speed at the time of injection-molding the easily-platable resin is set. 60-90 mm / s, The manufacturing method of the three-dimensional molded circuit board characterized by the above-mentioned. 3. A circuit-formed body is formed by injection-molding an easily-platable resin in the first mold, and the circuit-formed body is taken out from the inside of the first mold and housed inside the second mold, The second
In a method of manufacturing a three-dimensional molded circuit board in which a space between the mold and the circuit forming body is filled with a difficult-to-plate resin to form an insulator, a holding pressure at the time of injection-molding the easily-platable resin is increased. A method for producing a three-dimensional molded circuit board, which comprises 350 kg / cm ² and a suck back amount of 5 mm or less.