JPH05283849A - Method and apparatus for manufacturing three-dimensional molding circuit board - Google Patents

Abstract

(57) [Abstract] [Purpose] To form a high-quality three-dimensional molded circuit board efficiently and at low cost by using a transfer sheet and a thermoplastic resin for a substrate. [Structure] Using a transfer sheet 1 in which a conductive circuit 4 is laminated in advance on one of two surfaces of a carrier film and a thermoplastic resin for a base material, in a cavity of a first mold made of an injection molding mold. Then, simultaneously with the injection molding of the thermoplastic resin, a step of transferring the conductive circuit 4 of the transfer sheet 1 into a flat surface shape on a molded product made of a base resin to obtain a primary molded circuit board 27,
The primary molded circuit board 27 is softened by heating and partially pressed by using a second mold 28 made of a press mold having male and female concave-convex portions 31 to shape the concave-convex portions 35. And a step of obtaining the molded circuit board 34.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a three-dimensional molded circuit board using a transfer sheet having a conductive film previously laminated on one surface of a carrier film and a thermoplastic resin for a substrate.

[0002]

2. Description of the Related Art A conventional electronic device is formed by impregnating a paper or glass cloth with an unsaturated polyester resin, an epoxy resin, a polyimide resin, or the like, laminating a semi-solidified prepreg and a copper foil, and press forming. After obtaining a copper-clad laminated board, wiring was processed into a printed wiring board by etching on this copper-clad laminated board, and further, this printed wiring board was assembled by being assembled in a device housing.

In recent years, it has been attempted to form a conductor pattern on the back surface of an equipment housing and mount electronic parts on the conductor pattern in order to save space or reduce costs for downsizing electronic equipment. .. In this conventional technique, a conductive circuit is applied to a molded product obtained by injection molding of a thermoplastic resin for a base material.

FIG. 8 is a cross-sectional view showing a conventional technique in which transfer molding is performed using a mold having surface irregularities.

In the prior art shown in FIG. 8, the fixed die 10 is used.
And a movable mold 11 is used. Fixed type 1
A cavity 12 is formed between 0 and the movable die 11. The cavity 12 is provided with an uneven portion 13 for forming unevenness on the molded product. Further, the transfer sheet 1 is fed into the cavity 12 and installed therein. In this transfer sheet 1, a conductive circuit 4 is laminated on a carrier film 2 via a release material layer 3,
An adhesive layer 5 is formed on the surface of the conductive circuit 4.
Further, a thermoplastic resin for a substrate is injected into the cavity 12 from a nozzle 15 of an injector 14 through a runner 16.

In this prior art, the transfer sheet 1 is fed and installed at a position corresponding to the cavity 12 in the mold. Then, after performing mold clamping, the molten thermoplastic resin for the base material is injected from the nozzle 15 of the injection machine 14 through the runner 16 into the cavity 12 to obtain a molded product, and at the same time, the transfer sheet is transferred onto the surface of the molded product. 1 to the adhesive layer 5
The conductive circuit 4 is transferred via the to obtain a three-dimensional molded circuit board.
At this time, the molten thermoplastic resin for the base material is filled into the concave-convex portion 13 of the cavity 12 while stretching the transfer sheet 1, and the concave-convex shape is formed on the three-dimensional molded circuit board. After molding the three-dimensional molded circuit board to which the conductive circuit 4 is transferred, the three-dimensional molded circuit board is cooled and solidified. After cooling and solidifying the three-dimensional molded circuit board, the mold is opened, the three-dimensional molded circuit board is taken out, and then the portion having the conductive circuit 4 in the transfer sheet 1 is fed again to the position corresponding to the cavity 12 in the mold. Become.

[0007]

By the way, in the prior art in which the conductive circuit 4 of the transfer sheet 1 is transferred to a molded product having irregularities, the elongation rate of the sheet corresponding to the irregular shape of the three-dimensional molded circuit board is several. When it is extremely small within%, the carrier film 2 and the conductive circuit 4 of the transfer sheet 1 expand corresponding to the concave and convex portions 13 of the cavity 12, so that no serious problem occurs.

