JP2003243825A - Method of manufacturing printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a flat wiring board by applying an uncured resin to the surface of a substrate and curing the resin after the surface of the resin is roughly flattened with a roller. <P>SOLUTION: In a first step, the wiring board 15 obtained by forming a wiring pattern 2 on an insulating substrate 1a and applying the uncured insulating resin 3c to the substrate 1a is put on a belt 17 and transported to the right side in the figure. In a second step, a film 9 is brought into contact with the surface of the uncured insulating resin 3c and the wiring board 15 is moved to the right side in the figure while the surface of the resin 3c is pressed with a pressurizing roller 10 from the upside of the film 9. In a third step, the resin 3c is cured into a cured insulating resin 3c' by uniformly projecting ultraviolet rays upon the surface of the wiring board 15 from an ultraviolet-ray irradiating device 13. When the resin 3c is cured, the film 9 becomes peelable. In a fourth step, the film 9 is wound up by means of a wind-up roller 12' while the wiring board 15 is cooled by means of a cooler 14. Thus the flattened wiring board 15 can be obtained. <P>COPYRIGHT: (C)2003,JPO

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 printed wiring board for flattening a surface layer of a substrate on which a circuit pattern is formed, and more specifically, a multilayer substrate in which circuit patterns are laminated in a plurality of layers. The present invention relates to a method for manufacturing a printed wiring board, in which the surface of each board can be flattened and laminated in high density when the layers are laminated by a build-up method.

[0002]

2. Description of the Related Art In recent years, as electronic devices have become smaller, lighter and more multifunctional, the density of printed wiring boards has increased and the number of layers has increased, and so-called build-up multilayer printed wiring boards have become mainstream. is there. Hereinafter, a method for manufacturing a multilayer printed wiring board by a build-up method will be described with reference to the drawings. FIG. 7 is a process diagram showing a conventional method for manufacturing a multilayer printed wiring board. In FIG. 7, step (a)
Then, the copper-clad laminate 1 in which the copper foil 1b is attached to the upper surface of the insulating substrate 1a is prepared. Next, in step (b), the copper foil 1b laminated on the surface of the insulating substrate 1a is etched by a general photoetching method to form a wiring pattern 2 having a predetermined circuit configuration.

In step (c), a so-called resin-coated copper foil (RC) in which a semi-cured insulating resin 3a is applied to the copper foil 3b
C: Resin Cotted Copper) 3 is laminated on the insulating substrate 1a on which the wiring pattern 2 is formed. Then, in step (d), a predetermined hole is opened in the resin-coated copper foil 3 by mask etching or the like, and the inner wall of the hole is plated with copper to electrically connect the lower wiring pattern 2 and the upper copper foil 3b to each other. The via hole 4 is formed so as to be electrically connected. This via hole 4 is generally called through-hole plating.

Next, in the step (e), the second layer is formed by etching the copper foil 3b to form a circuit by the same method as the method of forming the wiring pattern 2 by the photo-etching method in the step (b). The wiring pattern 5 is formed. As a result, the second-layer wiring pattern 5 is formed and electrically connected to the first-layer wiring pattern 2. By repeating such steps, a multilayer printed wiring board can be formed.

[0005]

However, when the multilayer printed wiring board is formed by the above-mentioned build-up method, there occurs a problem that a high flatness cannot be obtained in the wiring patterns of the second or more layers. In the conventional manufacturing process, when the resin-coated copper foil 3 coated with the semi-cured insulating resin 3a is laminated on the insulating substrate 1a in the step (c) of FIG. 1, the insulating resin 3a is in the semi-cured state. Therefore, the thickness of the insulating resin 3a is different between the portion having the wiring pattern 2 in the lower layer and the portion not having the wiring pattern 2. That is, the wiring pattern 2
The surface of the insulating resin 3a is bulged (becomes a convex portion) in a portion right below, and the surface of the insulating resin 3a is dented (becomes a concave portion) in a portion not directly below.

