JPH0992958A - Manufacture of copper-clad lamination board for printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To respond to high density and fining of a wiring pattern by providing a manufacturing method whereby a copper-clad board of an extremely thin copper foil of a uniform thickness used for manufacturing of a printed wiring board by a subtractive method can be manufactured. SOLUTION: A copper-clad board P wherein a copper foil both sides is held in a horizontal position and is carried by a conveyor 60. After the entire surface of a copper foil is etched (pre-etched) by an etching device 10, cleaned by water, drained and dried, the copper foil board P is reversed by a board reversing device 50 and a copper foil is thinned uniformly by etching the entire surface of a copper foil again by the etching device 10 in a horizontal position. Then, water cleaning, draining and drying are carried out and the dried copper-clad board P is transferred to a board cutting and through-hole formation process. A printed wiring board is prepared by using the copper-clad board P whose copper foil is thinned.

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 copper clad laminate for a printed wiring board, and more particularly to a method for manufacturing a copper clad laminate used for manufacturing a printed wiring board by a subtractive method.

[0002]

2. Description of the Related Art In the manufacture of a printed wiring board by the subtractive method, a copper clad laminate having copper foils adhered on both sides is generally used to cut the substrate, form through holes, clean the inside of holes, and electroless copper plating. , Electrolytic copper semi-panel plating, pattern plating resist, electrolytic copper / solder plating,
A printed wiring board is manufactured by removing plating resist, etching, fusing, and solder resist / symbol printing.

The above-mentioned copper clad laminate is manufactured by pasting electrolytic copper foil on the front and back of the resin insulating plate, and the thickness of the electrolytic copper foil is 5 μm, 9 μm, 12 μm, 18 μm, 35 μm,
70 μm copper clad laminates are commercially available. However, an ultrathin copper-clad laminate having a copper foil thickness of 5 μm, 9 μm, and 12 μm is expensive and not only extremely difficult to manufacture,
Further, there is a defect that the variation in the thickness has no standard and lacks reliability. Therefore, conventionally, a printed circuit board is generally manufactured using a copper clad laminate having a copper foil thickness of 18 μm or 35 μm.

[0004]

However, with the recent miniaturization and higher functionality of equipment, the density of printed wiring boards has increased, and the wiring patterns of printed wiring boards have to be made finer. It is difficult to meet the requirement with a copper clad laminate having a copper foil thickness of 18 μm or 35 μm as described above, and there has been a strong demand for a copper clad laminate having an ultrathin copper foil having a uniform thickness. The present invention has been made in view of the above circumstances, and provides a method for manufacturing a copper clad laminate of an ultrathin copper foil having a uniform thickness, which is used for manufacturing a printed wiring board by a subtractive method. The purpose is to cope with the miniaturization of wiring patterns.

[0005]

In order to achieve the above object, the present invention is a method for producing a copper clad laminate for a printed wiring board having a copper foil on at least one side thereof, wherein the copper clad laminate is either horizontal or vertical. A pre-etching step of holding the posture and etching the entire surface of the copper foil, and a post-etching step of inverting the copper-clad laminate and holding the copper-clad laminate in the inverted posture to etch the entire surface of the copper foil. Prepared

[0006] The invention according to claim 2 is based on claim 1.
In the method for producing a copper-clad laminate for a printed wiring board according to the invention described above, the pre-etching step and the post-etching step, by impinging a jet of an etching solution on the copper foil in an etching solution, or The etching solution was sprayed against the copper foil in air. The invention according to claim 3 is the method for producing a copper-clad laminate for a printed wiring board according to claim 1 or 2, wherein the pre-etching step and the post-etching step are the copper-clad laminate. The plate was circulated and conveyed in the same etching apparatus.

[0007]

According to the present invention, the copper clad laminate is held in a horizontal or vertical posture to etch the entire surface of the copper foil, and then the copper clad laminate is inverted to etch the entire surface of the copper foil in a reversed posture. Therefore, the copper foil can be uniformly thinned. According to the second aspect of the present invention, the pre-etching step and / or the post-etching step is performed by causing the jet stream of the etching solution to strike the copper foil or spraying the etching solution onto the copper foil. Therefore, the time required for etching can be shortened, and the copper foil can be etched more uniformly. Further, according to the third aspect of the invention, since the pre-etching step and the post-etching step are performed by using the same etching apparatus, a plurality of etching apparatuses are unnecessary, and the equipment can be downsized and the cost can be reduced.