However, when the elongation rate of the sheet corresponding to the uneven shape of the three-dimensional molded circuit board becomes large, such as several percent to several dozen percent, the carrier film 2 and the conductive circuit 4 of the transfer sheet 1 are suddenly changed. However, there are inconveniences such as cutting and wrinkling of the carrier film 2, disconnection of the conductive circuit 4, and further, the conductive circuit 4 gets caught in the thermoplastic resin for the base material at the corners. To do. In particular, when a metal foil such as a copper foil is used as the material of the conductive circuit 4, there is a problem that the conductive circuit 4 is easily broken due to the shocking pressure of the injected thermoplastic resin for the base material. ..

On the other hand, the first object of the present invention is to mold a high quality three-dimensional molded circuit board efficiently and at low cost by using the transfer sheet and the thermoplastic resin for the substrate. To provide a method.

A second object of the present invention is to provide an apparatus for manufacturing a three-dimensional molded circuit board, which can accurately carry out the method for manufacturing a three-dimensional molded circuit board according to the present invention.

[0011]

In order to achieve the above-mentioned first object, the method of the present invention is a method of forming a transfer sheet on a molded article of a thermoplastic resin for a base material simultaneously with injection molding of a thermoplastic resin for a base material. It has a step of transferring a conductive circuit to a flat surface to obtain a primary molded circuit board, and a step of partially pressing with a mold to form irregularities to obtain a secondary molded circuit board. There is.

In order to achieve the first object, in the method of the present invention, the primary molded circuit board is cooled after the injection molding of the thermoplastic resin for the base material in the step of obtaining the primary molded circuit board. Before, unevenness is formed on the primary molding circuit board by a mold so as to obtain a secondary molding circuit board, and the method of the present invention further comprises an injection molding mold and a shaping mold in an injection molding machine. After arranging and molding the primary molding circuit board with the injection molding die, it is transferred to the shaping mold and another primary molding circuit board is injection-molded with the injection molding die and the above-mentioned secondary The step of obtaining a molded circuit board can be performed by a single mold clamping operation. Furthermore, in the method of the present invention, an injection molding mold capable of replacing a part of the mold with the primary molded circuit board. Molded by using the mold, then replace the replaceable part of the mold with the male and female concave and convex parts Replacing the mold, irregularities and shaping the mold after replacing this part mold, so as to obtain the secondary forming circuit board.

In order to achieve the second object,
The device of the present invention is provided with an injection molding cavity and a concave-convex shaping cavity in a single mold unit having a fixed mold and a movable mold, and the injection molding cavity is previously formed on one surface of a carrier film. Using a transfer sheet on which a conductive circuit is laminated and a thermoplastic resin for a base material, injection molding of the thermoplastic resin for the base material is performed, and at the same time, a conductive circuit of the transfer sheet is formed on a molded article made of the thermoplastic resin for the base material. Is formed so that a primary molded circuit board transferred to a flat surface can be molded, and the concave-convex shape forming cavity is partially pressed against the primary molded circuit board in a softened state to form a concave-convex secondary shape. A molding circuit board is configured to be moldable, and further, the injection molding cavity and the unevenness shaping cavity are clamped by a single mold clamping operation,
The primary molded circuit board and the secondary molded circuit board can be simultaneously molded.

The method and apparatus of the present invention will be described in more detail below.

1 to 3 show an embodiment of the present invention. FIG. 1 is a sectional view showing a molding state of a primary molding circuit board by a first mold, and FIG. 2 is a second mold. FIG. 3 is a cross-sectional view showing a state where the secondary molded circuit board has started to be molded, and FIG. 3 is a sectional view of a three-dimensional molded circuit board which is a product. Further, FIG. 4 is a partially enlarged view showing an example of the transfer sheet.

In the embodiments shown in these figures, a first mold 20 which is an injection mold and a second mold 28 which is a press mold are used.

As shown in FIG. 1, the first mold 20 has a fixed mold 21 and a movable mold 22. A cavity 23 is formed between the fixed die 21 and the movable die 22, but the cavity 23 is not provided with an uneven portion. A portion of the conductive circuit 4 of the transfer sheet 1 having the conductive circuit 4 is fed into the cavity 23,
It is supposed to be installed. Also, the cavity 2
A molten thermoplastic resin for a substrate is injected into the inside of the nozzle 3 through a nozzle 25 of an injector 24 and a runner 26.

