JPH0756909B2 - Method and apparatus for manufacturing single-sided printed circuit board and metal foil-clad laminate used for the manufacturing - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a single-sided printed circuit board, a manufacturing apparatus used for the method, and a metal foil-clad laminate used for the manufacturing.

2. Description of the Related Art In recent years, electronic devices have become smaller and lighter, and the thickness of a printed circuit board incorporated therein has been reduced. A single-sided printed circuit board has a circuit only on one side of the insulating substrate,
A single-sided metal (copper) foil-clad laminate is subjected to the printing / etching process to remove unnecessary parts of the copper foil to form a circuit, but warping and twisting occur due to the asymmetric configuration in the thickness direction. It's easy to do. This tendency becomes larger as the plate thickness becomes thinner, and the workability of the circuit forming process is significantly deteriorated.

Therefore, the means disclosed in JP-B-54-34142 and JP-B-55-5873 have been proposed. These are release films (triacetyl cellulose film)
Through this, two single-sided copper clad laminates are integrally molded so that the copper foil side is on the outside, and this is cut into a work size as it is and used for the printing / etching process. Circuit formation is performed as if printing and etching a copper clad laminate. And then 2 layers of release film
This is a method of separating into a single-sided printed circuit board. This makes the configuration in the thickness direction during circuit formation pseudo-symmetrical,
It is intended to suppress warpage and twist.

However, since the triacetyl cellulose film inherently has releasability, when cut into a work size, two single-sided copper-clad laminates are easily separated in layers of this film, From the cut surface, a circuit is formed by sealing the periphery with an adhesive tape so that the etching solution does not enter between the two laminated plates (Japanese Patent Publication No. 54-34142). In addition, in order to prevent the invasion of the etching solution, the release film is preliminarily coated with an adhesive corresponding to the position to be cut into the work size, and the two single-sided copper molded through the release film. There is a complicated aspect of the process of cutting the stretched laminated plate into a work size along the adhesive application portion (Japanese Patent Publication No. 55-5873). In the latter case, the work size cutting position is restricted by the adhesive application portion, and the work efficiency is poor as a whole and it is not suitable for mass production.

In view of the above points, the present invention is to provide a single-sided printed circuit board efficiently while suppressing the occurrence of warpage and twist in the circuit forming step, and to provide a metal foil-clad laminate for the same. It is intended. Further, it is an object of the present invention to provide an apparatus used for the above-mentioned manufacturing, which is capable of favorably separating a work after circuit formation into two single-sided printed circuit boards by a layer of a release film.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention arranges a prepreg and a metal foil on both surfaces thereof in this order through a polyvinyl alcohol film having a thickness of 30 to 300 μm, and heat-press molding the same. Then, two single-sided metal foil-clad laminates that are integrated via the polyvinyl alcohol film are obtained. And
This is cut into a work size and a circuit forming process is performed. The two single-sided printed circuit boards are then separated by a layer of polyvinyl alcohol film.

Further, instead of the polyvinyl alcohol film, a polyvinyl fluoride film having a roughened front and back surfaces and a thickness of 20 to 100 μm may be used.

The step of separating the two single-sided printed circuit boards is preferably a step of corrugating the work, and the apparatus has the following configurations (a) to (d).

(A) A gap through which the work after circuit formation is passed is formed by the upper roll row and the lower roll row.

(B) Positioning is performed in the front-rear direction so that the individual rolls of the other roll row are positioned between the individual rolls of the one roll row.

(C) The axial distance between the upper and lower rolls is adjusted so that the work passing through the gap is curved by the pressure of each roll.

(D) Each roll is arranged such that the bending is performed at least once in the opposite directions.

