JP3168091B2 - Three-dimensional circuit formation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a three-dimensional circuit by forming a required circuit pattern three-dimensionally on a three-dimensional circuit board.

[0002]

2. Description of the Related Art A method for forming a three-dimensional wiring pattern for a three-dimensional member such as a three-dimensional circuit board includes a full-addition method such as a two-shot method or a method in which a circuit is formed two-dimensionally on a film in advance and a molding die is formed. For example, a method of transferring the image to a shape along a mold is used. However, there is a limit to fine patterning and transfer to a complicated three-dimensional shape. Further, a method of forming a three-dimensional circuit using a three-dimensional circuit exposure mask having a circuit surface of a three-dimensional circuit board has also been proposed. As an example, a technique described in, for example, JP-A-2-251959 is known. .

[0003]

However, the light transmitting portion in the above-mentioned prior art uses a translucent resin, and there is a slight absorption of light (particularly ultraviolet light) in this portion, which results in energy loss and light exposure. However, there is a problem that the effective wavelength of light is cut, and the resin of the light transmitting portion is deteriorated. Also, it is considered that the three-dimensional mask transparent body is made by molding, but a mold is required for this, and it is difficult to completely match the mask and the circuit surface of the three-dimensional circuit forming substrate, and the exposure accuracy is reduced. Have the following problems. The present invention has been made to solve such a problem, and the purpose thereof is to:
An object of the present invention is to provide a method for forming a three-dimensional circuit using a three-dimensional mask which has the same surface as the three-dimensional circuit formation surface and can prevent loss of light energy for exposure and deterioration of the light transmitting portion resin.

[0004]

In order to achieve the above-mentioned object, the present invention provides a three-dimensional circuit exposure mask which conforms to the surface shape of a three-dimensional circuit forming substrate and is exposed to the surface of a photosensitive layer on the substrate. In the method of forming a three-dimensional circuit by forming a three-dimensional circuit by applying heat and pressure to the thermoplastic film, and pressing the thermoplastic film on the circuit forming surface of the three-dimensional circuit forming substrate to form the surface shape of the three-dimensional circuit forming substrate, and then using a laser The light-transmitting portion is opened in a slit shape, and thereafter, the light-transmitting portion is extracted from the substrate for forming a three-dimensional circuit, and the circuit is formed using a three-dimensional circuit exposure mask having the light-transmitting portion opened in a slit shape.

Further, in a three-dimensional circuit forming method for forming a three-dimensional circuit by exposing a three-dimensional circuit exposure mask conforming to the surface shape of a three-dimensional circuit forming substrate to a photosensitive layer surface on the substrate and exposing the same, a photocurable After applying heat and pressure to the film and pressing it against the circuit forming surface of the three-dimensional circuit forming substrate to form it into the surface shape of the three-dimensional circuit forming substrate, it is exposed to laser light to cure the resin, forming a light shielding portion, and Developing, removing the unexposed part, opening the light transmitting part in a slit shape, and then extracting it from the three-dimensional circuit board,
The circuit is formed using a three-dimensional circuit exposure mask having a light-transmitting portion opened in a slit shape.

In a three-dimensional circuit forming method for forming a three-dimensional circuit by exposing a three-dimensional circuit exposure mask conforming to the surface shape of a three-dimensional circuit forming substrate to a photosensitive layer surface of the substrate in close contact with the mask, the shape memory alloy Alternatively, using a shape memory resin, after storing the shape of the three-dimensional circuit forming substrate, returning to a flat plate and opening in a slit shape to form a light transmitting portion, and then returning to the stored three-dimensional shape, the light transmitting portion is The circuit is formed using a three-dimensional circuit exposure mask having a slit-like opening.

