| abstract |
PURPOSE:To increase the luminous intensity in the respective directions by disposing LED chips formed of an insulating base made of polygon. CONSTITUTION:Electrodes 2a, 2b and a circuit 3 are printed by a method of silk printing by using conductive ink made of silver or silver-palladium on the respective surfaces of an insulating base 1 formed in a tetrahedron, i.e., a trigonal pyramid having, for example, approx. 15mm of the lengths of respective edges made of ceramic, glass fiber-filed epoxy resin. LED chips 4 are bonded by a conductive adhesive to the electrodes 2a, and the upper surface is connected with the other electrodes 2b by fine wirings 5 having a plenty of ductility such as gold or aluminum welded by a method such as supersonic press bonding. Thus, when a DC voltage is applied to flow a forward current to the chip 4 to a lead pin 7, the chips 4 connected in parallel simultaneously emit lights over the entire periphery. |