In the method for manufacturing a copper clad laminate for a printed wiring board according to the present invention, the etching solution is
A chemical capable of dissolving copper, such as a cupric chloride solution, a ferric chloride solution, an alkaline etching solution, a hydrogen peroxide solution / sulfuric acid-based solution, and a persulfate-based solution, is used. Further, during etching, while carrying the copper clad laminate in a horizontal or vertical posture by a conveyor or the like, the pre-etching step and the post-etching step each include at least a well-known water washing treatment,
After the last post-etching step, further draining and drying processes are performed. Furthermore, the pre-etching step and the post-etching step can each be performed multiple times,
In this case, it is desirable to perform the pre-etching step and the post-etching step the same number of times.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are views for explaining a method of manufacturing a copper clad laminate for a printed wiring board according to an embodiment of the present invention, and FIG. 1 is a schematic diagram showing an outline of an etching apparatus, FIG. FIG. 3b is a view showing the posture of the copper clad laminate during etching, and FIG. 3 is a process flow chart.

In FIG. 1, 10 is an etching device, 3
Reference numeral 0 is a water washing device, 40 is a dryer, and 50 is a substrate reversing device, and the copper clad laminate P is conveyed by a conveyer 60 between them. As will be described in detail later, the transfer conveyor 60 is
The roller conveyor 61 is provided continuously with the etching apparatus 10 and the water washing apparatus 30.
1 conveys the copper clad laminate P in a horizontal posture. Although illustration is omitted, the copper clad laminate P is formed by attaching electrolytic copper foils on both front and back surfaces of a resin insulating plate.

The etching apparatus 10 has a processing tank 11, and inside the processing tank 11, the above-mentioned roller conveyor 61 is provided.
Are arranged horizontally. The roller conveyor 61 is configured by vertically arranging a plurality of rollers 61a and conveys the copper clad laminate P in a horizontal posture shown in FIG. 2a. The conveyor 6
0, that is, the roller conveyor 61 can be replaced with a conveyor that conveys the copper clad laminate P as shown in FIG. 2b in a vertical posture. In FIGS. 2a and 2b, X and Y are horizontal directions, Y is the transport direction, and Z is the vertically upper direction.

The processing tank 11 is provided with a plurality of nozzles 11a at the upper and lower sides of the roller conveyor 61 at predetermined intervals in the carrying direction, and the lower portion communicates with the processing storage tank 13 which stores an etching solution such as cupric chloride solution. Each of the nozzles 11 a is connected in parallel with a spray pump 14 that pressure-feeds the etching liquid in the processing storage tank 13.
The etching liquid pressure-fed from is sprayed toward the upper and lower surfaces (copper foil) of the copper-clad laminate P conveyed by the roller conveyor 61. Reference numeral 15 is a pressure gauge for detecting the pressure of the etching liquid supplied to the nozzle 11a.

A heater 16 for heating the etching liquid and a thermometer 1 for detecting the temperature of the etching liquid are provided in the processing storage tank 13.
7 and a liquid level gauge 20 for detecting the storage amount of the etching liquid are provided, and a circulation pump 18 and a filter 19 are connected in series. The heater 16, the thermometer 17, the liquid level gauge 20, and the spray pump 14 described above are connected to a controller (not shown), and the heater 16 and the spray pump 14 are controlled based on the outputs of the thermometer 17 and the liquid level gauge 20. Specifically, the heater 16 is controlled based on the detection output of the thermometer 17 to maintain the temperature of the etching solution at an appropriate temperature, and
When the liquid level gauge 20 detects that the liquid level of the etching liquid is below a predetermined level, the heater 16 and the spray pump 14 are stopped.

In the water washing apparatus 30, the above-mentioned roller conveyor 61 is continuously arranged in the water washing tank 31 from the etching apparatus 10, and a plurality of shower nozzles 32 are arranged above and below the roller conveyor 61. The water washing device 30 sprays washing water from the shower nozzle 32 onto the upper and lower surfaces of the copper clad laminate P conveyed in a horizontal posture by the roller conveyor 61 to wash the copper clad laminate P.

