JPH0132763Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printed wiring board constructed by pasting overlays on necessary parts of a conductive pattern formed by etching or the like.

In a conventional printed wiring board, as shown in FIG. 1, a conductive pattern 2 is formed on an insulating substrate 1 by a method such as etching. An overlay 4 made of polyimide film, polyester film, or the like with through holes 3 formed in corresponding positions is pasted, but alignment of the conductive pattern 2 and the through holes 3 of the overlay 4 is important. Conventionally, this alignment has been performed by visually determining the position when pasting the overlay 4, but this alignment has been inaccurate.

For this reason, as shown in FIGS. 2 and 3, a base 6 on which several guide pins 5 are set up is used, and positioning holes 7 provided in the insulating substrate 1 are fitted into the guide pins 5. Next, a method is adopted in which the positioning holes 8 provided in the overlay 4 are inserted into the guide pins 5 to position the insulating substrate 1 and the overlay 4, and the overlay 4 is attached to the insulating substrate 1 by thermocompression bonding or the like.

However, as the density of printed wiring boards has increased recently, it is not possible to perform positioning with sufficient accuracy even with the guide pins 5, let alone visual positioning, and unnecessarily increasing the number of guide pins 5 impedes work efficiency. Overlay 4 is usually at a disadvantage as the work size is increasing.
Even with 25μm adhesive, it is thin at less than 100μm, so even if it is possible to accurately position it around the guide pin 5, it is likely to shift position away from the guide pin 5 even if a small amount of external force is applied, making it unstable. I was getting used to it.

Moreover, confirmation of positional deviation after adhesion between the conductive pattern 2 of the insulating substrate 1 and the overlay 4 is performed in the fourth step.
As shown in the figure, measure the deviation between the land portion 2a of the conductive pattern 2 and the through hole 3 of the overlay 4, that is, the dimension h of the land covered portion by the circular conductive land 2a and the concentric through hole 3 of the overlay 4. This was done by checking the dimensions h' between the component mounting hole 9 provided in the land portion 2a of the conductive pattern 2 and the through hole 3 of the overlay 4 as shown in FIG. This was time-consuming and resulted in poor workability.

The present invention eliminates the above-mentioned conventional drawbacks, and aims to provide a printed wiring board in which the state of overlay attachment can be easily and reliably confirmed.

In order to achieve the above object, the present invention provides a conductor portion having a spear tip-shaped notch at a position that does not affect the conductive pattern formed on the insulating substrate, and this spear tip shaped notch allows the overlay to be attached easily. The structure is such that it can detect.

Embodiments of the present invention will be described below with reference to FIGS. 6 to 9.

First, in FIGS. 6 and 7, reference numeral 10 denotes an insulating substrate made of an insulating film or a hard insulating plate. On this insulating substrate 10, a conductive pattern 11 is formed by etching a copper foil or the like that has been pasted in advance. At the same time, a conductive layer 13 having a spear tip-shaped notch 12 is provided at a position that does not affect the conductive pattern 11 during the etching, and a conductive layer 13 is provided on the insulating substrate 10 corresponding to the land portion of the conductive pattern 11. An overlay 15 made of polyimide film, polyester film, or the like with through holes 14 formed therein is attached using an adhesive or the like. A portion of this overlay 15 corresponding to the notch 12 of the conductive layer 13 is arranged such that a straight end portion of a through hole for a land or the like is located. Further, as shown in FIG. 7, the notch 12 has a dimension m from its center with an allowable deviation of 0.2 mm.

Note that the notch 12 provided in the conductive layer 13 may have a V-shape as shown in FIG. 8, or may have a V-shape in the center of a rectangular shape as shown in FIG. .

That is, in the present invention, the notch 12 may have a V-shaped portion at its tip.

Furthermore, the conductive layer 13 provided with the notch 12 can be punched out and discarded as scrap when it is used as a finished printed wiring board.

Since the printed wiring board of the present invention is constructed as described above, the bonding condition between the conductive pattern and the overlay can be confirmed at a glance, and if the end of the overlay is located within the width of the notch, it can be judged as a good product. It has the advantage of being effective as a guide for positioning during lamination, greatly improving yield, and being effective even for products with high-density conductive patterns, and has great practical value. be.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of main parts showing a part of a conventional printed wiring board assembly process, FIG. 2 is an exploded perspective view of main parts showing a part of another conventional printed wiring board assembly process, Figure 3 is a cross-sectional view of the assembly, Figures 4 and 5 are top views of the main parts of the conventional printed wiring board that inspects the positional deviation, and Figure 6 is the printed wiring board of the present invention. FIG. 7 is a perspective view of a main part showing one embodiment, FIG. 7 is a top view of the main part, and FIGS. 8 and 9 are top views of a notch for positioning of other embodiments. 10... Insulating substrate, 11... Conductive pattern, 1
2... Notch, 13... Conductive layer, 14... Through hole,
15...Overlay.

Claims (1)

[Scope of utility model registration request] A conductive layer having a notch with a V-shaped portion at the tip is provided along with the conductive pattern on the insulating substrate in a portion that does not affect the conductive pattern, and a conductive layer is provided on the insulating substrate with a cutout portion having a V-shaped portion at the tip. A printed wiring board having a hole and further having an overlay attached thereto having a linear end at a position corresponding to the notch.