JPH0818375B2 - Printed wiring board base material using photocurable resin and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board substrate, and more particularly to a novel method for producing a printed wiring board substrate.

[0002]

2. Description of the Related Art Printed wiring boards are now widely used due to the development of computers and various communication devices. As a base material of a printed wiring board, a glass fiber woven fabric, a glass fiber non-woven fabric paper, etc. are used as a reinforcing material, and a laminated board using an epoxy resin polyester resin, a phenol resin, a polyimide resin, etc. as a matrix is mainstream. Has become. Since a current printed wiring board is manufactured by combining a raw material glass fiber base material and a matrix resin, it takes a very long process to form a printed wiring board. For example, in the case of a printed wiring board made of a glass fiber woven fabric and an epoxy resin, the glass fiber woven fabric is first impregnated with the epoxy resin and dried to form a prepreg. A required number of prepregs are laminated, copper foil or the like is further laminated, and hot pressed to form a laminated plate. Further, a circuit is created through a resist process and an etching process, and holes for through holes are drilled according to the circuit to obtain a chip-mountable printed wiring board.

As a method for manufacturing a printed wiring board using such a laminated board, a method for manufacturing a printed wiring board by injection molding has been proposed. In this method, a thermoplastic resin is used as a matrix resin, and a circuit already formed on a transfer sheet is transferred simultaneously with injection molding, so that the circuit is provided on the molded body simultaneously with the molding. The printed wiring board obtained by this method can be not only a plate-shaped one but also one having a complicated three-dimensional shape. The printed wiring board manufactured in this way is naturally limited in its application due to the performance of the board itself and the limitations of the wiring patterns that can be given, but there is also a merit that the molding cycle is greatly shortened. The field of use is expanding.

On the other hand, although not related to the field of printed wiring boards,
A stereolithography method has been proposed as a method for obtaining a plastic molded body. For example, JP-A-62-10140
8, JP-A-63-251227, JP-B-63-4065
There is 0 etc. In this method, a photocurable resin is placed in a container, and a resin beam is irradiated onto the resin surface according to a desired shape to cure the resin. Rubbing the resin surface and irradiating with a laser beam,
A cured resin layer is further formed on the cured resin layer.
By repeating this and slightly changing the shape irradiated by the laser beam each time, a desired three-dimensional object can be obtained.

The pattern irradiated by the laser is CA in advance.
A three-dimensional image designed by D is drawn by instructing a figure cut into a thin layer via a personal computer or the like to automatically move the irradiation unit, the resin container, or the like. It is said that laser light is suitable as a light beam because of its high energy level and light convergence.
As a modification of this optical shaping method, a method of irradiating a plane ray such as ultraviolet rays through a masking film or the like to perform shaping has been proposed.

[0006]

As a method for obtaining a printed wiring board, a method using a laminated board which is generally performed is as follows.
As mentioned above, the process is long and lacks responsiveness to small-volume production of other products and orders from users. In addition, the injection molding method requires designing, processing and time for producing a die, and the die cost is high. In addition, this method is not suitable for small-lot production of other products because it requires a mold. An object of the present application is to provide a substrate for a printed wiring board having a through hole formed in a desired shape according to the purpose of use in addition to a vertical through hole, and a method for manufacturing the same.

[0007]

According to a first aspect of the means for solving the above-mentioned problems, a photocurable resin is housed in a container, and a masking means is provided near and above the surface of the resin. Through which the planar light is transmitted to cure the planar light-irradiated portion of the photocurable resin into a thin layer, and relatively move the thin layer cured product, and masking means according to a desired shape. In the method for producing a substrate for printed wiring board having a desired three-dimensional shape by repeating the same operation as above while moving the substrate, and successively laminating and molding the cured thin layer product. The side surface of is in the substrate for a printed wiring board manufactured by this manufacturing method.