The second mold 28 has a lower mold 29 which is a fixed mold and an upper mold 30 which is a movable mold. The lower mold 29 and the upper mold 30 are provided with male and female concave / convex portions 31 for forming irregularities on the primary molded circuit board. further,
A heater 32 is embedded in each of the lower mold 29 and the upper mold 30. The upper die 30 is connected to a ram (not shown) via a rod 33.

The transfer sheet 1 is, as shown in FIG.
A conductive circuit 4 is laminated on one surface of the carrier film 2 via a release material layer 3, and an adhesive layer 5 is formed on the surface of the conductive circuit 4.
It is formed of a laminated sheet in which

[0020] The transfer sheet 1 having the laminated structure as described above,
For example, it is wound into a roll and the take-up roll
In the mold open state of the first mold 20 shown in FIG.
The part of the conductive circuit 4 is sent to the position corresponding to the cavity 23.
And place this conductive circuit 4 on the front side of the cavity 23.
And install.

Next, the movable mold 22 of the first mold 20 is moved to perform mold clamping, and then the nozzle 2 of the injection machine 24.
5. The molten thermoplastic resin as the resin for the base material is injected into the cavity 23 through the runner 26.

As the thermoplastic resin for the base material, for example, polybutylene terephthalate (PBT) is used, but any thermoplastic resin can be used without particular limitation.

A molten thermoplastic resin for a substrate is injected into the cavity 23 of the first mold 20 to fill the molded product to form a molded product, and at the same time, a molded product made of the thermoplastic resin for the substrate. Then, the conductive circuit 4 is transferred via the adhesive layer 5 of the transfer sheet 1. At this time, since the cavity 23 of the first mold 20 is not formed with the uneven portion, the primary molded circuit board in which the conductive circuit 4 is transferred in a flat surface shape to the molded product made of the thermoplastic resin for the base material. 27 is molded.

After the primary molding circuit board 27 in the cavity 23 of the first mold 20 is cooled and solidified, the movable mold 22 is moved to open the mold, and the primary molding circuit board 27 is separated from the carrier film and taken out. ..

Next, the portion of the primary molding circuit board 27 taken out from the first mold 20 where the unevenness is to be formed is the lower mold 29 in the mold open state of the second mold 28 shown in FIG. Place on top. Then, the heater 32 embedded in the lower die 29 and the upper die 30 of the second die 28 is heated in advance, the primary molded circuit board 27 is placed on the lower die 29, and then the rod 33 is rammed. The primary mold circuit board 27 is heated by lowering the upper mold 30 through the contact with the heated mold. The heating temperature at this time is, for example, about 50 to 250 ° C., and the portion of the primary molded circuit board 27 where the irregularities are to be shaped is sufficiently softened. In the above-described embodiment, a hot air heating method using another hot air gun, a hot wire heating method using a light beam heating device, or the like may be used instead of the heating method by contact with the mold. Particularly, according to the heating method using the light beam heating device, it is possible to locally heat and soften the portion of the primary molding circuit 27 where the unevenness is to be formed, in a short time.

After sufficiently heating and softening the portion of the primary molded circuit board 27 where the irregularities are to be formed, the upper die 30 is formed by a ram.
The secondary molded circuit board which is a three-dimensional molded circuit board in which the concave and convex portions of the primary molded circuit board 27 are pressed to form a concave and convex portion 35 at a predetermined portion including the portion where the conductive circuit 4 is transferred. Get 34. The pressing force at this time is, for example, 1 to
100 kg / cm ² or so, preferably 20 to 50 kg /
cm ² and the pressurizing time is, for example, 0.1 to 30 mi
n. Preferably about 0.2 to 1 min. And the range
The pressurizing speed is 1 to 30 mm / min so that the conductive circuit 4 or the like is not subjected to a shocking pressure. The mold is clamped at this speed and pressure is applied.

After the secondary molding circuit board 34 having the concave and convex portion 35 is molded by the second mold 28, the upper mold 30 is lifted and the mold is opened, and the secondary molding circuit board 34 is taken out and three-dimensionally molded. Complete one stroke of circuit board molding.

