Conductive adhesiveWhat are the steps in the packaging process?
Conductive adhesive is an indispensable adhesive in LED production and packaging. Its requirements for conductive silver paste are good conductivity and thermal conductivity, high shear strength, and strong adhesion. The task of LED packaging is to connect the external leads to the electrodes of the LED chip, while protecting the LED chip and improving the efficiency of light extraction. The key processes include shelving, pressure welding, and packaging. LED packaging forms can be said to be diverse, mainly adopting corresponding external dimensions, heat dissipation measures, and light output effects according to different application scenarios. The main forms of LED packaging include Lamp LED, TOP-LED, Side LED, SMD LED, High Power LED, etc.
1. Chip inspection
Microscopic examination: whether there is mechanical damage and locking pits on the surface of the material; Whether the chip size and electrode size meet the process requirements; Is the electrode pattern complete.
2. Expansion piece
Due to the close arrangement and small spacing (about 0.1mm) of LED chips after slicing, it is not conducive to the operation of subsequent processes. We use an expansion machine to expand the film of the bonded chips, stretching the spacing of the LED chips to about 0.6mm. Manual expansion can also be used, but it can easily cause problems such as chip dropping and waste.
3. Glue dispensing
At the corresponding position of the LED bracket, silver glue or insulation glue is applied. The process difficulty lies in controlling the amount of glue to be dispensed, and there are detailed process requirements for the height and position of the glue. due to
Conductive YB6001 silver adhesiveThere are strict requirements for the storage and use of insulation adhesive,
LED chip silver adhesiveThe awakening, mixing, and usage time are all important considerations in the manufacturing process.
4. Prepare adhesive
Unlike dispensing, preparing glue is done by using a dispensing machine to first apply it
YB6001 Conductive Silver AdhesiveApply it onto the back electrode of the LED, and then install the LED with silver adhesive on the LED bracket. The efficiency of preparing glue is much higher than dispensing, but not all products are suitable for the preparation glue process.
5. Handmade stab
Place the expanded LED chips on the fixture of the piercing table, place the LED bracket under the fixture, and use a needle to pierce the LED chips one by one to the corresponding positions under the microscope.
6. Automatic shelving
Automatic mounting is actually a combination of two steps: dispensing and installing chips. First, apply insulation glue on the LED bracket, then use a vacuum nozzle to lift the LED chip up and move it, and then place it in the corresponding bracket position.
7. Sintering
The purpose of sintering is to solidify the silver paste, and temperature monitoring is required to prevent batch defects during sintering. The temperature for silver paste sintering is generally controlled at 150 ℃ and the sintering time is 2 hours. According to the actual situation, it can be adjusted to 170 ℃ for 1 hour.
8. Pressure welding
The purpose of pressure welding is to lead the electrodes onto the LED chip and complete the connection of the internal and external leads of the product. There are two types of LED bonding processes: gold wire ball bonding and aluminum wire bonding. Pressure welding is a key link in LED packaging technology, and the main process that needs to be monitored is the shape of the pressure welding wire (aluminum wire) arch wire, the shape of the solder joint, and the tensile force.
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