JPH0730211A - Printed board - Google Patents

Abstract

PURPOSE:To prevent the edge of a board from entering and being caught between the belt and the guiding part of a belt conveyer which carries printed boards, and improve the strength of the printed boards. CONSTITUTION:Process layers (a copper foil part 3, a resist mask 6, a silk screen 7, a gird ring 10, etc). Which are to be formed at least on the board 2 of a product are simultaneously formed on the edge side parts of the waste board 5 on the circumference of the board 2. The thickness (t) at the edge plane on the circumference of a printed board 1 is permitted to be almost the same as the maximum thickness of the board 2 at least.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board on which electronic parts are mounted.

[0002]

2. Description of the Related Art A printed circuit board on which electronic components are mounted has a so-called discarded circuit board portion as a cut-off portion which is not used as a product, around a product circuit board portion on which components are mounted and used as a product. It has been known.
FIG. 5 is a perspective view showing an example of the printed circuit board as described above. The printed circuit board 1 is a double-sided mounting board on which both surfaces can be mounted with wiring patterns and the like. Only one side is shown. In this printed circuit board 1, a portion 2 inside a slit 4 described later is a product substrate portion, and a copper foil portion 3 showing a wiring pattern, a land and the like is formed. Further, a plurality of elongated hole-shaped 4 formed so as to partition the product substrate portion 2 and the discarded substrate portion 5 described below are slits, and in the figure, only one of the plurality of slits is given a reference numeral. And others are omitted. The outer peripheral portion of the printed board 1 outside the slits 4 is a waste board portion that is finally separated from the product board portion 2 and becomes an unnecessary portion. For example, after the electronic component is mounted on the copper foil portion 3 of the product board portion 2, the joint portion between the slit 4 and the slit 4 is cut with a tool. As a result, the discarded board portion 5 is cut off from the product board portion 2, and the product board portion 2 having a required size is incorporated into a specific device as a circuit board, for example.

The structure of the printed circuit board 1 is provided with layers by various processing steps as shown in the sectional view of FIG. 6, for example. In this figure, a hatched portion 1a is a substrate base, on which various processing layers are formed. For example, on the substrate base 1a, first, the wiring pattern and the copper foil portion 3 which is a land are formed by a process such as etching. Next, a resist mask 6 is printed to insulate portions of the formed copper foil portion 3 that are not soldered. After this, a step of printing the silk screen 7 on which characters, symbols, symbols and the like are further printed is performed. In this way, the printed circuit board 1 is configured, and thereafter, for example, components are mounted on the exposed portion of the copper foil portion 3 by soldering.

[0004]

By the way, as shown in the discarded substrate portion 5 on the left side of FIG. 6, since this portion is an unnecessary portion, the steps for various treatments are not normally performed, and therefore, The thickness t of the discarded substrate portion 5 is equal to the thickness of the substrate base 1a, and is thinner than the portion of the product substrate portion 2 where various processing layers are formed. Alternatively, as shown in the discarded substrate portion 5 on the right side of FIG. 6, a process may be performed such that at least the copper foil portion 3 is left (in this case, the resist mask 6 is also applied). However, even in such a case, for example, since the layer forming process is not performed up to the edge of the discarded substrate portion 5, the thickness t of the end face portion is equal to the thickness of the substrate base 1a, and the product substrate portion 2 has a thickness t. It is thinner than the part where the layers are formed.

In the process for mounting the electronic components on the printed circuit board 1 as described above, for example, as shown in the printed circuit boards A and B of FIG.
The printed circuit board is conveyed to the component mounting table M by the belt conveyor consisting of, and the component is mounted by the part feeder F as shown in the printed circuit board C. When the printed circuit board is conveyed by the belt conveyor, a guide portion G for guiding the printed circuit board is provided along the traveling direction of the belt conveyor, for example, located above one side of the belt BL. Since the guide portion G is located on the upper side of the belt BL, it is arranged so as not to come into contact with the belt BL as shown in FIG.
As shown in the side view of (a), the belt BL is provided with a slight gap. Therefore, as shown in the drawing, a gap having a width L is generated between the guide portion G and the belt BL.