Further, in the above embodiment, the first mold 2
0, the primary molded circuit board 27 is molded, and before the primary molded circuit board 27 is cooled, that is, when the primary molded circuit board 27 is in a softened state in which unevenness can be formed on the primary molded circuit board 27. Then, the first mold 20 is opened and the cavity 23
The primary molded circuit board 27 in the softened state is taken out from the inside and transferred to the second mold 28 which is a press mold, and the second mold 2
8 may be used to form irregularities on the primary molded circuit board 27.

Further, in the present invention, after the primary molding circuit board 27 is molded by the injection molding mold 20 in which a part of the mold is replaceable, the injection is performed before the primary molding circuit board 27 is cooled. The molding die 20 is opened, one part of the injection molding die is replaced with a partial die having male and female concave and convex portions, and the mold is clamped again by the mold clamping device of the mold 20. The uneven portion of the replaced partial mold may be shaped as the uneven portion 35 at a predetermined portion of the primary molded circuit board 27 by force.

That is, for example, the partial molds 46 and 47 of the mold shown by reference numeral 45 in FIG. 6 and the partial molds 49 and 50 having the male and female concave and convex portions shown in FIG. And the metal mold indicated by reference numeral 49 is placed so that it can be formed, the primary molding circuit board 27 is molded by the mold 45, and the portion of the mold 45 is cooled before the primary molding circuit board is cooled. Partial molds 49 and 5 having concave and convex parts
The secondary molded circuit board may be obtained by substituting 0 for shaping on the primary molded circuit board.

Next, FIG. 5 is a sectional view showing an embodiment of an apparatus for carrying out the method of the present invention.

In the apparatus for manufacturing a three-dimensional molded circuit board shown in FIG. 5, the mold unit 3 is composed of the fixed mold 37 and the movable mold 38.
6 are configured. An injection molding cavity 39 and an unevenness shaping cavity 43 are provided in parallel in the mold unit 36.

The transfer sheet 1 is fed into the injection molding cavity 39, and the portion of the conductive circuit 4 is installed therein. Also, this injection molding cavity 3
The molten thermoplastic resin for the base material is injected into the nozzle 9 through the nozzle 41 of the injector 40 and the runner 42. Then, the injection molding cavity 39 uses the transfer sheet 1 and the thermoplastic resin for the base material, and at the same time as the injection molding of the thermoplastic resin for the base material, a molded article made of the thermoplastic resin for the base material is formed. Conductive circuit 4 of the transfer sheet 1
Is formed so that the primary molded circuit board 27 obtained by transferring the above can be molded.

The concave-convex shaping cavity 43 is provided with a male-female concave-convex portion 44. Thus, the concave-convex shaping cavity 43 is configured such that the primary molded circuit board 27 in the softened state is partially pressed by the concave-convex portion 44 to mold the concave-convex shaped secondary molded circuit board 34. There is.

In the manufacturing apparatus having the above construction, the mold unit 3
The transfer sheet 1 is fed to a position corresponding to the injection molding cavity 39 in a state where the mold 6 is opened, and the portion of the conductive circuit 4 is set at a position corresponding to the injection molding cavity 39. Note that, at the beginning of molding the three-dimensional molded circuit board, the primary molded circuit board is not arranged at the position corresponding to the concave-convex shaping cavity 43.

After the conductive circuit 4 portion of the transfer sheet 1 is installed at a position corresponding to the injection molding cavity 39, the mold is clamped. Next, the molten thermoplastic resin for the base material is injected and filled into the injection molding cavity 39 through the nozzle 41 of the injection machine 40 and the runner 42 to form the adhesive layer 5 of the transfer sheet 1 on the base resin. The primary molded circuit board 27 on which the conductive circuit 4 has been transferred to a flat surface through the molding is molded.

Before the primary molded circuit board 27 is cooled,
That is, the mold opening is performed when the unevenness is softened to the extent that it can be molded. Then, the primary molded circuit board 27 molded in the injection molding cavity 39 is taken out and transferred to the unevenness shaping cavity 43. Also, the injection molding cavity 3
The conductive circuit 4 portion of the transfer sheet 1 is sent to the position corresponding to 9 and set, and the mold is clamped again. This mold clamping is
In order not to give impact force to the conductive circuit 4 and the like adhered to the primary molding circuit board 27 in the concave-convex shaping cavity 43,
For example, it is performed at a speed of about 1 to 30 mm / min.

