JP2536604B2 - Copper / organic insulation film wiring board manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a copper / organic insulating film wiring board, and more specifically,
The present invention relates to a method for manufacturing a copper / organic insulating film wiring board having a multilayer wiring pattern.

<Prior Art> With the increase in the speed and integration of LSIs, the wiring boards on which they are mounted are also required to support it. As a high-density mounting board for LSIs, copper with low electrical resistance and low dielectric constant are used. In addition, a wiring board using polyimide capable of forming a thick film is attracting attention because it can perform high-speed signal processing.

BACKGROUND ART Conventionally, generally known multilayer wiring boards have a first layer of titanium-copper deposited on the entire surface of an inorganic substrate such as alumina ceramic, and then a first conductor pattern forming a circuit is chemically etched. Then, polyimide is deposited on the entire surface of the substrate including the first conductor pattern after the etching to form a polyimide film, which is then etched, and a second layer of titanium-copper is vapor-deposited. After that, the second conductor pattern forming the circuit was formed by chemical etching, and the above treatment was repeated as necessary to form a multilayer.

As a method of attaching the polyimide, there are a spin coating method of liquid polyimide and a vapor phase film forming method by plasma polymerization.

<Problems to be Solved by the Invention> Circuit formation by etching is said to be extremely easy to process, but in the chemical etching of the titanium-copper vapor-deposited layer, an alkaline etchant, ammonium persulfate, hydrogen peroxide is used. Since an etching solution such as + sulfuric acid is used, there is a problem that the processing cost is higher than that of a chloride etching solution such as ferric chloride, and management of the etching solution and pollution control are complicated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel copper / organic insulating film wiring board which eliminates the above-mentioned drawbacks of the prior art and omits chemical etching of a vapor deposition layer.

<Means for Solving the Problems> In order to achieve the above object, according to the present invention, a titanium or chromium underlayer is pattern-deposited on a surface of a substrate using a mask, and the mask is formed on the underlayer. Is used to form a first conductor pattern by forming a copper vapor deposition layer, and then an organic insulating film is formed on the entire surface of the substrate including the first conductor pattern, and then at least one of the copper vapor deposition layer is etched. Exposed, and then using a mask to deposit a titanium or chromium underlayer on the organic insulating film in a pattern, using another mask on the exposed portion of the copper deposition layer and the underlayer. A copper / organic insulation characterized by providing a copper vapor deposition layer to form a second conductor pattern, and finally depositing titanium or chromium on the second conductor pattern using a mask to form an upper layer. How to manufacture a membrane wiring board Law is provided.

 The present invention will be described in more detail below.

Examples of the inorganic substrate typically used in the present invention include ceramic plates such as alumina plate, mullite plate, AlN plate, and SiC plate.

As the organic insulating film used in the present invention, in addition to a polyimide film, maleimide having a small dielectric constant and excellent heat resistance,
Although various polymer films such as Teflon can be mentioned, a polyimide film is particularly preferable because it has better adhesion to a metal than other organic insulating films and is economically inexpensive.

Titanium or chromium is used as a metal to be vapor-deposited as a base of each copper vapor-deposited layer and a base of the uppermost copper vapor-deposited layer in the present invention.

The titanium or chromium underlayer is provided to improve the adhesiveness between the inorganic substrate or the organic insulating film and the copper vapor deposition layer. Further, by providing a titanium or chromium underlayer, peeling of the copper layer from the inorganic substrate or the organic insulating film due to the penetration of copper ions can be prevented.

Further, the titanium or chromium upper layer is provided in order to prevent thin film oxidation and contamination by air on the surface of the copper layer, and to control the washout of copper ions.

A mask is used to form the metal thin film for the conductor pattern by the above titanium or chromium vapor deposition and copper vapor deposition. As a result, these deposited layers can be directly formed as an IC wiring pattern. Therefore, the step of forming the wiring pattern by chemical etching can be omitted, and the treatment with the etching solution is unnecessary.

Examples of the mask used for titanium or chromium vapor deposition and copper vapor deposition include those made of polyimide and those made of 42 alloy.

First, as shown in FIG. 1, a mask 2 having a desired pattern is positioned on an inorganic substrate 1, titanium or chromium is vapor-deposited on the surface of the inorganic substrate 1 to provide a base 3, and an equivalent mask is used. A copper vapor deposition layer 4 is provided thereon to form a first conductor pattern.

Next, from above the substrate including the first conductor pattern,
After coating the raw material liquid for the organic insulating film, solidifying and forming the film by a conventional method, hole etching is performed on a desired portion of the copper vapor deposition layer 4 of the first conductor pattern to expose a part of the copper vapor deposition layer. Let

Then, the organic insulating film 5 formed as shown in FIG.
Titanium or chromium is vapor-deposited on the surface of the substrate using a mask (not shown) having a predetermined pattern to provide the base 6, and a copper vapor-deposited layer 7 is provided using another mask (not shown) to form the second layer. Forming a conductor pattern of.

Finally, titanium or chromium is vapor-deposited as the upper layer 8 on the copper vapor deposition layer (copper vapor deposition layer 7 in FIG. 2) formed as described above.

In the above, the thickness of the organic insulating film of each layer, the base, the copper vapor deposition layer and the upper layer are 5 to 200 μm and 0.01 to, respectively.
0.4 μm, 5 to 30 μm and 0.01 to 0.4 μm are generally used, but the present invention is not limited to this and can be appropriately selected as necessary.

As the method for forming the thin-layer circuit metal, vacuum vapor deposition, ionization vapor deposition, a combination thereof, or a sputtering method can be used.

