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Old 01-20-2019, 02:36 AM   #1
capwizard
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Chip-on-film (COF) is a new technology after tape-automated bonding (TAB) and chip-on-glass (COG) in the interconnection of liquid crystal module (LCM). The thickness of the film, which is more flexible than TAB, can be as thin as 44 μm. It has pre-test capability, while COG does not have. It possesses great potential in many product fabrication applications.In this study, we used anisotropic-conductive film (ACF) as the adhesive to bind the desired IC chip and polyimide (PI) film. The electric path was formed by connecting the bump on the IC and the electrode on the PI film via the conductive particles in the ACF. In the COF bonding process experimental-design method was applied based on the parameters, such as bonding temperature, bonding pressure and bonding time. After reliability tests of (1) 60 C/95%RH/500 h and (2) C/500 cycles, contact resistance was measured and used as the quality inspection parameter. Correlation between the contact resistance and the three parameters was established and optimal processing condition was obtained. The COF samples analyzed were fabricated accordingly. The contact resistance of the COF samples was measured at varying temperature using the four points test method. The result helped us to realize the relationship between the contact resistance and the operation temperature of the COF technology. This yielded important information for circuit design.


Anisotropic conductive films (ACF) bonding was used to connect thin flexible cables to the mirror. ACF bonding is a commercially established approach for making electrical connections to liquid crystal display panels and other electronic packages. Custom ACF electrical cables were made with Cu traces spaced equidistant to the electrical contacts patterned at the mirror's axial edge Fig. 3(c). Each Cu trace was connected to the electrical contacts by using a bonding tool able to apply temperature and pressure with high precision. .


Mod-02 Lec-10 Wire bonding, TAB and flipchip-2; Tutorials
https://www.youtube.com/watch?v=vKj3eXgyC5c

COF (Chip-On-Film) Technology for LCD Driver ICs Using ... - Sharp
https://cgi.sharp-world.com/corporat...tj3/pdf/12.pdf

http://slideplayer.com/slide/5687749/release/woothee



Can we repair COF?

LC420DUE-FGA6 - BLANK SCREEN ISSUE IN LED PANEL, ONLY BACKLIGHT,
https://www.youtube.com/watch?v=-itHoG_GAhE

Last edited by capwizard; 01-20-2019 at 02:51 AM..
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Old 01-20-2019, 10:56 AM   #2
capwizard
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Default Re: Cof

COF Chip-on-film....This technology is also used on our credit card and cellphone sim card.


RFID Credit Card Chip Extracated For Your Viewing Pleasure
https://www.youtube.com/watch?v=kI-RAMBPz6w


How a criminal ring defeated the secure chip-and-PIN credit cards
https://arstechnica.com/tech-policy/...-credit-cards/

photo 2 : FUN card X-ray analysis. (1) External memory (AT24C64); (2) Microcontroller (AT90S8515A); (3) Connection wires; (4) Connection grid.

photo 1 : "Forgery X-ray analysis. (5) Stolen card’s module; (6) Connection wires added by the fraudster; (7) Weldings by the fraudster (only three are pointed out here)."
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Last edited by capwizard; 01-20-2019 at 11:00 AM..
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Old 01-26-2019, 01:54 PM   #3
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Default Re: Cof

I have bought some one time before and will never buy this again for the following reasons

The plastic that was used was very easily torn

Very hard to clean the solder traces so can try to solder it

The plastic is very hard to solder to with out burning hole through it even with low heat

Or

I got some poor quality shit

The concept is a good one but the quality of the materials are very important for this technology to be very useful

Thanks for sharing it
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These two repairs where found with a ESR meter...> Temp at 50*F then at 90*F the ESR reading more than 10%

1 Over Head Crane Current Sensing Board
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All of these had CAPs POOF
All of the mosfet that are taken out by bad caps

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Old 01-27-2019, 05:53 AM   #4
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Default Re: Cof

do you mean ACF films most those are made in US or Japan with good quality. but you have to store ACF in an icy place.
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Old 01-27-2019, 06:07 AM   #5
sam_sam_sam
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Default Re: Cof

This is what I am talking about

One note about these modules do not work very well and are not very reliable you hook your phone it might recognize one time the next time it will not recognize then the next time it might and so on or short out

https://www.ebay.com/itm/USB-fast-ch...53.m1438.l9372

I could be wrong we might not be talking about the same thing

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Old 01-27-2019, 06:09 AM   #6
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Default Re: Cof

Quote:
Originally Posted by capwizard View Post
but you have to store ACF in an icy place.
What in a freezer ?
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Old 01-27-2019, 10:06 PM   #7
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Default Re: Cof

Quote:
Originally Posted by sam_sam_sam View Post
What in a freezer ?
yes
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