JPH0734504B2 - Method for manufacturing thick film ceramic multilayer substrate - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thick film ceramic multilayer substrate which can be used as a high-density mounting substrate for a circuit on which ICs, LSIs, chip components, etc. are mounted and which are interconnected with each other. The present invention relates to a manufacturing method.

2. Description of the Related Art In recent years, thick-film multi-layer boards using copper as the conductor material are currently being studied for practical use in many fields because thick-film paste is easily available and can be prepared relatively easily because of the simple construction method. There is. The property required for the insulating layer of the multilayer substrate is that the insulating property between the wiring layers is good. Therefore, in general, in order to densify the insulating layer, amorphous glass or crystallized glass having a crystallization temperature higher than the firing temperature is used.

On the other hand, from the viewpoint of surface mounting, it is more advantageous to form a thick film resistor in a possible place than to form the entire surface of the multilayer substrate with chip components.

However, when a thick film resistor is formed on an amorphous glass or a glass-ceramic insulating layer, the glass component in the insulating layer and the glass component in the resistor interact with each other, resulting in a thick film resistor. It is difficult to form a thick film resistor on the insulating layer because the resistance value of 1 changes greatly compared with the value on the alumina substrate.

The present invention has been made to solve the above problems, and provides a thick film ceramic multilayer substrate capable of forming a thick film resistor on an insulating layer.

Means for Solving the Problems The present invention, in order to solve the above problems, a copper oxide conductor paste containing copper oxide as a main component on a ceramic fired substrate,
A step of alternately printing glass or an insulating paste containing glass-ceramic as a main component to form a multilayer wiring consisting of a wiring layer and an insulating layer; and an organic component contained in the paste in the atmosphere or an oxidizing atmosphere of the substrate. And a heat treatment at a temperature higher than a temperature sufficient for decomposing, and then a heat treatment at a temperature below the temperature at which the insulating layer is sintered and at a temperature above which copper oxide is reduced to metallic copper in a reducing atmosphere. The step of performing, and further comprising the step of sintering the insulating layer in an atmosphere that is non-oxidizing to copper, 800-900 to form the uppermost insulating layer exposed on the surface. An insulating paste made of crystallized glass or crystallized glass-ceramic having a crystallization temperature in the temperature range of ° C and a high degree of crystallinity is used, and amorphous glass is also used to form the other insulating layers. Shishi Crystallization temperature is to use an insulating paste consisting of 900 ° C. or more glass.

Action The present invention, as described above, has a crystallization temperature in the temperature range of 800 ~ 900 ℃ in the uppermost insulating layer exposed on the surface, and a high crystallinity crystallized glass or crystallized glass-ceramic By using it, even if a thick film resistor is formed on the insulating layer, the underlying insulating layer of the thick film resistor has less glass component due to crystallization of glass. The interaction of the glass components in the film resistor becomes small, and even if a thick film resistor is formed on the insulating layer, it is almost the same as the resistance value on the alumina substrate. Further, by using an amorphous glass or a glass material having a crystallization temperature of 900 ° C. or higher for the other insulating layer, the glass component is sufficiently softened and melted in the firing step, and a dense insulating layer is obtained. Therefore, good insulation between the wiring layers can be obtained.

Example A method for manufacturing a thick film ceramic multilayer substrate according to an example of the present invention will be described below with reference to the drawings. FIG. 1 is a manufacturing process diagram of a thick film ceramic multilayer substrate in one embodiment of the present invention, and FIG. 2 shows a cross section of an example of the thick film ceramic multilayer substrate.

First, the wiring layer 2 is screen-printed on the alumina fired substrate 1 with a copper oxide paste and dried. The copper oxide (CuO) used at this time had an average particle size of 3 μm. The vehicle for making the paste was a mixture of terpineol, benzyl alcohol and butyl carbitol as a solvent, and polyvinyl butyral as an organic binder (binder) was dissolved in the vehicle, which was kneaded with the copper oxide powder to form a paste. .