The dryer 40 and the substrate reversing machine 50 are provided with a conveyor 63 continuous with the roller conveyor 61 described above. As is well known, the dryer 40 dries the copper-clad laminate P conveyed by the conveyor 63, and the substrate reversing machine 50 reverses the copper-clad laminate P conveyed by the conveyor 63 and transfers it to the conveyor 63. The substrate reversing machine 50 reverses the carrying posture (etching posture) of the copper clad laminate P, that is, rotates 180 degrees around the X, Y or Z axis in FIG. 2a. In this embodiment, since the copper-clad laminate P has copper foils on both sides, it is desirable to rotate the copper-clad laminate P about the X-axis or the Y-axis. It only needs to rotate around the Z axis.

The conveyor 60 has a dryer 63 on the conveyor 63.
0 and the substrate reversing machine 50, and also has a switching mechanism 68 at the start end of the roller conveyor 61 so that the conveyor 63 can be switched to the conveyor 63 via the switching mechanism 67. A conveyor 63 and a loading conveyor 69 are switchably connected to the starting end of the roller conveyor 61 via a switching mechanism 68. The conveyor 60 is the switching mechanism 6 described above.
7, 68, etc. are controlled by a controller (not shown),
At the switching position 1 of the switching mechanisms 67 and 68, the conveyor 6
1, 63, the copper clad laminate P is conveyed in a horizontal posture and circulated between the etching device 10, the water washing device 30, the dryer 40 and the substrate reversing device 50, and the switching mechanisms 67, 68.
Copper-clad laminate P that came out of the dryer 40 at the other switching position of 1
Is transferred to the substrate cutting / through hole forming process by the conveyor 65.

Next, the manufacturing method will be described with reference to FIG. In this embodiment, the switching mechanism 68 of the conveyor 60 is switched to load the copper clad laminate P into the etching apparatus 10 by the loading conveyor 69, and each switching mechanism is operated to the switching position on the circulation side. When the copper-clad laminate P passes through the etching apparatus 10 twice, the switching mechanism 67 is switched to connect the conveyor 63 and the conveyor 65. Therefore, the copper clad laminate P is conveyed by the conveyor 60, and as shown in FIG. 3, etching, washing with water, draining, drying, substrate inversion,
Etching, washing with water, draining and drying are sequentially carried out, and thereafter, the substrate is transferred by a conveyor 65 to a substrate cutting / through hole forming step.

That is, in the copper clad laminate P, the spray of the etching solution collides with the copper foil in the etching apparatus 10 to uniformly and thinly etch the copper foil (pre-etching step), and subsequently, is washed by the water washing apparatus 30. After that, the substrate is turned over by the substrate reversing machine 50, and then the etching apparatus 10 again etches the copper foil thinner (post-etching step), followed by washing with water, draining and drying. After that, it is transferred to the substrate cutting / through hole forming process.

As described above, in this embodiment, the copper-clad laminate P is conveyed in a horizontal posture to etch the copper foils on both sides, and then the copper-clad laminate P is inverted to form a copper-clad laminate. Board P
Since the copper foils on both sides are etched again in the horizontal posture in which the above is reversed, the copper foils on both sides of the copper clad laminate P can be uniformly thinned. Therefore, using this copper-clad laminate P, steps such as substrate cutting and through hole formation are sequentially performed, that is, a printed wiring board is manufactured by the subtractive method. Since this printed wiring board is manufactured based on the copper clad laminate P in which the copper foil is thinned, high density mounting is possible and the wiring pattern can be made fine.

In the above-described embodiment, the pre-etching is performed and then the reversal is performed to perform the post-etching, that is, the etching is performed twice by changing the posture, but the etching can be performed more times. Is. In this case, it is desirable that the number of times of etching is set to an even number, that is, the number of times the posture is inverted is set to an odd number, and the number of times of the pre-etching step and the post-etching step is equal. Further, in the above-described embodiment, etching is performed by hitting the copper-clad laminate P with a spray of the etching liquid in the air, but the copper-clad laminate P is immersed in the etching liquid to jet the etching liquid. It is also possible to hit the copper clad laminate P to perform etching.

FIG. 4 is a process flow chart showing another embodiment of the method for manufacturing a copper clad laminate for a printed wiring board according to the present invention. In addition, in this embodiment and the embodiments described later, the same components as those in the above-described embodiment are designated by the same reference numerals, and the illustration and description thereof will be omitted. In this embodiment, two etching devices 10,
Using two water washing devices 30 and a substrate reversing machine 50, these are arranged in series to perform pre-etching and post-etching on the copper clad laminate P. That is, as shown in FIG. 4, the copper-clad laminate P is conveyed by a conveyor 60 in a horizontal or vertical posture, pre-etched, washed with water and inverted, and post-etched in an inverted horizontal or vertical posture. Then, draining and drying are performed.