In a three-dimensional circuit forming method for forming a three-dimensional circuit by exposing a three-dimensional circuit exposure mask conforming to the surface shape of a three-dimensional circuit formation substrate to a photosensitive layer surface of the substrate, and exposing the light, a light transmitting portion is provided. The mask is made of metal or laminated board for the part where the slit is opened, and the mask with the film is used for the part with the unevenness. A circuit is formed.

[0008]

According to the present invention, a three-dimensional circuit exposure mask having the same shape as the three-dimensional circuit substrate is closely adhered to the three-dimensional circuit forming substrate without any gap (completely coincides) and exposed with scattered light. The same circuit formation as that described above can be performed. In addition, since the light transmitting portion of the conventional film mask has a transparent resin, UV light around 250 nm is absorbed and a wavelength required for photocuring is not transmitted. It is added to the photoresist. In the mask of the present invention, since the light transmitting portion is opened in a slit shape, UV light near 250 nm is not absorbed and a photocuring reaction occurs, so that a photopolymerization initiator is unnecessary.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. Example 1 FIG. 1 shows a process for forming a mask for three-dimensional circuit exposure, in which a three-dimensional circuit forming substrate (molded product) 9a is used as a matrix, and holes (not shown) through which air can be vented or evacuated as necessary. The molded product 9a serving as a matrix as shown in FIG.
A thermoplastic film 29 is placed on top of the film 29, and heat and pressure are applied to the thermoplastic film 29 as shown in FIG.
Is molded in close contact with a molded article 9a to be a matrix. Further FIG.
As shown in (c), a circuit pattern (light transmitting portion) 31 is punched by an excimer laser 30. When the film 29 is light-transmissive (ultraviolet light-transmissive), light-shielding properties are imparted by electroless plating, metallization such as sputtering, or coating of a light-shielding material. Next, as shown in FIG. 1D, the molded film 29 is removed from the matrix 9a to complete the three-dimensional circuit exposure mask 6. The slit-shaped opening 31 is also completed at the same time.

Next, FIG. 2 shows a process of forming a three-dimensional circuit. In the method of forming a three-dimensional circuit, a molded article (three-dimensional circuit forming substrate) 9a as shown in FIG. 2A is given conductivity as shown in FIG. 2B. As a method for imparting conductivity, a conductive layer 9b of copper, nickel, aluminum, or the like is formed by electroless plating or electroless plating + electrolytic plating, sputtering, vacuum deposition, or the like. Then, as shown in FIG. 2C, a photoresist 9c is applied by an electrodeposition method, a spray method, a dipping method or the like, and the mask 6 for three-dimensional circuit exposure described above is brought into close contact with the photoresist 9c and exposed by scattered light (FIG. d)), development (FIG. 2)
(E)), the etching and the removing process (FIG. 2 (f)) are completed to complete the three-dimensional circuit wiring board 9.

(Embodiment 2) FIG. 3 shows a process for forming a mask for three-dimensional circuit exposure, in which a three-dimensional circuit forming substrate (molded product) 9a is used as a matrix, and holes or holes for bleeding air or evacuating (FIG. (Not shown). As shown in FIG. 3A, a molded product 9a to be a matrix
The photo-curable film 32 is placed on the upper part of the substrate, and heat and pressure are applied as shown in FIG. 3 (b), and if necessary, the film 32 is turned into a matrix by evacuating the molded article 9a to be a matrix. It is closely molded to the molded product 9a. Or FIG. 3 (a1)
The photocurable liquid resin (for example, polyimide) 33 is coated on the molded article 9a serving as a matrix with a spray 33a as shown in FIG. Further, as shown in FIG. 3C, the circuit pattern is directly exposed and developed using a laser beam 34 or the like to form a circuit pattern 31 of the photocurable film 32 (the circuit pattern is a slit-shaped opening at the light transmitting portion). 31) If the light-cured portion is light-transmissive (ultraviolet light-transmissive), light-shielding treatment is performed as in the first embodiment. Next, as shown in FIG.
The molded film 32 is removed from the mask a, and the three-dimensional circuit exposure mask 6 and the opening 31 are completed. The formation process of the three-dimensional circuit is the same as that of the first embodiment.

