JPS6267849A - Manufacture of thick film hybrid ic - Google Patents

Abstract

PURPOSE:To improve a yield by a single means and to contrive the improvement of productivity by a method wherein a laser beam is directed to an arbitrary art of the surface of an electrically insulative silicon carbide ceramic substrate and the substrate is changed into a good conductor by breaking its insulation quality. CONSTITUTION:A thick film conductor 2, glass films 3 and thick film resistors 4 are formed on an electrically insulative silicon carbide ceramic substrate 1 (SiC substrate). The thick film conductor 2 is previously provided with a conductor isolation part 5 with a printed mask, and after the thick film resistors 4 are trimmed in elements in a state that the conductor 2 is turned into a closed loop by cutting part of it, a laser beam is irradiated on the SiC substrate surface at the microscopic cut part of the conductor including the conductor isolation part 5 to selectively heat at high temperatures of 1,000 deg.C or more and the substrate is changed into a good conductor by breaking its insulation quality to form an electrical circuit network. Moreover, in irradiation with the laser beam on the SiC substrate surface at the conductor isolation part 5, if such reducing gas as hydrogen gas is locally supplied, the resistance of the irradiation part can be further lessened.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a manufacturing method suitable for element trimming of a thick film resistor in a thick film hybrid IC, particularly a thick film hybrid IC mounted with a high power semiconductor element. It is.

[Background of the invention]

An example of a conventional thick film hybrid IC is described with reference to FIG.
A thick film conductor 2, a glass film 3, and a thick film resistor 4 are sequentially formed on a substrate 1 by a technique shown in a known example (Japanese Patent Application Laid-Open No. 126665/1984). At this time, a conductor separation section 5 is provided in order to disconnect the closed loop circuit consisting of the thick film conductor 2 and the thick film resistor 4. The above-mentioned known example describes that since the use of an SLC substrate has a good heat dissipation effect, it is possible to directly connect a semiconductor element to a SiC substrate via a thick film conductor.

Next, each thick film resistor 4 is trimmed to a desired precision. Note that 6 in the figure indicates a trimming trace. Then,
After connecting mounted components, such as semiconductor elements and individual components (not shown), connect conductor separation fa5 with solder or jumper #7.
They were connected to form an electrical network. For this reason,
Since a special process is required to connect the conductor separation part 5, the manufacturing process may become complicated.

[Purpose of the invention]

An object of the present invention is to solve the problems of the prior art as described above, and to provide a method for manufacturing thick film hybrid ICs that can achieve a good yield (Q) and improve productivity using simple means. It is something to do.

[Summary of the invention]

In order to achieve the above object, the present invention includes a thick film conductor formed on an electrically insulating silicon carbide ceramic substrate, a semiconductor element and an individual mounting plate. In a thick film hybrid IC in which parts and the like are connected and a thick film resistor is formed on a glass film formed on the substrate, the thick film resistor is trimmed to a desired precision, and then the silicon carbide slamic is By melting any surface of the substrate via a laser beam, the insulating properties of silicon carbide are destroyed and the silicon carbide becomes electrically conductive.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, an electrically insulating silicon carbide ceramic substrate 1
A thick film conductor 2, a glass film 3, and a thick film resistor 4 are formed on a (SiC substrate) in the same manner as in the prior art (see Fig. 2). The SiC substrate 1 has been developed in recent years.
When heated at a high temperature of 00°C or higher, its electrical insulation properties are destroyed and it becomes a good conductor.

Therefore, a conductor separation part 5 is provided in advance on the thick film conductor 2 using a printing mask, and after cutting a part of the conductor 2 to form an open loop, the thick film resistor 4 is trimmed. Selectively 1
It is heated at a high temperature of 000°C or higher to break down its electrical insulation and become a good conductor, forming an electrical circuit network.

In particular, when trimming the element of the n-film resistor 4 using a laser beam, it is possible to perform the trimming operation simultaneously and continuously. Complications in the manufacturing process can be eliminated. Note that 8 in the figure indicates a laser trace when a laser beam is irradiated.

When the SiC group, f surface of the conductor separation section 5 is irradiated with a laser beam, the resistance of the irradiation section can be further reduced by locally supplying a reducing gas such as aqueous gas. There is.

〔Effect of the invention〕

As explained above, according to the present invention, a laser beam is irradiated onto any surface of an electric P-edge silicon carbide ceramic substrate,
By destroying the insulation and making it a good conductor, it is possible to improve the yield and productivity by simple means without requiring a separate connection process as in the past.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the thick-film hybrid ICQ return method of the present invention, and FIG. 2 is a plan view showing an example of the manufacturing method for a thick-film hybrid IC (thickness of the thickness of the film).

Claims (1)

[Claims] A thick film hybrid structure in which semiconductor elements, individual mounted components, etc. are connected to a thick film conductor formed on an electrically insulating silicon carbide ceramic substrate, and a thick film resistor is formed on a glass film formed on the substrate. In an IC, after trimming the thick film resistor to a desired precision, any surface of the silicon carbide ceramic substrate is melted using a laser beam, thereby breaking the insulation properties of the silicon carbide and making it electrically conductive. A method for manufacturing a thick film hybrid IC, characterized in that: