JPH10178241A - Printed wiring board and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat board which can be manufactured by a simple processing at low cost, and has accuracy of circuit position and high reliability, and further a printed wiring board is wide applicability to not only a multilayer board but also a metal core board. SOLUTION: A printed wiring board has copper foils 4, semi-cured or cured insulating resin layers 11 thicker than the copper foil 4 not including inorganic fiber etc., and an insulating core material 10 consisting of fillers such as a wring insulating resin and an inorganic fiber or an inorganic powder etc. The insulating resin layers 11 and the insulating core material 10 are formed sequentially on the copper foils 4, and desired circuits 6 are formed on the copper foils 4 using etching etc. Thereafter the insulating resin layer 11 are heated and pressed using a hot press etc., at the curing temperature higher than the softening temperature of the insulating resin layers 11 to embed the circuits 6 in the insulating resin layers 11 and form fla surfaces of the circuits 6 and the insulating resin layers 11.

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.

[0002]

2. Description of the Related Art A printed wiring board has an insulating material and a copper foil adhered to the surface of the insulating material (referred to as a copper-clad laminate), and a circuit is formed by the copper foil. The formation method is generally formed by removing the copper foil or the copper foil and the copper plating film thereon by etching or the like, so that the outer layer has a step between the circuit and the insulating material, Since the insulation characteristics and reliability of component mounting are likely to be lost, it is customary to apply a solder resist or coverlay to the surface of the insulating layer between circuits and the surface of the circuit unnecessary for component mounting. Also in the case of multilayer printed wiring boards, the inner layer is basically formed in the same way as the outer layer, and then the lamination with the prepreg eliminates the step between the inner layer circuit and the insulating material and the insulation between the circuits by softening and embedding the prepreg Then, the outer layer is usually formed by a method such as etching in the same manner as described above. Therefore, there has been a demand for a substrate formed so as to have no step, that is, a so-called smooth printed wiring board, for forming the outer layer.

Therefore, a conventional smooth printed wiring board is:
What is generally obtained by a transfer method as shown in FIGS. That is, (A) the copper film 4 was formed thin by electroplating or electroless copper plating on one side of a thin metal plate 2 (generally a stainless steel plate), or by bonding a thin copper foil 3 (copper 3). Thereafter, a plating resist 5 for forming a circuit is formed on the surface of the copper film 4 by a method such as printing or photographic method, and a circuit 6 is deposited between the resists 5 by electrolytic copper plating or electroless copper plating. Thereafter, the plating resist 5 is removed with a chemical or the like, and the surface of the circuit 6 is subjected to a pre-adhesion treatment such as a blackening treatment for improving the adhesion strength with the insulating layer, thereby forming a circuit board 7. In this case, the prepreg material 8 containing an inorganic filler such as glass fiber is placed between the circuit boards 7 'obtained in the same manner.
The circuit 6 is embedded in the prepreg material 8 by laminating and inserting the required number of sheets, and then heated and pressed using a heating and pressing press machine or the like, and then the thin metal plate 2 such as stainless steel is removed with a chemical or the like. After that, the surface of the circuit 6 and the surface of the prepreg material 8 as an insulating layer are smoothed by etching away the thin copper foil 3 with a chemical or the like.
The printed wiring board 1 ″ is formed by a process called a so-called transfer method.

[0004] As a simpler method, although not shown, (B) a resin (liquid) for providing electrical insulation and circuit protection after forming a circuit by etching a copper clad laminate. Is coated and dried and cured, and then, the resin protruding from the circuit surface is removed by mechanical polishing or the like to form a smooth printed wiring board, that is, a smooth printed wiring board is formed by a so-called coating polishing method. is there.

