JP3008376B2 - Solder resist printing method - 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 printing a solder resist in a printed circuit board manufacturing process.

[0002]

2. Description of the Related Art Conventionally, positioning of a printed board 1 and a screen plate 2 in solder resist printing in a printed board manufacturing process is performed by visually checking from above the screen plate 2 as shown in FIG. This is performed by aligning the through-hole land 3 at the position and the portion where the emulsion corresponding to that position is hardened on the screen plate 2 (hereinafter referred to as a stencil 4). However, in this method, when visually matching from above the screen plate 2,
In the point that the diameter of the through-hole land on the printed circuit board 1 is small and it is difficult to judge the deviation, and in FIG. For this reason, there is a disadvantage that it is not possible to confirm whether the alignment is performed at the center position before printing.

Therefore, as shown in FIG. 10, it is determined by using a test pattern (solder resist 5, copper foil 6) or the like that after printing, the printed board 1 and the screen plate 2 are properly aligned. I have.

[0004]

The diameter of the stencil on the screen plate 2 is larger than the diameter of the through hole land on the printed circuit board 1. When the stencils 4 are aligned, they cannot be seen as shown in FIG.
For this reason, it is not possible to confirm whether the center of the stencil 4 on the screen plate 2 is aligned with the center of the through-hole land 3 on the printed circuit board 1. Naturally, there is a variation between the value of the difference between the diameter of the through-hole land on the printed circuit board 1 and the diameter of the stencil on the screen plate 2. In addition, it is difficult and almost impossible to match the printing accuracy required for a high-density substrate visually with the size of the through-hole land diameter on the printed circuit board 1 because the shape is too small.

An object of the present invention is to provide a method of printing a solder resist on a printed circuit board in which the alignment accuracy between the printed circuit board and the screen plate can be confirmed before printing. It is.

[0006]

To achieve the above object of the Invention The present invention is, in any position on the printed circuit board, among them
Heart provided a grid reference marks intersect crosswise, on the reference mark corresponding to the position on the screen plate, smaller the center than the reference mark shape on the printed circuit board is enough
It is characterized in that reference marks are provided in a character shape , these reference marks are aligned, and the printed board and the screen plate are aligned.

[0007]

[Function] A reference mark large enough to allow easy visual confirmation is provided on a printed circuit board, and a reference mark smaller than the reference mark shape on the printed circuit board is provided on the screen plate at a position corresponding to the mark. Providing this leads to an improvement in the positioning accuracy of the printed board and the screen plate in solder resist printing, and can prevent the occurrence of defective products such as printing misalignment.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings shown in FIGS. In the following drawings, the same or corresponding parts as those in FIG. 9 for explaining the conventional example are denoted by the same reference numerals.

In the drawings, 1 is a printed board, 2 is a screen plate, 7 is a reference mark on the printed board 1, and 8 is a reference mark on the screen plate 2. There are three types of reference marks 8 provided on the screen plate 2 as shown in FIG.
One is a circle and its diameter is d. The others are circles, and the center is penetrated in a cross shape. The diameter of the circle is d, and the line width of the cross is l1. The other one is a rhombus, the center of which is cross-shaped, the diagonal length of the rhombus is l2, and the line width of the cross is l
It is one.

As shown in FIG. 3, there are four types of reference marks 7 provided on the printed circuit board 1, one of which is a circle, the diameter of which is D1, the other is a triple circle, and the outer shape of which is D2.
The inner diameter is D3, the other is a square, the length of one side is L1, and the other is a combination of six lines in a grid, and the distance between three lines Is L2 and the line width is L3. The comparison between the size of the reference mark 8 and the size of the reference mark 7 is d <D1, d ≦ D3, d = L1, and d = L.
2, 12 = L2, 11 = L3, and the reference mark 8 is smaller than the reference mark 7.

FIG. 4 shows a state in which the screen plate 2 and the printed board 1 are viewed from above when the printed board 1 is aligned. Reference numeral 9 in FIG. The screen plate 2 on which the reference mark 8 is formed at the reference mark forming position shown in FIG. 5 and the printed board 1 on which the reference mark 7 is formed at a position corresponding to the reference mark 8 on the screen plate 2 are prepared.