By the above-mentioned mold clamping, a cavitation for concavo-convex shaping is performed.
The primary molded circuit board
By pressing a predetermined portion of 27 to form unevenness, the conductive circuit 4
Predetermined number of primary molded circuit boards 27 including bonded parts
The secondary molded circuit board 34 having the concave and convex portions 35 formed therein is molded.
Ru .

During molding of the secondary molded circuit board 34 by the concave-convex shaping cavity 43, the molten thermoplastic material for the substrate is passed through the nozzle 41 of the injection machine 40 and the runner 42 into the injection molding cavity 39. The resin is injected again to mold the primary molded circuit board 27.

As described above, the primary molding circuit board 27 is molded in the injection molding cavity 39 provided in the single mold unit 36, and the secondary molding circuit board 34 is molded in the concave-convex shaping cavity 43. After that, the mold is opened. Then, from the unevenness shaping cavity 43 to the secondary molding circuit board 34.
Is taken out, the primary molding circuit board 27 in the injection molding cavity 39 is taken out and transferred into the concave-convex shaping cavity 43, and one stroke is completed.

In the above-described manufacturing apparatus shown in FIG. 5, a handler is provided which performs a sequence operation in accordance with mold opening and mold clamping of the mold unit 36, and this handler causes the injection molding cavity 39 to the unevenness shaping cavity 43. The transfer of the primary molded circuit board 27 to and the removal of the secondary molded circuit board 34 from the concave-convex shaping cavity 43 may be automatically performed.

[0042]

In the method of the present invention, the transfer sheet 1 having the conductive circuit 4 laminated on one surface of the carrier film 2 and the thermoplastic resin for the substrate are used, and at the same time as the injection molding of the thermoplastic resin for the substrate, The primary circuit board 27 is molded by transferring the conductive circuit 4 of the transfer sheet 1 on a flat surface to a molded product made of a thermoplastic resin for a base material, and then the primary circuit board is partly molded using a mold. Since the secondary molded circuit board 34 is molded by pressing the concave and convex portions 35 to shape the uneven portion 35,
The elongation of the transfer sheet corresponding to the shape of the uneven portion is several% to 1
Even with a three-dimensional molded circuit board having a size of 0% or more, the transfer sheet 1 is cut and wrinkles are generated, and the conductive circuit 4 is formed.
It is possible to manufacture a high-quality three-dimensional molded circuit board having no wire breakage and no penetration into the base resin of the conductive circuit 4 at the corners.

Further, since the transfer method using the transfer sheet 1 having the conductive circuit 4 is utilized in the method of the present invention, the advantage of this transfer method can be utilized as it is, and the manufacturing can be performed efficiently.
The cost can be reduced.

In the method of the present invention, the primary molded circuit board 27 is cooled by the mold before the primary molded circuit board 27 is cooled.
Since the secondary molded circuit board 34 is molded by forming unevenness on the secondary molded circuit board 34, the secondary molded circuit board 34 can be molded by utilizing the residual heat at the time of molding the primary molded circuit board 27. A heating device for heating and softening the plate 27 can be omitted or downsized. For this reason, it is possible to reduce the facility cost, save energy, and further reduce the cost.

Further, in the method of the present invention, the injection molding cavity and the molding cavity of the primary molding circuit board arranged in a single mold unit are used, and molding is performed by the injection molding cavity. Before cooling the formed primary molded circuit board, the primary molded circuit board is transferred to a shaping cavity,
Since the unevenness is shaped in the shaping cavity to mold the secondary molded circuit board, the facility cost can be reduced and energy saving can be achieved also in this method. Further, in this method, since the step of obtaining the primary molded circuit board and the step of obtaining the secondary molded circuit board are carried out at the same time, a significant cost reduction can be achieved.