FIG. 8 is an enlarged sectional view of a portion A in the laminated structure in the step (e) of FIG. That is, as mentioned above,
Since the semi-cured insulating resin 3a is laminated on the insulating substrate 1a in the step (c) of FIG. 7, the surface of the insulating resin 3a has a convex portion at a position directly below the wiring pattern 2 as shown in FIG. Therefore, the wiring pattern 2 becomes a recess at a place not directly below. Therefore, when the wiring pattern 5 of the second layer is formed, the surface height of the wiring pattern 5 of the second layer becomes uneven because the thickness of the insulating resin 3a is not uniform. Due to such a cause, the higher the flatness of the wiring pattern in the upper layer portion, the more the multilayer substrate becomes multilayered.

When the flatness of the wiring pattern of the multilayer printed wiring board is impaired, it causes various problems in electrical characteristics, especially in the multilayer printed wiring board of electronic equipment which is required to support high speed and high frequency. Become. For example, there is a possibility that the propagation of a high-frequency signal may be hindered or an insulation problem may occur. In particular, as the number of printed wiring boards is increased to three layers or four layers, the surface irregularities become large, which makes it difficult to form a fine wiring pattern by the subtractive method.

Therefore, in order to flatten the printed wiring board having the uneven surface as described above, for example, Japanese Unexamined Patent Application Publication No.
Japanese Patent Laid-Open No. 000-277921, Japanese Patent No. 3108024, and the like propose a method of embedding a resin between wiring patterns by a screen printing method and then flattening the surface of the resin. According to the techniques of these publications, in a build-up wiring board, a via hole is formed and then the surface is highly flattened to form an upper wiring pattern, thereby providing a high-quality and highly reliable multilayer printed wiring board. Can be realized.

However, as described above, when the resin is applied by the screen printing method, while the surface of the portion where the wiring pattern is formed in the lower layer is raised,
The portion where the wiring pattern is not formed in the lower layer is in a depressed state. Therefore, in the technique of each of the above-mentioned publications, in order to flatten the pattern surface on which the upper wiring pattern is formed, an insulating resin is printed on the surface by a screen printing method, and the insulating resin is ground to polish the surface. The whole is flattened. However, in such a flattening step, since there is a large variation in the film thickness when the insulating resin is printed on the surface of the printed wiring board, as a practical matter, it is difficult to flatten the surface with high accuracy. That is, according to the conventional technique, it is extremely difficult to highly accurately planar-polish a printed wiring board having an uneven surface.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to apply an uncured resin to the surface in the step of flattening the surface of a pattern on which a circuit is formed, It is an object of the present invention to provide a method for manufacturing a printed wiring board capable of forming a highly flat multi-layered board by substantially flattening with a roller, hardening the resin, and then polishing the surface.

[0011]

In order to achieve the above object, a method of manufacturing a printed wiring board according to the present invention is a method of manufacturing a printed wiring board for flattening a surface layer of a board on which a circuit pattern is formed. In the resin forming step of applying a uncured resin to the surface of the substrate to form a resin layer, the surface of the uncured resin is covered with a film, and the film is evenly pressed using a pressure roller to remove the uncured resin. It is characterized by including a flattening step of flattening the surface, a curing step of curing the uncured resin, and a peeling step of peeling the film.

Further, in the method for manufacturing a printed wiring board according to the present invention, the film is a transparent film, and in the curing step, the uncured resin is cured by irradiating the entire surface of the uncured resin with ultraviolet rays through the film. It is characterized by

Further, the method for manufacturing a printed wiring board according to the present invention is characterized in that a cooling step for cooling the substrate is provided between the curing step by irradiation heat of the uncured resin with ultraviolet rays and the peeling step.

Further, in the method for manufacturing a printed wiring board according to the present invention, after the resin forming step, a masking step of masking the surface of the uncured resin in the area where the circuit pattern is formed, and the unmasked area in the unmasked area And a partial curing step of irradiating the surface of the cured resin with ultraviolet rays to cure the uncured resin in the area irradiated with the ultraviolet rays.

Further, the method for manufacturing a printed wiring board according to the present invention comprises a resin forming step of forming a resin layer by applying an uncured resin on the surface of the board, and covering the surface of the uncured resin with a film, and applying a pressure roller. A flattening step for uniformly pressing the film by using the flattening surface of the uncured resin, a cutting step for cutting the film for each substrate, and a storage for storing the cut substrate in a thermosetting bath. The method is characterized by including a step, a thermosetting step of thermosetting the uncured resin of the substrate housed in the thermosetting tank, and a peeling step of peeling the film from the cured resin cured above.

