JPH021389B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a multilayer circuit board using an organic insulating resin layer as an interlayer insulating film. [Prior Art] FIGS. FIG. 2 is a cross-sectional view of a multilayer circuit board manufactured by the manufacturing method of FIG. In the figure, 1 is a substrate, 2 is a conductor, 3 is a first conductor, 4 is an organic insulating resin, 5 is a first organic insulating resin layer, 6 is a second organic insulating resin layer, and 7 is a second conductor.

A conventional method for manufacturing a multilayer circuit board will be described below. That is, after forming the conductor 2 using a sputtering method, vapor deposition method, etc. (FIG. 1a) and forming the first conductor 3 (FIG. 1b), an organic insulating resin 4 is applied using a spinner, a roll coater, or the like. (Figure 1c). next,
This organic insulating resin 4 is microfabricated. For example, when polyimide is used as this organic insulating resin,
After applying polyimide and baking, apply positive resist using a spinner and roll coater, bake,
After exposure, the resist is patterned using an alkaline positive resist developer, and
The first organic insulating resin layer 5 is formed by patterning the polyimide using a developing and etching method. (Figure 1d). In general, when an organic insulating resin is used as an interlayer insulating film, pinholes may occur, resulting in poor reliability as an interlayer insulating film. In order to solve this problem, we further coated an organic insulating resin (Fig. 1 e) and formed a second organic insulating resin layer 6 with the same pattern as Fig. 1 d (Fig. 1 f). The above multilayer organic insulating film is formed. Next, a conductor 2 is formed into a film using a sputtering method, a vapor deposition method, etc. (Fig. 1 g), and a second conductor 7 is formed by microfabrication using a photoresist (Fig. 1 h),
Obtain a multilayer circuit board.

However, in multilayer circuit boards manufactured using conventional manufacturing methods, the interlayer insulating film is formed by applying organic insulating resin multiple times as described above, resulting in a thick interlayer insulating film. Therefore, there is a drawback that the upper conductor is likely to be disconnected at the difference portion.

[Overview of the invention]

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional art.
A conductor is formed, a first organic insulating resin layer is formed in a second predetermined pattern so as to cover a desired portion of the first conductor, and post-curing is performed. Apply and
Pre-cure at a lower temperature than the post-cure temperature, and
forming a second organic insulating resin layer shifted and stacked on the first organic insulating resin layer in the same pattern as the predetermined pattern, and forming a second conductor in a third predetermined pattern on the substrate having the second organic insulating resin layer; Therefore, the same pattern can be used in the first organic insulating resin layer and the second organic insulating resin layer because if one end of the pattern is shifted, the other end will inevitably be shifted. It is an object of the present invention to provide a method for manufacturing a multilayer circuit board in which the upper conductor is less likely to be cut off because the amount of deviation at the end of an interlayer insulating film made of a resin layer is small.

[Embodiments of the invention]

FIGS. 2a to 2h are cross-sectional views of a multilayer circuit board according to an embodiment of the present invention, and show the manufacturing process of the multilayer circuit board that is sequentially manufactured. In the figure, numerals 1 to 7 are the same as in FIG.

A method of manufacturing a multilayer circuit board according to an embodiment of the present invention will be described below. That is, the conductor 2 is formed into a film using a sputtering method, a vapor deposition method, etc. (FIG. 2a),
After forming the first conductor in the first predetermined pattern by microfabrication (FIG. 2b), an organic insulating resin 4 is applied using a spinner, a roll coater, etc., and precured at 130° C. (FIG. 2c). Next, this organic insulating resin 4 is microfabricated. For example, when using polyimide as the organic insulating resin, apply a positive resist onto the polyimide using a spinner or roll coater, bake the positive resist at 80°C, expose it, and then pattern the resist using an alkaline positive resist developer. At the same time, the polyimide was patterned using a development and etching method.
Post-curing is performed at 200° C. to form the first organic insulating resin layer 5 in a second predetermined pattern (FIG. 2d). As already mentioned, when an organic insulating resin is used as an interlayer insulating film, pinholes may occur. Therefore, we added 4 organic insulating resins.
(Fig. 2e). Next, using the same mask as that used for patterning in FIG. 2d, the pattern formation position is moved by several tens of μm from the pattern position of the first organic insulating resin layer 5, microfabrication is performed, and postcuring is performed. As a result, a second organic insulating resin layer 6 is formed (FIG. 2f). Next, a conductor 2 is formed by sputtering and vapor deposition (FIG. 2g), and a second conductor having a third predetermined pattern is formed by microfabrication (FIG. 2h).

Since the interlayer insulating film of the multilayer circuit board formed in this way is composed of two organic insulating resin layers, even if a pinhole exists in the second or first organic insulating resin layer, both Since the probability of a pinhole penetrating the layer being generated is low, the reliability of the organic insulating resin as an interlayer insulating film is high. Moreover, although the interlayer insulating film is formed of two layers of organic insulating resin, the end portion of the interlayer insulating film is made of only one layer of organic insulating resin, and the depth of the step is shallow. Therefore, disconnection at the end of the organic insulating resin layer of the second conductor can be eliminated.

In the above embodiments, the organic insulating resin used as the interlayer insulating film is described as being used in two layers, but it may be used in multiple layers of three or more layers and the same effects as in the above embodiments can be obtained.

〔Effect of the invention〕

As explained above, the present invention provides a first
A first conductor of a predetermined pattern is formed, and a first conductor of a second predetermined pattern is formed so as to cover a desired portion of the first conductor.
An organic insulating resin layer is formed and post-curing is performed, an organic insulating resin is applied onto the substrate having the post-cured first organic insulating resin layer, pre-curing is performed at a temperature lower than the post-curing temperature, and a second pre-curing pattern is formed in the same pattern as the second predetermined pattern. A second organic insulating resin layer is formed on the first organic insulating resin layer in a shifted manner, and a third predetermined pattern of second conductors is formed on the substrate having the second organic insulating resin layer, thereby shifting one end of the pattern. A method for manufacturing a highly reliable multilayer circuit board in which the same pattern can be used since the other end is inevitably shifted, and the upper conductor is less likely to be cut off because the amount of deviation at the end of the interlayer insulating film is small. can be obtained.

[Brief explanation of drawings]

Figures 1a to 1h are cross-sectional views showing a multilayer circuit board manufactured by a conventional manufacturing method in the order of manufacturing steps;
Figures a to h are cross-sectional views showing a multilayer circuit board according to an embodiment of the present invention in the order of manufacturing steps. In the figure, 1 is a substrate, 2 is a conductor, 3 is a first conductor, 4 is an organic insulating resin, 5 is a first organic insulating resin layer, 6 is a second organic insulating resin layer, and 7 is a second conductor. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1. Forming a first conductor in a first predetermined pattern on a substrate, forming a first organic insulating resin layer in a second predetermined pattern so as to cover a desired portion of the conductor on the substrate having the first conductor, and performing post-curing. In the process, an organic insulating resin is applied onto the substrate having the first organic insulating resin layer which has been post-cured, pre-curing at a temperature lower than the post-curing temperature, and shifting the first organic insulating resin layer in the same pattern as the second predetermined pattern. a step of forming a second organic insulating resin layer overlaid with a second organic insulating resin layer;
A method for manufacturing a multilayer circuit board, comprising the step of forming a second conductor in a third predetermined pattern on a substrate having an organic insulating resin layer.