Action The polyvinyl alcohol film has an OH group that has an affinity for the hydrophilic groups of the thermosetting resin that composes the laminated plate, so its molecular interaction ensures proper adhesion to the tank plate. You can As a result, when two single-sided metal foil-clad laminates, which are integrated via the polyvinyl alcohol film, are cut into a work size, separation from the cut surface does not occur, and a special etching liquid as in the past is used. The circuit forming process can be efficiently performed without using an intrusion prevention means. Then, after the circuit is formed, it can be easily separated into two single-sided printed circuit boards by intruding a sharp wedge-shaped material into the layer of the polyvinyl alcohol film having the cut surface, or by passing through a group of rolls and corrugating. Is possible.

As a polyvinyl alcohol film, the thickness is 30μ
If a sheet thinner than m is used, the surface roughness of the circuit-free side of the two separated printed circuit boards becomes large, which is inconvenient for printing characters and the like. On the other hand, when the thickness exceeds 300 μm, the polyvinyl alcohol film and the laminated plate are peeled from each other on the cut surface when the work size is cut, and the etching solution enters.

When a polyvinyl fluoride film is used, the film has good releasability, so the front and back surfaces are roughened. The two single-sided metal foil-clad laminates integrally molded via this film have the resin of the laminate penetrated into the fine irregularities of the film, and have appropriate adhesiveness due to physical action. As a result, it becomes possible to form a circuit as in the case of using a polyvinyl alcohol film.

If a polyvinyl fluoride film having a thickness of less than 20 μm is used, the surface roughness of the circuit-free side of the two separated printed circuit boards becomes large, which is inconvenient for printing characters and the like. . On the other hand, if the thickness exceeds 100 μm,
When cut into a work size, the polyvinyl fluoride film and the laminated plate are peeled off on the cut surface, and the etching solution penetrates.

Further, in the step of separating the two single-sided printed circuit boards after the circuit is formed, the bending stress generated by corrugating the work becomes the separating force. As a result, the film is peeled off from the laminated plate and can be well separated. In this case, the works cannot be separated well unless they are bent at least once in the opposite directions.

Example The prepreg used in the practice of the present invention is obtained by impregnating and drying a sheet-shaped base material with a thermosetting resin, but the types of the thermosetting resin and the base material are not particularly limited. However, when an epoxy resin was used as the thermosetting resin, the best results were obtained in terms of adhesion and separability. The prepregs arranged on both sides of the polyvinyl alcohol film or the polyvinyl fluoride film may be of different types.

Hereinafter, examples of the present invention will be described in detail.

Examples 1-2, Comparative Examples 1-2 Epicomote 1001 (Epoxy resin manufactured by Yuka Shell Co., Ltd.) 100 parts by weight, dicyandiamide 3 parts by weight, and benzyldimethylamine 0.5 parts by weight were mixed with a glass cloth (basis weight 210
g) was impregnated with a resin amount of 42% by weight and dried to obtain a prepreg.

As shown in FIG. 1 (a), a predetermined number of prepregs 2 are stacked on the upper and lower sides of a polyvinyl alcohol film 1 having a smooth surface of various thicknesses, and copper foils (thickness 35 μm) 3 are arranged on the upper and lower sides thereof. It is sandwiched between mirror surface plates 4 and temperature is 160 ℃, pressure is 30kg /
It was heated and pressed at a cm ² for 60 minutes. And FIG. 1 (b)
As described above, two single-sided copper-clad laminates 5 having a plate thickness of 0.6 mm and integrated with the polyvinyl alcohol film 1 were obtained.

The single-sided copper-clad laminate in which the two sheets were integrated was cut into a work size (500 × 500 mm), and a circuit forming step by printing / etching was performed. The amount of warpage of the printed circuit board after the circuit is formed, the presence or absence of intrusion of the etching solution between the two circuit boards, and the surface roughness of the surface of the circuit board on the side without the circuit are firstly determined. Shown in the table.

The printed circuit board in which the two were integrated could be easily separated by introducing it into a roll group and passing it in a wavy manner.