The method for manufacturing a printed wiring board according to the present invention is the same as the method for manufacturing a printed wiring board for flattening the surface layer of a board on which a circuit pattern is formed, by applying an uncured resin to the surface of the board. A resin forming step of forming a resin layer with a film, a flattening step of covering the surface of the uncured resin with a film and uniformly pressing the film using a pressure roller to flatten the surface of the uncured resin, A semi-curing step of irradiating the uncured resin with ultraviolet rays to semi-cure the uncured resin, a peeling step of peeling the film from the semi-cured cured resin, and the substrate from which the film has been peeled is stored in a thermosetting tank And a heat curing step of thermally curing the semi-cured resin of the substrate stored in the heat curing tank.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Several embodiments of a method for manufacturing a printed wiring board according to the present invention will be described in detail below with reference to the drawings. The method for manufacturing a printed wiring board according to the present invention includes printing an uncured insulating resin such as a liquid epoxy resin on a substrate, laying a film on the surface and flattening the surface substantially with a pressure roller, and then curing the insulating resin with ultraviolet rays. After that, by performing surface polishing, a highly flat multilayer printed wiring board is manufactured. Alternatively, by curing only the portion where there is no wiring pattern in the lower layer with ultraviolet rays, the entire surface is flattened with a pressure roller, and then the entire resin is cured with ultraviolet rays to perform surface polishing,
It is characterized in that a highly flat multilayer printed wiring board is manufactured.

First Embodiment FIG. 1 is a process diagram of a method for manufacturing a printed wiring board according to the first embodiment of the present invention. In the first embodiment, in step (a), a copper-clad laminate 1 is prepared in which a copper foil 1b is attached to the upper surface of an insulating substrate 1a such as a glass epoxy substrate. Next, in step (b), the copper foil 1b laminated on the surface of the insulating substrate 1a is etched by a general photoetching method to form a wiring pattern 2 having a predetermined circuit configuration.

Further, the following steps are sequentially performed on the wiring board on which the wiring pattern 2 is formed as in step (b). First, "insulating resin coating step" shown in step (c1)
In, the uncured insulating resin 3c such as a liquid epoxy resin of ultraviolet curing type is applied by a screen printing method or the like between the wiring patterns 2 of the insulating substrate 1a and on the surface of the wiring pattern 2. Insulating resin 3b applied at this time
May contain fine bubbles, so vacuum is applied to remove the bubbles inside the uncured insulating resin 3c.

Next, in the "insulating resin flattening step" shown in step (d), a transparent film 9 such as a Teflon (registered trademark) film is laid on the uncured insulating resin 3c, and then the insulating substrate 1a is placed. The wiring board 15 is passed between the pressure rollers 10 while the pressure roller 10 applies pressure to the upper and lower sides of the wiring board 15 serving as a base. Then, the uncured insulating resin 3c is flattened by being pressed by the pressure roller 10. After that, in the "ultraviolet curing step" shown in step (e), ultraviolet rays 7 are applied to the entire uncured insulating resin 3c from above the transparent film 9 to cure the resin to cure the cured insulating resin 3c.
Set to c '.

As a result, as shown in the "film peeling step" of step (f), when the film 9 on the surface of the cured insulating resin 3c 'is peeled off, the wiring board 15 having a substantially flat surface is obtained. And the "polishing step" of step (g)
As shown in, the surface of the cured insulating resin 3c 'is highly flattened by polishing the surface of the cured insulating resin 3c' to a predetermined thickness by, for example, a belt polishing method. In this way, the hardened insulating resin 3c 'in the upper layer is uniformly and highly flattened in both the portion where the wiring pattern 2 is present in the lower layer and the portion where the wiring pattern 2 is not present. Therefore,
The wiring patterns of the second and subsequent layers formed on the surface of the cured insulating resin 3c 'are highly accurately flattened, and as a result, a printed wiring board suitable for a high-density mounted multi-layered board is manufactured. be able to.

