Speak with Strength #LED Packaging Book: the Knowledge of LED Packaging Technology

The packaging process of LED lamps is a high -tech content. In this circle, there are many so -called commercial secrets. Because these things are related to the life and death of a company, some things are not made public, including some processes or some processes or some processes or some processes or Craft. These things directly determine whether the company can have central competitiveness. Today, I will release the knowledge of the packaging technology of the LED industry here. I hope to help you help you. 1. Production process 1. Production: A) Cleaning: Using ultrasonic cleaning PCB or LED brackets, and drying. b) Loading: After the electrodes of the LED tube core (large circle) are expanded, the dilated tube (large round sheet) is placed on the spine crystal table, and the tube core is used under the microscope under the microscope. One by one is installed on the corresponding pads of PCB or LED brackets, and then sintering is performed to curing silver glue. C) Pressive welding: Use aluminum or gold wire welding machine to connect the electrode to the LED tube core to the lead in the current injection. The LED is directly installed on the PCB, and the aluminum welding machine is generally used. (Make a white light Top-LED requires a gold wire welding machine) D) Packaging: By point glue, protect the LED tube core and welded wire with epoxy. Point glue on the PCB board has strict requirements on the shape of the colloidal shape after curing, which is directly related to the brightness of the backlight finished product. This process will also undertake the task of fluorescence powder (white light LED). E) Welding: If the backlight is SMD-LED or other encapsulated LEDs, before the assembly process, the LED needs to be welded to the PCB board. F) Cutting membrane: Use the punching mold to cut the various diffusers, reflective membranes, etc. of the back light source. G) assembly: Manually install the correct position of the various materials of the backlight source according to the requirements of the drawing. H) Test: Check whether the backlight source optoelectronics parameters and the uniformity of light out of light. 2. Packaging: Packing the finished product as required and entering the warehouse. Second, packaging process 1. The task of packaging of LED is to connect the external lead to the electrode of the LED chip, at the same time protect the LED chip, and play a role in improving the efficiency of light extraction efficiency. Key processes are assembly, pressure welding, packaging. 2. LED packaging form LED packaging form can be said to be diverse. It mainly uses corresponding shape size, heat dissipation countermeasures and light effects according to different applications. LEDs are classified in the form of packaging include LAMP-LED, TOP-LED, SIDE-LED, SMD-LED, High-Power-LD, etc. 3. LED packaging process process A) Chip inspection mirror inspection: 1. Whether the material surface has mechanical damage and lockhill; 2. Whether the chip size and electrode size meet the process requirements; 3. Whether the electrode pattern is complete. B) Because the LED chip is still in a small spacing (about 0.1mm) after the LED chip is scratched, it is not conducive to the operation of the post -process. We expand the film of the adhesive chip using the expansion machine. It is the spacing of the LED chip stretching to about 0.6mm. It can also be manually expanded, but it is easy to cause bad problems such as chip dropping waste. C) Silver glue or insulating glue on the corresponding position of the point glue at the corresponding position of the LED bracket. (For GAAS and SIC conductive substrates, red light, yellow light, yellow -green chip with the back electrode on the back, use silver gum. For the blue light and green LED chip of sapphire insulating base, use insulating glue to fix the chip. ) The difficulty of the process lies in the control of the amount of adhesion, and there are detailed process requirements at the height of the colloid height and the point of the point of the point of the point of the point of the point of the point. Because silver glue and insulating glue have strict requirements in storage and use, the wake -up, stirring, and use time of silver glue are all matters that must be paid attention to. D) In contrast to the preparation and point replenishment, the glue prepares is to apply the silver glue to the LED back electrode with the preparation machine, and then install the LED with silver glue on the back on the LED bracket. The efficiency of preparation is much higher than that of point glue, but not all products are applicable to the preparation process. E) Handmade spines Set the expansion of the LED chip (preparation or unpaid gel) on the fixture of the thorn table. The LED bracket is placed under the fixture. Under the microscope, the LED chip is pierced on the corresponding