[0005]

In order to manufacture and provide the above-mentioned conventional smooth printed wiring board with high reliability and efficiency at a low cost, each of the conventional printed circuit board manufacturers and the conventional methods have been proposed. There were many problems with the substrates that were used. That is, in the transfer method of (A),
(1) Since many steps are involved, processing man-hours are required, and (2)
Unnecessary materials such as metal plates and thin copper are used and unnecessary to remove them by etching or the like, and the cost is high. (3) In general, the insulating resin of the prepreg material contains inorganic materials such as glass fiber. Because they contain fillers, these fillers hinder, that is, when they are press-fitted between circuit patterns by the pressing force when they are integrally formed, the rigidity of the inorganic fiber etc. prints them. A force is applied in the direction of the surface of the wiring board, and the circuit is likely to be displaced or deformed. (4) Therefore, the accuracy of interlayer alignment of the circuits on both sides is poor and the yield is poor. (5) A smooth multilayer board is manufactured by this method. If one or more double-sided flat substrates are used as a core substrate to form a multilayer, the circuit of the core substrate is likely to be displaced or deformed for the same reason as in (3) above. (3), the risk of circuit displacement between layers is amplified, the accuracy and reliability are lacking, and (6) adhesion between a metal plate such as stainless steel and thin copper When considering the metal plate removal in the subsequent process, it is desirable to have moderate moderate adhesion instead of strong adhesion, but it is difficult to maintain the strength, but it is a major problem in terms of cost, quality, technology and management There is.

[0006] In the coating polishing method of (B),
(1) Since a step is generated between the circuit surface and the insulating resin surface after the copper foil is etched out, it is difficult to apply a uniform resin (liquid) coating to the whole in terms of technical and management aspects. 2) There is a problem that excess resin on the circuit surface after curing of the coating resin damages the copper circuit surface.

Accordingly, the printed circuit board industry and its users have long been trying to solve these problems.
As an alternative to these conventional printed wiring boards,
(1) High reliability, (2) Simple manufacturing process, (3)
(4) It can be applied not only to single-sided / double-sided boards but also to multilayer boards in particular, and (5)
There has been a strong demand for a smooth printed wiring board that can be applied to a metal core substrate and (6) a build-up method or a continuous laminating method.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the conventional smooth printed wiring board, to manufacture it by a simple process, to be inexpensive, to obtain a circuit with high positional accuracy and high reliability. Providing a substrate. Another object of the present invention is to provide a printed wiring board having a wide applicability that can be applied not only to a multilayer substrate but also to a metal core substrate.

[0009]

SUMMARY OF THE INVENTION The present invention is directed to a smooth printed wiring board for achieving the above-mentioned object, and the invention according to claim 1 comprises a copper foil and a thickness of the copper foil. An insulating resin layer that does not contain a semi-cured or cured inorganic fiber or the like that is thicker than the insulating resin, a curable insulating resin, and an insulating core material made of a filler such as an inorganic fiber or an inorganic powder; An insulating resin layer and an insulating core material are sequentially laminated, a desired circuit is formed on the copper foil by etching or the like, and then a heat-pressing machine or the like is used at a curing temperature equal to or higher than the softening temperature of the insulating resin layer. The circuit is embedded in the insulating resin layer by heating and pressing, and the surfaces of the circuit and the insulating resin layer are formed to be smooth.

According to a second aspect of the present invention, in the first aspect of the present invention, an insulating resin layer is previously coated and adhered to the copper foil.

According to a third aspect of the present invention, in the first aspect of the present invention, the insulating resin layer is a film made of an insulating resin.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the insulating core material is obtained by etching only a copper foil from a single-sided or double-sided copper-clad laminate, and dissolving or removing the same. It is characterized by being peeled off.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the insulating core material is an unclad plate having no copper foil.

According to a sixth aspect of the present invention, in the first aspect of the present invention, the insulating core material is an insulating resin layer having a thickness that maintains insulation performance as a printed wiring board. Things.

According to a seventh aspect of the present invention, in the first aspect, the insulating core material is a prepreg material.

According to an eighth aspect of the present invention, in the first aspect, a multilayer printed wiring board is formed by laminating a plurality of smooth substrates.

According to a ninth aspect of the present invention, in the first or the eighth aspect of the present invention, the insulating core material has one surface or
A circuit formed on a double-sided copper-clad laminate, or a circuit formed on a resin foil with resin surfaces facing each other, or a transfer method or a smooth surface formed by polishing after coating with resin It is characterized by comprising a substrate.