However, as shown in FIG. 8B, when the printed circuit board 1 is carried on the belt BL and conveyed, the distance from the end of the upper surface of the printed circuit board 1 to the belt BL is slightly smaller than the width L of the gap. If the height t ¹ is low, there is a high possibility that the end portion of the waste substrate portion 5 of the printed board 1 will enter this gap. Then, as shown in the printed circuit board B in FIG. 7, the end of the discarded circuit board portion 5 is caught in the gap and stops the flow of the printed circuit board carried by the belt conveyor, or the printed circuit board to the proper position on the component mounting table M. May not be able to be loaded, which causes a decrease in manufacturing efficiency.

[0007]

In order to solve the above-mentioned problems, the present invention solves the above-mentioned problems by disposing a product board portion on which electronic parts and the like are mounted and used as a product, and a waste portion separated from the product board portion as an unnecessary portion. In a printed circuit board including a board portion, a layer is formed by an arbitrary processing step on at least the edge side portion of the waste board portion so as to have a thickness equal to or more than a required condition.

[0008]

[Function] Since the processing for forming various layers is performed on the discarded board portion as well, the thickness of the end portion of the printed board can be made thicker than the width of the gap between the belt and the guide portion of the belt conveyor. It is possible to prevent the substrate from getting caught in the gap between the belt and the guide portion and being caught during the transportation. Therefore, the manufacturing efficiency of the printed circuit board can be improved.

[0009]

1 is a perspective view showing a printed circuit board 1 according to an embodiment of the present invention. The same parts as those in FIG. In the present embodiment, a process of forming various layers is performed on the shaded portion of the drawing, that is, particularly on the edge portion side of the discarded substrate portion 5, similarly to the product substrate portion 2,
The thickness t of the end portion shown in the drawing is made equal to or larger than that of the product substrate portion 2.

FIG. 2 is a sectional view showing an embodiment of the printed circuit board 1 of the present invention. In this case, both sides of the board are subjected to a wiring pattern or other processing to enable mounting of parts. The case of a mounting board is shown. Further, the same parts as those in FIG. The product substrate portion 2 shown in this figure is, for example, a copper foil portion 3 having a thickness of 35 to 50 μm with respect to a substrate base 1a having a thickness of less than 0.6 mm, and approximately 1
The printed circuit board 1 is formed by performing a process of forming a resist mask 6 having a thickness of 0 μm and a layer of the silk screen 7 having a thickness of about 10 μm. In this case, the copper foil portion 3, the resist mask 6, and the various processing layers of the silk screen 7 are formed at the same time as the product substrate portion 2 even in the discarded substrate portion 5 up to the end portion. As a result, as shown by the broken line in the figure, the thickness t of the end portion is expanded to the same thickness as the layers of the product substrate portion 2 (or in some cases, more than that).

Then, such a printed circuit board 1 is shown in FIG.
In the case where it is conveyed by a belt conveyor as shown in FIG.
Since the width L of the gap is very narrow, the thickness t of the end portion of the printed circuit board 1 of this embodiment is equal to the above-mentioned guide portion G and belt B.
The thickness t exceeds the width L of the gap L. As a result, the end portion of the printed board 1 does not enter the gap between the guide portion G and the belt BL, and the printed board is smoothly conveyed.

FIG. 3 is a cross-sectional view showing another embodiment. In this case, a four-layer board in which a wiring pattern of two layers is formed on both sides of the board and in the inner layer, that is, a so-called multilayer board is shown. . The same parts as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted. In the case of this four-layer substrate, as shown in the product substrate portion 2 in the figure, first, copper foil portions 8 and 9 as inner layer wiring pattern lands are formed on both surfaces of the substrate base 1a by etching or the like. . next,
Laminated plates 1b and 1c are attached to both surfaces of the substrate base 1a on which the copper foil portions 8 and 9 of the inner layers are formed, for example, by a process such as laminating press, and further to the surfaces of the laminated plates 1b and 1c. A process of forming the copper foil portions 3 and 3 as the outer layer pattern is performed. As a result, four layers of wiring patterns are formed on one substrate. Next, a resist mask 6 is printed on each surface of the laminated plates 1b and 1c on which the copper foil portions 3 and 3 are formed, and a silk screen 7 is printed. In this way, the respective layers shown in the figure are formed on the substrate. Then, in the present embodiment, in the same step as above, each layer is formed on the discarded substrate portion 5 up to the end portion as shown in the figure. As a result, the thickness of the end portion t becomes the same as or thicker than the thickest portion of the product substrate portion 2. This can prevent the end portion of the printed board 1 from entering the gap between the guide portion G and the belt BL, as in the previous embodiment.