Embodiment 3 FIG. 4 shows a process for forming a mask for three-dimensional circuit exposure. First, as shown in FIG. 4A, a molded product (three-dimensional circuit forming substrate)
9a is used as a mother die, and the shape is memorized by heat and pressure using a shape memory alloy 35 or a shape memory resin on the circuit forming surface of the molded article 9a serving as the master. After storing, FIG.
Return to flat plate as shown. Thereafter, as shown in FIG. 4C, the metal or resin is removed by using the laser light 34 to form the slit-shaped opening 31 in the light transmitting portion. Alternatively, as shown in FIG. 4D, an etching resist 36 is formed in the same manner as a general etching method. As a method of forming the etching resist 36, there are a method of screen-printing the etching resist 36, a method of forming a liquid resist or a dry film and exposing and developing the same. Next, as shown in FIG. 4E, the metal not covered with the resist 36 is removed using, for example, a ferric chloride etching solution. In the case of the shape memory alloy 35, this etchant may be any solution that dissolves this metal such as an acid. In the case of a shape memory resin, any solution may be used as long as the resin is soluble in a solvent such as DMF. Next, as shown in FIG. 4 (f), the shape memory alloy 35 or the shape memory resin of the flat plate in which the slit-shaped opening 31 is formed is returned to the stored shape by applying heat or the like. As shown in FIG. 4G, a three-dimensional circuit exposure mask 6 is completed. At the same time, a slit-shaped opening (light transmitting portion) 31 is completed. The formation process of the three-dimensional circuit is the same as that of the first embodiment.

(Embodiment 4) As shown in FIG. 5, there is provided a three-dimensional circuit exposure mask in which a circuit 31a corresponding to a light transmitting portion of the three-dimensional circuit exposure mask is provided only on a flat part of a molded product (three-dimensional circuit forming substrate) 9a. The formation process is shown in FIG. First, as shown in FIG. 6A, a slit-shaped opening 31 is formed in a glass epoxy substrate 36a. The glass epoxy substrate 36a uses a metal plate, a laminated plate, or the like. The method of forming the slit-shaped opening 31 includes a method of forming an etching resist 37 and removing it by etching (FIG. 6E), and a method of removing and processing with a laser beam 34 (FIG. 6F). Next, as shown in FIG. 6B, the glass epoxy substrate 3 is placed on a flat portion of a molded product (three-dimensional circuit forming substrate) 9a of, for example, an 18 μm polyimide film 37a, that is, a portion on which the glass epoxy substrate 36a is placed.
Drill a hole 39 slightly smaller than 6a. Then, FIG.
As shown in (c), the glass epoxy substrate 36a is placed on the portion of the polyimide film 37a where the hole 39 is opened, and bonded. Further, as shown in FIG. 6 (d), a glass epoxy substrate 40 containing this polyimide film, that is, a hard substrate is provided on the polyimide film, and a member having both a hard portion and a flexible portion is molded by heat and pressure. (Three-dimensional circuit forming substrate) 9a glass epoxy substrate 36
a so as to be positioned on the flat portion.

[0014]

According to the present invention, as described above, a mold for forming a mask for three-dimensional exposure is unnecessary, and the light transmitting portion is opened in a slit shape without the presence of a transparent resin or the like. Since a connecting portion for connecting the masks is provided so as not to hinder the light transmission, the light energy for exposure is not absorbed in this portion, and there is no loss, so that the exposure time can be shortened.

[Brief description of the drawings]

FIGS. 1A to 1D are explanatory views of a process for forming a mask for three-dimensional circuit exposure.

FIGS. 2A to 2F show an example of a three-dimensional circuit forming process.

3 (a) to 3 (d), (a1) and (b1) are explanatory views of a process for forming a mask for three-dimensional circuit exposure.