Further, in the method of the present invention, the primary molded circuit board 27 is molded by an injection molding die, and then a part of the injection molding die is replaced with a partial die having male and female irregularities. Then, since the unevenness is formed by the metal mold after the replacement and the secondary molded circuit board 34 is molded, the heating device for heating and softening the primary molded circuit board 27 and the unevenness are formed. As a heating device for shaping, the injection molding die can be used as it is, and the equipment cost can be reduced, and the primary molding circuit board 27 and the secondary molding circuit board 3 can be formed in one molding cycle.
Since 4 and 4 can be molded, the three-dimensional molded circuit board can be manufactured more efficiently.

Further, in the apparatus of the present invention, the mold unit 36 is constituted by the fixed mold 37 and the movable mold 38, and the injection molding cavity 39 and the unevenness shaping cavity 43 are provided in the mold unit 36. .. Therefore, the conductive circuit 4 of the transfer sheet 1 is installed in the injection molding cavity 39 in the mold open state, and after the mold is clamped, the molten thermoplastic resin for the base material is injected into the injection molding cavity 39 to form the base material. A primary molded circuit board 27, in which the conductive circuit 4 is transferred to a flat surface, is molded on a molded product made of a thermoplastic resin. And after opening the mold,
The primary molding circuit board 27 molded by the injection molding cavity 39 is transferred into the concave-convex shaping cavity 43, and at the same time as the mold clamping, the concave-convex shaping cavity 43 is moved to a predetermined portion of the primary molding circuit board 27 including the conductive circuit 4. The unevenness is shaped so that the secondary molded circuit board 34, which is a three-dimensional molded circuit board, is molded. As a result, the primary molding circuit board 27 and the secondary molding circuit board 34 can be molded at the same time with a single mold unit 36, and a high quality three-dimensional molding circuit board can be molded extremely efficiently, resulting in a significant cost reduction. It is possible.

[0048]

EXAMPLES Specific examples of the present invention will be described below.

Example 1 A transfer sheet formed as follows was used. That is,
PET having a thickness of 50 μ was used as a carrier film.
A copper foil was pressure-bonded to one surface of the PET via a release agent layer, and the copper foil was subjected to etching processing to form a conductive circuit. An adhesive was applied to the surface of this conductive circuit to form an adhesive layer.

Next, the transfer sheet formed as described above was set in the cavity of the injection molding die. After the injection molding die is clamped, PBT (G / F 15%) as a thermoplastic resin for the base material is injected and filled in the cavity, and at the same time, a molded product made of the thermoplastic resin for the base material has a conductive circuit. To obtain a primary molded circuit board.

The primary molded circuit board is cooled by a conventional method,
After solidification, the mold was opened, and the primary molded circuit board was taken out from the cavity of the injection molding mold.

Next, the primary molded circuit board was transferred to a press die having male and female type concave and convex portions and having a heater, and heated to 150 ° C. by this press die. After heating and softening the primary molded circuit board, a pressing speed of 15 mm / min. ，
A pressing force of 30 kg / cm ² and a pressurizing time of 30 seconds are applied, and irregularities are formed at predetermined locations including the conductive circuit of the primary molding circuit board by the concave-convex portion of the press mold, and the secondary molding circuit is a three-dimensional molding circuit board. I got a board.

As a result, the conductive circuit (copper foil pattern) transferred to the molded product made of the thermoplastic resin for the base material was free from defects such as disconnection, and a good three-dimensional molded circuit board could be obtained.

Example 2 As a molding die, as shown in FIG. 5, a single die unit provided with an injection molding cavity and an unevenness forming cavity in parallel was used.

The same thermoplastic resin as used in Example 1 was used for the transfer sheet and the base material.

The conductive circuit of the transfer sheet is set in the injection molding cavity, and after the mold is clamped, the molten thermoplastic resin for the base material is injected and filled to obtain a molded product of the thermoplastic resin for the base material. A primary molded circuit board on which a conductive circuit was transferred was obtained.

After the primary molded circuit board was cooled in the injection molding cavity for 5 seconds, the mold was opened, and the unsolidified primary molded circuit board was taken out from the injection molding cavity and transferred into the unevenness molding cavity.

Then, the mold was clamped, and irregularities were formed in predetermined portions of the primary molding circuit board including the conductive circuit in the concave-convex shaping cavity to obtain a secondary molding circuit board which was a three-dimensional molding circuit board. Further, during the molding of the secondary molded circuit board, the thermoplastic resin for the base material melted in the injection molding cavity was injected and filled in the above-described manner to mold the primary molded circuit board.

