no gold package chip level white led fluorescent tube light repacements fixtures source production process the whole process
The current domestic LED packaging mainly using the traditional potting process, directly on the surface of the chip coated with fluorescent glue, in this way the formation of spherical corona phosphor coating has obvious structural defects, the same batch of led fluorescent tube light repacements fixtures source in the shape of the phosphor layer There will be some differences, it is difficult to control the uniformity and consistency, will bring a larger LED color difference between light sources.At present, the domestic LED encapsulation mainly adopts the traditional potting technology, and directly spots the fluorescent glue on the surface of the chip. In this way, the spherical corona phosphor coating has obvious structural defects (inconsistent thickness from the center to the edge). Moreover, regardless of manual or machine operation, the same batch of led fluorescent tube light repacements fixtures source phosphor layer in the shape will have some differences, it is difficult to control the uniformity and consistency, will bring led fluorescent tube light repacements fixtures source between the larger color difference; the same time, As the fluorescent coating micro surface uneven, large differences between individuals, when the light incident, it will form the color of the uneven white light, resulting in partial yellow or bluish non uniform spot appears.Chip level light source with the difference between traditional packaging, traditional packaging is a single point powder and sealant to complete the packaging process, chip level light source is the use of spraying, molding and other processes to complete the related packaging technology, single step process at the same time to complete multiple Light source of the package, which can overcome the single dispensing process to bring light color uneven, different light distribution and other defects. Moreover, in the same area, the chip level light source packaging density increased by 16 times the final package size than the traditional 80% reduction, lighting design space is greater.To Crystal Electronics E Star Series led fluorescent tube light repacements fixtures source products for the production process, for example, no gold chip level white led fluorescent tube light repacements fixtures source generally have to go through five production steps, as shown.Step one: flip bonding
Flip bonding is a blue LED chip and ceramic substrate together with a process, the combination of the principle of ultrasonic thermal welding, that is, plus ultrasonic heating while the LED chip to the ceramic substrate pressure welding electrodes. In order to ensure that the chip and the substrate can form a good combination, you need to advance in the chip or substrate to set the metal bump solder ball, and the need to ensure that the ultrasonic welding temperature reaches 160 ℃. By flip chip bonding together the chip and substrate, the electrode contact area of about 60% of the chip area, the chip thrust in 2000g or more, a solid combination of conduction and thermal conductivity will provide a good channel to ensure high current use Stable and reliable long term work.Step 2: Spray the phosphorThis is the first chip level package of key technologies, the first chip in the bonding of the ceramic substrate placed on the steel mesh, steel mesh holes and ceramic substrate on the corresponding chip position, and then use a professional phosphor powder coating machine pre deployment A good fluorescent adhesive is sprayed on the ceramic substrate on which the steel mesh is placed, and then the steel mesh is removed after spraying to prepare a phosphor coating with uniform coverage and uniformity on the chip of the whole ceramic substrate. In order to ensure the entire ceramic substrate white light source finished light color consistency, need to flip before the bonding of the chip sorting, in the spray can also be sprayed by way of many times to make the phosphor layer is more uniform.Step 3: Mold the lensThis is the second key technology in chip scale packaging, will be sprayed with fluorescent glue the entire piece of ceramic substrate into Moldin g (molding) machine cavity, while the silicone encapsulation into the mold, the equipment heating the mold After the silicone curing, mold release can be completed after the entire ceramic substrate lens Moklin g. Precision molds and stable demolding processes are key to ensuring good consistency of the silicone lens.Step four: cuttingAfter completing the entire ceramic substrate LED package, the need for cutting the next step in order to separate the test. Ceramic cutting process are mainly blade cutting and laser cutting of two, the process is relatively simple, the focus is to avoid the damage caused by the silicone lens.Step 5: Test the packingNeed to test the classification of the specifications of the main parameters are the following, operating voltage, luminous flux, color temperature and color rendering index. The same specifications of products to tape the form of packaging together, compatible with the follow up of the automatic placement process.