Microscopy: surface mechanical damage and pitting pits lockhill chip size and electrode size meets the process requirements electrode pattern is complete.
LED diffuser sheet
Since the LED chip after dicing still tightly packed closely spaced (about 0.1mm), is not conducive to the operation after the process. Expanding machine using the chip bonding film for expansion, so that the spacing of the LED chip stretched to about 0.6mm. It can also manually expand, but can easily lead to falling chip waste and other negative issues.
LED Dispensing
Position LED on the corresponding point of silver plastic stents or plastic insulation. For GaAs, SiC conductive substrate having a back electrode of red, yellow, green chips, using silver plastic. An insulating sapphire substrate for blue, green LED chip, the chip is fixed using insulating plastic.
The difficulty lies in the amount of craft glue control points in colloid height, dispensing position are detailed process requirements. Since the silver plastic and rubber insulation in the storage and use are strict requirements, reminder: silver plastic material awake and stirring time is important to note that the process matters.
LED prepare plastic
And dispensing the contrary, prepare gum is prepared melter first silver paste applied to the LED back electrode, and then back with silver plastic LED mounted on the LED bracket. Preparation of glue dispensing efficiency is much higher than, but not all products are suitable for preparation of plastic processes.
LED Hand thorn sheet
After the expansion of the LED chip (or standby equipment glue gum) disposed on the substrate stage thorn fixture, LED stent placed under the jig under a microscope with a needle prick LED chips one by one to the appropriate location. Manual and automatic pallet stab sheet compared to a benefit, to facilitate ready to switch to a different chip for the chip will need to install a variety of products and services.
LED automatic pallet
Automatic pallet is actually a combination of stick gum (glue) and two step installation chip, the first point on the LED holder silver plastic (insulating plastic), then vacuum suction nozzle from the LED chip mobile location, and then placed in the corresponding bracket position. Automatic pallet in the process should be familiar with the main equipment operation program, while James dispensing equipment and installation precision adjustment. On the choice of nozzle try to use bakelite nozzle to prevent damage to the surface of the LED chip, especially blue and green chip must bakelite. Because the steel tips can scratch the surface of the current diffusion layer chip.
LED sintering
Sintering aims to make silver adhesive curing, sintering temperature monitoring requirements, to prevent bad batch of. Silver plastic sintering temperature control in 150 ℃, sintering time 2 hours. According to actual conditions can be adjusted to 170 ℃, 1 hour. Insulating plastic generally 150 ℃, 1 hour.
Silver plastic sintering oven process requirements must be every 2 hours (or 1 hour) to open replace sintered products, intermediate not free to open. Sintering oven for other purposes shall not prevent pollution.
LED bonding
The purpose is to pressure welding electrode lead to the LED chip, complete the connection work products inside and outside leads.
LED's have a gold ball bonding process and brazing two aluminum wire. Aluminum wire bonding process for the first LED chip electrode pressure on the first point, then the aluminum strands to the appropriate top bracket, the pressure on the second point after tearing aluminum wire. Gold ball bonding process in the press before the first point before firing a ball, similar to the rest of the process.
Bonding LED packaging technology is the key link, the process needs to be monitored is the main bonding gold (aluminum wire) the shape of the arch wire, solder joint shape, tension.
LED sealed plastic
LED package mainly a little glue, potting, molding three. Difficulties in process control is basically a Bubble, more lack of material, black spots. Designed mainly for material selection, combined with a good selection of epoxy and bracket. (General LED can not leak test).
LED Dispensing TOP-LED and Side-LED is suitable dispensing package. Manual dispensing package for demanding operating level (especially white LED), the main difficulty is the amount of control dispensing, because the epoxy will thicken during use. White LED phosphor dispensing there is a light color precipitate cause problems.
Glue LED Lamp-LED package package in the form of potting. Potting process is the first in LED cavity injection molding liquid epoxy, and then insert bonding good LED bracket, let the epoxy curing oven, it will emerge that is shaped LED from the mold cavity.
LED molded package will be a good bonding LED stent placed in a mold, the upper and lower two mold clamping hydraulic machines and vacuum, the solid epoxy glue injection into the inlet channel heating hydraulic ram is pressed into a mold rubber Road, epoxy glue along the road into the individual LED molding grooves and cured.
LED curing and after curing
Curing means a curing epoxy encapsulation, typically an epoxy curing conditions at 135 ℃, 1 hour. Molded package is generally 150 ℃, 4 minutes. After curing is to make fully cured epoxy, while the LED thermal aging. After curing the epoxy it is very important for improving the bracket (PCB) of the adhesive strength. General conditions of 120 ℃, 4 hours.
LED cut tendons and dicing
Since the LED in production are linked together (not individual), Lamp LED package by cutting the tendons cut LED stents even tendons. SMD-LED is on a PCB board, we need to separate the dicing machine to complete the work.
LED test
LED photoelectric parameters of the test, the test dimensions, while the LED product sorting according to customer requirements.
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