Comparative Example 3 In place of the polyvinyl alcohol film, a biaxially oriented polypropylene film (thickness 40 μm) was used, and in the same manner as in Example 1 except that two single-sided copper-clad laminates having an integrated plate thickness of 0.6 mm were used. I got a plate. Thereafter, the circuit was formed in the same manner.

Conventional Example 1 Instead of a polyvinyl alcohol film, a triacetyl cellulose film (thickness: 25 μm) was used, and two other single-sided copper-clad laminates having a plate thickness of 0.6 mm were integrated in the same manner as in Example 1. Obtained. After cutting this into a work size, the cut four circumferences were sealed with a synthetic resin adhesive tape, and a circuit was formed in the same manner.

Conventional Example 2 Instead of the polyvinyl alcohol film, a triacetyl cellulose film (thickness: 25 μm) coated with an adhesive corresponding to the position to be cut into the work size in the subsequent step is used, and the others are the same as in Example 1. Integrated thickness of 0.6 m
Two m single-sided copper clad laminates were obtained. After cutting this into a work size along the adhesive application portion, a circuit was similarly formed.

Example 1 is 20% compared to Conventional Example 1, and compared to Conventional Example 2.
It was a reduction in man-hours of 80%. Table 2 shows the amount of warpage after forming a circuit in the conventional example.

Examples 3 to 4 and Comparative Examples 4 to 5 Instead of the polyvinyl alcohol film in the above-mentioned examples, a polyvinyl fluoride film having various thicknesses with roughened front and back surfaces was used, and the other ones were formed in the same manner to prepare a single-sided printed circuit board. Obtained. The amount of warpage of the printed circuit board in which the two are formed after the circuit is formed, the presence or absence of intrusion of the etching solution between the two circuit boards, and the surface roughness of the surface of the circuit board on the side without the circuit are determined by the third value. Shown in the table.

Comparative Example 6 A single-sided printed circuit board was manufactured in the same manner as in Example 3, except that the polyvinyl fluoride film having untreated front and back surfaces was used.

Next, an apparatus for separating the circuit-formed work into two single-sided printed circuit boards with a release film layer will be described in detail.

The work after formation of the circuit in Example 1 (in which two single-sided printed circuit boards are integrated via a polyvinyl alcohol film) is passed through the apparatus shown in FIG.
Separated into two single-sided printed circuit boards. This device forms a gap through which the work 8 is passed between the upper roll row 6 and the lower roll row 7. The rolls 6a of the upper roll row 6 are located between the individual rolls 7a of the lower roll row 7, and the upper roll row 6 and the lower roll row 7 are arranged so that the work 8 passing therethrough is pressed by the respective rolls and undulates.
Adjust the shaft center interval of. Further, the number of rolls is determined so that the corrugation is performed at least once in the opposite directions.

The upper roll row 6 has two rolls, the lower roll row 7 has three rolls, and the apparatus is configured based on FIG. 2 while changing the overlapping amount W of the upper roll row 7 and the lower roll row 8 in the embodiment. 1
It was separated into two single-sided printed circuit boards through the work in. The relationship between the overlapping amount W and the warp of the separated circuit board is shown in FIG. The roll diameters were all 60 mm, and the roll center distance L was 150 mm for both the upper roll row and the lower roll row.
In this case, the waviness of the work 8 is once in the opposite directions (preferably the same number of times).

As is apparent from FIG. 3, the amount of warpage of the separated single-sided printed circuit board changes depending on the overlapping amount W of the upper and lower roll rows, so that the amount of warpage is small and the separation can be performed reliably.
The overlap amount W is determined. Appropriate conditions for ensuring the separation and reducing the warp vary depending on the thickness of the work, the type of material, the roll center interval, etc., and thus are appropriately determined by experiments.

The warp after the work in Example 1 was separated from the end portion by tearing by hand was 30 to 50 mm.

The sled was 20 to 30 mm after the paper knife was inserted between the layers of the work and separated.

