Led conductive adhesive is suitable for packaging and bonding of various electronic components and components such as LED, high-power LED, LED digital tube, LCD, TR, IC, cob, PCB, FPC, FC, LCD, EL cold light sheet, display screen, piezoelectric crystal, crystal oscillator, resonator, solar cell, photovoltaic cell, buzzer, semiconductor discrete device, etc. The application scope covers electronic components, electronic components, circuit board assembly, display and lighting industry, communication, automobile electronics, smart card, radio frequency identification, electronic label and other fields.
Market status of LED conductive adhesive
At present, led conductive adhesives used in some high-end fields in the domestic market are mainly imported: America's ablistick company and 3M company occupy almost all IC and led fields, Sumitomo of Japan and Yihua of Taiwan are also involved in these fields. Three BD company of Japan controls the application of conductive silver glue in the whole quartz crystal resonator. Domestic conductive silver glue is mainly used in some medium and low-grade products, and the market in this field is mainly occupied by Metal Research Institute
Chbond series conductive silver adhesive is mainly suitable for LED, and high power LED LED digital tube, LCD, TR, IC, cob, pcba, lattice block, display screen, crystal oscillator, resonator, solar cell, photovoltaic cell, buzzer, ceramic capacitor, semiconductor discrete device, and other electronic components and components packaging and bonding. The application scope covers electronic components, electronic components, circuit board assembly, display and lighting industry, communication, automotive electronics, intelligence, etc. Card, RFID, and other fields
At present, a large number of SMT production lines are being introduced and developed in China's electronic industry, and conductive silver adhesives will surely have broad application prospects in China. However, the research in this field in China started late, and the high-performance Conductive Silver adhesives currently needed mainly rely on imports, Therefore, it is necessary to strengthen the research and application of the influence of bonding temperature, curing time, bonding pressure, particle content and other factors on the reliability of conductive silver adhesive, and prepare a new type of conductive silver adhesive to improve the international competitiveness of China's electronic product packaging industry
Application technology of LED conductive adhesive
a) Cleaning: ultrasonic cleaning PCB or LED, and drying.
b) Mounting: after the electrode at the bottom of the LED tube core (large disc) is prepared with silver glue, the expanded tube core (large disc) is placed on the spiny crystal table. Under the microscope, use the spiny crystal pen to mount the tube core one by one on the corresponding pad of PCB or LED bracket, and then carry out sintering to solidify the silver glue.
c） Pressure welding: use aluminum wire or gold wire welder to connect the electrode to the LED core for current injection. LED is directly installed on PCB, and an aluminum wire welding machine is generally used. (gold wire welder is required to make white top-led)
d) Package: protect the LED core and welding wire with epoxy through dispensing. Dispensing on the PCB board has strict requirements on the shape of the gel after curing, which is directly related to the brightness of the backlight products. This process will also take on the task of point fluorescent powder (white LED).
e) Welding: if the backlight is SMD-led or other packaged led, the LED needs to be welded to the PCB before the assembly process.
f) Film cutting: use punch to die cut all kinds of diffusion film and reflective film needed for a backlight.
g) Assembly: according to the requirements of the drawings, manually install the backlight source in the correct position.
h) Test: check whether the backlight source photoelectric parameters and light uniformity are good.
Common problems of LED conductive adhesive
1、 Led bubble problem.
Cause: 1. Air bubble in a bowl: poor glue dipping of the bracket.
2. Bracket bubble: the curing temperature is too high, and the epoxy curing is too intense.
3. Cracking and bursting: short curing time, incomplete or uneven curing of epoxy resin. Abglue is out of service time.
4. Surface bubbles: the epoxy adhesive is difficult to defoaming or the vacuum degree is not enough for users, and the dispensing time is too long.
Solution: improve the process or contact epoxy supplier according to usage.
2、 Led yellow.
Reasons: 1. Baking temperature is too high or time is too long;
2. The proportion of glue is not right, a glue is easy to turn yellow.
Solution: 1. Hy-7001a / B is cured and demoulded within 120-140 ℃ / 30 minutes, and it is easy to turn yellow after baking for more than 150 ℃.
2. Hy-7001-1a / B is cured and demoulded at 120-130 ℃ / 30-40 minutes, and it will turn yellow if it is baked over 150 ℃ or for a long time.
3. When making large lamp caps 8 and 10, lower the curing temperature.
3、 LED bracket climbing glue.
Causes: 1. The surface of the bracket is uneven, resulting in the capillary phenomenon.
2. AB glue contains volatile materials.
Solution: please contact the supplier.
4、 LED package changes color after short baking.
Cause: 1. The stack in the oven is too dense and the ventilation is poor.
2. The local temperature of the oven is too high.
3. There are other color pollutants in the oven.
Solution: improve ventilation. Remove the color pollution and confirm the actual temperature in the oven.
5、 Not easy to demould.
Cause: the problem of AB glue or the glue does not reach the curing hardness.
Solution: Contact the supplier to confirm the curing temperature and time.
6、 Some of the lamps on the same row of supports have coloring phenomenon or gelatinization time and uneven quality.
Cause: insufficient mixing.
Solution: stir well, especially at the corners of the container.
7、 Add the same batch and dose of colorant, but the color of the product is different.
Cause: uneven concentration of colorant; or precipitation of colorant.
Solution: the color agent is heated and stirred evenly before use.
9、 Red ink failure
Cause: incomplete curing and poor sealing of AB adhesive.
Solution: strengthen the mixing and mixing of AB glue, 1. Control the curing and aging temperature correctly, the AB glue is completely cured.
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