How To Repair Bonding Tape On Led Tv
LCD COF/TAB Bonding Process Steps
LCD COF/TAB Bonding Process Steps
Usage: Make a mark on the screen where fault announced(Vertical line, chugalug; Horizontal line, belt), afterwards bonding cheque again if the fault disappeared.
Usage: Brand a fixation between Drinking glass and Side PCB, this tin can prevent other COFs from damage during bonding process.
Usage: The polarizer may go scratched during bonding process. Put a film (Similar preservative film) on the polarizer can solve this problem. Please make sure the picture on the polarizer is shine and flat.
Usage: A properly parameter of the current of air station can make the COF flat, non-deformation, and unshrinking during removing.
Temperature Range: 300-330?.
Wind Ability: 3-4 degree.
Remark: Can set up a higher temperature for a thick COF.
Before disassembly, remove the sealing glue; When disassembling, left hand concord the blower, right manus have the disassembling tool, moving from left to right; Please note PCB side disassembly outset then glass side.
Please apply correct corporeality of liquid on ITO Glass and COF. Too less or too much is not working good. And also don't apply liquid on other office of them, considering the liquid is corrosion, volition harm the polarizer film or protection film.
Don't touch the liquid with your finger or skin. If the liquid splash to skin, please watching with a lot of water. You can vesture gloves to protect your hands.
The principle of liquid is chemical reaction, which will brand the ACF soft, loose and easy for cleaning. Delight waiting a holding fourth dimension for the reaction. For G-450, reaction time is 1-5 min, after reaction clean ACF past alcohol or acetone.
Delight annotation merely utilise liquid to pins and PCB board and ITO, don't bear upon the protection moving-picture show of them, otherwise will impairment the protection movie.
For ITO cleaning:
1. Scrup the residual ACF with cotton swab with alcohol;
2. Scrub with cotton swab(electrostatic cloth) and acetone.
iii. Repeat step ane and pace two until the ITO is clear.
Because used COF is more lower price than new ane, and for some model can but buy used i from the market. But before bonding, delight make sure the old COF is clean and not damaged.
one. Put the COF on a clean glass table;
two. Fix the COF by left hand finger (don't affect the chip on COF, will damage information technology);
3. Correct hand take a clean cotton swab (Electrostatic fabric) with alcohol;
4. Make clean the ACF follow the direction of pins from inside to exterior of COF. Delight note simply clean in one management, don't clear in vertical direction of the pivot, or from outside to inside of COF.
Property magnification (twenty*3), cheque if there is residual ACF or muddied tings on the ITO, and likewise cheque if ITO exist scratched or corrosive before bonding.
For some very small residual ACF and muddy tings, only can be check and clean under microscope.
Make clean the ACF follow the direction of pins from inside to outside of ITO with a properly direction and forcefulness, don't hurt the pins, and then clean the ITO with cotton wool swab and alcohol.
Check the COF under microscope.
ane. Check if there is residue ACF or dirty things on the pins, then scrape them by toothpick carefully.
two. If the pins curved or cleaved, please driblet this COF.
one. Before cutting, please bank check the cutter if it is undamaged and sharp;
ii. Put the COF reel nether the cutter at properly position;
iii. Cut the COF with fast speed;
4. After cut, bank check the COF with microscope;
5. If COF non very clean, make clean it with electrostatic cloth and alcohol.
ACF is necessary for COF boding, the ACF will connect COF with ITO and PCB. Should choose the correct ACF before bonding. The ACF for ITO side and PCB side is dissimilar.
ACF should exist stored in low temperature (similar store in fridge), before open ACF should in freezing chamber, after open should in common cold closet, and sealing with a hermetic handbag. Waiting 15 min for thawing later on pick ACF out from the refrigerator. Please noted the valid engagement of the ACF, which wrote on the ACF label. ACF should not exist used when expired. Put ACF back to the fridge after every day work finished.
Cut the ACF from reel with a tweezers and pair of scissors. The ACF should a piddling longer than the COF. And make sure the ACF very smoothen and flat.
