JPH0436148Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a multilayer printed wiring board, and particularly to a multilayer printed wiring board in which the conductive foil of the lower inner layer base material opposite to the stamped area on the surface of the outer layer base material has been removed. Regarding the board.

[Conventional technology]

Conventionally, a multilayer printed wiring board (hereinafter abbreviated as a multilayer wiring board) is composed of an inner layer base material 3 and an outer layer base material 2 having a conductive foil 3a, as shown in FIG. Further, the surface of the conductor foil 3a of the inner layer base material 3 is the same as that of the outer layer base material 2.
The surface is roughened to give it a black color in order to strengthen its adhesion. Therefore, when the inner layer substrate 3 is seen through the stamp display location 4 on the surface of the outer layer base material 2, the stamp display is applied to a portion where the multilayer base material 2 appears blackened. On the other hand, the ink for marking (a) has good marking properties on the outer layer base material 2 of the multilayer wiring board 1; (b)
Good visibility of the base color of the stamp display area,
(c) Blackened materials are used because of the requirement that readability does not deteriorate even when cleaning with a solvent after electronic components are mounted.

[Problem that the invention attempts to solve]

The above-mentioned conventional multilayer wiring board has a drawback that the stamp display is difficult to read because the color of the base of the stamp display area and the color of the stamp display ink are almost the same color, black.

An object of the present invention is to provide a multilayer printed wiring board in which the markings are easy to read and the readability does not deteriorate after parts are mounted.

[Means for solving problems]

The multilayer printed wiring board of the present invention is constructed by removing the conductor foil of the lower inner layer base material that is opposite to the stamp display location on the surface of the outer layer base material, and applying a stamp display to the stamp display location on the surface of the outer layer base material. Ru.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings. 1 and 2 are perspective views of a multilayer wiring board according to an embodiment of the present invention and an inner layer base material used in its construction. In the figure, reference numeral 14 indicates multilayer wiring board 1
This is the stamping location on the surface of the outer layer base material 12 of No. 1.

First, the conductor foil 13a of the inner layer base material 13 below the stamp display area 14 shown in FIG. 1 is removed by a known photo-etching method at the same time as the other conductor foil removal parts 20 and 30 are formed as shown in FIG. A conductor foil removal section 40 is provided. Next, the conductor foil 13 of the inner layer base material 13
A is subjected to surface roughening treatment, and further heated and pressed by a known heat press or the like to form an outer layer base material 12 and an inner layer base material 1.
3 are laminated and integrated to form a structure as shown in FIG. Next, a stamp 14a such as a lot number is applied to the stamp display location 14 of the outer layer base material 12 using black ink. When looking through the lower inner layer base material 13 from the stamp display location 14 of the multilayer wiring board 11 of FIG.
Lower inner layer base material 13 facing the stamp display location 14
Since the conductor foil 13a has been removed, the seal indication 1
The black color of 4a and the base color appear clearly different.

[Effect of idea]

As explained above, in the present invention, the conductor foil of the lower inner layer base material that opposes the stamp display location on the surface of the outer layer base material is removed, and the stamp display is applied to the stamp display location on the surface of the outer layer base material. Therefore, (1) the color of the seal display ink and the base color are different, making it easier to read the seal display. Furthermore, (2) since the conventionally selected ink can be used, the readability after mounting electronic components does not deteriorate, so that it is possible to obtain effects such as facilitating failure analysis.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a multilayer wiring board according to an embodiment of the present invention, Fig. 2 is a perspective view of an inner layer base material used in an embodiment of the invention, and Fig. 3 is a perspective view of a conventional multilayer wiring board. It is. DESCRIPTION OF SYMBOLS 1, 11... Multilayer wiring board, 2, 12... Outer layer base material, 3, 13... Inner layer base material, 3a, 13a... Conductor foil of inner layer base material, 4, 14... Stamp display location, 1
4a... Stamp display, 20, 30, 40... Conductor foil removed portion.

Claims (1)

[Scope of utility model registration request] A multilayer printed wiring board in which a conductive foil of a lower inner layer base material opposite to a stamp display location on the surface of the outer layer base material is removed, and a stamp display is applied to the stamp display location on the surface of the outer layer base material.