Hybrid integrated circuit device
View Patent ↗In a hybrid integrated circuit device that uses a metal substrate, a sound noise is prevented, which would otherwise be generated due to transmission, to the metal substrate, of vibration caused when a ceramic capacitor expands and contracts by switching ON and OFF a transistor. For improving a heat dissipation effect, a switching transistor driven by a driving pulse and a ceramic capacitor connected to the switching transistor are incorporated on a conductive path on an insulated metal substrate. Both ends of the ceramic capacitor are fixed to the conductive path by solders which are covered with a hard resin to be protected from a solder crack by thermal expansion of the metal substrate. The ceramic capacitor and the hard resin are wholly covered with a soft resin which absorbs noise due to expansion caused when the ceramic capacitor is switched, so that the metal substrate is prevented from resonating.
1. A hybrid integrated circuit device into which a switching transistor driven by a driving pulse, and a ceramic capacitor connected to the switching transistor are incorporated on a conductive path on an insulated metal substrate, wherein
both ends of the ceramic capacitor are fixed to the conductive path by solders,
the solders are covered with a hard resin, and
the ceramic capacitor and the hard resin are wholly covered with a soft resin such that the soft resin covers a lower surface of the ceramic capacitor.
2. The hybrid integrate d circuit device according to claim 1 , wherein the soft resin is a silicone resin.
3. The hybrid integrated circuit device according to claim 1 , wherein the hard resin is an epoxy resin.
4. The hybrid integrated circuit device according to claim 1 , wherein the surface of the metal substrate is covered with a transfer molded epoxy resin.