Simply passing the work through the gap made up of a total of three rolls on the top and bottom does not separate the work sufficiently because it bends in only one direction (overlapping amount of the top and bottom rolls: 30 mm). The sled was 10 to 20 mm.

In the apparatus described in the above embodiment, the upper roll row and the lower roll row are provided with belts, respectively, so that the passage of the work while waving can be guided smoothly by the belts.

EFFECTS OF THE INVENTION As described above, the two single-sided metal foil-clad laminates integrated with each other through the polyvinyl alcohol film having a thickness of 30 to 300 μm or the polyvinyl fluoride film having a thickness of 20 to 100 μm with the front and back surfaces roughened The two single-sided metal foil-clad laminates that have been integrated together have good adhesion to the film, and the single-sided metal foil-clad laminates that have been integrated into one are printed / etched to prevent warping and twisting. It is possible to reduce the warp of the circuit board after separation by separating the work after circuit formation into two single-sided printed circuits by undulating the work after circuit formation.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a layer structure of a laminated plate according to the present invention,
FIG. 2 is a side view of an apparatus for separating a circuit-formed work into two single-sided printed circuit boards, and FIG. 3 shows a warp of the separated circuit boards and an overlapping amount W of upper and lower roll rows of the separating apparatus. It is a curve figure which shows a relationship. 1 is a polyvinyl alcohol film, 2 is a prepreg,
3 is a copper foil, 5 is a single-sided copper clad laminate, 6 is an upper roll row, 7 is a lower roll row, 8 is a work

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-50-116955 (JP, A) JP-A-62-269391 (JP, A)

Claims (6)

[Claims] 1. A method for manufacturing a single-sided printed circuit board, which comprises the following steps (a) to (c). (A) Two sheets of which a prepreg and a metal foil are arranged in this order on both sides of a polyvinyl alcohol film having a thickness of 30 to 300 μm, and which are heat-pressed to be integrated through the polyvinyl alcohol film. The step of obtaining the single-sided metal foil-clad laminate. (B) A step of forming a circuit by cutting the two single-sided metal foil-clad laminates, which are integrated via a polyvinyl alcohol film, into a work size and removing unnecessary portions of the metal foil. (C) A step of separating two single-sided printed circuit boards with a layer of polyvinyl alcohol film after the circuit is formed. 2. Two single-sided metal foil-clad laminates obtained by stacking a prepreg and a metal foil under heat and pressure and integrated them with the metal foil side outside through a polyvinyl alcohol film having a thickness of 30 to 300 μm. Metal foil clad laminate for single sided printed circuit boards. 3. Instead of a polyvinyl alcohol film,
The method for producing a single-sided printed circuit board according to claim 1, wherein a polyvinyl fluoride film having a thickness of 20 to 100 μm whose front and back surfaces are roughened is used. 4. Instead of a polyvinyl alcohol film,
The metal foil-clad laminate for a single-sided printed circuit board according to claim 2, wherein a polyvinyl fluoride film having a thickness of 20 to 100 μm, whose front and back surfaces are roughened, is used. 5. The step of separating into two single-sided printed circuit boards,
The method for manufacturing a single-sided printed circuit board according to claim 1, which is a step of corrugating the work. 6. Two single-sided metal foil-clad laminates, which are integrated via a release film so that the metal foil is on the outside, are cut into a work size to remove unnecessary portions of the metal foil. In the step of separating the two single-sided printed circuit boards with the layer of the release film after the circuit is formed, the device used in the separating step is provided with the following configurations (a) to (d). Characteristic single-sided printed circuit board manufacturing equipment. (A) The gap through which the work after circuit formation is passed is composed of an upper roll row and a lower roll row, and (b) individual rolls of the other roll row are located between individual rolls of one roll row, (C) The axial center spacing of the upper and lower rolls is adjusted so that the work passing through the gap is curved by pressing of the individual rolls. (D) Each bending is performed at least once in opposite directions. It is characterized by arranging rolls.