LCD COF TAB BONDING PROCESS STEPS
- LCD/LED fault mark :
2) Glass and PCB fixation:
3) Tool for COF remove:
4) Hot gun parameter Setting:
Temperature Range: 330 degree.
Air flow of hot gun: 2-3.
5) COF disassembly:
6) ACF remover liquid G750 apply on COF
Don’t touch the liquid with your finger or skin. If the liquid splash to skin, please washing with a lot of water. You can wear gloves to protect your hands.
7) ACF removing liquid chemical reaction :
8) Wash in simple water :
9) Old COF cleaning :
1. Put the COF on a clean glass table;
2. Fix the COF by left hand finger (don’t touch the chip on COF, will damage it);
3. Right hand take a clean peace nano sponge with acetone;
4. Clean the ACF follow the direction of pins from inside to outside of COF. Please note only clean in one direction, don’t clear in vertical direction of the pin, or from outside to inside of COF.
10) Glass cleaning :
• Fix the panel little bit outer of the table.
• Put left hand on the panel to support it take a clean peace nano sponge with IP ;
•Clean vertically with nano sponge;
•Repeat step 3 and step 4 until the Glass is clean.
11) PCB cleaning :
12) Glass checking :
13) glass cleaning under microscope :
14) COF checking :
1. Check if there is residual ACF or dirty things on the pins, then scrape them by cotton swab carefully.
2. If the pins curved or broken, please drop this COF.
15) New COF cutting :
1. Before cutting, please check the cutter if it is undamaged and sharp;
2. Put the COF reel under the cutter at properly position;
3. Cut the COF with fast speed;
4. After cutting, check the COF with microscope;
5. If COF not very clean, clean it with electrostatic cloth and acetone.
16) ACF model :
ACF should be stored in low temperature (like store in fridge), before open ACF should in freezing chamber, after open should in cold closet, and sealing with a hermetic bag. Waiting 15 min for thawing after pick ACF out from the fridge. Please noted the valid date of the ACF, which wrote on the ACF label. ACF should not be used when expired. Put ACF back to the fridge after every day work finished.
17) ACF attaching part 1 :
When attaching, fix COF on glass table by left hand, put ACF on COF pins with a tweezers, and make sure a perfectly alignment between ACF and COF pins.
After attaching, pre-heating the ACF with a T type iron, this will make a good connection between ACF and COF, prevent ACF fall from the COF when moving.
18) ACF attaching part 2 :
19) Panel moving and placing :
Please note should put two hands in the center of the ITO. Make sure the ITO is smooth and steady.
Take care when placing ITO on platform, don’t let it strike the quartz holder and other part of the machine.
For big ITO, can move it with suckers.
20) Bonding machine operation – parameter selecting :
21) Bonding machine operation – panel alignment :
22) Bonding machine operation – camera adjusting :
23) Bonding machine operation – COF fixture :
24) Bonding machine operation – COF adjustment on XYZ direction:
25) Bonding machine operation – Teflon tape:
The bonding pressure should between 2.0Mpa~4.0Mpa, the pressure can be setting by the regulating valve.
26) Bonding machine operation – alignment image:
For new COF, alignment is more easy;
For used COF, is a little hard for aligning, because used COF will curved, shrink…
27) Bonding machine operation – double start:
During the automatic bonding process, you can press the emergency button at any time to stop the process.
28) Bonding machine – automatic Bonding :
If OK, please do next step, PCB side bonding.
29) Bonding machine – PCB side alignment :.
•The head should cover full bonding area.
•Align the PCB and COF pins, can assistant by a magnifying glass. There are marks on PCB and COF will help alignment.
30) Bonding machine operation – put silicon tape :
The length of silicone tape should longer than COF length.
31) Bonding machine operation – PCB side automatic bonding :
During the automatic bonding process, you can press the emergency button at any time to stop the process.
32) Testing after Bonding :
If not repaired, analyze the reason and repair again.
Usually, bright-line means short circuit; dark line means of the circuit.
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