The invention according to claim 10 is a method for manufacturing a smooth printed wiring board, wherein the insulating resin does not contain a copper foil and a semi-cured or cured inorganic fiber thicker than the thickness of the copper foil. Layer, having an insulating core material composed of a curable insulating resin and a filler such as inorganic fiber or inorganic powder,
An insulating resin layer and an insulating core material are sequentially laminated on the copper foil,
After a desired circuit is formed on the copper foil by etching or the like, the circuit is embedded in the insulating resin layer by heating and pressing at a curing temperature equal to or higher than the softening temperature of the insulating resin layer by a heating / pressing press or the like, A smooth printed wiring board is formed so that the surfaces of the circuit and the insulating resin layer are smooth.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention shown in the drawings, the same parts as those of the prior art are referred to by the same reference numerals, and description thereof will be omitted. The first embodiment of the present invention is as shown in FIGS. 1 and 2, in which a copper foil 4 and an insulating resin layer containing no semi-cured or cured inorganic fiber or the like that is thicker than the thickness of the copper foil 4. 11 and a hardening insulating resin, and an insulating core material 10 made of a filler such as an inorganic fiber or an inorganic powder. After a desired circuit 6 is formed on the copper foil 4 by etching or the like,
The insulating resin layer 11 and the insulating core material 10 are sequentially laminated on the copper foil 4, and the circuit 6 is heated and pressed at a curing temperature higher than the softening temperature of the insulating resin layer 11 by a heating / pressing press or the like to form the circuit 6 with the insulating resin. The smooth printed wiring board 1 is formed by embedding in the layer 11 so that the surfaces of the circuit 6 and the insulating resin layer 11 become smooth.

The insulating core material 10 on which the circuit 6 is formed
When the insulating resin layer 11 and the insulating resin layer 11 are laminated, the circuit 6 may be formed on both surfaces of the insulating core material 10 and the insulating resin layer 11 may be provided on both surfaces on which the circuit 6 is formed.

In such a device, a printed wiring board 1 (a curable insulating resin substrate containing a curable insulating resin and an inorganic fiber or an inorganic filler) in which a circuit 6 is formed on an insulating core material 10 is used. , Semi-cured that does not contain inorganic fibers, etc.
A hardened insulating resin layer 11 is formed to have a thickness equal to or greater than the conductor thickness of the circuit 6, and a substrate (one or both surfaces) having a copper foil 4 adhered to the surface layer is prepared and used. Note that the curable insulating resin 11 in the semi-cured to cured state is preferably in a state that does not affect pattern position accuracy or pattern deformation when embedding a pattern under predetermined conditions. It is important to appropriately adjust the degree of curing.

The second embodiment is different from the first embodiment in that
Although not shown, the insulating resin layer 11 is coated and adhered to the copper foil 4 in advance.

The third embodiment is different from the first embodiment in that
Although not shown, the insulating resin layer 11 is a film made of an insulating resin.

The fourth embodiment is different from the first embodiment in that
Although not shown, the insulating core material 10 is obtained by dissolving and removing only the copper foil 4 from a single-sided or double-sided copper-clad laminate, or by physically peeling it off.

The fifth embodiment is different from the first embodiment in that
Although not shown, the insulating core material 10 may be an unclad plate having no copper foil 4.

The sixth embodiment is different from the first embodiment in that
Although not shown, the insulating core material 10 is an insulating resin layer 11 having a thickness that maintains insulation performance as a printed wiring board.

The seventh embodiment is different from the first embodiment in that
Although not shown, the insulating core material 10 is a circuit formed on a single-sided or double-sided copper-clad laminate, or a circuit formed on a resin-coated copper foil bonded to each other, or is transferred. Alternatively, a smooth printed wiring board formed by polishing after coating a resin or a resin may be used.

The manufacturing method is as follows: a copper foil 4, an insulating resin layer 11 containing no semi-cured or cured inorganic fiber thicker than the thickness of the copper foil 4, a curable insulating resin and an inorganic fiber or Insulating core material consisting of filler such as inorganic powder
After the insulating resin layer 11 and the insulating core material 10 are sequentially laminated on the copper foil 4 and a desired circuit 6 is formed on the copper foil 4 by etching or the like, a heating / pressing machine or the like is used. The circuit 6 is embedded in the insulating resin layer 11 by heating and pressurizing at a curing temperature higher than the softening temperature of the insulating resin layer 11, and the surface of the circuit 6 and the insulating resin layer 11 is smoothed so as to be smooth. It forms a wiring board.

The method of heating and pressurizing is as follows: (1) After laminating the insulating resin layer 11 and the insulating core material 10 on the copper foil 4 in order, and forming a circuit on the copper foil 4 by etching or the like, the copper foil 4 is gradually cooled from room temperature. A method of pressing at 170 ° C. × 60 minutes at 5 kg / cm ² or more while heating, or (2) a method in which an insulating resin layer 11 and an insulating core material 10 are sequentially laminated on a copper foil 4 at a curing temperature of 170 ° C. , And then pressurizing at 5 kg / cm ² or more at 170 ° C. for 60 minutes.

When heating and pressing, the copper foil 4 and the insulating resin layer
After the desired circuit 6 is formed on the copper foil 4 by etching or the like, the release film 12 and the stainless steel plate 13 are placed on the copper foil 4 and the stainless steel plate 13 respectively. The hot plate 15 of the pressure press machine and the stainless plate 13
Is heated and pressed with the cushion material 14 interposed therebetween.

[0031]

[First Embodiment] A thermosetting epoxy resin-coated copper foil (copper thickness: 18 μm, resin thickness: 50 μm) is applied to a 0.3-t glass epoxy substrate (unclad material having no copper foil) at 130 ° C. for 10 minutes, 20 kg / cm. ^Two
Use a material that has been adhesively molded.

In the first embodiment, when manufacturing a shield board for a multilayer board, a 50 μm 18 μm copper foil with a thermosetting epoxy resin was adhered to both sides of a 0.2 mm glass epoxy board under predetermined conditions, and etching was performed by etching. After the circuit is formed, smoothing is performed under predetermined conditions, and the smoothed copper circuit that has been subjected to pre-adhesion treatment is used as a core material.
Press molding of a 50 μm thermosetting epoxy resin-attached 18 μm copper foil was performed under predetermined conditions. Since the circuit was already smooth, the thickness of the insulating layer, which is the adhesive layer, was completely free from the influence of the unevenness of the circuit after etching, and very high uniformity could be obtained. As a comparison, a core was formed by etching a 0.2 mmt 18 μm double-sided copper-clad double-sided laminated board as a core material, and a similar resin-coated copper foil was used thereon to perform multilayering. In comparison, since the circuit had irregularities with respect to the base material, the uniformity of the thickness of the insulating layer was very poor.

[0033]

[Second Embodiment] A thermosetting epoxy resin film (50 μm) on a 0.3 t glass epoxy substrate (unclad material)
And a 18 μm copper foil bonded and molded at 130 ° C. × 10 minutes at 20 kg / cm ² .

In the second embodiment, when manufacturing a shield board for a multilayer board, a 50 μm thermosetting epoxy resin-coated 18 μm copper foil was adhered to both sides of a 0.2 mmt glass epoxy board under predetermined conditions, and etching was performed by etching. After forming the circuit, smoothing was performed under predetermined conditions, and after performing pre-adhesion treatment using this as a core material, a molding process was performed using a vacuum laminating of 18 μm copper foil with 50 μm thermosetting epoxy resin,
A four-layer shield plate having no practical problem was obtained despite the fact that the resin was not undercoated.

[0035]

Third Embodiment In the second embodiment, the resin thickness is set to 80 μm,
A material obtained by changing the copper foil thickness to 35 μm and bonding at 130 ° C. × 10 minutes at 20 kg / cm ² is used.

[0036]

Fourth Embodiment In the first embodiment, a copper foil with a thermosetting epoxy resin is set to a resin thickness of 80 μm, a copper foil thickness of 18 μm, and a temperature of 130 ° C.
A material formed by adhesive molding at 20 kg / cm ^{2 for} 10 minutes is used.

[0037]

Fifth Embodiment Copper foil with a thermosetting epoxy resin (resin thickness 80
μm, copper foil thickness 18μm) facing each other, 130 ℃ × 10min, 20k
A material adhesively molded at g / cm ² is used.

[0038]

Sixth Embodiment A material obtained by curing the fifth embodiment at 170 ° C. for 60 minutes at 20 kg / cm ² is used.