Next, an example of a manufacturing process line for the printed wiring board shown in the first embodiment will be described. Figure 2
FIG. 3 is a diagram showing a manufacturing process line of the printed wiring board in the first embodiment shown in FIG. 1. This manufacturing process line is a line by belt conveyance, and while being supported by a large number of conveyance rollers 11, the rotary rollers 1 on both ends are supported.
The belt 17 drives the conveyor between 6 and 16 '.
The rotary rollers 16 and 16 'are rotationally driven by a motor (not shown).

In the first step, the wiring pattern 2 is formed on the insulating substrate 1a, and the wiring substrate 15 coated with the uncured insulating resin 3c is placed on the belt 17 to
Sheets are conveyed to the right in the figure one by one. Further, a film 9 wound around the winding roller 12 to the winding roller 12 ′ is arranged in the middle of the manufacturing process line. Film 9
Is provided to evenly press the uncured insulating resin 3c by the pressure roller 10 to flatten it and to prevent the uncured insulating resin 3c from adhering to the pressure roller 10.

In the second step, that is, the pressing step, the film 9 is brought into contact with the surface of the uncured insulating resin 3c, and the pressing roller 10 presses the film 9 from above the uncured insulating resin 3c.
The wiring board 15 moves to the right in the figure while pressing the surface of c. Further, in the third step, that is, the ultraviolet irradiation step, the surface of the wiring board 15 is uniformly irradiated by the ultraviolet irradiation device 13, so that the uncured insulating resin 3c is cured to be the cured insulating resin 3c '. Further, the film 9 becomes in a peelable state by the heating action of the ultraviolet rays.

Next, in the fourth step, that is, the cooling step, the film 9 is wound around the roller 9 while cooling the ultraviolet irradiation heat of the wiring board 15 by the cooler 14 such as a fan.
Take it up by 2 '. Since the film 9 is cooled by passing through the fourth step (cooling step), the film 9 can be easily peeled off. It is not necessary to provide the fourth step (cooling step) as long as the ultraviolet irradiation heat is sufficiently cooled after the third step (ultraviolet irradiation step). The cured insulating resin 3c ′ on the surface of the wiring substrate 15 is passed through these steps.
Is substantially flattened, the surface of the wiring board 15 can be highly flattened by performing a polishing operation in the next step (not shown).

FIG. 3 is an enlarged view of the film-bonded portion in the portion B of FIG. This drawing shows a state in which the film 9 is being pressed by the pressure roller 10 while being adhered to the surface of the uncured insulating resin 3c. As an example, when the size of the wiring board 15 to be processed is 250 × 340 (mm) to 79 × 125 (mm), the diameter of the pressure roller is 1.
Those of 0, 20, 30 (mm) can be used by appropriately exchanging them. The pressure roller 10 has, for example, a hardness of 75 °.
Made of elastic material such as ethylene propylene rubber.
Further, the input angle of the film 9 can be continuously changed from 45 ° to 100 °. The moving speed of the belt 17 can be continuously changed in the range of 0.1 to 3.0 (m / min).

Second Embodiment Next, a second embodiment of the method for manufacturing a printed wiring board according to the present invention will be described. FIG. 4 is a process drawing of the method for manufacturing a printed wiring board according to the second embodiment of the present invention. In the second embodiment, before the "insulating resin flattening step" by film pressing in the step (d) in the first embodiment, a step (c2) of partial ultraviolet irradiation by masking and a step of insulating resin The step (c3) of partial curing is added.

In FIG. 4, in step (a), a copper-clad laminate 1 in which a copper foil 1b is attached to the upper surface of an insulating substrate 1a such as a glass epoxy substrate is prepared. Next, in step (b),
By a general photo-etching method, the copper foil 1b laminated on the surface of the insulating substrate 1a is etched,
The wiring pattern 2 having a predetermined circuit configuration is formed.

Further, as in the step (b), the following steps are sequentially performed on the wiring board on which the wiring pattern 2 is formed. First, "insulating resin coating step" shown in step (c1)
In, the uncured insulating resin 3c such as a liquid epoxy resin of ultraviolet curing type is applied by a screen printing method or the like between the wiring patterns 2 of the insulating substrate 1a and on the surface of the wiring pattern 2. Insulating resin 3b applied at this time
May contain fine bubbles, so vacuum is applied to remove the bubbles inside the uncured insulating resin 3c.

