JP2699757B2 - Manufacturing method of printed wiring board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates are those which relate to a method for manufacturing a printed wiring board, such as those used in various electronic devices.

[0002]

2. Description of the Related Art In recent years, printed wiring boards, which are widely used in various kinds of electronic devices, are required to have higher densities of wiring and higher reliability as electronic devices become smaller and more multifunctional. Is coming. Therefore, the formation of an etching resist in the method of forming a conductor pattern on an insulating substrate to be a printed wiring is often performed by a photo-developing method having high resolution using a photosensitive dry film instead of a conventional screen printing method. It is becoming possible.

Hereinafter, a conventional method for manufacturing a printed wiring board will be described. FIG. 2 shows a conventional method for manufacturing a printed wiring board. In FIG. 2, 1 is an insulating substrate, 2
a is copper foil, 2b is a conductor pattern, 3 is a panel for manufacturing a printed wiring board, 4 is a photosensitive etching resist, 5 is an etching resist formed, 6 is an exposure device, 7 is a developing device, and 8 is a developed device. A washing / squeezing / drying device 9 is an etching device.

The operation of the method for manufacturing a printed wiring board having the above-described configuration will be described below.

First, as shown in FIG. 2 (b), a copper clad laminate composed of an insulating substrate 1 and a copper foil 2a is cut into a predetermined size on a copper foil 2a of a printed wiring board manufacturing panel 3 as shown in FIG. Is coated and formed with a photosensitive etching resist 4 in the form of a dry film. Next, the printed wiring board manufacturing panel 3 on which the photosensitive etching resist 4 in the form of a dry film is formed is transported to an exposure apparatus 6 as shown in FIG. 2A, and a mask film for forming a conductor pattern is brought into close contact with the vacuum. Exposure of the photosensitive etching resist 4 with ultraviolet light, FIG.
As shown in FIG. 2C, an unexposed portion of the photosensitive etching resist 4 is developed and removed with a predetermined alkali developing solution in a developing device 7 as shown in FIG. After the etching resist 5 is formed on the copper foil 2a via a water washing / squeezing / drying device 8, the printed wiring board manufacturing panel 3 is successively transferred to an etching device 9 as shown in FIG. Transport . Usually alkaline development type etching
The resist 5 is stripped with an alkali stripper such as caustic soda.
Thereafter, as shown in FIG. 2E, copper foil 2a is placed on the insulating substrate 1.
The conductor pattern 2b is formed.

[0006]

However, in the above-mentioned conventional configuration, the unexposed portion of the photosensitive etching resist 4 is developed and removed with an alkali developing solution, and then is passed through a washing / squeezing / drying device 8 and subsequently an etching device 9. The alkaline developer remaining on the printed wiring board manufacturing panel 3 after development is reduced to a thickness of 30 in the portion where the etching resist 5 is formed at a high density. Because it is as thick as ~ 50 µm,
The washing / removal in the squeezing / drying device 8 becomes insufficient, the surface state of the printed wiring board manufacturing panel 3 becomes an alkaline region, and the exposed / polymerized etching resist film is unstable in the alkaline region state. In the case of an alkali-developing dry film photosensitive etching resist having the property of becoming, the formed etching resist 5 is exposed to an etching solution at a high temperature, and the etching resist 5 and the copper foil 2 are exposed in the etching solution.
a becomes in an unstable state, and the etching device 9
Etching of the etching solution onto the printed wiring board manufacturing panel 3 or physical contact at the transporting portion in the inside of the inside causes peeling or loss of the etching resist 5 portion formed at a high density, and the conductive pattern 2b after the etching is removed . There has been a problem that disconnection or breakage is caused, and the suspension of the manufacturing process of the printed wiring board is remarkably deteriorated.

In order to avoid this problem, the spray pressure for washing in the washing / squeezing / drying device 8 is increased by 20 to 30% to sufficiently wash and wash the alkali developing solution in the high-density portion of the developed etching resist 5 pattern. flow and, although the panel 3 surface state for printed wiring board manufacture which may implement the method of the neutral state, damage to the edge Thing resist 5 of instability after the development at the time of washing, peeling the etching resist 5 And risk of deficiency,
It is not suitable for manufacturing a printed wiring board having a high-density and high-precision conductive pattern 2b.

An object of the present invention is to solve the above-mentioned conventional problems and to provide a printed wiring board having a high-density and high-precision conductive pattern with a high yield.

[0009]

[MEANS FOR SOLVING THE PROBLEMS] To achieve this object
In the present invention, the conductive layer on the insulating substrate alkali development and
Alkali stripping type photosensitive etching resist is formed
Before etching a printed wiring board manufacturing panel
Develop, rinse, and clean the unexposed areas of the photosensitive etching resist.
Immediately after being squeezed and dried, it is converted to an aqueous solution in the acidic region and at room temperature.
After soaking, by etching the exposed conductor layer
To manufacture a printed wiring board.

[0010]

[Action] Alkaline development type photosensitive etching resist
Resistance and adhesion when immersed in alkaline aqueous solution or high temperature aqueous solution
Has the property of deteriorating and developing and peeling.
Immersion in an aqueous solution at room temperature makes development and peeling difficult.
And exposure, development and washing with water, squeezing,
The photosensitive etching Gureji of alkali development type immediately after drying
By immersing the glass in an aqueous solution at room temperature in the acidic region,
Lukari developer and washing / squeezing and heating during drying
The etching resist with reduced resistance
By immersing it in an aqueous solution at room temperature
The contact resistance with the conductor layer.
it can. This exposes them to high temperature etching conditions
Before improving the resistance of the photosensitive etching resist,
And the etching resist in the etching apparatus
Partial peeling or loss can be prevented.

