SHIELDING STRUCTURE OF CIRCUIT BOARD

• Main Author: KIKUCHI MISAO
• Format: Patent
• Language: English
• Published: 01.06.1990
• Subjects: CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; PRINTED CIRCUITS

PURPOSE:To reduce constituent components and to enhance the workability of an assembly by a method wherein electronic circuits are encircled three- dimensionally with an earth wiring pattern, oblong hole-shaped through holes and a shielding case. CONSTITUTION:A first substrate 1a of a circuit board 1 is provided with an external layer earth wiring pattern 1a-1 to encircle electronic circuits 5 in a frame type on the side of the surface and is provided with respective external layer signal wiring patterns 1a-2 and 1a-3 to constitute the circuits 5 and an electronic circuit 6. On the side of the rear of the substrate 1a, an internal layer earth wiring pattern 2a-1 of an area to make entire surface opposition to a region which is encircled with the pattern 1a-1 on the side of the surface is provided and oblong hole-shaped through holes 1a-4, which make a conductive connection almost continuously the patterns 2a-1 and 1a-1 to each other along their outer peripheries, are provided. Moreover, components 5a and 6a of the circuits 5 and 6 are soldered, a shielding case 8 is made to cover from above the circuits 5, a conductive bonding agent 7 is held between flanges 8a and the pattern 1a-1, is heated and welded and the case 8 is bonded. Thereby, the circuits 5 are encircled three-dimensionally and are shielded.