JP2606661B2 - Manufacturing method of printed wiring board - Google Patents

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 printed wiring board, and more particularly to a method for forming a solder resist for a high-density printed wiring board.

[0002]

2. Description of the Related Art In a conventional method of forming a solder resist by a photo-developing method on a high-density printed wiring board, a standard of the printed wiring board is required to prevent a displacement of a solder resist pattern due to misalignment of a mask film in an exposure step. Points (holes, patterns, unique alignment marks,
In addition to the method of aligning the mask film with the mask substrate, the insulating substrate 1 on which the component mounting pads 2 are formed as shown in FIG. 3A as described in JP-A-1-261645. A photosensitive solder resist 4 is applied to the entire surface and touch drying is performed (FIG. 3B).
Is positioned through a mask 10 with a window (FIG. 3C).
A blind mask 11 having a shape for blocking a transmission part is superimposed on the mask 0 (FIG. 3D). Exposure and development are performed to form a solder resist in the gap between the component mounting pads 2 without displacement. There is a method (FIG. 3E).

[0003]

In a conventional method of aligning a mask film in an exposure step in the formation of a solder resist by a photographic developing method, a hole in a printed wiring board,
As described above, the mask film is visually adjusted through a mask with a window, based on a pattern and a specific alignment mark. In the exposure process, a photosensitive solder resist is applied to the entire surface of the printed wiring board. Since this mask film is of a positive type, the black part is covered with a photosensitive solder resist. The holes and patterns on the printed wiring board are the reference points for alignment, a specific alignment mark, or a mask with a window. It is extremely difficult to determine the overlap position deviation. A solder resist is required to be formed between the component mounting pads on the printed wiring board to prevent solder bridges during soldering. However, if the aforementioned misalignment occurs, solder There is a problem that the resist adheres and proper soldering cannot be performed.

[0004]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method of manufacturing a printed wiring board for forming a solder resist by using a photo-developing method, the method comprising the steps of: When conducting exposure through a mask film, inspection of the through-hole provided in the outer area of the printed wiring board and the conductivity corresponding to this inspection through-hole and taking into account the positional deviation of the solder resist to the land diameter Performing an electrical test after alignment with a mask film having through holes for use.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing a method for manufacturing a printed wiring board according to an embodiment of the present invention.

As shown in FIG. 1A, a component mounting pad 2 is provided at a desired position on an insulating substrate 1 and three of four corners of an outer diameter area.
Through hole 3 for positional deviation inspection with hole diameter φ0.3mm and land diameter φ0.75mm at each of four locations or four locations
To form Next, a photosensitive solder resist 4 is applied to the entire surface of one side of the insulating substrate 1, and touch drying is performed [FIG.
(B)]. Next, the positional deviation tolerance of the solder resist corresponds to the through-hole 3 for positional deviation inspection described above and is 5, 0.
A mask film 7 having a conductive through-hole 6 having a hole diameter of 0.95 mm and a land diameter of 1.40 mm in which 1 mm is added to the land diameter is overlapped and aligned. At this time, the probe pins 9 are brought into contact with the 1.0 mm × 0.5 mm conductive pads 8 connected to the positional deviation inspection through holes 3 and the corresponding conductive through holes 6, and the presence or absence of conduction is confirmed by electrical inspection. Thus, it is determined whether or not the alignment position of the mask film 7 is within the range of the positional deviation tolerance 5 of the solder resist [FIG. 1 (c)]. This electrical inspection is carried out for each of the four positional deviation inspection through holes and the corresponding conductive through holes on the insulating substrate.
Connect three or four through holes for displacement inspection on the insulating substrate to the inner layer, and also connect the corresponding conductive through holes of the mask film in a pattern, and connect one through hole for displacement inspection and the corresponding There is a method of performing an electrical test by using a conductive through hole. Next, exposure and development are performed to obtain a desired solder register pattern. [FIG. 2 (d)]. Hereinafter, the steps of FIGS. 1 and 2 are repeated on the opposite surface of the insulating substrate to obtain a printed wiring board according to the manufacturing method of the embodiment of the present invention [FIG.
(E)].

[0008]

As described above, in the method of forming a solder resist by using the photographic developing method of the present invention, when the mask film is aligned in the exposure step, the misalignment of the mask film is determined by an electrical inspection. For discrimination, it is possible to prevent the solder resist from adhering to the component mounting pad.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a part of a manufacturing process of a printed wiring board according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a manufacturing step following FIG. 1;

FIG. 3 is a longitudinal sectional view showing a manufacturing process of a conventional printed wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating board 2 Component mounting pad 3 Through hole for positional displacement inspection 4 Photosensitive through hole 7 Mask film 8 Conductive pad 9 Probe pin 10 Window mask 11 Blind mask

Claims (1)

(57) [Claims] In a method for manufacturing a printed wiring board, wherein a solder resist is formed by using a photo-developing method, a printed wiring board coated with a photosensitive solder resist after touch drying is exposed through a mask film. When doing
Positioned by the inspection through-hole provided in the outer area of the printed wiring board and a mask film having a conductive inspection through-hole corresponding to the inspection through-hole and taking into account the positional deviation tolerance of the solder resist to the land diameter. A method for manufacturing a printed wiring board, comprising performing an electrical inspection after the alignment.