In addition, in the present invention, a multilayer wiring pattern is formed on an inorganic substrate, but a metal substrate such as Cu / Fe-36% Ni is used.
Polyimide, maleimide, on top of alloy / Cu clad material
It is also possible to form an insulating film such as Teflon to form a multilayer wiring pattern afterwards.

<Examples> The present invention will be specifically described below based on Examples.

(Example 1) A polyimide mask was positioned on the alumina ceramic plate with a space of 1 mm, and the polyimide mask was placed on the surface of the alumina ceramic plate.
After titanium was vapor-deposited to a thickness of 0.2 μm at 10 ⁻⁵ torr, immediately, a copper vapor-deposited layer having a thickness of 5 μm of 3 × 10 ⁻⁶ torr was formed to form a first conductor pattern.

Next, a polyimide film is formed by spin coating using liquid polyimide on the substrate including the copper vapor deposition layer of the first conductor pattern, and then a hole is formed in a predetermined portion of the copper vapor deposition layer of the first conductor pattern. Etched.

Then, 0.2 μm thick titanium is vapor-deposited at 1 × 10 ⁻⁵ torr on the surface of the polyimide film using a polyimide mask, and copper is vapor-deposited at 5 μm thick at 3 × 10 ⁻⁶ torr using another mask. A layer was provided to form a second conductor pattern.

Finally, a 0.2 μm thick titanium layer was vacuum-deposited on the second conductor pattern using a polyimide mask to obtain a multilayer wiring board.

For this wiring board, a peeling test of a copper vapor deposition layer (including a titanium layer) using an adhesive tape was performed, and at the same time, the peeling test of the copper vapor deposition layer in a conventional method full-layer vacuum deposition-chemical etching product multilayer wiring board was performed. In both cases, there was no peeling and good adhesion was exhibited.

(Example 2) 0.2 mm with an interval of 1 mm kept on an alumina ceramic plate
A thick 42 alloy mask was provided, and 1 μm thick chromium was ionized and vapor-deposited on the surface of the alumina ceramic plate, and further a 2 μm thick copper vapor-deposited layer was ionized and vapor-deposited to form a first conductor pattern.

Then, a polyimide film having a thickness of 2.5 μm is formed on the substrate including the copper vapor-deposited layer of the first conductor pattern by a vapor deposition method by plasma polymerization, and then a predetermined copper-deposited layer of the first conductor pattern is formed. Holes were etched in the area.

Then, 0.1 μm thick chromium is ionized and evaporated on the surface of the polyimide film using a 0.2 mm thick 42 alloy mask, and a 2 μm thick copper evaporated layer is ionized and evaporated using another mask. Two conductor patterns were formed.

Finally, a chromium layer having a thickness of 0.1 μm was ionized and vapor-deposited on the copper vapor-deposited layer of the second conductor pattern using the same mask as above to obtain a multilayer wiring board.

This wiring board was tested in the same manner as in Example 1 together with the conventional method of full-scale ionization vapor deposition-chemical etching, but neither showed peeling and showed good adhesion.

Further, a heating test was carried out at 350 ° C. for 3 minutes, but the copper layer circuit did not swell and showed good heat resistance.

Example 3 A multilayer wiring board was obtained in the same manner as in Example 1, after depositing a polyimide layer of 100 μm on the upper surface of the Cu / Fe-36% Ni alloy / Cu clad material.

A peeling test was conducted on this wiring board in the same manner as in Example 1, but there was no peeling and good adhesion was exhibited.

<Effects of the Invention> Since the present invention is configured as described above,
Since the metal film for the conductor pattern is directly formed by a dry method by vapor deposition using a mask and can be performed without chemical etching,
Excellent adhesion and reliability such as dimensional accuracy can be obtained.

In addition, a chemical etching solution is not required, which brings about effects of cost reduction, management of the etching solution, and elimination of pollution treatment.

Furthermore, the etching of titanium or chromium, which is very time-consuming and unstable, is not necessary.

Further, since it is a dry method, there is little contamination on the surface of the copper vapor-deposited layer and organic residue, and there is an effect that a substrate having a low resistance wiring pattern can be obtained.

[Brief description of drawings]

FIG. 1 shows the first conductor pattern formation 1 in the present invention.
It is a cross-sectional view showing an example. FIG. 2 is a cross-sectional view showing an example of a wiring board obtained by the manufacturing method of the present invention. DESCRIPTION OF SYMBOLS 1 ... Inorganic substrate, 2 ... Mask, 3 ... Underlayer, 4 ... Copper deposited layer, 5 ... Organic insulating film, 6 ... Underlayer, 7 ... Copper deposited layer, 8 ... Upper layer

Front page continuation (72) Inventor Mamoru Mita 3-1-1 Sukegawa-cho, Hitachi, Hitachi, Ibaraki Electric Cable Factory (56) Reference JP-A-61-271899 (JP, A) JP-A Sho 63-53254 (JP, A)

Claims (1)

(57) [Claims] 1. An underlayer 3 of titanium or chrome is vapor-deposited in a pattern on a surface of a substrate 1 using a mask, and the underlayer 3 is formed.
A copper vapor-deposited layer 4 is provided on the above to form a first conductor pattern, and then an organic insulating film is formed on the entire surface of the substrate including the first conductor pattern, and then at least the above is formed by etching. A part of the copper vapor deposition layer 4 is exposed, and then a titanium or chromium underlayer 6 is vapor-deposited in a pattern on the organic insulating film using a mask. Then, the exposed portion of the copper vapor deposition layer and the underlayer 6 are removed. A copper vapor-deposited layer 7 is provided on the above by using another mask to form a second conductor pattern, and finally titanium or chromium is vapor-deposited on the second conductor pattern by using a mask to form an upper base 8. A method of manufacturing a copper / organic insulating film wiring board, comprising: