JPH0745953A - Manufacture of multilayer wiring board - Google Patents

Abstract

PURPOSE:To provide a manufacturing method, of a multilayer wiring board, which can reduce an irregularity in the interlayer positional accuracy of the multilayer wiring board whose sheet thickness after a molding operation is at a specific thickness. CONSTITUTION:In the manufacturing method of a multilayer wiring board, a laminated body in which prepregs 2 are arranged on every surface and every rear surface of a plurality of inner layer materials 1 is fixed by eyelet pins 3, metal foils 5 are arranged on outermost layers, the multilayer wiring board is molded, and a sheet thickness after its molding operation is 0.3 to 1.0mm. In the manufacturing method of the multilayer wiring board, the height (h) of the eyelet pins 3 before their caulking operation satisfies a formula of h<=b+d [in the formula, (h) represents the height of the eyelet pins before their caulking operation, (b) represents the width of a guard part at every eyelet pin, and (d) represents the sheet thickness after the molding operation of the multilayer wiring board].

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 multilayer wiring board used in electronic equipment and the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, a method for manufacturing a multilayer wiring board has a method in which a prepreg 2 is arranged between a plurality of inner layer materials 1 and 1 having a circuit 7, and these are caulked with eyelet pins 3 at required positions. There has been known a method of fixing, then prepreg 2 on both sides thereof, and metal foil 5 on the outermost layer, sandwiched by molding plates 6 and 6, and laminated molding. However, with this method, there is a problem that misalignment is likely to occur during lamination molding, molding abnormalities occur, and good products cannot be obtained with high yield,
A method for preventing this displacement has been studied, and the inventors of the present invention have also disclosed in Japanese Patent Laid-Open No. 3-129797 a laminated body in which prepregs 2 are arranged on the upper and / or lower surfaces of a plurality of inner layer materials 1, 1 as shown in FIG. A method for manufacturing a multilayer wiring board is proposed in which the prepreg 2 and the prepreg 2 are fixed by eyelet pins 3 and then the metal foil 5 is placed on the outermost layer to laminate-mold.

According to these methods of fixing with eyelet pins, the accuracy of the interlayer position of the multilayer wiring board could be kept relatively good when the plate thickness after lamination molding was thick, but after lamination molding. When the plate thickness is thin, there is a tendency that there is a large variation in the interlayer positional accuracy. In recent years, the plate thickness after lamination molding is 0.
With the increase in the production of thin multilayer wiring boards of 3 to 1.0 mm, it is required to develop a method capable of reducing the variation in the interlayer positional accuracy of the multilayer wiring board obtained by the method of fixing with eyelet pins.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, according to the present invention, a laminated body having prepregs on the upper and / or lower surfaces of a plurality of inner layer materials is fixed with eyelet pins, and then a metal foil is disposed on the outermost layer. The plate thickness after molding obtained by molding is 0.
It is an object of the present invention to provide a method for manufacturing a multilayer wiring board capable of reducing variations in interlayer positional accuracy of the multilayer wiring board of 3 to 1.0 mm.

[0005]

According to the present invention, a laminate having prepregs on the upper and / or lower surfaces of a plurality of inner layer members is fixed with eyelet pins, and then a metal foil is placed on the outermost layer to form a molded product, In the method of manufacturing a multilayer wiring board for manufacturing a multilayer wiring board having a thickness of 0.3 to 1.0 mm after molding, the height (h) of the eyelet pins before crimping is expressed by the following formula (I): h ≦ b + d ── (I) (where h is the height of the eyelet pin before crimping, b is the width of the collar portion of the eyelet pin, and d is the thickness of the multilayer wiring board after molding)
This is a method for manufacturing a multilayer wiring board, which is characterized by being satisfied.

The thickness of the eyelet pin is 0.1 to 0.3.
It is a method for manufacturing a multilayer wiring board having a size of mm.

The inner layer material used in the present invention is a conductor made of a metal component such as copper or nickel on one or both sides of a substrate made of a resin such as an epoxy resin, a polyimide resin or a fluorine resin and a base material such as paper or glass cloth. What has a circuit formed is used. The prepreg disposed on the upper surface and / or the lower surface of the inner layer material may be the same material as that used for manufacturing the substrate of the inner layer material, or a prepreg of a different material. Well, for example,
A material obtained by impregnating a base material such as paper or glass cloth with a resin such as an epoxy resin, a polyimide resin, or a fluororesin and drying the resin is used. Also, for the metal foil to be placed on the outermost layer,
For example, copper foil, nickel foil, aluminum foil and the like can be exemplified.

The material of the eyelet pin used in the present invention is not particularly limited, and, for example, metal such as iron, brass, stainless steel, or synthetic resin can be used. Further, in the present invention, in order to prevent misalignment at the time of molding, a laminated body made of a material other than the metal foil arranged as the outermost layer is fixed with eyelet pins. Regarding the height (h) of the eyelet pin before crimping, in order to fix the laminated body, it is essential that it is longer than the thickness of the laminated body after crimping, but the plate thickness after molding is 0.3 to 1. When manufacturing a multilayer wiring board as thin as 0 mm, it is important in the present invention to satisfy the above formula (I). This is because the height (h) of the eyelet pin before crimping does not satisfy the above formula (I), and the sum of the width (b) of the collar portion of the eyelet pin and the thickness (d) of the multilayer wiring board after molding. This is because if the length is long, abnormal deformation occurs in the eyelet pins during crimping or molding, and as a result, there is a high possibility that the inner layer material will be displaced between the layers. 2 and 3 are plan views and sectional views of the state before crimping of the eyelet pin, showing the length of the portion where the height (h) of the eyelet pin and the width (b) of the collar portion of the eyelet pin are referred to in the present invention. The fish is shown in FIG.

Regarding the wall thickness of the eyelet pin used in the present invention (shown as (c) in FIG. 3), the laminate can be fixed, and wrinkles do not occur in the outermost metal foil during molding. Is preferably 0.1 to 0.3 mm. This is because if the wall thickness is less than 0.1 mm, it becomes difficult to fix the laminate, and if it exceeds 0.3 mm, wrinkles are likely to occur on the metal foil due to the projections of the eyelet pins.

[0010]

The height h of the eyelet pin before crimping is not more than the sum of the width b of the collar portion of the eyelet pin and the thickness d of the multilayer wiring board after molding. That is, the eyelet pin is too long when the laminate is crimped. It acts to prevent abnormal deformation of the eyelet pin caused thereby.

The thickness of the eyelet pin is 0.1 to 0.3.
Since the protrusion of the eyelet pin with respect to the metal foil arranged on the outer side of the eyelet pin is made low by setting it to be mm, it has an action of preventing the generation of wrinkles in the metal foil at the time of molding.

[0012]

Embodiments of the present invention will now be described with reference to the drawings.

Example 1 A thickness of 0.1 as shown in FIG.
A circuit 7 is formed on both surfaces of a 5 mm double-sided copper-clad glass cloth base material epoxy resin laminated board to form an inner layer material 1, and the upper and lower surfaces of the two inner layer materials 1 and 1 have a thickness of 0.08 mm after molding.
A total of 6 prepregs 2 each of which is a sheet were arranged to form a laminated body, and holes having a diameter of 3.5 mm were opened at four corners of the obtained laminated body. Next, the material is brass and has the cross-sectional shape shown in FIG. 3, the overall diameter (a) of the collar is 7.5 mm, the width (b) of the collar is 2.5 mm, and the wall thickness (c) is 0.25 mm
The eyelet pin 3 having a height (h) of the eyelet pin of 3.0 mm was inserted into the above-mentioned opening portion and then caulked to fix the laminated body. Next, thickness of 18 μm on both outermost sides
The copper foil of No. 3 is placed as the metal foil 5, sandwiched between the molding plates 6 and 6, the molding pressure is 30 kg / cm ² , the molding temperature is 170 ° C.
Was laminated and molded for 90 minutes to obtain a 6-layer multilayer wiring board having a circuit 7 in the inner layer and having a thickness (d) of 0.8 mm after molding. In this case, h (3.0 mm) <b (2.5 m
m) + d (0.8 mm), which satisfies the above formula (I).

