JPS6148992A - Method of producing hybrid integrated circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Technical Field) The present invention forms passive elements such as resistors and capacitors on an insulating substrate using film technology, and furthermore, attaches active elements such as ICs to the above substrate by connecting between each element. The present invention relates to a method of manufacturing a hybrid integrated circuit formed by interconnecting conductor wiring.

(Prior art) In hybrid integrated circuits, the conductor wiring that serves as the connection conductor between each element on the board and the component connection conductor has conventionally had both conductivity and bonding property, and aluminum film or gold film has been used. Often used. However, in the case of aluminum and mini-lamb films, in order to obtain a wiring film with good conductivity, it is necessary to form an aluminum film to a thickness of approximately 5 μm or more, which requires a large amount of film formation time and requires a lot of time in pattern etching. Short circuits between wiring patterns were likely to occur due to air bubbles remaining.

Furthermore, there are problems with oxidation and corrosion in the external connection pattern of the crimp type. On the other hand, as for gold film, although it is good against corrosion in the external connection pattern of the pressure bonding method, gold is a precious metal, and the film structure by forming a gold film has to be expensive. There wasn't.

(Objective of the Invention) An object of the present invention is to provide a method for manufacturing a hybrid integrated circuit, which involves manufacturing at a low cost a conductor wiring that satisfies both bonding conductivity and corrosion resistance.

(Structure of the Invention) The method for manufacturing a hybrid integrated circuit according to the present invention includes an aluminum film having a bonding property, an aluminum film excluding a portion to be bonded to reduce conductor resistance loss, and an aluminum film at a terminal connection terminal portion. After screen-printing a silver paste on the film and firing, screen-print a copper paste overlapping both the aluminum film and the silver film, and after firing, gold plating is applied only to the terminal parts that require corrosion resistance. It is characterized by giving.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

1 to 6 are cross-sectional views of work-in-progress substrates in process sections for explaining the present invention. First, as shown in FIG. 1, a tantalum pentoxide film is formed as a base film to strengthen adhesion on a ceramic insulating substrate 1 to a thickness of 200 OA by sputtering, and then a conductor film is formed on the pentoxide mental film. An aluminum film with a thickness of 600 OA is formed by sputtering. The insulating substrate on which the metal film has been formed in this way is patterned using a well-known photoresist film and a phosphoric acid-based etching solution to obtain the wiring pattern shown in FIG. Next, after peeling off the photoresist film, apply silver paste manufactured by Asahi Chemical Laboratory (commercial product LS-500) screen printed,
The silver film was baked at 200° C. for 30 minutes to obtain a silver film with a thickness of about 80 μm, as shown in FIG. Next, f! of the above silver film wiring patterns excluding the crimp connection terminal pattern! &m Overlapping both the wiring part and the aluminum film, Asato Kagaku Institute Steelmaking Paste (trade name ACP-020J) was screen printed under the same conditions as above and fired to a thickness of 80 μm, resulting in the state shown in Figure 4. did.

At this time, the copper paste has a reducing effect to prevent oxidation of the steel, and at the same time serves as a medium to reduce the oxide film on the aluminum film and improve the conductivity between the silver film and the aluminum film. It is also □.

Thereafter, the parts excluding the bonding part and the external terminal part are overkneaded with an insulating resin by the conventional screen printing method, to obtain the state shown in FIG. 5. Gold plating is then formed to a thickness of about 0.5 .mu.m on only the external terminal pattern by using a known plating technique to obtain the structure shown in FIG.

(Effect) The conductor wiring pattern thus obtained has a corrosion-resistant part suitable for crimp connection with an external terminal, a part used for wire bonding with an IC chip mounted on the board, and a good conductor. A conductor wiring (turn configuration) that has the properties of a wiring turn can be formed at a lower cost, especially if aluminum, copper, silver, and expensive gold are used to a minimum.

[Brief explanation of the drawing]

1 to 6 are cross-sectional views illustrating the manufacturing process of an embodiment of the present invention. 1...Insulating substrate 1.2...Tantalum pentoxide base film, 3...Aluminum film, 4...
...Silver printed film, 5...Copper printed film, 6...
...Gold plated belly, 7...Protective resin, 8...
...Pondable wiring pattern with good conductivity, 9...Crimpable external connection wiring) (turn.

Claims (1)

[Claims] A step of forming a base film of tantalum pentoxide or the like to strengthen adhesion on an insulating substrate, a step of forming an aluminum film on the tantalum pentoxide film, and forming the aluminum film into a predetermined wiring pattern by etching or the like. Next, a step of printing and baking a silver paste on the wiring pattern excluding the bonded portion of the wiring pattern, and a step of printing and baking the silver film wiring pattern excluding the crimp connection wiring pattern of the silver film wiring pattern. 1. A method for manufacturing a hybrid integrated circuit, comprising the steps of: printing and firing a copper paste so as to overlap both the wiring portion and the aluminum film; and plating the silver film wiring portion with gold.