JPH05218291A - Hybrid integrated circuit device - Google Patents

Abstract

PURPOSE:To improve the reliability of a hybrid circuit. CONSTITUTION:When the size of a chip capacitor 4 is large in a hybrid integrated circuit device mounting a ceramic chip capacitor on a metal substrate, stress due to thermal expansion difference is generated, because the thermal expansion coefficients are different. A lead terminal 8 having a shape capable of surface mounting is previously connected with a large-sized ceramic capacitor 4, and soldered to a conductor pattern on a substrate 1, together with electronic parts like a minimold transistor. Thereby thermal stress is absorbed by the lead terminal, and excessive stress is not applied to a solder part 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid integrated circuit device, and more particularly to the structure of a hybrid integrated circuit using a metal substrate.

[0002]

2. Description of the Related Art A conventional hybrid integrated circuit using a metal substrate has a metal substrate 1 as a base and an insulating layer 2 made of a resin such as epoxy or polyimide on the metal substrate 1 as shown in FIG. A copper foil is attached, and then the conductor pattern 3 is formed by using the photolithography method. Next, the solder paste 6 is supplied by screen printing, electronic parts such as the ceramic chip capacitor 4 and the mini mold transistor 5 are mounted, and the substrate side electrode and the electrode of the electronic part are solder-connected by the reflow method. Next, the external leads 7 are soldered to the terminal lands on the substrate side to complete.

[0003]

In the above-mentioned conventional hybrid integrated circuit device using a metal substrate, when a ceramic chip component such as a chip resistor or a chip ceramic capacitor 4 is mounted on the aluminum metal substrate 1, a ceramic is used. And aluminum have a coefficient of thermal expansion of 6.4 × 1
0 ^-6 / ° C; 22.9 × 10 ^-6 / ° C, so when the size of the component increases, the stress due to the difference in thermal expansion causes cracks in the solder joint ⁶ and the connection reliability is improved. There was a problem that it decreased.

[0004]

SUMMARY OF THE INVENTION The gist of the present invention is a hybrid integrated circuit comprising a conductor pattern formed on a metal substrate via an insulating film, and a ceramic component connected to the conductor pattern. In the device, the ceramic component has a lead terminal extending from its own electrode, and the lead terminal is fixed to the conductor pattern.

[0005]

When the ceramic component is fixed to the conductor pattern and stress is generated due to the difference in coefficient of thermal expansion between the ceramic and the metal, the lead terminal absorbs the stress and the fixing portion is excessively large. No stress is generated.

[0006]

The present invention will be described below with reference to the drawings.
FIG. 1 is a sectional view showing a hybrid integrated circuit device using a metal substrate according to an embodiment of the present invention. Made of aluminum 1.
A resin insulating layer 2 having a thickness of about 100 μm is formed on a metal substrate 1 having a thickness of 5 mm, and a copper foil having a thickness of 18 μm is attached. Next, the copper foil is patterned using a photolithography technique to form the conductor pattern 3.

As shown in the perspective view of FIG. 2, the lead terminals 7 are soldered to the electrodes of the large-sized ceramic chip capacitor 4 in advance.

Next, the solder paste 6 is supplied to the soldered land on the substrate 1 by the screen printing method, the chip capacitor 4 and the mini mold transistor 5 are mounted, and the solder connection is made by the reflow method. Finally, the external leads 7 are soldered and completed.

FIG. 3 is a sectional view showing the main part of the second embodiment of the present invention. The second embodiment is a large ceramic capacitor 4
The height of the lead terminal 7 to be attached to the
By setting the height higher than m, components can be mounted under the large ceramic capacitor. As a result, the packaging density is improved and the size can be reduced.

[0010]

As described above, according to the present invention, when a large-sized ceramic chip capacitor is mounted on a metal substrate,
The surface mountable lead terminals are connected in advance to the large ceramic capacitor, and by mounting this, the lead terminals absorb the stress due to the difference in thermal expansion between the ceramic capacitor and the metal substrate, so the reliability of the solder joint is improved. Has the effect of being dramatically improved.

For example, when the size of the ceramic chip capacitor is 12.5 mm × 10 mm × 3 mm,
Comparing in the temperature cycle (-55 ° C to + 125 ° C) test, in the structure in which the conventional capacitor is directly mounted on the metal substrate, about 30% failure occurs in 160 cycles, whereas in the structure of the present invention, the failure occurs. Was not recognized.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment.

FIG. 2 is a perspective view of a ceramic chip capacitor of the first embodiment.

FIG. 3 is a sectional view of a second embodiment.

FIG. 4 is a sectional view of a conventional example.

[Explanation of symbols]

 1 Metal Substrate 2 Insulating Layer 3 Conductor Pattern 4 Ceramic Chip Capacitor 5 Mini Molded Transistor 6 Solder 7 External Lead 8 Lead Terminal

Claims (1)

[Claims] 1. A hybrid integrated circuit device comprising: a conductor pattern formed on a metal substrate via an insulating film; and a ceramic component connected to the conductor pattern.
The above-mentioned ceramic component has a lead terminal extending from its own electrode, and the lead terminal is fixed to a conductor pattern.