Circuit board and circuit apparatus using the same

• Main Authors: USUI RYOSUKE, SHIBATA KIYOSHI
• Format: Patent
• Language: English
• Published: 01.03.2007
• Subjects: BASIC ELECTRIC ELEMENTS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; ELECTRIC SWITCHES; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; EMERGENCY PROTECTIVE DEVICES; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; PRINTED CIRCUITS; RELAYS; SELECTORS

A circuit board and a circuit apparatus using the same are provided, which have an improved heat radiation capability near through holes piercing through its metal substrate so as to address a requirement as to heat radiation capability. The circuit apparatus has the circuit board in which a metal substrate having pierced holes is formed as a core member. Protrusions are formed at the top ends of the pierced holes, and round corners are formed at the bottom ends of the same. Insulating layers are formed on both sides of the metal substrate, and wiring pattern layers are formed on the respective insulating layers. The insulator formed on one side of the metal substrate and the insulator formed on the other side of the metal substrate are extended to inside the pierced holes. The joining surface between the extended portions is shifted off the center position of the metal substrate in the thickness direction, toward the same side as where the protrusions are formed. In order to electrically connect the wiring pattern layers, a conductor layer connecting the wiring layers is formed through the metal substrate via the pierced holes, thereby establishing conduction between the wiring layers. A semiconductor chip is connected directly to the top side of the circuit board via solder balls.