I was tearing down a TFT LCD from a medical device (ultrasound bone healer) for fun and did not understand the function of a component. It's a silver rectangle that sits between the LCD and the ACF location for the FPC. When held up to the light it appears that all the signals flow into this device and then fan out to the rows and columns of the LCD. If I had to guess it looks like some kind of control chip. The aspect ratio of this chip seems terrible for manufacturing (long and skinny). Can someone tell me what this device might be and what it's function is? If it is an integrated circuit how do they manage something like this, it seems very easy to fracture.
Based on the markings I think it's one of these displays:
http://www.trulyamerica.com/products/tft-modules/
Best Answer
That "silver rectangle" is the LCD driver chip.
The silver color is the back of the chip-die which is made of silicon
The function of that LCD driver chip is to take some input signals and drive many outputs which connect to the LCD.
Without the LCD driver all these lines would have to be connected over the connector making that connection unreliable as each line and connection point would need to be very small or you would need a very large connector.
Here's another example of an LCD driver chip:
where it can be clearly seen where there are some inputs but many outputs (note the thins traces).
The technology used to mount such a chip on a flexible PCB is called "chip on flex".