Next, as shown in "UV partial irradiation step" of step (c2), the mask 6 is applied to the uncured insulating resin 3c to irradiate it with ultraviolet light 7. As the mask 6 at this time, a mask is used such that the ultraviolet light 7 irradiates only the uncured insulating resin 3c above the portion where the wiring pattern 2 is absent. By performing such partial irradiation of ultraviolet rays, the step (c
As shown in "3) Insulating resin partial curing step", the uncured insulating resin 3c on the upper part of the part where the wiring pattern 2 is not formed on the lower part
Only ultraviolet rays are cured to become cured insulating resin 3c '. That is, the upper portion of the wiring pattern 2 remains the uncured insulating resin 3c.

Next, in the "insulating resin flattening step" shown in step (d), a transparent film 9 such as a Teflon (registered trademark) film is interposed on the upper surface, and then the insulating substrate 1
The wiring board 15 is passed between the pressure rollers 10 while the pressure roller 10 applies pressure to the upper and lower sides of the wiring board 15 whose base is a. Then, the uncured insulating resin 3 on the wiring pattern 2 is formed.
c is crushed by the pressure roller 10 and flattened. At this time, since the cured insulating resin 3c ′ on the upper surface of the portion where the wiring pattern 2 is not present is already cured, the cured insulating resin 3c ′ is not dented by the pressure of the pressure roller 10, and the surface is stably flattened. To be done. Since steps (e) to (g) are the same as those in the first embodiment, description thereof will be omitted.

Third Embodiment In the third embodiment, a process for thermosetting the semi-cured insulating resin only by heat treatment will be described. FIG. 5 is a process diagram of the manufacturing line in which the semi-cured insulating resin is thermoset only by the heat treatment in the third embodiment. Note that FIG. 5 shows only the main part in the process diagram of the manufacturing line in FIG. In the thermosetting process in the third embodiment, ultraviolet rays are applied while pressing the wiring substrate 15 with the pressure roller 10 with the film 9 interposed on the surface of the wiring substrate 15 (that is, the surface of the semi-cured insulating resin). The semi-cured insulating resin is conveyed to the right in the figure without irradiation.

At this time, since the surface layer of the wiring substrate 15 remains the semi-cured insulating resin, the film 9 remains adhered. Therefore, in the next step, the film 9 is cut by a cutter (not shown) or the like, and the wiring board 15 is sent out of the conveyor belt 17. As a result, the wiring board 15 to which the film 9 is attached becomes
Fall inside. Then, the wiring board 15 is left in the thermosetting tank 18 at a predetermined temperature for a predetermined time, for example, in the thermosetting tank 18 at 150 ° C. for 30 minutes, so that the semi-cured insulating resin is cured. The film 9 is in a peelable state. Of course, at this time, the surface of the cured insulating resin is almost flattened by pressing the film 9. Therefore, by polishing the wiring board 15 obtained in the third embodiment, it is possible to obtain higher planarization.

Fourth Embodiment In the fourth embodiment, a process of using ultraviolet irradiation and heat treatment together to peel off the film and cure the semi-cured insulating resin will be described. FIG. 6 is a process diagram of a manufacturing line in which the semi-cured insulating resin is cured by using ultraviolet irradiation and heat treatment in combination in the fourth embodiment. In the fourth embodiment, after the film 9 is interposed on the surface of the wiring board 15 (that is, the surface of the uncured insulating resin), the pressure roller 10 presses the wiring board 15 and then the ultraviolet light is irradiated by the ultraviolet irradiator 13. While irradiating the surface of the wiring board 15, the surface of the wiring board 15 is semi-cured and is transported to the right side of the drawing.

At this time, the irradiation amount of the ultraviolet rays is set to a semi-curing level at which only the film 9 can be peeled off without completely curing the uncured insulating resin. Alternatively, a resin material in which the uncured insulating resin is hard to be completely cured by ultraviolet rays is selected and applied. Next, the film 9 is wound by the winding roller 12 ′ while cooling the ultraviolet irradiation heat of the wiring substrate 15 by the cooler 14 such as a fan. In this way, the film 9 can be easily peeled off by cooling the wiring board 15. The cooler 14 need not be provided as long as the irradiation heat of the ultraviolet rays is sufficiently cooled.