Next, an inorganic composition (average particle diameter 2 μm) in which a crystallization temperature of 900 ° C. or higher and a crystallized glass (lead borosilicate type) powder and an alumina powder were mixed in a weight ratio of 50:50, and polyvinyl butyral was used as butyric acid. A first insulating paste prepared by kneading a vehicle dissolved in an ester solvent is screen-printed on a desired area on the copper oxide wiring and the alumina fired substrate 1, and is dried and not fired on the first insulating layer 3 Was formed.
Subsequently, an inorganic composition (average particle size 2 μm) in which a crystallized glass (lead borosilicate type) powder and an alumina powder having a crystallization temperature in a temperature range of 800 to 900 ° C. were mixed in a weight ratio of 50:50
And a second insulating paste prepared by kneading a vehicle in which polyvinyl butyral is dissolved in a butyric acid ester-based solvent is overlaid on the first insulating layer 3 and screen printed.
The second insulating layer 4 which was dried and not fired was formed. Although terpineol, benzyl alcohol, butyl carbitol, butyric acid ester, and polyvinyl butyral were used to prepare the copper oxide paste and the insulating paste, ethyl cellulose as an organic binder, an acrylic resin may be used, or sorbitan alkyl ester, Using a surfactant such as polyoxyethylene alkether is also an effective means. Further, the uppermost wiring layer was formed from the copper oxide paste. The printed substrate was heated in air to 300 to 700 ° C. to completely remove the organic components in the paste and remove the binder. Then, add 5 to 5 hydrogen gas.
In a nitrogen gas atmosphere containing 40%, after reducing copper oxide to metallic copper at 300 to 500 ° C, the metallic copper and unfired first and second insulating layers 3 and 4 are simultaneously formed at 900 ° C in a nitrogen gas atmosphere. Baked.

The uppermost second insulating layer 4 of the substrate obtained in the example was used.
When the thick film resistor 5 is formed on the alumina fired substrate 1
It was almost the same as the resistance value when the resistor was formed on it. The result shows that the crystallization temperature is 900 at the top insulating layer.
The results are shown in the table below together with the results when crystallized glass-alumina having a temperature of ℃ or higher is used.

Effects of the Invention According to the present invention, the following effects can be obtained.

(1) Since crystallized glass or crystallized glass-ceramic having a high crystallization temperature in the range of 800 to 900 ° C. is used for the uppermost insulating layer, the glass component in the insulating layer and the Since the interaction of the glass component becomes small, even if a resistor is formed on the insulating layer, it is almost the same as the resistance value on the alumina substrate.

(2) The crystallization temperature range is 800 ~ 900 ℃ in the uppermost insulating layer,
And while using a crystallized glass or crystallized glass-ceramic with a high degree of crystallinity, since amorphous glass or glass with a crystallization temperature of 900 ° C or higher is used for the other insulating layers, it is possible to use Since the glass components in the insulating layers other than the uppermost portion are softened and melted sufficiently to obtain a dense insulating layer, good insulation between the wiring layers can be obtained.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram of a thick film ceramic multilayer substrate in one embodiment of the present invention, and FIG. 2 is a sectional view of the thick film ceramic multilayer substrate. 1 ... Alumina firing substrate, 2 ... Wiring layer, 3 ... First insulating layer, 4 ... Second insulating layer.

Continuation of front page (56) Reference JP 62-145896 (JP, A) JP 62-252901 (JP, A) JP 56-131993 (JP, A)

Claims (1)

[Claims] 1. A copper oxide conductor paste containing copper oxide as a main component and glass or glass on a ceramic fired substrate.
A step of alternately printing an insulating paste containing ceramic as a main component to form a multilayer wiring consisting of a wiring layer and an insulating layer; and a step of decomposing an organic component contained in the paste in the atmosphere or an oxidizing atmosphere of the substrate. A step of performing a heat treatment at a sufficient temperature or higher, and a step of performing a heat treatment at a temperature lower than a temperature at which the insulating layer is subsequently sintered in a reducing atmosphere and at a temperature higher than that at which copper oxide is reduced to metallic copper; And a step of sintering the insulating layer in an atmosphere that is non-oxidizing to copper, to form the uppermost insulating layer exposed on the surface, in the temperature range of 800 ~ 900 ℃. An insulating paste having a crystallization temperature and a high crystallinity of crystallized glass or crystallized glass-ceramic is used, and an amorphous glass or a crystallization temperature of 900 is used to form the other insulating layer. Above ℃ Method for producing a thick film ceramic multilayer substrate, characterized by using an insulating paste consisting of lath.