Also in this embodiment, the copper clad laminate P
Since the copper foils on both sides can be uniformly thinned, the printed wiring board manufactured by the subtractive method based on the copper clad laminate P can be mounted at high density and the wiring pattern can be made fine. . And, in this embodiment, as compared with the above-described embodiment, the liquid draining step and the drying step between the pre-etching and the post-etching can be omitted,
The process can be shortened, and the entire facility can be downsized.

FIG. 5 is a process flow chart showing another embodiment of the method for manufacturing a copper clad laminate for a printed wiring board according to the present invention. In this embodiment, the substrate reversing machine 50,
The etching apparatus 10 and the water washing apparatus 30 are arranged in series, the copper clad laminate P is put into the etching apparatus 10, pre-etched, washed with the water washing apparatus 30, and then reversed with the substrate reversing machine 50, and again the water washing apparatus. The post-etching is carried out by guiding to the etching apparatus 10 via 30. Then, after this, the copper clad laminate P is washed with water, drained and dried, and transferred to the substrate cutting / through hole forming step, as in the case of FIG. 4 described above.

Also in this embodiment, the copper clad laminate P
It is possible to manufacture a printed wiring board capable of thinning the copper foils on both sides of the sheet evenly, and capable of high-density mounting and fine wiring patterns based on the copper-clad laminate P by the subtractive method. it can. As compared with the above-described embodiment shown in FIG. 4, only one etching apparatus 10 is sufficient, so that the overall equipment can be downsized and the installation cost can be reduced.

[0025]

As described above, according to the method for manufacturing a copper clad laminate for a printed wiring board according to the present invention, the copper clad laminate is held in a horizontal or vertical posture and the entire surface of the copper foil is etched ( After pre-etching), the copper clad laminate is inverted and the entire surface of the copper foil is etched again (post-etched) in the inverted horizontal or vertical posture, so that the copper foil of the copper clad laminate can be made evenly thin. It is possible to manufacture a printed wiring board that can be mounted at a high density by a subtractive method based on a laminated board and can have a fine wiring pattern.

[Brief description of drawings]

FIG. 1 is a schematic view of an apparatus used in a method for manufacturing a copper clad laminate for a printed wiring board according to an embodiment of the present invention.

2A and 2B are schematic perspective views showing a posture of a copper clad laminate at the time of etching in the manufacturing method, wherein a is a mode 1 and b is another mode.

FIG. 3 is a process flow chart of the manufacturing method.

FIG. 4 is a process flow chart of a method for manufacturing a copper clad laminate for a printed wiring board according to another embodiment of the present invention.

FIG. 5 is a process flow chart of a method for manufacturing a copper clad laminate for printed wiring boards according to still another embodiment of the present invention.

[Explanation of symbols]

 10 Etching Device 11 Processing Tank 11a Nozzle 13 Processing Storage Tank 14 Spray Pump 15 Pressure Gauge 16 Heater 17 Thermometer 18 Circulation Pump 19 Filtration Machine 20 Liquid Level Gauge 30 Cleaning Device 31 Rinsing Tank 32 Nozzle 40 Dryer 50 Substrate Reversing Machine 60 Conveyor 61 Roller conveyor 61a Roller 63 Conveyor 65 Conveyor 67 Switching mechanism 68 Switching mechanism 69 Conveyor P Copper clad laminate

Claims (3)

[Claims] 1. A method of manufacturing a copper clad laminate for a printed wiring board, which has a copper foil on at least one surface thereof, wherein a pre-etching step of holding the copper clad laminate in a horizontal or vertical posture and etching the entire surface of the copper foil. And a post-etching step of reversing the copper-clad laminate, holding the copper-clad laminate in an inverted posture and etching the entire surface of the copper foil, the copper-clad laminate for a printed wiring board. Method of manufacturing a plate. 2. In the pre-etching step and the post-etching step, a jet of an etching solution is applied to the copper foil in an etching solution, or a spray of the etching solution is applied to the copper foil in the air. The method for producing a copper-clad laminate for a printed wiring board according to claim 1, wherein the method is carried out. 3. The copper for printed wiring board according to claim 1, wherein the pre-etching step and the post-etching step are carried out by circulating the copper clad laminate in the same etching apparatus. Method for manufacturing a laminated laminate.