In this way, when the wiring substrate 15 from which the film 9 is peeled off is sent out of the conveyor belt 17,
Only the wiring board 15 falls into the thermosetting bath 18. Then, the wiring board 15 is left in the thermosetting bath 18 at a predetermined temperature for a predetermined time to perform a baking process, whereby the semi-cured insulating resin is thermoset. At this time, the surface of the cured insulating resin is almost flattened by pressing the film 9. By passing through such steps, the wiring board 1
Since the cured insulating resin 3c 'on the surface of 5 is almost flattened, the surface of the wiring board 15 is highly flattened by polishing work in the next step (not shown). In the case of the fourth embodiment, since the irradiation of ultraviolet rays is intended only for peeling the film, the types of insulating resin can be expanded.

The embodiment described above is an example for explaining the present invention, and the present invention is not limited to the above-mentioned embodiment, and various modifications can be made within the scope of the invention. is there. For example, the application range of the method for manufacturing a multilayer printed wiring board according to the present invention can be expanded as follows.

(1) The material of the insulating substrate 1a is not limited to the glass epoxy resin, but a phenol substrate, a liquid crystal polymer substrate, a silicon substrate, a glass substrate or the like can be used. (2) Although the structure is such that the copper foil 1b is attached as the conductive layer of the insulating substrate 1a, the drum powder may be formed by vapor deposition on the surface of the insulating substrate 1a by a sputtering method or the like. (3) Although an ultraviolet curing type liquid epoxy resin is used as the material of the uncured insulating resin 3c, the present invention is not limited to this, and a thermosetting type resin or a combination type resin of ultraviolet curing and heat curing may be used. . As the ultraviolet curable resin, an acrylic resin, a phenol resin or the like may be used in addition to the epoxy resin.

(4) When flattening the semi-cured insulating resin,
Although the method of applying pressure to the film by the pressure roller was used, in addition to this, the method of applying pressure to the film by a press, or the method of pressing the film in which the pressure roller and the press are used in combination with the above embodiment. Similar flattening effect can be obtained. (5) The surface of the semi-cured insulating resin is flattened by belt polishing, but the present invention is not limited to this, and the surface of the semi-cured insulating resin is flattened by a buff polishing method or a chemical mechanical polishing method using a slurry. Can be converted. (6) In each of the above-described embodiments, the case where only one side of the wiring board is flattened has been shown. However, by performing the flattening step of the above-mentioned embodiment on the back side as well, both sides of the wiring board are flattened. You can also do it.

[0040]

As described above, in the method for manufacturing a printed wiring board according to the present invention, after the insulating resin is printed on the substrate in the step of flattening the pattern surface on which the circuit is formed, the film and the roller are used. After the surface is flattened, the insulating resin is cured with ultraviolet rays, or after curing only the part without wiring patterns, the insulating resin on the surface is flattened with a film and roller, and then the entire resin is cured again with ultraviolet rays. is doing. by this,
Highly accurate flattening can be performed by polishing the insulating resin having a substantially flat surface.

Further, according to the method for manufacturing a multilayer printed wiring board of the present invention, a printed wiring board having an extremely flat surface can be manufactured. Therefore, by stacking such printed wiring boards, the thickness of the insulating layer can be increased. It is possible to manufacture a printed wiring board having a uniform multilayer structure. Further, by using a printed wiring board having a flat surface, it is possible to form a high-density wiring pattern and manufacture a high-density mounted multilayer printed wiring board.

[Brief description of drawings]

FIG. 1 is a process drawing of the method for manufacturing a printed wiring board according to the first embodiment of the present invention.

FIG. 2 is a diagram showing a manufacturing process line for a printed wiring board in the first embodiment shown in FIG.

FIG. 3 is an enlarged view of a film adhesion portion in a B part of FIG.

FIG. 4 is a process drawing of the method for manufacturing a printed wiring board according to the second embodiment of the present invention.

FIG. 5 is a process diagram of a manufacturing line in which a semi-cured insulating resin is thermoset only by heat treatment in the third embodiment.

FIG. 6 is a process diagram of a manufacturing line in which a semi-cured insulating resin is cured by using ultraviolet irradiation and heat treatment together in the fourth embodiment.

FIG. 7 is a process chart showing a method of manufacturing a conventional multilayer printed wiring board.

