JPH0413878B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method of manufacturing a thick film printed wiring board, and particularly relates to a cross-over printed wiring structure on a thick film board.

(Prior Art) Conventionally, when cross-over wiring is performed on a thick film substrate, the configuration is as shown in FIG. 3. In this figure, 1 is an alumina substrate, 2a,
2b, 3 are lower wiring conductors (hereinafter referred to as lower conductors) printed and fired on this alumina substrate 1;
is an upper wiring conductor (hereinafter referred to as an upper conductor) for connecting between the lower conductors 2a and 2b. 4a,
4b is an insulating layer that electrically insulates the lower conductor 3 and the upper conductor 5, 4a is a first insulating layer, and 4b is a second insulating layer provided on the first insulating layer 4a. The first insulating layer 4a and the second insulating layer 4b completely overlap, and the ends 5a, 5a of the insulating layers become steep, so the end 5a of the upper conductor 5 becomes thin and has the disadvantage of being easily broken. be.

FIG. 4 is a sectional view of a thick film printed wiring board showing another conventional configuration proposed to compensate for the drawbacks shown in FIG. 3, and FIG. 5 is a plan view thereof. In this conventional example, as shown in FIG. 4, the first insulating layer 6a and the second insulating layer 6b have different dimensions, and the ends of the insulating layers are formed with a smooth slope, and the upper The end portion 7a of the conductor 7 also does not become thinner and has been improved to prevent disconnection.

(Problems to be Solved by the Invention) As mentioned above, in the case shown in FIGS. 4 and 5, the thick film does not become extremely thin even at the ends where the upper conductors cross. This is improved compared to the one in Figure 3.

However, as is clear from FIGS. 4 and 5, the first insulating layer 6a and the second insulating layer 6b formed in the crossover portion need to have different dimensions, and the printing mask is There was a problem in that it was necessary to prepare two versions and print twice using each mask, which increased manufacturing costs.

The present invention eliminates the above-mentioned problems, uses one mask to form the insulating layer of the crossover portion, and after forming the first insulating layer, moves the mask to a diagonally shifted position. It is an object of the present invention to provide a method for manufacturing a thick film printed wiring board, which requires only setting and forming a second insulating layer, reduces manufacturing costs, and enables highly reliable multilayer wiring.

(Means for Solving the Problems) In order to solve the above problems, the present invention first forms a first insulating layer 14a on the lower conductor of the crossover section using a predetermined mask, and then The mask is set at a diagonally shifted position to form the second insulating layer 14b, and the upper conductor 15 is formed on the formed insulating layer.

(Function) According to the present invention, the first insulating layer 14a is formed on the lower conductor of the crossover portion using a predetermined mask.
Then, the predetermined mask is set at a diagonally shifted position to form the second insulating layer 14b. Since the upper conductor 15 is formed on the insulating layer formed in this way, the upper conductor 1
5 is wired on the insulating layer having a gentle hill shape, and the film thickness does not become thin especially at the end portion 15a of the upper conductor 15, so that good multilayer wiring can be achieved.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is an explanatory diagram of a method for manufacturing a thick film printed wiring board according to the present invention, and FIG. 2 is a plan view of a thick film printed wiring board manufactured using the manufacturing method of the present invention.

In the figure, 11 is an alumina substrate, 12a, 12b,
13 is a lower conductor printed and fired on the alumina substrate 11; 14a is a first insulating layer formed on the lower conductor 13 for cross-over wiring; 14b is a second insulating layer; is an upper conductor for connecting lower conductors 12a and 12b. As shown in FIG. 2, this upper conductor 15 is formed on the first and second insulating layers by printed wiring.

Next, a method for manufacturing this thick film printed wiring board will be explained.

First, as shown in FIG. 1a, lower conductors 12a, 12b, and 13 are printed and fired on an alumina substrate 11.
A first insulating layer 14a is formed thereon using a predetermined mask (not shown).

Next, as shown in FIG. 1b, the predetermined mask described above is set at a diagonally shifted position to form the second insulating layer 14b.

Next, as shown in FIG. 1c, the lower conductor 1
said first and second so as to bridge 2a and 12b.
An upper conductor 15 is formed on the insulating layer.

Crossover wiring is performed in this way.

As mentioned above, since the mask is shifted diagonally, all edges of the insulating layer have a gentle hill shape, and the film thickness does not become thinner even at the edge 15a of the upper conductor, as shown below. There are advantages. In other words, in Figures 1 and 2, only one cross-over wiring on a thick film board is shown, but if there are several such cross-over wiring positions (multi-point crossover wiring), By shifting the mask diagonally, it is possible to effectively deal with all of the crossover wiring at several locations.

This point will be explained in detail with reference to FIG.

As mentioned above, the crossover wiring location is A.
It exists not only in this place, but also in other places. The wiring direction of the upper conductor and lower conductor at that location is not necessarily constant at all locations. For example, as shown in FIG. 6, the wiring direction of each conductor in the crossover wiring at location B is reversed from that of the crossover wiring at location A.
In other words, at location A, the lower conductors 12a, 12
b is wired in the X direction, and the lower conductor 13 is wired in the Y direction, whereas at location B,
The lower conductors 12a' and 12b' are wired in the Y direction, and the lower conductor 13' is wired in the X direction. Therefore,
In order to effectively deal with the crossover wiring at both locations A and B, it is a good idea to shift the mask diagonally.

Further, even in the case of performing triple multilayer wiring, it is advantageous to shift the mask in an oblique direction to form the insulating layer.

Note that the present invention is not limited to the above-described embodiments, and various modifications can be made based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described above in detail, according to the present invention,
In a method for manufacturing a thick film printed wiring board that performs crossover wiring on a substrate, a first insulating layer is formed on a lower conductor of a crossover portion using a predetermined mask, and then the mask is shifted in an oblique direction. Since the upper conductor was printed and wired on the first and second insulating layers, the same mask was simply used diagonally when forming the second insulating layer. By simply setting the cross-over wiring portions in a different direction, it is possible to form good insulating layers for the crossover wiring portions at a plurality of locations, and it is possible to reduce manufacturing costs.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the method for manufacturing a thick film printed wiring board according to the present invention, Fig. 2 is a plan view of the thick film printed wiring board according to the present invention, and Fig. 3 is a cross section of a conventional thick film printed wiring board. 4 is a sectional view of another conventional thick film printed wiring board, FIG. 5 is a plan view of the same thick film printed wiring board, and FIG. 6 is an explanatory diagram of multipoint crossover wiring. 11...Substrate, 12a, 12b, 12a', 12
b', 13... lower conductor, 14a... first insulating layer, 14b... second insulating layer, 15... upper conductor, 15a... end of upper conductor.

Claims (1)

[Claims] 1. A method for manufacturing a thick film printed wiring board in which crossover wiring is performed on a substrate, comprising: (a) forming a first insulating layer on the lower wiring conductor of the crossover portion using a predetermined mask; (b) forming a second insulating layer by setting the mask in a diagonally shifted position; and (c) printing and wiring an upper wiring conductor on the first and second insulating layers. A method for manufacturing a thick film printed wiring board.