When the above-described material is prepared and the reference mark 7 on the printed board 1 and the reference mark 8 on the screen plate 1 are visually aligned from above when solder resist is printed, the reference mark 8 on the screen plate 2 is used. Is smaller than the shape of the reference mark 7 on the printed circuit board 1 and both the marks 7 and 8 are sufficiently large, so that alignment is easy,
It can be performed quickly, and the alignment accuracy can be improved before printing.

FIG. 6 shows an embodiment of a printed circuit board matching system of a printing machine already commercialized in the prior art, and FIGS. 7 and 8 show an embodiment in which the matching method is improved.
In FIG. 6, the recognition mark 11 is provided on the printed board 1, but the reference marks 7, 8 are not provided on the printed board 1 and the screen plate 2 unlike the present invention. The printed board 1 is transported from the alignment table 10 to the screen plate 2 position, dummy printing is performed, the printed board 1 is returned to the alignment table 10 again, and the recognition mark 11 is recognized by the camera 12 and aligned. After that, continuous printing is performed. In the case of this method, there is a possibility that the printed board 1 is displaced when the printed board 1 is transported from the alignment table 10 to the screen plate 2 position, which causes printing misalignment. Therefore, as shown in FIG. 7, reference marks 7 and 8 are provided on the printed board 1 and the screen plate 2, and after the printed board 1 is transported to the screen plate 2, the reference marks 7 and 8 are By recognizing and improving the method of alignment, it is possible to improve the displacement during the transfer of the printed circuit board and to improve the printing accuracy.

FIG. 8 shows the recognition camera 1 in the printing press shown in FIG.
The recognition camera 12b is a setting allowable value recognition camera. In the continuous printing, the reference mark 7 on the printed circuit board 1 is recognized by the recognition camera 12a and aligned by the alignment table 10, and then the printed circuit board 1 is transported below the screen plate 2. At this time, printing is performed if the recognition camera 12b determines that the value is within the setting allowable value. However, if the recognition camera 12b determines that the value is outside the setting allowable value, the printing is not performed. The alignment table 10 is in a state where the printed circuit board 1 is constantly aligned during continuous printing and is on standby.

According to this method, by using an apparatus as shown in FIG. 8, it is possible to improve the displacement during the transfer of the printed circuit board and to improve the printing accuracy and the printing ability. Reference numeral 13 in FIGS. 6, 7, and 8 denotes an image processing device.

[0016]

According to the present invention, as described in detail above, a reference mark having a sufficiently large shape is provided on a printed circuit board.
By setting reference marks smaller than the reference mark shape on the printed circuit board at the position corresponding to that position on the screen plate, aligning each and aligning the printed circuit board with the screen plate, the state before printing Thus, the printing position accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a side view of an embodiment of a method for aligning a printed circuit board and a screen plate in the method of the present invention. (2) It is the same top view.

FIGS. 2 (1), (2), and (3) are explanatory diagrams of different reference marks on a screen plate substrate.

FIGS. 3 (1), (2), (3), and (4) are explanatory diagrams of different reference marks on a printed circuit board.

FIGS. 4 (1), (2), (3), (4), and (5) are explanatory views of a state where a reference mark of a screen plate and a reference mark of a printed board are aligned and viewed from above. is there.

FIG. 5 is an explanatory diagram of a reference mark forming position on a screen plate and a printed board.

FIG. 6 is an explanatory diagram of an alignment method for a printing press according to the related art.

FIG. 7 is an explanatory diagram of an alignment method of a printing press in the method of the present invention.

FIG. 8 is an explanatory diagram of an alignment method of a printing press in the method of the present invention.

FIG. 9 is a side view of a conventional method for aligning a printed circuit board and a screen plate. (2) It is the same top view.

FIG. 10 is an explanatory diagram of a test pattern for confirming positional accuracy after printing.

FIG. 11 is an explanatory diagram of a difference in variation due to a conventional alignment method.

[Explanation of symbols]

 1 Printed circuit board 2 Screen plate 7, 8 Reference mark

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Claims (1)

(57) [Claims] At any position 1. A printed circuit board, among them
Heart provided a grid reference marks intersect crosswise, on the reference mark corresponding to the position on the screen plate, smaller the center than the reference mark shape on the printed circuit board is enough
A solder resist printing method, characterized in that reference marks are provided in a character shape , these reference marks are aligned, and the printed board and the screen plate are aligned.