The photocurable resin used in the present application is
Various resins that are cured by light irradiation can be used. For example, modified polyurethane methacrylate, oligoester acrylate, urethane acrylate, epoxy acrylate, photosensitive polyimide, aminoalkyd, etc. can be used. In addition, a UV curable resin (Spirac: Showa High Polymer Co., Ltd.), which has recently been developed and mainly uses diarylidene pentaerythritol, can also be used. It is also possible to add calcium carbonate, filler such as silica sand, milled fiber of glass fiber or the like to these resins.

As the light used in the present application, various kinds of light such as visible light and ultraviolet light can be used depending on the type of photocurable resin used. Also, it is desirable to use a wide range of collimated light to prevent interference.

The masking means may be a masking film or a light valve. The light valve referred to in the present application is a group of pixels that can freely change light into a transparent or non-transparent state according to an instruction from the outside, and is usually driven by a microcomputer or the like.

[0011]

OPERATION AND EXAMPLES Examples of the manufacturing method of the present application will be described using the apparatus illustrated in FIG. 1 which uses a light valve as a masking means. Is a UV light source, is a light valve,
Is a photocurable resin, is a position control device for a cured product, is a container, and is a cured product holding plate. The cured product holding plate is set at a position close to the surface in the photocurable resin contained in the container. Fix the light valve near the top of the resin surface. The plane light of ultraviolet rays is irradiated from the upper part of the light valve. By this irradiation, the portion irradiated with the UV light that has passed through the resin light valve above the holding plate is cured into a thin layer. After curing by irradiation for a certain period of time, when the position control device is shifted slightly downward, the uncured resin again covers the cured product formed on the holding plate. This portion is further irradiated with ultraviolet rays through a masking means to be cured into a thin layer.

By repeating such curing in order,
A laminate of the cured thin layer is formed on the holding plate. The planar shape of this laminated body is determined by the pattern drawn on the light valve. The three-dimensional shape is determined by changing the drawn pattern of the light valve. FIG. 2 shows an example of the printed wiring board substrate of the present invention, but the shape is determined according to the figure drawn on the light valve. That is, a figure having a small circular light-impermeable portion is drawn on a 30 cm square.
The same applies to the case of a masking film, but unlike the case of a light valve, the obtained three-dimensional shape is often slightly restricted.

After irradiation for a certain period of time, the thin-layer cured product is moved in the vertical direction, and then the light valve pattern is changed. Only the portion a is deviated, and this is sequentially performed at the same time when the thin layer cured product is relatively moved in the vertical direction.

The molded product obtained as a result has a small shape in the form of a 30 cm square plate as shown in FIGS. 3 and 4, depending on the desired shape previously stored in the microcomputer. One with holes is obtained. In this way, a printed wiring board substrate having through holes can be easily obtained.

By changing the shape of the light valve by variously changing the shape stored in the computer, as shown in FIG.
It is also possible to obtain a substrate for a printed wiring board having a through hole as shown in FIG. 6 or FIG. That is, according to this method, it is possible to relatively easily obtain a substrate for a printed wiring board having bent through holes in a single time. Therefore, by masking the positions of the through holes required from the circuit design drawing using the masking means, a substrate for a printed wiring board that does not require drilling can be obtained. The base material thus obtained has a circuit formed by an additive method such as electroless plating according to a conventional method to obtain a printed wiring board.

The method of the present application has a complicated three-dimensional shape.
Even in the case of molded products that use
Very easy to use, very easy equipment
As a result, the desired printed wiring board can be obtained in a short time as compared with the usual method for manufacturing a printed wiring board.
Further, it can be said that the method is suitable for high- mix low-volume production as compared with a method for producing a printed wiring board by injection molding using a transfer method. It is said that the stereolithography method using a laser beam is not suitable for a molded article having a large area because it requires point irradiation and thus is time-consuming.

Example 1 Using the apparatus schematically shown in FIG. 1, a high pressure mercury lamp 2 KW (80 W / cm) was used as an ultraviolet light source, and an irradiation distance of 1
0 cm, and as a photo-curable resin, Spylac T-502
(Showa High Polymer Co., Ltd.) and light valve (DAT
It is fixed at a position of about 2 mm on the surface of the resin by using A DISPLAY PANEL Eki Kogyo Co., Ltd. Under these conditions, the holding plate is moved downward at regular intervals,
A substrate for a printed wiring board having a size of 30 cm × 30 cm and a thickness of 1.6 mm and 6 through holes was obtained as shown in (1). It took about 30 minutes.