[0039]

Seventh Embodiment A material obtained by curing the fourth embodiment at 170 ° C. for 60 minutes at 20 kg / cm ² is used.

[0040]

Comparative Example 1 A 0.3 t 18 μm double-sided glass epoxy double-sided board (commercially available) is used.

[0041]

Comparative Example 2 A 0.3 t 35 μm double-sided glass epoxy double-sided board (commercially available) is used.

[0042]

Comparative Example 3 A base material obtained by temporarily forming 0.1 t glass epoxy prepreg (commercially available) and 18 μm copper foil at 130 ° C. for 10 minutes at 20 kg / cm ² was used.

The method of smoothing will be described below. After forming a circuit on the copper foil on the thermosetting insulating resin layer adjusted to a semi-cured to a cured state by an etching method or the like, under pressure and heating (which requires a resin softening temperature or higher and requires a curing temperature),
Utilizing the softening of the resin, the circuit is buried in the resin layer without deforming the circuit to form a smooth substrate. In the process of embedding, if inorganic fiber typified by glass cloth etc. is present in the resin layer, it will be an obstacle when the circuit sinks, not only will not obtain sufficient smoothness, but also cause deformation of the circuit Was confirmed.

The resin can be cured simultaneously with the smoothing. For this, the materials of the above-mentioned Examples and Comparative Examples were examined for smoothing. The pressurizing and heating conditions were 5 kg / cm ² or more, 170 ° C. × 60 minutes, and press molding was performed by the method shown in FIG. The test patterns were line and space 50, 100, 200 μm and 1 mmφ, 5 mmφ, 100 mm
A pattern in which a mm-square pattern was formed by an etching method was used.

Considering the case of the first, second, and fourth embodiments, as a result of performing the test at a pressure of 5 kg / cm ² , it was possible to achieve smoothness, and no distortion or deformation of the pattern was observed. Was at the same level as the general FR-4 multilayer. In the case of pressurized 20 kg / cm ² and pressurized 30 kg / cm ²
In the case of kg / cm ² , it is the same as above.

Considering the third embodiment, when the pressure is 5 kg / cm ² , perfect smoothness cannot be achieved, but 5 to 8 μm
It was a protrusion. When the pressure was 20 kg / cm ² , complete smoothness could not be achieved, but the protrusion was 5 μm or less. In the case of pressurized 30 kg / cm ² , smoothness can be achieved,
It was almost no problem.

Considering the fifth embodiment, the pressure is 5 kg / cm ^2-
Although the smoothness is good at 30 kg / cm ² , the dimensional shrinkage is slightly larger than that of general FR-4, but at a level that does not cause any problem.

Considering the sixth and seventh embodiments, the pressure is 5 kg / c.
In m ² , a protrusion of about 5 μm is seen, but 20 kg / cm ²
No protrusion was observed from the sample, and smoothness could be obtained. However, a slight deformation of the pattern is observed. The dimensional change was almost the same as in the FR-4 multilayer molding.

Considering Comparative Examples 1, 2, and 3, complete smoothness cannot be achieved, and pattern deformation and the like are observed. This is considered to be because the degree of crushing deformation increases as the copper thickness increases to 35 μm. Comparative Example 3 was milder than Comparative Example 1.

In the eighth embodiment, as shown in FIGS.
A multilayer printed wiring board is formed by laminating a plurality of smooth printed wiring boards according to the first embodiment. In the case of multilayering, when the circuits are facing each other, the insulating resin layer is substituted for the insulating core material, and the insulating core material is omitted as shown in FIG. The wiring board 1 'may be formed.

By using the smooth printed wiring board obtained by the above-described method as an inner layer, not only general multi-layer molding but also multi-layering by a build-up method and a continuous laminating method can be used. It is possible to obtain a high-quality and thinned multilayer printed wiring board in which circuit displacement and the like do not occur.