FIGS. 4A to 4G are explanatory views of a process of forming a mask for three-dimensional circuit exposure.

FIG. 5 is a sectional view of a three-dimensional circuit wiring board.

FIGS. 6A to 6F are explanatory views of a process of forming a mask for three-dimensional circuit exposure.

[Explanation of symbols]

 6, 10 Three-dimensional circuit exposure mask 9 Three-dimensional circuit wiring board 9a Molded product (three-dimensional circuit forming substrate) 9c, 36 Photoresist 18 Irregularities 34 Laser light 29 Thermoplastic film 30 Excimer laser 32 Photocurable film 35 Shape memory alloy 36a Glass epoxy board 37a Polyimide film

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H05K 3/18 H05K 3/18 D (72) Inventor Hiroaki Kitamura 1048 Ojidoma, Kadoma City, Osaka Prefecture Matsushita Electric Works, Ltd. (72 Inventor Norio Kamata 1048 Odakadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Works Co., Ltd. 1048 Kadoma, Ichidai-shi Matsushita Electric Works, Ltd. (56) References JP-A-54-27367 (JP, A) JP-A-54-27368 (JP, A) JP-A-2-111528 (JP, A) Kaihei 2-251959 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05K 3/00

Claims (4)

(57) [Claims] 1. A three-dimensional circuit forming method for forming a three-dimensional circuit by exposing a three-dimensional circuit exposure mask conforming to the surface shape of a three-dimensional circuit forming substrate to the surface of a photosensitive layer on the substrate so as to form a three-dimensional circuit. After applying heat and pressure to the substrate and pressing it against the circuit forming surface of the three-dimensional circuit forming substrate to form it into the surface shape of the three-dimensional circuit forming substrate, the light transmitting portion is opened in a slit shape with a laser, and then from the three-dimensional circuit forming substrate. A method of forming a three-dimensional circuit, wherein a circuit is formed using a three-dimensional circuit exposure mask in which a light-transmitting portion is opened in a slit shape. 2. A three-dimensional circuit forming method for forming a three-dimensional circuit by exposing a three-dimensional circuit exposure mask conforming to the surface shape of a three-dimensional circuit forming substrate to a photosensitive layer surface of the substrate in close contact with the photosensitive layer. After applying heat and pressure to the film and pressing it against the circuit forming surface of the three-dimensional circuit forming substrate to form it into the surface shape of the three-dimensional circuit forming substrate, it is exposed to laser light to cure the resin, forming a light shielding portion, and After developing, the unexposed portion is removed, the light transmitting portion is opened in a slit shape, and thereafter, the light transmitting portion is extracted from the three-dimensional circuit forming substrate, and the circuit is formed using a three-dimensional circuit exposure mask in which the light transmitting portion is opened in a slit shape. A method for forming a three-dimensional circuit, wherein the method is performed. 3. A three-dimensional circuit forming method for forming a three-dimensional circuit by exposing a three-dimensional circuit exposure mask conforming to the surface shape of a three-dimensional circuit formation substrate to a photosensitive layer surface of the substrate in close contact with the mask, and comprising: Alternatively, using a shape memory resin, after storing the shape of the three-dimensional circuit forming substrate, returning to a flat plate and opening in a slit shape to form a light transmitting portion, and then returning to the stored three-dimensional shape, the light transmitting portion is A method of forming a three-dimensional circuit, comprising forming a circuit using a three-dimensional circuit exposure mask having a slit-like opening. 4. A three-dimensional circuit forming method for forming a three-dimensional circuit by exposing a three-dimensional circuit exposure mask conforming to the surface shape of a three-dimensional circuit formation substrate to a photosensitive layer surface of the substrate and exposing the light to a light transmitting portion. The mask is made of metal or laminated board for the part where the slit is opened, and the mask with the film is used for the part with the unevenness. A method for forming a three-dimensional circuit, comprising forming a circuit.