| 摘要 |
PURPOSE:To provide a LED, white controls the diffusion of light and emits the light in the specified direction. CONSTITUTION:An N-type layer 3 is formed an upper surface 2a of a P-type layer 2 of a LED. A boundary line 4 of the P-N junction is displayed as the approximately square closed curve. The thickness of the P-type layer is relatively larger than the thickness of the N-type layer. An anode electrode 5 having a bump 6 is formed on the upper surface of the P-type layer. A cathode electrode 7 having a bump is formed on the N-type layer. Both the anode and cathode electrodes are located on the upper surface. Therefore, the LED can be direcly mounted on a wiring 11 at the inner surface of a front substrate 10 of a front lightemitting fluorescent display tube. A bonding wire is not required. Since the boundary line of the P-N junction appears only on the upper surface, the light is mainly emitted to the side of the upper surface. The light is emitted to the front side of the fluorescent display tube through the front substrate. The lower surface of the relatively thick P-type layer us directed to the inside of an envelope device. The possibility of the erroneous operation of the LED caused by the hitting of electrons is decreased. |