8 is an enlarged cross-sectional view of a portion A in the laminated structure of step (e) of FIG.

[Explanation of symbols]

1 ... Copper-clad laminate, 1a ... Insulating substrate, 1b ... Copper foil, 2 ...
Wiring pattern, 3 ... Copper foil with resin, 3a ... Insulating resin, 3
b ... Copper foil, 3c ... Semi-cured insulating resin, 3c '... Cured insulating resin, 4 ... Via hole, 5 ... Wiring pattern, 6 ... Mask, 7 ... Ultraviolet ray, 9 ... Film, 10 ... Pressure roller, 1
DESCRIPTION OF SYMBOLS 1 ... Conveying roller, 12, 12 '... Winding roller, 13 ... Ultraviolet irradiator, 14 ... Cooler, 15 ... Wiring board, 16, 1
6 '... rotary roller, 17 ... belt, 18 ... thermosetting bath

Continued front page    F term (reference) 5E343 AA02 AA12 BB24 ER50 GG08                 5E346 AA12 AA15 AA32 AA51 CC08                       CC32 DD02 DD03 EE38 EE39                       GG28 HH11 HH31

Claims (9)

[Claims] 1. A method for manufacturing a printed wiring board for flattening a surface layer of a substrate on which a circuit pattern is formed, comprising: a resin forming step of applying an uncured resin to the surface of the substrate to form a resin layer. A flattening step of covering the surface of the uncured resin with a film and flattening the surface of the uncured resin by uniformly pressing the film using a pressure roller, and a curing step of curing the uncured resin And a peeling step of peeling the film, the method for manufacturing a printed wiring board. 2. The film is a transparent film, and in the curing step, the uncured resin is cured by irradiating the entire surface of the uncured resin with ultraviolet rays through the film. A method for manufacturing a printed wiring board according to. 3. The method of manufacturing a printed wiring board according to claim 2, further comprising a cooling step of cooling the substrate between the curing step of irradiating the uncured resin with ultraviolet rays and the peeling step. 4. A masking step of masking the surface of the uncured resin in the area where the circuit pattern is formed after the resin forming step, and irradiating the surface of the uncured resin in the unmasked area with ultraviolet rays. The method of manufacturing a printed wiring board according to claim 1, further comprising a partial curing step of curing the uncured resin in the region irradiated with the ultraviolet rays. 5. The film is a transparent film, and in the curing step, the uncured resin is cured by irradiating the entire surface of the uncured resin with ultraviolet rays through the film. Item 5. A method for manufacturing a printed wiring board according to Item 4. 6. The method for manufacturing a printed wiring board according to claim 5, further comprising a cooling step of cooling the substrate between the curing step of irradiating the uncured resin with ultraviolet rays and the peeling step. 7. A method of manufacturing a printed wiring board for flattening a surface layer of a substrate on which a circuit pattern is formed, comprising a resin forming step of applying an uncured resin to the surface of the substrate to form a resin layer. A flattening step of covering the surface of the uncured resin with a film and uniformly pressing the film with a pressure roller to flatten the surface of the uncured resin; and cutting the film for each substrate. A cutting step, an accommodating step of accommodating the substrate cut in the above in a thermosetting bath, a thermosetting step of thermosetting the uncured resin of the substrate accommodated in the thermosetting tank, and a curing step And a peeling step of peeling the film from the cured resin, the method for manufacturing a printed wiring board. 8. A method of manufacturing a printed wiring board for flattening a surface layer of a substrate on which a circuit pattern is formed, comprising a resin forming step of applying an uncured resin to the surface of the substrate to form a resin layer. A flattening step of covering the surface of the uncured resin with a film and uniformly pressing the film with a pressure roller to flatten the surface of the uncured resin; and irradiating the uncured resin with ultraviolet rays. And a semi-curing step of semi-curing the uncured resin, a peeling step of peeling the film from the semi-cured cured resin, and a storing step of storing the substrate from which the film has been peeled in a thermosetting bath. And a heat curing step of thermally curing the semi-cured resin of the substrate housed in the heat curing bath, the method for producing a printed wiring board. 9. The method of manufacturing a printed wiring board according to claim 8, further comprising a cooling step of cooling the substrate between the semi-curing step of irradiating the uncured resin with ultraviolet rays and the peeling step. .