When the smooth printed wiring board 1 is used as the inner layer board in the multilayer board, the following advantages can be obtained. That is, without being affected by the copper thickness of the pattern,
Low-flow and non-flow prepregs or adhesive sheets (films) can be used. Low-pressure molding is possible, and it is effective in making the thickness of the adhesive layer uniform and reducing stress in multilayer molding, and a high-quality substrate can be obtained. Since the thickness of the adhesive layer can be made thinner than a general specification, the thickness can be reduced. When applying an insulating resin coat on the inner layer pattern surface in the build-up multilayer method, an insulating layer with a flat and uniform thickness can be formed without being affected by the unevenness of the pattern, and using a resin-coated copper foil or resin film etc. In addition, troubles such as insufficient pattern embedding can be resolved even when performing build-up multilayer molding, and an insulating layer having a more uniform thickness can be formed. Similar effects can be obtained when performing continuous laminating using a resin-coated copper foil or a resin film.

[0053]

As described above, the present invention is directed to a smooth printed wiring board, and the invention according to claim 1 is characterized in that a copper foil and a semi-cured or cured state which is thicker than the thickness of the copper foil. An insulating resin layer containing no inorganic fiber or the like, having an insulating core material made of a curable insulating resin, and a filler such as an inorganic fiber or an inorganic powder, and an insulating resin layer and an insulating core material on the copper foil. Are sequentially laminated, a desired circuit is formed on the copper foil by etching or the like, and then the circuit is heated and pressed at a curing temperature higher than the softening temperature of the insulating resin layer by a heating and pressing press or the like to form the circuit on the insulating resin layer. It is embedded so that the surface of the circuit and the insulating resin layer is smooth, so not only in general multilayer molding, but also in circuit buildup and continuous lamination, circuit misalignment etc. High quality that does not occur, and Board processing multilayer printed wiring board there is an effect that is e inexpensively.

According to the second aspect of the present invention, since the insulating resin layer is coated and adhered to the copper foil in advance, the process is simple and the thin copper foil can be easily handled.

According to a third aspect of the present invention, the insulating resin layer comprises:
Since the film is made of an insulating resin, it can be easily and inexpensively manufactured not only for general multilayer molding but also for multilayering by a build-up method or a continuous laminating method.

According to a fourth aspect of the present invention, the insulating core material comprises:
Since only the copper foil is dissolved and removed or physically peeled off from the single-sided or double-sided copper-clad laminate, there is an effect that the strength of the smooth printed wiring board of the printed wiring board is large.

According to a fifth aspect of the present invention, the insulating core material comprises:
Since it is an unclad plate having no copper foil, there is an effect that a smooth printed wiring board can be obtained at low cost.

According to a sixth aspect of the present invention, the insulating core material comprises:
Since it is an insulating resin layer having a thickness that maintains the insulating performance as a printed wiring board, there is an effect that electric characteristics are good.

According to a seventh aspect of the present invention, the insulating core material comprises:
Since it is a prepreg material, there is an effect that multilayering can be easily and inexpensively obtained.

According to the eighth aspect of the present invention, since a multilayer printed wiring board is formed by laminating a plurality of smooth printed wiring boards, not only general multilayer molding but also multilayering by a build-up method or a continuous laminating method. In this case, there is an effect that a high-quality thinned multilayer smooth printed wiring board free from circuit displacement or the like can be obtained at low cost.

According to a ninth aspect of the present invention, the insulating core material comprises:
Circuits formed on single-sided or double-sided copper-clad laminates,
Or, a circuit is formed on a resin foil of copper foil with resin facing and bonded, or a smooth printed wiring board formed by transfer method or resin coating and polished, so that multilayer smooth printed wiring board Is easily obtained.

A method for manufacturing a smooth printed wiring board, comprising:
The invention according to claim 10 is a copper foil, a semi-cured or cured insulating resin layer containing no inorganic fiber or the like thicker than the thickness of the copper foil, a curable insulating resin and an inorganic fiber or inorganic powder. And an insulating core material comprising a filler such as
An insulating resin layer and an insulating core material are sequentially laminated on the copper foil,
After a desired circuit is formed on the copper foil by etching or the like, the circuit is embedded in the insulating resin layer by heating and pressing at a curing temperature equal to or higher than the softening temperature of the insulating resin layer by a heating / pressing press or the like. And the surface of the insulating resin layer are formed so as to be smooth, so that not only general multilayer molding,
Even in the case of multi-layering by the build-up method or the continuous laminating method, there is an effect that a high-quality, thin-layered multi-layer board free from circuit displacement or the like can be easily and inexpensively manufactured.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a state of heating and pressing according to the first embodiment.