As a result, at one cycle of about 40 seconds,
The primary molded circuit board and the secondary molded circuit board could be continuously molded. Moreover, as in Example 1, there were no defects such as disconnection in the conductive circuit, and a good three-dimensional molded circuit board could be obtained.

[0060]

According to the invention described in claim 1 of the present invention described above, the transfer sheet having the conductive circuits laminated thereon and the thermoplastic resin for the base material are used, and the transfer sheet for the base material is used. Simultaneously with injection molding of the thermoplastic resin, a step of transferring the conductive circuit of the transfer sheet to a flat surface shape on a molded article made of the thermoplastic resin for the base material to obtain the primary molded circuit board, and heating and softening the primary molded circuit board. Then, a step of obtaining a secondary molded circuit board by shaping unevenness by partially pressing using a mold, the elongation percentage of the transfer sheet corresponding to the shape of the unevenness is several%. Even with a three-dimensional molded circuit board with a size of 10 to 10%, the transfer sheet is cut and wrinkled, the conductive circuit is broken, and the thermoplastic resin is used as the base material of the conductive circuit at the corners. Manufactures high quality 3D molded circuit boards with no digging It can be, because it uses the transfer method using a transfer sheet having a conductive circuit,
The advantage of this transfer method can be utilized as it is, and the production can be efficiently performed, and the cost can be reduced.

According to the second aspect of the present invention, before the primary molded circuit board is cooled, unevenness is formed on the primary molded circuit board by a mold to mold the secondary molded circuit board. Since, as a result, the secondary molded circuit board can be molded by using the residual heat at the time of molding the primary molded circuit board, the heating device for heating and softening the primary molded circuit board can be omitted or downsized, Since the facility cost can be reduced and the energy can be saved, the cost can be further reduced.

Further, according to the invention described in claim 3 of the present invention, the injection molding cavity and the shaping cavity of the primary molding circuit board arranged in a single mold unit are used. Before the primary molding circuit board formed by the injection molding cavity cools, transfer the primary molding circuit board to the molding cavity, shape irregularities in the molding cavity, and form the secondary molding circuit. Since the plate is formed, the present invention also has the effects of reducing the facility cost and saving energy. Further, in the method of the present invention, the step of obtaining the primary molded circuit board and the step of obtaining the secondary molded circuit board are carried out at the same time, so that a significant cost reduction can be achieved in this respect.

According to a fourth aspect of the present invention, the primary molded circuit board is molded by an injection molding mold, and then a part of the mold has male and female concave and convex portions. Substitution with a partial mold, shaping the unevenness by the mold after this replacement, so as to mold the secondary molded circuit board, a heating device for heating and softening the primary molded circuit board, The injection mold can be directly used as a heating device for shaping the unevenness. For this reason, not only the facility cost can be reduced, but also the primary molded circuit board and the secondary molded circuit board can be molded in one molding cycle, and the three-dimensional molded circuit board can be manufactured more efficiently.

According to a fifth aspect of the present invention, an injection molding cavity and an unevenness shaping cavity are provided in a single mold unit having a fixed mold and a movable mold. At the same time as the injection molding of the thermoplastic resin for the base material, the injection molding cavity is formed by using a transfer sheet in which a conductive circuit is laminated in advance on one surface of a carrier film and a thermoplastic resin for the base material, and at the same time as the base material. A primary molded circuit board in which the conductive circuit of the transfer sheet is transferred to a resin is formed into a flat surface so as to be moldable, and the shaping cavity is partially pressed against the softened primary molded circuit board to form unevenness. A shaped secondary molded circuit board is configured to be moldable, and further, the injection molding cavity and the concave-convex shaped cavity are simultaneously molded with a single mold clamping to form a primary molded circuit board and a secondary molded circuit board. Since it is possible to configure, Serial invention a method is effective, it may be carried out accurately.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, showing a molding state of a primary molded circuit board by a first mold.

FIG. 2 is a cross-sectional view showing the same embodiment as in FIG. 1 and showing a state at the start of molding of a secondary molded circuit board by a second mold.

FIG. 3 is a cross-sectional view of a three-dimensional molded circuit board that is a product obtained by the embodiment shown in FIGS. 1 and 2.