FIG. 4 is a cross-sectional view showing a double-sided mounting board according to still another embodiment. The same parts as those in FIG. 2 are designated by the same reference numerals and their description is omitted. In this figure, 10 is thickness 6
A guard ring with a thickness of 0-100 μm is shown. The guard ring 10 may be applied with a chip coating agent when mounting a chip component, for example, and has a role of blocking the chip coating agent from flowing to unnecessary portions on other substrates. It will be achieved. Then, this chip coating agent is treated, for example, with a copper foil portion 3, a resist mask 6, and a silk screen 7,
It is applied to required parts. In this embodiment, in addition to forming layers such as the copper foil portion 3, the resist mask 6, and the silk screen 7 on the discarded substrate portion 5, as in the previous embodiments, the guard ring 10 is formed. Is also formed in the same step as that applied to the product substrate portion 2. As a result, as in the previous embodiment, the thickness of the end portion t becomes the same as or thicker than the thickest portion of the product substrate portion 2, so that the end portion of the printed circuit board 1 has the guide portion G and the belt. It will not enter the BL gap.
In addition, even if the guard ring 10 is not provided on the product substrate portion 2, the guard ring 1 may be attached to the discarded substrate portion 5.
It is also possible to secure the thickness of the end portion t by performing the step of printing 0.

Further, conventionally, since the thickness of the portion of the discarded substrate portion 5, that is, the peripheral portion of the substrate is thin, the strength of the entire substrate cannot be secured, and there is a possibility that the problem of breakage or crack may occur. By increasing the thickness of the end portion of the waste substrate portion 5 as in each of the embodiments, the strength of the entire substrate is improved,
These problems can also be solved.

In each of the above embodiments, the double-sided mounting board or the multi-layered board is described, but the invention can be applied to a single-sided mounting board or the like. Further, the layers formed on the product substrate portion and the discarded substrate portion of the substrate are not limited to the various forming layers described in each of the above embodiments, and any other layer may be formed. Furthermore, the thickness of the end that does not get caught during transportation,
Alternatively, needless to say, if the required strength can be secured, it is only necessary to discard any of the various layers and form it on the substrate portion.

[0016]

As described above, according to the present invention, various layers are formed on at least the edge portion of the discarded substrate portion to obtain a thickness equal to or larger than the gap width between the belt and the guide portion of the apparatus for conveying the substrate. There is an advantage in that it is possible to prevent an inconvenience such as an edge of the substrate getting into this gap and being caught and stopping the work flow. Therefore, the manufacturing efficiency of the printed circuit board can be improved. In addition, since the peripheral edge portion of the printed circuit board becomes thicker, the strength of the circuit board is improved, and it is possible to prevent breakage and cracking.

[Brief description of drawings]

FIG. 1 is a perspective view showing a printed circuit board according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a printed circuit board according to an embodiment.

FIG. 3 is a sectional view showing a printed circuit board according to another embodiment.

FIG. 4 is a sectional view showing a printed circuit board according to still another embodiment.

FIG. 5 is a perspective view showing a printed circuit board in a conventional example.

FIG. 6 is a cross-sectional view showing a printed circuit board in a conventional example.

FIG. 7 is an explanatory diagram showing a state in which a printed circuit board is conveyed to a component mounting table.

FIG. 8 is an explanatory view showing a positional relationship between a belt conveyor and a guide section from a side direction, and an explanatory view showing a state in which a printed circuit board is conveyed in a conventional example from a front direction.

[Explanation of symbols]

 1 Printed circuit board 2 Product board part 3, 8, 9 Copper foil part 4 Slit 5 Discarded board part 6 Resist mask 7 Silk screen 10 Guard ring

Claims (3)

[Claims] 1. A printed circuit board comprising a product board part on which electronic parts and the like are mounted and used as a product, and a waste board part provided around the product board part and separated from the product board part as an unnecessary part. In at least the edge side portion of the waste substrate portion, by forming a layer by the processing step performed on the printed circuit board, at least a thickness substantially equal to the maximum thickness of the product substrate portion. Printed board. 2. The printed circuit board according to claim 1, wherein the layer formed by the processing step is formed on the product substrate portion and the discarded substrate portion at the same time. 3. The layer according to claim 1 or 2, wherein the layer formed by the treatment step comprises one or more layers of a copper foil pattern, a resist layer, a silk printing layer and a guard ring layer. Printed circuit board described.