FIG. 3 is a longitudinal sectional view showing a state in which the printed wiring boards according to the eighth embodiment are formed in an overlapping manner.

FIG. 4 is a longitudinal sectional view showing a state in which an insulating core material according to the eighth embodiment is removed and printed wiring boards are formed in an overlapping manner.

FIG. 5 is an explanatory view showing a manufacturing process of a conventional smooth printed wiring board.

FIG. 6 is an explanatory view showing a manufacturing process of a conventional smooth printed wiring board.

FIG. 7 is an explanatory view showing a manufacturing process of a conventional smooth printed wiring board.

FIG. 8 is an explanatory view showing a manufacturing process of a conventional smooth printed wiring board.

FIG. 9 is an explanatory view showing a manufacturing process of a conventional smooth printed wiring board.

FIG. 10 is an explanatory view showing a manufacturing process of a conventional smooth printed wiring board.

FIG. 11 is an explanatory view showing a manufacturing process of a conventional smooth printed wiring board.

[Explanation of symbols]

 Reference Signs List 1 smooth printed wiring board 4 copper film 6 circuit 10 insulating core material 11 insulating resin layer

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 28, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention shown in the drawings, the same parts as those of the prior art are referred to by the same reference numerals, and description thereof will be omitted. The first embodiment of the present invention is as shown in FIG. 1, in which a copper foil 4 and an insulating resin layer 11 containing no semi-cured or cured inorganic fiber which is thicker than the thickness of the copper foil 4 are formed. , A curable insulating resin, and an insulating core material 10 made of a filler such as an inorganic fiber or an inorganic powder. After a desired circuit 6 is formed on the copper foil 4 by etching or the like, the insulating resin is The layer 11 and the insulating core material 10 are sequentially laminated, and the circuit 6 is heated and pressed at a hardening temperature equal to or higher than the softening temperature of the insulating resin layer 11 by a heating / pressing machine or the like to form the circuit 6 on the insulating resin layer 11.
The smooth printed wiring board 1 is formed in such a manner that the surfaces of the circuit 6 and the insulating resin layer 11 are smoothed.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction contents]

The circuit 6 and the insulating resin layer 11 may be provided on both sides of the insulating core material 10, respectively.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction contents]

The curable insulating resin 11 in the semi-cured to cured state is
When embedding a pattern under predetermined conditions, the embedding is preferably performed under conditions that do not affect pattern position accuracy or pattern deformation, and it is important to appropriately adjust the degree of curing according to each resin system.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0029

[Correction method] Change

[Correction contents]

The method of heating and pressurizing is as follows: (1) An insulating resin layer 11 and an insulating core material 10 which are appropriately adjusted in a semi-cured or cured state are sequentially laminated on the copper foil 4, and then the copper foil 4 is etched or the like. A method in which a circuit is formed at a pressure of 5 kg / cm ² or more for 60 minutes while gradually heating from room temperature to 170 ° C., or
(2) After the insulating resin layer 11 and the insulating core material 10 are sequentially laminated on the copper foil 4 and heated to a curing temperature of 170 ° C.,
For example, there is a method of applying a pressure of g / cm ² or more for 60 minutes.

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0030

[Correction method] Change

[Correction contents]

At the time of heating and pressurizing, as shown in FIG.
The copper foil 4, the insulating resin layer 11, and the insulating core material 10 are sequentially laminated, and a desired film 6 is formed on the copper foil 4 by etching or the like.
The stainless steel plate 13 is placed, and the hot plate 15
Then, heating and pressurization are performed with the cushion material 14 interposed between the stainless steel plate 13.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0050

[Correction method] Change

[Correction contents]

In the eighth embodiment, as shown in FIGS.
FIG. 3 shows a four-layer board and FIG. 4 shows a six-layer board, which is a multilayer printed wiring board formed by laminating a plurality of smooth printed wiring boards of the first embodiment. In the case of multilayering, when the circuits are facing each other, the insulating resin layer is substituted for the insulating core material, and the insulating core material is omitted as shown in FIG. The wiring board 1 'may be formed. Further, an insulating resin layer 11 'containing the same or inorganic filler as the insulating resin layer 11 may be formed outside the insulating resin layer 11.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a state of heating and pressing according to the first embodiment.