When attaching, fix COF on glass tabular array 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 volition make a good connection betwixt ACF and COF, prevent ACF autumn from the COF when moving.
After attaching, plow over the COF and scrape the left and correct actress ACF from protection moving picture by a tweezers.
After cleaning, move the ITO to bonding machine platform by two hands. Delight note should put two easily in the middle of the ITO. Make sure the ITO is polish and steady.
Take intendance when placing ITO on platform, don't allow it strike the quartz holder and other office of the motorcar.
For big ITO, can motion it with suckers.
Before delivery, there are groups of default parameters are ready properly. Usually no need to set them, only in some special case, you can alter them on touch screen.
Change the functioning mode to transmission on touch screen.
Press the manual alignment button, and hold the caput past hand, allow the head come downward with low speed.
Arrange the camera with 3 screws, left and right, Front and back, focus, until there is a articulate image on screen
Open the COF fixture, put the COF in fixture, the fixture should not touch the chip on COF. Remove the protection film of ACF. And then put the COF on ITO pins and align them.
Check the alignment quality through LCD screen, and tin can conform the 3 adjustment screws on fixture to marshal ITO and COF pins. The ITO and COF pins should alignment perfectly
After alignment of COF and ITO, put a Teflon tape on the top of COF, the Teflon tape should about 5mm longer than COF. The Teflon tape will protect the COF while bonding.
The bonding pressure should betwixt ii.0Mpa~iv.0Mpa, the force per unit area tin be setting past the regulating valve.
Alignment is very important for bonding. Good alignment will make a practiced bonding, while bad alignment will make a failure bonding.
For new COF, alignment is more easy;
For used COF, is a little hard for aligning, because used COF will curved, shrink…
Earlier bonding, make certain the alignment, parameter, pressure level all in the correct setting, modify from manual to automatic bonding on touch screen, press the two beginning button at same time on panel to offset the automatic bonding process. The head will begin heated to the start temperature, then come downwardly with bonding pressure, proceed heating to the bonding temperature, afterwards waiting setting time, stop heating and cooled by air, when cooling finished, the caput will goes up automatically, the bonding process finished.
During the automatic bonding process, you can press the emergency button at any time to stop the process.
When bonding finished, can check the bonding outcome with the screen, each pin on ITO and COF should connect in a proficient quality. If non connect very well, please disassembly the COF and re-bail information technology carefully.
If OK, please do next step, PCB side bonding.
1. Put the PCB bonding area under the middle of the head, the same operation as ITO side.
2. The head should cover full bonding area.
3. Align the PCB and COF pins, can assistant by a magnifying drinking glass. There are marks on PCB and COF will assistance alignment.
After alignment, put a silicone table on the COF, it will protect the COF and make the heating more uniform. Delight annotation, ITO side utilize Teflon and PCB side use silicone.
The length of silicone tape should longer than COF length.
The bonding parameter of ITO side and PCB side is different. Should cull the right parameter before bonding. Normally the temperature of PCB side is college than ITO side, the bonding time is as well little longer.
And also make sure the bonding pressure is correct.
Before bonding, make sure the alignment, parameter, pressure all in the right setting, change from manual to automatic bonding on touch screen, printing the two start push at aforementioned time on panel to starting time the automated bonding procedure. The head will begin heated to the commencement temperature, then come down with bonding pressure, proceed heating to the bonding temperature, after waiting setting time, finish heating and cooled past air, when cooling finished, the head will goes up automatically, the bonding process finished.
During the automatic bonding process, you lot can press the emergency button at any fourth dimension to end the process.
After bonding, practise a testing with the screen, make sure the fault was repaired.
If not repaired, analyze the reason and repair again.
Unremarkably bright line means short circuit; dark line ways off circuit.
The left function is normal, the right part is colored belt
A quick view of how to supplant LCD COF with a bonding automobile
How To Repair Bonding Tape On Led Tv,
Source: http://lcd-repair-machine.com/case-share/lcd-cof-tab-bonding-process-steps.html
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