JPH01218095A - High density multilayer wiring board - Google Patents

Abstract

PURPOSE:To prevent corner rise of boards and to improve their crack resistance by forming the construction of an insulating interlayer by combining a filler polyimide film as its first layer and a filler polyimide containing a surface active agent as its second layer. CONSTITUTION:An insulating interlayer is formed of a filler polyimide film 3 containing SiO2 as a first layer and a filler polyimide 4 containing a surface active agent as a second layer are formed on the surface of the bottom layer wiring pattern 2 formed on a board 1. The high density multilayer wiring board thus arrange can prevent corners of the board from rising, thereby allowing not only flat films to be formed and but also an insulating interlayer excellent in developing property and crack resistance to be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high-density multilayer wiring board, and particularly to a high-density multilayer wiring board for LSI mounting used in electronic devices such as computers.

[Conventional technology]

Conventionally, the insulating layer between the eyebrows of this type of high-density multilayer wiring board has been an organic insulating layer consisting only of an ordinary filler polyimide film, as shown in Fig. 2. More than one layer was formed repeatedly. Referring to FIG. 2, SiO2 is formed on the surfaces of the substrate 1 and the lower wiring pattern 2.
The filler polyimide film 3, which contains the following materials and has excellent crack resistance, was formed in two layers with a thickness of 20 to 30 μm.

[Problem to be solved by the invention]

However, as shown in Figure 2, when a thick film is required when spin-coating ordinary filler polyimide, the film swells up on the edges of the substrate, significantly worsening the developability of the edges of the substrate, and making it difficult to pull out via holes during development. is the cause of the residual formation, and spin-coating a surfactant-containing filler polyimide as shown in FIG. 3 largely eliminates the swelling at the edge of the substrate, but has the disadvantage that the bottom of the via hole cannot be removed during development.

[Means to solve the problem]

In the high-density multilayer wiring board according to the present invention, the glabellar insulating layer of the multilayer wiring board has a combination structure in which the first layer is a filler polyimide film and the second layer is a surfactant-containing filler polyimide film, and spin coating is applied. It is characterized by excellent developability, crack resistance, and insulation properties because it prevents the edges of the substrate from bulging and forms a flat film.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.

Referring to FIG. 1, a filler polyimide film 3 containing SiO2 in the first layer is formed on the surface of the substrate 1 and the lower wiring pattern 2.
, and a glabellar insulating layer of a surfactant-containing filler polyimide film 4 is formed as the second layer. According to the high-density multilayer wiring board formed in this way, swelling at the edges of the board can be prevented and a flat film can be formed, thereby making it possible to form a glabellar insulating layer with excellent developability and crack resistance.

Referring to FIGS. 4(a) to 4(e), one method of manufacturing the structure of the insulating layer of FIG. 1 is shown. First, a lower wiring pattern 2 is formed on a substrate 1 (FIG. 4(a)).

Filler polyimide film 3' is applied to the entire back surface at the 1N position.
Then, a surfactant-containing filler polyimide film 4' is spin-coated as the second layer and dried at low temperature (fourth layer).
Figure (b)). Therefore, in this state, the filler polyimide film 3'' and the surfactant-containing filler polyimide film 4' are not imidized.

Then, the bulge at the edge of the substrate on the filler polyimide film 3' is replaced with a second layer of surfactant-containing filler polyimide film 4.
' to prevent the edges of the board from swelling.

Next, it is exposed to ultraviolet light through a glass mask 5 and dried at a low temperature (FIG. 4(C)). Next, when it is developed, the portions that are not irradiated with ultraviolet rays are removed (FIG. 4(D)). Finally, the dry unimidized filler polyimide film 3 and surfactant-containing polyimide film 4 are cured and imidized (FIG. 4(e)).

〔Effect of the invention〕

As explained above, the present invention combines the structure of the glabella insulating layer of a high-density multilayer wiring board with a filler polyimide film as the first layer and a surfactant-containing filler polyimide film as the second layer. This has the effect of preventing swelling at the edge of the substrate due to spin coating and forming a glabellar insulating layer with excellent developability and crack resistance.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the structure of the insulating layer according to the present invention, FIG. 2 is a cross-sectional view showing another example of the structure of the insulating layer, and FIGS. 3(a) to (e) are FIG. 1 is a cross-sectional view showing one method of manufacturing the insulating layer structure, and FIG. 4 is a cross-sectional view showing an example of the conventional insulating layer structure. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Wiring pattern, 3... Filler polyimide film, 3'... Filler polyimide film that is not imidized, 4... Filler polyimide film containing surfactant, 4'... - Filler polyimide film containing surfactant that is not imidized, 5...Glass mask.

Claims (3)

[Claims] 1. A high-density multilayer wiring board characterized in that an interlayer insulating layer has a combination of a filler polyimide film as a first layer and a surfactant-containing filler polyimide film as a second layer. 2. The filler component of the filler polyimide film is SiO
The high-density multilayer wiring board according to claim 1, which is _2. 3. 2. The high-density multilayer wiring board according to claim 1, wherein the filler polyimide film and the surfactant-containing filler polyimide film are a photosensitive filler polyimide film and a photosensitive surfactant-containing filler polyimide film.