FIG. 4 is a partially enlarged side view showing an example of a transfer sheet.

FIG. 5 shows another embodiment of the present invention and is a cross-sectional view of a manufacturing apparatus.

FIG. 6 is a schematic sectional view of an injection molding die in which a part of the die is replaced.

FIG. 7 is a schematic cross-sectional view illustrating a state after a part of the mold of FIG. 6 is replaced with a partial mold having an uneven portion.

FIG. 8 is a cross-sectional view showing a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transfer sheet 2 Carrier film 4 Conductive circuit 5 Adhesive layer 20 1st metal mold | die which consists of an injection mold 23 Cavities of a 1st metal mold | die 27 Primary molding circuit board 28 2nd metal mold | die which consists of press molds 31st Male and female mold irregularities in the second mold 32 Heater for heating and softening the primary molding circuit board 34 Secondary molding circuit board 35 Concavities and convexities formed on the secondary molding circuit board 36 Mold unit 39 Injection molding cavity 43 Cavity for concavo-convex shaping 44 Concavo-convex part of male / female mold 45 Injection mold capable of replacing part of mold 46, 47 Partial mold that can be replaced 48 Partial mold having concavo-convex part after replacement Injection mold 49,50 Partial mold having uneven parts

Claims (5)

[Claims] 1. A method for producing a three-dimensional molded circuit board using a transfer sheet in which a conductive circuit is previously laminated on one surface of a carrier film, and a thermoplastic resin for a base material, wherein the thermoplastic resin for the base material is used. Simultaneously with the injection molding of step 1, a step of transferring the conductive circuit of the transfer sheet to a flat surface shape on a molded article made of a thermoplastic resin for a base material to obtain a primary molded circuit board, and the primary molded circuit board using a mold. And a step of forming a concavo-convex shape by partially pressing to form a secondary molded circuit board. 2. In the step of obtaining the primary molded circuit board, after the thermoplastic resin for the base material is injection-molded and before the primary molded circuit board is cooled, the primary molded circuit board is roughened by a shaping die. The method for producing a three-dimensional molded circuit board according to claim 1, wherein the secondary molded circuit board is obtained by molding. 3. A cavity for injection molding using a die in which a cavity for injection molding and a cavity for shaping unevenness are provided in a single die unit having a fixed die and a movable die. Forming a first primary molded circuit board therein, and then transferring the first primary molded circuit board into a concavo-convex shaping cavity before the first primary molded circuit board cools;
By clamping the mold, a first secondary molded circuit board having irregularities is obtained, and a thermoplastic resin for a base material is injected into the injection molding cavity to form a second primary molded circuit. And a step of obtaining the first secondary molded circuit board and a step of obtaining the second primary molded circuit board at the same time by a single mold clamping operation. The method for producing a three-dimensional molded circuit board according to claim 1 or 2. 4. The primary molding circuit board is molded with an injection molding mold in which a part of the mold is replaceable, and then, before the primary molding circuit board is cooled, the injection molding mold. The replaceable portion of the mold is replaced with a partial mold having male and female concave and convex portions, and then the primary molding plate is concave and convex by a mold in which one portion is replaced by the partial mold having the concave and convex portions. The method for manufacturing a three-dimensional molded circuit board according to claim 1 or 2, wherein the secondary molded circuit board is obtained by molding. 5. A single mold unit having a fixed mold and a movable mold is provided with an injection molding cavity and a concavo-convex shape forming cavity, the injection molding cavity being one of carrier films. Using a transfer sheet in which a conductive circuit is previously laminated on the surface of and a thermoplastic resin for the base material,
Simultaneously with the injection molding of the thermoplastic resin for the base material, the primary molded circuit board in which the conductive circuit of the transfer sheet is transferred onto the flat surface of the molded product made of the thermoplastic resin for the base material is configured to be molded. The shaping cavity is configured to partially press the softened primary molded circuit board so as to mold a secondary molded circuit board with unevenness, and the injection molding cavity and the unevenness shaping cavity are An apparatus for manufacturing a three-dimensional molded circuit board, characterized in that the primary molded circuit board and the secondary molded circuit board can be simultaneously molded by a single mold clamping.