LED five raw materials were means: chips, stents, silver plastic, gold, epoxy resin Wafer Wafer composition: the gold pad, P pole, N pole, PN junction, the back gold layer (double pad wafers without back gold layer). P-layer semiconductor wafer is composed of elements, N layer of semiconductor elements by electrons moving rearranged into a combination of PN. It is this change in the wafer can be in a relatively stable state. When the wafer is applied to a certain voltage positive electrode, the positive hole P region is a steady stream of trips to the N zone, electronic N region is relative to the P zone hole motion. In electronics, the relative movement of the hole, while another knot electron-hole pair excitation photons, produce energy. The main classification, surface emission type: light emitted from the wafer surface most. Five surface emission type: surface, sides have more light emitted by the light emitting color component, red, orange, yellow, green, pure green, standard green, cyan, blue. Stand The structural support of a layer of iron, two-layer copper (good conductivity, heat dissipation), 3-layer nickel plating (oxidation), 4 silver plating layer (reflective, easy wire) Silver plastic (due to more categories, according to our case H20E) Also called white glue, white, turned adhesion (baking temperature: 100 ° C / 1.5H) silver (conductive, heat, holding the wafer) + epoxy resin (cured silver) + diluent (easy mixing). Storage conditions: silver plastic manufacturers will generally silver paste to -40 ° C storage, application unit generally silver paste to -5 ° C storage. A single dose of 25 ° C / 1 year (dry, well ventilated place), mixture 25 ° C / 72 hours (but the job is on the line because of other factors, "the temperature and humidity, ventilation conditions," to ensure the quality of products in general Use the mixture for 4 hours) Baking conditions: 150 ° C / 1.5H Stirring conditions: stirring in one direction even 15 minutes Gold (according φ1.0mil example) LED used by the gold lines are φ1.0mil, φ1.2mil, gold material, LED with gold thread of material is generally gold content of 99.9%, the use of gold Using its high gold content material is relatively soft, easily deformed and good conductivity, excellent heat dissipation properties, so between the wafer and the holder form a closed circuit. Epoxy resin (in EP400 example) Composition: A, B two agent components: A glue: is the main agent, epoxy resin + defoamers + heat + diluent agent B agent: curing agent, an acid release agent intoxicated + + accelerator Conditions of Use: Mixing ratio: A / B = 100/100 (weight ratio) Mixed Viscosity: 500-700CPS / 30 ° C Gel time: 120 ° C * 12 minutes or 110 ° C * 18 You can use conditions: room temperature 25 ° C for about six hours. General production line according to production needs, we will use its condition as two hours. Curing conditions: the initial setting 110 ° C-140 ° C 25 - 40 Late hardening 100 ° C * 6-10 hours (visual reality of mobility needs to be done to adjust)