Example 2 The same conditions as in Example 1 were used except that the photocurable resin was Spylac T-510. It took about 20 minutes to obtain a printed wiring board substrate having a size of 30 cm × 30 cm and a thickness of 1.6 mm.

Third Embodiment The same as the first embodiment except that one of the six through-hole patterns set in the light valve is slightly shifted to form a through-hole as shown in 9-a of FIG. I went under the conditions. A substrate for a printed wiring board having a size of 30 cm × 30 cm and a thickness of 1.6 mm could be obtained. Five of the six through holes of the obtained printed wiring board base material were parallel to the thickness direction of the base material, and the remaining one was obliquely inclined with respect to the thickness direction.

[0020]

According to the present invention, as compared with the conventional method, a simple method for preparing a large-area printed wiring board substrate, which is suitable for small-volume production of other products and has a very short time from order receipt to delivery,
Can be obtained with the device. Further, the printed wiring board substrate obtained according to the present application does not require a drilling process or a punching process, and has a great advantage that it can be obtained as a substrate having a through hole at the same time as molding.

Further, the present application provides a base for a printed wiring board in which a hole for a through hole is formed in a direction other than the direction perpendicular to the surface to be drilled and the path of the hole is a straight line or a curved line. Because it is a material, when connecting circuits on both sides of the wiring board, it is possible to connect the positions to be connected with the shortest distance, which reduces the circuit density on the surface of the wiring board and simplifies circuit formation. . Further, if the circuit density is the same, the wiring board can be made smaller.

[Brief description of drawings]

FIG. 1 is a schematic view of an apparatus used in a manufacturing method of the present application using a light valve.

FIG. 2 is a schematic diagram showing the printed wiring board substrate of the present application in relation to the light valve used in FIG.

FIG. 3 For the printed wiring board of the present application, in which one of the through holes has a relative position between the upper portion of the base material and the lower portion of the base material in order to make the shape other than the vertical state according to the purpose of use. The schematic diagram which shows a base material.

FIG. 4 is a cross-sectional perspective view of a schematic view showing a state of through holes of the wiring board base material of FIG.

FIG. 5 is a perspective view of a cross section schematically showing the shape of a through hole of one embodiment of the printed wiring board substrate of the present application.

FIG. 6 is a perspective view of a cross section schematically showing the shape of a through hole of one embodiment of the printed wiring board substrate of the present application.

FIG. 7 is a perspective view of a cross section schematically showing the shape of a through hole of one embodiment of the printed wiring board base material of the present application.

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Claims (3)

[Claims] 1. A photocurable resin is housed in a container, a masking means composed of a light valve is provided in the vicinity of an upper portion of the surface of the resin, a through hole pattern is set in the masking means, and a through hole pattern is set. The planar light is transmitted through the masking means, the planar light irradiated portion of the photocurable resin is cured into a thin layer having a through-hole pattern, and then the thin layer cured product is relatively moved. , The light is transmitted through the masking means having the through-hole pattern set thereon again, and the flat light of the photo-curing resin is irradiated with the irradiated portion to be newly molded as the thin-layer cured product, and the above-mentioned steps are sequentially performed. A method for producing a base material for a printed wiring board having a through hole, which is obtained by laminating and molding thin layer cured products by repeating the operation. 2. The at least one through hole is set as a base material by setting the positions of at least one through hole pattern among the through hole patterns set in the masking means according to claim 1 so as to be slightly shifted in sequence. Of manufacturing a substrate for a printed wiring board having through holes that are non-parallel to the thickness direction of the substrate. 3. A printed wiring board base material made of a photocurable resin, wherein the base material has through holes, and at least one of the through holes is non-parallel to the thickness direction of the base material. A substrate for a printed wiring board, which is characterized by being present.