(Example 2) Under the same conditions as in Example 1, except that eyelet pins having a thickness (c) of eyelet pins of 0.40 mm were used, the plate thickness after molding having a circuit as an inner layer was 0.8 mm. A 6-layer multilayer wiring board, which is (d), was obtained. In this case, h (3.0 mm) <b (2.5 m
m) + d (0.8 mm), which satisfies the above formula (I).

(Comparative Example 1) Under the same conditions as in Example 1, except that the eyelet pin having a height (h) of 4.2 mm was used, the plate thickness after molding having a circuit in the inner layer was 0.8 mm. A 6-layer multilayer wiring board, which is (d), was obtained.
In this case, h (4.2 mm)> b (2.5 mm)
+ D (0.8 mm), which does not satisfy the above formula (I).

With respect to the 6-layered multilayer wiring boards obtained in Examples 1 and 2 and Comparative Example 1, the interlayer positional accuracy and the presence or absence of wrinkles in the outermost copper foil were examined, and the results are shown in Table 1. . The interlayer positional accuracy was measured by detecting the degree of deviation of the reference points provided on the two inner layer members 1 and 1 using an X-ray device. This interlayer position accuracy was measured at 20 locations, and the minimum, maximum and average values are shown in Table 1. The presence or absence of wrinkles in the outermost copper foil was visually checked.

[0017]

[Table 1]

From the results shown in Table 1, in Examples 1 and 2 in which the height h of the eyelet pins before crimping was less than the sum of the width b of the collar portion of the eyelet pins and the thickness d of the multilayer wiring board after molding. It was confirmed that the interlayer position accuracy was better than in Comparative Example 1 in which the height h of the eyelet pin before crimping was larger than the sum of the width b of the collar portion of the eyelet pin and the thickness d of the multilayer wiring board after molding.

Further, in Example 2 in which the eyelet pin having a large thickness of 0.40 mm was used, the copper foil had wrinkles at the time of molding. To prevent the wrinkles from occurring, the thickness of the eyelet pin was 0.3 m.
It was also confirmed that m or less was effective.

[0020]

According to the manufacturing method of the present invention, a laminate having prepregs on the respective upper and / or lower surfaces of a plurality of inner layer materials is fixed by eyelet pins, and then a metal foil is disposed on the outermost layer to form the laminate. The plate thickness after molding is 0.3 to 1.0 mm
It is possible to reduce the variation in the interlayer positional accuracy of the multilayer wiring board.

According to the manufacturing method of the second aspect,
Wrinkles can be prevented from occurring on the metal foil.

[Brief description of drawings]

FIG. 1 is a sectional view according to an embodiment of the present invention.

FIG. 2 is a plan view of an eyelet pin according to an embodiment of the present invention.

FIG. 3 is a sectional view of an eyelet pin according to an embodiment of the present invention.

FIG. 4 is a sectional view according to a conventional example.

[Explanation of symbols]

 1 Inner layer material 2 Prepreg 3 Eyelet pin 5 Metal foil 6 Molding plate 7 Circuit

Claims (2)

[Claims] 1. A laminate in which a prepreg is arranged on each upper surface and / or lower surface of a plurality of inner layer materials is fixed by eyelet pins, and then a metal foil is arranged on the outermost layer for molding, so that the plate thickness after molding is 0. Three
In the method for manufacturing a multilayer wiring board for manufacturing a multilayer wiring board having a thickness of up to 1.0 mm, the height (h) of the eyelet pins before crimping is expressed by the following formula (I): h ≦ b + d ─── (I) (where h is (The height of the eyelet pin before crimping, b is the width of the collar portion of the eyelet pin, and d is the thickness of the multilayer wiring board after molding.)
A method for manufacturing a multilayer wiring board, which is satisfied. 2. The thickness of the eyelet pin is 0.1 to 0.3 mm.
The method for manufacturing a multilayer wiring board according to claim 1, wherein