[0011]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a method of manufacturing a printed wiring board according to one embodiment of the present invention.

In FIG. 1, 11 is an insulating substrate, 12a is copper foil, 12b is a conductor pattern, 13 is a panel for manufacturing a printed wiring board, 14 is a photosensitive etching resist, 15
Is the formed etching resist, 16 is the exposure device, 1
7 is a developing device, 18 is a washing / squeezing / drying device after development,
Reference numeral 19 denotes an etching apparatus, 19a denotes a first booth for treating an aqueous solution in an acidic region, and 19b denotes a second booth for etching.

The operation of the method for manufacturing a printed wiring board by the manufacturing apparatus configured as described above will be described with reference to FIG.

First, as shown in FIG. 1B, on a copper foil 12a of a printed wiring board manufacturing panel 13 obtained by cutting a copper-clad laminate composed of an insulating substrate 11 and a copper foil 12a into a predetermined size. Is coated and formed with a photosensitive etching resist 14 in the form of a dry film. The printed wiring board manufacturing panel 13 on which the dry film-shaped photosensitive etching resist 14 is formed is transported to the exposure device 16 as shown in FIG. The light-exposed resist 14 is exposed under the condition of a light amount of about 40 to 100 mj / cm ² .

Next, the exposed printed wiring board manufacturing panel 13 is transported on the transport conveyor to the developing device 17 at a constant speed as shown in FIG. Pressure of about 1.0 to 2.0 kg / cm ² , processing time of about 4
The unexposed portion of the photosensitive etching resist 14 is developed and removed under the conditions of 5 to 60 seconds, and an etching resist 15 is formed on the copper foil 12a as shown in FIG.

Next, as shown in FIG. 1A, the printed wiring board manufacturing panel 13 is conveyed to a washing / squeezing / drying device 18 to remove the developing solution remaining on the surface of the printed wiring board manufacturing panel 13. Washed, rinsed, squeezed and dried. Next, the printed wiring board manufacturing panel 13 is shown in FIG.
As shown in (a), in the first booth 19a of the etching apparatus 19, the pH is 2.0 to 6.0 and the liquid temperature is 20 to 30 ° C.
Spray pressure 0.5 to 2.0 depending on the aqueous solution of acidic region
The processing is performed under the conditions of kg / cm ² and a processing time of 5 to 10 seconds. The surface condition of the printed wiring board manufacturing panel 13 after the treatment is as follows.
The surface temperature of the printed wiring board manufacturing panel 13 after the squeezing and drying treatment has risen to about 50 to 60 ° C. at the same time. The surface temperature of the printed wiring board manufacturing panel 13 after passing through the booth 19a drops to about 20 to 30 ° C., and the strength of the formed etching resist 15 film and the adhesion to the copper foil 12a are strengthened and improved. .

Next, as shown in FIG. 1A, the printed wiring board manufacturing panel 13 transported to the second booth 19b of the etching apparatus 19 is etched by a strongly acidic etching melt such as cupric chloride. And etching resist
After peeling off the substrate 15 , as shown in FIG.
1, a conductor pattern 12b is formed.

[0018] Comparing the manufacturing method of this embodiment according to the printed wiring board manufacturing method of the conventional printed circuit board, occurrence of the conductor pattern breakage and defects due to etching resist peeling and defects in the etching apparatus improved about 90% or more The result was confirmed.

As described above, according to the present embodiment, before the etching, the panel for manufacturing a printed wiring board is treated with an aqueous solution in an acidic region and cooled, so that the occurrence of peeling of the etching resist and the occurrence of defects in the etching apparatus are remarkably improved. can do.

Although the printed wiring board is a single-sided printed wiring board in the embodiment of the present invention, the printed wiring board may be a double-sided or multilayer printed wiring board. Although the etching solution is cupric chloride, it goes without saying that the etching solution may be an acidic etching solution such as ferric chloride or copper sulfate.

[0021]

As described above, according to the present invention, a printed wiring board having a high-density and high-precision conductive pattern is produced with a high yield by treating and cooling the printed wiring board manufacturing panel with an acidic aqueous solution before etching. Can be excellent
A method for manufacturing a printed wiring board can be realized.

[Brief description of the drawings]

FIG. 1A is a conceptual diagram of a printed wiring board manufacturing apparatus according to an embodiment of the present invention. FIGS. 1B to 1E are cross-sectional views of a manufacturing process of a printed wiring board manufacturing method according to an embodiment of the present invention.

2A is a conceptual diagram of a conventional printed wiring board manufacturing apparatus, and FIGS. 2B to 2D are cross-sectional views of a manufacturing process of a conventional printed wiring board manufacturing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Insulating substrate 12a Copper foil 12b Conductive pattern 13 Panel for manufacturing printed wiring board 14 Photosensitive etching resist 15 Etching resist 16 Exposure device 17 Developing device 18 Rinsing / squeezing / drying device 19 Etching device 19a Aqueous solution treatment for acidic area aqueous solution Booth 1 19b Second booth for etching

Claims (1)

(57) [Claims] 1. An alkali-developing type conductive layer is provided on a conductive layer on an insulating substrate.
Printed wiring board with photosensitive etching resist
When etching a production panel, the photosensitive etchant
After developing, washing, squeezing and drying the unexposed part of the resist,
Later, after immersion in an aqueous solution at room temperature in an acidic area,
Printed wiring characterized by etching a conductive layer
Manufacturing method of wire plate.