position with a needle under the microscope. Compared with the automatic loading of hand -cranked, it has one benefit compared to it, which is convenient for changing different chips at any time. It is suitable for products that need to install a variety of chips. f) The automatic loading and automatic assembly are actually combined with two steps: silver gum (insulating gum) on the LED bracket on the LED bracket. Location, then place it on the corresponding bracket position. Automatic installation is mainly familiar with equipment operation programming in terms of technology, and at the same time adjust the staining and installation accuracy of the equipment. Try to use glue wood suction mouth in the choice of suction to prevent damage to the surface of the LED chip, especially the orchid and green chip must be used. Because the steel mouth will scratch the current spread layer of the chip surface. G) The purpose of sintering and sintering is to curing silver glue, sintering requires monitoring temperature to prevent batch failure. The temperature of the sintering sintering of silver gum is generally controlled at 150 C, and the sintering time is 2 hours. According to the actual situation, you can adjust to 170 C, 1 hour. Insulation glue is generally 150 C, 1 hour. The silver rubber sintering oven must open the product that is replaced by sintering according to the process requirements (or 1 hour), and you must not open it at will. The sintering oven must no longer use other purposes to prevent pollution. H) The purpose of the pressure welding and welding will lead the electrode to the LED chip to complete the connection work of the inside and outside of the product. There are two types of LED's pressure welding process: golden ball welding and aluminum wire pressure welding. The picture on the right is the process of aluminum wire pressure welding. First press the first point on the LED chip electrode, then pull the aluminum wire to the corresponding bracket, and then press the second point to break the aluminum wire. The gold silk ball welding process burn a ball before pressing the first point, and the rest of the process is similar. Pressive welding is the key link in LED packaging technology. The main process of the process needs to monitor the shape of the welding gold wire (aluminum) arched silk shape, the shape of the welded joint. In -depth research on the pressure welding process involves multiple problems, such as gold (aluminum) silk materials, ultrasonic power, pressure welding pressure, chopping knife (steel mouth), split -knife (steel mouth) movement trajectory, etc. (The figure below is the micro -photos of the welding joints pressed by the two different split -knife under the same conditions. The two have a difference in the micro structure, which affects the quality of the product. ) We are no longer tired here. I) The packaging of dot -glue packaging LED is mainly three types: a little glue, sealing, and mold pressure. Basically, the difficulty of craft control is bubbles, multiple materials, and black spots. The design is mainly selected by the material, and the combined epoxy and bracket are selected. (General LED cannot pass the gas tight test.) As shown in the figure shown on the right, the Top-LED and SIDE-LD applies to the point glue packaging. Manual tape packaging requirements are high (especially white light LED). The main difficulty is the control of the amount of point replenishment, because the epoxy will thicken during use. The point replenishment of the white light LED also has the problem of the color difference caused by fluorescent powder sedimentation. J) The packaging of lavage packaging LAMP-LED adopts the form of irrigation. The process of sealing is to inject liquid epoxy in the LED molding mold cavity, and then insert the lattice -welded LED bracket. After adding the oven to solidify the epoxy. K) Mooming packaging puts the welded LED bracket into the mold, and the upper and lower pairs of molds are used with hydraulic molds and pumped the vacuum. , Epoxy Enter the rubber trail into each LED molding slot and solidify. L) CICS and post -curing and curing refers to the curing of the encapsulation of epoxy. Generally, epoxy curing conditions are 135 C, 1 hour. Moving packaging is generally 150 C, 4 minutes. M) The rearcultation is cured in order to allow the epoxy to be fully cured, and at the same time, the LED is hot and aging. Relax curing is very important for improving the adhesion intensity of epoxy and bracket (PCB). The general conditions are 120 C, 4 hours. N) Jacking and slices Since the LED is connected in production (not a single), LAMP packaging LED uses the gluten to cut the LED bracket. SMD-LED is on a PCB board, which needs to be a chip machine to complete the separation work. O) Test the optoelectronics parameters of LED and test the size of the shape. P) Packaging to count the finished product. Ultra -high bright LED needs anti -static packaging