FIG. 3 is a longitudinal sectional view showing a state in which the printed wiring boards according to the eighth embodiment are formed in an overlapping manner.

FIG. 4 is a longitudinal sectional view showing a state in which an insulating core material according to the eighth embodiment is removed and printed wiring boards are formed in an overlapping manner.

FIG. 5 is an explanatory view showing a manufacturing process of a conventional smooth printed wiring board.

FIG. 6 is an explanatory view showing a manufacturing process of a conventional smooth printed wiring board.

FIG. 7 is an explanatory view showing a manufacturing process of a conventional smooth printed wiring board.

FIG. 8 is an explanatory view showing a manufacturing process of a conventional smooth printed wiring board.

FIG. 9 is an explanatory view showing a manufacturing process of a conventional smooth printed wiring board.

FIG. 10 is an explanatory view showing a manufacturing process of a conventional smooth printed wiring board.

[Procedure amendment 9]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

[Procedure amendment 10]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

[Procedure amendment 11]

[Document name to be amended] Drawing

[Correction target item name] Figure 3

[Correction method] Change

[Correction contents]

FIG. 3

[Procedure amendment 12]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

[Procedure amendment 13]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Change

[Correction contents]

FIG. 10

[Procedure amendment 14]

[Document name to be amended] Drawing

[Correction target item name] FIG.

[Correction method] Deleted

Claims (10)

[Claims] 1. A copper foil, a semi-cured or cured insulating resin layer containing no inorganic fiber or the like thicker than the thickness of the copper foil, a curable insulating resin, and filling with an inorganic fiber or inorganic powder. An insulating core material made of a material, an insulating resin layer and an insulating core material are sequentially laminated on the copper foil, and a desired circuit is formed on the copper foil by etching or the like, and then, a heating press machine or the like is used. The circuit is embedded in the insulating resin layer by heating and pressurizing at a curing temperature equal to or higher than the softening temperature of the insulating resin layer, so that the surfaces of the circuit and the insulating resin layer are formed to be smooth. Printed wiring board. 2. The printed wiring board according to claim 1, wherein an insulating resin layer is previously coated and adhered to the copper foil. 3. The printed wiring board according to claim 1, wherein the insulating resin layer is a film made of an insulating resin. 4. The method according to claim 1, wherein the insulating core material is obtained by etching only the copper foil from the single-sided or double-sided copper-clad laminate, dissolving and removing the copper foil, or physically peeling the copper foil. Printed wiring board. 5. The printed wiring board according to claim 1, wherein the insulating core material is an unclad board having no copper foil. 6. The printed wiring board according to claim 1, wherein the insulating core material is an insulating resin layer having a thickness that maintains insulation performance as the printed wiring board. 7. The printed wiring board according to claim 1, wherein the insulating core material is a prepreg material. 8. The printed wiring board according to claim 1, wherein a plurality of smooth substrates are laminated to form a multilayer printed wiring board. 9. An insulating core material having a circuit formed on a single-sided or double-sided copper-clad laminate, or having a circuit formed on a resin foil of a resin-coated copper foil opposed to and adhered thereto, or transferred. The printed wiring board according to claim 1, wherein the printed wiring board is made of a smooth substrate formed by polishing a method or a resin and then polishing the resin. 10. A copper foil, an insulating resin layer containing no semi-cured or cured inorganic fiber thicker than the thickness of the copper foil, and a curable insulating resin and a filler such as inorganic fiber or inorganic powder. And an insulating resin layer and an insulating core material are sequentially laminated on a copper foil, and a desired circuit is formed on the copper foil by etching or the like, and then a heating and pressing press machine or the like is used. The circuit is embedded in the insulating resin layer by heating and pressurizing at a curing temperature higher than the softening temperature of the insulating resin layer, so that the surfaces of the circuit and the insulating resin layer are formed to be smooth. Manufacturing method of printed wiring board.